[Git][ghc/ghc][wip/angerman/aarch64-ncg] 512 commits: .gitignore *.hiedb files

Moritz Angermann gitlab at gitlab.haskell.org
Tue Nov 10 04:00:56 UTC 2020



Moritz Angermann pushed to branch wip/angerman/aarch64-ncg at Glasgow Haskell Compiler / GHC


Commits:
6abe4a1c by Sebastian Graf at 2020-09-10T17:02:00+02:00
.gitignore *.hiedb files

- - - - -
3777be14 by Sebastian Graf at 2020-09-10T17:03:12+02:00
PmCheck: Handle ⊥ and strict fields correctly (#18341)

In #18341, we discovered an incorrect digression from Lower Your Guards.
This MR changes what's necessary to support properly fixing #18341.

In particular, bottomness constraints are now properly tracked in the
oracle/inhabitation testing, as an additional field
`vi_bot :: Maybe Bool` in `VarInfo`. That in turn allows us to
model newtypes as advertised in the Appendix of LYG and fix #17725.
Proper handling of ⊥ also fixes #17977 (once again) and fixes #18670.

For some reason I couldn't follow, this also fixes #18273.

I also added a couple of regression tests that were missing. Most of
them were already fixed before.

In summary, this patch fixes #18341, #17725, #18273, #17977 and #18670.

Metric Decrease:
    T12227

- - - - -
1bd28931 by David Himmelstrup at 2020-09-11T09:59:43-04:00
Define TICKY_TICKY when compiling cmm RTS files.

- - - - -
15e67801 by David Himmelstrup at 2020-09-11T09:59:43-04:00
Fix typos in TICKY_TICKY symbol names.

- - - - -
8a5a91cb by David Himmelstrup at 2020-09-11T09:59:43-04:00
Enable TICKY_TICKY for debug builds when building with makefiles.

- - - - -
fc965c09 by Sandy Maguire at 2020-09-12T00:31:36-04:00
Add clamp function to Data.Ord

- - - - -
fb6e29e8 by Sandy Maguire at 2020-09-12T00:31:37-04:00
Add tests

- - - - -
2a942285 by Sebastian Graf at 2020-09-12T00:32:13-04:00
PmCheck: Disattach COMPLETE pragma lookup from TyCons

By not attaching COMPLETE pragmas with a particular TyCon and instead
assume that every COMPLETE pragma is applicable everywhere, we can
drastically simplify the logic that tries to initialise available
COMPLETE sets of a variable during the pattern-match checking process,
as well as fixing a few bugs.

Of course, we have to make sure not to report any of the
ill-typed/unrelated COMPLETE sets, which came up in a few regression
tests.

In doing so, we fix #17207, #18277 and #14422.

There was a metric decrease in #18478 by ~20%.

Metric Decrease:
    T18478

- - - - -
389a6683 by Ben Gamari at 2020-09-12T00:32:49-04:00
hadrian: Pass input file to makeindex

Strangely I find that on Alpine (and apparently only on Alpine) the
latex makeindex command expects to be given a filename, lest it reads
from stdin.

- - - - -
853d121a by Ryan Scott at 2020-09-12T00:33:25-04:00
Don't quote argument to Hadrian's test-env flag (#18656)

Doing so causes the name of the test environment to gain an extra
set of double quotes, which changes the name entirely.

Fixes #18656.

- - - - -
8440b5fa by Krzysztof Gogolewski at 2020-09-12T00:33:25-04:00
Make sure we can read past perf notes

See #18656.

- - - - -
2157be52 by theobat at 2020-09-12T21:27:04-04:00
Avoid iterating twice in `zipTyEnv` (#18535)

zipToUFM is a new function to replace `listToUFM (zipEqual ks vs)`.
An explicit recursion is preferred due to the sensible nature of fusion.

    T12227 -6.0%
    T12545 -12.3%
    T5030  -9.0%
    T9872a -1.6%
    T9872b -1.6%
    T9872c -2.0%

 -------------------------
Metric Decrease:
    T12227
    T12545
    T5030
    T9872a
    T9872b
    T9872c
-------------------------

- - - - -
69ea2fee by Sebastian Graf at 2020-09-12T21:27:40-04:00
Make `tcCheckSatisfiability` incremental (#18645)

By taking and returning an `InertSet`.
Every new `TcS` session can then pick up where a prior session left with
`setTcSInerts`.

Since we don't want to unflatten the Givens (and because it leads to
infinite loops, see !3971), we introduced a new variant of `runTcS`,
`runTcSInerts`, that takes and returns the `InertSet` and makes
sure not to unflatten the Givens after running the `TcS` action.

Fixes #18645 and #17836.

Metric Decrease:
    T17977
    T18478

- - - - -
a77e48d2 by Sebastian Graf at 2020-09-12T21:27:40-04:00
Extract definition of DsM into GHC.HsToCore.Types

`DsM` was previously defined in `GHC.Tc.Types`, along with `TcM`. But
`GHC.Tc.Types` is in the set of transitive dependencies of `GHC.Parser`,
a set which we aim to minimise. Test case `CountParserDeps` checks for
that.

Having `DsM` in that set means the parser also depends on the innards of
the pattern-match checker in `GHC.HsToCore.PmCheck.Types`, which is the
reason we have that module in the first place.

In the previous commit, we represented the `TyState` by an `InertSet`,
but that pulls the constraint solver as well as 250 more modules into
the set of dependencies, triggering failure of `CountParserDeps`.
Clearly, we want to evolve the pattern-match checker (and the desugarer)
without being concerned by this test, so this patch includes a small
refactor that puts `DsM` into its own module.

- - - - -
fd5d622a by Sebastian Graf at 2020-09-12T21:27:40-04:00
Hackily decouple the parser from the desugarer

In a hopefully temporary hack, I re-used the idea from !1957 of using a
nullary type family to break the dependency from GHC.Driver.Hooks on the
definition of DsM ("Abstract Data").
This in turn broke the last dependency from the parser to the desugarer.
More details in `Note [The Decoupling Abstract Data Hack]`.

In the future, we hope to undo this hack again in favour of breaking the
dependency from the parser to DynFlags altogether.

- - - - -
35a7b7ec by Adam Sandberg Eriksson at 2020-09-14T17:46:16-04:00
docs: -B rts option sounds the bell on every GC (#18351)
- - - - -
5ae8212c by Wander Hillen at 2020-09-14T17:46:54-04:00
Populate gitlab cache after building

- - - - -
a5ffb39a by Wander Hillen at 2020-09-14T17:46:54-04:00
Move ahead cabal cache restoration to before use of cabal

- - - - -
e8b37c21 by Wander Hillen at 2020-09-14T17:46:54-04:00
Do the hadrian rebuild multicore

- - - - -
07762eb5 by Wander Hillen at 2020-09-14T17:46:54-04:00
Also cache other hadrian builds

- - - - -
8610bcbe by DenisFrezzato at 2020-09-15T15:19:08-04:00
Fix rtsopts documentation

- - - - -
c7182a5c by Simon Peyton Jones at 2020-09-15T15:19:44-04:00
Care with implicit-parameter superclasses

Two bugs, #18627 and #18649, had the same cause: we were not
account for the fact that a constaint tuple might hide an implicit
parameter.

The solution is not hard: look for implicit parameters in
superclasses.  See Note [Local implicit parameters] in
GHC.Core.Predicate.

Then we use this new function in two places

* The "short-cut solver" in GHC.Tc.Solver.Interact.shortCutSolver
  which simply didn't handle implicit parameters properly at all.
  This fixes #18627

* The specialiser, which should not specialise on implicit parameters
  This fixes #18649

There are some lingering worries (see Note [Local implicit
parameters]) but things are much better.

- - - - -
0f3884b0 by Zubin Duggal at 2020-09-15T15:20:23-04:00
Export enrichHie from GHC.Iface.Ext.Ast

This is useful for `ghcide`

- - - - -
b3143f5a by Sylvain Henry at 2020-09-15T15:21:06-04:00
Enhance metrics output

- - - - -
4283feaa by Ryan Scott at 2020-09-15T15:21:43-04:00
Introduce and use DerivClauseTys (#18662)

This switches `deriv_clause_tys` so that instead of using a list of
`LHsSigType`s to represent the types in a `deriving` clause, it now
uses a sum type. `DctSingle` represents a `deriving` clause with no
enclosing parentheses, while `DctMulti` represents a clause with
enclosing parentheses. This makes pretty-printing easier and avoids
confusion between `HsParTy` and the enclosing parentheses in
`deriving` clauses, which are different semantically.

Fixes #18662.

- - - - -
90229c4b by Ryan Scott at 2020-09-16T04:53:22-04:00
Include -f{write,validate}-ide-info in the User's Guide flag reference

Previously, these were omitted from the flag reference due to a
layout oversight in `docs/users_guide/flags.{rst,py}`.

Fixes #18426.

- - - - -
ce42e187 by Ben Gamari at 2020-09-16T04:53:59-04:00
rts: Fix erroneous usage of vsnprintf

As pointed out in #18685, this should be snprintf not vsnprintf. This
appears to be due to a cut-and-paste error.

Fixes #18658.

- - - - -
b695e7d7 by Sylvain Henry at 2020-09-16T04:54:38-04:00
Rename ghci flag into internal-interpreter

"ghci" as a flag name was confusing because it really enables the
internal-interpreter. Even the ghci library had a "ghci" flag...

- - - - -
8af954d2 by Sylvain Henry at 2020-09-16T04:55:17-04:00
Make ghc-boot reexport modules from ghc-boot-th

Packages don't have to import both ghc-boot and ghc-boot-th. It makes
the dependency graph easier to understand and to refactor.

- - - - -
6baa67f5 by Adam Sandberg Eriksson at 2020-09-16T07:45:47-04:00
docs: correct haddock reference

[skip ci]
- - - - -
7cf09ab0 by Simon Peyton Jones at 2020-09-17T01:27:25-04:00
Do absence analysis on stable unfoldings

Ticket #18638 showed that Very Bad Things happen if we fail
to do absence analysis on stable unfoldings.  It's all described
in Note [Absence analysis for stable unfoldings and RULES].

I'm a bit surprised this hasn't bitten us before. Fortunately
the fix is pretty simple.

- - - - -
76d3bcbc by Leif Metcalf at 2020-09-17T01:28:01-04:00
Replace deprecated git --recursive

The --recursive flag of git-clone has been replaced by the
--recurse-submodules flag since git 1.7.4, released in 2011.
- - - - -
da8f4ddd by Richard Eisenberg at 2020-09-17T01:28:38-04:00
Document IfaceTupleTy

- - - - -
3c94c816 by HaskellMouse at 2020-09-17T08:49:51-04:00
Added explicit fixity to (~).

Solves #18252

- - - - -
b612e396 by Cary Robbins at 2020-09-17T08:50:30-04:00
Make the 'IsString (Const a b)' instance polykinded on 'b'

- - - - -
8d0c26c4 by Ben Gamari at 2020-09-17T08:51:08-04:00
rts/win32: Fix missing #include's

These slipped through CI.

- - - - -
76009ec8 by Ben Gamari at 2020-09-17T08:51:08-04:00
Bump Win32 submodule to 2.9.0.0

Also bumps Cabal, directory

- - - - -
147bb598 by Ben Gamari at 2020-09-17T08:51:08-04:00
Bump version to 9.0

Bumps haskeline and haddock submodules.

(cherry picked from commit f218cfc92f7b1a1e01190851972bb9a0e0f3c682)

- - - - -
5c7387f6 by Leif Metcalf at 2020-09-17T08:51:43-04:00
Make Z-encoding comment into a note

- - - - -
c12b3041 by Leif Metcalf at 2020-09-17T08:51:43-04:00
Cosmetic

- - - - -
4f461e1a by Vladislav Zavialov at 2020-09-17T08:52:19-04:00
Parser.y: clarify treatment of @{-# UNPACK #-}

Before this patch, we had this parser production:

	ftype : ...
	      | ftype PREFIX_AT tyarg  { ... }

And 'tyarg' is defined as follows:

	tyarg : atype              { ... }
	      | unpackedness atype { ... }

So one might get the (false) impression that that parser production is
intended to parse things like:

	F @{-# UNPACK #-} X

However, the lexer wouldn't produce PREFIX_AT followed by 'unpackedness',
as the '@' operator followed by '{-' is not considered prefix.

Thus there's no point using 'tyarg' after PREFIX_AT,
and a simple 'atype' will suffice:

	ftype : ...
	      | ftype PREFIX_AT atype  { ... }

This change has no user-facing consequences. It just makes the grammar a
bit more clear.

- - - - -
9dec8600 by Benjamin Maurer at 2020-09-17T08:52:56-04:00
Documented '-m' flags for machine specific instruction extensions.
See #18641 'Documenting the Expected Undocumented Flags'

- - - - -
ca48076a by Sylvain Henry at 2020-09-17T20:04:08-04:00
Introduce OutputableP

Some types need a Platform value to be pretty-printed: CLabel, Cmm
types, instructions, etc.

Before this patch they had an Outputable instance and the Platform value
was obtained via sdocWithDynFlags. It meant that the *renderer* of the
SDoc was responsible of passing the appropriate Platform value (e.g. via
the DynFlags given to showSDoc).  It put the burden of passing the
Platform value on the renderer while the generator of the SDoc knows the
Platform it is generating the SDoc for and there is no point passing a
different Platform at rendering time.

With this patch, we introduce a new OutputableP class:

   class OutputableP a where
      pdoc :: Platform -> a -> SDoc

With this class we still have some polymorphism as we have with `ppr`
(i.e. we can use `pdoc` on a variety of types instead of having a
dedicated `pprXXX` function for each XXX type).

One step closer removing `sdocWithDynFlags` (#10143) and supporting
several platforms (#14335).

- - - - -
e45c8544 by Sylvain Henry at 2020-09-17T20:04:08-04:00
Generalize OutputableP

Add a type parameter for the environment required by OutputableP. It
avoids tying Platform with OutputableP.

- - - - -
37aa224a by Sylvain Henry at 2020-09-17T20:04:08-04:00
Add note about OutputableP

- - - - -
7f2785f2 by Sylvain Henry at 2020-09-17T20:04:08-04:00
Remove pprPrec from Outputable (unused)

- - - - -
b689f3db by Sylvain Henry at 2020-09-17T20:04:46-04:00
Bignum: add clamping naturalToWord (fix #18697)

- - - - -
0799b3de by Ben Gamari at 2020-09-18T15:55:50-04:00
rts/nonmoving: Add missing STM write barrier

When updating a TRec for a TVar already part of a transaction we
previously neglected to add the old value to the update remembered set.
I suspect this was the cause of #18587.

- - - - -
c4921349 by Ben Gamari at 2020-09-18T15:56:25-04:00
rts: Refactor foreign export tracking

This avoids calling `libc` in the initializers which are responsible for
registering foreign exports. We believe this should avoid the corruption
observed in #18548.

See Note [Tracking foreign exports] in rts/ForeignExports.c for an
overview of the new scheme.

- - - - -
40dc9106 by Ben Gamari at 2020-09-18T15:56:25-04:00
rts: Refactor unloading of foreign export StablePtrs

Previously we would allocate a linked list cell for each foreign export.
Now we can avoid this by taking advantage of the fact that they are
already broken into groups.

- - - - -
45fa8218 by Simon Jakobi at 2020-09-19T06:57:36-04:00
Deprecate Data.Semigroup.Option

Libraries email: https://mail.haskell.org/pipermail/libraries/2018-April/028724.html

GHC issue: https://gitlab.haskell.org/ghc/ghc/issues/15028

Corresponding PRs for deepseq:
* https://github.com/haskell/deepseq/pull/55
* https://github.com/haskell/deepseq/pull/57

Bumps the deepseq submodule.

- - - - -
2229d570 by Vladislav Zavialov at 2020-09-19T15:47:24-04:00
Require happy >=1.20

- - - - -
a89c2fba by Ben Gamari at 2020-09-19T15:47:24-04:00
ci.sh: Enforce minimum happy/alex versions

Also, always invoke cabal-install to ensure that happy/alex symlinks are
up-to-date.

- - - - -
2f7ef2fb by Ben Gamari at 2020-09-19T15:47:24-04:00
gitlab-ci: Ensure that cabal-install overwrites existing executables

Previously cabal-install wouldn't overwrite toolchain executables if
they already existed (as they likely would due to caching).

- - - - -
ac213d26 by Ryan Scott at 2020-09-19T15:48:01-04:00
Wire in constraint tuples

This wires in the definitions of the constraint tuple classes. The
key changes are in:

* `GHC.Builtin.Types`, where the `mk_ctuple` function is used to
  define constraint tuple type constructors, data constructors, and
  superclass selector functions, and
* `GHC.Builtin.Uniques`. In addition to wiring in the `Unique`s for
  constraint tuple type and data constructors, we now must wire in
  the superclass selector functions. Luckily, this proves to be not
  that challenging. See the newly added comments.

Historical note: constraint tuples used to be wired-in until about
five years ago, when commit 130e93aab220bdf14d08028771f83df210da340b
turned them into known-key names. This was done as part of a larger
refactor to reduce the number of special cases for constraint tuples,
but the commit message notes that the main reason that constraint
tuples were made known-key (as opposed to boxed/unboxed tuples, which
are wired in) is because it was awkward to wire in the superclass
selectors. This commit solves the problem of wiring in superclass
selectors.

Fixes #18635.

-------------------------
Metric Decrease:
    T10421
    T12150
    T12227
    T12234
    T12425
    T13056
    T13253-spj
    T18282
    T18304
    T5321FD
    T5321Fun
    T5837
    T9961
Metric Decrease (test_env='x86_64-linux-deb9-unreg-hadrian'):
    T12707
Metric Decrease (test_env='x86_64-darwin'):
    T4029
-------------------------

- - - - -
e195dae6 by Wander Hillen at 2020-09-19T15:48:41-04:00
Export singleton function from Data.List

Data.OldList exports a monomorphized singleton function but
it is not re-exported by Data.List. Adding the export to
Data.List causes a conflict with a 14-year old function of the
same name and type by SPJ in GHC.Utils.Misc. We can't just remove
this function because that leads to a problems when building
GHC with a stage0 compiler that does not have singleton in
Data.List yet. We also can't hide the function in GHC.Utils.Misc
since it is not possible to hide a function from a module if the
module does not export the function. To work around this, all
places where the Utils.Misc singleton was used now use a qualified
version like Utils.singleton and in GHC.Utils.Misc we are very
specific about which version we export.

- - - - -
9c1b8ad9 by Sylvain Henry at 2020-09-19T15:49:19-04:00
Bump Stack resolver

- - - - -
d05d13ce by John Ericson at 2020-09-19T15:49:57-04:00
Cinch -fno-warn-name-shadowing down to specific GHCi module

- - - - -
f1accd00 by Sylvain Henry at 2020-09-19T15:49:57-04:00
Add quick-validate Hadrian flavour (quick + -Werror)

- - - - -
8f8d51f1 by Andreas Klebinger at 2020-09-19T15:50:33-04:00
Fix docs who misstated how the RTS treats size suffixes.

They are parsed as multiples of 1024. Not 1000. The docs
used to imply otherwise.

See decodeSize in rts/RtsFlags.c for the logic for this.

- - - - -
2ae0edbd by Andreas Klebinger at 2020-09-19T15:50:33-04:00
Fix a codeblock in ghci.rst

- - - - -
4df3aa95 by Ben Gamari at 2020-09-19T15:51:07-04:00
users guide: Fix various documentation issues

- - - - -
885ecd18 by Ben Gamari at 2020-09-19T15:51:07-04:00
hadrian: Fail on Sphinx syntax errors

Specifically the "Inline literal start-string without end-string"
warning, which typically means that the user neglected to separate
an inline code block from suffix text with a backslash.

- - - - -
b26cd867 by David Feuer at 2020-09-19T15:51:44-04:00
Unpack the MVar in Compact

The `MVar` lock in `Compact` was unnecessarily lazy, creating an extra indirection and wasting two words. Make it strict.
- - - - -
760307cf by Artyom Kuznetsov at 2020-09-19T15:52:21-04:00
Remove GADT self-reference check (#11554, #12081, #12174, fixes #15942)

Reverts 430f5c84dac1eab550110d543831a70516b5cac8

- - - - -
057db94c by Ben Gamari at 2020-09-19T15:52:56-04:00
rts: Drop field initializer on thread_basic_info_data_t

This struct has a number of fields and we only care that the value is
initialized with zeros. This eliminates the warnings noted in #17905.

- - - - -
87e2e2b1 by Vladislav Zavialov at 2020-09-19T23:55:30+03:00
Resolve shift/reduce conflicts with %shift (#17232)

- - - - -
66cba46e by Ben Gamari at 2020-09-20T20:30:57-04:00
testsuite: Unmark T12971 as broken on Windows

It's unclear why, but this no longer seems to fail.

Closes #17945.

- - - - -
816811d4 by Ben Gamari at 2020-09-20T20:30:57-04:00
testsuite: Unmark T5975[ab] as broken on Windows

Sadly it's unclear *why* they have suddenly started working.

Closes #7305.

- - - - -
43a43d39 by Ben Gamari at 2020-09-20T20:30:57-04:00
base/testsuite: Add missing LANGUAGE pragma in ThreadDelay001

Only affected the Windows codepath.

- - - - -
ced8f113 by Ben Gamari at 2020-09-20T20:30:57-04:00
testsuite: Update expected output for outofmem on Windows

The error originates from osCommitMemory rather than getMBlocks.

- - - - -
ea08aead by Ben Gamari at 2020-09-20T20:30:57-04:00
testsuite: Mark some GHCi/Makefile tests as broken on Windows

See #18718.

- - - - -
caf6a5a3 by GHC GitLab CI at 2020-09-20T20:30:57-04:00
testsuite: Fix WinIO error message normalization

This wasn't being applied to stderr.

- - - - -
93ab3e8d by GHC GitLab CI at 2020-09-20T20:30:57-04:00
testsuite: Mark tempfiles as broken on Win32 without WinIO

The old POSIX emulation appears to ignore the user-requested prefix.

- - - - -
9df77fed by GHC GitLab CI at 2020-09-20T20:30:57-04:00
testsuite: Mark TH_spliceE5_prof as broken on Windows

Due to #18721.

- - - - -
1a0f8243 by Ryan Scott at 2020-09-21T16:45:47-04:00
Remove unused ThBrackCtxt and ResSigCtxt

Fixes #18715.

- - - - -
2f222b12 by Ryan Scott at 2020-09-21T16:45:47-04:00
Disallow constraints in KindSigCtxt

This patch cleans up how `GHC.Tc.Validity` classifies `UserTypeCtxt`s
that can only refer to kind-level positions, which is important for
rejecting certain classes of programs. In particular, this patch:

* Introduces a new `TypeOrKindCtxt` data type and
  `typeOrKindCtxt :: UserTypeCtxt -> TypeOrKindCtxt` function, which
  determines whether a `UserTypeCtxt` can refer to type-level
  contexts, kind-level contexts, or both.
* Defines the existing `allConstraintsAllowed` and `vdqAllowed`
  functions in terms of `typeOrKindCtxt`, which avoids code
  duplication and ensures that they stay in sync in the future.

The net effect of this patch is that it fixes #18714, in which it was
discovered that `allConstraintsAllowed` incorrectly returned `True`
for `KindSigCtxt`. Because `typeOrKindCtxt` now correctly classifies
`KindSigCtxt` as a kind-level context, this bug no longer occurs.

- - - - -
aaa51dcf by Ben Gamari at 2020-09-21T16:46:22-04:00
hadrian: Add extra-deps: happy-1.20 to stack.yaml

GHC now requires happy-1.20, which isn't available in LTS-16.14.

Fixes #18726.
- - - - -
6de40f83 by Simon Peyton Jones at 2020-09-22T05:37:24-04:00
Better eta-expansion (again) and don't specilise DFuns

This patch fixes #18223, which made GHC generate an exponential
amount of code.  There are three quite separate changes in here

1.  Re-engineer eta-expansion (again).  The eta-expander was
    generating lots of intermediate stuff, which could be optimised
    away, but which choked the simplifier meanwhile.  Relatively
    easy to kill it off at source.

    See Note [The EtaInfo mechanism] in GHC.Core.Opt.Arity.
    The main new thing is the use of pushCoArg in getArg_maybe.

2.  Stop Specialise specalising DFuns.  This is the cause of a huge
    (and utterly unnecessary) blowup in program size in #18223.
    See Note [Do not specialise DFuns] in GHC.Core.Opt.Specialise.

    I also refactored the Specialise monad a bit... it was silly,
    because it passed on unchanging values as if they were mutable
    state.

3.  Do an extra Simplifer run, after SpecConstra and before
    late-Specialise.  I found (investigating perf/compiler/T16473)
    that failing to do this was crippling *both* SpecConstr *and*
    Specialise.  See Note [Simplify after SpecConstr] in
    GHC.Core.Opt.Pipeline.

    This change does mean an extra run of the Simplifier, but only
    with -O2, and I think that's acceptable.

    T16473 allocates *three* times less with this change.  (I changed
    it to check runtime rather than compile time.)

Some smaller consequences

* I moved pushCoercion, pushCoArg and friends from SimpleOpt
  to Arity, because it was needed by the new etaInfoApp.

  And pushCoValArg now returns a MCoercion rather than Coercion for
  the argument Coercion.

* A minor, incidental improvement to Core pretty-printing

This does fix #18223, (which was otherwise uncompilable. Hooray.  But
there is still a big intermediate because there are some very deeply
nested types in that program.

Modest reductions in compile-time allocation on a couple of benchmarks
    T12425     -2.0%
    T13253    -10.3%

Metric increase with -O2, due to extra simplifier run
    T9233     +5.8%
    T12227    +1.8%
    T15630    +5.0%

There is a spurious apparent increase on heap residency on T9630,
on some architectures at least.  I tried it with -G1 and the residency
is essentially unchanged.

Metric Increase
    T9233
    T12227
    T9630

Metric Decrease
    T12425
    T13253

- - - - -
416bd50e by Simon Peyton Jones at 2020-09-22T05:37:59-04:00
Fix the occurrence analyser

Ticket #18603 demonstrated that the occurrence analyser's
handling of

  local RULES for imported Ids

(which I now call IMP-RULES) was inadequate.  It led the simplifier
into an infnite loop by failing to label a binder as a loop breaker.

The main change in this commit is to treat IMP-RULES in a simple and
uniform way: as extra rules for the local binder.  See
  Note [IMP-RULES: local rules for imported functions]

This led to quite a bit of refactoring.  The result is still tricky,
but it's much better than before, and better documented I think.

Oh, and it fixes the bug.

- - - - -
6fe8a0c7 by Sebastian Graf at 2020-09-22T05:38:35-04:00
PmCheck - Comments only: Replace /~ by ≁

- - - - -
e9501547 by Sebastian Graf at 2020-09-22T05:38:35-04:00
PmCheck: Rewrite inhabitation test

We used to produce inhabitants of a pattern-match refinement type Nabla
in the checker in at least two different and mostly redundant ways:

  1. There was `provideEvidence` (now called
     `generateInhabitingPatterns`) which is used by
     `GHC.HsToCore.PmCheck` to produce non-exhaustive patterns, which
     produces inhabitants of a Nabla as a sub-refinement type where all
     match variables are instantiated.
  2. There also was `ensure{,All}Inhabited` (now called
     `inhabitationTest`) which worked slightly different, but was
     whenever new type constraints or negative term constraints were
     added. See below why `provideEvidence` and `ensureAllInhabited`
     can't be the same function, the main reason being performance.
  3. And last but not least there was the `nonVoid` test, which tested
     that a given type was inhabited. We did use this for strict fields
     and -XEmptyCase in the past.

The overlap of (3) with (2) was always a major pet peeve of mine. The
latter was quite efficient and proven to work for recursive data types,
etc, but could not handle negative constraints well (e.g. we often want
to know if a *refined* type is empty, such as `{ x:[a] | x /= [] }`).

Lower Your Guards suggested that we could get by with just one, by
replacing both functions with `inhabitationTest` in this patch.
That was only possible by implementing the structure of φ constraints
as in the paper, namely the semantics of φ constructor constraints.

This has a number of benefits:

  a. Proper handling of unlifted types and strict fields, fixing #18249,
     without any code duplication between
     `GHC.HsToCore.PmCheck.Oracle.instCon` (was `mkOneConFull`) and
     `GHC.HsToCore.PmCheck.checkGrd`.
  b. `instCon` can perform the `nonVoid` test (3) simply by emitting
     unliftedness constraints for strict fields.
  c. `nonVoid` (3) is thus simply expressed by a call to
     `inhabitationTest`.
  d. Similarly, `ensureAllInhabited` (2), which we called after adding
     type info, now can similarly be expressed as the fuel-based
     `inhabitationTest`.

See the new `Note [Why inhabitationTest doesn't call generateInhabitingPatterns]`
why we still have tests (1) and (2).

Fixes #18249 and brings nice metric decreases for `T17836` (-76%) and
`T17836b` (-46%), as well as `T18478` (-8%) at the cost of a few very
minor regressions (< +2%), potentially due to the fact that
`generateInhabitingPatterns` does more work to suggest the minimal
COMPLETE set.

Metric Decrease:
    T17836
    T17836b

- - - - -
086ef018 by Hécate at 2020-09-23T06:52:08-04:00
Remove the list of loaded modules from the ghci prompt

- - - - -
d7385f70 by Ben Gamari at 2020-09-23T06:52:44-04:00
Bump submodules

* Bump bytestring to 0.10.12.0
* Bump Cabal to 3.4.0.0-rc3
* Bump Win32 to 2.10.0.0

- - - - -
667d6355 by Sylvain Henry at 2020-09-23T20:43:48-04:00
Refactor CLabel pretty-printing

* Don't depend on the selected backend to know if we print Asm or C
  labels: we already have PprStyle to determine this. Moreover even when
  a native backend is used (NCG, LLVM) we may want to C headers
  containing pretty-printed labels, so it wasn't a good predicate
  anyway.

* Make pretty-printing code clearer and avoid partiality

- - - - -
a584366b by Sylvain Henry at 2020-09-23T20:43:48-04:00
Remove sdocWithDynFlags (fix #10143)

- - - - -
a997fa01 by Sylvain Henry at 2020-09-23T20:43:48-04:00
Preliminary work towards removing DynFlags -> Driver.Ppr dependency

- - - - -
31fea307 by Hécate at 2020-09-23T20:44:24-04:00
Remove redundant "do", "return" and language extensions from base

- - - - -
04d64331 by syd at cs-syd.eu at 2020-09-24T13:15:54-04:00
Update Lock.hs with more documentation to make sure that the Boolean return value is clear.

[skip ci]

- - - - -
97cff919 by Simon Peyton Jones at 2020-09-24T13:16:32-04:00
Implement Quick Look impredicativity

This patch implements Quick Look impredicativity (#18126), sticking
very closely to the design in
    A quick look at impredicativity, Serrano et al, ICFP 2020

The main change is that a big chunk of GHC.Tc.Gen.Expr has been
extracted to two new modules
    GHC.Tc.Gen.App
    GHC.Tc.Gen.Head
which deal with typechecking n-ary applications, and the head of
such applications, respectively.  Both contain a good deal of
documentation.

Three other loosely-related changes are in this patch:

* I implemented (partly by accident) points (2,3)) of the accepted GHC
  proposal "Clean up printing of foralls", namely
  https://github.com/ghc-proposals/ghc-proposals/blob/
        master/proposals/0179-printing-foralls.rst
  (see #16320).

  In particular, see Note [TcRnExprMode] in GHC.Tc.Module
  - :type instantiates /inferred/, but not /specified/, quantifiers
  - :type +d instantiates /all/ quantifiers
  - :type +v is killed off

  That completes the implementation of the proposal,
  since point (1) was done in
    commit df08468113ab46832b7ac0a7311b608d1b418c4d
    Author: Krzysztof Gogolewski <krzysztof.gogolewski at tweag.io>
    Date:   Mon Feb 3 21:17:11 2020 +0100
    Always display inferred variables using braces

* HsRecFld (which the renamer introduces for record field selectors),
  is now preserved by the typechecker, rather than being rewritten
  back to HsVar.  This is more uniform, and turned out to be more
  convenient in the new scheme of things.

* The GHCi debugger uses a non-standard unification that allows the
  unification variables to unify with polytypes.  We used to hack
  this by using ImpredicativeTypes, but that doesn't work anymore
  so I introduces RuntimeUnkTv.  See Note [RuntimeUnkTv] in
  GHC.Runtime.Heap.Inspect

Updates haddock submodule.

WARNING: this patch won't validate on its own.  It was too
hard to fully disentangle it from the following patch, on
type errors and kind generalisation.

Changes to tests

* Fixes #9730 (test added)

* Fixes #7026 (test added)

* Fixes most of #8808, except function `g2'` which uses a
  section (which doesn't play with QL yet -- see #18126)
  Test added

* Fixes #1330. NB Church1.hs subsumes Church2.hs, which is now deleted

* Fixes #17332 (test added)

* Fixes #4295

* This patch makes typecheck/should_run/T7861 fail.
  But that turns out to be a pre-existing bug: #18467.
  So I have just made T7861 into expect_broken(18467)

- - - - -
9fa26aa1 by Simon Peyton Jones at 2020-09-24T13:16:32-04:00
Improve kind generalisation, error messages

This patch does two things:

* It refactors GHC.Tc.Errors a bit.  In debugging Quick Look I was
  forced to look in detail at error messages, and ended up doing a bit
  of refactoring, esp in mkTyVarEqErr'.  It's still quite a mess, but
  a bit better, I think.

* It makes a significant improvement to the kind checking of type and
  class declarations. Specifically, we now ensure that if kind
  checking fails with an unsolved constraint, all the skolems are in
  scope.  That wasn't the case before, which led to some obscure error
  messages; and occasional failures with "no skolem info" (eg #16245).

Both of these, and the main Quick Look patch itself, affect a /lot/ of
error messages, as you can see from the number of files changed.  I've
checked them all; I think they are as good or better than before.

Smaller things

* I documented the various instances of VarBndr better.
  See Note [The VarBndr tyep and its uses] in GHC.Types.Var

* Renamed GHC.Tc.Solver.simpl_top to simplifyTopWanteds

* A bit of refactoring in bindExplicitTKTele, to avoid the
  footwork with Either.  Simpler now.

* Move promoteTyVar from GHC.Tc.Solver to GHC.Tc.Utils.TcMType

Fixes #16245 (comment 211369), memorialised as
  typecheck/polykinds/T16245a
Also fixes the three bugs in #18640

- - - - -
6d0ce0eb by Sebastian Graf at 2020-09-24T13:17:07-04:00
PmCheck: Desugar string literal patterns with -XRebindableSyntax correctly (#18708)

Fixes #18708.

- - - - -
007940d2 by Hécate at 2020-09-24T13:17:44-04:00
Namespace the Hadrian linting rule for base

- - - - -
5b727189 by Andreas Klebinger at 2020-09-25T21:10:20-04:00
Make sizeExpr strict in the size threshold to facilitate WW.

- - - - -
dd664031 by Ben Gamari at 2020-09-25T21:10:56-04:00
ci.sh: Factor out common utilities

- - - - -
5b78e865 by Ben Gamari at 2020-09-25T21:10:56-04:00
ci: Add ad-hoc performance testing rule

- - - - -
29885f07 by Zubin Duggal at 2020-09-25T21:11:32-04:00
Stop removing definitions of record fields in GHC.Iface.Ext.Ast

- - - - -
0d6519d9 by Ben Gamari at 2020-09-25T21:12:08-04:00
gitlab-ci: Drop Darwin cleanup job

We now have a proper periodic clean-up script installed on the runners.

- - - - -
277d20af by Sebastian Graf at 2020-09-25T21:12:44-04:00
Add regression tests for #18371

They have been fixed by !3959, I believe.
Fixes #18371.

- - - - -
8edf6056 by Sebastian Graf at 2020-09-25T21:12:44-04:00
Add a regression test for #18609

The egregious performance hits are gone since !4050.
So we fix #18609.

- - - - -
4a1b89a4 by Sebastian Graf at 2020-09-25T21:12:44-04:00
Accept new test output for #17218

The expected test output was plain wrong.
It has been fixed for a long time.
Thus we can close #17218.

- - - - -
51606236 by Sven Tennie at 2020-09-25T21:13:19-04:00
Print RET_BIG stack closures

A RET_BIG closure has a large bitmap that describes it's payload and can
be printed with printLargeBitmap().

Additionally, the output for payload closures of small and big bitmaps is
changed: printObj() is used to print a bit more information about what's
on the stack.

- - - - -
2707c4ea by Arnaud Spiwack at 2020-09-25T21:13:58-04:00
Pattern guards BindStmt always use multiplicity Many

Fixes #18439 .

The rhs of the pattern guard was consumed with multiplicity one, while
the pattern assumed it was Many. We use Many everywhere instead.

This is behaviour consistent with that of `case` expression. See #18738.

- - - - -
92daad24 by Sylvain Henry at 2020-09-25T21:14:36-04:00
Bignum: refactor backend modules

* move backends into GHC.Num.Backend.*
* split backend selection into GHC.Num.Backend and
  GHC.Num.Backend.Selected to avoid duplication with the Check backend

- - - - -
04bc50b3 by Sylvain Henry at 2020-09-25T21:14:36-04:00
Bignum: implement extended GCD (#18427)

- - - - -
6a7dae4b by Krzysztof Gogolewski at 2020-09-25T21:15:14-04:00
Fix typed holes causing linearity errors (#18491)

- - - - -
83407ffc by Krzysztof Gogolewski at 2020-09-25T21:15:53-04:00
Various documentation fixes

* Remove UnliftedFFITypes from conf. Some time ago, this extension
  was undocumented and we had to silence a warning.
  This is no longer needed.
* Use r'' in conf.py. This fixes a Sphinx warning:
  WARNING: Support for evaluating Python 2 syntax is deprecated and will be removed in Sphinx 4.0. Convert docs/users_guide/conf.py to Python 3 syntax.
* Mark GHCForeignImportPrim as documented
* Fix formatting in template_haskell.rst
* Remove 'recursive do' from the list of unsupported items in TH

- - - - -
af1e84e7 by Sebastian Graf at 2020-09-26T05:36:46-04:00
PmCheck: Big refactor of module structure

  * Move everything from `GHC.HsToCore.PmCheck.*` to
    `GHC.HsToCore.Pmc.*` in analogy to `GHC.Tc`, rename exported
    `covCheck*` functions to `pmc*`
  * Rename `Pmc.Oracle` to `Pmc.Solver`
  * Split off the LYG desugaring and checking steps into their own
    modules (`Pmc.Desugar` and `Pmc.Check` respectively)
  * Split off a `Pmc.Utils` module with stuff shared by
    `Pmc.{,Desugar,Check,Solver}`
  * Move `Pmc.Types` to `Pmc.Solver.Types`, add a new `Pmc.Types` module
    with all the LYG types, which form the interfaces between
    `Pmc.{Desugar,Check,Solver,}`.

- - - - -
f08f98e8 by Sebastian Graf at 2020-09-26T05:36:46-04:00
Extract SharedIdEnv into its own module

It's now named `GHC.Types.Unique.SDFM.UniqSDFM`.
The implementation is more clear about its stated goals and supported
operations.

- - - - -
1cde295c by Sylvain Henry at 2020-09-26T05:37:23-04:00
Bignum: add bigNatFromWordArray

Reimplementation of integer-gmp's byteArrayToBigNat#

- - - - -
bda55fa0 by Krzysztof Gogolewski at 2020-09-26T13:18:22-04:00
Make 'undefined x' linear in 'x' (#18731)

- - - - -
160fba4a by Krzysztof Gogolewski at 2020-09-26T13:19:00-04:00
Disallow linear types in FFI (#18472)

- - - - -
e124f2a7 by Krzysztof Gogolewski at 2020-09-26T13:19:36-04:00
Fix handling of function coercions (#18747)

This was broken when we added multiplicity to the function type.

- - - - -
7ff43382 by Vladislav Zavialov at 2020-09-27T03:01:31+03:00
Comments: change outdated reference to mergeOps

As of 686e06c59c3aa6b66895e8a501c7afb019b09e36,
GHC.Parser.PostProcess.mergeOps no longer exists.

[ci skip]

- - - - -
4edf5527 by Vladislav Zavialov at 2020-09-27T10:04:12-04:00
Don't rearrange (->) in the renamer

The parser produces an AST where the (->)
is already associated correctly:

  1. (->) has the least possible precedence
  2. (->) is right-associative

Thus we don't need to handle it in mkHsOpTyRn.

- - - - -
a9ce159b by Vladislav Zavialov at 2020-09-27T10:04:12-04:00
Remove outdated comment in rnHsTyKi

This comment dates back to 3df40b7b78044206bbcffe3e2c0a57d901baf5e8
and does not seem relevant anymore.

- - - - -
583a2070 by Richard Eisenberg at 2020-09-29T00:31:27-04:00
Optimize NthCo (FunCo ...) in coercion opt

We were missing this case previously.

Close #18528.

Metric Decrease:
    T18223
    T5321Fun

- - - - -
b31a3360 by Krzysztof Gogolewski at 2020-09-29T00:32:05-04:00
Linear types: fix kind inference when checking datacons

- - - - -
5830a12c by Vladislav Zavialov at 2020-09-29T00:32:05-04:00
New linear types syntax: a %p -> b (#18459)

Implements GHC Proposal #356

Updates the haddock submodule.

- - - - -
bca4d36d by Vladislav Zavialov at 2020-09-29T00:32:05-04:00
Improve error messages for (a %m) without LinearTypes

Detect when the user forgets to enable the LinearTypes
extension and produce a better error message.

Steals the (a %m) syntax from TypeOperators, the workaround
is to write (a % m) instead.

- - - - -
b9635d0a by Benjamin Maurer at 2020-09-29T00:32:43-04:00
Description of flag `-H` was in 'verbosity options', moved to 'misc'.
Fixes #18699

- - - - -
74c797f6 by Benjamin Maurer at 2020-09-29T00:33:20-04:00
Workaround for #18623: GHC crashes bc. under rlimit for vmem it will reserve
_all_ of it, leaving nothing for, e.g., thread stacks.
Fix will only allocate 2/3rds and check whether remainder is at least large
enough for minimum amount of thread stacks.

- - - - -
4365d77a by Ryan Scott at 2020-09-29T00:33:57-04:00
Add regression test #18501

ghc/ghc!3220 ended up fixing #18501. This patch adds a regression
test for #18501 to ensure that it stays fixed.

- - - - -
8e3f00dd by Sylvain Henry at 2020-09-29T17:24:03+02:00
Make the parser module less dependent on DynFlags

Bump haddock submodule

- - - - -
3ab0d8f7 by Sebastian Graf at 2020-09-30T02:48:27-04:00
PmCheck: Long-distance information for LocalBinds (#18626)

Now `desugarLocalBind` (formerly `desugarLet`) reasons about

  * `FunBind`s that
    * Have no pattern matches (so which aren't functions)
    * Have a singleton match group with a single GRHS
    * (which may have guards)
  * and looks through trivial post-typechecking `AbsBinds` in doing so
    to pick up the introduced renamings.

And desugars to `PmLet` LYG-style guards. Since GRHSs are no longer
denoted simply by `NonEmpty PmGRHS`, but also need to carry a `[PmGrd]`
for the `PmLet`s from `LocalBind`s, I added `PmGRHSs` to capture that.

Since we call out to the desugarer more often, I found that there were
superfluous warnings emitted when desugaring e.g. case expressions.
Thus, I made sure that we deactivate any warnings in the LYG desugaring
steps by the new wrapper function `noCheckDs`.

There's a regression test in `T18626`. Fixes #18626.

- - - - -
f8f60efc by Ben Gamari at 2020-09-30T02:49:03-04:00
testsuite: Mark T12971 as broken on Windows

Due to #17945.

- - - - -
6527fc57 by Ben Gamari at 2020-09-30T02:49:03-04:00
Bump Cabal, hsc2hs, directory, process submodules

Necessary for recent Win32 bump.

- - - - -
df3f5880 by Sylvain Henry at 2020-09-30T02:49:41-04:00
Remove unsafeGlobalDynFlags (#17957, #14597)

There are still global variables but only 3 booleans instead of a single
DynFlags.

- - - - -
9befd94d by Sylvain Henry at 2020-09-30T02:49:41-04:00
Remove unused global variables

Some removed globals variables were still declared in the RTS.

They were removed in the following commits:

* 4fc6524a2a4a0003495a96c8b84783286f65c198
* 0dc7985663efa1739aafb480759e2e2e7fca2a36
* bbd3c399939311ec3e308721ab87ca6b9443f358

- - - - -
7c98699f by Richard Eisenberg at 2020-09-30T02:50:17-04:00
Omit redundant kind equality check in solver

See updated Note [Use loose types in inert set] in
GHC.Tc.Solver.Monad.

Close #18753.

- - - - -
39549826 by Sebastian Graf at 2020-09-30T02:50:54-04:00
Pmc: Don't call exprType on type arguments (#18767)

Fixes #18767.

- - - - -
235e410f by Richard Eisenberg at 2020-09-30T02:51:29-04:00
Regression test for #10709.

Close #10709

- - - - -
5c32655f by Ben Gamari at 2020-09-30T22:31:55-04:00
hadrian/doc: Clarify documentation of key-value configuration
- - - - -
0bb02873 by Sylvain Henry at 2020-10-01T18:34:53-04:00
Add test for T18574

- - - - -
e393f213 by Sylvain Henry at 2020-10-01T18:34:53-04:00
Allow fusion with catMaybes (#18574)

Metric Decrease:
   T18574

- - - - -
d2cfad96 by Fendor at 2020-10-01T18:35:33-04:00
Add mainModuleNameIs and demote mainModIs

Add `mainModuleNameIs` to DynFlags and demote
`mainModIs` to function which uses the homeUnit from DynFlags
it is created from.

- - - - -
fc351ab8 by Fendor at 2020-10-01T18:35:33-04:00
Use HomeUnit for main module without module declaration

- - - - -
dca1cb22 by Fendor at 2020-10-01T18:35:33-04:00
Remove mAIN completely

- - - - -
a5aaceec by Sylvain Henry at 2020-10-01T18:36:11-04:00
Use ADTs for parser errors/warnings

Haskell and Cmm parsers/lexers now report errors and warnings using ADTs
defined in GHC.Parser.Errors. They can be printed using functions in
GHC.Parser.Errors.Ppr.

Some of the errors provide hints with a separate ADT (e.g. to suggest to
turn on some extension). For now, however, hints are not consistent
across all messages. For example some errors contain the hints in the
main message. I didn't want to change any message with this patch. I
expect these changes to be discussed and implemented later.

Surprisingly, this patch enhances performance. On CI
(x86_64/deb9/hadrian, ghc/alloc):

   parsing001         -11.5%
   T13719             -2.7%
   MultiLayerModules  -3.5%
   Naperian           -3.1%

Bump haddock submodule

Metric Decrease:
    MultiLayerModules
    Naperian
    T13719
    parsing001

- - - - -
a946c7ef by Sylvain Henry at 2020-10-01T18:36:11-04:00
Less DynFlags in Header parsing

- - - - -
dafe7943 by Sylvain Henry at 2020-10-01T18:36:11-04:00
Parser: remove some unused imports

These are not reported by GHC because Happy adds {-# OPTIONS_GHC -w #-}

- - - - -
93d5de16 by Sylvain Henry at 2020-10-01T18:36:11-04:00
Don't import GHC.Unit to reduce the number of dependencies

- - - - -
e3655f81 by Sebastian Graf at 2020-10-01T18:36:47-04:00
Don't attach CPR signatures to NOINLINE data structures (#18154)

Because the generated `KindRep`s don't have an unfolding, !3230 did not
actually stop to compute, attach and serialise unnecessary CPR
signatures for them. As already said in
`Note [CPR for data structures]`, that leads to bloated interface
files which is ultimately quadratic for Nested CPR.

So we don't attach any CPR signature to bindings that

  * Are not thunks (because thunks are not in WHNF)
  * Have arity 0 (which means the top-level constructor is not a lambda)

If the data structure has an unfolding, we continue to look through it.
If not (as is the case for `KindRep`s), we look at the unchanged CPR
signature and see `topCprType`, as expected.

- - - - -
ba5965eb by Richard Eisenberg at 2020-10-01T18:37:23-04:00
Add regression test for #18755.

Close #18755

- - - - -
a8018c17 by Vladislav Zavialov at 2020-10-01T18:37:58-04:00
Fix pretty-printing of the mult-polymorphic arrow

A follow-up to !4020 (5830a12c46e7227c276a8a71213057595ee4fc04)

- - - - -
e5523324 by Sylvain Henry at 2020-10-01T18:38:35-04:00
Bignum: add integerNegate RULE

- - - - -
1edd6d21 by Vladislav Zavialov at 2020-10-01T18:39:10-04:00
Refactor: remove rnHsDoc

It did not do any useful work.

- - - - -
a9ae83af by Krzysztof Gogolewski at 2020-10-02T08:00:25-04:00
Fix typos in comments

[skip ci]

- - - - -
b81350bb by Icelandjack at 2020-10-02T08:01:01-04:00
Replaced MkT1 with T1 in type signatures.
- - - - -
3c9beab7 by Vladislav Zavialov at 2020-10-02T13:51:58-04:00
Minor TTG clean-up: comments, unused families, bottom

1. Fix and update section headers in GHC/Hs/Extension.hs
2. Delete the unused 'XCoreAnn' and 'XTickPragma' families
3. Avoid calls to 'panic' in 'pprStmt'

- - - - -
12c06927 by Sylvain Henry at 2020-10-02T13:52:38-04:00
Bignum: implement integerRecipMod (#18427)

- - - - -
8dd4f405 by Sylvain Henry at 2020-10-02T13:52:38-04:00
Bignum: implement integerPowMod (#18427)

Incidentally fix powModInteger which was crashing in integer-gmp for
negative exponents when the modular multiplicative inverse for the base
didn't exist. Now we compute it explicitly with integerRecipMod so that
every backend returns the same result without crashing.

- - - - -
1033a720 by Krzysztof Gogolewski at 2020-10-02T13:53:23-04:00
Reject linearity in kinds in checkValidType (#18780)

Patch taken from https://gitlab.haskell.org/ghc/ghc/-/issues/18624#note_300673

- - - - -
b0ccba66 by Krzysztof Gogolewski at 2020-10-03T19:33:02-04:00
Small documentation fixes

- Fix formatting of code blocks and a few sphinx warnings
- Move the Void# change to 9.2, it was done right after the branch was cut
- Fix typo in linear types documentation
- Note that -Wincomplete-uni-patterns affects lazy patterns

[skip ci]

- - - - -
70dc2f09 by Karel Gardas at 2020-10-03T19:33:06-04:00
fix rts.cabal to use real arch names and not aliasses (fixes #18654)

- - - - -
bc5de347 by Sebastian Graf at 2020-10-05T13:59:24-04:00
Inline `integerDecodeDouble#` and constant-fold `decodeDouble_Int64#` instead

Currently, `integerDecodeDouble#` is known-key so that it can be
recognised in constant folding. But that is very brittle and doesn't
survive worker/wrapper, which we even do for
`NOINLINE` things since #13143.
Also it is a trade-off: The implementation of `integerDecodeDouble#`
allocates an `Integer` box that never cancels aways if we don't inline
it.

Hence we recognise the `decodeDouble_Int64#` primop instead in constant
folding, so that we can inline `integerDecodeDouble#`. As a result,
`integerDecodeDouble#` no longer needs to be known-key.

While doing so, I realised that we don't constant-fold
`decodeFloat_Int#` either, so I also added a RULE for it.

`integerDecodeDouble` is dead, so I deleted it.

Part of #18092. This improves the 32-bit `realToFrac`/`toRational`:

Metric Decrease:
    T10359

- - - - -
802b5e6f by Krzysztof Gogolewski at 2020-10-05T13:59:33-04:00
Fix linear types in TH splices (#18465)

- - - - -
18a3ddf7 by Ben Gamari at 2020-10-05T13:59:33-04:00
rts: Fix integer width in TICK_BUMP_BY

Previously `TICK_BUMP_BY` was defined as

```c
 #define TICK_BUMP_BY(ctr,n) CLong[ctr] = CLong[ctr] + n
```

Yet the tickers themselves were defined as `StgInt`s. This happened to
work out correctly on Linux, where `CLong` is 64-bits. However, it
failed on Windows, where `CLong` is 32-bits, resulting in #18782.

Fixes #18783.

- - - - -
5fc4243b by Rachel at 2020-10-07T14:59:45-04:00
Document profiling flags, warning flags, and no-pie

- - - - -
b41f7c38 by Andreas Klebinger at 2020-10-07T15:00:20-04:00
WinIO: Small changes related to atomic request swaps.

Move the atomix exchange over the Ptr type to an internal module.

Fix a bug caused by us passing ptr-to-ptr instead of ptr to
atomic exchange.

Renamed interlockedExchange to exchangePtr.

I've also added an cas primitive. It turned out we don't need it
for WinIO but I'm leaving it in as it's useful for other things.

- - - - -
948a14e1 by Ben Gamari at 2020-10-07T15:00:55-04:00
gitlab-ci: Fix name of Ubuntu 20.04 image
- - - - -
74d4017b by Sylvain Henry at 2020-10-07T15:01:35-04:00
Fix -flink-rts (#18651)

Before this patch -flink-rts could link with GHC's rts instead of the
selected one.

- - - - -
0e8b923d by Sylvain Henry at 2020-10-07T15:01:35-04:00
Apply suggestion to compiler/GHC/SysTools.hs
- - - - -
d6dff830 by Alan Zimmerman at 2020-10-07T15:02:10-04:00
Preserve as-parsed arrow type for HsUnrestrictedArrow

When linear types are disabled, HsUnrestrictedArrow is treated as
HslinearArrow.

Move this adjustment into the type checking phase, so that the parsed
source accurately represents the source as parsed.

Closes #18791

- - - - -
030c5ce0 by Karel Gardas at 2020-10-07T15:02:48-04:00
hadrian: use stage0 linker to merge objects when done during the stage0

Fixes #18800.

- - - - -
a94db588 by Ben Gamari at 2020-10-07T15:03:23-04:00
testsuite: Allow whitespace before "Metric (in|de)crease"

Several people have struggled with metric change annotations
in their commit messages not being recognized due to the fact that
GitLab's job log inserts a space at the beginning of each line. Teach
the regular expression to accept this whitespace.

- - - - -
e91ddddd by Krzysztof Gogolewski at 2020-10-07T15:04:07-04:00
Misc cleanup

* Include funTyCon in exposedPrimTyCons.
  Every single place using exposedPrimTyCons was adding funTyCon
  manually.
* Remove unused synTyConResKind and ieLWrappedName
* Add recordSelectorTyCon_maybe
* In exprType, panic instead of giving a trace message and dummy output.
  This prevents #18767 reoccurring.
* Fix compilation error in fragile concprog001 test (part of #18732)

- - - - -
386c2d7f by Sylvain Henry at 2020-10-09T08:40:33-04:00
Use UnitId in the backend instead of Unit

In Cmm we can only have real units identified with an UnitId.  Other
units (on-the-fly instantiated units and holes) are only used in
type-checking backpack sessions that don't produce Cmm.

- - - - -
a566c83d by Simon Jakobi at 2020-10-09T08:41:09-04:00
Update containers to v0.6.4.1

Updates containers submodule.

- - - - -
fd984d68 by Tamar Christina at 2020-10-09T08:41:50-04:00
rts: fix race condition in StgCRun

On windows the stack has to be allocated 4k at a time, otherwise we get
a segfault. This is done by using a helper ___chkstk_ms that is provided
by libgcc. The Haskell side already knows how to handle this but we need
to do the same from STG. Previously we would drop the stack in StgRun
but would only make it valid whenever the scheduler loop ran.

This approach was fundamentally broken in that it falls apart when you
take a signal from the OS. We see it less often because you initially
get allocated a 1MB stack block which you have to blow past first.

Concretely this means we must always keep the stack valid.

Fixes #18601.

- - - - -
accdb24a by Sylvain Henry at 2020-10-09T08:42:31-04:00
Expose RTS-only ways (#18651)

Some RTS ways are exposed via settings (ghcThreaded, ghcDebugged) but
not all. It's simpler if the RTS exposes them all itself.

- - - - -
d360f343 by MaxGabriel at 2020-10-09T08:43:11-04:00
Document -Wderiving-typeable

Tracking: #18641

- - - - -
e48cab2a by Krzysztof Gogolewski at 2020-10-09T08:43:49-04:00
Add a flag to indicate that gcc supports -no-pie

Fixes #17919.

- - - - -
f7e2fff9 by Hécate at 2020-10-09T08:44:26-04:00
Add linting of `base` to the CI

- - - - -
45a1d493 by Andreas Klebinger at 2020-10-09T08:45:05-04:00
Use proper RTS flags when collecting residency in perf tests.

Replace options like collect_stats(['peak_megabytes_allocated'],4) with
collect_runtime_residency(4) and so forth. Reason being that the later
also supplies some default RTS arguments which make sure residency does
not fluctuate too much.

The new flags mean we get new (hopefully more accurate) baselines so
accept the stat changes.

-------------------------
Metric Decrease:
     T4029
     T4334
     T7850
Metric Increase:
     T13218
     T7436
-------------------------

- - - - -
ef65b154 by Andreas Klebinger at 2020-10-09T08:45:42-04:00
testsuite/timeout: Fix windows specific errors.

We now seem to use -Werror there. Which caused some long standing
warnings to become errors.

I applied changes to remove the warnings allowing the testsuite to
run on windows as well.

- - - - -
e691a5a0 by Sylvain Henry at 2020-10-09T08:46:22-04:00
Hadrian: add quick-debug flavour

- - - - -
12191a99 by Sylvain Henry at 2020-10-09T08:47:00-04:00
Bignum: match on small Integer/Natural

Previously we only matched on *variables* whose unfoldings were a ConApp
of the form `IS lit#` or `NS lit##`. But we forgot to match on the
ConApp directly... As a consequence, constant folding only worked after
the FloatOut pass which creates bindings for most sub-expressions. With
this patch, matching on bignums works even with -O0 (see bignumMatch
test).

- - - - -
36787bba by Alan Zimmerman at 2020-10-09T08:47:36-04:00
ApiAnnotations : preserve parens in GADTs

A cleanup in 7f418acf61e accidentally discarded some parens in
ConDeclGADT.

Make sure these stay in the AST in a usable format.

Also ensure the AnnLolly does not get lost in a GADT.

- - - - -
32dc7698 by Krzysztof Gogolewski at 2020-10-09T08:48:15-04:00
Linear types: fix roles in GADTs (#18799)

- - - - -
9657f6f3 by Ben Gamari at 2020-10-09T08:48:52-04:00
sdist: Include hadrian sources in source distribution

Previously the make build system's source distribution rules neglected
to include Hadrian's sources.

Fixes #18794.

- - - - -
c832f7e2 by Tamar Christina at 2020-10-09T08:49:33-04:00
winio: fixed timeouts non-threaded.

- - - - -
6f0243ae by Tamar Christina at 2020-10-09T08:50:13-04:00
winio: fix array splat

- - - - -
0fd3d360 by Tamar Christina at 2020-10-09T08:50:51-04:00
winio: fixed bytestring reading interface.

- - - - -
dfaef1ca by Tamar Christina at 2020-10-09T08:51:30-04:00
winio: fixed more data error.

- - - - -
bfdccac6 by Simon Peyton Jones at 2020-10-09T08:52:07-04:00
Fix desugaring of record updates on data families

This fixes a long-standing bug in the desugaring of record
updates for data families, when the latter involves a GADT. It's
all explained in Note [Update for GADTs] in GHC.HsToCore.Expr.

Building the correct cast is surprisingly tricky, as that Note
explains.

Fixes #18809.  The test case (in indexed-types/should_compile/T18809)
contains several examples that exercise the dark corners.

- - - - -
e5c7c9c8 by Ben Gamari at 2020-10-09T08:52:43-04:00
Bump win32-tarballs version to 0.3

This should fix #18774.

- - - - -
ef950b19 by Andreas Klebinger at 2020-10-09T08:53:21-04:00
Add TyCon Set/Env and use them in a few places.

Firstly this improves code clarity.

But it also has performance benefits as we no longer
go through the name of the TyCon to get at it's unique.

In order to make this work the recursion check for TyCon
has been moved into it's own module in order to avoid import
cycles.

- - - - -
fd302e93 by Krzysztof Gogolewski at 2020-10-09T08:54:02-04:00
Add -pgmlm and -optlm flags

!3798 added documentation and semantics for the flags,
but not parsing.

- - - - -
db236ffc by Sylvain Henry at 2020-10-09T08:54:41-04:00
Testsuite: increase timeout for T18223 (#18795)

- - - - -
6a243e9d by Sylvain Henry at 2020-10-09T08:55:21-04:00
Cache HomeUnit in HscEnv (#17957)

Instead of recreating the HomeUnit from the DynFlags every time we need
it, we store it in the HscEnv.

- - - - -
5884fd32 by Fendor at 2020-10-09T19:46:28+02:00
Move File Target parser to library #18596

- - - - -
ea59fd4d by Hécate at 2020-10-10T14:49:59-04:00
Lint the compiler for extraneous LANGUAGE pragmas

- - - - -
22f218b7 by Krzysztof Gogolewski at 2020-10-10T14:50:42-04:00
Linear types: fix quantification in GADTs (#18790)

- - - - -
74ee1237 by Sylvain Henry at 2020-10-10T14:51:20-04:00
Bignum: fix bigNatCompareWord# bug (#18813)

- - - - -
274e21f0 by Hécate at 2020-10-11T10:55:56+02:00
Remove the dependency on the ghc-linters stage

- - - - -
990ea991 by Daniel Rogozin at 2020-10-11T22:20:04+03:00
Fall back to types when looking up data constructors (#18740)

Before this patch, referring to a data constructor in a term-level
context led to a scoping error:

    ghci> id Int
    <interactive>:1:4: error: Data constructor not in scope: Int

After this patch, the renamer falls back to the type namespace
and successfully finds the Int. It is then rejected in the type
checker with a more useful error message:

    <interactive>:1:4: error:
    • Illegal term-level use of the type constructor ‘Int’
        imported from ‘Prelude’ (and originally defined in ‘GHC.Types’)
    • In the first argument of ‘id’, namely ‘Int’
      In the expression: id Int

We also do this for type variables.

- - - - -
9bbc84d2 by Sylvain Henry at 2020-10-12T18:21:51-04:00
DynFlags: refactor DmdAnal

Make demand analysis usable without having to provide DynFlags.

- - - - -
7fdcce6d by Wander Hillen at 2020-10-13T00:12:47-04:00
Initial ShortText code and conversion of package db code

Metric Decrease:
    Naperian
    T10421
    T10421a
    T10547
    T12150
    T12234
    T12425
    T13035
    T18140
    T18304
    T5837
    T6048
    T13253-spj
    T18282
    T18223
    T3064
    T9961
Metric Increase
    T13701

HFSKJH

- - - - -
0a5f2918 by Sylvain Henry at 2020-10-13T00:13:28-04:00
Parser: don't require the HomeUnitId

The HomeUnitId is only used by the Cmm parser and this one has access to
the DynFlags, so it can grab the UnitId of the HomeUnit from them.

Bump haddock submodule

- - - - -
8f4f5794 by HaskellMouse at 2020-10-13T13:05:49+03:00
Unification of Nat and Naturals

This commit removes the separate kind 'Nat' and enables promotion
of type 'Natural' for using as type literal.
It partially solves #10776

Now the following code will be successfully typechecked:
    data C = MkC Natural
    type CC = MkC 1

Before this change we had to create the separate type for promotion
    data C = MkC Natural
    data CP = MkCP Nat
    type CC = MkCP 1

But CP is uninhabited in terms.

For backward compatibility type synonym `Nat` has been made:
    type Nat = Natural

The user's documentation and tests have been updated.
The haddock submodule also have been updated.

- - - - -
0fc1cb54 by Ben Gamari at 2020-10-14T03:42:50-04:00
gitlab-ci: Verify that Hadrian builds with Stack

As noted in #18726, this regularly breaks. Let's test it.

Note that we don't actually perform a build of GHC itself; we merely
test that the Hadrian executable builds and works (by invoking `hadrian
--version`).

- - - - -
89f4d8e9 by Ben Gamari at 2020-10-14T12:03:57-04:00
Bump LLVM version to 10.0

Fixes #18267.

- - - - -
716385c9 by Ryan Scott at 2020-10-14T12:04:34-04:00
Make DataKinds the sole arbiter of kind-level literals (and friends)

Previously, the use of kind-level literals, promoted tuples,
and promoted lists required enabling both `DataKinds` and
`PolyKinds`. This made sense back in a `TypeInType` world, but not so
much now that `TypeInType`'s role has been superseded. Nowadays,
`PolyKinds` only controls kind polymorphism, so let's make `DataKinds`
the thing that controls the other aspects of `TypeInType`, which include
literals, promoted tuples and promoted lists.

There are some other things that overzealously required `PolyKinds`,
which this patch fixes as well:

* Previously, using constraints in kinds (e.g., `data T :: () -> Type`)
  required `PolyKinds`, despite the fact that this is orthogonal to kind
  polymorphism. This now requires `DataKinds` instead.
* Previously, using kind annotations in kinds
  (e.g., `data T :: (Type :: Type) -> Type`) required both `KindSignatures`
  and `PolyKinds`. This doesn't make much sense, so it only requires
  `KindSignatures` now.

Fixes #18831.

- - - - -
ac300a0d by Vladislav Zavialov at 2020-10-14T12:05:11-04:00
Remove "Operator sections" from docs/users_guide/bugs.rst

The issue described in that section was fixed by
2b89ca5b850b4097447cc4908cbb0631011ce979

- - - - -
bf2411a3 by Vladislav Zavialov at 2020-10-14T12:05:11-04:00
Fix PostfixOperators (#18151)

This fixes a regression introduced in 2b89ca5b850b4097447cc4908cbb0631011ce979
See the new T18151x test case.

- - - - -
e60ae8a3 by Fumiaki Kinoshita at 2020-10-14T18:06:12-04:00
Add -Wnoncanonical-{monad,monoid}-instances to standardWarnings

-------------------------
Metric Decrease:
   T12425
Metric Increase:
   T17516
-------------------------

- - - - -
15d2340c by Simon Peyton Jones at 2020-10-14T18:06:48-04:00
Fix some missed opportunities for preInlineUnconditionally

There are two signficant changes here:

* Ticket #18815 showed that we were missing some opportunities for
  preInlineUnconditionally.  The one-line fix is in the code for
  GHC.Core.Opt.Simplify.Utils.preInlineUnconditionally, which now
  switches off only for INLINE pragmas.  I expanded
  Note [Stable unfoldings and preInlineUnconditionally] to explain.

* When doing this I discovered a way in which preInlineUnconditionally
  was occasionally /too/ eager.  It's all explained in
  Note [Occurrences in stable unfoldings] in GHC.Core.Opt.OccurAnal,
  and the one-line change adding markAllMany to occAnalUnfolding.

I also got confused about what NoUserInline meant, so I've renamed
it to NoUserInlinePrag, and changed its pretty-printing slightly.
That led to soem error messate wibbling, and touches quite a few
files, but there is no change in functionality.

I did a nofib run.  As expected, no significant changes.

        Program           Size    Allocs
----------------------------------------
         sphere          -0.0%     -0.4%
----------------------------------------
            Min          -0.0%     -0.4%
            Max          -0.0%     +0.0%
 Geometric Mean          -0.0%     -0.0%

I'm allowing a max-residency increase for T10370, which seems
very irreproducible. (See comments on !4241.)  There is always
sampling error for max-residency measurements; and in any case
the change shows up on some platforms but not others.

Metric Increase:
    T10370

- - - - -
0c4bfed8 by Ben Gamari at 2020-10-14T18:07:25-04:00
users-guide: Add missing :ghc-flag: directive
- - - - -
51c4b851 by Krzysztof Gogolewski at 2020-10-15T04:30:27-04:00
Remove Proxy# argument in Data.Typeable.Internal

No longer neccessary - TypeRep is now indexed, there is no ambiguity.

Also fix a comment in Evidence.hs, IsLabel no longer takes a Proxy#.

- - - - -
809f09e8 by Sylvain Henry at 2020-10-15T04:31:07-04:00
Fix parsing of PIE flags

-fPIE and -fno-PIE flags were (un)setting Opt_PIC instead of Opt_PIE.

Original commit: 3625728a0e3a9b56c2b85ae7ea8bcabdd83ece6a

- - - - -
3d7db148 by Ben Gamari at 2020-10-15T04:31:42-04:00
testsuite: Add missing #include on <stdlib.h>

This otherwise fails on newer Clangs, which warn
more aggressively on undeclared symbols.
- - - - -
998803dc by Andrzej Rybczak at 2020-10-15T11:40:32+02:00
Add flags for annotating Generic{,1} methods INLINE[1] (#11068)

Makes it possible for GHC to optimize away intermediate Generic representation
for more types.

Metric Increase:
    T12227

- - - - -
6b14c418 by GHC GitLab CI at 2020-10-15T21:57:50-04:00
Extend mAX_TUPLE_SIZE to 64

As well a ctuples and sums.

- - - - -
d495f36a by Ben Gamari at 2020-10-15T21:58:27-04:00
rts: Clean-up whitespace in Interpreter

- - - - -
cf10becd by Ben Gamari at 2020-10-15T21:58:27-04:00
compiler/ByteCode: Use strict Maps in bytecode assembler

- - - - -
ae146b53 by Ben Gamari at 2020-10-15T21:58:27-04:00
compiler/ByteCode: Make LocalLabel a newtype

- - - - -
cc536288 by Ben Gamari at 2020-10-15T21:58:27-04:00
compiler/ByteCode: Allow 2^32 local labels

This widens LocalLabel to 2^16, avoiding the crash observed in #14334.

Closes #14334.

- - - - -
1bb0512f by Ben Gamari at 2020-10-16T00:15:31-04:00
mingw: Extract zst toolchain archives

This should have been done when the toolchain was bumped.

- - - - -
bf7c5b6d by Ben Gamari at 2020-10-16T00:15:31-04:00
base: Reintroduce necessary LANGUAGE pragmas

These were incorrectly removed in a recent cleanup commit.

- - - - -
c6b4be4b by Ben Gamari at 2020-10-16T00:15:31-04:00
testsuite: Sort metrics by metric type

Closes #18838.

- - - - -
c7989c93 by Ben Gamari at 2020-10-16T00:15:31-04:00
testsuite: Account for -Wnoncanonical-monoid-instances changes on Windows

- - - - -
330a5433 by Ben Gamari at 2020-10-16T00:15:31-04:00
rts: Add __mingw_vfprintf to RtsSymbols.c

Following the model of the other printf symbols. See Note [Symbols for
MinGW's printf].

- - - - -
c4a69f37 by Ben Gamari at 2020-10-16T00:15:31-04:00
gitlab-ci: Remove allow_failure from Windows jobs

- - - - -
9a9679db by Ben Gamari at 2020-10-16T00:15:31-04:00
gitlab-ci: Fix Hadrian bindist names

- - - - -
07b0db86 by f-a at 2020-10-16T10:14:39-04:00
Clarify Eq documentation #18713
- - - - -
aca0e63b by Ben Gamari at 2020-10-17T10:20:31-04:00
gitlab-ci: Allow doc-tarball job to fail

Currently the Hadrian build appears not to package documentation correctly,
causing doc-tarball to fail due to the Windows build.
- - - - -
b02a9ea7 by Ben Gamari at 2020-10-17T13:26:24-04:00
gitlab-ci: s/allow_newer/allow_failure

Silly mistake on my part.
- - - - -
59d7c9f4 by John Ericson at 2020-10-17T22:01:38-04:00
Skip type family defaults with hs-boot and hsig files

Works around #17190, possible resolution for #17224. New design is is
according to accepted [GHC Propoal 320].

Instances in signatures currently unconditionally opt into associated
family defaults if no explicit instance is given. This is bad for two
reasons:

  1. It constrains possible instantiations to use the default, rather
  than possibly define the associated family differently.

  2. It breaks compilation as type families are unsupported in
  signatures.

This PR simply turns off the filling in of defaults in those cases.
Additionally, it squelches a missing definition warning for hs-boot too
that was only squelched for hsig before.

The downsides are:

  1. There is no way to opt into the default, other than copying its
  definition.

  2. If we fixed type classes in signatures, and wanted instances to
  have to explicitly *out of* rather than into the default, that would
  now be a breaking change.

The change that is most unambiguously goood is harmonizing the warning
squelching between hs-boot or hsig. Maybe they should have the warning
(opt out of default) maybe they shouldn't (opt in to default), but
surely it should be the same for both.

Add hs-boot version of a backpack test regarding class-specified
defaults in instances that appear in an hs-boot file.

The metrics increase is very slight and makes no sense --- at least no
one has figured anything out after this languishing for a while, so I'm
just going to accept it.

Metric Increase:
  T10421a

[GHC proposal 320]: https://github.com/ghc-proposals/ghc-proposals/pull/320

- - - - -
7eb46a09 by Sebastian Graf at 2020-10-17T22:02:13-04:00
Arity: Refactor fixed-point iteration in GHC.Core.Opt.Arity

Arity analysis used to propagate optimistic arity types during
fixed-point interation through the `ArityEnv`'s `ae_cheap_fun` field,
which is like `GHC.Core.Utils.exprIsCheap`, but also considers the
current iteration's optimistic arity, for the binder in question only.

In #18793, we have seen that this is a problematic design, because it
doesn't allow us to look through PAP bindings of that binder.

Hence this patch refactors to a more traditional form with an explicit
signature environment, in which we record the optimistic `ArityType` of
the binder in question (and at the moment is the *only* binder that is
recorded in the arity environment).

- - - - -
6b3eb06a by Sebastian Graf at 2020-10-17T22:02:13-04:00
Arity: Record arity types for non-recursive lets

In #18793, we saw a compelling example which requires us to look at
non-recursive let-bindings during arity analysis and unleash their arity
types at use sites.

After the refactoring in the previous patch, the needed change is quite
simple and very local to `arityType`'s defn for non-recurisve `Let`.

Apart from that, we had to get rid of the second item of
`Note [Dealing with bottoms]`, which was entirely a safety measure and
hindered optimistic fixed-point iteration.

Fixes #18793.

The following metric increases are all caused by this commit and a
result of the fact that we just do more work now:

Metric Increase:
    T3294
    T12545
    T12707

- - - - -
451455fd by Sebastian Graf at 2020-10-17T22:02:13-04:00
Testsuite: Add dead arity analysis tests

We didn't seem to test these old tests at all, judging from their
expected output.

- - - - -
50e9df49 by Dylan Yudaken at 2020-10-17T22:02:50-04:00
When using rts_setInCallCapability, lock incall threads

This diff makes sure that incall threads, when using `rts_setInCallCapability`, will be created as locked.
If the thread is not locked, the thread might end up being scheduled to a different capability.
While this is mentioned in the docs for `rts_setInCallCapability,`, it makes the method significantly less useful as there is no guarantees on the capability being used.

This commit also adds a test to make sure things stay on the correct capability.

- - - - -
0b995759 by DylanZA at 2020-10-17T22:02:50-04:00
Apply suggestion to testsuite/tests/ffi/should_run/all.T
- - - - -
a91dcb66 by Sylvain Henry at 2020-10-17T22:04:02-04:00
Don't get host RTS ways via settings (#18651)

To correctly perform a linking hack for Windows we need to link with the
RTS GHC is currently using. We used to query the RTS ways via the
"settings" file but it is fragile (#18651). The hack hasn't been fixed
to take into account all the ways (Tracing) and it makes linking of GHC
with another RTS more difficult (we need to link with another RTS and to
regenerate the settings file).

So this patch uses the ways reported by the RTS itself
(GHC.Platform.Ways.hostWays) instead of the "settings" file.

- - - - -
d858a3ae by Hécate at 2020-10-17T22:04:38-04:00
Linting corrections

* Bring back LANGUAGE pragmas in GHC.IO.Handle.Lock.Windows
* Exclude some modules that are wrongfully reported

- - - - -
b5b3e34e by Vladislav Zavialov at 2020-10-19T18:16:20-04:00
Implement -Woperator-whitespace (#18834)

This patch implements two related warnings:

  -Woperator-whitespace-ext-conflict
      warns on uses of infix operators that would be parsed
      differently were a particular GHC extension enabled

  -Woperator-whitespace
      warns on prefix, suffix, and tight infix uses of infix
      operators

Updates submodules: haddock, containers.

- - - - -
9648d680 by Sylvain Henry at 2020-10-19T18:16:58-04:00
Remove pdocPrec

pdocPrec was only used in GHC.Cmm.DebugBlock.pprUnwindExpr, so remove
it. OutputableP becomes a one-function class which might be better for
performance.

- - - - -
ee5dcdf9 by Ben Gamari at 2020-10-20T00:47:54-04:00
testsuite: Add test for #18346

This was fixed by 4291bddaea3148908c55f235ee8978e1d9aa6f20.

- - - - -
6c7a5c0c by Krzysztof Gogolewski at 2020-10-20T00:48:29-04:00
Minor comments, update linear types docs

- Update comments: placeHolderTypeTc no longer exists
  "another level check problem" was a temporary comment from linear types
- Use Mult type synonym (reported in #18676)
- Mention multiplicity-polymorphic fields in linear types docs

- - - - -
58a1ca38 by nineonine at 2020-10-20T00:49:07-04:00
Compile modules with `-fobject-code` enabled to byte-code when loaded with `*` prefix in ghci (#8042)

The documentation states that when using :add and :load, the `*` prefix forces a module
to be loaded as byte-code. However, this seems to be ignored when -fobject-code has been
enabled. In that case, the compiled code is always used, regardless of whether the *-form
is used.

The idea is to consult the Targets in HscEnv and check the 'targetAllowObjCode' flag. If
the flag for given module is set, then patch up DynFlags and select compilation backend
accordingly.

This would require a linear scan of course, but that shouldn't be too costly.

- - - - -
59b08a5d by Ben Gamari at 2020-10-20T00:49:41-04:00
gitlab-ci: Rename FLAVOUR -> BUILD_FLAVOUR

Previously the Hadrian jobs used the `FLAVOUR` environment variable to
communicate which flavour `ci.sh` should build whereas `make` used
`BUILD_FLAVOUR`. This caused unnecessary confusion. Consolidate these
two.

- - - - -
ea736839 by Alan Zimmerman at 2020-10-20T08:35:34+01:00
API Annotations: Keep track of unicode for linear arrow notation

The linear arrow can be parsed as `%1 ->` or a direct single token unicode
equivalent.

Make sure that this distinction is captured in the parsed AST by using
IsUnicodeSyntax where it appears, and introduce a new API Annotation,
AnnMult to represent its location when unicode is not used.

Updated haddock submodule

- - - - -
cf3c3bcd by Ben Gamari at 2020-10-20T22:56:31-04:00
testsuite: Mark T12971 as fragile on Windows

Due to #17945.

- - - - -
e2c4a947 by Vladislav Zavialov at 2020-10-21T16:00:30+03:00
Parser regression tests, close #12862 #12446

These issues were fixed by earlier parser changes, most likely related
to whitespace-sensitive parsing.

- - - - -
711929e6 by Simon Peyton Jones at 2020-10-23T02:42:59-04:00
Fix error message location in tcCheckPatSynDecl

Ticket #18856 showed that we were failing to set the right location
for an error message.  Easy to fix, happily.

Turns out that this also improves the error location in test T11010,
which was bogus before but we had never noticed.

- - - - -
730bb590 by Ben Gamari at 2020-10-23T02:43:33-04:00
cmm: Add Note reference to ForeignHint
- - - - -
b9d4dd9c by Ben Gamari at 2020-10-24T20:44:17-04:00
SMP.h: Add C11-style atomic operations

- - - - -
ccf2d4b0 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts: Infrastructure for testing with ThreadSanitizer

- - - - -
a61f66d6 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/CNF: Initialize all bdescrs in group

It seems wise and cheap to ensure that the whole bdescr of all blocks of
a compact group is valid, even if most cases only look at the flags
field.

- - - - -
65136c13 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/Capability: Intialize interrupt field

Previously this was left uninitialized.

Also clarify some comments.

- - - - -
b3ce6aca by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/Task: Make comments proper Notes

- - - - -
d3890ac7 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/SpinLock: Move to proper atomics

This is fairly straightforward; we just needed to use relaxed operations
for the PROF_SPIN counters and a release store instead of a write
barrier.

- - - - -
ef88712f by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/OSThreads: Fix data race

Previously we would race on the cached processor count. Avoiding this is
straightforward; just use relaxed operations.

- - - - -
33a719c3 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts/ClosureMaros: Use relaxed atomics

- - - - -
f08951fd by Ben Gamari at 2020-10-24T20:59:39-04:00
configure: Bump minimum-supported gcc version to 4.7

Since the __atomic_* builtins are not supported until gcc 4.7. Given
that this version was released in 2012 I think this is acceptable.

- - - - -
d584923a by Ben Gamari at 2020-10-24T20:59:39-04:00
testsuite: Fix thread leak in hs_try_putmvar00[13]

- - - - -
bf1b0bc7 by Ben Gamari at 2020-10-24T20:59:39-04:00
rts: Introduce SET_HDR_RELEASE

Also ensure that we also store the info table pointer last to ensure
that the synchronization covers all stores.

- - - - -
1a2e9f5e by Ben Gamari at 2020-10-24T21:00:19-04:00
gitlab-ci: Add nightly-x86_64-linux-deb9-tsan job

- - - - -
58a5b0e5 by GHC GitLab CI at 2020-10-24T21:00:19-04:00
testsuite: Mark setnumcapabilities001 as broken with TSAN

Due to #18808.

- - - - -
d9bc7dea by GHC GitLab CI at 2020-10-24T21:00:19-04:00
testsuite: Skip divbyzero and derefnull under TSAN

ThreadSanitizer changes the output of these tests.

- - - - -
fcc42a10 by Ben Gamari at 2020-10-24T21:00:19-04:00
testsuite: Skip high memory usage tests with TSAN

ThreadSanitizer significantly increases the memory footprint of tests,
so much so that it can send machines into OOM.

- - - - -
cae4bb3e by Ben Gamari at 2020-10-24T21:00:19-04:00
testsuite: Mark hie002 as high_memory_usage

This test has a peak residency of 1GByte; this is large enough to
classify as "high" in my book.

- - - - -
dae1b86a by Ben Gamari at 2020-10-24T21:00:19-04:00
testsuite: Mark T9872[abc] as high_memory_usage

These all have a maximum residency of over 2 GB.

- - - - -
c5a0bb22 by Ben Gamari at 2020-10-24T21:00:19-04:00
gitlab-ci: Disable documentation in TSAN build

Haddock chews through enough memory to cause the CI builders to OOM and
there's frankly no reason to build documentation in this job anyways.

- - - - -
4cb1232e by Ben Gamari at 2020-10-24T21:00:19-04:00
TSANUtils: Ensure that C11 atomics are supported

- - - - -
7ed15f7f by Ben Gamari at 2020-10-24T21:00:19-04:00
testsuite: Mark T3807 as broken with TSAN

Due to #18883.

- - - - -
f7e6f012 by Ben Gamari at 2020-10-24T21:00:19-04:00
testsuite: Mark T13702 as broken with TSAN due to #18884

- - - - -
16b136b0 by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Factor out logic to identify a good capability for running a task

Not only does this make the control flow a bit clearer but it also
allows us to add a TSAN suppression on this logic, which requires
(harmless) data races.

- - - - -
2781d68c by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Annotate benign race in waitForCapability

- - - - -
f6b4b492 by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Clarify locking behavior of releaseCapability_

- - - - -
65219810 by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Add assertions for task ownership of capabilities

- - - - -
31fa87ec by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Use relaxed atomics on n_returning_tasks

This mitigates the warning of a benign race on n_returning_tasks in
shouldYieldCapability.

See #17261.

- - - - -
6517a2ea by Ben Gamari at 2020-10-24T21:00:36-04:00
rts: Mitigate races in capability interruption logic

- - - - -
2e9ba3f2 by Ben Gamari at 2020-10-24T21:00:36-04:00
rts/Capability: Use relaxed operations for last_free_capability

- - - - -
e10dde37 by Ben Gamari at 2020-10-24T21:00:37-04:00
rts: Use relaxed operations for cap->running_task (TODO)

This shouldn't be necessary since only the owning thread of the capability
should be touching this.

- - - - -
855325cd by Ben Gamari at 2020-10-24T21:00:37-04:00
rts/Schedule: Use relaxed operations for sched_state

- - - - -
811f915d by Ben Gamari at 2020-10-24T21:00:37-04:00
rts: Accept data race in work-stealing implementation

This race is okay since the task is owned by the capability pushing it.
By Note [Ownership of Task] this means that the capability is free to
write to `task->cap` without taking `task->lock`.

Fixes #17276.

- - - - -
8d2b3c3d by Ben Gamari at 2020-10-24T21:00:37-04:00
rts: Eliminate data races on pending_sync

- - - - -
f8871018 by Ben Gamari at 2020-10-24T21:00:37-04:00
rts/Schedule: Eliminate data races on recent_activity

We cannot safely use relaxed atomics here.

- - - - -
d079b943 by Ben Gamari at 2020-10-24T21:00:37-04:00
rts: Avoid data races in message handling

- - - - -
06f80497 by Ben Gamari at 2020-10-24T21:00:37-04:00
rts/Messages: Drop incredibly fishy write barrier

executeMessage previously had a write barrier at the beginning of its
loop apparently in an attempt to synchronize with another thread's
writes to the Message. I would guess that the author had intended to use
a load barrier here given that there are no globally-visible writes done
in executeMessage.

I've removed the redundant barrier since the necessary load barrier is
now provided by the ACQUIRE_LOAD.

- - - - -
d4a87779 by Ben Gamari at 2020-10-24T21:00:38-04:00
rts/ThreadPaused: Avoid data races

- - - - -
56778ab3 by Ben Gamari at 2020-10-24T21:00:38-04:00
rts/Schedule: Eliminate data races in run queue management

- - - - -
086521f7 by Ben Gamari at 2020-10-24T21:00:38-04:00
rts: Eliminate shutdown data race on task counters

- - - - -
abad9778 by Ben Gamari at 2020-10-24T21:00:38-04:00
rts/Threads: Avoid data races (TODO)

Replace barriers with appropriate ordering. Drop redundant barrier in
tryWakeupThread (the RELEASE barrier will be provided by sendMessage's
mutex release).

We use relaxed operations on why_blocked and the stack although it's not
clear to me why this is necessary.

- - - - -
2f56be8a by Ben Gamari at 2020-10-24T21:00:39-04:00
rts/Messages: Annotate benign race

- - - - -
7c0cdab1 by Ben Gamari at 2020-10-24T21:00:39-04:00
rts/RaiseAsync: Synchronize what_next read

- - - - -
6cc2a8a5 by Ben Gamari at 2020-10-24T21:00:39-04:00
rts/Task: Move debugTrace to avoid data race

Specifically, we need to hold all_tasks_mutex to read taskCount.

- - - - -
bbaec97d by Ben Gamari at 2020-10-24T21:00:39-04:00
Disable flawed assertion

- - - - -
dd175a92 by Ben Gamari at 2020-10-24T21:00:39-04:00
Document schedulePushWork race

- - - - -
3416244b by Ben Gamari at 2020-10-24T21:00:40-04:00
Capabiliity: Properly fix data race on n_returning_tasks

There is a real data race but can be made safe by using proper atomic
(but relaxed) accesses.

- - - - -
dffd9432 by Ben Gamari at 2020-10-24T21:00:40-04:00
rts: Make write of to_cap->inbox atomic

This is necessary since emptyInbox may read from to_cap->inbox without
taking cap->lock.

- - - - -
1f4cbc29 by Ben Gamari at 2020-10-24T21:00:57-04:00
rts/BlockAlloc: Use relaxed operations

- - - - -
d0d07cff by Ben Gamari at 2020-10-24T21:00:57-04:00
rts: Rework handling of mutlist scavenging statistics

- - - - -
9e5c7f6d by Ben Gamari at 2020-10-24T21:00:57-04:00
rts: Avoid data races in StablePtr implementation

This fixes two potentially problematic data races in the StablePtr
implementation:

 * We would fail to RELEASE the stable pointer table when enlarging it,
   causing other cores to potentially see uninitialized memory.

 * We would fail to ACQUIRE when dereferencing a stable pointer.

- - - - -
316add67 by Ben Gamari at 2020-10-24T21:00:57-04:00
rts/Storage: Use atomics

- - - - -
5c23bc4c by Ben Gamari at 2020-10-24T21:00:58-04:00
rts/Updates: Use proper atomic operations

- - - - -
3d0f033c by Ben Gamari at 2020-10-24T21:00:58-04:00
rts/Weak: Eliminate data races

By taking all_tasks_mutex in stat_exit. Also better-document the fact
that the task statistics are protected by all_tasks_mutex.

- - - - -
edb4b92b by Ben Gamari at 2020-10-24T21:01:18-04:00
rts/WSDeque: Rewrite with proper atomics

After a few attempts at shoring up the previous implementation, I ended
up turning to the literature and now use the proven implementation,

> N.M. Lê, A. Pop, A.Cohen, and F.Z. Nardelli. "Correct and Efficient
> Work-Stealing for Weak Memory Models". PPoPP'13, February 2013,
> ACM 978-1-4503-1922/13/02.

Note only is this approach formally proven correct under C11 semantics
but it is also proved to be a bit faster in practice.

- - - - -
d39bbd3d by Ben Gamari at 2020-10-24T21:01:33-04:00
rts: Use relaxed atomics for whitehole spin stats

- - - - -
8f802f38 by Ben Gamari at 2020-10-24T21:01:33-04:00
rts: Avoid lock order inversion during fork

Fixes #17275.

- - - - -
cef667b0 by GHC GitLab CI at 2020-10-24T21:01:34-04:00
rts: Use proper relaxe operations in getCurrentThreadCPUTime

Here we are doing lazy initialization; it's okay if we do the check more
than once, hence relaxed operation is fine.

- - - - -
8cf50eb1 by Ben Gamari at 2020-10-24T21:01:54-04:00
rts/STM: Use atomics

This fixes a potentially harmful race where we failed to synchronize
before looking at a TVar's current_value.

Also did a bit of refactoring to avoid abstract over management of
max_commits.

- - - - -
88a7ce38 by Ben Gamari at 2020-10-24T21:01:54-04:00
rts/stm: Strengthen orderings to SEQ_CST instead of volatile

Previously the `current_value`, `first_watch_queue_entry`, and
`num_updates` fields of `StgTVar` were marked as `volatile` in an
attempt to provide strong ordering. Of course, this isn't sufficient.

We now use proper atomic operations. In most of these cases I strengthen
the ordering all the way to SEQ_CST although it's possible that some
could be weakened with some thought.

- - - - -
f97c59ce by Ben Gamari at 2020-10-24T21:02:11-04:00
Mitigate data races in event manager startup/shutdown

- - - - -
c7c3f8aa by Ben Gamari at 2020-10-24T21:02:22-04:00
rts: Accept benign races in Proftimer

- - - - -
5a98dfca by Ben Gamari at 2020-10-24T21:02:22-04:00
rts: Pause timer while changing capability count

This avoids #17289.

- - - - -
01d95525 by Ben Gamari at 2020-10-24T21:02:22-04:00
Fix #17289

- - - - -
9a528985 by Ben Gamari at 2020-10-24T21:02:23-04:00
suppress #17289 (ticker) race

- - - - -
1726ec41 by Ben Gamari at 2020-10-24T21:02:23-04:00
rts: Fix timer initialization

Previously `initScheduler` would attempt to pause the ticker and in so
doing acquire the ticker mutex. However, initTicker, which is
responsible for initializing said mutex, hadn't been called
yet.

- - - - -
bfbe4366 by Ben Gamari at 2020-10-24T21:02:23-04:00
rts: Fix races in Pthread timer backend shudown

We can generally be pretty relaxed in the barriers here since the timer
thread is a loop.

- - - - -
297acc71 by Ben Gamari at 2020-10-24T21:02:44-04:00
rts/Stats: Hide a few unused unnecessarily global functions

- - - - -
9ad51bc9 by David Beacham at 2020-10-27T13:59:35-04:00
Fix `instance Bounded a => Bounded (Down a)` (#18716)

* Flip `minBound` and `maxBound` to respect the change in ordering
* Remove awkward `Enum` (and hence `Integral`) instances for
  `Data.Ord.Down`
* Update changelog

- - - - -
eedec53d by Vladislav Zavialov at 2020-10-27T14:00:11-04:00
Version bump: base-4.16 (#18712)

Also bumps upper bounds on base in boot libraries (incl. submodules).

- - - - -
412018c1 by Tamar Christina at 2020-10-27T14:00:49-04:00
winio: simplify logic remove optimization step.

- - - - -
4950dd07 by Ben Gamari at 2020-10-27T14:01:24-04:00
hadrian: Suppress xelatex output unless it fails

As noted in #18835, xelatex produces an absurd amount of output, nearly
all of which is meaningless. Silence this.

Fixes #18835.

- - - - -
f3d8ab2e by Ben Gamari at 2020-10-27T14:02:00-04:00
build system: Clean mingw tarballs

Tamar noticed in !4293 that the build systems fail to clean up the mingw
tarballs directory (`ghc-tarballs`). Fix this in both the make build
system and Hadrian.

- - - - -
0b3d23af by Simon Peyton Jones at 2020-10-27T14:02:34-04:00
Fix two constraint solving problems

This patch fixes two problems in the constraint solver.

* An actual bug #18555: we were floating out a constraint to eagerly,
  and that was ultimately fatal.  It's explained in
  Note [Do not float blocked constraints] in GHC.Core.Constraint.

  This is all very delicate, but it's all going to become irrelevant
  when we stop floating constraints (#17656).

* A major performance infelicity in the flattener.  When flattening
  (ty |> co) we *never* generated Refl, even when there was nothing
  at all to do.  Result: we would gratuitously rewrite the constraint
  to exactly the same thing, wasting work.  Described in #18413, and
  came up again in #18855.

  Solution: exploit the special case by calling the new function
  castCoercionKind1.  See Note [castCoercionKind1] in
  GHC.Core.Coercion

- - - - -
f76c5a08 by Sergei Trofimovich at 2020-10-27T14:03:14-04:00
ghc.mk: amend 'make sdist'

Noticed 'make sdist' failure seen as:

```
"rm" -rf sdistprep/ghc/ghc-9.1.0.20201020/hadrian/_build/ (SRC_DIST_GHC_DIR)/hadrian/dist-newstyle/
/bin/sh: -c: line 0: syntax error near unexpected token `('
```

commit 9657f6f34
("sdist: Include hadrian sources in source distribution")
added a new cleanup path without a variable expantion.

The change adds variable reference. While at it move directory
cleanup to a separate statement.

Amends #18794

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
78b52c88 by David Eichmann at 2020-10-27T14:03:51-04:00
Use config.run_ways for multi_compile_and_run tests

- - - - -
e3fdd419 by Alan Zimmerman at 2020-10-27T14:04:26-04:00
Api Annotations: Introduce AnnPercent for HsExplicitMult

For the case

  foo :: a %p -> b

The location of the '%' is captured, separate from the 'p'

- - - - -
d2a25f42 by Ben Gamari at 2020-10-27T14:05:02-04:00
gitlab-ci: Bump ci-images

Bumps bootstrap compiler to 8.10.1.

- - - - -
28f98b01 by Sebastian Graf at 2020-10-27T14:05:37-04:00
DmdAnal: Kill `is_thunk` case in `splitFV`

The `splitFV` function implements the highly dubious hack
described in `Note [Lazy und unleashable free variables]` in
GHC.Core.Opt.DmdAnal. It arranges it so that demand signatures only
carry strictness info on free variables. Usage info is released through
other means, see the Note. It's purely for analysis performance reasons.

It turns out that `splitFV` has a quite involved case for thunks that
produces slightly different usage signatures and it's not clear why we
need it: `splitFV` is only relevant in the LetDown case and the only
time we call it on thunks is for top-level or local recursive thunks.

Since usage signatures of top-level thunks can only reference other
top-level bindings and we completely discard demand info we have on
top-level things (see the lack of `setIdDemandInfo` in
`dmdAnalTopBind`), the `is_thunk` case is completely irrelevant here.

For local, recursive thunks, the added benefit of the `is_thunk` test
is marginal: We get used-multiple-times in some cases where previously
we had used-once if a recursive thunk has multiple call sites. It's
very unlikely and not a case to optimise for.

So we kill the `is_thunk` case and inline `splitFV` at its call site,
exposing `isWeakDmd` from `GHC.Types.Demand` instead.

The NoFib summary supports this decision:

```
            Min           0.0%     -0.0%
            Max           0.0%     +0.0%
 Geometric Mean          -0.0%     -0.0%
```

- - - - -
60322f93 by Ben Gamari at 2020-10-28T21:11:39-04:00
hadrian: Don't quote metric baseline argument

Previously this was quoted inappropriately.
- - - - -
c85eb372 by Alan Zimmerman at 2020-10-28T21:12:15-04:00
API Annotations: put constructors in alphabetical order

- - - - -
795908dc by John Ericson at 2020-10-29T03:53:14-04:00
Widen acceptance threshold for T10421a

Progress towards #18842. As @sgraf812 points out, widening the window is
dangerous until the exponential described in #17658 is fixed. But this
test has caused enough misery and is low stakes enough that we and
@bgamari think it's worth it in this one case for the time being.

- - - - -
0e9f6def by Sylvain Henry at 2020-10-29T03:53:52-04:00
Split GHC.Driver.Types

I was working on making DynFlags stateless (#17957), especially by
storing loaded plugins into HscEnv instead of DynFlags. It turned out to
be complicated because HscEnv is in GHC.Driver.Types but LoadedPlugin
isn't: it is in GHC.Driver.Plugins which depends on GHC.Driver.Types. I
didn't feel like introducing yet another hs-boot file to break the loop.

Additionally I remember that while we introduced the module hierarchy
(#13009) we talked about splitting GHC.Driver.Types because it contained
various unrelated types and functions, but we never executed. I didn't
feel like making GHC.Driver.Types bigger with more unrelated Plugins
related types, so finally I bit the bullet and split GHC.Driver.Types.

As a consequence this patch moves a lot of things. I've tried to put
them into appropriate modules but nothing is set in stone.

Several other things moved to avoid loops.

* Removed Binary instances from GHC.Utils.Binary for random compiler
  things
* Moved Typeable Binary instances into GHC.Utils.Binary.Typeable: they
  import a lot of things that users of GHC.Utils.Binary don't want to
  depend on.
* put everything related to Units/Modules under GHC.Unit:
  GHC.Unit.Finder, GHC.Unit.Module.{ModGuts,ModIface,Deps,etc.}
* Created several modules under GHC.Types: GHC.Types.Fixity, SourceText,
  etc.
* Split GHC.Utils.Error (into GHC.Types.Error)
* Finally removed GHC.Driver.Types

Note that this patch doesn't put loaded plugins into HscEnv. It's left
for another patch.

Bump haddock submodule

- - - - -
22f5d9a9 by Sylvain Henry at 2020-10-29T03:53:52-04:00
GC: Avoid data race (#18717, #17964)

- - - - -
2ef2fac4 by Ryan Scott at 2020-10-29T04:18:52-04:00
Check for large tuples more thoroughly

This fixes #18723 by:

* Moving the existing `GHC.Tc.Gen.HsType.bigConstraintTuple` validity
  check to `GHC.Rename.Utils.checkCTupSize` for consistency with
  `GHC.Rename.Utils.checkTupSize`, and
* Using `check(C)TupSize` when checking tuple _types_, in addition
  to checking names, expressions, and patterns.

Note that I put as many of these checks as possible in the typechecker so
that GHC can properly distinguish between boxed and constraint tuples. The
exception to this rule is checking names, which I perform in the renamer
(in `GHC.Rename.Env`) so that we can rule out `(,, ... ,,)` and
`''(,, ... ,,)` alike in one fell swoop.

While I was in town, I also removed the `HsConstraintTuple` and
`HsBoxedTuple` constructors of `HsTupleSort`, which are functionally
unused. This requires a `haddock` submodule bump.

- - - - -
7f8be3eb by Richard Eisenberg at 2020-10-29T22:08:13-04:00
Remove unnecessary gender from comments/docs

While, say, alternating "he" and "she" in sequential writing
may be nicer than always using "they", reading code/documentation
is almost never sequential. If this small change makes individuals
feel more welcome in GHC's codebase, that's a good thing.

- - - - -
aad1f803 by Ben Gamari at 2020-10-30T00:41:14-04:00
rts/GC: Use atomics

- - - - -
d0bc0517 by Ben Gamari at 2020-10-30T00:41:14-04:00
rts: Use RELEASE ordering in unlockClosure

- - - - -
d44f5232 by Ben Gamari at 2020-10-30T00:41:14-04:00
rts/Storage: Accept races on heap size counters

- - - - -
4e4a7386 by Ben Gamari at 2020-10-30T00:41:14-04:00
rts: Join to concurrent mark thread during shutdown

Previously we would take all capabilities but fail to join on the thread
itself, potentially resulting in a leaked thread.

- - - - -
a80cc857 by GHC GitLab CI at 2020-10-30T00:41:14-04:00
rts: Fix race in GC CPU time accounting

Ensure that the GC leader synchronizes with workers before calling
stat_endGC.

- - - - -
9902d9ec by Viktor Dukhovni at 2020-10-30T05:28:30-04:00
[skip ci] Fix typo in `callocBytes` haddock.

- - - - -
105d43db by Ben Gamari at 2020-10-30T14:02:19-04:00
rts/SpinLock: Separate out slow path

Not only is this in general a good idea, but it turns out that GCC
unrolls the retry loop, resulting is massive code bloat in critical
parts of the RTS (e.g. `evacuate`).

- - - - -
f7b45cde by Ben Gamari at 2020-10-30T14:02:19-04:00
rts: Use relaxed ordering on spinlock counters

- - - - -
31fcb55f by Ryan Scott at 2020-10-30T18:52:50-04:00
Split HsConDecl{H98,GADT}Details

Haskell98 and GADT constructors both use `HsConDeclDetails`, which includes
`InfixCon`. But `InfixCon` is never used for GADT constructors, which results
in an awkward unrepresentable state. This removes the unrepresentable state by:

* Renaming the existing `HsConDeclDetails` synonym to `HsConDeclH98Details`,
  which emphasizes the fact that it is now only used for Haskell98-style data
  constructors, and
* Creating a new `HsConDeclGADTDetails` data type with `PrefixConGADT` and
  `RecConGADT` constructors that closely resemble `PrefixCon` and `InfixCon`
  in `HsConDeclH98Details`. The key difference is that `HsConDeclGADTDetails`
  lacks any way to represent infix constructors.

The rest of the patch is refactoring to accommodate the new structure of
`HsConDecl{H98,GADT}Details`. Some highlights:

* The `getConArgs` and `hsConDeclArgTys` functions have been removed, as
  there is no way to implement these functions uniformly for all
  `ConDecl`s. For the most part, their previous call sites now
  pattern match on the `ConDecl`s directly and do different things for
  `ConDeclH98`s and `ConDeclGADT`s.

  I did introduce one new function to make the transition easier:
  `getRecConArgs_maybe`, which extracts the arguments from a `RecCon(GADT)`.
  This is still possible since `RecCon(GADT)`s still use the same representation
  in both `HsConDeclH98Details` and `HsConDeclGADTDetails`, and since the
  pattern that `getRecConArgs_maybe` implements is used in several places,
  I thought it worthwhile to factor it out into its own function.
* Previously, the `con_args` fields in `ConDeclH98` and `ConDeclGADT` were
  both of type `HsConDeclDetails`. Now, the former is of type
  `HsConDeclH98Details`, and the latter is of type `HsConDeclGADTDetails`,
  which are distinct types. As a result, I had to rename the `con_args` field
  in `ConDeclGADT` to `con_g_args` to make it typecheck.

  A consequence of all this is that the `con_args` field is now partial, so
  using `con_args` as a top-level field selector is dangerous. (Indeed, Haddock
  was using `con_args` at the top-level, which caused it to crash at runtime
  before I noticed what was wrong!) I decided to add a disclaimer in the 9.2.1
  release notes to advertise this pitfall.

Fixes #18844. Bumps the `haddock` submodule.

- - - - -
57c3db96 by Ryan Scott at 2020-10-31T02:53:55-04:00
Make typechecker equality consider visibility in ForAllTys

Previously, `can_eq_nc'` would equate `ForAllTy`s regardless of their
`ArgFlag`, including `forall i -> i -> Type` and `forall i. i -> Type`! To fix
this, `can_eq_nc'` now uses the `sameVis` function to first check if the
`ArgFlag`s are equal modulo specificity. I have also updated `tcEqType`'s
implementation to match this behavior. For more explanation on the "modulo
specificity" part, see the new `Note [ForAllTy and typechecker equality]`
in `GHC.Tc.Solver.Canonical`.

While I was in town, I fixed some related documentation issues:

* I added `Note [Typechecker equality]` to `GHC.Tc.Utils.TcType` to describe
  what exactly distinguishes `can_eq_nc'` and `tcEqType` (which implement
  typechecker equality) from `eqType` (which implements definitional equality,
  which does not care about the `ArgFlags` of `ForAllTy`s at all).
* The User's Guide had some outdated prose on the specified/inferred
  distinction being different for types and kinds, a holdover from #15079. This
  is no longer the case on today's GHC, so I removed this prose, added some new
  prose to take its place, and added a regression test for the programs in
  #15079.
* The User's Guide had some _more_ outdated prose on inferred type variables
  not being allowed in `default` type signatures for class methods, which is no
  longer true as of the resolution of #18432.
* The related `Note [Deferred Unification]` was being referenced as
  `Note [Deferred unification]` elsewhere, which made it harder to `grep`
  for. I decided to change the name of the Note to `Deferred unification`
  for consistency with the capitalization style used for most other Notes.

Fixes #18863.

- - - - -
a98593f0 by Sylvain Henry at 2020-10-31T02:54:34-04:00
Refactor numeric constant folding rules

Avoid the use of global pattern synonyms.

1) I think it's going to be helpful to implement constant folding for
   other numeric types, especially Natural which doesn't have a wrapping
   behavior. We'll have to refactor these rules even more so we'd better
   make them less cryptic.

2) It should also be slightly faster because global pattern synonyms
   matched operations for every numeric types instead of the current one:
   e.g., ":**:" pattern was matching multiplication for both Int# and
   Word# types. As we will probably want to implement constant folding
   for other numeric types (Int8#, Int16#, etc.), it is more efficient
   to only match primops for a given type as we do now.

- - - - -
730ef38f by Sylvain Henry at 2020-10-31T02:54:34-04:00
Simplify constant-folding (#18032)

See #18032 for the details.

* Use `Lit (LitNumber _ i)` instead of `isLitValue_maybe` which does
  more work but that is not needed for constant-folding
* Don't export `GHC.Types.Literal.isLitValue_maybe`
* Kill `GHC.Types.Literal.isLitValue` which isn't used

- - - - -
d5a53c1a by Ben Gamari at 2020-10-31T02:55:10-04:00
primops.txt.pp: Move ByteArray# primops to separate file

This file will be generated.

- - - - -
b4278a41 by Ben Gamari at 2020-10-31T02:55:10-04:00
primops: Generate ByteArray# index/read/write primops

Previously these were mostly undocumented and was ripe for potential
inconsistencies.

- - - - -
08e6993a by Sylvain Henry at 2020-10-31T02:55:50-04:00
Move loadDecl into IfaceToCore

- - - - -
cb1f755c by Tamar Christina at 2020-10-31T09:26:56-04:00
winio: Fix unused variables warnings

- - - - -
eb368078 by Andrzej Rybczak at 2020-10-31T09:27:34-04:00
Add testcase for #816

- - - - -
bd4abdc9 by Ben Gamari at 2020-11-01T01:10:31-04:00
testsuite: Add performance test for #18698

- - - - -
dfd27445 by Hécate at 2020-11-01T01:11:09-04:00
Add the proper HLint rules and remove redundant keywords from compiler

- - - - -
ce1bb995 by Hécate at 2020-11-01T08:52:08-05:00
Fix a leak in `transpose`

This patch was authored by David Feuer <david.feuer at gmail.com>

- - - - -
e63db32c by Ben Gamari at 2020-11-01T08:52:44-05:00
Scav: Use bd->gen_no instead of bd->gen->no

This potentially saves a cache miss per scavenge.

- - - - -
b1dda153 by Ben Gamari at 2020-11-01T12:58:36-05:00
rts/Stats: Protect with mutex

While on face value this seems a bit heavy, I think it's far better than
enforcing ordering on every access.

- - - - -
5c2e6bce by Ben Gamari at 2020-11-01T12:58:36-05:00
rts: Tear down stats_mutex after exitHeapProfiling

Since the latter wants to call getRTSStats.

- - - - -
ef25aaa1 by Ben Gamari at 2020-11-01T13:02:11-05:00
rts: Annotate hopefully "benign" races in freeGroup

- - - - -
3a181553 by Ben Gamari at 2020-11-01T13:02:18-05:00
Strengthen ordering in releaseGCThreads

- - - - -
af474f62 by Ben Gamari at 2020-11-01T13:05:38-05:00
Suppress data race due to close

This suppresses the other side of a race during shutdown.

- - - - -
b4686bff by Ben Gamari at 2020-11-01T13:09:59-05:00
Merge branch 'wip/tsan/ci' into wip/tsan/all

- - - - -
b8e66e0e by Ben Gamari at 2020-11-01T13:10:01-05:00
Merge branch 'wip/tsan/storage' into wip/tsan/all

- - - - -
375512cf by Ben Gamari at 2020-11-01T13:10:02-05:00
Merge branch 'wip/tsan/wsdeque' into wip/tsan/all

- - - - -
65ebf07e by Ben Gamari at 2020-11-01T13:10:03-05:00
Merge branch 'wip/tsan/misc' into wip/tsan/all

- - - - -
55c375d0 by Ben Gamari at 2020-11-01T13:10:04-05:00
Merge branch 'wip/tsan/stm' into wip/tsan/all

- - - - -
a9f75fe2 by Ben Gamari at 2020-11-01T13:10:06-05:00
Merge branch 'wip/tsan/event-mgr' into wip/tsan/all

- - - - -
8325d658 by Ben Gamari at 2020-11-01T13:10:24-05:00
Merge branch 'wip/tsan/timer' into wip/tsan/all

- - - - -
07e82ba5 by Ben Gamari at 2020-11-01T13:10:35-05:00
Merge branch 'wip/tsan/stats' into wip/tsan/all

- - - - -
4ce2f7d6 by GHC GitLab CI at 2020-11-02T23:45:06-05:00
testsuite: Add --top flag to driver

This allows us to make `config.top` a proper Path. Previously it was a
str, which caused the Ghostscript detection logic to break.

- - - - -
0b772221 by Ben Gamari at 2020-11-02T23:45:42-05:00
Document that ccall convention doesn't support varargs

We do not support foreign "C" imports of varargs functions. While this
works on amd64, in general the platform's calling convention may need
more type information that our Cmm representation can currently provide.
For instance, this is the case with Darwin's AArch64 calling convention.
Document this fact in the users guide and fix T5423 which makes use of a
disallowed foreign import.

Closes #18854.

- - - - -
81006a06 by David Eichmann at 2020-11-02T23:46:19-05:00
RtsAPI: pause and resume the RTS

The `rts_pause` and `rts_resume` functions have been added to `RtsAPI.h` and
allow an external process to completely pause and resume the RTS.

Co-authored-by: Sven Tennie <sven.tennie at gmail.com>
Co-authored-by: Matthew Pickering <matthewtpickering at gmail.com>
Co-authored-by: Ben Gamari <bgamari.foss at gmail.com>

- - - - -
bfb1e272 by Ryan Scott at 2020-11-02T23:46:55-05:00
Display results of GHC.Core.Lint.lint* functions consistently

Previously, the functions in `GHC.Core.Lint` used a patchwork of
different ways to display Core Lint errors:

* `lintPassResult` (which is the source of most Core Lint errors) renders
  Core Lint errors with a distinctive banner (e.g.,
  `*** Core Lint errors : in result of ... ***`) that sets them apart
  from ordinary GHC error messages.
* `lintAxioms`, in contrast, uses a completely different code path that
  displays Core Lint errors in a rather confusing manner. For example,
  the program in #18770 would give these results:

  ```
  Bug.hs:1:1: error:
      Bug.hs:12:1: warning:
          Non-*-like kind when *-like expected: RuntimeRep
          when checking the body of forall: 'TupleRep '[r]
          In the coercion axiom Bug.N:T :: []. Bug.T ~_R Any
          Substitution: [TCvSubst
                           In scope: InScope {r}
                           Type env: [axl :-> r]
                           Co env: []]
    |
  1 | {-# LANGUAGE DataKinds #-}
    | ^
  ```
* Further digging reveals that `GHC.IfaceToCore` displays Core Lint
  errors for iface unfoldings as though they were a GHC panic. See, for
  example, this excerpt from #17723:

  ```
  ghc: panic! (the 'impossible' happened)
    (GHC version 8.8.2 for x86_64-unknown-linux):
          Iface Lint failure
    In interface for Lib
    ...
  ```

This patch makes all of these code paths display Core Lint errors and
warnings consistently. I decided to adopt the conventions that
`lintPassResult` currently uses, as they appear to have been around the
longest (and look the best, in my subjective opinion). We now use the
`displayLintResult` function for all three scenarios mentioned above.
For example, here is what the Core Lint error for the program in #18770 looks
like after this patch:

```
[1 of 1] Compiling Bug              ( Bug.hs, Bug.o )
*** Core Lint errors : in result of TcGblEnv axioms ***
Bug.hs:12:1: warning:
    Non-*-like kind when *-like expected: RuntimeRep
    when checking the body of forall: 'TupleRep '[r_axn]
    In the coercion axiom N:T :: []. T ~_R Any
    Substitution: [TCvSubst
                     In scope: InScope {r_axn}
                     Type env: [axn :-> r_axn]
                     Co env: []]
*** Offending Program ***
axiom N:T :: T = Any -- Defined at Bug.hs:12:1
*** End of Offense ***

<no location info>: error:
Compilation had errors
```

Fixes #18770.

- - - - -
a9e5f52c by Simon Peyton Jones at 2020-11-02T23:47:31-05:00
Expand type synonyms with :kind!

The User's Guide claims that `:kind!` should expand type synonyms,
but GHCi wasn't doing this in practice. Let's just update the implementation
to match the specification in the User's Guide.

Fixes #13795. Fixes #18828.

Co-authored-by: Ryan Scott <ryan.gl.scott at gmail.com>

- - - - -
1370eda7 by Ben Gamari at 2020-11-02T23:48:06-05:00
hadrian: Don't capture RunTest output

There are a few reasons why capturing the output of the RunTest builder
is undesirable:

 * there is a large amount of output which then gets unnecessarily
   duplicated by Hadrian if the builder fails

 * the output may contain codepoints which are unrepresentable in the
   current codepage on Windows, causing Hadrian to crash

 * capturing the output causes the testsuite driver to disable
   its colorisation logic, making the output less legible.

- - - - -
78f2767d by Matthew Pickering at 2020-11-03T17:39:53-05:00
Update inlining flags documentation

- - - - -
14ce454f by Sylvain Henry at 2020-11-03T17:40:34-05:00
Linker: reorganize linker related code

Move linker related code into GHC.Linker. Previously it was scattered
into GHC.Unit.State, GHC.Driver.Pipeline, GHC.Runtime.Linker, etc.

Add documentation in GHC.Linker

- - - - -
616bec0d by Alan Zimmerman at 2020-11-03T17:41:10-05:00
Restrict Linear arrow %1 to exactly literal 1 only

This disallows `a %001 -> b`, and makes sure the type literal is
printed from its SourceText so it is clear why.

Closes #18888

- - - - -
3486ebe6 by Sylvain Henry at 2020-11-03T17:41:48-05:00
Hadrian: don't fail if ghc-tarballs dir doesn't exist

- - - - -
37f0434d by Sylvain Henry at 2020-11-03T17:42:26-05:00
Constant-folding: don't pass through GHC's Int/Word (fix #11704)

Constant-folding rules for integerToWord/integerToInt were performing
the following coercions at compilation time:

    integerToWord: target's Integer -> ghc's Word -> target's Word
    integerToInt : target's Integer -> ghc's Int -> target's Int

1) It was wrong for cross-compilers when GHC's word size is smaller than
   the target one. This patch avoids passing through GHC's word-sized
   types:

    integerToWord: target's Integer -> ghc's Integer -> target's Word
    integerToInt : target's Integer -> ghc's Integer -> target's Int

2) Additionally we didn't wrap the target word/int literal to make it
   fit into the target's range! This broke the invariant of literals
   only containing values in range.

   The existing code is wrong only with a 64-bit cross-compiling GHC,
   targeting a 32-bit platform, and performing constant folding on a
   literal that doesn't fit in a 32-bit word. If GHC was built with
   DEBUG, the assertion in GHC.Types.Literal.mkLitWord would fail.
   Otherwise the bad transformation would go unnoticed.

- - - - -
bff74de7 by Sylvain Henry at 2020-11-03T17:43:03-05:00
Bignum: make GMP's bignat_add not recursive

bignat_add was a loopbreaker with an INLINE pragma (spotted by
@mpickering). This patch makes it non recursive to avoid the issue.

- - - - -
bb100805 by Andreas Klebinger at 2020-11-04T16:47:24-05:00
NCG: Fix 64bit int comparisons on 32bit x86

We no compare these by doing 64bit subtraction and
checking the resulting flags.

We used to do this differently but the old approach was
broken when the high bits compared equal and the comparison
was one of >= or <=.

The new approach should be both correct and faster.

- - - - -
b790b7f9 by Andreas Klebinger at 2020-11-04T16:47:59-05:00
Testsuite: Support for user supplied package dbs

We can now supply additional package dbs to the testsuite.
For make the package db can be supplied by
passing PACKAGE_DB=/path/to/db.

In the testsuite driver it's passed via the --test-package-db
argument.

- - - - -
81560981 by Sylvain Henry at 2020-11-04T16:48:42-05:00
Don't use LEA with 8-bit registers (#18614)

- - - - -
17d5c518 by Viktor Dukhovni at 2020-11-05T00:50:23-05:00
Naming, value types and tests for Addr# atomics

The atomic Exchange and CAS operations on integral types are updated to
take and return more natural `Word#` rather than `Int#` values.  These
are bit-block not arithmetic operations, and the sign bit plays no
special role.

Standardises the names to `atomic<OpType><ValType>Addr#`, where `OpType` is one
of `Cas` or `Exchange` and `ValType` is presently either `Word` or `Addr`.
Eventually, variants for `Word32` and `Word64` can and should be added,
once #11953 and related issues (e.g. #13825) are resolved.

Adds tests for `Addr#` CAS that mirror existing tests for
`MutableByteArray#`.

- - - - -
2125b1d6 by Ryan Scott at 2020-11-05T00:51:01-05:00
Add a regression test for #18920

Commit f594a68a5500696d94ae36425bbf4d4073aca3b2
(`Use level numbers for generalisation`) ended up fixing #18920. Let's add a
regression test to ensure that it stays fixed.

Fixes #18920.

- - - - -
e07e383a by Ryan Scott at 2020-11-06T03:45:28-05:00
Replace HsImplicitBndrs with HsOuterTyVarBndrs

This refactors the GHC AST to remove `HsImplicitBndrs` and replace it with
`HsOuterTyVarBndrs`, a type which records whether the outermost quantification
in a type is explicit (i.e., with an outermost, invisible `forall`) or
implicit. As a result of this refactoring, it is now evident in the AST where
the `forall`-or-nothing rule applies: it's all the places that use
`HsOuterTyVarBndrs`. See the revamped `Note [forall-or-nothing rule]` in
`GHC.Hs.Type` (previously in `GHC.Rename.HsType`).

Moreover, the places where `ScopedTypeVariables` brings lexically scoped type
variables into scope are a subset of the places that adhere to the
`forall`-or-nothing rule, so this also makes places that interact with
`ScopedTypeVariables` easier to find. See the revamped
`Note [Lexically scoped type variables]` in `GHC.Hs.Type` (previously in
`GHC.Tc.Gen.Sig`).

`HsOuterTyVarBndrs` are used in type signatures (see `HsOuterSigTyVarBndrs`)
and type family equations (see `HsOuterFamEqnTyVarBndrs`). The main difference
between the former and the latter is that the former cares about specificity
but the latter does not.

There are a number of knock-on consequences:

* There is now a dedicated `HsSigType` type, which is the combination of
  `HsOuterSigTyVarBndrs` and `HsType`. `LHsSigType` is now an alias for an
  `XRec` of `HsSigType`.
* Working out the details led us to a substantial refactoring of
  the handling of explicit (user-written) and implicit type-variable
  bindings in `GHC.Tc.Gen.HsType`.

  Instead of a confusing family of higher order functions, we now
  have a local data type, `SkolemInfo`, that controls how these
  binders are kind-checked.

  It remains very fiddly, not fully satisfying. But it's better
  than it was.

Fixes #16762. Bumps the Haddock submodule.

Co-authored-by: Simon Peyton Jones <simonpj at microsoft.com>
Co-authored-by: Richard Eisenberg <rae at richarde.dev>
Co-authored-by: Zubin Duggal <zubin at cmi.ac.in>

- - - - -
c85f4928 by Sylvain Henry at 2020-11-06T03:46:08-05:00
Refactor -dynamic-too handling

1) Don't modify DynFlags (too much) for -dynamic-too: now when we
   generate dynamic outputs for "-dynamic-too", we only set "dynamicNow"
   boolean field in DynFlags instead of modifying several other fields.
   These fields now have accessors that take dynamicNow into account.

2) Use DynamicTooState ADT to represent -dynamic-too state. It's much
   clearer than the undocumented "DynamicTooConditional" that was used
   before.

As a result, we can finally remove the hscs_iface_dflags field in
HscRecomp. There was a comment on this field saying:

   "FIXME (osa): I don't understand why this is necessary, but I spent
   almost two days trying to figure this out and I couldn't .. perhaps
   someone who understands this code better will remove this later."

I don't fully understand the details, but it was needed because of the
changes made to the DynFlags for -dynamic-too.

There is still something very dubious in GHC.Iface.Recomp: we have to
disable the "dynamicNow" flag at some point for some Backpack's "heinous
hack" to continue to work. It may be because interfaces for indefinite
units are always non-dynamic, or because we mix and match dynamic and
non-dynamic interfaces (#9176), or something else, who knows?

- - - - -
2cb87909 by Moritz Angermann at 2020-11-06T03:46:44-05:00
[AArch64] Aarch64 Always PIC

- - - - -
b1d2c1f3 by Ben Gamari at 2020-11-06T03:47:19-05:00
rts/Sanity: Avoid nasty race in weak pointer sanity-checking

See Note [Racing weak pointer evacuation] for all of the gory details.

- - - - -
638f38c5 by Ben Gamari at 2020-11-08T09:29:16-05:00
Merge remote-tracking branch 'origin/wip/tsan/all'

- - - - -
22888798 by Ben Gamari at 2020-11-08T12:08:40-05:00
Fix haddock submodule

The previous merge mistakenly reverted it.

- - - - -
15c871cb by Moritz Angermann at 2020-11-09T03:13:11+00:00
[Sized Cmm] properly retain sizes.

This replaces all Word<N> = W<N># Word# and Int<N> = I<N># Int#  with
Word<N> = W<N># Word<N># and Int<N> = I<N># Int<N>#, thus providing us
with properly sized primitives in the codegenerator instead of pretending
they are all full machine words.

This came up when implementing darwinpcs for arm64.  The darwinpcs reqires
us to pack function argugments in excess of registers on the stack.  While
most procedure call standards (pcs) assume arguments are just passed in
8 byte slots; and thus the caller does not know the exact signature to make
the call, darwinpcs requires us to adhere to the prototype, and thus have
the correct sizes.  If we specify CInt in the FFI call, it should correspond
to the C int, and not just be Word sized, when it's only half the size.

- - - - -
d6ccd9ec by Moritz Angermann at 2020-11-09T11:38:26+08:00
Initial NCG

- - - - -
d248e4cd by Moritz Angermann at 2020-11-09T11:38:26+08:00
Address Takenobu's comments

- - - - -
89127738 by Moritz Angermann at 2020-11-09T11:38:26+08:00
Fix floating points handling of NaNs

- - - - -
02bcdbff by Moritz Angermann at 2020-11-09T11:38:26+08:00
Add basic Graph Coloring support

- - - - -
1b9382c1 by Moritz Angermann at 2020-11-09T11:38:26+08:00
Drop debug

- - - - -
321ffebb by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add primops_match.cmm testsuite

- - - - -
451ee4a8 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fix -NaN for real this time.

- - - - -
a64fa6d5 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Adds nan test.

- - - - -
6e2b113f by Moritz Angermann at 2020-11-09T11:38:27+08:00
no show

- - - - -
220e2971 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Some notes on PIC

- - - - -
2692e2ac by Moritz Angermann at 2020-11-09T11:38:27+08:00
Properly load W32 with bit 31 set.

- - - - -
5cf3b4b8 by Moritz Angermann at 2020-11-09T11:38:27+08:00
better relocation logging

- - - - -
93d5918b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add AsmOpt Flags

- - - - -
8ffa9d18 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Adds ANN instruction.

I wish I had a `pad n` function for SDoc, that would interact with the
layout, and just pad what ever was printed so far to `n` chars.

- - - - -
0a2ff4a7 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Drop dead 32bit logic.

- - - - -
6f3c9739 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add Show CmmExpr instances.

Why would we want this, when we have Outputtable CmmExpr? Quite often
when working on Code Generators, we want to structurally match on
a Cmm Expression. Having to recover the Cmm Expression from its
Outputtable text is not always trivial, and requires substantial effort.
By having a Show instance, we can almost copy the definition to match
on.

- - - - -
e129fb1b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Drop duplicate show instance for CLabel now.

- - - - -
6e36f6cf by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add link, lest I keep forgetting it.

- - - - -
d531a404 by Moritz Angermann at 2020-11-09T11:38:27+08:00
inline comments with //

- - - - -
213cae42 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Some optimizations; not yet sure if safe or not.

- - - - -
84395ed4 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add latest opt changes.

- - - - -
15c52abf by Moritz Angermann at 2020-11-09T11:38:27+08:00
Address Takenobu Tani's comments.

Thanks!

- - - - -
5a75680f by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fix gcd :blush:

- - - - -
08a7383f by Moritz Angermann at 2020-11-09T11:38:27+08:00
Overflow guard

- - - - -
eef63a00 by Moritz Angermann at 2020-11-09T11:38:27+08:00
More annotations.

- - - - -
1c08cbb1 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Revert "Overflow guard"

They are Integers not Ints.

This reverts commit 3ef94e593a2848cf2bdc4251f5be34536642675f.

Signed-off-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
021750bb by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add CmmAssign and CmmStore comments

- - - - -
926b8dae by Moritz Angermann at 2020-11-09T11:38:27+08:00
Minor address mode changes

- - - - -
a771893b by Moritz Angermann at 2020-11-09T11:38:27+08:00
More Amode optimizations

- - - - -
46eecdee by Moritz Angermann at 2020-11-09T11:38:27+08:00
I think this shoudl work for all Registers, not just CmmGlobal

- - - - -
5323e028 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Opt <<, >>

- - - - -
30980b7d by Moritz Angermann at 2020-11-09T11:38:27+08:00
Opt &&, ||

- - - - -
266d9443 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add branch ANNotations.

- - - - -
5a5a1f6b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Disable Opt &&, ||, due to mask immediate

- - - - -
d551bd8b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Opt: Adds CBZ, CBNZ

- - - - -
ad673eb8 by Moritz Angermann at 2020-11-09T11:38:27+08:00
More generic CBZ, CBNZ

- - - - -
ff3a224e by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fixup

- - - - -
6c4174e9 by Moritz Angermann at 2020-11-09T11:38:27+08:00
very rudimentary bitmask support.

- - - - -
defb2173 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add some more bitmasks

- - - - -
54160bab by Moritz Angermann at 2020-11-09T11:38:27+08:00
Opt STR

- - - - -
4270b359 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fixup

- - - - -
1bff99c8 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fix MO_SF_Conv

- - - - -
42847d4b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Add Comment re MO_Memcpy

- - - - -
3c2246d0 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Always PIC via GOT

- - - - -
cba0d9e3 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fix up generated assembly.

Don't generate identity moves
e.g. mov x18, x18

- - - - -
bfa0d5c2 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Drop superfulous alignment generation.

- - - - -
6616712f by Moritz Angermann at 2020-11-09T11:38:27+08:00
Hadrian :fire:

- - - - -
c43063ad by Moritz Angermann at 2020-11-09T11:38:27+08:00
Address Tekenobus comments.

Thanks!

- - - - -
6973fc12 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Adds J to distinguish jumps from B.

Maybe this would be better handled with a phantom type?

- - - - -
549fc6e5 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Make sp an Operand

- - - - -
4e841046 by Moritz Angermann at 2020-11-09T11:38:27+08:00
allocMoreStack

This is still broken, as we can't spill into arbitrary ranges. Hence while we can allocate extra space, we can't really spill past 4096 offsets due to the immediat having to be encoded. This leaves us with a max of 512 spill slots.

We *can* work around this if we change the sp though.

- - - - -
2269f930 by Moritz Angermann at 2020-11-09T11:38:27+08:00
[Spill/Reload] Spill Around :fire:

- - - - -
518337b5 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Address Takenobus observations!

Thanks!

- - - - -
98f4c9a5 by Moritz Angermann at 2020-11-09T11:38:27+08:00
:sob:

- - - - -
fb0ab61b by Moritz Angermann at 2020-11-09T11:38:27+08:00
Revert the Spill/Reload fix; undo :got: loads.

This breaks dynamic, however we can build a working
stage2 compiler with the following mk/build.mk

BuildFlavour = quick

ifneq "$(BuildFlavour)" ""
include mk/flavours/$(BuildFlavour).mk
endif

STRIP_CMD = :

DYNAMIC_BY_DEFAULT   = NO
DYNAMIC_GHC_PROGRAMS = NO

- - - - -
feb9392e by Moritz Angermann at 2020-11-09T11:38:27+08:00
Disable trivial deadlock detection

- - - - -
d125ffa1 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Adds some annotations

- - - - -
4a2e10e3 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Trying to get PIC right.

- - - - -
4248c7d0 by Moritz Angermann at 2020-11-09T11:38:27+08:00
[aarch64] Fix spill/reload

- - - - -
3d46c74c by Moritz Angermann at 2020-11-09T11:38:27+08:00
Try to get PIC right.

- - - - -
2a0f9441 by Moritz Angermann at 2020-11-09T11:38:27+08:00
Spill/Reload only need a smaller window

- - - - -
fa776c2c by Moritz Angermann at 2020-11-09T11:38:27+08:00
Drop bad/useless optimisation

This was due to not handling PIC symbols correctly and injecting CmmLoad
as we do on other platforms, but this doesn't translate to aarch64's got lookups.

- - - - -
60a591c8 by Moritz Angermann at 2020-11-09T11:38:27+08:00
B is b

- - - - -
87928e6d by Moritz Angermann at 2020-11-09T11:38:27+08:00
Fix CCall

|Now mark used registers properly for the Register Allocator.

- - - - -
7bb91696 by Moritz Angermann at 2020-11-09T11:38:27+08:00
:sob:

- - - - -
57876b45 by Moritz Angermann at 2020-11-09T11:38:27+08:00
:sob: :sob:

- - - - -
f844eea9 by Moritz Angermann at 2020-11-09T11:38:27+08:00
:sob: Segfault no 3. This showed up in T4114

- - - - -
7a003e12 by Moritz Angermann at 2020-11-09T11:38:55+08:00
Add mkComment to `Instruction`

- - - - -
b30ab6d7 by Moritz Angermann at 2020-11-09T11:38:55+08:00
Use mkComment for debugging

- - - - -
40d1c8a1 by Moritz Angermann at 2020-11-09T11:38:55+08:00
Fix T4114 crashes

T4114 causes this codepath to show up.

- - - - -
bdb773d4 by Moritz Angermann at 2020-11-09T11:38:55+08:00
Cleanup some compiler warnings

- - - - -
90b16775 by Moritz Angermann at 2020-11-09T11:38:55+08:00
[Aarch64] No div-by-zero; disable test.

- - - - -
a39fa5cf by Moritz Angermann at 2020-11-09T11:38:55+08:00
Simplify aarch64 StgRun

We don't need to do the callee save register dance. The compiler will
do this for us already:

0000000000000000 <StgRun>:
   0:   a9b653f3        stp     x19, x20, [sp, #-160]!
   4:   a9015bf5        stp     x21, x22, [sp, #16]
   8:   a90263f7        stp     x23, x24, [sp, #32]
   c:   a9036bf9        stp     x25, x26, [sp, #48]
  10:   a90473fb        stp     x27, x28, [sp, #64]
  14:   f9002bfe        str     x30, [sp, #80]
  18:   6d0627e8        stp     d8, d9, [sp, #96]
  1c:   6d072fea        stp     d10, d11, [sp, #112]
  20:   6d0837ec        stp     d12, d13, [sp, #128]
  24:   6d093fee        stp     d14, d15, [sp, #144]
  28:   a9bf47f0        stp     x16, x17, [sp, #-16]!
  2c:   d14013ff        sub     sp, sp, #0x4, lsl #12
  30:   aa0103f3        mov     x19, x1
  34:   d61f0000        br      x0

0000000000000038 <StgReturn>:
  38:   914013ff        add     sp, sp, #0x4, lsl #12
  3c:   aa1603e0        mov     x0, x22
  40:   a8c147f0        ldp     x16, x17, [sp], #16
  44:   a9415bf5        ldp     x21, x22, [sp, #16]
  48:   a94263f7        ldp     x23, x24, [sp, #32]
  4c:   a9436bf9        ldp     x25, x26, [sp, #48]
  50:   a94473fb        ldp     x27, x28, [sp, #64]
  54:   f9402bfe        ldr     x30, [sp, #80]
  58:   6d4627e8        ldp     d8, d9, [sp, #96]
  5c:   6d472fea        ldp     d10, d11, [sp, #112]
  60:   6d4837ec        ldp     d12, d13, [sp, #128]
  64:   6d493fee        ldp     d14, d15, [sp, #144]
  68:   a8ca53f3        ldp     x19, x20, [sp], #160
  6c:   d65f03c0        ret

- - - - -
1cfcd252 by Moritz Angermann at 2020-11-09T11:38:55+08:00
Use ip0 for spills/reloads

- - - - -
2cd77ea4 by Moritz Angermann at 2020-11-09T11:39:46+08:00
:broom: Cleanup

- - - - -
eda57783 by Moritz Angermann at 2020-11-09T11:39:46+08:00
Adds LLVM (AArch64) CI Job

- - - - -
4de02f6c by Moritz Angermann at 2020-11-09T11:39:46+08:00
Add validate as well.

- - - - -
5f435df5 by Moritz Angermann at 2020-11-09T11:39:46+08:00
Revert "Simplify aarch64 StgRun"

This reverts commit f27472c0483db2382344f4a8f4c1b2a192d98725.

- - - - -
4cee6853 by Moritz Angermann at 2020-11-09T11:39:46+08:00
Apply suggestion to compiler/GHC/CmmToAsm/AArch64/README.md
- - - - -
fc7817a2 by Moritz Angermann at 2020-11-09T11:39:46+08:00
Apply suggestion to compiler/GHC/CmmToAsm/AArch64/README.md
- - - - -
1e12c166 by Moritz Angermann at 2020-11-09T11:39:46+08:00
[macOS] support for arm64

Adding basic changes to support arm64-apple-darwin

- - - - -
d6e30e03 by Moritz Angermann at 2020-11-09T11:39:46+08:00
Add CLabel logic

- - - - -
f0ad898f by Moritz Angermann at 2020-11-09T11:39:46+08:00
[configure] make arm64-apple-darwin an LLVM Target

This is required as the llvm toolchain doesn't like
aarch64-apple-darwin, and only accepts arm64-apple-darwin.

- - - - -
f9a9678d by Moritz Angermann at 2020-11-09T11:39:46+08:00
[configure] disable subsections_via_symbols on arm64/macOS

LLVM's clang will not emit relocation entries for assembly local (L
prefixed) symbols.  In the presence of subsections_via_symbols, the
linker is free to strip dead symbols from the object code, however due
to the lack of relocations for assembly local symbols, branches will be
invalidated through this dead stripping.

As such we must not permit subsections_via_symbols on arm64/macho-o.

- - - - -
f5cab7f3 by Moritz Angermann at 2020-11-09T11:39:46+08:00
[arm64/mach-o] adrp/ldr symbol names

This will break elf. We need to find a better solution for this
symbol naming is platform dependent here.

:got: / @gotpage
:got_lo12: / @gotpageoff

:lo12: / @pageoff

- - - - -
3b4c9c48 by Moritz Angermann at 2020-11-09T11:39:46+08:00
[WIP] symbol garbage

Naming is hard.  Supporting assembler and linker even harder.

L is the assembly local prefix
l is the linker local prefix

L is not relocated at all.
l is relocated, but fails to for conditional branches.

Send help!

- - - - -
e56196bd by Moritz Angermann at 2020-11-09T11:39:46+08:00
[MachO] cleanup compiler warnings

- - - - -
6459ac58 by Moritz Angermann at 2020-11-09T11:42:40+08:00
[macOS/arm64] do not use read_only_relocs on arm64

The linker simply doesn't support it and will complain
loudly.

- - - - -
964a0c0c by Moritz Angermann at 2020-11-09T11:42:40+08:00
[Storage/Adjustor] Drop size check in allocExec

This is violated by ghci, in InfoTable.hsc we call
_allocateExec with a size that does not guarantee to
be of ffi_closure size.

Other allocateExec implementations do not have this
check either; I highly doubt it's sensible to have
this check in the presence of ghci's allocateExec calls.

- - - - -
7671f117 by Moritz Angermann at 2020-11-09T11:42:40+08:00
[linker/elf] better errors (with error message)

- - - - -
3b4ce6f4 by Moritz Angermann at 2020-11-09T11:43:26+08:00
[darwin] always pic, ios AND mac AND tv AND ...

- - - - -
72888cf4 by Moritz Angermann at 2020-11-09T11:43:26+08:00
[aarch64/codegen] pack ccall arguments on darwin

This is annoying, but the darwinpcs does not match the default aapcs :facepalm:

- - - - -
962237a9 by Moritz Angermann at 2020-11-09T11:43:26+08:00
[linker:MachO] split PLT logic out.

Why was this missing in the first place? It's now a bit more aligned to the
elf plt logic.

- - - - -
5d8f53fc by Moritz Angermann at 2020-11-09T11:43:26+08:00
[configure] fix LLVMTarget when native

uname -p return "arm", hence we can't work with target_cpu,
but need to match on the target triple.

- - - - -
4f4eb26c by Moritz Angermann at 2020-11-09T11:43:26+08:00
[testsuite] fix subsections_via_symbols test

- - - - -
88d2bfac by Moritz Angermann at 2020-11-09T11:43:26+08:00
[testsuite] FixT11649

- - - - -
99b84247 by Moritz Angermann at 2020-11-09T11:43:26+08:00
Fix conc059 test

- - - - -
b6545952 by Moritz Angermann at 2020-11-09T11:43:26+08:00
WIP: fix ghci adjustors on aarch64/arm (infotables)

- - - - -
188fc6e1 by Moritz Angermann at 2020-11-09T11:43:26+08:00
[DWARF] Enable only on elf platforms

- - - - -
18aeb254 by Moritz Angermann at 2020-11-09T11:43:26+08:00
[Testsuite/LLVM] Fix T5681, T7571, T8131b

- - - - -
aed6294a by Moritz Angermann at 2020-11-09T11:43:26+08:00
[testsuite/darwin] fix tests ghcilink003, ghcilink006

- - - - -
da7d11ed by Moritz Angermann at 2020-11-09T11:43:26+08:00
Fix linker_error2

- - - - -
65cbfcc1 by Moritz Angermann at 2020-11-09T11:44:41+08:00
Sized Hints

- - - - -
9e2e2b4d by Moritz Angermann at 2020-11-09T11:44:41+08:00
[Testsuite/arm64] Fix test derefnull

- - - - -
bf212421 by Moritz Angermann at 2020-11-09T11:44:41+08:00
[testsuite/arm64] fix section_alignment

- - - - -
b753727e by Moritz Angermann at 2020-11-09T11:44:42+08:00
[macOS/arm64] darwinpcs :facepalm:

- - - - -
6da5633b by Moritz Angermann at 2020-11-09T11:46:52+08:00
[aarch64/darwin] ifdef for got lables.

This should ideally be some runtime flag, but it would need access to the platform.

- - - - -
8673771a by Moritz Angermann at 2020-11-09T11:46:52+08:00
[aarch64/rts] fix missing prototypes

- - - - -
cb2a5824 by Moritz Angermann at 2020-11-09T11:46:52+08:00
Int has Word size in Haskell.

- - - - -
d6768afc by Moritz Angermann at 2020-11-09T11:46:52+08:00
[debug only] warn on hint/arg mismatch

- - - - -
fa89f86e by Moritz Angermann at 2020-11-09T11:46:52+08:00
[AArch64 NCG] User argument format rather than hint.

- - - - -
4953c7dd by Moritz Angermann at 2020-11-09T11:49:00+08:00
[Debug] Fix CmmFloat warnings.

- - - - -
419a0d65 by Moritz Angermann at 2020-11-09T11:49:00+08:00
[aarch64/elf] fixup elf symbols

- - - - -
94956097 by Moritz Angermann at 2020-11-09T11:49:00+08:00
:facepalm:

- - - - -
78fc1916 by Moritz Angermann at 2020-11-09T11:49:00+08:00
:facepalm:

- - - - -
309e9a52 by Moritz Angermann at 2020-11-09T11:49:00+08:00
[Adjustors] Proper allocator handling.

- - - - -
ee1b3b04 by Moritz Angermann at 2020-11-09T11:49:52+08:00
Revert "[AArch64] Aarch64 Always PIC"

This reverts commit 921276592218211f441fcf011fc52441e3a2f0a6.

- - - - -
48c259c6 by Moritz Angermann at 2020-11-09T11:49:52+08:00
Revert "[Storage/Adjustor] Drop size check in allocExec"

This reverts commit 37a62ae956a25e5832fbe125a4d8ee556fd11042.

- - - - -
b9971f5a by Moritz Angermann at 2020-11-09T11:49:52+08:00
[Storage] Reinstate check; add comment.

- - - - -
96a65e52 by Moritz Angermann at 2020-11-09T11:50:42+08:00
[AArch64] Aarch64 Always PIC

- - - - -
e463c589 by Moritz Angermann at 2020-11-09T11:51:06+08:00
[testsuite] static001 is not broken anymore.

- - - - -
028a34f4 by Moritz Angermann at 2020-11-09T12:08:20+08:00
Revert "Sized Hints"

This reverts commit 65cbfcc10e7ad32dd04ebce011860f5b557eacac.

- - - - -
a1104357 by Moritz Angermann at 2020-11-10T09:18:56+08:00
fix up rebase

- - - - -


29 changed files:

- .gitignore
- .gitlab-ci.yml
- .gitlab/ci.sh
- + .gitlab/common.sh
- README.md
- aclocal.m4
- + compiler/.hlint.yaml
- compiler/GHC.hs
- compiler/GHC/Builtin/Names.hs
- compiler/GHC/Builtin/Names/TH.hs
- compiler/GHC/Builtin/PrimOps.hs
- compiler/GHC/Builtin/Types.hs
- compiler/GHC/Builtin/Types.hs-boot
- compiler/GHC/Builtin/Types/Literals.hs
- compiler/GHC/Builtin/Types/Prim.hs
- compiler/GHC/Builtin/Uniques.hs
- compiler/GHC/Builtin/Utils.hs
- + compiler/GHC/Builtin/bytearray-ops.txt.pp
- compiler/GHC/Builtin/primops.txt.pp
- compiler/GHC/ByteCode/Asm.hs
- compiler/GHC/ByteCode/InfoTable.hs
- compiler/GHC/ByteCode/Instr.hs
- compiler/GHC/ByteCode/Linker.hs
- compiler/GHC/ByteCode/Types.hs
- compiler/GHC/Cmm.hs
- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Cmm/CallConv.hs
- compiler/GHC/Cmm/Dataflow/Collections.hs
- compiler/GHC/Cmm/Dataflow/Label.hs


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/e98e3d124a92cdf48108d918e501a132eaaee53a...a110435790495f25b750d0ef65aab6e0813ade11

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/e98e3d124a92cdf48108d918e501a132eaaee53a...a110435790495f25b750d0ef65aab6e0813ade11
You're receiving this email because of your account on gitlab.haskell.org.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-commits/attachments/20201109/f1e7e188/attachment-0001.html>


More information about the ghc-commits mailing list