[Git][ghc/ghc][wip/T18599] 542 commits: Do not print synonyms in :i (->), :i Type (#18594)

Shayne Fletcher gitlab at gitlab.haskell.org
Fri Nov 27 17:44:00 UTC 2020



Shayne Fletcher pushed to branch wip/T18599 at Glasgow Haskell Compiler / GHC


Commits:
8b865092 by Krzysztof Gogolewski at 2020-08-23T14:12:53+02:00
Do not print synonyms in :i (->), :i Type (#18594)

This adds a new printing flag `sdocPrintTypeAbbreviations` that is used
specifically to avoid ghci printing 'type (->) = (->)' and 'type Type = Type'.

- - - - -
d8f61182 by Krzysztof Gogolewski at 2020-08-23T14:12:56+02:00
Move pprTyTcApp' inside pprTyTcApp

No semantic change

- - - - -
364258e0 by Krzysztof Gogolewski at 2020-08-24T00:32:31-04:00
Fix types in silly shifts (#18589)

Patch written by Simon. I have only added a testcase.

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b1eb38a0 by Sylvain Henry at 2020-08-24T00:33:13-04:00
Perf: make SDoc monad one-shot (#18202)

With validate-x86_64-linux-deb9-hadrian:
   T1969  -3.4% (threshold: +/-1%)
   T3294  -3.3% (threshold: +/-1%)
   T12707 -1.4% (threshold: +/-1%)

Additionally with validate-x86_64-linux-deb9-unreg-hadrian:
   T4801  -2.4% (threshold: +/-2%)
   T13035 -1.4% (threshold: +/-1%)
   T13379 -2.4% (threshold: +/-2%)
   ManyAlternatives -2.5% (threshold: +/-2%)
   ManyConstructors -3.0% (threshold: +/-2%)

Metric Decrease:
    T12707
    T1969
    T3294
    ManyAlternatives
    ManyConstructors
    T13035
    T13379
    T4801

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a77b9ec2 by Krzysztof Gogolewski at 2020-08-24T10:04:20-04:00
Add a test for #18397

The bug was fixed by !3421.

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05550a5a by Sylvain Henry at 2020-08-24T10:04:59-04:00
Avoid roundtrip through SDoc

As found by @monoidal on https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3885#note_295126

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0a1ecc5f by Ben Gamari at 2020-08-25T07:37:05-04:00
SysTools.Process: Handle exceptions in readCreateProcessWithExitCode'

In #18069 we are observing MVar deadlocks from somewhere in ghc.exe.
This use of MVar stood out as being one of the more likely culprits.
Here we make sure that it is exception-safe.

- - - - -
db8793ad by Richard Eisenberg at 2020-08-25T07:37:40-04:00
Use tcView, not coreView, in the pure unifier.

Addresses a lingering point within #11715.

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fb77207a by Simon Peyton Jones at 2020-08-25T07:38:16-04:00
Use LIdP rather than (XRec p (IdP p))

This patch mainly just replaces use of
    XRec p (IdP p)
with
    LIdP p

One slightly more significant change is to parameterise
HsPatSynDetails over the pass rather than the argument type,
so that it's uniform with HsConDeclDetails and HsConPatDetails.

I also got rid of the dead code GHC.Hs.type.conDetailsArgs

But this is all just minor refactoring. No change in functionality.

- - - - -
8426a136 by Krzysztof Gogolewski at 2020-08-25T07:38:54-04:00
Add a test for #18585

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2d635a50 by Takenobu Tani at 2020-08-26T04:50:21-04:00
linters: Make CPP linter skip image files

This patch adds an exclusion rule for `docs/users_guide/images`,
to avoid lint errors of PDF files.

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b7d98cb2 by Takenobu Tani at 2020-08-26T04:50:21-04:00
users-guide: Color the logo on the front page of the PDF

This patch updates the logo with a recent color scheme.
This affects only the PDF version of the user's guide.

See also:
* https://mail.haskell.org/pipermail/ghc-devs/2020-August/019139.html
* https://gitlab.haskell.org/ghc/ghc/-/wikis/logo

- - - - -
0b17fa18 by Sylvain Henry at 2020-08-26T04:50:58-04:00
Refactor UnitId pretty-printing

When we pretty-print a UnitId for the user, we try to map it back to its
origin package name, version and component to print
"package-version:component" instead of some hash.

The UnitId type doesn't carry these information, so we have to look into
a UnitState to find them. This is why the Outputable instance of
UnitId used `sdocWithDynFlags` in order to access the `unitState` field
of DynFlags.

This is wrong for several reasons:

1. The DynFlags are accessed when the message is printed, not when it is
   generated. So we could imagine that the unitState may have changed
   in-between. Especially if we want to allow unit unloading.

2. We want GHC to support several independent sessions at once, hence
   several UnitState. The current approach supposes there is a unique
   UnitState as a UnitId doesn't indicate which UnitState to use.

See the Note [Pretty-printing UnitId] in GHC.Unit for the new approach
implemented by this patch.

One step closer to remove `sdocDynFlags` field from `SDocContext`
(#10143).

Fix #18124.

Also fix some Backpack code to use SDoc instead of String.

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dc476a50 by Sylvain Henry at 2020-08-26T04:51:35-04:00
Bignum: fix BigNat subtraction (#18604)

There was a confusion between the boolean expected by
withNewWordArrayTrimedMaybe and the boolean returned by subtracting
functions.

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fcb10b6c by Peter Trommler at 2020-08-26T10:42:30-04:00
PPC and X86: Portable printing of IEEE floats

GNU as and the AIX assembler support floating point literals.
SPARC seems to have support too but I cannot test on SPARC.
Curiously, `doubleToBytes` is also used in the LLVM backend.

To avoid endianness issues when cross-compiling float and double literals
are printed as C-style floating point values. The assembler then takes
care of memory layout and endianness.

This was brought up in #18431 by @hsyl20.

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770100e0 by Krzysztof Gogolewski at 2020-08-26T10:43:13-04:00
primops: Remove Monadic and Dyadic categories

There were four categories of primops: Monadic, Dyadic, Compare, GenPrimOp.

The compiler does not treat Monadic and Dyadic in any special way,
we can just replace them with GenPrimOp.

Compare is still used in isComparisonPrimOp.

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01ff8c89 by Aditya Gupta at 2020-08-27T14:19:26-04:00
Consolidate imports in getMinimalImports (#18264)

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bacccb73 by Ryan Scott at 2020-08-27T14:20:01-04:00
Make {hsExpr,hsType,pat}NeedsParens aware of boxed 1-tuples

`hsExprNeedsParens`, `hsTypeNeedsParens`, and `patNeedsParens`
previously assumed that all uses of explicit tuples in the source
syntax never need to be parenthesized. This is true save for one
exception: boxed one-tuples, which use the `Solo` data type from
`GHC.Tuple` instead of special tuple syntax. This patch adds the
necessary logic to the three `*NeedsParens` functions to handle
`Solo` correctly.

Fixes #18612.

- - - - -
c6f50cea by Krzysztof Gogolewski at 2020-08-28T02:22:36-04:00
Add missing primop documentation (#18454)

- Add three pseudoops to primops.txt.pp, so that Haddock renders
  the documentation
- Update comments
- Remove special case for "->" - it's no longer exported from GHC.Prim
- Remove reference to Note [Compiling GHC.Prim] - the ad-hoc fix is no
  longer there after updates to levity polymorphism.
- Document GHC.Prim
- Remove the comment that lazy is levity-polymorphic.
  As far as I can tell, it never was: in 80e399639,
  only the unfolding was given an open type variable.
- Remove haddock hack in GHC.Magic - no longer neccessary after
  adding realWorld# to primops.txt.pp.

- - - - -
f065b6b0 by Tamar Christina at 2020-08-28T02:23:13-04:00
Fix use distro toolchian

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4517a382 by Tamar Christina at 2020-08-28T02:23:13-04:00
document how build system find toolchains on Windows

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329f7cb9 by Ben Gamari at 2020-08-31T22:59:14-04:00
base: Better error message on invalid getSystemTimerManager call

Previously we would produce a rather unhelpful pattern match failure
error in the case where the user called `getSystemTimerManager` in a
program which isn't built with `-threaded`. This understandably confused
the user in #15616.

Fixes #15616.

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f6d70a8f by Roland Senn at 2020-08-31T22:59:50-04:00
Add tests for #15617.

Avoid a similar regression in the future.

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e5969fd0 by Roland Senn at 2020-08-31T23:00:27-04:00
Add additional tests for #18172 (Followup MR 3543)

There was still one active discussion [thread](https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3543#note_284325) when MR !3543 got merged.

This MR adds the requested tests exercising the changes in
`compiler/GHC/HsToCore/Match/Literal.hs:warnAboutEmptyEnumerations` and its sub-functions.

- - - - -
fe18b482 by Ben Gamari at 2020-08-31T23:01:02-04:00
Bump Win32 and process submodules

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2da93308 by Sylvain Henry at 2020-08-31T23:01:39-04:00
Hadrian: fix slow-validate flavour (#18586)

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85e13008 by Andreas Klebinger at 2020-08-31T23:02:15-04:00
Update dominator code with fixes from the dom-lt package.

Two bugs turned out in the package that have been fixed since.
This MR includes this fixes in the GHC port of the code.

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dffb38fa by Andreas Klebinger at 2020-08-31T23:02:15-04:00
Dominators.hs: Use unix line endings

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6189cc04 by Moritz Angermann at 2020-08-31T23:02:50-04:00
[fixup 3433] move debugBelch into IF_DEBUG(linker)

The commit in dff1cb3d9c111808fec60190747272b973547c52 incorrectly left
the `debugBelch` function without a comment or IF_DEBUG(linker,)
decoration. This rectifies it.

Needs at least a 8.10 backport, as it was backported in 6471cc6aff80d5deebbdb1bf7b677b31ed2af3d5

- - - - -
bcb68a3f by Sylvain Henry at 2020-08-31T23:03:27-04:00
Don't store HomeUnit in UnitConfig

Allow the creation of a UnitConfig (hence of a UnitState) without having
a HomeUnit. It's required for #14335.

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0a372387 by Sylvain Henry at 2020-08-31T23:04:04-04:00
Fix documentation and fix "check" bignum backend (#18604)

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eb85f125 by Moritz Angermann at 2020-08-31T23:04:39-04:00
Set the dynamic-system-linker flag to Manual

This flag should be user controllable, hence Manual: True.

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380ef845 by Sven Tennie at 2020-08-31T23:05:14-04:00
Ignore more files

Ignore files from "new style" cabal builds (dist-newstyle folders) and
from clangd (C language server).

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74a7fbff by Takenobu Tani at 2020-08-31T23:05:51-04:00
Limit upper version of Happy for ghc-9.0 and earlier (#18620)

This patch adds the upper bound of a happy version for ghc-9.0
and earlier.

Currently, we can't use happy-1.20.0 for ghc-9.0.

See #18620.

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a4473f02 by Takenobu Tani at 2020-08-31T23:05:51-04:00
Limit upper version of Happy for ghc-9.2 (#18620)

This patch adds the upper bound of a happy version for ghc-9.2.

Currently, We can use happy-1.19 or happy-1.20 for ghc-9.2.

See #18620.

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a8a2568b by Sylvain Henry at 2020-08-31T23:06:28-04:00
Bignum: add BigNat compat functions (#18613)

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884245dd by Sylvain Henry at 2020-09-01T12:39:36-04:00
Fix FastString lexicographic ordering (fix #18562)

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4b4fbc58 by Sylvain Henry at 2020-09-01T12:39:36-04:00
Remove "Ord FastString" instance

FastStrings can be compared in 2 ways: by Unique or lexically. We don't
want to bless one particular way with an "Ord" instance because it leads
to bugs (#18562) or to suboptimal code (e.g. using lexical comparison
while a Unique comparison would suffice).

UTF-8 encoding has the advantage that sorting strings by their encoded
bytes also sorts them by their Unicode code points, without having to
decode the actual code points. BUT GHC uses Modified UTF-8 which
diverges from UTF-8 by encoding \0 as 0xC080 instead of 0x00 (to avoid
null bytes in the middle of a String so that the string can still be
null-terminated). This patch adds a new `utf8CompareShortByteString`
function that performs sorting by bytes but that also takes Modified
UTF-8 into account. It is much more performant than decoding the strings
into [Char] to perform comparisons (which we did in the previous patch).

Bump haddock submodule

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b4edcde7 by Ben Gamari at 2020-09-01T14:53:42-04:00
testsuite: Add broken test for #18302

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bfab2a30 by Sebastian Graf at 2020-09-02T15:54:55-04:00
Turn on -XMonoLocalBinds by default (#18430)

And fix the resulting type errors.

Co-authored-by: Krzysztof Gogolewski <krz.gogolewski at gmail.com>

Metric Decrease:
    parsing001

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c30cc0e9 by David Feuer at 2020-09-02T15:55:31-04:00
Remove potential space leak from Data.List.transpose

Previously, `transpose` produced a list of heads
and a list of tails independently. This meant that
a function using only some heads, and only some tails,
could potentially leak space. Use `unzip` to work
around the problem by producing pairs and selector
thunks instead. Time and allocation behavior will
be worse, but there should be no more leak potential.
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ffc3da47 by Sylvain Henry at 2020-09-02T15:56:11-04:00
Remove outdated note

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85e62123 by Sylvain Henry at 2020-09-02T15:56:48-04:00
Bignum: add missing compat import/export functions

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397c2b03 by Ben Gamari at 2020-09-03T17:31:47-04:00
configure: Work around Raspbian's silly packaging decisions

See #17856.

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4891c18a by Kathryn Spiers at 2020-09-03T17:32:24-04:00
expected-undocumented-flags remove kill flags

It looks like the flags were removed in https://gitlab.haskell.org/ghc/ghc/-/commit/3e27205a66b06a4501d87eb31e285eadbc693eb7
and can safely be removed here
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1d6d6488 by Sylvain Henry at 2020-09-04T16:24:20-04:00
Don't rely on CLabel's Outputable instance in CmmToC

This is in preparation of the removal of sdocWithDynFlags (#10143),
hence of the refactoring of CLabel's Outputable instance.

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89ce7cdf by Sylvain Henry at 2020-09-04T16:24:59-04:00
DynFlags: use Platform in foldRegs*

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220ad8d6 by Sylvain Henry at 2020-09-04T16:24:59-04:00
DynFlags: don't pass DynFlags to cmmImplementSwitchPlans

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c1e54439 by Ryan Scott at 2020-09-04T16:25:35-04:00
Introduce isBoxedTupleDataCon and use it to fix #18644

The code that converts promoted tuple data constructors to
`IfaceType`s in `GHC.CoreToIface` was using `isTupleDataCon`, which
conflates boxed and unboxed tuple data constructors. To avoid this,
this patch introduces `isBoxedTupleDataCon`, which is like
`isTupleDataCon` but only works for _boxed_ tuple data constructors.

While I was in town, I was horribly confused by the fact that there
were separate functions named `isUnboxedTupleCon` and
`isUnboxedTupleTyCon` (similarly, `isUnboxedSumCon` and
`isUnboxedSumTyCon`). It turns out that the former only works for
data constructors, despite its very general name! I opted to rename
`isUnboxedTupleCon` to `isUnboxedTupleDataCon` (similarly, I renamed
`isUnboxedSumCon` to `isUnboxedSumDataCon`) to avoid this potential
confusion, as well as to be more consistent with
the naming convention I used for `isBoxedTupleDataCon`.

Fixes #18644.

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07bdcac3 by GHC GitLab CI at 2020-09-04T22:26:25-04:00
configure: Avoid hard-coded ld path on Windows

The fix to #17962 ended up regressing on Windows as it failed to
replicate the logic responsible for overriding the toolchain paths on
Windows. This resulted in a hard-coded path to a directory that likely
doesn't exist on the user's system (#18550).

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0be8e746 by Benjamin Maurer at 2020-09-04T22:27:01-04:00
Documented the as of yet undocumented '--print-*'  GHC flags,
as well as `-split-objs`, since that is related to
`--print-object-splitting-supported`.
See #18641

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4813486f by Sylvain Henry at 2020-09-04T22:27:44-04:00
Move Hadrian's wiki pages in tree (fix #16165)

Only the debugging page contains interesting stuff. Some of this stuff
looks old (e.g. recommending "cabal install")...

- - - - -
7980ae23 by GHC GitLab CI at 2020-09-05T14:50:52-04:00
rts: Consistently use stgMallocBytes instead of malloc

This can help in debugging RTS memory leaks since all allocations go
through the same interface.

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67059893 by Ben Gamari at 2020-09-05T14:51:27-04:00
configure: Fix whitespace

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be2cc0ad by Ben Gamari at 2020-09-05T14:51:27-04:00
gitlab-ci: More intelligent detection of locale availability

Previously ci.sh would unconditionally use C.UTF-8. However, this fails
on Centos 7, which appears not to provide this locale. Now we first try
C.UTF-8, then try en_US.UTF-8, then fail.

Works around #18607.

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15dca847 by Ben Gamari at 2020-09-05T14:51:27-04:00
gitlab-ci: Rename RELEASE variable to RELEASE_JOB

This interfered with the autoconf variable of the same name, breaking
pre-release builds.

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bec0d170 by Ben Gamari at 2020-09-05T14:51:27-04:00
gitlab-ci: Bump Windows toolchain version

This should have been done when we bumped the bootstrap compiler to
8.8.4.

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9fbaee21 by Ben Gamari at 2020-09-05T14:51:27-04:00
gitlab-ci: Drop Windows make job

These are a significant burden on our CI resources and end up failing
quite often due to #18274. Here I drop the make jobs during
validaion; it is now run only during the nightly builds.

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869f6e19 by Ben Gamari at 2020-09-05T14:51:27-04:00
testsuite: Drop Windows-specific output for parseTree

The normalise_slashes normaliser should handle this.

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2c9f743c by Ben Gamari at 2020-09-05T14:51:28-04:00
testsuite: Mark T5975[ab] as broken on Windows

Due to #7305.

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643785e3 by Ben Gamari at 2020-09-05T14:51:28-04:00
gitlab-ci: Fix typo

A small typo in a rule regular expression.

- - - - -
c5413fc6 by Wander Hillen at 2020-09-07T09:33:54-04:00
Add clarification regarding poll/kqueue flags

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10434d60 by Ben Gamari at 2020-09-07T09:34:32-04:00
gitlab-ci: Configure bignum backend in Hadrian builds

- - - - -
d4bc9f0d by Ben Gamari at 2020-09-07T09:34:32-04:00
gitlab-ci: Use hadrian builds for Windows release artifacts

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4ff93292 by Moritz Angermann at 2020-09-07T21:18:39-04:00
[macOS] improved runpath handling

In b592bd98ff25730bbe3c13d6f62a427df8c78e28 we started using
-dead_strip_dylib on macOS when lining dynamic libraries and binaries.
The underlying reason being the Load Command Size Limit in macOS
Sierra (10.14) and later.

GHC will produce @rpath/libHS... dependency entries together with a
corresponding RPATH entry pointing to the location of the libHS...
library. Thus for every library we produce two Load Commands.  One to
specify the dependent library, and one with the path where to find it.
This makes relocating libraries and binaries easier, as we just need to
update the RPATH entry with the install_name_tool. The dynamic linker
will then subsitute each @rpath with the RPATH entries it finds in the
libraries load commands or the environement, when looking up @rpath
relative libraries.

-dead_strip_dylibs intructs the linker to drop unused libraries. This in
turn help us reduce the number of referenced libraries, and subsequently
the size of the load commands.  This however does not remove the RPATH
entries.  Subsequently we can end up (in extreme cases) with only a
single @rpath/libHS... entry, but 100s or more RPATH entries in the Load
Commands.

This patch rectifies this (slighly unorthodox) by passing *no* -rpath
arguments to the linker at link time, but -headerpad 8000.  The
headerpad argument is in hexadecimal and the maxium 32k of the load
command size.  This tells the linker to pad the load command section
enough for us to inject the RPATHs later.  We then proceed to link the
library or binary with -dead_strip_dylibs, and *after* the linking
inspect the library to find the left over (non-dead-stripped)
dependencies (using otool).  We find the corresponding RPATHs for each
@rpath relative dependency, and inject them into the library or binary
using the install_name_tool.  Thus achieving a deadstripped dylib (and
rpaths) build product.

We can not do this in GHC, without starting to reimplement a dynamic
linker as we do not know which symbols and subsequently libraries are
necessary.

Commissioned-by: Mercury Technologies, Inc. (mercury.com)

- - - - -
df04b81e by Sylvain Henry at 2020-09-07T21:19:20-04:00
Move DynFlags test into updateModDetailsIdInfos's caller (#17957)

- - - - -
ea1cbb8f by Ben Gamari at 2020-09-08T15:42:02-04:00
rts: Add stg_copyArray_barrier to RtsSymbols list

It's incredible that this wasn't noticed until now.

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d7b2f799 by Daishi Nakajima at 2020-09-08T15:42:41-04:00
testsuite: Output performance test results in tabular format
this was suggested in #18417.

Change the print format of the values.
* Shorten commit hash
* Reduce precision of the "Value" field
* Shorten metrics name
  * e.g. runtime/bytes allocated -> run/alloc
* Shorten "MetricsChange"
  * e.g. unchanged -> unch, increased -> incr

And, print the baseline environment if there are baselines that were
measured in a different environment than the current environment.

If all "Baseline commit" are the same, print it once.

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44472daf by Ryan Scott at 2020-09-08T15:43:16-04:00
Make the forall-or-nothing rule only apply to invisible foralls (#18660)

This fixes #18660 by changing `isLHsForAllTy` to
`isLHsInvisForAllTy`, which is sufficient to make the
`forall`-or-nothing rule only apply to invisible `forall`s. I also
updated some related documentation and Notes while I was in the
neighborhood.

- - - - -
0c61cbff by Ben Gamari at 2020-09-08T15:43:54-04:00
gitlab-ci: Handle distributions without locales

Previously we would assume that the `locale` utility exists. However,
this is not so on Alpine as musl's locale support is essentially
non-existent.

(cherry picked from commit 17cdb7ac3b557a245fee1686e066f9f770ddc21e)

- - - - -
d989c842 by Ben Gamari at 2020-09-08T15:43:55-04:00
gitlab-ci: Accept Centos 7 C.utf8 locale

Centos apparently has C.utf8 rather than C.UTF-8.

(cherry picked from commit d9f85dd25a26a04d3485470afb3395ee2dec6464)

- - - - -
e5a2899c by John Ericson at 2020-09-09T00:46:05-04:00
Use "to" instead of "2" in internal names of conversion ops

Change the constructors for the primop union, and also names of the
literal conversion functions.

"2" runs into trouble when we need to do conversions from fixed-width
types, and end up with thing like "Int642Word".

Only the names internal to GHC are changed, as I don't want to worry
about breaking changes ATM.

- - - - -
822f1057 by Ryan Scott at 2020-09-09T00:46:41-04:00
Postpone associated tyfam default checks until after typechecking

Previously, associated type family defaults were validity-checked
during typechecking. Unfortunately, the error messages that these
checks produce run the risk of printing knot-tied type constructors,
which will cause GHC to diverge. In order to preserve the current
error message's descriptiveness, this patch postpones these validity
checks until after typechecking, which are now located in the new
function `GHC.Tc.Validity.checkValidAssocTyFamDeflt`.

Fixes #18648.

- - - - -
8c892689 by Sylvain Henry at 2020-09-09T11:19:24-04:00
DynFlags: add OptCoercionOpts

Use OptCoercionOpts to avoid threading DynFlags all the way down to
GHC.Core.Coercion.Opt

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3f32a9c0 by Sylvain Henry at 2020-09-09T11:19:24-04:00
DynFlags: add UnfoldingOpts and SimpleOpts

Milestone: after this patch, we only use 'unsafeGlobalDynFlags' for the
state hack and for debug in Outputable.

- - - - -
b3df72a6 by Sylvain Henry at 2020-09-09T11:19:24-04:00
DynFlags: add sm_pre_inline field into SimplMode (#17957)

It avoids passing and querying DynFlags down in the simplifier.

- - - - -
ffae5792 by Sylvain Henry at 2020-09-09T11:19:24-04:00
Add comments about sm_dflags and simpleOptExpr

- - - - -
7911d0d9 by Alan Zimmerman at 2020-09-09T11:20:03-04:00
Remove GENERATED pragma, as it is not being used

@alanz pointed out on ghc-devs that the payload of this pragma does
not appear to be used anywhere.

I (@bgamari) did some digging and traced the pragma's addition back to
d386e0d2 (way back in 2006!).

It appears that it was intended to be used by code generators for use
in informing the code coveraging checker about generated code
provenance. When it was added it used the pragma's "payload" fields as
source location information to build an "ExternalBox". However, it
looks like this was dropped a year later in 55a5d8d9.  At this point
it seems like the pragma serves no useful purpose.

Given that it also is not documented, I think we should remove it.

Updates haddock submodule

Closes #18639

- - - - -
5aae5b32 by Ben Gamari at 2020-09-09T18:31:40-04:00
gitlab-ci: Bump Docker images

We now generate our Docker images via Dhall definitions, as described in
ghc/ci-images!52. Additionally, we are far more careful about where tools
come from, using the ALEX, HAPPY, HSCOLOR, and GHC environment variables
(set in the Dockerfiles) to find bootstrapping tools.

- - - - -
4ce9fe88 by Ben Gamari at 2020-09-09T18:31:40-04:00
hadrian: Fix leakage of GHC in PATH into build

Previously hadrian would use GHC on PATH when configuring packages (or
fail if there is no such GHC). Fix this. Unfortunately this runs into
another bug in Cabal which we workaround.

- - - - -
291a15dd by Ben Gamari at 2020-09-09T18:31:40-04:00
utils: Bump cabal-version of hp2ps and unlit

- - - - -
4798caa0 by David Himmelstrup at 2020-09-09T18:32:16-04:00
rts comment: RTS_TICKY_SYMBOLS moved from rts/Linker.c to rts/RtsSymbols.c

- - - - -
67ce72da by Sebastian Graf at 2020-09-10T10:35:33-04:00
Add long-distance info for pattern bindings (#18572)

We didn't consider the RHS of a pattern-binding before, which led to
surprising warnings listed in #18572.

As can be seen from the regression test T18572, we get the expected
output now.

- - - - -
1207576a by Sebastian Graf at 2020-09-10T10:35:33-04:00
PmCheck: Big refactor using guard tree variants more closely following source syntax (#18565)

Previously, we desugared and coverage checked plain guard trees as
described in Lower Your Guards. That caused (in !3849) quite a bit of
pain when we need to partially recover tree structure of the input
syntax to return covered sets for long-distance information, for
example.

In this refactor, I introduced a guard tree variant for each relevant
source syntax component of a pattern-match (mainly match groups, match,
GRHS, empty case, pattern binding). I made sure to share as much
coverage checking code as possible, so that the syntax-specific checking
functions are just wrappers around the more substantial checking
functions for the LYG primitives (`checkSequence`, `checkGrds`).

The refactoring payed off in clearer code and elimination of all panics
related to assumed guard tree structure and thus fixes #18565.

I also took the liberty to rename and re-arrange the order of functions
and comments in the module, deleted some dead and irrelevant Notes,
wrote some new ones and gave an overview module haddock.

- - - - -
95455982 by GHC GitLab CI at 2020-09-10T10:36:09-04:00
hadrian: Don't include -fdiagnostics-color in argument hash

Otherwise the input hash will vary with whether colors are requested,
which changed with `isatty`.

Fixes #18672.

- - - - -
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
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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.
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b02a9ea7 by Ben Gamari at 2020-10-17T13:26:24-04:00
gitlab-ci: s/allow_newer/allow_failure

Silly mistake on my part.
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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

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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).

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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

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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.

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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.

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0b995759 by DylanZA at 2020-10-17T22:02:50-04:00
Apply suggestion to testsuite/tests/ffi/should_run/all.T
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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.

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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

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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.

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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.

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

This was fixed by 4291bddaea3148908c55f235ee8978e1d9aa6f20.

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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

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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.

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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.

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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

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

Due to #17945.

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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.

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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.

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

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

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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.

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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.

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

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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.

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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.

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

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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.

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

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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.

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

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

Due to #18808.

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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.

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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.

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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.

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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.

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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.

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

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

Due to #18883.

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

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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.

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

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

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

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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.

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

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

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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.

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

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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.

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

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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.

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

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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.

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

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

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

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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.

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

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

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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.

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

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

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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.

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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.

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

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

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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.

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

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

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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.

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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.

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

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

Fixes #17275.

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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.

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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.

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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.

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

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

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

This avoids #17289.

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

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

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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.

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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.

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

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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

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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.

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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.

- - - - -
d445cf05 by Ben Gamari at 2020-11-10T10:26:20-05:00
rts/linker: Fix relocation overflow in PE linker

Previously the overflow check for the IMAGE_REL_AMD64_ADDR32NB
relocation failed to account for the signed nature of the value.
Specifically, the overflow check was:

    uint64_t v;
    v = S + A;
    if (v >> 32) { ... }

However, `v` ultimately needs to fit into 32-bits as a signed value.
Consequently, values `v > 2^31` in fact overflow yet this is not caught
by the existing overflow check.

Here we rewrite the overflow check to rather ensure that
`INT32_MIN <= v <= INT32_MAX`. There is now quite a bit of repetition
between the `IMAGE_REL_AMD64_REL32` and `IMAGE_REL_AMD64_ADDR32` cases
but I am leaving fixing this for future work.

This bug was first noticed by @awson.

Fixes #15808.

- - - - -
4c407f6e by Sylvain Henry at 2020-11-10T10:27:00-05:00
Export SPEC from GHC.Exts (#13681)

- - - - -
7814cd5b by David Eichmann at 2020-11-10T10:27:35-05:00
ghc-heap: expose decoding from heap representation

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>

- - - - -
fa344d33 by Richard Eisenberg at 2020-11-10T10:28:10-05:00
Add test case for #17186.

This got fixed sometime recently; not worth it trying to
figure out which commit.

- - - - -
2e63a0fb by David Eichmann at 2020-11-10T10:28:46-05:00
Add code comments for StgInfoTable and StgStack structs

- - - - -
fcfda909 by Ben Gamari at 2020-11-11T03:19:59-05:00
nativeGen: Make makeImportsDoc take an NCGConfig rather than DynFlags

It appears this was an oversight as there is no reason the full DynFlags
is necessary.

- - - - -
6e23695e by Ben Gamari at 2020-11-11T03:19:59-05:00
Move this_module into NCGConfig

In various places in the NCG we need the Module currently being
compiled. Let's move this into the environment instead of chewing threw
another register.

- - - - -
c6264a2d by Ben Gamari at 2020-11-11T03:20:00-05:00
codeGen: Produce local symbols for module-internal functions

It turns out that some important native debugging/profiling tools (e.g.
perf) rely only on symbol tables for function name resolution (as
opposed to using DWARF DIEs). However, previously GHC would emit
temporary symbols (e.g. `.La42b`) to identify module-internal
entities. Such symbols are dropped during linking and therefore not
visible to runtime tools (in addition to having rather un-helpful unique
names). For instance, `perf report` would often end up attributing all
cost to the libc `frame_dummy` symbol since Haskell code was no covered
by any proper symbol (see #17605).

We now rather follow the model of C compilers and emit
descriptively-named local symbols for module internal things. Since this
will increase object file size this behavior can be disabled with the
`-fno-expose-internal-symbols` flag.

With this `perf record` can finally be used against Haskell executables.
Even more, with `-g3` `perf annotate` provides inline source code.

- - - - -
584058dd by Ben Gamari at 2020-11-11T03:20:00-05:00
Enable -fexpose-internal-symbols when debug level >=2

This seems like a reasonable default as the object file size increases
by around 5%.

- - - - -
c34a4b98 by Ömer Sinan Ağacan at 2020-11-11T03:20:35-05:00
Fix and enable object unloading in GHCi

Fixes #16525 by tracking dependencies between object file symbols and
marking symbol liveness during garbage collection

See Note [Object unloading] in CheckUnload.c for details.

- - - - -
2782487f by Ray Shih at 2020-11-11T03:20:35-05:00
Add loadNativeObj and unloadNativeObj

(This change is originally written by niteria)

This adds two functions:
* `loadNativeObj`
* `unloadNativeObj`
and implements them for Linux.

They are useful if you want to load a shared object with Haskell code
using the system linker and have GHC call dlclose() after the
code is no longer referenced from the heap.

Using the system linker allows you to load the shared object
above outside the low-mem region. It also loads the DWARF sections
in a way that `perf` understands.

`dl_iterate_phdr` is what makes this implementation Linux specific.

- - - - -
7a65f9e1 by GHC GitLab CI at 2020-11-11T03:20:35-05:00
rts: Introduce highMemDynamic

- - - - -
e9e1b2e7 by GHC GitLab CI at 2020-11-11T03:20:35-05:00
Introduce test for dynamic library unloading

This uses the highMemDynamic flag introduced earlier to verify that
dynamic objects are properly unloaded.

- - - - -
5506f134 by Krzysztof Gogolewski at 2020-11-11T03:21:14-05:00
Force argument in setIdMult (#18925)

- - - - -
787e93ae by Ben Gamari at 2020-11-11T23:14:11-05:00
testsuite: Add testcase for #18733

- - - - -
5353fd50 by Ben Gamari at 2020-11-12T10:05:30-05:00
compiler: Fix recompilation checking

In ticket #18733 we noticed a rather serious deficiency in the current
fingerprinting logic for recursive groups. I have described the old
fingerprinting story and its problems in Note [Fingerprinting recursive
groups] and have reworked the story accordingly to avoid these issues.

Fixes #18733.

- - - - -
63fa3997 by Sebastian Graf at 2020-11-13T14:29:39-05:00
Arity: Rework `ArityType` to fix monotonicity (#18870)

As we found out in #18870, `andArityType` is not monotone, with
potentially severe consequences for termination of fixed-point
iteration. That showed in an abundance of "Exciting arity" DEBUG
messages that are emitted whenever we do more than one step in
fixed-point iteration.

The solution necessitates also recording `OneShotInfo` info for
`ABot` arity type. Thus we get the following definition for `ArityType`:

```
data ArityType = AT [OneShotInfo] Divergence
```

The majority of changes in this patch are the result of refactoring use
sites of `ArityType` to match the new definition.

The regression test `T18870` asserts that we indeed don't emit any DEBUG
output anymore for a function where we previously would have.
Similarly, there's a regression test `T18937` for #18937, which we
expect to be broken for now.

Fixes #18870.

- - - - -
197d59fa by Sebastian Graf at 2020-11-13T14:29:39-05:00
Arity: Emit "Exciting arity" warning only after second iteration (#18937)

See Note [Exciting arity] why we emit the warning at all and why we only
do after the second iteration now.

Fixes #18937.

- - - - -
de7ec9dd by David Eichmann at 2020-11-13T14:30:16-05:00
Add rts_listThreads and rts_listMiscRoots to RtsAPI.h

These are used to find the current roots of the garbage collector.

Co-authored-by: Sven Tennie's avatarSven Tennie <sven.tennie at gmail.com>
Co-authored-by: Matthew Pickering's avatarMatthew Pickering <matthewtpickering at gmail.com>
Co-authored-by: default avatarBen Gamari <bgamari.foss at gmail.com>

- - - - -
24a86f09 by Ben Gamari at 2020-11-13T14:30:51-05:00
gitlab-ci: Cache cabal store in linting job

- - - - -
0a7e592c by Ben Gamari at 2020-11-15T03:35:45-05:00
nativeGen/dwarf: Fix procedure end addresses

Previously the `.debug_aranges` and `.debug_info` (DIE) DWARF
information would claim that procedures (represented with a
`DW_TAG_subprogram` DIE) would only span the range covered by their entry
block. This omitted all of the continuation blocks (represented by
`DW_TAG_lexical_block` DIEs), confusing `perf`. Fix this by introducing
a end-of-procedure label and using this as the `DW_AT_high_pc` of
procedure `DW_TAG_subprogram` DIEs

Fixes #17605.

- - - - -
1e19183d by Ben Gamari at 2020-11-15T03:35:45-05:00
nativeGen/dwarf: Only produce DW_AT_source_note DIEs in -g3

Standard debugging tools don't know how to understand these so let's not
produce them unless asked.

- - - - -
ad73370f by Ben Gamari at 2020-11-15T03:35:45-05:00
nativeGen/dwarf: Use DW_AT_linkage instead of DW_AT_MIPS_linkage

- - - - -
a2539650 by Ben Gamari at 2020-11-15T03:35:45-05:00
gitlab-ci: Add DWARF release jobs for Debian 10, Fedora27

- - - - -
d61adb3d by Ryan Scott at 2020-11-15T03:36:21-05:00
Name (tc)SplitForAll- functions more consistently

There is a zoo of `splitForAll-` functions in `GHC.Core.Type` (as well as
`tcSplitForAll-` functions in `GHC.Tc.Utils.TcType`) that all do very similar
things, but vary in the particular form of type variable that they return. To
make things worse, the names of these functions are often quite misleading.
Some particularly egregious examples:

* `splitForAllTys` returns `TyCoVar`s, but `splitSomeForAllTys` returns
  `VarBndr`s.
* `splitSomeForAllTys` returns `VarBndr`s, but `tcSplitSomeForAllTys` returns
  `TyVar`s.
* `splitForAllTys` returns `TyCoVar`s, but `splitForAllTysInvis` returns
  `InvisTVBinder`s. (This in particular arose in the context of #18939, and
  this finally motivated me to bite the bullet and improve the status quo
  vis-à-vis how we name these functions.)

In an attempt to bring some sanity to how these functions are named, I have
opted to rename most of these functions en masse to use consistent suffixes
that describe the particular form of type variable that each function returns.
In concrete terms, this amounts to:

* Functions that return a `TyVar` now use the suffix `-TyVar`.
  This caused the following functions to be renamed:
  * `splitTyVarForAllTys` -> `splitForAllTyVars`
  * `splitForAllTy_ty_maybe` -> `splitForAllTyVar_maybe`
  * `tcSplitForAllTys` -> `tcSplitForAllTyVars`
  * `tcSplitSomeForAllTys` -> `tcSplitSomeForAllTyVars`
* Functions that return a `CoVar` now use the suffix `-CoVar`.
  This caused the following functions to be renamed:
  * `splitForAllTy_co_maybe` -> `splitForAllCoVar_maybe`
* Functions that return a `TyCoVar` now use the suffix `-TyCoVar`.
  This caused the following functions to be renamed:
  * `splitForAllTy` -> `splitForAllTyCoVar`
  * `splitForAllTys` -> `splitForAllTyCoVars`
  * `splitForAllTys'` -> `splitForAllTyCoVars'`
  * `splitForAllTy_maybe` -> `splitForAllTyCoVar_maybe`
* Functions that return a `VarBndr` now use the suffix corresponding to the
  most relevant type synonym. This caused the following functions to be renamed:
  * `splitForAllVarBndrs` -> `splitForAllTyCoVarBinders`
  * `splitForAllTysInvis` -> `splitForAllInvisTVBinders`
  * `splitForAllTysReq` -> `splitForAllReqTVBinders`
  * `splitSomeForAllTys` -> `splitSomeForAllTyCoVarBndrs`
  * `tcSplitForAllVarBndrs` -> `tcSplitForAllTyVarBinders`
  * `tcSplitForAllTysInvis` -> `tcSplitForAllInvisTVBinders`
  * `tcSplitForAllTysReq` -> `tcSplitForAllReqTVBinders`
  * `tcSplitForAllTy_maybe` -> `tcSplitForAllTyVarBinder_maybe`

Note that I left the following functions alone:

* Functions that split apart things besides `ForAllTy`s, such as `splitFunTys`
  or `splitPiTys`. Thankfully, there are far fewer of these functions than
  there are functions that split apart `ForAllTy`s, so there isn't much of a
  pressing need to apply the new naming convention elsewhere.
* Functions that split apart `ForAllCo`s in `Coercion`s, such as
  `GHC.Core.Coercion.splitForAllCo_maybe`. We could theoretically apply the new
  naming convention here, but then we'd have to figure out how to disambiguate
  `Type`-splitting functions from `Coercion`-splitting functions. Ultimately,
  the `Coercion`-splitting functions aren't used nearly as much as the
  `Type`-splitting functions, so I decided to leave the former alone.

This is purely refactoring and should cause no change in behavior.

- - - - -
645444af by Ryan Scott at 2020-11-15T03:36:21-05:00
Use tcSplitForAllInvisTyVars (not tcSplitForAllTyVars) in more places

The use of `tcSplitForAllTyVars` in `tcDataFamInstHeader` was the immediate
cause of #18939, and replacing it with a new `tcSplitForAllInvisTyVars`
function (which behaves like `tcSplitForAllTyVars` but only splits invisible
type variables) fixes the issue. However, this led me to realize that _most_
uses of `tcSplitForAllTyVars` in GHC really ought to be
`tcSplitForAllInvisTyVars` instead. While I was in town, I opted to replace
most uses of `tcSplitForAllTys` with `tcSplitForAllTysInvis` to reduce the
likelihood of such bugs in the future.

I say "most uses" above since there is one notable place where we _do_ want
to use `tcSplitForAllTyVars`: in `GHC.Tc.Validity.forAllTyErr`, which produces
the "`Illegal polymorphic type`" error message if you try to use a higher-rank
`forall` without having `RankNTypes` enabled. Here, we really do want to split
all `forall`s, not just invisible ones, or we run the risk of giving an
inaccurate error message in the newly added `T18939_Fail` test case.

I debated at some length whether I wanted to name the new function
`tcSplitForAllInvisTyVars` or `tcSplitForAllTyVarsInvisible`, but in the end,
I decided that I liked the former better. For consistency's sake, I opted to
rename the existing `splitPiTysInvisible` and `splitPiTysInvisibleN` functions
to `splitInvisPiTys` and `splitPiTysInvisN`, respectively, so that they use the
same naming convention. As a consequence, this ended up requiring a `haddock`
submodule bump.

Fixes #18939.

- - - - -
8887102f by Moritz Angermann at 2020-11-15T03:36:56-05:00
AArch64/arm64 adjustments

This addes the necessary logic to support aarch64 on elf, as well
as aarch64 on mach-o, which Apple calls arm64.

We change architecture name to AArch64, which is the official arm
naming scheme.

- - - - -
fc644b1a by Ben Gamari at 2020-11-15T03:37:31-05:00
ghc-bin: Build with eventlogging by default

We now have all sorts of great facilities using the
eventlog which were previously unavailable without
building a custom GHC. Fix this by linking with
`-eventlog` by default.
- - - - -
52114fa0 by Sylvain Henry at 2020-11-16T11:48:47+01:00
Add Addr# atomic primops (#17751)

This reuses the codegen used for ByteArray#'s atomic primops.

- - - - -
8150f654 by Sebastian Graf at 2020-11-18T23:38:40-05:00
PmCheck: Print types of uncovered patterns (#18932)

In order to avoid confusion as in #18932, we display the type of the
match variables in the non-exhaustiveness warning, e.g.

```
T18932.hs:14:1: warning: [-Wincomplete-patterns]
    Pattern match(es) are non-exhaustive
    In an equation for ‘g’:
        Patterns of type  ‘T a’, ‘T a’, ‘T a’ not matched:
            (MkT2 _) (MkT1 _) (MkT1 _)
            (MkT2 _) (MkT1 _) (MkT2 _)
            (MkT2 _) (MkT2 _) (MkT1 _)
            (MkT2 _) (MkT2 _) (MkT2 _)
            ...
   |
14 | g (MkT1 x) (MkT1 _) (MkT1 _) = x
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```

It also allows us to omit the type signature on wildcard matches which
we previously showed in only some situations, particularly
`-XEmptyCase`.

Fixes #18932.

- - - - -
165352a2 by Krzysztof Gogolewski at 2020-11-20T02:08:36-05:00
Export indexError from GHC.Ix (#18579)

- - - - -
b57845c3 by Kamil Dworakowski at 2020-11-20T02:09:16-05:00
Clarify interruptible FFI wrt masking state

- - - - -
321d1bd8 by Sebastian Graf at 2020-11-20T02:09:51-05:00
Fix strictness signatures of `prefetchValue*#` primops

Their strictness signatures said the primops are strict in their first
argument, which is wrong: Handing it a thunk will prefetch the pointer
to the thunk, but not evaluate it. Hence not strict.

The regression test `T8256` actually tests for laziness in the first
argument, so GHC apparently never exploited the strictness signature.

See also https://gitlab.haskell.org/ghc/ghc/-/issues/8256#note_310867,
where this came up.

- - - - -
0aec78b6 by Sebastian Graf at 2020-11-20T02:09:51-05:00
Demand: Interleave usage and strictness demands (#18903)

As outlined in #18903, interleaving usage and strictness demands not
only means a more compact demand representation, but also allows us to
express demands that we weren't easily able to express before.

Call demands are *relative* in the sense that a call demand `Cn(cd)`
on `g` says "`g` is called `n` times. *Whenever `g` is called*, the
result is used according to `cd`". Example from #18903:

```hs
h :: Int -> Int
h m =
  let g :: Int -> (Int,Int)
      g 1 = (m, 0)
      g n = (2 * n, 2 `div` n)
      {-# NOINLINE g #-}
  in case m of
    1 -> 0
    2 -> snd (g m)
    _ -> uncurry (+) (g m)
```

Without the interleaved representation, we would just get `L` for the
strictness demand on `g`. Now we are able to express that whenever
`g` is called, its second component is used strictly in denoting `g`
by `1C1(P(1P(U),SP(U)))`. This would allow Nested CPR to unbox the
division, for example.

Fixes #18903.
While fixing regressions, I also discovered and fixed #18957.

Metric Decrease:
    T13253-spj

- - - - -
3a55b3a2 by Sebastian Graf at 2020-11-20T02:09:51-05:00
Update user's guide entry on demand analysis and worker/wrapper

The demand signature notation has been undocumented for a long time.
The only source to understand it, apart from reading the `Outputable`
instance, has been an outdated wiki page.

Since the previous commits have reworked the demand lattice, I took
it as an opportunity to also write some documentation about notation.

- - - - -
fc963932 by Greg Steuck at 2020-11-20T02:10:31-05:00
Find hadrian location more reliably in cabal-install output

Fix #18944

- - - - -
9f40cf6c by Ben Gamari at 2020-11-20T02:11:07-05:00
rts/linker: Align bssSize to page size when mapping symbol extras

We place symbol_extras right after bss. We also need
to ensure that symbol_extras can be mprotect'd independently from the
rest of the image. To ensure this we round up the size of bss to a page
boundary, thus ensuring that symbol_extras is also page-aligned.

- - - - -
b739c319 by Ben Gamari at 2020-11-20T02:11:43-05:00
gitlab-ci: Add usage message to ci.sh

- - - - -
802e9180 by Ben Gamari at 2020-11-20T02:11:43-05:00
gitlab-ci: Add VERBOSE environment variable

And change the make build system's default behavior to V=0, greatly
reducing build log sizes.

- - - - -
2a8a979c by Ben Gamari at 2020-11-21T01:13:26-05:00
users-guide: A bit of clean-up in profiling flag documentation

- - - - -
56804e33 by Ben Gamari at 2020-11-21T01:13:26-05:00
testsuite: Refactor CountParserDeps

- - - - -
53ad67ea by Ben Gamari at 2020-11-21T01:13:26-05:00
Introduce -fprof-callers flag

This introducing a new compiler flag to provide a convenient way to
introduce profiler cost-centers on all occurrences of the named
identifier.

Closes #18566.

- - - - -
ecfd0278 by Sylvain Henry at 2020-11-21T01:14:09-05:00
Move Plugins into HscEnv (#17957)

Loaded plugins have nothing to do in DynFlags so this patch moves them
into HscEnv (session state).

"DynFlags plugins" become "Driver plugins" to still be able to register
static plugins.

Bump haddock submodule

- - - - -
72f2257c by Sylvain Henry at 2020-11-21T01:14:09-05:00
Don't initialize plugins in the Core2Core pipeline

Some plugins can be added via TH (cf addCorePlugin). Initialize them in
the driver instead of in the Core2Core pipeline.

- - - - -
ddbeeb3c by Ryan Scott at 2020-11-21T01:14:44-05:00
Add regression test for #10504

This issue was fixed at some point between GHC 8.0 and 8.2. Let's add a
regression test to ensure that it stays fixed.

Fixes #10504.

- - - - -
a4a6dc2a by Ben Gamari at 2020-11-21T01:15:21-05:00
dwarf: Apply info table offset consistently

Previously we failed to apply the info table offset to the aranges and
DIEs, meaning that we often failed to unwind in gdb. For some reason
this only seemed to manifest in the RTS's Cmm closures. Nevertheless,
now we can unwind completely up to `main`

- - - - -
69bfbc21 by Ben Gamari at 2020-11-21T01:15:56-05:00
hadrian: Disable stripping when debug information is enabled

- - - - -
7e93ae8b by Ben Gamari at 2020-11-21T13:13:29-05:00
rts: Post ticky entry counts to the eventlog

We currently only post the entry counters, not the other global
counters as in my experience the former are more useful. We use the heap
profiler's census period to decide when to dump.

Also spruces up the documentation surrounding ticky-ticky a bit.

- - - - -
bc9c3916 by Ben Gamari at 2020-11-22T06:28:10-05:00
Implement -ddump-c-backend argument

To dump output of the C backend.

- - - - -
901bc220 by Ben Gamari at 2020-11-22T12:39:02-05:00
Bump time submodule to 1.11.1

Also bumps directory, Cabal, hpc, time, and unix submodules.

Closes #18847.

- - - - -
92c0afbf by Ben Gamari at 2020-11-22T12:39:38-05:00
hadrian: Dump STG when ticky is enabled

This changes the "ticky" modifier to enable dumping of final STG as this
is generally needed to make sense of the ticky profiles.

- - - - -
d23fef68 by Ben Gamari at 2020-11-22T12:39:38-05:00
hadrian: Introduce notion of flavour transformers

This extends Hadrian's notion of "flavour", as described in #18942.

- - - - -
179d0bec by Ben Gamari at 2020-11-22T12:39:38-05:00
hadrian: Add a viaLlvmBackend modifier

Note that this also slightly changes the semantics of these flavours as
we only use LLVM for >= stage1 builds.

- - - - -
d4d95e51 by Ben Gamari at 2020-11-22T12:39:38-05:00
hadrian: Add profiled_ghc and no_dynamic_ghc modifiers

- - - - -
6815603f by Ben Gamari at 2020-11-22T12:39:38-05:00
hadrian: Drop redundant flavour definitions

Drop the profiled, LLVM, and ThreadSanitizer flavour definitions as
these can now be realized with flavour transformers.

- - - - -
f88f4339 by Ben Gamari at 2020-11-24T02:43:20-05:00
rts: Flush eventlog buffers from flushEventLog

As noted in #18043, flushTrace failed flush anything beyond the writer.
This means that a significant amount of data sitting in capability-local
event buffers may never get flushed, despite the users' pleads for us to
flush.

Fix this by making flushEventLog flush all of the event buffers before
flushing the writer.

Fixes #18043.

- - - - -
7c03cc50 by Ben Gamari at 2020-11-24T02:43:55-05:00
gitlab-ci: Run LLVM job on appropriately-labelled MRs

Namely, those marked with the ~"LLVM backend" label

- - - - -
9b95d815 by Ben Gamari at 2020-11-24T02:43:55-05:00
gitlab-ci: Run LLVM builds on Debian 10

The current Debian 9 image doesn't provide LLVM 7.

- - - - -
2ed3e6c0 by Ben Gamari at 2020-11-24T02:43:55-05:00
CmmToLlvm: Declare signature for memcmp

Otherwise `opt` fails with:

    error: use of undefined value '@memcmp$def'

- - - - -
be5d74ca by Moritz Angermann at 2020-11-26T16:00:32-05:00
[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.

This does change the expected output of T16402 but the new result is no
less correct as it eliminates the narrowing (instead of the `and` as was
previously done).

Bumps the array, bytestring, text, and binary submodules.

Co-Authored-By: Ben Gamari <ben at well-typed.com>

Metric Increase:
    T13701
    T14697

- - - - -
a84e53f9 by Andreas Klebinger at 2020-11-26T16:00:32-05:00
RTS: Fix failed inlining of copy_tag.

On windows using gcc-10 gcc failed to inline copy_tag into evacuate.

To fix this we now set the always_inline attribute for the various
copy* functions in Evac.c. The main motivation here is not the
overhead of the function call, but rather that this allows the code
to "specialize" for the size of the closure we copy which is often
known at compile time.

An earlier commit also tried to avoid evacuate_large inlining. But
didn't quite succeed. So I also marked evacuate_large as noinline.

Fixes #12416

- - - - -
cdbd16f5 by Sylvain Henry at 2020-11-26T16:00:33-05:00
Fix toArgRep to support 64-bit reps on all systems

[This is @Ericson2314 writing a commit message for @hsyl20's patch.]

(Progress towards #11953, #17377, #17375)

`Int64Rep` and `Word64Rep` are currently broken on 64-bit systems.  This
is because they should use "native arg rep" but instead use "large arg
rep" as they do on 32-bit systems, which is either a non-concept or a
128-bit rep depending on one's vantage point.

Now, these reps currently aren't used during 64-bit compilation, so the
brokenness isn't observed, but I don't think that constitutes reasons
not to fix it. Firstly, the linked issues there is a clearly expressed
desire to use explicit-bitwidth constructs in more places. Secondly, per
[1], there are other bugs that *do* manifest from not threading
explicit-bitwidth information all the way through the compilation
pipeline. One can therefore view this as one piece of the larger effort
to do that, improve ergnomics, and squash remaining bugs.

Also, this is needed for !3658. I could just merge this as part of that,
but I'm keen on merging fixes "as they are ready" so the fixes that
aren't ready are isolated and easier to debug.

[1]: https://mail.haskell.org/pipermail/ghc-devs/2020-October/019332.html

- - - - -
a9378e69 by Tim Barnes at 2020-11-26T16:00:34-05:00
Set dynamic users-guide TOC spacing (fixes #18554)

- - - - -
86a59d93 by Ben Gamari at 2020-11-26T16:00:34-05:00
rts: Use RTS_LIKELY in CHECK

Most compilers probably already infer that
`barf` diverges but it nevertheless doesn't
hurt to be explicit.
- - - - -
5757e82b by Matthew Pickering at 2020-11-26T16:00:35-05:00
Remove special case for GHC.ByteCode.Instr

This was added in
https://github.com/nomeata/ghc-heap-view/commit/34935206e51b9c86902481d84d2f368a6fd93423

GHC.ByteCode.Instr.BreakInfo no longer exists so the special case is dead code.

Any check like this can be easily dealt with in client code.

- - - - -
d9c8b5b4 by Matthew Pickering at 2020-11-26T16:00:35-05:00
Split Up getClosureDataFromHeapRep

Motivation

1. Don't enforce the repeated decoding of an info table, when the client
can cache it (ghc-debug)
2. Allow the constructor information decoding to be overridden, this
casues segfaults in ghc-debug

- - - - -
3e3555cc by Andreas Klebinger at 2020-11-26T16:00:35-05:00
RegAlloc: Add missing raPlatformfield to RegAllocStatsSpill

Fixes #18994

Co-Author: Benjamin Maurer <maurer.benjamin at gmail.com>

- - - - -
a1a75aa9 by Ben Gamari at 2020-11-27T06:20:41-05:00
rts: Allocate MBlocks with MAP_TOP_DOWN on Windows

As noted in #18991, we would previously allocate heap in low memory.
Due to this the linker, which typically *needs* low memory, would end up
competing with the heap. In longer builds we end up running out of
low memory entirely, leading to linking failures.

- - - - -
b3915e9c by Shayne Fletcher at 2020-11-27T12:43:10-05:00
Record dot syntax

- - - - -


19 changed files:

- .gitignore
- .gitlab-ci.yml
- .gitlab/ci.sh
- + .gitlab/common.sh
- .gitlab/linters/check-cpp.py
- 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


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/b55cfb6777e4d32be25d2c4f6ea67a0f03be049b...b3915e9c503854839651b8b6917c1fef4d10f7b7

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/b55cfb6777e4d32be25d2c4f6ea67a0f03be049b...b3915e9c503854839651b8b6917c1fef4d10f7b7
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