[Git][ghc/ghc][wip/D4333] 2721 commits: Text.ParserCombinators.ReadP: use NonEmpty in Final

Ben Gamari gitlab at gitlab.haskell.org
Thu Jul 16 17:47:52 UTC 2020



Ben Gamari pushed to branch wip/D4333 at Glasgow Haskell Compiler / GHC


Commits:
2a0be146 by Vaibhav Sagar at 2019-02-21T04:14:01-05:00
Text.ParserCombinators.ReadP: use NonEmpty in Final

The `Final` constructor needed to maintain the invariant that the list
it is provided is always non-empty. Since NonEmpty is in `base` now, I
think it would be better to use it for this purpose.

- - - - -
32f44ed8 by David Eichmann at 2019-02-21T04:20:09-05:00
Fix test runner crash when not in a git repo

Respect `inside_git_repo()` when checking performance stats.

- - - - -
2f4af71e by Vladislav Zavialov at 2019-02-21T04:26:15-05:00
Dot/bang operators in export lists (Trac #16339)

The dot type operator was handled in the 'tyvarop' parser production, and the
bang type operator in 'tyapp'. However, export lists and role annotations use
'oqtycon', so these type operators could not be exported or assigned roles.

The fix is to handle them in a lower level production, 'tyconsym'.

- - - - -
e204431e by Vladislav Zavialov at 2019-02-21T04:26:15-05:00
Handle the (~) type operator in 'tyconsym'

By parsing '~' in 'tyconsym' instead of 'oqtycon', we
get one less shift/reduce conflict.

- - - - -
48aafc24 by Tamar Christina at 2019-02-21T20:52:42-05:00
Testsuite: opt-in to symlinks on Windows

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9db92cf0 by Tamar Christina at 2019-02-21T20:52:42-05:00
Set builder env

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0e2d300a by Niklas Hambüchen at 2019-02-21T20:58:47-05:00
compiler: Write .o files atomically. See #14533

This issue was reproduced with, and the fix confirmed with,
the `hatrace` tool for syscall-based fault injection:

    https://github.com/nh2/hatrace

The concrete test case for GHC is at

    https://github.com/nh2/hatrace/blob/e23d35a2d2c79e8bf49e9e2266b3ff7094267f29/test/HatraceSpec.hs#L185

A previous, nondeterministic reproducer for the issue was provided by
Alexey Kuleshevich in

    https://github.com/lehins/exec-kill-loop

Signed-off-by: Niklas Hambüchen <niklas at fpcomplete.com>
Reviewed-by: Alexey Kuleshevich <alexey at fpcomplete.com>

- - - - -
e8a08f40 by Niklas Hambüchen at 2019-02-21T20:58:47-05:00
compiler: Refactor: extract `withAtomicRename`

- - - - -
473632d7 by klebinger.andreas at gmx.at at 2019-02-21T21:04:55-05:00
Bump nofib submodule.

- - - - -
a07f46ea by Simon Peyton Jones at 2019-02-22T06:56:08+00:00
Remove tcTyConUserTyVars

The tcTyConUserTyVars field of TcTyCon was entirely unused.

This patch kills it off entirely.

- - - - -
0eb7cf03 by Simon Peyton Jones at 2019-02-22T06:56:08+00:00
Don't do binder-swap for GlobalIds

This patch disables the binder-swap transformation in the
(relatively rare) case when the scrutinee is a GlobalId.
Reason: we are getting Lint errors so that GHC doesn't
even validate.  Trac #16346.

This is NOT the final solution -- it's just a stop-gap
to get us running again.

The final solution is in Trac #16296

- - - - -
c25b135f by Simon Peyton Jones at 2019-02-22T06:56:08+00:00
Fix exprIsConApp_maybe

In this commit
   commit 7833cf407d1f608bebb1d38bb99d3035d8d735e6
   Date:   Thu Jan 24 17:58:50 2019 +0100
      Look through newtype wrappers (Trac #16254)

we made exprIsConApp_maybe quite a bit cleverer.  But I had not paid
enough attention to keeping exactly the correct substitution and
in-scope set, which led to Trac #16348.

There were several buglets (like applying the substitution twice in
exprIsConApp_maybe, but the proximate source of the bug was that we were
calling addNewInScopeIds, which deleted things from the substitution as
well as adding them to the in-scope set.  That's usually right, but not
here!

This was quite tricky to track down.  But it is nicer now.

- - - - -
44ad7215 by Matthew Pickering at 2019-02-22T06:56:08+00:00
Use validate flavour rather than devel2 for DEBUG CI job

This also builds stage2 with optimisations and -dcore-lint

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806cc234 by David Eichmann at 2019-02-22T23:35:18-05:00
Build and copy libffi shared libraries correctly and enable dynamically linking ghc.

Test Plan:
Ensure build environment does NOT have a system libffi installed (you may want to use a nix environment).
Then `hadrian/build.sh -c --flavour=default`

Reviewers: bgamari

Subscribers: rwbarton, carter

GHC Trac Issues: #15837

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4b752d52 by Oleg Grenrus at 2019-02-22T23:41:25-05:00
Update CI images to GHC-8.4.4 & cabal-install-2.4.1.0

Use official bindists, except for Debian 9/Stretch
http://downloads.haskell.org/debian/ is used. (There are no recent
GHC/cabal-install for Debian 8/Jessie there)

Use v2-update/v2-install to install Haskell tools.

Try to unify structure of the different Dockerfiles, incl installing GHC
in one step (this will prevent sublayers from existing, making final
image slightly smaller)

- - - - -
e87ae473 by Artem Pyanykh at 2019-02-22T23:47:32-05:00
Drop support for i386 and PowerPC in MachO linker

Some code is broken, there are no CI targets (so not obvious how to
test), and no one seems to have built GHC for any of the above
platforms in years.

- - - - -
04b7f4c1 by Ben Gamari at 2019-02-22T23:53:36-05:00
ghc-in-ghci: Fix capitalization of hieFile

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2e9426df by Tom Sydney Kerckhove at 2019-02-23T21:25:41-05:00
hWaitForInput-accurate-socket test

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ac34e784 by Simon Peyton Jones at 2019-02-23T21:31:47-05:00
Remove bogus assertion

Remove a bogus assertion in FamInst.newFamInst
(There is a comment to explain.)

This fixes Trac #16112.

- - - - -
6cce36f8 by Simon Peyton Jones at 2019-02-23T21:31:47-05:00
Add AnonArgFlag to FunTy

The big payload of this patch is:

  Add an AnonArgFlag to the FunTy constructor
  of Type, so that
    (FunTy VisArg   t1 t2) means (t1 -> t2)
    (FunTy InvisArg t1 t2) means (t1 => t2)

The big payoff is that we have a simple, local test to make
when decomposing a type, leading to many fewer calls to
isPredTy. To me the code seems a lot tidier, and probably
more efficient (isPredTy has to take the kind of the type).

See Note [Function types] in TyCoRep.

There are lots of consequences

* I made FunTy into a record, so that it'll be easier
  when we add a linearity field, something that is coming
  down the road.

* Lots of code gets touched in a routine way, simply because it
  pattern matches on FunTy.

* I wanted to make a pattern synonym for (FunTy2 arg res), which
  picks out just the argument and result type from the record. But
  alas the pattern-match overlap checker has a heart attack, and
  either reports false positives, or takes too long.  In the end
  I gave up on pattern synonyms.

  There's some commented-out code in TyCoRep that shows what I
  wanted to do.

* Much more clarity about predicate types, constraint types
  and (in particular) equality constraints in kinds.  See TyCoRep
  Note [Types for coercions, predicates, and evidence]
  and Note [Constraints in kinds].

  This made me realise that we need an AnonArgFlag on
  AnonTCB in a TyConBinder, something that was really plain
  wrong before. See TyCon Note [AnonTCB InivsArg]

* When building function types we must know whether we
  need VisArg (mkVisFunTy) or InvisArg (mkInvisFunTy).
  This turned out to be pretty easy in practice.

* Pretty-printing of types, esp in IfaceType, gets
  tidier, because we were already recording the (->)
  vs (=>) distinction in an ad-hoc way.  Death to
  IfaceFunTy.

* mkLamType needs to keep track of whether it is building
  (t1 -> t2) or (t1 => t2).  See Type
  Note [mkLamType: dictionary arguments]

Other minor stuff

* Some tidy-up in validity checking involving constraints;
  Trac #16263

- - - - -
e61f6e35 by Vladislav Zavialov at 2019-02-23T21:37:52-05:00
Expression/command ambiguity resolution

This patch removes 'HsArrApp' and 'HsArrForm' from 'HsExpr' by
introducing a new ambiguity resolution system in the parser.

Problem: there are places in the grammar where we do not know whether we
are parsing an expression or a command:

	proc x -> do { (stuff) -< x }   -- 'stuff' is an expression
	proc x -> do { (stuff) }        -- 'stuff' is a command

Until we encounter arrow syntax (-<) we don't know whether to parse
'stuff' as an expression or a command.

The old solution was to parse as HsExpr always, and rejig later:

	checkCommand :: LHsExpr GhcPs -> P (LHsCmd GhcPs)

This meant polluting 'HsExpr' with command-related constructors. In
other words, limitations of the parser were affecting the AST, and
all other code (the renamer, the typechecker) had to deal with these
extra constructors by panicking.

We fix this abstraction leak by parsing into an intermediate
representation, 'ExpCmd':

	data ExpCmdG b where
	  ExpG :: ExpCmdG HsExpr
	  CmdG :: ExpCmdG HsCmd

	type ExpCmd = forall b. ExpCmdG b -> PV (Located (b GhcPs))

	checkExp :: ExpCmd -> PV (LHsExpr GhcPs)
	checkCmd :: ExpCmd -> PV (LHsCmd GhcPs)
	checkExp f = f ExpG  -- interpret as an expression
	checkCmd f = f CmdG  -- interpret as a command

See Note [Ambiguous syntactic categories] for details.

Now the intricacies of parsing have no effect on the hsSyn AST when it
comes to the expression/command ambiguity.

Future work: apply the same principles to the expression/pattern
ambiguity.

- - - - -
ee284b85 by Herbert Valerio Riedel at 2019-02-23T21:43:58-05:00
Fix regression incorrectly advertising TH support

`--supported-languages` must only advertise language extensions
which are supported by the compiler in order for tooling such
as Cabal relying on this signalling not to behave incorrectly.

Fixes #16331

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a990312e by Matthew Pickering at 2019-02-23T21:50:02-05:00
Exit with exit code 1 when tests unexpectedly pass

This was causing gitlab to not report from builds as failing. It also
highlighted a problem with the LLVM tests where some of the external
interpreter tests are failing.

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1059e234 by Ben Gamari at 2019-02-23T21:56:06-05:00
gitlab-ci: Only build x86_64-deb8 and fedora27 for releases

These are largely redundant as they are covered by x86_64-deb9.

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b85068f6 by Sebastian Graf at 2019-02-23T22:02:10-05:00
Include closure header size in StgLamLift's estimations

While playing around with late lambda lifting, I realised that
StgLamLift.Analysis doesn't consider the removed closure header in its
allocation estimations.

That's because contrary to what I thought, the total word count returned
by `mkVirtHeapOffsets` doesn't include the size of the closure header.

We just add the header size manually now.

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88970187 by Vladislav Zavialov at 2019-02-23T22:08:15-05:00
User's Guide: update info on kind inference

We no longer put class variables in front,
see "Taming the Kind Inference Monster"

(also fix some markup issues)

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ae7d1ff6 by Vladislav Zavialov at 2019-02-23T22:14:19-05:00
User's Guide: forall is a keyword nowadays

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6ba3421e by Ben Gamari at 2019-02-23T22:20:25-05:00
testsuite: Fix whitespace in hp2ps error message

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9059343e by Alexandre at 2019-02-24T16:17:06-05:00
base: Allow fusion for zip7 and related

Fixes #14037.

Metric Decrease:
    T9872b
    T9872d

Reviewers: bgamari, simonpj, hvr

Reviewed By: simonpj

Subscribers: AndreasK, simonpj, osa1, dfeuer, rwbarton, carter

GHC Trac Issues: #14037

Differential Revision: https://phabricator.haskell.org/D5249

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14586f5d by Vladislav Zavialov at 2019-02-24T16:23:11-05:00
Disable fragile test cases: T14697 T5559 T3424

See Trac #15072, Trac #16349, Trac #16350

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f320f3b2 by Vladislav Zavialov at 2019-02-25T19:19:24+03:00
Fix the ghci063 test on Darwin (Trac #16201)

We use "touch -r" to set modification timestamps, which leads to precision loss
on Darwin. For example,

   before: 2019-02-25 01:11:23.807627350 +0300
   after:  2019-02-25 01:11:23.807627000 +0300
                                     ^^^
This means we can't trick GHCi into thinking the file hasn't been changed by
restoring its old timestamp, as we cannot faithfully restore all digits.

The solution is to nullify the insignificant digits before the first :load

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4dbacba5 by Vladislav Zavialov at 2019-02-26T12:36:42-05:00
Skip T3424 when fast()

14586f5d removed this by accident.

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5bc195b1 by Vladislav Zavialov at 2019-02-27T09:53:52-05:00
Treat kind/type variables identically, demolish FKTV

Implements GHC Proposal #24: .../ghc-proposals/blob/master/proposals/0024-no-kind-vars.rst
Fixes Trac #16334, Trac #16315

With this patch, scoping rules for type and kind variables have been
unified: kind variables no longer receieve special treatment. This
simplifies both the language and the implementation.

User-facing changes
-------------------

* Kind variables are no longer implicitly quantified when an explicit
  forall is used:

    p ::             Proxy (a :: k)    -- still accepted
    p :: forall k a. Proxy (a :: k)    -- still accepted
    p :: forall   a. Proxy (a :: k)    -- no longer accepted

  In other words, now we adhere to the "forall-or-nothing" rule more
  strictly.

  Related function: RnTypes.rnImplicitBndrs

* The -Wimplicit-kind-vars warning has been deprecated.

* Kind variables are no longer implicitly quantified in constructor
  declarations:

    data T a        = T1 (S (a :: k) | forall (b::k). T2 (S b)  -- no longer accepted
    data T (a :: k) = T1 (S (a :: k) | forall (b::k). T2 (S b)  -- still accepted

  Related function: RnTypes.extractRdrKindSigVars

* Implicitly quantified kind variables are no longer put in front of
  other variables:

    f :: Proxy (a :: k) -> Proxy (b :: j)

    f :: forall k j (a :: k) (b :: j). Proxy a -> Proxy b   -- old order
    f :: forall k (a :: k) j (b :: j). Proxy a -> Proxy b   -- new order

  This is a breaking change for users of TypeApplications. Note that
  we still respect the dpendency order: 'k' before 'a', 'j' before 'b'.
  See "Ordering of specified variables" in the User's Guide.

  Related function: RnTypes.rnImplicitBndrs

* In type synonyms and type family equations, free variables on the RHS
  are no longer implicitly quantified unless used in an outermost kind
  annotation:

    type T = Just (Nothing :: Maybe a)         -- no longer accepted
    type T = Just Nothing :: Maybe (Maybe a)   -- still accepted

  The latter form is a workaround due to temporary lack of an explicit
  quantification method. Ideally, we would write something along these
  lines:

    type T @a = Just (Nothing :: Maybe a)

  Related function: RnTypes.extractHsTyRdrTyVarsKindVars

* Named wildcards in kinds are fixed (Trac #16334):

    x :: (Int :: _t)    -- this compiles, infers (_t ~ Type)

  Related function: RnTypes.partition_nwcs

Implementation notes
--------------------

* One of the key changes is the removal of FKTV in RnTypes:

  - data FreeKiTyVars = FKTV { fktv_kis    :: [Located RdrName]
  -                          , fktv_tys    :: [Located RdrName] }
  + type FreeKiTyVars = [Located RdrName]

  We used to keep track of type and kind variables separately, but
  now that they are on equal footing when it comes to scoping, we
  can put them in the same list.

* extract_lty and family are no longer parametrized by TypeOrKind,
  as we now do not distinguish kind variables from type variables.

* PatSynExPE and the related Note [Pattern synonym existentials do not scope]
  have been removed (Trac #16315). With no implicit kind quantification,
  we can no longer trigger the error.

* reportFloatingKvs and the related Note [Free-floating kind vars]
  have been removed. With no implicit kind quantification,
  we can no longer trigger the error.

- - - - -
5c084e04 by Peter Trommler at 2019-02-27T09:59:59-05:00
RTS: Add missing memory barrier

In the work stealing queue a load-load-barrier is required to ensure
that a read of queue data cannot be reordered before a read of the
bottom pointer into the queue.

The added load-load-barrier ensures that the ordering of writes enforced
at the end of `pushWSDeque` is also respected in the order of reads in
`stealWSDeque_`. In other words, when reading `q->bottom` we want to make
sure that we see the updates to `q->elements`.

Fixes #13633

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2e8f6649 by Vladislav Zavialov at 2019-02-27T10:06:05-05:00
Fix intermittent hie002 failure

hie002 is a performance test that used to fail unpredictably:

	max_bytes_used Decrease from x86_64-linux-deb9-debug baseline @ HEAD~2:
	    Expected    hie002 (normal) max_bytes_used: 1190923992.0 +/-20%
	    Lower bound hie002 (normal) max_bytes_used:    952739193
	    Upper bound hie002 (normal) max_bytes_used:   1429108791
	    Actual      hie002 (normal) max_bytes_used:    726270784
	    Deviation   hie002 (normal) max_bytes_used:        -39.0 %
	peak_megabytes_allocated Decrease from x86_64-linux-deb9-debug baseline @ HEAD~2:
	    Expected    hie002 (normal) peak_megabytes_allocated: 2538.0 +/-20%
	    Lower bound hie002 (normal) peak_megabytes_allocated:   2030
	    Upper bound hie002 (normal) peak_megabytes_allocated:   3046
	    Actual      hie002 (normal) peak_megabytes_allocated:   1587
	    Deviation   hie002 (normal) peak_megabytes_allocated:  -37.5 %
	*** unexpected stat test failure for hie002(normal)

'max_bytes_used' and 'peak_megabytes_allocated' are too unstable without careful
control of the runtime configuration. We fix this by using a more predictable
metric, 'bytes allocated'.

- - - - -
f838809f by Moritz Angermann at 2019-02-28T02:20:05-05:00
Cleanup iserv/iserv-proxy

This adds trace messages that include the processes name and as such
make debugging and following the communication easier.

It also adds a note regarding the fwd*Call proxy-communication logic
between the proxy and the slave.

The proxy will now also poll for 60s to wait for the remote iserv
to come up. (Alternatively you can start the remote process
beforehand; and just have iserv-proxy connect to it)

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c26d299d by Ryan Scott at 2019-03-01T16:26:02-05:00
Visible dependent quantification

This implements GHC proposal 35
(https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0035-forall-arrow.rst)
by adding the ability to write kinds with
visible dependent quantification (VDQ).

Most of the work for supporting VDQ was actually done _before_ this
patch. That is, GHC has been able to reason about kinds with VDQ for
some time, but it lacked the ability to let programmers directly
write these kinds in the source syntax. This patch is primarly about
exposing this ability, by:

* Changing `HsForAllTy` to add an additional field of type
  `ForallVisFlag` to distinguish between invisible `forall`s (i.e,
  with dots) and visible `forall`s (i.e., with arrows)
* Changing `Parser.y` accordingly

The rest of the patch mostly concerns adding validity checking to
ensure that VDQ is never used in the type of a term (as permitting
this would require full-spectrum dependent types). This is
accomplished by:

* Adding a `vdqAllowed` predicate to `TcValidity`.
* Introducing `splitLHsSigmaTyInvis`, a variant of `splitLHsSigmaTy`
  that only splits invisible `forall`s. This function is used in
  certain places (e.g., in instance declarations) to ensure that GHC
  doesn't try to split visible `forall`s (e.g., if it tried splitting
  `instance forall a -> Show (Blah a)`, then GHC would mistakenly
  allow that declaration!)

This also updates Template Haskell by introducing a new `ForallVisT`
constructor to `Type`.

Fixes #16326. Also fixes #15658 by documenting this feature in the
users' guide.

- - - - -
f37efb11 by Alec Theriault at 2019-03-01T16:32:09-05:00
Lexer: turn some fatal errors into non-fatal ones

The following previously fatal lexer errors are now non-fatal:

  * errors about enabling `LambdaCase`
  * errors about enabling `NumericUnderscores`
  * errors about having valid characters in primitive strings

See #16270

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8442103a by Alp Mestanogullari at 2019-03-01T16:38:15-05:00
Hadrian: introduce ways to skip some documentation targets

The initial motivation for this is to have a chance to run the binary
distribution rules in our Windows CI without having to install
sphinx-build and xelatex there, while retaining the ability to
generate haddocks. I just ended up extending this idea a little bit so
as to have control over whether we build haddocks, (sphinx) HTML manuals,
(sphinx) PDF manuals and (sphinx) manpages.

- - - - -
9aa27273 by Alp Mestanogullari at 2019-03-01T16:38:15-05:00
use --docs=no-sphinx in both Hadrian CI jobs

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b1c7ffaf by David Eichmann at 2019-03-01T16:44:22-05:00
Fix parsing of expected performance changes for tests with non-alpha characters.

Python's split() function is used to split on all white space.

- - - - -
b90695cd by Ben Gamari at 2019-03-01T17:06:49-05:00
gitlab-ci: Pull docker images from ghc/ci-images registry

- - - - -
161f102b by Ben Gamari at 2019-03-01T17:07:28-05:00
Drop Docker images

These have been moved to the ghc/ci-images project.

- - - - -
d298cb9c by Ben Gamari at 2019-03-01T17:07:28-05:00
gitlab-ci: Produce DWARF-enabled binary distribution

- - - - -
aeefc90c by Ben Gamari at 2019-03-01T17:07:28-05:00
testsuite: Suppress ticks when comparing -ddump-simpl output

Otherwise these tests break spuriously when core libraries are compiled
with source notes.

- - - - -
1bceb643 by Ben Gamari at 2019-03-01T17:07:28-05:00
gitlab-ci: Give deb9-unreg job a distinct cache key

- - - - -
1285d6b9 by Ben Gamari at 2019-03-02T18:32:22-05:00
gitlab-ci: A bit of reorganization

- - - - -
f77229e3 by Alp Mestanogullari at 2019-03-03T19:35:18-05:00
detect 'autoreconf' path during configure, and use it in hadrian

- - - - -
e2ae52c3 by Alec Theriault at 2019-03-04T10:18:41-05:00
Don't leave .hi files after running Haddock tests

RyanGlScott observed in https://github.com/haskell/haddock/issues/1030
that running Haddock tests in GHC's testsuite left some `.hi` files
around in `utils/haddock`. This should fix that problem.

- - - - -
22c2713b by Alp Mestanogullari at 2019-03-04T10:18:41-05:00
Hadrian: track mingw, ship it in bindists, more robust install script

- - - - -
e7080bef by Ben Gamari at 2019-03-04T10:18:41-05:00
Revert "compiler: Refactor: extract `withAtomicRename`"

This reverts commit e8a08f400744a860d1366c6680c8419d30f7cc2a.

- - - - -
e6ce1743 by Ben Gamari at 2019-03-04T10:18:41-05:00
Revert "compiler: Write .o files atomically. See #14533"

This reverts commit 0e2d300a59b1b5c167d2e7d99a448c8663ba6d7d.

- - - - -
80dfcee6 by Simon Peyton Jones at 2019-03-05T03:09:41-05:00
Be more careful when naming TyCon binders

This patch fixes two rather gnarly test cases:
  * Trac #16342 (mutual recursion)
    See Note [Tricky scoping in generaliseTcTyCon]

  * Trac #16221 (shadowing)
    See Note [Unification variables need fresh Names]

The main changes are:

* Substantial reworking of TcTyClsDecls.generaliseTcTyCon
  This is the big change, and involves the rather tricky
  function TcHsSyn.zonkRecTyVarBndrs.

  See Note [Inferring kinds for type declarations] and
  Note [Tricky scoping in generaliseTcTyCon] for the details.

* bindExplicitTKBndrs_Tv and bindImplicitTKBndrs_Tv both now
  allocate /freshly-named/ unification variables. Indeed, more
  generally, unification variables are always fresh; see
  Note [Unification variables need fresh Names] in TcMType

* Clarify the role of tcTyConScopedTyVars.
  See Note [Scoped tyvars in a TcTyCon] in TyCon

As usual, this dragged in some more refactoring:

* Renamed TcMType.zonkTyCoVarBndr to zonkAndSkolemise

* I renamed checkValidTelescope to checkTyConTelescope;
  it's only used on TyCons, and indeed takes a TyCon as argument.

* I folded the slightly-mysterious reportFloatingKvs into
  checkTyConTelescope. (Previously all its calls immediately
  followed a call to checkTyConTelescope.)  It makes much more
  sense there.

* I inlined some called-once functions to simplify
  checkValidTyFamEqn. It's less spaghetti-like now.

* This patch also fixes Trac #16251.  I'm not quite sure why #16251
  went wrong in the first place, nor how this patch fixes it, but
  hey, it's good, and life is short.

- - - - -
6c4e45b0 by David Eichmann at 2019-03-05T03:15:47-05:00
Test Runner: don't show missing baseline warning for performance tests with expected changes on the current commit.

Trac #16359

- - - - -
646b6dfb by Krzysztof Gogolewski at 2019-03-05T03:21:53-05:00
Fix map/coerce rule for newtypes with wrappers

This addresses Trac #16208 by marking newtype wrapper
unfoldings as compulsory.

Furthermore, we can remove the special case for newtypes
in exprIsConApp_maybe (introduced in 7833cf407d1f).

- - - - -
37f257af by Ben Gamari at 2019-03-05T22:22:40-05:00
Rip out object splitting

The splitter is an evil Perl script that processes assembler code.
Its job can be done better by the linker's --gc-sections flag. GHC
passes this flag to the linker whenever -split-sections is passed on
the command line.

This is based on @DemiMarie's D2768.

Fixes Trac #11315
Fixes Trac #9832
Fixes Trac #8964
Fixes Trac #8685
Fixes Trac #8629

- - - - -
23342e1f by Ömer Sinan Ağacan at 2019-03-05T22:28:45-05:00
rts/Printer: Introduce a few more printing utilities

These include printLargeAndPinnedObjects, printWeakLists, and
printStaticObjects. These are generally useful things to have.

- - - - -
c19a401d by Ömer Sinan Ağacan at 2019-03-05T22:28:45-05:00
rts/Printer: Print forwarding pointers

- - - - -
db039a4a by Ryan Scott at 2019-03-05T22:40:54-05:00
Add regression test for #15918

The test case in #15918 no longer triggers an `ASSERT` failure on
GHC HEAD, likely due to commit
682783828275cca5fd8bf5be5b52054c75e0e22c (`Make a smart mkAppTyM`).
This patch adds a regression test for #15918 to finally put it to
rest.

- - - - -
2ff77b98 by P.C. Shyamshankar at 2019-03-06T09:17:22-05:00
Handle absolute paths to build roots in Hadrian.

Fixes #16187.

This patch fixes various path concatenation issues to allow functioning
builds with hadrian when the build root location is specified with an
absolute path.

Remarks:

- The path concatenation operator (-/-) now handles absolute second operands
  appropriately. Its behavior should match that of POSIX (</>) in this
  regard.

- The `getDirectoryFiles*` family of functions only searches for matches
  under the directory tree rooted by its first argument; all of the
  results are also relative to this root. If the first argument is the
  empty string, the current working directory is used.

  This patch passes the appropriate directory (almost always either `top`
  or `root`), and subsequently attaches that directory prefix so that
  the paths refer to the appropriate files.

- Windows `tar` does not like colons (':') in paths to archive files, it
  tries to resolve them as remote paths. The `--force-local` option
  remedies this, and is applied on windows builds.

- - - - -
5aab1d9c by Ömer Sinan Ağacan at 2019-03-06T15:53:32-05:00
rts: Unglobalize dead_weak_ptr_list and resurrected_threads

In the concurrent nonmoving collector we will need the ability to call
`traverseWeakPtrList` concurrently with minor generation collections.
This global state stands in the way of this. However, refactoring it
away is straightforward since this list only persists the length of a
single GC.

- - - - -
a4944d8d by Ben Gamari at 2019-03-06T15:53:32-05:00
Fix it

- - - - -
78dd04f9 by Ryan Scott at 2019-03-06T16:05:45-05:00
Fix #16385 by appending _maybe to a use of lookupGlobalOcc

`instance forall c. c` claimed that `c` was out of scope because the
renamer was invoking `lookupGlobalOcc` on `c` (in
`RnNames.getLocalNonValBinders`) without binding `c` first. To avoid
this, this patch changes GHC to invoke `lookupGlobalOcc_maybe` on `c`
instead, and if that returns `Nothing`, then bail out, resulting
in a better error message.

- - - - -
3caeb443 by Zejun Wu at 2019-03-06T16:11:52-05:00
Move reifyGHCi function into GhciMonad type class

This was the suggested change in !176 but missed the batch merge (!263).

- - - - -
4ca271d1 by Ben Gamari at 2019-03-06T21:48:10-05:00
testsuite: Introduce fragile modifier

Now since we have been a bit more stringent in testsuite cleanliness we
have been marking a lot of tests as fragile using the `skip` modifier.
However, this unfortunately means that we lose the association with the
ticket number documenting the fragility.

Here we introduce `fragile` and `fragile_for` to retain this
information.

- - - - -
910185a3 by Ben Gamari at 2019-03-06T21:48:10-05:00
testsuite: Mark heapprof001 as fragile on i386

- - - - -
a65bcbe7 by Ben Gamari at 2019-03-06T21:48:10-05:00
testsuite: Use fragile modifier for more tests

- - - - -
f624dc15 by Ben Gamari at 2019-03-06T21:48:10-05:00
gitlab-ci: Don't allow i386-deb9 to fail

Also account for testsuite metric drift.

Metric Increase:
    haddock.Cabal
    haddock.base
    T14683

- - - - -
07f378ce by Simon Peyton Jones at 2019-03-06T21:54:17-05:00
Add tests for Trac #16221 and #16342

- - - - -
25c3dd39 by Simon Peyton Jones at 2019-03-06T21:54:17-05:00
Test Trac #16263

- - - - -
7a68254a by Phuong Trinh at 2019-03-07T14:01:42-05:00
Fix #16392: revertCAFs in external interpreter when necessary

We revert CAFs when loading/adding modules in ghci (presumably to refresh
execution states and to allow for object code to be unloaded from the runtime).
However, with `-fexternal-interpreter` enabled, we are only doing it in the
ghci process instead of the external interpreter process where the cafs are
allocated and computed. This makes sure that revertCAFs is done in the
appropriate process no matter if that flag is present or not.

- - - - -
068b7e98 by Ryan Scott at 2019-03-07T14:07:49-05:00
Fix #16391 by using occCheckExpand in TcValidity

The type-variables-escaping-their-scope-via-kinds check in
`TcValidity` was failing to properly expand type synonyms, which led
to #16391. This is easily fixed by using `occCheckExpand` before
performing the validity check.

Along the way, I refactored this check out into its own function,
and sprinkled references to Notes to better explain all of the moving
parts. Many thanks to @simonpj for the suggestions.

Bumps the haddock submodule.

- - - - -
1675d40a by Sebastian Graf at 2019-03-07T20:44:08-05:00
Always do the worker/wrapper split for NOINLINEs

Trac #10069 revealed that small NOINLINE functions didn't get split
into worker and wrapper. This was due to `certainlyWillInline`
saying that any unfoldings with a guidance of `UnfWhen` inline
unconditionally. That isn't the case for NOINLINE functions, so we
catch this case earlier now.

Nofib results:

--------------------------------------------------------------------------------
        Program         Allocs    Instrs
--------------------------------------------------------------------------------
 fannkuch-redux          -0.3%      0.0%
             gg          +0.0%     +0.1%
       maillist          -0.2%     -0.2%
        minimax           0.0%     -0.8%
--------------------------------------------------------------------------------
            Min          -0.3%     -0.8%
            Max          +0.0%     +0.1%
 Geometric Mean          -0.0%     -0.0%

Fixes #10069.

-------------------------
Metric Increase:
    T9233
-------------------------

- - - - -
48927a9a by Alp Mestanogullari at 2019-03-08T05:50:26-05:00
Hadrian: various improvements around the 'test' rule

- introduce a -k/--keep-test-files flag to prevent cleanup
- add -dstg-lint to the options that are always passed to tests
- infer library ways from the compiler to be tested instead of getting them
  from the flavour (like make)
- likewise for figuring out whether the compiler to be tested is "debugged"
- specify config.exeext
- correctly specify config.in_tree_compiler, instead of always passing True
- fix formatting of how we pass a few test options
- add (potential) extensions to check-* program names
- build check-* programs with the compiler to be tested
- set TEST_HC_OPTS_INTERACTIVE and PYTHON env vars when running tests

- - - - -
5d744143 by Andrey Mokhov at 2019-03-08T05:56:32-05:00
Hadrian: Drop remaining symlink traversal code from build scripts

This partly resolves #16325 (https://ghc.haskell.org/trac/ghc/ticket/16325).

As previously discussed in https://github.com/snowleopard/hadrian/issues/667,
we do not need the symlink traversal code in build scripts. However, it
appears we forgot to delete this code from our Stack-based build scripts,
which led to placing all build artefacts in an unexpected location when
using Hadrian in combination with symlink trees. This commit fixes this.

- - - - -
82628254 by Vladislav Zavialov at 2019-03-08T06:02:37-05:00
Testsuite: use 'fragile' instead of 'skip' for T3424, T14697

Also, replace some tabs with spaces to avoid a "mixed indent" warning that vim
gives me.

- - - - -
5be7ad78 by Simon Peyton Jones at 2019-03-08T06:08:41-05:00
Use captureTopConstraints in TcRnDriver calls

Trac #16376 showed the danger of failing to report an error
that exists only in the unsolved constraints, if an exception
is raised (via failM).

Well, the commit 5c1f268e (Fail fast in solveLocalEqualities)
did just that -- i.e. it found errors in the constraints, and
called failM to avoid a misleading cascade.

So we need to be sure to call captureTopConstraints to report
those insolubles.  This was wrong in TcRnDriver.tcRnExpr and
in TcRnDriver.tcRnType.

As a result the error messages from test T13466 improved slightly,
a happy outcome.

- - - - -
224a6b86 by Sylvain Henry at 2019-03-08T14:05:10-05:00
TH: support raw bytes literals (#14741)

GHC represents String literals as ByteString internally for efficiency
reasons. However, until now it wasn't possible to efficiently create
large string literals with TH (e.g. to embed a file in a binary, cf #14741):
TH code had to unpack the bytes into a [Word8] that GHC then had to re-pack
into a ByteString.

This patch adds the possibility to efficiently create a "string" literal
from raw bytes. We get the following compile times for different sizes
of TH created literals:

|| Size || Before || After  || Gain ||
|| 30K  || 2.307s || 2.299  || 0%   ||
|| 3M   || 3.073s || 2.400s || 21%  ||
|| 30M  || 8.517s || 3.390s || 60%  ||

Ticket #14741 can be fixed if the original code uses this new TH feature.

- - - - -
2762f94d by Roland Senn at 2019-03-08T14:11:19-05:00
Fix #13839: GHCi warnings do not respect the default module header

- - - - -
1f5cc9dc by Simon Peyton Jones at 2019-03-09T02:07:53-05:00
Stop inferring over-polymorphic kinds

Before this patch GHC was trying to be too clever
(Trac #16344); it succeeded in kind-checking this
polymorphic-recursive declaration

    data T ka (a::ka) b
      = MkT (T Type           Int   Bool)
            (T (Type -> Type) Maybe Bool)

As Note [No polymorphic recursion] discusses, the "solution" was
horribly fragile.  So this patch deletes the key lines in
TcHsType, and a wodge of supporting stuff in the renamer.

There were two regressions, both the same: a closed type family
decl like this (T12785b) does not have a CUSK:
  type family Payload (n :: Peano) (s :: HTree n x) where
    Payload Z (Point a) = a
    Payload (S n) (a `Branch` stru) = a

To kind-check the equations we need a dependent kind for
Payload, and we don't get that any more.  Solution: make it
a CUSK by giving the result kind -- probably a good thing anyway.

The other case (T12442) was very similar: a close type family
declaration without a CUSK.

- - - - -
cfbedf17 by Niklas Hambüchen at 2019-03-09T02:14:13-05:00
compiler: Write .o files atomically. See #14533

This issue was reproduced with, and the fix confirmed with,
the `hatrace` tool for syscall-based fault injection:

    https://github.com/nh2/hatrace

The concrete test case for GHC is at

    https://github.com/nh2/hatrace/blob/e23d35a2d2c79e8bf49e9e2266b3ff7094267f29/test/HatraceSpec.hs#L185

A previous, nondeterministic reproducer for the issue was provided by
Alexey Kuleshevich in

    https://github.com/lehins/exec-kill-loop

Signed-off-by: Niklas Hambüchen <niklas at fpcomplete.com>
Reviewed-by: Alexey Kuleshevich <alexey at fpcomplete.com>

- - - - -
08ad38a9 by Niklas Hambüchen at 2019-03-09T02:14:13-05:00
compiler: Refactor: extract `withAtomicRename`

- - - - -
e76ee675 by Ben Gamari at 2019-03-09T07:30:17-05:00
rts: Factor out large bitmap walking

This will be needed by the mark phase of the non-moving collector
so let's factor it out.

- - - - -
6e3e537e by Edward Z. Yang at 2019-03-09T07:36:26-05:00
Make bkpcabal01 test compatible with new ordering requirements.

Previously, our test did something like this:

1. Typecheck p
2. Typecheck q (which made use of an instantiated p)
3. Build instantiated p
4. Build instantiated q

Cabal previously permitted this, under the reasoning that during
typechecking there's no harm in using the instantiated p even if we
haven't build it yet; we'll just instantiate it on the fly with p.

However, this is not true!  If q makes use of a Template Haskell
splice from p, we absolutely must have built the instantiated p
before we typecheck q, since this typechecking will need to
run some splices.  Cabal now complains that you haven't done
it correctly, which we indeed have not!

Reordering so that we do this:

1. Typecheck p
3. Build instantiated p
2. Typecheck q (which made use of an instantiated p)
4. Build instantiated q

Fixes the problem.  If Cabal had managed the ordering itself, it would
have gotten it right.

Signed-off-by: Edward Z. Yang <ezyang at fb.com>

- - - - -
6b2f0991 by Sylvain Henry at 2019-03-09T07:42:34-05:00
NCG: correctly escape path strings on Windows (#16389)

GHC native code generator generates .incbin and .file directives. We
need to escape those strings correctly on Windows (see #16389).

- - - - -
b760269c by Ben Gamari at 2019-03-09T07:48:38-05:00
Rip out perl dependency

The object splitter was the last major user of perl. There remain a few
uses in nofib but we can just rely on the system's perl for this since
it's not critical to the build.

- - - - -
0cd98957 by Ben Gamari at 2019-03-09T07:48:38-05:00
Drop utils/count_lines

This doesn't appear to be used anywhere in the build system and it
relies on perl. Drop it.

- - - - -
bcb6769c by Alec Theriault at 2019-03-11T18:11:59-04:00
Ignore more version numbers in the testsuite

Prevents some tests from failing just due to mismatched version numbers.

These version numbers shouldn't cause tests to fail, especially since
we *expect* them to be regularly incremented. The motivation for this
particular set of changes came from the changes that came along with
the `base` version bump in 8f19ecc95fbaf2cc977531d721085d8441dc09b7.

- - - - -
60b03ade by Krzysztof Gogolewski at 2019-03-11T18:18:06-04:00
Change the warning in substTy back to an assertion

We'd like to enforce the substitution invariant (Trac #11371).
In a492af06d326453 the assertion was downgraded to a warning;
I'm restoring the assertion and making the calls that
don't maintain the invariant as unchecked.

- - - - -
2f453414 by Krzysztof Gogolewski at 2019-03-11T18:18:06-04:00
Add a test for Trac #13951

It no longer gives a warning.

- - - - -
b2322310 by Matthew Pickering at 2019-03-12T09:04:52-04:00
Hadrian: Allow passing CABFLAGS into build.cabal.sh

Setting `CABFLAGS=args` will pass the additional arguments to cabal
when it is invoked.

- - - - -
61264556 by Matthew Pickering at 2019-03-12T09:04:52-04:00
Hadrian: Make libsuf and distDir stage aware

The version suffix needs to be the version of the stage 0 compiler
when building shared libraries with the stage 0 compiler.

- - - - -
705fa21d by Matthew Pickering at 2019-03-12T09:04:52-04:00
Hadrian: Make makeRelativeNoSysLink total

makeRelativeNoSysLink would previously crash for no reason if the first
argument as `./` due to the call to `head`. This refactoring keeps the
behaviour the same but doesn't crash in this corner case.

- - - - -
4cf2160a by Matthew Pickering at 2019-03-12T09:04:52-04:00
Hadrian: Fix rpath so shared objects work after being copied

After being copied all the shared objects end up in the same directory.
Therefore the correct rpath is `$ORIGIN` rather than the computed
path which is relative to the directory where it is built.

- - - - -
2d7dd028 by Matthew Pickering at 2019-03-12T09:04:52-04:00
Hadrian: Add ./hadrian/ghci.sh script for fast development feedback

Running the `./hadrian/ghci` target will load the main compiler into
a ghci session. This is intended for fast development feedback, modules are only
typechecked so it isn't possible to run any functions in the repl.

You can also use this target with `ghcid`.

The first time this command is run hadrian will need to compile a few dependencies
which will take 1-2 minutes. Loading GHC into GHCi itself takes about 30 seconds.

Internally this works by calling a new hadrian target called `tool-args`.
This target prints out the package and include flags which are necessary
to load files into ghci. The same target is intended to be used by other
tooling which uses the GHC API in order to set up the correct GHC API
session. For example, using this target it is also possible to use HIE
when developing on GHC.

- - - - -
bb684e65 by Matthew Pickering at 2019-03-12T09:04:52-04:00
Remove training whitespace

- - - - -
72c455a4 by Matthew Pickering at 2019-03-12T09:04:52-04:00
CI: Add ghc-in-ghci build job

This is a separate build job to the other hadrian jobs as it only takes
about 2-3 minutes to run from cold. The CI tests that the
`./hadrian/ghci` script loads `ghc/Main.hs` successfully.

- - - - -
5165378d by Matthew Pickering at 2019-03-12T09:04:52-04:00
Remove trailing whitespace

- - - - -
50249a9f by Simon Peyton Jones at 2019-03-12T09:13:28-04:00
Use transSuperClasses in TcErrors

Code in TcErrors was recursively using immSuperClasses,
which loops in the presence of UndecidableSuperClasses.

Better to use transSuperClasses instead, which has a loop-breaker
mechanism built in.

Fixes issue #16414.

- - - - -
62db9295 by Ömer Sinan Ağacan at 2019-03-12T09:19:29-04:00
Remove duplicate functions in StgCmmUtils, use functions from CgUtils

Also remove unused arg from get_Regtable_addr_from_offset

- - - - -
4db9bdd9 by Ryan Scott at 2019-03-12T09:25:39-04:00
Add regression test for #16347

Commit 1f5cc9dc8aeeafa439d6d12c3c4565ada524b926 ended up
fixing #16347. Let's add a regression test to ensure that it stays
fixed.

- - - - -
02ddf947 by Matthew Pickering at 2019-03-12T09:42:53-04:00
CI: Update ci-images commit
- - - - -
a0cab873 by Matthew Pickering at 2019-03-12T09:44:45-04:00
Revert: Update ci-images commit
- - - - -
23fc6156 by Ben Gamari at 2019-03-13T15:03:53-04:00
testsuite: Mark heapprof001 as fragile on all platforms

See #15382.

- - - - -
cb17c2da by Alp Mestanogullari at 2019-03-13T15:10:01-04:00
Hadrian: build (and retrieve) binary distributions in CI

With all the recent fixes to the binary-dist rule in Hadrian, we can now run
that rule in CI and keep the bindists around in gitlab as artifacts, just like
we do for the make CI jobs.

To get 'autoreconf' to work in the Windows CI, we have to run it through the
shell interpreter, so this commit does that along the way.

- - - - -
36546a43 by Ryan Scott at 2019-03-13T15:16:08-04:00
Fix #16411 by making dataConCannotMatch aware of (~~)

The `dataConCannotMatch` function (which powers the
`-Wpartial-fields` warning, among other things) had special reasoning
for explicit equality constraints of the form `a ~ b`, but it did
not extend that reasoning to `a ~~ b` constraints, leading to #16411.
Easily fixed.

- - - - -
10a97120 by Ben Gamari at 2019-03-14T12:20:50-04:00
testsuite: Add testcase for #16394

- - - - -
8162eab2 by Ryan Scott at 2019-03-15T09:59:30-04:00
Remove the GHCi debugger's panicking isUnliftedType check

The GHCi debugger has never been that robust in the face of
higher-rank types, or even types that are _interally_ higher-rank,
such as the types of many class methods (e.g., `fmap`). In GHC 8.2,
however, things became even worse, as the debugger would start to
_panic_ when a user tries passing the name of a higher-rank thing
to `:print`. This all ties back to a strange `isUnliftedType` check
in `Debugger` that was mysteriously added 11 years ago
(in commit 4d71f5ee6dbbfedb4a55767e4375f4c0aadf70bb) with no
explanation whatsoever.

After some experimentation, no one is quite sure what this
`isUnliftedType` check is actually accomplishing. The test suite
still passes if it's removed, and I am unable to observe any
differences in debugger before even with data types that _do_ have
fields of unlifted types (e.g., `data T = MkT Int#`). Given that
this is actively causing problems (see #14828), the prudent thing
to do seems to be just removing this `isUnliftedType` check, and
waiting to see if anyone shouts about it. This patch accomplishes
just that.

Note that this patch fix the underlying issues behind #14828, as the
debugger will still print unhelpful info if you try this:

```
λ> f :: (forall a. a -> a) -> b -> b; f g x = g x
λ> :print f
f = (_t1::t1)
```

But fixing this will require much more work, so let's start with the
simple stuff for now.

- - - - -
d10e2368 by David Eichmann at 2019-03-15T10:05:38-04:00
Hadrian: remove unneeded imports.

- - - - -
4df75772 by David Eichmann at 2019-03-15T10:05:38-04:00
Hadrian: remove unneeded rpaths.

Issue #12770

- - - - -
afc80730 by David Eichmann at 2019-03-15T10:11:47-04:00
Git ignore .hadrian_ghci (generated by the ./hadrian/ghci.sh)

[skip ci]

- - - - -
610ec224 by Ryan Scott at 2019-03-15T10:17:54-04:00
Update Trac ticket URLs to point to GitLab

This moves all URL references to Trac tickets to their corresponding
GitLab counterparts.

- - - - -
97032ed9 by Simon Peyton Jones at 2019-03-15T10:24:01-04:00
Report better suggestion for GADT data constructor

This addresses issue #16427. An easy fix.

- - - - -
83e09d3c by Peter Trommler at 2019-03-15T10:30:08-04:00
PPC NCG: Use liveness information in CmmCall

We make liveness information for global registers
available on `JMP` and `BCTR`, which were the last instructions
missing. With complete liveness information we do not need to
reserve global registers in `freeReg` anymore. Moreover we
assign R9 and R10 to callee saves registers.

Cleanup by removing `Reg_Su`, which was unused, from `freeReg`
and removing unused register definitions.

The calculation of the number of floating point registers is too
conservative. Just follow X86 and specify the constants directly.

Overall on PowerPC this results in 0.3 % smaller code size in nofib
while runtime is slightly better in some tests.

- - - - -
57201beb by Simon Peyton Jones at 2019-03-15T10:36:14-04:00
Add flavours link
- - - - -
4927117c by Simon Peyton Jones at 2019-03-16T08:08:25-04:00
Improve error recovery in the typechecker

Issue #16418 showed that we were carrying on too eagerly after a bogus
type signature was identified (a bad telescope in fact), leading to a
subsequent crash.

This led me in to a maze of twisty little passages in the typechecker's
error recovery, and I ended up doing some refactoring in TcRnMonad.
Some specfifics

* TcRnMonad.try_m is now called attemptM.

* I switched the order of the result pair in tryTc,
  to make it consistent with other similar functions.

* The actual exception used in the Tc monad is irrelevant so,
  to avoid polluting type signatures, I made tcTryM, a simple
  wrapper around tryM, and used it.

The more important changes are in

* TcSimplify.captureTopConstraints, where we should have been calling
  simplifyTop rather than reportUnsolved, so that levity defaulting
  takes place properly.

* TcUnify.emitResidualTvConstraint, where we need to set the correct
  status for a new implication constraint.  (Previously we ended up
  with an Insoluble constraint wrapped in an Unsolved implication,
  which meant that insolubleWC gave the wrong answer.

- - - - -
600a1ac3 by Simon Peyton Jones at 2019-03-16T08:08:25-04:00
Add location to the extra-constraints wildcard

The extra-constraints wildcard had lost its location
(issue #16431).

Happily this is easy to fix.  Lots of error improvements.

- - - - -
1c1b63d6 by Ben Gamari at 2019-03-16T19:13:36-04:00
compiler: Disable atomic renaming on Windows

As discussed in #16450, this feature regresses CI on Windows, causing
non-deterministic failures due to missing files.

- - - - -
6764da43 by Ben Gamari at 2019-03-16T19:16:56-04:00
gitlab-ci: Explicitly set bindist tarball name

- - - - -
ad79ccd9 by Ben Gamari at 2019-03-16T19:17:46-04:00
gitlab-ci: Generate documentation tarball

- - - - -
3f2291e4 by Ben Gamari at 2019-03-16T19:17:46-04:00
gitlab-ci: Generate source tarballs

- - - - -
cb61371e by Ben Gamari at 2019-03-17T05:05:10-04:00
ghc-heap: Introduce closureSize

This function allows the user to compute the (non-transitive) size of a
heap object in words. The "closure" in the name is admittedly confusing
but we are stuck with this nomenclature at this point.

- - - - -
c01d5af3 by Michael Sloan at 2019-03-17T22:23:19-04:00
Extract out use of UnboxedTuples from GHCi.Leak

See #13101 + #15454 for motivation.  This change reduces the number of
modules that need to be compiled to object code when loading GHC into
GHCi.

- - - - -
6113d0d4 by Radosław Rowicki at 2019-03-17T22:29:25-04:00
Update bug tracker link to point to gitlab instead of deprecated trac
- - - - -
b8326897 by Ben Gamari at 2019-03-17T23:16:12-04:00
gitlab-ci: Always build fedora27

This ends up being much easier to use than Debian 9 under NixOS.

- - - - -
acf2129d by Ben Gamari at 2019-03-17T23:17:36-04:00
gitlab-ci: Implement head.hackage jobs

- - - - -
71648c35 by Ben Gamari at 2019-03-19T23:04:18-04:00
gitlab-ci: Implement support for i386/Windows bindists

- - - - -
d94ca74f by Tamar Christina at 2019-03-19T23:10:23-04:00
err: clean up error handler

- - - - -
398f2cbc by Ben Gamari at 2019-03-19T23:16:32-04:00
Bump Cabal submodule to 3.0

Metric Increase:
    haddock.Cabal

- - - - -
89a201e8 by Takenobu Tani at 2019-03-19T23:22:36-04:00
users-guide: Update Wiki URLs to point to GitLab

The user's guide uses the `ghc-wiki` macro, and substitution rules
are complicated. So I manually edited `.rst` files without sed.

I changed `Commentary/Latedmd` only to a different page.
It is more appropriate as an example.

[ci skip]

- - - - -
98ff1a56 by Krzysztof Gogolewski at 2019-03-19T23:28:42-04:00
Replace nOfThem by replicate

- - - - -
6a47414f by Krzysztof Gogolewski at 2019-03-19T23:28:42-04:00
Fix typos

- - - - -
1e26e60d by Krzysztof Gogolewski at 2019-03-19T23:28:42-04:00
Simplify monadic code

- - - - -
c045bd7c by Krzysztof Gogolewski at 2019-03-19T23:28:42-04:00
Remove deprecated reinitializeGlobals

- - - - -
6d19ad72 by Ben Gamari at 2019-03-19T23:34:49-04:00
gitlab-ci: Bump docker images

To install lndir and un-break the source distribution job.

- - - - -
c7a84a60 by Matthew Pickering at 2019-03-19T23:34:50-04:00
Update .gitlab-ci.yml
- - - - -
db136237 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Mark T16219 and cabal09 as broken on Windows

See #16386.

- - - - -
7cd8e330 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Fix expected output on Windows for various ghci tests

Broke as -Wimplicit-kind-vars no longer exists. Specifically ghci024,
ghci057 and T9293.

- - - - -
23b639fd by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Mark T5836 as broken on Windows

See #16387.

- - - - -
a1bda08d by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Mark T15904 as broken on Windows

It seems to look for some sort of manifest file. See #16388.

- - - - -
b7f5d552 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Mark T16190 as broken on Windows

There seems to be some filepath funniness due to TH embedding going on
here. See #16389.

- - - - -
a0c31f78 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite/plugins: Add multi_cpu_race modifier on Windows

A few tests previously failed with various failure modes. For instance,
  `plugin-recomp-change` fails with:

```
Wrong exit code for plugin-recomp-change()(expected 0 , actual 2 )
Stderr ( plugin-recomp-change ):
Simple Plugin Passes Queried
Got options:
Simple Plugin Pass Run
C://GitLabRunner//builds//8fc0e283//0//ghc//ghc//inplace//mingw//bin/ld.exe: cannot find -lHSplugin-recompilation-0.1-CPeObcGoBuvHdwBnpK9jQq
collect2.exe: error: ld returned 1 exit status
`gcc.exe' failed in phase `Linker'. (Exit code: 1)
make[2]: *** [Makefile:112: plugin-recomp-change] Error 1
*** unexpected failure for plugin-recomp-change(normal)
```

It's unclear whether the ghc-pkg concurrency issue mentioned in all.T is
the culprit but the set of tests that fail overlaps strongly with the
set of tests that lack the `multi_cpu_race` modifier. Let's see if
adding it fixes them.

- - - - -
88a6e9a4 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Mark T10672 as broken

This test, which is only run on Windows, seems to be reliably timing
out.

See #16390.

- - - - -
f4d3aaaf by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite/plugins: Increase compile timeout on Windows

I think the linker is routinely eating through the timeout,
leading to many spurious failures.

- - - - -
ae382245 by Ben Gamari at 2019-03-20T18:41:32-04:00
rts/RtsSymbols: Drop __mingw_vsnwprintf

As described in #16387, this is already defined by mingw and
consequently defining it in the RTS as well leads to multiple definition
errors from the RTS linker at runtime.

- - - - -
f79f93e4 by Ben Gamari at 2019-03-20T18:41:32-04:00
Don't mark cabal09 as broken

It doesn't fail reliably.

- - - - -
d98cb763 by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Don't mark T5836 as broken

I believe removing __mingw_vsnwprintf from RtsSymbols fixed #16387.

- - - - -
8c1a2743 by Ben Gamari at 2019-03-20T18:41:32-04:00
Try again

- - - - -
3394a7cd by Ben Gamari at 2019-03-20T18:41:32-04:00
testsuite: Display observed exit code on failure due to bad exit code

- - - - -
36818759 by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Adjust section placement and relocation logic for Mach-O

1. Place each section on a separate page to ensure required
alignment (wastes lots ot space, needs to be improved).
2. Unwire relocation logic from macho sections (the most fiddly part
is adjusting internal relocations).

Other todos:
0. Add a test for section alignment.
1. Investigate 32bit relocations!
2. Fix memory leak in ZEROPAGE section allocation.
3. Fix creating redundant jump islands for GOT.
4. Investigate more compact section placement.

- - - - -
78c61acf by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Use segments for section layout

- - - - -
7bbfb789 by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Address some todos and fixmes

- - - - -
3cdcc0b5 by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Add a linker test re: section alignment

- - - - -
cb745c84 by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Add missing levels to SegmentProt enum

- - - - -
d950f11e by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Directly test section alignment, fix internal reloc probing length

- - - - -
3fb10fcf by Artem Pyanykh at 2019-03-20T19:52:39-04:00
Gracefully handle error condition in Mach-O relocateSection

- - - - -
dc713c71 by Ben Gamari at 2019-03-20T19:58:49-04:00
ci: Move validate-x86_64-linux-deb9 to full-build stage

The `build` stage is meant to be a minimal smoke test to weed out broken
commits. The `validate-x86_64-linux-deb9` build will generally catch a
subset of issues caught by `validate-x86_64-linux-deb9-debug` so only
the latter should be in `build`.

- - - - -
505c5ab2 by Ben Gamari at 2019-03-20T19:58:49-04:00
ci: Add some descriptions of the stages

- - - - -
646e3dc2 by Sebastian Graf at 2019-03-20T20:04:49-04:00
Add a bench flavour to Hadrian

- - - - -
8d18a873 by Ryan Scott at 2019-03-20T20:10:57-04:00
Reject nested predicates in impredicativity checking

When GHC attempts to unify a metavariable with a type containing
foralls, it will be rejected as an occurrence of impredicativity.
GHC was /not/ extending the same treatment to predicate types, such
as in the following (erroneous) example from #11514:

```haskell
foo :: forall a. (Show a => a -> a) -> ()
foo = undefined
```

This will attempt to instantiate `undefined` at
`(Show a => a -> a) -> ()`, which is impredicative. This patch
catches impredicativity arising from predicates in this fashion.

Since GHC is pickier about impredicative instantiations, some test
cases needed to be updated to be updated so as not to fall afoul of
the new validity check. (There were a surprising number of
impredicative uses of `undefined`!) Moreover, the `T14828` test case
now has slightly less informative types shown with `:print`. This is
due to a a much deeper issue with the GHCi debugger (see #14828).

Fixes #11514.

- - - - -
7b213b8d by Ömer Sinan Ağacan at 2019-03-20T20:17:05-04:00
Print test suite results ("unexpected failures" etc.) in sorted order

Fixes #16425

- - - - -
f199a843 by Simon Jakobi at 2019-03-20T20:23:15-04:00
Check.hs: Fix a few typos

- - - - -
07d44ed1 by Ben Gamari at 2019-03-20T20:29:20-04:00
base: Depend upon shlwapi on Windows

As noted in #16466, `System.Environment.getExecutablePath` depends upon
`PathFileExistsW` which is defined by `shlwapi`.

Fixes #16466.

- - - - -
1382d09e by Ryan Scott at 2019-03-20T20:35:28-04:00
Remove unused XArrApp and XArrForm extension points

!301 removed the `HsArrApp` and `HsArrForm` constructors, which
renders the corresponding extension points `XArrApp` and `XArrForm`
useless. This patch finally rips them out.

- - - - -
3423664b by Peter Trommler at 2019-03-20T20:41:35-04:00
Fix specification of load_load_barrier [skip-ci]

- - - - -
84c77a67 by Alexandre Esteves at 2019-03-21T17:43:03-04:00
Fix typo [skip ci]
- - - - -
7092b2de by Matthew Pickering at 2019-03-21T23:38:58-04:00
Only run check-makefiles.py linter in testsuite dir

- - - - -
322239de by Matthew Pickering at 2019-03-21T23:38:58-04:00
Run linters on merge requests

It seems that it has failed to execute at all since it was implemented.

We now run the linters on merge requests.

- - - - -
8f8d532c by Ben Gamari at 2019-03-21T23:45:03-04:00
gitlab-ci: Do full `perf` build when building Windows releases

- - - - -
2ef72d3f by Ben Gamari at 2019-03-21T23:45:03-04:00
gitlab-ci: Pass --target explicitly to configure on Windows

Otherwise configure fails in the 32-bit case with
```
This GHC (c:/GitLabRunner/builds/8fc0e283/0/ghc/ghc/toolchain/bin/ghc) does not generate code for the build platform
   GHC target platform    : x86_64-unknown-mingw32
   Desired build platform : i386-unknown-mingw32
```

- - - - -
8b14f536 by Ben Gamari at 2019-03-21T23:51:08-04:00
Bump cabal submodule

Due to https://github.com/haskell/cabal/issues/5953.

- - - - -
dbe4557f by Matthew Pickering at 2019-03-22T10:02:32-04:00
CI: Allow failure in packaging step

This depends on the windows build which is still allowed to fail. If
that job fails then the packaging job will also fail.

- - - - -
366f1c68 by Ben Gamari at 2019-03-22T10:08:38-04:00
gitlab: Deploy documentation snapshot via GitLab Pages

- - - - -
d608d543 by Tamar Christina at 2019-03-22T10:14:45-04:00
Force LF line ending for md5sum [skip-ci]

- - - - -
cd07086a by Ben Gamari at 2019-03-22T10:34:51-04:00
gitlab-ci: Fix linters

- - - - -
ab51bee4 by Herbert Valerio Riedel at 2019-03-22T10:34:51-04:00
base: Remove `Monad(fail)` method and reexport `MonadFail(fail)` instead

As per https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail

Coauthored-by: Ben Gamari <ben at well-typed.com>

- - - - -
266b49ca by Ben Gamari at 2019-03-22T18:33:20-04:00
gitlab-ci: Clean up linter

I'm not sure why these steps were done but they seem counterproductive
and unnecessary.

- - - - -
44b08ede by Ben Gamari at 2019-03-22T18:38:11-04:00
gitlab-ci: Fix YAML syntax

- - - - -
971f4530 by Ben Gamari at 2019-03-22T18:49:34-04:00
gitlab-ci: Compute merge base against remote tracking branch

Previously we would use the local branch with the name
`$CI_MERGE_REQUEST_TARGET_BRANCH_NAME` to compute the merge base when
linting. However, this branch isn't necessarily up-to-date. We should
rather use `origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME`.

- - - - -
8d01b572 by Ben Gamari at 2019-03-23T12:37:56-04:00
gitlab-ci: Explicitly fetch target branch

`git fetch`, which we used previously, doesn't update the remote
tracking branches.

- - - - -
cd85f8a7 by Ben Gamari at 2019-03-24T08:46:13-04:00
gitlab-ci: Allow linters to fail for now

They are broken and I don't have time to fix them at the moment.
- - - - -
d763b2e7 by Haskell-mouse at 2019-03-25T14:02:22-04:00
User's Guide: extensions compatibility

Adds the mention that extensions "AllowAmbiguousTypes" and "RankNTypes"
are not always compatible with each other.
Specifies the conditions and causes of failing in resolving
of ambiguity.

- - - - -
200d65ef by Matthew Pickering at 2019-03-25T14:02:25-04:00
Check hadrian/ghci.sh script output to determine pass/fail

ghci always exits with exit code 0 so you have to check the output
to see if the modules loaded succesfully.

- - - - -
8e07368f by Matthew Pickering at 2019-03-25T14:02:27-04:00
Refactor ./hadrian/ghci.sh for better error messages

By separating these two lines, if the first command fails then `ghci` is
not loaded. Before it would still load ghci but display lots of errors
about not being able to find modules.

- - - - -
3769e3a8 by Takenobu Tani at 2019-03-25T14:02:29-04:00
Update Wiki URLs to point to GitLab

This moves all URL references to Trac Wiki to their corresponding
GitLab counterparts.

This substitution is classified as follows:

1. Automated substitution using sed with Ben's mapping rule [1]
    Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy...
    New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy...

2. Manual substitution for URLs containing `#` index
    Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy...#Zzz
    New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy...#zzz

3. Manual substitution for strings starting with `Commentary`
    Old: Commentary/XxxYyy...
    New: commentary/xxx-yyy...

See also !539

[1]: https://gitlab.haskell.org/bgamari/gitlab-migration/blob/master/wiki-mapping.json

- - - - -
b9da2868 by Ryan Scott at 2019-03-25T14:02:33-04:00
Correct duplicate 4.12.0.0 entry in base's changelog

See #16490.

[ci skip]

- - - - -
ab41c1b4 by Andrey Mokhov at 2019-03-27T07:20:03-04:00
Hadrian: Bump Shake to 0.17.6

The new release of Shake comes with these relevant features:

* use symlinks for --shared
* add --compact for a Bazel/Buck style output

- - - - -
646f2e79 by Andrey Mokhov at 2019-03-27T07:20:03-04:00
Hadrian: trace the execution of expensive Cabal calls

We use Cabal to parse, configure, register and copy packages, which are
expensive operations that are currently not visible to Shake's profiling
infrastructure. By using `traced` we tell Shake to add these IO actions
to the profiling report, helping us to identify performance bottlenecks.

We use short tracing keys, as recommended in Shake docs: the name of the
current target is already available in the rest of the profiling
information.

- - - - -
fb12f53c by Alp Mestanogullari at 2019-03-27T07:20:05-04:00
Hadrian: introduce an easy way for users to build with -split-sections

Any user can now trivially build any number of Haskell packages with
`-split-sections` by using `splitSections`/`splitSectionsIf` on any
existing or new flavour:

    -- build all packages but the ghc library with -split-sections
    splitSections :: Flavour -> Flavour

    -- build all packages that satisfy the given predicate
    -- with --split-sections
    splitSectionsIf :: (Package -> Bool) -> Flavour -> Flavour

See the new section in `doc/user-settings.md`.

- - - - -
3dec527a by David Eichmann at 2019-03-27T07:20:09-04:00
Hadrian: don't use -zorigin on darwin.

- - - - -
5730f863 by Ömer Sinan Ağacan at 2019-03-27T07:20:10-04:00
Minor refactoring in copy array primops:

- `emitCopySmallArray` now checks size before generating code and
  doesn't generate any code when size is 0. `emitCopyArray` already does
  this so this makes small/large array cases the same in argument
  checking.

- In both `emitCopySmallArray` and `emitCopyArray` read the `dflags`
  after checking the argument.

- - - - -
4acdb769 by Chaitanya Koparkar at 2019-03-27T07:20:11-04:00
Fix a few broken Trac links [skip ci]

This patch only attempts to fix links that don't automatically re-direct to the correct URL.

- - - - -
97ad5cfb by Artem Pelenitsyn at 2019-03-29T14:18:12-04:00
Add some tips to the Troubleshooting section of README

- - - - -
8a20bfc2 by Michael Peyton Jones at 2019-03-29T14:18:14-04:00
Visibility: handle multiple units with the same name

Fixes #16228. The included test case is adapted from the reproduction in
the issue, and fails without this patch.

------

We compute an initial visilibity mapping for units based on what is
present in the package databases. To seed this, we compute a set of all
the package configs to add visibilities for.

However, this set was keyed off the unit's *package name*. This is
correct, since we compare packages across databases by version. However,
we would only ever consider a single, most-preferable unit from the
database in which it was found.

The effect of this was that only one of the libraries in a Cabal package
would be added to this initial set. This would cause attempts to use
modules from the omitted libraries to fail, claiming that the package
was hidden (even though `ghc-pkg` would correctly show it as visible).

A solution is to do the selection of the most preferable packages
separately, and then be sure to consider exposing all units in the
same package in the same package db. We can do this by picking a
most-preferable unit for each package name, and then considering
exposing all units that are equi-preferable with that unit.

------

Why wasn't this bug apparent to all people trying to use sub-libraries
in Cabal? The answer is that Cabal explicitly passes `-package` and
`-package-id` flags for all the packages it wants to use, rather than
relying on the state of the package database. So this bug only really
affects people who are trying to use package databases produced by Cabal
outside of Cabal itself.

One particular example of this is the way that the
Nixpkgs Haskell infrastructure provides wrapped GHCs: typically these
are equipped with a package database containing all the needed
package dependencies, and the user is not expected to pass
`-package` flags explicitly.

- - - - -
754b5455 by Artem Pelenitsyn at 2019-03-29T14:18:20-04:00
docs: make nfib compute the Fibonacci sequence [skipci]
- - - - -
1a567133 by Ben Gamari at 2019-03-29T14:18:20-04:00
ci: Check that changelogs don't contain "TBA"

This ensures that the release dates in the library changelogs are
properly set.

- - - - -
6e15ca54 by Ben Gamari at 2019-03-29T14:18:22-04:00
Bump transformers to 0.5.6.2

See #16199.

- - - - -
6f7115df by Ben Gamari at 2019-03-30T07:42:38-04:00
ci: Ensure index.html is preserved in documentation tarball

- - - - -
33173a51 by Alexandre at 2019-04-01T03:32:28-04:00
    Add support for bitreverse primop

    This commit includes the necessary changes in code and
    documentation to support a primop that reverses a word's
    bits. It also includes a test.

- - - - -
a3971b4e by Alexandre at 2019-04-01T03:32:28-04:00
Bump ghc-prim's version where needed

- - - - -
061276ea by Michael Sloan at 2019-04-01T03:32:30-04:00
Remove unnecessary uses of UnboxedTuples pragma (see #13101 / #15454)

Also removes a couple unnecessary MagicHash pragmas

- - - - -
e468c613 by David Eichmann at 2019-04-01T03:32:34-04:00
Support Shake's --lint-fsatrace feature.

Using this feature requires fsatrace (e.g. https://github.com/jacereda/fsatrace).
Simply use the `--lint-fsatrace` option when running hadrian.
Shake version >= 0.17.7 is required to support linting out of tree build dirs.

- - - - -
1e9e4197 by Ben Gamari at 2019-04-01T03:32:34-04:00
gitlab: Add merge request template for backports for 8.8

- - - - -
55650d14 by Ben Gamari at 2019-04-01T03:32:34-04:00
gitlab: Add some simply issue templates

- - - - -
27b99ed8 by Takenobu Tani at 2019-04-01T03:32:36-04:00
Clean up URLs to point to GitLab

This moves URL references to old Trac to their corresponding
GitLab counterparts.

This patch does not update the submodule library, such as
libraries/Cabal.

See also !539, !606, !618

[ci skip]

- - - - -
18d1555d by Adam Sandberg Eriksson at 2019-04-01T03:32:38-04:00
configure: document the use of the LD variable

- - - - -
10352efa by Ben Gamari at 2019-04-01T18:22:34-04:00
gitlab: Add feature request MR template

- - - - -
1e52054b by Ben Gamari at 2019-04-01T19:16:21-04:00
gitlab: Move feature request template to issue_templates

Whoops.

- - - - -
e5c21ca9 by Ben Gamari at 2019-04-01T19:16:25-04:00
gitlab: Mention ~"user facing" label

- - - - -
39282422 by Ryan Scott at 2019-04-01T20:01:38-04:00
Bump array submodule

This bumps `array` to version 0.5.4.0 so that we can distinguish
it with `MIN_VERSION_array` (as it introduces some changes to the
`Show` instance for `UArray`).

- - - - -
7cf5ba3d by Michal Terepeta at 2019-04-01T20:07:49-04:00
Improve performance of newSmallArray#

This:
- Hoists part of the condition outside of the initialization loop in
  `stg_newSmallArrayzh`.
- Annotates one of the unlikely branches as unlikely, also in
  `stg_newSmallArrayzh`.
- Adds a couple of annotations to `allocateMightFail` indicating which
  branches are likely to be taken.

Together this gives about 5% improvement.

Signed-off-by: Michal Terepeta <michal.terepeta at gmail.com>

- - - - -
dd9c82ef by David Eichmann at 2019-04-01T20:13:55-04:00
Hadrian: correct deps for ghc builder.

Previously, when needing ghc as a builder, the ghcDeps (Files
the GHC binary depends on) for the current stage were needed.
This is incorrect as the previous stage's ghc is used for building.
This commit fixes the issue, needing the previous stage's ghcDeps.

- - - - -
345306d3 by Alexandre Baldé at 2019-04-02T12:34:30-04:00
Fix formatting issue in ghc-prim's changelog [skip ci]

- - - - -
f54b5124 by David Eichmann at 2019-04-02T12:40:39-04:00
Hadrian: traceAllow deep dependencies when compilling haskell object files.

- - - - -
d132b30a by David Eichmann at 2019-04-02T12:40:39-04:00
Hadrian: lint ignore autom4te and ghc-pkg cache files.

- - - - -
bf734195 by Simon Marlow at 2019-04-02T12:46:46-04:00
Add myself to libraries/ghci
- - - - -
5a75ccd0 by klebinger.andreas at gmx.at at 2019-04-03T00:34:57-04:00
Fix faulty substitutions in StgCse (#11532).

`substBndr` should rename bindings which shadow existing ids.
However while it was renaming the bindings it was not adding proper substitutions
for renamed bindings.
Instead of adding a substitution of the form `old -> new` for renamed
bindings it mistakenly added `old -> old` if no replacement had taken
place while adding none if `old` had been renamed.

As a byproduct this should improve performance, as we no longer add
useless substitutions for unshadowed bindings.

- - - - -
2ec749b5 by Nathan Collins at 2019-04-03T00:41:05-04:00
users-guide: Fix typo

- - - - -
ea192a09 by Andrew Martin at 2019-04-03T00:41:05-04:00
base: Add documentation that liftA2 used to not be a typeclass method

- - - - -
733f1b52 by Frank Steffahn at 2019-04-03T00:41:05-04:00
users-guide: Typo in Users Guide, Glasgow Exts

- - - - -
3364def0 by Ben Gamari at 2019-04-03T00:41:05-04:00
integer-gmp: Write friendlier documentation for Integer

- - - - -
dd3a3d08 by Ben Gamari at 2019-04-03T00:41:05-04:00
integer-simple: Add documentation for Integer type

- - - - -
722fdddf by Chris Martin at 2019-04-03T00:41:05-04:00
Correct two misspellings of "separately"

- - - - -
bf6dbe3d by Chris Martin at 2019-04-03T00:41:05-04:00
Inline the definition of 'ap' in the Monad laws

The law as it is currently written is meaningless, because nowhere have
we defined the implementation of 'ap'. The reader of the Control.Monad
documentation is provided with only a type signature,

> ap :: Monad m => m (a -> b) -> m a -> m b

an informal description,

> In many situations, the liftM operations can be replaced by uses of
> ap, which promotes function application.

and a relationship between 'ap' and the 'liftM' functions

> return f `ap` x1 `ap` ... `ap` xn
> is equivalent to
> liftMn f x1 x2 ... xn

Without knowing how 'ap' is defined, a law involving 'ap' cannot
provide any guidance for how to write a lawful Monad instance, nor can
we conclude anything from the law.

I suspect that a reader equipped with the understanding that 'ap' was
defined prior to the invention of the Applicative class could deduce
that 'ap' must be defined in terms of (>>=), but nowhere as far as I can
tell have we written this down explicitly for readers without the
benefit of historical context.

If the law is meant to express a relationship among (<*>), (>>=), and
'return', it seems that it is better off making this statement directly,
sidestepping 'ap' altogether.

- - - - -
7b090b53 by Ben Gamari at 2019-04-03T03:57:40-04:00
configure: Always use AC_LINK_ELSEIF when testing against assembler

This fixes #16440, where the build system incorrectly concluded that the
`.subsections_via_symbols` assembler directive was supported on a Linux
system. This was caused by the fact that gcc was invoked with `-flto`;
when so-configured gcc does not call the assembler but rather simply
serialises its AST for compilation during the final link.

This is described in Note [autoconf assembler checks and -flto].

- - - - -
4626cf21 by Sebastian Graf at 2019-04-03T04:03:47-04:00
Fix Uncovered set of literal patterns

Issues #16289 and #15713 are proof that the pattern match checker did
an unsound job of estimating the value set abstraction corresponding to
the uncovered set.

The reason is that the fix from #11303 introducing `NLit` was
incomplete: The `LitCon` case desugared to `Var` rather than `LitVar`,
which would have done the necessary case splitting analogous to the
`ConVar` case.

This patch rectifies that by introducing the fresh unification variable
in `LitCon` in value abstraction position rather than pattern postition,
recording a constraint equating it to the constructor expression rather
than the literal. Fixes #16289 and #15713.

- - - - -
6f13e7b1 by Ben Gamari at 2019-04-03T08:12:26-04:00
gitlab-ci: Build hyperlinked sources for releases

Fixes #16445.

- - - - -
895394c2 by Ben Gamari at 2019-04-03T08:15:06-04:00
gitlab: Fix label names in issue templates

- - - - -
75abaaea by Yuriy Syrovetskiy at 2019-04-04T04:23:19-04:00
Replace git.haskell.org with gitlab.haskell.org (#16196)

- - - - -
25c02ea1 by Ryan Scott at 2019-04-04T04:29:29-04:00
Fix #16518 with some more kind-splitting smarts

This patch corrects two simple oversights that led to #16518:

1. `HsUtils.typeToLHsType` was taking visibility into account in the
   `TyConApp` case, but not the `AppTy` case. I've factored out the
   visibility-related logic into its own `go_app` function and now
   invoke `go_app` from both the `TyConApp` and `AppTy` cases.
2. `Type.fun_kind_arg_flags` did not properly split kinds with
   nested `forall`s, such as
   `(forall k. k -> Type) -> (forall k. k -> Type)`. This was simply
   because `fun_kind_arg_flags`'s `FunTy` case always bailed out and
   assumed all subsequent arguments were `Required`, which clearly
   isn't the case for nested `forall`s. I tweaked the `FunTy` case
   to recur on the result kind.

- - - - -
51fd3571 by Ryan Scott at 2019-04-04T04:35:39-04:00
Use funPrec, not topPrec, to parenthesize GADT argument types

A simple oversight. Fixes #16527.

- - - - -
6c0dd085 by Ben Gamari at 2019-04-04T08:12:24-04:00
testsuite: Add testcase for #16111

- - - - -
cbb88865 by klebinger.andreas at gmx.at at 2019-04-04T08:12:25-04:00
Restore Xmm registers properly in StgCRun.c

This fixes #16514: Xmm6-15 was restored based off rax instead of rsp.
The code was introduced in the fix for #14619.

- - - - -
33b0a291 by Ryan Scott at 2019-04-04T08:12:28-04:00
Tweak error messages for narrowly-kinded assoc default decls

This program, from #13971, currently has a rather confusing error
message:

```hs
class C a where
  type T a :: k
  type T a = Int
```
```
    • Kind mis-match on LHS of default declaration for ‘T’
    • In the default type instance declaration for ‘T’
      In the class declaration for ‘C’
```

It's not at all obvious why GHC is complaining about the LHS until
you realize that the default, when printed with
`-fprint-explicit-kinds`, is actually `type T @{k} @* a = Int`.
That is to say, the kind of `a` is being instantiated to `Type`,
whereas it ought to be a kind variable. The primary thrust of this
patch is to weak the error message to make this connection
more obvious:

```
    • Illegal argument ‘*’ in:
        ‘type T @{k} @* a = Int’
        The arguments to ‘T’ must all be type variables
    • In the default type instance declaration for ‘T’
      In the class declaration for ‘C’
```

Along the way, I performed some code cleanup suggested by @rae in
https://gitlab.haskell.org/ghc/ghc/issues/13971#note_191287. Before,
we were creating a substitution from the default declaration's type
variables to the type family tycon's type variables by way of
`tcMatchTys`. But this is overkill, since we already know (from the
aforementioned validity checking) that all the arguments in a default
declaration must be type variables anyway. Therefore, creating the
substitution is as simple as using `zipTvSubst`. I took the
opportunity to perform this refactoring while I was in town.

Fixes #13971.

- - - - -
3a38ea44 by Eric Crockett at 2019-04-07T15:21:59-04:00
Fix #16282.

Previously, -W(all-)missed-specs was created with 'NoReason',
so no information about the flag was printed along with the warning.
Now, -Wall-missed-specs is listed as the Reason if it was set,
otherwise -Wmissed-specs is listed as the reason.

- - - - -
63b7d5fb by Michal Terepeta at 2019-04-08T14:29:34-04:00
Generate straightline code for inline array allocation

GHC has an optimization for allocating arrays when the size is
statically known -- it'll generate the code allocating and initializing
the array inline (instead of a call to a procedure from
`rts/PrimOps.cmm`).

However, the generated code uses a loop to do the initialization. Since
we already check that the requested size is small (we check against
`maxInlineAllocSize`), we can generate faster straightline code instead.
This brings about 15% improvement for `newSmallArray#` in my testing and
slightly simplifies the code in GHC.

Signed-off-by: Michal Terepeta <michal.terepeta at gmail.com>

- - - - -
2b3f4718 by Phuong Trinh at 2019-04-08T14:35:43-04:00
Fix #16500: look for interface files in -hidir flag in OneShot mode

We are currently ignoring options set in the hiDir field of hsc_dflags
when looking for interface files while compiling in OneShot mode. This
is inconsistent with the behaviour of other directory redirecting fields
(such as objectDir or hieDir). It is also inconsistent with the
behaviour of compilation in CompManager mode (a.k.a `ghc --make`) which
looks for interface files in the directory set in hidir flag. This
changes Finder.hs so that we use the value of hiDir while looking for
interface in OneShot mode.

- - - - -
97502be8 by Yuriy Syrovetskiy at 2019-04-08T14:41:51-04:00
Add `-optcxx` option (#16477)

- - - - -
97d3d546 by Ben Gamari at 2019-04-08T14:47:54-04:00
testsuite: Unmark T16190 as broken

Was broken via #16389 yet strangely it has started passing despite the
fact that the suggested root cause has not changed.

- - - - -
a42d206a by Yuriy Syrovetskiy at 2019-04-08T14:54:02-04:00
Fix whitespace style

- - - - -
4dda2270 by Matthew Pickering at 2019-04-08T15:00:08-04:00
Use ./hadrian/ghci.sh in .ghcid

- - - - -
d236d9d0 by Sebastian Graf at 2019-04-08T15:06:15-04:00
Make `singleConstructor` cope with pattern synonyms

Previously, `singleConstructor` didn't handle singleton `COMPLETE` sets
of a single pattern synonym, resulting in incomplete pattern warnings
in #15753.

This is fixed by making `singleConstructor` (now named
`singleMatchConstructor`) query `allCompleteMatches`, necessarily making
it effectful. As a result, most of this patch is concerned with
threading the side-effect through to `singleMatchConstructor`.

Unfortunately, this is not enough to completely fix the original
reproduction from #15753 and #15884, which are related to function
applications in pattern guards being translated too conservatively.

- - - - -
1085090e by Ömer Sinan Ağacan at 2019-04-08T15:12:22-04:00
Skip test ArithInt16 and ArithWord16 in GHCi way

These tests use unboxed tuples, which GHCi doesn't support

- - - - -
7287bb9e by Ömer Sinan Ağacan at 2019-04-08T15:18:33-04:00
testsuite: Show exit code of GHCi tests on failure

- - - - -
f5604d37 by John Ericson at 2019-04-08T15:24:43-04:00
settings.in: Reformat

We're might be about to switch to generating it in Hadrian/Make. This
reformat makes it easier to programmingmatically generate and end up
with the exact same thing, which is good for diffing to ensure no
regressions.

I had this as part of !712, but given the difficulty of satisfying CI, I
figured I should break things up even further.

- - - - -
cf9e1837 by Ryan Scott at 2019-04-08T15:30:51-04:00
Bump hpc submodule

Currently, the `hpc` submodule is pinned against the `wip/final-mfp`
branch, not against `master`. This pins it back against `master`.

- - - - -
36d38047 by Ben Gamari at 2019-04-09T10:23:47-04:00
users-guide: Document how to disable package environments

As noted in #16309 this somehow went undocumented.

- - - - -
af4cea7f by Artem Pyanykh at 2019-04-09T10:30:13-04:00
codegen: fix memset unroll for small bytearrays, add 64-bit sets

Fixes #16052

When the offset in `setByteArray#` is statically known, we can provide
better alignment guarantees then just 1 byte.

Also, memset can now do 64-bit wide sets.

The current memset intrinsic is not optimal however and can be
improved for the case when we know that we deal with

(baseAddress at known alignment) + offset

For instance, on 64-bit

`setByteArray# s 1# 23# 0#`

given that bytearray is 8 bytes aligned could be unrolled into
`movb, movw, movl, movq, movq`; but currently it is
`movb x23` since alignment of 1 is all we can embed into MO_Memset op.

- - - - -
bd2de4f0 by Artem Pyanykh at 2019-04-09T10:30:13-04:00
codegen: use newtype for Alignment in BasicTypes

- - - - -
14a78707 by Artem Pyanykh at 2019-04-09T10:30:13-04:00
docs: add a note about changes in memset unrolling to 8.10.1-notes

- - - - -
fe40ddd9 by Sylvain Henry at 2019-04-09T12:50:15-04:00
Hadrian: fix library install paths in bindist Makefile (#16498)

GHC now works out-of-the-box (i.e. without any wrapper script) by
assuming that @bin@ and @lib@ directories sit next to each other. In
particular, its RUNPATH uses $ORIGIN-based relative path to find the
libraries.

However, to be good citizens we want to support the case where @bin@ and
@lib@ directories (respectively BINDIR and LIBDIR) don't sit next to
each other or are renamed. To do that the install script simply creates
GHC specific @bin@ and @lib@ siblings directories into:

   LIBDIR/ghc-VERSION/{bin,lib}

Then it installs wrapper scripts into BINDIR that call the appropriate
programs into LIBDIR/ghc-VERSION/bin/.

The issue fixed by this patch is that libraries were not installed into
LIBDIR/ghc-VERSION/lib but directly into LIBDIR.

- - - - -
9acdc4c0 by Ben Gamari at 2019-04-09T12:56:38-04:00
gitlab: Bump cabal-install version used by Windows builds to 2.4

Hopefully fixes Windows Hadrian build.

- - - - -
fc3f421b by Joachim Breitner at 2019-04-09T23:17:37-04:00
GHC no longer ever defines TABLES_NEXT_TO_CODE on its own

It should be entirely the responsibility of make/Hadrian to ensure that
everything that needs this flag gets it. GHC shouldn't be hardcoded to
assist with bootstrapping since it builds other things besides itself.

Reviewers:

Subscribers: TerrorJack, rwbarton, carter

GHC Trac Issues: #15548 -- progress towards but not fix

Differential Revision: https://phabricator.haskell.org/D5082 -- extract
from that

- - - - -
be0dde8e by Ryan Scott at 2019-04-09T23:23:50-04:00
Use ghc-prim < 0.7, not <= 0.6.1, as upper version bounds

Using `ghc-prim <= 0.6.1` is somewhat dodgy from a PVP point of view,
as it makes it awkward to support new minor releases of `ghc-prim`.
Let's instead use `< 0.7`, which is the idiomatic way of expressing
PVP-compliant upper version bounds.

- - - - -
42504f4a by Carter Schonwald at 2019-04-10T20:28:41-04:00
removing x87 register support from native code gen

* simplifies registers to have GPR, Float and Double, by removing the SSE2 and X87 Constructors
* makes -msse2 assumed/default for x86 platforms, fixing a long standing nondeterminism in rounding
behavior in 32bit haskell code
* removes the 80bit floating point representation from the supported float sizes
* theres still 1 tiny bit of x87 support needed,
for handling float and double return values in FFI calls  wrt the C ABI on x86_32,
but this one piece does not leak into the rest of NCG.
* Lots of code thats not been touched in a long time got deleted as a
consequence of all of this

all in all, this change paves the way towards a lot of future further
improvements in how GHC handles floating point computations, along with
making the native code gen more accessible to a larger pool of contributors.

- - - - -
c401f8a4 by Sylvain Henry at 2019-04-11T19:51:24-04:00
Hadrian: fix binary-dir with --docs=none

Hadrian's "binary-dist" target must check that the "docs" directory
exists (it may not since we can disable docs generation).

- - - - -
091195a4 by Ömer Sinan Ağacan at 2019-04-11T19:57:38-04:00
Remove unused remilestoning script

- - - - -
fa0ccbb8 by Ömer Sinan Ağacan at 2019-04-11T19:57:38-04:00
Update a panic message

Point users to the right URL

- - - - -
beaa07d2 by Sylvain Henry at 2019-04-12T13:17:21-04:00
Hadrian: fix ghci wrapper script generation (#16508)

- - - - -
e05df3e1 by Ben Gamari at 2019-04-12T13:23:30-04:00
gitlab-ci: Ensure that version number has three components

- - - - -
885d2e04 by klebinger.andreas at gmx.at at 2019-04-12T14:40:04-04:00
Add -ddump-stg-final to dump stg as it is used for codegen.

Intermediate STG does not contain free variables which can be useful
sometimes. So adding a flag to dump that info.

- - - - -
3c759ced by Alp Mestanogullari at 2019-04-12T14:46:54-04:00
Hadrian: add a --test-accept/-a flag, to mimic 'make accept'

When -a or --test-accept is passed, and if one runs the 'test' target, then
any test failing because of mismatching output and which is not expected to
fail will have its expected output adjusted by the test driver, effectively
considering the new output correct from now on.

When this flag is passed, hadrian's 'test' target becomes sensitive to the
PLATFORM and OS environment variable, just like the Make build system:
- when the PLATFORM env var is set to "YES", when accepting a result, accept it
  for the current platform;
- when the OS env var is set to "YES", when accepting a result, accept it
  for all wordsizes of the current operating system.

This can all be combined with `--only="..."` and `TEST="..." to only accept
the new output of a subset of tests.

- - - - -
f4b5a6c0 by Alp Mestanogullari at 2019-04-12T14:46:54-04:00
Hadrian: document -a/--test-accept

- - - - -
30a0988d by Ben Gamari at 2019-04-12T15:41:07-04:00
gitlab: Disable windows-hadrian job

Not only is it reliably failing due to #16574 but all of the quickly
failing builds also causes the Windows runners to run out of disk space.

- - - - -
8870a51b by Ben Gamari at 2019-04-12T15:41:07-04:00
gitlab: Don't run lint-submods job on Marge branches

This broke Marge by creating a second pipeline (consisting of only the
`lint-submods` job). Marge then looked at this pipeline and concluded
that CI for her merge branch passed. However, this is ignores the fact
that the majority of the CI jobs are triggered on `merge_request` and
are therefore in another pipeline.

- - - - -
7876d088 by Ben Gamari at 2019-04-13T09:51:59-04:00
linters: Fix check-version-number

This should have used `grep -E`, not `grep -e`
- - - - -
2e7b2e55 by Ara Adkins at 2019-04-13T10:00:02-04:00
[skip ci] Update CI badge in readme

This trivial MR updates the CI badge in the readme to point to the
new CI on gitlab, rather than the very out-of-date badge from
Travis.

- - - - -
40848a43 by Ben Gamari at 2019-04-13T10:02:36-04:00
base: Better document implementation implications of Data.Timeout

As noted in #16546 timeout uses asynchronous exceptions internally, an
implementation detail which can leak out in surprising ways.  Note this
fact.

Also expose the `Timeout` tycon.

[skip ci]

- - - - -
5f183081 by David Eichmann at 2019-04-14T01:08:15-04:00
Hadrian: add rts shared library symlinks for backwards compatability

Fixes test T3807 when building with Hadrian.

Trac #16370

- - - - -
9b142c53 by Sylvain Henry at 2019-04-14T01:14:23-04:00
Hadrian: add binary-dist-dir target

This patch adds an Hadrian target "binary-dist-dir". Compared to
"binary-dist", it only builds a binary distribution directory without
creating the Tar archive. It makes the use/test of the bindist
installation script easier.

- - - - -
6febc444 by Krzysztof Gogolewski at 2019-04-14T01:20:29-04:00
Fix assertion failures reported in #16533

- - - - -
edcef7b3 by Artem Pyanykh at 2019-04-14T01:26:35-04:00
codegen: unroll memcpy calls for small bytearrays

- - - - -
6094d43f by Artem Pyanykh at 2019-04-14T01:26:35-04:00
docs: mention memcpy optimization for ByteArrays in 8.10.1-notes

- - - - -
d2271fe4 by Simon Jakobi at 2019-04-14T08:43:17-04:00
Ord docs: Add explanation on 'min' and 'max' operator interactions

[ci skip]

- - - - -
e7cad16c by Krzysztof Gogolewski at 2019-04-14T08:49:23-04:00
Add a safeguard to Core Lint

Lint returns a pair (Maybe a, WarnsAndErrs). The Maybe monad
allows to handle an unrecoverable failure.
In case of such a failure, the error should be added to the second
component of the pair. If this is not done, Lint will silently
accept bad programs. This situation actually happened during
development of linear types. This adds a safeguard.

- - - - -
c54a093f by Ben Gamari at 2019-04-14T08:55:29-04:00
CODEOWNERS: Add simonmar as owner of rts/linker

I suspect this is why @simonmar wasn't notified of !706.

[skip ci]

- - - - -
1825f50d by Alp Mestanogullari at 2019-04-14T09:01:38-04:00
Hadrian: don't accept p_dyn for executables, to fix --flavour=prof

- - - - -
b024e289 by Giles Anderson at 2019-04-15T06:20:29-04:00
Document how -O3 is handled by GHC

    -O2 is the highest value of optimization.
    -O3 will be reverted to -O2.

- - - - -
4b1ef06d by Giles Anderson at 2019-04-15T06:20:29-04:00
Apply suggestion to docs/users_guide/using-optimisation.rst
- - - - -
71cf94db by Fraser Tweedale at 2019-04-15T06:26:37-04:00
GHCi: fix load order of .ghci files

Directives in .ghci files in the current directory ("local .ghci")
can be overridden by global files.  Change the order in which the
configs are loaded: global and $HOME/.ghci first, then local.

Also introduce a new field to GHCiState to control whether local
.ghci gets sourced or ignored.  This commit does not add a way to
set this value (a subsequent commit will add this), but the .ghci
sourcing routine respects its value.

Fixes: https://gitlab.haskell.org/ghc/ghc/issues/14689
Related: https://gitlab.haskell.org/ghc/ghc/issues/6017
Related: https://gitlab.haskell.org/ghc/ghc/issues/14250

- - - - -
5c06b60d by Fraser Tweedale at 2019-04-15T06:26:38-04:00
users-guide: update startup script order

Update users guide to match the new startup script order.  Also
clarify that -ignore-dot-ghci does not apply to scripts specified
via the -ghci-script option.

Part of: https://gitlab.haskell.org/ghc/ghc/issues/14689

- - - - -
aa490b35 by Fraser Tweedale at 2019-04-15T06:26:38-04:00
GHCi: add 'local-config' setting

Add the ':set local-config { source | ignore }' setting to control
whether .ghci file in current directory will be sourced or not.  The
directive can be set in global config or $HOME/.ghci, which are
processed before local .ghci files.

The default is "source", preserving current behaviour.

Related: https://gitlab.haskell.org/ghc/ghc/issues/6017
Related: https://gitlab.haskell.org/ghc/ghc/issues/14250

- - - - -
ed94d345 by Fraser Tweedale at 2019-04-15T06:26:38-04:00
users-guide: document :set local-config

Document the ':set local-config' command and add a warning about
sourcing untrusted local .ghci scripts.

Related: https://gitlab.haskell.org/ghc/ghc/issues/6017
Related: https://gitlab.haskell.org/ghc/ghc/issues/14250

- - - - -
be05bd81 by Gabor Greif at 2019-04-15T17:19:03-04:00
asm-emit-time IND_STATIC elimination

When a new closure identifier is being established to a
local or exported closure already emitted into the same
module, refrain from adding an IND_STATIC closure, and
instead emit an assembly-language alias.

Inter-module IND_STATIC objects still remain, and need to be
addressed by other measures.

Binary-size savings on nofib are around 0.1%.

- - - - -
57eb5bc6 by erthalion at 2019-04-16T15:40:36-04:00
Show dynamic object files (#16062)

Closes #16062. When -dynamic-too is specified, reflect that in the
progress message, like:

$ ghc Main.hs -dynamic-too
[1 of 1] Compiling Lib              ( Main.hs, Main.o, Main.dyn_o )

instead of:

$ ghc Main.hs -dynamic-too
[1 of 1] Compiling Lib              ( Main.hs, Main.o )

- - - - -
894ec447 by Andrey Mokhov at 2019-04-16T15:46:44-04:00
Hadrian: Generate GHC wrapper scripts

This is a temporary workaround for #16534. We generate wrapper scripts
<build-root>/ghc-stage1 and <build-root>/ghc-stage2 that can be used to
run Stage1 and Stage2 GHCs with the right arguments.

See https://gitlab.haskell.org/ghc/ghc/issues/16534.

- - - - -
e142ec99 by Sven Tennie at 2019-04-17T23:19:00-04:00
Typeset Big-O complexities with Tex-style notation (#16090)

E.g. use `\(\mathcal{O}(n^2)\)` instead of `/O(n^2)/`.

- - - - -
f0f495f0 by klebinger.andreas at gmx.at at 2019-04-17T23:25:10-04:00
Add an Outputable instance for SDoc with ppr = id.

When printf debugging this can be helpful.

- - - - -
e28706ea by Sylvain Henry at 2019-04-18T08:12:07-04:00
Gitlab: allow execution of CI pipeline from the web interface
[skip ci]

- - - - -
4c8a67a4 by Alp Mestanogullari at 2019-04-18T08:18:18-04:00
Hadrian: fix ghcDebugged and document it

- - - - -
5988f17a by Alp Mestanogullari at 2019-04-18T22:46:12-04:00
Hadrian: fix the value we pass to the test driver for config.compiler_debugged

We used to pass YES/NO, while that particular field is set to True/False. This
happens to fix an unexpected pass, T9208.

- - - - -
57cf1133 by Alec Theriault at 2019-04-18T22:52:25-04:00
TH: make `Lift` and `TExp` levity-polymorphic

Besides the obvious benefits of being able to manipulate `TExp`'s of
unboxed types, this also simplified `-XDeriveLift` all while making
it more capable.

  * `ghc-prim` is explicitly depended upon by `template-haskell`

  * The following TH things are parametrized over `RuntimeRep`:

      - `TExp(..)`
      - `unTypeQ`
      - `unsafeTExpCoerce`
      - `Lift(..)`

  * The following instances have been added to `Lift`:

      - `Int#`, `Word#`, `Float#`, `Double#`, `Char#`, `Addr#`
      - unboxed tuples of lifted types up to arity 7
      - unboxed sums of lifted types up to arity 7

    Ideally we would have levity-polymorphic _instances_ of unboxed
    tuples and sums.

  * The code generated by `-XDeriveLift` uses expression quotes
    instead of generating large amounts of TH code and having
    special hard-coded cases for some unboxed types.

- - - - -
fdfd9731 by Alec Theriault at 2019-04-18T22:52:25-04:00
Add test case for #16384

Now that `TExp` accepts unlifted types, #16384 is fixed. Since the real
issue there was GHC letting through an ill-kinded type which
`-dcore-lint` rightly rejected, a reasonable regression test is that
the program from #16384 can now be accepted without `-dcore-lint`
complaining.

- - - - -
eb2a4df8 by Michal Terepeta at 2019-04-19T23:32:08-04:00
StgCmmPrim: remove an unnecessary instruction in doNewArrayOp

Previously we would generate a local variable pointing after the array
header and use it to initialize the array elements. But we already use
stores with offset, so it's easy to just add the header to those offsets
during compilation and avoid generating the local variable (which would
become a LEA instruction when using native codegen; LLVM already
optimizes it away).

Signed-off-by: Michal Terepeta <michal.terepeta at gmail.com>

- - - - -
fcef26b6 by klebinger.andreas at gmx.at at 2019-04-19T23:38:16-04:00
Don't indent single alternative case expressions for STG.

Makes the width of STG dumps slightly saner.
Especially for things like unboxing.

Fixes #16580

- - - - -
e7280c93 by Vladislav Zavialov at 2019-04-19T23:44:24-04:00
Tagless final encoding of ExpCmdI in the parser

Before this change, we used a roundabout encoding:

1. a GADT (ExpCmdG)
2. a class to pass it around (ExpCmdI)
3. helpers to match on it (ecHsApp, ecHsIf, ecHsCase, ...)

It is more straightforward to turn these helpers into class methods,
removing the need for a GADT.

- - - - -
99dd5d6b by Alec Theriault at 2019-04-19T23:50:29-04:00
Haddock: support strict GADT args with docs

Rather than massaging the output of the parser to re-arrange docs and
bangs, it is simpler to patch the two places in which the strictness
info is needed (to accept that the `HsBangTy` may be inside an
`HsDocTy`).

Fixes #16585.

- - - - -
10776562 by Andrey Mokhov at 2019-04-19T23:56:38-04:00
Hadrian: Drop old/unused CI scripts

- - - - -
37b1a6da by Ben Gamari at 2019-04-20T11:55:20-04:00
gitlab-ci: Improve error message on failure of doc-tarball job

Previously the failure was quite nondescript.

- - - - -
e3fe2601 by Ben Gamari at 2019-04-20T11:55:35-04:00
gitlab-ci: Allow doc-tarball job to fail

Due to allowed failure of Windows job.

- - - - -
bd3872df by Ben Gamari at 2019-04-20T11:55:38-04:00
gitlab-ci: Only run release notes lint on release tags

- - - - -
2145b738 by Ben Gamari at 2019-04-20T11:55:38-04:00
gitlab-ci: Add centos7 release job

- - - - -
983c53c3 by Ben Gamari at 2019-04-20T11:55:38-04:00
gitlab-ci: Do not build profiled libraries on 32-bit Windows

Due to #15934.

- - - - -
5cf771f3 by Ben Gamari at 2019-04-21T09:07:13-04:00
users-guide: Add pretty to package list

- - - - -
6ac5da78 by Ben Gamari at 2019-04-21T09:07:13-04:00
users-guide: Add libraries section to 8.10.1 release notes

- - - - -
3e963de3 by Andrew Martin at 2019-04-21T09:13:20-04:00
improve docs for casArray and casSmallArray

- - - - -
98bffb07 by Andrew Martin at 2019-04-21T09:13:20-04:00
[skip ci] say "machine words" instead of "Int units" in the primops docs

- - - - -
3aefc14a by Andrew Martin at 2019-04-21T09:13:20-04:00
[skip ci] correct formatting of casArray# in docs for casSmallArray#

- - - - -
0e96d120 by Andrew Martin at 2019-04-21T09:13:20-04:00
[skip ci] correct the docs for casArray a little more. clarify that the returned element may be two different things

- - - - -
687152f2 by Artem Pyanykh at 2019-04-21T09:19:29-04:00
testsuite: move tests related to linker under tests/rts/linker

- - - - -
36e51406 by Artem Pyanykh at 2019-04-21T09:19:29-04:00
testsuite: fix ifdef lint errors under tests/rts/linker

- - - - -
1a7a329b by Matthew Pickering at 2019-04-22T14:37:30-04:00
Correct off by one error in ghci +c

Fixes #16569

- - - - -
51655fd8 by Alp Mestanogullari at 2019-04-22T14:44:11-04:00
Hadrian: use the testsuite driver's config.haddock arg more correctly

4 haddock tests assume that .haddock files have been produced, by using the
'req_haddock' modifier. The testsuite driver assumes that this condition is
satisfied if 'config.haddock' is non-empty, but before this patch Hadrian was
always passing the path to where the haddock executable should be, regardless
of whether it is actually there or not.

Instead, we now pass an empty config.haddock when we can't find all of
<build root>/docs/html/libraries/<pkg>/<pkg>.haddock>, where <pkg> ranges over
array, base, ghc-prim, process and template-haskell, and pass the path
to haddock when all those file exists. This has the (desired) effect of skipping
the 4 tests (marked as 'missing library') when the docs haven't been built,
and running the haddock tests when they have.

- - - - -
1959bad3 by Vladislav Zavialov at 2019-04-22T14:50:18-04:00
Stop misusing EWildPat in pattern match coverage checking

EWildPat is a constructor of HsExpr used in the parser to represent
wildcards in ambiguous positions:

* in expression context, EWildPat is turned into hsHoleExpr (see rnExpr)
* in pattern context, EWildPat is turned into WildPat (see checkPattern)

Since EWildPat exists solely for the needs of the parser, we could
remove it by improving the parser.

However, EWildPat has also been used for a different purpose since
8a50610: to represent patterns that the coverage checker cannot handle.
Not only this is a misuse of EWildPat, it also stymies the removal of
EWildPat.

- - - - -
6a491726 by Fraser Tweedale at 2019-04-23T09:27:30-04:00
osReserveHeapMemory: handle signed rlim_t

rlim_t is a signed type on FreeBSD, and the build fails with a
sign-compare error.  Add explicit (unsigned) cast to handle this
case.

- - - - -
ab9b3ace by Alexandre Baldé at 2019-04-23T09:33:37-04:00
Fix error message for './configure' regarding '--with-ghc' [skip ci]

- - - - -
465f8f48 by Ben Gamari at 2019-04-24T12:19:24-04:00
gitlab-ci: source-tarball job should have no dependencies

- - - - -
0fc69416 by Vladislav Zavialov at 2019-04-25T14:28:56-04:00
Introduce MonadP, make PV a newtype

Previously we defined   type PV = P,
this had the downside that if we wanted to change PV,
we would have to modify P as well.

Now PV is free to evolve independently from P.

The common operations addError, addFatalError, getBit, addAnnsAt,
were abstracted into a class called MonadP.

- - - - -
f85efdec by Vladislav Zavialov at 2019-04-25T14:28:56-04:00
checkPattern error hint is PV context

There is a hint added to error messages reported in checkPattern.
Instead of passing it manually, we put it in a ReaderT environment inside PV.

- - - - -
4e228267 by Ömer Sinan Ağacan at 2019-04-25T14:35:09-04:00
Minor RTS refactoring:

- Remove redundant casting in evacuate_static_object
- Remove redundant parens in STATIC_LINK
- Fix a typo in GC.c

- - - - -
faa94d47 by Ben Gamari at 2019-04-25T17:16:21-04:00
update-autoconf: Initial commit

- - - - -
4811cd39 by Ben Gamari at 2019-04-25T17:16:21-04:00
Update autoconf scripts

Scripts taken from autoconf a8d79c3130da83c7cacd6fee31b9acc53799c406

- - - - -
0040af59 by Ben Gamari at 2019-04-25T17:16:21-04:00
gitlab-ci: Reintroduce DWARF-enabled bindists

It seems that this was inadvertently dropped in
1285d6b95fbae7858abbc4722bc2301d7fe40425.

- - - - -
2c115085 by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
rename: hadle type signatures with typos

When encountering type signatures for unknown names, suggest similar
alternatives.

This fixes issue #16504

- - - - -
fb9408dd by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
Print suggestions in a single message

- - - - -
e8bf8834 by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
osa1's patch: consistent suggestion message

- - - - -
1deb2bb0 by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
Comment on 'candidates' function

- - - - -
8ee47432 by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
Suggest only local candidates from global env

- - - - -
e23f78ba by Wojciech Baranowski at 2019-04-29T21:02:38-04:00
Use pp_item

- - - - -
1abb76ab by Ben Gamari at 2019-04-29T21:08:45-04:00
ghci: Ensure that system libffi include path is searched

Previously hsc2hs failed when building against a system FFI.

- - - - -
014ed644 by Sebastian Graf at 2019-04-30T20:23:21-04:00
Compute demand signatures assuming idArity

This does four things:

1. Look at `idArity` instead of manifest lambdas to decide whether to use LetUp
2. Compute the strictness signature in LetDown assuming at least `idArity`
   incoming arguments
3. Remove the special case for trivial RHSs, which is subsumed by 2
4. Don't perform the W/W split when doing so would eta expand a binding.
   Otherwise we would eta expand PAPs, causing unnecessary churn in the
   Simplifier.

NoFib Results

--------------------------------------------------------------------------------
        Program         Allocs    Instrs
--------------------------------------------------------------------------------
 fannkuch-redux          +0.3%      0.0%
             gg          -0.0%     -0.1%
       maillist          +0.2%     +0.2%
        minimax           0.0%     +0.8%
         pretty           0.0%     -0.1%
        reptile          -0.0%     -1.2%
--------------------------------------------------------------------------------
            Min          -0.0%     -1.2%
            Max          +0.3%     +0.8%
 Geometric Mean          +0.0%     -0.0%

- - - - -
d37d91e9 by John Ericson at 2019-04-30T20:29:31-04:00
Generate settings by make/hadrian instead of configure

This allows it to eventually become stage-specific

- - - - -
53d1cd96 by John Ericson at 2019-04-30T20:29:31-04:00
Remove settings.in

It is no longer needed

- - - - -
2988ef5e by John Ericson at 2019-04-30T20:29:31-04:00
Move cGHC_UNLIT_PGM to be "unlit command" in settings

The bulk of the work was done in #712, making settings be make/Hadrian
controlled. This commit then just moves the unlit command rules in
make/Hadrian from the `Config.hs` generator to the `settings` generator
in each build system.

I think this is a good change because the crucial benefit is *settings*
don't affect the build: ghc gets one baby step closer to being a regular
cabal executable, and make/Hadrian just maintains settings as part of
bootstrapping.

- - - - -
37a4fd97 by Alp Mestanogullari at 2019-04-30T20:35:35-04:00
Build Hadrian with -Werror in the 'ghc-in-ghci' CI job

- - - - -
1bef62c3 by Ben Gamari at 2019-04-30T20:41:42-04:00
ErrUtils: Emit progress messages to eventlog

- - - - -
ebfa3528 by Ben Gamari at 2019-04-30T20:41:42-04:00
Emit GHC timing events to eventlog

- - - - -
4186b410 by Sven Tennie at 2019-05-03T13:40:36-04:00
Typeset Big-O complexities with Tex-style notation (#16090)

Use `\min` instead of `min` to typeset it as an operator.

- - - - -
9047f184 by Shayne Fletcher at 2019-05-03T21:54:50+03:00
Make Extension derive Bounded

- - - - -
0dde64f2 by Ben Gamari at 2019-05-03T21:54:50+03:00
testsuite: Mark concprog001 as fragile

Due to #16604.
- - - - -
8f929388 by Alp Mestanogullari at 2019-05-03T21:54:50+03:00
Hadrian: generate JUnit testsuite report in Linux CI job

We also keep it as an artifact, like we do for non-Hadrian jobs, and list it
as a junit report, so that the test results are reported in the GitLab UI for
merge requests.

- - - - -
52fc2719 by Vladislav Zavialov at 2019-05-03T21:54:50+03:00
Pattern/expression ambiguity resolution

This patch removes 'EWildPat', 'EAsPat', 'EViewPat', and 'ELazyPat'
from 'HsExpr' by using the ambiguity resolution system introduced
earlier for the command/expression ambiguity.

Problem: there are places in the grammar where we do not know whether we
are parsing an expression or a pattern, for example:

	do { Con a b <- x } -- 'Con a b' is a pattern
	do { Con a b }      -- 'Con a b' is an expression

Until we encounter binding syntax (<-) we don't know whether to parse
'Con a b' as an expression or a pattern.

The old solution was to parse as HsExpr always, and rejig later:

	checkPattern :: LHsExpr GhcPs -> P (LPat GhcPs)

This meant polluting 'HsExpr' with pattern-related constructors. In
other words, limitations of the parser were affecting the AST, and all
other code (the renamer, the typechecker) had to deal with these extra
constructors.

We fix this abstraction leak by parsing into an overloaded
representation:

	class DisambECP b where ...
	newtype ECP = ECP { runECP_PV :: forall b. DisambECP b => PV (Located b) }

See Note [Ambiguous syntactic categories] for details.

Now the intricacies of parsing have no effect on the hsSyn AST when it
comes to the expression/pattern ambiguity.

- - - - -
9b59e126 by Ningning Xie at 2019-05-03T21:54:50+03:00
Only skip decls with CUSKs with PolyKinds on (fix #16609)

- - - - -
87bc954a by Ömer Sinan Ağacan at 2019-05-03T21:54:50+03:00
Fix interface version number printing in --show-iface

Before

    Version: Wanted [8, 0, 9, 0, 2, 0, 1, 9, 0, 4, 2, 5],
             got    [8, 0, 9, 0, 2, 0, 1, 9, 0, 4, 2, 5]

After

    Version: Wanted 809020190425,
             got    809020190425

- - - - -
cc495d57 by Ryan Scott at 2019-05-03T21:54:50+03:00
Make equality constraints in kinds invisible

Issues #12102 and #15872 revealed something strange about the way GHC
handles equality constraints in kinds: it treats them as _visible_
arguments! This causes a litany of strange effects, from strange
error messages
(https://gitlab.haskell.org/ghc/ghc/issues/12102#note_169035)
to bizarre `Eq#`-related things leaking through to GHCi output, even
without any special flags enabled.

This patch is an attempt to contain some of this strangeness.
In particular:

* In `TcHsType.etaExpandAlgTyCon`, we propagate through the
  `AnonArgFlag`s of any `Anon` binders. Previously, we were always
  hard-coding them to `VisArg`, which meant that invisible binders
  (like those whose kinds were equality constraint) would mistakenly
  get flagged as visible.
* In `ToIface.toIfaceAppArgsX`, we previously assumed that the
  argument to a `FunTy` always corresponding to a `Required`
  argument. We now dispatch on the `FunTy`'s `AnonArgFlag` and map
  `VisArg` to `Required` and `InvisArg` to `Inferred`. As a
  consequence, the iface pretty-printer correctly recognizes that
  equality coercions are inferred arguments, and as a result,
  only displays them in `-fprint-explicit-kinds` is enabled.
* Speaking of iface pretty-printing, `Anon InvisArg` binders were
  previously being pretty-printed like `T (a :: b ~ c)`, as if they
  were required. This seemed inconsistent with other invisible
  arguments (that are printed like `T @{d}`), so I decided to switch
  this to `T @{a :: b ~ c}`.

Along the way, I also cleaned up a minor inaccuracy in the users'
guide section for constraints in kinds that was spotted in
https://gitlab.haskell.org/ghc/ghc/issues/12102#note_136220.

Fixes #12102 and #15872.

- - - - -
f862963b by Ömer Sinan Ağacan at 2019-05-03T20:50:03-04:00
rts: Properly free the RTSSummaryStats structure

`stat_exit` always allocates a `RTSSummaryStats` but only sometimes
frees it, which casues leaks. With this patch we unconditionally free
the structure, fixing the leak.

Fixes #16584

- - - - -
0af93d16 by Ömer Sinan Ağacan at 2019-05-03T20:56:18-04:00
StgCmmMonad: remove emitProc_, don't export emitProc

- - - - -
0a3e4db3 by Ömer Sinan Ağacan at 2019-05-03T20:56:18-04:00
PrimOps.cmm: remove unused stuff

- - - - -
63150b9e by iustin at 2019-05-04T17:54:23-04:00
Fix typo in 8.8.1 notes related to traceBinaryEvent

- fixes double mention of `traceBinaryEvent#` (the second one should be `traceEvent#`, I think)
- fixes note about `traceEvent#` taking a `String` - the docs say it takes a zero-terminated ByteString.
- - - - -
dc8a5868 by gallais at 2019-05-04T18:00:30-04:00
[ typo ] 'castFloatToWord32' -> 'castFloatToWord64'

Probably due to a copy/paste gone wrong.
- - - - -
615b4be6 by Chaitanya Koparkar at 2019-05-05T10:39:24-04:00
Fix #16593 by having only one definition of -fprint-explicit-runtime-reps

[skip ci]

- - - - -
ead3f835 by Vladislav Zavialov at 2019-05-05T10:39:24-04:00
'warnSpaceAfterBang' only in patterns (#16619)

- - - - -
27941064 by John Ericson at 2019-05-06T14:59:29-04:00
Remove cGhcEnableTablesNextToCode

Get "Tables next to code" from the settings file instead.

- - - - -
821fa9e8 by Takenobu Tani at 2019-05-06T15:05:36-04:00
Remove `$(TOP)/ANNOUNCE` file

Remove `$(TOP)/ANNOUNCE` because maintaining this file is expensive
for each release.

Currently, release announcements of ghc are made on ghc blogs and wikis.

[skip ci]

- - - - -
e172a6d1 by Alp Mestanogullari at 2019-05-06T15:11:43-04:00
Enable external interpreter when TH is requested but no internal interpreter is available

- - - - -
ba0aed2e by Alp Mestanogullari at 2019-05-06T17:32:56-04:00
Hadrian: override $(ghc-config-mk), to prevent redundant config generation

This required making the 'ghc-config-mk' variable overridable in
testsuite/mk/boilerplate.mk, and then making use of this in hadrian
to point to '<build root>/test/ghcconfig' instead, which is where we
always put the test config.

Previously, we would build ghc-config and run it against the
GHC to be tested, a second time, while we're running the tests, because some
include testsuite/mk/boilerplate.mk. This was causing unexpected output
failures.

- - - - -
96197961 by Ryan Scott at 2019-05-07T06:35:58-04:00
Add /includes/dist to .gitignore

As of commit d37d91e9a444a7822eef1558198d21511558515e, the GHC build
now autogenerates a `includes/dist/build/settings` file. To avoid
dirtying the current `git` status, this adds `includes/dist` to
`.gitignore`.

[ci skip]

- - - - -
78a5c4ce by Ryan Scott at 2019-05-07T17:03:04-04:00
Check for duplicate variables in associated default equations

A follow-up to !696's, which attempted to clean up the error messages
for ill formed associated type family default equations. The previous
attempt, !696, forgot to account for the possibility of duplicate
kind variable arguments, as in the following example:

```hs
class C (a :: j) where
  type T (a :: j) (b :: k)
  type T (a :: k) (b :: k) = k
```

This patch addresses this shortcoming by adding an additional check
for this. Fixes #13971 (hopefully for good this time).

- - - - -
f58ea556 by Kevin Buhr at 2019-05-07T17:09:13-04:00
Add regression test for old typechecking issue #505

- - - - -
786e665b by Ryan Scott at 2019-05-08T01:55:45-04:00
Fix #16603 by documenting some important changes in changelogs

This addresses some glaring omissions from
`libraries/base/changelog.md` and
`docs/users_guide/8.8.1-notes.rst`, fixing #16603 in the process.

- - - - -
0eeb4cfa by Ryan Scott at 2019-05-08T02:01:54-04:00
Fix #16632 by using the correct SrcSpan in checkTyClHdr

`checkTyClHdr`'s case for `HsTyVar` was grabbing the wrong `SrcSpan`,
which lead to error messages pointing to the wrong location. Easily
fixed.

- - - - -
ed5f858b by Shayne Fletcher at 2019-05-08T15:29:01-04:00
Implement ImportQualifiedPost

- - - - -
d9bdff60 by Kevin Buhr at 2019-05-08T15:35:13-04:00
stg_floatToWord32zh: zero-extend the Word32 (#16617)

The primop stgFloatToWord32 was sign-extending the 32-bit word, resulting
in weird negative Word32s.  Zero-extend them instead.

Closes #16617.

- - - - -
9a3acac9 by Ömer Sinan Ağacan at 2019-05-08T15:41:17-04:00
Print PAP object address in stg_PAP_info entry code

Continuation to ce23451c

- - - - -
4c86187c by Richard Eisenberg at 2019-05-08T15:47:33-04:00
Regression test for #16627.

test: typecheck/should_fail/T16627

- - - - -
93f34bbd by John Ericson at 2019-05-08T15:53:40-04:00
Purge TargetPlatform_NAME and cTargetPlatformString

- - - - -
9d9af0ee by Kevin Buhr at 2019-05-08T15:59:46-04:00
Add regression test for old issue #507

- - - - -
396e01b4 by Vladislav Zavialov at 2019-05-08T16:05:52-04:00
Add a regression test for #14548

- - - - -
5eb94454 by Oleg Grenrus at 2019-05-10T16:26:28-04:00
Add Generic tuple instances up to 15-tuple

Why 15? Because we have Eq instances up to 15.

Metric Increase:
    T9630
    haddock.base

- - - - -
c7913f71 by Roland Senn at 2019-05-10T16:32:38-04:00
Fix bugs and documentation for #13456

- - - - -
bfcd986d by David Eichmann at 2019-05-10T16:38:57-04:00
Hadrian: programs need registered ghc-pkg libraries

In Hadrian, building programs (e.g. `ghc` or `haddock`) requires libraries located in the ghc-pkg package database i.e.

    _build/stage1/lib/x86_64-linux-ghc-8.9.0.20190430/libHSdeepseq-1.4.4.0-ghc8.9.0.20190430.so

Add the corresponding `need`s for these library files and the subsequent rules.

- - - - -
10f579ad by Ben Gamari at 2019-05-10T16:45:05-04:00
gitlab-ci: Disable cleanup job on Windows

As discussed in the Note, we now have a cron job to handle this and the
cleanup job itself is quite fragile.

[skip ci]

- - - - -
6f07f828 by Kevin Buhr at 2019-05-10T16:51:11-04:00
Add regression test case for old issue #493

- - - - -
4e25bf46 by Giles Anderson at 2019-05-13T19:01:52-04:00
Change GHC.hs to Packages.hs in Hadrian user-settings.md

... "all packages that are currently built as part of the GHC are
defined in src/Packages.hs"

- - - - -
357be128 by Kevin Buhr at 2019-05-14T16:41:19-04:00
Add regression test for old parser issue #504

- - - - -
015a21b8 by John Ericson at 2019-05-14T16:41:19-04:00
hadrian: Make settings stage specific

- - - - -
f9e4ea40 by John Ericson at 2019-05-14T16:41:19-04:00
Dont refer to `cLeadingUnderscore` in test

Can't use this config entry because it's about to go away

- - - - -
e529c65e by John Ericson at 2019-05-14T16:41:19-04:00
Remove all target-specific portions of Config.hs

1. If GHC is to be multi-target, these cannot be baked in at compile
   time.

2. Compile-time flags have a higher maintenance than run-time flags.

3. The old way makes build system implementation (various bootstrapping
   details) with the thing being built. E.g. GHC doesn't need to care
   about which integer library *will* be used---this is purely a crutch
   so the build system doesn't need to pass flags later when using that
   library.

4. Experience with cross compilation in Nixpkgs has shown things work
   nicer when compiler's can *optionally* delegate the bootstrapping the
   package manager. The package manager knows the entire end-goal build
   plan, and thus can make top-down decisions on bootstrapping. GHC can
   just worry about GHC, not even core library like base and ghc-prim!

- - - - -
5cf8032e by Oleg Grenrus at 2019-05-14T16:41:19-04:00
Update terminal title while running test-suite

Useful progress indicator even when `make test VERBOSE=1`,
and when you do something else, but have terminal title visible.

- - - - -
c72c369b by Vladislav Zavialov at 2019-05-14T16:41:19-04:00
Add a minimized regression test for #12928

- - - - -
a5fdd185 by Vladislav Zavialov at 2019-05-14T16:41:19-04:00
Guard CUSKs behind a language pragma

GHC Proposal #36 describes a transition plan away from CUSKs and to
top-level kind signatures:

1. Introduce a new extension, -XCUSKs, on by default, that detects CUSKs
   as they currently exist.
2. We turn off the -XCUSKs extension in a few releases and remove it
   sometime thereafter.

This patch implements phase 1 of this plan, introducing a new language
extension to control whether CUSKs are enabled. When top-level kind
signatures are implemented, we can transition to phase 2.

- - - - -
684dc290 by Vladislav Zavialov at 2019-05-14T16:41:19-04:00
Restore the --coerce option in 'happy' configuration

happy-1.19.10 has been released with a fix for --coerce in the presence
of higher rank types. This should result in about 10% performance
improvement in the parser.

- - - - -
a416ae26 by Alp Mestanogullari at 2019-05-14T16:41:20-04:00
Hadrian: 'need' source files for various docs in Rules.Documentation

Previously, changing one of the .rst files from the user guide would not cause
the user guide to be rebuilt. This patch take a first stab at declaring the
documentation source files that our documentation rules depend on, focusing
on the .rst files only for now.

We eventually might want to rebuild docs when we, say, change the haddock style
file, but this level of tracking isn't really necessary for now.

This fixes #16645.

- - - - -
7105fb66 by Ben Gamari at 2019-05-16T12:47:59-04:00
rts: Explicit state that CONSTR tag field is zero-based

This was a bit unclear as we use both one-based and zero-based
tags in GHC.

[skip ci]
- - - - -
5bb80cf2 by David Eichmann at 2019-05-20T15:41:55+01:00
Improve test runner logging when calculating performance metric baseline #16662

We attempt to get 75 commit hashes via `git log`, but this only gave 10
hashes in a CI run (see #16662). Better logging may help solve this
error if it occurs again in the future.

- - - - -
b46efa2b by David Eichmann at 2019-05-20T19:45:56+01:00
Recalculate Performance Test Baseline T9630 #16680

Metric Decrease:
    T9630

- - - - -
54095bbd by Takenobu Tani at 2019-05-21T16:54:00-04:00
users-guide: Fix directive errors on 8.10

The following sections are not displayed due to a directive error:

  * -Wunused-record-wildcards
  * -Wredundant-record-wildcards

I changed the location of the `since` directive.

[skip ci]

- - - - -
8fc654c3 by David Eichmann at 2019-05-21T16:57:37-04:00
Include CPP preprocessor dependencies in -M output

Issue #16521

- - - - -
0af519ac by David Eichmann at 2019-05-21T17:01:16-04:00
Refactor Libffi and RTS rules

This removes a hack that copies libffi files to the rts
build directory. This was done in a libffi rule, but now
an rts rule correctly needs and copies the relevant
files from the libffi build dir to the rts build dir.

Issues: #16272 #16304

- - - - -
9342b1fa by Kirill Elagin at 2019-05-21T17:04:54-04:00
users-guide: Fix -rtsopts default
- - - - -
d0142f21 by Javran Cheng at 2019-05-21T17:08:29-04:00
Fix doc for Data.Function.fix.

Doc-only change.

- - - - -
ddd905b4 by Shayne Fletcher at 2019-05-21T17:12:07-04:00
Update resolver for for happy 1.19.10

- - - - -
e32c30ca by Alp Mestanogullari at 2019-05-21T17:15:45-04:00
distrib/configure.ac.in: remove mention to 'settings', since settings.in is gone

Otherwise, when `./configure`ing a GHC bindist, produced by either Make or
Hadrian, we would try to generate the `settings` file from the `settings.in`
template that we used to have around but which has been gone since d37d91e9.
That commit generates the settings file using the build systems instead, but
forgot to remove this mention to the `settings` file.

- - - - -
4a6c8436 by Ryan Scott at 2019-05-21T17:19:22-04:00
Fix #16666 by parenthesizing contexts in Convert

Most places where we convert contexts in `Convert` are actually in
positions that are to the left of some `=>`, such as in superclasses
and instance contexts. Accordingly, these contexts need to be
parenthesized at `funPrec`. To accomplish this, this patch changes
`cvtContext` to require a precedence argument for the purposes of
calling `parenthesizeHsContext` and adjusts all `cvtContext` call
sites accordingly.

- - - - -
c32f64e5 by Ben Gamari at 2019-05-21T17:23:01-04:00
gitlab-ci: Allow Windows Hadrian build to fail

Due to #16574.
- - - - -
412a1f39 by Ben Gamari at 2019-05-21T17:23:01-04:00
Update .gitlab-ci.yml
- - - - -
0dc79856 by Julian Leviston at 2019-05-21T20:55:44-04:00
Allow for multiple linker instances. Fixes Haskell portion of #3372.

- - - - -
21272670 by Michael Sloan at 2019-05-22T16:37:57-04:00
Have GHCi use object code for UnboxedTuples modules #15454

The idea is to automatically enable -fobject-code for modules that use
UnboxedTuples, along with all the modules they depend on. When looking
into how to solve this, I was pleased to find that there was already
highly similar logic for enabling code generation when -fno-code is
specified but TemplateHaskell is used.

The state before this patch was that if you used unboxed tuples then you
had to enable `-fobject-code` globally rather than on a per module
basis.

- - - - -
ddae344e by Michael Sloan at 2019-05-22T16:41:31-04:00
Use datatype for unboxed returns when loading ghc into ghci

See #13101 and #15454

- - - - -
78c3f330 by Kevin Buhr at 2019-05-22T16:45:08-04:00
Add regression test for old Word32 arithmetic issue (#497)

- - - - -
ecc9366a by Alec Theriault at 2019-05-22T16:48:45-04:00
RTS: Fix restrictive cast

Commit e75a9afd2989e0460f9b49fa07c1667299d93ee9 added an `unsigned` cast
to account for OSes that have signed `rlim_t` signed. Unfortunately,
the `unsigned` cast has the unintended effect of narrowing `rlim_t` to
only 4 bytes. This leads to some spurious out of memory crashes
(in particular: Haddock crashes with OOM whenn building docs of
`ghc`-the-library).

In this case, `W_` is a better type to cast to: we know it will be
unsigned too and it has the same type as `*len` (so we don't suffer from
accidental narrowing).

- - - - -
2c15b85e by Alp Mestanogullari at 2019-05-22T16:52:22-04:00
Hadrian: add --test-root-dirs, to only run specific directories of tests

We can specify several of those, by using the flag multiple times or
just once but combining the directories with ':'.

Along the way, this patch also fixes the testsuite-related --only flag,
so that we can use it many times instead of being force to specify a
space-separated list of test in a single --only flag.

- - - - -
6efe04de by Ryan Scott at 2019-05-22T16:56:01-04:00
Use HsTyPats in associated type family defaults

Associated type family default declarations behave strangely in a
couple of ways:

1. If one tries to bind the type variables with an explicit `forall`,
   the `forall`'d part will simply be ignored. (#16110)
2. One cannot use visible kind application syntax on the left-hand
   sides of associated default equations, unlike every other form
   of type family equation. (#16356)

Both of these issues have a common solution. Instead of using
`LHsQTyVars` to represent the left-hand side arguments of an
associated default equation, we instead use `HsTyPats`, which is what
other forms of type family equations use. In particular, here are
some highlights of this patch:

* `FamEqn` is no longer parameterized by a `pats` type variable, as
  the `feqn_pats` field is now always `HsTyPats`.
* The new design for `FamEqn` in chronicled in
  `Note [Type family instance declarations in HsSyn]`.
* `TyFamDefltEqn` now becomes the same thing as `TyFamInstEqn`. This
  means that many of `TyFamDefltEqn`'s code paths can now reuse the
  code paths for `TyFamInstEqn`, resulting in substantial
  simplifications to various parts of the code dealing with
  associated type family defaults.

Fixes #16110 and #16356.

- - - - -
4ba73e00 by Luite Stegeman at 2019-05-22T16:59:39-04:00
fix Template Haskell cross compilation on 64 bit compiler with 32 bit target

- - - - -
535a26c9 by David Eichmann at 2019-05-23T18:26:37+01:00
Revert "Add Generic tuple instances up to 15-tuple" #16688

This reverts commit 5eb9445444c4099fc9ee0803ba45db390900a80f.
It has caused an increase in variance of performance test T9630,
causing CI to fail.

- - - - -
04b4b984 by Alp Mestanogullari at 2019-05-23T22:32:15-04:00
add an --hadrian mode to ./validate

When the '--hadrian' flag is passed to the validate script, we use hadrian
to build GHC, package it up in a binary distribution and later on run GHC's
testsuite against the said bindist, which gets installed locally in the process.

Along the way, this commit fixes a typo, an omission (build iserv binaries
before producing the bindist archive) and moves the Makefile that enables
'make install' on those bindists from being a list of strings in the code to
an actual file (it was becoming increasingly annoying to work with).

Finally, the Settings.Builders.Ghc part of this patch is necessary for being
able to use the installed binary distribution, in 'validate'.

- - - - -
0b449d34 by Ömer Sinan Ağacan at 2019-05-23T22:35:54-04:00
Add a test for #16597

- - - - -
59f4cb6f by Iavor Diatchki at 2019-05-23T22:39:35-04:00
Add a `NOINLINE` pragma on `someNatVal` (#16586)

This fixes #16586, see `Note [NOINLINE someNatVal]` for details.

- - - - -
6eedbd83 by Ryan Scott at 2019-05-23T22:43:12-04:00
Some forall-related cleanup in deriving code

* Tweak the parser to allow `deriving` clauses to mention explicit
  `forall`s or kind signatures without gratuitous parentheses.
  (This fixes #14332 as a consequence.)
* Allow Haddock comments on `deriving` clauses with explicit
  `forall`s. This requires corresponding changes in Haddock.

- - - - -
c931f256 by David Eichmann at 2019-05-24T11:22:29+01:00
Allow metric change after reverting "Add Generic tuple instances up to 15-tuple" #16688

Metrics increased on commit 5eb9445444c4099fc9ee0803ba45db390900a80f and
decreased on revert commit 535a26c90f458801aeb1e941a3f541200d171e8f.

Metric Decrease:
    T9630
    haddock.base

- - - - -
d9dfbde3 by Michael Sloan at 2019-05-24T16:55:07+01:00
Add PlainPanic for throwing exceptions without depending on pprint

This commit splits out a subset of GhcException which do not depend on
pretty printing (SDoc), as a new datatype called
PlainGhcException. These exceptions can be caught as GhcException,
because 'fromException' will convert them.

The motivation for this change is that that the Panic module
transitively depends on many modules, primarily due to pretty printing
code.  It's on the order of about 130 modules.  This large set of
dependencies has a few implications:

1. To avoid cycles / use of boot files, these dependencies cannot
throw GhcException.

2. There are some utility modules that use UnboxedTuples and also use
`panic`. This means that when loading GHC into GHCi, about 130
additional modules would need to be compiled instead of
interpreted. Splitting the non-pprint exception throwing into a new
module resolves this issue. See #13101

- - - - -
70c24471 by Moritz Angermann at 2019-05-25T17:51:30-04:00
Add `keepCAFs` to RtsSymbols

- - - - -
9be1749d by David Eichmann at 2019-05-25T17:55:05-04:00
Hadrian: Add Mising Libffi Dependencies #16653

Libffi is ultimately built from a single archive file (e.g.
libffi-tarballs/libffi-3.99999+git20171002+77e130c.tar.gz).
The file can be seen as the shallow dependency for the whole
libffi build. Hence, in all libffi rules, the archive is
`need`ed and the build directory is `trackAllow`ed.

- - - - -
2d0cf625 by Sandy Maguire at 2019-05-26T08:57:20-04:00
Let the specialiser work on dicts under lambdas

Following the discussion under #16473, this change allows the
specializer to work on any dicts in a lambda, not just those that occur
at the beginning.

For example, if you use data types which contain dictionaries and
higher-rank functions then once these are erased by the optimiser you
end up with functions such as:

```
  go_s4K9
  Int#
  -> forall (m :: * -> *).
     Monad m =>
     (forall x. Union '[State (Sum Int)] x -> m x) -> m ()
```

The dictionary argument is after the Int# value argument, this patch
allows `go` to be specialised.

- - - - -
4b228768 by Moritz Angermann at 2019-05-27T01:19:49-04:00
Lowercase windows imports

While windows and macOS are currently on case-insensitive file
systems, this poses no issue on those.  When cross compiling from
linux with a case sensitive file system and mingw providing only
lowercase headers, this in fact produces an issue.  As such we just
lowercase the import headers, which should still work fine on a
case insensitive file system and also enable mingw's headers to
be usable porperly.

- - - - -
01f8e390 by Alp Mestanogullari at 2019-05-27T10:06:26-04:00
Hadrian: Fix problem with unlit path in settings file

e529c65e introduced a problem in the logic for generating the
path to the unlit command in the settings file, and this patches
fixes it.

This fixes many tests, the simplest of which is:

> _build/stage1/bin/ghc testsuite/tests/parser/should_fail/T8430.lhs

which failed because of a wrong path for unlit, and now fails for the right
reason, with the error message expected for this test.

This addresses #16659.

- - - - -
dcd843ac by mizunashi_mana at 2019-05-27T10:06:27-04:00
Fix typo of primop format
- - - - -
3f6e5b97 by Joshua Price at 2019-05-27T10:06:28-04:00
Correct the large tuples section in user's guide

Fixes #16644.

- - - - -
1f51aad6 by Krzysztof Gogolewski at 2019-05-27T10:06:28-04:00
Fix tcfail158 (#15899)

As described in #15899, this test was broken, but now it's back
to normal.

- - - - -
723216e3 by Sebastian Graf at 2019-05-27T10:06:29-04:00
Add a pprTraceWith function

- - - - -
6d188dd5 by Simon Jakobi at 2019-05-27T10:06:31-04:00
base: Include (<$) in all exports of Functor

Previously the haddocks for Control.Monad and Data.Functor gave
the impression that `fmap` was the only Functor method.

Fixes #16681.

- - - - -
95b79173 by Jasper Van der Jeugt at 2019-05-27T10:06:32-04:00
Fix padding of entries in .prof files

When the number of entries of a cost centre reaches 11 digits, it takes
up the whole space reserved for it and the prof file ends up looking
like:

    ... no.        entries  %time %alloc   %time %alloc

        ...
    ... 120918     978250    0.0    0.0     0.0    0.0
    ... 118891          0    0.0    0.0    73.3   80.8
    ... 11890229702412351    8.9   13.5    73.3   80.8
    ... 118903  153799689    0.0    0.1     0.0    0.1
        ...

This results in tooling not being able to parse the .prof file.  I
realise we have the JSON output as well now, but still it'd be good to
fix this little weirdness.

Original bug report and full prof file can be seen here:
<https://github.com/jaspervdj/profiteur/issues/28>.

- - - - -
f80d3afd by John Ericson at 2019-05-27T10:06:33-04:00
hadrian: Fix generation of settings

I jumbled some lines in e529c65eacf595006dd5358491d28c202d673732,
messing up the leading underscores and rts ways settings. This broke at
least stage1 linking on macOS, but probably loads of other things too.

Should fix #16685 and #16658.

- - - - -
db8e3275 by Ömer Sinan Ağacan at 2019-05-27T10:06:37-04:00
Add missing opening braces in Cmm dumps

Previously -ddump-cmm was generating code with unbalanced curly braces:

     stg_atomically_entry() //  [R1]
             { info_tbls: [(cfl,
                            label: stg_atomically_info
                            rep: tag:16 HeapRep 1 ptrs { Thunk }
                            srt: Nothing)]
               stack_info: arg_space: 8 updfr_space: Just 8
             }
         {offset
           cfl: // cfk
               unwind Sp = Just Sp + 0;
               _cfk::P64 = R1;
               //tick src<rts/PrimOps.cmm:(1243,1)-(1245,1)>
               R1 = I64[_cfk::P64 + 8 + 8 + 0 * 8];
               call stg_atomicallyzh(R1) args: 8, res: 0, upd: 8;
         }
     }, <---- OPENING BRACE MISSING

After this patch:

     stg_atomically_entry() { //  [R1] <---- MISSING OPENING BRACE HERE
             { info_tbls: [(cfl,
                            label: stg_atomically_info
                            rep: tag:16 HeapRep 1 ptrs { Thunk }
                            srt: Nothing)]
               stack_info: arg_space: 8 updfr_space: Just 8
             }
         {offset
           cfl: // cfk
               unwind Sp = Just Sp + 0;
               _cfk::P64 = R1;
               //tick src<rts/PrimOps.cmm:(1243,1)-(1245,1)>
               R1 = I64[_cfk::P64 + 8 + 8 + 0 * 8];
               call stg_atomicallyzh(R1) args: 8, res: 0, upd: 8;
         }
     },

- - - - -
9334467f by Richard Eisenberg at 2019-05-28T00:24:50-04:00
Improve comments around injectivity checks

- - - - -
c8380a4a by Krzysztof Gogolewski at 2019-05-29T10:35:50-04:00
Handle hs-boot files in -Wmissing-home-modules (#16551)

- - - - -
7a75a094 by Alp Mestanogullari at 2019-05-29T10:36:35-04:00
testsuite: introduce 'static_stats' tests

They are a particular type of perf tests. This patch introduces a
'stats_files_dir' configuration field in the testsuite driver where all
haddock timing files (and possibly others in the future) are assumed to live.
We also change both the Make and Hadrian build systems to pass respectively
$(TOP)/testsuite/tests/perf/haddock/ and
<build root>/stage1/haddock-timing-files/ as the value of that new
configuration field, and to generate the timing files in those directories
in the first place while generating documentation with haddock.

This new test type can be seen as one dedicated to examining stats files that
are generated while building a GHC distribution. This also lets us get rid of
the 'extra_files' directives in the all.T entries for haddock.base,
haddock.Cabal and haddock.compiler.

- - - - -
32acecc2 by P.C. Shyamshankar at 2019-05-29T10:37:16-04:00
Minor spelling fixes to users guide.

- - - - -
b58b389b by Oleg Grenrus at 2019-05-29T10:37:54-04:00
Remove stale 8.2.1-notes

- - - - -
5bfd28f5 by Oleg Grenrus at 2019-05-29T10:37:54-04:00
Fix some warnings in users_guide (incl #16640)

- short underline
- :ghc-flag:, not :ghc-flags:
- :since: have to be separate
- newline before code block
- workaround anchor generation so

    - pragma:SPECIALISE
    - pragma:SPECIALIZE-INLINE
    - pragma:SPECIALIZE-inline

  are different anchors, not all the same `pragma:SPECIALIZE`

- - - - -
a5b14ad4 by Kevin Buhr at 2019-05-29T10:38:30-04:00
Add test for old issue displaying unboxed tuples in error messages (#502)

- - - - -
f9d61ebb by Krzysztof Gogolewski at 2019-05-29T10:39:05-04:00
In hole fits, don't show VTA for inferred variables (#16456)

We fetch the ArgFlag for every argument by using splitForAllVarBndrs
instead of splitForAllTys in unwrapTypeVars.

- - - - -
69b16331 by Krzysztof Gogolewski at 2019-05-29T10:39:43-04:00
Fix missing unboxed tuple RuntimeReps (#16565)

Unboxed tuples and sums take extra RuntimeRep arguments,
which must be manually passed in a few places.
This was not done in deSugar/Check.

This error was hidden because zipping functions in TyCoRep
ignored lists with mismatching length. This is now fixed;
the lengths are now checked by calling zipEqual.

As suggested in #16565, I moved checking for isTyVar and
isCoVar to zipTyEnv and zipCoEnv.

- - - - -
9062b625 by Nathan Collins at 2019-05-29T10:40:21-04:00
Don't lose parentheses in show SomeAsyncException
- - - - -
cc0d05a7 by Daniel Gröber at 2019-05-29T10:41:02-04:00
Add hPutStringBuffer utility

- - - - -
5b90e0a1 by Daniel Gröber at 2019-05-29T10:41:02-04:00
Allow using tagetContents for modules needing preprocessing

This allows GHC API clients, most notably tooling such as
Haskell-IDE-Engine, to pass unsaved files to GHC more easily.

Currently when targetContents is used but the module requires preprocessing
'preprocessFile' simply throws an error because the pipeline does not
support passing a buffer.

This change extends `runPipeline` to allow passing the input buffer into
the pipeline. Before proceeding with the actual pipeline loop the input
buffer is immediately written out to a new tempfile.

I briefly considered refactoring the pipeline at large to pass around
in-memory buffers instead of files, but this seems needlessly complicated
since no pipeline stages other than Hsc could really support this at the
moment.

- - - - -
fb26d467 by Daniel Gröber at 2019-05-29T10:41:02-04:00
downsweep: Allow TargetFile not to exist when a buffer is given

Currently 'getRootSummary' will fail with an exception if a 'TargetFile' is
given but it does not exist even if an input buffer is passed along for
this target.

In this case it is not necessary for the file to exist since the buffer
will be used as input for the compilation pipeline instead of the file
anyways.

- - - - -
4d51e0d8 by Ömer Sinan Ağacan at 2019-05-29T10:41:44-04:00
CNF.c: Move debug functions behind ifdef

- - - - -
ae968d41 by Vladislav Zavialov at 2019-05-29T10:42:20-04:00
tcMatchesFun s/rho/sigma #16692

- - - - -
2d2aa203 by Josh Meredith at 2019-05-29T10:43:03-04:00
Provide details in `plusSimplCount` errors

- - - - -
ace2e335 by John Ericson at 2019-05-29T16:06:45-04:00
Break up `Settings` into smaller structs

As far as I can tell, the fields within `Settings` aren't *intrinsicly*
related. They just happen to be initialized the same way (in particular
prior to the rest of `DynFlags`), and that is why they are grouped
together.

Within `Settings`, however, there are groups of settings that clearly do
share something in common, regardless of how they anything is
initialized.

In the spirit of GHC being a library, where the end cosumer may choose
to initialize this configuration in arbitrary ways, I made some new data
types for thoses groups internal to `Settings`, and used them to define
`Settings` instead. Hopefully this is a baby step towards a general
decoupling of the stateful and stateless parts of GHC.

- - - - -
bfccd832 by John Ericson at 2019-05-29T16:06:45-04:00
Inline `Settings` into `DynFlags`

After the previous commit, `Settings` is just a thin wrapper around
other groups of settings. While `Settings` is used by GHC-the-executable
to initalize `DynFlags`, in principle another consumer of
GHC-the-library could initialize `DynFlags` a different way. It
therefore doesn't make sense for `DynFlags` itself (library code) to
separate the settings that typically come from `Settings` from the
settings that typically don't.

- - - - -
a1bf3413 by David Eichmann at 2019-05-29T16:07:24-04:00
Hadrian: Add note about Libffi's Indicating Inputs #16653

[skip ci]

- - - - -
3aa71a22 by Alp Mestanogullari at 2019-05-30T07:28:32-04:00
Hadrian: always generate the libffi dynlibs manifest with globbing

Instead of trying to deduce which dynlibs are expected to be found (and then
copied to the RTS's build dir) in libffi's build directory, with some OS
specific logic, we now always just use `getDirectoryFilesIO` to look for
those dynlibs and record their names in the manifest. The previous logic
ended up causing problems on Windows, where we don't build dynlibs at all
for now but the manifest file's logic didn't take that into account because
it was only partially reproducing the criterions that determine whether or not
we will be building shared libraries.

This patch also re-enables the Hadrian/Windows CI job, which was failing to
build GHC precisely because of libffi shared libraries and the aforementionned
duplicated logic.

- - - - -
ade53ce2 by Ben Gamari at 2019-05-30T07:29:10-04:00
CODEOWNERS: Use correct username for Richard Eisenberg

In !980 Richard noted that he could not approve the MR.
This mis-spelling was the reason.

[skip ci]

- - - - -
4ad37a32 by Ben Gamari at 2019-05-30T07:29:47-04:00
rts: Handle zero-sized mappings in MachO linker

As noted in #16701, it is possible that we will find that an object has
no segments needing to be mapped. Previously this would result in mmap
being called for a zero-length mapping, which would fail. We now simply
skip the mmap call in this case; the rest of the logic just works.

- - - - -
f81f3964 by Phuong Trinh at 2019-05-30T16:43:31-04:00
Use binary search to speedup checkUnload

We are iterating through all object code for each heap objects when
checking whether object code can be unloaded. For large projects in
GHCi, this can be very expensive due to the large number of object code
that needs to be loaded/unloaded. To speed it up, this arrangess all
mapped sections of unloaded object code in a sorted array and use binary
search to check if an address location fall on them.

- - - - -
42129180 by Trịnh Tuấn Phương at 2019-05-30T16:43:31-04:00
Apply suggestion to rts/CheckUnload.c
- - - - -
8e42e98e by Trịnh Tuấn Phương at 2019-05-30T16:43:31-04:00
Apply suggestion to rts/CheckUnload.c
- - - - -
70afa539 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Export GhcMake.downsweep

This is to enable #10887 as well as to make it possible to test downsweep
on its own in the testsuite.

- - - - -
a8de5c5a by Daniel Gröber at 2019-05-30T16:44:08-04:00
Add failing test for #10887

- - - - -
8906bd66 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Refactor downsweep to allow returning multiple errors per module

- - - - -
8e85ebf7 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Refactor summarise{File,Module} to reduce code duplication

- - - - -
76c86fca by Daniel Gröber at 2019-05-30T16:44:08-04:00
Refactor summarise{File,Module} to extract checkSummaryTimestamp

This introduces a slight change of behaviour in the interrest of keeping
the code simple: Previously summariseModule would not call
addHomeModuleToFinder for summaries that are being re-used but now we do.

We're forced to to do this in summariseFile because the file being
summarised might not even be on the regular search path! So if GHC is to
find it at all we have to pre-populate the cache with its location. For
modules however the finder cache is really just a cache so we don't have to
pre-populate it with the module's location.

As straightforward as that seems I did almost manage to introduce a bug (or
so I thought) because the call to addHomeModuleToFinder I copied from
summariseFile used to use `ms_location old_summary` instead of the
`location` argument to checkSummaryTimestamp. If this call were to
overwrite the existing entry in the cache that would have resulted in us
using the old location of any module even if it was, say, moved to a
different directory between calls to 'depanal'.

However it turns out the cache just ignores the location if the module is
already in the cache. Since summariseModule has to search for the module,
which has the side effect of populating the cache, everything would have
been fine either way.

Well I'm adding a test for this anyways: tests/depanal/OldModLocation.hs.

- - - - -
18d3f01d by Daniel Gröber at 2019-05-30T16:44:08-04:00
Make downsweep return all errors per-module instead of throwing some

This enables API clients to handle such errors instead of immideately
crashing in the face of some kinds of user errors, which is arguably quite
bad UX.

Fixes #10887

- - - - -
99e72769 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Catch preprocessor errors in downsweep

This changes the way preprocessor failures are presented to the
user. Previously the user would simply get an unlocated message on stderr
such as:

    `gcc' failed in phase `C pre-processor'. (Exit code: 1)

Now at the problematic source file is mentioned:

    A.hs:1:1: error:
        `gcc' failed in phase `C pre-processor'. (Exit code: 1)

This also makes live easier for GHC API clients as the preprocessor error
is now thrown as a SourceError exception.

- - - - -
b7ca94fd by Daniel Gröber at 2019-05-30T16:44:08-04:00
PartialDownsweep: Add test for import errors

- - - - -
98e39818 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Add depanalPartial to make getting a partial modgraph easier

As per @mpickering's suggestion on IRC this is to make the partial
module-graph more easily accessible for API clients which don't intend to
re-implementing depanal.

- - - - -
d2784771 by Daniel Gröber at 2019-05-30T16:44:08-04:00
Improve targetContents code docs

- - - - -
424e85b2 by Ben Gamari at 2019-05-30T16:44:43-04:00
testsuite: Compile T9630 with +RTS -G1

For the reasons described in Note [residency] we run programs with -G1
when we care about the max_bytes_used metric.

- - - - -
4879d7af by Matthew Pickering at 2019-05-31T01:56:16-04:00
Eventlog: Document the fact timestamps are nanoseconds

[skip ci]

- - - - -
0b01a354 by Takenobu Tani at 2019-05-31T01:56:54-04:00
Update `$(TOP)/*.md` documents

I updated the top documents to the latest status:

  - HACKING.md:
    - Modify Phabricator to GitLab infomation
    - Remove old Trac information
    - Add link to GitLab activity

  - MAKEHELP.md:
    - Add link to hadrian wiki
    - Fix markdown format

  - INSTALL.md:
    - Modify boot command to remove python3
    - Fix markdown format

  - README.md:
    - Modify tarball file suffix
    - Fix markdown format

I checked the page display on the GitHub and GitLab web.

[skip ci]

- - - - -
973077ac by Sergei Trofimovich at 2019-05-31T01:57:31-04:00
powerpc32: fix 64-bit comparison (#16465)

On powerpc32 64-bit comparison code generated dangling
target labels. This caused ghc build failure as:

    $ ./configure --target=powerpc-unknown-linux-gnu && make
    ...
    SCCs aren't in reverse dependent order
    bad blockId n3U

This happened because condIntCode' in PPC codegen generated
label name but did not place the label into `cmp_lo` code block.

The change adds the `cmp_lo` label into the case of negative
comparison.

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
bb2ee86a by Sergei Trofimovich at 2019-05-31T01:57:31-04:00
powerpc32: fix stack allocation code generation

When ghc was built for powerpc32 built failed as:

It's a fallout of commit 3f46cffcc2850e68405a1
("PPC NCG: Refactor stack allocation code") where
word size used to be
    II32/II64
and changed to
    II8/panic "no width for given number of bytes"
    widthFromBytes ((platformWordSize platform) `quot` 8)

The change restores initial behaviour by removing extra division.

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
08b4c813 by Matthew Pickering at 2019-05-31T01:58:08-04:00
Use types already in AST when making .hie file

These were meant to be added in !214 but for some reason wasn't included
in the patch.

Update Haddock submodule for new Types.hs hyperlinker output

- - - - -
284cca51 by David Hewson at 2019-05-31T01:58:47-04:00
support small arrays and CONSTR_NOCAF in ghc-heap

- - - - -
f071576c by Neil Mitchell at 2019-05-31T01:59:24-04:00
Expose doCpp
- - - - -
c70d039e by Ömer Sinan Ağacan at 2019-05-31T02:00:02-04:00
Remove unused RTS function 'unmark'

- - - - -
bb929009 by Ömer Sinan Ağacan at 2019-05-31T02:00:40-04:00
Fix arity type of coerced types in CoreArity

Previously if we had

    f |> co

where `f` had arity type `ABot N` and `co` had arity M and M < N,
`arityType` would return `ABot M` which is wrong, because `f` is only
known to diverge when applied to `N` args, as described in Note
[ArityType]:

    If at = ABot n, then (f x1..xn) definitely diverges. Partial
    applications to fewer than n args may *or may not* diverge.

This caused incorrect eta expansion in the simplifier, causing #16066.

We now return `ATop M` for the same expression so the simplifier can't
assume partial applications of `f |> co` is divergent.

A regression test T16066 is also added.

- - - - -
e32786df by Ryan Scott at 2019-05-31T02:01:18-04:00
Put COMPLETE sigs into ModDetails with -fno-code (#16682)

`mkBootModDetailsTc`, which creates a special `ModDetails` when
`-fno-code` is enabled, was not properly filling in the `COMPLETE`
signatures from the `TcGblEnv`, resulting in incorrect pattern-match
coverage warnings. Easily fixed.

Fixes #16682.

- - - - -
0c6f7f7e by Simon Jakobi at 2019-05-31T02:01:55-04:00
Implement (Functor.<$) for Array

- - - - -
495a65cb by Simon Jakobi at 2019-05-31T02:02:33-04:00
Implement (Functor.<$) for Data.Functor.{Compose,Product,Sum}

This allows us to make use of the (<$) implementations of the
underlying functors.

- - - - -
0e0d87da by Zubin Duggal at 2019-05-31T07:34:57+01:00
Fix and enforce validation of header for .hie files

Implements #16686

The files version is automatically generated from the current GHC
version in the same manner as normal interface files.

This means that clients can first read the version and then decide how
to read the rest of the file.

- - - - -
1d43d4a3 by Nathan Collins at 2019-05-31T23:55:49-04:00
Improve ThreadId Show instance

By making it include parens when a derived instance would. For example, this changes the (hypothetical) code `show (Just (ThreadId 3))` to produce `"Just (ThreadId 3)"` instead of the current `"Just ThreadId 3"`.

- - - - -
45f88494 by Ryan Scott at 2019-05-31T23:56:27-04:00
Reject nested foralls in foreign imports (#16702)

This replaces a panic observed in #16702 with a simple error message
stating that nested `forall`s simply aren't allowed in the type
signature of a `foreign import` (at least, not at present).

Fixes #16702.

- - - - -
76e58890 by Ryan Scott at 2019-05-31T23:57:05-04:00
Fix space leaks in dynLoadObjs (#16708)

When running the test suite on a GHC built with the `quick` build
flavour, `-fghci-leak-check` noticed some space leaks. Careful
investigation led to `Linker.dynLoadObjs` being the culprit.
Pattern-matching on `PeristentLinkerState` and a dash of `$!` were
sufficient to fix the issue. (ht to mpickering for his suggestions,
which were crucial to discovering a fix)

Fixes #16708.

- - - - -
1503da32 by Ömer Sinan Ağacan at 2019-06-01T11:18:57-04:00
Fix rewriting invalid shifts to errors

Fixes #16449.

5341edf3 removed a code in rewrite rules for bit shifts, which broke the
"silly shift guard", causing generating invalid bit shifts or heap
overflow in compile time while trying to evaluate those invalid bit
shifts.

The "guard" is explained in Note [Guarding against silly shifts] in
PrelRules.hs.

More specifically, this was the breaking change:

    --- a/compiler/prelude/PrelRules.hs
    +++ b/compiler/prelude/PrelRules.hs
    @@ -474,12 +474,11 @@ shiftRule shift_op
            ; case e1 of
                _ | shift_len == 0
                  -> return e1
    -             | shift_len < 0 || wordSizeInBits dflags < shift_len
    -             -> return (mkRuntimeErrorApp rUNTIME_ERROR_ID wordPrimTy
    -                                        ("Bad shift length" ++ show shift_len))

This patch reverts this change.

Two new tests added:

- T16449_1: The original reproducer in #16449. This was previously
  casing a heap overflow in compile time when CmmOpt tries to evaluate
  the large (invalid) bit shift in compile time, using `Integer` as the
  result type. Now it builds as expected. We now generate an error for
  the shift as expected.

- T16449_2: Tests code generator for large (invalid) bit shifts.

- - - - -
2e297b36 by Ömer Sinan Ağacan at 2019-06-01T11:19:35-04:00
rts: Remove unused decls from CNF.h

- - - - -
33e37d06 by Takenobu Tani at 2019-06-02T22:54:43-04:00
Add `-haddock` option under ci condition to fix #16415

In order to use the `:doc` command in ghci, it is necessary
to compile for core libraries with `-haddock` option.

Especially, the `-haddock` option is essential for release building.

Note:
  * The `-haddock` option may affect compile time and binary size.
  * But hadrian has already set `-haddock` as the default.
  * This patch affects the make-based building.

This patch has been split from !532.

- - - - -
43a39c3c by Takenobu Tani at 2019-06-02T22:54:43-04:00
Add `-haddock` to perf.mk rather than prepare-system.sh

To cover ci conditions from ghc8.6 to 8.9, I add `-haddock` option
to `mk/flavours/perf.mk` rather than `.circleci/prepare-system.sh`.

Because in windows condition of ghc-8.9, `mk/flavours/*` is included
after `prepare-system.sh`.

In addition, in linux condition of ghc-8.6, `mk/flavors/perf.mk` is used.

- - - - -
c4f94320 by Takenobu Tani at 2019-06-02T22:54:43-04:00
Add `-haddock` to prepare-system.sh and .gitlab-ci.yml

To cover ci conditions from ghc8.6 to 8.9, I add `-haddock` option
to `.circleci/prepare-system.sh` and .gitlab-ci.yml.
after including `mk/flavours/*`.

- - - - -
799b1d26 by Ben Gamari at 2019-06-02T22:55:18-04:00
gitlab-ci: Use GHC 8.6.5 for Windows CI builds

- - - - -
286827be by David Eichmann at 2019-06-04T01:09:05-04:00
TestRunner: Added --chart to display a chart of performance tests

This uses the Chart.js javascript library.
Everything is put into a standalone .html file and opened with the
default browser.
I also simplified the text output to use the same data as the chart.
You can now use a commit range with git's ".." syntax.
The --ci option will use results from CI (you'll need to fetch them
first):

  $ git fetch https://gitlab.haskell.org/ghc/ghc-performance-notes.git refs/notes/perf:refs/notes/ci/perf
  $ python3 testsuite/driver/perf_notes.py --ci --chart --test-env x86_64-darwin --test-name T9630 master~500..master

- - - - -
db78ac6f by Andrew Martin at 2019-06-04T01:09:43-04:00
Use a better strategy for determining the offset applied to foreign function arguments that have an unlifted boxed type. We used to use the type of the argument. We now use the type of the foreign function. Add a test to confirm that the roundtrip conversion between an unlifted boxed type and Any is sound in the presence of a foreign function call.

- - - - -
114b014f by Alp Mestanogullari at 2019-06-04T01:10:20-04:00
Hadrian: fix OSX build failure and add an OSX/Hadrian CI job

The OSX build failure introduced in 3aa71a22 was due to a change in the
glob we use to collect libffi shared libraries in hadrian/src/Rules/Libffi.hs.
This commit fixes the problem and adds an OSX CI job that builds GHC with
Hadrian, to make sure we don't break it again.

- - - - -
002594b7 by Xavier Denis at 2019-06-04T14:41:29-04:00
Add GHCi :instances command

This commit adds the `:instances` command to ghci following proosal
number 41.

This makes it possible to query which instances are available to a given
type.

The output of this command is all the possible instances with type
variables and constraints instantiated.

- - - - -
3ecc03df by Ben Gamari at 2019-06-04T14:42:04-04:00
gitlab-ci: Run bindisttest during CI

- - - - -
c16f3297 by Ben Gamari at 2019-06-04T14:42:04-04:00
make: Fix bindist installation

This fixes a few vestigial references to `settings` left over from !655.
Fixes #16715.

- - - - -
ba4e3934 by Alp Mestanogullari at 2019-06-04T14:43:17-04:00
Hadrian: profiling and debug enabled ways support -eventlog too

- - - - -
567894b4 by Matthew Pickering at 2019-06-07T09:36:32+01:00
gitlab-ci: Disable darwin hadrian job

See #16771

We don't have enough capacity for the two jobs currently.

[skip ci]

- - - - -
d3915b30 by Andrew Martin at 2019-06-07T10:20:42-04:00
[skip ci] Improve the documentation of the CNF primops. In this context, the term "size" is ambiguous and is now avoided. Additionally, the distinction between a CNF and the blocks that comprise it has been emphasize. The vocabulary has been made more consistent with the vocabulary in the C source for CNF.

- - - - -
e963beb5 by Sebastian Graf at 2019-06-07T10:21:21-04:00
TmOracle: Replace negative term equalities by refutable PmAltCons

The `PmExprEq` business was a huge hack and was at the same time vastly
too powerful and not powerful enough to encode negative term equalities,
i.e. facts of the form "forall y. x ≁ Just y".

This patch introduces the concept of 'refutable shapes': What matters
for the pattern match checker is being able to encode knowledge of the
kind "x can no longer be the literal 5". We encode this knowledge in a
`PmRefutEnv`, mapping a set of newly introduced `PmAltCon`s (which are
just `PmLit`s at the moment) to each variable denoting above
inequalities.

So, say we have `x ≁ 42 ∈ refuts` in the term oracle context and
try to solve an equality like `x ~ 42`. The entry in the refutable
environment will immediately lead to a contradiction.

This machinery renders the whole `PmExprEq` and `ComplexEq` business
unnecessary, getting rid of a lot of (mostly dead) code.

See the Note [Refutable shapes] in TmOracle for a place to start.

Metric Decrease:
    T11195

- - - - -
0b7372f6 by Matthew Pickering at 2019-06-07T10:21:57-04:00
Add HEAP_PROF_SAMPLE_END event to mark end of samples

This allows a user to observe how long a sampling period lasts so that
the time taken can be removed from the profiling output.

Fixes #16697

- - - - -
d1dc0ed7 by Roland Senn at 2019-06-07T10:22:47-04:00
Fix #16700: Tiny errors in output of GHCi commands :forward and :info

`:info Coercible` now outputs the correct section number of the GHCi User's guide together with the secion title.

`:forward x` gives the correct syntax hint.

- - - - -
387050d0 by John Ericson at 2019-06-07T10:23:23-04:00
Factor out 'getLibDir' / 'getBaseDir' into a new GHC.BaseDir ghc-boot module

ghc-pkg and ghc already both needed this. I figure it is better to
deduplicate, especially seeing that changes to one (FreeBSD CPP) didn't
make it to the other.

Additionally in !1090 I make ghc-pkg look up the settings file, which
makes it use the top dir a bit more widely. If that lands, any
difference in the way they find the top dir would be more noticable.

That change also means sharing more code between ghc and ghc-package
(namely the settings file parsing code), so I'd think it better to get
off the slipperly slope of duplicating code now.

- - - - -
da26ffe7 by Simon Peyton Jones at 2019-06-07T10:24:00-04:00
Preserve ShadowInfo when rewriting evidence

When the canonicaliser rewrites evidence of a Wanted, it
should preserve the ShadowInfo (ctev_nosh) field.  That is,
a WDerive should rewrite to WDerive, and WOnly to WOnly.

Previously we were unconditionally making a WDeriv, thereby
rewriting WOnly to WDeriv.  This bit Nick Frisby (issue #16735)
in the context of his plugin, but we don't have a compact test
case.

The fix is simple, but does involve a bit more plumbing,
to pass the old ShadowInfo around, to use when building
the new Wanted.

- - - - -
9bb58799 by Ben Gamari at 2019-06-07T10:24:38-04:00
Hadrian: Delete target symlink in createFileLinkUntracked

Previously createFileLinkUntracked would fail if the symlink already
existed.

- - - - -
be63d299 by Simon Jakobi at 2019-06-07T10:25:16-04:00
Fix isValidNatural: The BigNat in NatJ# must have at least 2 limbs

Previously the `integer-gmp` variant of `isValidNatural` would fail to
detect values `<= maxBound::Word` that were incorrectly encoded using
the `NatJ#` constructor.

- - - - -
e87b9f87 by Moritz Angermann at 2019-06-07T10:26:04-04:00
llvm-targets: Add x86_64 android layout

- - - - -
60db142b by code5hot at 2019-06-07T10:26:46-04:00
Update Traversable.hs with a note about an intuitive law
- - - - -
f11aca52 by code5hot at 2019-06-07T10:26:46-04:00
Used terminology from a paper. Added it as a reference.
- - - - -
13b3d45d by code5hot at 2019-06-07T10:26:46-04:00
remove backticks from markup - it doesn't mean what I think it means
- - - - -
cfd3e0f1 by Zejun Wu at 2019-06-07T10:27:34-04:00
Pass preprocessor options to C compiler when building foreign C files (#16737)

- - - - -
5991d877 by Ben Gamari at 2019-06-07T10:28:09-04:00
base: Export Finalizers

As requested in #16750.

- - - - -
3d97bad6 by Alp Mestanogullari at 2019-06-07T10:28:47-04:00
Hadrian: use deb9 Docker images instead of deb8 for CI jobs

This should fix #16739, where we seem to be getting extra carets in
a test's output because of the gcc that ships with the deb8 image,
whule we're not observing those extra carets in the deb9-based (Make)
jobs.

- - - - -
1afb4995 by Ben Gamari at 2019-06-07T10:29:23-04:00
gitlab-ci: Create index.html in documentation deployment

Otherwise navigating to https://ghc.gitlab.haskell.org/ghc will result
in a 404.

- - - - -
07dc79c3 by Matthew Pickering at 2019-06-08T13:34:18-04:00
gitlab-ci: Linters, don't allow to fail

Ben disabled them in cd85f8a71bb56cff332560e1d571b3406789fb71 but didn't
say how or why they were broken.

- - - - -
fd840b64 by Matthew Pickering at 2019-06-08T13:34:18-04:00
gitlab-ci: Don't run two submodule checking jobs on Marge jobs

- - - - -
310d0c4c by Matthew Pickering at 2019-06-08T13:34:18-04:00
Fix two lint failures in rts/linker/MachO.c

- - - - -
fe965316 by Ben Gamari at 2019-06-08T13:34:18-04:00
gitlab-ci: Use --unshallow when fetching for linters

GitLab creates a shallow clone. However, this means that we may not have
the base commit of an MR when linting, causing `git merge-base` to fail.
Fix this by passing `--unshallow` to `git fetch`, ensuring that we have
the entire history.

- - - - -
f58234ea by Ben Gamari at 2019-06-08T13:34:18-04:00
gitlab-ci: Fix submodule linter

The job script didn't even try to compute the base commit to lint with
respect to.

- - - - -
c392f987 by Ben Gamari at 2019-06-08T13:34:18-04:00
gitlab-ci: A few clarifying comments

- - - - -
709290b0 by Matthew Pickering at 2019-06-08T13:38:15-04:00
Remove trailing whitespace

[skip ci]

This should really be caught by the linters! (#16711)

- - - - -
b2f106f5 by Ben Gamari at 2019-06-08T14:02:02-04:00
gitlab-ci: Disable shallow clones

Previously we were passing `--unshallow` to `git fetch` in the linting
rules to ensure that the base commit which we were linting with respect
to was available. However, this breaks due to GitLab's re-use of
working directories since `git fetch --unshallow` fails on a repository
which is not currently shallow.

Given that `git fetch --unshallow` circumvents the efficiencies provided
by shallow clones anyways, let's just disable them entirely.

There is no documented way to do disable shallow clones but on checking
the GitLab implementation it seems that setting `GIT_DEPTH=0` should do
the trick.

- - - - -
4a72259d by Ben Gamari at 2019-06-08T14:40:55-04:00
gitlab-ci: Fix submodule linting of commits

There is no notion of a base commit when we aren't checking a merge
request. Just check the HEAD commit.

- - - - -
87540029 by Ben Gamari at 2019-06-08T16:44:55-04:00
gitlab-ci: Ensure that all commits on a branch are submodule-linted

The previous commit reworked things such that the submodule linter would
only run on the head commit. However, the linter only checks the
submodules which are touched by the commits it is asked to lint.
Consequently it would be possible for a bad submodule to sneak through.

Thankfully, we can use the handy CI_COMMIT_BEFORE_SHA attribute to
find the base commit of the push.

- - - - -
0462b0e0 by Alexandre Baldé at 2019-06-09T11:48:34-04:00
Explain that 'mappend' and '(<>)' should be the same [skip ci]

- - - - -
970e4802 by Matthew Pickering at 2019-06-09T11:49:09-04:00
hadrian: Properly partition options in sourceArgs

Previously if you build the `ghc` package then it would has the default
opts and the library opts. This is different behaviour to make where the
library opts are only reserved for things in the `libraries`
subdirectory (I believe)

Fixes #16716

- - - - -
a018c3a8 by Ben Gamari at 2019-06-09T11:49:44-04:00
testsuite: Suppress ticks in T4918 output

As noted in #16741, this test otherwise breaks when `base` is compiled
with `-g`.

- - - - -
f7370333 by chessai at 2019-06-09T18:41:02-04:00
Introduce log1p and expm1 primops

Previously log and exp were primitives yet log1p and expm1 were FFI
calls. Fix this non-uniformity.

- - - - -
41bf4045 by Ben Gamari at 2019-06-09T18:41:38-04:00
testsuite: Add test for #16514

- - - - -
b9fe91fc by Simon Jakobi at 2019-06-09T18:42:21-04:00
Small refactorings in ExtractDocs

- - - - -
9d238791 by Kevin Buhr at 2019-06-09T18:42:57-04:00
Handle trailing path separator in package DB names (#16360)

Package DB directories with trailing separator (provided via
GHC_PACKAGE_PATH or via -package-db) resulted in incorrect calculation of
${pkgroot} substitution variable.  Keep the trailing separator while
resolving as directory or file, but remove it before dropping the last
path component with takeDirectory.

Closes #16360.

- - - - -
a22e51ea by Richard Eisenberg at 2019-06-09T18:43:38-04:00
Fix #16517 by bumping the TcLevel for method sigs

There were actually two bugs fixed here:

1. candidateQTyVarsOfType needs to be careful that it does not
   try to zap metavariables from an outer scope as "naughty"
   quantification candidates. This commit adds a simple check
   to avoid doing so.

2. We weren't bumping the TcLevel in kcHsKindSig, which was used
   only for class method sigs. This mistake led to the acceptance
   of

     class C a where
       meth :: forall k. Proxy (a :: k) -> ()

   Note that k is *locally* quantified. This patch fixes the
   problem by using tcClassSigType, which correctly bumps the
   level. It's a bit inefficient because tcClassSigType does other
   work, too, but it would be tedious to repeat much of the code
   there with only a few changes. This version works well and is
   simple.

And, while updating comments, etc., I noticed that tcRnType was
missing a pushTcLevel, leading to #16767, which this patch also
fixes, by bumping the level. In the refactoring here, I also
use solveEqualities. This initially failed ghci/scripts/T15415,
but that was fixed by teaching solveEqualities to respect
-XPartialTypeSignatures.

This patch also cleans up some Notes around error generation that
came up in conversation.

Test case: typecheck/should_fail/T16517, ghci/scripts/T16767

- - - - -
10452959 by Roland Senn at 2019-06-09T18:44:18-04:00
Add disable/enable commands to ghci debugger #2215

This patch adds two new commands `:enable` and `:disable` to the GHCi debugger.
Opposite to `:set stop <n> :continue` a breakpoint disabled with `:disable` will
not loose its previously set stop command.
A new field breakEnabled is added to the BreakLocation data structure to
track the enable/disable state. When a breakpoint is disabled with a `:disable`
command, the following happens:

The corresponding BreakLocation data element is searched dictionary of the
`breaks` field of the GHCiStateMonad. If the break point is found and not
already in the disabled state, the breakpoint is removed from bytecode.
The BreakLocation data structure is kept in the breaks list and the new
breakEnabled field is set to false.

The `:enable` command works similar.

The breaks field in the GHCiStateMonad was changed from an association list
to int `IntMap`.

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13572480 by Ben Gamari at 2019-06-09T18:44:54-04:00
rts: Separate population of eventTypes from initial event generation

Previously these two orthogonal concerns were both implemented in
postHeaderEvents which made it difficult to send header events after RTS
initialization.

- - - - -
ed20412a by nineonine at 2019-06-09T18:45:31-04:00
Do not report error if Name in pragma is unbound

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8a48a8a4 by Ben Gamari at 2019-06-09T18:46:08-04:00
testsuite: Add test for #16509

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69c58f8a by David Eichmann at 2019-06-09T18:46:46-04:00
Hadrian: need CPP preprocessor dependencies #16660

Use the new -include-cpp-deps ghc option (#16521)
when generating .dependencies files in hadrian.
This is version gated as -include-cpp-deps is a
relatively new option.

- - - - -
1c7bb03d by Richard Eisenberg at 2019-06-09T18:47:24-04:00
Comments only: document tcdDataCusk better.

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5023adce by John Ericson at 2019-06-09T18:47:59-04:00
Remove CPP ensuring word size is 32 or 64 bits around Addr# <-> int# primops

It shouldn't be needed these days, and those primops are "highly
deprecated" anyways.

This fits with my plans because it removes one bit of target-dependence
of the builtin primops, and this is the hardest part of GHC to make
multi-target.

CC @carter

- - - - -
8e60e3f0 by Daniel Gröber at 2019-06-09T18:48:38-04:00
rts: Fix RetainerProfile early return with TREC_CHUNK

When pop() returns with `*c == NULL` retainerProfile will immediately
return. All other code paths is pop() continue with the next stackElement
when this happens so it seems weird to me that TREC_CHUNK we would suddenly
abort everything even though the stack might still have elements left to
process.

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1a3420ca by Ben Gamari at 2019-06-10T07:59:41-04:00
base: Mark CPUTime001 as fragile

As noted in #16224, CPUTime001 has been quite problematic, reporting
non-monotonic timestamps in CI. Unfortunately I've been unable to
reproduce this locally.

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9bc10993 by Vladislav Zavialov at 2019-06-10T08:00:16-04:00
Print role annotations in TemplateHaskell brackets (#16718)

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0345b1b0 by Richard Eisenberg at 2019-06-10T23:52:10-04:00
Comments only: document newtypes' DataConWrapId

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58a5d728 by David Eichmann at 2019-06-10T23:52:50-04:00
Refactor the rules for .hi and .o into a single rule using `&%>` #16764

Currently the rule for .hi files just triggers (via need) the rule
for the .o file, and .o rule generates both the .o and .hi file.
Likewise for .o-boot and .hi-boot files. This is a bit of an abuse
of Shake, and in fact shake supports rules with multiple output
with the &%> function. This exact use case appears in Neil
Mitchell's paper *Shake Before Building* section 6.3.

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2f945086 by Ben Gamari at 2019-06-10T23:53:25-04:00
testsuite: Fix and extend closure_size test

This was previously broken in several ways. This is fixed and it also
now tests arrays. Unfortunately I was unable to find a way to continue
testing PAP and FUN sizes; these simply depend too much upon the
behavior of the simplifier.

I also tried to extend this to test non-empty arrays as well but
unfortunately this was non-trivial as the array card size constant isn't
readily available from haskell.

Fixes #16531.

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e5d275f4 by Ben Gamari at 2019-06-10T23:53:25-04:00
ghc-heap: Add closure_size_noopt test

This adds a new test, only run in the `normal` way, to verify the size
of FUNs and PAPs.

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fe7e7e4a by Yuras Shumovich at 2019-06-11T18:39:58-04:00
Warn about unused packages

Reviewers: bgamari, simonpj

Reviewed By: simonpj

Subscribers: hvr, simonpj, mpickering, rwbarton, carter

GHC Trac Issues: #15838

Differential Revision: https://phabricator.haskell.org/D5285

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39f50bff by Alp Mestanogullari at 2019-06-11T18:40:37-04:00
Refine the GHCI macro into HAVE[_{INTERNAL, EXTERNAL}]_INTERPRETER

As discussed in #16331, the GHCI macro, defined through 'ghci' flags
in ghc.cabal.in, ghc-bin.cabal.in and ghci.cabal.in, is supposed to indicate
whether GHC is built with support for an internal interpreter, that runs in
the same process. It is however overloaded in a few places to mean
"there is an interpreter available", regardless of whether it's an internal
or external interpreter.

For the sake of clarity and with the hope of more easily being able to
build stage 1 GHCs with external interpreter support, this patch splits
the previous GHCI macro into 3 different ones:

- HAVE_INTERNAL_INTERPRETER: GHC is built with an internal interpreter
- HAVE_EXTERNAL_INTERPRETER: GHC is built with support for external interpreters
- HAVE_INTERPRETER: HAVE_INTERNAL_INTERPRETER || HAVE_EXTERNAL_INTERPRETER

- - - - -
45616133 by Alec Theriault at 2019-06-11T18:41:14-04:00
Make `haddock_testsuite` respect `--test-accept`

Suppose you've made changes that affect the output of `haddockHtmlTest`
so that the following is failing:

    ./hadrian/build.sh -c --only=haddockHtmlTest test

Then, the following will accept new output for Haddock's test cases.

    ./hadrian/build.sh -c --only=haddockHtmlTest test --test-accept

You still do need to make sure those new changes (which show up in
Haddock's tree) get committed though.

Fixes #16694

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762098bf by Alp Mestanogullari at 2019-06-11T18:41:52-04:00
rts/RtsFlags.c: mention that -prof too enables support for +RTS -l

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457fe789 by Alp Mestanogullari at 2019-06-11T18:42:30-04:00
Hadrian: teach the RTS that PROFILING implies TRACING

As discussed in #16744, both the Make and Hadrian build systems
have special code to always pass -eventlog whenever -prof or -debug
are passed. However, there is some similar logic in the RTS itself only
for defining TRACING when the DEBUG macro is defined, but no such logic
is implemented to define TRACING when the PROFILING macro is defined.
This patch adds such a logic and therefore fixes #16744.

- - - - -
cf7f36ae by Ben Gamari at 2019-06-11T18:43:05-04:00
rts/linker: Mmap into low memory on AArch64

This extends mmapForLinker to use the same low-memory mapping
strategy used on x86_64 on AArch64. See #16784.

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0b7f81f5 by Ben Gamari at 2019-06-11T18:43:05-04:00
rts/linker: Use mmapForLinker to map PLT

The PLT needs to be located within a close distance of
the code calling it under the small memory model.

Fixes #16784.

- - - - -
1389b2cc by Ömer Sinan Ağacan at 2019-06-11T18:43:43-04:00
Fix an error message in CheckUnload.c:searchHeapBlocks

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aad6115a by Alp Mestanogullari at 2019-06-11T18:44:20-04:00
testsuite/mk/boilerplate.mk: rename 'ghc-config-mk' to 'ghc_config_mk'

Make/shell variable names which contain dashes can cause problems under
some conditions. The 'ghc-config-mk' variable from testsuite/mk/boilerplate.mk
that I made overridable (by Hadrian) in ba0aed2e was working as expected when
our Hadrian/Linux job was based off the deb8 Docker image, but broke when
I switched the job to use our deb9-based image, in 3d97bad6. The exact
circumstances/tool versions that trigger this problem are unknown, but
changing the variable's name to 'ghc_config_mk' lets us work around the issue.

This fixes the annth_compunits and annth_make test failures that showed up
when we switched the Hadrian/Linux job to use the deb9 environment.

- - - - -
9b4ff57d by Ben Gamari at 2019-06-12T07:35:25-04:00
llvm-targets: Add armv7l-unknown-linux-gnueabi

Fixes #15208.

[skip ci]

- - - - -
c05ca251 by Ben Gamari at 2019-06-12T07:36:01-04:00
testsuite: Add haddock perf test output to gitignore

[skip ci]

- - - - -
bbc752c5 by Ben Gamari at 2019-06-12T07:36:36-04:00
rts/linker: Make elf_got.c a bit more legible

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217e6db4 by Ben Gamari at 2019-06-12T07:36:36-04:00
rts/linker: Only mprotect GOT after it is filled

This fixes a regression, introduced by 67c422ca, where we mprotect'd the
global offset table (GOT) region to PROT_READ before we had finished
filling it, resulting in a linker crash.

Fixes #16779.

- - - - -
1219f8e8 by Krzysztof Gogolewski at 2019-06-12T07:37:12-04:00
Use DeriveFunctor throughout the codebase (#15654)

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bd2d13ff by Ben Gamari at 2019-06-12T08:19:59-04:00
Bump binary to 0.8.7.0

(cherry picked from commit 983ada70a013c7642a751f6e41587ff95b57d0f8)

- - - - -
381c3ae3 by Ben Gamari at 2019-06-12T08:19:59-04:00
Bump Cabal submodule

(cherry picked from commit ff438786613f07df9b2d43eaeac49b13815d849d)

Metric Increase:
    haddock.Cabal

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0354c7de by Ben Gamari at 2019-06-12T08:19:59-04:00
Bump time submodule to 1.9.3

(cherry picked from commit fdb07571036b1498800589d45b61781e6acdd368)

- - - - -
e0b16eaa by Ben Gamari at 2019-06-12T08:19:59-04:00
Bump terminfo to 0.4.1.4

(cherry picked from commit 1134488b4c9cef904ea82f22f1978646eea612df)

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2ce320b0 by Ben Gamari at 2019-06-12T08:19:59-04:00
gitlab-ci: Test using slowtest in deb9-debug job

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90e7c450 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Mark hWaitForInput-accurate-stdin as broken in threaded ways

As noted in #16535.

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488187f8 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Mark T13167 as fragile in threaded2

As noted in #16536.

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9b583320 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Mark T13910 as broken in optasm

Due to #16537.

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eb644865 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Mark T14761c as broken in hpc, profasm, and optasm ways

As noted in #16540.

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1a204e07 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Mark T16180 as broken in ghci and ext-interp ways

As noted in #16541.

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8d482e45 by Ben Gamari at 2019-06-12T08:19:59-04:00
testsuite: Omit tcrun022 in hpc way

As noted in #16542, the expected rule doesn't fire. However, this
doesn't seem terribly surpring given the circumstances.

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68cfdfdb by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Mark Overflow as broken in hpc way

As noted in #16543.

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a3929a4f by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Mark T2783 as fragile in threaded1

It was previously marked as broken but it passes non-deterministically.
See #2783.

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bb7ed32f by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Skip T7919 in ghci way

It times out pretty reliably. It's not clear that much is gained by
running this test in the ghci way anyways.

- - - - -
329dcd7a by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Fix fragile_for test modifier

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55b5bb14 by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Fix omit_ways usage

omit_ways expects a list but this was broken in several cases.

- - - - -
264ad286 by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Mark threadstatus-T9333 as fragile in ghci way

As noted in #16555.

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587bef66 by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Omit profasm way for cc017

cc017 requires TH but we can't load dynamic profiled objects.

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dc5a37fd by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Skip T493 in ghci way.

T493 tests #493, which is an FFI test. FFI tests should be skipped
in ghci way.

- - - - -
e3f71d0e by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Mark T16449_2 as broken due to #16742

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b5a13a1e by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Mark T16737 as broken in ghci way due to #16541

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b09374a4 by Ben Gamari at 2019-06-12T08:20:25-04:00
testsuite: Note intentional typo in T7130

I earlier accidentally corrected it breaking the test.

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a798c130 by Ben Gamari at 2019-06-12T08:20:25-04:00
linters/check-makefiles: Limit lint to Makefiles

Previously we would apply this rule, which is only intended for
testsuite Makefiles, to all files. This lead to a number of
false-positives in all.T files.

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0782141e by Ben Gamari at 2019-06-12T08:20:25-04:00
gitlab-ci: Fetch submodules before running submodule linter

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898f7e92 by Ben Gamari at 2019-06-12T08:20:25-04:00
Fix uses of #ifdef/#ifndef

The linter now enforces our preference for `#if defined()` and
`#if !defined()`.

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0a13a04c by Ben Gamari at 2019-06-12T08:20:25-04:00
Bump unix submodule

Marks posix002 as fragile in threaded2 way due to #16550.

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a8579e5b by Ben Gamari at 2019-06-12T08:27:25-04:00
process: Bump submodule

 * Skip process005 in ghci way
 * Mark process002 as fragile in threaded2

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3f1022c5 by Ben Gamari at 2019-06-12T08:27:25-04:00
testsuite: Skip cgrun078 in ghci way

This test requires FFI usage.

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1cbfef47 by Ben Gamari at 2019-06-12T08:27:25-04:00
testsuite: Unbreak galois_raytrace on i386

galois_raytrace was previously broken on i386 due to use of x87
arithmethic on that platform. However,
42504f4a575395a35eec5c3fd7c9ef6e2b54e68e removes x87 support; this
resulted in an unexpected pass. Unmark this test as broken.

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20160f1a by Ben Gamari at 2019-06-12T08:27:25-04:00
testsuite: Don't run tests requiring TH in profasm way when GhcDynamic

Since we can't load profiled objects when GhcDynamic==YES. Affects:

* T16737
* T16384
* T16718
* T16619
* T16190

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7b751ed8 by Ben Gamari at 2019-06-12T17:52:35-04:00
gitlab-ci: Bump Docker image

Fixes linters.

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5ffc266e by Ben Gamari at 2019-06-13T02:48:13-04:00
Add a few missing llvm-targets

This should finally fix #14261.

[skip ci]

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fc6b23be by Phuong Trinh at 2019-06-13T02:48:50-04:00
Fix #16525: ObjectCode freed wrongly because of lack of info header check

`checkUnload` currently doesn't check the info header of static objects.
Thus, it may free an `ObjectCode` struct wrongly even if there's still a
live static object whose info header lies in a mapped section of that
`ObjectCode`. This fixes the issue by adding an appropriate check.

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a657543c by Ben Gamari at 2019-06-13T02:49:25-04:00
PrelRules: Ensure that string unpack/append rule fires with source notes

Previously the presence of source notes could hide nested applications
of `unpackFoldrCString#` from our constant folding logic. For instance,
consider the expression:

```haskell
unpackFoldrCString# "foo" c (unpackFoldrCString# "baz" c n)
```

Specifically, ticks appearing in two places can defeat the rule:

  a. Surrounding the inner application of `unpackFoldrCString#`
  b. Surrounding the fold function, `c`

The latter caused the `str_rules` testcase to fail when `base` was built
with `-g3`.

Fixes #16740.

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e98d32a6 by David Eichmann at 2019-06-13T02:50:00-04:00
Hadrian: Track RTS library symlink targets

This requires creating RTS library symlinks when registering, outside
of the rule for the registered library file.

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35113117 by Alp Mestanogullari at 2019-06-13T02:50:37-04:00
Hadrian: Do not allow the Linux jobs to fail anymore

MR !1151 makes the Hadrian/Linux job pass by fixing the last two test failures,
so we can now be stricter and not allow those jobs to fail anymore, easily
letting us see when patches introduce test failures.

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70b5eefe by Ben Gamari at 2019-06-13T02:51:13-04:00
users-guide: Fix a few markup issues

Strangely these were only causing the build to fail in the aarch64-linux
job, despite Sphinx throwing errors in all jobs I checked.

Also changes some `#ifdef`s to `#if defined` to satisfy the linter.

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9721b40d by Ben Gamari at 2019-06-13T02:51:13-04:00
gitlab-ci: Don't build PDF user's guide on AArch64

For reasons I don't understand sphinx seems to fail to produce a .idx
file for makeindex.

- - - - -
d550b771 by Ben Gamari at 2019-06-13T02:51:50-04:00
Clean up .circleci

Move prepare-system.sh to .gitlab and remove everything else.

- - - - -
c53dfb3b by Ben Gamari at 2019-06-13T11:52:47-04:00
testsuite: A more portable solution to #9399

Previously we used an awful hybrid batch script/Bourne shell script to
allow this test to run both on Windows and Linux (fixing #9399).
However, this breaks on some libc implementations (e.g. musl). Fix this.

Fixes #16798.

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74b5d049 by Ben Gamari at 2019-06-13T11:53:22-04:00
gitlab-ci: Disable deb9-llvm job, introduce nightly LLVM job

This should help alleviate queue times as the LLVM job is one of the
longest that we have.

- - - - -
5ce63d52 by Ben Gamari at 2019-06-13T11:53:22-04:00
gitlab-ci: Disable validate-x86_64-linux-deb9 job to reduce load

Enable artifacts on to ensure we have bindist coverage.

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7bc5d6c6 by Ben Gamari at 2019-06-13T23:34:41-04:00
Maintain separate flags for C++ compiler invocations

Previously we would pass flags intended for the C compiler to the C++
compiler (see #16738). This would cause, for instance, `-std=gnu99` to
be passed to the C++ compiler, causing spurious test failures. Fix this
by maintaining a separate set of flags for C++ compilation invocations.

- - - - -
71e75ba6 by Ömer Sinan Ağacan at 2019-06-13T23:35:19-04:00
Remove unused Unique field from StgFCallOp

Fixes #16696

- - - - -
ec25fe59 by Alp Mestanogullari at 2019-06-13T23:35:56-04:00
Hadrian: remove superfluous dependencies in Rules.Compile

Each package's object files were 'need'ing the library files of all transitive
dependencies of the current package, whichi is pointless since the said
libraries are not needed until we link those object files together.

This fixes #16759.

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3bc6df32 by Andreas Klebinger at 2019-06-13T23:36:34-04:00
Add Outputable instances for Float, Double.

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effdd948 by Andrew Martin at 2019-06-14T10:48:13-04:00
Implement the -XUnliftedNewtypes extension.

GHC Proposal: 0013-unlifted-newtypes.rst
Discussion: https://github.com/ghc-proposals/ghc-proposals/pull/98
Issues: #15219, #1311, #13595, #15883
Implementation Details:
  Note [Implementation of UnliftedNewtypes]
  Note [Unifying data family kinds]
  Note [Compulsory newtype unfolding]

This patch introduces the -XUnliftedNewtypes extension. When this
extension is enabled, GHC drops the restriction that the field in
a newtype must be of kind (TYPE 'LiftedRep). This allows types
like Int# and ByteArray# to be used in a newtype. Additionally,
coerce is made levity-polymorphic so that it can be used with
newtypes over unlifted types.

The bulk of the changes are in TcTyClsDecls.hs. With -XUnliftedNewtypes,
getInitialKind is more liberal, introducing a unification variable to
return the kind (TYPE r0) rather than just returning (TYPE 'LiftedRep).
When kind-checking a data constructor with kcConDecl, we attempt to
unify the kind of a newtype with the kind of its field's type. When
typechecking a data declaration with tcTyClDecl, we again perform a
unification. See the implementation note for more on this.

Co-authored-by: Richard Eisenberg <rae at richarde.dev>

- - - - -
5279dda8 by Ben Gamari at 2019-06-14T10:48:51-04:00
PrelRules: Don't break let/app invariant in shiftRule

Previously shiftRule would rewrite as invalid shift like
```
let x = I# (uncheckedIShiftL# n 80)
in ...
```
to
```
let x = I# (error "invalid shift")
in ...
```
However, this breaks the let/app invariant as `error` is not
okay-for-speculation. There isn't an easy way to avoid this so let's not
try. Instead we just take advantage of the undefined nature of invalid
shifts and return zero.

Fixes #16742.

- - - - -
503e830c by Ben Gamari at 2019-06-14T23:10:08-04:00
gitlab-ci: Lint testsuite for framework failures

This introduces a new lint job checking for framework failures and
listing broken tests.

- - - - -
b5ea9323 by Ben Gamari at 2019-06-14T23:10:08-04:00
lint: Only apply --interactive lint to testsuite .T files

- - - - -
5c97211c by Ben Gamari at 2019-06-14T23:10:08-04:00
gitlab-ci: Lint the linters

- - - - -
257165b4 by Alp Mestanogullari at 2019-06-14T23:10:46-04:00
Remove duplicates from 'ghc --info' output

- - - - -
5da6c86f by Ben Gamari at 2019-06-15T15:14:01-04:00
Bump unix submodule

Skips `executeFile001` test in `threaded2` way. Fixes #16814.

- - - - -
20b4d5ec by Ben Gamari at 2019-06-15T23:32:38-04:00
Disable optimisation when building Cabal lib for stage0

This disables optimisation when building Cabal for Hadrian and
stage0 `ghc-cabal`. Cabal is performance critical in neither case nor
will any performance difference here be visible to the end-user.

See #16817.

- - - - -
76b7f619 by Ben Gamari at 2019-06-15T23:32:38-04:00
Disable optimisation when building Cabal in development flavours

This updates the make and Hadrian build flavours targetting developers
to disable optimisation when building the Cabal library. Cabal tends to
tickle some very bad compiler performance cases (e.g. #16577) so
disabling optimisation here makes a sizeable impact on overall build
time.

See #16817.

- - - - -
0d2a4258 by Ben Gamari at 2019-06-15T23:33:13-04:00
testsuite: Introduce concurrent_ways set

Previously we just tested for the threaded2 when determining whether to
skip tests which are fragile under concurrent execution. However, this
isn't the only way which is concurrent.

- - - - -
beacb6fd by Ben Gamari at 2019-06-15T23:33:13-04:00
testsuite: Skip hDuplicateTo001 in concurrent ways

As noted in #16819, this operation is racy under concurrent execution.

- - - - -
ca721193 by Aiken Cairncross at 2019-06-15T23:33:50-04:00
Fix typo in error message

- - - - -
57b71848 by Ben Gamari at 2019-06-15T23:34:25-04:00
testsuite: Add assertions that way lists are in fact lists

Previously there were a few cases where operations like `omit_ways`
were incorrectly passed a single way (e.g. `omit_ways('threaded2')`).
This won't work as the author expected.

- - - - -
25ee60cd by Ryan Scott at 2019-06-15T23:35:03-04:00
Synchronize ClsInst.doTyConApp with TcTypeable validity checks (#15862)

Issue #15862 demonstrated examples of type constructors on which
`TcTypeable.tyConIsTypeable` would return `False`, but the `Typeable`
constraint solver in `ClsInst` (in particular, `doTyConApp`) would
try to generate `Typeable` evidence for anyway, resulting in
disaster. This incongruity was caused by the fact that `doTyConApp`
was using a weaker validity check than `tyConIsTypeable` to determine
if a type constructor warrants `Typeable` evidence or not. The
solution, perhaps unsurprisingly, is to use `tyConIsTypeable` in
`doTyConApp` instead.

To avoid import cycles between `ClsInst` and `TcTypeable`, I factored
out `tyConIsTypeable` into its own module, `TcTypeableValidity`.

Fixes #15862.

- - - - -
4138bf86 by Krzysztof Gogolewski at 2019-06-15T23:35:38-04:00
Remove dead code

- - - - -
db313f98 by Ben Gamari at 2019-06-16T06:26:38-04:00
base/Event/Poll: Drop POLLRDHUP enum item

Previously the Event enumeration produced by hsc2hs would sometimes
include a currently-unused POLLRDHUP item. This unused binding would
result in a build failure. Drop it.

- - - - -
81608e82 by Ben Gamari at 2019-06-16T06:26:38-04:00
testsuite: Fix T8602 on musl

Musl wants hash-bangs on all executables.

- - - - -
a0f68379 by Ben Gamari at 2019-06-16T06:26:38-04:00
testsuite: Ensure T5423 flushes C output buffer

Previously T5423 would fail to flush the printf output buffer.
Consequently it was platform-dependent whether the C or Haskell print
output would be emitted first.

- - - - -
543dfaab by Ben Gamari at 2019-06-16T06:26:38-04:00
testsuite: Flush conc059's printf buffer

Otherwise it the order out the Haskell and C output will be
system-dependent.

- - - - -
e647752e by Ben Gamari at 2019-06-16T06:26:38-04:00
testsuite: Ensure that ffi005 output order is predictable

The libc output buffer wasn't being flushed, making the order
system-depedent.

- - - - -
338336d3 by Ben Gamari at 2019-06-16T06:26:38-04:00
gitlab-ci: Build alpine release bindists

- - - - -
75c6ccf7 by Alp Mestanogullari at 2019-06-16T06:27:17-04:00
fix runghc's GHC detection logic to cover the "in-tree Hadrian build" scenario

Before this patch, runghc would only run the GHC detection logic on Windows and
assume that it was invoked through a wrapper script on all other platforms.
This patch lifts this limitation and makes that logic work for the scenario
where someone is calling the runghc executable directly, without passing an
explicit path to GHC.

- - - - -
3c35e140 by Ben Gamari at 2019-06-16T19:38:51-04:00
testsuite: Really fix #16741

The previous fix, !1095, didn't work as `--show-iface` ignores
`-dsuppress-ticks`. Rework the test instead.

- - - - -
b3bb1b06 by Ben Gamari at 2019-06-16T19:38:51-04:00
gitlab-ci: Don't allow failure of deb9-dwarf job

This #16741 out of the way this should now pass.

- - - - -
b965de1e by Ömer Sinan Ağacan at 2019-06-16T19:39:29-04:00
Use TupleSections in CmmParse.y, simplify a few exprs

- - - - -
63965ae3 by Ben Gamari at 2019-06-17T01:20:21-04:00
make: Clean includes/settings file

Now since this is generated by the build system we should ensure that it
is properly cleaned.

[skip ci]

- - - - -
bb141114 by Siddharth Bhat at 2019-06-17T01:20:57-04:00
Add link to mfix.github.io/ghc in HACKING.md

- - - - -
24afbfe9 by Ben Gamari at 2019-06-17T10:20:32-04:00
gitlab-ci: Run nofib on binary distributions

Updates docker images to ensure that the `time` utility is available.

- - - - -
62f0213d by Fumiaki Kinoshita at 2019-06-18T16:00:20-04:00
Data.Ord: give a field name getDown to Down

- - - - -
da33f2bb by Fumiaki Kinoshita at 2019-06-18T16:00:20-04:00
Add more newtype-derived instances to Data.Ord.Down

Metric Increase:
    haddock.base

- - - - -
dbf9ca20 by Ben Gamari at 2019-06-18T16:00:56-04:00
testsuite: Add testcase for #16689

- - - - -
29ec33cd by Ben Gamari at 2019-06-18T16:00:56-04:00
SafeHaskell: Don't throw -Wsafe warning if module is declared Safe

Fixes #16689.

- - - - -
a491e40c by Ben Gamari at 2019-06-18T16:01:31-04:00
hadrian: Compile UserSettings with -O0

This guarantees that the interface file for `UserSettings` doesn't 
contain any unfoldings, ensuring that a change in it requires minimal 
rebuilds.
- - - - -
74bd6b22 by Ben Gamari at 2019-06-18T16:02:07-04:00
testsuite: Add test for #16832

- - - - -
6a92f59d by Ben Gamari at 2019-06-18T16:02:42-04:00
gitlab-ci: Run alpine builds during nightly job

- - - - -
4549cadf by Andreas Klebinger at 2019-06-18T16:03:19-04:00
Make sure mkSplitUniqSupply stores the precomputed mask only.

mkSplitUniqSupply was lazy on the boxed char.

This caused a bunch of issues:
* The closure captured the boxed Char
* The mask was recomputed on every split of the supply.
* It also caused the allocation of MkSplitSupply to happen in it's own
(allocated) closure. The reason of which I did not further investigate.

We know force the computation of the mask inside mkSplitUniqSupply.
* This way the mask is computed at most once per UniqSupply creation.
* It allows ww to kick in, causing the closure to retain the unboxed
value.

Requesting Uniques in a loop is now faster by about 20%.

I did not check the impact on the overall compiler, but I added a test
to avoid regressions.

- - - - -
8584430e by Ömer Sinan Ağacan at 2019-06-19T15:00:11+03:00
Fix a Note name in CmmNode

("Continuation BlockIds" is referenced in CmmProcPoint)

[skip ci]

- - - - -
9d58554f by Ömer Sinan Ağacan at 2019-06-19T22:14:26-04:00
Properly trim IdInfos of DFunIds and PatSyns in TidyPgm

Not doing this right caused #16608. We now properly trim IdInfos of
DFunIds and PatSyns.

Some further refactoring done by SPJ.

Two regression tests T16608_1 and T16608_2 added.

Fixes #16608

- - - - -
39c758e1 by Roland Senn at 2019-06-19T22:15:04-04:00
Fix #1620: ModBreaks.modBreaks_array not initialised

After a :cd command and after setting some package flags,
GHCi unloads all loaded modules by resetting the list of targets.

This patch deletes eventually defined debugger breakpoints, before GHCi resets the target list.

The common code is factored out into the new function clearAllTargets.

- - - - -
3c9b57b0 by Simon Peyton Jones at 2019-06-19T22:15:39-04:00
Fix two places that failed the substitution invariant

The substition invariant relies on keeping the in-scope
set in sync, and we weren't always doing so, which means that
a DEBUG compiler crashes sometimes with an assertion failure

This patch fixes a couple more cases.  Still not validate
clean (with -DEEBUG) but closer!

- - - - -
48fb3482 by Simon Peyton Jones at 2019-06-19T22:15:39-04:00
Fix typechecking of partial type signatures

Partial type sigs had grown hair.  tcHsParialSigType was
doing lots of unnecessary work, and tcInstSig was cloning it
unnecessarily -- and the result didn't even work: #16728.

This patch cleans it all up, described by TcHsType
  Note [Checking parital type signatures]

I basically just deleted code... but very carefully!

Some refactoring along the way

* Distinguish more explicintly between "anonymous" wildcards "_"
  and "named" wildcards "_a".  I changed the names of a number
  of functions to make this distinction much more apparent.

The patch also revealed that the code in `TcExpr`
that implements the special typing rule for `($)` was wrong.
It called `getRuntimeRep` in a situation where where was no
particular reason to suppose that the thing had kind `TYPE r`.

This caused a crash in typecheck/should_run/T10846.

The fix was easy, and actually simplifies the code in `TcExpr`
quite a bit.  Hooray.

- - - - -
3ae23992 by Simon Peyton Jones at 2019-06-19T22:15:39-04:00
Comments and tiny refactor

* Added Note [Quantified varaibles in partial type signatures]
  in TcRnTypes

* Kill dVarSetElemsWellScoped; it was only called in
  one function, quantifyTyVars.  I inlined it because it
  was only scopedSort . dVarSetElems

* Kill Type.tyCoVarsOfBindersWellScoped, never called.

- - - - -
bff2f24b by John Ericson at 2019-06-19T22:16:16-04:00
Move 'Platform' to ghc-boot

ghc-pkg needs to be aware of platforms so it can figure out which
subdire within the user package db to use. This is admittedly
roundabout, but maybe Cabal could use the same notion of a platform as
GHC to good affect too.

- - - - -
a298b96e by John Ericson at 2019-06-19T22:16:16-04:00
Add 'stringEncodeArch' and 'stringEncodeOS' to GHC.Platform

- - - - -
d406a16a by John Ericson at 2019-06-19T22:16:16-04:00
ghc-pkg needs settings file to un-hardcode target platform

This matches GHC itself getting the target platform from there.

- - - - -
aa4891a7 by Ben Gamari at 2019-06-19T22:16:51-04:00
users-guide: Fix a variety of broken links and syntax

- - - - -
fe819dd6 by Ben Gamari at 2019-06-19T22:16:51-04:00
users-guide: Update -Wsafe description for #16689

We no longer emit a warning when a safe module is explicitly declared as
such.

- - - - -
c311277b by Matthías Páll Gissurarson at 2019-06-21T03:21:21+02:00
Add HoleFitPlugins and RawHoleFits

This patch adds a new kind of plugin, Hole fit plugins. These plugins
can change what candidates are considered when looking for valid hole
fits, and add hole fits of their own. The type of a plugin is relatively
simple,

```
type FitPlugin = TypedHole -> [HoleFit] -> TcM [HoleFit]
type CandPlugin = TypedHole -> [HoleFitCandidate] -> TcM [HoleFitCandidate]
data HoleFitPlugin = HoleFitPlugin { candPlugin :: CandPlugin
                                   , fitPlugin :: FitPlugin }

data TypedHole = TyH { tyHRelevantCts :: Cts
                       -- ^ Any relevant Cts to the hole
                     , tyHImplics :: [Implication]
                       -- ^ The nested implications of the hole with the
                       --   innermost implication first.
                     , tyHCt :: Maybe Ct
                       -- ^ The hole constraint itself, if available.
                     }

This allows users and plugin writers to interact with the candidates and
fits as they wish, even going as far as to allow them to reimplement the
current functionality (since `TypedHole` contains all the relevant
information).

As an example, consider the following plugin:

```
module HolePlugin where

import GhcPlugins

import TcHoleErrors

import Data.List (intersect, stripPrefix)
import RdrName (importSpecModule)

import TcRnTypes

import System.Process

plugin :: Plugin
plugin = defaultPlugin { holeFitPlugin = hfp, pluginRecompile = purePlugin }

hfp :: [CommandLineOption] -> Maybe HoleFitPluginR
hfp opts = Just (fromPureHFPlugin $ HoleFitPlugin (candP opts) (fp opts))

toFilter :: Maybe String -> Maybe String
toFilter = flip (>>=) (stripPrefix "_module_")

replace :: Eq a => a -> a -> [a] -> [a]
replace match repl str = replace' [] str
  where
    replace' sofar (x:xs) | x == match = replace' (repl:sofar) xs
    replace' sofar (x:xs) = replace' (x:sofar) xs
    replace' sofar [] = reverse sofar

-- | This candidate plugin filters the candidates by module,
--   using the name of the hole as module to search in
candP :: [CommandLineOption] -> CandPlugin
candP _ hole cands =
  do let he = case tyHCt hole of
                Just (CHoleCan _ h) -> Just (occNameString $ holeOcc h)
                _ -> Nothing
     case toFilter he of
        Just undscModName -> do let replaced = replace '_' '.' undscModName
                                let res = filter (greNotInOpts [replaced]) cands
                                return $ res
        _ -> return cands
  where greNotInOpts opts (GreHFCand gre)  = not $ null $ intersect (inScopeVia gre) opts
        greNotInOpts _ _ = True
        inScopeVia = map (moduleNameString . importSpecModule) . gre_imp

-- Yes, it's pretty hacky, but it is just an example :)
searchHoogle :: String -> IO [String]
searchHoogle ty = lines <$> (readProcess "hoogle" [(show ty)] [])

fp :: [CommandLineOption] -> FitPlugin
fp ("hoogle":[]) hole hfs =
    do dflags <- getDynFlags
       let tyString = showSDoc dflags . ppr . ctPred <$> tyHCt hole
       res <- case tyString of
                Just ty -> liftIO $ searchHoogle ty
                _ -> return []
       return $ (take 2 $ map (RawHoleFit . text . ("Hoogle says: " ++)) res) ++ hfs
fp _ _ hfs = return hfs

```

with this plugin available, you can compile the following file

```
{-# OPTIONS -fplugin=HolePlugin -fplugin-opt=HolePlugin:hoogle #-}
module Main where

import Prelude hiding (head, last)

import Data.List (head, last)

t :: [Int] -> Int
t = _module_Prelude

g :: [Int] -> Int
g = _module_Data_List

main :: IO ()
main = print $ t [1,2,3]
```

and get the following output:

```
Main.hs:14:5: error:
    • Found hole: _module_Prelude :: [Int] -> Int
      Or perhaps ‘_module_Prelude’ is mis-spelled, or not in scope
    • In the expression: _module_Prelude
      In an equation for ‘t’: t = _module_Prelude
    • Relevant bindings include
        t :: [Int] -> Int (bound at Main.hs:14:1)
      Valid hole fits include
        Hoogle says: GHC.List length :: [a] -> Int
        Hoogle says: GHC.OldList length :: [a] -> Int
        t :: [Int] -> Int (bound at Main.hs:14:1)
        g :: [Int] -> Int (bound at Main.hs:17:1)
        length :: forall (t :: * -> *) a. Foldable t => t a -> Int
          with length @[] @Int
          (imported from ‘Prelude’ at Main.hs:5:1-34
           (and originally defined in ‘Data.Foldable’))
        maximum :: forall (t :: * -> *) a. (Foldable t, Ord a) => t a -> a
          with maximum @[] @Int
          (imported from ‘Prelude’ at Main.hs:5:1-34
           (and originally defined in ‘Data.Foldable’))
        (Some hole fits suppressed; use -fmax-valid-hole-fits=N or -fno-max-valid-hole-fits)
   |
14 | t = _module_Prelude
   |     ^^^^^^^^^^^^^^^

Main.hs:17:5: error:
    • Found hole: _module_Data_List :: [Int] -> Int
      Or perhaps ‘_module_Data_List’ is mis-spelled, or not in scope
    • In the expression: _module_Data_List
      In an equation for ‘g’: g = _module_Data_List
    • Relevant bindings include
        g :: [Int] -> Int (bound at Main.hs:17:1)
      Valid hole fits include
        Hoogle says: GHC.List length :: [a] -> Int
        Hoogle says: GHC.OldList length :: [a] -> Int
        g :: [Int] -> Int (bound at Main.hs:17:1)
        head :: forall a. [a] -> a
          with head @Int
          (imported from ‘Data.List’ at Main.hs:7:19-22
           (and originally defined in ‘GHC.List’))
        last :: forall a. [a] -> a
          with last @Int
          (imported from ‘Data.List’ at Main.hs:7:25-28
           (and originally defined in ‘GHC.List’))
   |
17 | g = _module_Data_List

```

This relatively simple plugin has two functions, as an example of what
is possible to do with hole fit plugins. The candidate plugin starts by
filtering the candidates considered by module, indicated by the name of
the hole (`_module_Data_List`). The second function is in the fit
plugin, where the plugin invokes a local hoogle instance to search by
the type of the hole.

By adding the `RawHoleFit` type, we can also allow these completely free
suggestions, used in the plugin above to display fits found by Hoogle.

Additionally, the `HoleFitPluginR` wrapper can be used for plugins to
maintain state between invocations, which can be used to speed up
invocation of plugins that have expensive initialization.

```
-- | HoleFitPluginR adds a TcRef to hole fit plugins so that plugins can
-- track internal state. Note the existential quantification, ensuring that
-- the state cannot be modified from outside the plugin.
data HoleFitPluginR = forall s. HoleFitPluginR
  { hfPluginInit :: TcM (TcRef s)
    -- ^ Initializes the TcRef to be passed to the plugin
  , hfPluginRun :: TcRef s -> HoleFitPlugin
    -- ^ The function defining the plugin itself
  , hfPluginStop :: TcRef s -> TcM ()
    -- ^ Cleanup of state, guaranteed to be called even on error
  }
```

Of course, the syntax here is up for debate, but hole fit plugins allow
us to experiment relatively easily with ways to interact with
typed-holes without having to dig deep into GHC.

Reviewers: bgamari

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5373

- - - - -
2485c08a by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Skip dynamicToo006 when dynamic linking is not available

This was previously failling on Windows.

- - - - -
aa516431 by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Mark T3372 as fragile on Windows

On Windows we must lock package databases even when opening for
read-only access. This means that concurrent GHC sessions are very
likely to fail with file lock contention.

See #16773.

- - - - -
2eedb120 by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Add stderr output for UnsafeInfered02 on Windows

This test uses TemplateHaskell causing GHC to build dynamic objects on
platforms where dynamic linking is available. However, Windows doesn't support
dynamic linking. Consequently the test would fail on Windows with:

```patch
--- safeHaskell/safeInfered/UnsafeInfered02.run/UnsafeInfered02.stderr.normalised	2019-06-04 15:10:10.521594200 +0000
+++ safeHaskell/safeInfered/UnsafeInfered02.run/UnsafeInfered02.comp.stderr.normalised	2019-06-04 15:10:10.523546200 +0000
@@ -1,5 +1,5 @@
-[1 of 2] Compiling UnsafeInfered02_A ( UnsafeInfered02_A.hs, UnsafeInfered02_A.o, UnsafeInfered02_A.dyn_o )
-[2 of 2] Compiling UnsafeInfered02  ( UnsafeInfered02.hs, UnsafeInfered02.o, UnsafeInfered02.dyn_o )
+[1 of 2] Compiling UnsafeInfered02_A ( UnsafeInfered02_A.hs, UnsafeInfered02_A.o )
+[2 of 2] Compiling UnsafeInfered02  ( UnsafeInfered02.hs, UnsafeInfered02.o )

 UnsafeInfered02.hs:4:1:
     UnsafeInfered02_A: Can't be safely imported!
```

The other approach I considered for this issue is to pass `-v0` to GHC.
However, I felt we should probably do this consistently for all of the tests in
this directory and this would take more time than I currently have.

- - - - -
3967d13a by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Mark OldModLocation as broken on Windows

Strangely the path it emits contains duplicate path delimiters (#16772),
```patch
--- ghc-api/downsweep/OldModLocation.run/OldModLocation.stderr.normalised	2019-06-04 14:40:26.326075000 +0000
+++ ghc-api/downsweep/OldModLocation.run/OldModLocation.run.stderr.normalised	2019-06-04 14:40:26.328029200 +0000
@@ -1 +1 @@
-[Just "A.hs",Just "mydir/B.hs"]
+[Just "A.hs",Just "mydir//B.hs"]
```

- - - - -
31f2ea68 by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Mark T7170 as broken on Windows

Due to #16801.

- - - - -
7bd1c3e1 by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Mark T7702 as broken on Windows

Due to #16799.

- - - - -
84900724 by Ben Gamari at 2019-06-21T13:32:34-04:00
testsuite: Mark T15633a and T15633b as fragile on Windows

As noted in #16813, these tests seem to be fragile on Windows.

- - - - -
49fff41d by Ben Gamari at 2019-06-21T13:32:34-04:00
linker: Disable code unloading

As noted in #16841, there are currently a variety of bugs in the
unloading logic. These only affect Windows since code unloading is
disabled on Linux, where we build with `GhcDynamic=YES` by default.

In the interest of getting the tree green on Windows disable code
unloading until the issues are resolved.

- - - - -
e0595d22 by Ben Gamari at 2019-06-22T09:36:53-04:00
testsuite: Mark T16608_* as fragile on Darwin

As noted in #16855.

- - - - -
655c6e26 by Ben Gamari at 2019-06-22T10:06:05-04:00
ghci: Don't rely on resolution of System.IO to base module

Previously we would hackily evaluate a textual code snippet to compute
actions to disable I/O buffering and flush the stdout/stderr handles.
This broke in a number of ways (#15336, #16563).

Instead we now ship a module (`GHC.GHCi.Helpers`) with `base` containing
the needed actions. We can then easily refer to these via `Orig` names.

- - - - -
8f8fc31b by Ben Gamari at 2019-06-22T10:06:05-04:00
testsuite: Add test for #16563

- - - - -
22e721c1 by Ben Gamari at 2019-06-22T10:06:05-04:00
testsuite: Mark T5611 as broken in ghci way

As described in #16845.

- - - - -
b0d6bf2a by Ben Gamari at 2019-06-22T10:06:05-04:00
rts: Reset STATIC_LINK field of reverted CAFs

When we revert a CAF we must reset the STATIC_LINK field lest the GC
might ignore the CAF (e.g. as it carries the STATIC_FLAG_LIST flag) and
will consequently overlook references to object code that we are trying
to unload. This would result in the reachable object code being
unloaded. See Note [CAF lists] and Note [STATIC_LINK fields].

This fixes #16842.

Idea-due-to: Phuong Trinh <lolotp at fb.com>

- - - - -
1f2fff89 by Ben Gamari at 2019-06-22T10:06:05-04:00
testsuite: Add caf_crash testcase

- - - - -
ade3db53 by Ben Gamari at 2019-06-23T17:19:48-04:00
testsuite: Test for #13786

- - - - -
5a502cd1 by Ben Gamari at 2019-06-23T17:19:48-04:00
ghci: Load static objects in batches

Previously in the case where GHC was dynamically linked we would load
static objects one-by-one by linking each into its own shared object and
dlopen'ing each in order. However, this meant that the link would fail
in the event that the objects had cyclic symbol dependencies.

Here we fix this by merging each "run" of static objects into a single
shared object and loading this.

Fixes #13786 for the case where GHC is dynamically linked.

- - - - -
9bbcc3be by Ryan Scott at 2019-06-23T17:20:41-04:00
Refactor UnliftedNewtypes-relation kind signature validity checks

This fixes three infelicities related to the programs that are
(and aren't) accepted with `UnliftedNewtypes`:

* Enabling `UnliftedNewtypes` would permit newtypes to have return
  kind `Id Type`, which had disastrous results (i.e., GHC panics).
* Data family declarations ending in kind `TYPE r` (for some `r`)
  weren't being accepted if `UnliftedNewtypes` wasn't enabled,
  despite the GHC proposal specifying otherwise.
* GHC wasn't warning about programs that _would_ typecheck if
  `UnliftedNewtypes` were enabled in certain common cases.

As part of fixing these issues, I factored out the logic for checking
all of the various properties about data type/data family return
kinds into a single `checkDataKindSig` function. I also cleaned up
some of the formatting in the existing error message that gets
thrown.

Fixes #16821, fixes #16827, and fixes #16829.

- - - - -
71aca77c by Erik de Castro Lopo at 2019-06-24T01:11:46-04:00
Fixes for LLVM 7

LLVM version numberinf changed recently. Previously, releases were numbered
4.0, 5.0 and 6.0 but with version 7, they dropped the redundant ".0".

Fix requires for Llvm detection and some code.

- - - - -
581cbc28 by Erik de Castro Lopo at 2019-06-24T01:12:22-04:00
Add MonadFail instance for ParserM

- - - - -
15b26223 by Andrey Mokhov at 2019-06-25T01:36:10-04:00
Fix cyclic dependencies when using --configure

This resolves #16809 (https://gitlab.haskell.org/ghc/ghc/issues/16809).

This patch removes the unnecessary dependency on configure-generated
flags `windowsHost`, `osxHost` and `iosHost`, using the information
provided by the module `System.Info` instead.

We also take care to use the `CrossCompiling` flag generated by the
configure script only after the latter had a chance to run.

- - - - -
ebd63e8d by Ömer Sinan Ağacan at 2019-06-25T01:36:50-04:00
Simplify link_caf and mkForeignLabel functions

- - - - -
c346585b by Ben Gamari at 2019-06-25T08:37:46-04:00
testsuite: A major revamp of the driver

This tries to put the testsuite driver into a slightly more maintainable
condition:

* Add type annotations where easily done
* Use pathlib.Path instead of str paths
* Make it pass the mypy typechecker

- - - - -
bb40bd37 by Ben Gamari at 2019-06-25T08:37:46-04:00
testsuite: Fix a few issues in JUnit output

 * Make it pass mypy
 * Fix a typo in test name field
 * Report more stderr output
 * Report stdout output

- - - - -
95f56853 by Ben Gamari at 2019-06-25T08:37:46-04:00
gitlab-ci: Add testsuite typechecking lint

- - - - -
9542ab06 by Ben Gamari at 2019-06-25T08:38:22-04:00
testsuite: Don't run T16525a with -DS unless compiler_debugged

Originally I was thinking of just skipping the test unless
compiled_debugged==True. However, the test will likely be useful even
without -DS, so let's run it either way.

- - - - -
d0993a29 by Ben Gamari at 2019-06-25T08:38:22-04:00
testsuite: Fix expected output for caf_crash

- - - - -
757b71d9 by Ben Gamari at 2019-06-25T08:38:22-04:00
testsuite: Mark ghci058 as broken on Windows

Due to #16858.

- - - - -
38ded743 by Siddharth Bhat at 2019-06-25T15:15:16+02:00
[skip ci] Typo fix: b*ar*nches -> b*ra*nches

- - - - -
8a03d5a1 by Ben Gamari at 2019-06-25T22:20:24-04:00
testsuite: Add test for #16846

- - - - -
5ff0a171 by Ben Gamari at 2019-06-25T22:20:24-04:00
CoreToStg: Enable CAFfyness checking with -dstg-lint

The debugging involved in finding #16846 wouldn't have been necessary
had the consistentCafInfo check been enabled. However, :wq

- - - - -
cac8dc9f by Ben Gamari at 2019-06-25T22:20:24-04:00
Don't eta-expand unsaturated primops

Previously, as described in Note [Primop wrappers], `hasNoBinding` would
return False in the case of `PrimOpId`s. This would result in eta
expansion of unsaturated primop applications during CorePrep. Not only
did this expansion result in unnecessary allocations, but it also meant
lead to rather nasty inconsistencies between the CAFfy-ness
determinations made by TidyPgm and CorePrep.

This fixes #16846.

- - - - -
b90437d8 by Ben Gamari at 2019-06-25T22:20:59-04:00
testsuite: Unbreak T16608 tests

Sleep to avoid non-determinism due to Darwin's poor mtime resolution.
Fixes #16855.

- - - - -
ff2b99e1 by Ömer Sinan Ağacan at 2019-06-25T22:21:38-04:00
Remove unused UniqSupply functions

- - - - -
4c2127c4 by Ben Gamari at 2019-06-25T22:52:26-04:00
Bump containers submodule to v0.6.2.1

- - - - -
5c3f2080 by Ben Gamari at 2019-06-25T22:52:26-04:00
Bump Cabal submodule to what will become 3.0.0.0

Metric Increase:
    haddock.Cabal

- - - - -
a863c44f by Oleg Grenrus at 2019-06-25T23:25:08-04:00
Add -Winferred-safe-imports warning

This commit partly reverts e69619e923e84ae61a6bb4357f06862264daa94b
commit by reintroducing Sf_SafeInferred SafeHaskellMode.

We preserve whether module was declared or inferred Safe.  When
declared-Safe module imports inferred-Safe, we warn.  This inferred
status is volatile, often enough it's a happy coincidence, something
which cannot be relied upon. However, explicitly Safe or Trustworthy
packages won't accidentally become Unsafe.

Updates haddock submodule.

- - - - -
8ec5ceb0 by Oleg Grenrus at 2019-06-25T23:25:08-04:00
Add -Wmissing-safe-haskell-mode warning

- - - - -
c99d9aab by Ben Gamari at 2019-06-26T08:15:02-04:00
testsuite: Fix T16832

The test seems to have been missing the name of its script and didn't
build with HEAD. How it made it through CI is beyond me.

- - - - -
e0899925 by Siddharth Bhat at 2019-06-26T08:16:30-04:00
[skip ci] add a blurb about the purpose of Printer.c

- - - - -
58e84b30 by Ben Gamari at 2019-06-26T08:18:25-04:00
testsuite: Use safe FFI call in T5611

The original issue, #5611, was concerned with safe calls. However, the
test inexplicably used an unsafe call. Fix this.

- - - - -
12752342 by Ben Gamari at 2019-06-26T08:18:25-04:00
testsuite: Add T5611a

This is the same as T5611 but with an unsafe call to sleep.

- - - - -
551b79e4 by Ben Gamari at 2019-06-26T08:18:25-04:00
testsuite: Mark T5611 and T5611a as fragile

- - - - -
44d08c32 by Ben Gamari at 2019-06-26T08:20:54-04:00
testsuite: Run and report on fragile tests

This allows us to run (but ignore the result of) fragile testcases.
Hopefully this should allow us to more easily spot when a fragile test
becomes un-fragile.

- - - - -
1c4f18d0 by Ben Gamari at 2019-06-26T08:20:54-04:00
testsuite: More type signatures

- - - - -
a586b33f by Matthew Pickering at 2019-06-27T10:42:29-04:00
rts: Correct handling of LARGE ARR_WORDS in LDV profiler

This implements the correct fix for #11627 by skipping over the slop
(which is zeroed) rather than adding special case logic for LARGE
ARR_WORDS which runs the risk of not performing a correct census by
ignoring any subsequent blocks.

This approach implements similar logic to that in Sanity.c

- - - - -
ed4cbd93 by Matthew Pickering at 2019-06-27T10:42:29-04:00
rts: Correct assertion in LDV_recordDead

It is possible that void_total is exactly equal to not_used and the
other assertions for this check for <= rather than <.

- - - - -
07cffc49 by Matthew Pickering at 2019-06-27T10:42:29-04:00
rts: Do not traverse nursery for dead closures in LDV profile

It is important that `heapCensus` and `LdvCensusForDead` traverse the
same areas.

`heapCensus` increases the `not_used` counter which tracks how many
closures are live but haven't been used yet.

`LdvCensusForDead` increases the `void_total` counter which tracks how
many dead closures there are.

The `LAG` is then calculated by substracting the `void_total` from
`not_used` and so it is essential that `not_used >= void_total`. This
fact is checked by quite a few assertions.

However, if a program has low maximum residency but allocates a lot in
the nursery then these assertions were failing (see #16753 and #15903)
because `LdvCensusForDead` was observing dead closures from the nursery
which totalled more than the `not_used`. The same closures were not
counted by `heapCensus`.

Therefore, it seems that the correct fix is to make `LdvCensusForDead`
agree with `heapCensus` and not traverse the nursery for dead closures.

Fixes #16100 #16753 #15903 #8982

- - - - -
c1f67887 by Roland Senn at 2019-06-27T10:43:10-04:00
Improve doc for :type-at. (#14780)

- - - - -
52f10216 by Roland Zumkeller at 2019-06-27T10:43:47-04:00
configure: prefer cc over gcc

Fixes #16857.

- - - - -
90e0ab7d by Sylvain Henry at 2019-06-27T10:44:25-04:00
Fix Happy deps for Stack (#16825)

- - - - -
d35cec7a by Fraser Tweedale at 2019-06-27T10:45:01-04:00
getExecutablePath: get path from sysctl on FreeBSD

- - - - -
2a68b8b7 by nineonine at 2019-06-27T10:45:39-04:00
Fix #16805 by formatting warning message

- - - - -
217258d0 by Ben Gamari at 2019-06-27T10:46:18-04:00
testsuite: Add more type annotations to perf_notes

- - - - -
4ec233ec by Sylvain Henry at 2019-06-27T23:58:37-04:00
Fix GCC warnings with __clear_cache builtin (#16867)

- - - - -
ef6d9a50 by Artem Pelenitsyn at 2019-06-27T23:59:15-04:00
typo in the docs for DynFlags.hs
- - - - -
11bac115 by Travis Whitaker at 2019-06-28T15:25:05-04:00
Correct closure observation, construction, and mutation on weak memory machines.

Here the following changes are introduced:
    - A read barrier machine op is added to Cmm.
    - The order in which a closure's fields are read and written is changed.
    - Memory barriers are added to RTS code to ensure correctness on
      out-or-order machines with weak memory ordering.

Cmm has a new CallishMachOp called MO_ReadBarrier. On weak memory machines, this
is lowered to an instruction that ensures memory reads that occur after said
instruction in program order are not performed before reads coming before said
instruction in program order. On machines with strong memory ordering properties
(e.g. X86, SPARC in TSO mode) no such instruction is necessary, so
MO_ReadBarrier is simply erased. However, such an instruction is necessary on
weakly ordered machines, e.g. ARM and PowerPC.

Weam memory ordering has consequences for how closures are observed and mutated.
For example, consider a closure that needs to be updated to an indirection. In
order for the indirection to be safe for concurrent observers to enter, said
observers must read the indirection's info table before they read the
indirectee. Furthermore, the entering observer makes assumptions about the
closure based on its info table contents, e.g. an INFO_TYPE of IND imples the
closure has an indirectee pointer that is safe to follow.

When a closure is updated with an indirection, both its info table and its
indirectee must be written. With weak memory ordering, these two writes can be
arbitrarily reordered, and perhaps even interleaved with other threads' reads
and writes (in the absence of memory barrier instructions). Consider this
example of a bad reordering:

- An updater writes to a closure's info table (INFO_TYPE is now IND).
- A concurrent observer branches upon reading the closure's INFO_TYPE as IND.
- A concurrent observer reads the closure's indirectee and enters it. (!!!)
- An updater writes the closure's indirectee.

Here the update to the indirectee comes too late and the concurrent observer has
jumped off into the abyss. Speculative execution can also cause us issues,
consider:

- An observer is about to case on a value in closure's info table.
- The observer speculatively reads one or more of closure's fields.
- An updater writes to closure's info table.
- The observer takes a branch based on the new info table value, but with the
  old closure fields!
- The updater writes to the closure's other fields, but its too late.

Because of these effects, reads and writes to a closure's info table must be
ordered carefully with respect to reads and writes to the closure's other
fields, and memory barriers must be placed to ensure that reads and writes occur
in program order. Specifically, updates to a closure must follow the following
pattern:

- Update the closure's (non-info table) fields.
- Write barrier.
- Update the closure's info table.

Observing a closure's fields must follow the following pattern:

- Read the closure's info pointer.
- Read barrier.
- Read the closure's (non-info table) fields.

This patch updates RTS code to obey this pattern. This should fix long-standing
SMP bugs on ARM (specifically newer aarch64 microarchitectures supporting
out-of-order execution) and PowerPC. This fixes issue #15449.

Co-Authored-By: Ben Gamari <ben at well-typed.com>

- - - - -
bd660ede by Ben Gamari at 2019-06-28T15:25:30-04:00
rts: Assert that LDV profiling isn't used with parallel GC

I'm not entirely sure we are careful about ensuring this; this is a
last-ditch check.

- - - - -
82693938 by Moritz Angermann at 2019-07-02T16:18:05-04:00
Add _GLOBAL_OFFSET_TABLE_ support

This adds lookup logic for _GLOBAL_OFFSET_TABLE_ as well as
relocation logic for R_ARM_BASE_PREL and R_ARM_GOT_BREL which
the gnu toolchain (gas, gcc, ...) prefers to produce.  Apparently
recent llvm toolchains will produce those as well.

- - - - -
348e3f8e by Edward Amsden at 2019-07-02T16:18:05-04:00
Lookup _GLOBAL_OFFSET_TABLE by symbol->addr when doing relocations

- - - - -
e9abcad4 by Moritz Angermann at 2019-07-02T16:18:05-04:00
No atomics on arm32; this will just yield stubs.

As such the internal linker will fail for them.  The alternative
would be to implement them as stubs in the linker and have them
barf when called.

> Not all operations are supported by all target processors. If a
  particular operation cannot be implemented on the target processor,
  a warning is generated and a call an external function is
  generated. The external function carries the same name as the
  built-in version, with an additional suffix ‘_n’ where n is the size
  of the data type.

(https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html)

- - - - -
023a2bc7 by Ben Gamari at 2019-07-02T16:18:05-04:00
Apply suggestion to rts/linker/elf_got.c
- - - - -
0bed9647 by Ben Gamari at 2019-07-02T16:18:05-04:00
Apply suggestion to rts/linker/Elf.c
- - - - -
cef80c0b by nineonine at 2019-07-02T16:18:44-04:00
Fix #15843 by extending Template Haskell AST for tuples to support sections

- - - - -
294b55dc by Eric Wolf at 2019-07-02T16:19:21-04:00
Add test for #16575

just use the test to show the defective behaviour, so we can see
the difference, when it gets fixed

- - - - -
60b9eab9 by Ömer Sinan Ağacan at 2019-07-02T16:19:59-04:00
Fix stage 1 warnings

- - - - -
df3e5b74 by David Eichmann at 2019-07-02T16:20:36-04:00
Hadrian: disable cloud build cache for symlinks #16800

This is a temporary workaround shake not supporting symlinks
when using cloud/cached builds.

- - - - -
acd79558 by Abhiroop Sarkar at 2019-07-03T09:33:39-04:00
Add support for SIMD operations in the NCG

This adds support for constructing vector types from Float#, Double# etc
and performing arithmetic operations on them

Cleaned-Up-By: Ben Gamari <ben at well-typed.com>

- - - - -
973c61b5 by Ben Gamari at 2019-07-03T09:34:16-04:00
gitlab-ci: Fix doc-tarball job

Previously we used the deb9-debug job which used the `validate` build
flavour which disabled `BUILD_SPHINX_PDF`. Fix this.

Fixes #16890.

- - - - -
a25f6f55 by Ryan Scott at 2019-07-03T09:34:54-04:00
Bump template-haskell version to 2.16.0.0

Commit cef80c0b9edca3d21b5c762f51dfbab4c5857d8a debuted a breaking
change to `template-haskell`, so in order to guard against it
properly with CPP, we need to bump the `template-haskell` version
number accordingly.

- - - - -
f7a2e709 by Ben Gamari at 2019-07-04T15:29:49-04:00
Bump parsec submodule to 3.1.14.0

- - - - -
d7f7e1ed by Siddharth Bhat at 2019-07-04T21:22:00-04:00
Make printer untag when chasing a pointer in a RET_FUN frame

This is to mimic what `Scav.c` does. This should fix a crash in
the printer.

- - - - -
675d27fc by Ben Gamari at 2019-07-04T21:22:35-04:00
gitlab: Reduce size of template headings

- - - - -
679427f8 by Vladislav Zavialov at 2019-07-04T21:23:10-04:00
Produce all DerivInfo in tcTyAndClassDecls

Before this refactoring:

* DerivInfo for data family instances was returned from tcTyAndClassDecls
* DerivInfo for data declarations was generated with mkDerivInfos and added at a
  later stage of the pipeline in tcInstDeclsDeriv

After this refactoring:

* DerivInfo for both data family instances and data declarations is returned from
  tcTyAndClassDecls in a single list.

This uniform treatment results in a more convenient arrangement to fix #16731.

- - - - -
53aa59f3 by Simon Peyton Jones at 2019-07-04T21:23:49-04:00
Add a missing zonk (fixes #16902)

In the eager unifier, when unifying (tv1 ~ tv2),
when we decide to swap them over, to unify (tv2 ~ tv1),
I'd forgotten to ensure that tv1's kind was fully zonked,
which is an invariant of uUnfilledTyVar2.

That could lead us to build an infinite kind, or (in the
case of #16902) update the same unification variable twice.

Yikes.

Now we get an error message rather than non-termination,
which is much better.  The error message is not great,
but it's a very strange program, and I can't see an easy way
to improve it, so for now I'm just committing this fix.

Here's the decl
 data F (a :: k) :: (a ~~ k) => Type where
    MkF :: F a

and the rather error message of which I am not proud

  T16902.hs:11:10: error:
    • Expected a type, but found something with kind ‘a1’
    • In the type ‘F a’

- - - - -
ed662901 by Daniel Gröber at 2019-07-04T21:24:26-04:00
rts: Fix -hT option with profiling rts

In dumpCensus we switch/case on doHeapProfile twice. The second switch
tries to barf on unknown doHeapProfile modes but HEAP_BY_CLOSURE_TYPE is
checked by the first switch and not included in the second.

So when trying to pass -hT to the profiling rts it barfs.

This commit simply merges the two switches into one which fixes this
problem.

- - - - -
80afdf6b by Simon Peyton Jones at 2019-07-04T21:25:05-04:00
Fix over-eager implication constraint discard

Ticket #16247 showed that we were discarding an implication
constraint that had empty ic_wanted, when we still needed to
keep it so we could check whether it had a bad telescope.

Happily it's a one line fix.  All the rest is comments!

- - - - -
f002250a by Andreas Klebinger at 2019-07-04T21:25:43-04:00
Dont gather ticks when only striping them in STG.

Adds stripStgTicksTopE which only returns the stripped expression.
So far we also allocated a list for the stripped ticks which was
never used.

Allocation difference is as expected very small but present.
About 0.02% difference when compiling with -O.

- - - - -
a76b233d by Artem Pelenitsyn at 2019-07-05T07:06:55-04:00
Make all submodules have absolute URLs

The relative URLs were a workaround to let most contributors fork from
Github due to a weakness in the haskell.org server.

This workaround is no longer needed. And relative submodule URLs are
an impediment to forking which makes contributions harder than they
should be.

The URLs are chosen to clone from https, because this makes sure that
anybody, even not a registered Gitlab user, can clone a fork
recursively.

- - - - -
62b82135 by Ryan Scott at 2019-07-05T07:07:38-04:00
More sensible SrcSpans for recursive pattern synonym errors (#16900)

Attach the `SrcSpan` of the first pattern synonym binding involved in
the recursive group when throwing the corresponding error message,
similarly to how it is done for type synonyms.

Fixes #16900.

- - - - -
2fd1ed54 by nineonine at 2019-07-05T07:08:17-04:00
Fix #16895 by checking whether infix expression operator is a variable

- - - - -
03f5adcd by David Eichmann at 2019-07-08T07:07:10-04:00
Bump Shake and copy instead of hard link from cloud cache

This is important as in hard link mode shake  makes all such files
read only to avoid accidentally modifying cache files via the
hard link. It turns out, many Hadrian rules attempt read access
to such files and hence fail in the hard link mode. These
rules could be refactored to avoid write access, but using
copy instead of hard link a much simpler solution.

- - - - -
5af815f2 by Kevin Buhr at 2019-07-08T07:07:11-04:00
Add test for old issue w/ bad source locations for warnings in .lhs files (#515)

- - - - -
6a03d77b by Ryan Scott at 2019-07-09T11:52:45-04:00
Use an empty data type in TTG extension constructors (#15247)

To avoid having to `panic` any time a TTG extension constructor is
consumed, this MR introduces an uninhabited 'NoExtCon' type and uses
that in every extension constructor's type family instance where it
is appropriate. This also introduces a 'noExtCon' function which
eliminates a 'NoExtCon', much like 'Data.Void.absurd' eliminates
a 'Void'.

I also renamed the existing `NoExt` type to `NoExtField` to better
distinguish it from `NoExtCon`. Unsurprisingly, there is a lot of
code churn resulting from this.

Bumps the Haddock submodule. Fixes #15247.

- - - - -
b05c8423 by Phuong Trinh at 2019-07-09T22:55:41-04:00
Fix #16511: changes in interface dependencies should trigger recompilation

If the union of dependencies of imported modules change, the `mi_deps`
field of the interface files should change as well. Because of that, we
need to check for changes in this in recompilation checker which we are
not doing right now. This adds a checks for that.

- - - - -
fb43bddc by John Ericson at 2019-07-09T22:56:18-04:00
Fix two more `#ifndef` for the linter

- - - - -
0472f0f6 by John Ericson at 2019-07-09T22:56:18-04:00
Remove most uses of TARGET platform macros

These prevent multi-target builds. They were gotten rid of in 3 ways:

1. In the compiler itself, replacing `#if` with runtime `if`. In these
cases, we care about the target platform still, but the target platform
is dynamic so we must delay the elimination to run time.

2. In the compiler itself, replacing `TARGET` with `HOST`. There was
just one bit of this, in some code splitting strings representing lists
of paths. These paths are used by GHC itself, and not by the compiled
binary. (They are compiler lookup paths, rather than RPATHS or something
that does matter to the compiled binary, and thus would legitamentally
be target-sensative.) As such, the path-splitting method only depends on
where GHC runs and not where code it produces runs. This should have
been `HOST` all along.

3. Changing the RTS. The RTS doesn't care about the target platform,
full stop.

4. `includes/stg/HaskellMachRegs.h` This file is also included in the
genapply executable. This is tricky because the RTS's host platform
really is that utility's target platform. so that utility really really
isn't multi-target either. But at least it isn't an installed part of
GHC, but just a one-off tool when building the RTS. Lying with the
`HOST` to a one-off program (genapply) that isn't installed doesn't seem so bad.
It's certainly better than the other way around of lying to the RTS
though not to genapply. The RTS is more important, and it is installed,
*and* this header is installed as part of the RTS.

- - - - -
24782b89 by John Ericson at 2019-07-09T22:56:18-04:00
Deduplicate "unique subdir" code between GHC and Cabal

The code, including the generated module with the version, is now in
ghc-boot. Config.hs reexports stuff as needed, ghc-pkg doesn't need any
tricks at all.

- - - - -
42ff8653 by Ben Gamari at 2019-07-09T22:56:53-04:00
testsuite: Fix #16818

Renames performance metrics to include whether they are compile-time or
runtime metrics.

- - - - -
18ac9ad4 by Alp Mestanogullari at 2019-07-09T22:57:31-04:00
Hadrian: implement key-value settings for builder options

They take the general form `foo.bar.baz [+]= some values`, where
`=` completely overrides the arguments for a builder and `+=` extends
them. We currenly only support settings for updating the GHC and C
compiler options, of the form:

```
  {stage0, ..., stage3 or *}.{package name or *}
                            .ghc.{c, hs, link, deps, toolargs or *}.opts

  {stage0, ..., stage3 or *}.{package name or *}
                            .cc.{c, deps or *}.opts
```

The supported settings and their use is covered in the new section
of `hadrian/doc/user-settings.md`, while the implementation is explained
in a new Note [Hadrian settings].

Most of the logic is implemented in a new module, `Settings.Parser`, which
contains key-value assignment/extension parsers as well as utilities for
specifying allowed settings at a high-level, generating a `Predicate` from
such a description or generating the list of possible completions for a given
string.

The additions to the `Settings` module make use of this to describe the
settings that Hadrian currently supports, and apply all such
key-value settings (from the command line and `<root>/hadrian.settings`)
to the flavour that Hadrian is going to proceed with.

This new setting system comes with support for generating Bash completions,
implemented in `hadrian/completion.sh` and Hadrian's `autocomplete` target:

> source hadrian/completion.sh
> hadrian/build.sh stage1.base.ghc.<TAB>
stage1.base.ghc.c.opts     stage1.base.ghc.hs.opts
stage1.base.ghc.*.opts     stage1.base.ghc.deps.opts
stage1.base.ghc.link.opts  stage1.base.ghc.toolargs.opts

- - - - -
7f8bf98e by Alp Mestanogullari at 2019-07-09T22:58:09-04:00
Hadrian: fix source-dist rule

The first problem was that the list of files/dirs to embed or ignore was not
up-to-date. The second problem was that the 'Cwd' option used when running the
Tar builder in the source-dist rule didn't actually change the current directory
and was therefore failing. Finally, the source-dist rule did not pre-generate
Haskell modules derived from .x (alex) and .y (happy) files, like the Make
build system does -- this is now fixed.

We might be doing too much work for that last step (we seem to be building
many things until we get to generating the source distribution), but extracting
the distribution and running

    ./configure && hadrian/build.sh --flavour=quickest -j

from there does work for me now.

- - - - -
d7423f10 by Ömer Sinan Ağacan at 2019-07-09T22:58:48-04:00
Testsuite tweaks and refactoring

- Rename requires_th to req_th for consistency with other req functions
  (e.g. req_interp, req_profiling etc.)

- req_th (previously requires_th) now checks for interpreter (via
  req_interp). With this running TH tests are skipped when running the
  test suite with stage=1.

- Test tweaks:
    - T9360a, T9360b: Use req_interp
    - recomp009, T13938, RAE_T32a: Use req_th

- Fix check-makefiles linter: it now looks for Makefiles instead of .T
  files (which are actually Python files)

- - - - -
897a59a5 by Ömer Sinan Ağacan at 2019-07-09T22:59:26-04:00
Minor refactoring in CoreSimpl

When `join_ids` is empty `extendVarSetList existing_joins join_ids` is
already no-op, so no need to check whether `join_ids` is empty or not
before extending the joins set.

- - - - -
85da17e5 by Eric Wolf at 2019-07-09T23:00:03-04:00
Add testcase T16804 for #16804

slightly larger testcase for :type-at and :uses
so we can see changes, if #16804 is done.

- - - - -
8fcc931c by Eric Wolf at 2019-07-09T23:00:03-04:00
T16804: adjust src spans

- - - - -
a35e0916 by Ben Gamari at 2019-07-09T23:00:42-04:00
hadrian/doc: Add some discussion of compilation stages

This documents some of the lore surrounding the nature and naming of
GHC's stage numbers.

- - - - -
d2e290d3 by Simon Peyton Jones at 2019-07-09T23:01:24-04:00
Fix erroneous float in CoreOpt

The simple optimiser was making an invalid transformation
to join points -- yikes.  The fix is easy.

I also added some documentation about the fact that GHC uses
a slightly more restrictive version of join points than does
the paper.

Fix #16918

- - - - -
cb5271ac by Kevin Buhr at 2019-07-11T17:46:19-04:00
Add regression test for old panic on inlining undeclared identifier (#495)

- - - - -
01ec8549 by Andreas Klebinger at 2019-07-11T17:46:57-04:00
Special case a few common patterns in unionLists.

In particular we very often pass one empty list and in these
cases we want to avoid the overhead of computing `xs ++ []`.

This should fix #14759 and #16911.

- - - - -
b507aceb by Ryan Scott at 2019-07-11T17:47:41-04:00
Don't typecheck too much (or too little) in DerivingVia (#16923)

Previously, GHC would typecheck the `via` type once per class in a
`deriving` clause, which caused the problems observed in #16923.
This patch restructures some of the functionality in `TcDeriv` and
`TcHsType` to avoid this problem. We now typecheck the `via` type
exactly once per `deriving` clause and *then* typecheck all of the
classes in the clause.
See `Note [Don't typecheck too much in DerivingVia]` in `TcDeriv`
for the full details.

- - - - -
8449c5b6 by nineonine at 2019-07-11T17:48:18-04:00
Allow reusing temporary object files generated by GHCi by writing to -odir in case -fwrite-interface was specified (#16670)

- - - - -
d5c899d1 by Ben Gamari at 2019-07-11T17:48:54-04:00
head.hackage: Run build on head.hackage's master branch

The GitLab CI infrastructure is now in the master branch.

- - - - -
8a209384 by Ben Gamari at 2019-07-11T17:48:54-04:00
head.hackage: Run builds with -dcore-lint

- - - - -
e4c73514 by Simon Peyton Jones at 2019-07-12T02:20:01-04:00
Fix kind-checking for data/newtypes

In one spot in kcConDecl we were passing in the return
kind signature rether than the return kind. e.g. #16828

   newtype instance Foo :: Type -> Type where
     MkFoo :: a -> Foo a

We were giving kcConDecl the kind (Type -> Type), whereas it
was expecting the ultimate return kind, namely Type.

This "looking past arrows" was being done, independently,
in several places, but we'd missed one.  This patch moves it all
to one place -- the new function kcConDecls (note the plural).

I also took the opportunity to rename
  tcDataFamHeader  to   tcDataFamInstHeader

(The previous name was consistently a source of confusion.)

- - - - -
de3935a6 by Shayne Fletcher at 2019-07-12T02:20:43-04:00
Add shake 0.18.3 to extra deps

- - - - -
a31b24a5 by Ashley Yakeley at 2019-07-13T16:35:41-04:00
base: Data.Fixed: make HasResolution poly-kinded (#10055, #15622)

- - - - -
688a1b89 by Alp Mestanogullari at 2019-07-13T16:36:18-04:00
compiler: trace SysTools commands to emit start/stop eventlog markers

This patch was motivated by some performance characterization work done
for #16822, where we suspected that GHC was spending a lot of time waiting
on the linker to be done. (That turned out to be true.)

The tracing is taken care of by ErrUtils.withTiming, so this patch just defines
and uses a little wrapper around that function in all the helpers for
calling the various systools (C compiler, linker, unlit, ...).

With this patch, assuming a GHC executable linked against an eventlog-capable
RTS (RTS ways that contain the debug, profiling or eventlog way units), we can
measure how much time is spent in each of the SysTools when building hello.hs
by simply doing:

  ghc hello.hs -ddump-timings +RTS -l

The event names are "systool:{cc, linker, as, unlit, ...}".

- - - - -
348cc8eb by Andreas Klebinger at 2019-07-13T16:36:57-04:00
Add two CmmSwitch optimizations.

Move switch expressions into a local variable when generating switches.
This avoids duplicating the expression if we translate the switch
to a tree search. This fixes #16933.

Further we now check if all branches of a switch have the same
destination, replacing the switch with a direct branch if that
is the case.

Both of these patterns appear in the ENTER macro used by the RTS
but are unlikely to occur in intermediate Cmm generated by GHC.

Nofib result summary:

--------------------------------------------------------------------------------
        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
            Min          -0.0%     -0.0%    -15.7%    -15.6%      0.0%
            Max          -0.0%      0.0%     +5.4%     +5.5%      0.0%
 Geometric Mean          -0.0%     -0.0%     -1.0%     -1.0%     -0.0%

Compiler allocations go up slightly: +0.2%

Example output before and after the change taken from RTS code below.

All but one of the memory loads `I32[_c3::I64 - 8]` are eliminated.
Instead the data is loaded once from memory in block c6.

Also the switch in block `ud` in the original code has been
eliminated completely.

Cmm without this commit:

```
stg_ap_0_fast() { //  [R1]
        { []
        }
    {offset
      ca: _c1::P64 = R1;   // CmmAssign
          goto c2;   // CmmBranch
      c2: if (_c1::P64 & 7 != 0) goto c4; else goto c6;
      c6: _c3::I64 = I64[_c1::P64];
          if (I32[_c3::I64 - 8] < 26 :: W32) goto ub; else goto ug;
      ub: if (I32[_c3::I64 - 8] < 15 :: W32) goto uc; else goto ue;
      uc: if (I32[_c3::I64 - 8] < 8 :: W32) goto c7; else goto ud;
      ud: switch [8 .. 14] (%MO_SS_Conv_W32_W64(I32[_c3::I64 - 8])) {
              case 8, 9, 10, 11, 12, 13, 14 : goto c4;
          }
      ue: if (I32[_c3::I64 - 8] >= 25 :: W32) goto c4; else goto uf;
      uf: if (%MO_SS_Conv_W32_W64(I32[_c3::I64 - 8]) != 23) goto c7; else goto c4;
      c4: R1 = _c1::P64;
          call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
      ug: if (I32[_c3::I64 - 8] < 28 :: W32) goto uh; else goto ui;
      uh: if (I32[_c3::I64 - 8] < 27 :: W32) goto c7; else goto c8;
      ui: if (I32[_c3::I64 - 8] < 29 :: W32) goto c8; else goto c7;
      c8: _c1::P64 = P64[_c1::P64 + 8];
          goto c2;
      c7: R1 = _c1::P64;
          call (_c3::I64)(R1) args: 8, res: 0, upd: 8;
    }
}
```

Cmm with this commit:

```
stg_ap_0_fast() { //  [R1]
        { []
        }
    {offset
      ca: _c1::P64 = R1;
          goto c2;
      c2: if (_c1::P64 & 7 != 0) goto c4; else goto c6;
      c6: _c3::I64 = I64[_c1::P64];
          _ub::I64 = %MO_SS_Conv_W32_W64(I32[_c3::I64 - 8]);
          if (_ub::I64 < 26) goto uc; else goto uh;
      uc: if (_ub::I64 < 15) goto ud; else goto uf;
      ud: if (_ub::I64 < 8) goto c7; else goto c4;
      uf: if (_ub::I64 >= 25) goto c4; else goto ug;
      ug: if (_ub::I64 != 23) goto c7; else goto c4;
      c4: R1 = _c1::P64;
          call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
      uh: if (_ub::I64 < 28) goto ui; else goto uj;
      ui: if (_ub::I64 < 27) goto c7; else goto c8;
      uj: if (_ub::I64 < 29) goto c8; else goto c7;
      c8: _c1::P64 = P64[_c1::P64 + 8];
          goto c2;
      c7: R1 = _c1::P64;
          call (_c3::I64)(R1) args: 8, res: 0, upd: 8;
    }
}
```

- - - - -
232002c4 by James Foster at 2019-07-13T16:37:34-04:00
Make HsInstances and DynFlags compile with -O0 for Stage0 to speed up Hadrian builds (fixes #16936)

- - - - -
a7176fa1 by Ömer Sinan Ağacan at 2019-07-13T16:38:13-04:00
Minor refactoring in CmmBuildInfoTables

- Replace `catMaybes (map ...)` with `mapMaybe ...`
- Remove a list->set->list conversion

- - - - -
ff04eb59 by John Ericson at 2019-07-14T01:19:22-04:00
Remove purely external primops

The compiler doesn't create uses nor compiles the uses that exist
specially. These are just plain C-- FFI.

These `await*` ones are especially important to so convert because "true"
primops are hard to make platform-specific currently.

The other exports are part of this commit so this module always exports
something, which avoids silly CPP elsewhere. More will be added later
once `foreign import prim` is extended.

- - - - -
f9b00038 by Matthew Pickering at 2019-07-14T01:19:58-04:00
hadrian: Build debug rts with -O0 -g3 and disable rts stripping

Fixes #16920

- - - - -
f508b7ce by Ben Gamari at 2019-07-14T01:20:34-04:00
Don't package settings in bindist

Since !712 the `settings` file is produced by the build system instead
of autoconf. However, this introduced a subtle bug where we would fail
to rebuild the `settings` file with what we have learned from the
install-time `configure` invocation. Fix this by not packaging
`settings` in the bindist tarball. The build system will take care of
the rest.

Also fix a bug where the value of `UseLibdw` was not being persisted to
the install time `configure`.

- - - - -
e7ed53c9 by John Ericson at 2019-07-14T01:21:11-04:00
Remove LLVM_TARGET platform macros

Instead following @angerman's suggestion put them in the config file.
Maybe we could re-key llvm-targets someday, but this is good for now.

- - - - -
bd9fc1b2 by John Ericson at 2019-07-14T01:21:48-04:00
Make CPP linter skip certain files

 - docs which document the lint and need to contain the unutterable

 - vendored code which is outside our purview

- - - - -
d7c6c471 by John Ericson at 2019-07-14T01:21:48-04:00
Expunge #ifdef and #ifndef from the codebase

These are unexploded minds as far as the linter is concerned. I don't
want to hit in my MRs by mistake!

I did this with `sed`, and then rolled back some changes in the docs,
config.guess, and the linter itself.

- - - - -
fce8f240 by xplorld at 2019-07-14T08:32:48-04:00
rename type parameter in `instance Applicative ((->) a)`, fixing #16928

- - - - -
78ed46f3 by Niklas Hambüchen at 2019-07-14T08:33:26-04:00
primops: haddock: Fix typo in referenced function.

Found by @lehins.
- - - - -
a39a3cd6 by Ben Gamari at 2019-07-15T00:14:40-04:00
gitlab-ci: Disable submodule linter for now

- - - - -
0670f98a by Arnaud Spiwack at 2019-07-15T09:23:15+02:00
Add a note in the simplifier about in-scope set as a substitution

See also the discussion at #16592

- - - - -
284a2f44 by Vladislav Zavialov at 2019-07-15T18:29:05-04:00
Decouple AddAnn from P

- - - - -
1befd2c0 by Vladislav Zavialov at 2019-07-15T18:29:05-04:00
PV is not P (#16611)

- - - - -
5728d9fa by Artem Pelenitsyn at 2019-07-16T02:40:08-04:00
Sort out Hadrian colored output flags (fix #16397)

Hadrian used to have a separate flag --progress-colour to control
colored output during the build. After introduction of a Shake flag
with similar purpose Hadrian's flag became redundant. The commit removes
--progress-colour and switches to Shake's flag. The only difference
between the two is that Hadrian has special default mode when it tries
to determine if the terminal support colored output. The user can
override it using (Shake's) `--[no-]color`.

- - - - -
db948dae by Ben Gamari at 2019-07-16T02:40:43-04:00
Revert "Add support for SIMD operations in the NCG"

Unfortunately this will require more work; register allocation is
quite broken.

This reverts commit acd795583625401c5554f8e04ec7efca18814011.

- - - - -
373c9cb3 by Daniel Gröber at 2019-07-16T02:41:23-04:00
rts: Divorce init of Heap profiler from CCS profiler

Currently initProfiling gets defined by Profiling.c only if PROFILING is
defined. Otherwise the ProfHeap.c defines it.

This is just needlessly complicated so in this commit I make Profiling and
ProfHeap into properly seperate modules and call their respective init
functions from RtsStartup.c.

- - - - -
52f755aa by Daniel Gröber at 2019-07-16T02:41:23-04:00
rts: Rename the nondescript initProfiling2 to refreshProfilingCCSs

- - - - -
0a9b77b8 by John Ericson at 2019-07-17T12:20:26-04:00
Create {Int,Word}32Rep

This prepares the way for making Int32# and Word32# the actual size they
claim to be.

Updates binary submodule for (de)serializing the new runtime reps.

- - - - -
8add024f by Sebastian Graf at 2019-07-17T12:20:27-04:00
Make GHC-in-GHCi work on Windows

By not building anything in the dynamic way on Windows, where we don't
have a working story for DLLs yet.

Also the ghcid command needs to call bash on the hadrian/ghci.sh script
explicitly as the path gets interpreted differently otherwise.

- - - - -
d48da6ff by Ben Gamari at 2019-07-18T20:55:11-04:00
gitlab-ci: Run slow validate in -debug job

Otherwise we don't compile the stage2 compiler with DEBUG, meaning the
testsuite isn't checked with assertions.

Metric Increase:
    haddock.Cabal

- - - - -
272246bf by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: More type checking fixes

- - - - -
c7bcd017 by Ben Gamari at 2019-07-18T20:55:11-04:00
Add HasDebugCallStack to unionLists

This should help identify a few cases where this is throwing warnings

- - - - -
3cec2af6 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Mark static-plugins as broken in profiled ways

See #16803.

- - - - -
e8adffb5 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Set -dinitial-unique when reversing uniques

Otherwise the unique counter starts at 0, causing us to immediately
underflow.

- - - - -
b9e9d8c9 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Fix req_th

- - - - -
d238d306 by Ben Gamari at 2019-07-18T20:55:11-04:00
Fix formatting of --info's "Debug on" field

As noted in #16914, the value `True` was used instead of `YES` here, in
contrast to the other boolean fields emitted by `--info`. This confused
the testsuite driver and broke the `ghc_debugged` testsuite predicate.

- - - - -
eb8c40e3 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Mark hWaitForInput-accurate-stdin as broken in all threaded ways

Previously it was not marked as broken in profthreaded

- - - - -
b16cabc1 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Print output from hp2ps

- - - - -
b62a2dfb by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Fix some ints used as bools

- - - - -
b3df1efb by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Skip forking tests in profiled ways

As noted in #11645 and #8862, forking and profiling don't go well
together.

Bumps hpc and unix submodules.

- - - - -
49dcbf86 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Mark test-hole-plugin as req_th

This requires code loading and therefore can't be run in the profiled
ways when GHC is dynamically linked.

- - - - -
ce8ffd80 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Unmark recomp007 as broken

Fixed in #14759.

- - - - -
82abc479 by Ben Gamari at 2019-07-18T20:55:11-04:00
testsuite: Mark T4808 as broken in threaded2 way

As noted in #16909.

- - - - -
73703d9b by Artem Pelenitsyn at 2019-07-19T18:06:22-04:00
Hide "Loading package environment" message with -v0 (fix #16879)

- - - - -
9372ff92 by Vladislav Zavialov at 2019-07-19T18:06:57-04:00
Drop the orphan roles check (#16941)

9366e019 introduced a check for orphan roles to fix #8485

6ab5da99 changed the lookup code and made the check redundant.

Now it is removed.

- - - - -
69adb253 by Richard Eisenberg at 2019-07-19T18:07:37-04:00
Fix #16870 by improving documentation (only)

- - - - -
f1980a1e by Sebastian Graf at 2019-07-19T18:08:15-04:00
Make generated ghc-stage<n> scripts executable

- - - - -
bec17997 by James Foster at 2019-07-19T18:08:51-04:00
users-guide: corrected -fmax-relevant-binds reverse to be -fno-max-relevant-binds
- - - - -
257d1fd8 by Ryan Scott at 2019-07-19T18:09:28-04:00
Don't maintainer-clean libraries/ghc-boot/ghc.mk (#16953)

This makes the `maintainer-clean` rule in `ghc.mk` slightly more
sophisticated so that it does not remove the version-controlled
file `libraries/ghc-boot/ghc.mk`, which was checked into version
control in commit 24782b89907ab36fb5aef3a17584f4c10f1e2690.

Fixes #16953.

- - - - -
ff996555 by Richard Eisenberg at 2019-07-19T18:10:06-04:00
Add module doc for Plugins.

This was requested in #15650.

- - - - -
08ad7ef4 by Baldur Blöndal at 2019-07-20T07:51:22-04:00
Added do-notation examples for Functor, Applicative and Monad combinators.

- - - - -
7b42ece5 by Alfredo Di Napoli at 2019-07-20T07:52:01-04:00
Line wrap when pp long expressions (fixes #16874)

This commit fixes #16874 by using `fsep` rather than `sep` when pretty
printing long patterns and expressions.

- - - - -
3676375f by Andreas Klebinger at 2019-07-20T07:52:39-04:00
Bump nofib submodule.

- - - - -
4dfd6a5f by Matthew Pickering at 2019-07-20T07:53:15-04:00
hadrian: Remove RTS -Waggregate-return warning

This was removed from make in 077b92fa39839a8e83cd87398435424403cf6486
- - - - -
5042ba9d by Andreas Klebinger at 2019-07-21T05:03:04-04:00
Expose the GhcPrelude module.

This makes it simpler to load Modules importing it
when using ghc-the-package.

-------------------------
Metric Decrease:
    haddock.compiler
-------------------------

- - - - -
67ee741b by Ivan Kasatenko at 2019-07-21T05:03:40-04:00
Do not ignore events deletion when events to be added are provided (#16916)

Kqueue/kevent implementation used to ignore events to be unsubscribed
from when events to be subscribed to were provided. This resulted in a
lost notification subscription, when GHC runtime didn't listen for any
events, yet the kernel considered otherwise and kept waking up the IO
manager thread.

This commit fixes this issue by always adding and removing all of the
provided subscriptions.

- - - - -
32be4461 by Roland Senn at 2019-07-21T05:04:17-04:00
Fix #8487: Debugger confuses variables

To display the free variables for a single breakpoint, GHCi pulls out the
information from the fields `modBreaks_breakInfo` and `modBreaks_vars`
of the `ModBreaks` data structure. For a specific breakpoint this gives 2
lists of types 'Id` (`Var`) and `OccName`. They are used to create the Id's
for the free variables and must be kept in sync:
If we remove an element from the Names list, then we also must remove the
corresponding element from the OccNames list.

- - - - -
4854a349 by Ben Gamari at 2019-07-21T05:04:53-04:00
ghc-cabal: Use fromFlagOrDefault instead of fromFlag

As fromFlag is partial. The only case where we used fromFlag is when
determining whether to strip libraries; we now assume that we shouldn't.

- - - - -
4c7a8462 by Xavier Denis at 2019-07-23T11:43:59-04:00
Make sure to load interfaces when running :instances

- - - - -
f9af30f8 by Ömer Sinan Ağacan at 2019-07-23T11:44:38-04:00
Remove fix-submodules.py

Now that we have absolute paths for submodules (since a76b233d) we no
longer need this script.

- - - - -
6ade71fb by Alp Mestanogullari at 2019-07-23T23:06:36-04:00
Hadrian: run the testsuite in Windows CI job

Since MR !1025 fixed the Windows build, allowing us to build a binary
distribution, we can now run the testsuite in that CI job.

This required fixing 'createFileLink': it should not try to create
symlinks on Windows (that requires admin priviledges, which Hadrian can't
assume). We now instead fall back to copying.

This patch also removes some duplicated logic for iserv in the test rules,
where we handle our dependency on the iserv binaries in a special way.

- - - - -
3dbcc368 by Richard Eisenberg at 2019-07-23T23:07:13-04:00
Simon and I like to work in hsSyn, too.

- - - - -
b95b6380 by John Ericson at 2019-07-24T16:49:53-04:00
Make stage 1 GHC target independent

Now that the target macros are not being used, we remove them. This
prevents target hardcoding regressions.

- - - - -
d0f8ed20 by Ben Gamari at 2019-07-24T16:50:28-04:00
gitlab-ci: Fix source tarball job

* Use show! in source tarball job. Since we aren't actually building
  anything in this job `show` won't
  work.

* Fix Docker image name

* Make `version` file contain only version string

- - - - -
90dd2ea0 by Vladislav Zavialov at 2019-07-24T23:11:22-04:00
ASSERT(vis_flag==ForallInvis) in hsScopedTvs

- - - - -
e07f0e2b by Vladislav Zavialov at 2019-07-24T23:11:57-04:00
Drop unused helpers 'mkTyClGroup' and 'emptyTyClGroup'

- - - - -
cb495b3c by Ryan Scott at 2019-07-25T17:25:26-04:00
Make DefUses = OrdList DefUse

Before, `type DefUses = [DefUse]`. But lists are a terrible choice of
data structure here, as we frequently append to the right of a
`DefUses`, which yields some displeasing asymptotics. Let's instead
use `OrdList`, which has constant-time appending to the right.

This is one step on the way to #10347.

- - - - -
b9c99df1 by Ömer Sinan Ağacan at 2019-07-25T17:26:03-04:00
Printer: add an empty line between bindings in Rec STG binding groups

Before:

    Rec {
    x2_r10T :: Lib.Bar
    [GblId, Unf=OtherCon []] =
        CCS_DONT_CARE Lib.Bar! [x3_r10U];
    x3_r10U :: Lib.Foo
    [GblId, Unf=OtherCon []] =
        CCS_DONT_CARE Lib.Foo! [x1_r10p x2_r10T];
    end Rec }

After:

    Rec {
    x2_r10T :: Lib.Bar
    [GblId, Unf=OtherCon []] =
        CCS_DONT_CARE Lib.Bar! [x3_r10U];

    x3_r10U :: Lib.Foo
    [GblId, Unf=OtherCon []] =
        CCS_DONT_CARE Lib.Foo! [x1_r10p x2_r10T];
    end Rec }

- - - - -
30b6f391 by Ryan Scott at 2019-07-26T00:57:02-04:00
Banish reportFloatingViaTvs to the shadow realm (#15831, #16181)

GHC used to reject programs of this form:

```
newtype Age = MkAge Int
  deriving Eq via Const Int a
```

That's because an earlier implementation of `DerivingVia` would
generate the following instance:

```
instance Eq Age where
  (==) = coerce @(Const Int a -> Const Int a -> Bool)
                @(Age         -> Age         -> Bool)
                (==)
```

Note that the `a` in `Const Int a` is not bound anywhere, which
causes all sorts of issues. I figured that no one would ever want to
write code like this anyway, so I simply banned "floating" `via` type
variables like `a`, checking for their presence in the aptly named
`reportFloatingViaTvs` function.

`reportFloatingViaTvs` ended up being implemented in a subtly
incorrect way, as #15831 demonstrates. Following counsel with the
sage of gold fire, I decided to abandon `reportFloatingViaTvs`
entirely and opt for a different approach that would _accept_
the instance above. This is because GHC now generates this instance
instead:

```
instance forall a. Eq Age where
  (==) = coerce @(Const Int a -> Const Int a -> Bool)
                @(Age         -> Age         -> Bool)
                (==)
```

Notice that we now explicitly quantify the `a` in
`instance forall a. Eq Age`, so everything is peachy scoping-wise.
See `Note [Floating `via` type variables]` in `TcDeriv` for the full
scoop.

A pleasant benefit of this refactoring is that it made it much easier
to catch the problem observed in #16181, so this patch fixes that
issue too.

Fixes #15831. Fixes #16181.

- - - - -
aae0457f by nineonine at 2019-07-26T00:57:39-04:00
Change behaviour of -ddump-cmm-verbose to dump each Cmm pass output to a separate file and add -ddump-cmm-verbose-by-proc to keep old behaviour (#16930)

- - - - -
00d9d284 by Vladislav Zavialov at 2019-07-26T00:58:15-04:00
TemplateHaskell: reifyType (#16976)

- - - - -
ea08fa37 by Vladislav Zavialov at 2019-07-26T00:58:15-04:00
reifyTypeOfThing: panic on impossible cases

- - - - -
7c9fb2f0 by Adam Sandberg Eriksson at 2019-07-26T09:49:14-04:00
ghc-heap: implement WEAK closure type #16974

- - - - -
26314386 by nineonine at 2019-07-26T09:49:51-04:00
Add regression test for #16946

- - - - -
cd11f81f by Fumiaki Kinoshita at 2019-07-28T19:47:50-04:00
base: add Functor, Applicative, Monad, Alternative, MonadPlus, Generic and Generic1 instances to Kleisli

- - - - -
c1a06d49 by Dale Wijnand at 2019-07-28T19:48:27-04:00
hadrian: relink to the flavours doc in the ghc repo
- - - - -
9f8cdb35 by Richard Eisenberg at 2019-07-29T19:32:16-04:00
Add Note [RuntimeRep and PrimRep] in RepType

Also adds Note [Getting from RuntimeRep to PrimRep], which
deocuments a related thorny process.

This Note addresses #16964, which correctly observes that
documentation for this thorny design is lacking.

Documentation only.

- - - - -
86f47b8e by Dale Wijnand at 2019-07-29T19:32:52-04:00
hadrian: Drop a stale limitation tracking issue

https://github.com/snowleopard/hadrian/issues/187 was superseded by
https://github.com/snowleopard/hadrian/issues/669, which has also
been closed.

So, optimistically, dropping this as a limitation issue.
- - - - -
9c8a211a by Andreas Klebinger at 2019-07-30T01:33:50-04:00
Expand the preallocated Int range to [-16,255]

Effects as I measured them:

RTS Size: +0.1%
Compile times: -0.5%
Runtine nofib: -1.1%

Nofib runtime result seems to mostly come from the `CS` benchmark
which is very sensible to alignment changes so this is likely over
represented.

However the compile time changes are realistic.

This is related to #16961.

- - - - -
2829f6da by Simon Peyton Jones at 2019-07-30T01:34:27-04:00
Apply a missing substitution in mkEtaWW (#16979)

The `mkEtaWW` case for newtypes forgot to apply the substitution to
the newtype coercion, resulting in the Core Lint errors observed
in #16979. Easily fixed.

Fixes #16979.

Co-authored-by: Ryan Scott <ryan.gl.scott at gmail.com>

- - - - -
371dadfb by Ben Gamari at 2019-07-31T04:27:59-04:00
Break up TyCoRep

This breaks up the monstrous TyCoReps module into several new modules by
topic:

 * TyCoRep: Contains the `Coercion`, `Type`, and related type
   definitions and a few simple predicates but nothing further

 * TyCoPpr: Contains the the pretty-printer logic

 * TyCoFVs: Contains the free variable computations (and
   `tyConAppNeedsKindSig`, although I suspect this should change)

 * TyCoSubst: Contains the substitution logic for types and coercions

 * TyCoTidy: Contains the tidying logic for types

While we are able to eliminate a good number of `SOURCE` imports (and
make a few others smaller) with this change, we must introduce one new
`hs-boot` file for `TyCoPpr` so that `TyCoRep` can define `Outputable`
instances for the types it defines.

Metric Increase:
    haddock.Cabal
    haddock.compiler

- - - - -
b6fa7fe3 by Ben Gamari at 2019-07-31T04:27:59-04:00
gitignore: Add .mypy_cache

- - - - -
88410e77 by Ben Gamari at 2019-07-31T04:27:59-04:00
Move tyConAppNeedsKindSig to Type

Previously it was awkwardly in TyCoFVs (and before that in TyCoRep).
Type seems like a sensible place for it to live.

- - - - -
787fab43 by Ben Gamari at 2019-07-31T04:27:59-04:00
Work around redundant import issue

As mentioned in #16997, GHC currently complains about this import.
In general I'm reluctant to paper over things like this but in the case
of an hs-boot file I think adding an import list is the right thing to
do regardless of the bug.

- - - - -
5e04841c by Ben Gamari at 2019-07-31T13:53:58-04:00
gitlab-ci: Fix it after upgrade

It seems that the regular expression parser changed in GitLab 12.1 and
now does now support forward slashes in the RE, even when escaped.

- - - - -
986643cb by Ivan Kasatenko at 2019-08-01T13:49:50-04:00
Fix T16916 CI failures (#16966)

1. Slightly increased the waiting time for the tested effect to be more
   profound.

2. Introduced measuring of the actual time spent waiting and adjusing
   CPU time by it to compensate for threadDelay waiting time
   inconsistencies.

- - - - -
95521140 by Andreas Klebinger at 2019-08-02T08:14:10-04:00
Add StandaloneDeriving example for DerivingVia.

[skip-ci]

- - - - -
1b9d32b8 by Ryan Scott at 2019-08-02T08:14:47-04:00
Rip out 9-year-old pattern variable hack (#17007)

GHC had an ad hoc validity check in place to rule out pattern
variables bound by type synonyms, such as in the following example:

```hs
type ItemColID a b = Int  -- Discards a,b

get :: ItemColID a b -> ItemColID a b
get (x :: ItemColID a b) = x :: ItemColID a b
```

This hack is wholly unnecessary nowadays, since OutsideIn(X) is more
than capable of instantiating `a` and `b` to `Any`. In light of this,
let's rip out this validity check.

Fixes #17007.

- - - - -
93bed40a by Ryan Scott at 2019-08-02T08:15:25-04:00
Use injectiveVarsOfType to catch dodgy type family instance binders (#17008)

Previously, we detected dodgy type family instances binders by
expanding type synonyms (via `exactTyCoVarsOfType`) and looking for
type variables on the RHS that weren't mentioned on the (expanded)
LHS. But this doesn't account for type families (like the example
in #17008), so we instead use `injectiveVarsOfType` to only count
LHS type variables that are in injective positions. That way, the `a`
in `type instance F (x :: T a) = a` will not count if `T` is a type
synonym _or_ a type family.

Along the way, I moved `exactTyCoVarsOfType` to `TyCoFVs` to live
alongside its sibling functions that also compute free variables.

Fixes #17008.

- - - - -
c902f56b by Krzysztof Gogolewski at 2019-08-02T08:16:03-04:00
Remove build.nix.sh

This file refers to shell.nix, which was removed in
430e6fedfda and c00d2f59d.

- - - - -
5e960287 by Adam Sandberg Eriksson at 2019-08-02T08:16:45-04:00
docs: fixs -prof links in rts-flags section

- - - - -
0c5cd771 by Alp Mestanogullari at 2019-08-02T22:20:14-04:00
compiler: emit finer grained codegen events to eventlog

- - - - -
0ecacb1e by Alp Mestanogullari at 2019-08-02T22:20:14-04:00
Add Note [withTiming] in compiler/main/ErrUtils.hs

- - - - -
4664bafc by Ben Gamari at 2019-08-02T22:20:50-04:00
rts: Always truncate output files

Previously there were numerous places in the RTS where we would fopen
with the "w" flag string. This is wrong as it will not truncate the
file. Consequently if we write less data than the previous length of the
file we will leave garbage at its end.

Fixes #16993.

- - - - -
e3cbe319 by Ben Gamari at 2019-08-02T22:21:26-04:00
Packages: Add timing for package database initialization

- - - - -
a5227080 by Alp Mestanogullari at 2019-08-02T22:22:06-04:00
Hadrian: make settings, platformConstants, etc dependencies of lib:ghc

This fixes #17003, where a user directly asked for the 'docs-haddock' target
without building a complete stage 2 GHC first. Since haddock only depends on
lib:ghc, the stage 2 GHC executable wasn't built, and neither were the
settings, platformConstants, llvm-passes and llvm-targets files, since they
are declared to be dependencies of exe:ghc.

This makes sense in general since all GHC API users (haddock is one) will likely
want those files to be there.

- - - - -
7e404afd by Ben Gamari at 2019-08-04T18:16:51-04:00
gitlab-ci: Manually set SPHINXBUILD on Windows

For some reason configure seems unable to find it on its own. Let's try
giving it a hint.

Addresses #16398.

- - - - -
8a061d18 by Matthew Pickering at 2019-08-04T18:17:28-04:00
Update .gitignore

Add some files generated by hadrian and some tooling files

- - - - -
7d8d0012 by Simon Peyton Jones at 2019-08-04T18:18:08-04:00
Don't float unlifted join points to top level

Ticket #16978 showed that we were floating a recursive,
unlifted join point to top level.  It's very much a corner
case:

    joinrec j :: Int#
            j = jump j
    in ...

But somehow it showed up in a real program.

For non-recursive bindings in SetLevels.lvlBind we were already
(correctly) checking for unlifted bindings, but when I wrote
that code I didn't think that a /recursive/ binding could be
unlifted but /join-points/ can be!

Actually I don't think that SetLevels should be floating
join points at all.  SetLevels really floats things to move
stuff out of loops and save allocation; but none of that applies
to join points.  The only reason to float join points is in
cases like
   join j1 x = join j2 y = ...
               in ...
which we might want to swizzle to
   join j2 x y = ... in
   join j1 x = ...
   in ...
because now j1 looks small and might be inlined away altogether.
But this is a very local float perhaps better done in the simplifier.

Still: this patch fixes the crash, and does so in a way that is
harmless if/when we change our strategy for floating join points.

- - - - -
3b31a94d by Ben Gamari at 2019-08-04T18:18:08-04:00
testsuite: Add testsuite for #16978

- - - - -
2e031806 by Ben Gamari at 2019-08-04T18:18:45-04:00
configure: Search for LLVM executables with two-number versions

Fedora uses the naming llc-7.0 while Debian uses llc-7. Ensure that both
are found.

Fixes #16990.

- - - - -
6e5dfcd2 by Ben Gamari at 2019-08-04T18:19:21-04:00
testsuite: Rework tracking of fragile tests

Breaks fragile tests into two groups, allowing us to easily preserve
stdout/stderr of failing fragile tests.

- - - - -
ea16f6cb by Simon Peyton Jones at 2019-08-06T20:24:41-04:00
Remove dead parameter from coreToStgApp

- - - - -
0c1ccf3c by James Foster at 2019-08-06T20:25:18-04:00
hadrian: Refactor file patterns for future Shake changes (fixes #17005)

Shake will be moving from its current implementation of ?== to one from
System.FilePattern. Support for `//` is being dropped, leaving only `*`
and `**` as special forms. This commit converts the existing file
patterns in Hadrian to the new format. It also removes all occurances
of <//> and changes the user-settings docs to remove references to //
and add **.

The conversion is as follows:

- //a ==> **/a

- a// ==> a/**

- a//b ==> a/**/b

- - - - -
c83e39bf by Matthew Pickering at 2019-08-06T20:25:54-04:00
Remove old/broken(?) .ghci script

I was attempting to load hadrian into ghci by using
`cabal new-repl exe:hadrian` but it failed because it tried
to use this `.ghci` configuration.

I'm not sure who used this script but you should really use the new-repl
method.

- - - - -
6f116005 by Ömer Sinan Ağacan at 2019-08-06T20:26:32-04:00
Introduce a type for "platform word size", use it instead of Int

We introduce a PlatformWordSize type and use it in platformWordSize
field.

This removes to panic/error calls called when platform word size is not
32 or 64. We now check for this when reading the platform config.

- - - - -
2073745c by mniip at 2019-08-07T10:18:07-04:00
Add a -fprint-axiom-incomps option (#15546)

Supply branch incomps when building an IfaceClosedSynFamilyTyCon

`pprTyThing` now has access to incomps. This also causes them to be
written out to .hi files, but that doesn't pose an issue other than a
more faithful bijection between `tyThingToIfaceDecl` and `tcIfaceDecl`.

The machinery for displaying axiom incomps was already present but not
in use. Since this is now a thing that pops up in ghci's :info the
format was modified to look like a haskell comment.

Documentation and a test for the new feature included.

Test Plan: T15546

Reviewers: simonpj, bgamari, goldfire

Reviewed By: simonpj

Subscribers: rwbarton, carter

GHC Trac Issues: #15546

Differential Revision: https://phabricator.haskell.org/D5097

- - - - -
bca79345 by mniip at 2019-08-07T10:18:07-04:00
Fix test

- - - - -
3d32286d by mniip at 2019-08-07T10:18:07-04:00
Explicitly number equations when printing axiom incompatibilities

- - - - -
ca8efc49 by mniip at 2019-08-07T10:18:07-04:00
Fix documentation

- - - - -
2c1b1ad7 by mniip at 2019-08-07T10:18:07-04:00
Fix test

- - - - -
8e2fe575 by Zubin Duggal at 2019-08-07T10:18:44-04:00
Fix bug preventing information about patterns from being serialized in .hie files

- - - - -
f1d0e49f by Ben Gamari at 2019-08-07T10:19:21-04:00
testsuite: Add tests for #16943

- - - - -
83ca42de by Ben Gamari at 2019-08-07T10:19:21-04:00
Revert "Make scanr a good producer and consumer"

This reverts commit 4e1dfc3767167dddd0e151a2df8305b12aa0f49c.

Due to #16943.

- - - - -
81860281 by Joachim Breitner at 2019-08-10T14:39:27-04:00
Consolidate `TablesNextToCode` and `GhcUnreigsterised` in configure (#15548)

`TablesNextToCode` is now a substituted by configure, where it has the
correct defaults and error handling. Nowhere else needs to duplicate
that, though we may want the compiler to to guard against bogus settings
files.

I renamed it from `GhcEnableTablesNextToCode` to `TablesNextToCode` to:

 - Help me guard against any unfixed usages

 - Remove any lingering connotation that this flag needs to be combined
   with `GhcUnreigsterised`.

Original reviewers:

Original subscribers: TerrorJack, rwbarton, carter

Original Differential Revision: https://phabricator.haskell.org/D5082

- - - - -
422ffce0 by Ben Gamari at 2019-08-10T14:40:03-04:00
Add timing on loadInterface

AndreasK recently mentioned that he thought that interface file loading
may be a non-trivial cost. Let's measure.

- - - - -
0424de2d by Ömer Sinan Ağacan at 2019-08-10T14:40:46-04:00
Add test for #16893

- - - - -
672cbab2 by Ömer Sinan Ağacan at 2019-08-10T14:41:26-04:00
Reformat comments in StgSyn

This does not make any changes in the contents -- formatting only.

Previously the comments were too noisy and I've always found it very
hard to read. Hopefully it's easier to read now.

- - - - -
328a0efa by Sebastian Graf at 2019-08-13T17:30:15-04:00
Add Foldable, Traversable instances for Uniq(D)FM

The `UniqDFM` is deterministic, of course, while we provide an unsafe
`NonDetUniqFM` wrapper for `UniqFM` to opt into nondeterministic instances.

- - - - -
b1d29c67 by Tamar Christina at 2019-08-13T17:30:50-04:00
Fix binary distribution
- - - - -
a38104b4 by Andreas Klebinger at 2019-08-14T16:55:42-04:00
Rework the Binary Integer instance.

We used to serialise large integers as strings. Now they are serialized
as a list of Bytes.

This changes the size for a Integer in the higher 64bit range from 77 to
9 bytes when written to disk.

The impact on the general case is small (<1% for interface files) as we
don't use many Integers. But for code that uses many this should be a
nice benefit.

- - - - -
aa4d8b07 by Andreas Klebinger at 2019-08-14T16:56:20-04:00
Use os.devnull instead of '/dev/null' in the testsuite driver.

The later caused issues on windows by being translated into
"\\dev\\null" and python then trying to open this non-existant file.

So we now use os.devnull inside python and convert it to "/dev/null"
when calling out to the shell, which is bound to run in a unix like
environment.

This fixes an issue a test producing unexpected stderr output failed
with a framework failure instead of showing a diff of the output.

- - - - -
6329c70a by Richard Eisenberg at 2019-08-14T17:47:25-04:00
GHCi supports not-necessarily-lifted join points

Fixes #16509.

See Note [Not-necessarily-lifted join points] in ByteCodeGen,
which tells the full story.

This commit also adds some comments and cleans some code
in the byte-code generator, as I was exploring around trying
to understand it.

(This commit removes an old test -- this is really a GHCi problem,
not a pattern-synonym problem.)

test case: ghci/scripts/T16509

- - - - -
ca71d551 by James Foster at 2019-08-15T12:01:43-04:00
Remove unused imports of the form 'import foo ()' (Fixes #17065)

These kinds of imports are necessary in some cases such as
importing instances of typeclasses or intentionally creating
dependencies in the build system, but '-Wunused-imports' can't
detect when they are no longer needed. This commit removes the
unused ones currently in the code base (not including test files
or submodules), with the hope that doing so may increase
parallelism in the build system by removing unnecessary
dependencies.

- - - - -
95837c0f by Tobias Dammers at 2019-08-15T22:13:13-04:00
Add test cases for #16615

- - - - -
8d076841 by Tobias Dammers at 2019-08-15T22:13:13-04:00
Make add_info attach unfoldings (#16615)

- - - - -
14208853 by Sylvain Henry at 2019-08-15T22:13:52-04:00
Cmm: constant folding `quotRem x 2^N`

`quot` and `rem` are implemented efficiently when the second argument
is a constant power of 2. This patch uses the same implementations for
`quotRem` primop.

- - - - -
47e16237 by Ömer Sinan Ağacan at 2019-08-15T22:14:31-04:00
Document types of LitNumbers, minor refactoring in Literal.hs

- - - - -
ac73c1b1 by Sylvain Henry at 2019-08-18T05:16:40-04:00
Faster exactLog2

Make `exactLog2` faster (use `countLeadingZeros` and Int32 bit-ops).

On my Core i7-9700k Criterion reports ~50% speedup (from 16 to 8ns).

- - - - -
1230d6f9 by Ömer Sinan Ağacan at 2019-08-18T05:17:20-04:00
Typo fix in CoreToStg

- - - - -
d0716279 by Ryan Scott at 2019-08-18T05:18:01-04:00
Fix #17067 by making data family type constructors actually injective

`TcTyClsDecls.tcFamDecl1` was using `NotInjective` when creating data
family type constructors, which is just plain wrong. This tweaks it
to use `Injective` instead.

Fixes #17067.

- - - - -
993804bf by Sam Halliday at 2019-08-18T16:39:21-04:00
expose ModuleInfo.minf_rdr_env for tooling authors

- - - - -
5b713aa3 by Ömer Sinan Ağacan at 2019-08-18T16:40:03-04:00
Fix COMPACT_NFDATA closure size, more CNF sanity checking

We now do a shallow closure check on objects in compact regions.

See the new comment on why we can't do a "normal" closure check.

- - - - -
ac7c738b by Richard Lupton at 2019-08-19T02:11:59-04:00
Generalized MonadUtils folds to Foldable (#16969)

- - - - -
3a1efe1a by Richard Lupton at 2019-08-19T02:12:00-04:00
Re-export foldlM and foldrM from Data.Foldable in MonadUtils (#16969)

- - - - -
2a394246 by Richard Lupton at 2019-08-19T02:12:00-04:00
Use Foldable instance of Bag for specialised Bag folds (#16969)

- - - - -
ac79dfe9 by Richard Lupton at 2019-08-19T02:12:00-04:00
Remove Bag fold specialisations (#16969)

- - - - -
5e40356f by Ben Gamari at 2019-08-19T02:12:36-04:00
gitlab-ci: Update bootstrap compiled used for Darwin builds

- - - - -
d5055248 by Ben Gamari at 2019-08-22T09:25:08-04:00
gitlab-ci: Add Windows full build during the nightly pipeline

- - - - -
a33bad2d by Sylvain Henry at 2019-08-22T09:25:47-04:00
Doc: add Haddocks for quotRemWord2 primop

- - - - -
605bce26 by James Foster at 2019-08-22T18:47:20-04:00
Add documentation for Hadrian expressions

This commit adds documentation on Hadrian's 'Expr' type and
references the documentation in hadrian/README.md

- - - - -
8f32d2bc by TDecki at 2019-08-22T18:47:57-04:00
base: Reintroduce fusion for scanr

While avoiding #16943.

- - - - -
c3e26ab3 by Ömer Sinan Ağacan at 2019-08-22T22:19:26-04:00
Remove special case in SRT generation with -split-sections

Previously we were using an empty ModuleSRTInfo for each Cmm group with
-split-section. As far as I can see this has no benefits, and
simplifying this makes another patch simpler (!1304).

We also remove some outdated comments: we no longer generate one
module-level SRT.

- - - - -
a8300520 by Ömer Sinan Ağacan at 2019-08-23T12:04:15+03:00
Make non-streaming LLVM and C backends streaming

This adds a Stream.consume function, uses it in LLVM and C code
generators, and removes the use of Stream.collect function which was
used to collect streaming Cmm generation results into a list.

LLVM and C backends now properly use streamed Cmm generation, instead of
collecting Cmm groups into a list before generating LLVM/C code.

- - - - -
47070144 by Andreas Klebinger at 2019-08-23T19:26:42-04:00
Use variable length encoding for Binary instances.

Use LEB128 encoding for Int/Word variants. This reduces
the size of interface files significantly. (~19%).

Also includes a few small optimizations to make unboxing
work better that I have noticed while looking at the core.

- - - - -
cff44d86 by Sergei Trofimovich at 2019-08-23T19:27:21-04:00
configure.ac: fix '--disable-dwarf-debug'

Before the change
    ./configure --disable-dwarf-debug
enabled DWARF debugging unconditionally.

This happened due to use of 5-argument form of `AC_ARG_ENABLE`
without actually checking the passed  `$enableval` parameter:

```
AC_ARG_ENABLE(dwarf-unwind,
    [AC_HELP_STRING([--enable-dwarf-unwind],
        [Enable DWARF unwinding support in the runtime system via elfutils' libdw [default=no]])],
    [AC_CHECK_LIB(dw, dwfl_attach_state,
      [UseLibdw=YES],
      [AC_MSG_ERROR([Cannot find system libdw (required by --enable-dwarf-unwind)])])]
    [UseLibdw=NO]
)
```

Note:

- `[UseLibdw=NO]` is called when `--{enable,disable}-dwarf-unwind`
  is not passed at all as a parameter (ok).
- `[AC_CHECK_LIB(dw, dwfl_attach_state, [UseLibdw=YES],` is called
  for both:

  * `--enable-dwarf-unwind` being passed: `$enableval = "yes"` (ok).
  *  --disable-dwarf-unwind` being passed: `$enableval = "no"` (bad).

The change is to use 3-argument `AC_ARG_ENABLE` and check for passed
value as `"$enable_dwarf_unwind" = "yes"`.

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
10763ce0 by Ömer Sinan Ağacan at 2019-08-27T10:45:02+03:00
Some more documentation for typePrimRep1 stuff

[skip ci]

- - - - -
89487be2 by Ömer Sinan Ağacan at 2019-08-27T15:21:50-04:00
Some tweaks in GHC.Compact haddocks

- - - - -
ee2fad9e by Andreas Klebinger at 2019-08-27T15:22:28-04:00
Remove redundant OPTIONS_GHC in BlockLayout.hs

- - - - -
1c7ec449 by Ömer Sinan Ağacan at 2019-08-28T12:51:12+03:00
Return results of Cmm streams in backends

This generalizes code generators (outputAsm, outputLlvm, outputC, and
the call site codeOutput) so that they'll return the return values of
the passed Cmm streams.

This allows accumulating data during Cmm generation and returning it to
the call site in HscMain.

Previously the Cmm streams were assumed to return (), so the code
generators returned () as well.

This change is required by !1304 and !1530.

Skipping CI as this was tested before and I only updated the commit
message.

[skip ci]

- - - - -
a308b435 by Sebastian Graf at 2019-08-28T11:33:49-04:00
Fix #17112

The `mkOneConFull` function of the pattern match checker used to try to
guess the type arguments of the data type's type constructor by looking
at the ambient type of the match. This doesn't work well for Pattern
Synonyms, where the result type isn't even necessarily a TyCon
application, and it shows in #11336 and #17112.

Also the effort seems futile; why try to try hard when the type checker
has already done the hard lifting? After this patch, we instead supply
the type constructors arguments as an argument to the function and
lean on the type-annotated AST.

- - - - -
137c24e1 by Ryan Scott at 2019-08-28T22:36:40-04:00
Balance parentheses in GHC 8.10.1 release notes

[ci skip]

- - - - -
66282ba5 by luca at 2019-08-28T22:37:19-04:00
Remove Unused flag -ddump-shape [skip ci]

- - - - -
bf9dfe1c by Ömer Sinan Ağacan at 2019-08-29T04:28:35-04:00
Fix LLVM version check yet again

There were two problems with LLVM version checking:

- The parser would only parse x and x.y formatted versions. E.g. 1.2.3
  would be rejected.

- The version check was too strict and would reject x.y formatted
  versions. E.g. when we support version 7 it'd reject 7.0 ("LLVM
  version 7.0") and only accept 7 ("LLVM version 7").

We now parse versions with arbitrarily deep minor numbering (x.y.z.t...)
and accept versions as long as the major version matches the supported
version (e.g. 7.1, 7.1.2, 7.1.2.3 ...).

- - - - -
fc746e98 by Ben Gamari at 2019-08-29T04:29:13-04:00
gitlab-ci: Fix URL of Darwin's cabal-install tarball

This was inadvertently referring to the cabal-install-latest/ directory
which is volatile.

- - - - -
304067a0 by Ömer Sinan Ağacan at 2019-08-29T09:38:25-04:00
Small optimization in the SRT algorithm

Noticed by @simonmar in !1362:

    If the srtEntry is Nothing, then it should be safe to omit
    references to this SRT from other SRTs, even if it is a static
    function.

When updating SRT map we don't omit references to static functions (see
Note [Invalid optimisation: shortcutting]), but there's no reason to add
an SRT entry for a static function if the function is not CAFFY.

(Previously we'd add SRT entries for static functions even when they're
not CAFFY)

Using 9151b99e I checked sizes of all SRTs when building GHC and
containers:

- GHC: 583736 (HEAD), 581695 (this patch). 2041 less SRT entries.
- containers: 2457 (HEAD), 2381 (this patch). 76 less SRT entries.

- - - - -
78afc2c9 by Sergei Trofimovich at 2019-08-30T06:14:44-04:00
configure.ac: add --enable-numa switch

Before the change ./configure detected numa support automatically
withoun a nice way to disable autodetection.

The change adds `--enable-numa` / `--disable-numa` switch to
override the default. If `--enable-numa` is passed and `libnuma`
is not present then configure will fail.

Reported-by: Sergey Alirzaev
Bug: https://github.com/gentoo-haskell/gentoo-haskell/issues/955
Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
c0956c14 by Vladislav Zavialov at 2019-08-30T06:15:21-04:00
Remove HsUtils/userHsLTyVarBndrs

This patch removes 'userHsLTyVarBndrs' and 'userHsTyVarBndrs' from HsUtils.
These helper functions were not used anywhere.

- - - - -
7e6aeb13 by Eric Wolf at 2019-08-31T10:25:39+02:00
Add additional step to T16804

Add another small test step

Use the same identifier name in different
scopes and see, if ':uses' handles that.

Add another test step

to check wether local bindings with the
same identifier name might get confused

Add easier to understand test output

Fix annotated lines from file correctly

- - - - -
e56251f6 by Ömer Sinan Ağacan at 2019-08-31T17:55:13-04:00
Remove redundant special case in STG pretty-printer

This special case existed for no reason, and made things inconsistent.

Before

    Boolean.$bT :: Boolean.Boolean
    [GblId, Str=m, Unf=OtherCon []] =
        CAF_ccs  \ u  []  Boolean.$bT1;

After

    Boolean.$bF :: Boolean.Boolean
    [GblId, Str=m, Unf=OtherCon []] =
        \u [] Boolean.$bF1;

The cost-centre is now hidden when not profiling, as is the case with
other types of closures.

- - - - -
cfab4abe by Gershom Bazerman at 2019-09-01T00:34:05-04:00
cap max stack size at 32 bit limit (#17019)

- - - - -
9acba780 by John Ericson at 2019-09-01T22:44:45-04:00
Use C99 Fixed width types to avoid hack in base's configure

Define MD5Context in terms of `uint*_t` and don't use `HsFFI.h`.

- - - - -
11679e5b by Ömer Sinan Ağacan at 2019-09-02T13:17:49+03:00
Few tweaks in -ddump-debug output, minor refactoring

- Fixes crazy indentation in -ddump-debug output
- We no longer dump empty sections in -ddump-debug when a code block
  does not have any generated debug info
- Minor refactoring in Debug.hs and AsmCodeGen.hs

- - - - -
f96d57b8 by John Ericson at 2019-09-05T18:50:19-04:00
Make the C-- O and C types constructors with DataKinds

The tightens up the kinds a bit. I use type synnonyms to avoid adding
promotion ticks everywhere.

- - - - -
b55ee979 by John Ericson at 2019-09-05T18:50:56-04:00
Make sure all boolean settings entries use `YES` / `NO`

Some where using `True` / `False`, a legacy of when they were in
`Config.hs`. See #16914 / d238d3062a9858 for a similar problem.

Also clean up the configure variables names for consistency and clarity
while we're at it. "Target" makes clear we are talking about outputted
code, not where GHC itself runs.

- - - - -
821bece9 by Ömer Sinan Ağacan at 2019-09-07T04:50:21-04:00
Minor refactoring in deriveConstants

Mainly we now generate this

    data PlatformConstants = PlatformConstants {
          pc_CONTROL_GROUP_CONST_291 :: Int,
          pc_STD_HDR_SIZE :: Int,
          pc_PROF_HDR_SIZE :: Int,
          pc_BLOCK_SIZE :: Int,
      }

instead of

    data PlatformConstants = PlatformConstants {
        pc_platformConstants :: ()
        , pc_CONTROL_GROUP_CONST_291 :: Int
        , pc_STD_HDR_SIZE :: Int
        , pc_PROF_HDR_SIZE :: Int
        , pc_BLOCK_SIZE :: Int
        ...
      }

The first field has no use and according to (removed) comments it was to
make code generator's work easier.. if anything this version is simpler
because it has less repetition (the commas in strings are gone).

- - - - -
b0fdd7fe by Alp Mestanogullari at 2019-09-07T04:50:59-04:00
hadrian: fix _build/ghc-stage1 to make it callable from any directory

- - - - -
51379b89 by Ömer Sinan Ağacan at 2019-09-08T21:40:32-04:00
Add a new flag -dno-typeable-binds for debugging

See the user manual entry -- this helps when debugging as generated Core
gets smaller without these bindings.

- - - - -
d0b45ac6 by Moritz Kiefer at 2019-09-08T21:41:12-04:00
Fix GHC version guard for Int32Rep/Word32Rep

Those constructors have been added after GHC 8.8. The version guards
in `binary` are correct, see https://github.com/kolmodin/binary/pull/167/files.

- - - - -
4cf91d1a by Daniel Gröber at 2019-09-09T05:42:33-04:00
Use lazyness for FastString's z-encoding memoization

Having an IORef in FastString to memoize the z-encoded version is
unecessary because there is this amazing thing Haskell can do natively,
it's called "lazyness" :)

We simply remove the UNPACK and strictness annotations from the constructor
field corresponding to the z-encoding, making it lazy, and store the
(pure) z-encoded string there.

The only complication here is 'hasZEncoding' which allows cheking if a
z-encoding was computed for a given string. Since this is only used for
compiler performance statistics though it's not actually necessary to have
the current per-string granularity.

Instead I add a global IORef counter to the FastStringTable and use
unsafePerformIO to increment the counter whenever a lazy z-encoding is
forced.

- - - - -
f5e2fde4 by Daniel Gröber at 2019-09-09T05:42:33-04:00
Update FastString docstrings

1) FastStrings are always UTF-8 encoded now.
2) Clarify what is meant by "hashed"
3) Add mention of lazy z-enc

- - - - -
270fbe85 by Ryan Scott at 2019-09-09T05:43:12-04:00
Replace queryCygwinTerminal with Win32's isMinTTYHandle

`SysTools.Terminal.queryCygwinTerminal` now exists in the `Win32`
library under the name `isMinTTYHandle` since `Win32-2.5.0.0`.
(GHC 8.4.4 ships with `Win32-2.6.1.0`, so this is well within GHC's
support window.) We can therefore get replace `queryCygwinTerminal`
with `isMinTTYHandle` and delete quite a bit of code from
`SysTools.Terminal` in the process.

Along the way I needed to replace some uses of `#if defined x` with
`#if defined(x)` to please the CI linters.

- - - - -
447864a9 by Sylvain Henry at 2019-09-10T00:04:50+02:00
Module hierarchy: StgToCmm (#13009)

Add StgToCmm module hierarchy. Platform modules that are used in several
other places (NCG, LLVM codegen, Cmm transformations) are put into
GHC.Platform.

- - - - -
60c26403 by Niklas Hambüchen at 2019-09-11T09:44:23-04:00
linker: Move -optl flags to end of linker invocation.

Until now, giving `-optl` linker flags to `ghc` on the command line placed
them in the wrong place in the `ld` command line:

They were given before all the Haskell libararies, when they should appear after.

Background:
Most linkers like `ld.bfd` and `ld.gold`, but not the newer LLVM `lld`, work in
a way where the order of `-l` flags given matters; earlier `-lmylib1` flags are
supposed to create "holes" for linker symbols that are to be filled with later
`lmylib2` flags that "fill the holes" for these symbols.

As discovered in
https://github.com/haskell/cabal/pull/5451#issuecomment-518001240,
the `-optl` flags appeared before e.g. the

    -lHStext-1.2.3.1
    -lHSbinary-0.8.6.0
    -lHScontainers-0.6.0.1

flags that GHC added at the very end.

Haskell libraries typically depend on C libraries, so `-lHS*` flags will create
holes for the C libraries to fill in, but that only works when those libraries'
`-l` flags are given **after** the `-lHS*` flags; until now they were given
before, which was wrong.

This meant that Cabal's `--ld-options` flag and `ld-options` `.cabal` file field
were pretty ineffective, unless you used the `--ld-option=--start-group` hack as
(https://github.com/haskell/cabal/pull/5451#issuecomment-406761676) that
convinces the classical linkers to not be dependent on the order of linker flags
given.

This commit fixes the problem by simply flipping the order, putting `-optl`
flags at the end, after Haskell libraries.

The code change is effectively only `args1 ++ args` -> `args ++ args1`
but the commit also renames the variables for improved clarity.

Simple way to test it:

    ghc --make Main.hs -fforce-recomp -v -optl-s

on a `Main.hs` like:

    import qualified Data.Set as Set
    main = print $ Set.fromList "hello"

- - - - -
7032a913 by John Ericson at 2019-09-11T09:45:02-04:00
Remove COMPILING_GHC

It is no longer used. I guess we are sharing fewer headers with the RTS
than the comment claims. That's a relief!

- - - - -
58569a5b by Peter Trommler at 2019-09-11T09:45:47-04:00
testsuite: check for RTS linker

Fixes #16833

- - - - -
df6fbe03 by Luke Lau at 2019-09-11T09:46:36-04:00
Bump Hadrian's QuickCheck dependency

- - - - -
d9e637df by John Ericson at 2019-09-11T09:47:26-04:00
Remove dead `ncgDebugIsOn` and `NCG_DEBUG`

Haven't been used since 16206a6603e87e15d61c57456267c5f7ba68050e.

- - - - -
7ef6fe8f by Ben Gamari at 2019-09-11T09:48:03-04:00
SetLevels: Fix potential panic in lvlBind

3b31a94d introduced a use of isUnliftedType which can panic in the case
of levity-polymorphic types. Fix this by introducing mightBeUnliftedType
which returns whether the type is *guaranteed* to be lifted.

- - - - -
c76cc0c6 by Ömer Sinan Ağacan at 2019-09-11T19:40:06-04:00
Refactor bad coercion checking in a few places

We do bad coercion checking in a few places in the compiler, but they
all checked it differently:

- CoreToStg.coreToStgArgs:

  Disallowed lifted-to-unlifted, disallowed changing prim reps even when
  the sizes are the same.

- StgCmmExpr.cgCase:

  Checked primRepSlot equality. This disallowed Int to Int64 coercions
  on 64-bit systems (and Int to Int32 on 32-bit) even though those are
  fine.

- CoreLint:

  Only place where we do this right. Full rules are explained in Note
  [Bad unsafe coercion].

This patch implements the check explained in Note [Bad unsafe coercion]
in CoreLint and uses it in CoreToStg.coreToStgArgs and
StgCmmExpr.cgCase.

This fixes #16952 and unblocks !1381 (which fixes #16893).

This is the most conservative and correct change I came up with that
fixes #16952.

One remaining problem with coercion checking is that it's currently done
in seemingly random places. What's special about CoreToStg.coreToStgArgs
and StgCmmExpr.cgCase? My guess is that adding assertions to those
places caught bugs before so we left assertions in those places. I think
we should remove these assertions and do coercion checking in CoreLint
and StgLint only (#17041).

- - - - -
3a7d3923 by Tamar Christina at 2019-09-11T19:40:53-04:00
Windows: make openTempFile fully atomic.

- - - - -
98b0d6ee by Pranay Sashank at 2019-09-12T04:52:33-04:00
Print the correct system memory in use with +RTS -s (#17158)

Use `stats.max_mem_in_use_bytes` to print the memory usage instead of
`stats.max_live_bytes` which prints maximum residency.

Fixes (#17158).

- - - - -
a06629b4 by John Ericson at 2019-09-12T04:53:13-04:00
Do not throw away backpack instantiations for module lookup cache

Currently, there is only one home package so this probably doesn't
matter. But if we support multiple home packages, they could differ only
in arguments (same indef component being applied).

It looks like it used to be this way before
4e8a0607140b23561248a41aeaf837224aa6315b, but that commit doesn't seem
to comment on this change in the particular. (It's main purpose is
creating the InstalledUnitId and recategorizing the UnitId expressions
accordingly.)

Trying this as a separate commit for testing purposes. I leave it to
others to decide whether this is a good change on its own.

- - - - -
09fa5654 by John Ericson at 2019-09-12T04:53:51-04:00
Remove unused `#include`s from parser/cutils.c

Looks like these have been unused since
7c665f9ce0980ee7c81a44c8f861686395637453.

- - - - -
2b37a79d by Sebastian Graf at 2019-09-12T14:05:29-04:00
Bump Cabal submodule to 3.1

-------------------------
Metric Increase:
    haddock.Cabal
    T4029
-------------------------

- - - - -
86753475 by Ningning Xie at 2019-09-12T14:06:07-04:00
Fix StandaloneDeriving

If I understand correctly, `deriving instance _ => Eq (Foo a)`
is equivalent to `data Foo a deriving Eq`, rather than
`data Foo a deriving Foo`.
- - - - -
a733002a by Ben Gamari at 2019-09-13T03:09:47-04:00
Update mailmap

- - - - -
5b64aee2 by Simon Peyton Jones at 2019-09-13T03:10:26-04:00
Fix scoping of implicit parameters

There was an outright bug in TcInteract.solveOneFromTheOther
which meant that we did not always pick the innermost
implicit parameter binding, causing #17104.

The fix is easy, just a rearrangement of conditional tests

- - - - -
47b12660 by Tamar Christina at 2019-09-13T03:11:06-04:00
Windows: Fix hsc2hs non-deterministic failures.

- - - - -
e3a7592b by Alp Mestanogullari at 2019-09-13T03:11:50-04:00
Add a test to make sure we don't regress on #17140 in the future

- - - - -
6f3cd50e by Zubin Duggal at 2019-09-13T11:24:51-04:00
Explain how to update HieAst [skip ci]

- - - - -
71428a43 by Zubin Duggal at 2019-09-13T11:24:51-04:00
Address review comments [skip CI]

- - - - -
ccb4e646 by John Ericson at 2019-09-13T11:25:29-04:00
Compiler should always get fingerprinting impl from base

07ee15915d5a0d6d1aeee137541eec6e9c153e65 started the transition, but the
job was never finished.

- - - - -
c45c89d6 by Ben Gamari at 2019-09-13T11:26:05-04:00
gitlab: Add issue template for documentation issues

Fixes #17180.

- - - - -
a0e220b7 by John Ericson at 2019-09-13T11:26:43-04:00
Remove empty NCG.h

- - - - -
046ca133 by Andrew Martin at 2019-09-13T15:43:16-04:00
Add predicates for testing if IOError is ResourceVanished.

This adds isResourceVanished, resourceVanishedErrorType, and
isResourceVanishedErrorType to System.IO.Error, resolving #14730.

- - - - -
bd079345 by taylorfausak at 2019-09-14T06:25:27-04:00
Fix CONLIKE typo
- - - - -
cf7e78a3 by Ben Gamari at 2019-09-15T23:46:36-04:00
Rename GHC.StgToCmm.Con -> GHC.StgToCmm.DataCon

Incredibly, Windows disallows the manipulation of any file matching
Con(\..*)?. The `GHC.StgToCmm.Con` was introduced in the renamings in
447864a9, breaking the Windows build. Work around this by renaming it to
`GHC.StgToCmm.DataCon`

Fixes #17187.

- - - - -
7208160d by Sylvain Henry at 2019-09-15T23:47:22-04:00
Fix Hadrian build with Stack (#17189)

Broken by 2b37a79d61e9b3787873dc9f7458ef2bde4809b0

- - - - -
b5ae3868 by Sylvain Henry at 2019-09-16T13:32:22-04:00
Allow validation with Hadrian built with Stack [skip ci]

- - - - -
7915afc6 by Sebastian Graf at 2019-09-16T13:33:05-04:00
Encode shape information in `PmOracle`

Previously, we had an elaborate mechanism for selecting the warnings to
generate in the presence of different `COMPLETE` matching groups that,
albeit finely-tuned, produced wrong results from an end user's
perspective in some cases (#13363).

The underlying issue is that at the point where the `ConVar` case has to
commit to a particular `COMPLETE` group, there's not enough information
to do so and the status quo was to just enumerate all possible complete
sets nondeterministically.  The `getResult` function would then pick the
outcome according to metrics defined in accordance to the user's guide.
But crucially, it lacked knowledge about the order in which affected
clauses appear, leading to the surprising behavior in #13363.

In !1010 we taught the term oracle to reason about literal values a
variable can certainly not take on. This MR extends that idea to
`ConLike`s and thereby fixes #13363: Instead of committing to a
particular `COMPLETE` group in the `ConVar` case, we now split off the
matching constructor incrementally and record the newly covered case as
a refutable shape in the oracle. Whenever the set of refutable shapes
covers any `COMPLETE` set, the oracle recognises vacuosity of the
uncovered set.

This patch goes a step further: Since at this point the information
in value abstractions is merely a cut down representation of what the
oracle knows, value abstractions degenerate to a single `Id`, the
semantics of which is determined by the oracle state `Delta`.
Value vectors become lists of `[Id]` given meaning to by a single
`Delta`, value set abstractions (of which the uncovered set is an
instance) correspond to a union of `Delta`s which instantiate the
same `[Id]` (akin to models of formula).

Fixes #11528 #13021, #13363, #13965, #14059, #14253, #14851, #15753, #17096, #17149

-------------------------
Metric Decrease:
    ManyAlternatives
    T11195
-------------------------

- - - - -
ae4415b9 by Matthew Pickering at 2019-09-17T19:21:10-04:00
eventlog: Add biographical and retainer profiling traces

This patch adds a new eventlog event which indicates the start of
a biographical profiler sample. These are different to normal events as
they also include the timestamp of when the census took place. This is
because the LDV profiler only emits samples at the end of the run.

Now all the different profiling modes emit consumable events to the
eventlog.

- - - - -
9c21b2fd by Richard Eisenberg at 2019-09-17T19:22:00-04:00
Fix #13571 by adding an extension flag check

Test case: indexed-types/should_fail/T13571

- - - - -
8039b125 by Simon Peyton Jones at 2019-09-17T19:22:50-04:00
Comments only

- - - - -
1c3af277 by Simon Peyton Jones at 2019-09-17T19:23:37-04:00
Improve error message for out-of-scope variables + VTA

As #13834 and #17150 report, we get a TERRIBLE error message when you
have an out of scope variable applied in a visible type application:
     (outOfScope @Int True)

This very simple patch improves matters.

See TcExpr Note [VTA for out-of-scope functions]

- - - - -
c77fc3b2 by John Ericson at 2019-09-17T19:24:20-04:00
Deduplicate `HaskellMachRegs.h` and `RtsMachRegs.h` headers

Until 0472f0f6a92395d478e9644c0dbd12948518099f there was a meaningful
host vs target distinction (though it wasn't used right, in genapply).
After that, they did not differ in meaningful ways, so it's best to just
only keep one.

- - - - -
c3eaaca6 by Simon Peyton Jones at 2019-09-19T09:03:19-04:00
Add a missing update of sc_hole_ty (#16312)

In simplCast I totally failed to keep the sc_hole_ty field of
ApplyToTy (see Note [The hole type in ApplyToTy]) up to date.
When a cast goes by, of course the hole type changes.

Amazingly this has not bitten us before, but #16312 finally
triggered it.  Fortunately the fix is simple.

Fixes #16312.

- - - - -
de1723b2 by Ben Gamari at 2019-09-19T09:03:19-04:00
Simplify: Lazy pattern match

- - - - -
d9c6b86e by Richard Eisenberg at 2019-09-19T09:04:03-04:00
Refactor kindGeneralize and friends

This commit should have no change in behavior.(*)

The observation was that Note [Recipe for checking a signature]
says that every metavariable in a type-checked type must either
  (A) be generalized
  (B) be promoted
  (C) be zapped.
Yet the code paths for doing these were all somewhat separate.
This led to some steps being skipped. This commit shores this
all up. The key innovation is TcHsType.kindGeneralizeSome, with
appropriate commentary.

This commit also sets the stage for #15809, by turning the
WARNing about bad level-numbers in generalisation into an
ASSERTion. The actual fix for #15809 will be in a separate
commit.

Other changes:
 * zonkPromoteType is now replaced by kindGeneralizeNone.
   This might have a small performance degradation, because
   zonkPromoteType zonked and promoted all at once. The new
   code path promotes first, and then zonks.

 * A call to kindGeneralizeNone was added in tcHsPartialSigType.
   I think this was a lurking bug, because it did not follow
   Note [Recipe for checking a signature]. I did not try to
   come up with an example showing the bug. This is the (*)
   above.

   Because of this change, there is an error message regression
   in partial-sigs/should_fail/T14040a. This problem isn't really
   a direct result of this refactoring, but is a symptom of
   something deeper. See #16775, which addresses the deeper
   problem.

 * I added a short-cut to quantifyTyVars, in case there's
   nothing to quantify.

 * There was a horribly-outdated Note that wasn't referred
   to. Gone now.

 * While poking around with T14040a, I discovered a small
   mistake in the Coercion.simplifyArgsWorker. Easy to fix,
   happily.

 * See new Note [Free vars in coercion hole] in TcMType.
   Previously, we were doing the wrong thing when looking
   at a coercion hole in the gather-candidates algorithm.
   Fixed now, with lengthy explanation.

Metric Decrease:
  T14683

- - - - -
f594a68a by Richard Eisenberg at 2019-09-19T09:04:03-04:00
Use level numbers for generalisation

This fixes #15809, and is covered in
Note [Use level numbers for quantification] in TcMType.

This patch removes the "global tyvars" from the
environment, a nice little win.

- - - - -
c675d08f by Richard Eisenberg at 2019-09-19T09:04:03-04:00
Test #17077.

- - - - -
912afaf4 by Ben Gamari at 2019-09-19T09:04:39-04:00
CoreUtils: Use mightBeUnliftedType in exprIsTopLevelBindable

Also add reference from isUnliftedType to mightBeUnliftedType.

- - - - -
baf47661 by Sebastian Graf at 2019-09-19T09:05:20-04:00
Extract PmTypes module from PmExpr and PmOracle

Apparently ghc-lib-parser's API blew up because the newly induced cyclic
dependency between TcRnTypes and PmOracle pulled in the other half of
GHC into the relevant strongly-connected component.

This patch arranges it so that PmTypes exposes mostly data type
definitions and type class instances to be used within PmOracle, without
importing the any of the possibly offending modules DsMonad, TcSimplify
and FamInst.

- - - - -
2a8867cf by Sebastian Graf at 2019-09-19T09:05:58-04:00
Add a regression test for #11822

The particular test is already fixed, but the issue seems to have
multiple different test cases lumped together.

- - - - -
52173990 by Ben Gamari at 2019-09-19T09:06:36-04:00
testsuite: Add testcase for #17206

- - - - -
b3e5c731 by Alp Mestanogullari at 2019-09-19T21:42:17-04:00
ErrUtils: split withTiming into withTiming and withTimingSilent

'withTiming' becomes a function that, when passed '-vN' (N >= 2) or
'-ddump-timings', will print timing (and possibly allocations) related
information. When additionally built with '-eventlog' and executed with
'+RTS -l', 'withTiming' will also emit both 'traceMarker' and 'traceEvent'
events to the eventlog.

'withTimingSilent' on the other hand will never print any timing information,
under any circumstance, and will only emit 'traceEvent' events to the eventlog.
As pointed out in !1672, 'traceMarker' is better suited for things that we
might want to visualize in tools like eventlog2html, while 'traceEvent'
is better suited for internal events that occur a lot more often and that we
don't necessarily want to visualize.

This addresses #17138 by using 'withTimingSilent' for all the codegen bits
that are expressed as a bunch of small computations over streams of codegen
ASTs.

- - - - -
4853d962 by Ben Gamari at 2019-09-19T21:42:55-04:00
users guide: Fix link to let generalization blog post

Fixes #17200.

- - - - -
51192964 by Sylvain Henry at 2019-09-20T05:14:34-04:00
Module hierarchy: Hs (#13009)

Add GHC.Hs module hierarchy replacing hsSyn.

Metric Increase:
    haddock.compiler

- - - - -
2f8ce45a by Ben Gamari at 2019-09-20T05:15:11-04:00
testsuite: Add test for #17202

- - - - -
f257bf73 by Matthew Pickering at 2019-09-20T05:15:52-04:00
hadrian/ghci.sh: Enable building in parallel

- - - - -
070f7b85 by Matthew Pickering at 2019-09-20T05:15:52-04:00
Remove trailing whitespace

- - - - -
5390b553 by Matthew Pickering at 2019-09-20T05:15:52-04:00
Pass -j to ghc-in-ghci CI job

- - - - -
1b7e1d31 by John Ericson at 2019-09-20T05:16:36-04:00
Remove pointless partiality in `Parser.ajs`

- - - - -
17554248 by Simon Peyton Jones at 2019-09-20T10:50:21+01:00
Fix PmOracle.addVarCoreCt in-scope set

PmOracle.addVarCoreCt was giving a bogus (empty) in-scope set to
exprIsConApp_maybe, which resulted in a substitution-invariant
failure (see MR !1647 discussion).

This patch fixes it, by taking the free vars of the expression.

- - - - -
0dad81ca by Simon Peyton Jones at 2019-09-20T10:50:21+01:00
Fix bogus type of case expression

Issue #17056 revealed that we were sometimes building a case
expression whose type field (in the Case constructor) was bogus.

Consider a phantom type synonym
   type S a = Int
and we want to form the case expression
   case x of K (a::*) -> (e :: S a)
We must not make the type field of the Case constructor be (S a)
because 'a' isn't in scope.  We must instead expand the synonym.

Changes in this patch:

* Expand synonyms in the new function CoreUtils.mkSingleAltCase.

* Use mkSingleAltCase in MkCore.wrapFloat, which was the proximate
  source of the bug (when called by exprIsConApp_maybe)

* Use mkSingleAltCase elsewhere

* Documentation
    CoreSyn   new invariant (6) in Note [Case expression invariants]
    CoreSyn   Note [Why does Case have a 'Type' field?]
    CoreUtils Note [Care with the type of a case expression]

* I improved Core Lint's error reporting, which was pretty
  confusing in this case, because it didn't mention that the offending
  type was the return type of a case expression.

* A little bit of cosmetic refactoring in CoreUtils

- - - - -
1ea8c451 by Sebastian Graf at 2019-09-21T09:52:34-04:00
PredType for type constraints in the pattern match checker instead of EvVar

Using EvVars for capturing type constraints implied side-effects in DsM
when we just wanted to *construct* type constraints.

But giving names to type constraints is only necessary when passing
Givens to the type checker, of which the majority of the pattern match
checker should be unaware.

Thus, we simply generate `newtype TyCt = TyCt PredType`, which are
nicely stateless. But at the same time this means we have to allocate
EvVars when we want to query the type oracle! So we keep the type oracle
state as `newtype TyState = TySt (Bag EvVar)`, which nicely makes a
distinction between new, unchecked `TyCt`s and the inert set in
`TyState`.

- - - - -
ded96fb3 by Ömer Sinan Ağacan at 2019-09-21T09:53:29-04:00
Document MIN_PAYLOAD_SIZE and mark-compact GC mark bits

This updates the documentation of the MIN_PAYLOAD_SIZE constant and adds
a new Note [Mark bits in mark-compact collector] explaning why the
mark-compact collector uses two bits per objet and why we need
MIN_PAYLOAD_SIZE.

- - - - -
a7867c79 by Sebastian Graf at 2019-09-21T14:56:58+01:00
Get rid of PmFake

The pattern match oracle can now cope with the abundance of information
that ViewPatterns, NPlusKPats, overloaded lists, etc. provide.

No need to have PmFake anymore!

Also got rid of a spurious call to `allCompleteMatches`, which we used to call
*for every constructor* match. Naturally this blows up quadratically for
programs like `ManyAlternatives`.

-------------------------
Metric Decrease:
    ManyAlternatives

Metric Increase:
    T11822
-------------------------

- - - - -
fa66e3e5 by Alp Mestanogullari at 2019-09-21T23:31:08-04:00
Fix haddocks for marker events in Debug.Trace
- - - - -
da12da79 by Daniel Gröber at 2019-09-22T14:34:56+02:00
rts: retainer: Remove cStackSize debug counter

This can only ever be one since 5f1d949ab9 ("Remove explicit recursion in
retainer profiling"), so it's pointless.

- - - - -
3ebaa4b5 by Daniel Gröber at 2019-09-22T15:17:53+02:00
rts: Remove bitrotten retainer debug code

The `defined(DEBUG_RETAINER) == true` branch doesn't even compile anymore
because 1) retainerSet was renamed to RetainerSet and 2) even if I fix that
the context in Rts.h seems to have changed such that it's not in scope. If
3) I fix that 'flip' is still not in scope :)  At that point I just gave up.

- - - - -
63023dc2 by Daniel Gröber at 2019-09-22T15:18:09+02:00
rts: Fix outdated references to 'ldvTime'

This got renamed to 'era' in dbef766ce7 ("[project @ 2001-11-26 16:54:21 by
simonmar] Profiling cleanup").

- - - - -
ead05f80 by Daniel Gröber at 2019-09-22T15:18:09+02:00
rts: retainer: Turn global traversal state into a struct

Global state is ugly and hard to test. Since the profiling code isn't quite
as performance critical as, say, GC we should prefer better code here.

I would like to move the 'flip' bit into the struct too but that's
complicated by the fact that the defines which use it directly are also
called from ProfHeap where the traversalState is not easily
available. Maybe in a future commit.

- - - - -
94ecdb4f by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Move info.next.parent to stackElement

I don't see a point in having this live in 'info', just seems to make the
code more complicated.

- - - - -
f79ac2ef by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Generalise per-stackElement data

This essentially ammounts to s/retainer/stackData/, s/c_child_r/data/ and
some temporary casting of c_child_r to stackData until refactoring of this
module is completed by a subsequent commit. We also introduce a new union
'stackData' which will contain the actual extra data to be stored on the
stack.

The idea is to make the heap traversal logic of the retainer profiler ready
for extraction into it's own module. So talking about "retainers" there
doesn't really make sense anymore.

Essentially the "retainers" we store in the stack are just data associated
with the push()ed closures which we return when pop()ing it.

- - - - -
f083358b by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Fix comment typo s/keeps/keep/

- - - - -
2f2f6dd5 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: Generalise profiling heap traversal flip bit handling

This commit starts renaming some flip bit related functions for the
generalised heap traversal code and adds provitions for sharing the
per-closure profiling header field currently used exclusively for retainer
profiling with other heap traversal profiling modes.

- - - - -
e40b3c23 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: GC: Remove redundant #include "RetainerProfiler.h"

- - - - -
b03db9da by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Pull retainer specific code into a callback

This essentially turns the heap traversal code into a visitor. You add a
bunch of roots to the work-stack and then the callback you give to
traverseWorkStack() will be called with every reachable closure at least
once.

- - - - -
48e816f0 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: simplify pop() control flow

Instead of breaking out of the switch-in-while construct using `return` this
uses `goto out` which makes it possible to share a lot of the out-variable
assignment code in all the cases.

I also replaced the nasty `while(true)` business by the real loop
condition: `while(*c == NULL)`. All `break` calls inside the switch aready
have either a check for NULL or an assignment of `c` to NULL so this should
not change any behaviour.

Using `goto out` also allowed me to remove another minor wart: In the
MVAR_*/WEAK cases the popOff() call used to happen before reading the
stackElement. This looked like a use-after-free hazard to me as the stack
is allocated in blocks and depletion of a block could mean it getting freed
and possibly overwritten by zero or garbage, depending on the block
allocator's behaviour.

- - - - -
b92ed68a by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: Add note reference to SET_PROF_HDR for profiling 'flip' bit

- - - - -
f3bb7397 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: RetainerSet: Remove obsolete fist/second-approach choice

In the old code when DEBUG_RETAINER was set, FIRST_APPROACH is
implied. However ProfHeap.c now depends on printRetainerSetShort which is
only available with SECOND_APPROACH. This is because with FIRST_APPROACH
retainerProfile() will free all retainer sets before returning so by the
time ProfHeap calls dumpCensus the retainer set pointers are segfaulty.

Since all of this debugging code obviously hasn't been compiled in ages
anyways I'm taking the liberty of just removing it.

Remember guys: Dead code is a liability not an asset :)

- - - - -
ec1d76e2 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Remove obsolete debug code

Commit dbef766ce7 ("Profiling cleanup.") made this debug code obsolete by
removing the 'cost' function without a replacement. As best I can tell the
retainer profiler used to do some heap census too and this debug code was
mainly concerned with that.

- - - - -
b7e15d17 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Rename heap traversal functions for extraction

This gets all remaining functions in-line with the new 'traverse' prefix
and module name.

- - - - -
64ec45a7 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Reduce DEBUG_RETAINER ifdef noise

Keeping track of the maximum stack seems like a good idea in all
configurations. The associated ASSERTs only materialize in debug mode but
having the statistic is nice.

To make the debug code less prone to bitrotting I introduce a function
'debug()' which doesn't actually print by default and is #define'd away
only when the standard DEBUG define is off.

- - - - -
bd78b696 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Cleanup comments and strings for traversal extraction

A lot of comments and strings are still talking about old names, fix
that.

- - - - -
cb7220b3 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Remove outdated invariants on traversePushStack

These invariants don't seem to make any sense in the current code.  The
text talks about c_child_r as if it were an StgClosure, for which RSET()
would make sense, but it's a retainer aka 'CostCentreStack*'.

- - - - -
bb92660c by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Use global STATIC_INLINE macro

STATIC_INLINE already does what the code wanted here, no need to duplicate
the functionality here.

- - - - -
2b76cf9e by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Move heap traversal declarations to new header

- - - - -
44d5cc0d by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Abstract maxStackSize for generic traversal

- - - - -
fd213d17 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Update obsolete docs for traverseMaybeInitClosureData

- - - - -
39f2878c by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Move actual 'flip' bit flip to generic traversal code

- - - - -
f9b4c4f2 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Remove traverse-stack chunk support

There's simply no need anymore for this whole business. Instead of
individually traversing roots in retainRoot() we just push them all onto
the stack and traverse everything in one go.

This feature was not really used anyways. There is an
`ASSERT(isEmptyWorkStack(ts))` at the top of retainRoot() which means there
really can't ever have been any chunks at the toplevel.

The only place where this was probably used is in traversePushStack but
only way back when we were still using explicit recursion on the
C callstack.

Since the code was changed to use an explicit traversal-stack these
stack-chunks can never escape one call to traversePushStack anymore.  See
commit 5f1d949ab9 ("Remove explicit recursion in retainer profiling")

- - - - -
c7def600 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Move mut_list reset to generic traversal code

- - - - -
9bf27060 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Make visit callback easier to implement

Currently it is necessary for user code to expend at least one extra bit in
the closure header just to know whether visit() should return true or
false, to indicate if children should be traversed.

The generic traversal code already has this information in the visited bit
so simply pass it to the visit callback.

- - - - -
96adf179 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: retainer: Improve Note [Profiling heap traversal visited bit]

- - - - -
187192a6 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: RetainerProfile.c: Re-enable and fix warnings

Turns out some genius disabled warnings for RetainerProfile.c in the build
system. That would have been good to know about five silent type mismatch
crashes ago.. :)

- - - - -
eb29735e by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: RetainerProfile.c: Minimize #includes

A lot of these includes are presumably leftovers from when the retainer
profiler still did it's own heap profiling.

- - - - -
383f9089 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: Split heap traversal from retainer profiler

This finally moves the newly generalised heap traversal code from the
retainer profiler into it's own file.

- - - - -
52c5ea71 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: TraverseHeap: Make comment style consistent

- - - - -
75355228 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: TraverseHeap: Make pushStackElement argument const

- - - - -
a8137780 by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: TraverseHeap: Move stackElement.cp back into nextPos union

The 'cp' field really is only used when type==posTypeFresh so it's more
space efficient to have it in the nextPos union.

- - - - -
7f10cc2d by Daniel Gröber at 2019-09-22T15:18:10+02:00
rts: RetainerProfile: Explain retainVisitClosure return values

[ci skip]

- - - - -
111f2761 by Daniel Gröber at 2019-09-22T15:33:41+02:00
rts: TraverseHeap: Add doc comment for getTraverseStackMaxSize

- - - - -
68ddb43c by Ben Gamari at 2019-09-23T00:34:00-04:00
gitlab-ci: Fix URL of Windows cabal-install tarball

- - - - -
0e478407 by Takenobu Tani at 2019-09-23T17:51:37-04:00
users-guide: Fix links and formats for GHC 8.10

This commit only fixes links and markdown syntax.

[skip ci]

- - - - -
74631bbc by Adam Sandberg Eriksson at 2019-09-23T17:52:32-04:00
base: add newtypes for socklen_t and ndfs_t to System.Posix.Types #16568

Metric Increase:
    haddock.base
    T4029

- - - - -
4470a144 by Björn Gohla at 2019-09-23T17:53:23-04:00
add Hadrian rule to build user guide as Info book

- - - - -
dbbea5a8 by Björn Gohla at 2019-09-23T17:53:23-04:00
use the Make builder instead of raw cmd_

- - - - -
b0e3b173 by Björn Gohla at 2019-09-23T17:53:23-04:00
detect makeinfo in configure(.ac)

- - - - -
9fe4d2df by Björn Gohla at 2019-09-23T17:53:23-04:00
explicit dependence on makeinfo

- - - - -
b650c2b6 by Björn Gohla at 2019-09-23T17:53:23-04:00
alphabetical ordering

- - - - -
27789294 by Björn Gohla at 2019-09-23T17:53:23-04:00
sort-paragraphs in runBuilderWith

- - - - -
d0c2f3a2 by Artem Pyanykh at 2019-09-23T17:54:04-04:00
[hadrian] Rebuild programs on dynamicGhcPrograms/ghcProfiled change

Currently, if you change these ^ flavour parameters, rebuilding is not
triggered, since `programContext` doesn't set up a dependency on
those values.

Exposing these values via an oracle does set the dependency and
properly triggers a rebuild of binaries.

Several attempts to factor out these actions ended up in cyclic
dependency here or there. I'm not absolutely happy with this variant
either, but at least it works.

====

Issue repro:

In UserSettings.hs:
```
dbgDynamic = defaultFlavour { name = "dbg-dynamic"
                            , dynamicGhcPrograms = pure True,
                            ... }

dbgStatic = defaultFlavour { name = "dbg-static"
                           , dynamicGhcPrograms = pure False
                           ... }
```

Then in console:

```
$ hadrian/build.sh -j --flavour=dbg-dynamic
... does the build
$ hadrian/build.sh -j --flavour=dbg-static
... does nothing, considers binaries up to date
```

- - - - -
238b58e4 by Kari Pahula at 2019-09-23T17:54:42-04:00
Add -fkeep-going to make compiler continue despite errors (#15424)

Add a new optional failure handling for upsweep which continues
the compilation on other modules if any of them has errors.

- - - - -
146f26cc by Sebastian Graf at 2019-09-24T01:06:40-04:00
Some leftovers from !1732. Comments only [skip ci]

- - - - -
b5f24fb4 by Takenobu Tani at 2019-09-24T01:07:19-04:00
Hadrian: Add -haddock option for GHCi's :doc command

This commit adds -haddock option to Hadrian-based build system.

To enable :doc command on GHCi, core libraries must be compiled
with -haddock option.
Especially, the `-haddock` option is essential for a release build.

Assuming current GitLab CI condition (.gitlab-ci.yml),
I add -haddock option to the default flavour only.

This has already been done for Make-based build system.
Please see #16415.

- - - - -
f97a7aac by Sebastian Graf at 2019-09-24T01:07:57-04:00
Fix some duplication in the parser

D3673 experienced reduce/reduce conflicts when trying to use
opt_instance for associated data families.

That was probably because the author tried to use it for
Haskell98-syntax without also applying it to GADT-syntax, which actually
leads to a reduce/reduce conflict. Consider the following state:

```
data . T = T
data . T where T :: T
```

The parser must decide at this point whether or not to reduce an empty
`opt_instance`. But doing so would also commit to either
Haskell98 or GADT syntax! Good thing we also accept an optional
"instance" for GADT syntax, so the `opt_instance` is there in both
productions and there's no reduce/reduce conflict anymore.

Also no need to inline `opt_instance`, how it used to be.

- - - - -
b23f01fd by Ben Gamari at 2019-09-24T08:49:43-04:00
base: Add link to "A reflection on types"

Fixes #17181.

- - - - -
4bbe0dba by Ben Gamari at 2019-09-24T08:50:20-04:00
gitlab-ci: Bump ci-images

This bumps the CI Docker images to
ghc/ci-images at 990c5217d1d0e03aea415f951afbc3b1a89240c6.

- - - - -
6bca867c by Ben Gamari at 2019-09-24T08:50:59-04:00
hadrian: Update source-repository
- - - - -
b2d47536 by Ben Gamari at 2019-09-24T08:51:45-04:00
testsuite: Mark threadstatus-9333 as fragile in profthreaded

Due to #16555.

- - - - -
ed520678 by Andreas Klebinger at 2019-09-24T21:08:42-04:00
Fix bounds check in ocResolve_PEi386 for relocation values.

The old test was wrong at least for gcc and the value -2287728808L.

It also relied on implementation defined behaviour (right shift
on a negative value), which might or might not be ok.
Either way it's now a simple comparison which will always work.

- - - - -
218c5dbf by Matthew Pickering at 2019-09-24T21:09:23-04:00
Add ghcide configuration files

This commit adds three new files

1. A hie.yaml file to the project root which specifies to IDEs how to
set up the correct environment for loading GHC. This currently
specifies to call the `./hadrian/hie-bios` script.
2. A `hie.yaml` file for the hadrian subcomponent, which uses the
`cabal` cradle type.
2. The `./hadrian/hie-bios` script which supplies the correct arguments
for an IDE to start a session.

With these two files it is possible to run

```
ghcide compiler/
```

and successfully load all the modules for use in the IDE.

or

```
ghcide --cwd hadrian/ src/
```

to test loading all of Hadrian's modules.

Closes #17194

- - - - -
2970dc7a by Kari Pahula at 2019-09-25T13:52:48-04:00
Add -Wderiving-defaults (#15839)

Enabling both DeriveAnyClass and GeneralizedNewtypeDeriving can cause
a warning when no explicit deriving strategy is in use. This change adds
an enable/suppress flag for it.

- - - - -
4540bbe2 by John Ericson at 2019-09-25T13:53:42-04:00
includes/CodeGen.Platform.hs don't include ghcautoconf.h

It doesn't need it, and it shouldn't need it or else multi-target will
break.

- - - - -
ebc65025 by Sebastian Graf at 2019-09-25T13:54:22-04:00
PmCheck: Only ever check constantly many models against a single pattern

Introduces a new flag `-fmax-pmcheck-deltas` to achieve that. Deprecates
the old `-fmax-pmcheck-iter` mechanism in favor of this new flag.

>From the user's guide:

Pattern match checking can be exponential in some cases. This limit makes sure
we scale polynomially in the number of patterns, by forgetting refined
information gained from a partially successful match. For example, when
matching `x` against `Just 4`, we split each incoming matching model into two
sub-models: One where `x` is not `Nothing` and one where `x` is `Just y` but
`y` is not `4`. When the number of incoming models exceeds the limit, we
continue checking the next clause with the original, unrefined model.

This also retires the incredibly hard to understand "maximum number of
refinements" mechanism, because the current mechanism is more general
and should catch the same exponential cases like PrelRules at the same
time.

-------------------------
Metric Decrease:
    T11822
-------------------------

- - - - -
d90d0bad by Ben Gamari at 2019-09-25T13:55:09-04:00
base: Move Ix typeclass to GHC.Ix

The `Ix` class seems rather orthogonal to its original home in
`GHC.Arr`.

- - - - -
795986aa by Ryan Scott at 2019-09-25T13:56:07-04:00
Remove unneeded CPP now that GHC 8.6 is the minimum

The minimum required GHC version for bootstrapping is 8.6, so we can
get rid of some unneeded `#if `__GLASGOW_HASKELL__` CPP guards, as
well as one `MIN_VERSION_ghc_prim(0,5,3)` guard (since GHC 8.6 bundles
`ghc-prim-0.5.3`).

- - - - -
0b5eede9 by Vladislav Zavialov at 2019-09-25T21:06:04+03:00
Standalone kind signatures (#16794)

Implements GHC Proposal #54: .../ghc-proposals/blob/master/proposals/0054-kind-signatures.rst

With this patch, a type constructor can now be given an explicit
standalone kind signature:

  {-# LANGUAGE StandaloneKindSignatures #-}
  type Functor :: (Type -> Type) -> Constraint
  class Functor f where
    fmap :: (a -> b) -> f a -> f b

This is a replacement for CUSKs (complete user-specified
kind signatures), which are now scheduled for deprecation.

User-facing changes
-------------------

* A new extension flag has been added, -XStandaloneKindSignatures, which
  implies -XNoCUSKs.

* There is a new syntactic construct, a standalone kind signature:

    type <name> :: <kind>

  Declarations of data types, classes, data families, type families, and
  type synonyms may be accompanied by a standalone kind signature.

* A standalone kind signature enables polymorphic recursion in types,
  just like a function type signature enables polymorphic recursion in
  terms. This obviates the need for CUSKs.

* TemplateHaskell AST has been extended with 'KiSigD' to represent
  standalone kind signatures.

* GHCi :info command now prints the kind signature of type constructors:

    ghci> :info Functor
    type Functor :: (Type -> Type) -> Constraint
    ...

Limitations
-----------

* 'forall'-bound type variables of a standalone kind signature do not
  scope over the declaration body, even if the -XScopedTypeVariables is
  enabled. See #16635 and #16734.

* Wildcards are not allowed in standalone kind signatures, as partial
  signatures do not allow for polymorphic recursion.

* Associated types may not be given an explicit standalone kind
  signature. Instead, they are assumed to have a CUSK if the parent class
  has a standalone kind signature and regardless of the -XCUSKs flag.

* Standalone kind signatures do not support multiple names at the moment:

    type T1, T2 :: Type -> Type   -- rejected
    type T1 = Maybe
    type T2 = Either String

  See #16754.

* Creative use of equality constraints in standalone kind signatures may
  lead to GHC panics:

    type C :: forall (a :: Type) -> a ~ Int => Constraint
    class C a where
      f :: C a => a -> Int

  See #16758.

Implementation notes
--------------------

* The heart of this patch is the 'kcDeclHeader' function, which is used to
  kind-check a declaration header against its standalone kind signature.
  It does so in two rounds:

    1. check user-written binders
    2. instantiate invisible binders a la 'checkExpectedKind'

* 'kcTyClGroup' now partitions declarations into declarations with a
  standalone kind signature or a CUSK (kinded_decls) and declarations
  without either (kindless_decls):

    * 'kinded_decls' are kind-checked with 'checkInitialKinds'
    * 'kindless_decls' are kind-checked with 'getInitialKinds'

* DerivInfo has been extended with a new field:

    di_scoped_tvs :: ![(Name,TyVar)]

  These variables must be added to the context in case the deriving clause
  references tcTyConScopedTyVars. See #16731.

- - - - -
4f81fab0 by Ryan Scott at 2019-09-26T14:04:38-04:00
Make -fbyte-code prevent unboxed tuples/sums from implying object code (#16876)

This resolves #16876 by making the explicit use of `-fbyte-code`
prevent code that enables `UnboxedTuples` or `UnboxedSums` from
automatically compiling to object code. This allows for a nice
middle ground where most code that enables `UnboxedTuples`/-`Sums`
will still benefit from automatically enabling `-fobject-code`, but
allows power users who wish to avoid this behavior in certain corner
cases (such as `lens`, whose use case is documented in #16876) to do
so.

Along the way, I did a little cleanup of the relevant code and
documentation:

* `enableCodeGenForUnboxedTuples` was only checking for the presence
  of `UnboxedTuples`, but `UnboxedSums` has the same complications.
  I fixed this and renamed the function to
  `enableCodeGenForUnboxedTuplesOrSums`.
* I amended the users' guide with a discussion of these issues.

- - - - -
289fc8da by Sebastian Graf at 2019-09-27T22:10:17-04:00
PmCheck: Elaborate what 'model' means in the user guide [skip ci]

- - - - -
9c02a793 by Ron Mordechai at 2019-09-27T22:11:06-04:00
Allow users to disable Unicode with an env var

Unicode renders funny on my terminal and I like to avoid it where
possible. Most applications which print out non-ascii characters allow
users to disable such prints with an environment variable (e.g.
Homebrew).

This diff disables Unicode usage when the environment variable
`GHC_NO_UNICODE` is set. To test, set the env var and compile a bad
program. Note that GHC does not print Unicode bullets but instead prints
out asterisks:

```
$ GHC_NO_UNICODE= _build/stage1/bin/ghc ../Temp.hs
[1 of 1] Compiling Temp             ( ../Temp.hs, ../Temp.o )

../Temp.hs:4:23: error:
    * Couldn't match type `Bool' with `a -> Bool'
      Expected type: Bool -> a -> Bool
        Actual type: Bool -> Bool
    * In the first argument of `foldl', namely `(&& (flip $ elem u))'
      In the expression: foldl (&& (flip $ elem u)) True v
      In an equation for `isPermut':
          isPermut u v = foldl (&& (flip $ elem u)) True v
    * Relevant bindings include
        v :: [a] (bound at ../Temp.hs:4:12)
        u :: [a] (bound at ../Temp.hs:4:10)
        isPermut :: [a] -> [a] -> Bool (bound at ../Temp.hs:4:1)
  |
4 | isPermut u v = foldl (&& (flip $ elem u)) True v
  |                       ^^^^^^^^^^^^^^^^^^
```

(Broken code taken from Stack Overflow)

- - - - -
144abba3 by Ben Gamari at 2019-09-27T22:11:53-04:00
configure: Don't depend upon alex in source dist build

This fixes #16860 by verifying that the generated sources don't already
exist before asserting that the `alex` executable was found. This
replicates the logic already used for `happy` in the case of `alex`.

- - - - -
c6fb913c by John Ericson at 2019-09-27T22:12:35-04:00
Just get RTS libs from its package conf

`rts.conf` already contains this exact information in its
`extra-libraries` stanza.

- - - - -
f07862b4 by Ben Gamari at 2019-09-27T22:13:16-04:00
ghc-prim: Fix documentation of Type

As pointed out in #17243, `Type` is not the only kind
having values.
- - - - -
0201d0bf by chris-martin at 2019-09-27T22:14:00-04:00
Clarify the purpose and status of the GHC.TypeLits module
- - - - -
444e554f by chris-martin at 2019-09-27T22:14:00-04:00
Expand description of DataKinds to mention data constructors, and include mention of TypeError
- - - - -
1582dafa by Sebastian Graf at 2019-09-27T22:14:44-04:00
PmCheck: Look at precendence to give type signatures to some wildcards

Basically do what we currently only do for -XEmptyCase in other cases
where adding the type signature won't distract from pattern
matches in other positions.

We use the precedence to guide us, equating "need to parenthesise" with
"too much noise".

- - - - -
ad0c4390 by Shayne Fletcher at 2019-09-27T22:15:27-04:00
Add test for expected dependencies of 'Parser'

- - - - -
0b1fa64d by Ben Gamari at 2019-09-27T22:16:04-04:00
testsuite: Mark cgrun071 as broken on i386

As described in #17247.

- - - - -
24620182 by Daniel Gröber at 2019-09-27T22:17:04-04:00
Raise minimum GHC version to 8.6

commit 795986aaf33e ("Remove unneeded CPP now that GHC 8.6 is the minimum")
broke the 8.4 build.

- - - - -
e0bbb961 by Ben Gamari at 2019-09-27T22:17:44-04:00
testsuite: Mark compact_gc as fragile in the ghci way

As noted in #17253.

- - - - -
bb984ac6 by Ben Gamari at 2019-09-27T22:18:42-04:00
testsuite: Mark hs_try_putmvar003 as fragile in threaded1

Due to #16361. Note that I'm leaving out threaded2 since it's not clear
whether the single crash in that way was due to other causes.

- - - - -
ad2a1f99 by Ben Gamari at 2019-09-27T22:19:26-04:00
testsuite: Mark T3389 as broken in profiled ways on i386

As noted in #17256.

- - - - -
6f9fa0be by Ben Gamari at 2019-09-27T22:20:04-04:00
testsuite: Mark TH tests as fragile in LLVM built external-interpreter

Due to #16087. This drops the previous explicit list of broken tests and rather
encompasses the entire set of tests since they all appear to be broken.

- - - - -
c5d888d4 by Sebastian Graf at 2019-09-28T17:11:41-04:00
PmCheck: No ConLike instantiation in pmcheck

`pmcheck` used to call `refineToAltCon` which would refine the knowledge
we had about a variable by equating it to a `ConLike` application.
Since we weren't particularly smart about this in the Check module, we
simply freshened the constructors existential and term binders utimately
through a call to `mkOneConFull`.

But that instantiation is unnecessary for when we match against a
concrete pattern! The pattern will already have fresh binders and field
types. So we don't call `refineToAltCon` from `Check` anymore.

Subsequently, we can simplify a couple of call sites and functions in
`PmOracle`. Also implementing `computeCovered` becomes viable and we
don't have to live with the hack that was `addVarPatVecCt` anymore.

A side-effect of not indirectly calling `mkOneConFull` anymore is that
we don't generate the proper strict argument field constraints anymore.
Instead we now desugar ConPatOuts as if they had bangs on their strict
fields. This implies that `PmVar` now carries a `HsImplBang` that we
need to respect by a (somewhat ephemeral) non-void check. We fix #17234
in doing so.

- - - - -
ce64b397 by Sebastian Graf at 2019-09-28T17:12:26-04:00
`exprOkForSpeculation` for Note [IO hack in the demand analyser]

In #14998 I realised that the notion of speculative execution
*exactly matches* eager evaluation of expressions in a case alternative
where the scrutinee is an IO action.

Normally we have to `deferIO` any result from that single case
alternative to prevent this speculative execution, so we had a special
case in place in the demand analyser that would check if the scrutinee
was a prim-op, in which case we assumed that it would be ok to do the
eager evaluation.

Now we just check if the scrutinee is `exprOkForSpeculation`,
corresponding to the notion that we want to push evaluation of the
scrutinee *after* eagerly evaluating stuff from the case alternative.

This fixes #14988, because it resolves the last open Item 4 there.

- - - - -
f3cb8c7c by Ömer Sinan Ağacan at 2019-09-30T22:39:53-04:00
Refactor iface file generation:

This commit refactors interface file generation to allow information
from the later passed (NCG, STG) to be stored in interface files.

We achieve this by splitting interface file generation into two parts:
* Partial interfaces, built based on the result of the core pipeline
* A fully instantiated interface, which also contains the final
fingerprints and can optionally contain information produced by the backend.

This change is required by !1304 and !1530.

-dynamic-too handling is refactored too: previously when generating code
we'd branch on -dynamic-too *before* code generation, but now we do it
after.

(Original code written by @AndreasK in !1530)

Performance
~~~~~~~~~~~

Before this patch interface files where created and immediately flushed
to disk which made space leaks impossible.
With this change we instead use NFData to force all iface related data
structures to avoid space leaks.

In the process of refactoring it was discovered that the code in the
ToIface Module allocated a lot of thunks which were immediately forced
when writing/forcing the interface file. So we made this module more
strict to avoid creating many of those thunks.

Bottom line is that allocations go down by about ~0.1% compared to
master.
Residency is not meaningfully different after this patch.
Runtime was not benchmarked.

Co-Authored-By: Andreas Klebinger <klebinger.andreas at gmx.at>
Co-Authored-By: Ömer Sinan Ağacan <omer at well-typed.com>

- - - - -
6a1700aa by Simon Peyton Jones at 2019-09-30T22:40:30-04:00
Fix arguments for unbound binders in RULE application

We were failing to correctly implement Note [Unbound RULE binders]
in Rules.hs.  In particular, when cooking up a fake Refl,
were were failing to apply the substitition.

This patch fixes that problem, and simultaneously tidies
up the impedence mis-match between RuleSubst and TCvSubst.

Thanks to Sebastian!

- - - - -
97811ef5 by Takenobu Tani at 2019-09-30T22:41:35-04:00
Add help message for GHCi :instances command

This commit updates GHCi's help message for GHC 8.10.

- - - - -
6f8550a3 by Sebastian Graf at 2019-09-30T22:42:14-04:00
Move pattern match checker modules to GHC.HsToCore.PmCheck

- - - - -
b36dd49b by Takenobu Tani at 2019-09-30T22:42:53-04:00
testsuite: Add minimal test for :doc command

Currently, there are no testcases for GHCi `:doc` command.
Perhaps because it was experimental. And it could be changed in the future.

But `:doc` command is already useful, so I add a minimal regression test
to keep current behavior.

See also 85309a3cda for implementation of `:doc` command.

- - - - -
bdba6ac2 by Vladislav Zavialov at 2019-09-30T22:43:31-04:00
Do not rely on CUSKs in 'base'

Use standalone kind signatures instead of complete user-specified kinds
in Data.Type.Equality and Data.Typeable

- - - - -
dbdf6a3d by Ben Gamari at 2019-09-30T22:44:07-04:00
testsuite: Mark T3389 as broken in hpc way on i386

See #17256.

- - - - -
822481d5 by Ben Gamari at 2019-09-30T22:44:44-04:00
Bump process submodule

Marks process003 as fragile, as noted in #17245.

- - - - -
6548b7b0 by Sebastian Graf at 2019-10-01T09:22:10+00:00
Add a bunch of testcases for the pattern match checker

Adds regression tests for tickets #17207, #17208, #17215, #17216,
 #17218, #17219, #17248

- - - - -
58013220 by Sebastian Graf at 2019-10-01T09:22:18+00:00
Add testcases inspired by Luke Maranget's pattern match series

In his paper "Warnings for Pattern Matching", Luke Maranget describes
three series in his appendix for which GHC's pattern match checker
scaled very badly. We mostly avoid this now with !1752. This commit adds
regression tests for each of the series.

Fixes #17264.

- - - - -
9c002177 by Ryan Scott at 2019-10-01T16:24:12-04:00
Refactor some cruft in TcDeriv

* `mk_eqn_stock`, `mk_eqn_anyclass`, and `mk_eqn_no_mechanism` all
  took a continuation of type
  `DerivSpecMechanism -> DerivM EarlyDerivSpec` to represent its
  primary control flow. However, in practice this continuation was
  always instantiated with the `mk_originative_eqn` function, so
  there's not much point in making this be a continuation in the
  first place.

  This patch removes these continuations in favor of invoking
  `mk_originative_eqn` directly, which is simpler.
* There were several parts of `TcDeriv` that took different code
  paths if compiling an `.hs-boot` file. But this is silly, because
  ever since 101a8c770b9d3abd57ff289bffea3d838cf25c80 we simply error
  eagerly whenever attempting to derive any instances in an
  `.hs-boot` file.

  This patch removes all of the unnecessary `.hs-boot` code paths,
  leaving only one (which errors out).
* Remove various error continuation arguments from `mk_eqn_stock`
  and related functions.

- - - - -
9a27a063 by David Eichmann at 2019-10-01T16:55:33-04:00
Hadrian: Libffi rule now `produces` dynamic library files.

- - - - -
0956c194 by David Eichmann at 2019-10-01T16:55:33-04:00
Hadrian: do not cache GHC configure rule

- - - - -
8924224e by Ömer Sinan Ağacan at 2019-10-01T16:55:37-04:00
Make small INLINE functions behave properly

Simon writes:

Currently we check for a type arg rather than isTyCoArg.   This in turn
makes INLINE things look bigger than they should be, and stops them
being inlined into boring contexts when they perfectly well could be.
E.g.

    f x = g <refl> x
    {-# INLINE g #-}

    ... (map (f x) xs) ...

The context is boring, so don't inline unconditionally.  But f's RHS is
no bigger than its call, provided you realise that the coercion argument
is ultimately cost-free.

This happens in practice for $WHRefl. It's not a big deal: at most it
means we have an extra function call overhead.  But it's untidy, and
actually worse than what happens without an INLINE pragma.

Fixes #17182

This makes 0.0% change in nofib binary sizes.

- - - - -
53b0c6e0 by Gabor Greif at 2019-10-03T08:15:50-04:00
Typo in comment [ci skip]
- - - - -
60229e9e by Ryan Scott at 2019-10-03T12:17:10-04:00
Merge TcTypeableValidity into TcTypeable, document treatment of casts

This patch:

* Implements a refactoring (suggested in
  https://gitlab.haskell.org/ghc/ghc/merge_requests/1199#note_207345)
  that moves all functions from `TcTypeableValidity` back to
  `TcTypeable`, as the former module doesn't really need to live on its
  own.
* Adds `Note [Typeable instances for casted types]` to `TcTypeable`
  explaining why the `Typeable` solver currently does not support
  types containing casts.

Resolves #16835.

- - - - -
3b9d4907 by Richard Eisenberg at 2019-10-03T12:17:13-04:00
Note [Don't flatten tuples from HsSyn] in MkCore

Previously, we would sometimes flatten 1-tuples and sometimes
not. This didn't cause damage because there is no way to
generate HsSyn with 1-tuples. But, with the upcoming fix to #16881,
there will be. Without this patch, obscure lint errors would
have resulted.

No test case, as there is not yet a way to tickle this.

- - - - -
8a254d6b by Ömer Sinan Ağacan at 2019-10-03T12:17:19-04:00
Fix new compact block allocation in allocateForCompact

allocateForCompact() is called when nursery of a compact region is
full, to add new blocks to the compact. New blocks added to an existing
region needs a StgCompactNFDataBlock header, not a StgCompactNFData.

This fixes allocateForCompact() so that it now correctly allocates space
for StgCompactNFDataBlock instead of StgCompactNFData as before.

Fixes #17044.

A regression test T17044 added.

- - - - -
3c7b172b by James Brock at 2019-10-03T12:17:24-04:00
docs String, hyperlink to Data.List

Add a reference to the documentation for Data.List in the description
for String.

On the generated Haddock for Data.String,

http://hackage.haskell.org/package/base-4.12.0.0/docs/Data-String.html

there is curently no hyperlink to Data.List, which is where a reader will find most of the useful functions which can operate on Strings. I imagine this has confused beginners who came to this page looking for String operations.

- - - - -
67bf734c by John Ericson at 2019-10-03T12:17:28-04:00
Add `module {-# SOURCE #-} Foo` syntax for hs-boot in bkp

This is a good convenience for testing.

- - - - -
6655ec73 by Richard Eisenberg at 2019-10-03T12:17:30-04:00
Improve documentation around empty tuples/lists

This patch also changes the way we handle empty lists, simplifying
them somewhat. See Note [Empty lists]. Previously, we had to
special-case empty lists in the type-checker. Now no more!

Finally, this patch improves some documentation around the ir_inst
field used in the type-checker.

This breaks a test case, but I really think the problem is #17251,
not really related to this patch.

Test case: typecheck/should_compile/T13680

- - - - -
9a4ff210 by John Ericson at 2019-10-03T12:17:31-04:00
Make Haddock submodule remote point to gitlab mirror

This makes it match the others

- - - - -
cb364bc2 by Ben Gamari at 2019-10-03T12:17:32-04:00
testsuite:  Mark print037 as fragile, not broken

See #16205.

- - - - -
259f4dff by Ben Gamari at 2019-10-03T12:17:32-04:00
Exclude rts.cabal from source distributions

This modifies both the Hadrian and make build systems to avoid included
the rts.cabal generated by autoconf in the source distribution.

Fixes #17265.

- - - - -
e4c93896 by Ben Gamari at 2019-10-03T12:17:32-04:00
DynFlags: Only warn when split-sections is ignored

Previously we would throw an error which seems a bit harsh. As reported
in #17283.

- - - - -
ee6324ad by Tobias Guggenmos at 2019-10-03T12:17:33-04:00
Improve documentation for runtime debugging flags

- - - - -
47386fe8 by Tobias Guggenmos at 2019-10-03T12:17:33-04:00
Add new debug flag -DZ

Zeros heap memory after gc freed it.

- - - - -
d0924b15 by Stefan Schulze Frielinghaus at 2019-10-03T12:17:34-04:00
Extend argument of createIOThread to word size

Function createIOThread expects its second argument to be of size word.
The natural size of the second parameter is 32bits. Thus for some 64bit
architectures, where a write of the lower half of a register does not
clear the upper half, the value must be zero extended.

- - - - -
1357d023 by Ben Gamari at 2019-10-03T12:17:34-04:00
rules/haddock: Ensure that RTS stats directory exists

It may not exist if the source tarball was extracted yet not the
testsuite tarball.

- - - - -
ec93d2a9 by Fumiaki Kinoshita at 2019-10-04T21:43:49-04:00
Add Monad instances to `(,,) a b` and `(,,,) a b c`

- - - - -
05419e55 by John Ericson at 2019-10-04T21:44:29-04:00
Per stage headers, ghc_boot_platform.h -> stage 0 ghcplatform.h

The generated headers are now generated per stage, which means we can
skip hacks like `ghc_boot_platform.h` and just have that be the stage 0
header as proper. In general, stages are to be embraced: freely generate
everything in each stage but then just build what you depend on, and
everything is symmetrical and efficient. Trying to avoid stages because
bootstrapping is a mind bender just creates tons of bespoke
mini-mind-benders that add up to something far crazier.

Hadrian was pretty close to this "stage-major" approach already, and so
was fairly easy to fix. Make needed more work, however: it did know
about stages so at least there was a scaffold, but few packages except
for the compiler cared, and the compiler used its own counting system.
That said, make and Hadrian now work more similarly, which is good for
the transition to Hadrian. The merits of embracing stage aside, the
change may be worthy for easing that transition alone.

- - - - -
75a5dd8e by John Ericson at 2019-10-04T21:44:29-04:00
Remove {Build,Host}Platform_NAME from header

They are only used in a file we construct directly, so just skip CPP.

- - - - -
b538476b by Daroc Alden at 2019-10-04T21:45:09-04:00
Deprecate -fwarn-hi-shadowing, because it was never implemented and is
not used.

This fixes #10913.

- - - - -
dd8f76b2 by John Ericson at 2019-10-04T21:45:48-04:00
Factor out a smaller part of Platform for host fallback

- - - - -
d15b44d6 by John Ericson at 2019-10-04T21:45:49-04:00
Pull out the settings file parsing code into it's own module.

This has two benefits:

1. One less hunk of code dependent on DynFlags

2. Add a little bit of error granularity to distrinugish between missing
   data and bad data. This could someday be shared with ghc-pkg which
   aims to work even with a missing file. I also am about to to make
   --supported-extensions use this too.

- - - - -
eb892b28 by John Ericson at 2019-10-04T21:45:49-04:00
Add tryFindTopDir to look for the top dir without blowing up if it is
not found.

- - - - -
0dded5ec by John Ericson at 2019-10-04T21:45:49-04:00
Always enable the external interpreter

You can always just not use or even build `iserv`. I don't think the
maintenance cost of the CPP is worth...I can't even tell what the
benefit is.

- - - - -
0d31ccdd by Artem Pyanykh at 2019-10-04T21:46:28-04:00
[linker, macho] Don't map/allocate zero size sections and segments

Zero size sections are common even during regular build on MacOS. For
instance:

```
$ ar -xv libHSghc-prim-0.6.1.a longlong.o
$ otool -l longlong.o
longlong.o:
Mach header
      magic cputype cpusubtype  caps    filetype ncmds sizeofcmds      flags
 0xfeedfacf 16777223          3  0x00           1     2        176 0x00002000
Load command 0
      cmd LC_SEGMENT_64
  cmdsize 152
  segname
   vmaddr 0x0000000000000000
   vmsize 0x0000000000000000 <-- segment size = 0
  fileoff 208
 filesize 0
  maxprot 0x00000007
 initprot 0x00000007
   nsects 1
    flags 0x0
Section
  sectname __text
   segname __TEXT
      addr 0x0000000000000000
      size 0x0000000000000000 <-- section size = 0
    offset 208
     align 2^0 (1)
    reloff 0
    nreloc 0
     flags 0x80000000
 reserved1 0
 reserved2 0
       cmd LC_BUILD_VERSION
   cmdsize 24
  platform macos
       sdk 10.14
     minos 10.14
    ntools 0
```

The issue of `mmap`ing 0 bytes was resolved in !1050, but the problem
remained. These 0 size segments and sections were still allocated in
object code, which lead to failed `ASSERT(size > 0)` in
`addProddableBlock` further down the road.

With this change zero size segments **and** sections are not
mapped/allocated at all.

Test plan:

1. Build statically linked GHC.

2. Run `ghc --interactive`. Observe that REPL loads
successfully (which was not the case before).

3. Load several more compiled hs files into repl. No failures.

- - - - -
93f02b62 by Roland Senn at 2019-10-04T21:47:07-04:00
New fix for #11647. Avoid side effects like #17171

If a main module doesn't contain a header, we omit the check whether the main module is exported.
With this patch GHC, GHCi and runghc use the same code.

- - - - -
8039b625 by Matthew Bauer at 2019-10-04T21:47:47-04:00
Add musl systems to llvm-targets

This was done in Nixpkgs, but never upstreamed. Musl is pretty much
the same as gnu, but with a different libc. I’ve used the same values
for everything.

- - - - -
ee8118ca by John Ericson at 2019-10-05T00:11:58-04:00
Clean up `#include`s in the compiler

 - Remove unneeded ones

 - Use <..> for inter-package.
   Besides general clean up, helps distinguish between the RTS we link
   against vs the RTS we compile for.

- - - - -
241921a0 by Ben Gamari at 2019-10-05T19:18:40-04:00
rts: Fix CNF dirtying logic

Previously due to a silly implementation bug CNFs would never have their
dirty flag set, resulting in their being added again and again to the
`mut_list`. Fix this.

Fixes #17297.

- - - - -
825c108b by Ryan Scott at 2019-10-07T12:00:59-04:00
Only flatten up to type family arity in coreFlattenTyFamApp (#16995)

Among other uses, `coreFlattenTyFamApp` is used by Core Lint as a
part of its check to ensure that each type family axiom reduces
according to the way it is defined in the source code. Unfortunately,
the logic that `coreFlattenTyFamApp` uses to flatten type family
applications disagreed with the logic in `TcFlatten`, which caused
it to spuriously complain this program:

```hs
type family Param :: Type -> Type

type family LookupParam (a :: Type) :: Type where
  LookupParam (f Char) = Bool
  LookupParam x        = Int

foo :: LookupParam (Param ())
foo = 42
```

This is because `coreFlattenTyFamApp` tries to flatten the `Param ()`
in `LookupParam (Param ())` to `alpha` (where `alpha` is a flattening
skolem), and GHC is unable to conclude that `alpha` is apart from
`f Char`. This patch spruces up `coreFlattenTyFamApp` so that it
instead flattens `Param ()` to `alpha ()`, which GHC _can_ know for
sure is apart from `f Char`. See
`Note [Flatten], wrinkle 3` in `FamInstEnv`.

- - - - -
b2577081 by Ben Gamari at 2019-10-07T12:01:46-04:00
Refactor, document, and optimize LLVM configuration loading

As described in the new Note [LLVM Configuration] in SysTools, we now
load llvm-targets and llvm-passes lazily to avoid the overhead of doing
so when -fllvm isn't used (also known as "the common case").

Noticed in #17003.

Metric Decrease:
    T12234
    T12150

- - - - -
93c71ae6 by Ben Gamari at 2019-10-07T12:02:23-04:00
configure: Determine library versions of template-haskell, et al.

These are needed by the user guide documentation. Fixes #17260.

- - - - -
b7890611 by Andrey Mokhov at 2019-10-07T12:03:13-04:00
Hadrian: Stop using in-tree Cabal

- - - - -
0ceb98f6 by Andrey Mokhov at 2019-10-07T12:03:13-04:00
Switch to cabal-version=3.0 in ghc-heap.cabal

- - - - -
e3418e96 by Andrey Mokhov at 2019-10-07T12:03:13-04:00
Switch to cabal-version=3.0 in base.cabal and rts.cabal

- - - - -
805653f6 by John Ericson at 2019-10-07T12:04:19-04:00
Get rid of wildcard patterns in prim Cmm emitting code

This way, we can be sure we don't miss a case.

- - - - -
ab945819 by Ryan Scott at 2019-10-07T12:05:09-04:00
Refactor some cruft in TcGenGenerics

* `foldBal` contains needless partiality that can easily be avoided.
* `mkProd_E` and `mkProd_P` both contain unique supply arguments that
  are completely unused, which can be removed.

- - - - -
d0edba3a by John Ericson at 2019-10-07T12:05:47-04:00
Remove CONFIGURE_ARGS from configure.ac

It looks like it's been unused since at least
34cc75e1a62638f2833815746ebce0a9114dc26b.

- - - - -
9a6bfb0a by John Ericson at 2019-10-07T12:06:26-04:00
Keep OSTYPE local to configure.ac

Unused outside it since b6be81b841e34ca45b3549c4c79e886a8761e59a.

- - - - -
4df39fd0 by John Ericson at 2019-10-07T12:07:08-04:00
Get rid of GHC_PACKAGE_DB_FLAG

We no longer support booting from older GHC since
527bcc41630918977c73584d99125ff164400695.

- - - - -
31a29a7a by John Ericson at 2019-10-07T12:07:46-04:00
Remove GhcLibsWithUnix

d679ca43e7477284d733b94ff542be5363be3353 meant to remove it but did not
finish the job.

- - - - -
77ca39e3 by Ben Gamari at 2019-10-08T05:11:03-04:00
gitlab-ci: Add missing TEST_ENV variables

This should fix #16985.

- - - - -
9a2798e1 by Ben Gamari at 2019-10-08T05:11:03-04:00
hadrian: Add `validate` and `slow validate` flavours

- - - - -
ab311696 by Ben Gamari at 2019-10-08T05:11:03-04:00
validate: Use Hadrian's validate flavour

- - - - -
98179a77 by Ben Gamari at 2019-10-08T05:11:03-04:00
gitlab-ci: Use validate flavour in hadrian builds

- - - - -
8af9eba8 by Ben Gamari at 2019-10-08T05:11:40-04:00
base: Document the fact that Typeable is automatically "derived"

This fixes #17060.

- - - - -
397c6ed5 by Sebastian Graf at 2019-10-08T05:12:15-04:00
PmCheck: Identify some semantically equivalent expressions

By introducing a `CoreMap Id` to the term oracle, we can represent
syntactically equivalent expressions by the same `Id`. Combine that with
`CoreOpt.simpleCoreExpr` and it might even catch non-trivial semantic
equalities.

Unfortunately due to scoping issues, this will not solve #17208 for
view patterns yet.

- - - - -
8a2e8408 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Refer to language extension flags via :extension:

Previously several were referred to via :ghc-flag:`-X...`.

- - - - -
7cd54538 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Make reverse flags addressable via :ghc-flag:

Previously one could not easily link to the :reverse: flag of a
ghc-flag.

- - - - -
e9813afc by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Document -XHaskell98 and -XHaskell2010

- - - - -
eaeb28a1 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Fix various warnings

- - - - -
180cf177 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Document NondecreasingIndentation

- - - - -
0a26f9e8 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Document -fworker-wrapper

- - - - -
ca4791db by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Rework pragma key generation

Previously we had a hack to handle the case of multi-token SPECIALISE
pragmas. Now we use a slightly more general rule of using a prefix of
tokens containing only alphabetical characters.

- - - - -
98c09422 by Ben Gamari at 2019-10-08T05:12:58-04:00
users-guide: Run sphinx in nit-picky mode

This ensure that it blurts an error on missing references.

- - - - -
a95f7185 by Ben Gamari at 2019-10-08T05:12:58-04:00
doc: Write out documented flag list

- - - - -
9402608e by Ben Gamari at 2019-10-08T05:12:58-04:00
gitlab-ci: Check coverage of GHC flags in users guide

This ensures that all GHC flags are documented during the documentation
build.

Fixes #17315.

- - - - -
9ac3bcbb by Andrew Martin at 2019-10-08T13:24:52-04:00
Document the UnliftedFFITypes extension.

- - - - -
77f3ba23 by Andrew Martin at 2019-10-08T13:24:52-04:00
Rephrase a bunch of things in the unlifted ffi types documentation. Add a section on pinned byte arrays.

- - - - -
a70db7bf by Andrew Martin at 2019-10-08T13:24:52-04:00
[skip ci] link to foreign cmm call

- - - - -
0d413259 by Andrew Martin at 2019-10-08T13:24:52-04:00
[skip ci] make the table better

- - - - -
0c7a5bcd by Andrew Martin at 2019-10-08T13:24:52-04:00
[skip ci] can not -> may not

- - - - -
6a5c249d by Andrew Martin at 2019-10-08T13:24:52-04:00
[skip ci] clarify what unsound means

- - - - -
bf02c264 by Ryan Scott at 2019-10-08T13:25:37-04:00
Mark newtype constructors as used in the Coercible solver (#10347)

Currently, newtype constructors are not marked as used when they are
accessed under the hood by uses of `coerce`, as described in #10347.
This fixes #10347 by co-opting the `tcg_keep` field of `TcGblEnv`
to track uses of newtype constructors in the `Coercible` solver.
See `Note [Tracking unused binding and imports]` in `TcRnTypes`.

Since #10347 is fixed, I was able to simplify the code in `TcDeriv`
slightly, as the hack described in
`Note [Newtype deriving and unused constructors]`
is no longer necessary.

- - - - -
9612e91c by Richard Eisenberg at 2019-10-08T13:26:20-04:00
Solve constraints from top-level groups sooner

Previously, all constraints from all top-level groups (as
separated by top-level splices) were lumped together and solved
at the end. This could leak metavariables to TH, though, and
that's bad. This patch solves each group's constraints before
running the next group's splice.

Naturally, we now report fewer errors in some cases.

One nice benefit is that this also fixes #11680, but in a much
simpler way than the original fix for that ticket. Admittedly,
the error messages degrade just a bit from the fix from #11680
(previously, we informed users about variables that will be
brought into scope below a top-level splice, and now we just
report an out-of-scope error), but the amount of complexity
required throughout GHC to get that error was just not worth it.

This patch thus reverts much of
f93c9517a2c6e158e4a5c5bc7a3d3f88cb4ed119.

Fixes #16980

Test cases: th/T16980{,a}

- - - - -
c2d4011c by Vladislav Zavialov at 2019-10-08T13:27:12-04:00
Bump array and haddock submodules

- - - - -
f691f0c2 by Sebastian Graf at 2019-10-08T13:27:49-04:00
PmCheck: Look up parent data family TyCon when populating `PossibleMatches`

The vanilla COMPLETE set is attached to the representation TyCon of a
data family instance, whereas the user-defined COMPLETE sets are
attached to the parent data family TyCon itself.

Previously, we weren't trying particularly hard to get back to the
representation TyCon to the parent data family TyCon, resulting in bugs
like #17207. Now we should do much better.

Fixes the original issue in #17207, but I found another related bug that
isn't so easy to fix.

- - - - -
0c0a15a8 by Ben Gamari at 2019-10-09T16:21:14-04:00
Rename STAGE macro to GHC_STAGE

To avoid polluting the macro namespace

- - - - -
63a5371d by Ben Gamari at 2019-10-09T16:21:14-04:00
Relayout generated header body

- - - - -
817c1a94 by Ben Gamari at 2019-10-09T16:21:14-04:00
Define GHC_STAGE in headers instead of command-line

- - - - -
5f2c49d8 by Ben Gamari at 2019-10-09T16:21:14-04:00
Remove GHC_STAGE guards from MachDeps

This allows the stage1 compiler (which needs to run on the build
platform and produce code for the host) to depend upon properties of the
target. This is wrong. However, it's no more wrong than it was
previously and @Erichson2314 is working on fixing this so I'm going to
remove the guard so we can finally bootstrap HEAD with ghc-8.8 (see
issue #17146).

- - - - -
35cc5eff by Ben Gamari at 2019-10-09T16:21:15-04:00
Test

- - - - -
d584e3f0 by Ryan Scott at 2019-10-09T16:21:50-04:00
Use addUsedDataCons more judiciously in TcDeriv (#17324)

If you derive an instance like this:

```hs
deriving <...> instance Foo C
```

And the data constructors for `C` aren't in scope, then
`doDerivInstErrorChecks1` throws an error. Moreover, it will
_only_ throw an error if `<...>` is either `stock` or `newtype`.
This is because the code that the `anyclass` or `via` strategies
would generate would not require the use of the data constructors
for `C`.

However, `doDerivInstErrorChecks1` has another purpose. If you
write this:

```hs
import M (C(MkC1, ..., MkCn))

deriving <...> instance Foo C
```

Then `doDerivInstErrorChecks1` will call `addUsedDataCons` on
`MkC1` through `MkCn` to ensure that `-Wunused-imports` does not
complain about them. However, `doDerivInstErrorChecks1` was doing
this for _every_ deriving strategy, which mean that if `<...>` were
`anyclass` or `via`, then the warning about `MkC1` through `MkCn`
being unused would be suppressed!

The fix is simple enough: only call `addUsedDataCons` when the
strategy is `stock` or `newtype`, just like the other code paths
in `doDerivInstErrorChecks1`.

Fixes #17324.

- - - - -
30f5ac07 by Sebastian Graf at 2019-10-11T22:10:12-04:00
Much simpler language for PmCheck

Simon realised that the simple language composed of let bindings, bang
patterns and flat constructor patterns is enough to capture the
semantics of the source pattern language that are important for
pattern-match checking. Well, given that the Oracle is smart enough to
connect the dots in this less informationally dense form, which it is
now.

So we transform `translatePat` to return a list of `PmGrd`s relative to
an incoming match variable. `pmCheck` then trivially translates each of
the `PmGrd`s into constraints that the oracle understands.

Since we pass in the match variable, we incidentally fix #15884
(coverage checks for view patterns) through an interaction with !1746.

- - - - -
166e1c2a by Stefan Schulze Frielinghaus at 2019-10-11T22:10:51-04:00
Hadrian: Take care of assembler source files

Fixes #17286.

- - - - -
c2290596 by John Ericson at 2019-10-12T06:32:18-04:00
Simplify Configure in a few ways

 - No need to distinguish between gcc-llvm and clang. First of all,
   gcc-llvm is quite old and surely unmaintained by now. Second of all,
   none of the code actually care about that distinction!

   Now, it does make sense to consider C multiple frontends for LLVMs in
   the form of clang vs clang-cl (same clang, yes, but tweaked
   interface). But this is better handled in terms of "gccish vs
   mvscish" and "is LLVM", yielding 4 combinations. Therefore, I don't
   think it is useful saving the existing code for that.

 - Get the remaining CC_LLVM_BACKEND, and also TABLES_NEXT_TO_CODE in
   mk/config.h the normal way, rather than hacking it post-hoc. No point
   keeping these special cases around for now reason.

 - Get rid of hand-rolled `die` function and just use `AC_MSG_ERROR`.

 - Abstract check + flag override for unregisterised and tables next to
   code.

Oh, and as part of the above I also renamed/combined some variables
where it felt appropriate.

 - GccIsClang -> CcLlvmBackend. This is for `AC_SUBST`, like the other
 Camal case ones. It was never about gcc-llvm, or Apple's renamed clang,
 to be clear.

 - llvm_CC_FLAVOR -> CC_LLVM_BACKEND. This is for `AC_DEFINE`, like the
 other all-caps snake case ones. llvm_CC_FLAVOR was just silly
 indirection *and* an odd name to boot.

- - - - -
f1ce3535 by Vladislav Zavialov at 2019-10-12T06:33:05-04:00
Escape stats file command (#13676)

- - - - -
cd1a8808 by Vladislav Zavialov at 2019-10-12T06:33:05-04:00
Skip T13767 on Darwin

The CI job fails with:

	+++ rts/T13676.run/T13676.run.stderr.normalised	2019-10-09 12:27:56.000000000 -0700
	@@ -0,0 +1,4 @@
	+dyld: Library not loaded: @rpath/libHShaskeline-0.7.5.0-ghc8.9.0.20191009.dylib
	+  Referenced from: /Users/builder/builds/ewzE5N2p/0/ghc/ghc/inplace/lib/bin/ghc
	+  Reason: image not found
	+*** Exception: readCreateProcess: '/Users/builder/builds/ewzE5N2p/0/ghc/ghc/inplace/lib/bin/ghc' '-B/Users/builder/builds/ewzE5N2p/0/ghc/ghc/inplace/lib' '-e' ''/''$'/'' == '/''/x0024'/''' +RTS '-tT13676.t'  (exit -6): failed

Unable to reproduce locally.

- - - - -
0a338264 by Ryan Scott at 2019-10-12T06:33:42-04:00
Use newDFunName for both manual and derived instances (#17339)

Issue #17339 was caused by using a slightly different version of
`newDFunName` for derived instances that, confusingly enough, did not
take all arguments to the class into account when generating the
`DFun` name. I cannot think of any good reason for doing this, so
this patch uses `newDFunName` uniformly for both derived instances
and manually written instances alike.

Fixes #17339.

- - - - -
c50e4c92 by Simon Peyton Jones at 2019-10-12T13:35:24-04:00
Fix validity checking for inferred types

GHC is suposed to uphold the principle that an /inferred/ type
for a let-binding should obey the rules for that module.  E.g.
we should only accept an inferred higher rank type if we have
RankNTypes on.

But we were failing to check this: TcValidity.checkValidType
allowed arbitrary rank for inferred types.

This patch fixes the bug.  It might in principle cause some breakage,
but if so that's good: the user should add RankNTypes and/or a
manual signature.  (And almost every package has explicit user
signatures for all top-level things anyway.)  Let's see.

Fixes #17213.

Metric Decrease:
    T10370

- - - - -
226d86d2 by Simon Peyton Jones at 2019-10-12T13:36:02-04:00
Do not add a 'solved dict' for quantified constraints

GHC has a wonderful-but-delicate mechanism for building recursive
dictionaries by adding a goal to the "solved dictionaries" before
solving the sub-goals.  See Note [Solved dictionaries] in TcSMonad

Ticket #17267 showed that if you use this mechanism for local
/quantified/ constraints you can get a loop -- or even unsafe
coerce.   This patch fixes the bug.

Specifically

* Make TcSMonad.addSolvedDict be conditional on using a
  /top level/ instance, not a quantified one.

* Moreover, we /also/ don't want to add a solved dict
  for equalities (a~b).

* Add lots more comments to Note [Solved dictionaries]
  to explain the above cryptic stuff.

* Extend InstanceWhat to identify those strange built-in
  equality instances.

A couple of other things along the way

* Delete the unused Type.isIPPred_maybe.

* Stop making addSolvedDict conditional on not being an
  impolicit parameter.  This comes from way back. But
  it's irrelevant now because IP dicts are never solved
  via an instance.

- - - - -
5ab1a28d by nineonine at 2019-10-13T06:31:40-04:00
Template Haskell: make unary tuples legal (#16881)

- - - - -
c1bd07cd by Andreas Klebinger at 2019-10-13T06:32:19-04:00
Fix #17334 where NCG did not properly update the CFG.

Statements can change the basic block in which instructions
are placed during instruction selection.

We have to keep track of this switch of the current basic block
as we need this information in order to properly update the CFG.

This commit implements this change and fixes #17334.

We do so by having stmtToInstr return the new block id
if a statement changed the basic block.

- - - - -
1eda9f28 by Takenobu Tani at 2019-10-13T19:06:02-04:00
users-guide: Add GHCi's ::<builtin-command> form

This commit explicitly adds description about double colon command
of GHCi.

[skip ci]

- - - - -
27145351 by Takenobu Tani at 2019-10-13T19:06:40-04:00
Add GHCi help message for :def! and :: commands

- - - - -
78463fc5 by Ryan Scott at 2019-10-14T08:38:36-04:00
Add docs/users_guide/.log to .gitignore

When the users guide fails to build (as in #17346), a
`docs/users_guide/.log` file will be generated with contents that
look something like this:

```
WARNING: unknown config value 'latex_paper_size' in override, ignoring
/home/rgscott/Software/ghc5/docs/users_guide/ghci.rst:3410: WARNING: u'ghc-flag' reference target not found: -pgmo ?option?
/home/rgscott/Software/ghc5/docs/users_guide/ghci.rst:3410: WARNING: u'ghc-flag' reference target not found: -pgmo ?port?

Encoding error:
'ascii' codec can't encode character u'\u27e8' in position 132: ordinal not in range(128)
The full traceback has been saved in /tmp/sphinx-err-rDF2LX.log, if you want to report the issue to the developers.
```

This definitely should not be checked in to version control, so let's
add this to `.gitignore`.

- - - - -
4aba72d6 by Ryan Scott at 2019-10-14T08:39:12-04:00
Mention changes from #16980, #17213 in 8.10.1 release notes

The fixes for these issues both have user-facing consequences, so it
would be good to mention them in the release notes for GHC 8.10.1.

While I'm in town, also mention `UnboxedSums` in the release notes
entry related to `-fobject-code`.

- - - - -
0ca044fd by Ben Gamari at 2019-10-14T08:39:48-04:00
gitlab-ci: Move hadrian-ghc-in-ghci job first

This is a very cheap job and can catch a number of "easy" failure modes
(e.g. missing imports in the compiler). Let's run it first.

- - - - -
a2d3594c by Ryan Scott at 2019-10-15T01:35:34-04:00
Refactor some cruft in TcDerivInfer.inferConstraints

The latest installment in my quest to clean up the code in
`TcDeriv*`. This time, my sights are set on
`TcDerivInfer.inferConstraints`, which infers the context for derived
instances. This function is a wee bit awkward at the moment:

* It's not terribly obvious from a quick glance, but
  `inferConstraints` is only ever invoked when using the `stock` or
  `anyclass` deriving strategies, as the code for inferring the
  context for `newtype`- or `via`-derived instances is located
  separately in `mk_coerce_based_eqn`. But there's no good reason
  for things to be this way, so I moved this code from
  `mk_coerce_based_eqn` to `inferConstraints` so that everything
  related to inferring instance contexts is located in one place.
* In this process, I discovered that the Haddocks for the auxiliary
  function `inferConstraintsDataConArgs` are completely wrong. It
  claims that it handles both `stock` and `newtype` deriving, but
  this is completely wrong, as discussed above—it only handles
  `stock`. To rectify this, I renamed this function to
  `inferConstraintsStock` to reflect its actual purpose and created
  a new `inferConstraintsCoerceBased` function to specifically
  handle `newtype` (and `via`) deriving.

Doing this revealed some opportunities for further simplification:

* Removing the context-inference–related code from
  `mk_coerce_based_eqn` made me realize that the overall structure
  of the function is basically identical to `mk_originative_eqn`.
  In fact, I was easily able to combine the two functions into a
  single `mk_eqn_from_mechanism` function.

  As part of this merger, I now invoke
  `atf_coerce_based_error_checks` from `doDerivInstErrorChecks1`.
* I discovered that GHC defined this function:

  ```hs
  typeToTypeKind = liftedTypeKind `mkVisFunTy` liftedTypeKind
  ```

  No fewer than four times in different modules. I consolidated all
  of these definitions in a single location in `TysWiredIn`.

- - - - -
426b0ddc by Ryan Scott at 2019-10-15T01:36:14-04:00
Don't skip validity checks for built-in classes (#17355)

Issue #17355 occurred because the control flow for
`TcValidity.check_valid_inst_head` was structured in such a way that
whenever it checked a special, built-in class (like `Generic` or
`HasField`), it would skip the most important check of all:
`checkValidTypePats`, which rejects nonsense like this:

```hs
instance Generic (forall a. a)
```

This fixes the issue by carving out `checkValidTypePats` from
`check_valid_inst_head` so that `checkValidTypePats` is always
invoked. `check_valid_inst_head` has also been renamed to
`check_special_inst_head` to reflect its new purpose of _only_
checking for instances headed by special classes.

Fixes #17355.

- - - - -
a55b8a65 by Alp Mestanogullari at 2019-10-15T18:41:18-04:00
iface: export a few more functions from BinIface

- - - - -
9c11f817 by Ben Gamari at 2019-10-15T18:41:54-04:00
hadrian: Add support for bindist compressors other than Xz

Fixes #17351.

- - - - -
535a88e1 by klebinger.andreas at gmx.at at 2019-10-16T07:04:21-04:00
Add loop level analysis to the NCG backend.

For backends maintaining the CFG during codegen
we can now find loops and their nesting level.

This is based on the Cmm CFG and dominator analysis.

As a result we can estimate edge frequencies a lot better
for methods, resulting in far better code layout.

Speedup on nofib: ~1.5%
Increase in compile times: ~1.9%

To make this feasible this commit adds:
* Dominator analysis based on the Lengauer-Tarjan Algorithm.
* An algorithm estimating global edge frequences from branch
probabilities - In CFG.hs

A few static branch prediction heuristics:

* Expect to take the backedge in loops.
* Expect to take the branch NOT exiting a loop.
* Expect integer vs constant comparisons to be false.

We also treat heap/stack checks special for branch prediction
to avoid them being treated as loops.

- - - - -
cc2bda50 by adithyaov at 2019-10-16T07:05:01-04:00
Compiling with -S and -fno-code no longer panics (fixes #17143)

- - - - -
19641957 by Takenobu Tani at 2019-10-16T07:05:41-04:00
testsuite: Add test for #8305

This is a test for the current algorithm of GHCi command name resolution.

I add this test in preparation for updating GHCi command name resolution.

For the current algorithm, see https://downloads.haskell.org/ghc/latest/docs/html/users_guide/ghci.html#the-ghci-files

- - - - -
6ede3554 by Sebastian Graf at 2019-10-16T07:06:20-04:00
Infer rho-types instead of sigma-types in guard BindStmts and TransStmts

In #17343 we saw that we didn't handle the pattern guard `!_ <-
undefined` correctly: The `undefined` was never evaluated. Indeed,
elaboration failed to insert the invisible type aruments to `undefined`.
So `undefined` was trivially a normal-form and in turn never entered.

The problem is that we used to infer a sigma-type for the RHS of the
guard, the leading qualifiers of which will never be useful in a pattern
match situation. Hence we infer a rho-type now.

Fixes #17343.

- - - - -
798037a1 by John Ericson at 2019-10-16T07:06:58-04:00
Delete ghctags cabal file

It came back to life in 381c3ae31b68019177f1cd20cb4da2f9d3b7d6c6 by
mistake.

- - - - -
51fad9e6 by Richard Eisenberg at 2019-10-16T15:58:58-04:00
Break up TcRnTypes, among other modules.

This introduces three new modules:

 - basicTypes/Predicate.hs describes predicates, moving
   this logic out of Type. Predicates don't really exist
   in Core, and so don't belong in Type.

 - typecheck/TcOrigin.hs describes the origin of constraints
   and types. It was easy to remove from other modules and
   can often be imported instead of other, scarier modules.

 - typecheck/Constraint.hs describes constraints as used in
   the solver. It is taken from TcRnTypes.

No work other than module splitting is in this patch.

This is the first step toward homogeneous equality, which will
rely more strongly on predicates. And homogeneous equality is the
next step toward a dependently typed core language.

- - - - -
11d4fc50 by Ben Gamari at 2019-10-16T15:59:52-04:00
hadrian: Introduce enableDebugInfo flavour transformer

Also refactor things a bit to eliminate repetition.

- - - - -
deb96399 by Ryan Scott at 2019-10-16T16:00:29-04:00
Make Coverage.TM a newtype

- - - - -
42ebc3f6 by Brian Wignall at 2019-10-16T16:01:06-04:00
Add hyperlinks to PDF/HTML documentation; closes #17342

- - - - -
b15a7fb8 by Ben Gamari at 2019-10-17T01:03:11-04:00
testsuite: Ensure that makefile tests get run

Previously `makefile_test` and `run_command` tests could easily end up
in a situation where they wouldn't be run if the user used the
`only_ways` modifier. The reason is to build the set of a ways to run
the test in we first start with a candidate set determined by the test
type (e.g. `makefile_test`, `compile_run`, etc.) and then filter that
set with the constraints given by the test's modifiers.

`makefile_test` and `run_command` tests' candidate sets were simply
`{normal}`, and consequently most uses of `only_ways` would result in
the test being never run.

To avoid this we rather use all ways as the candidate sets for these
test types. This may result in a few more testcases than we would like
(given that some `run_command` tests are insensitive to way) but this
can be fixed by adding modifiers and we would much rather run too many
tests than too few.

This fixes #16042 and a number of other tests afflicted by the same issue.
However, there were a few cases that required special attention:

 * `T14028` is currently failing and is therefore marked as broken due
   to #17300

 * `T-signals-child` is fragile in the `threaded1` and `threaded2` ways
   (tracked in #17307)

- - - - -
4efdda90 by Richard Eisenberg at 2019-10-17T01:03:51-04:00
Tiny fixes to comments around flattening.

- - - - -
c4c9904b by Ben Gamari at 2019-10-17T01:04:26-04:00
testsuite: Assert that testsuite ways are known

This ensures that all testsuite way names given to `omit_ways`,
`only_ways`, etc. are known ways.

- - - - -
697be2b6 by Ömer Sinan Ağacan at 2019-10-18T15:26:53-04:00
rts/GC: Add an obvious assertion during block initialization

Namely ensure that block descriptors are initialized with valid
generation numbers.

Co-Authored-By: Ben Gamari <ben at well-typed.com>

- - - - -
61d2ed42 by Ben Gamari at 2019-10-18T15:26:53-04:00
rts: Add Note explaining applicability of selector optimisation depth limit

This was slightly non-obvious so a note seems deserved.

- - - - -
11395037 by Ben Gamari at 2019-10-18T15:26:53-04:00
rts/Capability: A few documentation comments

- - - - -
206f782a by Ben Gamari at 2019-10-18T15:26:53-04:00
rts: Give stack flags proper macros

This were previously quite unclear and will change a bit under the
non-moving collector so let's clear this up now.

- - - - -
81d4675e by Ben Gamari at 2019-10-18T15:26:53-04:00
rts/GC: Refactor gcCAFs

- - - - -
4d674c4e by Ben Gamari at 2019-10-18T15:26:53-04:00
rts: Fix macro parenthesisation

- - - - -
bfcafd39 by Ben Gamari at 2019-10-18T15:27:42-04:00
rts/Schedule: Allow synchronization without holding a capability

The concurrent mark-and-sweep will be performed by a GHC task which will
not hold a capability. This is necessary to avoid a concurrent mark from
interfering with minor generation collections.

However, the major collector must synchronize with the mutators at the
end of marking to flush their update remembered sets. This patch extends
the `requestSync` mechanism used to synchronize garbage collectors to
allow synchronization without holding a capability.

This change is fairly straightforward as the capability was previously
only required for two reasons:

 1. to ensure that we don't try to re-acquire a capability that we
    the sync requestor already holds.

 2. to provide a way to suspend and later resume the sync request if
    there is already a sync pending.

When synchronizing without holding a capability we needn't worry about
consideration (1) at all.

(2) is slightly trickier and may happen, for instance, when a capability
requests a minor collection and shortly thereafter the non-moving mark
thread requests a post-mark synchronization. In this case we need to
ensure that the non-moving mark thread suspends his request until after
the minor GC has concluded to avoid dead-locking. For this we introduce
a condition variable, `sync_finished_cond`, which a
non-capability-bearing requestor will wait on and which is signalled
after a synchronization or GC has finished.

- - - - -
921e4e36 by Ömer Sinan Ağacan at 2019-10-18T15:27:56-04:00
rts/BlockAlloc: Allow aligned allocation requests

This implements support for block group allocations which are aligned to
an integral number of blocks.

This will be used by the nonmoving garbage collector, which uses the
block allocator to allocate the segments which back its heap. These
segments are a fixed number of blocks in size, with each segment being
aligned to the segment size boundary. This allows us to easily find the
segment metadata stored at the beginning of the segment.

- - - - -
4b431f33 by Tamar Christina at 2019-10-20T16:21:10+01:00
Windows: Update tarballs to GCC 9.2 and remove MAX_PATH limit.

- - - - -
8057ac96 by Ben Gamari at 2019-10-20T21:15:14-04:00
Merge branches 'wip/gc/sync-without-capability' and 'wip/gc/aligned-block-allocation' into wip/gc/preparation

- - - - -
32500f64 by Ömer Sinan Ağacan at 2019-10-20T21:15:37-04:00
rts/StableName: Expose FOR_EACH_STABLE_NAME, freeSnEntry, SNT_size

These will be needed when we implement sweeping in the nonmoving
collector.

- - - - -
4be5152a by Ben Gamari at 2019-10-20T21:15:37-04:00
rts: Disable aggregate-return warnings from gcc

This warning is a bit of a relic; there is little reason to avoid
aggregate return values in 2019.

- - - - -
04471c4f by Ömer Sinan Ağacan at 2019-10-20T21:15:37-04:00
rts/Scav: Expose scavenging functions

To keep the non-moving collector nicely separated from the moving
collector its scavenging phase will live in another file,
`NonMovingScav.c`. However, it will need to use these functions so
let's expose them.

- - - - -
6ff29c06 by Ben Gamari at 2019-10-20T21:15:37-04:00
rts: Introduce flag to enable the nonmoving old generation

This flag will enable the use of a non-moving oldest generation.

- - - - -
b3ef2d1a by Ben Gamari at 2019-10-20T21:15:37-04:00
rts: Introduce debug flag for non-moving GC

- - - - -
68e0647f by Ömer Sinan Ağacan at 2019-10-20T21:15:37-04:00
rts: Non-concurrent mark and sweep

This implements the core heap structure and a serial mark/sweep
collector which can be used to manage the oldest-generation heap.
This is the first step towards a concurrent mark-and-sweep collector
aimed at low-latency applications.

The full design of the collector implemented here is described in detail
in a technical note

    B. Gamari. "A Concurrent Garbage Collector For the Glasgow Haskell
    Compiler" (2018)

The basic heap structure used in this design is heavily inspired by

    K. Ueno & A. Ohori. "A fully concurrent garbage collector for
    functional programs on multicore processors." /ACM SIGPLAN Notices/
    Vol. 51. No. 9 (presented by ICFP 2016)

This design is intended to allow both marking and sweeping
concurrent to execution of a multi-core mutator. Unlike the Ueno design,
which requires no global synchronization pauses, the collector
introduced here requires a stop-the-world pause at the beginning and end
of the mark phase.

To avoid heap fragmentation, the allocator consists of a number of
fixed-size /sub-allocators/. Each of these sub-allocators allocators into
its own set of /segments/, themselves allocated from the block
allocator. Each segment is broken into a set of fixed-size allocation
blocks (which back allocations) in addition to a bitmap (used to track
the liveness of blocks) and some additional metadata (used also used
to track liveness).

This heap structure enables collection via mark-and-sweep, which can be
performed concurrently via a snapshot-at-the-beginning scheme (although
concurrent collection is not implemented in this patch).

The mark queue is a fairly straightforward chunked-array structure.
The representation is a bit more verbose than a typical mark queue to
accomodate a combination of two features:

 * a mark FIFO, which improves the locality of marking, reducing one of
   the major overheads seen in mark/sweep allocators (see [1] for
   details)

 * the selector optimization and indirection shortcutting, which
   requires that we track where we found each reference to an object
   in case we need to update the reference at a later point (e.g. when
   we find that it is an indirection). See Note [Origin references in
   the nonmoving collector] (in `NonMovingMark.h`) for details.

Beyond this the mark/sweep is fairly run-of-the-mill.

[1] R. Garner, S.M. Blackburn, D. Frampton. "Effective Prefetch for
    Mark-Sweep Garbage Collection." ISMM 2007.

Co-Authored-By: Ben Gamari <ben at well-typed.com>

- - - - -
c7e73d12 by Ben Gamari at 2019-10-20T21:15:37-04:00
testsuite: Add nonmoving WAY

This simply runs the compile_and_run tests with `-xn`, enabling the
nonmoving oldest generation.

- - - - -
f8f77a07 by Ben Gamari at 2019-10-20T21:15:37-04:00
rts: Mark binder as const

- - - - -
bd8e3ff4 by Ben Gamari at 2019-10-20T21:15:52-04:00
rts: Implement concurrent collection in the nonmoving collector

This extends the non-moving collector to allow concurrent collection.

The full design of the collector implemented here is described in detail
in a technical note

    B. Gamari. "A Concurrent Garbage Collector For the Glasgow Haskell
    Compiler" (2018)

This extension involves the introduction of a capability-local
remembered set, known as the /update remembered set/, which tracks
objects which may no longer be visible to the collector due to mutation.
To maintain this remembered set we introduce a write barrier on
mutations which is enabled while a concurrent mark is underway.

The update remembered set representation is similar to that of the
nonmoving mark queue, being a chunked array of `MarkEntry`s. Each
`Capability` maintains a single accumulator chunk, which it flushed
when it (a) is filled, or (b) when the nonmoving collector enters its
post-mark synchronization phase.

While the write barrier touches a significant amount of code it is
conceptually straightforward: the mutator must ensure that the referee
of any pointer it overwrites is added to the update remembered set.
However, there are a few details:

 * In the case of objects with a dirty flag (e.g. `MVar`s) we can
   exploit the fact that only the *first* mutation requires a write
   barrier.

 * Weak references, as usual, complicate things. In particular, we must
   ensure that the referee of a weak object is marked if dereferenced by
   the mutator. For this we (unfortunately) must introduce a read
   barrier, as described in Note [Concurrent read barrier on deRefWeak#]
   (in `NonMovingMark.c`).

 * Stable names are also a bit tricky as described in Note [Sweeping
   stable names in the concurrent collector] (`NonMovingSweep.c`).

We take quite some pains to ensure that the high thread count often seen
in parallel Haskell applications doesn't affect pause times. To this end
we allow thread stacks to be marked either by the thread itself (when it
is executed or stack-underflows) or the concurrent mark thread (if the
thread owning the stack is never scheduled). There is a non-trivial
handshake to ensure that this happens without racing which is described
in Note [StgStack dirtiness flags and concurrent marking].

Co-Authored-by: Ömer Sinan Ağacan <omer at well-typed.com>

- - - - -
dd1b4fdd by Ben Gamari at 2019-10-20T21:15:52-04:00
Nonmoving: Disable memory inventory with concurrent collection

- - - - -
4a44ab33 by Ben Gamari at 2019-10-20T21:15:52-04:00
rts: Shrink size of STACK's dirty and marking fields

- - - - -
10373416 by Ben Gamari at 2019-10-20T21:15:52-04:00
Don't cleanup until we've stopped the collector

This requires that we break nonmovingExit into two pieces since we need
to first stop the collector to relinquish any capabilities, then we need
to shutdown the scheduler, then we need to free the nonmoving
allocators.

- - - - -
26c3827f by Ben Gamari at 2019-10-21T11:43:54-04:00
Nonmoving: Ensure write barrier vanishes in non-threaded RTS

- - - - -
17e5a032 by Ben Gamari at 2019-10-21T11:43:54-04:00
ThreadPaused: Add barrer on updated thunk

- - - - -
8ea316da by David Eichmann at 2019-10-22T02:07:48-04:00
CI: Always dump performance metrics.

- - - - -
aa31ceaf by Matthew Bauer at 2019-10-22T02:39:01-04:00
Replace freebsd-gnueabihf with freebsd

FreeBSD does not support GNU libc, so it makes no sense to use this
triple. Most likely previous builds were just using the FreeBSD libc
instead of gnueabihf. To fix this, we should just use
armv6-unknown-freebsd and armv7-unknown-freebsd triples. Note that
both of these are actually "soft-float", not "hard-float". FreeBSD has
never officially released hard-float arm32:

https://wiki.freebsd.org/ARMTier1

- - - - -
fd8b666a by Stefan Schulze Frielinghaus at 2019-10-22T02:39:03-04:00
Implement s390x LLVM backend.

This patch adds support for the s390x architecture for the LLVM code
generator. The patch includes a register mapping of STG registers onto
s390x machine registers which enables a registerised build.

- - - - -
2d2cc76f by Tilman Blumhagen at 2019-10-22T02:39:04-04:00
Documentation for (&&) and (&&) states that they are lazy in their second argument (fixes #17354)

- - - - -
06d51c4e by Ben Gamari at 2019-10-22T12:13:36-04:00
Fix unregisterised build

This required some fiddling around with the location of forward
declarations since the C sources generated by GHC's C backend only
includes Stg.h.

- - - - -
912e440e by Ben Gamari at 2019-10-22T12:17:00-04:00
rts: Tracing support for nonmoving collection events

This introduces a few events to mark key points in the nonmoving
garbage collection cycle. These include:

 * `EVENT_CONC_MARK_BEGIN`, denoting the beginning of a round of
   marking. This may happen more than once in a single major collection
   since we the major collector iterates until it hits a fixed point.

 * `EVENT_CONC_MARK_END`, denoting the end of a round of marking.

 * `EVENT_CONC_SYNC_BEGIN`, denoting the beginning of the post-mark
   synchronization phase

 * `EVENT_CONC_UPD_REM_SET_FLUSH`, indicating that a capability has
   flushed its update remembered set.

 * `EVENT_CONC_SYNC_END`, denoting that all mutators have flushed their
   update remembered sets.

 * `EVENT_CONC_SWEEP_BEGIN`, denoting the beginning of the sweep portion
   of the major collection.

 * `EVENT_CONC_SWEEP_END`, denoting the end of the sweep portion of the
   major collection.

- - - - -
9f42cd81 by Ben Gamari at 2019-10-22T12:17:00-04:00
rts: Introduce non-moving heap census

This introduces a simple census of the non-moving heap (not to be
confused with the heap census used by the heap profiler). This
collects basic heap usage information (number of allocated and free
blocks) which is useful when characterising fragmentation of the
nonmoving heap.

- - - - -
711837cc by Ben Gamari at 2019-10-22T12:17:00-04:00
rts/Eventlog: More descriptive error message

- - - - -
0d31819e by Ben Gamari at 2019-10-22T12:17:00-04:00
Allow census without live word count

Otherwise the census is unsafe when mutators are running due to
concurrent mutation.

- - - - -
6f173181 by Ben Gamari at 2019-10-22T12:17:00-04:00
NonmovingCensus: Emit samples to eventlog

- - - - -
13dd78dd by Ben Gamari at 2019-10-22T12:18:33-04:00
Nonmoving: Allow aging and refactor static objects logic

This commit does two things:

 * Allow aging of objects during the preparatory minor GC
 * Refactor handling of static objects to avoid the use of a hashtable

- - - - -
7b79e8b4 by Ben Gamari at 2019-10-22T12:18:33-04:00
Disable aging when doing deadlock detection GC

- - - - -
8fffe12b by Ben Gamari at 2019-10-22T12:18:33-04:00
More comments for aging

- - - - -
039d2906 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Eliminate integer division in nonmovingBlockCount

Perf showed that the this single div was capturing up to 10% of samples
in nonmovingMark. However, the overwhelming majority of cases is looking
at small block sizes. These cases we can easily compute explicitly,
allowing the compiler to turn the division into a significantly more
efficient division-by-constant.

While the increase in source code looks scary, this all optimises down
to very nice looking assembler. At this point the only remaining
hotspots in nonmovingBlockCount are due to memory access.

- - - - -
d15ac82d by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Allocate mark queues in larger block groups

- - - - -
26d2d331 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMovingMark: Optimize representation of mark queue

This shortens MarkQueueEntry by 30% (one word)

- - - - -
e5eda61e by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Optimize bitmap search during allocation

Use memchr instead of a open-coded loop. This is nearly twice as fast in
a synthetic benchmark.

- - - - -
dacf4cae by Ben Gamari at 2019-10-22T12:18:39-04:00
rts: Add prefetch macros

- - - - -
786c52d2 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Prefetch when clearing bitmaps

Ensure that the bitmap of the segmentt that we will clear next is in
cache by the time we reach it.

- - - - -
0387df5b by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Inline nonmovingClearAllBitmaps

- - - - -
e893877e by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Fuse sweep preparation into mark prep

- - - - -
e6f6823f by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Pre-fetch during mark

This improved overall runtime on nofib's constraints test by nearly 10%.

- - - - -
56c5ebdc by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Prefetch segment header

- - - - -
19bfe460 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Optimise allocator cache behavior

Previously we would look at the segment header to determine the block
size despite the fact that we already had the block size at hand.

- - - - -
53a1a27e by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMovingMark: Eliminate redundant check_in_nonmoving_heaps

- - - - -
b967e470 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Don't do major GC if one is already running

Previously we would perform a preparatory moving collection, resulting
in many things being added to the mark queue. When we finished with this
we would realize in nonmovingCollect that there was already a collection
running, in which case we would simply not run the nonmoving collector.

However, it was very easy to end up in a "treadmilling" situation: all
subsequent GC following the first failed major GC would be scheduled as
major GCs. Consequently we would continuously feed the concurrent
collector with more mark queue entries and it would never finish.

This patch aborts the major collection far earlier, meaning that we
avoid adding nonmoving objects to the mark queue and allowing the
concurrent collector to finish.

- - - - -
3bc172a4 by Ben Gamari at 2019-10-22T12:18:39-04:00
NonMoving: Clean mut_list

- - - - -
8e79e2a9 by Ben Gamari at 2019-10-22T12:18:39-04:00
Unconditionally flush update remembered set during minor GC

Flush the update remembered set. The goal here is to flush periodically to
ensure that we don't end up with a thread who marks their stack on their
local update remembered set and doesn't flush until the nonmoving sync
period as this would result in a large fraction of the heap being marked
during the sync pause.

- - - - -
b281e80b by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Add nonmoving_thr way

- - - - -
07987957 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Add nonmoving_thr_ghc way

This uses the nonmoving collector when compiling the testcases.

- - - - -
01fd0242 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Don't run T15892 in nonmoving ways

The nonmoving GC doesn't support `+RTS -G1`, which this test insists on.

- - - - -
097f4fd0 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Nonmoving collector doesn't support -G1

- - - - -
4b91dd25 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Ensure that threaded tests are run in nonmoving_thr

- - - - -
78ce35b9 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: bug1010 requires -c, which isn't supported by nonmoving

- - - - -
6e97cc47 by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Skip T15892 in nonmoving_thr_ghc

- - - - -
5ce853c8 by Ben Gamari at 2019-10-22T12:18:44-04:00
ghc-heap: Skip heap_all test with debugged RTS

The debugged RTS initializes the heap with 0xaa, which breaks the
(admittedly rather fragile) assumption that uninitialized fields are set
to 0x00:
```
Wrong exit code for heap_all(nonmoving)(expected 0 , actual 1 )
Stderr ( heap_all ):
heap_all: user error (assertClosuresEq: Closures do not match
Expected: FunClosure {info = StgInfoTable {entry = Nothing, ptrs = 0, nptrs = 1, tipe = FUN_0_1, srtlen = 0, code = Nothing}, ptrArgs = [], dataArgs = [0]}
Actual:   FunClosure {info = StgInfoTable {entry = Nothing, ptrs = 0, nptrs = 1, tipe = FUN_0_1, srtlen = 1032832, code = Nothing}, ptrArgs = [], dataArgs = [12297829382473034410]}

CallStack (from HasCallStack):
  assertClosuresEq, called at heap_all.hs:230:9 in main:Main
)
```

- - - - -
6abefce7 by Ben Gamari at 2019-10-22T12:18:44-04:00
Skip ghc_heap_all test in nonmoving ways

- - - - -
99baff8c by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Don't run T9630 in nonmoving ways

The nonmoving collector doesn't support -G1

- - - - -
25ae8f7d by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Don't run T7160 in nonmoving_thr ways

The nonmoving way finalizes things in a different order.

- - - - -
8cab149b by Ben Gamari at 2019-10-22T12:18:44-04:00
testsuite: Mark length001 as failing under nonmoving ways

This is consistent with the other unoptimized ways.

- - - - -
5b130b3d by Ben Gamari at 2019-10-22T12:18:46-04:00
Merge branches 'wip/gc/optimize' and 'wip/gc/test' into wip/gc/everything

- - - - -
246ce2af by Ömer Sinan Ağacan at 2019-10-22T12:20:15-04:00
NonMoving: Implement indirection shortcutting

This allows indirection chains residing in the non-moving heap to be
shorted-out.

- - - - -
875861ef by Ömer Sinan Ağacan at 2019-10-22T12:20:15-04:00
NonMoving: Implement selector optimisation

- - - - -
c72e84c6 by Ben Gamari at 2019-10-22T12:20:15-04:00
NonMovingMark: Handle INDs left by shortcutting

- - - - -
0f8fd3c6 by Ömer Sinan Ağacan at 2019-10-22T12:20:15-04:00
NonMoving: Implement -xns to disable selector optimization

- - - - -
c936a245 by Ben Gamari at 2019-10-22T12:20:37-04:00
NonMoving: Introduce nonmovingSegmentLogBlockSize acccessor

This will allow us to easily move the block size elsewhere.

- - - - -
6dcef5ee by Ben Gamari at 2019-10-22T12:20:37-04:00
NonMoving: Move block size to block descriptor

- - - - -
dd8d1b49 by Ben Gamari at 2019-10-22T12:20:37-04:00
NonMoving: Move next_free_snap to block descriptor

- - - - -
116e4646 by Ben Gamari at 2019-10-22T12:20:46-04:00
NonMoving: Add summarizing Note

- - - - -
22eee2bc by Ben Gamari at 2019-10-22T12:20:48-04:00
Merge branches 'wip/gc/segment-header-to-bdescr' and 'wip/gc/docs' into wip/gc/everything2

- - - - -
3a862703 by Ömer Sinan Ağacan at 2019-10-22T18:56:32-04:00
rts: COMPACT_NFDATA support for the nonmoving collector

This largely follows the model used for large objects, with appropriate
adjustments made to account for references in the sharing deduplication
hashtable.

- - - - -
7c35d39b by Ben Gamari at 2019-10-22T18:56:32-04:00
rts: Mark nonmoving GC paths in moving collector as unlikely

The expectation here is that the nonmoving GC is latency-centric,
whereas the moving GC emphasizes throughput. Therefore we give the
latter the benefit of better static branch prediction.

- - - - -
91109404 by Ben Gamari at 2019-10-22T18:57:27-04:00
nonmoving: Trace GC preparation steps

- - - - -
a69b28f4 by Ben Gamari at 2019-10-22T18:57:27-04:00
nonmoving: Don't do two passes over large and compact object lists

Previously we would first move the new objects to their appropriate
non-moving GC list, then do another pass over that list to clear their
mark bits. This is needlessly expensive. First clear the mark bits of
the existing objects, then add the newly evacuated objects and, at the
same time, clear their mark bits.

This cuts the preparatory GC time in half for the Pusher benchmark with
a large queue size.

- - - - -
984745b0 by Ben Gamari at 2019-10-22T18:57:27-04:00
nonmoving: Upper-bound time we hold SM_MUTEX for during sweep

- - - - -
96c5411a by David Feuer at 2019-10-23T05:58:37-04:00
Use an IORef for QSemN

Replace the outer `MVar` in `QSemN` with an `IORef`. This should
probably be lighter, and it removes the need for `uninterruptibleMask`.

Previously Differential Revision https://phabricator.haskell.org/D4896

- - - - -
faa30dcb by Andreas Klebinger at 2019-10-23T05:58:43-04:00
Warn about missing profiled libs when using the Interpreter.

When GHC itself, or it's interpreter is profiled we need to load
profiled libraries as well.

This requirement is not always obvious, especially when TH
implicilty uses the interpreter.

When the libs were not found we fall back to assuming the
are in a DLL. This is usually not the case so now we warn
users when we do so. This makes it more obvious what is
happening and gives users a way to fix the issue.

This fixes #17121.

- - - - -
1cd3fa29 by Richard Eisenberg at 2019-10-23T05:58:46-04:00
Implement a coverage checker for injectivity

This fixes #16512.

There are lots of parts of this patch:

* The main payload is in FamInst. See
Note [Coverage condition for injective type families] there
for the overview. But it doesn't fix the bug.

* We now bump the reduction depth every time we discharge
a CFunEqCan. See Note [Flatten when discharging CFunEqCan]
in TcInteract.

* Exploration of this revealed a new, easy to maintain invariant
for CTyEqCans. See Note [Almost function-free] in TcRnTypes.

* We also realized that type inference for injectivity was a
bit incomplete. This means we exchanged lookupFlattenTyVar for
rewriteTyVar. See Note [rewriteTyVar] in TcFlatten. The new
function is monadic while the previous one was pure, necessitating
some faff in TcInteract. Nothing too bad.

* zonkCt did not maintain invariants on CTyEqCan. It's not worth
the bother doing so, so we just transmute CTyEqCans to
CNonCanonicals.

* The pure unifier was finding the fixpoint of the returned
substitution, even when doing one-way matching (in tcUnifyTysWithTFs).
Fixed now.

Test cases: typecheck/should_fail/T16512{a,b}

- - - - -
900cf195 by Alp Mestanogullari at 2019-10-23T05:58:48-04:00
compiler: introduce DynFlags plugins

They have type '[CommandLineOpts] -> Maybe (DynFlags -> IO DynFlags)'.
All plugins that supply a non-Nothing 'dynflagsPlugin' will see their
updates applied to the current DynFlags right after the plugins are
loaded.

One use case for this is to superseede !1580 for registering hooks
from a plugin. Frontend/parser plugins were considered to achieve this
but they respectively conflict with how this plugin is going to be used
and don't allow overriding/modifying the DynFlags, which is how hooks have
to be registered.

This commit comes with a test, 'test-hook-plugin', that registers a "fake"
meta hook that replaces TH expressions with the 0 integer literal.

- - - - -
a19c7d17 by Ryan Scott at 2019-10-23T05:58:49-04:00
Reify oversaturated data family instances correctly (#17296)

`TcSplice` was not properly handling oversaturated data family
instances, such as the example in #17296, as it dropped arguments due
to carelessly zipping data family instance arguments with
`tyConTyVars`. For data families, the number of `tyConTyVars` can
sometimes be less than the number of arguments it can accept in a
data family instance due to the fact that data family instances can
be oversaturated.

To account for this, `TcSplice.mkIsPolyTvs` has now been renamed to
`tyConArgsPolyKinded` and now factors in `tyConResKind` in addition
to `tyConTyVars`. I've also added
`Note [Reified instances and explicit kind signatures]` which
explains the various subtleties in play here.

Fixes #17296.

- - - - -
9b2a5008 by Ben Gamari at 2019-10-23T05:58:50-04:00
testsuite: Don't run T7653 in ghci and profiled ways

Currently this routinely fails in the i386 job.
See #7653.

- - - - -
b521e8b6 by Ömer Sinan Ağacan at 2019-10-23T05:58:57-04:00
Refactor Compact.c:

- Remove forward declarations
- Introduce UNTAG_PTR and GET_PTR_TAG for dealing with pointer tags
  without having to cast arguments to StgClosure*
- Remove dead code
- Use W_ instead of StgWord
- Use P_ instead of StgPtr

- - - - -
17987a4b by Matthew Pickering at 2019-10-23T05:58:58-04:00
eventlog: Dump cost centre stack on each sample

With this change it is possible to reconstruct the timing portion of a
`.prof` file after the fact. By logging the stacks at each time point
a more precise executation trace of the program can be observed rather
than all identical cost centres being identified in the report.

There are two new events:

1. `EVENT_PROF_BEGIN` - emitted at the start of profiling to communicate
the tick interval
2. `EVENT_PROF_SAMPLE_COST_CENTRE` - emitted on each tick to communicate the
current call stack.

Fixes #17322

- - - - -
4798f3b9 by Takenobu Tani at 2019-10-23T05:59:00-04:00
Allow command name resolution for GHCi commands with option `!` #17345

This commit allows command name resolution for GHCi commands
with option `!` as follows:

    ghci> :k! Int
    Int :: *
    = Int

This commit changes implementation as follows:

Before:
  * Prefix match with full string including the option `!` (e.g. `k!`)

After (this patch):
  * Prefix match without option suffix `!` (e.g. `k`)
  * in addition, suffix match with option `!`

See also #8305 and #8113

- - - - -
aa778152 by Andreas Klebinger at 2019-10-23T05:59:01-04:00
Fix bug in the x86 backend involving the CFG.

This is part two of fixing #17334.

There are two parts to this commit:

- A bugfix for computing loop levels
- A bugfix of basic block invariants in the NCG.

-----------------------------------------------------------

In the first bug we ended up with a CFG of the sort: [A -> B -> C]
This was represented via maps as fromList [(A,B),(B,C)] and later
transformed into a adjacency array. However the transformation did
not include block C in the array (since we only looked at the keys of
the map).

This was still fine until we tried to look up successors for C and tried
to read outside of the array bounds when accessing C.

In order to prevent this in the future I refactored to code to include
all nodes as keys in the map representation. And make this a invariant
which is checked in a few places.

Overall I expect this to make the code more robust as now any failed
lookup will represent an error, versus failed lookups sometimes being
expected and sometimes not.

In terms of performance this makes some things cheaper (getting a list
of all nodes) and others more expensive (adding a new edge). Overall
this adds up to no noteable performance difference.

-----------------------------------------------------------

Part 2: When the NCG generated a new basic block, it did
not always insert a NEWBLOCK meta instruction in the stream which
caused a quite subtle bug.

    During instruction selection a statement `s`
    in a block B with control of the sort: B -> C
    will sometimes result in control
    flow of the sort:

            ┌ < ┐
            v   ^
      B ->  B1  ┴ -> C

    as is the case for some atomic operations.

    Now to keep the CFG in sync when introducing B1 we clearly
    want to insert it between B and C. However there is
    a catch when we have to deal with self loops.

    We might start with code and a CFG of these forms:

    loop:
        stmt1               ┌ < ┐
        ....                v   ^
        stmtX              loop ┘
        stmtY
        ....
        goto loop:

    Now we introduce B1:
                            ┌ ─ ─ ─ ─ ─┐
        loop:               │   ┌ <  ┐ │
        instrs              v   │    │ ^
        ....               loop ┴ B1 ┴ ┘
        instrsFromX
        stmtY
        goto loop:

    This is simple, all outgoing edges from loop now simply
    start from B1 instead and the code generator knows which
    new edges it introduced for the self loop of B1.

    Disaster strikes if the statement Y follows the same pattern.
    If we apply the same rule that all outgoing edges change then
    we end up with:

        loop ─> B1 ─> B2 ┬─┐
          │      │    └─<┤ │
          │      └───<───┘ │
          └───────<────────┘

    This is problematic. The edge B1->B1 is modified as expected.
    However the modification is wrong!

    The assembly in this case looked like this:

    _loop:
        <instrs>
    _B1:
        ...
        cmpxchgq ...
        jne _B1
        <instrs>
        <end _B1>
    _B2:
        ...
        cmpxchgq ...
        jne _B2
        <instrs>
        jmp loop

    There is no edge _B2 -> _B1 here. It's still a self loop onto _B1.

    The problem here is that really B1 should be two basic blocks.
    Otherwise we have control flow in the *middle* of a basic block.
    A contradiction!

    So to account for this we add yet another basic block marker:

    _B:
        <instrs>
    _B1:
        ...
        cmpxchgq ...
        jne _B1
        jmp _B1'
    _B1':
        <instrs>
        <end _B1>
    _B2:
        ...

    Now when inserting B2 we will only look at the outgoing edges of B1' and
    everything will work out nicely.

    You might also wonder why we don't insert jumps at the end of _B1'. There is
    no way another block ends up jumping to the labels _B1 or _B2 since they are
    essentially invisible to other blocks. View them as control flow labels local
    to the basic block if you'd like.

    Not doing this ultimately caused (part 2 of) #17334.

- - - - -
1f40e68a by Ryan Yates at 2019-10-23T05:59:03-04:00
Full abort on validate failure merging `orElse`.

Previously partial roll back of a branch of an `orElse` was attempted
if validation failure was observed.  Validation here, however, does
not account for what part of the transaction observed inconsistent
state.  This commit fixes this by fully aborting and restarting the
transaction.

- - - - -
9c1f0f7c by Ben Gamari at 2019-10-23T05:59:03-04:00
Bump stm submodule

- - - - -
6beea836 by Andreas Klebinger at 2019-10-23T05:59:04-04:00
Make dynflag argument for withTiming pure.

19 times out of 20 we already have dynflags in scope.

We could just always use `return dflags`. But this is in fact not free.
When looking at some STG code I noticed that we always allocate a
closure for this expression in the heap. Clearly a waste in these cases.

For the other cases we can either just modify the callsite to
get dynflags or use the _D variants of withTiming I added which
will use getDynFlags under the hood.

- - - - -
8dd480cc by Matthew Pickering at 2019-10-23T05:59:06-04:00
Performance tests: Reduce acceptance threshold for bytes allocated tests

The "new" performance testing infrastructure resets the baseline after
every test so it's easy to miss gradual performance regressions over
time. We should at least make these numbers smaller to catch patches
which affect performance earlier.

- - - - -
4af20bbc by Ben Gamari at 2019-10-23T05:59:06-04:00
users-guide: Fix :since: for -Wunused-packages

Fixes #17382.

- - - - -
21663693 by Ben Gamari at 2019-10-23T05:59:07-04:00
Drop duplicate -optl's from GHC invocations

Previously the make build system would pass things like
`-optl-optl-Wl,-x -optl-optl-Wl,noexecstack` to GHC. This would
naturally result in mass confusion as GHC would pass `-optl-Wl,-x` to
GCC. GCC would in turn interpret this as `-o ptl-Wl,-x`, setting the
output pass of the invocation.

The problem that `-optl` was added to the command-line in two places in
the build system. Fix this.

Fixes #17385.

- - - - -
bb0dc5a5 by Andreas Klebinger at 2019-10-23T05:59:07-04:00
Hadrian: Invoke ghc0 via bash when running tests to fix #17362.

cmd uses RawCommand which uses Windows semantics to find the executable
which sometimes seems to fail for unclear reasons.

If we invoke ghc via bash then bash will find the ghc executable and
the issue goes away.

- - - - -
266435a7 by Ömer Sinan Ağacan at 2019-10-23T05:59:09-04:00
Add new flag for unarised STG dumps

Previously -ddump-stg would dump pre and post-unarise STGs. Now we have
a new flag for post-unarise STG and -ddump-stg only dumps coreToStg
output.

STG dump flags after this commit:

- -ddump-stg: Dumps CoreToStg output
- -ddump-stg-unarised: Unarise output
- -ddump-stg-final: STG right before code gen (includes CSE and lambda
  lifting)

- - - - -
8abddac8 by Ben Gamari at 2019-10-23T05:59:10-04:00
base: Add @since on GHC.IO.Handle.Lock.hUnlock

Unfortunately this was introduced in base-4.11.0 (GHC 8.4.1)
whereas the other locking primitives were added in base-4.10.0 (GHC
8.2.1).

- - - - -
7f72b540 by Ben Gamari at 2019-10-23T14:56:46-04:00
Merge non-moving garbage collector

This introduces a concurrent mark & sweep garbage collector to manage the old
generation. The concurrent nature of this collector typically results in
significantly reduced maximum and mean pause times in applications with large
working sets.

Due to the large and intricate nature of the change I have opted to
preserve the fully-buildable history, including merge commits, which is
described in the "Branch overview" section below.

Collector design
================

The full design of the collector implemented here is described in detail
in a technical note

> B. Gamari. "A Concurrent Garbage Collector For the Glasgow Haskell
> Compiler" (2018)

This document can be requested from @bgamari.
The basic heap structure used in this design is heavily inspired by

> K. Ueno & A. Ohori. "A fully concurrent garbage collector for
> functional programs on multicore processors." /ACM SIGPLAN Notices/
> Vol. 51. No. 9 (presented at ICFP 2016)

This design is intended to allow both marking and sweeping
concurrent to execution of a multi-core mutator. Unlike the Ueno design,
which requires no global synchronization pauses, the collector
introduced here requires a stop-the-world pause at the beginning and end
of the mark phase.

To avoid heap fragmentation, the allocator consists of a number of
fixed-size /sub-allocators/. Each of these sub-allocators allocators into
its own set of /segments/, themselves allocated from the block
allocator. Each segment is broken into a set of fixed-size allocation
blocks (which back allocations) in addition to a bitmap (used to track
the liveness of blocks) and some additional metadata (used also used
to track liveness).

This heap structure enables collection via mark-and-sweep, which can be
performed concurrently via a snapshot-at-the-beginning scheme (although
concurrent collection is not implemented in this patch).

Implementation structure
========================

The majority of the collector is implemented in a handful of files:

 * `rts/Nonmoving.c` is the heart of the beast. It implements the entry-point
   to the nonmoving collector (`nonmoving_collect`), as well as the allocator
   (`nonmoving_allocate`) and a number of utilities for manipulating the heap.

 * `rts/NonmovingMark.c` implements the mark queue functionality, update
   remembered set, and mark loop.

 * `rts/NonmovingSweep.c` implements the sweep loop.

 * `rts/NonmovingScav.c` implements the logic necessary to scavenge the
   nonmoving heap.

Branch overview
===============

```
 * wip/gc/opt-pause:
 |   A variety of small optimisations to further reduce pause times.
 |
 * wip/gc/compact-nfdata:
 |   Introduce support for compact regions into the non-moving
 |\  collector
 | \
 |  \
 | | * wip/gc/segment-header-to-bdescr:
 | | |   Another optimization that we are considering, pushing
 | | |   some segment metadata into the segment descriptor for
 | | |   the sake of locality during mark
 | | |
 | * | wip/gc/shortcutting:
 | | |   Support for indirection shortcutting and the selector optimization
 | | |   in the non-moving heap.
 | | |
 * | | wip/gc/docs:
 | |/    Work on implementation documentation.
 | /
 |/
 * wip/gc/everything:
 |   A roll-up of everything below.
 |\
 | \
 | |\
 | | \
 | | * wip/gc/optimize:
 | | |   A variety of optimizations, primarily to the mark loop.
 | | |   Some of these are microoptimizations but a few are quite
 | | |   significant. In particular, the prefetch patches have
 | | |   produced a nontrivial improvement in mark performance.
 | | |
 | | * wip/gc/aging:
 | | |   Enable support for aging in major collections.
 | | |
 | * | wip/gc/test:
 | | |   Fix up the testsuite to more or less pass.
 | | |
 * | | wip/gc/instrumentation:
 | | |   A variety of runtime instrumentation including statistics
 | | /   support, the nonmoving census, and eventlog support.
 | |/
 | /
 |/
 * wip/gc/nonmoving-concurrent:
 |   The concurrent write barriers.
 |
 * wip/gc/nonmoving-nonconcurrent:
 |   The nonmoving collector without the write barriers necessary
 |   for concurrent collection.
 |
 * wip/gc/preparation:
 |   A merge of the various preparatory patches that aren't directly
 |   implementing the GC.
 |
 |
 * GHC HEAD
 .
 .
 .
```

- - - - -
83655b06 by Ben Gamari at 2019-10-24T08:45:41-04:00
hadrian: Warn user if hadrian build fails due to lack of threaded RTS

See #16873.

- - - - -
6824f29a by Ryan Scott at 2019-10-24T08:46:19-04:00
Parenthesize GADT return types in pprIfaceConDecl (#17384)

We were using `pprIfaceAppArgs` instead of `pprParendIfaceAppArgs`
in `pprIfaceConDecl`. Oops.

Fixes #17384.

- - - - -
9de3f8b1 by Ryan Scott at 2019-10-24T18:38:32-04:00
Make isTcLevPoly more conservative with newtypes (#17360)

`isTcLevPoly` gives an approximate answer for when a type constructor
is levity polymorphic when fully applied, where `True` means
"possibly levity polymorphic" and `False` means "definitely not
levity polymorphic". `isTcLevPoly` returned `False` for newtypes,
which is incorrect in the presence of `UnliftedNewtypes`, leading
to #17360. This patch tweaks `isTcLevPoly` to return `True` for
newtypes instead.

Fixes #17360.

- - - - -
243c72eb by Ryan Scott at 2019-10-24T18:39:08-04:00
Mark promoted InfixT names as IsPromoted (#17394)

We applied a similar fix for `ConT` in #15572 but forgot to apply the
fix to `InfixT` as well. This patch fixes #17394 by doing just that.

- - - - -
87175e78 by James Foster at 2019-10-25T09:01:08-04:00
Make Hadrian use -dynamic-too in the basic case

This commit makes Hadrian use the `-dynamic-too` flag when the current
Flavour's libraryWays contains both vanilla and dynamic, cutting down
the amount of repeated work caused by separate compilation of dynamic
and static files. It does this for the basic case where '.o' and
'.dyn_o' files are built with one command, but does not generalise to
cases like '.prof_o' and '.prof_dyn_o'.

- - - - -
ecd89062 by Alp Mestanogullari at 2019-10-25T09:01:47-04:00
hadrian/ci: run testsuite against a freshly produced and installed bindist

- - - - -
2a16b555 by Ben Gamari at 2019-10-25T09:02:26-04:00
testsuite: Mark T13786 as fragile in unreg build

Due to #17018.

- - - - -
08298926 by Ben Gamari at 2019-10-25T09:02:26-04:00
testsuite: Use fragile modifier in TH_foreignInterruptible

It looks like this use of `skip` snuck through my previous refactoring.

- - - - -
4c7d45d1 by Brian Wignall at 2019-10-25T09:03:04-04:00
Make documentation for byteSwap16 consistent with byteSwap32 (impl is same, with s/16/32)

- - - - -
02822d84 by Ben Gamari at 2019-10-25T09:03:40-04:00
aclocal: A bit of reformatting

- - - - -
519f5162 by Ben Gamari at 2019-10-25T09:03:40-04:00
configure: Drop GccLT46

GCC 4.6 was released 7 years ago. I think we can finally assume that
it's available. This is a simplification prompted by #15742.

- - - - -
acedfc8b by Ben Gamari at 2019-10-25T09:04:16-04:00
gitlab-ci: Run check-uniques during lint job

- - - - -
8916e64e by Andrew Martin at 2019-10-26T05:19:38-04:00
Implement shrinkSmallMutableArray# and resizeSmallMutableArray#.

This is a part of GHC Proposal #25: "Offer more array resizing primitives".
Resources related to the proposal:

  - Discussion: https://github.com/ghc-proposals/ghc-proposals/pull/121
  - Proposal: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0025-resize-boxed.rst

Only shrinkSmallMutableArray# is implemented as a primop since a
library-space implementation of resizeSmallMutableArray# (in GHC.Exts)
is no less efficient than a primop would be. This may be replaced by
a primop in the future if someone devises a strategy for growing
arrays in-place. The library-space implementation always copies the
array when growing it.

This commit also tweaks the documentation of the deprecated
sizeofMutableByteArray#, removing the mention of concurrency. That
primop is unsound even in single-threaded applications. Additionally,
the non-negativity assertion on the existing shrinkMutableByteArray#
primop has been removed since this predicate is trivially always true.

- - - - -
1be9c35c by Roland Senn at 2019-10-26T05:20:14-04:00
Fix #14690 - :steplocal panics after break-on-error

`:steplocal` enables only breakpoints in the current top-level binding.

When a normal breakpoint is hit, then the module name and the break id from the `BRK_FUN` byte code
allow us to access the corresponding entry in a ModBreak table. From this entry we then get the SrcSpan
(see compiler/main/InteractiveEval.hs:bindLocalsAtBreakpoint).
With this source-span we can then determine the current top-level binding, needed for the steplocal command.

However, if we break at an exception or at an error, we don't have an BRK_FUN byte-code, so we don't have any source information.
The function `bindLocalsAtBreakpoint` creates an `UnhelpfulSpan`, which doesn't allow us to determine the current top-level binding.
To avoid a `panic`, we have to check for `UnhelpfulSpan` in the function `ghc/GHCi/UI.hs:stepLocalCmd`.
Hence a :steplocal command after a break-on-exception or a break-on-error is not possible.

- - - - -
4820af10 by Adam Sandberg Eriksson at 2019-10-26T19:53:01-04:00
hadrian: point link to ghc gitlab

[skip ci]

- - - - -
609c7ee6 by Ben Gamari at 2019-10-26T19:53:36-04:00
gitlab-ci: Produce ARMv7 binary distributions

- - - - -
8ac49411 by Ben Gamari at 2019-10-26T19:53:36-04:00
testsuite: Skip regalloc_unit_tests unless have_ncg

This is a unit test for the native code generator's register allocator;
naturally. the NCG is required.

- - - - -
60575596 by Ben Gamari at 2019-10-26T19:53:36-04:00
Enable PDF documentation

- - - - -
417f59d4 by Ben Gamari at 2019-10-26T19:53:36-04:00
rts: Fix ARM linker includes

 * Prefer #pragma once over guard macros
 * Drop redundant #includes
 * Fix order to ensure that necessary macros are defined when we
   condition on them

- - - - -
4054f0e5 by Ömer Sinan Ağacan at 2019-10-26T19:54:16-04:00
Remove redundant -fno-cse options

These were probably added with some GLOBAL_VARs, but those GLOBAL_VARs
are now gone.

- - - - -
c62817f2 by Luke Lau at 2019-10-27T11:35:40-04:00
Fix RankNTypes :ghc-flag: in users guide

This fixes a hadrian `build docs` failure

- - - - -
fc3a5205 by Luke Lau at 2019-10-27T11:35:40-04:00
Remove unused import

- - - - -
d2520bef by Luke Lau at 2019-10-27T11:35:40-04:00
Fix path to ghc-flags in users guide Hadrian rules

It should point to the _build directory, not the source

- - - - -
896d470a by Luke Lau at 2019-10-27T11:35:40-04:00
Add back documentation for deprecated -Whi-shadowing

This was removed in b538476be3706264620c072e6e436debf9e0d3e4, but
without it the compare-flags.py script fails. This adds it back and
marks it as deprecated, with a notice that it is slated for removal.

- - - - -
7d80f8b5 by Luke Lau at 2019-10-27T11:35:40-04:00
Remove documented flags from expected-undocumented-flags.txt

- - - - -
fa0d4809 by Ryan Scott at 2019-10-27T11:36:17-04:00
Parenthesize nullary constraint tuples using sigPrec (#17403)

We were using `appPrec`, not `sigPrec`, as the precedence when
determining whether or not to parenthesize `() :: Constraint`,
which lead to the parentheses being omitted in function contexts
like `(() :: Constraint) => String`. Easily fixed.

Fixes #17403.

- - - - -
90d06fd0 by Ben Gamari at 2019-10-27T17:27:17-04:00
hadrian: Silence output from Support SMP check

Previously we would allow the output from the check of SMP support
introduced by 83655b06e6d3e93b2d15bb0fa250fbb113d7fe68 leak to
stdout. Silence this.

See #16873.
- - - - -
6635a3f6 by Josef Svenningsson at 2019-10-28T09:20:34-04:00
Fix #15344: use fail when desugaring applicative-do

Applicative-do has a bug where it fails to use the monadic fail method
when desugaring patternmatches which can fail. See #15344.

This patch fixes that problem. It required more rewiring than I had expected.
Applicative-do happens mostly in the renamer; that's where decisions about
scheduling are made. This schedule is then carried through the typechecker and
into the desugarer which performs the actual translation. Fixing this bug
required sending information about the fail method from the renamer, through
the type checker and into the desugarer. Previously, the desugarer didn't
have enough information to actually desugar pattern matches correctly.

As a side effect, we also fix #16628, where GHC wouldn't catch missing
MonadFail instances with -XApplicativeDo.

- - - - -
cd9b9459 by Ryan Scott at 2019-10-28T09:21:13-04:00
Refactor TcDeriv to validity-check less in anyclass/via deriving (#13154)

Due to the way `DerivEnv` is currently structured, there is an
invariant that every derived instance must consist of a class applied
to a non-empty list of argument types, where the last argument *must*
be an application of a type constructor to some arguments. This works
for many cases, but there are also some design patterns in standalone
`anyclass`/`via` deriving that are made impossible due to enforcing
this invariant, as documented in #13154.

This fixes #13154 by refactoring `TcDeriv` and friends to perform
fewer validity checks when using the `anyclass` or `via` strategies.
The highlights are as followed:

* Five fields of `DerivEnv` have been factored out into a new
  `DerivInstTys` data type. These fields only make sense for
  instances that satisfy the invariant mentioned above, so
  `DerivInstTys` is now only used in `stock` and `newtype` deriving,
  but not in other deriving strategies.
* There is now a `Note [DerivEnv and DerivSpecMechanism]` describing
  the bullet point above in more detail, as well as explaining the
  exact requirements that each deriving strategy imposes.
* I've refactored `mkEqnHelp`'s call graph to be slightly less
  complicated. Instead of the previous `mkDataTypeEqn`/`mkNewTypeEqn`
  dichotomy, there is now a single entrypoint `mk_eqn`.
* Various bits of code were tweaked so as not to use fields that are
  specific to `DerivInstTys` so that they may be used by all deriving
  strategies, since not all deriving strategies use `DerivInstTys`.

- - - - -
e0e04856 by Alan Zimmerman at 2019-10-28T09:21:58-04:00
Attach API Annotations for {-# SOURCE #-} import pragma

Attach the API annotations for the start and end locations of the
{-# SOURCE #-} pragma in an ImportDecl.

Closes #17388

- - - - -
e951f219 by Sebastian Graf at 2019-10-28T09:22:35-04:00
Use FlexibleInstances for `Outputable (* p)` instead of match-all instances with equality constraints

In #17304, Richard and Simon dicovered that using `-XFlexibleInstances`
for `Outputable` instances of AST data types means users can provide orphan
`Outputable` instances for passes other than `GhcPass`.

Type inference doesn't currently to suffer, and Richard gave an example
in #17304 that shows how rare a case would be where the slightly worse
type inference would matter.

So I went ahead with the refactoring, attempting to fix #17304.

- - - - -
ad1fe274 by Simon Peyton Jones at 2019-10-28T09:23:14-04:00
Better arity for join points

A join point was getting too large an arity, leading to #17294.
I've tightened up the invariant: see
  CoreSyn, Note [Invariants on join points], invariant 2b

- - - - -
fb4f245c by Takenobu Tani at 2019-10-29T03:45:02-04:00
users-guide: Fix :since: for -xn flag

[skip ci]

- - - - -
35abbfee by Takenobu Tani at 2019-10-29T03:45:41-04:00
users-guide: Add some new features and fix warnings for GHC 8.10

This updates the following:

* Add description for ImportQualifiedPost extension
* Add description for ghci command name resolution
* Fix markdown warnings

[skip ci]

- - - - -
57dc1565 by Sylvain Henry at 2019-10-29T03:46:22-04:00
Use `not#` primitive to implement Word's complement

- - - - -
28e52732 by Ben Gamari at 2019-10-29T03:46:59-04:00
linters: Add mode to lint given set of files

This makes testing much easier.

- - - - -
db43b3b3 by Ben Gamari at 2019-10-29T03:46:59-04:00
linters: Add linter to catch unquoted use of $(TEST_HC)

This is a common bug that creeps into Makefiles (e.g. see T12674).

- - - - -
ebee0d6b by Ben Gamari at 2019-10-29T03:46:59-04:00
testsuite: Fix quoting of $(TEST_HC) in T12674

I have no idea how this went unnoticed until now.

- - - - -
3bd3456f by Ömer Sinan Ağacan at 2019-10-29T03:47:44-04:00
Refactor HscRecomp constructors:

Make it evident in the constructors that the final interface is only
available when HscStatus is not HscRecomp.

(When HscStatus == HscRecomp we need to finish the compilation to get
the final interface)

`Maybe ModIface` return value of hscIncrementalCompile and the partial
`expectIface` function are removed.

- - - - -
bbdd54aa by Ömer Sinan Ağacan at 2019-10-29T03:47:44-04:00
Return ModIface in compilation pipeline, remove IORef hack for generating ModIfaces

The compilation phases now optionally return ModIface (for phases that
generate an interface, currently only HscOut when (re)compiling a file).
The value is then used by compileOne' to return the generated interface
with HomeModInfo (which is then used by the batch mode compiler when
building rest of the tree).

hscIncrementalMode also returns a DynFlags with plugin info, to be used
in the rest of the pipeline.

Unfortunately this introduces a (perhaps less bad) hack in place of the
previous IORef: we now record the DynFlags used to generate the partial
infterface in HscRecomp and use the same DynFlags when generating the
full interface. I spent almost three days trying to understand what's
changing in DynFlags that causes a backpack test to fail, but I couldn't
figure it out. There's a FIXME added next to the field so hopefully
someone who understands this better than I do will fix it leter.

- - - - -
a56433a9 by Ömer Sinan Ağacan at 2019-10-29T03:47:44-04:00
Remove unused DynFlags arg of lookupIfaceByModule

- - - - -
dcd40c71 by Ömer Sinan Ağacan at 2019-10-29T03:47:44-04:00
HscMain: Move a comment closer to the relevant site

- - - - -
593f6543 by Ömer Sinan Ağacan at 2019-10-29T03:47:44-04:00
MkIface: Remove redundant parameter and outdated comments from addFingerprints

- - - - -
f868e1fe by Ben Gamari at 2019-10-29T03:48:20-04:00
gitlab-ci: Use Hadrian for unregisterised job

- - - - -
7b2ecbc0 by Ben Gamari at 2019-10-29T03:48:20-04:00
gitlab-ci: Factor out Linux Hadrian validation logic

- - - - -
8e5de15d by Ben Gamari at 2019-10-29T03:48:20-04:00
hadrian: Define USE_LIBFFI_FOR_ADJUSTORS when necessary

- - - - -
6a090270 by Ben Gamari at 2019-10-29T03:48:20-04:00
hadrian: Define NOSMP when building rts unregisterised

It seems that NOSMP was previously only defined when compiling the
compiler, not the RTS. Fix this.

In addition do some spring-cleaning and make the logic match that of the
Make build system.

- - - - -
b741d19d by Ben Gamari at 2019-10-29T03:48:20-04:00
hadrian: Shuffle around RTS build flags

Some of these flags wanted to be passed to .cmm builds as well as C
builds.

- - - - -
d7cedd9d by Ben Gamari at 2019-10-29T03:48:20-04:00
hadrian: Drop -Werror=unused-but-set-variable from GHC flags

Previously `hadrian` would pass `-optc-Werror=unused-but-set-variable`
to all GHC invocations. This was a difference from the make build system
and cause the unregisterised build to fail as the C that GHC produces
contains many unused functions. Drop it from the GHC flags.

Note, however, that the flag is still present in
`Settings.Builders.Common.cWarnings` and therefore will still be applied
during compilation of C sources.

- - - - -
7d3a15c7 by Ben Gamari at 2019-10-29T03:48:55-04:00
base: Fix open-file locking

The OFD locking path introduced in
3b784d440d4b01b4c549df7c9a3ed2058edfc780 due to #13945 appears to have
never actually worked but we never noticed due to an oversight in the
autoconf check. Fix it.

Thanks to Oleg Grenrus for noticing this.

- - - - -
78b70e63 by Ben Gamari at 2019-10-29T03:48:55-04:00
base: Split up file locking implementation

This makes the CPP significantly easier to follow.

- - - - -
63977398 by Ben Gamari at 2019-10-29T03:49:31-04:00
Don't substitute GccVersion variable

Not only is it now unused but we generally can't assume that we are
compiling with GCC, so it really shouldn't be used.

- - - - -
72f7ac9a by Ben Gamari at 2019-10-29T03:50:06-04:00
Revert "Replace freebsd-gnueabihf with freebsd"

This reverts commit aa31ceaf7568802590f73a740ffbc8b800096342 as
suggested in #17392.

- - - - -
3c0372d6 by Ben Gamari at 2019-10-29T20:31:36-04:00
distrib: Fix binary distribution installation

This had silently regressed due to 81860281 and the variable renaming performed
in b55ee979, as noted in #17374.

- - - - -
a7f423ee by Ben Gamari at 2019-10-29T20:31:36-04:00
gitlab-ci: Use pxz to compress binary distributions

- - - - -
db602643 by Ben Gamari at 2019-10-29T20:31:36-04:00
Don't include settings file in binary distribution

The configuration in the installation environment (as determined by
`autoconf`) may differ from the build environment and therefore we
need to be sure to rebuild the settings file.

Fixes #17374.

- - - - -
260e2379 by Ben Gamari at 2019-10-29T20:31:36-04:00
gitlab-ci: Fix binary distribution testing

- - - - -
01ef3e1f by Ömer Sinan Ağacan at 2019-10-29T20:32:18-04:00
Interpreter: initialize arity fields of AP_NOUPDs

AP_NOUPD entry code doesn't use the arity field, but not initializing
this field confuses printers/debuggers, and also makes testing harder as
the field's value changes randomly.

- - - - -
93ff9197 by Ben Gamari at 2019-10-30T07:36:49-04:00
rts: More aarch64 header fixes

- - - - -
3e7569bc by Vladislav Zavialov at 2019-10-30T07:36:50-04:00
Whitespace forward compatibility for proposal #229

GHC Proposal #229 changes the lexical rules of Haskell, which may
require slight whitespace adjustments in certain cases.

This patch changes formatting in a few places in GHC and its testsuite
in a way that enables it to compile under the proposed rules.

- - - - -
4898df1c by Ben Gamari at 2019-10-30T18:15:52-04:00
gitlab-ci: Fix the ARMv7 triple

Previously we were configuring the ARMv7 builds with a host/target
triple of arm-linux-gnueabihf, which caused us to target ARMv6 and
consequently rely on the old CP15 memory barrier implementation. This
barrier has to be emulated on ARMv8 machines which is glacially slow.

Hopefully this should fix the ARMv7 builds which currently consistently
time out.

- - - - -
337e9b5a by Ömer Sinan Ağacan at 2019-10-31T19:01:54-04:00
Remove redundant 0s in ghc-heap pointer strings

Before: 0x0000004200c86888
After:  0x42000224f8

This is more concise and consistent with the RTS's printer (which uses
%p formatter, and at least on Linux gcc prints the short form) and gdb's
pointer formatter.

- - - - -
97b6f7a3 by Ben Gamari at 2019-10-31T19:02:32-04:00
base: Clamp IO operation size to 2GB on Darwin

As reported in #17414, Darwin throws EINVAL in response to large
writes.

- - - - -
a9743eb7 by Ben Gamari at 2019-10-31T19:02:32-04:00
testsuite: Add test for #17414

- - - - -
73d6e508 by Ben Gamari at 2019-10-31T19:03:10-04:00
base: Various haddock fixes

Just a few things I found while looking at #17383.

- - - - -
dc487642 by taylorfausak at 2019-11-01T04:54:47-04:00
Implement `round` for `Ratio` that doesn't explode with `Natural`s
- - - - -
3932fb97 by taylorfausak at 2019-11-01T04:54:47-04:00
Fix rounding around 0
- - - - -
baf47ff8 by taylorfausak at 2019-11-01T04:54:47-04:00
Add tests for rounding ratios
- - - - -
214d8122 by taylorfausak at 2019-11-01T04:54:47-04:00
Fix running of ratio test case
- - - - -
70b62c97 by Ben Gamari at 2019-11-01T04:55:24-04:00
mmap: Factor out protection flags

- - - - -
c6759080 by Ben Gamari at 2019-11-01T04:55:24-04:00
rts: Make m32 allocator per-ObjectCode

MacOS Catalina is finally going to force our hand in forbidden writable
exeutable mappings. Unfortunately, this is quite incompatible with the
current global m32 allocator, which mixes symbols from various objects
in a single page. The problem here is that some of these symbols may not
yet be resolved (e.g. had relocations performed) as this happens lazily
(and therefore we can't yet make the section read-only and therefore
executable).

The easiest way around this is to simply create one m32 allocator per
ObjectCode. This may slightly increase fragmentation for short-running
programs but I suspect will actually improve fragmentation for programs
doing lots of loading/unloading since we can always free all of the
pages allocated to an object when it is unloaded (although this ability
will only be implemented in a later patch).

- - - - -
35c99e72 by Simon Peyton Jones at 2019-11-01T04:56:02-04:00
Makes Lint less chatty:

I found in #17415 that Lint was printing out truly gigantic
warnings, unmanageably huge, with repeated copies of the
same thing.

This patch makes Lint less chatty, especially for warnings:

* For **warnings**, I don't print details of the location,
  unless you add `-dppr-debug`.

* For **errors**, I still print all the info. They are fatal
  and stop exection, whereas warnings appear repeatedly.

* I've made much less use of `AnExpr` in `LintLocInfo`;
  the expression can be gigantic.

- - - - -
d2471964 by Simon Peyton Jones at 2019-11-01T04:56:38-04:00
Add another test for #17267

This one came in a comment from James Payor

- - - - -
1e2e82aa by Simon Peyton Jones at 2019-11-01T04:57:15-04:00
Fix a bad error in tcMatchTy

This patch fixes #17395, a very subtle and hard-to-trigger
bug in tcMatchTy.  It's all explained in
  Note [Matching in the presence of casts (2)]

I have not added a regression test because it is very hard
to trigger it, until we have the upcoming mkAppTyM patch,
after which lacking this patch means you can't even compile
the libraries.

- - - - -
51067194 by Ben Gamari at 2019-11-01T15:48:37-04:00
base: Ensure that failIO isn't SOURCE imported

failIO has useful information in its demand signature (specifically that
it bottoms) which is hidden if it is SOURCE imported, as noted
in #16588. Rejigger things such that we don't SOURCE import it.

Metric Increase:
    T13701

- - - - -
c751082c by Ben Gamari at 2019-11-01T15:48:37-04:00
testsuite: Make ExplicitForAllRules1 more robust

Previously the test relied on `id` not inlining. Fix this.

- - - - -
dab12c87 by Ben Gamari at 2019-11-01T15:48:37-04:00
Describe optimisation of demand analysis of noinline

As described in #16588.

- - - - -
c9236384 by Adam Sandberg Eriksson at 2019-11-01T15:49:16-04:00
template-haskell: require at least 1 GADT constructor name (#17379)

- - - - -
a4ce26e0 by Ben Gamari at 2019-11-01T15:49:53-04:00
hadrian: Make runtest invocation consistency with Make

Use True/False instead of 0/1. This shouldn't be a functional change but
we should be consistent.

- - - - -
cabafe34 by Ben Gamari at 2019-11-01T15:50:29-04:00
testsuite: Add test for #17423

- - - - -
4a6d3d68 by Simon Peyton Jones at 2019-11-01T23:11:37-04:00
Make CSE delay inlining less

CSE delays inlining a little bit, to avoid losing vital
specialisations; see Note [Delay inlining after CSE] in CSE.

But it was being over-enthusiastic.  This patch makes the
delay only apply to Ids with specialisation rules, which
avoids unnecessary delay (#17409).

- - - - -
01006bc7 by Niklas Hambüchen at 2019-11-01T23:12:17-04:00
doc: Fix backticks

- - - - -
9980fb58 by Niklas Hambüchen at 2019-11-01T23:12:17-04:00
Add +RTS --disable-delayed-os-memory-return. Fixes #17411.

Sets `MiscFlags.disableDelayedOsMemoryReturn`.

See the added `Note [MADV_FREE and MADV_DONTNEED]` for details.

- - - - -
182b1199 by Sebastian Graf at 2019-11-02T20:16:33-04:00
Separate `LPat` from `Pat` on the type-level

Since the Trees That Grow effort started, we had `type LPat = Pat`.
This is so that `SrcLoc`s would only be annotated in GHC's AST, which is
the reason why all GHC passes use the extension constructor `XPat` to
attach source locations. See #15495 for the design discussion behind
that.

But now suddenly there are `XPat`s everywhere!
There are several functions which dont't cope with `XPat`s by either
crashing (`hsPatType`) or simply returning incorrect results
(`collectEvVarsPat`).

This issue was raised in #17330. I also came up with a rather clean and
type-safe solution to the problem: We define

```haskell
type family XRec p (f :: * -> *) = r | r -> p f
type instance XRec (GhcPass p) f = Located (f (GhcPass p))
type instance XRec TH          f =          f p
type LPat p = XRec p Pat
```

This is a rather modular embedding of the old "ping-pong" style, while
we only pay for the `Located` wrapper within GHC. No ping-ponging in
a potential Template Haskell AST, for example. Yet, we miss no case
where we should've handled a `SrcLoc`: `hsPatType` and
`collectEvVarsPat` are not callable at an `LPat`.

Also, this gets rid of one indirection in `Located` variants:
Previously, we'd have to go through `XPat` and `Located` to get from
`LPat` to the wrapped `Pat`. Now it's just `Located` again.

Thus we fix #17330.

- - - - -
3c916162 by Richard Eisenberg at 2019-11-02T20:17:13-04:00
Update Note references -- comments only

Follow-on from !2041.

- - - - -
3b65655c by Ben Gamari at 2019-11-04T03:40:31-05:00
SysTools: Only apply Windows-specific workaround on Windows

Issue #1110 was apparently due to a bug in Vista which prevented GCC
from finding its binaries unless we explicitly added it to PATH.
However, this workaround was incorrectly applied on non-Windows
platforms as well, resulting in ill-formed PATHs (#17266).

Fixes #17266.

- - - - -
5d4f16ee by Leif Metcalf at 2019-11-04T03:41:09-05:00
Rephrase note on full-laziness

- - - - -
120f2e53 by Ben Gamari at 2019-11-04T03:41:44-05:00
rts/linker: Ensure that code isn't writable

For many years the linker would simply map all of its memory with
PROT_READ|PROT_WRITE|PROT_EXEC. However operating systems have been
becoming increasingly reluctant to accept this practice (e.g. #17353
and #12657) and for good reason: writable code is ripe for exploitation.

Consequently mmapForLinker now maps its memory with
PROT_READ|PROT_WRITE.  After the linker has finished filling/relocating
the mapping it must then call mmapForLinkerMarkExecutable on the
sections of the mapping which contain executable code.

Moreover, to make all of this possible it was necessary to redesign the
m32 allocator. First, we gave (in an earlier commit) each ObjectCode its
own m32_allocator. This was necessary since code loading and symbol
resolution/relocation are currently interleaved, meaning that it is not
possible to enforce W^X when symbols from different objects reside in
the same page.

We then redesigned the m32 allocator to take advantage of the fact that
all of the pages allocated with the allocator die at the same time
(namely, when the owning ObjectCode is unloaded). This makes a number of
things simpler (e.g. no more page reference counting; the interface
provided by the allocator for freeing is simpler). See
Note [M32 Allocator] for details.

- - - - -
7c28087a by Takenobu Tani at 2019-11-05T02:45:31-05:00
users-guide: Improve documentaion of CPP extension

Currently, the description of CPP extension is given in the section of
command-line options.
Therefore, it is a little difficult to understand that it is a language
extension.

This commit explicitly adds a description for it.

[skip ci]

- - - - -
d57059f7 by Ben Gamari at 2019-11-05T02:46:10-05:00
rts: Add missing const in HEAP_ALLOCED_GC

This was previously unnoticed as this code-path is hit on very few
platforms (e.g. OpenBSD).

- - - - -
487ede42 by Peter Trommler at 2019-11-05T02:46:48-05:00
testsuite: skip test requiring RTS linker on PowerPC

The RTS linker is not available on 64-bit PowerPC. Instead of
marking tests that require the RTS linker as broken on PowerPC
64-bit skip the respective tests on all platforms where the
RTS linker or a statically linked external interpreter is not
available.

Fixes #11259

- - - - -
1593debf by Sebastian Graf at 2019-11-05T11:38:30-05:00
Check EmptyCase by simply adding a non-void constraint

We can handle non-void constraints since !1733, so we can now express
the strictness of `-XEmptyCase` just by adding a non-void constraint
to the initial Uncovered set.

For `case x of {}` we thus check that the Uncovered set `{ x | x /~ ⊥ }`
is non-empty. This is conceptually simpler than the plan outlined in
 #17376, because it talks to the oracle directly.

In order for this patch to pass the testsuite, I had to fix handling of
newtypes in the pattern-match checker (#17248).

Since we use a different code path (well, the main code path) for
`-XEmptyCase` now, we apparently also handle #13717 correctly.
There's also some dead code that we can get rid off now.

`provideEvidence` has been updated to provide output more in line with
the old logic, which used `inhabitationCandidates` under the hood.

A consequence of the shift away from the `UncoveredPatterns` type is
that we don't report reduced type families for empty case matches,
because the pretty printer is pure and only knows the match variable's
type.

Fixes #13717, #17248, #17386

- - - - -
e6ffe148 by Ömer Sinan Ağacan at 2019-11-05T11:39:13-05:00
TidyPgm: replace an explicit loop with mapAccumL

- - - - -
b7460492 by Ömer Sinan Ağacan at 2019-11-05T11:39:13-05:00
CoreTidy: hide tidyRule

- - - - -
f9978f53 by Stefan Schulze Frielinghaus at 2019-11-05T11:39:51-05:00
Hadrian: enable interpreter for s390x

- - - - -
3ce18700 by Ben Gamari at 2019-11-06T08:05:57-05:00
rts: Drop redundant flags for libffi

These are now handled in the cabal file's include-dirs field.

- - - - -
ce9e2a1a by Ben Gamari at 2019-11-06T08:05:57-05:00
configure: Add --with-libdw-{includes,libraries} flags

Fixing #17255.

- - - - -
97f9674b by Takenobu Tani at 2019-11-06T08:06:37-05:00
configure: Add checking python3-sphinx

This checks the configuration about python3-sphinx.
We need python3-sphinx instead of python2-sphinx to build documentation.

The approach is as follows:
* Check python3 version with custom `conf.py` invoked from
  sphinx-build` executable
* Place custom `conf.py` into new `utils/check-sphinx` directory

If sphinx is for python2 not python3, it's treated as config ERROR
instead of WARN.

See also #17346 and #17356.

- - - - -
b4fb2328 by Dan Brooks at 2019-11-06T08:07:15-05:00
Adding examples to Semigroup/monoid

- - - - -
708c60aa by Ryan Scott at 2019-11-07T08:39:36-05:00
Clean up TH's treatment of unary tuples (or, #16881 part two)

!1906 left some loose ends in regards to Template Haskell's treatment
of unary tuples. This patch ends to tie up those loose ends:

* In addition to having `TupleT 1` produce unary tuples, `TupE [exp]`
  and `TupP [pat]` also now produce unary tuples.
* I have added various special cases in GHC's pretty-printers to
  ensure that explicit 1-tuples are printed using the `Unit` type.
  See `testsuite/tests/th/T17380`.
* The GHC 8.10.1 release notes entry has been tidied up a little.

Fixes #16881. Fixes #17371. Fixes #17380.

- - - - -
a424229d by Stefan Schulze Frielinghaus at 2019-11-07T08:40:13-05:00
For s390x issue a warning if LLVM 9 or older is used

For s390x the GHC calling convention is only supported since LLVM
version 10.  Issue a warning in case an older version of LLVM is used.

- - - - -
55bc3787 by Ben Gamari at 2019-11-07T08:40:50-05:00
FlagChecker: Add ticky flags to hashed flags

These affect output and therefore should be part of the flag hash.

- - - - -
fa0b1b4b by Stefan Schulze Frielinghaus at 2019-11-07T08:41:33-05:00
Bump libffi-tarballs submodule

- - - - -
a9566632 by Takenobu Tani at 2019-11-07T08:42:15-05:00
configure: Modify ERROR to WARN for sphinx's python check

If sphinx's python version check failed, many people prefer to build
without documents instead of stopping on the error.

So this commit fixes the following:

* Modify AC_MSG_ERROR to AC_MSG_WARN
* Add clearing of SPHINXBUILD variable when check fails

See also !2016.

- - - - -
d0ef8312 by Alp Mestanogullari at 2019-11-07T21:24:59-05:00
hadrian: fix support for the recording of perf test results

Before this patch, Hadrian didn't care about the TEST_ENV and
METRICS_FILE environment variables, that the performance testing
infrastructure uses to record perf tests results from CI jobs.

It now looks them up right before running the testsuite driver,
and passes suitable --test-env/--metrics-file arguments when
these environment variables are set.

- - - - -
601e554c by Ben Gamari at 2019-11-07T21:25:36-05:00
Bump the process submodule

This should fix the #17108 and #17249 with the fix from
https://github.com/haskell/process/pull/159.

- - - - -
6b7d7e1c by Ben Gamari at 2019-11-07T21:25:36-05:00
Bump hsc2hs submodule

- - - - -
b1c158c9 by Ben Gamari at 2019-11-07T21:25:36-05:00
rts: Fix m32 allocator build on Windows

An inconsistency in the name of m32_allocator_flush caused the build to
fail with a missing prototype error.

- - - - -
ae431cf4 by Ben Gamari at 2019-11-07T21:25:36-05:00
rts: Ensure that Rts.h is always included first

In general this is the convention that we use in the RTS. On Windows
things actually fail if we break it. For instance, you see things like:

   includes\stg\Types.h:26:9: error:
     warning: #warning "Mismatch between __USE_MINGW_ANSI_STDIO
     definitions. If using Rts.h make sure it is the first header
     included." [-Wcpp]

- - - - -
0d141d28 by Ben Gamari at 2019-11-07T21:25:36-05:00
rts: Remove undesireable inline specifier

I have no idea why I marked this as inline originally but clearly it
shouldn't be inlined.

- - - - -
870376f9 by Ben Gamari at 2019-11-07T21:25:36-05:00
base: Add missing imports in Windows locking implementation

- - - - -
23994738 by Ben Gamari at 2019-11-07T21:25:36-05:00
rts/NonMoving: Fix various Windows build issues

The Windows build seems to be stricter about not providing threading
primitives in the non-threaded RTS.

- - - - -
a3ce52fd by Ben Gamari at 2019-11-07T21:25:36-05:00
users_guide: Set flags list file encoding

Otherwise this fails on Windows.

- - - - -
9db2e905 by Stefan Schulze Frielinghaus at 2019-11-08T05:36:54-05:00
Testsuite: Introduce req_rts_linker

Some tests depend on the RTS linker. Introduce a modifier to skip such
tests, in case the RTS linker is not available.

- - - - -
a4631335 by Szymon Nowicki-Korgol at 2019-11-08T05:37:34-05:00
Set correct length of DWARF .debug_aranges section (fixes #17428)

- - - - -
3db2ab30 by Ben Gamari at 2019-11-08T05:38:11-05:00
hadrian: Add enableTickyGhc helper

This took a bit of trial-and-error to get working so it seems worth
having in the tree.

- - - - -
5c87ebd7 by Ben Gamari at 2019-11-08T12:09:22-05:00
SetLevels: Don't set context level when floating cases

When floating a single-alternative case we previously would set the
context level to the level where we were floating the case. However,
this is wrong as we are only moving the case and its binders. This
resulted in #16978, where the disrepancy caused us to
unnecessarily abstract over some free variables of the case body,
resulting in shadowing and consequently Core Lint failures.

(cherry picked from commit a2a0e6f3bb2d02a9347dec4c7c4f6d4480bc2421)

- - - - -
43623b09 by Ben Gamari at 2019-11-08T12:10:01-05:00
testsuite: Run tests in nonmoving_thr in speed==slow

- - - - -
6e4656cc by Ben Gamari at 2019-11-08T12:10:01-05:00
rts/nonmoving: Catch failure of createOSThread

- - - - -
2e4fc04b by Ben Gamari at 2019-11-08T12:10:01-05:00
Bump unix submodule

Marks executeFile001 as broken in all concurrent ways.

- - - - -
8a10f9fb by Ben Gamari at 2019-11-09T18:03:01-05:00
template-haskell: Document assembler foreign file support

See #16180.

- - - - -
5ad3cb53 by Ben Gamari at 2019-11-09T18:03:01-05:00
template-haskell: Fix TBAs in changelog

- - - - -
4a75a832 by Ben Gamari at 2019-11-09T18:03:01-05:00
base: Fix TBA in changelog

- - - - -
d7de0d81 by Ryan Scott at 2019-11-09T18:03:02-05:00
template-haskell: Fix italics in changelog

[ci-skip]

- - - - -
0fb246c3 by Ben Gamari at 2019-11-09T18:03:37-05:00
testsuite: Fix Windows cleanup path

This was a regression introduced with the Path refactoring.

- - - - -
925fbdbb by Ben Gamari at 2019-11-09T18:03:37-05:00
testsuite: Skip T16916 on Windows

The event manager is not supported on Windows.

- - - - -
7c2ce0a0 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Skip T14931 on Windows

This test uses -dynamic-too, which is not supported on Windows.

- - - - -
7c63edb4 by Ben Gamari at 2019-11-09T18:03:38-05:00
gitlab-ci: Don't allow Windows make job to fail

While linking is still slow (#16084) all of the correctness issues which were
preventing us from being able to enforce testsuite-green on Windows are now
resolved.

- - - - -
a50ecda6 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Fix header #include order on Windows

<Rts.h> must always come first.

- - - - -
dcb23ec9 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Mark T13676 as broken on Darwin and Windows

Due to #17447.

- - - - -
411ba7ba by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Mark T11627b as fragile

It was previously marked as broken due to #12236 however it passes for
me locally while failing on CI.

- - - - -
c1f1f3f9 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Mark T16219 as unbroken

This was previously broken due to #16386 yet it passes for me locally.

- - - - -
1f871e70 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Remove redundant cleaning logic from T16511

The GHCi script for T16511 had some `rm` commands to clean up output
from previous runs. This should be harmless since stderr was redirected
to /dev/null; however, it seems that this redirection doesn't work on
Windows (perhaps because GHCi uses `cmd` to execute the command-line;
I'm not sure). I tried to fix it but was unable to find a sensible
solution.

Regardless, the cleaning logic is quite redundant now that we run each
test in a hermetic environment. Let's just remove it.

- - - - -
4d523cb1 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Mark T17414 as fragile on Windows

This consistently times out on Windows as described in #17453. I have tried
increasing the timeout multiplier to two yet it stills fails. Disabling
until we have time to investigate.

- - - - -
f73fbd2d by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Ignore stderr in PartialDownsweep

As described in #17449, PartialDownsweep is currently fragile due to its
dependence on the error messages produced by the C preprocessor. To eliminate
this dependence we simply ignore stderr output, instead relying on the fact
that the test will exit with a non-zero exit code on failure.

Fixes #17449.

- - - - -
a9b14790 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Fix putStrLn in saks028

Bizarrely, `saks028` previously failed reliably, but only on Windows
(#17450). The test would exit with a zero exit code but simply didn't
emit the expected text to stderr.

I believe this was due to the fact that the test used `putStrLn`,
resulting in the output ending up on stdout. This worked on other
platforms since (apparently) we redirect stdout to stderr when
evaluating splices. However, on Windows it seems that the redirected
output wasn't flushed as it was on other platforms.

Anyways, it seems like the right thing to do here is to be explicit
about our desire for the output to end up on stderr.

Closes #17450.

- - - - -
b62ca659 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Drop T7995

This test is quite sensitive to the build configuration as it requires that ghc
have unfoldings, which isn't true in the quick build flavours. I considered
various options to make the test more robust but none of them seemed
particularly appealing. Moreover, Simon PJ was a bit skeptical of the value of
the test to begin with and I strongly suspect that any regression in #7995
would be accompanied by failures in our other compiler performance tests.

Closes #17399.

- - - - -
011f3121 by Ben Gamari at 2019-11-09T18:03:38-05:00
testsuite: Mark T16219 as fragile on Windows

As noted in #17452, this test produces very long file paths which
exceed the Windows MAX_PATH limitation. Mark the test as fragile for not
until we can come up with a better solution.

- - - - -
1f98e47d by Simon Peyton Jones at 2019-11-09T18:04:14-05:00
Use the right type in :force

A missing prime meant that we were considering the wrong
type in the GHCi debugger, when doing :force on multiple
arguments (issue #17431).

The fix is trivial.

- - - - -
1f911de4 by Brian Wignall at 2019-11-09T18:04:57-05:00
Add IsList instance for ZipList (closes #17433)

- - - - -
e3672f40 by Brian Wignall at 2019-11-09T18:04:57-05:00
Incorporate MR review suggestions; add change in changelog

- - - - -
3957bdf2 by Brian Wignall at 2019-11-09T18:04:57-05:00
Fix incorrect plurals

- - - - -
6f4c1250 by Alina Banerjee at 2019-11-10T01:06:12-05:00
Improve SPECIALIZE pragma error messages (Fixes #12126)

- - - - -
fa25c8c4 by Richard Eisenberg at 2019-11-10T01:06:48-05:00
Update release notes about #16512 / #17405.

- - - - -
55ca1085 by Richard Eisenberg at 2019-11-10T01:06:48-05:00
Fix #17405 by not checking imported equations

Previously, we checked all imported type family equations
for injectivity. This is very silly. Now, we check only
for conflicts.

Before I could even imagine doing the fix, I needed to untangle
several functions that were (in my opinion) overly complicated.
It's still not quite as perfect as I'd like, but it's good enough
for now.

Test case: typecheck/should_compile/T17405

- - - - -
a9467f4f by Ben Gamari at 2019-11-10T21:06:33-05:00
testsuite: Mark tests fragile in threaded2 as fragile in all concurrent ways

- - - - -
3e07ea8d by Ben Gamari at 2019-11-10T21:10:30-05:00
testsuite: Use small allocation area when measuring residency

As suggested in #17387; this helps reduce the variance in our residency
sampling.

Metric Increase:
    T10370
    T3586
    lazy-bs-alloc

Metric Decrease 'compile_time/peak_megabytes_allocated':
    T1969

Metric Decrease 'runtime/bytes allocated':
    space_leak_001

Metric Increase 'compile_time/bytes allocated':
    T1969

Metric Increase 'runtime/peak_megabytes_allocated':
    space_leak_001

Metric Decrease:
    T3064
    T9675

- - - - -
049d9ae0 by Ben Gamari at 2019-11-10T21:10:30-05:00
testsuite: Don't check_stats at runtime if not requested

Previously we would call check_stats to check the runtime metrics even
if the test definition hadn't requested it. This would result in an
error since the .stats file doesn't exist.

- - - - -
64433428 by Alp Mestanogullari at 2019-11-11T08:49:01-05:00
hadrian: export METRICS_FILE to make it accessible to perf notes script

This addresses #17456 and also fixes the --metrics-file argument that Hadrian
passes to the testsuite driver.

- - - - -
06640394 by Ben Gamari at 2019-11-11T08:50:45-05:00
testsuite: Disable T4334 in nonmoving_thr way

- - - - -
f8ec32d7 by Alp Mestanogullari at 2019-11-11T11:36:44-05:00
ci: push perf test metrics even when the testsuite doesn't pass

The corresponding commit might introduce a regression on a perf test, in which
case we certainly want to record it. The testsuite might also fail because
of a test unrelated to performance, in which case we want to record that the
perf test results were good.

Either way, we likely want to record them under all circumstances but
we don't without this patch.

Metric Decrease:
    T3586

Metric Increase:
    lazy-bs-alloc

- - - - -
643d42fc by Alp Mestanogullari at 2019-11-12T18:40:19-05:00
testsuite: don't collect compiler stats in collect_runtime_residency

We instead want to collect the runtime stats (with collect_stats, instead of
collect_compiler_stats).

This should fix a number of perf tests failures we have been seeing, where
we suddenly started measuring metrics we didn't intend to measure, which
tend to fall outside of the acceptance window.

Metric Decrease:
    lazy-bs-alloc
    T3586

Metric Increase:
    space_leak_001
    T4801
    T5835
    T12791

- - - - -
535d0edc by Ömer Sinan Ağacan at 2019-11-13T07:06:12-05:00
Document CmmTopInfo type

[ci skip]

- - - - -
2d4f9ad8 by Ben Gamari at 2019-11-13T07:06:49-05:00
Ensure that coreView/tcView are able to inline

Previously an import cycle between Type and TyCoRep meant that several
functions in TyCoRep ended up SOURCE import coreView. This is quite
unfortunate as coreView is intended to be fused into a larger pattern
match and not incur an extra call.

Fix this with a bit of restructuring:

 * Move the functions in `TyCoRep` which depend upon things in `Type`
   into `Type`
 * Fold contents of `Kind` into `Type` and turn `Kind` into a simple
   wrapper re-exporting kind-ish things from `Type`
 * Clean up the redundant imports that popped up as a result

Closes #17441.

Metric Decrease:
    T4334

- - - - -
b795637f by Alp Mestanogullari at 2019-11-13T07:07:28-05:00
hadrian: fix Windows CI script

By only using 'export' from within bash commands.

- - - - -
6885e22c by Ben Gamari at 2019-11-13T07:08:03-05:00
testsuite: Add test for #17458

As noted in #17458, QuantifiedConstraints and UndecideableInstances
could previously be used to write programs which can loop at runtime.
This was fixed in !1870.

- - - - -
b4b19d89 by Ben Gamari at 2019-11-13T07:08:03-05:00
users guide: Fix broken link

- - - - -
9a939a6c by Ryan Scott at 2019-11-13T07:08:40-05:00
Print name prefixly in the Outputable instance for StandaloneKindSig

Issue #17461 was occurring because the `Outputable` instance for
standalone kind signatures was simply calling `ppr` on the name in
the kind signature, which does not add parentheses to infix names.
The solution is simple: use `pprPrefixOcc` instead.

Fixes #17461.

- - - - -
a06cfb59 by Ömer Sinan Ağacan at 2019-11-13T07:09:18-05:00
Only pass mod_location with HscRecomp instead of the entire ModSummary

HscRecomp users only need the ModLocation of the module being compiled,
so only pass that to users instead of the entire ModSummary

Metric Decrease:
    T4801

- - - - -
dd49b3f0 by Ben Gamari at 2019-11-13T17:01:21-05:00
Bump Haskeline and add exceptions as boot library

Haskeline now depends upon exceptions. See #16752.

- - - - -
b06b1858 by Ben Gamari at 2019-11-14T11:30:20-05:00
base: Bump version to 4.14.0.0

Metric Increase:
    T4801

- - - - -
6ab80439 by Ben Gamari at 2019-11-14T23:05:30-05:00
gitlab-ci: Allow Windows to fail again

- - - - -
46afc380 by Ben Gamari at 2019-11-15T09:45:36-05:00
gitlab-ci: Install process to global pkgdb before starting build

This is an attempt to mitigate #17480 by ensuring that a functional version of
the process library is available before attempting the build.

- - - - -
8c5cb806 by Ben Gamari at 2019-11-15T10:45:55-05:00
Bump supported LLVM version to 9.0

- - - - -
8e5851f0 by Ben Gamari at 2019-11-15T10:45:55-05:00
llvm-targets: Update with Clang 9

- - - - -
f3ffec27 by Ben Gamari at 2019-11-15T11:54:26-05:00
testsuite: Increase acceptance window of T4801

This statistic is rather unstable. Hopefully fixes #17475.

- - - - -
c2991f16 by Ben Gamari at 2019-11-15T11:56:10-05:00
users-guide: Drop 8.6.1 release notes

- - - - -
e8da1354 by Ben Gamari at 2019-11-17T06:48:16-05:00
gitlab-ci: Fix submodule linter

We ran it against the .git directory despite the fact that the linter
wants to be run against the repository.

- - - - -
13290f91 by Ben Gamari at 2019-11-17T06:48:16-05:00
Bump version to 8.10.0

Bumps haddock submodule.

- - - - -
fa98f823 by Ben Gamari at 2019-11-17T06:48:16-05:00
testsuite: Don't collect residency for T4801

I previously increased the size of the acceptance window from 2% to 5%
but this still isn't enough. Regardless, measuring bytes allocated
should be sufficient to catch any regressions.

- - - - -
002b2842 by Ivan Kasatenko at 2019-11-17T06:49:22-05:00
Make test 16916 more stable across runs

- - - - -
ca89dd3b by Ben Gamari at 2019-11-17T06:58:17-05:00
users-guide: Address #17329

Adopts the language suggested by @JakobBruenker.

- - - - -
2f5ed225 by Ben Gamari at 2019-11-17T07:16:32-05:00
exceptions: Bump submodule back to master

The previous commit hasn't made it to master yet.

- - - - -
34515e7c by nineonine at 2019-11-17T13:33:22-08:00
Fix random typos [skip ci]

- - - - -
4a37a29b by Mario Blažević at 2019-11-17T17:26:24-05:00
Fixed issue #17435, missing Data instances

- - - - -
97f1bcae by Andreas Klebinger at 2019-11-17T17:26:24-05:00
Turn some comments into GHC.Hs.Utils into haddocks

- - - - -
cf7f8e5b by Ben Gamari at 2019-11-17T17:26:26-05:00
testsuite: Skip T17414 on Linux

It is typical for $TMP to be a small tmpfson Linux. This test will fail
in such cases since we must create a file larger than the filesystem.
See #17459.

- - - - -
88013b78 by nineonine at 2019-11-19T11:53:16-05:00
Optimize MonadUnique instances based on IO (#16843)

Metric Decrease:
    T14683

- - - - -
a8adb5b4 by Ben Gamari at 2019-11-19T11:53:55-05:00
desugar: Drop stale Note [Matching seqId]

The need for this note vanished in
eae703aa60f41fd232be5478e196b661839ec3de.

- - - - -
08d595c0 by Ben Gamari at 2019-11-19T11:53:55-05:00
Give seq a more precise type and remove magic

`GHC.Prim.seq` previously had the rather plain type:

    seq :: forall a b. a -> b -> b

However, it also had a special typing rule to applications
where `b` is not of kind `Type`.

Issue #17440 noted that levity polymorphism allows us to rather give
it the more precise type:

    seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b

This allows us to remove the special typing rule that we previously
required to allow applications on unlifted arguments. T9404 contains a
non-Type application of `seq` which should verify that this works as
expected.

Closes #17440.

- - - - -
ec8a463d by Viktor Dukhovni at 2019-11-19T11:54:45-05:00
Enable USE_PTHREAD_FOR_ITIMER also on FreeBSD

If using a pthread instead of a timer signal is more reliable, and
has no known drawbacks, then FreeBSD is also capable of supporting
this mode of operation (tested on FreeBSD 12 with GHC 8.8.1, but
no reason why it would not also work on FreeBSD 11 or GHC 8.6).

Proposed by Kevin Zhang in:

    https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=241849

- - - - -
cd40e12a by Ömer Sinan Ağacan at 2019-11-19T11:55:36-05:00
Packages.hs: use O(n*log(n)) ordNub instead of O(n*n) nub

As reported in #8173 in some environments package lists can get quite
long, so we use more efficient ordNub instead of nub on package lists.

- - - - -
2b27cc16 by Ben Gamari at 2019-11-19T11:56:21-05:00
Properly account for libdw paths in make build system

Should finally fix #17255.

- - - - -
0418c38d by Ben Gamari at 2019-11-19T11:56:58-05:00
rts: Add missing include of SymbolExtras.h

This broke the Windows build.

- - - - -
c819c0e4 by Ben Gamari at 2019-11-19T11:57:36-05:00
nonmoving: Use correct info table pointer accessor

Previously we used INFO_PTR_TO_STRUCT instead of
THUNK_INFO_PTR_TO_STRUCT when looking at a thunk. These two happen to be
equivalent on 64-bit architectures due to alignment considerations
however they are different on 32-bit platforms. This lead to #17487.

To fix this we also employ a small optimization: there is only one thunk
of type WHITEHOLE (namely stg_WHITEHOLE_info). Consequently, we can just
use a plain pointer comparison instead of testing against info->type.

- - - - -
deed8e31 by Ben Gamari at 2019-11-19T11:57:36-05:00
nonmoving: Fix incorrect masking in mark queue type test

We were using TAG_BITS instead of TAG_MASK. This happened to work on
64-bit platforms where TAG_BITS==3 since we only use tag values 0 and
3. However, this broken on 32-bit platforms where TAG_BITS==2.

- - - - -
097f8072 by Ben Gamari at 2019-11-19T11:57:36-05:00
nonmoving: Rework mark queue representation

The previous representation needlessly limited the array length to
16-bits on 32-bit platforms.

- - - - -
eb7b233a by Ben Gamari at 2019-11-19T11:57:36-05:00
nonmoving: Fix handling on large object marking on 32-bit

Previously we would reset the pointer pointing to the object to be
marked to the beginning of the block when marking a large object. This
did no harm on 64-bit but on 32-bit it broke, e.g. `arr020`, since we
align pinned ByteArray allocations such that the payload is 8
byte-aligned. This means that the object might not begin at the
beginning of the block.,

- - - - -
a7571a74 by Ben Gamari at 2019-11-19T11:57:36-05:00
testsuite: Increase width of stack003 test

Previously the returned tuple seemed to fit in registers on amd64. This
meant that non-moving collector bug would cause the test to fail on i386
yet not amd64.

- - - - -
098d5017 by Ben Gamari at 2019-11-19T11:57:36-05:00
nonmoving: Drop redundant write barrier on stack underflow

Previously we would push stack-carried return values to the new stack on
a stack overflow. While the precise reasoning for this barrier is
unfortunately lost to history, in hindsight I suspect it was prompted by
a missing barrier elsewhere (that has been since fixed).

Moreover, there the redundant barrier is actively harmful: the stack may
contain non-pointer values; blindly pushing these to the mark queue will
result in a crash. This is precisely what happened in the `stack003`
test. However, because of a (now fixed) deficiency in the test this
crash did not trigger on amd64.

- - - - -
e57b7cc6 by Roland Zumkeller at 2019-11-19T20:39:19-05:00
Changing Thread IDs from 32 bits to 64 bits.

- - - - -
d1f3c637 by Roland Zumkeller at 2019-11-19T20:39:19-05:00
Use pointer equality in Eq/Ord for ThreadId

Changes (==) to use only pointer equality. This is safe because two
threads are the same iff they have the same id.

Changes `compare` to check pointer equality first and fall back on ids
only in case of inequality.

See discussion in #16761.

- - - - -
ef8a08e0 by Alexey Kuleshevich at 2019-11-19T20:39:20-05:00
hpc: Fix encoding issues. Add test for and fix #17073

* Make sure files are being read/written in UTF-8. Set encoding while writing
  HTML output. Also set encoding while writing and reading .tix files although
  we don't yet have a ticket complaining that this poses problems.
* Set encoding in html header to utf8
* Upgrade to new version of 'hpc' library and reuse `readFileUtf8`
  and `writeFileUtf8` functions
* Update git submodule for `hpc`
* Bump up `hpc` executable version

Co-authored-by: Ben Gamari <ben at smart-cactus.org>

- - - - -
b79e46d6 by Vladislav Zavialov at 2019-11-19T20:39:20-05:00
Strip parentheses in expressions contexts in error messages

This makes error messages a tad less noisy.

- - - - -
13bbde77 by Ben Gamari at 2019-11-21T13:56:56-05:00
Bump hsc2hs submodule

Including Phyx's backport of the process changes fixing #17480.

- - - - -
d4d10501 by Ben Gamari at 2019-11-23T09:42:38-05:00
Bump hsc2hs submodule again

This fixes the Darwin build.

- - - - -
889d475b by nineonine at 2019-11-23T18:53:29-05:00
Fix typo in Note reference [skip ci]

- - - - -
8a33abfc by Ryan Scott at 2019-11-23T18:54:05-05:00
Target the IsList instance for ZipList at base-4.14.0.0 (#17489)

This moves the changelog entry about the instance from
`base-4.15.0.0` to `base-4.14.0.0`. This accomplishes part (1)
from #17489.

[ci skip]

- - - - -
e43e6ece by Ben Gamari at 2019-11-23T18:54:41-05:00
rts: Expose interface for configuring EventLogWriters

This exposes a set of interfaces from the GHC API for configuring
EventLogWriters. These can be used by consumers like
[ghc-eventlog-socket](https://github.com/bgamari/ghc-eventlog-socket).

- - - - -
de6bbdf2 by Matheus Magalhães de Alcantara at 2019-11-23T18:55:23-05:00
Take care to not eta-reduce jumps in CorePrep

CorePrep already had a check to prevent it from eta-reducing Ids that
respond true to hasNoBinding (foreign calls, constructors for unboxed
sums and products, and Ids with compulsory unfoldings). It did not,
however, consider join points as ids that 'must be saturated'.

Checking whether the Id responds True to 'isJoinId' should prevent
CorePrep from turning saturated jumps like the following (from #17429)
into undersaturated ones:

      (\ eta_XP ->
         join { mapped_s1vo _ = lvl_s1vs } in jump mapped_s1vo eta_XP)

- - - - -
4a1e7e47 by Matheus Magalhães de Alcantara at 2019-11-23T18:55:23-05:00
Make CorePrep.tryEtaReducePrep and CoreUtils.tryEtaReduce line up

Simon PJ says he prefers this fix to #17429 over banning eta-reduction
for jumps entirely. Sure enough, this also works.

Test case: simplCore/should_compile/T17429.hs

- - - - -
15f1dc33 by Ryan Scott at 2019-11-23T18:56:00-05:00
Prevent -optc arguments from being duplicated in reverse order (#17471)

This reverts a part of commit
7bc5d6c6578ab9d60a83b81c7cc14819afef32ba that causes all arguments
to `-optc` (and `-optcxx`) to be passed twice to the C/C++ compiler,
once in reverse order and then again in the correct order. While
passing duplicate arguments is usually harmless it can cause breakage
in this pattern, which is employed by Hackage libraries in the wild:

```
ghc Foo.hs foo.c -optc-D -optcFOO
```

As `FOO -D -D FOO` will cause compilers to error.

Fixes #17471.

- - - - -
e85c9b22 by Ben Gamari at 2019-11-23T18:56:36-05:00
Bump ghc version to 8.11

- - - - -
0e6c2045 by Ben Gamari at 2019-11-23T18:57:12-05:00
rts: Consolidate spinlock implementation

Previously we had two distinct implementations: one with spinlock
profiling and another without. This seems like needless duplication.

- - - - -
cb11fcb5 by Ben Gamari at 2019-11-23T18:57:49-05:00
Packages: Don't use expectJust

Throw a slightly more informative error on failure. Motivated by the
errors seen in !2160.

- - - - -
5747ebe9 by Sebastian Graf at 2019-11-23T18:58:25-05:00
Stricten functions ins GHC.Natural

This brings `Natural` on par with `Integer` and fixes #17499.
Also does some manual CSE for 0 and 1 literals.

- - - - -
c14b723f by Ömer Sinan Ağacan at 2019-11-23T18:59:06-05:00
Bump exceptions submodule

Adds a few files generated by GHC's configure script to .gitignore

- - - - -
7b4c7b75 by Brian Wignall at 2019-11-23T19:04:52-05:00
Fix typos

- - - - -
6008206a by Viktor Dukhovni at 2019-11-24T14:33:18-05:00
On FreeBSD 12 sys/sysctl.h requires sys/types.h

Else build fails with:

    In file included from ExecutablePath.hsc:42:
    /usr/include/sys/sysctl.h:1062:25: error: unknown type name 'u_int'; did you mean 'int'?
     int sysctl(const int *, u_int, void *, size_t *, const void *, size_t);
			     ^~~~~
			     int
    compiling libraries/base/dist-install/build/System/Environment/ExecutablePath_hsc_make.c failed (exit code 1)

Perhaps also also other FreeBSD releases, but additional include
will no harm even if not needed.

- - - - -
b694b566 by Ben Gamari at 2019-11-24T14:33:54-05:00
configure: Fix HAVE_C11_ATOMICS macro

Previously we were using AC_DEFINE instead of
AC_DEFINE_UNQUOTED, resulted in the variable not being
interpolated.

Fixes #17505.

- - - - -
8b8dc366 by Krzysztof Gogolewski at 2019-11-25T14:37:38+01:00
Remove prefix arrow support for GADTs (#17211)

This reverts the change in #9096.

The specialcasing done for prefix (->) is brittle and
does not support VTA, type families, type synonyms etc.

- - - - -
5a08f7d4 by Sebastian Graf at 2019-11-27T00:14:59-05:00
Make warnings for TH splices opt-in

In #17270 we have the pattern-match checker emit incorrect warnings. The
reason for that behavior is ultimately an inconsistency in whether we
treat TH splices as written by the user (`FromSource :: Origin`) or as
generated code (`Generated`). This was first reported in #14838.

The current solution is to TH splices as `Generated` by default and only
treat them as `FromSource` when the user requests so
(-fenable-th-splice-warnings). There are multiple reasons for opt-in
rather than opt-out:

  * It's not clear that the user that compiles a splice is the author of the code
    that produces the warning. Think of the situation where she just splices in
    code from a third-party library that produces incomplete pattern matches.
    In this scenario, the user isn't even able to fix that warning.
  * Gathering information for producing the warnings (pattern-match check
    warnings in particular) is costly. There's no point in doing so if the user
    is not interested in those warnings.

Fixes #17270, but not #14838, because the proper solution needs a GHC
proposal extending the TH AST syntax.

- - - - -
8168b42a by Vladislav Zavialov at 2019-11-27T11:32:18+03:00
Whitespace-sensitive bang patterns (#1087, #17162)

This patch implements a part of GHC Proposal #229 that covers five
operators:

* the bang operator (!)
* the tilde operator (~)
* the at operator (@)
* the dollar operator ($)
* the double dollar operator ($$)

Based on surrounding whitespace, these operators are disambiguated into
bang patterns, lazy patterns, strictness annotations, type
applications, splices, and typed splices.

This patch doesn't cover the (-) operator or the -Woperator-whitespace
warning, which are left as future work.

- - - - -
9e5477c4 by Ryan Scott at 2019-11-27T20:01:50-05:00
Fix @since annotations for isResourceVanishedError and friends (#17488)

- - - - -
e122ba33 by Sergei Trofimovich at 2019-11-27T20:02:29-05:00
.gitmodules: tweak 'exception' URL to avoid redirection warnings

Avoid initial close warning of form:

```
Cloning into 'exceptions'...
warning: redirecting to https://gitlab.haskell.org/ghc/packages/exceptions.git/
```

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
5f84b52a by Philipp Krüger at 2019-11-28T02:54:05-05:00
Reduce boolean blindness in OccInfo(OneOcc) #17482

* Transformed the type aliases `InterestingCxt`, `InsideLam` and `OneBranch`
  into data types.
* Added Semigroup and Monoid instances for use in orOccInfo in OccurAnal.hs
* Simplified some usage sites by using pattern matching instead of boolean algebra.

Metric Increase:
    T12150

This increase was on a Mac-build of exactly 1%. This commit does *not* re-intruduce
the asymptotic memory usage described in T12150.

- - - - -
3748ba3a by Brian Wignall at 2019-11-28T02:54:52-05:00
Fix typos, using Wikipedia list of common typos

- - - - -
6c59cc71 by Stefan Schulze Frielinghaus at 2019-11-28T02:55:33-05:00
Fix endian handling of LLVM backend

Get rid of CPP macro WORDS_BIGENDIAN which is not defined anymore, and
replace it by DynFlag. This fixes partially #17337.

- - - - -
6985e0fc by Vladislav Zavialov at 2019-11-28T15:47:53+03:00
Factor out HsSCC/HsCoreAnn/HsTickPragma into HsPragE

This is a refactoring with no user-visible changes (except for GHC API
users). Consider the HsExpr constructors that correspond to user-written
pragmas:

  HsSCC         representing  {-# SCC ... #-}
  HsCoreAnn     representing  {-# CORE ... #-}
  HsTickPragma  representing  {-# GENERATED ... #-}

We can factor them out into a separate datatype, HsPragE. It makes the
code a bit tidier, especially in the parser.

Before this patch:

  hpc_annot :: { Located ( (([AddAnn],SourceText),(StringLiteral,(Int,Int),(Int,Int))),
                           ((SourceText,SourceText),(SourceText,SourceText))
                         ) }

After this patch:

  prag_hpc :: { Located ([AddAnn], HsPragE GhcPs) }

- - - - -
7f695a20 by Ömer Sinan Ağacan at 2019-11-29T08:25:28-05:00
Pass ModDetails with (partial) ModIface in HscStatus

(Partial) ModIface and ModDetails are generated at the same time, but
they're passed differently: ModIface is passed in HscStatus consturctors
while ModDetails is returned in a tuple. This refactors ModDetails
passing so that it's passed around with ModIface in HscStatus
constructors. This makes the code more consistent and hopefully easier
to understand: ModIface and ModDetails are really very closely related.
It makes sense to treat them the same way.

- - - - -
e921c90f by Ömer Sinan Ağacan at 2019-11-29T08:26:07-05:00
Improve few Foreign.Marshal.Utils docs

In copyBytes and moveBytes mention which argument is source and which is
destination.

Also fixes some of the crazy indentation in the module and cleans
trailing whitespace.

- - - - -
316f2431 by Sebastian Graf at 2019-11-30T02:57:58-05:00
Hadrian docs: Rename the second "validate" entry to "slow-validate" [ci skip]

That would be in line with the implementation.

- - - - -
5aba5d32 by Vladislav Zavialov at 2019-11-30T02:58:34-05:00
Remove HasSrcSpan (#17494)

Metric Decrease:
    haddock.compiler

- - - - -
d1de5c22 by Sylvain Henry at 2019-11-30T02:59:13-05:00
Use Hadrian by default in validate script (#17527)

- - - - -
3a96a0b6 by Sebastian Graf at 2019-11-30T02:59:55-05:00
Simpler Semigroup instance for InsideLam and InterestingCtxt

This mirrors the definition of `(&&)` and `(||)` now, relieving the
Simplifier of a marginal amount of pressure.

- - - - -
f8cfe81a by Roland Senn at 2019-11-30T20:33:49+01:00
Improve tests for #17171

While backporting MR !1806 to 8.8.2 (!1885) I learnt the following:

* Tests with `expect_fail` do not compare `*.stderr` output files. So a test using `expect_fail` will not detect future regressions on the `stderr` output.
* To compare the `*.stderr` output files, I have to use the `exit_code(n)` function.
* When a release is made, tests with `makefile_test` are converted to use `run_command`.
* For the test `T17171a` the return code is `1` when running `makefile_test`, however it's `2` when running `run_command`.

Therefore I decided:

* To improve my tests for #17171
* To change test T17171a from `expect_fail` to `exit_code(2)`
* To change both tests from  `makefile_test` to `run_command`

- - - - -
2b113fc9 by Vladislav Zavialov at 2019-12-01T08:17:05-05:00
Update DisambECP-related comments

- - - - -
beed7c3e by Ben Gamari at 2019-12-02T03:41:37-05:00
testsuite: Fix location of typing_stubs module

This should fix the build on Debian 8.

- - - - -
53251413 by Ben Gamari at 2019-12-02T03:42:14-05:00
testsuite: Don't override LD_LIBRARY_PATH, only prepend

NixOS development environments often require that LD_LIBRARY_PATH
be set in order to find system libraries. T1407 was overriding
LD_LIBRARY_PATH, dropping these directories. Now it merely prepends,
its directory.
- - - - -
65400314 by Krzysztof Gogolewski at 2019-12-02T03:42:57-05:00
Convert warnings into assertions

Since the invariants always hold in the testsuite, we can convert
them to asserts.

- - - - -
18baed64 by Alan Zimmerman at 2019-12-02T03:43:37-05:00
API Annotations: Unicode '->' on HsForallTy

The code fragment

  type family Proxy2' ∷ ∀ k → k → Type where
    Proxy2' = Proxy'

Generates AnnRarrow instead of AnnRarrowU for the first →.

Fixes #17519

- - - - -
717f3236 by Brian Wignall at 2019-12-02T03:44:16-05:00
Fix more typos

- - - - -
bde48f8e by Ben Gamari at 2019-12-02T11:55:34-05:00
More Haddock syntax in GHC.Hs.Utils

As suggested by RyanGlScott in !2163.

- - - - -
038bedbc by Ben Gamari at 2019-12-02T11:56:18-05:00
Simplify: Fix pretty-printing of strictness

A colleague recently hit the panic in Simplify.addEvals and I noticed
that the message is quite unreadable due to incorrect pretty-printing.
Fix this.

- - - - -
c500f652 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Fix changelog linting logic

- - - - -
8ead967d by Ben Gamari at 2019-12-02T11:56:54-05:00
win32-init: Drop workaround for #17480

The `process` changes have now been merged into `hsc2hs`.

(cherry picked from commit fa029f53132ad59f847ed012d3b835452cf16615)

- - - - -
d402209a by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Disable Sphinx build on Debian 8

The docutils version available appears to be too old to support the
`table` directive's `:widths:` options.

(cherry picked from commit 75764487a96a7a026948b5af5022781872d12baa)

- - - - -
f1f68824 by Ben Gamari at 2019-12-02T11:56:54-05:00
base: Fix <unistd.h> #include

Previously we were including <sys/unistd.h> which is available on glibc
but not musl.

(cherry picked from commit e44b695ca7cb5f3f99eecfba05c9672c6a22205e)

- - - - -
37eb94b3 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Bump Docker images

Installs pxz on Centos7

(cherry picked from commit 86960e691f7a600be247c32a7cf795bf9abf7cc4)

- - - - -
aec98a79 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: pxz is unavailable on CentOS 7

Fall back to xz

- - - - -
6708b8e5 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Set LANG on CentOS 7

It otherwise seems to default to ascii

- - - - -
470ef0e7 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Consolidate release build configuration

- - - - -
38338757 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Add Debian 10 builds

- - - - -
012f13b5 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Fix Windows bindist collection

Apparently variable interpolation in the `artifacts.paths` key of
`gitlab-ci.yml` doesn't work on Windows as it does on WIndows.

(cherry picked from commit 100cc756faa4468ed6950116bae30609c1c3468b)

- - - - -
a0f09e23 by Ben Gamari at 2019-12-02T11:56:54-05:00
testsuite: Simplify Python <3.5 fallback for TextIO

(cherry picked from commit d092d8598694c23bc07cdcc504dff52fa5f33be1)

- - - - -
2b2370ec by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Add release-x86_64-linux-deb9 job

(cherry picked from commit cbedb3c4a90649f474cb716842ba53afc5a642ca)

- - - - -
b1c206fd by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Always build source tarball

(cherry picked from commit 67b5de88ef923971f1980335137e3c7193213abd)

- - - - -
4cbd5b47 by Sergei Trofimovich at 2019-12-02T11:57:33-05:00
configure.ac: make cross-compiler detection stricter

Be more precise at detecting cross-compilation case.

Before the change configuration
  $ ./configure --host=x86_64-pc-linux-gnu --target=x86_64-gentoo-linux-musl
was not considered a cross-target. Even though libcs are different (`glibc` vs. `musl`).

Without this patch build fails as:

```
"inplace/bin/ghc-cabal" check libraries/integer-gmp
"inplace/bin/ghc-cabal" configure libraries/integer-gmp dist-install \
    --with-ghc="/home/slyfox/dev/git/ghc/inplace/bin/ghc-stage1" \
    --with-ghc-pkg="/home/slyfox/dev/git/ghc/inplace/bin/ghc-pkg" \
    --disable-library-for-ghci --enable-library-vanilla --enable-library-for-ghci \
    --enable-library-profiling --enable-shared --with-hscolour="/usr/bin/HsColour" \
    --configure-option=CFLAGS="-Wall \
    -Werror=unused-but-set-variable -Wno-error=inline \
    -iquote /home/slyfox/dev/git/ghc/libraries/integer-gmp" \
    --configure-option=LDFLAGS="  " --configure-option=CPPFLAGS="   \
    " --gcc-options="-Wall     -Werror=unused-but-set-variable -Wno-error=inline -iquote /home/slyfox/dev/git/ghc/libraries/integer-gmp   \
    " --with-gcc="x86_64-gentoo-linux-musl-gcc" --with-ld="x86_64-gentoo-linux-musl-ld.gold" --with-ar="x86_64-gentoo-linux-musl-ar" \
    --with-alex="/usr/bin/alex" --with-happy="/usr/bin/happy"
Configuring integer-gmp-1.0.2.0...
configure: WARNING: unrecognized options: --with-compiler
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking for gcc... /usr/lib/ccache/bin/x86_64-gentoo-linux-musl-gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... configure: error: in `/home/slyfox/dev/git/ghc/libraries/integer-gmp/dist-install/build':
configure: error: cannot run C compiled programs.
If you meant to cross compile, use `--host'.
See `config.log' for more details
make[1]: *** [libraries/integer-gmp/ghc.mk:5: libraries/integer-gmp/dist-install/package-data.mk] Error 1
make: *** [Makefile:126: all] Error 2
```

Note: here `ghc-stage1` is assumed to target `musl` target but is passed
`glibc` toolchain. It happens because initial ./configure phase did not
detect host/target as different.

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
5f7cb423 by Sylvain Henry at 2019-12-02T23:59:29-05:00
Add `timesInt2#` primop

- - - - -
fbbe18a2 by Sylvain Henry at 2019-12-02T23:59:29-05:00
Use the new timesInt2# primop in integer-gmp (#9431)

- - - - -
5a4b8d0c by Athas at 2019-12-03T00:00:09-05:00
Document RTS behaviour upon encountering '--'.
- - - - -
705a16df by Ben Gamari at 2019-12-03T07:11:33-05:00
Make BCO# lifted

In #17424 Simon PJ noted that there is a potentially unsafe occurrence
of unsafeCoerce#, coercing from an unlifted to lifted type. However,
nowhere in the compiler do we assume that a BCO# is not a thunk.
Moreover, in the case of a CAF the result returned by `createBCO` *will*
be a thunk (as noted in [Updatable CAF BCOs]).  Consequently it seems
better to rather make BCO# a lifted type and rename it to BCO.

- - - - -
35afe4f3 by Sylvain Henry at 2019-12-03T07:12:13-05:00
Use Int# primops in `Bits Int{8,16,32,64}` instances

- - - - -
7a51b587 by Sylvain Henry at 2019-12-03T07:12:13-05:00
Add constant folding rule (#16402)

    narrowN (x .&. m)
    m .&. (2^N-1) = 2^N-1
    ==> narrowN x

e.g.  narrow16 (x .&. 0x12FFFF) ==> narrow16 x

- - - - -
10caee7f by Ben Gamari at 2019-12-03T21:04:50-05:00
users-guide: Add 8.12.1 release notes

- - - - -
25019d18 by Ben Gamari at 2019-12-03T21:04:50-05:00
Drop Uniquable constraint for AnnTarget

This relied on deriveUnique, which was far too subtle to be safely
applied. Thankfully the instance doesn't appear to be used so let's just
drop it.

- - - - -
78b67ad0 by Ben Gamari at 2019-12-03T21:04:50-05:00
Simplify uniqAway

This does two things:

 * Eliminate all uses of Unique.deriveUnique, which was quite easy to
   mis-use and extremely subtle.

 * Rename the previous "derived unique" notion to "local unique". This
   is possible because the only places where `uniqAway` can be safely
   used are those where local uniqueness (with respect to some
   InScopeSet) is sufficient.

 * Rework the implementation of VarEnv.uniqAway, as discussed in #17462.
   This should make the operation significantly more efficient than its
   previous iterative implementation..

Metric Decrease:
    T9872c
    T12227
    T9233
    T14683
    T5030
    T12545
    hie002

Metric Increase:
    T9961

- - - - -
f03a41d4 by Ben Gamari at 2019-12-03T21:05:27-05:00
Elf: Fix link info note generation

Previously we would use the `.int` assembler directive to generate
32-bit words in the note section. However, `.int` is note guaranteed to
produce 4-bytes; in fact, on some platforms (e.g. AArch64) it produces
8-bytes. Use the `.4bytes` directive to avoid this.

Moreover, we used the `.align` directive, which is quite platform
dependent. On AArch64 it appears to not even be idempotent (despite what
the documentation claims). `.balign` is consequentially preferred as it
offers consistent behavior across platforms.

- - - - -
84585e5e by Vladislav Zavialov at 2019-12-05T16:07:44-05:00
Meaning-preserving SCC annotations (#15730)

This patch implements GHC Proposal #176:
  https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0176-scc-parsing.rst

Before the change:

  1 /                    2 / 2 = 0.25
  1 / {-# SCC "name" #-} 2 / 2 = 1.0

After the change:

  1 /                    2 / 2 = 0.25
  1 / {-# SCC "name" #-} 2 / 2 = parse error

- - - - -
e49e5470 by Vladislav Zavialov at 2019-12-05T16:07:44-05:00
Improve error messages for SCC pragmas

- - - - -
a2b535d9 by Ben Gamari at 2019-12-05T16:07:45-05:00
users guide: Try to silence underfull \hbox warnings

We use two tricks, as suggested here [1]:

 * Use microtype to try to reduce the incidence of underfull boxes
 * Bump up \hbadness to eliminate the warnings

- - - - -
4e47217f by Bodigrim at 2019-12-05T16:07:47-05:00
Make sameNat and sameSymbol proxy-polymorphic

- - - - -
8324f0b7 by Bodigrim at 2019-12-05T16:07:47-05:00
Test proxy-polymorphic sameNat and sameSymbol

- - - - -
69001f54 by Ben Gamari at 2019-12-05T16:07:48-05:00
nonmoving: Clear segment bitmaps during sweep

Previously we would clear the bitmaps of segments which we are going to
sweep during the preparatory pause. However, this is unnecessary: the
existence of the mark epoch ensures that the sweep will correctly
identify non-reachable objects, even if we do not clear the bitmap.

We now defer clearing the bitmap to sweep, which happens concurrently
with mutation.

- - - - -
58a9c429 by Ben Gamari at 2019-12-05T16:07:48-05:00
testsuite: Disable divByZero on non-NCG targets

The LLVM backend does not guarantee any particular semantics for
division by zero, making this test unreliable across platforms.

- - - - -
8280bd8a by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Factor out terminal coloring

- - - - -
92a52aaa by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Make performance metric summary more readable

Along with some refactoring.

- - - - -
c4ca29c7 by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Use colors more consistently

- - - - -
3354c68e by Vladislav Zavialov at 2019-12-05T16:07:49-05:00
Pretty-printing of the * kind

Before this patch, GHC always printed the * kind unparenthesized.

This led to two issues:

1. Sometimes GHC printed invalid or incorrect code.
   For example, GHC would print:  type F @*   x = x
         when it meant to print:  type F @(*) x = x
   In the former case, instead of a kind application we were getting a
   type operator (@*).

2. Sometimes GHC printed kinds that were correct but hard to read.
   Should  Either * Int  be read as  Either (*) Int
                              or as  (*) Either Int  ?
   This depends on whether -XStarIsType is enabled, but it would be
   easier if we didn't have to check for the flag when reading the code.

We can solve both problems by assigning (*) a different precedence. Note
that Haskell98 kinds are not affected:

  ((* -> *) -> *) -> *  does NOT become  (((*) -> (*)) -> (*)) -> (*)

The parentheses are added when (*) is used in a function argument
position:

   F * * *   becomes  F (*) (*) (*)
   F A * B   becomes  F A (*) B
   Proxy *   becomes  Proxy (*)
   a * -> *  becomes  a (*) -> *

- - - - -
70dd0e4b by Vladislav Zavialov at 2019-12-05T16:07:49-05:00
Parenthesize the * kind in TH.Ppr

- - - - -
a7a4efbf by Ben Gamari at 2019-12-05T16:07:49-05:00
rts/NonMovingSweep: Fix locking of new mutable list allocation

Previously we used allocBlockOnNode_sync in nonmovingSweepMutLists
despite the fact that we aren't in the GC and therefore the allocation
spinlock isn't in use. This meant that sweep would end up spinning until
the next minor GC, when the SM lock was moved away from the SM_MUTEX to
the spinlock. This isn't a correctness issue but it sure isn't good for
performance.

Found thanks for Ward.

Fixes #17539.

- - - - -
f171b358 by Matthias Braun at 2019-12-05T16:07:51-05:00
Fix typo in documentation of Base.hs.
- - - - -
9897e8c8 by Gabor Greif at 2019-12-06T21:20:38-05:00
Implement pointer tagging for big families (#14373)

Formerly we punted on these and evaluated constructors always got a tag
of 1.

We now cascade switches because we have to check the tag first and when
it is MAX_PTR_TAG then get the precise tag from the info table and
switch on that. The only technically tricky part is that the default
case needs (logical) duplication. To do this we emit an extra label for
it and branch to that from the second switch. This avoids duplicated
codegen.

Here's a simple example of the new code gen:

    data D = D1 | D2 | D3 | D4 | D5 | D6 | D7 | D8

On a 64-bit system previously all constructors would be tagged 1. With
the new code gen D7 and D8 are tagged 7:

    [Lib.D7_con_entry() {
         ...
         {offset
           c1eu: // global
               R1 = R1 + 7;
               call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
         }
     }]

    [Lib.D8_con_entry() {
         ...
         {offset
           c1ez: // global
               R1 = R1 + 7;
               call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
         }
     }]

When switching we now look at the info table only when the tag is 7. For
example, if we derive Enum for the type above, the Cmm looks like this:

    c2Le:
        _s2Js::P64 = R1;
        _c2Lq::P64 = _s2Js::P64 & 7;
        switch [1 .. 7] _c2Lq::P64 {
            case 1 : goto c2Lk;
            case 2 : goto c2Ll;
            case 3 : goto c2Lm;
            case 4 : goto c2Ln;
            case 5 : goto c2Lo;
            case 6 : goto c2Lp;
            case 7 : goto c2Lj;
        }

    // Read info table for tag
    c2Lj:
        _c2Lv::I64 = %MO_UU_Conv_W32_W64(I32[I64[_s2Js::P64 & (-8)] - 4]);
        if (_c2Lv::I64 != 6) goto c2Lu; else goto c2Lt;

Generated Cmm sizes do not change too much, but binaries are very
slightly larger, due to the fact that the new instructions are longer in
encoded form. E.g. previously entry code for D8 above would be

    00000000000001c0 <Lib_D8_con_info>:
     1c0:	48 ff c3             	inc    %rbx
     1c3:	ff 65 00             	jmpq   *0x0(%rbp)

With this patch

    00000000000001d0 <Lib_D8_con_info>:
     1d0:	48 83 c3 07          	add    $0x7,%rbx
     1d4:	ff 65 00             	jmpq   *0x0(%rbp)

This is one byte longer.

Secondly, reading info table directly and then switching is shorter

    _c1co:
            movq -1(%rbx),%rax
            movl -4(%rax),%eax
            // Switch on info table tag
            jmp *_n1d5(,%rax,8)

than doing the same switch, and then for the tag 7 doing another switch:

    // When tag is 7
    _c1ct:
            andq $-8,%rbx
            movq (%rbx),%rax
            movl -4(%rax),%eax
            // Switch on info table tag
            ...

Some changes of binary sizes in actual programs:

- In NoFib the worst case is 0.1% increase in benchmark "parser" (see
  NoFib results below). All programs get slightly larger.

- Stage 2 compiler size does not change.

- In "containers" (the library) size of all object files increases
  0.0005%. Size of the test program "bitqueue-properties" increases
  0.03%.

nofib benchmarks kindly provided by Ömer (@osa1):

NoFib Results
=============

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          +0.0%      0.0%      0.0%     +0.0%     +0.0%
             FS          +0.0%      0.0%      0.0%     +0.0%      0.0%
              S          +0.0%      0.0%     -0.0%      0.0%      0.0%
             VS          +0.0%      0.0%     -0.0%     +0.0%     +0.0%
            VSD          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
            VSM          +0.0%      0.0%      0.0%      0.0%      0.0%
           anna          +0.0%      0.0%     +0.1%     -0.9%     -0.0%
           ansi          +0.0%      0.0%     -0.0%     +0.0%     +0.0%
           atom          +0.0%      0.0%      0.0%      0.0%      0.0%
         awards          +0.0%      0.0%     -0.0%     +0.0%      0.0%
         banner          +0.0%      0.0%     -0.0%     +0.0%      0.0%
     bernouilli          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
   binary-trees          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          +0.0%      0.0%     +0.0%      0.0%     -0.0%
         boyer2          +0.0%      0.0%     +0.0%      0.0%     -0.0%
           bspt          +0.0%      0.0%     +0.0%     +0.0%      0.0%
      cacheprof          +0.0%      0.0%     +0.1%     -0.8%      0.0%
       calendar          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
       cichelli          +0.0%      0.0%     +0.0%      0.0%      0.0%
        circsim          +0.0%      0.0%     -0.0%     -0.1%     -0.0%
       clausify          +0.0%      0.0%     +0.0%     +0.0%      0.0%
  comp_lab_zift          +0.0%      0.0%     +0.0%      0.0%     -0.0%
       compress          +0.0%      0.0%     +0.0%     +0.0%      0.0%
      compress2          +0.0%      0.0%      0.0%      0.0%      0.0%
    constraints          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          +0.0%      0.0%     +0.0%      0.0%      0.0%
   cryptarithm2          +0.0%      0.0%     +0.0%     -0.0%      0.0%
            cse          +0.0%      0.0%     +0.0%     +0.0%      0.0%
   digits-of-e1          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         dom-lt          +0.0%      0.0%     +0.0%     +0.0%      0.0%
          eliza          +0.0%      0.0%     -0.0%     +0.0%      0.0%
          event          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         exp3_8          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
         expert          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
 fannkuch-redux          +0.0%      0.0%     +0.0%      0.0%      0.0%
          fasta          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fem          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            fft          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           fft2          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
       fibheaps          +0.0%      0.0%     +0.0%     +0.0%      0.0%
           fish          +0.0%      0.0%     +0.0%     +0.0%      0.0%
          fluid          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         fulsom          +0.0%      0.0%     +0.0%     -0.0%     +0.0%
         gamteb          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
            gcd          +0.0%      0.0%     +0.0%     +0.0%      0.0%
    gen_regexps          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         genfft          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
             gg          +0.0%      0.0%      0.0%     -0.0%      0.0%
           grep          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         hidden          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
            hpg          +0.0%      0.0%     +0.0%     -0.1%     -0.0%
            ida          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
          infer          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        integer          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          +0.0%      0.0%      0.0%     +0.0%      0.0%
   k-nucleotide          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        knights          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         lambda          +0.0%      0.0%     +1.2%     -6.1%     -0.0%
     last-piece          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           lcss          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           life          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           lift          +0.0%      0.0%     +0.0%     +0.0%      0.0%
         linear          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      listcompr          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         mandel          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
        mandel2          +0.0%      0.0%     +0.0%     +0.0%     -0.0%
           mate          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
        minimax          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
        mkhprog          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
     multiplier          +0.0%      0.0%      0.0%     +0.0%     -0.0%
         n-body          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
       nucleic2          +0.0%      0.0%     +0.0%     +0.0%     -0.0%
           para          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      paraffins          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         parser          +0.1%      0.0%     +0.4%     -1.7%     -0.0%
        parstof          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            pic          +0.0%      0.0%     +0.0%      0.0%     -0.0%
       pidigits          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         pretty          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         primes          +0.0%      0.0%     +0.0%      0.0%      0.0%
      primetest          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         prolog          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         puzzle          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         queens          +0.0%      0.0%      0.0%     +0.0%     +0.0%
        reptile          +0.0%      0.0%     +0.0%     +0.0%      0.0%
reverse-complem          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          +0.0%      0.0%     +0.0%      0.0%     -0.0%
           rfib          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            rsa          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            scc          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
          sched          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            scs          +0.0%      0.0%     +0.0%     +0.0%      0.0%
         simple          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
          solid          +0.0%      0.0%     +0.0%     +0.0%      0.0%
        sorting          +0.0%      0.0%     +0.0%     -0.0%      0.0%
  spectral-norm          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          +0.0%      0.0%     +0.0%     -1.0%      0.0%
         symalg          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            tak          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      transform          +0.0%      0.0%     +0.4%     -1.3%     +0.0%
       treejoin          +0.0%      0.0%     +0.0%     -0.0%      0.0%
      typecheck          +0.0%      0.0%     -0.0%     +0.0%      0.0%
        veritas          +0.0%      0.0%     +0.0%     -0.1%     +0.0%
           wang          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      wave4main          +0.0%      0.0%     +0.0%      0.0%     -0.0%
   wheel-sieve1          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
   wheel-sieve2          +0.0%      0.0%     +0.0%     +0.0%      0.0%
           x2n1          +0.0%      0.0%     +0.0%     +0.0%      0.0%
--------------------------------------------------------------------------------
            Min          +0.0%      0.0%     -0.0%     -6.1%     -0.0%
            Max          +0.1%      0.0%     +1.2%     +0.0%     +0.0%
 Geometric Mean          +0.0%     -0.0%     +0.0%     -0.1%     -0.0%

NoFib GC Results
================

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
        circsim          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          +0.0%      0.0%     -0.0%      0.0%     -0.0%
       fibheaps          +0.0%      0.0%      0.0%     -0.0%     -0.0%
         fulsom          +0.0%      0.0%      0.0%     -0.6%     -0.0%
       gc_bench          +0.0%      0.0%      0.0%      0.0%     -0.0%
           hash          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          +0.0%      0.0%      0.0%     -0.0%      0.0%
      mutstore1          +0.0%      0.0%      0.0%     -0.0%     -0.0%
      mutstore2          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
          power          +0.0%      0.0%     -0.0%      0.0%     -0.0%
     spellcheck          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          +0.0%      0.0%     -0.0%     -0.6%     -0.0%
            Max          +0.0%      0.0%     +0.0%      0.0%      0.0%
 Geometric Mean          +0.0%     +0.0%     +0.0%     -0.1%     +0.0%

Fixes #14373

These performance regressions appear to be a fluke in CI. See the
discussion in !1742 for details.

Metric Increase:
    T6048
    T12234
    T12425
    Naperian
    T12150
    T5837
    T13035

- - - - -
ee07421f by Simon Peyton Jones at 2019-12-06T21:21:14-05:00
Work in progress on coercionLKind, coercionRKind

This is a preliminary patch for #17515

- - - - -
0a4ca9eb by Simon Peyton Jones at 2019-12-06T21:21:14-05:00
Split up coercionKind

This patch implements the idea in #17515, splitting `coercionKind` into:

 * `coercion{Left,Right}Kind`, which computes the left/right side of the
    pair
 * `coercionKind`, which computes the pair of coercible types

This is reduces allocation since we frequently only need only one side
of the pair. Specifically, we see the following improvements on x86-64
Debian 9:

| test     | new        | old           | relative chg. |
| :------- | ---------: | ------------: | ------------: |
| T5030	   | 695537752  | 747641152.0   | -6.97%        |
| T5321Fun | 449315744  | 474009040.0   | -5.21%        |
| T9872a   | 2611071400 | 2645040952.0  | -1.28%        |
| T9872c   | 2957097904 | 2994260264.0  | -1.24%        |
| T12227   | 773435072  | 812367768.0   | -4.79%        |
| T12545   | 3142687224 | 3215714752.0  | -2.27%        |
| T14683   | 9392407664 | 9824775000.0  | -4.40%        |

Metric Decrease:
    T12545
    T9872a
    T14683
    T5030
    T12227
    T9872c
    T5321Fun
    T9872b

- - - - -
d46a72e1 by Gabor Greif at 2019-12-09T12:05:15-05:00
Fix comment typos

The below is only necessary to fix the CI perf fluke that
happened in 9897e8c8ef0b19a9571ef97a1d9bb050c1ee9121:
-------------------------
Metric Decrease:
    T5837
    T6048
    T9020
    T12425
    T12234
    T13035
    T12150
    Naperian
-------------------------

- - - - -
e3bba7e4 by Micha Wiedenmann at 2019-12-10T19:52:44-05:00
users guide: Motivation of DefaultSignatures

- - - - -
843ceb38 by Ben Gamari at 2019-12-10T19:53:54-05:00
rts: Add a long form flag to enable the non-moving GC

The old flag, `-xn`, was quite cryptic. Here we add `--nonmoving-gc` in
addition.

- - - - -
921d3238 by Ryan Scott at 2019-12-10T19:54:34-05:00
Ignore unary constraint tuples during typechecking (#17511)

We deliberately avoid defining a magical `Unit%` class, for reasons
that I have expounded upon in the newly added
`Note [Ignore unary constraint tuples]` in `TcHsType`. However, a
sneaky user could try to insert `Unit%` into their program by way of
Template Haskell, leading to the interface-file error observed
in #17511. To avoid this, any time we encounter a unary constraint
tuple during typechecking, we drop the surrounding constraint tuple
application. This is safe to do since `Unit% a` and `a` would be
semantically equivalent (unlike other forms of unary tuples).

Fixes #17511.

- - - - -
436ec9f3 by Ben Gamari at 2019-12-10T19:55:37-05:00
gitlab-ci: Move changelog linting logic to shell script

Allowing it to be easily used locally.

- - - - -
2f6b434f by Ben Gamari at 2019-12-10T19:55:37-05:00
gitlab-ci: Move changelog linting logic to shell script

Allowing it to be easily used locally.

- - - - -
7a5a6e07 by Ben Gamari at 2019-12-10T19:56:25-05:00
base: Fix incorrect @since in GHC.Natural

Fixes #17547.

- - - - -
2bbfaf8a by Ben Gamari at 2019-12-10T19:57:01-05:00
hadrian: AArch64 supports the GHCi interpreter and SMP

I'm not sure how this was omitted from the list of supported
architectures.

- - - - -
8f1ceb67 by John Ericson at 2019-12-10T19:57:39-05:00
Move Int# section of primops.txt.pp

This matches the organization of the fixed-sized ones, and keeps each
Int* next to its corresponding Word*.

- - - - -
7a823b0f by John Ericson at 2019-12-10T19:57:39-05:00
Move Int64# and Word64# sections of primops.txt.pp

This way it is next to the other fixed-sized ones.

- - - - -
8dd9929a by Ben Gamari at 2019-12-10T19:58:19-05:00
testsuite: Add (broken) test for #17510

- - - - -
6e47a76a by Ben Gamari at 2019-12-10T19:58:59-05:00
Re-layout validate script

This script was previously a whitespace nightmare.

- - - - -
f80c4a66 by Crazycolorz5 at 2019-12-11T14:12:17-05:00
rts: Specialize hashing at call site rather than in struct.

Separate word and string hash tables on the type level, and do not store
the hashing function.  Thus when a different hash function is desire it
is provided upon accessing the table. This is worst case the same as
before the change, and in the majority of cases is better. Also mark the
functions for aggressive inlining to improve performance.  {F1686506}

Reviewers: bgamari, erikd, simonmar

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #13165

Differential Revision: https://phabricator.haskell.org/D4889

- - - - -
2d1b9619 by Richard Eisenberg at 2019-12-11T14:12:55-05:00
Warn on inferred polymorphic recursion

Silly users sometimes try to use visible dependent quantification
and polymorphic recursion without a CUSK or SAK. This causes
unexpected errors. So we now adjust expectations with a bit
of helpful messaging.

Closes #17541 and closes #17131.

test cases: dependent/should_fail/T{17541{,b},17131}

- - - - -
4dde485e by Oleg Grenrus at 2019-12-12T02:24:46-05:00
Add --show-unit-ids flag to ghc-pkg

I only added it into --simple-output and ghc-pkg check output;
there are probably other places where it can be adopted.

- - - - -
e6e1ec08 by Ben Gamari at 2019-12-12T02:25:33-05:00
testsuite: Simplify and clarify performance test baseline search

The previous implementation was extremely complicated, seemingly to
allow the local and CI namespaces to be searched incrementally. However,
it's quite unclear why this is needed and moreover the implementation
seems to have had quadratic runtime cost in the search depth(!).

- - - - -
29c4609c by Ben Gamari at 2019-12-12T02:26:19-05:00
testsuite: Add test for #17549

- - - - -
9f0ee253 by Ben Gamari at 2019-12-12T02:26:56-05:00
gitlab-ci: Move -dwarf and -debug jobs to full-build stage

This sacrifices some precision in favor of improving parallelism.

- - - - -
7179b968 by Ben Gamari at 2019-12-12T02:27:34-05:00
Revert "rts: Drop redundant flags for libffi"

This seems to have regressed builds using `--with-system-libffi`
(#17520).

This reverts commit 3ce18700f80a12c48a029b49c6201ad2410071bb.

- - - - -
cc7d5650 by Oleg Grenrus at 2019-12-16T10:20:56+02:00
Having no shake upper bound is irresposible

Given that shake is far from "done" API wise,
and is central component to the build system.

- - - - -
9431f905 by Oleg Grenrus at 2019-12-16T10:55:50+02:00
Add index-state to hadrian/cabal.project

Then one is freer to omit upper bounds, as we won't pick
any new entries on Hackage while building hadrian itself.

- - - - -
3e17a866 by Krzysztof Gogolewski at 2019-12-16T19:31:44-05:00
Remove dataConSig

As suggested in #17291

- - - - -
75355fde by Krzysztof Gogolewski at 2019-12-16T19:31:44-05:00
Use "OrCoVar" functions less

As described in #17291, we'd like to separate coercions and expressions
in a more robust fashion.
This is a small step in this direction.

- `mkLocalId` now panicks on a covar.
  Calls where this was not the case were changed to `mkLocalIdOrCoVar`.
- Don't use "OrCoVar" functions in places where we know the type is
  not a coercion.

- - - - -
f9686e13 by Richard Eisenberg at 2019-12-16T19:32:21-05:00
Do more validity checks for quantified constraints

Close #17583.

Test case: typecheck/should_fail/T17563

- - - - -
af763765 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Fix Windows artifact collection

Variable interpolation in gitlab-ci.yml apparently doesn't work. Sigh.

- - - - -
e6d4b902 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Use xz --threads on Debian 10

- - - - -
8ba650e9 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Allow debian 8 build to fail

The python release shipped with deb8 (3.3) is too old for our testsuite
driver.

- - - - -
ac25a3f6 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Use xz --threads on Alpine

- - - - -
cc628088 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Another approach for xz detection

- - - - -
37d788ab by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Re-add release-x86_64-deb9 job

Also eliminate some redundancy.

- - - - -
f8279138 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Drop redundant release-x86_64-linux-deb9 job

- - - - -
8148ff06 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark cgrun057 as broken on ARMv7

Due to #17554. It's very surprising that this only occurs on ARMv7 but
this is the only place I've seen this failure thusfar.

- - - - -
85e5696d by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark prog001 as fragile on ARMv7

Due to #17555.

- - - - -
a5f0aab0 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T10272 as broken on ARMv7

Due to #17556.

- - - - -
1e6827c6 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T13825-debugger as broken on ARMv7

Due to #17557.

- - - - -
7cef0b7d by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T14028 as broken on ARMv7

Due to #17558.

- - - - -
6ea4eb4b by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Make ghc_built_by_llvm check more precise

Previously it would hackily look at the flavour name to determine
whether LLVM was used to build stage2 ghc. However, this didn't work at
all with Hadrian and would miss cases like ARM where we use the LLVM
backend by default.

See #16087 for the motivation for why ghc_built_by_llvm is needed at
all. This should catch one of the ARMv7 failures described in #17555.

- - - - -
c3e82bf7 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T5435_* tests as broken on ARM

`T5435_v_asm_a`, `T5435_v_asm_b`, and `T5435_v_gcc` all fail on ARMv7.
See #17559.

- - - - -
eb2aa851 by Ben Gamari at 2019-12-17T07:24:40-05:00
gitlab-ci: Don't allow armv7 jobs to fail

- - - - -
efc92216 by Ben Gamari at 2019-12-17T07:24:40-05:00
Revert "testsuite: Mark cgrun057 as broken on ARMv7"

This reverts commit 6cfc47ec8a478e1751cb3e7338954da1853c3996.

- - - - -
1d2bb9eb by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark print002 as fragile on ARM

Due to #17557.

Also accepting spurious performance change.

Metric Decrease:
    T1969

- - - - -
41f4e4fb by Josh Meredith at 2019-12-17T07:25:17-05:00
Fix ambiguous occurence error when building Hadrian

- - - - -
4374983a by Josh Meredith at 2019-12-17T07:25:17-05:00
Rename SphinxMode constructors

- - - - -
a8f7ecd5 by Josh Meredith at 2019-12-17T07:25:17-05:00
Use *Mode suffix instead of *M

- - - - -
58655b9d by Sylvain Henry at 2019-12-18T13:43:37+01:00
Add GHC-API logging hooks

* Add 'dumpAction' hook to DynFlags.

It allows GHC API users to catch dumped intermediate codes and
information. The format of the dump (Core, Stg, raw text, etc.) is now
reported allowing easier automatic handling.

* Add 'traceAction' hook to DynFlags.

Some dumps go through the trace mechanism (for instance unfoldings that
have been considered for inlining). This is problematic because:
1) dumps aren't written into files even with -ddump-to-file on
2) dumps are written on stdout even with GHC API
3) in this specific case, dumping depends on unsafe globally stored
DynFlags which is bad for GHC API users

We introduce 'traceAction' hook which allows GHC API to catch those
traces and to avoid using globally stored DynFlags.

* Avoid dumping empty logs via dumpAction/traceAction (but still write
empty files to keep the existing behavior)

- - - - -
fad866e0 by Moritz Kiefer at 2019-12-19T11:15:39-05:00
Avoid race condition in hDuplicateTo

In our codebase we have some code along the lines of

```
newStdout <- hDuplicate stdout
stderr `hDuplicateTo` stdout
```

to avoid stray `putStrLn`s from corrupting a protocol (LSP) that is
run over stdout.

On CI we have seen a bunch of issues where `dup2` returned `EBUSY` so
this fails with `ResourceExhausted` in Haskell.

I’ve spent some time looking at the docs for `dup2` and the code in
`base` and afaict the following race condition is being triggered
here:

1. The user calls `hDuplicateTo stderr stdout`.
2. `hDuplicateTo` calls `hClose_help stdout_`, this closes the file
handle for stdout.
3. The file handle for stdout is now free, so another thread
allocating a file might get stdout.
4. If `dup2` is called while `stdout` (now pointing to something
else) is half-open, it returns EBUSY.

I think there might actually be an even worse case where `dup2` is run
after FD 1 is fully open again. In that case, you will end up not just
redirecting the original stdout to stderr but also the whatever
resulted in that file handle being allocated.

As far as I can tell, `dup2` takes care of closing the file handle
itself so there is no reason to do this in `hDuplicateTo`. So this PR
replaces the call to `hClose_help` by the only part of `hClose_help`
that we actually care about, namely, `flushWriteBuffer`.

I tested this on our codebase fairly extensively and haven’t been able
to reproduce the issue with this patch.

- - - - -
0c114c65 by Sylvain Henry at 2019-12-19T11:16:17-05:00
Handle large ARR_WORDS in heap census (fix #17572)

We can do a heap census with a non-profiling RTS. With a non-profiling
RTS we don't zero superfluous bytes of shrunk arrays hence a need to
handle the case specifically to avoid a crash.

Revert part of a586b33f8e8ad60b5c5ef3501c89e9b71794bbed

- - - - -
1a0d1a65 by John Ericson at 2019-12-20T10:50:22-05:00
Deduplicate copied monad failure handler code

- - - - -
70e56b27 by Ryan Scott at 2019-12-20T10:50:57-05:00
lookupBindGroupOcc: recommend names in the same namespace (#17593)

Previously, `lookupBindGroupOcc`'s error message would recommend all
similar names in scope, regardless of whether they were type
constructors, data constructors, or functions, leading to the
confusion witnessed in #17593. This is easily fixed by only
recommending names in the same namespace, using the
`nameSpacesRelated` function.

Fixes #17593.

- - - - -
3c12355e by Stefan Schulze Frielinghaus at 2019-12-24T01:03:44-05:00
Fix endian handling w.r.t. CPP macro WORDS_BIGENDIAN

Include header file `ghcautoconf.h` where the CPP macro
`WORDS_BIGENDIAN` is defined. This finally fixes #17337 (in conjunction
with commit 6c59cc71dc).

- - - - -
11f8eef5 by Stefan Schulze Frielinghaus at 2019-12-24T01:03:44-05:00
fixup! Fix endian handling w.r.t. CPP macro WORDS_BIGENDIAN

- - - - -
40327b03 by Sylvain Henry at 2019-12-24T01:04:24-05:00
Remove outdated comment

- - - - -
aeea92ef by Sylvain Henry at 2019-12-25T19:23:54-05:00
Switch to ReadTheDocs theme for the user-guide

- - - - -
26493eab by Gabor Greif at 2019-12-25T19:24:32-05:00
Fix copy-paste error in comment
- - - - -
776df719 by Gabor Greif at 2019-12-25T19:24:32-05:00
Fix comment about minimal gcc version

to be consistent what FP_GCC_VERSION requires
- - - - -
3b17114d by Ömer Sinan Ağacan at 2019-12-26T14:09:11-05:00
Minor refactor in ghc.cabal.in:

- Remove outdated comments
- Move cutils.c from parser to cbits
- Remove unused cutils.h

- - - - -
334290b6 by Ryan Scott at 2019-12-26T14:09:48-05:00
Replace panic/notHandled with noExtCon in DsMeta

There are many spots in `DsMeta` where `panic` or `notHandled` is
used after pattern-matching on a TTG extension constructor. This is
overkill, however, as using `noExtCon` would work just as well. This
patch switches out these panics for `noExtCon`.

- - - - -
68252aa3 by Ben Gamari at 2019-12-27T15:11:38-05:00
testsuite: Skip T17499 when built against integer-simple

Since it routinely times out in CI.

- - - - -
0c51aeeb by Gabor Greif at 2019-12-27T15:12:17-05:00
suppress popup dialog about missing Xcode at configure

tested with `bash` and `zsh`.

- - - - -
8d76bcc2 by Gabor Greif at 2019-12-27T15:12:17-05:00
while at it rename XCode to the official Xcode

- - - - -
47a68205 by Ben Gamari at 2019-12-27T15:12:55-05:00
testsuite: Mark cgrun057 as fragile on ARM

As reported in #17554. Only marking on ARM for now although there is
evidence to suggest that the issue may occur on other platforms as well.

- - - - -
d03dec8f by Gabor Greif at 2019-12-27T15:13:32-05:00
use shell variable CcLlvmBackend for test

Previously we used `AC_DEFINE`d variable `CC_LLVM_BACKEND` which has an empty shell expansion.
- - - - -
2528e684 by Ben Gamari at 2019-12-30T06:51:32-05:00
driver: Include debug level in the recompilation check hash

Fixes #17586.

- - - - -
f14bb50b by Ben Gamari at 2019-12-30T06:52:09-05:00
rts: Ensure that nonmoving gc isn't used with profiling

- - - - -
b426de37 by Ben Gamari at 2019-12-30T06:52:45-05:00
llvmGen: Ensure that entry labels don't have predecessors

The LLVM IR forbids the entry label of a procedure from having any
predecessors. In the case of a simple looping function the LLVM code
generator broke this invariant, as noted in #17589. Fix this by
moving the function prologue to its own basic block, as suggested by
@kavon in #11649.

Fixes #11649 and #17589.

- - - - -
613f7265 by Ben Gamari at 2019-12-30T06:52:45-05:00
llvmGen: Drop old fix for #11649

This was a hack which is no longer necessary now since we introduce a
dedicated entry block for each procedure.

- - - - -
fdeffa5e by Ben Gamari at 2019-12-30T06:53:23-05:00
rts: Error on invalid --numa flags

Previously things like `+RTS --numa-debug` would enable NUMA support,
despite being an invalid flag.

- - - - -
9ce3ba68 by Ben Gamari at 2019-12-30T06:53:23-05:00
rts: Fix --debug-numa mode under Docker

As noted in #17606, Docker disallows the get_mempolicy syscall by
default. This caused numerous tests to fail under CI in the `debug_numa`
way. Avoid this by disabling the NUMA probing logic when --debug-numa is
in use, instead setting n_numa_nodes in RtsFlags.c.

Fixes #17606.

- - - - -
5baa2a43 by Ben Gamari at 2019-12-30T06:54:01-05:00
testsuite: Disable derefnull when built with LLVM

LLVM does not guarantee any particular semantics when dereferencing null
pointers. Consequently, this test actually passes when built with the
LLVM backend.

- - - - -
bd544d3d by Ben Gamari at 2019-12-30T06:54:38-05:00
hadrian: Track hash of Cabal Setup builder arguments

Lest we fail to rebuild when they change. Fixes #17611.

- - - - -
6e2c495e by Ben Gamari at 2019-12-30T06:55:19-05:00
TcIface: Fix inverted logic in typechecking of source ticks

Previously we would throw away source ticks when the debug level was
non-zero. This is precisely the opposite of what was intended.

Fixes #17616.

Metric Decrease:
    T13056
    T9020
    T9961
    T12425

- - - - -
7fad387d by Ben Gamari at 2019-12-30T06:55:55-05:00
perf_notes: Add --zero-y argument

This makes it easier to see the true magnitude of fluctuations.
Also do some house-keeping in the argument parsing department.

- - - - -
0d42b287 by Ben Gamari at 2019-12-30T06:55:55-05:00
testsuite: Enlarge acceptance window for T1969

As noted in #17624, it's quite unstable, especially, for some reason, on
i386 and armv7 (something about 32-bit platforms perhaps?).

Metric Increase:
    T1969

- - - - -
eb608235 by Sylvain Henry at 2019-12-31T14:22:32-05:00
Module hierarchy (#13009): Stg

- - - - -
d710fd66 by Vladislav Zavialov at 2019-12-31T14:23:10-05:00
Testsuite: update some Haddock tests

Fixed tests:

* haddockA039: added to all.T
* haddockE004: replaced with T17561 (marked as expect_broken)

New tests:

* haddockA040: deriving clause for a data instance
* haddockA041: haddock and CPP #include

- - - - -
859ebdd4 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Add "-Iw" RTS flag for minimum wait between idle GCs (#11134)

- - - - -
dd4b6551 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Add additional Note explaining the -Iw flag

- - - - -
c4279ff1 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Fix some sloppy indentation

- - - - -
b84c09d5 by Ömer Sinan Ağacan at 2019-12-31T23:45:19-05:00
Tweak Cmm dumps to avoid generating sections for empty groups

When dumping Cmm groups check if the group is empty, to avoid generating
empty sections in dump files like

    ==================== Output Cmm ====================
    []

Also fixes a few bad indentation in the code around changes.

- - - - -
b2e0323f by Gabor Greif at 2020-01-03T21:22:36-05:00
Simplify mrStr

- - - - -
3c9dc06b by Brian Wignall at 2020-01-04T15:55:06-05:00
Fix typos, via a Levenshtein-style corrector

- - - - -
d561c8f6 by Sylvain Henry at 2020-01-04T15:55:46-05:00
Add Cmm related hooks

* stgToCmm hook
* cmmToRawCmm hook

These hooks are used by Asterius and could be useful to other clients of
the GHC API.

It increases the Parser dependencies (test CountParserDeps) to 184. It's
still less than 200 which was the initial request (cf
https://mail.haskell.org/pipermail/ghc-devs/2019-September/018122.html)
so I think it's ok to merge this.

- - - - -
ae6b6276 by Oleg Grenrus at 2020-01-04T15:56:22-05:00
Update to Cabal submodule to v3.2.0.0-alpha3

Metric Increase:
    haddock.Cabal

- - - - -
073f7cfd by Vladislav Zavialov at 2020-01-04T15:56:59-05:00
Add lexerDbg to dump the tokens fed to the parser

This a small utility function that comes in handy when debugging the
lexer and the parser.

- - - - -
558d4d4a by Sylvain Henry at 2020-01-04T15:57:38-05:00
Split integerGmpInternals test in several parts

This is to prepare for ghc-bignum which implements some but not all of
gmp functions.

- - - - -
4056b966 by Ben Gamari at 2020-01-04T15:58:15-05:00
testsuite: Mark cgrun057 as fragile on all platforms

I have seen this fail both on x86-64/Debian 9 and armv7/Debian 9

See #17554.

- - - - -
5ffea0c6 by Tamar Christina at 2020-01-06T18:38:37-05:00
Fix overflow.

- - - - -
99a9f51b by Sylvain Henry at 2020-01-06T18:39:22-05:00
Module hierarchy: Iface (cf #13009)

- - - - -
7aa4a061 by Ben Gamari at 2020-01-07T13:11:48-05:00
configure: Only check GCC version if CC is GCC

Also refactor FP_GCC_EXTRA_FLAGS in a few ways:

 * We no longer support compilers which lack support for -fno-builtin
   and -fwrapv so remove the condition on GccVersion
 * These flags are only necessary when using the via-C backend
   so make them conditional on Unregisterised.

Fixes #15742.

- - - - -
0805ed7e by John Ericson at 2020-01-07T13:12:25-05:00
Use non-empty lists to remove partiality in matching code

- - - - -
7844f3a8 by Ben Gamari at 2020-01-07T13:13:02-05:00
testsuite: Mark T17073 as broken on Windows

Due to #17607.

- - - - -
acf40cae by Ben Gamari at 2020-01-07T13:13:02-05:00
gitlab-ci: Disallow Windows from failing

- - - - -
34bc02c7 by Ben Gamari at 2020-01-07T13:13:02-05:00
configure: Find Python3 for testsuite

In addition, we prefer the Mingw64 Python distribution on Windows due
to #17483.

- - - - -
e35fe8d5 by Ben Gamari at 2020-01-07T13:13:02-05:00
testsuite: Fix Windows platform test

Previously we used platform.system() and while this worked fine (e.g.
returned `Windows`, as expected) locally under both msys and MingW64
Python distributions, it inexplicably returned `MINGW64_NT-10.0`
under MingW64 Python on CI. It seems os.name is more reliable so we now
use that instead..

- - - - -
48ef6217 by Ben Gamari at 2020-01-07T13:13:39-05:00
gitlab-ci: Rename push-test-metrics.sh to test-metrics.sh

Refactoring to follow.

- - - - -
2234fa92 by Ben Gamari at 2020-01-07T13:13:39-05:00
gitlab-ci: Pull test metrics before running testsuite

Otherwise the testsuite driver may not have an up-to-date
baseline.

- - - - -
1ca9adbc by Sylvain Henry at 2020-01-07T13:14:18-05:00
Remove `parallel` check from configure.ac

`parallel` is no longer a submodule since 3cb063c805ec841ca33b8371ef8aba9329221b6c

- - - - -
b69a3460 by Ryan Scott at 2020-01-07T13:14:57-05:00
Monomorphize HsModule to GhcPs (#17642)

Analyzing the call sites for `HsModule` reveals that it is only ever
used with parsed code (i.e., `GhcPs`). This simplifies `HsModule` by
concretizing its `pass` parameter to always be `GhcPs`.

Fixes #17642.

- - - - -
d491a679 by Sylvain Henry at 2020-01-08T06:16:31-05:00
Module hierarchy: Renamer (cf #13009)

- - - - -
d589410f by Ben Gamari at 2020-01-08T06:17:09-05:00
Bump haskeline submodule to 0.8.0.1

(cherry picked from commit feb3b955402d53c3875dd7a9a39f322827e5bd69)

- - - - -
923a1272 by Ryan Scott at 2020-01-08T06:17:47-05:00
Print Core type applications with no whitespace after @ (#17643)

This brings the pretty-printer for Core in line with how visible
type applications are normally printed: namely, with no whitespace
after the `@` character (i.e., `f @a` instead of `f @ a`). While I'm
in town, I also give the same treatment to type abstractions (i.e.,
`\(@a)` instead of `\(@ a)`) and coercion applications (i.e.,
`f @~x` instead of `f @~ x`).

Fixes #17643.

- - - - -
49f83a0d by Adam Sandberg Eriksson at 2020-01-12T21:28:09-05:00
improve docs for HeaderInfo.getImports

[skip ci]

- - - - -
9129210f by Matthew Pickering at 2020-01-12T21:28:47-05:00
Overloaded Quotation Brackets (#246)

This patch implements overloaded quotation brackets which generalise the
desugaring of all quotation forms in terms of a new minimal interface.

The main change is that a quotation, for example, [e| 5 |], will now
have type `Quote m => m Exp` rather than `Q Exp`. The `Quote` typeclass
contains a single method for generating new names which is used when
desugaring binding structures.

The return type of functions from the `Lift` type class, `lift` and `liftTyped` have
been restricted to `forall m . Quote m => m Exp` rather than returning a
result in a Q monad.

More details about the feature can be read in the GHC proposal.

https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst

- - - - -
350e2b78 by Richard Eisenberg at 2020-01-12T21:29:27-05:00
Don't zap to Any; error instead

This changes GHC's treatment of so-called Naughty Quantification
Candidates to issue errors, instead of zapping to Any.

Close #16775.

No new test cases, because existing ones cover this well.

- - - - -
0b5ddc7f by Brian Wignall at 2020-01-12T21:30:08-05:00
Fix more typos, via an improved Levenshtein-style corrector

- - - - -
f732dbec by Ben Gamari at 2020-01-12T21:30:49-05:00
gitlab-ci: Retain bindists used by head.hackage for longer

Previously we would keep them for two weeks. However, on the stable
branches two weeks can easily elapse with no pushes.

- - - - -
c8636da5 by Sylvain Henry at 2020-01-12T21:31:30-05:00
Fix LANG=C for readelf invocation in T14999

The test fails when used with LANG=fr_FR.UTF-8

- - - - -
077a88de by Jean-Baptiste Mazon at 2020-01-12T21:32:08-05:00
users-guide/debug-info: typo “behivior”
- - - - -
61916c5d by Simon Peyton Jones at 2020-01-12T21:32:44-05:00
Add comments about TH levels

- - - - -
1fd766ca by Simon Peyton Jones at 2020-01-12T21:32:44-05:00
Comments about constraint floating

- - - - -
de01427e by Simon Peyton Jones at 2020-01-12T21:32:45-05:00
Minor refactor around quantified constraints

This patch clarifies a dark corner of quantified
constraints.

* See Note [Yukky eq_sel for a HoleDest] in TcSMonad

* Minor refactor, breaking out new function
     TcInteract.doTopReactEqPred

- - - - -
30be3bf1 by Simon Peyton Jones at 2020-01-12T21:32:45-05:00
Comments in TcHsType

- - - - -
c5977d4d by Sebastian Graf at 2020-01-16T05:58:58-05:00
Better documentation for mkEtaWW [skip ci]

So that hopefully I understand it faster next time. Also got rid of the
confusing `orig_expr`, which makes the call site in `etaExpand` look out
of sync with the passed `n` (which is not the original `n`).

- - - - -
22c0bdc3 by John Ericson at 2020-01-16T05:59:37-05:00
Handle TagToEnum in the same big case as the other primops

Before, it was a panic because it was handled above. But there must have
been an error in my reasoning (another caller?) because #17442 reported
the panic was hit.

But, rather than figuring out what happened, I can just make it
impossible by construction. By adding just a bit more bureaucracy in the
return types, I can handle TagToEnum in the same case as all the others,
so the big case is is now total, and the panic is removed.

Fixes #17442

- - - - -
ee5d63f4 by John Ericson at 2020-01-16T05:59:37-05:00
Get rid of OpDest

`OpDest` was basically a defunctionalization. Just turn the code that
cased on it into those functions, and call them directly.

- - - - -
1ff55226 by John Ericson at 2020-01-16T06:00:16-05:00
Remove special case case of bool during STG -> C--

Allow removing the no longer needed cgPrimOp, getting rid of a small a
small layer violation too.

Change which made the special case no longer needed was #6135 /
6579a6c73082387f82b994305011f011d9d8382b, which dates back to 2013,
making me feel better.

- - - - -
f416fe64 by Adam Wespiser at 2020-01-16T06:00:53-05:00
replace dead html link (fixes #17661)

- - - - -
f6bf2ce8 by Sebastian Graf at 2020-01-16T06:01:32-05:00
Revert "`exprOkForSpeculation` for Note [IO hack in the demand analyser]"

This reverts commit ce64b397777408731c6dd3f5c55ea8415f9f565b on the
grounds of the regression it would introduce in a couple of packages.

Fixes #17653.

Also undoes a slight metric increase in #13701 introduced by that commit
that we didn't see prior to !1983.

Metric Decrease:
    T13701

- - - - -
a71323ff by Ben Gamari at 2020-01-17T08:43:16-05:00
gitlab-ci: Don't FORCE_SYMLINKS on Windows

Not all runners have symlink permissions enabled.
- - - - -
0499e3bc by Ömer Sinan Ağacan at 2020-01-20T15:31:33-05:00
Fix +RTS -Z flag documentation

Stack squeezing is done on context switch, not on GC or stack overflow.
Fix the documentation.

Fixes #17685

[ci skip]

- - - - -
a661df91 by Ömer Sinan Ağacan at 2020-01-20T15:32:13-05:00
Document Stg.FVs module

Fixes #17662

[ci skip]

- - - - -
db24e480 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Don't trash STG registers

Fixes #13904.

- - - - -
f3d7fdb3 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Fix typo in readnone attribute

- - - - -
442751c6 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Add lower-expect to the -O0 optimisation set

@kavon says that this will improve block layout for stack checks.

- - - - -
e90ecc93 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Fix #14251

Fixes the calling convention for functions passing raw SSE-register
values by adding padding as needed to get the values in the right
registers. This problem cropped up when some args were unused an dropped
from the live list.

This folds together 2e23e1c7de01c92b038e55ce53d11bf9db993dd4 and
73273be476a8cc6c13368660b042b3b0614fd928 previously from @kavon.

Metric Increase:
    T12707
    ManyConstructors

- - - - -
66e511a4 by Ben Gamari at 2020-01-20T15:33:28-05:00
testsuite: Preserve more information in framework failures

Namely print the entire exception in hopes that this will help track
down #17649.

- - - - -
b62b8cea by Ömer Sinan Ağacan at 2020-01-20T15:34:06-05:00
Remove deprecated -smp flag

It was deprecated in 2012 with 46258b40

- - - - -
0c04a86a by Ben Gamari at 2020-01-20T15:34:43-05:00
gitlab-ci: Reenable submodule linter

- - - - -
2bfabd22 by Ben Gamari at 2020-01-20T15:34:43-05:00
gitlab-ci: Allow submodule cleaning to fail on Windows

Currently CI is inexplicably failing with
```
$ git submodule foreach git clean -xdf
fatal: not a git repository: libffi-tarballs/../.git/modules/libffi-tarballs
```
I have no idea how this working tree got into such a state but we do
need to fail more gracefully when it happens. Consequently, we allow the
cleaning step to fail.

- - - - -
14bced99 by Xavier Denis at 2020-01-20T15:35:21-05:00
Put the docs for :instances in alphabetical position

- - - - -
7e0bb82b by Ben Gamari at 2020-01-20T15:35:57-05:00
Add missing Note [Improvement from Ground Wanteds]

Closes #17659.

- - - - -
17e43a7c by Ben Gamari at 2020-01-20T15:36:32-05:00
unregisterised: Fix declaration for stg_NO_FINALIZER

Previously it had a redundant _entry suffix. We never noticed this
previously presumably because we never generated references to it
(however hard to believe this may be). However, it did start failing in
!1304.

- - - - -
3dae006f by PHO at 2020-01-20T15:37:08-05:00
Avoid ./configure failure on NetBSD

- - - - -
738e2912 by Ben Gamari at 2020-01-24T13:42:56-05:00
testsuite: Widen acceptance window of T1969

I have seen >20% fluctuations in this number, leading to spurious
failures.

- - - - -
ad4eb7a7 by Gabor Greif at 2020-01-25T05:19:07-05:00
Document the fact, that openFileBlocking can consume an OS thread indefinitely.

Also state that a deadlock can happen with the non-threaded runtime.
[ci skip]
- - - - -
be910728 by Sebastian Graf at 2020-01-25T05:19:46-05:00
`-ddump-str-signatures` dumps Text, not STG [skip ci]

- - - - -
0e57d8a1 by Ömer Sinan Ağacan at 2020-01-25T05:20:27-05:00
Fix chaining tagged and untagged ptrs in compacting GC

Currently compacting GC has the invariant that in a chain all fields are tagged
the same. However this does not really hold: root pointers are not tagged, so
when we thread a root we initialize a chain without a tag. When the pointed
objects is evaluated and we have more pointers to it from the heap, we then add
*tagged* fields to the chain (because pointers to it from the heap are tagged),
ending up chaining fields with different tags (pointers from roots are NOT
tagged, pointers from heap are). This breaks the invariant and as a result
compacting GC turns tagged pointers into non-tagged.

This later causes problem in the generated code where we do reads assuming that
the pointer is aligned, e.g.

    0x7(%rax) -- assumes that pointer is tagged 1

which causes misaligned reads. This caused #17088.

We fix this using the "pointer tagging for large families" patch (#14373,
!1742):

- With the pointer tagging patch the GC can know what the tagged pointer to a
  CONSTR should be (previously we'd need to know the family size -- large
  families are always tagged 1, small families are tagged depending on the
  constructor).

- Since we now know what the tags should be we no longer need to store the
  pointer tag in the info table pointers when forming chains in the compacting
  GC.

As a result we no longer need to tag pointers in chains with 1/2 depending on
whether the field points to an info table pointer, or to another field: an info
table pointer is always tagged 0, everything else in the chain is tagged 1. The
lost tags in pointers can be retrieved by looking at the info table.

Finally, instead of using tag 1 for fields and tag 0 for info table pointers, we
use two different tags for fields:

- 1 for fields that have untagged pointers
- 2 for fields that have tagged pointers

When unchaining we then look at the pointer to a field, and depending on its tag
we either leave a tagged pointer or an untagged pointer in the field.

This allows chaining untagged and tagged fields together in compacting GC.

Fixes #17088

Nofib results
-------------

Binaries are smaller because of smaller `Compact.c` code.

make mode=fast EXTRA_RUNTEST_OPTS="-cachegrind" EXTRA_HC_OPTS="-with-rtsopts=-c" NoFibRuns=1

    --------------------------------------------------------------------------------
            Program           Size    Allocs    Instrs     Reads    Writes
    --------------------------------------------------------------------------------
                 CS          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                CSD          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                 FS          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
                  S          -0.3%      0.0%     +5.4%     +0.8%     +3.9%
                 VS          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
                VSD          -0.3%      0.0%     -0.0%     -0.0%     -0.2%
                VSM          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               anna          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
               ansi          -0.3%      0.0%     +0.1%     +0.0%     +0.0%
               atom          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             awards          -0.2%      0.0%     +0.0%      0.0%     -0.0%
             banner          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
         bernouilli          -0.3%      0.0%     +0.1%     +0.0%     +0.0%
       binary-trees          -0.2%      0.0%     +0.0%      0.0%     +0.0%
              boyer          -0.3%      0.0%     +0.2%     +0.0%     +0.0%
             boyer2          -0.2%      0.0%     +0.2%     +0.1%     +0.0%
               bspt          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
          cacheprof          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
           calendar          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           cichelli          -0.3%      0.0%     +1.1%     +0.2%     +0.5%
            circsim          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
           clausify          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
      comp_lab_zift          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
           compress          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
          compress2          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
        constraints          -0.3%      0.0%     +0.2%     +0.1%     +0.1%
       cryptarithm1          -0.3%      0.0%     +0.0%     -0.0%      0.0%
       cryptarithm2          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                cse          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
       digits-of-e1          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
       digits-of-e2          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
             dom-lt          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
              eliza          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
              event          -0.3%      0.0%     +0.1%     +0.0%     -0.0%
        exact-reals          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             exp3_8          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
             expert          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
     fannkuch-redux          -0.3%      0.0%     -0.0%     -0.0%     -0.0%
              fasta          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                fem          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                fft          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
               fft2          -0.2%      0.0%     +0.0%     -0.0%     +0.0%
           fibheaps          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               fish          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              fluid          -0.2%      0.0%     +0.4%     +0.1%     +0.1%
             fulsom          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             gamteb          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                gcd          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
        gen_regexps          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             genfft          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                 gg          -0.2%      0.0%     +0.7%     +0.3%     +0.2%
               grep          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             hidden          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                hpg          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                ida          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              infer          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
            integer          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
          integrate          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
       k-nucleotide          -0.2%      0.0%     +0.0%     +0.0%     -0.0%
              kahan          -0.3%      0.0%     -0.0%     -0.0%     -0.0%
            knights          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             lambda          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
         last-piece          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               lcss          -0.3%      0.0%     +0.0%     +0.0%      0.0%
               life          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               lift          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             linear          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
          listcompr          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           listcopy          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           maillist          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             mandel          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            mandel2          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               mate          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            minimax          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            mkhprog          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
         multiplier          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             n-body          -0.2%      0.0%     -0.0%     -0.0%     -0.0%
           nucleic2          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
               para          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
          paraffins          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             parser          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            parstof          -0.2%      0.0%     +0.8%     +0.2%     +0.2%
                pic          -0.2%      0.0%     +0.1%     -0.1%     -0.1%
           pidigits          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              power          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
             pretty          -0.3%      0.0%     -0.0%     -0.0%     -0.1%
             primes          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
          primetest          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
             prolog          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             puzzle          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
             queens          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            reptile          -0.2%      0.0%     +0.2%     +0.1%     +0.0%
    reverse-complem          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            rewrite          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               rfib          -0.2%      0.0%     +0.0%     +0.0%     -0.0%
                rsa          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                scc          -0.3%      0.0%     -0.0%     -0.0%     -0.1%
              sched          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                scs          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
             simple          -0.2%      0.0%     +3.4%     +1.0%     +1.8%
              solid          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            sorting          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
      spectral-norm          -0.2%      0.0%     -0.0%     -0.0%     -0.0%
             sphere          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             symalg          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                tak          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
          transform          -0.2%      0.0%     +0.2%     +0.1%     +0.1%
           treejoin          -0.3%      0.0%     +0.2%     -0.0%     -0.1%
          typecheck          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            veritas          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
               wang          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
          wave4main          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
       wheel-sieve1          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
       wheel-sieve2          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               x2n1          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
    --------------------------------------------------------------------------------
                Min          -0.3%      0.0%     -0.0%     -0.1%     -0.2%
                Max          -0.1%      0.0%     +5.4%     +1.0%     +3.9%
     Geometric Mean          -0.3%     -0.0%     +0.1%     +0.0%     +0.1%

    --------------------------------------------------------------------------------
            Program           Size    Allocs    Instrs     Reads    Writes
    --------------------------------------------------------------------------------
            circsim          -0.2%      0.0%     +1.6%     +0.4%     +0.7%
        constraints          -0.3%      0.0%     +4.3%     +1.5%     +2.3%
           fibheaps          -0.3%      0.0%     +3.5%     +1.2%     +1.3%
             fulsom          -0.2%      0.0%     +3.6%     +1.2%     +1.8%
           gc_bench          -0.3%      0.0%     +4.1%     +1.3%     +2.3%
               hash          -0.3%      0.0%     +6.6%     +2.2%     +3.6%
               lcss          -0.3%      0.0%     +0.7%     +0.2%     +0.7%
          mutstore1          -0.3%      0.0%     +4.8%     +1.4%     +2.8%
          mutstore2          -0.3%      0.0%     +3.4%     +1.0%     +1.7%
              power          -0.2%      0.0%     +2.7%     +0.6%     +1.9%
         spellcheck          -0.3%      0.0%     +1.1%     +0.4%     +0.4%
    --------------------------------------------------------------------------------
                Min          -0.3%      0.0%     +0.7%     +0.2%     +0.4%
                Max          -0.2%      0.0%     +6.6%     +2.2%     +3.6%
     Geometric Mean          -0.3%     +0.0%     +3.3%     +1.0%     +1.8%

Metric changes
--------------

While it sounds ridiculous, this change causes increased allocations in
the following tests. We concluded that this change can't cause a
difference in allocations and decided to land this patch. Fluctuations
in "bytes allocated" metric is tracked in #17686.

Metric Increase:
    Naperian
    T10547
    T12150
    T12234
    T12425
    T13035
    T5837
    T6048

- - - - -
8038cbd9 by Sebastian Graf at 2020-01-25T05:21:05-05:00
PmCheck: Formulate as translation between Clause Trees

We used to check `GrdVec`s arising from multiple clauses and guards in
isolation. That resulted in a split between `pmCheck` and
`pmCheckGuards`, the implementations of which were similar, but subtly
different in detail. Also the throttling mechanism described in
`Note [Countering exponential blowup]` ultimately got quite complicated
because it had to cater for both checking functions.

This patch realises that pattern match checking doesn't just consider
single guarded RHSs, but that it's always a whole set of clauses, each
of which can have multiple guarded RHSs in turn. We do so by
translating a list of `Match`es to a `GrdTree`:

```haskell
data GrdTree
  = Rhs !RhsInfo
  | Guard !PmGrd !GrdTree      -- captures lef-to-right  match semantics
  | Sequence !GrdTree !GrdTree -- captures top-to-bottom match semantics
  | Empty                      -- For -XEmptyCase, neutral element of Sequence
```

Then we have a function `checkGrdTree` that matches a given `GrdTree`
against an incoming set of values, represented by `Deltas`:

```haskell
checkGrdTree :: GrdTree -> Deltas -> CheckResult
...
```

Throttling is isolated to the `Sequence` case and becomes as easy as one
would expect: When the union of uncovered values becomes too big, just
return the original incoming `Deltas` instead (which is always a
superset of the union, thus a sound approximation).

The returned `CheckResult` contains two things:

1. The set of values that were not covered by any of the clauses, for
   exhaustivity warnings.
2. The `AnnotatedTree` that enriches the syntactic structure of the
   input program with divergence and inaccessibility information.

This is `AnnotatedTree`:

```haskell
data AnnotatedTree
  = AccessibleRhs !RhsInfo
  | InaccessibleRhs !RhsInfo
  | MayDiverge !AnnotatedTree
  | SequenceAnn !AnnotatedTree !AnnotatedTree
  | EmptyAnn
```

Crucially, `MayDiverge` asserts that the tree may force diverging
values, so not all of its wrapped clauses can be redundant.

While the set of uncovered values can be used to generate the missing
equations for warning messages, redundant and proper inaccessible
equations can be extracted from `AnnotatedTree` by
`redundantAndInaccessibleRhss`.

For this to work properly, the interface to the Oracle had to change.
There's only `addPmCts` now, which takes a bag of `PmCt`s. There's a
whole bunch of `PmCt` variants to replace the different oracle functions
from before.

The new `AnnotatedTree` structure allows for more accurate warning
reporting (as evidenced by a number of changes spread throughout GHC's
code base), thus we fix #17465.

Fixes #17646 on the go.

Metric Decrease:
    T11822
    T9233
    PmSeriesS
    haddock.compiler

- - - - -
86966d48 by Sebastian Graf at 2020-01-25T05:21:05-05:00
PmCheck: Properly handle constructor-bound type variables

In https://gitlab.haskell.org/ghc/ghc/merge_requests/2192#note_246551
Simon convinced me that ignoring type variables existentially bound by
data constructors have to be the same way as value binders.

Sadly I couldn't think of a regression test, but I'm confident that this
change strictly improves on the status quo.

- - - - -
c3fde723 by Ryan Scott at 2020-01-25T05:21:40-05:00
Handle local fixity declarations in DsMeta properly

`DsMeta.rep_sig` used to skip over `FixSig` entirely, which had the
effect of causing local fixity declarations to be dropped when quoted
in Template Haskell. But there is no good reason for this state of
affairs, as the code in `DsMeta.repFixD` (which handles top-level
fixity declarations) handles local fixity declarations just fine.
This patch factors out the necessary parts of `repFixD` so that they
can be used in `rep_sig` as well.

There was one minor complication: the fixity signatures for class
methods in each `HsGroup` were stored both in `FixSig`s _and_ the
list of `LFixitySig`s for top-level fixity signatures, so I needed
to take action to prevent fixity signatures for class methods being
converted to `Dec`s twice. I tweaked `RnSource.add` to avoid putting
these fixity signatures in two places and added
`Note [Top-level fixity signatures in an HsGroup]` in `GHC.Hs.Decls`
to explain the new design.

Fixes #17608. Bumps the Haddock submodule.

- - - - -
6e2d9ee2 by Sylvain Henry at 2020-01-25T05:22:20-05:00
Module hierarchy: Cmm (cf #13009)

- - - - -
8b726534 by PHO at 2020-01-25T05:23:01-05:00
Fix rts allocateExec() on NetBSD

Similar to SELinux, NetBSD "PaX mprotect" prohibits marking a page
mapping both writable and executable at the same time. Use libffi
which knows how to work around it.

- - - - -
6eb566a0 by Xavier Denis at 2020-01-25T05:23:39-05:00
Add ghc-in-ghci for stack based builds

- - - - -
b1a32170 by Xavier Denis at 2020-01-25T05:23:39-05:00
Create ghci.cabal.sh

- - - - -
0a5e4f5f by Sylvain Henry at 2020-01-25T05:24:19-05:00
Split glasgow_exts into several files (#17316)

- - - - -
b3e5c678 by Ben Gamari at 2020-01-25T05:24:57-05:00
hadrian: Throw error on duplicate-named flavours

Throw an error if the user requests a flavour for which there is more
than one match.

Fixes #17156.

- - - - -
0940b59a by Ryan Scott at 2020-01-25T08:15:05-05:00
Do not bring visible foralls into scope in hsScopedTvs

Previously, `hsScopedTvs` (and its cousin `hsWcScopedTvs`) pretended
that visible dependent quantification could not possibly happen at
the term level, and cemented that assumption with an `ASSERT`:

```hs
    hsScopedTvs (HsForAllTy { hst_fvf = vis_flag, ... }) =
      ASSERT( vis_flag == ForallInvis )
      ...
```

It turns out that this assumption is wrong. You can end up tripping
this `ASSERT` if you stick it to the man and write a type for a term
that uses visible dependent quantification anyway, like in this
example:

```hs
{-# LANGUAGE ScopedTypeVariables #-}

x :: forall a -> a -> a
x = x
```

That won't typecheck, but that's not the point. Before the
typechecker has a chance to reject this, the renamer will try
to use `hsScopedTvs` to bring `a` into scope over the body of `x`,
since `a` is quantified by a `forall`. This, in turn, causes the
`ASSERT` to fail. Bummer.

Instead of walking on this dangerous ground, this patch makes GHC
adopt a more hardline stance by pattern-matching directly on
`ForallInvis` in `hsScopedTvs`:

```hs
    hsScopedTvs (HsForAllTy { hst_fvf = ForallInvis, ... }) = ...
```

Now `a` will not be brought over the body of `x` at all (which is how
it should be), there's no chance of the `ASSERT` failing anymore (as
it's gone), and best of all, the behavior of `hsScopedTvs` does not
change. Everyone wins!

Fixes #17687.

- - - - -
1132602f by Ryan Scott at 2020-01-27T10:03:42-05:00
Use splitLHs{ForAll,Sigma}TyInvis throughout the codebase

Richard points out in #17688 that we use `splitLHsForAllTy` and
`splitLHsSigmaTy` in places that we ought to be using the
corresponding `-Invis` variants instead, identifying two bugs
that are caused by this oversight:

* Certain TH-quoted type signatures, such as those that appear in
  quoted `SPECIALISE` pragmas, silently turn visible `forall`s into
  invisible `forall`s.
* When quoted, the type `forall a -> (a ~ a) => a` will turn into
  `forall a -> a` due to a bug in `DsMeta.repForall` that drops
  contexts that follow visible `forall`s.

These are both ultimately caused by the fact that `splitLHsForAllTy`
and `splitLHsSigmaTy` split apart visible `forall`s in addition to
invisible ones. This patch cleans things up:

* We now use `splitLHsForAllTyInvis` and `splitLHsSigmaTyInvis`
  throughout the codebase. Relatedly, the `splitLHsForAllTy` and
  `splitLHsSigmaTy` have been removed, as they are easy to misuse.
* `DsMeta.repForall` now only handles invisible `forall`s to reduce
  the chance for confusion with visible `forall`s, which need to be
  handled differently. I also renamed it from `repForall` to
  `repForallT` to emphasize that its distinguishing characteristic
  is the fact that it desugars down to `L.H.TH.Syntax.ForallT`.

Fixes #17688.

- - - - -
97d0b0a3 by Matthew Pickering at 2020-01-27T10:04:19-05:00
Make Block.h compile with c++ compilers

- - - - -
4bada77d by Tom Ellis at 2020-01-27T12:30:46-05:00
Disable two warnings for files that trigger them

incomplete-uni-patterns and incomplete-record-updates will be in -Wall at a
future date, so prepare for that by disabling those warnings on files that
trigger them.

- - - - -
0188404a by Tom Ellis at 2020-01-27T12:30:46-05:00
Add two warnings to stage 2 build

- - - - -
acae02c1 by Tom Ellis at 2020-01-27T12:30:46-05:00
Add two warnings to Hadrian

- - - - -
bf38a20e by Sylvain Henry at 2020-01-31T02:46:15-05:00
Call `interpretPackageEnv` from `setSessionDynFlags`

interpretPackageEnv modifies the flags by reading the dreaded package
environments. It is much less surprising to call it from
`setSessionDynFlags` instead of reading package environments as a
side-effect of `initPackages`.

- - - - -
29c701c1 by Sylvain Henry at 2020-01-31T02:46:15-05:00
Refactor package related code

The package terminology is a bit of a mess. Cabal packages contain
components. Instances of these components when built with some
flags/options/dependencies are called units. Units are registered into
package databases and their metadata are called PackageConfig.

GHC only knows about package databases containing units. It is a sad
mismatch not fixed by this patch (we would have to rename parameters
such as `package-id <unit-id>` which would affect users).

This patch however fixes the following internal names:

- Renames PackageConfig into UnitInfo.
- Rename systemPackageConfig into globalPackageDatabase[Path]
- Rename PkgConfXX into PkgDbXX
- Rename pkgIdMap into unitIdMap
- Rename ModuleToPkgDbAll into ModuleNameProvidersMap
- Rename lookupPackage into lookupUnit
- Add comments on DynFlags package related fields

It also introduces a new `PackageDatabase` datatype instead of
explicitly passing the following tuple: `(FilePath,[PackageConfig])`.

The `pkgDatabase` field in `DynFlags` now contains the unit info for
each unit of each package database exactly as they have been read from
disk. Previously the command-line flag `-distrust-all-packages` would
modify these unit info. Now this flag only affects the "dynamic"
consolidated package state found in `pkgState` field. It makes sense
because `initPackages` could be called first with this
`distrust-all-packages` flag set and then again (using ghc-api) without
and it should work (package databases are not read again from disk when
`initPackages` is called the second time).

Bump haddock submodule

- - - - -
942c7148 by Ben Gamari at 2020-01-31T02:46:54-05:00
rename: Eliminate usage of mkVarOccUnique

Replacing it with `newSysName`. Fixes #17061.

- - - - -
41117d71 by Ben Gamari at 2020-01-31T02:47:31-05:00
base: Use one-shot kqueue on macOS

The underlying reason requiring that one-shot usage be disabled (#13903)
has been fixed.

Closes #15768.

- - - - -
01b15b83 by Ben Gamari at 2020-01-31T02:48:08-05:00
testsuite: Don't crash on encoding failure in print

If the user doesn't use a Unicode locale then the testsuite driver would
previously throw framework failures due to encoding failures. We now
rather use the `replace` error-handling strategy.

- - - - -
c846618a by Ömer Sinan Ağacan at 2020-01-31T12:21:10+03:00
Do CafInfo/SRT analysis in Cmm

This patch removes all CafInfo predictions and various hacks to preserve
predicted CafInfos from the compiler and assigns final CafInfos to
interface Ids after code generation. SRT analysis is extended to support
static data, and Cmm generator is modified to allow generating
static_link fields after SRT analysis.

This also fixes `-fcatch-bottoms`, which introduces error calls in case
expressions in CorePrep, which runs *after* CoreTidy (which is where we
decide on CafInfos) and turns previously non-CAFFY things into CAFFY.

Fixes #17648
Fixes #9718

Evaluation
==========

NoFib
-----

Boot with: `make boot mode=fast`
Run: `make mode=fast EXTRA_RUNTEST_OPTS="-cachegrind" NoFibRuns=1`

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             FS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
              S          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             VS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            VSD          -0.0%      0.0%     -0.0%     -0.0%     -0.5%
            VSM          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           anna          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           ansi          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           atom          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         awards          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         banner          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     bernouilli          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   binary-trees          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         boyer2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           bspt          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      cacheprof          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       calendar          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       cichelli          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        circsim          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       clausify          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
  comp_lab_zift          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       compress          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      compress2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            cse          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          eliza          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          event          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         exp3_8          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         expert          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 fannkuch-redux          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          fasta          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fem          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fft          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           fft2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           fish          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          fluid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         fulsom          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         gamteb          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            gcd          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    gen_regexps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         genfft          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             gg          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           grep          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         hidden          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            hpg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            ida          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          infer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        integer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   k-nucleotide          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        knights          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         lambda          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     last-piece          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           life          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lift          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         linear          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      listcompr          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         mandel          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        mandel2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           mate          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        minimax          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        mkhprog          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     multiplier          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         n-body          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       nucleic2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           para          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      paraffins          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         parser          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        parstof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            pic          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       pidigits          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         pretty          -0.0%      0.0%     -0.3%     -0.4%     -0.4%
         primes          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      primetest          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         prolog          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         puzzle          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         queens          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        reptile          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
reverse-complem          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           rfib          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            rsa          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            scc          -0.0%      0.0%     -0.3%     -0.5%     -0.4%
          sched          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            scs          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         simple          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          solid          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        sorting          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
  spectral-norm          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         symalg          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            tak          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      transform          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       treejoin          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      typecheck          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        veritas          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           wang          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      wave4main          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           x2n1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.3%     -0.5%     -0.5%
            Max          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 Geometric Mean          -0.0%     -0.0%     -0.0%     -0.0%     -0.0%

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
        circsim          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       gc_bench          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           hash          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     spellcheck          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            Max          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 Geometric Mean          -0.0%     +0.0%     -0.0%     -0.0%     -0.0%

Manual inspection of programs in testsuite/tests/programs
---------------------------------------------------------

I built these programs with a bunch of dump flags and `-O` and compared
STG, Cmm, and Asm dumps and file sizes.

(Below the numbers in parenthesis show number of modules in the program)

These programs have identical compiler (same .hi and .o sizes, STG, and
Cmm and Asm dumps):

- Queens (1), andre_monad (1), cholewo-eval (2), cvh_unboxing (3),
  andy_cherry (7), fun_insts (1), hs-boot (4), fast2haskell (2),
  jl_defaults (1), jq_readsPrec (1), jules_xref (1), jtod_circint (4),
  jules_xref2 (1), lennart_range (1), lex (1), life_space_leak (1),
  bargon-mangler-bug (7), record_upd (1), rittri (1), sanders_array (1),
  strict_anns (1), thurston-module-arith (2), okeefe_neural (1),
  joao-circular (6), 10queens (1)

Programs with different compiler outputs:

- jl_defaults (1): For some reason GHC HEAD marks a lot of top-level
  `[Int]` closures as CAFFY for no reason. With this patch we no longer
  make them CAFFY and generate less SRT entries. For some reason Main.o
  is slightly larger with this patch (1.3%) and the executable sizes are
  the same. (I'd expect both to be smaller)

- launchbury (1): Same as jl_defaults: top-level `[Int]` closures marked
  as CAFFY for no reason. Similarly `Main.o` is 1.4% larger but the
  executable sizes are the same.

- galois_raytrace (13): Differences are in the Parse module. There are a
  lot, but some of the changes are caused by the fact that for some
  reason (I think a bug) GHC HEAD marks the dictionary for `Functor
  Identity` as CAFFY. Parse.o is 0.4% larger, the executable size is the
  same.

- north_array: We now generate less SRT entries because some of array
  primops used in this program like `NewArrayOp` get eliminated during
  Stg-to-Cmm and turn some CAFFY things into non-CAFFY. Main.o gets 24%
  larger (9224 bytes from 9000 bytes), executable sizes are the same.

- seward-space-leak: Difference in this program is better shown by this
  smaller example:

      module Lib where

      data CDS
        = Case [CDS] [(Int, CDS)]
        | Call CDS CDS

      instance Eq CDS where
        Case sels1 rets1 == Case sels2 rets2 =
            sels1 == sels2 && rets1 == rets2
        Call a1 b1 == Call a2 b2 =
            a1 == a2 && b1 == b2
        _ == _ =
            False

   In this program GHC HEAD builds a new SRT for the recursive group of
   `(==)`, `(/=)` and the dictionary closure. Then `/=` points to `==`
   in its SRT field, and `==` uses the SRT object as its SRT. With this
   patch we use the closure for `/=` as the SRT and add `==` there. Then
   `/=` gets an empty SRT field and `==` points to `/=` in its SRT
   field.

   This change looks fine to me.

   Main.o gets 0.07% larger, executable sizes are identical.

head.hackage
------------

head.hackage's CI script builds 428 packages from Hackage using this
patch with no failures.

Compiler performance
--------------------

The compiler perf tests report that the compiler allocates slightly more
(worst case observed so far is 4%). However most programs in the test
suite are small, single file programs. To benchmark compiler performance
on something more realistic I build Cabal (the library, 236 modules)
with different optimisation levels. For the "max residency" row I run
GHC with `+RTS -s -A100k -i0 -h` for more accurate numbers. Other rows
are generated with just `-s`. (This is because `-i0` causes running GC
much more frequently and as a result "bytes copied" gets inflated by
more than 25x in some cases)

* -O0

|                 | GHC HEAD       | This MR        | Diff   |
| --------------- | -------------- | -------------- | ------ |
| Bytes allocated | 54,413,350,872 | 54,701,099,464 | +0.52% |
| Bytes copied    |  4,926,037,184 |  4,990,638,760 | +1.31% |
| Max residency   |    421,225,624 |    424,324,264 | +0.73% |

* -O1

|                 | GHC HEAD        | This MR         | Diff   |
| --------------- | --------------- | --------------- | ------ |
| Bytes allocated | 245,849,209,992 | 246,562,088,672 | +0.28% |
| Bytes copied    |  26,943,452,560 |  27,089,972,296 | +0.54% |
| Max residency   |     982,643,440 |     991,663,432 | +0.91% |

* -O2

|                 | GHC HEAD        | This MR         | Diff   |
| --------------- | --------------- | --------------- | ------ |
| Bytes allocated | 291,044,511,408 | 291,863,910,912 | +0.28% |
| Bytes copied    |  37,044,237,616 |  36,121,690,472 | -2.49% |
| Max residency   |   1,071,600,328 |   1,086,396,256 | +1.38% |

Extra compiler allocations
--------------------------

Runtime allocations of programs are as reported above (NoFib section).

The compiler now allocates more than before. Main source of allocation
in this patch compared to base commit is the new SRT algorithm
(GHC.Cmm.Info.Build). Below is some of the extra work we do with this
patch, numbers generated by profiled stage 2 compiler when building a
pathological case (the test 'ManyConstructors') with '-O2':

- We now sort the final STG for a module, which means traversing the
  entire program, generating free variable set for each top-level
  binding, doing SCC analysis, and re-ordering the program. In
  ManyConstructors this step allocates 97,889,952 bytes.

- We now do SRT analysis on static data, which in a program like
  ManyConstructors causes analysing 10,000 bindings that we would
  previously just skip. This step allocates 70,898,352 bytes.

- We now maintain an SRT map for the entire module as we compile Cmm
  groups:

      data ModuleSRTInfo = ModuleSRTInfo
        { ...
        , moduleSRTMap :: SRTMap
        }

   (SRTMap is just a strict Map from the 'containers' library)

   This map gets an entry for most bindings in a module (exceptions are
   THUNKs and CAFFY static functions). For ManyConstructors this map
   gets 50015 entries.

- Once we're done with code generation we generate a NameSet from SRTMap
  for the non-CAFFY names in the current module. This set gets the same
  number of entries as the SRTMap.

- Finally we update CafInfos in ModDetails for the non-CAFFY Ids, using
  the NameSet generated in the previous step. This usually does the
  least amount of allocation among the work listed here.

Only place with this patch where we do less work in the CAF analysis in
the tidying pass (CoreTidy). However that doesn't save us much, as the
pass still needs to traverse the whole program and update IdInfos for
other reasons. Only thing we don't here do is the `hasCafRefs` pass over
the RHS of bindings, which is a stateless pass that returns a boolean
value, so it doesn't allocate much.

(Metric changes blow are all increased allocations)

Metric changes
--------------

Metric Increase:
    ManyAlternatives
    ManyConstructors
    T13035
    T14683
    T1969
    T9961

- - - - -
2a87a565 by Andreas Klebinger at 2020-01-31T12:21:10+03:00
A few optimizations in STG and Cmm parts:

(Guided by the profiler output)

- Add a few bang patterns, INLINABLE annotations, and a seqList in a few
  places in Cmm and STG parts.

- Do not add external variables as dependencies in STG dependency
  analysis (GHC.Stg.DepAnal).

- - - - -
bef704b6 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Improve skolemisation

This patch avoids skolemiseUnboundMetaTyVar making
up a fresh Name when it doesn't need to.

See Note [Skolemising and identity]

Improves error messsages for partial type signatures.

- - - - -
cd110423 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Improve pretty-printing for TyConBinders

In particular, show their kinds.

- - - - -
913287a0 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Fix scoping of TyCon binders in TcTyClsDecls

This patch fixes #17566 by refactoring the way we decide the final
identity of the tyvars in the TyCons of a possibly-recursive nest
of type and class decls, possibly with associated types.

It's all laid out in
  Note [Swizzling the tyvars before generaliseTcTyCon]

Main changes:

* We have to generalise each decl (with its associated types)
  all at once: TcTyClsDecls.generaliseTyClDecl

* The main new work is done in TcTyClsDecls.swizzleTcTyConBndrs

* The mysterious TcHsSyn.zonkRecTyVarBndrs dies altogether

Other smaller things:

* A little refactoring, moving bindTyClTyVars from tcTyClDecl1
  to tcDataDefn, tcSynRhs, etc.  Clearer, reduces the number of
  parameters

* Reduce the amount of swizzling required.
  Specifically, bindExplicitTKBndrs_Q_Tv doesn't need
    to clone a new Name for the TyVarTv, and not
    cloning means that in the vasly common case,
    swizzleTyConBndrs is a no-op

  In detail:
    Rename newTyVarTyVar --> cloneTyVarTyVar
    Add newTyVarTyTyVar that doesn't clone
    Use the non-cloning newTyVarTyVar in
       bindExplicitTKBndrs_Q_Tv
       Rename newFlexiKindedTyVarTyVar
           --> cloneFlexiKindedTyVarTyVar

* Define new utility function and use it
     HsDecls.familyDeclName ::
        FamilyDecl (GhcPass p) -> IdP (GhcPass p)

Updates haddock submodule.

- - - - -
58ed6c4a by Ben Gamari at 2020-02-01T02:29:23-05:00
rts/M32Alloc: Don't attempt to unmap non-existent pages

The m32 allocator's `pages` list may contain NULLs in the case that the
page was flushed. Some `munmap` implementations (e.g. FreeBSD's) don't
like it if we pass them NULL. Don't do that.

- - - - -
859db7d6 by Ömer Sinan Ağacan at 2020-02-01T14:18:49+03:00
Improve/fix -fcatch-bottoms documentation

Old documentation suggests that -fcatch-bottoms only adds a default
alternative to bottoming case expression, but that's not true. We use a
very simplistic "is exhaustive" check and add default alternatives to
any case expression that does not cover all constructors of the type. In
case of GADTs this simple check assumes all constructors should be
covered, even the ones ruled out by the type of the scrutinee.

Update the documentation to reflect this.

(Originally noticed in #17648)

[ci skip]

- - - - -
54dfa94a by John Ericson at 2020-02-03T21:14:24-05:00
Fix docs for FrontendResult

Other variant was removed in ac1a379363618a6f2f17fff65ce9129164b6ef30
but docs were no changed.

- - - - -
5e63d9c0 by John Ericson at 2020-02-03T21:15:02-05:00
Refactor HscMain.finish

I found the old control flow a bit hard to follow; I rewrote it to first
decide whether to desugar, and then use that choice when computing
whether to simplify / what sort of interface file to write.

I hope eventually we will always write post-tc interface files, which
will make the logic of this function even simpler, and continue the
thrust of this refactor.

- - - - -
e580e5b8 by Stefan Schulze Frielinghaus at 2020-02-04T09:29:00-05:00
Do not build StgCRunAsm.S for unregisterised builds

For unregisterised builds StgRun/StgReturn are implemented via a mini
interpreter in StgCRun.c and therefore would collide with the
implementations in StgCRunAsm.S.

- - - - -
e3b0bd97 by Stefan Schulze Frielinghaus at 2020-02-04T09:29:00-05:00
fixup! fixup! Do not build StgCRunAsm.S for unregisterised builds

- - - - -
eb629fab by John Ericson at 2020-02-04T09:29:38-05:00
Delete some superfluous helper functions in HscMain

The driver code is some of the nastiest in GHC, and I am worried about
being able to untangle all the tech debt. In `HscMain` we have a number
of helpers which are either not-used or little used. I delete them so we
can reduce cognative load, distilling the essential complexity away from
the cruft.

- - - - -
c90eca55 by Sebastian Graf at 2020-02-05T09:21:29-05:00
PmCheck: Record type constraints arising from existentials in `PmCoreCt`s

In #17703 (a follow-up of !2192), we established that contrary to my
belief, type constraints arising from existentials in code like

```hs
data Ex where Ex :: a -> Ex
f _ | let x = Ex @Int 15 = case x of Ex -> ...
```

are in fact useful.

This commit makes a number of refactorings and improvements to comments,
but fundamentally changes `addCoreCt.core_expr` to record the type
constraint `a ~ Int` in addition to `x ~ Ex @a y` and `y ~ 15`.

Fixes #17703.

- - - - -
6d3b5d57 by Ömer Sinan Ağacan at 2020-02-05T09:22:10-05:00
testlib: Extend existing *_opts in extra_*_opts

Previously we'd override the existing {run,hc} opts in
extra_{run,hc}_opts, which caused flakiness in T1969, see #17712.

extra_{run,hc}_opts now extends {run,hc} opts, instead of overriding.

Also we shrank the allocation area for T1969 in order to increase
residency sampling frequency.

Fixes #17712

- - - - -
9c89a48d by Ömer Sinan Ağacan at 2020-02-05T09:22:52-05:00
Remove CafInfo-related code from STG lambda lift pass

After c846618ae0 we don't have accurate CafInfos for Ids in the current
module and we're free to introduce new CAFFY or non-CAFFY bindings or
change CafInfos of existing binders; so no we no longer need to
maintain CafInfos in Core or STG passes.

- - - - -
70ddb8bf by Ryan Scott at 2020-02-05T09:23:30-05:00
Add regression test for #17773

- - - - -
e8004e5d by Ben Gamari at 2020-02-05T13:55:19-05:00
gitlab-ci: Allow Windows builds to fail again

Due to T7702 and the process issues described in #17777.
- - - - -
29b72c00 by Ben Gamari at 2020-02-06T11:55:41-05:00
VarSet: Introduce nonDetFoldVarSet

- - - - -
c4e6b35d by Ben Gamari at 2020-02-06T11:55:41-05:00
Move closeOverKinds and friends to TyCoFVs

- - - - -
ed2f0e5c by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Reform the free variable finders for types

This patch delivers on (much of) #17509.

* Introduces the shallow vs deep free variable distinction

* Introduce TyCoRep.foldType,
    foldType :: Monoid a => TyCoFolder env a
                         -> env -> Type -> a
  and use it in the free variable finders.

* Substitution in TyCoSubst
   * ASSERTs are on for checkValidSubst
   * checkValidSubst uses shallowTyCoVarsOfTypes etc

Quite a few things still to do

* We could use foldType in lots of other places

* We could use mapType for substitution.  (Check that we get
  good code!)

* Some (but not yet all) clients of substitution can now
  save time by using shallowTyCoVarsOfTypes

* All calls to tyCoVarsOfTypes should be inspected; most of
  them should be shallow.  Maybe.

* Currently shallowTyCoVarsOfTypes still returns
  unification variables, but not CoVarHoles.
  Reason: we need to return unification variables
  in some of the calls in TcSimplify, eg when promoting.

* We should do the same thing for tyCoFVsOfTypes, which is
  currently unchanged.

* tyCoFVsOfTypes returns CoVarHoles, because of the
  use in TcSimplify.mkResidualConstraints.  See
  Note [Emitting the residual implication in simplifyInfer]

* #17509 talks about "relevant" variables too.

- - - - -
01a1f4fb by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for noFreeVarsOfType

- - - - -
0e59afd6 by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Simplify closeOverKinds

- - - - -
9ca5c88e by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for coVarsOfType

- - - - -
5541b87c by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for exactTyCoVarsOfType

This entailed

* Adding a tcf_view field to TyCoFolder

* Moving exactTyCoVarsOtType to TcType.  It properly belongs
  there, since only the typechecker calls this function. But
  it also means that we can "see" and inline tcView.

Metric Decrease:
  T14683

- - - - -
7c122851 by Simon Peyton Jones at 2020-02-06T11:56:02-05:00
Comments only

- - - - -
588acb99 by Adam Sandberg Eriksson at 2020-02-08T10:15:38-05:00
slightly better named cost-centres for simple pattern bindings #17006

```
main = do
  print $ g [1..100] a
  where g xs x   = map (`mod` x) xs
        a :: Int = 324
```

The above program previously attributed the cost of computing 324 to a cost
centre named `(...)`, with this change the cost is attributed to `a` instead.

This change only affects simple pattern bindings (decorated variables: type
signatures, parens, ~ annotations and ! annotations).

- - - - -
309f8cfd by Richard Eisenberg at 2020-02-08T10:16:33-05:00
Remove unnecessary parentheses

- - - - -
7755ffc2 by Richard Eisenberg at 2020-02-08T10:16:33-05:00
Introduce IsPass; refactor wrappers.

There are two main payloads of this patch:

1. This introduces IsPass, which allows e.g. printing
   code to ask what pass it is running in (Renamed vs
   Typechecked) and thus print extension fields. See
   Note [IsPass] in Hs.Extension

2. This moves the HsWrap constructor into an extension
   field, where it rightly belongs. This is done for
   HsExpr and HsCmd, but not for HsPat, which is left
   as an exercise for the reader.

There is also some refactoring around SyntaxExprs, but this
is really just incidental.

This patch subsumes !1721 (sorry @chreekat).

Along the way, there is a bit of refactoring in GHC.Hs.Extension,
including the removal of NameOrRdrName in favor of NoGhcTc.
This meant that we had no real need for GHC.Hs.PlaceHolder, so
I got rid of it.

Updates haddock submodule.

-------------------------
Metric Decrease:
    haddock.compiler
-------------------------

- - - - -
7d452be4 by Dylan Yudaken at 2020-02-08T10:17:17-05:00
Fix hs_try_putmvar losing track of running cap

If hs_try_putmvar was called through an unsafe import, it would lose track of the running cap causing a deadlock

- - - - -
c2e301ae by Ben Gamari at 2020-02-08T10:17:55-05:00
compiler: Qualify imports of Data.List

- - - - -
aede171a by Ben Gamari at 2020-02-08T10:17:55-05:00
testsuite: Fix -Wcompat-unqualified-imports issues

- - - - -
4435a8e0 by Ben Gamari at 2020-02-08T10:17:55-05:00
Introduce -Wcompat-unqualified-imports

This implements the warning proposed in option (B) of the
Data.List.singleton CLC [discussion][].
This warning, which is included in `-Wcompat` is intended to help users
identify imports of modules that will change incompatibly in future GHC
releases. This currently only includes `Data.List` due to the expected
specialisation and addition of `Data.List.singleton`.

Fixes #17244.

[discussion]: https://groups.google.com/d/msg/haskell-core-libraries/q3zHLmzBa5E/PmlAs_kYAQAJ

- - - - -
28b5349a by Ben Gamari at 2020-02-08T10:17:55-05:00
Bump stm and process submodules

- - - - -
7d04b9f2 by Ben Gamari at 2020-02-08T10:18:31-05:00
hadrian: Allow override of Cabal configuration in hadrian.settings

Fixes #17612 by adding a `cabal.configure.opts` key for
`hadrian.settings`.

- - - - -
88bf81aa by Andreas Klebinger at 2020-02-08T10:19:10-05:00
Optimize unpackCString# to allocate less.

unpackCString# is a recursive function which for each iteration
returns a Cons cell containing the current Char, and a thunk for
unpacking the rest of the string.

In this patch we change from storing addr + offset inside this thunk
to storing only the addr, simply incrementing the address on each
iteration.

This saves one word of allocation per unpacked character.
For a program like "main = print "<largishString>" this amounts
to 2-3% fewer % in bytes allocated.

I also removed the now redundant local unpack definitions.
This removes one call per unpack operation.

- - - - -
bec76733 by Ben Gamari at 2020-02-08T10:19:57-05:00
Fix GhcThreaded setting

This adopts a patch from NetBSD's packaging fixing the `GhcThreaded`
option of the make build system. In addition we introduce a `ghcThreaded`
option in hadrian's `Flavour` type.

Also fix Hadrian's treatment of the `Use Threaded` entry in `settings`.
Previously it would incorrectly claim `Use Threaded = True` if we were
building the `threaded` runtime way. However, this is inconsistent with
the `make` build system, which defines it to be whether the `ghc`
executable is linked against the threaded runtime.

Fixes #17692.

- - - - -
545cf1e1 by Ben Gamari at 2020-02-08T10:20:37-05:00
hadrian: Depend upon libray dependencies when configuring packages

This will hopefully fix #17631.

- - - - -
047d3d75 by Ben Gamari at 2020-02-08T10:21:16-05:00
testsuite: Add test for #15316

This is the full testcase for T15316.

- - - - -
768e5866 by Julien Debon at 2020-02-08T10:22:07-05:00
doc(Data.List): Add some examples to Data.List

- - - - -
3900cb83 by Julien Debon at 2020-02-08T10:22:07-05:00
Apply suggestion to libraries/base/GHC/List.hs
- - - - -
bd666766 by Ben Gamari at 2020-02-08T10:22:45-05:00
users-guide: Clarify that bundled patsyns were introduced in GHC 8.0

Closes #17094.

- - - - -
95741ea1 by Pepe Iborra at 2020-02-08T10:23:23-05:00
Update to hie-bios 0.3.2 style program cradle

- - - - -
fb5c1912 by Sylvain Henry at 2020-02-08T10:24:07-05:00
Remove redundant case

This alternative is redundant and triggers no warning when building with 8.6.5

- - - - -
5d83d948 by Matthew Pickering at 2020-02-08T10:24:43-05:00
Add mkHieFileWithSource which doesn't read the source file from disk

cc/ @pepeiborra

- - - - -
dfdae56d by Andreas Klebinger at 2020-02-08T10:25:20-05:00
Rename ghcAssert to stgAssert in hp2ps/Main.h.

This fixes #17763
- - - - -
658f7ac6 by Ben Gamari at 2020-02-08T10:26:00-05:00
includes: Avoid using single-line comments in HsFFI.h

While single-line comments are supported by C99, dtrace on SmartOS
apparently doesn't support them yet.

- - - - -
c95920a6 by Ömer Sinan Ağacan at 2020-02-08T10:26:42-05:00
Import qualified Prelude in parser

This is in preparation of backwards-incompatible changes in happy.
See https://github.com/simonmar/happy/issues/166

- - - - -
b6dc319a by Ömer Sinan Ağacan at 2020-02-08T10:27:23-05:00
Add regression test for #12760

The bug seems to be fixed in the meantime, make sure it stays fixed.

Closes #12760

- - - - -
b3857b62 by Ben Gamari at 2020-02-08T10:28:03-05:00
base: Drop out-of-date comment

The comment in GHC.Base claimed that ($) couldn't be used in that module
as it was wired-in. However, this is no longer true; ($) is merely known
key and is defined in Haskell (with a RuntimeRep-polymorphic type) in
GHC.Base.

The one piece of magic that ($) retains is that it a special typing
rule to allow type inference with higher-rank types
(e.g. `runST $ blah`; see Note [Typing rule for ($)] in TcExpr).

- - - - -
1183ae94 by Daniel Gröber at 2020-02-08T10:29:00-05:00
rts: Fix Arena blocks accounting for MBlock sized allocations

When requesting more than BLOCKS_PER_MBLOCK blocks allocGroup can return a
different number of blocks than requested. Here we use the number of
requested blocks, however arenaFree will subtract the actual number of
blocks we got from arena_blocks (possibly) resulting in a negative value
and triggering ASSERT(arena_blocks >= 0).

- - - - -
97d59db5 by Daniel Gröber at 2020-02-08T10:29:48-05:00
rts: Fix need_prealloc being reset when retainer profiling is on

- - - - -
1f630025 by Krzysztof Gogolewski at 2020-02-09T02:52:27-05:00
Add a test for #15712

- - - - -
2ac784ab by Ben Gamari at 2020-02-09T02:53:05-05:00
hadrian: Add --test-metrics argument

Allowing the test metric output to be captured to a file, a la
the METRIC_FILE environment variable of the make build system.

- - - - -
f432d8c6 by Ben Gamari at 2020-02-09T02:53:05-05:00
hadrian: Fix --test-summary argument

This appears to be a cut-and-paste error.

- - - - -
a906595f by Arnaud Spiwack at 2020-02-09T02:53:50-05:00
Fix an outdated note link

This link appears to have been forgotten in
0dad81ca5fd1f63bf8a3b6ad09787559e8bd05c0 .

- - - - -
3ae83da1 by Alp Mestanogullari at 2020-02-09T02:54:28-05:00
hadrian: Windows fixes (bindists, CI)

This commit implements a few Windows-specific fixes which get us from a CI
job that can't even get as far as starting the testsuite driver, to a state
where we can run the entire testssuite (but have test failures to fix).

- Don't forget about a potential extension for the haddock program, when
  preparing the bindist.
- Build the timeout program, used by the testsuite driver on Windows in place
  of the Python script used elsewhere, using the boot compiler. We could
  alternatively build it with the compiler that we're going to test but this
  would be a lot more tedious to write.
- Implement a wrapper-script less installation procedure for Windows, in
  `hadrian/bindist/Makefile.
- Make dependencies a bit more accurate in the aforementioned Makefile.
- Update Windows/Hadrian CI job accordingly.

This patch fixes #17486.

- - - - -
82f9be8c by Roland Senn at 2020-02-09T02:55:06-05:00
Fix #14628: Panic (No skolem Info) in GHCi

This patch implements the [sugggestion from Simon (PJ)](https://gitlab.haskell.org/ghc/ghc/issues/14628#note_146559):
- Make `TcErrors.getSkolemInfo` return a `SkolemInfo` rather than an `Implication`.
- If `getSkolemInfo` gets `RuntimeUnk`s, just return a new data constructor in `SkolemInfo`, called `RuntimeUnkSkol`.
- In `TcErrors.pprSkols` print something sensible for a `RuntimeUnkSkol`.

The `getSkolemInfo` function paniced while formating suggestions to add type annotations (subfunction `suggestAddSig`)
to a *"Couldn't match type ‘x’ with ‘y’"* error message.
The `getSkolemInfo` function didn't find any Implication value and paniced.
With this patch the `getSkolemInfo` function does no longer panic, if it finds `RuntimeUnkSkol`s.

As the panic occured while processing an error message, we don't need to implement any new error message!

- - - - -
b2e18e26 by Andreas Klebinger at 2020-02-09T02:55:46-05:00
Fix -ddump-stg-final.

Once again make sure this dumps the STG used for codegen.

- - - - -
414e2f62 by Sylvain Henry at 2020-02-09T02:56:26-05:00
Force -fPIC for intree GMP (fix #17799)

Configure intree GMP with `--with-pic` instead of patching it. Moreover
the correct patching was only done for x86_64/darwin (see #17799).

- - - - -
f0fd72ee by Sebastian Graf at 2020-02-09T17:22:38-05:00
8.10 Release notes for improvements to the pattern-match checker [skip ci]

A little late to the game, but better late than never.

- - - - -
00dc0f7e by Ömer Sinan Ağacan at 2020-02-09T17:23:17-05:00
Add regression test for #13142

Closes #13142

- - - - -
f3e737bb by Sebastian Graf at 2020-02-10T20:04:09-05:00
Fix long distance info for record updates

For record updates where the `record_expr` is a variable, as in #17783:

```hs
data PartialRec = No
                | Yes { a :: Int, b :: Bool }
update No = No
update r@(Yes {}) = r { b = False }
```

We should make use of long distance info in
`-Wincomplete-record-updates` checking. But the call to `matchWrapper`
in the `RecUpd` case didn't specify a scrutinee expression, which would
correspond to the `record_expr` `r` here. That is fixed now.

Fixes #17783.

- - - - -
5670881d by Tamar Christina at 2020-02-10T20:05:04-05:00
Fs: Fix UNC remapping code.

- - - - -
375b3c45 by Oleg Grenrus at 2020-02-11T05:07:30-05:00
Add singleton to Data.OldList

- - - - -
de32beff by Richard Eisenberg at 2020-02-11T05:08:10-05:00
Do not create nested quantified constraints

Previously, we would accidentally make constraints like
forall a. C a => forall b. D b => E a b c as we traversed
superclasses. No longer!

This patch also expands Note [Eagerly expand given superclasses]
to work over quantified constraints; necessary for T16502b.

Close #17202 and #16502.

test cases: typecheck/should_compile/T{17202,16502{,b}}

- - - - -
e319570e by Ben Gamari at 2020-02-11T05:08:47-05:00
rts: Use nanosleep instead of usleep

usleep was removed in POSIX.1-2008.

- - - - -
b75e7486 by Ben Gamari at 2020-02-11T05:09:24-05:00
rts: Remove incorrect assertions around MSG_THROWTO messages

Previously we would assert that threads which are sending a
`MSG_THROWTO` message must have their blocking status be blocked on the
message. In the usual case of a thread throwing to another thread this
is guaranteed by `stg_killThreadzh`.  However, `throwToSelf`, used by
the GC to kill threads which ran out of heap, failed to guarantee this.

Noted while debugging #17785.

- - - - -
aba51b65 by Sylvain Henry at 2020-02-11T05:10:04-05:00
Add arithmetic exception primops (#14664)

- - - - -
b157399f by Ben Gamari at 2020-02-11T05:10:40-05:00
configure: Don't assume Gnu linker on Solaris

Compl Yue noticed that the linker was dumping the link map on SmartOS. This is
because Smartos uses the Solaris linker, which uses the `-64` flag, not
`-m64` like Gnu ld, to indicate that it should link for 64-bits. Fix the
configure script to handle the Solaris linker correctly.

- - - - -
d8d73d77 by Simon Peyton Jones at 2020-02-11T05:11:18-05:00
Notes only: telescopes

This documentation-only patch fixes #17793

- - - - -
58a4ddef by Alp Mestanogullari at 2020-02-11T05:12:17-05:00
hadrian: build (and ship) iserv on Windows

- - - - -
82023524 by Matthew Pickering at 2020-02-11T18:04:17-05:00
TemplateHaskellQuotes: Allow nested splices

There is no issue with nested splices as they do not require any compile
time code execution. All execution is delayed until the top-level
splice.

- - - - -
50e24edd by Ömer Sinan Ağacan at 2020-02-11T18:04:57-05:00
Remove Hadrian's copy of (Data.Functor.<&>)

The function was added to base with base-4.11 (GHC 8.4)

- - - - -
f82a2f90 by Sylvain Henry at 2020-02-12T01:56:46-05:00
Document GMP build [skip ci]

- - - - -
da7f7479 by Sylvain Henry at 2020-02-12T01:57:27-05:00
Module hierarchy: ByteCode and Runtime (cf #13009)

Update haddock submodule

- - - - -
04f51297 by Ömer Sinan Ağacan at 2020-02-12T01:58:11-05:00
Fix naming of tests for #12923

- - - - -
31fc3321 by Ömer Sinan Ağacan at 2020-02-12T01:58:11-05:00
Add regression test for #12926

Closes #12926

- - - - -
f0c0ee7d by Krzysztof Gogolewski at 2020-02-12T01:58:51-05:00
Fix order of arguments in specializer (#17801)

See https://gitlab.haskell.org/ghc/ghc/issues/17801#note_253330

No regression test, as it's hard to trigger.

- - - - -
059c3c9d by Sebastian Graf at 2020-02-12T11:00:58+01:00
Separate CPR analysis from the Demand analyser

The reasons for that can be found in the wiki:
https://gitlab.haskell.org/ghc/ghc/wikis/nested-cpr/split-off-cpr

We now run CPR after demand analysis (except for after the final demand
analysis run just before code gen). CPR got its own dump flags
(`-ddump-cpr-anal`, `-ddump-cpr-signatures`), but not its own flag to
activate/deactivate. It will run with `-fstrictness`/`-fworker-wrapper`.

As explained on the wiki page, this step is necessary for a sane Nested
CPR analysis. And it has quite positive impact on compiler performance:

Metric Decrease:
    T9233
    T9675
    T9961
    T15263

- - - - -
f5ffd8d9 by Ben Gamari at 2020-02-12T17:22:37-05:00
base: Expose GHC.Unicode.unicodeVersion

This exposes a Data.Version.Version representing the version of the
Unicode database used by `base`. This should clear up some confusion I
have seen in tickets regarding with which Unicode versions a given GHC
can be expected to work.

While in town I also regenerated (but did not update) the Unicode
database with database 12.0.0. Strangely, the file cited in the README
no longer existed. Consequently, I used
https://www.unicode.org/Public/12.0.0/ucd/UnicodeData.txt and was
slightly surprised to find that there were a few changes.

- - - - -
6c2585e0 by Ben Gamari at 2020-02-12T17:22:37-05:00
base: Update Unicode database to 12.1.0

Using `curl https://www.unicode.org/Public/12.1.0/ucd/UnicodeData.txt |
libraries/base/cbits/ubconfc 12.1.0`.

- - - - -
df084681 by Krzysztof Gogolewski at 2020-02-12T23:58:52+01:00
Always display inferred variables using braces

We now always show "forall {a}. T" for inferred variables,
previously this was controlled by -fprint-explicit-foralls.

This implements part 1 of https://github.com/ghc-proposals/ghc-proposals/pull/179.

Part of GHC ticket #16320.

Furthermore, when printing a levity restriction error, we now display
the HsWrap of the expression. This lets users see the full elaboration with
-fprint-typechecker-elaboration (see also #17670)

- - - - -
16d643cf by Sylvain Henry at 2020-02-13T09:16:04-05:00
Remove -ddump-srts flag

This flag is deemed not useful.

- - - - -
fa28ae95 by Sylvain Henry at 2020-02-13T09:16:04-05:00
Fix flag documentation (#17826)

- - - - -
1bfd8259 by Sylvain Henry at 2020-02-13T09:16:43-05:00
Ensure that Hadrian is built correctly before using it

When Hadrian failed to build, the script would pick a previously built
Hadrian (if available) instead of failing.

- - - - -
cd6e786a by Ömer Sinan Ağacan at 2020-02-14T05:29:56-05:00
Add test for #17648

- - - - -
9f2c3677 by Sylvain Henry at 2020-02-14T05:30:39-05:00
GMP expects the Target platform as --host parameter

- - - - -
aa6086fd by Oleg Grenrus at 2020-02-14T05:31:16-05:00
Add explicit LANGUAGE Safe to template-haskell


(cherry picked from commit a5e0f376821ca882880b03b07b451aa574e289ec)
- - - - -
af6a0c36 by Ben Gamari at 2020-02-14T05:31:53-05:00
hadrian: Add execution and target architecture to stage-compilation figure

- - - - -
cf739945 by Sylvain Henry at 2020-02-14T05:32:37-05:00
Module hierarchy: HsToCore (cf #13009)

- - - - -
719db318 by Simon Peyton Jones at 2020-02-14T05:33:16-05:00
De-duplicate overlapping Notes

Documentation only.  Fixes #17827

- - - - -
7550417a by Sylvain Henry at 2020-02-14T05:33:56-05:00
Hadrian: drop Sphinx flag checking for PDF documentation (#17825)

It seems that Sphinx produces the ghc-flags.txt in
doc/users_guide/_build rather than pdfRoot. We could copy ghc-flags.txt
into pdfRoot (like happens naturally in the HTML case) but the benefit
is pretty small. Let's just only check the HTML case.

- - - - -
813842f4 by Ben Gamari at 2020-02-14T10:16:36-05:00
make: Be more selective in building windows-extra-src tarball

- - - - -
0725f4bb by Ben Gamari at 2020-02-14T10:16:36-05:00
Rework handling of win32 toolchain tarballs

- - - - -
565ce7ae by Ben Gamari at 2020-02-14T10:16:36-05:00
gitlab-ci: Consolidate CI logic

This moves nearly all of the CI logic to .gitlab/ci.sh. This improves
things in a number of ways:

 * it's harder for inconsistencies to arise between architectures
 * it's easier to share logic between architectures
 * on Windows, it's easier to ensure that all CI steps are executed from
   within a properly initialized mingw session.

While in town I also add a FreeBSD build job and update the Windows job
to use the gitlab-runner PowerShell executor, since cmd.exe will be
deprecated soon (fixing #17699).

- - - - -
9cbace74 by Ben Gamari at 2020-02-14T10:16:36-05:00
gitlab-ci: Deduplicate nightly job configuration

- - - - -
6e837144 by Ben Gamari at 2020-02-14T10:16:36-05:00
integer-gmp: Fix unused command-line argument

-L is only needed during linking.

- - - - -
e5ee07ab by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Don't ask sed to operate in-place on symlinks

Some sed implementations (e.g. FreeBSD) refuse to operate in-place on
symlinks.

- - - - -
71e5e68f by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Disable tests that assume name of libstdc++ on FreeBSD

- - - - -
7b2da0f4 by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Mark T6132 as broken on FreeBSD

- - - - -
8ef7a15a by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite/T16930: Don't rely on gnu grep specific --include

In BSD grep this flag only affects directory recursion.

- - - - -
6060003e by Ben Gamari at 2020-02-14T10:16:36-05:00
Pass -Wno-unused-command-line-arguments during link on FreeBSD

FreeBSD cc throws a warning if we pass -pthread without actually using
any pthread symbols.

- - - - -
97497bae by Ben Gamari at 2020-02-14T10:16:36-05:00
base: Always clamp reads/writes to 2GB in length

Previously we did this only on Darwin due to #17414. However, even on
other platforms >2GB writes are on shaky ground. POSIX explicitly says
that the result is implementation-specified and Linux will write at most
0x7ffff000, even on 64-bit platforms. Moreover, getting the sign
of the syscall result correct is tricky, as demonstrated by the fact
that T17414 currently fails on FreeBSD.

For simplicity we now just uniformly clamp to 0x7ffff000 on all
platforms.

- - - - -
49be2a3f by Ben Gamari at 2020-02-14T10:16:36-05:00
configure: Fix sphinx version test

The check for the "v" prefix is redundant.

- - - - -
f7f7a556 by Ben Gamari at 2020-02-14T10:16:37-05:00
users-guide: Fix unknown link targets

- - - - -
a204102c by Ben Gamari at 2020-02-14T10:16:37-05:00
docs/compare-flags: Don't use python f-strings

- - - - -
92e15a37 by Ben Gamari at 2020-02-14T10:16:37-05:00
gitlab-ci: Fix various shellcheck warnings

- - - - -
459f7c6e by Ben Gamari at 2020-02-14T10:16:37-05:00
hadrian: Drop empty arguments from target list

Fixes #17748.

- - - - -
c06df28d by Ben Gamari at 2020-02-14T10:16:37-05:00
users-guide: Fix "invalid file" failure

I have no idea how this worked previously. Different Python version?

- - - - -
3fe8444f by Ben Gamari at 2020-02-14T10:16:59-05:00
testsuite: Mark T7702 as fragile on Windows

Due to #16799. There was previously an attempt to mark it as broken but
the `opsys` name was incorrect.

- - - - -
fe02f781 by Ben Gamari at 2020-02-14T10:16:59-05:00
testsuite: Assert the opsys names are known

Previously opsys would take any string. This meant it was very easy for
a typo to silently render the predicate ineffective. Fix this by
checking the given operating system name against a list of known values.

- - - - -
149e2a3a by Ben Gamari at 2020-02-14T10:16:59-05:00
compare-flags: Don't rely on encoding flag of subprocess.check_output

Apparently it isn't supported by some slightly older Python versions.

- - - - -
798d59f6 by Ben Gamari at 2020-02-14T10:16:59-05:00
rts: Add more debug output to failed path in onIOComplete

This will help track down #17035.

- - - - -
e35f3f98 by Ben Gamari at 2020-02-14T10:16:59-05:00
gitlab-ci: Allow i386 Windows builds to fail again

Due to the resistance of #17736 to resolution.

- - - - -
261a3cf8 by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Build integer-simple job in the validate flavour

- - - - -
b613a961 by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Always use mingw64 python on Windows

- - - - -
1bc8c8cd by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Allow Windows build to fail due to #17777

The fact that `exec` isn't POSIX compliant means that things can break
in arbitrarily bad ways. Sometimes things happen to work correctly but
sadly this isn't always the case.

- - - - -
ac63020d by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Drop unnecessary GHC_VERSION check

- - - - -
6926f369 by Ben Gamari at 2020-02-14T10:17:00-05:00
Bump process submodule

Folds in the second part of Phyx's Windows process exit fixes [1],
hopefully finally resolving issue #17480.

[1] https://github.com/haskell/process/pull/160

- - - - -
584eee71 by Tamar Christina at 2020-02-14T10:17:00-05:00
SysTools: Use "process job" when spawning processes on Windows

GHC should make calls using process jobs when calling out to GCC and LD.
The reason is these use the exec () family of posix functions.  Window's
process model doesn't allow replacement of processes so this is emulated
by creating a new process and immediately exiting the old one.  Because
of this when using normal Windows wait functions you would return even
without the child process having finished.  In this case if you are
depending on data from the child you will enter a race condition.

The usual fix for this is to use process jobs and wait for the
termination of all children that have ever been spawn by the process you
called. But also waiting for the freeing of all resources.

- - - - -
ecabfa28 by Tamar Christina at 2020-02-14T10:17:00-05:00
Revert "compiler: Disable atomic renaming on Windows"

The original reason this was disabled should be fixed by the previous
commit.

This reverts commit 1c1b63d63efe8b0f789aa7d5b87cfac3edd213eb.

- - - - -
06d60c66 by Ben Gamari at 2020-02-14T10:17:00-05:00
Bump Cabal submodule

- - - - -
8cabb384 by Ben Gamari at 2020-02-14T10:17:00-05:00
compare-flags: Fix output

- - - - -
8cf646d3 by Ben Gamari at 2020-02-14T10:17:00-05:00
users-guide: Document -ddump-srts

- - - - -
932307a5 by Ben Gamari at 2020-02-14T10:17:00-05:00
users-guide: Fix broken reference

- - - - -
e77818de by Ben Gamari at 2020-02-15T09:26:55-05:00
Accept performance changes

These manifested in the integer-simple job.

Metric Decrease:
    T12227
    T5549
    T14936
    T4830
    Conversions
    T5237
    T8766
    T4801
    T10359

Metric Increase:
    T12234
    T6048
    T3294
    T14683
    T3064
    T9872b
    T9872c
    T783
    T5837
    T10678
    T14697
    T5631
    T9203
    T13719
    T12707
    T13056
    T9630
    T10547
    T9872d
    T1969
    WWRec
    T10370
    T5321FD
    haddock.Cabal
    T5642
    T9872a
    T15263
    T12425
    MultiLayerModules
    T5205
    T9233
    T13379
    haddock.base
    T9020
    T13035
    T12150
    T9961

- - - - -
785008c1 by Ben Gamari at 2020-02-15T09:30:13-05:00
testsuite: Sort test names in expected change output

- - - - -
9e851472 by Ömer Sinan Ağacan at 2020-02-16T10:38:41+03:00
Revert "users-guide: Document -ddump-srts"

This reverts commit 8cf646d36b02b8ea1c289cb52781c9171853b514.

The flag was removed by 16d643cf.

[ci skip]

- - - - -
9792c816 by Ben Gamari at 2020-02-16T09:47:08-05:00
testsuite: Probe whether symlinks are usable on Windows

Closes #17706.

- - - - -
ee1e5342 by Vladislav Zavialov at 2020-02-16T09:47:44-05:00
Fix the "unused terminals: 2" warning in Parser.y

- - - - -
b4a8ce52 by Roland Senn at 2020-02-18T20:14:42-05:00
If a :reload finds syntax errors in the module graph, remove the loaded modules. (Fixes #17549)

The processing in `compiler/main/GhcMake.hs` computes the ModuleGraph. If it finds errors
in the module header or in the import specifications, then the new module graph is
incomplete and should not be used.
The code before #17549 just reported the errors and left the old ModuleGraph in place.
The new code of this MR replaces the old ModuleGraph with an empty one.

- - - - -
d7029cc0 by Sylvain Henry at 2020-02-18T20:15:30-05:00
Hadrian: refactor GMP in-tree build support (#17756)

* Hadrian doesn't use integer-gmp/config.mk file anymore to determine if
  building GMP in-tree is required.

  "config.mk" is created by Cabal when the integer-gmp package is
  configured and this file is still untracked by Hadrian. This led to a
  tricky configure "race" because "config.mk" is built by the
  "setup-config" rule, but this rule is also used to find dependencies,
  in particular the "ghc-gmp.h" header, but the creation of this file
  was depending (without being tracked) on "config.mk".

  Now Hadrian only builds in-tree GMP if `--with-intree-gmp` is passed
  to the top-level configure script.

* in-tree GMP isn't built once for all in a fixed stage (Stage1)
  anymore. It is built per stage which is required if we build a
  cross-compiler

* switching between in-tree and external GMP is now supported without
  having to clean the build directory first.

* "wrappers.c" now includes "ghc-gmp.h" instead of "ghc.h". It
  helps ensuring that the build system generates "ghc-gmp.h".

* build in-tree GMP in "<root>/stageN/gmp/gmpbuild" and produce useful
  artefacts (libgmp.a, gmp.h, objs/*.o) in "<root>/stageN/gmp"

- - - - -
40d917fb by Vladislav Zavialov at 2020-02-18T20:16:07-05:00
Remove the MonadFail P instance

There were two issues with this instance:

* its existence meant that a pattern match failure in the P monad would
  produce a user-visible parse error, but the error message would not be
  helpful to the user

* due to the MFP migration strategy, we had to use CPP in Lexer.x,
  and that created issues for #17750

Updates haddock submodule.

- - - - -
5a1ce45d by Joshua Price at 2020-02-18T20:16:47-05:00
Fix unboxed tuple size limit (#17837)

- - - - -
192caf58 by Vladislav Zavialov at 2020-02-18T20:17:24-05:00
Fix testsuite driver output (#17847)

- - - - -
1500f089 by Sylvain Henry at 2020-02-18T20:18:12-05:00
Modules: Llvm (#13009)

- - - - -
d53e81c0 by Niklas Hambüchen at 2020-02-20T10:36:22-05:00
8.10 Release notes for atomic .o writes [skip ci]

- - - - -
19680ee5 by Niklas Hambüchen at 2020-02-20T10:37:53-05:00
8.10 Release notes for --disable-delayed-os-memory-return [skip ci]

- - - - -
74ad75e8 by Simon Peyton Jones at 2020-02-20T21:17:57-05:00
Re-implement unsafe coercions in terms of unsafe equality proofs

(Commit message written by Omer, most of the code is written by Simon
and Richard)

See Note [Implementing unsafeCoerce] for how unsafe equality proofs and
the new unsafeCoerce# are implemented.

New notes added:

- [Checking for levity polymorphism] in CoreLint.hs
- [Implementing unsafeCoerce] in base/Unsafe/Coerce.hs
- [Patching magic definitions] in Desugar.hs
- [Wiring in unsafeCoerce#] in Desugar.hs

Only breaking change in this patch is unsafeCoerce# is not exported from
GHC.Exts, instead of GHC.Prim.

Fixes #17443
Fixes #16893

NoFib
-----

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             FS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
              S          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             VS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            VSD          -0.1%      0.0%     -0.0%     -0.0%     -0.1%
            VSM          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           anna          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           ansi          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           atom          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         awards          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         banner          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     bernouilli          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   binary-trees          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         boyer2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           bspt          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      cacheprof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       calendar          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       cichelli          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        circsim          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       clausify          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
  comp_lab_zift          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       compress          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      compress2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            cse          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          eliza          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          event          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         exp3_8          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         expert          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
 fannkuch-redux          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          fasta          -0.1%      0.0%     -0.5%     -0.3%     -0.4%
            fem          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            fft          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           fft2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           fish          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          fluid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         fulsom          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
         gamteb          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            gcd          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    gen_regexps          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         genfft          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             gg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           grep          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         hidden          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            hpg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            ida          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          infer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        integer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   k-nucleotide          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        knights          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         lambda          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     last-piece          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           life          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           lift          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         linear          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      listcompr          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         mandel          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        mandel2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           mate          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        minimax          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        mkhprog          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     multiplier          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         n-body          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       nucleic2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           para          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      paraffins          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         parser          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        parstof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            pic          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       pidigits          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         pretty          -0.1%      0.0%     -0.1%     -0.1%     -0.1%
         primes          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      primetest          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         prolog          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         puzzle          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         queens          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        reptile          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
reverse-complem          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           rfib          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            rsa          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            scc          -0.1%      0.0%     -0.1%     -0.1%     -0.1%
          sched          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            scs          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         simple          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          solid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        sorting          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
  spectral-norm          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         symalg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            tak          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      transform          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       treejoin          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      typecheck          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        veritas          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           wang          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      wave4main          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           x2n1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.5%     -0.3%     -0.4%
            Max          -0.0%      0.0%     +0.0%     +0.0%     +0.0%
 Geometric Mean          -0.1%     -0.0%     -0.0%     -0.0%     -0.0%

Test changes
------------

- break006 is marked as broken, see #17833
- The compiler allocates less when building T14683 (an unsafeCoerce#-
  heavy happy-generated code) on 64-platforms. Allocates more on 32-bit
  platforms.
- Rest of the increases are tiny amounts (still enough to pass the
  threshold) in micro-benchmarks. I briefly looked at each one in a
  profiling build: most of the increased allocations seem to be because
  of random changes in the generated code.

Metric Decrease:
    T14683

Metric Increase:
    T12150
    T12234
    T12425
    T13035
    T14683
    T5837
    T6048

Co-Authored-By: Richard Eisenberg <rae at cs.brynmawr.edu>
Co-Authored-By: Ömer Sinan Ağacan <omeragacan at gmail.com>

- - - - -
6880d6aa by Sylvain Henry at 2020-02-20T21:18:48-05:00
Disentangle DynFlags and SDoc

Remove several uses of `sdocWithDynFlags`. The remaining ones are mostly
CodeGen related (e.g. depend on target platform constants) and will be
fixed separately.

Metric Decrease:
   T12425
   T9961
   WWRec
   T1969
   T14683

- - - - -
70a90110 by Julien Debon at 2020-02-20T21:19:27-05:00
doc(List): Add examples to GHC.List

* Add examples
* Cleanup documentation
* Clarify merge process and Marge bot

- - - - -
c8439fc7 by Peter Trommler at 2020-02-20T21:20:05-05:00
Fix testsuite on powerpc64le

Remove expect broken on recomp tests, #11260 was closed
by !2264 and #11323 most likely by !2264 as well.

GHCi scripts tests work on GHCi but not the external interpreter,
adjust test configuration accordingly. Fixes unexpected passes.

Mark test requiring DWARF expect fail on powerpc64[le] for #11261.

- - - - -
65b7256a by Ömer Sinan Ağacan at 2020-02-20T21:20:45-05:00
Use concatMap(M) instead of `concat . map` and the monadic variant

- - - - -
8b76d457 by Roland Senn at 2020-02-20T21:21:28-05:00
Fix #17832: Weird handling of exports named main in 8.10-rc1

Switching from `lookupGlobalOccRn_maybe` to `lookupInfoOccRn`
to check whether a `main` function is in scope. Unfortunately
`lookupGlobalOccRn_maybe` complains if there are multiple `main`
functions in scope.

- - - - -
466e1ad5 by Krzysztof Gogolewski at 2020-02-20T21:22:11-05:00
Use TTG for HsSplicedT constructor

The constructor HsSplicedT occurs only in the GhcTc pass.
This enforces this fact statically via TTG.

- - - - -
4e622fca by Alexis King at 2020-02-20T21:22:49-05:00
Normalize types when dropping absent arguments from workers

fixes #17852

- - - - -
a533e547 by Adam Sandberg Eriksson at 2020-02-20T21:23:31-05:00
Mention users guide and release notes in merge request template
- - - - -
05251b17 by Ben Gamari at 2020-02-20T21:24:08-05:00
gitlab-ci: Fix typo in BIN_DIST_PREP_TAR_COMP variable name
- - - - -
f44c7e67 by Ben Gamari at 2020-02-20T21:24:46-05:00
gitlab-ci: Avoid duplicating ~/.cabal contents with every build

Previously our attempt to cache the cabal store would
`cp cabal-cache ~/.cabal`. However, if the latter already
 existed this meant that we would end up with
~/.cabal/cabal-cache. Not only would this not help caching
but it would exponentially grow the size of ~/.cabal. Not
good!
- - - - -
c5ec9965 by Ben Gamari at 2020-02-20T21:56:13-05:00
GHC.Hs.Extension: Use Type instead of *

- - - - -
89cb4cc4 by Ben Gamari at 2020-02-20T21:56:13-05:00
Use Type instead of * in GHC

- - - - -
04eb0d6c by Ben Gamari at 2020-02-20T21:56:13-05:00
Enable -Wstar-is-type in -Wall

As noted in [proposal 0143][proposal] this is supposed to happen in
8.12.

Also fix an incorrect claim in the users guide that -Wstar-is-type is
enabled by default.

[proposal]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0143-remove-star-kind.rst

- - - - -
6de966f1 by Andreas Klebinger at 2020-02-20T21:56:15-05:00
Fix #17724 by having occAnal preserve used bindings.

It sometimes happened that occAnal would remove bindings
as dead code by relying on bindings to be in dependency
order. The fix was contributed by SPJ.

- - - - -
abd7f962 by Ben Gamari at 2020-02-20T21:56:15-05:00
users-guide: Mention dependency on `exceptions` in release notes

Fixes #17845.

- - - - -
58175379 by Sylvain Henry at 2020-02-20T21:56:20-05:00
Hadrian: minor GMP refactoring

Somehow I forgot to totally remove `gmpContext` in
d7029cc09edc052c2f97effe33233c53340fcce0. This patch fixes it and adds
some additional comments.

- - - - -
33fa8d94 by Ryan Scott at 2020-02-20T21:56:21-05:00
Generalize liftData to work over any Quote (#17857)

The Overloaded Quotations proposal generalized the type of `lift`
to work over any `Quote`, but not the type of `liftData`, leading
to #17857. Thankfully, generalizing `liftData` is extremely
straightforward.

Fixes #17857.

- - - - -
3cea6795 by Sylvain Henry at 2020-02-20T21:56:23-05:00
Make: fix sdist target (#17848)

- - - - -
e2cce997 by Sylvain Henry at 2020-02-20T21:56:23-05:00
Hadrian: fix source-dist target (#17849)

- - - - -
0a4c89b2 by Matthew Pickering at 2020-02-21T20:44:45-05:00
Special case `mkTyConApp liftedTypeKind []`

We really need to make sure that these are shared because otherwise GHC
will allocate thousands of identical `TyConApp` nodes.

See #17292

-------------------------
Metric Decrease:
    haddock.Cabal
    T14683
-------------------------

- - - - -
0482f58a by Matthew Pickering at 2020-02-21T20:45:21-05:00
TH: wrapGenSyns, don't split the element type too much

The invariant which allowed the pervious method of splitting the type of
the body to find the type of the elements didn't work in the new
overloaded quotation world as the type can be something like
`WriterT () m a` rather than `Q a` like before.

Fixes #17839

- - - - -
be7068a6 by Vladislav Zavialov at 2020-02-21T20:45:59-05:00
Parser API annotations: RealSrcLoc

During parsing, GHC collects lexical information about AST nodes and
stores it in a map. It is needed to faithfully restore original source
code, e.g. compare these expressions:

	a =  b
	a  = b

The position of the equality sign is not recorded in the AST, so it must
be stored elsewhere.

This system is described in Note [Api annotations].

Before this patch, the mapping was represented by:

	Map (SrcSpan, AnnKeywordId) SrcSpan

After this patch, the mapping is represented by:

	Map (RealSrcSpan, AnnKeywordId) RealSrcSpan

The motivation behind this change is to avoid using the Ord SrcSpan
instance (required by Map here), as it interferes with #17632 (see the
discussion there).

SrcSpan is isomorphic to  Either String RealSrcSpan,  but we shouldn't
use those strings as Map keys. Those strings are intended as hints to
the user, e.g. "<interactive>" or "<compiler-generated code>", so they
are not a valid way to identify nodes in the source code.

- - - - -
240f5bf6 by Sylvain Henry at 2020-02-21T20:46:40-05:00
Modules: Driver (#13009)

submodule updates: nofib, haddock

- - - - -
9d094111 by Sylvain Henry at 2020-02-21T20:47:19-05:00
Hadrian: `docs` rule needs `configure` (#17840)

- - - - -
1674353a by Ben Gamari at 2020-02-23T17:31:19-05:00
fs: Port fixes from ghc-jailbreak repository

* Override rename, unlink, and remove
* Factor out wchar conversion

- - - - -
853210f2 by Adam Sandberg Ericsson at 2020-02-23T17:32:03-05:00
show gcc linker options in configure summary

- - - - -
2831544a by Adam Sandberg Ericsson at 2020-02-23T17:32:44-05:00
hadrian: docs depend on stage1 ghc

- - - - -
1d9df9e0 by Adam Sandberg Ericsson at 2020-02-23T17:33:23-05:00
ci: after 5ce63d52fed the linux bindist for doc-tarball has changed name

- - - - -
26e8fff3 by Vladislav Zavialov at 2020-02-24T02:05:30-05:00
Remove Ord SrcLoc, Ord SrcSpan

Before this patch, GHC relied on Ord SrcSpan to identify source elements, by
using SrcSpan as Map keys:

	blackList :: Map SrcSpan ()      -- compiler/GHC/HsToCore/Coverage.hs
	instanceMap :: Map SrcSpan Name  -- compiler/GHC/HsToCore/Docs.hs

Firstly, this design is not valid in presence of UnhelpfulSpan, as it
distinguishes between  UnhelpfulSpan "X"  and  UnhelpfulSpan "Y", but those
strings are messages for the user, unfit to serve as identifiers for source
elements.

Secondly, this design made it hard to extend SrcSpan with additional data.
Recall that the definition of SrcSpan is:

	data SrcSpan =
	    RealSrcSpan !RealSrcSpan
	  | UnhelpfulSpan !FastString

Say we want to extend the RealSrcSpan constructor with additional information:

	data SrcSpan =
	    RealSrcSpan !RealSrcSpan !AdditionalInformation
	  | UnhelpfulSpan !FastString

	getAdditionalInformation :: SrcSpan -> AdditionalInformation
	getAdditionalInformation (RealSrcSpan _ a) = a

Now, in order for  Map SrcSpan  to keep working correctly, we must *ignore* additional
information when comparing SrcSpan values:

	instance Ord SrcSpan where
	  compare (RealSrcSpan r1 _) (RealSrcSpan r2 _) = compare r1 r2
	  ...

However, this would violate an important law:

	a == b  therefore  f a == f b

Ignoring  AdditionalInformation  in comparisons would mean that with
f=getAdditionalInformation, the law above does not hold.

A more robust design is to avoid  Ord SrcSpan  altogether, which is what this patch implements.
The mappings are changed to use RealSrcSpan instead:

	blackList :: Set RealSrcSpan         -- compiler/GHC/HsToCore/Coverage.hs
	instanceMap :: Map RealSrcSpan Name  -- compiler/GHC/HsToCore/Docs.hs

All SrcSpan comparisons are now done with explicit comparison strategies:

	SrcLoc.leftmost_smallest
	SrcLoc.leftmost_largest
	SrcLoc.rightmost_smallest

These strategies are not subject to the law mentioned above and can easily
discard both the string stored in  UnhelpfulSpan  and  AdditionalInformation.

Updates haddock submodule.

- - - - -
5aa6c188 by Ben Gamari at 2020-02-24T02:06:09-05:00
users-guide: Shuffle text

- - - - -
e3f17413 by Ben Gamari at 2020-02-24T02:06:09-05:00
users-guide: Drop old release notes

- - - - -
84dd9610 by Ben Gamari at 2020-02-24T02:06:09-05:00
Bump directory submodule to 1.3.6.0

- - - - -
e295a024 by Stefan Pavikevik at 2020-02-24T20:53:44-05:00
check for safe arguments, raising error when invalid (fix #17720)

- - - - -
354e2787 by Krzysztof Gogolewski at 2020-02-24T20:54:35-05:00
Comments, small refactor

* Remove outdated Note [HsForAllTy tyvar binders] and [Context quantification].
  Since the wildcard refactor 1e041b7382, HsForAllTy no longer has an flag
  controlling explicity. The field `hsq_implicit` is gone too.
  The current situation is covered by Note [HsType binders] which is already
  linked from LHsQTyVars.
* Small refactor in CoreLint, extracting common code to a function
* Remove "not so sure about WpFun" in TcEvidence, per Richard's comment
  https://gitlab.haskell.org/ghc/ghc/merge_requests/852#note_223226
* Use mkIfThenElse in Foreign/Call, as it does exactly what we need.

- - - - -
1b1067d1 by Sylvain Henry at 2020-02-24T20:55:25-05:00
Modules: CmmToAsm (#13009)

- - - - -
621468f6 by Alexis King at 2020-02-26T15:08:09-05:00
Treat coercions as arguments for floating and inlining

This reverts commit 8924224ecfa065ebc67b96a90d01cf9d2edd0e77
and fixes #17787.

- - - - -
def486c9 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Allow libnuma library path to be specified

- - - - -
ed03d4e7 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Refactor gmp arguments

Move the gmp configuration to its own binding.

- - - - -
09b88384 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Tell Cabal about integer-gmp library location

- - - - -
161e08c5 by Krzysztof Gogolewski at 2020-02-26T15:09:30-05:00
Remove dead code

* FailablePattern can no longer be created since ab51bee40c82
  Therefore, Opt_WarnMissingMonadFailInstances has no effect anymore.
* XWrap is no longer used, it was moved to an extension field

- - - - -
e0d09db3 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Use 8.8.3 to bootstrap on Windows

This should fix #17861.

- - - - -
972bcf3a by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Fix symlink test

Needs to `write` bytes, not str.

- - - - -
273e60de by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Add shell subcommand for debugging within CI environment

- - - - -
43b13ed3 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Fix colors on Darwin

Darwin sh doesn't support \e.

- - - - -
217546a7 by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Flush stdout buffers in InitEventLogging

Otherwise we are sensitive to libc's buffering strategy.
Similar to the issue fixed in 543dfaab166c81f46ac4af76918ce32190aaab22.

- - - - -
c7d4fa55 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Add run_hadrian subcommand

I've ruined two trees already by failing to pass --flavour to hadrian.
Let's factor this out so it can be reused during troubleshooting.

- - - - -
7dc54873 by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Allow tests to be marked as broken on the command line

This allows us to work-around distribution-specific breakage easily.

- - - - -
25e2458e by Ben Gamari at 2020-02-26T15:10:09-05:00
hadrian: Add --broken-test flag

This exposes the flag of the same name supported by the testsuite
driver.

- - - - -
55769996 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Mark some tests as broken on Alpine

- - - - -
9ee7f87d by Ben Gamari at 2020-02-26T15:10:09-05:00
SysTools: Don't use process jobs if they are broken

- - - - -
bfaa3961 by Ben Gamari at 2020-02-26T15:10:09-05:00
Bump hsc2hs submodule

Fixes name of C compiler.

- - - - -
b2b49a0a by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Make hasMetricsFile RHS more descriptive

- - - - -
817f93ea by Sylvain Henry at 2020-02-26T15:10:58-05:00
Modules: Core (#13009)

Update haddock submodule

- - - - -
74311e10 by Sebastian Graf at 2020-02-27T16:22:45-05:00
PmCheck: Implement Long-distance information with Covered sets

Consider

```hs
data T = A | B | C

f :: T -> Int
f A = 1
f x = case x of
  A -> 2
  B -> 3
  C -> 4
```

Clearly, the RHS returning 2 is redundant. But we don't currently see
that, because our approximation to the covered set of the inner case
expression just picks up the positive information from surrounding
pattern matches. It lacks the context sensivity that `x` can't be `A`
anymore!

Therefore, we adopt the conceptually and practically superior approach
of reusing the covered set of a particular GRHS from an outer pattern
match. In this case, we begin checking the `case` expression with the
covered set of `f`s second clause, which encodes the information that
`x` can't be `A` anymore. After this MR, we will successfully warn about
the RHS returning 2 being redundant.

Perhaps surprisingly, this was a great simplification to the code of
both the coverage checker and the desugarer.

Found a redundant case alternative in `unix` submodule, so we have to
bump it with a fix.

Metric Decrease:
    T12227

- - - - -
59c023ba by Adam Sandberg Ericsson at 2020-02-27T16:23:25-05:00
configure: correctly generate LIBRARY_template_haskell_VERSION

- - - - -
9be82389 by Krzysztof Gogolewski at 2020-02-28T02:35:35-05:00
boot: Remove remote origin check

Previously, we used relative paths in submodules. When cloning from
GitHub, they had to be manually tweaked.
Since a76b233d we use absolute paths, so this workaround can be removed.

- - - - -
f4b6b594 by Ben Gamari at 2020-02-28T02:36:12-05:00
nonmoving: Fix marking in compact regions

Previously we were tracing the object we were asked to mark, even if it
lives in a compact region. However, there is no need to do this; we need
only to mark the region itself as live.

I have seen a segfault due to this due to the concurrent mark seeing a
an object in the process of being compacted by the mutator.

- - - - -
f97d1fb6 by Alp Mestanogullari at 2020-02-28T02:36:59-05:00
base: use an explicit import list in System.Environment.ExecutablePath

This was making -Werror builds fail on Windows (at least with Hadrian).

- - - - -
66f5d6d6 by Simon Peyton Jones at 2020-02-28T22:03:23-05:00
Improve error handling for VTA + deferred type errors

This fixes #17792

See Note [VTA for out-of-scope functions] in TcExpr

- - - - -
37f12603 by Ilias Tsitsimpis at 2020-02-28T22:04:04-05:00
llvm-targets: Add arm-unknown-linux-gnueabi

Add arm-unknown-linux-gnueabi, which is used by Debian's ARM EABI port
(armel), as an LLVM target.

- - - - -
327b29e1 by Vladislav Zavialov at 2020-02-29T05:06:31-05:00
Monotonic locations (#17632)

When GHC is parsing a file generated by a tool, e.g. by the C preprocessor, the
tool may insert #line pragmas to adjust the locations reported to the user.

As the result, the locations recorded in RealSrcLoc are not monotonic. Elements
that appear later in the StringBuffer are not guaranteed to have a higher
line/column number.

In fact, there are no guarantees whatsoever, as #line pragmas can arbitrarily
modify locations. This lack of guarantees makes ideas such as #17544
infeasible.

This patch adds an additional bit of information to every SrcLoc:

	newtype BufPos = BufPos { bufPos :: Int }

A BufPos represents the location in the StringBuffer, unaffected by any
pragmas.

Updates haddock submodule.

Metric Increase:
    haddock.Cabal
    haddock.base
    haddock.compiler
    MultiLayerModules
    Naperian
    parsing001
    T12150

- - - - -
99d2de86 by Ben Gamari at 2020-02-29T05:07:10-05:00
plugins: Ensure that loadInterface plugins can see annotations

loadInterface replaces the `mi_decls`, `mi_insts`, `mi_fam_insts`,
`mi_rules`, `mi_anns` fields of ModIface with `undefined` before
inserting the interface into the EPS. However, we still want to give
loadInterface plugins access to these fields. Consequently, we want to
pass the unmodified `ModIface` the plugin.

- - - - -
a999ee96 by Xavier Denis at 2020-02-29T05:07:50-05:00
Rename ghci.sh and build.sh to ghci and build respectively

Convert hadrian buildscripts to unsuffixed, dashed form

final cleanups

- - - - -
b5fb58fd by Ömer Sinan Ağacan at 2020-02-29T05:08:36-05:00
Document and refactor a few things around bitmap scavenging

- Added a few comments in StgPAP
- Added a few comments and assertions in scavenge_small_bitmap and
  walk_large_bitmap
- Did tiny refactor in GHC.Data.Bitmap: added some comments, deleted
  dead code, used PlatformWordSize type.

- - - - -
18757cab by Sylvain Henry at 2020-02-29T05:09:25-05:00
Refactor runtime interpreter code

In #14335 we want to be able to use both the internal interpreter (for
the plugins) and the external interpreter (for TH and GHCi) at the same
time.

This patch performs some preliminary refactoring: the `hsc_interp` field
of HscEnv replaces `hsc_iserv` and is now used to indicate which
interpreter (internal, external) to use to execute TH and GHCi.

Opt_ExternalInterpreter flag and iserv options in DynFlags are now
queried only when we set the session DynFlags. It should help making GHC
multi-target in the future by selecting an interpreter according to the
selected target.

- - - - -
b86a6395 by Adam Sandberg Ericsson at 2020-02-29T05:10:06-05:00
docs: correct relative links to haddocks from users guide (fixes #17866)

- - - - -
0f55df7f by Adam Sandberg Ericsson at 2020-02-29T05:10:06-05:00
docs: correct link to th haddocks from users guide

- - - - -
252e5117 by Jean-Baptiste Mazon at 2020-02-29T05:10:46-05:00
rts: enforce POSIX numeric locale for heap profiles

- - - - -
34c7d230 by Sylvain Henry at 2020-02-29T05:11:27-05:00
Fix Hadrian's ``--configure`` (fix #17883)

- - - - -
04d30137 by Ömer Sinan Ağacan at 2020-02-29T05:12:06-05:00
Simplify IfaceIdInfo type

IfaceIdInfo type is confusing: there's practically no difference between
`NoInfo` and `HasInfo []`. The comments say NoInfo is used when
-fomit-interface-pragmas is enabled, but we don't need to distinguish
`NoInfo` from `HasInfo []` in when reading the interface so the
distinction is not important.

This patch simplifies the type by removing NoInfo. When we have no info
we use an empty list.

With this change we no longer read the info list lazily when reading an
IfaceInfoItem, but when reading an IfaceId the ifIdInfo field is
read lazily, so I doubt this is going to be a problem.

- - - - -
3979485b by Roland Senn at 2020-02-29T17:36:59+01:00
Show breakpoint locations of breakpoints which were ignored during :force (#2950)

GHCi is split up into 2 major parts: The user-interface (UI)
and the byte-code interpreter. With `-fexternal-interpreter`
they even run in different processes. Communication between
the UI and the Interpreter (called `iserv`) is done using
messages over a pipe. This is called `Remote GHCI` and
explained in the Note [Remote GHCi] in `compiler/ghci/GHCi.hs`.

To process a `:force` command the UI sends a `Seq` message
to the `iserv` process. Then `iserv` does the effective
evaluation of the value. When during this process a breakpoint
is hit, the `iserv` process has no additional information to
enhance the `Ignoring breakpoint` output with the breakpoint
location.

To be able to print additional breakpoint information,
there are 2 possible implementation choices:
1. Store the needed information in the `iserv` process.
2. Print the `Ignoring breakpoint` from the UI process.

For option 1 we need to store the breakpoint info redundantely
in 2 places and this is bad. Therfore option 2 was implemented
in this MR:
- The user enters a `force` command
- The UI sends  a `Seq` message to the `iserv` process.
- If processing of the `Seq` message hits a breakpoint,
  the `iserv` process returns control to the UI process.
- The UI looks up the source location of the breakpoint,
  and prints the enhanced `Ignoring breakpoint` output.
- The UI sends a `ResumeSeq` message to the `iserv` process,
  to continue forcing.

- - - - -
3cf7303b by Krzysztof Gogolewski at 2020-03-02T01:18:33-05:00
Remove dead code

* The names in PrelName and THNames are no longer used
  since TH merged types and kinds, Typeable is kind-polymorphic,
  .net support was removed
* unqualQuasiQuote no longer used since 6f8ff0bbad3b9fa3

- - - - -
dbea7e9d by Ilias Tsitsimpis at 2020-03-02T01:19:12-05:00
Do not define hs_atomic{read,write}64() on non-64bit

Do not define hs_atomicread64() and hs_atomicwrite64() on machines where
WORD_SIZE_IN_BITS is less than 64, just like we do with the rest of the atomic
functions which work on 64-bit values.

Without this, compilation fails on MIPSel and PowerPC with the following error:

/usr/bin/ld: /<<PKGBUILDDIR>>/libraries/ghc-prim/dist-install/build/libHSghc-prim-0.5.3_p.a(atomic.p_o): in function `hs_atomicread64':
atomic.c:(.text.hs_atomicread64+0x8): undefined reference to `__sync_add_and_fetch_8'
/usr/bin/ld: /<<PKGBUILDDIR>>/libraries/ghc-prim/dist-install/build/libHSghc-prim-0.5.3_p.a(atomic.p_o): in function `hs_atomicwrite64':
atomic.c:(.text.hs_atomicwrite64+0x38): undefined reference to `__sync_bool_compare_and_swap_8'

Fixes #17886.

- - - - -
7c0c76fb by Roland Senn at 2020-03-02T17:13:55-05:00
Set `ImpredicativeTypes` during :print command. (#14828)

If ImpredicativeTypes is not enabled, then `:print <term>` will fail if the
type of <term> has nested `forall`s or `=>`s.
This is because the GHCi debugger's internals will attempt to unify a
metavariable with the type of <term> and then display the result, but if the
type has nested `forall`s or `=>`s, then unification will fail.
As a result, `:print` will bail out and the unhelpful result will be
`<term> = (_t1::t1)` (where `t1` is a metavariable).

Beware: <term> can have nested `forall`s even if its definition doesn't use
RankNTypes! Here is an example from #14828:

  class Functor f where
    fmap :: (a -> b) -> f a -> f b

Somewhat surprisingly, `:print fmap` considers the type of fmap to have
nested foralls. This is because the GHCi debugger sees the type
`fmap :: forall f. Functor f => forall a b. (a -> b) -> f a -> f b`.
We could envision deeply instantiating this type to get the type
`forall f a b. Functor f => (a -> b) -> f a -> f b`,
but this trick wouldn't work for higher-rank types.

Instead, we adopt a simpler fix: enable `ImpredicativeTypes` when using
`:print` and friends in the GHCi debugger. This is allows metavariables
to unify with types that have nested (or higher-rank) `forall`s/`=>`s,
which makes `:print fmap` display as
`fmap = (_t1::forall a b. Functor f => (a -> b) -> f a -> f b)`, as expected.

Although ImpredicativeTypes is a somewhat unpredictable from a type inference
perspective, there is no danger in using it in the GHCi debugger, since all
of the terms that the GHCi debugger deals with have already been typechecked.

- - - - -
2a2f51d7 by Sylvain Henry at 2020-03-02T17:14:38-05:00
Use configure script to detect that we should use in-tree GMP on Windows

- - - - -
8c663c2c by Andreas Klebinger at 2020-03-04T16:12:14+01:00
Be explicit about how stack usage of mvar primops are covered.

This fixes #17893

[skip-ci]

- - - - -
cedd6f30 by Ben Gamari at 2020-03-05T14:53:12-05:00
rts: Add getCurrentThreadCPUTime helper

- - - - -
ace618cd by Ben Gamari at 2020-03-05T14:53:12-05:00
nonmoving-gc: Track time usage of nonmoving marking

- - - - -
022b5ad5 by Ben Gamari at 2020-03-05T14:53:12-05:00
Stats: Add sync pauses to +RTS -S output

- - - - -
06763234 by Ben Gamari at 2020-03-05T14:53:12-05:00
rts: Report nonmoving collector statistics in machine-readable output

- - - - -
70d2b995 by Ben Gamari at 2020-03-09T06:10:52-04:00
nonmoving: Fix collection of sparks

Previously sparks living in the non-moving heap would be promptly GC'd
by the minor collector since pruneSparkQueue uses the BF_EVACUATED flag,
which non-moving heap blocks do not have set.

Fix this by implementing proper support in pruneSparkQueue for
determining reachability in the non-moving heap. The story is told in
Note [Spark management in the nonmoving heap].

- - - - -
9668781a by Ben Gamari at 2020-03-09T06:11:30-04:00
gitlab-ci: Disable Sphinx documentation in Alpine build
- - - - -
8eb2c263 by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
Fix Windows breakage by not touching locales on Windows

- - - - -
b8dab057 by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
rts: ensure C numerics in heap profiles using Windows locales if needed

- - - - -
7d95260f by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
rts: refactor and comment profile locales

- - - - -
5b627813 by Ryan Scott at 2020-03-09T16:34:14-04:00
Use InstanceSigs in GND/DerivingVia-generated code (#17899)

Aside from making the generated code easier to read when
`-ddump-deriv` is enabled, this makes the error message in `T15073`
substantially simpler (see the updated `T15073` expected stderr).

Fixes #17899.

- - - - -
70b50778 by Ben Gamari at 2020-03-10T02:05:42-04:00
SysTools: Ensure that error parser can handle absolute paths on Windows

This fixes #17786, where the error parser fails to correctly handle the
drive name in absolute Windows paths.

Unfortunately I couldn't find a satisfactory way to test this.

- - - - -
85b861d8 by Ben Gamari at 2020-03-10T02:05:42-04:00
testsuite: Add test for #17786

This isn't pretty but it's perhaps better than nothing.

- - - - -
ee2c50cb by Sylvain Henry at 2020-03-10T02:06:33-04:00
Hadrian: track missing configure results

- - - - -
ca8f51d4 by Ömer Sinan Ağacan at 2020-03-10T02:07:22-04:00
Add regression test for T17904

Closes #17904

- - - - -
5fa9cb82 by Richard Eisenberg at 2020-03-10T12:29:46-04:00
anyRewritableTyVar now looks in RuntimeReps

Previously, anyRewritableTyVar looked only at the arg and res
of `arg -> res`, but their RuntimeReps are also subject to
rewriting. Easy to fix.

Test case: typecheck/should_compile/T17024

Fixes #17024.

- - - - -
5ba01d83 by Ben Price at 2020-03-10T12:30:27-04:00
Clarify a Lint message

When developing a plugin I had a shadowing problem, where I generated
code
  app = \f{v r7B} x{v r7B} -> f{v r7B} x{v r7B}
This is obviously wrong, since the occurrence of `f` to the right of the
arrow refers to the `x` binder (they share a Unique). However, it is
rather confusing when Lint reports
  Mismatch in type between binder and occurrence
  Var: x{v rB7}
since it is printing the binder, rather than the occurrence.
It is rather easy to read this as claiming there is something wrong with
the `x` occurrence!

We change the report to explicitly print both the binder and the
occurrence variables.

- - - - -
7b2c827b by Simon Peyton Jones at 2020-03-10T12:31:15-04:00
Comments only

Clarify code added in #17852 and MR !2724

- - - - -
3300eeac by Krzysztof Gogolewski at 2020-03-10T12:31:54-04:00
Misc cleanup

- Remove Note [Existentials in shift_con_pat].
  The function shift_con_pat has been removed 15 years ago in 23f40f0e9be6d4.
- Remove kcLookupTcTyCon - it's the same as tcLookupTcTyCon
- Remove ASSERT in tyConAppArgN. It's already done by getNth,
  and it's the only reason getNth exists.
- Remove unused function nextRole

- - - - -
abf5736b by Krzysztof Gogolewski at 2020-03-10T18:05:01+01:00
Typos in comments [skip ci]

- - - - -
bb586f89 by Ben Gamari at 2020-03-11T00:14:59-04:00
rts: Prefer darwin-specific getCurrentThreadCPUTime

macOS Catalina now supports a non-POSIX-compliant version of clock_gettime
which cannot use the clock_gettime codepath.

Fixes #17906.

- - - - -
20800b9a by Sylvain Henry at 2020-03-11T08:17:19-04:00
Split GHC.Iface.Utils module

* GHC.Iface.Recomp: recompilation avoidance stuff
* GHC.Iface.Make: mkIface*

Moved `writeIfaceFile` into GHC.Iface.Load alongside `readIface` and
renamed it `writeIface` for consistency.

- - - - -
1daa2029 by Greg Steuck at 2020-03-11T08:17:56-04:00
Fixed a minor typo in codegen.rst
- - - - -
0bc23338 by Ryan Scott at 2020-03-11T08:18:32-04:00
Re-quantify when generalising over rewrite rule types

Previously, `tcRules` would check for naughty quantification
candidates (see `Note [Naughty quantification candidates]` in
`TcMType`) when generalising over the type of a rewrite rule. This
caused sensible-looking rewrite rules (like those in #17710) to be
rejected. A more permissing (and easier-to-implement) approach is to
do what is described in `Note [Generalising in tcTyFamInstEqnGuts]`
in `TcTyClsDecls`: just re-quantify all the type variable binders,
regardless of the order in which the user specified them. After all,
the notion of type variable specificity has no real meaning in
rewrite rules, since one cannot "visibly apply" a rewrite rule.
I have written up this wisdom in
`Note [Re-quantify type variables in rules]` in `TcRules`.

As a result of this patch, compiling the `ExplicitForAllRules1` test
case now generates one fewer warning than it used to. As far as I can
tell, this is benign, since the thing that the disappearing warning
talked about was also mentioned in an entirely separate warning.

Fixes #17710.

- - - - -
336eac7e by Ben Gamari at 2020-03-11T08:19:08-04:00
testsuite: Mark ghci056 and ghcilink004 as fragile in unreg

As noted in #17018.

Also fix fragile declaration of T13786, which only runs in the normal
way.

- - - - -
c61b9b02 by Simon Peyton Jones at 2020-03-11T08:19:44-04:00
Deepen call stack for isIn

I see quite a few warnings like:

  WARNING: file compiler/utils/Util.hs, line 593
    Over-long elem in unionLists

But the call stack is uninformative.   Better to add HasDebugCallStack
to isIn.  Ditto isn'tIn.

- - - - -
3aa9b35f by Ömer Sinan Ağacan at 2020-03-11T08:20:27-04:00
Zero any slop after compaction in compacting GC

In copying GC, with the relevant debug flags enabled, we release the old
blocks after a GC, and the block allocator zeroes the space before
releasing a block. This effectively zeros the old heap.

In compacting GC we reuse the blocks and previously we didn't zero the
unused space in a compacting generation after compaction. With this
patch we zero the slop between the free pointer and the end of the block
when we're done with compaction and when switching to a new block
(because the current block doesn't have enough space for the next object
we're shifting).

- - - - -
8e6febce by Sylvain Henry at 2020-03-11T20:33:37-04:00
Refactor GHC.Driver.Session (Ways and Flags)

* extract flags and ways into their own modules (with some renaming)

* remove one SOURCE import of GHC.Driver.Session from GHC.Driver.Phases

* when GHC uses dynamic linking (WayDyn), `interpWays` was only
  reporting WayDyn even if the host was profiled (WayProf).  Now it
  returns both as expected (might fix #16803).

* `mkBuildTag :: [Way] -> String` wasn't reporting a canonical tag for
  differently ordered lists. Now we sort and nub the list to fix this.

- - - - -
bc41e471 by Sylvain Henry at 2020-03-11T20:33:37-04:00
Refactor interpreterDynamic and interpreterProfiled

* `interpreterDynamic` and `interpreterProfiled` now take `Interp`
  parameters instead of DynFlags

* slight refactoring of `ExternalInterp` so that we can read the iserv
  configuration (which is pure) without reading an MVar.

- - - - -
a6989971 by Sylvain Henry at 2020-03-11T20:33:37-04:00
Use a Set to represent Ways

Should make `member` queries faster and avoid messing up with missing
`nubSort`.

Metric Increase:
    hie002

- - - - -
cb93a1a4 by Ryan Scott at 2020-03-11T20:34:14-04:00
Make DeriveFunctor-generated code require fewer beta reductions

Issue #17880 demonstrates that `DeriveFunctor`-generated code is
surprisingly fragile when rank-_n_ types are involved. The culprit is
that `$fmap` (the algorithm used to generate `fmap` implementations)
was too keen on applying arguments with rank-_n_ types to lambdas,
which fail to typecheck more often than not.

In this patch, I change `$fmap` (both the specification and the
implementation) to produce code that avoids creating as many lambdas,
avoiding problems when rank-_n_ field types arise.
See the comments titled "Functor instances" in `TcGenFunctor` for a
more detailed description. Not only does this fix #17880, but it also
ensures that the code that `DeriveFunctor` generates will continue
to work after simplified subsumption is implemented (see #17775).

What is truly amazing is that #17880 is actually a regression
(introduced in GHC 7.6.3) caused by commit
49ca2a37bef18aa57235ff1dbbf1cc0434979b1e, the fix #7436. Prior to
that commit, the version of `$fmap` that was used was almost
identical to the one used in this patch! Why did that commit change
`$fmap` then? It was to avoid severe performance issues that would
arise for recursive `fmap` implementations, such as in the example
below:

```hs
data List a = Nil | Cons a (List a) deriving Functor

-- ===>

instance Functor List where
  fmap f Nil = Nil
  fmap f (Cons x xs) = Cons (f x) (fmap (\y -> f y) xs)
```

The fact that `\y -> f y` was eta expanded caused significant
performance overheads. Commit
49ca2a37bef18aa57235ff1dbbf1cc0434979b1e fixed this performance
issue, but it went too far. As a result, this patch partially
reverts 49ca2a37bef18aa57235ff1dbbf1cc0434979b1e.

To ensure that the performance issues pre-#7436 do not resurface,
I have taken some precautionary measures:

* I have added a special case to `$fmap` for situations where the
  last type variable in an application of some type occurs directly.
  If this special case fires, we avoid creating a lambda expression.
  This ensures that we generate
  `fmap f (Cons x xs) = Cons (f x) (fmap f xs)` in the derived
  `Functor List` instance above. For more details, see
  `Note [Avoid unnecessary eta expansion in derived fmap implementations]`
  in `TcGenFunctor`.
* I have added a `T7436b` test case to ensure that the performance
  of this derived `Functor List`-style code does not regress.

When implementing this, I discovered that `$replace`, the algorithm
which generates implementations of `(<$)`, has a special case that is
very similar to the `$fmap` special case described above. `$replace`
marked this special case with a custom `Replacer` data type, which
was a bit overkill. In order to use the same machinery for both
`Functor` methods, I ripped out `Replacer` and instead implemented
a simple way to detect the special case. See the updated commentary
in `Note [Deriving <$]` for more details.

- - - - -
1f9db3e7 by Kirill Elagin at 2020-03-12T09:45:51-04:00
pretty-printer: Properly parenthesise LastStmt

After ApplicatveDo strips the last `return` during renaming, the pretty
printer has to restore it. However, if the return was followed by `$`,
the dollar was stripped too and not restored.

For example, the last stamement in:

```
  foo = do
    x <- ...
    ...
    return $ f x
```

would be printed as:

```
    return f x
```

This commit preserved the dolar, so it becomes:

```
    return $ f x
```

- - - - -
5cb93af7 by Kirill Elagin at 2020-03-12T09:45:51-04:00
pretty-printer: Do not print ApplicativeDo join

* Do not print `join` in ApplictiveStmt, unless ppr-debug
* Print parens around multiple parallel binds

When ApplicativeDo is enabled, the renamer analyses the statements of a
`do` block and in certain cases marks them as needing to be rewritten
using `join`.

For example, if you have:

```
foo = do
  a <- e1
  b <- e2
  doSomething a b
```

it will be desugared into:

```
foo = join (doSomething <$> e1 <*> e2)
```

After renaming but before desugaring the expression is stored
essentially as:

```
foo = do
  [will need join] (a <- e1 | b <- e2)
  [no return] doSomething a b
```

Before this change, the pretty printer would print a call to `join`,
even though it is not needed at this stage at all. The expression will be
actually rewritten into one using join only at desugaring, at which
point a literal call to join will be inserted.

- - - - -
3a259092 by Simon Peyton Jones at 2020-03-12T09:46:29-04:00
Expose compulsory unfoldings always

The unsafeCoerce# patch requires that unsafeCoerce# has
a compulsory unfolding that is always available.  So we have
to be careful to expose compulsory unfoldings unconditionally
and consistently.

We didn't get this quite right: #17871.  This patch fixes
it.  No real surprises here.

See Note [Always expose compulsory unfoldings] in GHC.Iface.Tidy

- - - - -
6a65b8c2 by Alp Mestanogullari at 2020-03-13T02:29:20-04:00
hadrian: improve dependency tracking for the check-* programs

The code in Rules.Register responsible for finding all the build artifacts
that Cabal installs when registering a library (static/shared libs, .hi files,
...) was looking in the wrong place. This patch fixes that logic and makes sure
we gather all those artifacts in a list to declare that the rule for a given
`.conf` file, our proxy for "Hadrian, please install this package in the package
db for this stage", also produces those artifacts under the said package
database.

We also were completely missing some logic to declare that the check-* programs
have dependencies besides their source code, at least when testing an in-tree
compiler.

Finally, this patch also removes redundant packages from 'testsuitePackages',
since they should already be covered by the stage<N>Packages lists from
Settings.Default.

With this patch, after a complete build and freezing stage 1, a change to
`compiler/parser/Parser.y` results in rebuilding the ghc lib, reinstalling it,
and rebuilding the few programs that depend on it, _including_ `check-ppr` and
`check-api-annotations` (therefore fixing #17273).

- - - - -
44fad4a9 by Sylvain Henry at 2020-03-13T02:30:22-04:00
Rename isDllName

I wanted to fix the dangling comment in `isDllName` ("This is the cause
of #", #8696 is already mentioned earlier). I took the opportunity to
change the function name to better reflect what it does.

- - - - -
2f292db8 by Paavo at 2020-03-13T02:31:03-04:00
Update documentation for closureSize

- - - - -
f124ff0d by Ben Gamari at 2020-03-13T02:31:40-04:00
gitlab-ci: Rework triggering of release builds

Use a push option instead of tagging.

- - - - -
7f25557a by Ben Gamari at 2020-03-13T10:38:09-04:00
gitlab-ci: Distinguish integer-simple test envs

Previously two integer-simple jobs declared the same test environment. One (the nightly job) was built in the perf way, the other in the validate way. Consequently they had appreciably different performance characteristics, causing in the nightly job to spuriously fail with performance changes.
- - - - -
c12a2ec5 by Simon Peyton Jones at 2020-03-14T05:25:30-04:00
Fix Lint

Ticket #17590 pointed out a bug in the way the linter dealt with
type lets, exposed by the new uniqAway story.

The fix is described in Note [Linting type lets]. I ended up
putting the in-scope Ids in a different env field, le_ids,
rather than (as before) sneaking them into the TCvSubst.

Surprisingly tiresome, but done.

Metric Decrease:
    hie002

- - - - -
b989845e by Sylvain Henry at 2020-03-14T05:26:11-04:00
Hadrian: fix absolute buildroot support (#17822)

Shake's "**" wildcard doesn't match absolute root. We must use "//" instead.

- - - - -
4f117135 by Sylvain Henry at 2020-03-14T05:26:49-04:00
Make: refactor GMP rules

Document and use simpler rules for the ghc-gmp.h header.

- - - - -
7432b327 by Sylvain Henry at 2020-03-14T05:27:28-04:00
Use correct option name (-opti) (fix #17314)

s/pgmo/opti

- - - - -
8f7dd571 by Judah Jacobson at 2020-03-14T05:28:07-04:00
Allow overriding LD_STAGE0 and AR_STAGE0 in the configure script.

Previously it was possible to override the stage0 C compiler via `CC_STAGE0`,
but you couldn't override `ld` or `ar` in stage0.  This change allows overriding them
by setting `LD_STAGE0` or `AR_STAGE0`, respectively.

Our team uses this feature internally to take more control of our GHC build
and make it run more hermetically.

- - - - -
7c3e39a9 by Judah Jacobson at 2020-03-14T05:28:07-04:00
Use AC_ARG_VAR for LD_STAGE0 and AR_STAGE0.

- - - - -
20d4d676 by Ben Gamari at 2020-03-14T05:28:43-04:00
nonmoving: Don't traverse filled segment list in pause

The non-moving collector would previously walk the entire filled segment
list during the preparatory pause. However, this is far more work than
is strictly necessary. We can rather get away with merely collecting the
allocators' filled segment list heads and process the lists themselves
during the concurrent phase. This can significantly reduce the maximum
gen1 GC pause time in programs with high rates of long-lived allocations.

- - - - -
fdfa2d01 by Ben Gamari at 2020-03-14T05:29:18-04:00
nonmoving: Remove redundant bitmap clearing

nonmovingSweep already clears the bitmap in the sweep loop. There is no
reason to do so a second time.

- - - - -
2f8c7767 by Simon Peyton Jones at 2020-03-14T05:29:55-04:00
Simple refactor of cheapEqExpr

No change in functionality.  Just seems tidier (and signficantly more
efficient) to deal with ticks directly than to call stripTicksTopE.

- - - - -
88f7a762 by Simon Peyton Jones at 2020-03-14T05:29:55-04:00
Improve CSE.combineAlts

This patch improves the way that CSE combines identical
alternatives.  See #17901.

I'm still not happy about the duplication between CSE.combineAlts
and GHC.Core.Utils.combineIdenticalAlts; see the Notes with those
functions.  But this patch is a step forward.

Metric Decrease:
    T12425
    T5642

- - - - -
8b95ddd3 by Ben Gamari at 2020-03-14T05:30:31-04:00
gitlab-ci: Add integer-simple release build for Windows

Closes #16144.

- - - - -
e3c374cc by Simon Peyton Jones at 2020-03-14T05:31:07-04:00
Wrap an implication around class-sig kind errors

Ticket #17841 showed that we can get a kind error
in a class signature, but lack an enclosing implication
that binds its skolems.

This patch

* Adds the wrapping implication: the new call to
  checkTvConstraints in tcClassDecl1

* Simplifies the API to checkTvConstraints, which
  was not otherwise called at all.

* Simplifies TcErrors.report_unsolved by *not*
  initialising the TidyEnv from the typechecker lexical
  envt.  It's enough to do so from the free vars of the
  unsolved constraints; and we get silly renamings if
  we add variables twice: once from the lexical scope
  and once from the implication constraint.

- - - - -
73133a3b by Simon Peyton Jones at 2020-03-14T05:31:07-04:00
Refactoring in TcSMonad

This patch is just refactoring: no change in
behaviour.

I removed the rather complicated
    checkConstraintsTcS
    checkTvConstraintsTcS

in favour of simpler functions
    emitImplicationTcS
    emitTvImplicationTcS
    pushLevelNoWorkList

The last of these is a little strange, but overall
it's much better I think.

- - - - -
93c88c26 by Ben Gamari at 2020-03-14T05:31:42-04:00
base: Make `open` calls interruptible

As noted in #17912, `open` system calls were `safe` rather than
`interruptible`. Consequently, the program could not be interrupted with
SIGINT if stuck in a slow open operation. Fix this by marking
`c_safe_open` as interruptible.

- - - - -
bee4cdad by Vladislav Zavialov at 2020-03-14T05:32:18-04:00
Remove second tcLookupTcTyCon in tcDataDefn

Before this patch, tcDataDefn used to call tcLookupTcTyCon twice in a row:
	1. in bindTyClTyVars itself
	2. in the continuation passed to it

Now bindTyClTyVars passes the TcTyCon to the continuation, making
the second lookup unnecessary.

- - - - -
3f116d35 by Cale Gibbard at 2020-03-14T19:34:42-04:00
Enable stage1 build of haddock

The submodule has already been bumped to contain the fix.

- - - - -
49e9d739 by Ömer Sinan Ağacan at 2020-03-14T19:35:24-04:00
rts: Fix printClosure when printing fwd ptrs

- - - - -
1de3ab4a by Krzysztof Gogolewski at 2020-03-14T19:36:04-04:00
Remove unused field var_inline (#17915)

- - - - -
d30aeb4b by Krzysztof Gogolewski at 2020-03-15T03:57:41-04:00
Document restriction on SCC pragma syntax

Currently, the names of cost centres must be quoted or
be lowercase identifiers.

Fixes #17916.

- - - - -
b4774598 by Brian Foley at 2020-03-15T03:58:18-04:00
Remove some dead code

>From the notes.ghc.drop list found using weeder in #17713

- - - - -
dd6ffe6b by Viktor Dukhovni at 2020-03-15T03:58:55-04:00
Note platform-specific Foreign.C.Types in context

Also fix the markup in the general note at the top of the module.  Haddock
(usability trade-off), does not support multi-line emphasised text.

- - - - -
2e82465f by Sylvain Henry at 2020-03-15T10:57:10-04:00
Refactor CmmToAsm (disentangle DynFlags)

This patch disentangles a bit more DynFlags from the native code
generator (CmmToAsm).

In more details:

- add a new NCGConfig datatype in GHC.CmmToAsm.Config which contains the
  configuration of a native code generation session
- explicitly pass NCGConfig/Platform arguments when necessary
- as a consequence `sdocWithPlatform` is gone and there are only a few
  `sdocWithDynFlags` left
- remove the use of `unsafeGlobalDynFlags` from GHC.CmmToAsm.CFG
- remove `sdocDebugLevel` (now we pass the debug level via NCGConfig)

There are still some places where DynFlags is used, especially because
of pretty-printing (CLabel), because of Cmm helpers (such as
`cmmExprType`) and because of `Outputable` instance for the
instructions. These are left for future refactoring as this patch is
already big.

- - - - -
c35c545d by Judah Jacobson at 2020-03-15T10:57:48-04:00
Add a -no-haddock flag.

This flag undoes the effect of a previous "-haddock" flag.  Having both flags makes it easier
for build systems to enable Haddock parsing in a set of global flags, but then disable it locally for
specific targets (e.g., third-party packages whose comments don't pass the validation in the latest GHC).

I added the flag to expected-undocumented-flags.txt since `-haddock` was alreadyin that list.

- - - - -
cfcc3c9a by Ömer Sinan Ağacan at 2020-03-15T10:58:27-04:00
Fix global_link of TSOs for threads reachable via dead weaks

Fixes #17785

Here's how the problem occurs:

- In generation 0 we have a TSO that is finished (i.e. it has no more
  work to do or it is killed).

- The TSO only becomes reachable after collectDeadWeakPtrs().

- After collectDeadWeakPtrs() we switch to WeakDone phase where we don't
  move TSOs to different lists anymore (like the next gen's thread list
  or the resurrected_threads list).

- So the TSO will never be moved to a generation's thread list, but it
  will be promoted to generation 1.

- Generation 1 collected via mark-compact, and because the TSO is
  reachable it is marked, and its `global_link` field, which is bogus at
  this point (because the TSO is not in a list), will be threaded.

- Chaos ensues.

In other words, when these conditions hold:

- A TSO is reachable only after collectDeadWeakPtrs()
- It's finished (what_next is ThreadComplete or ThreadKilled)
- It's retained by mark-compact collector (moving collector doesn't
  evacuate the global_list field)

We end up doing random mutations on the heap because the TSO's
global_list field is not valid, but it still looks like a heap pointer
so we thread it during compacting GC.

The fix is simple: when we traverse old_threads lists to resurrect
unreachable threads the threads that won't be resurrected currently
stays on the old_threads lists. Those threads will never be visited
again by MarkWeak so we now reset the global_list fields. This way
compacting GC does not thread pointers to nowhere.

Testing
-------

The reproducer in #17785 is quite large and hard to build, because of
the dependencies, so I'm not adding a regression test.

In my testing the reproducer would take a less than 5 seconds to run,
and once in every ~5 runs would fail with a segfault or an assertion
error. In other cases it also fails with a test failure. Because the
tests never fail with the bug fix, assuming the code is correct, this
also means that this bug can sometimes lead to incorrect runtime
results.

After the fix I was able to run the reproducer repeatedly for about an
hour, with no runtime crashes or test failures.

To run the reproducer clone the git repo:

    $ git clone https://github.com/osa1/streamly --branch ghc-segfault

Then clone primitive and atomic-primops from their git repos and point
to the clones in cabal.project.local. The project should then be
buildable using GHC HEAD. Run the executable `properties` with `+RTS -c
-DZ`.

In addition to the reproducer above I run the test suite using:

    $ make slowtest EXTRA_HC_OPTS="-debug -with-rtsopts=-DS \
        -with-rtsopts=-c +RTS -c -RTS" SKIPWAY='nonmoving nonmoving_thr'

This enables compacting GC always in both GHC when building the test
programs and when running the test programs, and also enables sanity
checking when running the test programs. These set of flags are not
compatible for all tests so there are some failures, but I got the same
set of failures with this patch compared to GHC HEAD.

- - - - -
818b3c38 by Lysxia at 2020-03-16T23:52:42-04:00
base: add strict IO functions: readFile', getContents', hGetContents'

- - - - -
18a346a4 by Sylvain Henry at 2020-03-16T23:53:24-04:00
Modules: Core (#13009)

Update submodule: haddock

- - - - -
92327e3a by Ömer Sinan Ağacan at 2020-03-16T23:54:04-04:00
Update sanity checking for TSOs:

- Remove an invalid assumption about GC checking what_next field. The GC
  doesn't care about what_next at all, if a TSO is reachable then all
  its pointers are followed (other than global_tso, which is only
  followed by compacting GC).

- Remove checkSTACK in checkTSO: TSO stacks will be visited in
  checkHeapChain, or checkLargeObjects etc.

- Add an assertion in checkTSO to check that the global_link field is
  sane.

- Did some refactor to remove forward decls in checkGlobalTSOList and
  added braces around single-statement if statements.

- - - - -
e1aa4052 by PHO at 2020-03-17T07:36:09-04:00
Don't use non-portable operator "==" in configure.ac

The test operator "==" is a Bash extension and produces a wrong result
if /bin/sh is not Bash.

- - - - -
89f034dd by Maximilian Tagher at 2020-03-17T07:36:48-04:00
Document the units of -ddump-timings

Right now, in the output of -ddump-timings to a file, you can't tell what the units are:

```
CodeGen [TemplateTestImports]: alloc=22454880 time=14.597
```

I believe bytes/milliseconds are the correct units, but confirmation would be appreciated. I'm basing it off of this snippet from `withTiming'`:

```
when (verbosity dflags >= 2 && prtimings == PrintTimings)
  $ liftIO $ logInfo dflags (defaultUserStyle dflags)
      (text "!!!" <+> what <> colon <+> text "finished in"
       <+> doublePrec 2 time
       <+> text "milliseconds"
       <> comma
       <+> text "allocated"
       <+> doublePrec 3 (realToFrac alloc / 1024 / 1024)
       <+> text "megabytes")
```

which implies time is in milliseconds, and allocations in bytes (which divided by 1024 would be KB, and again would be MB)

- - - - -
beffa147 by Simon Peyton Jones at 2020-03-17T07:37:25-04:00
Implement mapTyCo like foldTyCo

This patch makes mapType use the successful idiom described
in TyCoRep
   Note [Specialising foldType]

I have not yet changed any functions to use mapType, though there
may be some suitable candidates.

This patch should be a no-op in terms of functionality but,
because it inlines the mapper itself, I'm hoping that there may
be some modest perf improvements.

Metric Decrease:
    T5631
    T5642
    T3064
    T9020
    T14683
    hie002
    haddock.Cabal
    haddock.base
    haddock.compiler

- - - - -
5800ebfe by Ömer Sinan Ağacan at 2020-03-17T07:38:08-04:00
Don't update ModDetails with CafInfos when opts are disabled

This is consistent with the interface file behavior where we omit
HsNoCafRefs annotations with -fomit-interface-pragmas (implied by -O0).

ModDetails and ModIface are just different representations of the same
thing, so they really need to be in sync. This patch does the right
thing and does not need too much explanation, but here's an example of a
problem not doing this causes in !2842:

    -- MyInteger.hs
    module MyInteger
      ( MyInteger (MyInteger)
      , ToMyInteger (toMyInteger)
      ) where

    newtype MyInteger = MyInteger Integer

    class ToMyInteger a where
      toMyInteger :: a -> MyInteger

    instance ToMyInteger Integer where
      toMyInteger = MyInteger {- . succ -}

    -- Main.hs
    module Main
      ( main
      ) where

    import MyInteger (MyInteger (MyInteger), toMyInteger)

    main :: IO ()
    main = do
      let (MyInteger i) = (id . toMyInteger) (41 :: Integer)
      print i

If I build this with -O0, without this fix, we generate a ModDetails with
accurate LFInfo for toMyInteger (MyInteger.$fToMyIntegerInteger) which says that
it's a LFReEntrant with arity 1. This means in the use site (Main) we tag the
value:

    R3 = MyInteger.$fToMyIntegerInteger_closure + 1;
    R2 = GHC.Base.id_closure;
    R1 = GHC.Base.._closure;
    Sp = Sp - 16;
    call stg_ap_ppp_fast(R4, R3, R2, R1) args: 24, res: 0, upd: 24;

Now we change the definition by uncommenting the `succ` part and it becomes a thunk:

    MyInteger.$fToMyIntegerInteger [InlPrag=INLINE (sat-args=0)]
      :: MyInteger.ToMyInteger GHC.Integer.Type.Integer
    [GblId[DFunId(nt)]] =
        {} \u [] $ctoMyInteger_rEA;

and its LFInfo is now LFThunk. This change in LFInfo makes a difference in the
use site: we can no longer tag it.

But becuase the interface fingerprint does not change (because ModIface does not
change) we don't rebuild Main and tag the thunk.

(1.2% increase in allocations when building T12545 on armv7 because we
generate more code without CafInfos)

Metric Increase:
    T12545

- - - - -
5b632dad by Paavo at 2020-03-17T07:38:48-04:00
Add example for Data.Semigroup.diff

- - - - -
4d85d68b by Paavo at 2020-03-17T07:38:48-04:00
Clean up

- - - - -
75168d07 by Paavo at 2020-03-17T07:38:48-04:00
Make example collapsible

- - - - -
53ff2cd0 by Richard Eisenberg at 2020-03-17T13:46:57+00:00
Fix #17021 by checking more return kinds

All the details are in new Note [Datatype return kinds] in
TcTyClsDecls.

Test case: typecheck/should_fail/T17021{,b}
           typecheck/should_compile/T17021a

Updates haddock submodule

- - - - -
528df8ec by Sylvain Henry at 2020-03-18T10:06:43-04:00
Modules: Core operations (#13009)

- - - - -
4e8a71c1 by Richard Eisenberg at 2020-03-18T10:07:19-04:00
Add release note about fix to #16502.

We thought we needed to update the manual, but the fix for #16502
actually brings the implementation in line with the manual. So we
just alert users of how to update their code.

- - - - -
5cbf9934 by Andreas Klebinger at 2020-03-19T00:39:27-04:00
Update "GHC differences to the FFI Chapter" in user guide.

The old entry had a heavy focus on how things had been. Which is
not what I generally look for in a user guide.

I also added a small section on behaviour of nested safe ffi calls.

[skip-ci]

- - - - -
b03fd3bc by Sebastian Graf at 2020-03-19T00:40:06-04:00
PmCheck: Use ConLikeSet to model negative info

In #17911, Simon recognised many warnings stemming from over-long list
unions while coverage checking Cabal's `LicenseId` module.

This patch introduces a new `PmAltConSet` type which uses a `UniqDSet`
instead of an association list for `ConLike`s. For `PmLit`s, it will
still use an assocation list, though, because a similar map data
structure would entail a lot of busy work.

Fixes #17911.

- - - - -
64f20756 by Sylvain Henry at 2020-03-19T12:16:49-04:00
Refactoring: use Platform instead of DynFlags when possible

Metric Decrease:
    ManyConstructors
    T12707
    T13035
    T1969

- - - - -
cb1785d9 by Ömer Sinan Ağacan at 2020-03-19T12:16:54-04:00
FastString: fix eager reading of string ptr in hashStr

This read causes NULL dereferencing when len is 0.

Fixes #17909

In the reproducer in #17909 this bug is triggered as follows:

- SimplOpt.dealWithStringLiteral is called with a single-char string
  ("=" in #17909)

- tailFS gets called on the FastString of the single-char string.

- tailFS checks the length of the string, which is 1, and calls
  mkFastStringByteString on the tail of the ByteString, which is an
  empty ByteString as the original ByteString has only one char.

- ByteString's unsafeUseAsCStringLen returns (NULL, 0) for the empty
  ByteString, which is passed to mkFastStringWith.

- mkFastStringWith gets hash of the NULL pointer via hashStr, which
  fails on empty strings because of this bug.

- - - - -
73a7383e by Richard Eisenberg at 2020-03-20T20:42:56-04:00
Simplify treatment of heterogeneous equality

Previously, if we had a [W] (a :: k1) ~ (rhs :: k2), we would
spit out a [D] k1 ~ k2 and part the W as irreducible, hoping for
a unification. But we needn't do this. Instead, we now spit out
a [W] co :: k2 ~ k1 and then use co to cast the rhs of the original
Wanted. This means that we retain the connection between the
spat-out constraint and the original.

The problem with this new approach is that we cannot use the
casted equality for substitution; it's too like wanteds-rewriting-
wanteds. So, we forbid CTyEqCans that mention coercion holes.

All the details are in Note [Equalities with incompatible kinds]
in TcCanonical.

There are a few knock-on effects, documented where they occur.

While debugging an error in this patch, Simon and I ran into
infelicities in how patterns and matches are printed; we made
small improvements.

This patch includes mitigations for #17828, which causes spurious
pattern-match warnings. When #17828 is fixed, these lines should
be removed.

- - - - -
faa36e5b by Sylvain Henry at 2020-03-20T20:43:41-04:00
Hadrian: ignore in-tree GMP objects with ``--lint``

- - - - -
9a96ff6b by Richard Eisenberg at 2020-03-20T20:44:17-04:00
Update core spec to reflect changes to Core.

Key changes:
 * Adds a new rule for forall-coercions over coercion variables, which
was implemented but conspicuously missing from the spec.
 * Adds treatment for FunCo.
 * Adds treatment for ForAllTy over coercion variables.
 * Improves commentary (including restoring a Note lost in
03d4852658e1b7407abb4da84b1b03bfa6f6db3b) in the source.

No changes to running code.

- - - - -
7e0451c6 by Sergej Jaskiewicz at 2020-03-20T20:44:55-04:00
Fix event message in withTiming'

This typo caused generating 'end' events without the corresponding 'begin' events.

- - - - -
1542a626 by Ben Gamari at 2020-03-22T22:37:47-04:00
fs.h: Add missing declarations on Windows

- - - - -
3bcf2ccd by Ben Gamari at 2020-03-22T22:37:47-04:00
Bump process submodule

Avoids redundant case alternative warning.

- - - - -
3b363ef9 by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Normalize slashes in ghc-api annotations output

Enable `normalise_slashes` on `annotations`, `listcomps`, and
`parseTree` to fix Windows failures.

- - - - -
25fc9429 by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Update expected output on Windows

- - - - -
7f58ec6d by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Fix TOP of T17786

- - - - -
aadcd909 by GHC GitLab CI at 2020-03-22T22:37:47-04:00
testsuite: Update expected output on Windows

- - - - -
dc1eb10d by GHC GitLab CI at 2020-03-22T22:37:47-04:00
hadrian: Fix executable extension passed to testsuite driver

- - - - -
58f62e2c by GHC GitLab CI at 2020-03-22T22:37:47-04:00
gitlab-ci: Require that Windows-hadrian job passes

- - - - -
8dd2415d by Ben Gamari at 2020-03-22T22:37:47-04:00
hadrian: Eliminate redundant .exe from GHC path

Previously we were invoking:

    bash -c
    "c:/GitLabRunner/builds/eEQrxK4p/0/ghc/ghc/toolchain/bin/ghc.exe.exe
    testsuite/mk/ghc-config.hs -o _build/test/bin/ghc-config.exe"

- - - - -
373621f6 by Ben Gamari at 2020-03-22T22:37:47-04:00
Bump hsc2hs submodule

- - - - -
abc02b40 by Hécate at 2020-03-22T22:38:33-04:00
Annotate the non-total function in Data.Foldable as such

- - - - -
19f12557 by Josef Svenningsson at 2020-03-23T14:05:33-04:00
Fix ApplicativeDo regression #17835

A previous fix for #15344 made sure that monadic 'fail' is used properly
when translating ApplicativeDo. However, it didn't properly account
for when a 'fail' will be inserted which resulted in some programs
failing with a type error.

- - - - -
2643ba46 by Paavo at 2020-03-24T08:31:32-04:00
Add example and doc for Arg (Fixes #17153)

- - - - -
703221f4 by Roland Senn at 2020-03-25T14:45:04-04:00
Use export list of Main module in function TcRnDriver.hs:check_main (Fix #16453)

- Provide the export list of the `Main` module as parameter to the
  `compiler/typecheck/TcRnDriver.hs:check_main` function.
- Instead of `lookupOccRn_maybe` call the function `lookupInfoOccRn`.
  It returns the list `mains_all` of all the main functions in scope.
- Select from this list `mains_all` all `main` functions that are in
  the export list of the `Main` module.
- If this new list contains exactly one single `main` function, then
  typechecking continues.
- Otherwise issue an appropriate error message.

- - - - -
3e27205a by Sebastian Graf at 2020-03-25T14:45:40-04:00
Remove -fkill-absence and -fkill-one-shot flags

They seem to be a benchmarking vestige of the Cardinality paper and
probably shouldn't have been merged to HEAD in the first place.

- - - - -
262e42aa by Peter Trommler at 2020-03-25T22:41:39-04:00
Do not panic on linker errors

- - - - -
0de03cd7 by Sylvain Henry at 2020-03-25T22:42:02-04:00
DynFlags refactoring III

Use Platform instead of DynFlags when possible:
* `tARGET_MIN_INT` et al. replaced with `platformMinInt` et al.
* no more DynFlags in PreRules: added a new `RuleOpts` datatype
* don't use `wORD_SIZE` in the compiler
* make `wordAlignment` use `Platform`
* make `dOUBLE_SIZE` a constant

Metric Decrease:
    T13035
    T1969

- - - - -
7a04920b by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: fix a typo in liftA doc

This change removes an extra '|' that should not be rendered in
the liftA documentation.

Tracking: #17929

- - - - -
1c5a15f7 by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: add Control.Applicative optional example

This change adds an optional example.

Tracking: #17929

- - - - -
6d172e63 by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: add markup around Except

- - - - -
eb2162c8 by John Ericson at 2020-03-26T12:37:08-04:00
Remove unused `ghciTablesNextToCode` from compiler proper

- - - - -
f51efc4b by Joachim Breitner at 2020-03-26T12:37:09-04:00
Prepare to use run-time tablesNextToCode in compiler exclusively

Factor out CPP as much as possible to prepare for runtime
determinattion.

Progress towards #15548

- - - - -
1c446220 by Joachim Breitner at 2020-03-26T12:37:09-04:00
Use run-time tablesNextToCode in compiler exclusively (#15548)

Summary:

 - There is no more use of the TABLES_NEXT_TO_CODE CPP macro in
   `compiler/`. GHCI_TABLES_NEXT_TO_CODE is also removed entirely.
   The field within `PlatformMisc` within `DynFlags` is used instead.

 - The field is still not exposed as a CLI flag. We might consider some
   way to ensure the right RTS / libraries are used before doing that.

Original reviewers:

Original subscribers: TerrorJack, rwbarton, carter

Original Differential Revision: https://phabricator.haskell.org/D5082

- - - - -
1941ef4f by Sylvain Henry at 2020-03-29T17:28:51-04:00
Modules: Types (#13009)

Update Haddock submodule

Metric Increase:
   haddock.compiler

- - - - -
1c7c6f1a by Sylvain Henry at 2020-03-29T17:28:51-04:00
Remove GHC.Types.Unique.Map module

This module isn't used anywhere in GHC.

- - - - -
f1a6c73d by Sylvain Henry at 2020-03-29T17:28:51-04:00
Merge GHC.Types.CostCentre.Init into GHC.Driver.CodeOutput

- - - - -
54250f2d by Simon Peyton Jones at 2020-03-29T17:29:30-04:00
Demand analysis: simplify the demand for a RHS

Ticket #17932 showed that we were using a stupid demand for the RHS
of a let-binding, when the result is a product.  This was the result
of a "fix" in 2013, which (happily) turns out to no longer be
necessary.

So I just deleted the code, which simplifies the demand analyser,
and fixes #17932. That in turn uncovered that the anticipation
of worker/wrapper in CPR analysis was inaccurate, hence the logic
that decides whether to unbox an argument in WW was extracted into
a function `wantToUnbox`, now consulted by CPR analysis.

I tried nofib, and got 0.0% perf changes.

All this came up when messing about with !2873 (ticket #17917),
but is idependent of it.

Unfortunately, this patch regresses #4267 and realised that it is now
blocked on #16335.

- - - - -
03060b2f by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Fix T17786 on Windows

Fixes line ending normalization issue.

- - - - -
1f7995ba by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Fix T17786

Fix missing quoting and expected exit code.

- - - - -
ef9c608e by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Mark T12971 as broken on Windows

Due to #17945.

- - - - -
e54500c1 by Sylvain Henry at 2020-03-29T17:30:47-04:00
Store ComponentId details

As far as GHC is concerned, installed package components ("units") are
identified by an opaque ComponentId string provided by Cabal. But we
don't want to display it to users (as it contains a hash) so GHC queries
the database to retrieve some infos about the original source package
(name, version, component name).

This patch caches these infos in the ComponentId itself so that we don't
need to provide DynFlags (which contains installed package informations)
to print a ComponentId.

In the future we want GHC to support several independent package states
(e.g. for plugins and for target code), hence we need to avoid
implicitly querying a single global package state.

- - - - -
7e7cb714 by Marius Bakke at 2020-03-29T17:31:27-04:00
testsuite: Remove test that dlopens a PIE object.

glibc 2.30 disallowed dlopening PIE objects, so just remove the test.
Fixes #17952.

- - - - -
6c8f80d8 by Andreas Klebinger at 2020-03-29T17:32:04-04:00
Correct haddocks for testBit in Data.Bits

It conflated the nth bit with the bit at offset n.

Now we instead give the definition in terms of `bit and `.&.`
on top of clearer phrasing.

- - - - -
c916f190 by Andreas Klebinger at 2020-03-29T17:32:04-04:00
Apply suggestion to libraries/base/Data/Bits.hs
- - - - -
64bf7f51 by Ben Gamari at 2020-03-29T17:32:41-04:00
gitlab-ci: Add FreeBSD release job

- - - - -
a0d8e92e by Ryan Scott at 2020-03-29T17:33:20-04:00
Run checkNewDataCon before constraint-solving newtype constructors

Within `checkValidDataCon`, we used to run `checkValidType` on the
argument types of a newtype constructor before running
`checkNewDataCon`, which ensures that the user does not attempt
non-sensical things such as newtypes with multiple arguments or
constraints. This works out in most situations, but this falls over
on a corner case revealed in #17955:

```hs
newtype T = Coercible () T => T ()
```

`checkValidType`, among other things, peforms an ambiguity check on
the context of a data constructor, and that it turn invokes the
constraint solver. It turns out that there is a special case in the
constraint solver for representational equalities (read: `Coercible`
constraints) that causes newtypes to be unwrapped (see
`Note [Unwrap newtypes first]` in `TcCanonical`). This special case
does not know how to cope with an ill formed newtype like `T`, so
it ends up panicking.

The solution is surprisingly simple: just invoke `checkNewDataCon`
before `checkValidType` to ensure that the illicit newtype
constructor context is detected before the constraint solver can
run amok with it.

Fixes #17955.

- - - - -
45eb9d8c by Krzysztof Gogolewski at 2020-03-29T17:33:59-04:00
Minor cleanup

- Simplify mkBuildExpr, the function newTyVars was called
  only on a one-element list.
- TTG: use noExtCon in more places. This is more future-proof.
- In zonkExpr, panic instead of printing a warning.

- - - - -
f024b6e3 by Sylvain Henry at 2020-03-30T12:48:39+02:00
Expect T4267 to pass

Since 54250f2d8de910b094070c1b48f086030df634b1 we expected T4267 to
fail, but it passes on CI.

- - - - -
57b888c0 by Ryan Scott at 2020-03-31T10:54:20-04:00
Require GHC 8.8 as the minimum compiler for bootstrapping

This allows us to remove several bits of CPP that are either always
true or no longer reachable. As an added bonus, we no longer need to
worry about importing `Control.Monad.Fail.fail` qualified to avoid
clashing with `Control.Monad.fail`, since the latter is now the same
as the former.

- - - - -
33f09551 by Ryan Scott at 2020-03-31T10:54:57-04:00
Add regression test for #17963

The panic in #17963 happened to be fixed by commit
e3c374cc5bd7eb49649b9f507f9f7740697e3f70. This patch adds a
regression test to ensure that it remains fixed.

Fixes #17963.

- - - - -
09a36e80 by Ömer Sinan Ağacan at 2020-03-31T10:55:37-04:00
Simplify stderrSupportsAnsiColors

The combinator andM is used only once, and the code is shorter and
simpler if you inline it.

- - - - -
95bccdd0 by Ben Gamari at 2020-03-31T10:56:19-04:00
base: Ensure that encoding global variables aren't inlined

As noted in #17970, these (e.g. `getFileSystemEncoding` and
`setFileSystemEncoding`) previously had unfoldings, which would
break their global-ness.

While not strictly necessary, I also add a NOINLINE on
`initLocaleEncoding` since it is used in `System.IO`, ensuring that we
only system's query the locale encoding once.

Fixes #17970.

- - - - -
982aaa83 by Andreas Klebinger at 2020-03-31T10:56:55-04:00
Update hadrian index revision.

Required in order to build hadrian using ghc-8.10

- - - - -
4b9c5864 by Ben Gamari at 2020-03-31T10:57:32-04:00
integer-gmp: Bump version and add changelog entry

- - - - -
9b39f2e6 by Ryan Scott at 2020-04-01T01:20:00-04:00
Clean up "Eta reduction for data families" Notes

Before, there were two distinct Notes named
"Eta reduction for data families". This renames one of them to
"Implementing eta reduction for data families" to disambiguate the
two and fixes references in other parts of the codebase to ensure
that they are pointing to the right place.

Fixes #17313.

[ci skip]

- - - - -
7627eab5 by Ryan Scott at 2020-04-01T01:20:38-04:00
Fix the changelog/@since information for hGetContents'/getContents'/readFile'

Fixes #17979.

[ci skip]

- - - - -
0002db1b by Sylvain Henry at 2020-04-01T01:21:27-04:00
Kill wORDS_BIGENDIAN and replace it with platformByteOrder (#17957)

Metric Decrease:
    T13035
    T1969

- - - - -
7b217179 by Sebastian Graf at 2020-04-01T15:03:24-04:00
PmCheck: Adjust recursion depth for inhabitation test

In #17977, we ran into the reduction depth limit of the typechecker.
That was only a symptom of a much broader issue: The recursion depth
of the coverage checker for trying to instantiate strict fields in the
`nonVoid` test was far too high (100, the `defaultMaxTcBound`).

As a result, we were performing quite poorly on `T17977`.
Short of a proper termination analysis to prove emptyness of a type,
we just arbitrarily default to a much lower recursion limit of 3.

Fixes #17977.

- - - - -
3c09f636 by Andreas Klebinger at 2020-04-01T15:03:59-04:00
Make hadrian pass on the no-colour setting to GHC.

Fixes #17983.

- - - - -
b943b25d by Simon Peyton Jones at 2020-04-02T01:45:58-04:00
Re-engineer the binder-swap transformation

The binder-swap transformation is implemented by the occurrence
analyser -- see Note [Binder swap] in OccurAnal. However it had
a very nasty corner in it, for the case where the case scrutinee
was a GlobalId.  This led to trouble and hacks, and ultimately
to #16296.

This patch re-engineers how the occurrence analyser implements
the binder-swap, by actually carrying out a substitution rather
than by adding a let-binding.  It's all described in
Note [The binder-swap substitution].

I did a few other things along the way

* Fix a bug in StgCse, which could allow a loop breaker to be CSE'd
  away.  See Note [Care with loop breakers] in StgCse.  I think it can
  only show up if occurrence analyser sets up bad loop breakers, but
  still.

* Better commenting in SimplUtils.prepareAlts

* A little refactoring in CoreUnfold; nothing significant
  e.g. rename CoreUnfold.mkTopUnfolding to mkFinalUnfolding

* Renamed CoreSyn.isFragileUnfolding to hasCoreUnfolding

* Move mkRuleInfo to CoreFVs

We observed respectively 4.6% and 5.9% allocation decreases for the following
tests:

Metric Decrease:
    T9961
    haddock.base

- - - - -
42d68364 by Sebastian Graf at 2020-04-02T01:46:34-04:00
Preserve precise exceptions in strictness analysis

Fix #13380 and #17676 by

1. Changing `raiseIO#` to have `topDiv` instead of `botDiv`
2. Give it special treatment in `Simplifier.Util.mkArgInfo`, treating it
   as if it still had `botDiv`, to recover dead code elimination.

This is the first commit of the plan outlined in
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/2525#note_260886.

- - - - -
0a88dd11 by Ömer Sinan Ağacan at 2020-04-02T01:47:25-04:00
Fix a pointer format string in RTS

- - - - -
5beac042 by Ömer Sinan Ağacan at 2020-04-02T01:48:05-04:00
Remove unused closure stg_IND_direct

- - - - -
88f38b03 by Ben Gamari at 2020-04-02T01:48:42-04:00
Session: Memoize stderrSupportsAnsiColors

Not only is this a reasonable efficiency measure but it avoids making
reentrant calls into ncurses, which is not thread-safe. See #17922.

- - - - -
27740f24 by Ryan Scott at 2020-04-02T01:49:21-04:00
Make Hadrian build with Cabal-3.2

GHC 8.10 ships with `Cabal-3.2.0.0`, so it would be convenient to
make Hadrian supporting building against 3.2.* instead of having to
rebuild the entirety of `Cabal-3.0.0.0`. There is one API change in
`Cabal-3.2.*` that affects Hadrian: the `synopsis` and `description`
functions now return `ShortText` instead of `String`. Since Hadrian
manipulates these `String`s in various places, I found that the
simplest fix was to use CPP to convert `ShortText` to `String`s
where appropriate.

- - - - -
49802002 by Sylvain Henry at 2020-04-02T01:50:00-04:00
Update Stack resolver for hadrian/build-stack

Broken by 57b888c0e90be7189285a6b078c30b26d0923809

- - - - -
30a63e79 by Ryan Scott at 2020-04-02T01:50:36-04:00
Fix two ASSERT buglets in reifyDataCon

Two `ASSERT`s in `reifyDataCon` were always using `arg_tys`, but
`arg_tys` is not meaningful for GADT constructors. In fact, it's
worse than non-meaningful, since using `arg_tys` when reifying a
GADT constructor can lead to failed `ASSERT`ions, as #17305
demonstrates.

This patch applies the simplest possible fix to the immediate
problem. The `ASSERT`s now use `r_arg_tys` instead of `arg_tys`, as
the former makes sure to give something meaningful for GADT
constructors. This makes the panic go away at the very least. There
is still an underlying issue with the way the internals of
`reifyDataCon` work, as described in
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227023, but we
leave that as future work, since fixing the underlying issue is
much trickier (see
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227087).

- - - - -
ef7576c4 by Zubin Duggal at 2020-04-03T06:24:56-04:00
Add outputable instances for the types in GHC.Iface.Ext.Types, add -ddump-hie
flag to dump pretty printed contents of the .hie file

Metric Increase:
   hie002

Because of the regression on i386:

compile_time/bytes allocated increased from i386-linux-deb9 baseline @ HEAD~10:
    Expected    hie002 (normal) compile_time/bytes allocated: 583014888.0 +/-10%
    Lower bound hie002 (normal) compile_time/bytes allocated:   524713399
    Upper bound hie002 (normal) compile_time/bytes allocated:   641316377
    Actual      hie002 (normal) compile_time/bytes allocated:   877986292
    Deviation   hie002 (normal) compile_time/bytes allocated:        50.6 %
*** unexpected stat test failure for hie002(normal)

- - - - -
9462452a by Andreas Klebinger at 2020-04-03T06:25:33-04:00
Improve and refactor StgToCmm codegen for DataCons.

We now differentiate three cases of constructor bindings:

1)Bindings which we can "replace" with a reference to
  an existing closure. Reference the replacement closure
  when accessing the binding.
2)Bindings which we can "replace" as above. But we still
  generate a closure which will be referenced by modules
  importing this binding.
3)For any other binding generate a closure. Then reference
  it.

Before this patch 1) did only apply to local bindings and we
didn't do 2) at all.

- - - - -
a214d214 by Moritz Bruder at 2020-04-03T06:26:11-04:00
Add singleton to NonEmpty in libraries/base

This adds a definition to construct a singleton non-empty list
(Data.List.NonEmpty) according to issue #17851.

- - - - -
f7597aa0 by Sylvain Henry at 2020-04-03T06:26:54-04:00
Testsuite: measure compiler stats for T16190

We were mistakenly measuring program stats

- - - - -
a485c3c4 by Sylvain Henry at 2020-04-03T06:26:54-04:00
Move blob handling into StgToCmm

Move handling of big literal strings from CmmToAsm to StgToCmm. It
avoids the use of `sdocWithDynFlags` (cf #10143). We might need to move
this handling even higher in the pipeline in the future (cf #17960):
this patch will make it easier.

- - - - -
cc2918a0 by Sylvain Henry at 2020-04-03T06:26:54-04:00
Refactor CmmStatics

In !2959 we noticed that there was some redundant code (in GHC.Cmm.Utils
and GHC.Cmm.StgToCmm.Utils) used to deal with `CmmStatics` datatype
(before SRT generation) and `RawCmmStatics` datatype (after SRT
generation).

This patch removes this redundant code by using a single GADT for
(Raw)CmmStatics.

- - - - -
9e60273d by Maxim Koltsov at 2020-04-03T06:27:32-04:00
Fix haddock formatting in Control.Monad.ST.Lazy.Imp.hs

- - - - -
1b7e8a94 by Andreas Klebinger at 2020-04-03T06:28:08-04:00
Turn newlines into spaces for hadrian/ghci.

The newlines break the command on windows.

- - - - -
4291bdda by Simon Peyton Jones at 2020-04-03T06:28:44-04:00
Major improvements to the specialiser

This patch is joint work of Alexis King and Simon PJ.  It does some
significant refactoring of the type-class specialiser.  Main highlights:

* We can specialise functions with types like
     f :: Eq a => a -> Ord b => b => blah
  where the classes aren't all at the front (#16473).  Here we can
  correctly specialise 'f' based on a call like
     f @Int @Bool dEqInt x dOrdBool
  This change really happened in an earlier patch
     commit 2d0cf6252957b8980d89481ecd0b79891da4b14b
     Author: Sandy Maguire <sandy at sandymaguire.me>
     Date:   Thu May 16 12:12:10 2019 -0400
  work that this new patch builds directly on that work, and refactors
  it a bit.

* We can specialise functions with implicit parameters (#17930)
     g :: (?foo :: Bool, Show a) => a -> String
  Previously we could not, but now they behave just like a non-class
  argument as in 'f' above.

* We can specialise under-saturated calls, where some (but not all of
  the dictionary arguments are provided (#17966).  For example, we can
  specialise the above 'f' based on a call
     map (f @Int dEqInt) xs
  even though we don't (and can't) give Ord dictionary.

  This may sound exotic, but #17966 is a program from the wild, and
  showed significant perf loss for functions like f, if you need
  saturation of all dictionaries.

* We fix a buglet in which a floated dictionary had a bogus demand
  (#17810), by using zapIdDemandInfo in the NonRec case of specBind.

* A tiny side benefit: we can drop dead arguments to specialised
  functions; see Note [Drop dead args from specialisations]

* Fixed a bug in deciding what dictionaries are "interesting"; see
  Note [Keep the old dictionaries interesting]

This is all achieved by by building on Sandy Macguire's work in
defining SpecArg, which mkCallUDs uses to describe the arguments of
the call. Main changes:

* Main work is in specHeader, which marched down the [InBndr] from the
  function definition and the [SpecArg] from the call site, together.

* specCalls no longer has an arity check; the entire mechanism now
  handles unders-saturated calls fine.

* mkCallUDs decides on an argument-by-argument basis whether to
  specialise a particular dictionary argument; this is new.
  See mk_spec_arg in mkCallUDs.

It looks as if there are many more lines of code, but I think that
all the extra lines are comments!

- - - - -
40a85563 by Ömer Sinan Ağacan at 2020-04-03T18:26:19+03:00
Revert accidental change in 9462452

[ci skip]

- - - - -
bd75e5da by Ryan Scott at 2020-04-04T07:07:58-04:00
Enable ImpredicativeTypes internally when typechecking selector bindings

This is necessary for certain record selectors with higher-rank
types, such as the examples in #18005. See
`Note [Impredicative record selectors]` in `TcTyDecls`.

Fixes #18005.

- - - - -
dcfe29c8 by Ömer Sinan Ağacan at 2020-04-06T13:16:08-04:00
Don't override proc CafInfos in ticky builds

Fixes #17947

When we have a ticky label for a proc, IdLabels for the ticky counter
and proc entry share the same Name. This caused overriding proc CafInfos
with the ticky CafInfos (i.e. NoCafRefs) during SRT analysis.

We now ignore the ticky labels when building SRTMaps. This makes sense
because:

- When building the current module they don't need to be in SRTMaps as
  they're initialized as non-CAFFY (see mkRednCountsLabel), so they
  don't take part in the dependency analysis and they're never added to
  SRTs.

  (Reminder: a "dependency" in the SRT analysis is a CAFFY dependency,
  non-CAFFY uses are not considered as dependencies for the algorithm)

- They don't appear in the interfaces as they're not exported, so it
  doesn't matter for cross-module concerns whether they're in the SRTMap
  or not.

See also the new Note [Ticky labels in SRT analysis].

- - - - -
cec2c71f by Simon Peyton Jones at 2020-04-06T13:16:44-04:00
Fix an tricky specialiser loop

Issue #17151 was a very tricky example of a bug in which the
specialiser accidentally constructs a recurive dictionary,
so that everything turns into bottom.

I have fixed variants of this bug at least twice before:
see Note [Avoiding loops].  It was a bit of a struggle
to isolate the problem, greatly aided by the work that
Alexey Kuleshevich did in distilling a test case.

Once I'd understood the problem, it was not difficult to fix,
though it did lead me a bit of refactoring in specImports.

- - - - -
e850d14f by Simon Peyton Jones at 2020-04-06T13:16:44-04:00
Refactoring only

This refactors DictBinds into a data type rather than a pair.
No change in behaviour, just better code

- - - - -
f38e8d61 by Daniel Gröber at 2020-04-07T02:00:05-04:00
rts: ProfHeap: Fix memory leak when not compiled with profiling

If we're doing heap profiling on an unprofiled executable we keep
allocating new space in initEra via nextEra on each profiler run but we
don't have a corresponding freeEra call.

We do free the last era in endHeapProfiling but previous eras will have
been overwritten by initEra and will never get free()ed.

Metric Decrease:
    space_leak_001

- - - - -
bcd66859 by Sebastian Graf at 2020-04-07T02:00:41-04:00
Re-export GHC.Magic.noinline from base

- - - - -
3d2991f8 by Ben Gamari at 2020-04-07T18:36:09-04:00
simplifier: Kill off ufKeenessFactor

We used to have another factor, ufKeenessFactor, which would scale the
discounts before they were subtracted from the size. This was justified
with the following comment:

  -- We multiple the raw discounts (args_discount and result_discount)
  -- ty opt_UnfoldingKeenessFactor because the former have to do with
  --  *size* whereas the discounts imply that there's some extra
  --  *efficiency* to be gained (e.g. beta reductions, case reductions)
  -- by inlining.

However, this is highly suspect since it means that we subtract a
*scaled* size from an absolute size, resulting in crazy (e.g. negative)
scores in some cases (#15304). We consequently killed off
ufKeenessFactor and bumped up the ufUseThreshold to compensate.

Adjustment of unfolding use threshold
=====================================

Since this removes a discount from our inlining heuristic, I revisited our
default choice of -funfolding-use-threshold to minimize the change in
overall inlining behavior. Specifically, I measured runtime allocations
and executable size of nofib and the testsuite performance tests built
using compilers (and core libraries) built with several values of
-funfolding-use-threshold.

This comes as a result of a quantitative comparison of testsuite
performance and code size as a function of ufUseThreshold, comparing
GHC trees using values of 50, 60, 70, 80, 90, and 100. The test set
consisted of nofib and the testsuite performance tests.
A full summary of these measurements are found in the description of
!2608

Comparing executable sizes (relative to the base commit) across all
nofib tests, we see that sizes are similar to the baseline:

            gmean      min      max   median
thresh
50         -6.36%   -7.04%   -4.82%   -6.46%
60         -5.04%   -5.97%   -3.83%   -5.11%
70         -2.90%   -3.84%   -2.31%   -2.92%
80         -0.75%   -2.16%   -0.42%   -0.73%
90         +0.24%   -0.41%   +0.55%   +0.26%
100        +1.36%   +0.80%   +1.64%   +1.37%
baseline   +0.00%   +0.00%   +0.00%   +0.00%

Likewise, looking at runtime allocations we see that 80 gives slightly
better optimisation than the baseline:

            gmean      min      max   median
thresh
50         +0.16%   -0.16%   +4.43%   +0.00%
60         +0.09%   -0.00%   +3.10%   +0.00%
70         +0.04%   -0.09%   +2.29%   +0.00%
80         +0.02%   -1.17%   +2.29%   +0.00%
90         -0.02%   -2.59%   +1.86%   +0.00%
100        +0.00%   -2.59%   +7.51%   -0.00%
baseline   +0.00%   +0.00%   +0.00%   +0.00%

Finally, I had to add a NOINLINE in T4306 to ensure that `upd` is
worker-wrappered as the test expects. This makes me wonder whether the
inlining heuristic is now too liberal as `upd` is quite a large
function. The same measure was taken in T12600.

             Wall clock time compiling Cabal with -O0
thresh       50     60     70     80     90      100    baseline
build-Cabal  93.88  89.58  92.59  90.09  100.26  94.81  89.13

Also, this change happens to avoid the spurious test output in
`plugin-recomp-change` and `plugin-recomp-change-prof` (see #17308).

Metric Decrease:
    hie002
    T12234
    T13035
    T13719
    T14683
    T4801
    T5631
    T5642
    T9020
    T9872d
    T9961
Metric Increase:
    T12150
    T12425
    T13701
    T14697
    T15426
    T1969
    T3064
    T5837
    T6048
    T9203
    T9872a
    T9872b
    T9872c
    T9872d
    haddock.Cabal
    haddock.base
    haddock.compiler

- - - - -
255418da by Sylvain Henry at 2020-04-07T18:36:49-04:00
Modules: type-checker (#13009)

Update Haddock submodule

- - - - -
04b6cf94 by Ryan Scott at 2020-04-07T19:43:20-04:00
Make NoExtCon fields strict

This changes every unused TTG extension constructor to be strict in
its field so that the pattern-match coverage checker is smart enough
any such constructors are unreachable in pattern matches. This lets
us remove nearly every use of `noExtCon` in the GHC API. The only
ones we cannot remove are ones underneath uses of `ghcPass`, but that
is only because GHC 8.8's and 8.10's coverage checkers weren't smart
enough to perform this kind of reasoning. GHC HEAD's coverage
checker, on the other hand, _is_ smart enough, so we guard these uses
of `noExtCon` with CPP for now.

Bumps the `haddock` submodule.

Fixes #17992.

- - - - -
7802fa17 by Ryan Scott at 2020-04-08T16:43:44-04:00
Handle promoted data constructors in typeToLHsType correctly

Instead of using `nlHsTyVar`, which hardcodes `NotPromoted`, have
`typeToLHsType` pick between `Promoted` and `NotPromoted` by checking
if a type constructor is promoted using `isPromotedDataCon`.

Fixes #18020.

- - - - -
ce481361 by Ben Gamari at 2020-04-09T16:17:21-04:00
hadrian: Use --export-dynamic when linking iserv

As noticed in #17962, the make build system currently does this (see
3ce0e0ba) but the change was never ported to Hadrian.

- - - - -
fa66f143 by Ben Gamari at 2020-04-09T16:17:21-04:00
iserv: Don't pass --export-dynamic on FreeBSD

This is definitely a hack but it's probably the best we can do for now.
Hadrian does the right thing here by passing --export-dynamic only to
the linker.

- - - - -
39075176 by Ömer Sinan Ağacan at 2020-04-09T16:18:00-04:00
Fix CNF handling in compacting GC

Fixes #17937

Previously compacting GC simply ignored CNFs. This is mostly fine as
most (see "What about small compacts?" below) CNF objects don't have
outgoing pointers, and are "large" (allocated in large blocks) and large
objects are not moved or compacted.

However if we do GC *during* sharing-preserving compaction then the CNF
will have a hash table mapping objects that have been moved to the CNF
to their location in the CNF, to be able to preserve sharing.

This case is handled in the copying collector, in `scavenge_compact`,
where we evacuate hash table entries and then rehash the table.

Compacting GC ignored this case.

We now visit CNFs in all generations when threading pointers to the
compacted heap and thread hash table keys. A visited CNF is added to the
list `nfdata_chain`. After compaction is done, we re-visit the CNFs in
that list and rehash the tables.

The overhead is minimal: the list is static in `Compact.c`, and link
field is added to `StgCompactNFData` closure. Programs that don't use
CNFs should not be affected.

To test this CNF tests are now also run in a new way 'compacting_gc',
which just passes `-c` to the RTS, enabling compacting GC for the oldest
generation. Before this patch the result would be:

    Unexpected failures:
       compact_gc.run          compact_gc [bad exit code (139)] (compacting_gc)
       compact_huge_array.run  compact_huge_array [bad exit code (1)] (compacting_gc)

With this patch all tests pass. I can also pass `-c -DS` without any
failures.

What about small compacts? Small CNFs are still not handled by the
compacting GC. However so far I'm unable to write a test that triggers a
runtime panic ("update_fwd: unknown/strange object") by allocating a
small CNF in a compated heap. It's possible that I'm missing something
and it's not possible to have a small CNF.

NoFib Results:

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          +0.1%      0.0%      0.0%     +0.0%     +0.0%
            CSD          +0.1%      0.0%      0.0%      0.0%      0.0%
             FS          +0.1%      0.0%      0.0%      0.0%      0.0%
              S          +0.1%      0.0%      0.0%      0.0%      0.0%
             VS          +0.1%      0.0%      0.0%      0.0%      0.0%
            VSD          +0.1%      0.0%     +0.0%     +0.0%     -0.0%
            VSM          +0.1%      0.0%     +0.0%     -0.0%      0.0%
           anna          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
           ansi          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           atom          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         awards          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         banner          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
     bernouilli          +0.1%      0.0%      0.0%     -0.0%     +0.0%
   binary-trees          +0.1%      0.0%     -0.0%     -0.0%      0.0%
          boyer          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         boyer2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           bspt          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
      cacheprof          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
       calendar          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       cichelli          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
        circsim          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       clausify          +0.1%      0.0%     -0.0%     +0.0%     +0.0%
  comp_lab_zift          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       compress          +0.1%      0.0%     +0.0%     +0.0%      0.0%
      compress2          +0.1%      0.0%     -0.0%      0.0%      0.0%
    constraints          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
   cryptarithm1          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
   cryptarithm2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
            cse          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
   digits-of-e1          +0.1%      0.0%     +0.0%     -0.0%     -0.0%
   digits-of-e2          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
          eliza          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
          event          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
    exact-reals          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         exp3_8          +0.1%      0.0%     +0.0%     -0.0%      0.0%
         expert          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
 fannkuch-redux          +0.1%      0.0%     -0.0%      0.0%      0.0%
          fasta          +0.1%      0.0%     -0.0%     +0.0%     +0.0%
            fem          +0.1%      0.0%     -0.0%     +0.0%      0.0%
            fft          +0.1%      0.0%     -0.0%     +0.0%     +0.0%
           fft2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       fibheaps          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           fish          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
          fluid          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         fulsom          +0.1%      0.0%     -0.0%     +0.0%      0.0%
         gamteb          +0.1%      0.0%     +0.0%     +0.0%      0.0%
            gcd          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
    gen_regexps          +0.1%      0.0%     -0.0%     +0.0%      0.0%
         genfft          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
             gg          +0.1%      0.0%      0.0%     +0.0%     +0.0%
           grep          +0.1%      0.0%     -0.0%     +0.0%     +0.0%
         hidden          +0.1%      0.0%     +0.0%     -0.0%      0.0%
            hpg          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
            ida          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
          infer          +0.1%      0.0%     +0.0%      0.0%     -0.0%
        integer          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
      integrate          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
   k-nucleotide          +0.1%      0.0%     +0.0%     +0.0%      0.0%
          kahan          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
        knights          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         lambda          +0.1%      0.0%     +0.0%     +0.0%     -0.0%
     last-piece          +0.1%      0.0%     +0.0%      0.0%      0.0%
           lcss          +0.1%      0.0%     +0.0%     +0.0%      0.0%
           life          +0.1%      0.0%     -0.0%     +0.0%     +0.0%
           lift          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         linear          +0.1%      0.0%     -0.0%     +0.0%      0.0%
      listcompr          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       listcopy          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       maillist          +0.1%      0.0%     +0.0%     -0.0%     -0.0%
         mandel          +0.1%      0.0%     +0.0%     +0.0%      0.0%
        mandel2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           mate          +0.1%      0.0%     +0.0%      0.0%     +0.0%
        minimax          +0.1%      0.0%     -0.0%      0.0%     -0.0%
        mkhprog          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
     multiplier          +0.1%      0.0%     +0.0%      0.0%      0.0%
         n-body          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       nucleic2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           para          +0.1%      0.0%      0.0%     +0.0%     +0.0%
      paraffins          +0.1%      0.0%     +0.0%     -0.0%      0.0%
         parser          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
        parstof          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
            pic          +0.1%      0.0%     -0.0%     -0.0%      0.0%
       pidigits          +0.1%      0.0%     +0.0%     -0.0%     -0.0%
          power          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         pretty          +0.1%      0.0%     -0.0%     -0.0%     -0.1%
         primes          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
      primetest          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         prolog          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         puzzle          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         queens          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
        reptile          +0.1%      0.0%     -0.0%     -0.0%     +0.0%
reverse-complem          +0.1%      0.0%     +0.0%      0.0%     -0.0%
        rewrite          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
           rfib          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
            rsa          +0.1%      0.0%     -0.0%     +0.0%     -0.0%
            scc          +0.1%      0.0%     -0.0%     -0.0%     -0.1%
          sched          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
            scs          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         simple          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
          solid          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
        sorting          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
  spectral-norm          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
         sphere          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
         symalg          +0.1%      0.0%     -0.0%     -0.0%     -0.0%
            tak          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
      transform          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
       treejoin          +0.1%      0.0%     +0.0%     -0.0%     -0.0%
      typecheck          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
        veritas          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
           wang          +0.1%      0.0%      0.0%     +0.0%     +0.0%
      wave4main          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
   wheel-sieve1          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
   wheel-sieve2          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
           x2n1          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
--------------------------------------------------------------------------------
            Min          +0.0%      0.0%     -0.0%     -0.0%     -0.1%
            Max          +0.1%      0.0%     +0.0%     +0.0%     +0.0%
 Geometric Mean          +0.1%     -0.0%     -0.0%     -0.0%     -0.0%

Bumping numbers of nonsensical perf tests:

Metric Increase:
    T12150
    T12234
    T12425
    T13035
    T5837
    T6048

It's simply not possible for this patch to increase allocations, and
I've wasted enough time on these test in the past (see #17686). I think
these tests should not be perf tests, but for now I'll bump the numbers.

- - - - -
dce50062 by Sylvain Henry at 2020-04-09T16:18:44-04:00
Rts: show errno on failure (#18033)

- - - - -
045139f4 by Hécate at 2020-04-09T23:10:44-04:00
Add an example to liftIO and explain its purpose

- - - - -
101fab6e by Sebastian Graf at 2020-04-09T23:11:21-04:00
Special case `isConstraintKindCon` on `AlgTyCon`

Previously, the `tyConUnique` record selector would unfold into a huge
case expression that would be inlined in all call sites, such as the
`INLINE`-annotated `coreView`, see #18026. `constraintKindTyConKey` only
occurs as the `Unique` of an `AlgTyCon` anyway, so we can make the code
a lot more compact, but have to move it to GHC.Core.TyCon.

Metric Decrease:
    T12150
    T12234

- - - - -
f5212dfc by Sebastian Graf at 2020-04-09T23:11:57-04:00
DmdAnal: No need to attach a StrictSig to DataCon workers

In GHC.Types.Id.Make we were giving a strictness signature to every data
constructor wrapper Id that we weren't looking at in demand analysis
anyway. We used to use its CPR info, but that has its own CPR signature
now.

`Note [Data-con worker strictness]` then felt very out of place, so I
moved it to GHC.Core.DataCon.

- - - - -
75a185dc by Sylvain Henry at 2020-04-09T23:12:37-04:00
Hadrian: fix --summary

- - - - -
723062ed by Ömer Sinan Ağacan at 2020-04-10T09:18:14+03:00
testsuite: Move no_lint to the top level, tweak hie002

- We don't want to benchmark linting so disable lints in hie002 perf
  test

- Move no_lint to the top-level to be able to use it in tests other than
  those in `testsuite/tests/perf/compiler`.

- Filter out -dstg-lint in no_lint.

- hie002 allocation numbers on 32-bit are unstable, so skip it on 32-bit

Metric Decrease:
    hie002
    ManyConstructors
    T12150
    T12234
    T13035
    T1969
    T4801
    T9233
    T9961

- - - - -
bcafaa82 by Peter Trommler at 2020-04-10T19:29:33-04:00
Testsuite: mark T11531 fragile

The test depends on a link editor allowing undefined symbols in an ELF
shared object. This is the standard but it seems some distributions
patch their link editor. See the report by @hsyl20 in #11531.

Fixes #11531

- - - - -
0889f5ee by Takenobu Tani at 2020-04-12T11:44:52+09:00
testsuite: Fix comment for a language extension

[skip ci]

- - - - -
cd4f92b5 by Simon Peyton Jones at 2020-04-12T11:20:58-04:00
Significant refactor of Lint

This refactoring of Lint was triggered by #17923, which is
fixed by this patch.

The main change is this.  Instead of
   lintType :: Type -> LintM LintedKind
we now have
   lintType :: Type -> LintM LintedType

Previously, all of typeKind was effectively duplicate in lintType.
Moreover, since we have an ambient substitution, we still had to
apply the substition here and there, sometimes more than once. It
was all very tricky, in the end, and made my head hurt.

Now, lintType returns a fully linted type, with all substitutions
performed on it.  This is much simpler.

The same thing is needed for Coercions.  Instead of
  lintCoercion :: OutCoercion
               -> LintM (LintedKind, LintedKind,
                         LintedType, LintedType, Role)
we now have
  lintCoercion :: Coercion -> LintM LintedCoercion

Much simpler!  The code is shorter and less bug-prone.

There are a lot of knock on effects.  But life is now better.

Metric Decrease:
    T1969

- - - - -
0efaf301 by Josh Meredith at 2020-04-12T11:21:34-04:00
Implement extensible interface files

- - - - -
54ca66a7 by Ryan Scott at 2020-04-12T11:22:10-04:00
Use conLikeUserTyVarBinders to quantify field selector types

This patch:

1. Writes up a specification for how the types of top-level field
   selectors should be determined in a new section of the GHC User's
   Guide, and
2. Makes GHC actually implement that specification by using
   `conLikeUserTyVarBinders` in `mkOneRecordSelector` to preserve the
   order and specificity of type variables written by the user.

Fixes #18023.

- - - - -
35799dda by Ben Gamari at 2020-04-12T11:22:50-04:00
hadrian: Don't --export-dynamic on Darwin

When fixing #17962 I neglected to consider that --export-dynamic is only
supported on ELF platforms.

- - - - -
e8029816 by Alexis King at 2020-04-12T11:23:27-04:00
Add an INLINE pragma to Control.Category.>>>

This fixes #18013 by adding INLINE pragmas to both Control.Category.>>>
and GHC.Desugar.>>>. The functional change in this patch is tiny (just
two lines of pragmas!), but an accompanying Note explains in gory
detail what’s going on.

- - - - -
0da186c1 by Krzysztof Gogolewski at 2020-04-14T07:55:20-04:00
Change zipWith to zipWithEqual in a few places

- - - - -
074c1ccd by Andreas Klebinger at 2020-04-14T07:55:55-04:00
Small change to the windows ticker.

We already have a function to go from time to ms so use it.
Also expand on the state of timer resolution.

- - - - -
b69cc884 by Alp Mestanogullari at 2020-04-14T07:56:38-04:00
hadrian: get rid of unnecessary levels of nesting in source-dist

- - - - -
d0c3b069 by Julien Debon at 2020-04-14T07:57:16-04:00
doc (Foldable): Add examples to Data.Foldable

See #17929

- - - - -
5b08e0c0 by Ben Gamari at 2020-04-14T23:28:20-04:00
StgCRun: Enable unwinding only on Linux

It's broken on macOS due and SmartOS due to assembler differences
(#15207) so let's be conservative in enabling it. Also, refactor things
to make the intent clearer.

- - - - -
27cc2e7b by Ben Gamari at 2020-04-14T23:28:57-04:00
rts: Don't mark evacuate_large as inline

This function has two callsites and is quite large. GCC consequently
decides not to inline and warns instead. Given the situation, I can't
blame it. Let's just remove the inline specifier.

- - - - -
9853fc5e by Ben Gamari at 2020-04-14T23:29:48-04:00
base: Enable large file support for OFD locking impl.

Not only is this a good idea in general but this should also avoid
issue #17950 by ensuring that off_t is 64-bits.

- - - - -
7b41f21b by Matthew Pickering at 2020-04-14T23:30:24-04:00
Hadrian: Make -i paths absolute

The primary reason for this change is that ghcide does not work with
relative paths. It also matches what cabal and stack do, they always
pass absolute paths.

- - - - -
41230e26 by Daniel Gröber at 2020-04-14T23:31:01-04:00
Zero out pinned block alignment slop when profiling

The heap profiler currently cannot traverse pinned blocks because of
alignment slop. This used to just be a minor annoyance as the whole block
is accounted into a special cost center rather than the respective object's
CCS, cf. #7275. However for the new root profiler we would like to be able
to visit _every_ closure on the heap. We need to do this so we can get rid
of the current 'flip' bit hack in the heap traversal code.

Since info pointers are always non-zero we can in principle skip all the
slop in the profiler if we can rely on it being zeroed. This assumption
caused problems in the past though, commit a586b33f8e ("rts: Correct
handling of LARGE ARR_WORDS in LDV profiler"), part of !1118, tried to use
the same trick for BF_LARGE objects but neglected to take into account that
shrink*Array# functions don't ensure that slop is zeroed when not
compiling with profiling.

Later, commit 0c114c6599 ("Handle large ARR_WORDS in heap census (fix
as we will only be assuming slop is zeroed when profiling is on.

This commit also reduces the ammount of slop we introduce in the first
place by calculating the needed alignment before doing the allocation for
small objects where we know the next available address. For large objects
we don't know how much alignment we'll have to do yet since those details
are hidden behind the allocateMightFail function so there we continue to
allocate the maximum additional words we'll need to do the alignment.

So we don't have to duplicate all this logic in the cmm code we pull it
into the RTS allocatePinned function instead.

Metric Decrease:
    T7257
    haddock.Cabal
    haddock.base

- - - - -
15fa9bd6 by Daniel Gröber at 2020-04-14T23:31:01-04:00
rts: Expand and add more notes regarding slop

- - - - -
caf3f444 by Daniel Gröber at 2020-04-14T23:31:01-04:00
rts: allocatePinned: Fix confusion about word/byte units

- - - - -
c3c0f662 by Daniel Gröber at 2020-04-14T23:31:01-04:00
rts: Underline some Notes as is conventional

- - - - -
e149dea9 by Daniel Gröber at 2020-04-14T23:31:38-04:00
rts: Fix nomenclature in OVERWRITING_CLOSURE macros

The additional commentary introduced by commit 8916e64e5437 ("Implement
shrinkSmallMutableArray# and resizeSmallMutableArray#.") unfortunately got
this wrong. We set 'prim' to true in overwritingClosureOfs because we
_don't_ want to call LDV_recordDead().

The reason is because of this "inherently used" distinction made in the LDV
profiler so I rename the variable to be more appropriate.

- - - - -
1dd3d18c by Daniel Gröber at 2020-04-14T23:31:38-04:00
Remove call to LDV_RECORD_CREATE for array resizing

- - - - -
19de2fb0 by Daniel Gröber at 2020-04-14T23:31:38-04:00
rts: Assert LDV_recordDead is not called for inherently used closures

The comments make it clear LDV_recordDead should not be called for
inhererently used closures, so add an assertion to codify this fact.

- - - - -
0b934e30 by Ryan Scott at 2020-04-14T23:32:14-04:00
Bump template-haskell version to 2.17.0.0

This requires bumping the `exceptions` and `text` submodules to bring
in commits that bump their respective upper version bounds on
`template-haskell`.

Fixes #17645. Fixes #17696.

Note that the new `text` commit includes a fair number of additions
to the Haddocks in that library. As a result, Haddock has to do more
work during the `haddock.Cabal` test case, increasing the number of
allocations it requires. Therefore,

-------------------------
Metric Increase:
    haddock.Cabal
-------------------------

- - - - -
22cc8e51 by Ryan Scott at 2020-04-15T17:48:47-04:00
Fix #18052 by using pprPrefixOcc in more places

This fixes several small oversights in the choice of pretty-printing
function to use. Fixes #18052.

- - - - -
ec77b2f1 by Daniel Gröber at 2020-04-15T17:49:24-04:00
rts: ProfHeap: Fix wrong time in last heap profile sample

We've had this longstanding issue in the heap profiler, where the time of
the last sample in the profile is sometimes way off causing the rendered
graph to be quite useless for long runs.

It seems to me the problem is that we use mut_user_time() for the last
sample as opposed to getRTSStats(), which we use when calling heapProfile()
in GC.c.

The former is equivalent to getProcessCPUTime() but the latter does
some additional stuff:

    getProcessCPUTime() - end_init_cpu - stats.gc_cpu_ns -
    stats.nonmoving_gc_cpu_ns

So to fix this just use getRTSStats() in both places.

- - - - -
85fc32f0 by Sylvain Henry at 2020-04-17T12:45:25-04:00
Hadrian: fix dyn_o/dyn_hi rule (#17534)

- - - - -
bfde3b76 by Ryan Scott at 2020-04-17T12:46:02-04:00
Fix #18065 by fixing an InstCo oversight in Core Lint

There was a small thinko in Core Lint's treatment of `InstCo`
coercions that ultimately led to #18065. The fix: add an apostrophe.
That's it!

Fixes #18065.

Co-authored-by: Simon Peyton Jones <simonpj at microsoft.com>

- - - - -
a05348eb by Cale Gibbard at 2020-04-17T13:08:47-04:00
Change the fail operator argument of BindStmt to be a Maybe

Don't use noSyntaxExpr for it. There is no good way to defensively case
on that, nor is it clear one ought to do so.

- - - - -
79e27144 by John Ericson at 2020-04-17T13:08:47-04:00
Use trees that grow for rebindable operators for `<-` binds

Also add more documentation.

- - - - -
18bc16ed by Cale Gibbard at 2020-04-17T13:08:47-04:00
Use FailOperator in more places, define a couple datatypes (XBindStmtRn and XBindStmtTc) to help clarify the meaning of XBindStmt in the renamer and typechecker

- - - - -
84cc8394 by Simon Peyton Jones at 2020-04-18T13:20:29-04:00
Add a missing zonk in tcHsPartialType

I omitted a vital zonk when refactoring tcHsPartialType in
   commit 48fb3482f8cbc8a4b37161021e846105f980eed4
   Author: Simon Peyton Jones <simonpj at microsoft.com>
   Date:   Wed Jun 5 08:55:17 2019 +0100

   Fix typechecking of partial type signatures

This patch fixes it and adds commentary to explain why.

Fixes #18008

- - - - -
2ee96ac1 by Ben Gamari at 2020-04-18T13:21:05-04:00
gitlab-ci: Bump FreeBSD bootstrap compiler to 8.10.1

- - - - -
434312e5 by Ben Gamari at 2020-04-18T13:21:05-04:00
gitlab-ci: Enable FreeBSD job for so-labelled MRs

- - - - -
ddffb227 by Ben Gamari at 2020-04-18T13:21:05-04:00
gitlab-ci: Use rules syntax for conditional jobs

- - - - -
e2586828 by Ben Gamari at 2020-04-18T13:21:05-04:00
Bump hsc2hs submodule

- - - - -
15ab6cd5 by Ömer Sinan Ağacan at 2020-04-18T13:21:44-04:00
Improve prepForeignCall error reporting

Show parameters and description of the error code when ffi_prep_cif
fails.

This may be helpful for debugging #17018.

- - - - -
3ca52151 by Sylvain Henry at 2020-04-18T20:04:14+02:00
GHC.Core.Opt renaming

* GHC.Core.Op                  => GHC.Core.Opt
* GHC.Core.Opt.Simplify.Driver => GHC.Core.Opt.Driver
* GHC.Core.Opt.Tidy            => GHC.Core.Tidy
* GHC.Core.Opt.WorkWrap.Lib    => GHC.Core.Opt.WorkWrap.Utils

As discussed in:
 * https://mail.haskell.org/pipermail/ghc-devs/2020-April/018758.html
 * https://gitlab.haskell.org/ghc/ghc/issues/13009#note_264650

- - - - -
15312bbb by Sylvain Henry at 2020-04-18T20:04:46+02:00
Modules (#13009)

* SysTools
* Parser
* GHC.Builtin
* GHC.Iface.Recomp
* Settings

Update Haddock submodule

Metric Decrease:
    Naperian
    parsing001

- - - - -
eaed0a32 by Alexis King at 2020-04-19T03:16:44-04:00
Add missing addInScope call for letrec binders in OccurAnal

This fixes #18044, where a shadowed variable was incorrectly substituted
by the binder swap on the RHS of a floated-in letrec. This can only
happen when the uniques line up *just* right, so writing a regression
test would be very difficult, but at least the fix is small and
straightforward.

- - - - -
36882493 by Shayne Fletcher at 2020-04-20T04:36:43-04:00
Derive Ord instance for Extension

Metric Increase:
   T12150
   T12234

- - - - -
b43365ad by Simon Peyton Jones at 2020-04-20T04:37:20-04:00
Fix a buglet in redundant-constraint warnings

Ticket #18036 pointed out that we were reporting a redundant
constraint when it really really wasn't.

Turned out to be a buglet in the SkolemInfo for the
relevant implication constraint.  Easily fixed!

- - - - -
d5fae7da by Ömer Sinan Ağacan at 2020-04-20T14:39:28-04:00
Mark T12010 fragile on 32-bit

- - - - -
bca02fca by Adam Sandberg Ericsson at 2020-04-21T06:38:45-04:00
docs: drop note about not supporting shared libraries on unix systems

[skip ci]

- - - - -
6655f933 by Sylvain Henry at 2020-04-21T06:39:32-04:00
Use ParserFlags in GHC.Runtime.Eval (#17957)

Instead of passing `DynFlags` to functions such as `isStmt` and
`hasImport` in `GHC.Runtime.Eval` we pass `ParserFlags`. It's a much
simpler structure that can be created purely with `mkParserFlags'`.

- - - - -
70be0fbc by Sylvain Henry at 2020-04-21T06:39:32-04:00
GHC.Runtime: avoid DynFlags (#17957)

* add `getPlatform :: TcM Platform` helper
* remove unused `DynFlags` parameter from `emptyPLS`

- - - - -
35e43d48 by Sylvain Henry at 2020-04-21T06:39:32-04:00
Avoid DynFlags in Ppr code (#17957)

* replace `DynFlags` parameters with `SDocContext` parameters for a few
  Ppr related functions: `bufLeftRenderSDoc`, `printSDoc`,
  `printSDocLn`, `showSDocOneLine`.

* remove the use of `pprCols :: DynFlags -> Int` in Outputable. We
  already have the information via `sdocLineLength :: SDocContext ->
  Int`

- - - - -
ce5c2999 by Sylvain Henry at 2020-04-21T06:39:32-04:00
Avoid using sdocWithDynFlags (#17957)

Remove one use of `sdocWithDynFlags` from `GHC.CmmToLlvm.llvmCodeGen'`
and from `GHC.Driver.CodeOutput.profilingInitCode`

- - - - -
f2a98996 by Sylvain Henry at 2020-04-21T06:39:32-04:00
Avoid `sdocWithDynFlags` in `pprCLbl` (#17957)

* add a `DynFlags` parameter to `pprCLbl`
* put `maybe_underscore` and `pprAsmCLbl` in a `where` clause to avoid
  `DynFlags` parameters

- - - - -
747093b7 by Sylvain Henry at 2020-04-21T06:39:32-04:00
CmmToAsm DynFlags refactoring (#17957)

* Remove `DynFlags` parameter from `isDynLinkName`: `isDynLinkName` used
  to test the global `ExternalDynamicRefs` flag. Now we test it outside of
  `isDynLinkName`

* Add new fields into `NCGConfig`: current unit id, sse/bmi versions,
  externalDynamicRefs, etc.

* Replace many uses of `DynFlags` by `NCGConfig`

* Moved `BMI/SSE` datatypes into `GHC.Platform`

- - - - -
ffd7eef2 by Takenobu Tani at 2020-04-22T23:09:50-04:00
stg-spec: Modify file paths according to new module hierarchy

This patch updates file paths according to new module hierarchy [1]:

  * GHC/Stg/Syntax.hs       <= stgSyn/StgSyn.hs
  * GHC/Types/Literal.hs    <= basicTypes/Literal.hs
  * GHC/Types/CostCentre.hs <= profiling/CostCentre.hs

This patch also updates old file path [2]:

  * utils/genapply/Main.hs  <= utils/genapply/GenApply.hs

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular
[2]: commit 0cc4aad36f

[skip ci]

- - - - -
e8a5d81b by Jonathan DK Gibbons at 2020-04-22T23:10:28-04:00
Refactor the `MatchResult` type in the desugarer

This way, it does a better job of proving whether or not the fail operator is used.

- - - - -
dcb7fe5a by John Ericson at 2020-04-22T23:10:28-04:00
Remove panic in dsHandleMonadicFailure

Rework dsHandleMonadicFailure to be correct by construction instead of
using an unreachable panic.

- - - - -
cde23cd4 by John Ericson at 2020-04-22T23:10:28-04:00
Inline `adjustMatchResult`

It is just `fmap`

- - - - -
72cb6bcc by John Ericson at 2020-04-22T23:10:28-04:00
Generalize type of `matchCanFail`

- - - - -
401f7bb3 by John Ericson at 2020-04-22T23:10:28-04:00
`MatchResult'` -> `MatchResult`

Inline `MatchResult` alias accordingly.

- - - - -
6c9fae23 by Alexis King at 2020-04-22T23:11:12-04:00
Mark DataCon wrappers CONLIKE

Now that DataCon wrappers don’t inline until phase 0 (see commit
b78cc64e923716ac0512c299f42d4d0012306c05), it’s important that
case-of-known-constructor and RULE matching be able to see saturated
applications of DataCon wrappers in unfoldings. Making them conlike is a
natural way to do it, since they are, in fact, precisely the sort of
thing the CONLIKE pragma exists to solve.

Fixes #18012.

This also bumps the version of the parsec submodule to incorporate a
patch that avoids a metric increase on the haddock perf tests. The
increase was not really a flaw in this patch, as parsec was implicitly
relying on inlining heuristics. The patch to parsec just adds some
INLINABLE pragmas, and we get a nice performance bump out of it (well
beyond the performance we lost from this patch).

Metric Decrease:
    T12234
    WWRec
    haddock.Cabal
    haddock.base
    haddock.compiler

- - - - -
48b8951e by Roland Senn at 2020-04-22T23:11:51-04:00
Fix tab-completion for :break (#17989)

In tab-completion for the `:break` command, only those
identifiers should be shown, that are accepted in the
`:break` command. Hence these identifiers must be

- defined in an interpreted module
- top-level
- currently in scope
- listed in a `ModBreaks` value as a possible breakpoint.

The identifiers my be qualified or unqualified.

To get all possible top-level breakpoints for tab-completeion
with the correct qualification do:

1. Build the  list called `pifsBreaks` of all pairs of
(Identifier, module-filename) from the `ModBreaks` values.
Here all identifiers are unqualified.

2. Build the list called `pifInscope` of all pairs of
(Identifiers, module-filename) with identifiers from
the `GlobalRdrEnv`. Take only those identifiers that are
in scope and have the  correct prefix.
Here the identifiers may be qualified.

3. From the `pifInscope` list seclect all pairs that can be
found in the `pifsBreaks` list, by comparing only the
unqualified part of the identifier.
The remaining identifiers can be used for tab-completion.

This ensures, that we show only identifiers, that can be used
in a `:break` command.

- - - - -
34a45ee6 by Peter Trommler at 2020-04-22T23:12:27-04:00
PPC NCG: Add DWARF constants and debug labels

Fixes #11261

- - - - -
ffde2348 by Simon Peyton Jones at 2020-04-22T23:13:06-04:00
Do eager instantation in terms

This patch implements eager instantiation, a small but critical change
to the type inference engine, #17173.  The main change is this:

  When inferring types, always return an instantiated type
  (for now, deeply instantiated; in future shallowly instantiated)

There is more discussion in
https://www.tweag.io/posts/2020-04-02-lazy-eager-instantiation.html

There is quite a bit of refactoring in this patch:

* The ir_inst field of GHC.Tc.Utils.TcType.InferResultk
  has entirely gone.  So tcInferInst and tcInferNoInst have collapsed
  into tcInfer.

* Type inference of applications, via tcInferApp and
  tcInferAppHead, are substantially refactored, preparing
  the way for Quick Look impredicativity.

* New pure function GHC.Tc.Gen.Expr.collectHsArgs and applyHsArgs
  are beatifully dual.  We can see the zipper!

* GHC.Tc.Gen.Expr.tcArgs is now much nicer; no longer needs to return
  a wrapper

* In HsExpr, HsTypeApp now contains the the actual type argument,
  and is used in desugaring, rather than putting it in a mysterious
  wrapper.

* I struggled a bit with good error reporting in
  Unify.matchActualFunTysPart. It's a little bit simpler than before,
  but still not great.

Some smaller things

* Rename tcPolyExpr --> tcCheckExpr
         tcMonoExpr --> tcLExpr
* tcPatSig moves from GHC.Tc.Gen.HsType to GHC.Tc.Gen.Pat

Metric Decrease:
    T9961

Reduction of 1.6% in comiler allocation on T9961, I think.

- - - - -
6f84aca3 by Ben Gamari at 2020-04-22T23:13:43-04:00
rts: Ensure that sigaction structs are initialized

I noticed these may have uninitialized fields when looking into #18037.
The reporter says that zeroing them doesn't fix the MSAN failures they
observe but zeroing them is the right thing to do regardless.

- - - - -
c29f0fa6 by Andreas Klebinger at 2020-04-22T23:14:21-04:00
Add "ddump-cmm-opt" as alias for "ddump-opt-cmm".

- - - - -
4b4a8b60 by Ben Gamari at 2020-04-22T23:14:57-04:00
llvmGen: Remove -fast-llvm flag

Issue #18076 drew my attention to the undocumented `-fast-llvm` flag for
the LLVM code generator introduced in
22733532171330136d87533d523f565f2a4f102f. Speaking to Moritz about this,
the motivation for this flag was to avoid potential incompatibilities
between LLVM and the assembler/linker toolchain by making LLVM
responsible for machine-code generation.

Unfortunately, this cannot possibly work: the LLVM backend's mangler
performs a number of transforms on the assembler generated by LLVM that
are necessary for correctness. These are currently:

 * mangling Haskell functions' symbol types to be `object` instead of
   `function` on ELF platforms (necessary for tables-next-to-code)
 * mangling AVX instructions to ensure that we don't assume alignment
   (which LLVM otherwise does)
 * mangling Darwin's  subsections-via-symbols directives

Given that these are all necessary I don't believe that we can support
`-fast-llvm`. Let's rather remove it.

- - - - -
831b6642 by Moritz Angermann at 2020-04-22T23:15:33-04:00
Fix build warning; add more informative information to the linker; fix linker for empty sections

- - - - -
c409961a by Ryan Scott at 2020-04-22T23:16:12-04:00
Update commentary and slightly refactor GHC.Tc.Deriv.Infer

There was some out-of-date commentary in `GHC.Tc.Deriv.Infer` that
has been modernized. Along the way, I removed the `bad` constraints
in `simplifyDeriv`, which did not serve any useful purpose (besides
being printed in debugging output).

Fixes #18073.

- - - - -
125aa2b8 by Ömer Sinan Ağacan at 2020-04-22T23:16:51-04:00
Remove leftover comment in tcRnModule', redundant bind

The code for the comment was moved in dc8c03b2a5c but the comment was
forgotten.

- - - - -
8ea37b01 by Sylvain Henry at 2020-04-22T23:17:34-04:00
RTS: workaround a Linux kernel bug in timerfd

Reading a timerfd may return 0: https://lkml.org/lkml/2019/8/16/335.

This is currently undocumented behavior and documentation "won't happen
anytime soon" (https://lkml.org/lkml/2020/2/13/295).

With this patch, we just ignore the result instead of crashing. It may
fix #18033 but we can't be sure because we don't have enough
information.

See also this discussion about the kernel bug:
https://github.com/Azure/sonic-swss-common/pull/302/files/1f070e7920c2e5d63316c0105bf4481e73d72dc9

- - - - -
cd8409c2 by Ryan Scott at 2020-04-23T11:39:24-04:00
Create di_scoped_tvs for associated data family instances properly

See `Note [Associated data family instances and di_scoped_tvs]` in
`GHC.Tc.TyCl.Instance`, which explains all of the moving parts.

Fixes #18055.

- - - - -
339e8ece by Ben Gamari at 2020-04-23T11:40:02-04:00
hadrian/ghci: Allow arguments to be passed to GHCi

Previously the arguments passed to hadrian/ghci were passed both to
`hadrian` and GHCi. This is rather odd given that there are essentially
not arguments in the intersection of the two. Let's just pass them to
GHCi; this allows `hadrian/ghci -Werror`.

- - - - -
5946c85a by Ben Gamari at 2020-04-23T11:40:38-04:00
testsuite: Don't attempt to read .std{err,out} files if they don't exist

Simon reports that he was previously seeing framework failures due to
an attempt to read the non-existing T13456.stderr. While I don't know
exactly what this is due to, it does seem like a non-existing
.std{out,err} file should be equivalent to an empty file. Teach the
testsuite driver to treat it as such.

- - - - -
c42754d5 by John Ericson at 2020-04-23T18:32:43-04:00
Trees That Grow refactor for `ConPat` and `CoPat`

- `ConPat{In,Out}` -> `ConPat`

- `CoPat` -> `XPat (CoPat ..)`

Note that `GHC.HS.*` still uses `HsWrap`, but only when `p ~ GhcTc`.
After this change, moving the type family instances out of `GHC.HS.*` is
sufficient to break the cycle.

Add XCollectPat class to decide how binders are collected from XXPat based on the pass.

Previously we did this with IsPass, but that doesn't work for Haddock's
DocNameI, and the constraint doesn't express what actual distinction is being
made. Perhaps a class for collecting binders more generally is in order, but we
haven't attempted this yet.

Pure refactor of code around ConPat

 - InPat/OutPat synonyms removed

 - rename several identifiers

 - redundant constraints removed

 - move extension field in ConPat to be first

 - make ConPat use record syntax more consistently

Fix T6145 (ConPatIn became ConPat)

Add comments from SPJ.

Add comment about haddock's use of CollectPass.

Updates haddock submodule.

- - - - -
72da0c29 by mniip at 2020-04-23T18:33:21-04:00
Add :doc to GHC.Prim

- - - - -
2c23e2e3 by mniip at 2020-04-23T18:33:21-04:00
Include docs for non-primop entries in primops.txt as well

- - - - -
0ac29c88 by mniip at 2020-04-23T18:33:21-04:00
GHC.Prim docs: note and test

- - - - -
b0fbfc75 by John Ericson at 2020-04-24T12:07:14-04:00
Switch order on `GhcMake.IsBoot`

In !1798 we were requested to replace many `Bool`s with this data type.
But those bools had `False` meaning `NotBoot`, so the `Ord` instance
would be flipped if we use this data-type as-is.

Since the planned formally-`Bool` occurrences vastly outnumber the
current occurrences, we figured it would be better to conform the `Ord`
instance to how the `Bool` is used now, fixing any issues, rather than
fix them currently with the bigger refactor later in !1798. That way,
!1798 can be a "pure" refactor with no behavioral changes.

- - - - -
af332442 by Sylvain Henry at 2020-04-26T13:55:14-04:00
Modules: Utils and Data (#13009)

Update Haddock submodule

Metric Increase:
   haddock.compiler

- - - - -
cd4434c8 by Sylvain Henry at 2020-04-26T13:55:16-04:00
Fix misleading Ptr phantom type in SerializedCompact (#15653)

- - - - -
22bf5c73 by Ömer Sinan Ağacan at 2020-04-26T13:55:22-04:00
Tweak includes in non-moving GC headers

We don't use hash tables in non-moving GC so remove the includes.

This breaks Compact.c as existing includes no longer include Hash.h, so
include Hash.h explicitly in Compact.c.

- - - - -
99823ed2 by Sylvain Henry at 2020-04-27T20:24:46-04:00
TH: fix Show/Eq/Ord instances for Bytes (#16457)

We shouldn't compare pointer values but the actual bytes.

- - - - -
c62271a2 by Alp Mestanogullari at 2020-04-27T20:25:33-04:00
hadrian: always capture both stdout and stderr when running a builder fails

The idea being that when a builder('s command) fails, we quite likely want to
have all the information available to figure out why. Depending on the builder
_and_ the particular problem, the useful bits of information can be printed
on stdout or stderr.

We accomplish this by defining a simple wrapper for Shake's `cmd` function,
that just _always_ captures both streams in case the command returns a non-zero
exit code, and by using this wrapper everywhere in `hadrian/src/Builder.hs`.

Fixes #18089.

- - - - -
4b9764db by Ryan Scott at 2020-04-28T15:40:04-04:00
Define a Quote IO instance

Fixes #18103.

- - - - -
518a63d4 by Ryan Scott at 2020-04-28T15:40:42-04:00
Make boxed 1-tuples have known keys

Unlike other tuples, which use special syntax and are "known" by way
of a special `isBuiltInOcc_maybe` code path, boxed 1-tuples do not
use special syntax. Therefore, in order to make sure that the
internals of GHC are aware of the `data Unit a = Unit a` definition
in `GHC.Tuple`, we give `Unit` known keys. For the full details, see
`Note [One-tuples] (Wrinkle: Make boxed one-tuple names have known keys)`
in `GHC.Builtin.Types`.

Fixes #18097.

- - - - -
2cfc4ab9 by Sylvain Henry at 2020-04-30T01:56:56-04:00
Document backpack fields in DynFlags

- - - - -
10a2ba90 by Sylvain Henry at 2020-04-30T01:56:56-04:00
Refactor UnitInfo

* Rename InstalledPackageInfo into GenericUnitInfo

The name InstalledPackageInfo is only kept for alleged backward
compatibility reason in Cabal. ghc-boot has its own stripped down copy
of this datatype but it doesn't need to keep the name. Internally we
already use type aliases (UnitInfo in GHC, PackageCacheFormat in
ghc-pkg).

* Rename UnitInfo fields: add "unit" prefix and fix misleading names

* Add comments on every UnitInfo field

* Rename SourcePackageId into PackageId

"Package" already indicates that it's a "source package". Installed
package components are called units.

Update Haddock submodule

- - - - -
69562e34 by Sylvain Henry at 2020-04-30T01:56:56-04:00
Remove unused `emptyGenericUnitInfo`

- - - - -
9e2c8e0e by Sylvain Henry at 2020-04-30T01:56:56-04:00
Refactor UnitInfo load/store from databases

Converting between UnitInfo stored in package databases and UnitInfo as
they are used in ghc-pkg and ghc was done in a very convoluted way (via
BinaryStringRep and DbUnitModuleRep type classes using fun deps, etc.).
It was difficult to understand and even more to modify (I wanted to
try to use a GADT for UnitId but fun deps got in the way).

The new code uses much more straightforward functions to convert between
the different representations. Much simpler.

- - - - -
ea717aa4 by Sylvain Henry at 2020-04-30T01:56:56-04:00
Factorize mungePackagePaths code

This patch factorizes the duplicated code used in ghc-pkg and in GHC to
munge package paths/urls.

It also fixes haddock-html munging in GHC (allowed to be either a file
or a url) to mimic ghc-pkg behavior.

- - - - -
10d15f1e by Sylvain Henry at 2020-04-30T01:56:56-04:00
Refactoring unit management code

Over the years the unit management code has been modified a lot to keep
up with changes in Cabal (e.g. support for several library components in
the same package), to integrate BackPack, etc. I found it very hard to
understand as the terminology wasn't consistent, was referring to past
concepts, etc.

The terminology is now explained as clearly as I could in the Note
"About Units" and the code is refactored to reflect it.

-------------------

Many names were misleading: UnitId is not an Id but could be a virtual
unit (an indefinite one instantiated on the fly), IndefUnitId
constructor may contain a definite instantiated unit, etc.

   * Rename IndefUnitId into InstantiatedUnit
   * Rename IndefModule into InstantiatedModule
   * Rename UnitId type into Unit
   * Rename IndefiniteUnitId constructor into VirtUnit
   * Rename DefiniteUnitId constructor into RealUnit
   * Rename packageConfigId into mkUnit
   * Rename getPackageDetails into unsafeGetUnitInfo
   * Rename InstalledUnitId into UnitId

Remove references to misleading ComponentId: a ComponentId is just an
indefinite unit-id to be instantiated.

   * Rename ComponentId into IndefUnitId
   * Rename ComponentDetails into UnitPprInfo
   * Fix display of UnitPprInfo with empty version: this is now used for
     units dynamically generated by BackPack

Generalize several types (Module, Unit, etc.) so that they can be used
with different unit identifier types: UnitKey, UnitId, Unit, etc.

   * GenModule: Module, InstantiatedModule and InstalledModule are now
     instances of this type
   * Generalize DefUnitId, IndefUnitId, Unit, InstantiatedUnit,
     PackageDatabase

Replace BackPack fake "hole" UnitId by a proper HoleUnit constructor.

Add basic support for UnitKey. They should be used more in the future to
avoid mixing them up with UnitId as we do now.

Add many comments.

Update Haddock submodule

- - - - -
8bfb0219 by Sylvain Henry at 2020-04-30T01:56:56-04:00
Unit: split and rename modules

Introduce GHC.Unit.* hierarchy for everything concerning units, packages
and modules.

Update Haddock submodule

- - - - -
71484b09 by Alexis King at 2020-04-30T01:57:35-04:00
Allow block arguments in arrow control operators

Arrow control operators have their own entries in the grammar, so they
did not cooperate with BlockArguments. This was just a minor oversight,
so this patch adjusts the grammar to add the desired behavior.

fixes #18050

- - - - -
a48cd2a0 by Alexis King at 2020-04-30T01:57:35-04:00
Allow LambdaCase to be used as a command in proc notation

- - - - -
f4d3773c by Alexis King at 2020-04-30T01:57:35-04:00
Document BlockArguments/LambdaCase support in arrow notation

- - - - -
5bdfdd13 by Simon Peyton Jones at 2020-04-30T01:58:15-04:00
Add tests for #17873

- - - - -
19b701c2 by Simon Peyton Jones at 2020-04-30T07:30:13-04:00
Mark rule args as non-tail-called

This was just an omission...b I'd failed to call markAllNonTailCall on
rule args.  I think this bug has been here a long time, but it's quite
hard to trigger.

Fixes #18098

- - - - -
014ef4a3 by Matthew Pickering at 2020-04-30T07:30:50-04:00
Hadrian: Improve tool-args command to support more components

There is a new command to hadrian, tool:path/to/file.hs, which returns
the options needed to compile that file in GHCi.

This is now used in the ghci script with argument `ghc/Main.hs` but its
main purpose is to support the new multi-component branch of ghcide.

- - - - -
2aa67611 by Ben Gamari at 2020-04-30T21:34:44-04:00
nonmoving: Clear bitmap after initializing block size

Previously nonmovingInitSegment would clear the bitmap before
initializing the segment's block size. This is broken since
nonmovingClearBitmap looks at the segment's block size to determine how
much bitmap to clear.

- - - - -
54dad3cf by Ben Gamari at 2020-04-30T21:34:44-04:00
nonmoving: Explicitly memoize block count

A profile cast doubt on whether the compiler hoisted the bound out the
loop as I would have expected here. It turns out it did but nevertheless
it seems clearer to just do this manually.

- - - - -
99ff8145 by Ben Gamari at 2020-04-30T21:34:44-04:00
nonmoving: Eagerly flush all capabilities' update remembered sets

(cherry picked from commit 2fa79119570b358a4db61446396889b8260d7957)

- - - - -
05b0a9fd by Ömer Sinan Ağacan at 2020-04-30T21:35:24-04:00
Remove OneShotInfo field of LFReEntrant, document OneShotInfo

The field is only used in withNewTickyCounterFun and it's easier to
directly pass a parameter for one-shot info to withNewTickyCounterFun
instead of passing it via LFReEntrant. This also makes !2842 simpler.

Other changes:

- New Note (by SPJ) [OneShotInfo overview] added.
- Arity argument of thunkCode removed as it's always 0.

- - - - -
a43620c6 by Ömer Sinan Ağacan at 2020-04-30T21:35:24-04:00
GHC.StgToCmm.Ticky: remove a few unused stuff

- - - - -
780de9e1 by Sylvain Henry at 2020-05-01T10:37:39-04:00
Use platform in Iface Binary

- - - - -
f8386c7b by Sylvain Henry at 2020-05-01T10:37:39-04:00
Refactor PprDebug handling

If `-dppr-debug` is set, then PprUser and PprDump styles are silently
replaced with PprDebug style. This was done in `mkUserStyle` and
`mkDumpStyle` smart constructors. As a consequence they needed a
DynFlags parameter.

Now we keep the original PprUser and PprDump styles until they are used
to create an `SDocContext`. I.e. the substitution is only performed in
`initSDocContext`.

- - - - -
b3df9e78 by Sylvain Henry at 2020-05-01T10:37:39-04:00
Remove PprStyle param of logging actions

Use `withPprStyle` instead to apply a specific style to a SDoc.

- - - - -
de9fc995 by Sylvain Henry at 2020-05-01T10:37:39-04:00
Fully remove PprDebug

PprDebug was a pain to deal with consistently as it is implied by
`-dppr-debug` but it isn't really a PprStyle. We remove it completely
and query the appropriate SDoc flag instead (`sdocPprDebug`) via
helpers (`getPprDebug` and its friends).

- - - - -
8b51fcbd by Sebastian Graf at 2020-05-01T10:38:16-04:00
PmCheck: Only call checkSingle if we would report warnings

- - - - -
fd7ea0fe by Sebastian Graf at 2020-05-01T10:38:16-04:00
PmCheck: Pick up `EvVar`s bound in `HsWrapper`s for long-distance info

`HsWrapper`s introduce evidence bindings through `WpEvLam` which the
pattern-match coverage checker should be made aware of.

Failing to do so caused #18049, where the resulting impreciseness of
imcompleteness warnings seemingly contradicted with
`-Winaccessible-code`.

The solution is simple: Collect all the evidence binders of an
`HsWrapper` and add it to the ambient `Deltas` before desugaring
the wrapped expression.

But that means we pick up many more evidence bindings, even when they
wrap around code without a single pattern match to check! That regressed
`T3064` by over 300%, so now we are adding long-distance info lazily
through judicious use of `unsafeInterleaveIO`.

Fixes #18049.

- - - - -
7bfe9ac5 by Ben Gamari at 2020-05-03T04:41:33-04:00
rts: Enable tracing of nonmoving heap census with -ln

Previously this was not easily available to the user. Fix this.
Non-moving collection lifecycle events are now reported with -lg.

- - - - -
c560dd07 by Ben Gamari at 2020-05-03T04:41:33-04:00
users guide: Move eventlog documentation users guide

- - - - -
02543d5e by Ben Gamari at 2020-05-03T04:41:33-04:00
users guide: Add documentation for non-moving GC events

- - - - -
b465dd45 by Alexis King at 2020-05-03T04:42:12-04:00
Flatten nested casts in the simple optimizer

Normally, we aren’t supposed to generated any nested casts, since mkCast
takes care to flatten them, but the simple optimizer didn’t use mkCast,
so they could show up after inlining. This isn’t really a problem, since
the simplifier will clean them up immediately anyway, but it can clutter
the -ddump-ds output, and it’s an extremely easy fix.

closes #18112

- - - - -
8bdc03d6 by Simon Peyton Jones at 2020-05-04T01:56:59-04:00
Don't return a panic in tcNestedSplice

In GHC.Tc.Gen.Splice.tcNestedSplice we were returning a
typechecked expression of "panic". That is usually OK, because
the result is discarded.  But it happens that tcApp now looks at
the typechecked expression, trivially, to ask if it is tagToEnum.
So being bottom is bad.

Moreover a debug-trace might print it out.

So better to return a civilised expression, even though it is
usually discarded.

- - - - -
0bf640b1 by Baldur Blöndal at 2020-05-04T01:57:36-04:00
Don't require parentheses around via type (`-XDerivingVia'). Fixes #18130".

- - - - -
30272412 by Artem Pelenitsyn at 2020-05-04T13:19:59-04:00
Remove custom ExceptionMonad class (#18075) (updating haddock submodule accordingly)

- - - - -
b9f7c08f by jneira at 2020-05-04T13:20:37-04:00
Remove unused hs-boot file

- - - - -
1d8f80cd by Sylvain Henry at 2020-05-05T03:22:46-04:00
Remove references to -package-key

* remove references to `-package-key` which has been removed in 2016
  (240ddd7c39536776e955e881d709bbb039b48513)

* remove support for `-this-package-key` which has been deprecated at the
  same time

- - - - -
7bc3a65b by Sylvain Henry at 2020-05-05T03:23:31-04:00
Remove SpecConstrAnnotation (#13681)

This has been deprecated since 2013. Use GHC.Types.SPEC instead.

Make GHC.Exts "not-home" for haddock

Metric Decrease:
   haddock.base

- - - - -
3c862f63 by DenisFrezzato at 2020-05-05T03:24:15-04:00
Fix Haskell98 short description in documentation

- - - - -
2420c555 by Ryan Scott at 2020-05-05T03:24:53-04:00
Add regression tests for #16244, #16245, #16758

Commit e3c374cc5bd7eb49649b9f507f9f7740697e3f70 ended up
fixing quite a few bugs:

* This commit fixes #16244 completely. A regression test has been
  added.
* This commit fixes one program from #16245. (The program in
  https://gitlab.haskell.org/ghc/ghc/issues/16245#note_211369 still
  panics, and the program in
  https://gitlab.haskell.org/ghc/ghc/issues/16245#note_211400 still
  loops infinitely.) A regression test has been added for this
  program.
* This commit fixes #16758. Accordingly, this patch removes the
  `expect_broken` label from the `T16758` test case, moves it from
  `should_compile` to `should_fail` (as it should produce an error
  message), and checks in the expected stderr.

- - - - -
40c71c2c by Sylvain Henry at 2020-05-05T03:25:31-04:00
Fix colorized error messages (#18128)

In b3df9e780fb2f5658412c644849cd0f1e6f50331 I broke colorized messages
by using "dump" style instead of "user" style. This commits fixes it.

- - - - -
7ab6ab09 by Richard Eisenberg at 2020-05-06T04:39:32-04:00
Refactor hole constraints.

Previously, holes (both expression holes / out of scope variables and
partial-type-signature wildcards) were emitted as *constraints* via
the CHoleCan constructor. While this worked fine for error reporting,
there was a fair amount of faff in keeping these constraints in line.
In particular, and unlike other constraints, we could never change
a CHoleCan to become CNonCanonical. In addition:
 * the "predicate" of a CHoleCan constraint was really the type
   of the hole, which is not a predicate at all
 * type-level holes (partial type signature wildcards) carried
   evidence, which was never used
 * tcNormalise (used in the pattern-match checker) had to create
   a hole constraint just to extract it again; it was quite messy

The new approach is to record holes directly in WantedConstraints.
It flows much more nicely now.

Along the way, I did some cleaning up of commentary in
GHC.Tc.Errors.Hole, which I had a hard time understanding.

This was instigated by a future patch that will refactor
the way predicates are handled. The fact that CHoleCan's
"predicate" wasn't really a predicate is incompatible with
that future patch.

No test case, because this is meant to be purely internal.

It turns out that this change improves the performance of
the pattern-match checker, likely because fewer constraints
are sloshing about in tcNormalise. I have not investigated
deeply, but an improvement is not a surprise here:

-------------------------
Metric Decrease:
    PmSeriesG
-------------------------

- - - - -
420b957d by Ben Gamari at 2020-05-06T04:40:08-04:00
rts: Zero block flags with -DZ

Block flags are very useful for determining the state of a block.
However, some block allocator users don't touch them, leading to
misleading values. Ensure that we zero then when zero-on-gc is set. This
is safe and makes the flags more useful during debugging.

- - - - -
740b3b8d by Ben Gamari at 2020-05-06T04:40:08-04:00
nonmoving: Fix incorrect failed_to_evac value during deadlock gc

Previously we would incorrectly set the failed_to_evac flag if we
evacuated a value due to a deadlock GC. This would cause us to mark more
things as dirty than strictly necessary. It also turned up a nasty but
which I will fix next.

- - - - -
b2d72c75 by Ben Gamari at 2020-05-06T04:40:08-04:00
nonmoving: Fix handling of dirty objects

Previously we (incorrectly) relied on failed_to_evac to be "precise".
That is, we expected it to only be true if *all* of an object's fields
lived outside of the non-moving heap. However, does not match the
behavior of failed_to_evac, which is true if *any* of the object's
fields weren't promoted (meaning that some others *may* live in the
non-moving heap).

This is problematic as we skip the non-moving write barrier for dirty
objects (which we can only safely do if *all* fields point outside of
the non-moving heap).

Clearly this arises due to a fundamental difference in the behavior
expected of failed_to_evac in the moving and non-moving collector.
e.g., in the moving collector it is always safe to conservatively say
failed_to_evac=true whereas in the non-moving collector the safe value
is false.

This issue went unnoticed as I never wrote down the dirtiness
invariant enforced by the non-moving collector. We now define this
invariant as

    An object being marked as dirty implies that all of its fields are
    on the mark queue (or, equivalently, update remembered set).

To maintain this invariant we teach nonmovingScavengeOne to push the
fields of objects which we fail to evacuate to the update remembered
set. This is a simple and reasonably cheap solution and avoids the
complexity and fragility that other, more strict alternative invariants
would require.

All of this is described in a new Note, Note [Dirty flags in the
non-moving collector] in NonMoving.c.

- - - - -
9f3e6884 by Zubin Duggal at 2020-05-06T04:41:08-04:00
Allow atomic update of NameCache in readHieFile

The situation arises in ghcide where multiple different threads may need to
update the name cache, therefore with the older interface it could happen
that you start reading a hie file with name cache A and produce name cache
A + B, but another thread in the meantime updated the namecache to A +
C. Therefore if you write the new namecache you will lose the A' updates
from the second thread.

Updates haddock submodule

- - - - -
edec6a6c by Ryan Scott at 2020-05-06T04:41:57-04:00
Make isTauTy detect higher-rank contexts

Previously, `isTauTy` would only detect higher-rank `forall`s, not
higher-rank contexts, which led to some minor bugs observed
in #18127. Easily fixed by adding a case for
`(FunTy InvisArg _ _)`.

Fixes #18127.

- - - - -
a95e7fe0 by Ömer Sinan Ağacan at 2020-05-06T04:42:39-04:00
ELF linker: increment curSymbol after filling in fields of current entry

The bug was introduced in a8b7cef4d45 which added a field to the
`symbols` array elements and then updated this code incorrectly:

    - oc->symbols[curSymbol++] = nm;
    + oc->symbols[curSymbol++].name = nm;
    + oc->symbols[curSymbol].addr = symbol->addr;

- - - - -
cab1871a by Sylvain Henry at 2020-05-06T04:43:21-04:00
Move LeadingUnderscore into Platform (#17957)

Avoid direct use of DynFlags to know if symbols must be prefixed by an
underscore.

- - - - -
94e7c563 by Sylvain Henry at 2020-05-06T04:43:21-04:00
Don't use DynFlags in showLinkerState (#17957)

- - - - -
9afd9251 by Ryan Scott at 2020-05-06T04:43:58-04:00
Refactoring: Use bindSigTyVarsFV in rnMethodBinds

`rnMethodBinds` was explicitly using `xoptM` to determine if
`ScopedTypeVariables` is enabled before bringing type variables
bound by the class/instance header into scope. However, this `xoptM`
logic is already performed by the `bindSigTyVarsFV` function. This
patch uses `bindSigTyVarsFV` in `rnMethodBinds` to reduce the number
of places where we need to consult if `ScopedTypeVariables` is on.

This is purely refactoring, and there should be no user-visible
change in behavior.

- - - - -
6f6d72b2 by Brian Foley at 2020-05-08T15:29:25-04:00
Remove further dead code found by a simple Python script.

Avoid removing some functions that are part of an API even
though they're not used in-tree at the moment.

- - - - -
78bf8bf9 by Julien Debon at 2020-05-08T15:29:28-04:00
Add doc examples for Bifoldable

See #17929

- - - - -
66f0a847 by Julien Debon at 2020-05-08T15:29:29-04:00
doc (Bitraversable): Add examples to Bitraversable

* Add examples to Data.Bitraversable
* Fix formatting for (,) in Bitraversable and Bifoldable
* Fix mistake on bimapAccumR documentation

See #17929

- - - - -
9749fe12 by Baldur Blöndal at 2020-05-08T15:29:32-04:00
Specify kind variables for inferred kinds in base.

- - - - -
4e9aef9e by John Ericson at 2020-05-08T15:29:36-04:00
HsSigWcTypeScoping: Pull in documentation from stray location

- - - - -
f4d5c6df by John Ericson at 2020-05-08T15:29:36-04:00
Rename local `real_fvs` to `implicit_vs`

It doesn't make sense to call the "free" variables we are about to
implicitly bind the real ones.

- - - - -
20570b4b by John Ericson at 2020-05-08T15:29:36-04:00
A few tiny style nits with renaming

 - Use case rather than guards that repeatedly scrutenize same thing.

 - No need for view pattern when `L` is fine.

 - Use type synnonym to convey the intent like elsewhere.

- - - - -
09ac8de5 by John Ericson at 2020-05-08T15:29:36-04:00
Add `forAllOrNothing` function with note

- - - - -
bb35c0e5 by Joseph C. Sible at 2020-05-08T15:29:40-04:00
Document lawlessness of Ap's Num instance
- - - - -
cdd229ff by Joseph C. Sible at 2020-05-08T15:29:40-04:00
Apply suggestion to libraries/base/Data/Monoid.hs
- - - - -
926d2aab by Joseph C. Sible at 2020-05-08T15:29:40-04:00
Apply more suggestions from Simon Jakobi
- - - - -
7a763cff by Adam Gundry at 2020-05-08T15:29:41-04:00
Reject all duplicate declarations involving DuplicateRecordFields (fixes #17965)

This fixes a bug that resulted in some programs being accepted that used the same
identifier as a field label and another declaration, depending on the order they
appeared in the source code.

- - - - -
88e3c815 by Simon Peyton Jones at 2020-05-08T15:29:41-04:00
Fix specialisation for DFuns

When specialising a DFun we must take care to saturate the
unfolding.  See Note [Specialising DFuns] in Specialise.

Fixes #18120

- - - - -
86c77b36 by Greg Steuck at 2020-05-08T15:29:45-04:00
Remove unused SEGMENT_PROT_RWX

It's been unused for a year and is problematic on any OS which
requires W^X for security.

- - - - -
9d97f4b5 by nineonine at 2020-05-08T15:30:03-04:00
Add test for #16167

- - - - -
aa318338 by Ryan Scott at 2020-05-08T15:30:04-04:00
Bump exceptions submodule so that dist-boot is .gitignore'd

`exceptions` is a stage-0 boot library as of commit
30272412fa437ab8e7a8035db94a278e10513413, which means that building
`exceptions` in a GHC tree will generate a `dist-boot` directory.
However, this directory was not specified in `exceptions`'
`.gitignore` file, which causes it to dirty up the current `git`
working directory.

Accordingly, this bumps the `exceptions` submodule to commit
ghc/packages/exceptions at 23c0b8a50d7592af37ca09beeec16b93080df98f,
which adds `dist-boot` to the `.gitignore` file.

- - - - -
ea86360f by Ömer Sinan Ağacan at 2020-05-08T15:30:30-04:00
Linker.c: initialize n_symbols of ObjectCode with other fields

- - - - -
951c1fb0 by Sylvain Henry at 2020-05-09T21:46:38-04:00
Fix unboxed-sums GC ptr-slot rubbish value (#17791)

This patch allows boot libraries to use unboxed sums without implicitly
depending on `base` package because of `absentSumFieldError`.

See updated Note [aBSENT_SUM_FIELD_ERROR_ID] in GHC.Core.Make

- - - - -
b352d63c by Ben Gamari at 2020-05-09T21:47:14-04:00
rts: Make non-existent linker search path merely a warning

As noted in #18105, previously this resulted in a rather intrusive error
message. This is in contrast to the general expectation that search
paths are merely places to look, not places that must exist.

Fixes #18105.

- - - - -
cf4f1e2f by Ben Gamari at 2020-05-13T02:02:33-04:00
rts/CNF: Fix fixup comparison function

Previously we would implicitly convert the difference between two words
to an int, resulting in an integer overflow on 64-bit machines.

Fixes #16992

- - - - -
a03da9bf by Ömer Sinan Ağacan at 2020-05-13T02:03:16-04:00
Pack some of IdInfo fields into a bit field

This reduces residency of compiler quite a bit on some programs.
Example stats when building T10370:

Before:

   2,871,242,832 bytes allocated in the heap
   4,693,328,008 bytes copied during GC
      33,941,448 bytes maximum residency (276 sample(s))
         375,976 bytes maximum slop
              83 MiB total memory in use (0 MB lost due to fragmentation)

After:

   2,858,897,344 bytes allocated in the heap
   4,629,255,440 bytes copied during GC
      32,616,624 bytes maximum residency (278 sample(s))
         314,400 bytes maximum slop
              80 MiB total memory in use (0 MB lost due to fragmentation)

So -3.9% residency, -1.3% bytes copied and -0.4% allocations.

Fixes #17497

Metric Decrease:
    T9233
    T9675

- - - - -
670c3e5c by Ben Gamari at 2020-05-13T02:03:54-04:00
get-win32-tarballs: Fix base URL

Revert a change previously made for testing purposes.

- - - - -
8ad8dc41 by Ben Gamari at 2020-05-13T02:03:54-04:00
get-win32-tarballs: Improve diagnostics output

- - - - -
8c0740b7 by Simon Jakobi at 2020-05-13T02:04:33-04:00
docs: Add examples for Data.Semigroup.Arg{Min,Max}

Context: #17153

- - - - -
cb22348f by Ben Gamari at 2020-05-13T02:05:11-04:00
Add few cleanups of the CAF logic

Give the NameSet of non-CAFfy names a proper newtype to distinguish it
from all of the other NameSets floating about.

- - - - -
90e38b81 by Emeka Nkurumeh at 2020-05-13T02:05:51-04:00
fix printf warning when using with ghc with clang on mingw
- - - - -
86d8ac22 by Sebastian Graf at 2020-05-13T02:06:29-04:00
CprAnal: Don't attach CPR sigs to expandable bindings (#18154)

Instead, look through expandable unfoldings in `cprTransform`.
See the new Note [CPR for expandable unfoldings]:

```
Long static data structures (whether top-level or not) like

  xs = x1 : xs1
  xs1 = x2 : xs2
  xs2 = x3 : xs3

should not get CPR signatures, because they

  * Never get WW'd, so their CPR signature should be irrelevant after analysis
    (in fact the signature might even be harmful for that reason)
  * Would need to be inlined/expanded to see their constructed product
  * Recording CPR on them blows up interface file sizes and is redundant with
    their unfolding. In case of Nested CPR, this blow-up can be quadratic!

But we can't just stop giving DataCon application bindings the CPR property,
for example

  fac 0 = 1
  fac n = n * fac (n-1)

fac certainly has the CPR property and should be WW'd! But FloatOut will
transform the first clause to

  lvl = 1
  fac 0 = lvl

If lvl doesn't have the CPR property, fac won't either. But lvl doesn't have a
CPR signature to extrapolate into a CPR transformer ('cprTransform'). So
instead we keep on cprAnal'ing through *expandable* unfoldings for these arity
0 bindings via 'cprExpandUnfolding_maybe'.

In practice, GHC generates a lot of (nested) TyCon and KindRep bindings, one
for each data declaration. It's wasteful to attach CPR signatures to each of
them (and intractable in case of Nested CPR).
```

Fixes #18154.

- - - - -
e34bf656 by Ben Gamari at 2020-05-13T02:07:08-04:00
users-guide: Add discussion of shared object naming

Fixes #18074.

- - - - -
5d0f2445 by Ben Gamari at 2020-05-13T02:07:47-04:00
testsuite: Print sign of performance changes

Executes the minor formatting change in the tabulated performance
changes suggested in #18135.

- - - - -
9e4b981f by Ben Gamari at 2020-05-13T02:08:24-04:00
testsuite: Add testcase for #18129

- - - - -
266310c3 by Ivan-Yudin at 2020-05-13T02:09:03-04:00
doc: Reformulate the opening paragraph of Ch. 4 in User's guide

Removes mentioning of Hugs
(it is not helpful for new users anymore).

Changes the wording for the rest of the paragraph.

Fixes #18132.

- - - - -
55e35c0b by Baldur Blöndal at 2020-05-13T20:02:48-04:00
Predicate, Equivalence derive via `.. -> a -> All'

- - - - -
d7e0b57f by Alp Mestanogullari at 2020-05-13T20:03:30-04:00
hadrian: add a --freeze2 option to freeze stage 1 and 2

- - - - -
d880d6b2 by Artem Pelenitsyn at 2020-05-13T20:04:11-04:00
Don't reload environment files on every setSessionDynFlags

Makes `interpretPackageEnv` (which loads envirinment files) a part of
`parseDynamicFlags` (parsing command-line arguments, which is typically
done once) instead of `setSessionDynFlags` (which is typically called
several times). Making several (transitive) calls to `interpretPackageEnv`,
as before, caused #18125 #16318, which should be fixed now.

- - - - -
102cfd67 by Ryan Scott at 2020-05-13T20:04:46-04:00
Factor out HsPatSigType for pat sigs/RULE term sigs (#16762)

This implements chunks (2) and (3) of
https://gitlab.haskell.org/ghc/ghc/issues/16762#note_270170. Namely,
it introduces a dedicated `HsPatSigType` AST type, which represents
the types that can appear in pattern signatures and term-level `RULE`
binders. Previously, these were represented with `LHsSigWcType`.
Although `LHsSigWcType` is isomorphic to `HsPatSigType`, the intended
semantics of the two types are slightly different, as evidenced by
the fact that they have different code paths in the renamer and
typechecker.

See also the new `Note [Pattern signature binders and scoping]` in
`GHC.Hs.Types`.

- - - - -
b17574f7 by Hécate at 2020-05-13T20:05:28-04:00
fix(documentation): Fix the RST links to GHC.Prim

- - - - -
df021fb1 by Baldur Blöndal at 2020-05-13T20:06:06-04:00
Document (->) using inferred quantification for its runtime representations.

Fixes #18142.

- - - - -
1a93ea57 by Takenobu Tani at 2020-05-13T20:06:54-04:00
Tweak man page for ghc command

This commit updates the ghc command's man page as followings:

* Enable `man_show_urls` to show URL addresses in the `DESCRIPTION`
section of ghc.rst, because sphinx currently removes hyperlinks
for man pages.

* Add a `SEE ALSO` section to point to the GHC homepage

- - - - -
a951e1ba by Takenobu Tani at 2020-05-13T20:07:37-04:00
GHCi: Add link to the user's guide in help message

This commit adds a link to the user's guide in ghci's
`:help` message.

Newcomers could easily reach to details of ghci.

- - - - -
404581ea by Jeff Happily at 2020-05-13T20:08:15-04:00
Handle single unused import

- - - - -
1c999e5d by Ben Gamari at 2020-05-13T20:09:07-04:00
Ensure that printMinimalImports closes handle

Fixes #18166.

- - - - -
c9f5a8f4 by Ben Gamari at 2020-05-13T20:09:51-04:00
hadrian: Tell testsuite driver about LLVM availability

This reflects the logic present in the Make build system into Hadrian.

Fixes #18167.

- - - - -
c05c0659 by Simon Jakobi at 2020-05-14T03:31:21-04:00
Improve some folds over Uniq[D]FM

* Replace some non-deterministic lazy folds with
  strict folds.
* Replace some O(n log n) folds in deterministic order
  with O(n) non-deterministic folds.
* Replace some folds with set-operations on the underlying
  IntMaps.

This reduces max residency when compiling
`nofib/spectral/simple/Main.hs` with -O0 by about 1%.

Maximum residency when compiling Cabal also seems reduced on the
order of 3-9%.

- - - - -
477f13bb by Simon Jakobi at 2020-05-14T03:31:58-04:00
Use Data.IntMap.disjoint

Data.IntMap gained a dedicated `disjoint` function in containers-0.6.2.1.

This patch applies this function where appropriate in hopes of modest
compiler performance improvements.

Closes #16806.

- - - - -
e9c0110c by Ben Gamari at 2020-05-14T12:25:53-04:00
IdInfo: Add reference to bitfield-packing ticket

- - - - -
9bd20e83 by Sebastian Graf at 2020-05-15T10:42:09-04:00
DmdAnal: Improve handling of precise exceptions

This patch does two things: Fix possible unsoundness in what was called
the "IO hack" and implement part 2.1 of the "fixing precise exceptions"
plan in
https://gitlab.haskell.org/ghc/ghc/wikis/fixing-precise-exceptions,
which, in combination with !2956, supersedes !3014 and !2525.

**IO hack**

The "IO hack" (which is a fallback to preserve precise exceptions
semantics and thus soundness, rather than some smart thing that
increases precision) is called `exprMayThrowPreciseException` now.
I came up with two testcases exemplifying possible unsoundness (if
twisted enough) in the old approach:

- `T13380d`: Demonstrating unsoundness of the "IO hack" when resorting
             to manual state token threading and direct use of primops.
             More details below.
- `T13380e`: Demonstrating unsoundness of the "IO hack" when we have
             Nested CPR. Not currently relevant, as we don't have Nested
             CPR yet.
- `T13380f`: Demonstrating unsoundness of the "IO hack" for safe FFI
             calls.

Basically, the IO hack assumed that precise exceptions can only be
thrown from a case scrutinee of type `(# State# RealWorld, _ #)`. I
couldn't come up with a program using the `IO` abstraction that violates
this assumption. But it's easy to do so via manual state token threading
and direct use of primops, see `T13380d`. Also similar code might be
generated by Nested CPR in the (hopefully not too) distant future, see
`T13380e`. Hence, we now have a more careful test in `forcesRealWorld`
that passes `T13380{d,e}` (and will hopefully be robust to Nested CPR).

**Precise exceptions**

In #13380 and #17676 we saw that we didn't preserve precise exception
semantics in demand analysis. We fixed that with minimal changes in
!2956, but that was terribly unprincipled.

That unprincipledness resulted in a loss of precision, which is tracked
by these new test cases:

- `T13380b`: Regression in dead code elimination, because !2956 was too
             syntactic about `raiseIO#`
- `T13380c`: No need to apply the "IO hack" when the IO action may not
             throw a precise exception (and the existing IO hack doesn't
             detect that)

Fixing both issues in !3014 turned out to be too complicated and had
the potential to regress in the future. Hence we decided to only fix
`T13380b` and augment the `Divergence` lattice with a new middle-layer
element, `ExnOrDiv`, which means either `Diverges` (, throws an
imprecise exception) or throws a *precise* exception.

See the wiki page on Step 2.1 for more implementational details:
https://gitlab.haskell.org/ghc/ghc/wikis/fixing-precise-exceptions#dead-code-elimination-for-raiseio-with-isdeadenddiv-introducing-exnordiv-step-21

- - - - -
568d7279 by Ben Gamari at 2020-05-15T10:42:46-04:00
GHC.Cmm.Opt: Handle MO_XX_Conv

This MachOp was introduced by 2c959a1894311e59cd2fd469c1967491c1e488f3
but a wildcard match in cmmMachOpFoldM hid the fact that it wasn't
handled. Ideally we would eliminate the match but this appears to be a
larger task.

Fixes #18141.

- - - - -
5bcf8606 by Ryan Scott at 2020-05-17T08:46:38-04:00
Remove duplicate Note [When to print foralls] in GHC.Core.TyCo.Ppr

There are two different Notes named `[When to print foralls]`. The
most up-to-date one is in `GHC.Iface.Type`, but there is a second
one in `GHC.Core.TyCo.Ppr`. The latter is less up-to-date, as it was
written before GHC switched over to using ifaces to pretty-print
types. I decided to just remove the latter and replace it with a
reference to the former.

[ci skip]

- - - - -
55f0e783 by Fumiaki Kinoshita at 2020-05-21T12:10:44-04:00
base: Add Generic instances to various datatypes under GHC.*

* GHC.Fingerprint.Types: Fingerprint
* GHC.RTS.Flags: GiveGCStats, GCFlags, ConcFlags, DebugFlags, CCFlags, DoHeapProfile, ProfFlags, DoTrace, TraceFlags, TickyFlags, ParFlags and RTSFlags
* GHC.Stats: RTSStats and GCStats
* GHC.ByteOrder: ByteOrder
* GHC.Unicode: GeneralCategory
* GHC.Stack.Types: SrcLoc

Metric Increase:
    haddock.base

- - - - -
a9311cd5 by Gert-Jan Bottu at 2020-05-21T12:11:31-04:00
Explicit Specificity

Implementation for Ticket #16393.
Explicit specificity allows users to manually create inferred type variables,
by marking them with braces.
This way, the user determines which variables can be instantiated through
visible type application.

The additional syntax is included in the parser, allowing users to write
braces in type variable binders (type signatures, data constructors etc).
This information is passed along through the renamer and verified in the
type checker.
The AST for type variable binders, data constructors, pattern synonyms,
partial signatures and Template Haskell has been updated to include the
specificity of type variables.

Minor notes:
- Bumps haddock submodule
- Disables pattern match checking in GHC.Iface.Type with GHC 8.8

- - - - -
24e61aad by Ben Price at 2020-05-21T12:12:17-04:00
Lint should say when it is checking a rule

It is rather confusing that when lint finds an error in a rule attached
to a binder, it reports the error as in the RHS, not the rule:
  ...
  In the RHS of foo

We add a clarifying line:
  ...
  In the RHS of foo
  In a rule attached to foo

The implication that the rule lives inside the RHS is a bit odd, but
this niggle is already present for unfoldings, whose pattern we are
following.

- - - - -
78c6523c by Ben Gamari at 2020-05-21T12:13:01-04:00
nonmoving: Optimise the write barrier

- - - - -
13f6c9d0 by Andreas Klebinger at 2020-05-21T12:13:45-04:00
Refactor linear reg alloc to remember past assignments.

When assigning registers we now first try registers we
assigned to in the past, instead of picking the "first"
one.

This is in extremely helpful when dealing with loops for
which variables are dead for part of the loop.

This is important for patterns like this:

        foo = arg1
    loop:
        use(foo)
        ...
        foo = getVal()
        goto loop;

There we:
* assign foo to the register of arg1.
* use foo, it's dead after this use as it's overwritten after.
* do other things.
* look for a register to put foo in.

If we pick an arbitrary one it might differ from the register the
start of the loop expect's foo to be in.
To fix this we simply look for past register assignments for
the given variable. If we find one and the register is free we
use that register.

This reduces the need for fixup blocks which match the register
assignment between blocks. In the example above between the end
and the head of the loop.

This patch also moves branch weight estimation ahead of register
allocation and adds a flag to control it (cmm-static-pred).
* It means the linear allocator is more likely to assign the hotter
  code paths first.
* If it assign these first we are:
  + Less likely to spill on the hot path.
  + Less likely to introduce fixup blocks on the hot path.

These two measure combined are surprisingly effective. Based on nofib
we get in the mean:

* -0.9% instructions executed
* -0.1% reads/writes
* -0.2% code size.
* -0.1% compiler allocations.
* -0.9% compile time.
* -0.8% runtime.

Most of the benefits are simply a result of removing redundant moves
and spills.

Reduced compiler allocations likely are the result of less code being
generated. (The added lookup is mostly non-allocating).

- - - - -
edc2cc58 by Andreas Klebinger at 2020-05-21T12:14:25-04:00
NCG: Codelayout: Distinguish conditional and other branches.

In #18053 we ended up with a suboptimal code layout because
the code layout algorithm didn't distinguish between conditional
and unconditional control flow.

We can completely eliminate unconditional control flow instructions
by placing blocks next to each other, not so much for conditionals.

In terms of implementation we simply give conditional branches less
weight before computing the layout.

Fixes #18053

- - - - -
b7a6b2f4 by Gleb Popov at 2020-05-21T12:15:26-04:00
gitlab-ci: Set locale to C.UTF-8.

- - - - -
a8c27cf6 by Stefan Holdermans at 2020-05-21T12:16:08-04:00
Allow spaces in GHCi :script file names

This patch updates the user interface of GHCi so that file names passed
to the ':script' command may contain spaces escaped with a backslash.

For example:

  :script foo\ bar.script

The implementation uses a modified version of 'words' that does not
break on escaped spaces.

Fixes #18027.

- - - - -
82663959 by Stefan Holdermans at 2020-05-21T12:16:08-04:00
Add extra tests for GHCi :script syntax checks

The syntax for GHCi's ":script" command allows for only a single file
name to be passed as an argument. This patch adds a test for the cases
in which a file name is missing or multiple file names are passed.

Related to #T18027.

- - - - -
a0b79e1b by Stefan Holdermans at 2020-05-21T12:16:08-04:00
Allow GHCi :script file names in double quotes

This patch updates the user interface of GHCi so that file names passed
to the ':script' command can be wrapped in double quotes.

For example:

  :script "foo bar.script"

The implementation uses a modified version of 'words' that treats
character sequences enclosed in double quotes as single words.

Fixes #18027.

- - - - -
cf566330 by Stefan Holdermans at 2020-05-21T12:16:08-04:00
Update documentation for GHCi :script

This patch adds the fixes that allow for file names containing spaces to
be passed to GHCi's ':script' command to the release notes for 8.12 and
expands the user-guide documentation for ':script' by mentioning how
such file names can be passed.

Related to #18027.

- - - - -
0004ccb8 by Tuan Le at 2020-05-21T12:16:46-04:00
llvmGen: Consider Relocatable read-only data as not constantReferences: #18137

- - - - -
964d3ea2 by John Ericson at 2020-05-21T12:17:30-04:00
Use `Checker` for `tc_pat`

- - - - -
b797aa42 by John Ericson at 2020-05-21T12:17:30-04:00
Use `Checker` for `tc_lpat` and `tc_lpats`

- - - - -
5108e84a by John Ericson at 2020-05-21T12:17:30-04:00
More judiciously panic in `ts_pat`

- - - - -
510e0451 by John Ericson at 2020-05-21T12:17:30-04:00
Put `PatEnv` first in `GHC.Tc.Gen.Pat.Checker`

- - - - -
cb4231db by John Ericson at 2020-05-21T12:17:30-04:00
Tiny cleaup eta-reduce away a function argument

In GHC, not in the code being compiled!

- - - - -
6890c38d by John Ericson at 2020-05-21T12:17:30-04:00
Use braces with do in `SplicePat` case for consistency

- - - - -
3451584f by buggymcbugfix at 2020-05-21T12:18:06-04:00
Fix spelling mistakes and typos

- - - - -
b552e531 by buggymcbugfix at 2020-05-21T12:18:06-04:00
Add INLINABLE pragmas to Enum list producers

The INLINABLE pragmas ensure that we export stable (unoptimised) unfoldings in
the interface file so we can do list fusion at usage sites.

Related tickets: #15185, #8763, #18178.

- - - - -
e7480063 by buggymcbugfix at 2020-05-21T12:18:06-04:00
Piggyback on Enum Word methods for Word64

If we are on a 64 bit platform, we can use the efficient Enum Word
methods for the Enum Word64 instance.

- - - - -
892b0c41 by buggymcbugfix at 2020-05-21T12:18:06-04:00
Document INLINE(ABLE) pragmas that enable fusion

- - - - -
2b363ebb by Richard Eisenberg at 2020-05-21T12:18:45-04:00
MR template should ask for key part
- - - - -
a95bbd0b by Sebastian Graf at 2020-05-21T12:19:37-04:00
Make `Int`'s `mod` and `rem` strict in their first arguments

They used to be strict until 4d2ac2d (9 years ago).

It's obviously better to be strict for performance reasons.
It also blocks #18067.

NoFib results:

```
--------------------------------------------------------------------------------
        Program         Allocs    Instrs
--------------------------------------------------------------------------------
        integer          -1.1%     +0.4%
   wheel-sieve2         +21.2%    +20.7%
--------------------------------------------------------------------------------
            Min          -1.1%     -0.0%
            Max         +21.2%    +20.7%
 Geometric Mean          +0.2%     +0.2%
```

The regression in `wheel-sieve2` is due to reboxing that likely will go
away with the resolution of #18067. See !3282 for details.

Fixes #18187.

- - - - -
d3d055b8 by Galen Huntington at 2020-05-21T12:20:18-04:00
Clarify pitfalls of NegativeLiterals; see #18022.
- - - - -
1b508a9e by Alexey Kuleshevich at 2020-05-21T12:21:02-04:00
Fix wording in primops documentation to reflect the correct reasoning:

* Besides resizing functions, shrinking ones also mutate the
  size of a mutable array and because of those two `sizeofMutabeByteArray`
  and `sizeofSmallMutableArray` are now deprecated
* Change reference in documentation to the newer functions `getSizeof*`
  instead of `sizeof*` for shrinking functions
* Fix incorrect mention of "byte" instead of "small"

- - - - -
4ca0c8a1 by Andreas Klebinger at 2020-05-21T12:21:53-04:00
Don't variable-length encode magic iface constant.

We changed to use variable length encodings for many types by default,
including Word32. This makes sense for numbers but not when Word32 is
meant to represent four bytes.

I added a FixedLengthEncoding newtype to Binary who's instances
interpret their argument as a collection of bytes instead of a number.

We then use this when writing/reading magic numbers to the iface file.

I also took the libery to remove the dummy iface field.

This fixes #18180.

- - - - -
a1275081 by Krzysztof Gogolewski at 2020-05-21T12:22:35-04:00
Add a regression test for #11506

The testcase works now.
See explanation in https://gitlab.haskell.org/ghc/ghc/issues/11506#note_273202

- - - - -
8a816e5f by Krzysztof Gogolewski at 2020-05-21T12:23:55-04:00
Sort deterministically metric output

Previously, we sorted according to the test name and way,
but the metrics (max_bytes_used/peak_megabytes_allocated etc.)
were appearing in nondeterministic order.

- - - - -
566cc73f by Sylvain Henry at 2020-05-21T12:24:45-04:00
Move isDynLinkName into GHC.Types.Name

It doesn't belong into GHC.Unit.State

- - - - -
d830bbc9 by Adam Sandberg Ericsson at 2020-05-23T13:36:20-04:00
docs: fix formatting and add some links

[skip ci]

- - - - -
49301ad6 by Andrew Martin at 2020-05-23T13:37:01-04:00
Implement cstringLength# and FinalPtr

This function and its accompanying rule resolve issue #5218.
A future PR to the bytestring library will make the internal
Data.ByteString.Internal.unsafePackAddress compute string length
with cstringLength#. This will improve the status quo because it is
eligible for constant folding.

Additionally, introduce a new data constructor to ForeignPtrContents
named FinalPtr. This additional data constructor, when used in the
IsString instance for ByteString, leads to more Core-to-Core
optimization opportunities, fewer runtime allocations, and smaller
binaries.

Also, this commit re-exports all the functions from GHC.CString
(including cstringLength#) in GHC.Exts. It also adds a new test
driver. This test driver is used to perform substring matches on Core
that is dumped after all the simplifier passes. In this commit, it is
used to check that constant folding of cstringLength# works.

- - - - -
dcd6bdcc by Ben Gamari at 2020-05-23T13:37:48-04:00
simplCore: Ignore ticks in rule templates

This fixes #17619, where a tick snuck in to the template of a rule,
resulting in a panic during rule matching. The tick in question was
introduced via post-inlining, as discussed in `Note [Simplifying
rules]`. The solution we decided upon was to simply ignore ticks in the
rule template, as discussed in `Note [Tick annotations in RULE
matching]`.

Fixes #18162.
Fixes #17619.

- - - - -
82cb8913 by John Ericson at 2020-05-23T13:38:32-04:00
Fix #18145 and also avoid needless work with implicit vars

 - `forAllOrNothing` now is monadic, so we can trace whether we bind
   an explicit `forall` or not.

 - #18145 arose because the free vars calculation was needlessly
   complex. It is now greatly simplified.

 - Replaced some other implicit var code with `filterFreeVarsToBind`.

Co-authored-by: Ryan Scott <ryan.gl.scott at gmail.com>

- - - - -
a60dc835 by Ben Gamari at 2020-05-23T13:39:12-04:00
Bump process submodule

Fixes #17926.

- - - - -
856adf54 by Ben Gamari at 2020-05-23T13:40:21-04:00
users-guide: Clarify meaning of -haddock flag

Fixes #18206.

- - - - -
7ae57afd by Ben Gamari at 2020-05-23T13:41:03-04:00
git: Add ignored commits file

This can be used to tell git to ignore bulk renaming commits like the
recently-finished module hierarchy refactoring. Configured with,

    git config blame.ignoreRevsFile .git-ignore-revs

- - - - -
63d30e60 by jneira at 2020-05-24T01:54:42-04:00
Add hie-bios script for windows systems
It is a direct translation of the sh script

- - - - -
59182b88 by jneira at 2020-05-24T01:54:42-04:00
Honour previous values for CABAL and CABFLAGS
The immediate goal is let the hie-bios.bat script
set CABFLAGS with `-v0` and remove all cabal output
except the compiler arguments

- - - - -
932dc54e by jneira at 2020-05-24T01:54:42-04:00
Add specific configuration for windows in hie.yaml

- - - - -
e0eda070 by jneira at 2020-05-24T01:54:42-04:00
Remove not needed hie-bios output

- - - - -
a0ea59d6 by Sylvain Henry at 2020-05-24T01:55:24-04:00
Move Config module into GHC.Settings

- - - - -
37430251 by Sylvain Henry at 2020-05-24T01:55:24-04:00
Rename GHC.Core.Arity into GHC.Core.Opt.Arity

- - - - -
a426abb9 by Sylvain Henry at 2020-05-24T01:55:24-04:00
Rename GHC.Hs.Types into GHC.Hs.Type

See discussion in https://gitlab.haskell.org/ghc/ghc/issues/13009#note_268610

- - - - -
1c91a7a0 by Sylvain Henry at 2020-05-24T01:55:24-04:00
Bump haddock submodule

- - - - -
66bd24d1 by Ryan Scott at 2020-05-24T01:56:03-04:00
Add orderingTyCon to wiredInTyCons (#18185)

`Ordering` needs to be wired in for use in the built-in `CmpNat` and
`CmpSymbol` type families, but somehow it was never added to the list
of `wiredInTyCons`, leading to the various oddities observed
in #18185. Easily fixed by moving `orderingTyCon` from
`basicKnownKeyNames` to `wiredInTyCons`.

Fixes #18185.

- - - - -
01c43634 by Matthew Pickering at 2020-05-24T01:56:42-04:00
Remove unused hs-boot file

- - - - -
7a07aa71 by Sylvain Henry at 2020-05-24T15:22:17-04:00
Hadrian: fix cross-compiler build (#16051)

- - - - -
15ccca16 by Sylvain Henry at 2020-05-24T15:22:17-04:00
Hadrian: fix distDir per stage

- - - - -
b420fb24 by Sylvain Henry at 2020-05-24T15:22:17-04:00
Hadrian: fix hp2ps error during cross-compilation

Fixed by @alp (see https://gitlab.haskell.org/ghc/ghc/issues/16051#note_274265)

- - - - -
cd339ef0 by Joshua Price at 2020-05-24T15:22:56-04:00
Make Unicode brackets opening/closing tokens (#18225)

The tokens `[|`, `|]`, `(|`, and `|)` are opening/closing tokens as
described in GHC Proposal #229. This commit makes the unicode
variants (`⟦`, `⟧`, `⦇`, and `⦈`) act the same as their ASCII
counterparts.

- - - - -
013d7120 by Ben Gamari at 2020-05-25T09:48:17-04:00
Revert "Specify kind variables for inferred kinds in base."

As noted in !3132, this has rather severe knock-on consequences in
user-code. We'll need to revisit this before merging something along
these lines.

This reverts commit 9749fe1223d182b1f8e7e4f7378df661c509f396.

- - - - -
4c4312ed by Ben Gamari at 2020-05-25T09:48:53-04:00
Coverage: Drop redundant ad-hoc boot module check

To determine whether the module is a boot module
Coverage.addTicksToBinds was checking for a `boot` suffix in the module
source filename. This is quite ad-hoc and shouldn't be necessary; the
callsite in `deSugar` already checks that the module isn't a boot
module.

- - - - -
1abf3c84 by Ben Gamari at 2020-05-25T09:48:53-04:00
Coverage: Make tickBoxCount strict

This could otherwise easily cause a leak of (+) thunks.

- - - - -
b2813750 by Ben Gamari at 2020-05-25T09:48:53-04:00
Coverage: Make ccIndices strict

This just seems like a good idea.

- - - - -
02e278eb by Ben Gamari at 2020-05-25T09:48:53-04:00
Coverage: Don't produce ModBreaks if not HscInterpreted

emptyModBreaks contains a bottom and consequently it's important that we
don't use it unless necessary.

- - - - -
b8c014ce by Ben Gamari at 2020-05-25T09:48:53-04:00
Coverage: Factor out addMixEntry

- - - - -
53814a64 by Zubin Duggal at 2020-05-26T03:03:24-04:00
Add info about typeclass evidence to .hie files

See `testsuite/tests/hiefile/should_run/HieQueries.hs` and
`testsuite/tests/hiefile/should_run/HieQueries.stdout` for an example of this

We add two new fields, `EvidenceVarBind` and `EvidenceVarUse` to the
`ContextInfo` associated with an Identifier. These are associated with the
appropriate identifiers for the evidence variables collected when we come across
`HsWrappers`, `TcEvBinds` and `IPBinds` while traversing the AST.

Instance dictionary and superclass selector dictionaries from `tcg_insts` and
classes defined in `tcg_tcs` are also recorded in the AST as originating from
their definition span

This allows us to save a complete picture of the evidence constructed by the
constraint solver, and will let us report this to the user, enabling features
like going to the instance definition from the invocation of a class method(or
any other method taking a constraint) and finding all usages of a particular
instance.

Additionally,

- Mark NodeInfo with an origin so we can differentiate between bindings
  origininating in the source vs those in ghc
- Along with typeclass evidence info, also include information on Implicit
  Parameters
- Add a few utility functions to HieUtils in order to query the new info

Updates haddock submodule

- - - - -
6604906c by Sebastian Graf at 2020-05-26T03:04:04-04:00
Make WorkWrap.Lib.isWorkerSmallEnough aware of the old arity

We should allow a wrapper with up to 82 parameters when the original
function had 82 parameters to begin with.

I verified that this made no difference on NoFib, but then again
it doesn't use huge records...

Fixes #18122.

- - - - -
cf772f19 by Sylvain Henry at 2020-05-26T03:04:45-04:00
Enhance Note [About units] for Backpack

- - - - -
ede24126 by Takenobu Tani at 2020-05-27T00:13:55-04:00
core-spec: Modify file paths according to new module hierarchy

This patch updates file paths according to new module hierarchy [1]:

  * GHC/Core.hs                <= coreSyn/CoreSyn.hs
  * GHC/Core/Coercion.hs       <= types/Coercion.hs
  * GHC/Core/Coercion/Axiom.hs <= types/CoAxiom.hs
  * GHC/Core/Coercion/Opt.hs   <= types/OptCoercion.hs
  * GHC/Core/DataCon.hs        <= basicTypes/DataCon.hs
  * GHC/Core/FamInstEnv.hs     <= types/FamInstEnv.hs
  * GHC/Core/Lint.hs           <= coreSyn/CoreLint.hs
  * GHC/Core/Subst.hs          <= coreSyn/CoreSubst.hs
  * GHC/Core/TyCo/Rep.hs       <= types/TyCoRep.hs
  * GHC/Core/TyCon.hs          <= types/TyCon.hs
  * GHC/Core/Type.hs           <= types/Type.hs
  * GHC/Core/Unify.hs          <= types/Unify.hs
  * GHC/Types/Literal.hs       <= basicTypes/Literal.hs
  * GHC/Types/Var.hs           <= basicTypes/Var.hs

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular

[skip ci]

- - - - -
04750304 by Ben Gamari at 2020-05-27T00:14:33-04:00
eventlog: Fix racy flushing

Previously no attempt was made to avoid multiple threads writing their
capability-local eventlog buffers to the eventlog writer simultaneously.
This could result in multiple eventlog streams being interleaved. Fix
this by documenting that the EventLogWriter's write() and flush()
functions may be called reentrantly and fix the default writer to
protect its FILE* by a mutex.

Fixes #18210.

- - - - -
d6203f24 by Joshua Price at 2020-05-27T00:15:17-04:00
Make `identifier` parse unparenthesized `->` (#18060)

- - - - -
28deee28 by Ben Gamari at 2020-05-28T16:23:21-04:00
GHC.Core.Unfold: Refactor traceInline

This reduces duplication as well as fixes a bug wherein -dinlining-check
would override -ddump-inlinings. Moreover, the new variant

- - - - -
1f393e1e by Ben Gamari at 2020-05-28T16:23:21-04:00
Avoid unnecessary allocations due to tracing utilities

While ticky-profiling the typechecker I noticed that hundreds of
millions of SDocs are being allocated just in case -ddump-*-trace is
enabled. This is awful.

We avoid this by ensuring that the dump flag check is inlined into the
call site, ensuring that the tracing document needn't be allocated
unless it's actually needed.

See Note [INLINE conditional tracing utilities] for details.

Fixes #18168.

Metric Decrease:
  T9961
  haddock.Cabal
  haddock.base
  haddock.compiler

- - - - -
5f621a78 by Vladislav Zavialov at 2020-05-28T16:23:58-04:00
Add Semigroup/Monoid for Q (#18123)

- - - - -
dc5f004c by Xavier Denis at 2020-05-28T16:24:37-04:00
Fix #18071

Run the core linter on candidate instances to ensure they are
well-kinded.

Better handle quantified constraints by using a CtWanted to avoid
having unsolved constraints thrown away at the end by the solver.

- - - - -
10e6982c by Sebastian Graf at 2020-05-28T16:25:14-04:00
FloatOut: Only eta-expand dead-end RHS if arity will increase (#18231)

Otherwise we risk turning trivial RHS into non-trivial RHS, introducing
unnecessary bindings in the next Simplifier run, resulting in more
churn.

Fixes #18231.

- - - - -
08dab5f7 by Sebastian Graf at 2020-05-28T16:25:14-04:00
DmdAnal: Recognise precise exceptions from case alternatives (#18086)

Consider

```hs
m :: IO ()
m = do
  putStrLn "foo"
  error "bar"
```

`m` (from #18086) always throws a (precise or imprecise) exception or
diverges. Yet demand analysis infers `<L,A>` as demand signature instead
of `<L,A>x` for it.

That's because the demand analyser sees `putStrLn` occuring in a case
scrutinee and decides that it has to `deferAfterPreciseException`,
because `putStrLn` throws a precise exception on some control flow
paths. This will mask the `botDiv` `Divergence`of the single case alt
containing `error` to `topDiv`. Since `putStrLn` has `topDiv` itself,
the final `Divergence` is `topDiv`.

This is easily fixed: `deferAfterPreciseException` works by `lub`ing
with the demand type of a virtual case branch denoting the precise
exceptional control flow. We used `nopDmdType` before, but we can be
more precise and use `exnDmdType`, which is `nopDmdType` with `exnDiv`.

Now the `Divergence` from the case alt will degrade `botDiv` to `exnDiv`
instead of `topDiv`, which combines with the result from the scrutinee
to `exnDiv`, and all is well.

Fixes #18086.

- - - - -
aef95f11 by Ben Gamari at 2020-05-28T16:25:53-04:00
Ticky-ticky: Record DataCon name in ticker name

This makes it significantly easier to spot the nature of
allocations regressions and comes at a reasonably low cost.

- - - - -
8f021b8c by Ben Gamari at 2020-05-28T16:26:34-04:00
hadrian: Don't track GHC's verbosity argument

Teach hadrian to ignore GHC's -v argument in its recompilation check,
thus fixing #18131.

- - - - -
13d9380b by Ben Gamari at 2020-05-28T16:27:20-04:00
Rip out CmmStackInfo(updfr_space)

As noted in #18232, this field is currently completely unused and
moreover doesn't have a clear meaning.

- - - - -
f10d11fa by Andreas Klebinger at 2020-05-29T01:38:42-04:00
Fix "build/elem" RULE.

An redundant constraint prevented the rule from matching.

Fixing this allows a call to elem on a known list to be translated
into a series of equality checks, and eventually a simple case
expression.

Surprisingly this seems to regress elem for strings. To avoid
this we now also allow foldrCString to inline and add an UTF8
variant. This results in elem being compiled to a tight
non-allocating loop over the primitive string literal which
performs a linear search.

In the process this commit adds UTF8 variants for some of the
functions in GHC.CString. This is required to make this work for
both ASCII and UTF8 strings.

There are also small tweaks to the CString related rules.
We now allow ourselfes the luxury to compare the folding function
via eqExpr, which helps to ensure the rule fires before we inline
foldrCString*. Together with a few changes to allow matching on both
the UTF8 and ASCII variants of the CString functions.

- - - - -
bbeb2389 by Ben Gamari at 2020-05-29T01:39:19-04:00
CoreToStg: Add Outputable ArgInfo instance

- - - - -
0e3361ca by Simon Peyton Jones at 2020-05-29T01:39:19-04:00
Make Lint check return type of a join point

Consider
   join x = rhs in body
It's important that the type of 'rhs' is the same as the type of
'body', but Lint wasn't checking that invariant.

Now it does!  This was exposed by investigation into !3113.

- - - - -
c49f7df0 by Simon Peyton Jones at 2020-05-29T01:39:19-04:00
Do not float join points in exprIsConApp_maybe

We hvae been making exprIsConApp_maybe cleverer in recent times:

    commit b78cc64e923716ac0512c299f42d4d0012306c05
    Date:   Thu Nov 15 17:14:31 2018 +0100
    Make constructor wrappers inline only during the final phase

    commit 7833cf407d1f608bebb1d38bb99d3035d8d735e6
    Date:   Thu Jan 24 17:58:50 2019 +0100
    Look through newtype wrappers (Trac #16254)

    commit c25b135ff5b9c69a90df0ccf51b04952c2dc6ee1
    Date:   Thu Feb 21 12:03:22 2019 +0000
    Fix exprIsConApp_maybe

But alas there was still a bug, now immortalised in
  Note [Don't float join points]
in SimpleOpt.

It's quite hard to trigger because it requires a dead
join point, but it came up when compiling Cabal
Cabal.Distribution.Fields.Lexer.hs, when working on
!3113.

Happily, the fix is extremly easy.  Finding the
bug was not so easy.

- - - - -
46720997 by Ben Gamari at 2020-05-29T01:39:19-04:00
Allow simplification through runRW#

Because runRW# inlines so late, we were previously able to do very
little simplification across it. For instance, given even a simple
program like

    case runRW# (\s -> let n = I# 42# in n) of
      I# n# -> f n#

we previously had no way to avoid the allocation of the I#.

This patch allows the simplifier to push strict contexts into the
continuation of a runRW# application, as explained in
in Note [Simplification of runRW#] in GHC.CoreToStg.Prep.

Fixes #15127.

Metric Increase:
    T9961
Metric Decrease:
    ManyConstructors

Co-Authored-By: Simon Peyton-Jone <simonpj at microsoft.com>

- - - - -
277c2f26 by Ben Gamari at 2020-05-29T01:39:55-04:00
Eta expand un-saturated primops

Now since we no longer try to predict CAFfyness we have no need for the
solution to #16846. Eta expanding unsaturated primop applications is
conceptually simpler, especially in the presence of levity polymorphism.

This essentially reverts cac8dc9f51e31e4c0a6cd9bc302f7e1bc7c03beb,
as suggested in #18079.

Closes #18079.

- - - - -
f44d7ae0 by Simon Jakobi at 2020-05-29T01:40:34-04:00
base: Scrap deprecation plan for Data.Monoid.{First,Last}

See the discussion on the libraries mailing list for context:

https://mail.haskell.org/pipermail/libraries/2020-April/030357.html

- - - - -
8b494895 by Jeremy Schlatter at 2020-05-29T01:41:12-04:00
Fix typo in documentation

- - - - -
998450f4 by Gleb Popov at 2020-05-29T01:41:53-04:00
Always define USE_PTHREAD_FOR_ITIMER for FreeBSD.

- - - - -
f9a513e0 by Alp Mestanogullari at 2020-05-29T01:42:36-04:00
hadrian: introduce 'install' target

Its logic is very simple. It `need`s the `binary-dist-dir` target
and runs suitable `configure` and `make install` commands for the
user. A new `--prefix` command line argument is introduced to
specify where GHC should be installed.

- - - - -
67738db1 by Travis Whitaker at 2020-05-29T13:34:48-04:00
Build a threaded stage 1 if the bootstrapping GHC supports it.

- - - - -
aac19e6c by Peter Trommler at 2020-05-29T13:35:24-04:00
PPC NCG: No per-symbol .section ".toc" directives

All position independent symbols are collected during code generation
and emitted in one go. Prepending each symbol with a .section ".toc"
directive is redundant. This patch drops the per-symbol directives
leading to smaller assembler files.

Fixes #18250

- - - - -
4413828b by Ben Gamari at 2020-05-30T06:07:31-04:00
rts: Teach getNumProcessors to return available processors

Previously we would report the number of physical processors, which
can be quite wrong in a containerized setting. Now we rather return how
many processors are in our affinity mask when possible.

I also refactored the code to prefer platform-specific since this will
report logical CPUs instead of physical (using
`machdep.cpu.thread_count` on Darwin and `cpuset_getaffinity` on FreeBSD).

Fixes #14781.

- - - - -
1449435c by Ben Gamari at 2020-05-30T06:07:31-04:00
users-guide: Note change in getNumProcessors in users guide

- - - - -
3d960169 by Ben Gamari at 2020-05-30T06:07:31-04:00
rts: Drop compatibility shims for Windows Vista

We can now assume that the thread and processor group interfaces are
available.

- - - - -
7f8f948c by Peter Trommler at 2020-05-30T06:08:07-04:00
PPC NCG: Fix .size directive on powerpc64 ELF v1

Thanks to Sergei Trofimovich for pointing out the issue.

Fixes #18237

- - - - -
7c555b05 by Andreas Klebinger at 2020-05-30T06:08:43-04:00
Optimize GHC.Utils.Monad.

Many functions in this module are recursive and as such are marked
loop breakers. Which means they are unlikely to get an unfolding.

This is *bad*. We always want to specialize them to specific Monads.
Which requires a visible unfolding at the use site.

I rewrote the recursive ones from:

    foo f x = ... foo x' ...

to

    foo f x = go x
      where
        go x = ...

As well as giving some pragmas to make all of them available
for specialization.

The end result is a reduction of allocations of about -1.4% for
nofib/spectral/simple/Main.hs when compiled with `-O`.

-------------------------
Metric Decrease:
    T12425
    T14683
    T5631
    T9233
    T9675
    T9961
    WWRec
-------------------------

- - - - -
8b1cb5df by Ben Gamari at 2020-05-30T06:09:20-04:00
Windows: Bump Windows toolchain to 0.2

- - - - -
6947231a by Zubin Duggal at 2020-05-30T06:10:02-04:00
Simplify contexts in GHC.Iface.Ext.Ast

- - - - -
2ee4f36c by Daniel Gröber at 2020-06-01T06:32:56-04:00
Cleanup OVERWRITING_CLOSURE logic

The code is just more confusing than it needs to be. We don't need to mix
the threaded check with the ldv profiling check since ldv's init already
checks for this. Hence they can be two separate checks. Taking the sanity
checking into account is also cleaner via DebugFlags.sanity. No need for
checking the DEBUG define.

The ZERO_SLOP_FOR_LDV_PROF and ZERO_SLOP_FOR_SANITY_CHECK definitions the
old code had also make things a lot more opaque IMO so I removed those.

- - - - -
6159559b by Daniel Gröber at 2020-06-01T06:32:56-04:00
Fix OVERWRITING_CLOSURE assuming closures are not inherently used

The new ASSERT in LDV_recordDead() was being tripped up by MVars when
removeFromMVarBlockedQueue() calls OVERWRITING_CLOSURE() via
OVERWRITE_INFO().

- - - - -
38992085 by Daniel Gröber at 2020-06-01T06:32:56-04:00
Always zero shrunk mutable array slop when profiling

When shrinking arrays in the profiling way we currently don't always zero
the leftover slop. This means we can't traverse such closures in the heap
profiler. The old Note [zeroing slop] and #8402 have some rationale for why
this is so but I belive the reasoning doesn't apply to mutable
closures. There users already have to ensure multiple threads don't step on
each other's toes so zeroing should be safe.

- - - - -
b0c1f2a6 by Ben Gamari at 2020-06-01T06:33:37-04:00
testsuite: Add test for #18151

- - - - -
9a99a178 by Ben Gamari at 2020-06-01T06:33:37-04:00
testsuite: Add test for desugaring of PostfixOperators

- - - - -
2b89ca5b by Ben Gamari at 2020-06-01T06:33:37-04:00
HsToCore: Eta expand left sections

Strangely, the comment next to this code already alluded to the fact
that even simply eta-expanding will sacrifice laziness. It's quite
unclear how we regressed so far.

See #18151.

- - - - -
d412d7a3 by Kirill Elagin at 2020-06-01T06:34:21-04:00
Winferred-safe-imports: Do not exit with error

Currently, when -Winferred-safe-imports is enabled, even when it is not
turned into an error, the compiler will still exit with exit code 1 if
this warning was emitted.

Make sure it is really treated as a warning.

- - - - -
f945eea5 by Ben Gamari at 2020-06-01T06:34:58-04:00
nonmoving: Optimise log2_ceil

- - - - -
aab606e4 by Bodigrim at 2020-06-01T06:35:36-04:00
Clarify description of fromListN
- - - - -
7e5220e2 by Bodigrim at 2020-06-01T06:35:36-04:00
Apply suggestion to libraries/base/GHC/Exts.hs
- - - - -
f3fb1ce9 by fendor at 2020-06-01T06:36:18-04:00
Add `isInScope` check to `lintCoercion`

Mirrors the behaviour of `lintType`.

- - - - -
5ac4d946 by fendor at 2020-06-01T06:36:18-04:00
Lint rhs of IfaceRule

- - - - -
1cef6126 by Jeremy Schlatter at 2020-06-01T06:37:00-04:00
Fix wording in documentation

The duplicate "orphan instance" phrase here doesn't make sense, and was
probably an accident.

- - - - -
5aaf08f2 by Takenobu Tani at 2020-06-01T06:37:43-04:00
configure: Modify aclocal.m4 according to new module hierarchy

This patch updates file paths according to new module hierarchy [1]:

* Rename:
  * compiler/GHC/Parser.hs       <= compiler/parser/Parser.hs
  * compiler/GHC/Parser/Lexer.hs <= compiler/Parser/Lexer.hs

* Add:
  * compiler/GHC/Cmm/Lexer.hs

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular

- - - - -
15857ad8 by Ben Gamari at 2020-06-01T06:38:26-04:00
testsuite: Don't fail if we can't unlink __symlink_test

Afterall, it's possible we were unable to create it due to lack of
symlink permission.

- - - - -
4a7229ef by Ben Gamari at 2020-06-01T06:38:26-04:00
testsuite: Refactor ghostscript detection

Tamar reported that he saw crashes due to unhandled exceptions.

- - - - -
2ab37eaf by Ben Gamari at 2020-06-01T06:38:26-04:00
testsuite/perf_notes: Fix ill-typed assignments

- - - - -
e45d5b66 by Ben Gamari at 2020-06-01T06:38:26-04:00
testsuite/testutil: Fix bytes/str mismatch

- - - - -
7002d0cb by Ben Gamari at 2020-06-01T06:38:26-04:00
testsuite: Work around spurious mypy failure

- - - - -
11390e3a by Takenobu Tani at 2020-06-01T06:39:05-04:00
Clean up file paths for new module hierarchy

This updates comments only.
This patch replaces file references according to new module hierarchy.

See also:
* https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular
* https://gitlab.haskell.org/ghc/ghc/issues/13009

- - - - -
8f2e5732 by Takenobu Tani at 2020-06-01T06:39:05-04:00
Modify file paths to module paths for new module hierarchy

This updates comments only.

This patch replaces module references according to new module
hierarchy [1][2].

For files under the `compiler/` directory, I replace them as
module paths instead of file paths. For instance,
`GHC.Unit.State` instead of `compiler/GHC/Unit/State.hs` [3].

For current and future haddock's markup, this patch encloses
the module name with "" [4].

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular
[2]: https://gitlab.haskell.org/ghc/ghc/issues/13009
[3]: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3375#note_276613
[4]: https://haskell-haddock.readthedocs.io/en/latest/markup.html#linking-to-modules

- - - - -
68b71c4a by Tom Ellis at 2020-06-01T06:39:55-04:00
Rename the singleton tuple GHC.Tuple.Unit to GHC.Tuple.Solo

- - - - -
95da76c2 by Sylvain Henry at 2020-06-01T06:40:41-04:00
Hadrian: fix binary-dist target for cross-compilation

- - - - -
730fcd54 by Vladislav Zavialov at 2020-06-01T06:41:18-04:00
Improve parser error messages for the @-operator

Since GHC diverges from the Haskell Report by allowing the user
to define (@) as an infix operator, we better give a good
error message when the user does so unintentionally.

In general, this is rather hard to do, as some failures will be
discovered only in the renamer or the type checker:

	x :: (Integer, Integer)
	x @ (a, b) = (1, 2)

This patch does *not* address this general case.

However, it gives much better error messages when the binding
is not syntactically valid:

	pairs xs @ (_:xs') = zip xs xs'

Before this patch, the error message was rather puzzling:

	<interactive>:1:1: error: Parse error in pattern: pairs

After this patch, the error message includes a hint:

	<interactive>:1:1: error:
	    Parse error in pattern: pairs
	    In a function binding for the ‘@’ operator.
	    Perhaps you meant an as-pattern, which must not be surrounded by whitespace

- - - - -
0fde5377 by Vladislav Zavialov at 2020-06-01T06:41:18-04:00
Improve parser error messages for TypeApplications

With this patch, we always parse  f @t  as a type application,
thereby producing better error messages.

This steals two syntactic forms:

* Prefix form of the @-operator in expressions. Since the @-operator is
  a divergence from the Haskell Report anyway, this is not a major loss.

* Prefix form of @-patterns. Since we are stealing loose infix form
  anyway, might as well sacrifice the prefix form for the sake of much
  better error messages.

- - - - -
c68e7e1e by Vladislav Zavialov at 2020-06-01T06:41:18-04:00
Improve parser error messages for TemplateHaskellQuotes

While [e| |], [t| |], [d| |], and so on, steal syntax from list
comprehensions, [| |] and [|| ||] do not steal any syntax.

Thus we can improve error messages by always accepting them in the
lexer. Turns out the renamer already performs necessary validation.

- - - - -
120aedbd by Ben Gamari at 2020-06-01T16:07:02-04:00
gitlab-ci: Disable use of ld.lld on ARMv7

It turns out that lld non-deterministically fails on ARMv7. I suspect
this may be due to the a kernel regression as this only started
happening when we upgraded to 5.4. Nevertheless, easily avoided by
simply sticking with gold.

Works around #18280.

- - - - -
d6279ff0 by Ben Gamari at 2020-06-02T13:03:30-04:00
gitlab-ci: Ensure that workaround for #18280 applies to bindisttest

We need to ensure that the `configure` flags working around #18280 are
propagated to the bindisttest `configure` as well.

- - - - -
cb5c31b5 by Ben Gamari at 2020-06-03T17:55:04-04:00
gitlab-ci: Allow ARMv7 job to fail

Due to #18298.

- - - - -
32a4ae90 by John Ericson at 2020-06-04T04:34:42-04:00
Clean up boot vs non-boot disambiguating types

We often have (ModuleName, Bool) or (Module, Bool) pairs for "extended"
module names (without or with a unit id) disambiguating boot and normal
modules. We think this is important enough across the compiler that it
deserves a new nominal product type. We do this with synnoyms and a
functor named with a `Gen` prefix, matching other newly created
definitions.

It was also requested that we keep custom `IsBoot` / `NotBoot` sum type.
So we have it too. This means changing many the many bools to use that
instead.

Updates `haddock` submodule.

- - - - -
c05756cd by Niklas Hambüchen at 2020-06-04T04:35:24-04:00
docs: Add more details on InterruptibleFFI.

Details from https://gitlab.haskell.org/ghc/ghc/issues/8684
and https://github.com/takano-akio/filelock/pull/7#discussion_r280332430

- - - - -
1b975aed by Andrew Martin at 2020-06-04T04:36:03-04:00
Allow finalizeForeignPtr to be called on FinalPtr/PlainPtr.

MR 2165 (commit 49301ad6226d9a83d110bee8c419615dd94f5ded) regressed
finalizeForeignPtr by throwing exceptions when PlainPtr was encounterd.
This regression did not make it into a release of GHC. Here, the
original behavior is restored, and FinalPtr is given the same treatment
as PlainPtr.

- - - - -
2bd3929a by Luke Lau at 2020-06-04T04:36:41-04:00
Fix documentation on type families not being extracted

It looks like the location of the Names used for CoAxioms on type
families are now located at their type constructors. Previously, Docs.hs
thought the Names were located in the RHS, so the RealSrcSpan in the
instanceMap and getInstLoc didn't match up. Fixes #18241

- - - - -
6735b9d9 by Ben Gamari at 2020-06-04T04:37:21-04:00
GHC.Hs.Instances: Compile with -O0

This module contains exclusively Data instances, which are going to be
slow no matter what we do. Furthermore, they are incredibly slow to
compile with optimisation (see #9557). Consequently we compile this with
-O0.  See #18254.

- - - - -
c330331a by nineonine at 2020-06-04T04:37:59-04:00
Add test for #17669

- - - - -
cab684f0 by Ben Gamari at 2020-06-04T04:38:36-04:00
rts: Add Windows-specific implementation of rtsSleep

Previously we would use the POSIX path, which uses `nanosleep`. However,
it turns out that `nanosleep` is provided by `libpthread` on Windows. In
general we don't want to incur such a dependency. Avoid this by simply
using `Sleep` on Windows.

Fixes #18272.

- - - - -
ad44b504 by Ben Gamari at 2020-06-04T04:38:36-04:00
compiler: Disable use of process jobs with process < 1.6.9

Due to #17926.

- - - - -
6a4098a4 by Moritz Angermann at 2020-06-04T04:55:51-04:00
[linker] Adds void printLoadedObjects(void);

This allows us to dump in-memory object code locations for debugging.

Fixup printLoadedObjects prototype

- - - - -
af5e3a88 by Artem Pelenitsyn at 2020-06-05T03:18:49-04:00
base: fix sign confusion in log1mexp implementation (fix #17125)

author: claude (https://gitlab.haskell.org/trac-claude)

The correct threshold for log1mexp is -(log 2) with the current specification
of log1mexp. This change improves accuracy for large negative inputs.

To avoid code duplication, a small helper function is added;
it isn't the default implementation in Floating because it needs Ord.

This patch does nothing to address that the Haskell specification is
different from that in common use in other languages.

- - - - -
2b792fac by Simon Peyton Jones at 2020-06-05T09:27:50-04:00
Simple subsumption

This patch simplifies GHC to use simple subsumption.
  Ticket #17775

Implements GHC proposal #287
   https://github.com/ghc-proposals/ghc-proposals/blob/master/
   proposals/0287-simplify-subsumption.rst

All the motivation is described there; I will not repeat it here.
The implementation payload:
 * tcSubType and friends become noticably simpler, because it no
   longer uses eta-expansion when checking subsumption.
 * No deeplyInstantiate or deeplySkolemise

That in turn means that some tests fail, by design; they can all
be fixed by eta expansion.  There is a list of such changes below.

Implementing the patch led me into a variety of sticky corners, so
the patch includes several othe changes, some quite significant:

* I made String wired-in, so that
    "foo" :: String   rather than
    "foo" :: [Char]
  This improves error messages, and fixes #15679

* The pattern match checker relies on knowing about in-scope equality
  constraints, andd adds them to the desugarer's environment using
  addTyCsDs.  But the co_fn in a FunBind was missed, and for some reason
  simple-subsumption ends up with dictionaries there. So I added a
  call to addTyCsDs.  This is really part of #18049.

* I moved the ic_telescope field out of Implication and into
  ForAllSkol instead.  This is a nice win; just expresses the code
  much better.

* There was a bug in GHC.Tc.TyCl.Instance.tcDataFamInstHeader.
  We called checkDataKindSig inside tc_kind_sig, /before/
  solveEqualities and zonking.  Obviously wrong, easily fixed.

* solveLocalEqualitiesX: there was a whole mess in here, around
  failing fast enough.  I discovered a bad latent bug where we
  could successfully kind-check a type signature, and use it,
  but have unsolved constraints that could fill in coercion
  holes in that signature --  aargh.

  It's all explained in Note [Failure in local type signatures]
  in GHC.Tc.Solver. Much better now.

* I fixed a serious bug in anonymous type holes. IN
    f :: Int -> (forall a. a -> _) -> Int
  that "_" should be a unification variable at the /outer/
  level; it cannot be instantiated to 'a'.  This was plain
  wrong.  New fields mode_lvl and mode_holes in TcTyMode,
  and auxiliary data type GHC.Tc.Gen.HsType.HoleMode.

  This fixes #16292, but makes no progress towards the more
  ambitious #16082

* I got sucked into an enormous refactoring of the reporting of
  equality errors in GHC.Tc.Errors, especially in
      mkEqErr1
      mkTyVarEqErr
      misMatchMsg
      misMatchMsgOrCND
  In particular, the very tricky mkExpectedActualMsg function
  is gone.

  It took me a full day.  But the result is far easier to understand.
  (Still not easy!)  This led to various minor improvements in error
  output, and an enormous number of test-case error wibbles.

  One particular point: for occurs-check errors I now just say
     Can't match 'a' against '[a]'
  rather than using the intimidating language of "occurs check".

* Pretty-printing AbsBinds

Tests review

* Eta expansions
   T11305: one eta expansion
   T12082: one eta expansion (undefined)
   T13585a: one eta expansion
   T3102:  one eta expansion
   T3692:  two eta expansions (tricky)
   T2239:  two eta expansions
   T16473: one eta
   determ004: two eta expansions (undefined)
   annfail06: two eta (undefined)
   T17923: four eta expansions (a strange program indeed!)
   tcrun035: one eta expansion

* Ambiguity check at higher rank.  Now that we have simple
  subsumption, a type like
     f :: (forall a. Eq a => Int) -> Int
  is no longer ambiguous, because we could write
     g :: (forall a. Eq a => Int) -> Int
     g = f
  and it'd typecheck just fine.  But f's type is a bit
  suspicious, and we might want to consider making the
  ambiguity check do a check on each sub-term.  Meanwhile,
  these tests are accepted, whereas they were previously
  rejected as ambiguous:
     T7220a
     T15438
     T10503
     T9222

* Some more interesting error message wibbles
   T13381: Fine: one error (Int ~ Exp Int)
           rather than two (Int ~ Exp Int, Exp Int ~ Int)
   T9834:  Small change in error (improvement)
   T10619: Improved
   T2414:  Small change, due to order of unification, fine
   T2534:  A very simple case in which a change of unification order
           means we get tow unsolved constraints instead of one
   tc211: bizarre impredicative tests; just accept this for now

Updates Cabal and haddock submodules.

Metric Increase:
  T12150
  T12234
  T5837
  haddock.base
Metric Decrease:
  haddock.compiler
  haddock.Cabal
  haddock.base

Merge note: This appears to break the
`UnliftedNewtypesDifficultUnification` test. It has been marked as
broken in the interest of merging.

(cherry picked from commit 66b7b195cb3dce93ed5078b80bf568efae904cc5)

- - - - -
2dff8141 by Ryan Scott at 2020-06-05T14:21:24-04:00
Simplify bindLHsTyVarBndrs and bindHsQTyVars

Both `bindLHsTyVarBndrs` and `bindHsQTyVars` take two separate
`Maybe` arguments, which I find terribly confusing. Thankfully, it's
possible to remove one `Maybe` argument from each of these functions,
which this patch accomplishes:

* `bindHsQTyVars` takes a `Maybe SDoc` argument, which is `Just` if
  GHC should warn about any of the quantified type variables going
  unused. However, every call site uses `Nothing` in practice. This
  makes sense, since it doesn't really make sense to warn about
  unused type variables bound by an `LHsQTyVars`. For instance, you
  wouldn't warn about the `a` in `data Proxy a = Proxy` going unused.

  As a result, I simply remove this `Maybe SDoc` argument altogether.
* `bindLHsTyVarBndrs` also takes a `Maybe SDoc` argument for the same
  reasons that `bindHsQTyVars` took one. To make things more
  confusing, however, `bindLHsTyVarBndrs` also takes a separate
  `HsDocContext` argument, which is pretty-printed (to an `SDoc`) in
  warnings and error messages.

  In practice, the `Maybe SDoc` and the `HsDocContext` often contain
  the same text. See the call sites for `bindLHsTyVarBndrs` in
  `rnFamInstEqn` and `rnConDecl`, for instance. There are only a
  handful of call sites where the text differs between the
  `Maybe SDoc` and `HsDocContext` arguments:

  * In `rnHsRuleDecl`, where the `Maybe SDoc` says "`In the rule`"
    and the `HsDocContext` says "`In the transformation rule`".
  * In `rnHsTyKi`/`rn_ty`, where the `Maybe SDoc` says
    "`In the type`" but the `HsDocContext` is inhereted from the
    surrounding context (e.g., if `rnHsTyKi` were called on a
    top-level type signature, the `HsDocContext` would be
    "`In the type signature`" instead)

  In both cases, warnings/error messages arguably _improve_ by
  unifying making the `Maybe SDoc`'s text match that of the
  `HsDocContext`. As a result, I decided to remove the `Maybe SDoc`
  argument to `bindLHsTyVarBndrs` entirely and simply reuse the text
  from the `HsDocContext`. (I decided to change the phrase
  "transformation rule" to "rewrite rule" while I was in the area.)

  The `Maybe SDoc` argument has one other purpose: signaling when to
  emit "`Unused quantified type variable`" warnings. To recover this
  functionality, I replaced the `Maybe SDoc` argument with a
  boolean-like `WarnUnusedForalls` argument. The only
  `bindLHsTyVarBndrs` call site that chooses _not_ to emit these
  warnings in `bindHsQTyVars`.

- - - - -
e372331b by Ben Gamari at 2020-06-07T08:46:41-04:00
hadrian: Add missing deriveConstants dependency on ghcplatform.h

deriveConstants wants to compile C sources which #include PosixSource.h,
which itself #includes ghcplatform.h. Make sure that Hadrian knows
about this dependency.

Fixes #18290.

- - - - -
b022051a by Moritz Angermann at 2020-06-07T08:46:42-04:00
ghc-prim needs to depend on libc and libm

libm is just an empty shell on musl, and all the math functions are contained in
libc.

- - - - -
6dae6548 by Moritz Angermann at 2020-06-07T08:46:42-04:00
Disable DLL loading if without system linker

Some platforms (musl, aarch64) do not have a working dynamic linker
implemented in the libc, even though we might see dlopen.  It will
ultimately just return that this is not supported.  Hence we'll add
a flag to the compiler to flat our disable loading dlls.  This is
needed as we will otherwise try to load the shared library even
if this will subsequently fail.  At that point we have given up
looking for static options though.

- - - - -
4a158ffc by Moritz Angermann at 2020-06-07T08:46:43-04:00
Range is actually +/-2^32, not +/-2^31

See also: https://static.docs.arm.com/ihi0056/g/aaelf64.pdf

- - - - -
f1bfb806 by Ben Gamari at 2020-06-07T10:49:30-04:00
OccurAnal: Avoid exponential behavior due to where clauses

Previously the `Var` case of `occAnalApp` could in some cases (namely
in the case of `runRW#` applications) call `occAnalRhs` two. In the case
of nested `runRW#`s this results in exponential complexity. In some
cases the compilation time that resulted would be very long indeed
(see #18296).

Fixes #18296.

Metric Decrease:
    T9961
    T12150
    T12234

- - - - -
9b607671 by Takenobu Tani at 2020-06-09T08:05:46-04:00
Add link to GHC's wiki in the GHC API header

This adds a URL to point to GHC's wiki in the GHC API header.
Newcomers could easily find more information from the GHC API's
web like [1].

[1]: Current version, https://ghc.gitlab.haskell.org/ghc/doc/libraries/ghc-8.11.0.20200604/index.html

[skip ci]

- - - - -
72c7fe9a by Ryan Scott at 2020-06-09T08:06:24-04:00
Make GADT constructors adhere to the forall-or-nothing rule properly

Issue #18191 revealed that the types of GADT constructors don't quite
adhere to the `forall`-or-nothing rule. This patch serves to clean up
this sad state of affairs somewhat. The main change is not in the
code itself, but in the documentation, as this patch introduces two
sections to the GHC User's Guide:

* A "Formal syntax for GADTs" section that presents a BNF-style
  grammar for what is and isn't allowed in GADT constructor types.
  This mostly exists to codify GHC's existing behavior, but it also
  imposes a new restriction that addresses #18191: the outermost
  `forall` and/or context in a GADT constructor is not allowed to be
  surrounded by parentheses. Doing so would make these
  `forall`s/contexts nested, and GADTs do not support nested
  `forall`s/contexts at present.

* A "`forall`-or-nothing rule" section that describes exactly what
  the `forall`-or-nothing rule is all about. Surprisingly, there was
  no mention of this anywhere in the User's Guide up until now!

To adhere the new specification in the "Formal syntax for GADTs"
section of the User's Guide, the following code changes were made:

* A new function, `GHC.Hs.Type.splitLHsGADTPrefixTy`, was introduced.
  This is very much like `splitLHsSigmaTy`, except that it avoids
  splitting apart any parentheses, which can be syntactically
  significant for GADT types. See
  `Note [No nested foralls or contexts in GADT constructors]` in
  `GHC.Hs.Type`.

* `ConDeclGADTPrefixPs`, an extension constructor for `XConDecl`, was
  introduced so that `GHC.Parser.PostProcess.mkGadtDecl` can return
  it when given a prefix GADT constructor. Unlike `ConDeclGADT`,
  `ConDeclGADTPrefixPs` does not split the GADT type into its argument
  and result types, as this cannot be done until after the type is
  renamed (see `Note [GADT abstract syntax]` in `GHC.Hs.Decls` for why
  this is the case).

* `GHC.Renamer.Module.rnConDecl` now has an additional case for
  `ConDeclGADTPrefixPs` that (1) splits apart the full `LHsType` into
  its `forall`s, context, argument types, and result type, and
  (2) checks for nested `forall`s/contexts. Step (2) used to be
  performed the typechecker (in `GHC.Tc.TyCl.badDataConTyCon`) rather
  than the renamer, but now the relevant code from the typechecker
  can simply be deleted.

  One nice side effect of this change is that we are able to give a
  more accurate error message for GADT constructors that use visible
  dependent quantification (e.g., `MkFoo :: forall a -> a -> Foo a`),
  which improves the stderr in the `T16326_Fail6` test case.

Fixes #18191. Bumps the Haddock submodule.

- - - - -
a47e6442 by Ryan Scott at 2020-06-10T03:39:12-04:00
Always use rnImplicitBndrs to bring implicit tyvars into scope

This implements a first step towards #16762 by changing the renamer
to always use `rnImplicitBndrs` to bring implicitly bound type
variables into scope. The main change is in `rnFamInstEqn` and
`bindHsQTyVars`, which previously used _ad hoc_ methods of binding
their implicit tyvars.

There are a number of knock-on consequences:

* One of the reasons that `rnFamInstEqn` used an _ad hoc_ binding
  mechanism was to give more precise source locations in
  `-Wunused-type-patterns` warnings. (See
  https://gitlab.haskell.org/ghc/ghc/issues/16762#note_273343 for an
  example of this.) However, these warnings are actually a little
  _too_ precise, since implicitly bound type variables don't have
  exact binding sites like explicitly bound type variables do.
  A similar problem existed for
  "`Different names for the same type variable`" errors involving
  implicit tyvars bound by `bindHsQTyVars`.
  Therefore, we simply accept the less precise (but more accurate)
  source locations from `rnImplicitBndrs` in `rnFamInstEqn` and
  `bindHsQTyVars`. See
  `Note [Source locations for implicitly bound type variables]` in
  `GHC.Rename.HsType` for the full story.
* In order for `rnImplicitBndrs` to work in `rnFamInstEqn`, it needs
  to be able to look up names from the parent class (in the event
  that we are renaming an associated type family instance). As a
  result, `rnImplicitBndrs` now takes an argument of type
  `Maybe assoc`, which is `Just` in the event that a type family
  instance is associated with a class.
* Previously, GHC kept track of three type synonyms for free type
  variables in the renamer: `FreeKiTyVars`, `FreeKiTyVarsDups`
  (which are allowed to contain duplicates), and
  `FreeKiTyVarsNoDups` (which contain no duplicates). However, making
  is a distinction between `-Dups` and `-NoDups` is now pointless, as
  all code that returns `FreeKiTyVars{,Dups,NoDups}` will eventually
  end up being passed to `rnImplicitBndrs`, which removes duplicates.
  As a result, I decided to just get rid of `FreeKiTyVarsDups` and
  `FreeKiTyVarsNoDups`, leaving only `FreeKiTyVars`.
* The `bindLRdrNames` and `deleteBys` functions are now dead code, so
  I took the liberty of removing them.

- - - - -
24879129 by Takenobu Tani at 2020-06-10T03:39:59-04:00
Clarify leaf module names for new module hierarchy

This updates comments only.

This patch replaces leaf module names according to new module
hierarchy [1][2] as followings:

* Expand leaf names to easily find the module path:
  for instance, `Id.hs` to `GHC.Types.Id`.

* Modify leaf names according to new module hierarchy:
  for instance, `Convert.hs` to `GHC.ThToHs`.

* Fix typo:
  for instance, `GHC.Core.TyCo.Rep.hs` to `GHC.Core.TyCo.Rep`

See also !3375

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular
[2]: https://gitlab.haskell.org/ghc/ghc/issues/13009

- - - - -
92de9e25 by Ömer Sinan Ağacan at 2020-06-10T03:41:07-04:00
rts: Remove unused GET_ENTRY closure macro

This macro is not used and got broken in the meantime, as ENTRY_CODE was
deleted.

- - - - -
87102928 by Ömer Sinan Ağacan at 2020-06-10T03:41:50-04:00
Fix -fkeep-cafs flag name in users guide

- - - - -
ccd6843d by Shayne Fletcher at 2020-06-10T04:14:57-04:00
Expose impliedGFlags, impledOffGFlags, impliedXFlags

- - - - -
7a737e89 by Ömer Sinan Ağacan at 2020-06-10T04:14:58-04:00
Cross-module LambdaFormInfo passing

- Store LambdaFormInfos of exported Ids in interface files
- Use them in importing modules

This is for optimization purposes: if we know LambdaFormInfo of imported
Ids we can generate more efficient calling code, see `getCallMethod`.

Exporting (putting them in interface files or in ModDetails) and
importing (reading them from interface files) are both optional. We
don't assume known LambdaFormInfos anywhere and do not change how we
call Ids with unknown LambdaFormInfos.

Runtime, allocation, and residency numbers when building
Cabal-the-library (commit 0d4ee7ba3):

(Log and .hp files are in the MR: !2842)

|     | GHC HEAD | This patch | Diff           |
|-----|----------|------------|----------------|
| -O0 |  0:35.89 |    0:34.10 | -1.78s, -4.98% |
| -O1 |  2:24.01 |    2:23.62 | -0.39s, -0.27% |
| -O2 |  2:52.23 |    2:51.35 | -0.88s, -0.51% |

|     | GHC HEAD        | This patch      | Diff                       |
|-----|-----------------|-----------------|----------------------------|
| -O0 |  54,843,608,416 |  54,878,769,544 |  +35,161,128 bytes, +0.06% |
| -O1 | 227,136,076,400 | 227,569,045,168 | +432,968,768 bytes, +0.19% |
| -O2 | 266,147,063,296 | 266,749,643,440 | +602,580,144 bytes, +0.22% |

NOTE: Residency is measured with extra runtime args: `-i0 -h` which effectively
turn all GCs into major GCs, and do GC more often.

|     | GHC HEAD                   | This patch                   | Diff                       |
|-----|----------------------------|------------------------------|----------------------------|
| -O0 | 410,284,000 (910 samples)  | 411,745,008 (906 samples)    | +1,461,008 bytes, +0.35%   |
| -O1 | 928,580,856 (2109 samples) | 943,506,552 (2103 samples)   | +14,925,696 bytes, +1.60%  |
| -O2 | 993,951,352 (2549 samples) | 1,010,156,328 (2545 samples) | +16,204,9760 bytes, +1.63% |

NoFib results:

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS           0.0%      0.0%     +0.0%     +0.0%     +0.0%
            CSD           0.0%      0.0%      0.0%     +0.0%     +0.0%
             FS           0.0%      0.0%     +0.0%     +0.0%     +0.0%
              S           0.0%      0.0%     +0.0%     +0.0%     +0.0%
             VS           0.0%      0.0%     +0.0%     +0.0%     +0.0%
            VSD           0.0%      0.0%     +0.0%     +0.0%     +0.1%
            VSM           0.0%      0.0%     +0.0%     +0.0%     +0.0%
           anna           0.0%      0.0%     -0.3%     -0.8%     -0.0%
           ansi           0.0%      0.0%     -0.0%     -0.0%      0.0%
           atom           0.0%      0.0%     -0.0%     -0.0%      0.0%
         awards           0.0%      0.0%     -0.1%     -0.3%      0.0%
         banner           0.0%      0.0%     -0.0%     -0.0%     -0.0%
     bernouilli           0.0%      0.0%     -0.0%     -0.0%     -0.0%
   binary-trees           0.0%      0.0%     -0.0%     -0.0%     +0.0%
          boyer           0.0%      0.0%     -0.0%     -0.0%      0.0%
         boyer2           0.0%      0.0%     -0.0%     -0.0%      0.0%
           bspt           0.0%      0.0%     -0.0%     -0.2%      0.0%
      cacheprof           0.0%      0.0%     -0.1%     -0.4%     +0.0%
       calendar           0.0%      0.0%     -0.0%     -0.0%      0.0%
       cichelli           0.0%      0.0%     -0.9%     -2.4%      0.0%
        circsim           0.0%      0.0%     -0.0%     -0.0%      0.0%
       clausify           0.0%      0.0%     -0.1%     -0.3%      0.0%
  comp_lab_zift           0.0%      0.0%     -0.0%     -0.0%     +0.0%
       compress           0.0%      0.0%     -0.0%     -0.0%     -0.0%
      compress2           0.0%      0.0%     -0.0%     -0.0%      0.0%
    constraints           0.0%      0.0%     -0.1%     -0.2%     -0.0%
   cryptarithm1           0.0%      0.0%     -0.0%     -0.0%      0.0%
   cryptarithm2           0.0%      0.0%     -1.4%     -4.1%     -0.0%
            cse           0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e1           0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt           0.0%      0.0%     -0.1%     -0.2%      0.0%
          eliza           0.0%      0.0%     -0.5%     -1.5%      0.0%
          event           0.0%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals           0.0%      0.0%     -0.1%     -0.3%     +0.0%
         exp3_8           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         expert           0.0%      0.0%     -0.3%     -1.0%     -0.0%
 fannkuch-redux           0.0%      0.0%     +0.0%     +0.0%     +0.0%
          fasta           0.0%      0.0%     -0.0%     -0.0%     +0.0%
            fem           0.0%      0.0%     -0.0%     -0.0%      0.0%
            fft           0.0%      0.0%     -0.0%     -0.0%      0.0%
           fft2           0.0%      0.0%     -0.0%     -0.0%      0.0%
       fibheaps           0.0%      0.0%     -0.0%     -0.0%     +0.0%
           fish           0.0%      0.0%      0.0%     -0.0%     +0.0%
          fluid           0.0%      0.0%     -0.4%     -1.2%     +0.0%
         fulsom           0.0%      0.0%     -0.0%     -0.0%      0.0%
         gamteb           0.0%      0.0%     -0.1%     -0.3%      0.0%
            gcd           0.0%      0.0%     -0.0%     -0.0%      0.0%
    gen_regexps           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         genfft           0.0%      0.0%     -0.0%     -0.0%      0.0%
             gg           0.0%      0.0%     -0.0%     -0.0%     +0.0%
           grep           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         hidden           0.0%      0.0%     -0.1%     -0.4%     -0.0%
            hpg           0.0%      0.0%     -0.2%     -0.5%     +0.0%
            ida           0.0%      0.0%     -0.0%     -0.0%     +0.0%
          infer           0.0%      0.0%     -0.3%     -0.8%     -0.0%
        integer           0.0%      0.0%     -0.0%     -0.0%     +0.0%
      integrate           0.0%      0.0%     -0.0%     -0.0%      0.0%
   k-nucleotide           0.0%      0.0%     -0.0%     -0.0%     +0.0%
          kahan           0.0%      0.0%     -0.0%     -0.0%     +0.0%
        knights           0.0%      0.0%     -2.2%     -5.4%      0.0%
         lambda           0.0%      0.0%     -0.6%     -1.8%      0.0%
     last-piece           0.0%      0.0%     -0.0%     -0.0%      0.0%
           lcss           0.0%      0.0%     -0.0%     -0.1%      0.0%
           life           0.0%      0.0%     -0.0%     -0.1%      0.0%
           lift           0.0%      0.0%     -0.2%     -0.6%     +0.0%
         linear           0.0%      0.0%     -0.0%     -0.0%     -0.0%
      listcompr           0.0%      0.0%     -0.0%     -0.0%      0.0%
       listcopy           0.0%      0.0%     -0.0%     -0.0%      0.0%
       maillist           0.0%      0.0%     -0.1%     -0.3%     +0.0%
         mandel           0.0%      0.0%     -0.0%     -0.0%      0.0%
        mandel2           0.0%      0.0%     -0.0%     -0.0%     -0.0%
           mate          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        minimax           0.0%      0.0%     -0.2%     -1.0%      0.0%
        mkhprog           0.0%      0.0%     -0.1%     -0.2%     -0.0%
     multiplier           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         n-body           0.0%      0.0%     -0.0%     -0.0%     +0.0%
       nucleic2           0.0%      0.0%     -0.1%     -0.2%      0.0%
           para           0.0%      0.0%     -0.0%     -0.0%     -0.0%
      paraffins           0.0%      0.0%     -0.0%     -0.0%      0.0%
         parser           0.0%      0.0%     -0.2%     -0.7%      0.0%
        parstof           0.0%      0.0%     -0.0%     -0.0%     +0.0%
            pic           0.0%      0.0%     -0.0%     -0.0%      0.0%
       pidigits           0.0%      0.0%     +0.0%     +0.0%     +0.0%
          power           0.0%      0.0%     -0.2%     -0.6%     +0.0%
         pretty           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         primes           0.0%      0.0%     -0.0%     -0.0%      0.0%
      primetest           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         prolog           0.0%      0.0%     -0.3%     -1.1%      0.0%
         puzzle           0.0%      0.0%     -0.0%     -0.0%      0.0%
         queens           0.0%      0.0%     -0.0%     -0.0%     +0.0%
        reptile           0.0%      0.0%     -0.0%     -0.0%      0.0%
reverse-complem           0.0%      0.0%     -0.0%     -0.0%     +0.0%
        rewrite           0.0%      0.0%     -0.7%     -2.5%     -0.0%
           rfib           0.0%      0.0%     -0.0%     -0.0%      0.0%
            rsa           0.0%      0.0%     -0.0%     -0.0%      0.0%
            scc           0.0%      0.0%     -0.1%     -0.2%     -0.0%
          sched           0.0%      0.0%     -0.0%     -0.0%     -0.0%
            scs           0.0%      0.0%     -1.0%     -2.6%     +0.0%
         simple           0.0%      0.0%     +0.0%     -0.0%     +0.0%
          solid           0.0%      0.0%     -0.0%     -0.0%      0.0%
        sorting           0.0%      0.0%     -0.6%     -1.6%      0.0%
  spectral-norm           0.0%      0.0%     +0.0%      0.0%     +0.0%
         sphere           0.0%      0.0%     -0.0%     -0.0%     -0.0%
         symalg           0.0%      0.0%     -0.0%     -0.0%     +0.0%
            tak           0.0%      0.0%     -0.0%     -0.0%      0.0%
      transform           0.0%      0.0%     -0.0%     -0.0%      0.0%
       treejoin           0.0%      0.0%     -0.0%     -0.0%      0.0%
      typecheck           0.0%      0.0%     -0.0%     -0.0%     +0.0%
        veritas          +0.0%      0.0%     -0.2%     -0.4%     +0.0%
           wang           0.0%      0.0%     -0.0%     -0.0%      0.0%
      wave4main           0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve1           0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve2           0.0%      0.0%     -0.0%     -0.0%     +0.0%
           x2n1           0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min           0.0%      0.0%     -2.2%     -5.4%     -0.0%
            Max          +0.0%      0.0%     +0.0%     +0.0%     +0.1%
 Geometric Mean          -0.0%     -0.0%     -0.1%     -0.3%     +0.0%

Metric increases micro benchmarks tracked in #17686:

Metric Increase:
    T12150
    T12234
    T12425
    T13035
    T5837
    T6048
    T9233

Co-authored-by: Andreas Klebinger <klebinger.andreas at gmx.at>

- - - - -
3b22b14a by Shayne Fletcher at 2020-06-10T04:15:01-04:00
Give Language a Bounded instance

- - - - -
9454511b by Simon Peyton Jones at 2020-06-10T04:17:06-04:00
Optimisation in Unique.Supply

This patch switches on -fno-state-hack in GHC.Types.Unique.Supply.

It turned out that my fixes for #18078 (coercion floating) changed the
optimisation pathway for mkSplitUniqSupply in such a way that we had
an extra allocation inside the inner loop.  Adding -fno-state-hack
fixed that -- and indeed the loop in mkSplitUniqSupply is a classic
example of the way in which -fno-state-hack can be bad; see #18238.

Moreover, the new code is better than the old.  They allocate
the same, but the old code ends up with a partial application.
The net effect is that the test
    perf/should_run/UniqLoop
runs 20% faster!   From 2.5s down to 2.0s.  The allocation numbers
are the same -- but elapsed time falls. Good!

The bad thing about this is that it's terribly delicate.  But
at least it's a good example of such delicacy in action.

There is a long Note [Optimising the unique supply] which now
explains all this.

- - - - -
6d49d5be by Simon Peyton Jones at 2020-06-10T04:17:06-04:00
Implement cast worker/wrapper properly

The cast worker/wrapper transformation transforms
   x = e |> co
into
   y = e
   x = y |> co

This is done by the simplifier, but we were being
careless about transferring IdInfo from x to y,
and about what to do if x is a NOINLNE function.
This resulted in a series of bugs:
     #17673, #18093, #18078.

This patch fixes all that:

* Main change is in GHC.Core.Opt.Simplify, and
  the new prepareBinding function, which does this
  cast worker/wrapper transform.
  See Note [Cast worker/wrappers].

* There is quite a bit of refactoring around
  prepareRhs, makeTrivial etc.  It's nicer now.

* Some wrappers from strictness and cast w/w, notably those for
  a function with a NOINLINE, should inline very late. There
  wasn't really a mechanism for that, which was an existing bug
  really; so I invented a new finalPhase = Phase (-1).  It's used
  for all simplifier runs after the user-visible phase 2,1,0 have
  run.  (No new runs of the simplifier are introduced thereby.)

  See new Note [Compiler phases] in GHC.Types.Basic;
  the main changes are in GHC.Core.Opt.Driver

* Doing this made me trip over two places where the AnonArgFlag on a
  FunTy was being lost so we could end up with (Num a -> ty)
  rather than (Num a => ty)
    - In coercionLKind/coercionRKind
    - In contHoleType in the Simplifier

  I fixed the former by defining mkFunctionType and using it in
  coercionLKind/RKind.

  I could have done the same for the latter, but the information
  is almost to hand.  So I fixed the latter by
    - adding sc_hole_ty to ApplyToVal (like ApplyToTy),
    - adding as_hole_ty to ValArg (like TyArg)
    - adding sc_fun_ty to StrictArg
  Turned out I could then remove ai_type from ArgInfo.  This is
  just moving the deck chairs around, but it worked out nicely.

  See the new Note [AnonArgFlag] in GHC.Types.Var

* When looking at the 'arity decrease' thing (#18093) I discovered
  that stable unfoldings had a much lower arity than the actual
  optimised function.  That's what led to the arity-decrease
  message.  Simple solution: eta-expand.

  It's described in Note [Eta-expand stable unfoldings]
  in GHC.Core.Opt.Simplify

* I also discovered that unsafeCoerce wasn't being inlined if
  the context was boring.  So (\x. f (unsafeCoerce x)) would
  create a thunk -- yikes!  I fixed that by making inlineBoringOK
  a bit cleverer: see Note [Inline unsafeCoerce] in GHC.Core.Unfold.

  I also found that unsafeCoerceName was unused, so I removed it.

I made a test case for #18078, and a very similar one for #17673.

The net effect of all this on nofib is very modest, but positive:

--------------------------------------------------------------------------------
        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
           anna          -0.4%     -0.1%     -3.1%     -3.1%      0.0%
 fannkuch-redux          -0.4%     -0.3%     -0.1%     -0.1%      0.0%
       maillist          -0.4%     -0.1%     -7.8%     -1.0%    -14.3%
      primetest          -0.4%    -15.6%     -7.1%     -6.6%      0.0%
--------------------------------------------------------------------------------
            Min          -0.9%    -15.6%    -13.3%    -14.2%    -14.3%
            Max          -0.3%      0.0%    +12.1%    +12.4%      0.0%
 Geometric Mean          -0.4%     -0.2%     -2.3%     -2.2%     -0.1%

All following metric decreases are compile-time allocation decreases
between -1% and -3%:

Metric Decrease:
  T5631
  T13701
  T14697
  T15164

- - - - -
32fd37f5 by Luke Lau at 2020-06-10T04:17:22-04:00
Fix lookupGlobalOccRn_maybe sometimes reporting an error

In some cases it was possible for lookupGlobalOccRn_maybe to return an
error, when it should be returning a Nothing. If it called
lookupExactOcc_either when there were no matching GlobalRdrElts in the
otherwise case, it would return an error message. This could be caused
when lookupThName_maybe in Template Haskell was looking in different
namespaces (thRdrNameGuesses), guessing different namespaces that the
name wasn't guaranteed to be found in.

However, by addressing this some more accurate errors were being lost in
the conversion to Maybes. So some of the lookup* functions have been
shuffled about so that errors should always be ignored in
lookup*_maybes, and propagated otherwise.

This fixes #18263

- - - - -
9b283e1b by Roland Senn at 2020-06-10T04:17:34-04:00
Initialize the allocation counter in GHCi to 0 (Fixes #16012)

According to the documentation for the function `getAllocationCounter` in
[System.Mem](http://hackage.haskell.org/package/base-4.14.0.0/docs/System-Mem.html)
initialize the allocationCounter also in GHCi to 0.

- - - - -
8d07c48c by Sylvain Henry at 2020-06-10T04:17:36-04:00
test: fix conc038

We had spurious failures of conc038 test on CI with stdout:

```
 newThread started
-mainThread
-Haskell: 2
 newThread back again
+mainThread
 1 sec later

 shutting down
+Haskell: 2
```

- - - - -
4c7e9689 by Sebastian Graf at 2020-06-11T10:37:38+02:00
Release Notes: Add news from the pattern-match checker [skip ci]

- - - - -
3445b965 by Sylvain Henry at 2020-06-13T02:13:01-04:00
Only test T16190 with the NCG

T16190 is meant to test a NCG feature. It has already caused spurious
failures in other MRs (e.g. !2165) when LLVM is used.

- - - - -
2517a51c by Sylvain Henry at 2020-06-13T02:13:01-04:00
DynFlags refactoring VIII (#17957)

* Remove several uses of `sdocWithDynFlags`, especially in GHC.Llvm.*

* Add LlvmOpts datatype to store Llvm backend options

* Remove Outputable instances (for LlvmVar, LlvmLit, LlvmStatic and
  Llvm.MetaExpr) which require LlvmOpts.

* Rename ppMetaExpr into ppMetaAnnotExpr (pprMetaExpr is now used in place of `ppr :: MetaExpr -> SDoc`)

- - - - -
7a02599a by Sylvain Henry at 2020-06-13T02:13:02-04:00
Remove unused code

- - - - -
72d08610 by Sylvain Henry at 2020-06-13T02:13:02-04:00
Refactor homeUnit

* rename thisPackage into homeUnit
* document and refactor several Backpack things

- - - - -
8dc71f55 by Sylvain Henry at 2020-06-13T02:13:02-04:00
Rename unsafeGetUnitInfo into unsafeLookupUnit

- - - - -
f6be6e43 by Sylvain Henry at 2020-06-13T02:13:02-04:00
Add allowVirtualUnits field in PackageState

Instead of always querying DynFlags to know whether we are allowed to
use virtual units (i.e. instantiated on-the-fly, cf Note [About units]
in GHC.Unit), we store it once for all in
`PackageState.allowVirtualUnits`.

This avoids using DynFlags too much (cf #17957) and is preliminary work
for #14335.

- - - - -
e7272d53 by Sylvain Henry at 2020-06-13T02:13:02-04:00
Enhance UnitId use

* use UnitId instead of String to identify wired-in units
* use UnitId instead of Unit in the backend (Unit are only use by
  Backpack to produce type-checked interfaces, not real code)
* rename lookup functions for consistency
* documentation

- - - - -
9c5572cd by Sylvain Henry at 2020-06-13T02:13:02-04:00
Remove LinkerUnitId type alias

- - - - -
d345edfe by Sylvain Henry at 2020-06-13T02:13:02-04:00
Refactor WiredMap

* Remove WiredInUnitId and WiredUnitId type aliases

- - - - -
3d171cd6 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Document and refactor `mkUnit` and `mkUnitInfoMap`

- - - - -
d2109b4f by Sylvain Henry at 2020-06-13T02:13:03-04:00
Remove PreloadUnitId type alias

- - - - -
f50c19b8 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Rename listUnitInfoMap into listUnitInfo

There is no Map involved

- - - - -
ed533ec2 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Rename Package into Unit

The terminology changed over time and now package databases contain
"units" (there can be several units compiled from a single Cabal
package: one per-component, one for each option set, one per
instantiation, etc.). We should try to be consistent internally and use
"units": that's what this renaming does. Maybe one day we'll fix the UI
too (e.g. replace -package-id with -unit-id, we already have
-this-unit-id and ghc-pkg has -unit-id...) but it's not done in this
patch.

* rename getPkgFrameworkOpts into getUnitFrameworkOpts
* rename UnitInfoMap into ClosureUnitInfoMap
* rename InstalledPackageIndex into UnitInfoMap
* rename UnusablePackages into UnusableUnits
* rename PackagePrecedenceIndex into UnitPrecedenceMap
* rename PackageDatabase into UnitDatabase
* rename pkgDatabase into unitDatabases
* rename pkgState into unitState
* rename initPackages into initUnits
* rename renamePackage into renameUnitInfo
* rename UnusablePackageReason into UnusableUnitReason
* rename getPackage* into getUnit*
* etc.

- - - - -
202728e5 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Make ClosureUnitInfoMap uses UnitInfoMap

- - - - -
55b4263e by Sylvain Henry at 2020-06-13T02:13:03-04:00
Remove ClosureUnitInfoMap

- - - - -
653d17bd by Sylvain Henry at 2020-06-13T02:13:03-04:00
Rename Package into Unit (2)

* rename PackageState into UnitState
* rename findWiredInPackages into findWiredInUnits
* rename lookupModuleInAll[Packages,Units]
* etc.

- - - - -
ae900605 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Move dump_mod_map into initUnits

- - - - -
598cc1dd by Sylvain Henry at 2020-06-13T02:13:03-04:00
Move wiring of homeUnitInstantiations outside of mkUnitState

- - - - -
437265eb by Sylvain Henry at 2020-06-13T02:13:03-04:00
Avoid timing module map dump in initUnits

- - - - -
9400aa93 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Remove preload parameter of mkUnitState

* Remove preload parameter (unused)
* Don't explicitly return preloaded units: redundant because already
  returned as "preloadUnits" field of UnitState

- - - - -
266bc3d9 by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: refactor unwireUnit

- - - - -
9e715c1b by Sylvain Henry at 2020-06-13T02:13:03-04:00
Document getPreloadUnitsAnd

- - - - -
bd5810dc by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: remove useless add_package parameter

- - - - -
36e1daf0 by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: make listVisibleModuleNames take a UnitState

- - - - -
5226da37 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Refactor and document add_package

- - - - -
4b53aac1 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Refactor and document closeUnitDeps

- - - - -
42c054f6 by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: findWiredInUnits

- - - - -
a444d01b by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: reportCycles, reportUnusable

- - - - -
8408d521 by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: merge_databases

- - - - -
fca2d25f by Sylvain Henry at 2020-06-13T02:13:03-04:00
DynFlags: add UnitConfig datatype

Avoid directly querying flags from DynFlags to build the UnitState.
Instead go via UnitConfig so that we could reuse this to make another
UnitState for plugins.

- - - - -
4274688a by Sylvain Henry at 2020-06-13T02:13:03-04:00
Move distrustAll into mkUnitState

- - - - -
28d804e1 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Create helper upd_wired_in_home_instantiations

- - - - -
ac964c83 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Put database cache in UnitConfig

- - - - -
bfd0a78c by Sylvain Henry at 2020-06-13T02:13:03-04:00
Don't return preload units when we set DyNFlags

Preload units can be retrieved in UnitState when needed (i.e. in GHCi)

- - - - -
1fbb4bf5 by Sylvain Henry at 2020-06-13T02:13:03-04:00
NCGConfig: remove useless ncgUnitId field

- - - - -
c10ff7e7 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Doc: fix some comments

- - - - -
456e17f0 by Sylvain Henry at 2020-06-13T02:13:03-04:00
Bump haddock submodule and allow metric decrease

Metric Decrease:
    T12150
    T12234
    T5837

Metric Increase:
    T16190

- - - - -
42953902 by Simon Peyton Jones at 2020-06-13T02:13:03-04:00
Trim the demand for recursive product types

Ticket #18304 showed that we need to be very careful
when exploring the demand (esp usage demand) on recursive
product types.

This patch solves the problem by trimming the demand on such types --
in effect, a form of "widening".

See the Note [Trimming a demand to a type] in DmdAnal, which explains
how I did this by piggy-backing on an existing mechansim for trimming
demands becuase of GADTs.  The significant payload of this patch is
very small indeed:

* Make GHC.Core.Opt.WorkWrap.Utils.typeShape use RecTcChecker to
  avoid looking through recursive types.

But on the way

* I found that ae_rec_tc was entirely inoperative and did nothing.
  So I removed it altogether from DmdAnal.

* I moved some code around in DmdAnal and Demand.
  (There are no actual changes in dmdFix.)

* I changed the API of DmsAnal.dmdAnalRhsLetDown to return
  a StrictSig rather than a decorated Id

* I removed the dead function peelTsFuns from Demand

Performance effects:

Nofib: 0.0% changes.  Not surprising, because they don't
       use recursive products

Perf tests

T12227:
  1% increase in compiler allocation, becuase $cto gets w/w'd.
  It did not w/w before because it takes a deeply nested
  argument, so the worker gets too many args, so we abandon w/w
  altogether (see GHC.Core.Opt.WorkWrap.Utils.isWorkerSmallEnough)

  With this patch we trim the demands.  That is not strictly
  necessary (since these Generic type constructors are like
  tuples -- they can't cause a loop) but the net result is that
  we now w/w $cto which is fine.

UniqLoop:
  16% decrease in /runtime/ allocation. The UniqSupply is a
  recursive product, so currently we abandon all strictness on
  'churn'.  With this patch 'churn' gets useful strictness, and
  we w/w it.  Hooray

Metric Decrease:
    UniqLoop

Metric Increase:
    T12227

- - - - -
87d504f4 by Viktor Dukhovni at 2020-06-13T02:13:05-04:00
Add introductory prose for Data.Traversable

- - - - -
9f09b608 by Oleg Grenrus at 2020-06-13T02:13:07-04:00
Fix #12073: Add MonadFix Q instance

- - - - -
220c2d34 by Ben Gamari at 2020-06-13T02:13:07-04:00
testsuite: Increase size of T12150

As noted in #18319, this test was previously very fragile. Increase its
size to make it more likely that its fails with its newly-increased
acceptance threshold.

Metric Increase:
    T12150

- - - - -
8bba1c26 by Ben Gamari at 2020-06-13T04:59:06-04:00
gitlab-ci: Always push perf notes

Previously we ci.sh would run with `set -e` implying that we wouldn't
push perf notes if the testsuite were to fail, even if it *only* failed
due to perf notes. This rendered the whole performance testing story
quite fragile as a single regressing commit would cause every successive
commit to fail since a new baseline would not be uploaded.

Fix this by ensuring that we always push performance notes.

- - - - -
7a773f16 by Ben Gamari at 2020-06-13T15:10:55-04:00
gitlab-ci: Eliminate redundant push of CI metrics

- - - - -
a31218f7 by Ryan Scott at 2020-06-13T15:58:37-04:00
Use HsForAllTelescope to avoid inferred, visible foralls

Currently, `HsForAllTy` permits the combination of `ForallVis` and
`Inferred`, but you can't actually typecheck code that uses it
(e.g., `forall {a} ->`). This patch refactors `HsForAllTy` to use a
new `HsForAllTelescope` data type that makes a type-level distinction
between visible and invisible `forall`s such that visible `forall`s
do not track `Specificity`. That part of the patch is actually quite
small; the rest is simply changing consumers of `HsType` to
accommodate this new type.

Fixes #18235. Bumps the `haddock` submodule.

- - - - -
c0e6dee9 by Tamar Christina at 2020-06-14T09:07:44-04:00
winio: Add Atomic Exchange PrimOp and implement Atomic Ptr exchanges.

The initial version was rewritten by Tamar Christina.
It was rewritten in large parts by Andreas Klebinger.

Co-authored-by: Andreas Klebinger <klebinger.andreas at gmx.at>

- - - - -
9a7462fb by Ben Gamari at 2020-06-14T15:35:23-04:00
codeGen: Don't discard live case binders in unsafeEqualityProof logic

Previously CoreToStg would unconditionally discard cases of the form:

    case unsafeEqualityProof of wild { _ -> rhs }

and rather replace the whole thing with `rhs`. However, in some cases
(see #18227) the case binder is still live, resulting in unbound
occurrences in `rhs`. Fix this by only discarding the case if the case
binder is dead.

Fixes #18227.

- - - - -
e4137c48 by Ben Gamari at 2020-06-14T15:35:23-04:00
testsuite: Add tests for #18227

T18227A is the original issue which gave rise to the ticket and depends
upon bytestring. T18227B is a minimized reproducer.

- - - - -
8bab9ff1 by Ben Gamari at 2020-06-14T15:35:59-04:00
hadrian: Fix rts include and library paths

Fixes two bugs:

 * (?) and (<>) associated in a surprising way
 * We neglected to include libdw paths in the rts configure flags

- - - - -
bd761185 by Ben Gamari at 2020-06-14T15:35:59-04:00
hadrian: Drop redundant GHC arguments

Cabal should already be passing this arguments to GHC.

- - - - -
01f7052c by Peter Trommler at 2020-06-14T15:36:38-04:00
FFI: Fix pass small ints in foreign call wrappers

The Haskell calling convention requires integer parameters smaller
than wordsize to be promoted to wordsize (where the upper bits are
don't care). To access such small integer parameter read a word from
the parameter array and then cast that word to the small integer
target type.

Fixes #15933

- - - - -
502647f7 by Krzysztof Gogolewski at 2020-06-14T15:37:14-04:00
Fix "ndecreasingIndentation" in manual (#18116)

- - - - -
9a9cc089 by Simon Jakobi at 2020-06-15T13:10:00-04:00
Use foldl' in unionManyUniqDSets

- - - - -
761dcb84 by Moritz Angermann at 2020-06-15T13:10:36-04:00
Load .lo as well.

Some archives contain so called linker objects, with the affectionate
.lo suffic.  For example the musl libc.a will come in that form.  We
still want to load those objects, hence we should not discard them and
look for .lo as well.  Ultimately we might want to fix this proerly by
looking at the file magic.

- - - - -
cf01477f by Vladislav Zavialov at 2020-06-15T13:11:20-04:00
User's Guide: KnownNat evidence is Natural

This bit of documentation got outdated after commit
1fcede43d2b30f33b7505e25eb6b1f321be0407f

- - - - -
d0dcbfe6 by Jan Hrček at 2020-06-16T20:36:38+02:00
Fix typos and formatting in user guide

- - - - -
56a9e95f by Jan Hrček at 2020-06-16T20:36:38+02:00
Resolve TODO

- - - - -
3e884d14 by Jan Hrček at 2020-06-16T20:36:38+02:00
Rename TcHoleErrors to GHC.Tc.Errors.Hole

- - - - -
d23fc678 by Stefan Schulze Frielinghaus at 2020-06-17T15:31:09-04:00
hadrian: Build with threaded runtime if available

See #16873.

- - - - -
0639dc10 by Sylvain Henry at 2020-06-17T15:31:53-04:00
T16190: only measure bytes_allocated

Just adding `{-# LANGUAGE BangPatterns #-}` makes the two other metrics
fluctuate by 13%.

- - - - -
4cab6897 by Adam Sandberg Ericsson at 2020-06-17T15:32:44-04:00
docs: fix formatting in users guide

- - - - -
eb8115a8 by Sylvain Henry at 2020-06-17T15:33:23-04:00
Move CLabel assertions into smart constructors (#17957)

It avoids using DynFlags in the Outputable instance of Clabel to check
assertions at pretty-printing time.

- - - - -
7faa4509 by Ben Gamari at 2020-06-17T15:43:31-04:00
base: Bump to 4.15.0.0

- - - - -
20616959 by Ben Gamari at 2020-06-17T15:43:31-04:00
configure: Use grep -q instead of --quiet

The latter is apparently not supported by busybox.

- - - - -
40fa237e by Krzysztof Gogolewski at 2020-06-17T16:21:58-04:00
Linear types (#15981)

This is the first step towards implementation of the linear types proposal
(https://github.com/ghc-proposals/ghc-proposals/pull/111).

It features

* A language extension -XLinearTypes
* Syntax for linear functions in the surface language
* Linearity checking in Core Lint, enabled with -dlinear-core-lint
* Core-to-core passes are mostly compatible with linearity
* Fields in a data type can be linear or unrestricted; linear fields
  have multiplicity-polymorphic constructors.
  If -XLinearTypes is disabled, the GADT syntax defaults to linear fields

The following items are not yet supported:

* a # m -> b syntax (only prefix FUN is supported for now)
* Full multiplicity inference (multiplicities are really only checked)
* Decent linearity error messages
* Linear let, where, and case expressions in the surface language
  (each of these currently introduce the unrestricted variant)
* Multiplicity-parametric fields
* Syntax for annotating lambda-bound or let-bound with a multiplicity
* Syntax for non-linear/multiple-field-multiplicity records
* Linear projections for records with a single linear field
* Linear pattern synonyms
* Multiplicity coercions (test LinearPolyType)

A high-level description can be found at
https://ghc.haskell.org/trac/ghc/wiki/LinearTypes/Implementation
Following the link above you will find a description of the changes made to Core.
This commit has been authored by

* Richard Eisenberg
* Krzysztof Gogolewski
* Matthew Pickering
* Arnaud Spiwack

With contributions from:

* Mark Barbone
* Alexander Vershilov

Updates haddock submodule.

- - - - -
6cb84c46 by Krzysztof Gogolewski at 2020-06-17T16:22:03-04:00
Various performance improvements

This implements several general performance improvements to GHC,
to offset the effect of the linear types change.

General optimisations:
- Add a `coreFullView` function which iterates `coreView` on the
  head. This avoids making function recursive solely because the
  iterate `coreView` themselves. As a consequence, this functions can
  be inlined, and trigger case-of-known constructor (_e.g._
  `kindRep_maybe`, `isLiftedRuntimeRep`, `isMultiplicityTy`,
  `getTyVar_maybe`, `splitAppTy_maybe`, `splitFunType_maybe`,
  `tyConAppTyCon_maybe`). The common pattern about all these functions
  is that they are almost always used as views, and immediately
  consumed by a case expression. This commit also mark them asx `INLINE`.
- In `subst_ty` add a special case for nullary `TyConApp`, which avoid
  allocations altogether.
- Use `mkTyConApp` in `subst_ty` for the general `TyConApp`. This
  required quite a bit of module shuffling.
  case. `myTyConApp` enforces crucial sharing, which was lost during
  substitution. See also !2952 .
- Make `subst_ty` stricter.
- In `eqType` (specifically, in `nonDetCmpType`), add a special case,
  tested first, for the very common case of nullary `TyConApp`.
  `nonDetCmpType` has been made `INLINE` otherwise it is actually a
  regression. This is similar to the optimisations in !2952.

Linear-type specific optimisations:
- Use `tyConAppTyCon_maybe` instead of the more complex `eqType` in
  the definition of the pattern synonyms `One` and `Many`.
- Break the `hs-boot` cycles between `Multiplicity.hs` and `Type.hs`:
  `Multiplicity` now import `Type` normally, rather than from the
  `hs-boot`. This way `tyConAppTyCon_maybe` can inline properly in the
  `One` and `Many` pattern synonyms.
- Make `updateIdTypeAndMult` strict in its type and multiplicity
- The `scaleIdBy` gets a specialised definition rather than being an
  alias to `scaleVarBy`
- `splitFunTy_maybe` is given the type `Type -> Maybe (Mult, Type,
  Type)` instead of `Type -> Maybe (Scaled Type, Type)`
- Remove the `MultMul` pattern synonym in favour of a view `isMultMul`
  because pattern synonyms appear not to inline well.
- in `eqType`, in a `FunTy`, compare multiplicities last: they are
  almost always both `Many`, so it helps failing faster.
- Cache `manyDataConTy` in `mkTyConApp`, to make sure that all the
  instances of `TyConApp ManyDataConTy []` are physically the same.

This commit has been authored by
* Richard Eisenberg
* Krzysztof Gogolewski
* Arnaud Spiwack

Metric Decrease:
    haddock.base
    T12227
    T12545
    T12990
    T1969
    T3064
    T5030
    T9872b

Metric Increase:
    haddock.base
    haddock.Cabal
    haddock.compiler
    T12150
    T12234
    T12425
    T12707
    T13035
    T13056
    T15164
    T16190
    T18304
    T1969
    T3064
    T3294
    T5631
    T5642
    T5837
    T6048
    T9020
    T9233
    T9675
    T9872a
    T9961
    WWRec

- - - - -
57db91d8 by Sylvain Henry at 2020-06-17T16:22:03-04:00
Remove integer-simple

integer-simple uses lists of words (`[Word]`) to represent big numbers
instead of ByteArray#:

   * it is less efficient than the newer ghc-bignum native backend

   * it isn't compatible with the big number representation that is now
     shared by all the ghc-bignum backends (based on the one that was
     used only in integer-gmp before).

As a consequence, we simply drop integer-simple

- - - - -
9f96bc12 by Sylvain Henry at 2020-06-17T16:22:03-04:00
ghc-bignum library

ghc-bignum is a newer package that aims to replace the legacy
integer-simple and integer-gmp packages.

* it supports several backends. In particular GMP is still supported and
  most of the code from integer-gmp has been merged in the "gmp"
  backend.

* the pure Haskell "native" backend is new and is much faster than the
  previous pure Haskell implementation provided by integer-simple

* new backends are easier to write because they only have to provide a
  few well defined functions. All the other code is common to all
  backends. In particular they all share the efficient small/big number
  distinction previously used only in integer-gmp.

* backends can all be tested against the "native" backend with a simple
  Cabal flag. Backends are only allowed to differ in performance, their
  results should be the same.

* Add `integer-gmp` compat package: provide some pattern synonyms and
  function aliases for those in `ghc-bignum`. It is intended to avoid
  breaking packages that depend on `integer-gmp` internals.

Update submodules: text, bytestring

Metric Decrease:
    Conversions
    ManyAlternatives
    ManyConstructors
    Naperian
    T10359
    T10547
    T10678
    T12150
    T12227
    T12234
    T12425
    T13035
    T13719
    T14936
    T1969
    T4801
    T4830
    T5237
    T5549
    T5837
    T8766
    T9020
    parsing001
    space_leak_001
    T16190
    haddock.base

On ARM and i386, T17499 regresses (+6% > 5%).
On x86_64 unregistered, T13701 sometimes regresses (+2.2% > 2%).

Metric Increase:
    T17499
    T13701

- - - - -
96aa5787 by Sylvain Henry at 2020-06-17T16:22:03-04:00
Update compiler

Thanks to ghc-bignum, the compiler can be simplified:

* Types and constructors of Integer and Natural can be wired-in. It
  means that we don't have to query them from interfaces. It also means
  that numeric literals don't have to carry their type with them.

* The same code is used whatever ghc-bignum backend is enabled. In
  particular, conversion of bignum literals into final Core expressions
  is now much more straightforward. Bignum closure inspection too.

* GHC itself doesn't depend on any integer-* package anymore

* The `integerLibrary` setting is gone.

- - - - -
0f67e344 by Sylvain Henry at 2020-06-17T16:22:03-04:00
Update `base` package

* GHC.Natural isn't implemented in `base` anymore. It is provided by
  ghc-bignum in GHC.Num.Natural. It means that we can safely use Natural
  primitives in `base` without fearing issues with built-in rewrite
  rules (cf #15286)

* `base` doesn't conditionally depend on an integer-* package anymore,
  it depends on ghc-bignum

* Some duplicated code in integer-* can now be factored in GHC.Float

* ghc-bignum tries to use a uniform naming convention so most of the
  other changes are renaming

- - - - -
aa9e7b71 by Sylvain Henry at 2020-06-17T16:22:03-04:00
Update `make` based build system

* replace integer-* package selection with ghc-bignum backend selection

- - - - -
f817d816 by Sylvain Henry at 2020-06-17T16:22:04-04:00
Update testsuite

* support detection of slow ghc-bignum backend (to replace the detection
  of integer-simple use). There are still some test cases that the
  native backend doesn't handle efficiently enough.

* remove tests for GMP only functions that have been removed from
  ghc-bignum

* fix test results showing dependent packages (e.g. integer-gmp) or
  showing suggested instances

* fix test using Integer/Natural API or showing internal names

- - - - -
dceecb09 by Sylvain Henry at 2020-06-17T16:22:04-04:00
Update Hadrian

* support ghc-bignum backend selection in flavours and command-line

* support ghc-bignum "--check" flag (compare results of selected backend
  against results of the native one) in flavours and command-line (e.g.
  pass --bignum=check-gmp" to check the "gmp" backend)

* remove the hack to workaround #15286

* build GMP only when the gmp backend is used

* remove hacks to workaround `text` package flags about integer-*. We
  fix `text` to use ghc-bignum unconditionally in another patch

- - - - -
fa4281d6 by Sylvain Henry at 2020-06-17T16:22:04-04:00
Bump bytestring and text submodules

- - - - -
1a3f6f34 by Adam Sandberg Ericsson at 2020-06-18T23:03:36-04:00
docs: mention -hiedir in docs for -outputdir

[skip ci]

- - - - -
729bcb02 by Sylvain Henry at 2020-06-18T23:04:17-04:00
Hadrian: fix build on Mac OS Catalina (#17798)

- - - - -
95e18292 by Andreas Klebinger at 2020-06-18T23:04:58-04:00
Relax allocation threshold for T12150.

This test performs little work, so the most minor allocation
changes often cause the test to fail.

Increasing the threshold to 2% should help with this.

- - - - -
8ce6c393 by Sebastian Graf at 2020-06-18T23:05:36-04:00
hadrian: Bump pinned cabal.project to an existent index-state

- - - - -
08c1cb0f by Ömer Sinan Ağacan at 2020-06-18T23:06:21-04:00
Fix uninitialized field read in Linker.c

Valgrind report of the bug when running the test `linker_unload`:

    ==29666== Conditional jump or move depends on uninitialised value(s)
    ==29666==    at 0x369C5B4: setOcInitialStatus (Linker.c:1305)
    ==29666==    by 0x369C6C5: mkOc (Linker.c:1347)
    ==29666==    by 0x36C027A: loadArchive_ (LoadArchive.c:522)
    ==29666==    by 0x36C0600: loadArchive (LoadArchive.c:626)
    ==29666==    by 0x2C144CD: ??? (in /home/omer/haskell/ghc_2/testsuite/tests/rts/linker/linker_unload.run/linker_unload)
    ==29666==
    ==29666== Conditional jump or move depends on uninitialised value(s)
    ==29666==    at 0x369C5B4: setOcInitialStatus (Linker.c:1305)
    ==29666==    by 0x369C6C5: mkOc (Linker.c:1347)
    ==29666==    by 0x369C9F6: preloadObjectFile (Linker.c:1507)
    ==29666==    by 0x369CA8D: loadObj_ (Linker.c:1536)
    ==29666==    by 0x369CB17: loadObj (Linker.c:1557)
    ==29666==    by 0x3866BC: main (linker_unload.c:33)

The problem is `mkOc` allocates a new `ObjectCode` and calls
`setOcInitialStatus` without initializing the `status` field.
`setOcInitialStatus` reads the field as first thing:

    static void setOcInitialStatus(ObjectCode* oc) {
        if (oc->status == OBJECT_DONT_RESOLVE)
          return;

        if (oc->archiveMemberName == NULL) {
            oc->status = OBJECT_NEEDED;
        } else {
            oc->status = OBJECT_LOADED;
        }
    }

`setOcInitialStatus` is unsed in two places for two different purposes:
in `mkOc` where we don't have the `status` field initialized yet (`mkOc`
is supposed to initialize it), and `loadOc` where we do have `status`
field initialized and we want to update it. Instead of splitting the
function into two functions which are both called just once I inline the
functions in the use sites and remove it.

Fixes #18342

- - - - -
da18ff99 by Tamar Christina at 2020-06-18T23:07:03-04:00
fix windows bootstrap due to linker changes

- - - - -
2af0ec90 by Sylvain Henry at 2020-06-18T23:07:47-04:00
DynFlags: store default depth in SDocContext (#17957)

It avoids having to use DynFlags to reach for pprUserLength.

- - - - -
d4a0be75 by Sylvain Henry at 2020-06-18T23:08:35-04:00
Move tablesNextToCode field into Platform

tablesNextToCode is a platform setting and doesn't belong into DynFlags
(#17957). Doing this is also a prerequisite to fix #14335 where we deal
with two platforms (target and host) that may have different platform
settings.

- - - - -
809caedf by John Ericson at 2020-06-23T22:47:37-04:00
Switch from HscSource to IsBootInterface for module lookup in GhcMake

We look up modules by their name, and not their contents. There is no
way to separately reference a signature vs regular module; you get what
you get. Only boot files can be referenced indepenently with `import {-#
SOURCE #-}`.

- - - - -
7750bd45 by Sylvain Henry at 2020-06-23T22:48:18-04:00
Cmm: introduce SAVE_REGS/RESTORE_REGS

We don't want to save both Fn and Dn register sets on x86-64 as they are
aliased to the same arch register (XMMn).

Moreover, when SAVE_STGREGS was used in conjunction with `jump foo [*]`
which makes a set of Cmm registers alive so that they cover all arch
registers used to pass parameter, we could have Fn, Dn and XMMn alive at
the same time. It made the LLVM code generator choke (see #17920).

Now `SAVE_REGS/RESTORE_REGS` and `jump foo [*]` use the same set of
registers.

- - - - -
2636794d by Sylvain Henry at 2020-06-23T22:48:18-04:00
CmmToC: don't add extern decl to parsed Cmm data

Previously, if a .cmm file *not in the RTS* contained something like:

```cmm
section "rodata" { msg : bits8[] "Test\n"; }
```

It would get compiled by CmmToC into:

```c
ERW_(msg);
const char msg[] = "Test\012";
```

and fail with:

```
/tmp/ghc32129_0/ghc_4.hc:5:12: error:
     error: conflicting types for \u2018msg\u2019
     const char msg[] = "Test\012";
                ^~~

In file included from /tmp/ghc32129_0/ghc_4.hc:3:0: error:

/tmp/ghc32129_0/ghc_4.hc:4:6: error:
     note: previous declaration of \u2018msg\u2019 was here
     ERW_(msg);
          ^

/builds/hsyl20/ghc/_build/install/lib/ghc-8.11.0.20200605/lib/../lib/x86_64-linux-ghc-8.11.0.20200605/rts-1.0/include/Stg.h:253:46: error:
     note: in definition of macro \u2018ERW_\u2019
     #define ERW_(X)   extern       StgWordArray (X)
                                                  ^
```

See the rationale for this on https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler/backends/ppr-c#prototypes

Now we don't generate these extern declarations (ERW_, etc.) for
top-level data. It shouldn't change anything for the RTS (the only place
we use .cmm files) as it is already special cased in
`GHC.Cmm.CLabel.needsCDecl`. And hand-written Cmm can use explicit
extern declarations when needed.

Note that it allows `cgrun069` test to pass with CmmToC (cf #15467).

- - - - -
5f6a0665 by Sylvain Henry at 2020-06-23T22:48:18-04:00
LLVM: refactor and comment register padding code (#17920)

- - - - -
cad62ef1 by Sylvain Henry at 2020-06-23T22:48:18-04:00
Add tests for #17920

Metric Decrease:
    T12150
    T12234

- - - - -
a2a9006b by Xavier Denis at 2020-06-23T22:48:56-04:00
Fix issue #18262 by zonking constraints after solving

Zonk residual constraints in checkForExistence to reveal user type
errors.

Previously when `:instances` was used with instances that have TypeError
constraints the result would look something like:

instance [safe] s0 => Err 'A -- Defined at ../Bug2.hs:8:10

whereas after zonking, `:instances` now sees the `TypeError` and
properly eliminates the constraint from the results.

- - - - -
181516bc by Simon Peyton Jones at 2020-06-23T22:49:33-04:00
Fix a buglet in Simplify.simplCast

This bug, revealed by #18347, is just a missing update to
sc_hole_ty in simplCast.  I'd missed a code path when I
made the recentchanges in

    commit 6d49d5be904c0c01788fa7aae1b112d5b4dfaf1c
    Author: Simon Peyton Jones <simonpj at microsoft.com>
    Date:   Thu May 21 12:53:35 2020 +0100

    Implement cast worker/wrapper properly

The fix is very easy.

Two other minor changes

* Tidy up in SimpleOpt.simple_opt_expr. In fact I think this is an
  outright bug, introduced in the fix to #18112: we were simplifying
  the same coercion twice *with the same substitution*, which is just
  wrong.  It'd be a hard bug to trigger, so I just fixed it; less code
  too.

* Better debug printing of ApplyToVal

- - - - -
625a7f54 by Simon Peyton Jones at 2020-06-23T22:50:11-04:00
Two small tweaks to Coercion.simplifyArgsWorker

These tweaks affect the inner loop of simplifyArgsWorker, which
in turn is called from the flattener in Flatten.hs.  This is
a key perf bottleneck to T9872{a,b,c,d}.

These two small changes have a modest but useful benefit.
No change in functionality whatsoever.

Relates to #18354

- - - - -
b5768cce by Sylvain Henry at 2020-06-23T22:50:49-04:00
Don't use timesInt2# with GHC < 8.11 (fix #18358)

- - - - -
7ad4085c by Sylvain Henry at 2020-06-23T22:51:27-04:00
Fix invalid printf format

- - - - -
a1f34d37 by Krzysztof Gogolewski at 2020-06-23T22:52:09-04:00
Add missing entry to freeNamesItem (#18369)

- - - - -
03a708ba by Andreas Klebinger at 2020-06-25T03:54:37-04:00
Enable large address space optimization on windows.

Starting with Win 8.1/Server 2012 windows no longer preallocates
page tables for reserverd memory eagerly, which prevented us from
using this approach in the past.

We also try to allocate the heap high in the memory space.
Hopefully this makes it easier to allocate things in the low
4GB of memory that need to be there. Like jump islands for the
linker.

- - - - -
7e6d3d09 by Roland Senn at 2020-06-25T03:54:38-04:00
In `:break ident` allow out of scope and nested identifiers (Fix #3000)

This patch fixes the bug and implements the feature request of #3000.

1. If `Module` is a real module name and `identifier` a name of a
top-level function in `Module` then `:break Module.identifer` works
also for an `identifier` that is out of scope.

2. Extend the syntax for `:break identifier` to:

    :break [ModQual.]topLevelIdent[.nestedIdent]...[.nestedIdent]

`ModQual` is optional and is either the effective name of a module or
the local alias of a qualified import statement.

`topLevelIdent` is the name of a top level function in the module
referenced by `ModQual`.

`nestedIdent` is optional and the name of a function nested in a let or
where clause inside the previously mentioned function `nestedIdent` or
`topLevelIdent`.

If `ModQual` is a module name, then `topLevelIdent` can be any top level
identifier in this module. If `ModQual` is missing or a local alias of a
qualified import, then `topLevelIdent` must be in scope.

Breakpoints can be set on arbitrarily deeply nested functions, but the
whole chain of nested function names must be specified.

3. To support the new functionality rewrite the code to tab complete `:break`.

- - - - -
30e42652 by Ben Gamari at 2020-06-25T03:54:39-04:00
make: Respect XELATEX variable

Previously we simply ignored the XELATEX variable when building
PDF documentation.

- - - - -
4acc2934 by Ben Gamari at 2020-06-25T03:54:39-04:00
hadrian/make: Detect makeindex

Previously we would simply assume that makeindex was available.
Now we correctly detect it in `configure` and respect this conclusion in
hadrian and make.

- - - - -
0d61f866 by Simon Peyton Jones at 2020-06-25T03:54:40-04:00
Expunge GhcTcId

GHC.Hs.Extension had

  type GhcPs   = GhcPass 'Parsed
  type GhcRn   = GhcPass 'Renamed
  type GhcTc   = GhcPass 'Typechecked
  type GhcTcId = GhcTc

The last of these, GhcTcId, is a vestige of the past.

This patch expunges it from GHC.

- - - - -
8ddbed4a by Adam Wespiser at 2020-06-25T03:54:40-04:00
add examples to Data.Traversable

- - - - -
284001d0 by Oleg Grenrus at 2020-06-25T03:54:42-04:00
Export readBinIface_

- - - - -
90f43872 by Zubin Duggal at 2020-06-25T03:54:43-04:00
Export everything from HsToCore.

This lets us reuse these functions in haddock, avoiding synchronization bugs.

Also fixed some divergences with haddock in that file

Updates haddock submodule

- - - - -
c7dd6da7 by Takenobu Tani at 2020-06-25T03:54:44-04:00
Clean up haddock hyperlinks of GHC.* (part1)

This updates haddock comments only.

This patch focuses to update for hyperlinks in GHC API's haddock comments,
because broken links especially discourage newcomers.

This includes the following hierarchies:
  - GHC.Hs.*
  - GHC.Core.*
  - GHC.Stg.*
  - GHC.Cmm.*
  - GHC.Types.*
  - GHC.Data.*
  - GHC.Builtin.*
  - GHC.Parser.*
  - GHC.Driver.*
  - GHC top

- - - - -
1eb997a8 by Takenobu Tani at 2020-06-25T03:54:44-04:00
Clean up haddock hyperlinks of GHC.* (part2)

This updates haddock comments only.

This patch focuses to update for hyperlinks in GHC API's haddock comments,
because broken links especially discourage newcomers.

This includes the following hierarchies:

  - GHC.Iface.*
  - GHC.Llvm.*

  - GHC.Rename.*
  - GHC.Tc.*

  - GHC.HsToCore.*
  - GHC.StgToCmm.*
  - GHC.CmmToAsm.*

  - GHC.Runtime.*

  - GHC.Unit.*
  - GHC.Utils.*
  - GHC.SysTools.*

- - - - -
67a86b4d by Oleg Grenrus at 2020-06-25T03:54:46-04:00
Add MonadZip and MonadFix instances for Complex

These instances are taken from
https://hackage.haskell.org/package/linear-1.21/docs/Linear-Instances.html

They are the unique possible, so let they be in `base`.

- - - - -
c50ef26e by Artem Pelenitsyn at 2020-06-25T03:54:47-04:00
test suite: add reproducer for #17516

- - - - -
fe281b27 by Roland Senn at 2020-06-25T03:54:48-04:00
Enable maxBound checks for OverloadedLists (Fixes #18172)

Consider the Literal `[256] :: [Data.Word.Word8]`

When the `OverloadedLists` extension is not active, then the `ol_ext` field
in the `OverLitTc` record that is passed to the function `getIntegralLit`
contains the type `Word8`. This is a simple type, and we can use its
type constructor immediately for the `warnAboutOverflowedLiterals` function.

When the `OverloadedLists` extension is active, then the `ol_ext` field
contains the type family `Item [Word8]`. The function `nomaliseType` is used
to convert it to the needed type `Word8`.

- - - - -
a788d4d1 by Ben Gamari at 2020-06-25T03:54:52-04:00
rts/Hash: Simplify freeing of HashListChunks

While looking at #18348 I noticed that the treatment of HashLists are a
bit more complex than necessary (which lead to some initial confusion on
my part). Specifically, we allocate HashLists in chunks. Each chunk
allocation makes two allocations: one for the chunk itself and one for a
HashListChunk to link together the chunks for the purposes of freeing.

Simplify this (and hopefully make the relationship between these
clearer) but allocating the HashLists and HashListChunk in a single
malloc. This will both make the implementation easier to follow and
reduce C heap fragmentation.

Note that even after this patch we fail to bound the size of the free
HashList pool. However, this is a separate bug.

- - - - -
d3c2d59b by Sylvain Henry at 2020-06-25T03:54:55-04:00
RTS: avoid overflow on 32-bit arch (#18375)

We're now correctly computing allocated bytes on 32-bit arch, so we get
huge increases.

Metric Increase:
    haddock.Cabal
    haddock.base
    haddock.compiler
    space_leak_001

- - - - -
a3d69dc6 by Sebastian Graf at 2020-06-25T23:06:18-04:00
GHC.Core.Unify: Make UM actions one-shot by default

This MR makes the UM monad in GHC.Core.Unify into a one-shot
monad.  See the long Note [The one-shot state monad trick].

See also #18202 and !3309, which applies this to all Reader/State-like
monads in GHC for compile-time perf improvements. The pattern used
here enables something similar to the state-hack, but is applicable to
user-defined monads, not just `IO`.

Metric Decrease 'runtime/bytes allocated' (test_env='i386-linux-deb9'):
    haddock.Cabal

- - - - -
9ee58f8d by Matthias Pall Gissurarson at 2020-06-26T17:12:45+00:00
Implement the proposed -XQualifiedDo extension

Co-authored-by: Facundo Domínguez <facundo.dominguez at tweag.io>

QualifiedDo is implemented using the same placeholders for operation names in
the AST that were devised for RebindableSyntax. Whenever the renamer checks
which names to use for do syntax, it first checks if the do block is qualified
(e.g. M.do { stmts }), in which case it searches for qualified names in
the module M.

This allows users to write

    {-# LANGUAGE QualifiedDo #-}
    import qualified SomeModule as M

    f x = M.do           -- desugars to:
      y <- M.return x    -- M.return x M.>>= \y ->
      M.return y         -- M.return y M.>>
      M.return y         -- M.return y

See Note [QualifiedDo] and the users' guide for more details.

Issue #18214

Proposal:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0216-qualified-do.rst

Since we change the constructors `ITdo` and `ITmdo` to carry the new module
name, we need to bump the haddock submodule to account or the new shape of
these constructors.

- - - - -
ce987865 by Ryan Scott at 2020-06-27T11:55:21-04:00
Revamp the treatment of auxiliary bindings for derived instances

This started as a simple fix for #18321 that organically grew into a
much more sweeping refactor of how auxiliary bindings for derived
instances are handled. I have rewritten `Note [Auxiliary binders]`
in `GHC.Tc.Deriv.Generate` to explain all of the moving parts, but
the highlights are:

* Previously, the OccName of each auxiliary binding would be given
  a suffix containing a hash of its package name, module name, and
  parent data type to avoid name clashes. This was needlessly
  complicated, so we take the more direct approach of generating
  `Exact` `RdrName`s for each auxiliary binding with the same
  `OccName`, but using an underlying `System` `Name` with a fresh
  `Unique` for each binding. Unlike hashes, allocating new `Unique`s
  does not require any cleverness and avoid name clashes all the
  same...
* ...speaking of which, in order to convince the renamer that multiple
  auxiliary bindings with the same `OccName` (but different
  `Unique`s) are kosher, we now use `rnLocalValBindsLHS` instead of
  `rnTopBindsLHS` to rename auxiliary bindings. Again, see
  `Note [Auxiliary binders]` for the full story.
* I have removed the `DerivHsBind` constructor for
  `DerivStuff`—which was only used for `Data.Data`-related
  auxiliary bindings—and refactored `gen_Data_binds` to use
  `DerivAuxBind` instead. This brings the treatment of
  `Data.Data`-related auxiliary bindings in line with every other
  form of auxiliary binding.

Fixes #18321.

- - - - -
a403eb91 by Sylvain Henry at 2020-06-27T11:55:59-04:00
ghc-bignum: fix division by zero (#18359)

- - - - -
1b3d13b6 by Sylvain Henry at 2020-06-27T11:55:59-04:00
Fix ghc-bignum exceptions

We must ensure that exceptions are not simplified. Previously we used:

   case raiseDivZero of
      _ -> 0## -- dummyValue

But it was wrong because the evaluation of `raiseDivZero` was removed and
the dummy value was directly returned. See new Note [ghc-bignum exceptions].

I've also removed the exception triggering primops which were fragile.
We don't need them to be primops, we can have them exported by ghc-prim.

I've also added a test for #18359 which triggered this patch.

- - - - -
a74ec37c by Simon Peyton Jones at 2020-06-27T11:56:34-04:00
Better loop detection in findTypeShape

Andreas pointed out, in !3466, that my fix for #18304 was not
quite right.  This patch fixes it properly, by having just one
RecTcChecker rather than (implicitly) two nested ones, in
findTypeShape.

- - - - -
a04020b8 by Sylvain Henry at 2020-06-27T11:57:11-04:00
DynFlags: don't store buildTag

`DynFlags.buildTag` was a field created from the set of Ways in
`DynFlags.ways`. It had to be kept in sync with `DynFlags.ways` which
was fragile. We want to avoid global state like this (#17957).

Moreover in #14335 we also want to support loading units with different
ways: target units would still use `DynFlags.ways` but plugins would use
`GHC.Driver.Ways.hostFullWays`. To avoid having to deal both with build
tag and with ways, we recompute the buildTag on-the-fly (should be
pretty cheap) and we remove `DynFlags.buildTag` field.

- - - - -
0e83efa2 by Krzysztof Gogolewski at 2020-06-27T11:57:49-04:00
Don't generalize when typechecking a tuple section

The code is simpler and cleaner.

- - - - -
d8ba9e6f by Peter Trommler at 2020-06-28T09:19:11-04:00
RTS: Refactor Haskell-C glue for PPC 64-bit

Make sure the stack is 16 byte aligned even when reserved stack
bytes are not a multiple of 16 bytes.

Avoid saving r2 (TOC). On ELF v1 the function descriptor of StgReturn
has the same TOC as StgRun, on ELF v2 the TOC is recomputed in the
function prologue.

Use the ABI provided functions to save clobbered GPRs and FPRs.

Improve comments. Describe what the stack looks like and how it relates
to the respective ABIs.

- - - - -
42f797b0 by Ryan Scott at 2020-06-28T09:19:46-04:00
Use NHsCoreTy to embed types into GND-generated code

`GeneralizedNewtypeDeriving` is in the unique situation where it must
produce an `LHsType GhcPs` from a Core `Type`. Historically, this was
done with the `typeToLHsType` function, which walked over the entire
`Type` and attempted to construct an `LHsType` with the same overall
structure. `typeToLHsType` is quite complicated, however, and has
been the subject of numerous bugs over the years (e.g., #14579).

Luckily, there is an easier way to accomplish the same thing: the
`XHsType` constructor of `HsType`. `XHsType` bundles an `NHsCoreTy`,
which allows embedding a Core `Type` directly into an `HsType`,
avoiding the need to laboriously convert from one to another (as
`typeToLHsType` did). Moreover, renaming and typechecking an
`XHsType` is simple, since one doesn't need to do anything to a
Core `Type`...

...well, almost. For the reasons described in
`Note [Typechecking NHsCoreTys]` in `GHC.Tc.Gen.HsType`, we must
apply a substitution that we build from the local `tcl_env` type
environment. But that's a relatively modest price to pay.

Now that `GeneralizedNewtypeDeriving` uses `NHsCoreTy`, the
`typeToLHsType` function no longer has any uses in GHC, so this patch
rips it out. Some additional tweaks to `hsTypeNeedsParens` were
necessary to make the new `-ddump-deriv` output correctly
parenthesized, but other than that, this patch is quite
straightforward.

This is a mostly internal refactoring, although it is likely that
`GeneralizedNewtypeDeriving`-generated code will now need fewer
language extensions in certain situations than it did before.

- - - - -
68530b1c by Jan Hrček at 2020-06-28T09:20:22-04:00
Fix duplicated words and typos in comments and user guide

- - - - -
15b79bef by Ryan Scott at 2020-06-28T09:20:57-04:00
Add integer-gmp's ghc.mk and GNUmakefile to .gitignore

- - - - -
bfa5698b by Simon Peyton Jones at 2020-06-28T09:21:32-04:00
Fix a typo in Lint

This simple error in GHC.Core.Litn.lintJoinLams meant that
Lint reported bogus errors.

Fixes #18399

- - - - -
71006532 by Ryan Scott at 2020-06-30T07:10:42-04:00
Reject nested foralls/contexts in instance types more consistently

GHC is very wishy-washy about rejecting instance declarations with
nested `forall`s or contexts that are surrounded by outermost
parentheses. This can even lead to some strange interactions with
`ScopedTypeVariables`, as demonstrated in #18240. This patch makes
GHC more consistently reject instance types with nested
`forall`s/contexts so as to prevent these strange interactions.

On the implementation side, this patch tweaks `splitLHsInstDeclTy`
and `getLHsInstDeclHead` to not look through parentheses, which can
be semantically significant. I've added a
`Note [No nested foralls or contexts in instance types]` in
`GHC.Hs.Type` to explain why. This also introduces a
`no_nested_foralls_contexts_err` function in `GHC.Rename.HsType` to
catch nested `forall`s/contexts in instance types. This function is
now used in `rnClsInstDecl` (for ordinary instance declarations) and
`rnSrcDerivDecl` (for standalone `deriving` declarations), the latter
of which fixes #18271.

On the documentation side, this adds a new
"Formal syntax for instance declaration types" section to the GHC
User's Guide that presents a BNF-style grammar for what is and isn't
allowed in instance types.

Fixes #18240. Fixes #18271.

- - - - -
bccf3351 by Sylvain Henry at 2020-06-30T07:10:46-04:00
Add ghc-bignum to 8.12 release notes

- - - - -
81704a6f by David Eichmann at 2020-06-30T07:10:48-04:00
Update ssh keys in CI performance metrics upload script

- - - - -
85310fb8 by Joshua Price at 2020-06-30T07:10:49-04:00
Add missing Ix instances for tuples of size 6 through 15 (#16643)

- - - - -
cbb6b62f by Vladislav Zavialov at 2020-07-01T15:41:38-04:00
Implement -XLexicalNegation (GHC Proposal #229)

This patch introduces a new extension, -XLexicalNegation, which detects
whether the minus sign stands for negation or subtraction using the
whitespace-based rules described in GHC Proposal #229.

Updates haddock submodule.

- - - - -
fb5a0d01 by Martin Handley at 2020-07-01T15:42:14-04:00
#17169: Clarify Fixed's Enum instance.

- - - - -
b316804d by Simon Peyton Jones at 2020-07-01T15:42:49-04:00
Improve debug tracing for substitution

This patch improves debug tracing a bit (#18395)

* Remove the ancient SDoc argument to substitution, replacing it
  with a HasDebugCallStack constraint. The latter does the same
  job (indicate the call site) but much better.

* Add HasDebugCallStack to simpleOptExpr, exprIsConApp_maybe
  I needed this to help nail the lookupIdSubst panic in
  #18326, #17784

- - - - -
5c9fabb8 by Hécate at 2020-07-01T15:43:25-04:00
Add most common return values for `os` and `arch`

- - - - -
76d8cc74 by Ryan Scott at 2020-07-01T15:44:01-04:00
Desugar quoted uses of DerivingVia and expression type signatures properly

The way that `GHC.HsToCore.Quote` desugared quoted `via` types (e.g.,
`deriving via forall a. [a] instance Eq a => Eq (List a)`) and
explicit type annotations in signatures (e.g.,
`f = id @a :: forall a. a -> a`) was completely wrong, as it did not
implement the scoping guidelines laid out in
`Note [Scoped type variables in bindings]`. This is easily fixed.

While I was in town, I did some minor cleanup of related Notes:

* `Note [Scoped type variables in bindings]` and
  `Note [Scoped type variables in class and instance declarations]`
  say very nearly the same thing. I decided to just consolidate the
  two Notes into `Note [Scoped type variables in quotes]`.
* `Note [Don't quantify implicit type variables in quotes]` is
  somewhat outdated, as it predates GHC 8.10, where the
  `forall`-or-nothing rule requires kind variables to be explicitly
  quantified in the presence of an explicit `forall`. As a result,
  the running example in that Note doesn't even compile. I have
  changed the example to something simpler that illustrates the
  same point that the original Note was making.

Fixes #18388.

- - - - -
44d6a335 by Andreas Klebinger at 2020-07-02T02:54:54-04:00
T16012: Be verbose on failure.

- - - - -
f9853330 by Ryan Scott at 2020-07-02T02:55:29-04:00
Bump ghc-prim version to 0.7.0

Fixes #18279. Bumps the `text` submodule.

- - - - -
23e4e047 by Sylvain Henry at 2020-07-02T10:46:31-04:00
Hadrian: fix PowerPC64le support (#17601)

[ci skip]

- - - - -
3cdd8d69 by Sylvain Henry at 2020-07-02T10:47:08-04:00
NCG: correctly handle addresses with huge offsets (#15570)

Before this patch we could generate addresses of this form:

   movzbl cP0_str+-9223372036854775808,%eax

The linker can't handle them because the offset is too large:

   ld.lld: error: Main.o:(.text+0xB3): relocation R_X86_64_32S out of range: -9223372036852653050 is not in [-2147483648, 2147483647]

With this patch we detect those cases and generate:

   movq $-9223372036854775808,%rax
   addq $cP0_str,%rax
   movzbl (%rax),%eax

I've also refactored `getAmode` a little bit to make it easier to
understand and to trace.

- - - - -
4d90b3ff by Gabor Greif at 2020-07-02T20:07:59-04:00
No need for CURSES_INCLUDE_DIRS

This is a leftover from ef63ff27251a20ff11e58c9303677fa31e609a88
- - - - -
f08d6316 by Sylvain Henry at 2020-07-02T20:08:36-04:00
Replace Opt_SccProfilingOn flag with sccProfilingEnabled helper function

SCC profiling was enabled in a convoluted way: if WayProf was enabled,
Opt_SccProfilingOn general flag was set (in
`GHC.Driver.Ways.wayGeneralFlags`), and then this flag was queried in
various places.

There is no need to go via general flags, so this patch defines a
`sccProfilingEnabled :: DynFlags -> Bool` helper function that just
checks whether WayProf is enabled.

- - - - -
8cc7274b by Ben Gamari at 2020-07-03T02:49:27-04:00
rts/ProfHeap: Only allocate the Censuses that we need

When not LDV profiling there is no reason to allocate 32 Censuses; one
will do. This is a very small memory footprint optimisation, but it
comes for free.

- - - - -
b835112c by Ben Gamari at 2020-07-03T02:49:27-04:00
rts/ProfHeap: Free old allocations when reinitialising Censuses

Previously when not LDV profiling we would repeatedly reinitialise
`censuses[0]` with `initEra`. This failed to free the `Arena` and
`HashTable` from the old census, resulting in a memory leak.

Fixes #18348.

- - - - -
34be6523 by Valery Tolstov at 2020-07-03T02:50:03-04:00
Mention flags that are not enabled by -Wall (#18372)

* Mention missing flags that are not actually enabled by -Wall (docs/users_guide/using-warnings.rst)
* Additionally remove -Wmissing-monadfail-instances from the list of flags enabled by -Wcompat, as it is not the case since 8.8

- - - - -
edc8d22b by Sylvain Henry at 2020-07-03T02:50:40-04:00
LLVM: support R9 and R10 registers

d535ef006d85dbdb7cda2b09c5bc35cb80108909 allowed the use of up to 10
vanilla registers but didn't update LLVM backend to support them. This
patch fixes it.

- - - - -
4bf18646 by Simon Peyton Jones at 2020-07-03T08:37:42+01:00
Improve handling of data type return kinds

Following a long conversation with Richard, this patch tidies up the
handling of return kinds for data/newtype declarations (vanilla,
family, and instance).

I have substantially edited the Notes in TyCl, so they would
bear careful reading.

Fixes #18300, #18357

In GHC.Tc.Instance.Family.newFamInst we were checking some Lint-like
properties with ASSSERT.  Instead Richard and I have added
a proper linter for axioms, and called it from lintGblEnv, which in
turn is called in tcRnModuleTcRnM

New tests (T18300, T18357) cause an ASSERT failure in HEAD.

- - - - -
41d26492 by Sylvain Henry at 2020-07-03T17:33:59-04:00
DynFlags: avoid the use of sdocWithDynFlags in GHC.Core.Rules (#17957)

- - - - -
7aa6ef11 by Hécate at 2020-07-03T17:34:36-04:00
Add the __GHC_FULL_VERSION__ CPP macro to expose the full GHC version

- - - - -
e61d5395 by Chaitanya Koparkar at 2020-07-07T13:55:59-04:00
ghc-prim: Turn some comments into haddocks

[ci skip]

- - - - -
37743f91 by John Ericson at 2020-07-07T13:56:00-04:00
Support `timesInt2#` in LLVM backend

- - - - -
46397e53 by John Ericson at 2020-07-07T13:56:00-04:00
`genericIntMul2Op`: Call `genericWordMul2Op` directly

This unblocks a refactor, and removes partiality. It might be a PowerPC
regression but that should be fixable.

- - - - -
8a1c0584 by John Ericson at 2020-07-07T13:56:00-04:00
Simplify `PrimopCmmEmit`

Follow @simonpj's suggestion of pushing the "into regs" logic into
`emitPrimOp`. With the previous commit getting rid of the recursion in
`genericIntMul2Op`, this is now an easy refactor.

- - - - -
6607f203 by John Ericson at 2020-07-07T13:56:00-04:00
`opAllDone` -> `opIntoRegs`

The old name was and terrible and became worse after the previous
commit's refactor moved non-trivial funcationlity into its body.

- - - - -
fdcc53ba by Sylvain Henry at 2020-07-07T13:56:00-04:00
Optimise genericIntMul2Op

We shouldn't directly call 'genericWordMul2Op' in genericIntMul2Op
because a target may provide a faster primop for 'WordMul2Op': we'd
better use it!

- - - - -
686e7225 by Moritz Angermann at 2020-07-07T13:56:01-04:00
[linker/rtsSymbols] More linker symbols

Mostly symbols needed for aarch64/armv7l
and in combination with musl, where we have
to rely on loading *all* objects/archives

- __stack_chk_* only when not DYNAMIC

- - - - -
3f60b94d by Moritz Angermann at 2020-07-07T13:56:01-04:00
better if guards.

- - - - -
7abffced by Moritz Angermann at 2020-07-07T13:56:01-04:00
Fix (1)

- - - - -
cdfeb3f2 by Moritz Angermann at 2020-07-07T13:56:01-04:00
AArch32 symbols only on aarch32.

- - - - -
f496c955 by Adam Sandberg Ericsson at 2020-07-07T13:56:02-04:00
add -flink-rts flag to link the rts when linking a shared or static library #18072

By default we don't link the RTS when linking shared libraries because in the
most usual mode a shared library is an intermediary product, for example a
Haskell library, that will be linked into some executable in the end. So we
wish to defer the RTS flavour to link to the final link.

However sometimes the final product is the shared library, for example when
writing a plugin for some other system, so we do wish the shared library to
link the RTS.

For consistency we also make -staticlib honor this flag and its inversion.
-staticlib currently implies -flink-shared.

- - - - -
c59faf67 by Stefan Schulze Frielinghaus at 2020-07-07T13:56:04-04:00
hadrian: link check-ppr against debugging RTS if ghcDebugged

- - - - -
0effc57d by Adam Sandberg Ericsson at 2020-07-07T13:56:05-04:00
rts linker: teach the linker about GLIBC's special handling of *stat, mknod and atexit functions #7072

- - - - -
96153433 by Adam Sandberg Ericsson at 2020-07-07T13:56:06-04:00
hadrian: make hadrian/ghci use the bootstrap compiler from configure #18190

- - - - -
4d24f886 by Adam Sandberg Ericsson at 2020-07-07T13:56:07-04:00
hadrian: ignore cabal configure verbosity related flags #18131

- - - - -
7332bbff by Ben Gamari at 2020-07-07T13:56:08-04:00
testsuite: Widen T12234 acceptance window to 2%

Previously it wasn't uncommon to see +/-1% fluctuations in compiler
allocations on this test.

- - - - -
180b6313 by Gabor Greif at 2020-07-07T13:56:08-04:00
When running libtool, report it as such
- - - - -
d3bd6897 by Sylvain Henry at 2020-07-07T13:56:11-04:00
BigNum: rename BigNat types

Before this patch BigNat names were confusing because we had:

* GHC.Num.BigNat.BigNat: unlifted type used everywhere else
* GHC.Num.BigNat.BigNatW: lifted type only used to share static constants
* GHC.Natural.BigNat: lifted type only used for backward compatibility

After this patch we have:

* GHC.Num.BigNat.BigNat#: unlifted type
* GHC.Num.BigNat.BigNat: lifted type (reexported from GHC.Natural)

Thanks to @RyanGlScott for spotting this.

- - - - -
929d26db by Sylvain Henry at 2020-07-07T13:56:12-04:00
Bignum: don't build ghc-bignum with stage0

Noticed by @Ericson2314

- - - - -
d25b6851 by Sylvain Henry at 2020-07-07T13:56:12-04:00
Hadrian: ghc-gmp.h shouldn't be a compiler dependency

- - - - -
0ddae2ba by Sylvain Henry at 2020-07-07T13:56:14-04:00
DynFlags: factor out pprUnitId from "Outputable UnitId" instance

- - - - -
204f3f5d by Krzysztof Gogolewski at 2020-07-07T13:56:18-04:00
Remove unused function pprHsForAllExtra (#18423)

The function `pprHsForAllExtra` was called only on `Nothing`
since 2015 (1e041b7382b6aa).

- - - - -
3033e0e4 by Adam Sandberg Ericsson at 2020-07-08T20:36:49-04:00
hadrian: add flag to skip rebuilding dependency information #17636

- - - - -
b7de4b96 by Stefan Schulze Frielinghaus at 2020-07-09T09:49:22-04:00
Fix GHCi :print on big-endian platforms

On big-endian platforms executing

  import GHC.Exts
  data Foo = Foo Float# deriving Show
  foo = Foo 42.0#
  foo
  :print foo

results in an arithmetic overflow exception which is caused by function
index where moveBytes equals
  word_size - (r + item_size_b) * 8
Here we have a mixture of units. Both, word_size and item_size_b have
unit bytes whereas r has unit bits.  On 64-bit platforms moveBytes
equals then
  8 - (0 + 4) * 8
which results in a negative and therefore invalid second parameter for a
shiftL operation.

In order to make things more clear the expression
  (word .&. (mask `shiftL` moveBytes)) `shiftR` moveBytes
is equivalent to
  (word `shiftR` moveBytes) .&. mask
On big-endian platforms the shift must be a left shift instead of a
right shift. For symmetry reasons not a mask is used but two shifts in
order to zero out bits. Thus the fixed version equals
  case endian of
    BigEndian    -> (word `shiftL` moveBits) `shiftR` zeroOutBits `shiftL` zeroOutBits
    LittleEndian -> (word `shiftR` moveBits) `shiftL` zeroOutBits `shiftR` zeroOutBits

Fixes #16548 and #14455

- - - - -
3656dff8 by Sylvain Henry at 2020-07-09T09:50:01-04:00
LLVM: fix MO_S_Mul2 support (#18434)

The value indicating if the carry is useful wasn't taken into account.

- - - - -
d9f09506 by Simon Peyton Jones at 2020-07-10T10:33:44-04:00
Define multiShotIO and use it in mkSplitUniqueSupply

This patch is part of the ongoing eta-expansion saga;
see #18238.

It implements a neat trick (suggested by Sebastian Graf)
that allows the programmer to disable the default one-shot behaviour
of IO (the "state hack").  The trick is to use a new multiShotIO
function; see Note [multiShotIO].  For now, multiShotIO is defined
here in Unique.Supply; but it should ultimately be moved to the IO
library.

The change is necessary to get good code for GHC's unique supply;
see Note [Optimising the unique supply].

However it makes no difference to GHC as-is.  Rather, it makes
a difference when a subsequent commit

   Improve eta-expansion using ArityType

lands.

- - - - -
bce695cc by Simon Peyton Jones at 2020-07-10T10:33:44-04:00
Make arityType deal with join points

As Note [Eta-expansion and join points] describes,
this patch makes arityType deal correctly with join points.
What was there before was not wrong, but yielded lower
arities than it could.

Fixes #18328

In base GHC this makes no difference to nofib.

        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
         n-body          -0.1%     -0.1%     -1.2%     -1.1%      0.0%
--------------------------------------------------------------------------------
            Min          -0.1%     -0.1%    -55.0%    -56.5%      0.0%
            Max          -0.0%      0.0%    +16.1%    +13.4%      0.0%
 Geometric Mean          -0.0%     -0.0%    -30.1%    -31.0%     -0.0%

But it starts to make real difference when we land the change to the
way mkDupableAlts handles StrictArg, in fixing #13253 and friends.
I think this is because we then get more non-inlined join points.

- - - - -
2b7c71cb by Simon Peyton Jones at 2020-07-11T12:17:02-04:00
Improve eta-expansion using ArityType

As #18355 shows, we were failing to preserve one-shot info when
eta-expanding.  It's rather easy to fix, by using ArityType more,
rather than just Arity.

This patch is important to suport the one-shot monad trick;
see #18202.  But the extra tracking of one-shot-ness requires
the patch

   Define multiShotIO and use it in mkSplitUniqueSupply

If that patch is missing, ths patch makes things worse in
GHC.Types.Uniq.Supply.  With it, however, we see these improvements

    T3064     compiler bytes allocated -2.2%
    T3294     compiler bytes allocated -1.3%
    T12707    compiler bytes allocated -1.3%
    T13056    compiler bytes allocated -2.2%

Metric Decrease:
    T3064
    T3294
    T12707
    T13056

- - - - -
de139cc4 by Artem Pelenitsyn at 2020-07-12T02:53:20-04:00
add reproducer for #15630

- - - - -
c4de6a7a by Andreas Klebinger at 2020-07-12T02:53:55-04:00
Give Uniq[D]FM a phantom type for its key.

This fixes #17667 and should help to avoid such issues going forward.

The changes are mostly mechanical in nature. With two notable
exceptions.

* The register allocator.

  The register allocator references registers by distinct uniques.
  However they come from the types of VirtualReg, Reg or Unique in
  various places. As a result we sometimes cast the key type of the
  map and use functions which operate on the now typed map but take
  a raw Unique as actual key. The logic itself has not changed it
  just becomes obvious where we do so now.

* <Type>Env Modules.

As an example a ClassEnv is currently queried using the types `Class`,
`Name`, and `TyCon`. This is safe since for a distinct class value all
these expressions give the same unique.

    getUnique cls
    getUnique (classTyCon cls)
    getUnique (className cls)
    getUnique (tcName $ classTyCon cls)

This is for the most part contained within the modules defining the
interface. However it requires us to play dirty when we are given a
`Name` to lookup in a `UniqFM Class a` map. But again the logic did
not change and it's for the most part hidden behind the Env Module.

Some of these cases could be avoided by refactoring but this is left
for future work.

We also bump the haddock submodule as it uses UniqFM.

- - - - -
c2cfdfde by Aaron Allen at 2020-07-13T09:00:33-04:00
Warn about empty Char enumerations (#18402)

Currently the "Enumeration is empty" warning (-Wempty-enumerations)
only fires for numeric literals. This patch adds support for `Char`
literals so that enumerating an empty list of `Char`s will also
trigger the warning.

- - - - -
c3ac87ec by Stefan Schulze Frielinghaus at 2020-07-13T09:01:10-04:00
hadrian: build check-ppr dynamic if GHC is build dynamic

Fixes #18361

- - - - -
9ad072b4 by Simon Peyton Jones at 2020-07-13T14:52:49-04:00
Use dumpStyle when printing inlinings

This just makes debug-printing consistent,
and more informative.

- - - - -
e78c4efb by Simon Peyton Jones at 2020-07-13T14:52:49-04:00
Comments only

- - - - -
7ccb760b by Simon Peyton Jones at 2020-07-13T14:52:49-04:00
Reduce result discount in conSize

Ticket #18282 showed that the result discount given by conSize
was massively too large.  This patch reduces that discount to
a constant 10, which just balances the cost of the constructor
application itself.

Note [Constructor size and result discount] elaborates, as
does the ticket #18282.

Reducing result discount reduces inlining, which affects perf.  I
found that I could increase the unfoldingUseThrehold from 80 to 90 in
compensation; in combination with the result discount change I get
these overall nofib numbers:

        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
          boyer          -0.2%     +5.4%     -3.2%     -3.4%      0.0%
       cichelli          -0.1%     +5.9%    -11.2%    -11.7%      0.0%
      compress2          -0.2%     +9.6%     -6.0%     -6.8%      0.0%
   cryptarithm2          -0.1%     -3.9%     -6.0%     -5.7%      0.0%
         gamteb          -0.2%     +2.6%    -13.8%    -14.4%      0.0%
         genfft          -0.1%     -1.6%    -29.5%    -29.9%      0.0%
             gg          -0.0%     -2.2%    -17.2%    -17.8%    -20.0%
           life          -0.1%     -2.2%    -62.3%    -63.4%      0.0%
           mate          +0.0%     +1.4%     -5.1%     -5.1%    -14.3%
         parser          -0.2%     -2.1%     +7.4%     +6.7%      0.0%
      primetest          -0.2%    -12.8%    -14.3%    -14.2%      0.0%
         puzzle          -0.2%     +2.1%    -10.0%    -10.4%      0.0%
            rsa          -0.2%    -11.7%     -3.7%     -3.8%      0.0%
         simple          -0.2%     +2.8%    -36.7%    -38.3%     -2.2%
   wheel-sieve2          -0.1%    -19.2%    -48.8%    -49.2%    -42.9%
--------------------------------------------------------------------------------
            Min          -0.4%    -19.2%    -62.3%    -63.4%    -42.9%
            Max          +0.3%     +9.6%     +7.4%    +11.0%    +16.7%
 Geometric Mean          -0.1%     -0.3%    -17.6%    -18.0%     -0.7%

I'm ok with these numbers, remembering that this change removes
an *exponential* increase in code size in some in-the-wild cases.

I investigated compress2.  The difference is entirely caused by this
function no longer inlining

WriteRoutines.$woutputCodes
  = \ (w :: [CodeEvent]) ->
      let result_s1Sr
            = case WriteRoutines.outputCodes_$s$woutput w 0# 0# 8# 9# of
                (# ww1, ww2 #) -> (ww1, ww2)
      in (# case result_s1Sr of (x, _) ->
              map @Int @Char WriteRoutines.outputCodes1 x
         , case result_s1Sr of { (_, y) -> y } #)

It was right on the cusp before, driven by the excessive result
discount.  Too bad!

Happily, the compiler/perf tests show a number of improvements:
    T12227     compiler bytes-alloc  -6.6%
    T12545     compiler bytes-alloc  -4.7%
    T13056     compiler bytes-alloc  -3.3%
    T15263     runtime  bytes-alloc -13.1%
    T17499     runtime  bytes-alloc -14.3%
    T3294      compiler bytes-alloc  -1.1%
    T5030      compiler bytes-alloc -11.7%
    T9872a     compiler bytes-alloc  -2.0%
    T9872b     compiler bytes-alloc  -1.2%
    T9872c     compiler bytes-alloc  -1.5%

Metric Decrease:
    T12227
    T12545
    T13056
    T15263
    T17499
    T3294
    T5030
    T9872a
    T9872b
    T9872c

- - - - -
7f0b671e by Ben Gamari at 2020-07-13T14:52:49-04:00
testsuite: Widen acceptance threshold on T5837

This test is positively tiny and consequently the bytes allocated
measurement will be relatively noisy. Consequently I have seen this
fail spuriously quite often.

- - - - -
118e1c3d by Alp Mestanogullari at 2020-07-14T21:30:52-04:00
compiler: re-engineer the treatment of rebindable if

Executing on the plan described in #17582, this patch changes the way if expressions
are handled in the compiler in the presence of rebindable syntax. We get rid of the
SyntaxExpr field of HsIf and instead, when rebindable syntax is on, we rewrite the HsIf
node to the appropriate sequence of applications of the local `ifThenElse` function.

In order to be able to report good error messages, with expressions as they were
written by the user (and not as desugared by the renamer), we make use of TTG
extensions to extend GhcRn expression ASTs with an `HsExpansion` construct, which
keeps track of a source (GhcPs) expression and the desugared (GhcRn) expression that
it gives rise to. This way, we can typecheck the latter while reporting the former in
error messages.

In order to discard the error context lines that arise from typechecking the desugared
expressions (because they talk about expressions that the user has not written), we
carefully give a special treatment to the nodes fabricated by this new renaming-time
transformation when typechecking them. See Note [Rebindable syntax and HsExpansion]
for more details. The note also includes a recipe to apply the same treatment to
other rebindable constructs.

Tests 'rebindable11' and 'rebindable12' have been added to make sure we report
identical error messages as before this patch under various circumstances.

We also now disable rebindable syntax when processing untyped TH quotes, as per
the discussion in #18102 and document the interaction of rebindable syntax and
Template Haskell, both in Note [Template Haskell quotes and Rebindable Syntax]
and in the user guide, adding a test to make sure that we do not regress in
that regard.

- - - - -
64c774b0 by Andreas Klebinger at 2020-07-14T21:31:27-04:00
Explain why keeping DynFlags in AnalEnv saves allocation.

- - - - -
254245d0 by Ben Gamari at 2020-07-14T21:32:03-04:00
docs/users-guide: Update default -funfolding-use-threshold value

This was changed in 3d2991f8 but I neglected to update the
documentation. Fixes #18419.

- - - - -
4c259f86 by Andreas Klebinger at 2020-07-14T21:32:41-04:00
Escape backslashes in json profiling reports properly.

I also took the liberty to do away the fixed buffer size for escaping.
Using a fixed size here can only lead to issues down the line.

Fixes #18438.

- - - - -
23797224 by Sergei Trofimovich at 2020-07-14T21:33:19-04:00
.gitlab: re-enable integer-simple substitute (BIGNUM_BACKEND)

Recently build system migrated from INTEGER_LIBRARY to BIGNUM_BACKEND.
But gitlab CI was never updated. Let's enable BIGNUM_BACKEND=native.

Bug: https://gitlab.haskell.org/ghc/ghc/-/issues/18437
Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
e0db878a by Sergei Trofimovich at 2020-07-14T21:33:19-04:00
ghc-bignum: bring in sync .hs-boot files with module declarations

Before this change `BIGNUM_BACKEND=native` build was failing as:

```
libraries/ghc-bignum/src/GHC/Num/BigNat/Native.hs:708:16: error:
    * Variable not in scope: naturalFromBigNat# :: WordArray# -> t
    * Perhaps you meant one of these:
        `naturalFromBigNat' (imported from GHC.Num.Natural),
        `naturalToBigNat' (imported from GHC.Num.Natural)
    |
708 |           m' = naturalFromBigNat# m
    |
```

This happens because `.hs-boot` files are slightly out of date.
This change brings in data and function types in sync.

Bug: https://gitlab.haskell.org/ghc/ghc/-/issues/18437
Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
c9f65c36 by Stefan Schulze Frielinghaus at 2020-07-14T21:33:57-04:00
rts/Disassembler.c: Use FMT_HexWord for printing values in hex format

- - - - -
58ae62eb by Matthias Andreas Benkard at 2020-07-14T21:34:35-04:00
macOS: Load frameworks without stating them first.

macOS Big Sur makes the following change to how frameworks are shipped
with the OS:

> New in macOS Big Sur 11 beta, the system ships with a built-in
> dynamic linker cache of all system-provided libraries. As part of
> this change, copies of dynamic libraries are no longer present on
> the filesystem. Code that attempts to check for dynamic library
> presence by looking for a file at a path or enumerating a directory
> will fail. Instead, check for library presence by attempting to
> dlopen() the path, which will correctly check for the library in the
> cache. (62986286)

https://developer.apple.com/documentation/macos-release-notes/macos-big-sur-11-beta-release-notes/

Therefore, the previous method of checking whether a library exists
before attempting to load it makes GHC.Runtime.Linker.loadFramework
fail to find frameworks installed at /System/Library/Frameworks.

GHC.Runtime.Linker.loadFramework now opportunistically loads the
framework libraries without checking for their existence first,
failing only if all attempts to load a given framework from any of the
various possible locations fail.

- - - - -
cdc4a6b0 by Matthias Andreas Benkard at 2020-07-14T21:34:35-04:00
loadFramework: Output the errors collected in all loading attempts.

With the recent change away from first finding and then loading a
framework, loadFramework had no way of communicating the real reason
why loadDLL failed if it was any reason other than the framework
missing from the file system.  It now collects all loading attempt
errors into a list and concatenates them into a string to return to
the caller.

- - - - -
51dbfa52 by Ben Gamari at 2020-07-15T04:05:34-04:00
StgToCmm: Use CmmRegOff smart constructor

Previously we would generate expressions of the form
`CmmRegOff BaseReg 0`. This should do no harm (and really should be
handled by the NCG anyways) but it's better to just generate a plain
`CmmReg`.

- - - - -
ae11bdfd by Ben Gamari at 2020-07-15T04:06:08-04:00
testsuite: Add regression test for #17744

Test due to @monoidal.

- - - - -
0e3c277a by Ben Gamari at 2020-07-15T16:41:01-04:00
Bump Cabal submodule

Updates a variety of tests as Cabal is now more strict about Cabal file
form.

- - - - -
ceed994a by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Drop Windows Vista support, require Windows 7

- - - - -
00a23bfd by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Update Windows FileSystem wrapper utilities.

- - - - -
459e1c5f by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Use SlimReaderLocks and ConditonalVariables provided by the OS instead of emulated ones

- - - - -
763088fc by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Small linker comment and ifdef cleanups

- - - - -
1a228ff9 by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Flush event logs eagerly.

- - - - -
e9e04dda by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Refactor Buffer structures to be able to track async operations

- - - - -
356dc3fe by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Implement new Console API

- - - - -
90e69f77 by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Add IOPort synchronization primitive

- - - - -
71245fcc by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Add new io-manager cmdline options

- - - - -
d548a3b3 by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Init Windows console Codepage to UTF-8.

- - - - -
58ef6366 by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Add unsafeSplat to GHC.Event.Array

- - - - -
d660725e by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Add size and iterate to GHC.Event.IntTable.

- - - - -
050da6dd by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Switch Testsuite to test winio by default

- - - - -
4bf542bf by Tamar Christina at 2020-07-15T16:41:01-04:00
winio: Multiple refactorings and support changes.

- - - - -
4489af6b by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: core threaded I/O manager

- - - - -
64d8f2fe by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: core non-threaded I/O manager

- - - - -
8da15a09 by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: Fix a scheduler bug with the threaded-runtime.

- - - - -
84ea3d14 by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: Relaxing some constraints in io-manager.

- - - - -
ccf0d107 by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: Fix issues with non-threaded I/O manager after split.

- - - - -
b492fe6e by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: Remove some barf statements that are a bit strict.

- - - - -
01423fd2 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Expand comments describing non-threaded loop

- - - - -
4b69004f by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: fix FileSize unstat-able handles

- - - - -
9b384270 by Tamar Christina at 2020-07-15T16:41:02-04:00
winio: Implement new tempfile routines for winio

- - - - -
f1e0be82 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix input truncation when reading from handle.

This was caused by not upholding the read buffer invariant
that bufR == bufL == 0 for empty read buffers.

- - - - -
e176b625 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix output truncation for writes larger than buffer size

- - - - -
a831ce0e by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Rewrite bufWrite.

I think it's far easier to follow the code now.
It's also correct now as I had still missed a spot
where we didn't update the offset.

- - - - -
6aefdf62 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix offset set by bufReadEmpty.

bufReadEmpty returns the bytes read *including* content that
was already buffered,
But for calculating the offset we only care about the number
of bytes read into the new buffer.

- - - - -
750ebaee by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Clean up code surrounding IOPort primitives.

According to phyx these should only be read and written once per
object. Not neccesarily in that order.

To strengthen that guarantee the primitives will now throw an
exception if we violate this invariant.

As a consequence we can eliminate some code from their primops.
In particular code dealing with multiple queued readers/writers
now simply checks the invariant and throws an exception if it
was violated. That is in contrast to mvars which will do things
like wake up all readers, queue multi writers etc.

- - - - -
ffd31db9 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix multi threaded threadDelay and a few other small changes.

Multithreaded threadDelay suffered from a race condition
based on the ioManagerStatus. Since the status isn't needed
for WIO I removed it completely.

This resulted in a light refactoring, as consequence we will always
wake up the IO manager using interruptSystemManager, which uses
`postQueuedCompletionStatus` internally.

I also added a few comments which hopefully makes the code easier to
dive into for the next person diving in.

- - - - -
6ec26df2 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
wionio: Make IO subsystem check a no-op on non-windows platforms.

- - - - -
29bcd936 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Set handle offset when opening files in Append mode.

Otherwise we would truncate the file.

- - - - -
55c29700 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Remove debug event log trace

- - - - -
9acb9f40 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix sqrt and openFile009 test cases

- - - - -
57017cb7 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Allow hp2ps to build with -DDEBUG

- - - - -
b8cd9995 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Update output of T9681 since we now actually run it.

- - - - -
10af5b14 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: A few more improvements to the IOPort primitives.

- - - - -
39afc4a7 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix expected tempfiles output.

Tempfiles now works properly on windows, as such we can
delete the win32 specific output.

- - - - -
99db46e0 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Assign thread labels to IOManager threads.

- - - - -
be6af732 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Properly check for the tso of an incall to be zero.

- - - - -
e2c6dac7 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Mark FD instances as unsupported under WINIO.

- - - - -
fd02ceed by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Fix threadDelay maxBound invocations.

Instead of letting the ns timer overflow now clamp it at
(maxBound :: Word64) ns. That still gives a few hundred
years.

- - - - -
bc79f9f1 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Add comments/cleanup an import in base

- - - - -
1d197f4b by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Mark outstanding_service_requests volatile.

As far as I know C(99) gives no guarantees for code like

    bool condition;

    ...

    while(condition)
        sleep();

that condition will be updated if it's changed by another thread.
So we are explicit here and mark it as volatile, this will force
a reload from memory on each iteration.

- - - - -
dc438186 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Make last_event a local variable

- - - - -
2fc957c5 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Add comment about thread safety of processCompletion.

- - - - -
4c026b6c by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: nonthreaded: Create io processing threads in main thread.

We now set a flag in the IO thread. The scheduler when looking for work
will check the flag and create/queue threads accordingly.

We used to create these in the IO thread. This improved performance
but caused frequent segfaults. Thread creation/allocation is only safe to
do if nothing currently accesses the storeagemanager. However without
locks in the non-threaded runtime this can't be guaranteed.

This shouldn't change performance all too much.

In the past we had:
* IO: Create/Queue thread.
* Scheduler: Runs a few times. Eventually picks up IO processing thread.

Now it's:
* IO: Set flag to queue thread.
* Scheduler: Pick up flag, if set create/queue thread. Eventually picks up IO processing thread.

- - - - -
f47c7208 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Add an exported isHeapAlloced function to the RTS

- - - - -
cc5d7bb1 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Queue IO processing threads at the front of the queue.

This will unblock the IO thread sooner hopefully leading to higher
throughput in some situations.

- - - - -
e7630115 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: ThreadDelay001: Use higher resolution timer.

- - - - -
451b5f96 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Update T9681 output, disable T4808 on windows.

T4808 tests functionality of the FD interface which won't be supported
under WINIO.

T9681 just has it's expected output tweaked.

- - - - -
dd06f930 by Andreas Klebinger at 2020-07-15T16:41:02-04:00
winio: Wake io manager once per registerTimeout.

Which is implicitly done in editTimeouts, so need to wake it
up twice.

- - - - -
e87d0bf9 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Update placeholder comment with actual function name.

- - - - -
fc9025db by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Always lock win32 event queue

- - - - -
c24c9a1f by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Display thread labels when tracing scheduler events.

- - - - -
06542b03 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Refactor non-threaded runner thread and scheduler interface.

Only use a single communication point (registerAlertableWait) to inform
the C side aobut both timeouts to use as well as outstanding requests.

Also queue a haskell processing thread after each return from alertable
waits. This way there is no risk of us missing a timer event.

- - - - -
256299b1 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Remove outstanding_requests from runner.

We used a variable to keep track of situations where we got
entries from the IO port, but all of them had already been
canceled. While we can avoid some work that way this case
seems quite rare.

So we give up on tracking this and instead always assume at
least one of the returned entries is valid.

If that's not the case no harm is done, we just perform some
additional work. But it makes the runner easier to reason about.

In particular we don't need to care if another thread modifies
oustanding_requests after we return from waiting on the IO Port.

- - - - -
3ebd8ad9 by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: Various fixes related to rebase and testdriver

- - - - -
6be6bcba by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: Fix rebase artifacts

- - - - -
2c649dc3 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Rename unsafeSplat to unsafeCopyFromBuffer

- - - - -
a18b73f3 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Remove unused size/iterate operations from IntTable

- - - - -
16bab48e by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Detect running IO Backend via peeking at RtsConfig

- - - - -
8b8405a0 by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: update temp path so GCC etc can handle it.

Also fix PIPE support, clean up error casting, fix memory leaks

- - - - -
2092bc54 by Ben Gamari at 2020-07-15T16:41:03-04:00
winio: Minor comments/renamings

- - - - -
a5b5b6c0 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Checking if an error code indicates completion is now a function.

- - - - -
362176fd by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Small refactor in withOverlappedEx

- - - - -
32e20597 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: A few comments and commented out dbxIO

- - - - -
a4bfc1d9 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Don't drop buffer offset in byteView/cwcharView

- - - - -
b3ad2a54 by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: revert BHandle changes.

- - - - -
3dcd87e2 by Ben Gamari at 2020-07-15T16:41:03-04:00
winio: Fix imports

- - - - -
5a371890 by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: update ghc-cabal to handle new Cabal submodule bump

- - - - -
d07ebe0d by Ben Gamari at 2020-07-15T16:41:03-04:00
winio: Only compile sources on Windows

- - - - -
dcb42393 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Actually return Nothing on EOF for non-blocking read

- - - - -
895a3beb by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Deduplicate logic in encodeMultiByte[Raw]IO.

- - - - -
e06e6734 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Deduplicate openFile logic

- - - - -
b59430c0 by Tamar Christina at 2020-07-15T16:41:03-04:00
winio: fix -werror issue in encoding file

- - - - -
f8d39a51 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Don't mention windows specific functions when building on Linux.

- - - - -
6a533d2a by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: add a note about file locking in the RTS.

- - - - -
cf37ce34 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Add version to @since annotation

- - - - -
0fafa2eb by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Rename GHC.Conc.IOCP -> GHC.Conc.WinIO

- - - - -
1854fc23 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Expand GHC.Conc.POSIX description

It now explains users may not use these functions when
using the old IO manager.

- - - - -
fcc7ba41 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Fix potential spaceleak in __createUUIDTempFileErrNo

- - - - -
6b3fd9fa by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Remove redundant -Wno-missing-signatures pragmas

- - - - -
916fc861 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Make it explicit that we only create one IO manager

- - - - -
f260a721 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Note why we don't use blocking waits.

- - - - -
aa0a4bbf by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Remove commented out pragma

- - - - -
d679b544 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Remove redundant buffer write in Handle/Text.hs:bufReadEmpty

- - - - -
d3f94368 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Rename SmartHandles to StdHandles

- - - - -
bd6b8ec1 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: add comment stating failure behaviour for getUniqueFileInfo.

- - - - -
12846b85 by Andreas Klebinger at 2020-07-15T16:41:03-04:00
winio: Update IOPort haddocks.

- - - - -
9f39fb14 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Add a note cross reference

- - - - -
62dd5a73 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Name Haskell/OS I/O Manager explicitly in Note

- - - - -
fa807828 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Expand BlockedOnIOCompletion description.

- - - - -
f0880a1d by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Remove historical todos

- - - - -
8e58e714 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Update note, remove debugging pragma.

- - - - -
aa4d84d5 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: flushCharReadBuffer shouldn't need to adjust offsets.

- - - - -
e580893a by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Remove obsolete comment about cond. variables

- - - - -
d54e9d79 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix initial linux validate build

- - - - -
3cd4de46 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Fix ThreadDelay001 CPP

- - - - -
c88b1b9f by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Fix openFile009 merge conflict leftover

- - - - -
849e8889 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Accept T9681 output.

GHC now reports String instead of [Char].

- - - - -
e7701818 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Fix cabal006 after upgrading cabal submodule

Demand cabal 2.0 syntax instead of >= 1.20 as required by newer cabal versions.

- - - - -
a44f0373 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Fix stderr output for ghci/linking/dyn tests.

We used to filter rtsopts, i opted to instead just accept the warning of it having no effect.
This works both for -rtsopts, as well as -with-rtsopts which winio adds.

- - - - -
515d9896 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Adjust T15261b stdout for --io-manager flag.

- - - - -
949aaacc by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Adjust T5435_dyn_asm stderr

The warning about rtsopts having no consequences is expected.
So accept new stderr.

- - - - -
7d424e1e by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Also accept T7037 stderr

- - - - -
1f009768 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix cabal04 by filtering rts args

- - - - -
981a9f2e by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix cabal01 by accepting expected stderr

- - - - -
b7b0464e by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix safePkg01 by accepting expected stderr

- - - - -
32734b29 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix T5435_dyn_gcc by accepting expected stderr

- - - - -
acc5cebf by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: fix tempfiles test on linux

- - - - -
c577b789 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Accept accepted stderr for T3807

- - - - -
c108c527 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Accept accepted stderr for linker_unload

- - - - -
2b0b9a08 by Andreas Klebinger at 2020-07-15T16:41:04-04:00
winio: Accept accepted stderr for linker_unload_multiple_objs

- - - - -
67afb03c by Tamar Christina at 2020-07-15T16:41:04-04:00
winio: clarify wording on conditional variables.

- - - - -
3bd41572 by Tamar Christina at 2020-07-15T16:41:04-04:00
winio: clarify comment on cooked mode.

- - - - -
ded58a03 by Tamar Christina at 2020-07-15T16:41:04-04:00
winio: update lockfile signature and remove mistaken symbol in rts.

- - - - -
2143c492 by Ben Gamari at 2020-07-15T16:41:04-04:00
testsuite: Add winio and winio_threaded ways

Reverts many of the testsuite changes

- - - - -
c0979cc5 by Ben Gamari at 2020-07-16T10:56:54-04:00
Merge remote-tracking branch 'origin/wip/winio'

- - - - -
69afa45f by Ben Gamari at 2020-07-16T13:47:46-04:00
testsuite: Don't disable LLVM ways due to unversioned llc

Previously we would silently disable the LLVM testsuite ways when LLC is
set to an unversioned llc executable (e.g. `llc` instead of `llc-5.0`).
Presumably this was because we were lax in checking the LLVM version in
configure.  However, this is no longer the case and consequently this
confusing behavior is no longer necessary.

See Trac #16121.

Test Plan: Validate

Reviewers: angerman

Reviewed By: angerman

Subscribers: michalt, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4333

- - - - -


30 changed files:

- − .circleci/config.yml
- − .circleci/fetch-submodules.sh
- − .circleci/images/aarch64-linux-deb9/Dockerfile
- − .circleci/images/i386-linux-deb8/Dockerfile
- − .circleci/images/i386-linux-deb9/Dockerfile
- − .circleci/images/linters/Dockerfile
- − .circleci/images/update-image
- − .circleci/images/x86_64-freebsd/Dockerfile
- − .circleci/images/x86_64-freebsd/build-toolchain.sh
- − .circleci/images/x86_64-linux-centos7/Dockerfile
- − .circleci/images/x86_64-linux-deb8/Dockerfile
- − .circleci/images/x86_64-linux-deb9/Dockerfile
- − .circleci/images/x86_64-linux-fedora27/Dockerfile
- − .circleci/prepare-system.sh
- − .circleci/push-test-metrics.sh
- .ghcid
- + .git-ignore-revs
- + .gitattributes
- .gitignore
- .gitlab-ci.yml
- + .gitlab/ci.sh
- − .gitlab/darwin-init.sh
- − .gitlab/fix-submodules.py
- + .gitlab/issue_templates/bug.md
- + .gitlab/issue_templates/documentation_issue.md
- + .gitlab/issue_templates/feature_request.md
- + .gitlab/linters/check-changelogs.sh
- .gitlab/linters/check-cpp.py
- .gitlab/linters/check-makefiles.py
- + .gitlab/linters/check-version-number.sh


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/eb4eb5f30022e01c5df06c81b698fdcf4ddb74c0...69afa45ff3914d3e593b52b845706a1fddd831a8

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View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/eb4eb5f30022e01c5df06c81b698fdcf4ddb74c0...69afa45ff3914d3e593b52b845706a1fddd831a8
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