[Git][ghc/ghc][wip/CLC208] 181 commits: haddock: decrease margin on top of small headings

Ben Gamari (@bgamari) gitlab at gitlab.haskell.org
Tue Oct 1 13:38:37 UTC 2024



Ben Gamari pushed to branch wip/CLC208 at Glasgow Haskell Compiler / GHC


Commits:
af2ae742 by M. Taimoor Zaeem at 2024-08-03T18:52:50+05:00
haddock: decrease margin on top of small headings

- - - - -
a1e42e7a by Rodrigo Mesquita at 2024-08-05T21:03:04-04:00
hi: Deterministic ImportedMods in Usages

The `mi_usages` field of the interface files must use a deterministic
list of `Usage`s to guarantee a deterministic interface. However, this
list was, in its origins, constructed from a `ModuleEnv` which uses a
non-deterministic ordering that was leaking into the interface.

Specifically, ImportedMods = ModuleEnv ... would get converted to a list and
then passed to `mkUsageInfo` to construct the Usages.

The solution is simple. Back `ImportedMods` with a deterministic map.
`Map Module ...` is enough, since the Ord instance for `Module` already
uses a stable, deterministic, comparison.

Fixes #25131

- - - - -
eb1cb536 by Serge S. Gulin at 2024-08-06T08:54:55+00:00
testsuite: extend size performance tests with gzip (fixes #25046)

The main purpose is to create tests for minimal app (hello world and its variations, i.e. unicode used) distribution size metric.

Many platforms support distribution in compressed form via gzip. It would be nice to collect information on how much size is taken by the executional bundle for each platform at minimal edge case.

2 groups of tests are added:
1. We extend javascript backend size tests with gzip-enabled versions for all cases where an optimizing compiler is used (for now it is google closure compiler).
2. We add trivial hello world tests with gzip-enabled versions for all other platforms at CI pipeline where no external optimizing compiler is used.

- - - - -
d94410f8 by Rodrigo Mesquita at 2024-08-07T11:49:19-04:00
ghc-internal: @since for backtraceDesired

Fixes point 1 in #25052

- - - - -
bfe600f5 by Rodrigo Mesquita at 2024-08-07T11:49:19-04:00
ghc-internal: No trailing whitespace in exceptions

Fixes #25052

- - - - -
62650d9f by Andreas Klebinger at 2024-08-07T11:49:54-04:00
Add since annotation for -fkeep-auto-rules.

This partially addresses #25082.

- - - - -
5f0e23fd by Andreas Klebinger at 2024-08-07T11:49:54-04:00
Mention `-fkeep-auto-rules` in release notes.

It was added earlier but hadn't appeared in any release notes yet.
Partially addresses #25082.

- - - - -
7446a09a by Sylvain Henry at 2024-08-07T11:50:35-04:00
Cmm: don't perform unsound optimizations on 32-bit compiler hosts

- beef61351b240967b49169d27a9a19565cf3c4af enabled the use of
  MO_Add/MO_Sub for 64-bit operations in the C and LLVM backends
- 6755d833af8c21bbad6585144b10e20ac4a0a1ab did the same for the x86 NCG
  backend

However we store some literal values as `Int` in the compiler. As a
result, some Cmm optimizations transformed target 64-bit literals into
compiler `Int`. If the compiler is 32-bit, this leads to computing with
wrong literals (see #24893 and #24700).

This patch disables these Cmm optimizations for 32-bit compilers. This
is unsatisfying (optimizations shouldn't be compiler-word-size
dependent) but it fixes the bug and it makes the patch easy to backport.
A proper fix would be much more invasive but it shall be implemented in
the future.

Co-authored-by: amesgen <amesgen at amesgen.de>

- - - - -
d59faaf2 by Vladislav Zavialov at 2024-08-07T11:51:11-04:00
docs: Update info on RequiredTypeArguments

Add a section on "types in terms" that were implemented in 8b2f70a202
and remove the now outdated suggestion of using `type` for them.

- - - - -
39fd6714 by Sylvain Henry at 2024-08-07T11:51:52-04:00
JS: fix minor typo in base's jsbits

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e7764575 by Sylvain Henry at 2024-08-07T11:51:52-04:00
RTS: remove hack to force old cabal to build a library with only JS sources

Need to extend JSC externs with Emscripten RTS definitions to avoid
JSC_UNDEFINED_VARIABLE errors when linking without the emcc rts.

Fix #25138

Some recompilation avoidance tests now fail. This is tracked with the
other instances of this failure in #23013. My hunch is that they were
working by chance when we used the emcc linker.

Metric Decrease:
    T24602_perf_size

- - - - -
d1a40233 by Brandon Chinn at 2024-08-07T11:53:08-04:00
Support multiline strings in type literals (#25132)

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610840eb by Sylvain Henry at 2024-08-07T11:53:50-04:00
JS: fix callback documentation (#24377)

Fix #24377

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6ae4b76a by Zubin Duggal at 2024-08-13T13:36:57-04:00
haddock: Build haddock-api and haddock-library using hadrian

We build these two packages as regular boot library dependencies rather
than using the `in-ghc-tree` flag to include the source files into the haddock
executable.

The `in-ghc-tree` flag is moved into haddock-api to ensure that haddock built
from hackage can still find the location of the GHC bindist using `ghc-paths`.

Addresses #24834

This causes a metric decrease under non-release flavours because under these
flavours libraries are compiled with optimisation but executables are not.

Since we move the bulk of the code from the haddock executable to the
haddock-api library, we see a metric decrease on the validate flavours.

Metric Decrease:
    haddock.Cabal
    haddock.base
    haddock.compiler

- - - - -
51ffba5d by Arnaud Spiwack at 2024-08-13T13:37:50-04:00
Add an extension field to HsRecFields

This is the Right Thing to Do™. And it prepares for storing a
multiplicity coercion there.

First step of the plan outlined here and below
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12947#note_573091

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4d2faeeb by Arnaud Spiwack at 2024-08-13T13:37:50-04:00
Add test for #24961

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623b4337 by Arnaud Spiwack at 2024-08-13T13:37:50-04:00
Ensures that omitted record fields in pattern have multiplicity Many

Omitted fields were simply ignored in the type checker and produced
incorrect Core code.

Fixes #24961

Metric Increase:
    RecordUpdPerf

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c749bdfd by Sylvain Henry at 2024-08-13T13:38:41-04:00
AARCH64 linker: skip NONE relocations

This patch is part of the patches upstreamed from haskell.nix.
See https://github.com/input-output-hk/haskell.nix/pull/1960 for the
original report/patch.

- - - - -
682a6a41 by Brandon Chinn at 2024-08-13T13:39:17-04:00
Support multiline strings in TH

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ee0a9c18 by Matthew Pickering at 2024-08-14T14:27:39-04:00
Extend -reexported-module flag to support module renaming

The -reexported-module flag now supports renaming -rexported-modules.

```
-rexported-module "A as B"
```

This feature is only relevant to multi-component sessions.

Fixes #25139

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e9496000 by Arnaud Spiwack at 2024-08-14T14:28:20-04:00
Don't restrict eta-reduction of linear functions

This commit simply removes code. All the supporting implementation has
been done as part of !12883.

Closes #25129

- - - - -
2bb4156e by sheaf at 2024-08-14T14:28:56-04:00
Allow @ character in C labels

Generated symbol names can include the '@' character, for example when using
`__attribute__((vectorcall))`.
- - - - -
7602ca23 by Sylvain Henry at 2024-08-14T14:29:36-04:00
Linker: replace blind tuple with a datatype + docs

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bdd77b9e by sheaf at 2024-08-16T12:47:11-04:00
isIrrefutableHsPat: look up ConLikes in the HscEnv

At GhcRn stage, in isIrrefutableHsPat we only looked up data constructors
in the RdrEnv, which meant that we lacked fallibility information for
out-of-scope constructors (which can arise from Template Haskell splices).

Instead, we use 'lookupGREInfo', which looks up the information in
the type environment. This was the correct function to call all along,
but was not used in 572fbc44 due to import cycle reasons. The appropriate
functions, 'irrefutableConLike{Rn,Tc}' have been moved to 'GHC.Rename.Env',
which avoids import cycles.

Fixes #25164

- - - - -
4bee377c by Sylvain Henry at 2024-08-16T12:47:53-04:00
Linker: some refactoring to prepare for #24886

- Rename LoadedBCOs into LazyBCOs
- Bundle SptEntries with CompiledByteCode and removed [SptEntry] field
  from the BCOs constructor
- Rename Linkable's LM constructor into Linkable: in the past we had LM
  and LP for Module and Package, now we only have the former.
- Rename Unlinked into LinkablePart (and linkableUnlinked into
  linkableParts)
- Use NonEmpty to encode invariant in Linkable's linkableParts type
- Add helpers: linkableLibs, linkableBCOs, etc.
- Add documentation
- Remove partial nameOfObject
- Rename nameOfObject_maybe into linkablePartPath
- Rename byteCodeOfObject into linkablePartAllBCOs.
- Refactor linkablePartAllBCOs to avoid a panic if a LazyBCO has a C
  stub. Document the fact that LazyBCOs are returned in this case
  (contrary to linkableBCOs which only returns non-lazy ones)

Refactoring done while trying to understand how to adapt the linker code
to support the JS backend too (cf #24886).

- - - - -
fa0dbaca by Mario Blažević at 2024-08-17T03:31:32+00:00
Implements the Exportable Named Default proposal (#24305)

This squashed commit adds support for exportable named defaults, the accepted
GHC proposal at https://github.com/ghc-proposals/ghc-proposals/pull/409

The proposal extends the Haskell '98 declarations

    default (Int, Double)

which were implicitly always applying to Num class alone, to allow specifying
an arbitrary single-parameter class:

    default IsString (Text, String)

The effect of this declaration would be to eliminate the ambiguous type errors
around string literals when OverloadedStrings extension is active. The
declaration by itself has effect only in its module, so the proposal also adds
the ability to export class defaults:

    module MyModule (default IsIstring)

Once the language extension is published and established, we can consider using
it in base and other libraries.

See Note [Named default declarations] in GHC.Tc.Gen.Default
for implementation details.

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1deba6b2 by Simon Peyton Jones at 2024-08-17T13:58:13-04:00
Make kick-out more selective

This MR revised the crucial kick-out criteria in the constraint solver.

Ticket #24984 showed an example in which
 * We were kicking out unnecessarily
 * That gave rise to extra work, of course
 * But it /also/ led to exponentially-sized coercions due to lack
   of sharing in coercions (something we want to fix separately #20264)

This MR sharpens up the kick-out criteria; specifially in (KK2) we look
only under type family applications if (fs>=fw).

This forced me to understand the existing kick-out story, and I ended
up rewriting many of the careful Notes in GHC.Tc.Solver.InertSet.
Especially look at the new `Note [The KickOut Criteria]`

The proof of termination is not air-tight, but it is better than before,
and both Richard and I think it's correct :-).

- - - - -
88488847 by Cheng Shao at 2024-08-18T04:44:01+02:00
testsuite: remove undesired -fasm flag from test ways

This patch removes the -fasm flag from test ways, except ways like
optasm that explicitly state they are meant to be compiled with NCG
backend. Most test ways should use the default codegen backend, and
the precense of -fasm can cause stderr mismatches like this when GHC
is configured with the unregisterised backend:

```
--- /dev/null
+++ /tmp/ghctest-3hydwldj/test   spaces/testsuite/tests/profiling/should_compile/prof-late-cc.run/prof-late-cc.comp.stderr.normalised
@@ -0,0 +1,2 @@
+when making flags consistent: warning: [GHC-74335] [-Winconsistent-flags (in -Wdefault)]
+    Target platform uses unregisterised ABI, so compiling via C
*** unexpected failure for prof-late-cc(prof_no_auto)
```

This has been breaking the wasm unreg nightly job since !12595 landed.

- - - - -
3a145315 by Cheng Shao at 2024-08-18T13:05:45-04:00
ghci: fix isMinTTY.h casing for Windows targets

This commit fixes isMinTTY.h casing in isMinTTY.c that's compiled for
Windows targets. While this looks harmless given Windows filesystems
are case-insensitive by default, it does cause a compilation warning
with recent versions of clang, so we might as well fix the casing:

```
driver\ghci\isMinTTY.c:10:10: error:
     warning: non-portable path to file '"isMinTTY.h"'; specified path differs in case from file name on disk [-Wnonportable-include-path]
   |
10 | #include "isMINTTY.h"
   |          ^

 #include "isMINTTY.h"
         ^~~~~~~~~~~~
         "isMinTTY.h"
1 warning generated.
```

- - - - -
5f972bfb by Zubin Duggal at 2024-08-21T03:18:15-04:00
compiler: Fix pretty printing of ticked prefix constructors (#24237)

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ef0a08e7 by Mike Pilgrem at 2024-08-21T03:18:57-04:00
Fix #15773 Clarify further -rtsopts 'defaults' in docs

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05a4be58 by Sebastian Graf at 2024-08-21T03:19:33-04:00
Improve efficiency of `assertError` (#24625)

... by moving `lazy` to the exception-throwing branch.
It's all documented in `Note [Strictness of assertError]`.

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c29b2b5a by sheaf at 2024-08-21T13:11:30-04:00
GHCi debugger: drop record name spaces for Ids

When binding new local variables at a breakpoint, we should create
Ids with variable namespace, and not record field namespace. Otherwise
the rest of the compiler falls over because the IdDetails are wrong.

Fixes #25109

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bd82ac9f by Hécate Kleidukos at 2024-08-21T13:12:12-04:00
base: Final deprecation of GHC.Pack

The timeline mandated by #21461 has come to its term and after two years
and four minor releases, we are finally removing GHC.Pack from base.

Closes #21536

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5092dbff by Sylvain Henry at 2024-08-21T13:12:54-04:00
JS: support rubbish static literals (#25177)

Support for rubbish dynamic literals was added in #24664. This patch
does the same for static literals.

Fix #25177

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b5a2c061 by Phil de Joux at 2024-08-21T13:13:33-04:00
haddock docs: prefix comes before, postfix comes after

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6fde3685 by Marcin Szamotulski at 2024-08-21T23:15:39-04:00
haddock: include package info with --show-interface

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7e02111b by Andreas Klebinger at 2024-08-21T23:16:15-04:00
Document the (x86) SIMD macros.

Fixes #25021.

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05116c83 by Rodrigo Mesquita at 2024-08-22T10:37:44-04:00
ghc-internal: Derive version from ghc's version

Fixes #25005

- - - - -
73f5897d by Ben Gamari at 2024-08-22T10:37:44-04:00
base: Deprecate GHC.Desugar

See https://github.com/haskell/core-libraries-committee/issues/216.

This will be removed in GHC 9.14.

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821d0a9a by Cheng Shao at 2024-08-22T10:38:22-04:00
compiler: Store ForeignStubs and foreign C files in interfaces

This data is used alongside Core bindings to reconstruct intermediate
build products when linking Template Haskell splices with bytecode.

Since foreign stubs and files are generated in the pipeline, they were
lost with only Core bindings stored in interfaces.

The interface codec type `IfaceForeign` contains a simplified
representation of `ForeignStubs` and the set of foreign sources that
were manually added by the user.

When the backend phase writes an interface, `mkFullIface` calls
`encodeIfaceForeign` to read foreign source file contents and assemble
`IfaceForeign`.

After the recompilation status check of an upstream module,
`initWholeCoreBindings` calls `decodeIfaceForeign` to restore
`ForeignStubs` and write the contents of foreign sources to the file
system as temporary files.
The restored foreign inputs are then processed by `hscInteractive` in
the same manner as in a regular pipeline.

When linking the stub objects for splices, they are excluded from suffix
adjustment for the interpreter way through a new flag in `Unlinked`.

For details about these processes, please consult Note [Foreign stubs
and TH bytecode linking].

Metric Decrease:
    T13701

- - - - -
f0408eeb by Cheng Shao at 2024-08-23T10:37:10-04:00
git: remove a.out and include it in .gitignore

a.out is a configure script byproduct. It was mistakenly checked into
the tree in !13118. This patch removes it, and include it in
.gitignore to prevent a similar error in the future.

- - - - -
1f95c5e4 by Matthew Pickering at 2024-08-23T10:37:46-04:00
docs: Fix code-block syntax on old sphinx version

This code-block directive breaks the deb9 sphinx build.

Fixes #25201

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27dceb42 by Sylvain Henry at 2024-08-26T11:05:11-04:00
JS: add basic support for POSIX *at functions (#25190)

openat/fstatat/unlinkat/dup are now used in the recent release of the
`directory` and `file-io` packages.

As such, these functions are (indirectly) used in the following tests
one we'll bump the `directory` submodule (see !13122):
- openFile008
- jsOptimizer
- T20509
- bkpcabal02
- bkpcabal03
- bkpcabal04

- - - - -
c68be356 by Matthew Pickering at 2024-08-26T11:05:11-04:00
Update directory submodule to latest master

The primary reason for this bump is to fix the warning from `ghc-pkg
check`:

```
Warning: include-dirs: /data/home/ubuntu/.ghcup/ghc/9.6.2/lib/ghc-9.6.2/lib/../lib/aarch64-linux-ghc-9.6.2/directory-1.3.8.1/include doesn't exist or isn't a directory
```

This also requires adding the `file-io` package as a boot library (which
is discussed in #25145)

Fixes #23594 #25145

- - - - -
4ee094d4 by Matthew Pickering at 2024-08-26T11:05:47-04:00
Fix aarch64-alpine target platform description

We are producing bindists where the target triple is

aarch64-alpine-linux

when it should be

aarch64-unknown-linux

This is because the bootstrapped compiler originally set the target
triple to `aarch64-alpine-linux` which is when propagated forwards by
setting `bootstrap_target` from the bootstrap compiler target.

In order to break this chain we explicitly specify build/host/target for
aarch64-alpine.

This requires a new configure flag `--enable-ignore-` which just
switches off a validation check that the target platform of the
bootstrap compiler is the same as the build platform. It is the same,
but the name is just wrong.

These commits can be removed when the bootstrap compiler has the correct
target triple (I looked into patching this on ci-images, but it looked
hard to do correctly as the build/host platform is not in the settings
file).

Fixes #25200

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e0e0f2b2 by Matthew Pickering at 2024-08-26T11:05:47-04:00
Bump nixpkgs commit for gen_ci script

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63a27091 by doyougnu at 2024-08-26T20:39:30-04:00
rts: win32: emit additional debugging information

-- migration from haskell.nix

- - - - -
aaab3d10 by Vladislav Zavialov at 2024-08-26T20:40:06-04:00
Only export defaults when NamedDefaults are enabled (#25206)

This is a reinterpretation of GHC Proposal #409 that avoids a breaking
change introduced in fa0dbaca6c "Implements the Exportable Named Default proposal"

Consider a module M that has no explicit export list:

	module M where
	default (Rational)

Should it export the default (Rational)?

The proposal says "yes", and there's a test case for that:

	default/DefaultImport04.hs

However, as it turns out, this change in behavior breaks existing
programs, e.g. the colour-2.3.6 package can no longer be compiled,
as reported in #25206.

In this patch, we make implicit exports of defaults conditional on
the NamedDefaults extension. This fix is unintrusive and compliant
with the existing proposal text (i.e. it does not require a proposal
amendment). Should the proposal be amended, we can go for a simpler
solution, such as requiring all defaults to be exported explicitly.

Test case: testsuite/tests/default/T25206.hs

- - - - -
3a5bebf8 by Matthew Pickering at 2024-08-28T14:16:42-04:00
simplifier: Fix space leak during demand analysis

The lazy structure (a list) in a strict field in `DmdType` is not fully
forced which leads to a very large thunk build-up.

It seems there is likely still more work to be done here as it seems we
may be trading space usage for work done. For now, this is the right
choice as rather than using all the memory on my computer, compilation
just takes a little bit longer.

See #25196

- - - - -
c2525e9e by Ryan Scott at 2024-08-28T14:17:17-04:00
Add missing parenthesizeHsType in cvtp's InvisP case

We need to ensure that when we convert an `InvisP` (invisible type pattern) to
a `Pat`, we parenthesize it (at precedence `appPrec`) so that patterns such as
`@(a :: k)` will parse correctly when roundtripped back through the parser.

Fixes #25209.

- - - - -
1499764f by Sjoerd Visscher at 2024-08-29T16:52:56+02:00
Haddock: Add no-compilation flag

This flag makes sure to avoid recompilation of the code when generating documentation by only reading the .hi and .hie files, and throw an error if it can't find them.

- - - - -
768fe644 by Andreas Klebinger at 2024-09-03T13:15:20-04:00
Add functions to check for weakly pinned arrays.

This commit adds `isByteArrayWeaklyPinned#` and `isMutableByteArrayWeaklyPinned#` primops.
These check if a bytearray is *weakly* pinned. Which means it can still be explicitly moved
by the user via compaction but won't be moved by the RTS.

This moves us one more stop closer to nailing down #22255.

- - - - -
b16605e7 by Arsen Arsenović at 2024-09-03T13:16:05-04:00
ghc-toolchain: Don't leave stranded a.outs when testing for -g0

This happened because, when ghc-toolchain tests for -g0, it does so by
compiling an empty program.  This compilation creates an a.out.

Since we create a temporary directory, lets place the test program
compilation in it also, so that it gets cleaned up.

Fixes: 25b0b40467d0a12601497117c0ad14e1fcab0b74
Closes: https://gitlab.haskell.org/ghc/ghc/-/issues/25203

- - - - -
83e70b14 by Torsten Schmits at 2024-09-03T13:16:41-04:00
Build foreign objects for TH with interpreter's way when loading from iface

Fixes #25211

When linking bytecode for TH from interface core bindings with
`-fprefer-byte-code`, foreign sources are loaded from the interface as
well and compiled to object code in an ad-hoc manner.

The results are then loaded by the interpreter, whose way may differ
from the current build's target way.

This patch ensures that foreign objects are compiled with the
interpreter's way.

- - - - -
0d3bc2fa by Cheng Shao at 2024-09-04T07:20:06-04:00
rts: fix checkClosure error message

This patch fixes an error message in checkClosure() when the closure
has already been evacuated. The previous logic was meant to print the
evacuated closure's type in the error message, but it was completely
wrong, given info was not really an info table, but a tagged pointer
that points to the closure's new address.

- - - - -
fb0a4e5c by Sven Tennie at 2024-09-04T07:20:43-04:00
MO_AcquireFence: Less restrictive barrier

GCC and CLang translate the built-in `atomic_thread_fence(memory_order_acquire)`
to `dmb ishld`, which is a bit less restrictive than `dmb ish` (which
also implies stores.)

- - - - -
a45f1488 by Fendor at 2024-09-04T20:22:00-04:00
testsuite: Add support to capture performance metrics via 'perf'

Performance metrics collected via 'perf' can be more accurate for
run-time performance than GHC's rts, due to the usage of hardware
counters.

We allow performance tests to also record PMU events according to 'perf
list'.

- - - - -
ce61fca5 by Fendor at 2024-09-04T20:22:00-04:00
gitlab-ci: Add nightly job for running the testsuite with perf profiling support

- - - - -
6dfb9471 by Fendor at 2024-09-04T20:22:00-04:00
Enable perf profiling for compiler performance tests

- - - - -
da306610 by sheaf at 2024-09-04T20:22:41-04:00
RecordCon lookup: don't allow a TyCon

This commit adds extra logic when looking up a record constructor.
If GHC.Rename.Env.lookupOccRnConstr returns a TyCon (as it may, due to
the logic explained in Note [Pattern to type (P2T) conversion]),
we emit an error saying that the data constructor is not in scope.

This avoids the compiler falling over shortly thereafter, in the call to
'lookupConstructorInfo' inside 'GHC.Rename.Env.lookupRecFieldOcc',
because the record constructor would not have been a ConLike.

Fixes #25056

- - - - -
9c354beb by Matthew Pickering at 2024-09-04T20:23:16-04:00
Use deterministic names for temporary files

When there are multiple threads they can race to create a temporary
file, in some situations the thread will create ghc_1.c and in some it
will create ghc_2.c. This filename ends up in the debug info for object
files after compiling a C file, therefore contributes to object
nondeterminism.

In order to fix this we store a prefix in `TmpFs` which serves to
namespace temporary files. The prefix is populated from the counter in
TmpFs when the TmpFs is forked. Therefore the TmpFs must be forked
outside the thread which consumes it, in a deterministic order, so each
thread always receives a TmpFs with the same prefix.

This assumes that after the initial TmpFs is created, all other TmpFs
are created from forking the original TmpFs. Which should have been try
anyway as otherwise there would be file collisions and non-determinism.

Fixes #25224

- - - - -
59906975 by Hécate Kleidukos at 2024-09-05T10:57:15-04:00
Silence x-partial in Haddock.Backends.Xhtml

This is an unfortunate consequence of two mechanisms:
  * GHC provides (possibly-empty) lists of names
  * The functions that retrieve those names are not equipped to do error
    reporting, and thus accept these lists at face value. They will have
    to be attached an effect for error reporting in a later refactoring

- - - - -
8afbab62 by Hécate Kleidukos at 2024-09-05T10:57:15-04:00
hadrian: Support loading haddock in ghci

There is one tricky aspect with wired-in packages where the boot package
is built with `-this-unit-id ghc` but the dependency is reported as
`-package-id ghc-9.6...`. This has never been fixed in GHC as the
situation of loading wired-in packages into the multi-repl seems like
quite a niche feature that is always just easier to workaround.

- - - - -
6cac9eb8 by Matthew Pickering at 2024-09-05T10:57:15-04:00
hadrian/multi: Load all targets when ./hadrian/ghci-multi is called

This seems to make a bit more sense than just loading `ghc` component
(and dependencies).

- - - - -
7d84df86 by Matthew Pickering at 2024-09-05T10:57:51-04:00
ci: Beef up determinism interface test

There have recently been some determinism issues with the simplifier and
documentation. We enable more things to test in the ABI test to check
that we produce interface files deterministically.

- - - - -
5456e02e by Sylvain Henry at 2024-09-06T11:57:01+02:00
Transform some StgRhsClosure into StgRhsCon after unarisation (#25166)

Before unarisation we may have code like:

  Test.foo :: Test.D
  [GblId, Unf=OtherCon []] =
      \u []
          case (# |_| #) [GHC.Types.(##)] of sat_sAw [Occ=Once1] {
          __DEFAULT -> Test.D [GHC.Types.True sat_sAw];
          };

After unarisation we get:

  Test.foo :: Test.D
  [GblId, Unf=OtherCon []] =
      {} \u [] Test.D [GHC.Types.True 2#];

Notice that it's still an Updatable closure for no reason anymore. This
patch transforms appropriate StgRhsClosures into StgRhsCons after
unarisation, allowing these closures to be statically allocated. Now we
get the expected:

  Test.foo :: Test.D
  [GblId, Unf=OtherCon []] =
      Test.D! [GHC.Types.True 2#];

Fix #25166

To avoid duplicating code, this patch refactors the mk(Top)StgRhs
functions and put them in a GHC.Stg.Make module alongside the new
mk(Top)StgRhsCon_maybe functions.

- - - - -
958b4518 by Hécate Kleidukos at 2024-09-06T16:40:56-04:00
haddock: Add missing requirements.txt for the online manual

- - - - -
573f9833 by Sven Tennie at 2024-09-08T09:58:21+00:00
AArch64: Implement takeRegRegMoveInstr

This has likely been forgotten.

- - - - -
20b0de7d by Hécate Kleidukos at 2024-09-08T14:19:28-04:00
haddock: Configuration fix for ReadTheDocs

- - - - -
03055c71 by Sylvain Henry at 2024-09-09T14:58:15-04:00
JS: fake support for native adjustors (#25159)

The JS backend doesn't support adjustors (I believe) and in any case if
it ever supports them it will be a native support, not one via libffi.

- - - - -
5bf0e6bc by Sylvain Henry at 2024-09-09T14:58:56-04:00
JS: remove redundant h$lstat

It was introduced a second time by mistake in
27dceb42376c34b99a38e36a33b2abc346ed390f (cf #25190)

- - - - -
ffbc2ab0 by Simon Peyton Jones at 2024-09-10T00:40:37-04:00
Refactor only newSysLocalDs

* Change newSysLocalDs to take a scaled type
* Add newSysLocalMDs that takes a type and makes a ManyTy local

Lots of files touched, nothing deep.

- - - - -
7124e4ad by Simon Peyton Jones at 2024-09-10T00:40:37-04:00
Don't introduce 'nospec' on the LHS of a RULE

This patch address #25160.  The main payload is:

* When desugaring the LHS of a RULE, do not introduce the `nospec` call
  for non-canonical evidence.  See GHC.Core.InstEnv
  Note [Coherence and specialisation: overview]

  The `nospec` call usually introdued in `dsHsWrapper`, but we don't want it
  on the LHS of a RULE (that's what caused #25160).  So now `dsHsWrapper` takes
  a flag to say if it's on the LHS of a RULE.  See wrinkle (NC1) in
  `Note [Desugaring non-canonical evidence]` in GHC.HsToCore.Binds.

But I think this flag will go away again when I have finished with my
(entirely separate) speciaise-on-values patch (#24359).

All this meant I had to re-understand the `nospec` stuff and coherence, and
that in turn made me do some refactoring, and add a lot of new documentation

The big change is that in GHC.Core.InstEnv, I changed
  the /type synonym/ `Canonical` into
  a /data type/ `CanonicalEvidence`
and documented it a lot better.

That in turn made me realise that CalLStacks were being treated with a
bit of a hack, which I documented in `Note [CallStack and ExecptionContext hack]`.

- - - - -
663daf8d by Simon Peyton Jones at 2024-09-10T00:40:37-04:00
Add defaulting of equalities

This MR adds one new defaulting strategy to the top-level
defaulting story: see Note [Defaulting equalities] in GHC.Tc.Solver.

This resolves #25029 and #25125, which showed that users were
accidentally relying on a GHC bug, which was fixed by

    commit 04f5bb85c8109843b9ac2af2a3e26544d05e02f4
    Author: Simon Peyton Jones <simon.peytonjones at gmail.com>
    Date:   Wed Jun 12 17:44:59 2024 +0100

    Fix untouchability test

    This MR fixes #24938.  The underlying problem was tha the test for
    "does this implication bring in scope any equalities" was plain wrong.

This fix gave rise to a number of user complaints; but the improved
defaulting story of this MR largely resolves them.

On the way I did a bit of refactoring, of course

* Completely restructure the extremely messy top-level defaulting
  code. The new code is in GHC.Tc.Solver.tryDefaulting, and is much,
  much, much esaier to grok.

- - - - -
e28cd021 by Andrzej Rybczak at 2024-09-10T00:41:18-04:00
Don't name a binding pattern

It's a keyword when PatternSynonyms are set.

- - - - -
b09571e2 by Simon Peyton Jones at 2024-09-10T00:41:54-04:00
Do not use an error thunk for an absent dictionary

In worker/wrapper we were using an error thunk for an absent dictionary,
but that works very badly for -XDictsStrict, or even (as #24934 showed)
in some complicated cases involving strictness analysis and unfoldings.

This MR just uses RubbishLit for dictionaries. Simple.

No test case, sadly because our only repro case is rather complicated.

- - - - -
8bc9f5f6 by Hécate Kleidukos at 2024-09-10T00:42:34-04:00
haddock: Remove support for applehelp format in the Manual

- - - - -
9ca15506 by doyougnu at 2024-09-10T10:46:38-04:00
RTS linker: add support for hidden symbols (#25191)

Add linker support for hidden symbols. We basically treat them as weak
symbols.

Patch upstreamed from haskell.nix

Co-authored-by: Sylvain Henry <sylvain at haskus.fr>
Co-authored-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
3b2dc826 by Sven Tennie at 2024-09-10T10:47:14-04:00
Fix C warnings (#25237)

GCC 14 treats the fixed warnings as errors by default. I.e. we're
gaining GCC 14 compatibility with these fixes.

- - - - -
05715994 by Sylvain Henry at 2024-09-10T10:47:55-04:00
JS: fix codegen of static string data

Before this patch, when string literals are made trivial, we would
generate `h$("foo")` instead of `h$str("foo")`. This was
introduced by mistake in 6bd850e887b82c5a28bdacf5870d3dc2fc0f5091.

- - - - -
949ebced by Hécate Kleidukos at 2024-09-10T19:19:40-04:00
haddock: Re-organise cross-OS compatibility layer

- - - - -
84ac9a99 by Hécate Kleidukos at 2024-09-10T19:19:40-04:00
haddock: Remove CPP for obsolete GHC and Cabal versions

- - - - -
370d1599 by Hécate Kleidukos at 2024-09-10T19:19:40-04:00
haddock: Move the changelog file to the 'extra-doc-files' section in the cabal file

- - - - -
cfbff65a by Simon Peyton Jones at 2024-09-10T19:20:16-04:00
Add ZonkAny and document it

This MR fixed #24817 by adding ZonkAny, which takes a Nat
argument.

See Note [Any types] in GHC.Builtin.Types, especially
wrinkle (Any4).

- - - - -
0167e472 by Matthew Pickering at 2024-09-11T02:41:42-04:00
hadrian: Make sure ffi headers are built before using a compiler

When we are using ffi adjustors then we rely on `ffi.h` and
`ffitarget.h` files during code generation when compiling stubs.

Therefore we need to add this dependency to the build system (which this
patch does).

Reproducer, configure with `--enable-libffi-adjustors` and then build
"_build/stage1/libraries/ghc-prim/build/GHC/Types.p_o".

Observe that this fails before this patch and works afterwards.

Fixes #24864

Co-authored-by: Sylvain Henry <sylvain at haskus.fr>

- - - - -
0f696958 by Rodrigo Mesquita at 2024-09-11T02:42:18-04:00
base: Deprecate BCO primops exports from GHC.Exts

See https://github.com/haskell/core-libraries-committee/issues/212.

These reexports will be removed in GHC 9.14.

- - - - -
cf0e7729 by Alan Zimmerman at 2024-09-11T02:42:54-04:00
EPA: Remove Anchor = EpaLocation synonym

This just causes confusion.

- - - - -
8e462f4d by Andrew Lelechenko at 2024-09-11T22:20:37-04:00
Bump submodule deepseq to 1.5.1.0

- - - - -
aa4500ae by Sebastian Graf at 2024-09-11T22:21:13-04:00
User's guide: Fix the "no-backtracking" example of -XOrPatterns (#25250)

Fixes #25250.

- - - - -
1c479c01 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Add Native Code Generator (NCG)

This architecture wasn't supported before.

Co-authored-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
51b678e1 by Sven Tennie at 2024-09-12T10:39:38+00:00
Adjust test timings for slower computers

Increase the delays a bit to be able to run these tests on slower
computers.

The reference was a Lichee Pi 4a RISCV64 machine.

- - - - -
a0e41741 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Add RTS linker

This architecture wasn't supported before.

Co-authored-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
d365b1d4 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Ignore divbyzero test

The architecture's behaviour differs from the test's expectations. See
comment in code why this is okay.

- - - - -
abf3d699 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Enable MulMayOflo_full test

It works and thus can be tested.

- - - - -
38c7ea8c by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: LibffiAdjustor: Ensure code caches are flushed

RISCV64 needs a specific code flushing sequence (involving fence.i) when
new code is created/loaded.

- - - - -
7edc6965 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Add additional linker symbols for builtins

We're relying on some GCC/Clang builtins. These need to be visible to
the linker (and not be stripped away.)

- - - - -
92ad3d42 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Add GHCi support

As we got a RTS linker for this architecture now, we can enable GHCi for
it.

- - - - -
a145f701 by Sven Tennie at 2024-09-12T10:39:38+00:00
RISCV64: Set codeowners of the NCG

- - - - -
8e6d58cf by Sven Tennie at 2024-09-12T10:39:38+00:00
Add test for C calling convention

Ensure that parameters and return values are correctly processed. A
dedicated test (like this) helps to get the subtleties of calling
conventions easily right.

The test is failing for WASM32 and marked as fragile to not forget to
investigate this (#25249).

- - - - -
fff55592 by Torsten Schmits at 2024-09-12T21:50:34-04:00
finder: Add `IsBootInterface` to finder cache keys

- - - - -
cdf530df by Alan Zimmerman at 2024-09-12T21:51:10-04:00
EPA: Sync ghc-exactprint to GHC

- - - - -
1374349b by Sebastian Graf at 2024-09-13T07:52:11-04:00
DmdAnal: Fast path for `multDmdType` (#25196)

This is in order to counter a regression exposed by SpecConstr.

Fixes #25196.

- - - - -
80769bc9 by Andrew Lelechenko at 2024-09-13T07:52:47-04:00
Bump submodule array to 0.5.8.0

- - - - -
49ac3fb8 by Sylvain Henry at 2024-09-16T10:33:01-04:00
Linker: add support for extra built-in symbols (#25155)

See added Note [Extra RTS symbols] and new user guide entry.

Co-authored-by: Hamish Mackenzie <Hamish.K.Mackenzie at gmail.com>
Co-authored-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
3939a8bf by Samuel Thibault at 2024-09-16T10:33:44-04:00
GNU/Hurd: Add getExecutablePath support

GNU/Hurd exposes it as /proc/self/exe just like on Linux.

- - - - -
d3b19851 by Sylvain Henry at 2024-09-17T11:03:28-04:00
RTS: expose closure_sizeW_ (#25252)

C code using the closure_sizeW macro can't be linked with the RTS linker
without this patch. It fails with:

  ghc-9.11.20240911: Failed to lookup symbol: closure_sizeW_

Fix #25252

Co-authored-by: Hamish Mackenzie <Hamish.K.Mackenzie at gmail.com>
Co-authored-by: Moritz Angermann <moritz.angermann at gmail.com>

- - - - -
137bf74d by Sebastian Graf at 2024-09-17T11:04:05-04:00
HsExpr: Inline `HsWrap` into `WrapExpr`

This nice refactoring was suggested by Simon during review:
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/13261#note_583374

Fixes #25264.

- - - - -
7fd9e5e2 by Sebastian Graf at 2024-09-17T11:04:05-04:00
Pmc: Improve Desugaring of overloaded list patterns (#25257)

This actually makes things simpler.

Fixes #25257.

- - - - -
e4169ba9 by Ben Gamari at 2024-09-18T07:55:28-04:00
configure: Correctly report when subsections-via-symbols is disabled

As noted in #24962, currently subsections-via-symbols is disabled on
AArch64/Darwin due to alleged breakage. However, `configure` reports to
the user that it is enabled. Fix this.

- - - - -
9d20a787 by Mario Blažević at 2024-09-18T07:56:08-04:00
Modified the default export implementation to match the amended spec

- - - - -
35eb4f42 by Sylvain Henry at 2024-09-18T07:57:00-04:00
FFI: don't ppr Id/Var symbols with debug info (#25255)

Even if `-dpp-debug` is enabled we should still generate valid C code.
So we disable debug info printing when rendering with Code style.

- - - - -
9e96dad8 by Sebastian Graf at 2024-09-21T17:47:59-04:00
Demand: Combine examples into Note (#25107)

Just a leftover from !13060.

Fixes #25107.

- - - - -
21aaa34b by sheaf at 2024-09-21T17:48:36-04:00
Use x86_64-unknown-windows-gnu target for LLVM on Windows

- - - - -
992a7624 by sheaf at 2024-09-21T17:48:36-04:00
LLVM: use -relocation-model=pic on Windows

This is necessary to avoid the segfaults reported in #22487.

Fixes #22487

- - - - -
c50d29be by Ryan Hendrickson at 2024-09-21T17:49:15-04:00
compiler: Use type abstractions when deriving

For deriving newtype and deriving via, in order to bring type variables
needed for the coercions into scope, GHC generates type signatures for
derived class methods. As a simplification, drop the type signatures and
instead use type abstractions to bring method type variables into scope.

- - - - -
f04fd0ae by Zubin Duggal at 2024-09-21T17:49:51-04:00
driver: Ensure we run driverPlugin for staticPlugins (#25217)

driverPlugins are only run when the plugin state changes. This meant they were
never run for static plugins, as their state never changes.

We need to keep track of whether a static plugin has been initialised to ensure
we run static driver plugins at least once. This necessitates an additional field
in the `StaticPlugin` constructor as this state has to be bundled with the plugin
itself, as static plugins have no name/identifier we can use to otherwise reference
them

- - - - -
620becd7 by Andreas Klebinger at 2024-09-21T17:50:27-04:00
Allow unknown fd device types for setNonBlockingMode.

This allows fds with a unknown device type to have blocking mode
set. This happens for example for fds from the inotify subsystem.

Fixes #25199.

- - - - -
c76e25b3 by Hécate Kleidukos at 2024-09-21T17:51:07-04:00
Use Hackage version of Cabal 3.14.0.0 for Hadrian.
We remove the vendored Cabal submodule.

Also update the bootstrap plans

Fixes #25086

- - - - -
6c83fd7f by Zubin Duggal at 2024-09-21T17:51:07-04:00
ci: Ensure we source ci.sh in any jobs that run commands outside of ci.sh

ci.sh sets up the toolchain environment, including paths for the cabal directory, the
toolchain binaries etc. If we run any commands outside of ci.sh, unless we
source ci.sh we will use the wrong values for these environment variables.

In particular, I ran into an issue where the cabal invocation `hadrian/ghci` was
using an old index state despite `ci.sh setup` updating and setting the correct
index state. This is because `ci.sh` sets the `CABAL_DIR` to a different place, which
is where the index was downloaded to, but we were using the default cabal directory
outside ci.sh

The solution is to source the correct environment `ci.sh` using `. ci.sh setup`

- - - - -
9586998d by Sven Tennie at 2024-09-21T17:51:43-04:00
ghc-toolchain: Set -fuse-ld even for ld.bfd

This reflects the behaviour of the autoconf scripts.

- - - - -
d7016e0d by Sylvain Henry at 2024-09-21T17:52:24-04:00
Parser: be more careful when lexing extended literals (#25258)

Previously we would lex invalid prefixes like "8#Int3" as [8#Int, 3].

A side-effect of this patch is that we now allow negative unsigned
extended literals. They trigger an overflow warning later anyway.

- - - - -
ca67d7cb by Zubin Duggal at 2024-09-22T02:34:06-04:00
rts: Ensure we dump new Cost Centres added by freshly loaded objects to the eventlog.

To do this, we keep track of the ID of the last cost centre we dumped in DUMPED_CC_ID,
and call dumpCostCentresToEventLog from refreshProfilingCCSs, which will dump all the new
cost centres up to the one we already dumped in DUMPED_CC_ID.

Fixes #24148

- - - - -
c0df5aa9 by Alan Zimmerman at 2024-09-22T02:34:42-04:00
EPA: Replace AnnsModule am_main with EpTokens

Working towards removing `AddEpAnn`

- - - - -
2a551cd5 by Matthew Pickering at 2024-09-24T16:33:50+05:30
ci: Run abi-test on test-abi label

- - - - -
ab4039ac by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
testsuite: Add a test for object determinism

Extends the abi_test with an object determinism check
Also includes a standalone test to be run by developers manually when
debugging issues with determinism.

- - - - -
d62c18d8 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: Sampling uniques in the CG

To achieve object determinism, the passes processing Cmm and the rest of
the code generation pipeline musn't create new uniques which are
non-deterministic.

This commit changes occurrences of non-deterministic unique sampling
within these code generation passes by a deterministic unique sampling
strategy by propagating and threading through a deterministic
incrementing counter in them. The threading is done implicitly with
`UniqDSM` and `UniqDSMT`.

Secondly, the `DUniqSupply` used to run a `UniqDSM` must be threaded
through all passes to guarantee uniques in different passes are unique
amongst them altogether. Specifically, the same `DUniqSupply` must be
threaded through the CG Streaming pipeline, starting with Driver.Main
calling `StgToCmm.codeGen`, `cmmPipeline`, `cmmToRawCmm`, and
`codeOutput` in sequence.

To thread resources through the `Stream` abstraction, we use the `UniqDSMT`
transformer on top of `IO` as the Monad underlying the Stream. `UniqDSMT` will
thread the `DUniqSupply` through every pass applied to the `Stream`, for every
element. We use @type CgStream = Stream (UniqDSMT IO)@ for the Stream used in
code generation which that carries through the deterministic unique supply.

See Note [Deterministic Uniques in the CG]

- - - - -
3bbe4af4 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: Cmm unique renaming pass

To achieve object determinism, we need to prevent the non-deterministic
uniques from leaking into the object code. We can do this by
deterministically renaming the non-external uniques in the Cmm groups
that are yielded right after StgToCmm.

The key to deterministic renaming is observing that the order of
declarations, instructions, and data in the Cmm groups are already
deterministic (modulo other determinism bugs), regardless of the
uniques. We traverse the Cmm AST in this deterministic order and
rename the uniques, incrementally, in the order they are found, thus
making them deterministic. This renaming is guarded by
-fobject-determinism which is disabled by default for now.

This is one of the key passes for object determinism. Read about the
overview of object determinism and a more detailed explanation of this
pass in:
* Note [Object determinism]
* Note [Renaming uniques deterministically]

Significantly closes the gap to #12935

- - - - -
8357ed50 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: DCmmGroup vs CmmGroup

Part of our strategy in producing deterministic objects, namely,
renaming all Cmm uniques in order, depend on the object code produced
having a deterministic order (say, A_closure always comes before
B_closure).

However, the use of LabelMaps in the Cmm representation invalidated this
requirement because the LabelMaps elements would already be in a
non-deterministic order (due to the original uniques), and the renaming
in sequence wouldn't work because of that non-deterministic order.

Therefore, we now start off with lists in CmmGroup (which preserve the
original order), and convert them into LabelMaps (for performance in the
code generator) after the uniques of the list elements have been
renamed.

See Note [DCmmGroup vs CmmGroup or: Deterministic Info Tables] and #12935.

Co-authored-by: Matthew Pickering <matthewtpickering at gmail.com>

- - - - -
0e675fb8 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: Don't print unique in pprFullName

This unique was leaking as part of the profiling description in info
tables when profiling was enabled, despite not providing information
relevant to the profile.

- - - - -
340f58b0 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: UDFM for distinct-constructor-tables

In order to produce deterministic objects when compiling with
-distinct-constructor-tables, we also have to update the data
constructor map to be backed by a deterministic unique map (UDFM) rather
than a non-deterministic one (UniqMap).

- - - - -
282f37a0 by Rodrigo Mesquita at 2024-09-24T16:33:50+05:30
determinism: InfoTableMap uniques in generateCgIPEStub

Fixes object determinism when using -finfo-table-map

Make sure to also deterministically rename the IPE map (as per Note
[Renaming uniques deterministically]), and to use a deterministic unique
supply when creating new labels for the IPE information to guarantee
deterministic objects when IPE information is requested.

Note that the Cmm group produced in generateCgIPEStub must /not/ be
renamed because renaming uniques is not idempotent, and the references
to the previously renamed code in the IPE Cmm group would be renamed
twice and become invalid references to non-existent symbols.

We do need to det-rename the InfoTableMap that is created in the
conversion from Core to Stg. This is not a problem since that map won't
refer any already renamed names (since it was created before the
renaming).

- - - - -
7b37afc9 by Zubin Duggal at 2024-09-24T16:33:50+05:30
ci: Allow abi-test to fail.

We are not fully deterministic yet, see #12935 for work that remains to be done.

- - - - -
a63ee33a by Simon Peyton Jones at 2024-09-25T17:08:24-04:00
Add Given injectivity for built-in type families

Ticket #24845 asks (reasonably enough) that if we have
   [G] a+b ~ 0
then we also know
   [G] a ~ 0, b ~ 0
and similar injectivity-like facts for other built-in type
families.  The status quo was that we never generate evidence for
injectivity among Givens -- but it is quite reasonnable to do so.
All we need is to have /evidence/ for the new constraints

This MR implements that goal.  I also took the opportunity to
* Address #24978: refactoring UnivCo
* Fix #25248, which was a consequences of the previous formulation of UnivCo

As a result this MR touches a lot of code.  The big things are:

* Coercion constructor UnivCo now takes a [Coercion] as argument to
  express the coercions on which the UnivCo depends. A nice consequence
  is that UnivCoProvenance now has no free variables, simpler in a number
  of places.

* Coercion constructors AxiomInstCo and AxiomRuleCo are combined into
  AxiomCo.  The new AxiomCo, carries a (slightly oddly named)
  CoAxiomRule, which itself is a sum type of the various forms of
  built-in axiom.  See Note [CoAxiomRule] in GHC.Core.Coercion.Axiom

  A merit of this is that we can separate the case of open and closed
  type families, and eliminate the redundant `BranchIndex` in the former
  case.

* Much better representation for data BuiltInSynFamily, which means we
  no longer need to enumerate built-in axioms as well as built-in tycons.

* There is a massive refactor in GHC.Builtin.Types.Literals, which contains all
  the built-in axioms for type-level operations (arithmetic, append, cons etc).

  A big change is that instead of redundantly having (a) a hand-written
  matcher, and (b) a template-based "proves" function, which were hard to
  keep in sync, the two are derive from one set of human-supplied info.
  See GHC.Builtin.Types.Literals.mkRewriteAxiom, and friends.

* Significant changes in GHC.Tc.Solver.Equality to account for the new
  opportunity for Given/Given equalities.

Smaller things

* Improve pretty-printing to avoid parens around atomic coercions.

* Do proper eqType in findMatchingIrreds, not `eqTypeNoKindCheck`.
  Looks like a bug, Richard agrees.

* coercionLKind and coercionRKind are hot functions.  I refactored the
  implementation (which I had to change anyway) to increase sharing.
  See Note [coercionKind performance] in GHC.Core.Coercion

* I wrote a new Note [Finding orphan names] in GHC.Core.FVs about orphan
  names

* I improved the `is_concrete` flag in GHC.Core.Type.buildSynTyCon, to avoid
  calling tyConsOfType.  I forget exactly why I did this, but it's definitely
  better now.

* I moved some code from GHC.Tc.Types.Constraint into GHC.Tc.Types.CtLocEnv
  and I renamed the module GHC.Tc.Types.CtLocEnv to GHC.Tc.Types.CtLoc

- - - - -
dd8ef342 by Ryan Scott at 2024-09-25T17:09:01-04:00
Resolve ambiguous method-bound type variables in vanilla defaults and GND

When defining an instance of a class with a "vanilla" default, such as in the
following example (from #14266):

```hs
class A t where
  f :: forall x m. Monoid x => t m -> m
  f = <blah>

instance A []
```

We have to reckon with the fact that the type of `x` (bound by the type
signature for the `f` method) is ambiguous. If we don't deal with the ambiguity
somehow, then when we generate the following code:

```hs
instance A [] where
  f = $dmf @[] -- NB: the type of `x` is still ambiguous
```

Then the generated code will not typecheck. (Issue #25148 is a more recent
example of the same problem.)

To fix this, we bind the type variables from the method's original type
signature using `TypeAbstractions` and instantiate `$dmf` with them using
`TypeApplications`:

```hs
instance A [] where
  f @x @m = $dmf @[] @x @m -- `x` is no longer ambiguous
```

Note that we only do this for vanilla defaults and not for generic defaults
(i.e., defaults using `DefaultSignatures`). For the full details, see `Note
[Default methods in instances] (Wrinkle: Ambiguous types from vanilla method
type signatures)`.

The same problem arose in the code generated by `GeneralizedNewtypeDeriving`,
as we also fix it here using the same technique. This time, we can take
advantage of the fact that `GeneralizedNewtypeDeriving`-generated code
_already_ brings method-bound type variables into scope via `TypeAbstractions`
(after !13190), so it is very straightforward to visibly apply the type
variables on the right-hand sides of equations. See `Note [GND and ambiguity]`.

Fixes #14266. Fixes #25148.

- - - - -
0a4da5d2 by ARATA Mizuki at 2024-09-25T17:09:41-04:00
Document primitive string literals and desugaring of string literals

Fixes #17474 and #17974

Co-authored-by: Matthew Craven <5086-clyring at users.noreply.gitlab.haskell.org>

- - - - -
ad0731ad by Zubin Duggal at 2024-09-25T17:10:18-04:00
rts: Fix segfault when using non-moving GC with profiling

`nonMovingCollect()` swaps out the `static_flag` value used as a
sentinel for `gct->scavenged_static_objects`, but the subsequent call
`resetStaticObjectForProfiling()` sees the old value of `static_flag` used as
the sentinel and segfaults. So we must call `resetStaticObjectForProfiling()`
before calling `nonMovingCollect()` as otherwise it looks for the incorrect
sentinel value

Fixes #25232 and #23958

Also teach the testsuite driver about nonmoving profiling ways
and stop disabling metric collection when nonmoving GC is enabled.

- - - - -
e7a26d7a by Sylvain Henry at 2024-09-25T17:11:00-04:00
Fix interaction between fork and kqueue (#24672)

A kqueue file descriptor isn't inherited by a child created with fork.
As such we mustn't try to close this file descriptor as we would close a
random one, e.g. the one used by timerfd.

Fix #24672

- - - - -
6863503c by Simon Peyton Jones at 2024-09-25T17:11:37-04:00
Improve GHC.Tc.Solver.defaultEquality

This MR improves GHC.Tc.Solver.defaultEquality to solve #25251.

The main change is to use checkTyEqRhs to check the equality, so
that we do promotion properly.

But within that we needed a small enhancement to LC_Promote.  See
Note [Defaulting equalites] (DE4) and (DE5)

The tricky case is (alas) hard to trigger, so I have not added a
regression test.

- - - - -
97a6c6c3 by Sylvain Henry at 2024-09-25T17:12:18-04:00
JS: fix h$withCStringOnHeap helper (#25288)

strlen returns the length of the string without the \0 terminating byte,
hence CString weren't properly allocated on the heap (ending \0 byte was
missing).

- - - - -
5f7c20bc by Ben Gamari at 2024-09-26T04:14:05-04:00
base: Propagate `error` CallStack to thrown exception

Previously `errorCallWithCallStackException` failed to propagate its
`CallStack` argument, which represents the call-chain of the preceding
`error` call, to the exception that it returned. Consequently, the
call-stack of `error` calls were quite useless.

Unfortunately, this is the second time that I have fixed this but it
seems the first must have been lost in rebasing.

Fixes a bug in the implementation of CLC proposal 164
<https://github.com/haskell/core-libraries-committee/issues/164>

Fixes #24807.

- - - - -
c20d5186 by Matthew Pickering at 2024-09-26T04:14:42-04:00
driver: Fix -working-dir for foreign files

-working-dir definitely needs more serious testing, there are some easy
ways to test this.

* Modify Cabal to call ghc using -working-dir rather than changing
  directory.
* Modify the testsuite to run ghc using `-working-dir` rather than
  running GHC with cwd = temporary directory.

However this will have to wait until after 9.12.

Fixes #25150

- - - - -
88eaa7ac by Sylvain Henry at 2024-09-26T04:15:24-04:00
Enum deriving: reuse predError, succError, toEnumError

Reuse predError, succError, and toEnumError when deriving Enum instances
to avoid generating different error strings per instance. E.g. before
this patch for every instance for a type FOO we would generate a string:

  "pred{FOO}: tried to take `pred' of first tag in enumeration"#

- - - - -
e9fa1163 by Sylvain Henry at 2024-09-26T04:15:24-04:00
Enum deriving: generate better code (#16364)

Generate better code for Enum.toEnum: check both the lower and the upper
bounds at once with an unsigned comparison.

Initially I've used a type ascription with a call to 'fromIntegral',
hence the slight refactoring of nlAscribe. Using 'fromIntegral' was
problematic (too low in the module hierarchy) so 'enumIntToWord' was
introduced instead.

Combined with the previous commit, T21839c ghc/alloc decrease by 5%

Metric Decrease:
    T21839c

- - - - -
383af074 by Sylvain Henry at 2024-09-26T04:16:06-04:00
Core: add absorb rules for binary or/and (#16351)

Rules:
  x or (x and y) ==> x
  x and (x or y) ==> x

- - - - -
783c8b29 by Matthew Pickering at 2024-09-26T12:07:44-04:00
Don't compile `asBox` with -fprof-late

The `asBox` function is intended to store exactly the closure which the
user passes to it. Placing a cost centre on asBox introduces a thunk,
which violates this expectation and can change the result of using asBox
when profiling is enabled.

See #25212 for more details and ample opportunity to discuss if this is
a bug or not.

- - - - -
0967dcc7 by Matthew Pickering at 2024-09-26T12:07:44-04:00
Fix normalisation of .prof files

Fix 1: If a cost centre contained CAF then the normalisation was
corrupted, now only check if CAF is at the start of a line.

Fix 2: "no location info" contain a space, which messed up the next
normalisation logic which assumed that columns didn't have spaced in.

- - - - -
9eda1cb9 by Matthew Pickering at 2024-09-26T12:07:44-04:00
testsuite: Fix normalisation of prof_files removing newlines

These normalisation steps were collapsing lines together, which made
subsequent normalisation steps fail.

```
foo x y z
CAF x y z
qux x y z
```

was getting normalised to

```
foo x y z qux x y z
```

which means that subsequent line based filters would not work correctly.

- - - - -
2b25f9e2 by Matthew Pickering at 2024-09-26T12:07:44-04:00
packaging: Enable late-ccs for release flavour

This enables late cost centres when building profiled libraries and
subsequently greatly improves the resolution of cost centre stacks when
profiling.

This patch also introduces the `grep_prof` test modifier which is used
to apply a further filter to the .prof file before they are compared.

Fixes #21732

-------------------------
Metric Increase:
    libdir
-------------------------

- - - - -
bb030d0d by Brandon Chinn at 2024-09-26T12:08:21-04:00
Replace manual string lexing (#25158)

Metric Increase:
    MultilineStringsPerf

This commit replaces the manual string lexing logic with native Alex
lexing syntax. This aligns the lexer much closer to the Haskell Report,
making it easier to see how the implementation and spec relate. This
slightly increases memory usage when compiling multiline strings because
we now have two distinct phases: lexing the multiline string with Alex
and post-processing the string afterwards. Before, these were done at
the same time, but separating them allows us to push as much logic into
normal Alex lexing as possible.

Since multiline strings are a new feature, this regression shouldn't be
too noticeable. We can optimize this over time.

- - - - -
16742987 by Matthew Pickering at 2024-09-26T12:08:57-04:00
Revert !4655: Stop 'import "base" Prelude' removing implicit Prelude import

This behaviour is problematic for the principle reason that `import
Prelude` may not refer to the `base` package, and in which case
importing an entirely unrelated module causing your implicit prelude to
leave the scope is extremely surprising. See the added test for this
example. Discussion on #17045.

The secondary reason for reverting this patch is that "base" can't be a
wired in package any more (see #24903), so we have to remove special
logic which singles out base from the compiler.

The rule for implicit shadowing is now simply:

* If you write import Prelude (..) then you don't get an implicit prelude import
* If you write import "foobar" Prelude (..) for all pkgs foobar,
  you get an implicit import of prelude.

If you want to write a package import of Prelude, then you can enable
`NoImplicitPrelude` for the module in question to recover the behaviour
of ghc-9.2-9.10.

Fixes #17045

- - - - -
57c50f41 by Matthew Pickering at 2024-09-26T12:08:57-04:00
Rename COMPILING_BASE_PACKAGE to COMPILING_GHC_INTERNAL_PACKAGE

The COMPILING_BASE_PACKAGE macro is concerned with issues defining
symbols and using symbols in the same compilation unit. However, these
symbols now exist in ghc-internal rather than base, so we should rename
the macro accordingly.

The code is guards is likely never used as we never produce windows DLLs
but it is simpler to just perform the renaming for now.

These days there is little doubt that this macro defined in this ad-hoc
manner would be permitted to exist, but these days are not those days.

Fixes #25221

- - - - -
70764243 by Matthew Pickering at 2024-09-26T12:08:57-04:00
Preload ghc-internal rather than base

This occurence of baseUnitId was missed when moving the bulk of internal
definitions into `ghc-internal`.

We need to remove this preloading of `base` now because `base` should
not be wired in.

Towards #24903

- - - - -
12915609 by Matthew Pickering at 2024-09-26T12:08:57-04:00
Remove Data.List compat warning

There is currently a warning implemented in -Wcompat which warns you
when importing Data.List in a non-qualified manner.

```
A.hs:3:8: warning: [-Wcompat-unqualified-imports]
    To ensure compatibility with future core libraries changes
    imports to Data.List should be
    either qualified or have an explicit import list.
  |
3 | import Data.List
  |        ^^^^^^^^^
Ok, one module loaded.
```

GHC ticket: https://gitlab.haskell.org/ghc/ghc/-/issues/17244
CLC discussion: https://groups.google.com/g/haskell-core-libraries/c/q3zHLmzBa5E

This warning was implemented as part of the migration to making
Data.List monomorphic again (and to be used like Data.Set, Data.Map
etc). That doesn't seem like it happened, and I imagine that the current
CLC would require a new proposal anyway in order to do that now. It's
not clear in any case what "future core libraries changes" we are
waiting to happen before this warning can be removed.

Given the first phase of the proposal has lasted 5 years it doesn't seem
that anyone is motivated to carry the proposal to completion. It does
seem a bit unnecessary to include a warning in the compiler about
"future changes to the module" when there's no timeline or volunteer to
implement these changes.

The removal of this warning was discussed again at:
https://github.com/haskell/core-libraries-committee/issues/269

During the discussion there was no new enthusiasm to move onto the next
stages of the proposal so we are removing the warning to unblock the
reinstallable "base" project (#24903)

Fixes #24904

- - - - -
d4e4d498 by Matthew Pickering at 2024-09-26T12:08:57-04:00
Move Control.Monad.Zip into ghc-internal

mzip is wired in and therefore needs to be in ghc-internal.

Fixes #25222

Towards #24903

- - - - -
d3dacdfb by Matthew Pickering at 2024-09-26T12:08:57-04:00
Unwire the base package

This patch just removes all the functions related to wiring-in the base
package and the `-this-unit-id=base` flag from the cabal file.

After this commit "base" becomes just like any other package and the
door is opened to moving base into an external repo and releasing base
on a separate schedule to the rest of ghc.

Closes #24903

- - - - -
1b39363b by Patrick at 2024-09-27T06:10:19-04:00
Add entity information to HieFile #24544

Enhanced HieFile to capture entity information for identifiers, enabling better support for language tools and protocols. See issue #24544 for more details.

Work have been done:
* Introduction of new data type `EntityInfo` in `GHC.Iface.Ext.Types`.
* Add extra field `hie_entity_infos :: NameEntityInfo` to `HieFile`
  to store the mapping from entity name to corresponding entity infos
  in `GHC.Iface.Ext.Types`.
* Compute `EntityInfo` for each entity name in the HieAst from `TyThing,
  Id, OccName` when generating the `HieFile` in `GHC.Iface.Ext.Ast`.
* Add test T24544 to test the generation of `EntityInfo`.

- - - - -
4f3618d8 by sheaf at 2024-09-27T06:10:57-04:00
The X86 SIMD patch.

This commit adds support for 128 bit wide SIMD vectors and vector
operations to GHC's X86 native code generator.

Main changes:

  - Introduction of vector formats (`GHC.CmmToAsm.Format`)
  - Introduction of 128-bit virtual register (`GHC.Platform.Reg`),
    and removal of unused Float virtual register.
  - Refactor of `GHC.Platform.Reg.Class.RegClass`: it now only contains
    two classes, `RcInteger` (for general purpose registers) and `RcFloatOrVector`
    (for registers that can be used for scalar floating point values as well
    as vectors).
  - Modify `GHC.CmmToAsm.X86.Instr.regUsageOfInstr` to keep track
    of which format each register is used at, so that the register
    allocator can know if it needs to spill the entire vector register
    or just the lower 64 bits.
  - Modify spill/load/reg-2-reg code to account for vector registers
    (`GHC.CmmToAsm.X86.Instr.{mkSpillInstr, mkLoadInstr, mkRegRegMoveInstr, takeRegRegMoveInstr}`).
  - Modify the register allocator code (`GHC.CmmToAsm.Reg.*`) to propagate
    the format we are storing in any given register, for instance changing
    `Reg` to `RegFormat` or `GlobalReg` to `GlobalRegUse`.
  - Add logic to lower vector `MachOp`s to X86 assembly
    (see `GHC.CmmToAsm.X86.CodeGen`)
  - Minor cleanups to genprimopcode, to remove the llvm_only attribute
    which is no longer applicable.

Tests for this feature are provided in the "testsuite/tests/simd" directory.

Fixes #7741

Keeping track of register formats adds a small memory overhead to the
register allocator (in particular, regUsageOfInstr now allocates more
to keep track of the `Format` each register is used at). This explains
the following metric increases.

-------------------------
Metric Increase:
    T12707
    T13035
    T13379
    T3294
    T4801
    T5321FD
    T5321Fun
    T783
-------------------------

- - - - -
10e431ef by sheaf at 2024-09-27T06:10:57-04:00
Use xmm registers in genapply

This commit updates genapply to use xmm, ymm and zmm registers, for
stg_ap_v16/stg_ap_v32/stg_ap_v64, respectively.

It also updates the Cmm lexer and parser to produce Cmm vectors rather
than 128/256/512 bit wide scalars for V16/V32/V64, removing bits128,
bits256 and bits512 in favour of vectors.

The Cmm Lint check is weakened for vectors, as (in practice, e.g. on X86)
it is okay to use a single vector register to hold multiple different
types of data, and we don't know just from seeing e.g. "XMM1" how to
interpret the 128 bits of data within.

Fixes #25062

- - - - -
8238fb2d by sheaf at 2024-09-27T06:10:57-04:00
Add vector fused multiply-add operations

This commit adds fused multiply add operations such as `fmaddDoubleX2#`.
These are handled both in the X86 NCG and the LLVM backends.

- - - - -
2cb7b748 by sheaf at 2024-09-27T06:10:57-04:00
Add vector shuffle primops

This adds vector shuffle primops, such as

```
shuffleFloatX4# :: FloatX4# -> FloatX4# -> (# Int#, Int#, Int#, Int# #) -> FloatX4#
```

which shuffle the components of the input two vectors into the output vector.

NB: the indices must be compile time literals, to match the X86 SHUFPD
instruction immediate and the LLVM shufflevector instruction.

These are handled in the X86 NCG and the LLVM backend.

Tested in simd009.

- - - - -
0d2428d6 by sheaf at 2024-09-27T06:10:57-04:00
Add Broadcast MachOps

This adds proper MachOps for broadcast instructions, allowing us to
produce better code for broadcasting a value than simply packing that
value (doing many vector insertions in a row).

These are lowered in the X86 NCG and LLVM backends. In the LLVM backend,
it uses the previously introduced shuffle instructions.

- - - - -
e6c19a41 by sheaf at 2024-09-27T06:10:57-04:00
Fix treatment of signed zero in vector negation

This commit fixes the handling of signed zero in floating-point vector
negation.

A slight hack was introduced to work around the fact that Cmm doesn't
currently have a notion of signed floating point literals
(see get_float_broadcast_value_reg). This can be removed once CmmFloat
can express the value -0.0.

The simd006 test has been updated to use a stricter notion of equality
of floating-point values, which ensure the validity of this change.

- - - - -
f496ff7f by sheaf at 2024-09-27T06:10:57-04:00
Add min/max primops

This commit adds min/max primops, such as

  minDouble# :: Double# -> Double# -> Double#
  minFloatX4# :: FloatX4# -> FloatX4# -> FloatX4#
  minWord16X8# :: Word16X8# -> Word16X8# -> Word16X8#

These are supported in:
  - the X86, AArch64 and PowerPC NCGs,
  - the LLVM backend,
  - the WebAssembly and JavaScript backends.

Fixes #25120

- - - - -
5dd2a423 by sheaf at 2024-09-27T06:10:57-04:00
Add test for C calls & SIMD vectors

- - - - -
f824e1ee by sheaf at 2024-09-27T06:10:58-04:00
Add test for #25169

- - - - -
d54db7f3 by sheaf at 2024-09-27T06:10:58-04:00
Fix #25169 using Plan A from the ticket

We now compile certain low-level Cmm functions in the RTS multiple
times, with different levels of vector support. We then dispatch
at runtime in the RTS, based on what instructions are supported.

See Note [realArgRegsCover] in GHC.Cmm.CallConv.

Fixes #25169

-------------------------
Metric Increase:
    T10421
    T12425
    T18730
    T1969
    T9198
-------------------------

- - - - -
d5f8778a by sheaf at 2024-09-27T06:10:58-04:00
Fix C calls with SIMD vectors

This commit fixes the code generation for C calls, to take into account
the calling convention.

This is particularly tricky on Windows, where all vectors are expected
to be passed by reference. See Note [The Windows X64 C calling convention]
in GHC.CmmToAsm.X86.CodeGen.

- - - - -
f64bd564 by sheaf at 2024-09-27T06:10:58-04:00
X86 CodeGen: refactor getRegister CmmLit

This refactors the code dealing with loading literals into registers,
removing duplication and putting all the code in a single place.
It also changes which XOR instruction is used to place a zero value
into a register, so that we use VPXOR for a 128-bit integer vector
when AVX is supported.

- - - - -
ab12de6b by sheaf at 2024-09-27T06:10:58-04:00
X86 genCCall: promote arg before calling evalArgs

The job of evalArgs is to ensure each argument is put into a temporary
register, so that it can then be loaded directly into one of the
argument registers for the C call, without the generated code clobbering
any other register used for argument passing.

However, if we promote arguments after calling evalArgs, there is the
possibility that the code used for the promotion will clobber a register,
defeating the work of evalArgs.
To avoid this, we first promote arguments, and only then call evalArgs.

- - - - -
8fd12429 by sheaf at 2024-09-27T06:10:58-04:00
X86 genCCall64: simplify loadArg code

This commit simplifies the argument loading code by making the
assumption that it is safe to directly load the argument into register,
because doing so will not clobber any previous assignments.

This assumption is borne from the use of 'evalArgs', which evaluates
any arguments which might necessitate non-trivial code generation into
separate temporary registers.

- - - - -
12504a9f by sheaf at 2024-09-27T06:10:58-04:00
LLVM: propagate GlobalRegUse information

This commit ensures we keep track of how any particular global register
is being used in the LLVM backend. This informs the LLVM type
annotations, and avoids type mismatches of the following form:

  argument is not of expected type '<2 x double>'
    call ccc <2 x double> (<2 x double>)
      (<4 x i32> arg)

- - - - -
2bb1e8df by Cheng Shao at 2024-09-27T06:11:35-04:00
Link bytecode from interface-stored core bindings in oneshot mode

!13042

Part of #T25090

If the flag `-fprefer-byte-code` is given when compiling a module
containing TH, GHC will use Core bindings stored in interfaces to
compile and link bytecode for splices.

This was only implemented for `--make` mode initially, so this commit
adds the same mechanism to oneshot mode (`-c`).

When an interface is loaded into the EPS in `loadInterface` that has
dehydrated Core bindings, an entry is added to the new field
`eps_iface_bytecode`, containing an IO action that produces a bytecode
`Linkable`, lazily processing the `mi_extra_decls` by calling
`loadIfaceByteCode`.

When Template Haskell dependencies are resolved in `getLinkDeps`, this
action is looked up after loading a module's interface.
If it exists, the action is evaluated and the bytecode is added to the
set of `Linkable`s used for execution of the splice; otherwise it falls
back on the traditional object file.

Metric Decrease:
    MultiLayerModules
    T13701

- - - - -
7cb7172e by Matthew Pickering at 2024-09-27T06:12:12-04:00
ci: Fix variable inheritence for ghcup-metadata testing job

Downstream in ghcup-ci we use the CONFIGURE_ARGS variable to determine
how to setup all the different jobs.

On the downstream trigger this was being inherited from the default
setting in .gitlab.yml file.

Therefore this led to job failures as the necessary CONFIGURE_ARGS were
not being passed to the configure script when installing the bindist.

See docs:

* https://docs.gitlab.com/ee/ci/yaml/#inherit
* https://docs.gitlab.com/ee/ci/yaml/#triggerforward

1. inherit:variables:fals
  - This stops the global variables being inherited into the job and
    hence forwarded onto the downstream job.

2. trigger:forward:*
  - yaml_variables: true (default) pass yaml variables to downstream,
    this is important to pass the upstream pipeline id to downstream.
  - pipeline_variables: false (default) but don't pass pipeline
    variables (normal environment variables).

Fixes #25294

- - - - -
9ffd6163 by Leo at 2024-09-27T16:26:01+05:30
Fix typo in Prelude doc for (>>=)

Fix a minor typo ("equivialent" instead of "equivalent") in the documentation for (>>=) in the prelude.

- - - - -
5745dbd3 by Vladislav Zavialov at 2024-09-27T16:26:52+05:30
Wildcard binders in type declarations (#23501)

Add support for wildcard binders in type declarations:

	type Const a b = a   -- BEFORE: the `b` had to be named
	                     --         even if unused on the RHS

	type Const a _ = a   -- AFTER: the compiler accepts
	                     --        a wildcard binder `_`

The new feature is part of GHC Proposal #425 "Invisible binders
in type declarations", and more specifically its amendment #641.

Just like a named binder, a wildcard binder `_` may be:

	* plain:      _
	* kinded:    (_ :: k -> Type)
	* invisible, plain:  @_
	* invisible, kinded: @(_ :: k -> Type)

Those new forms of binders are allowed to occur on the LHSs of
data, newtype, type, class, and type/data family declarations:

	data D _ = ...
	newtype N _ = ...
	type T _ = ...
	class C _ where ...
	type family F _
	data family DF _

(Test case: testsuite/tests/typecheck/should_compile/T23501a.hs)

However, we choose to reject them in forall telescopes and
type family result variable binders (the latter being part
of the TypeFamilyDependencies extension):

	type family Fd a = _    -- disallowed  (WildcardBndrInTyFamResultVar)
	fn :: forall _. Int     -- disallowed  (WildcardBndrInForallTelescope)

(Test case: testsuite/tests/rename/should_fail/T23501_fail.hs)

See the new Notes:
	* Note [Type variable binders]
	* Note [Wildcard binders in disallowed contexts]

To accommodate the new forms of binders, HsTyVarBndr was changed
as follows (demonstrated without x-fields for clarity)

	-- BEFORE (ignoring x-fields and locations)
	data HsTyVarBndr flag
	  = UserTyVar   flag Name
	  | KindedTyVar flag Name HsKind

	-- AFTER (ignoring x-fields and locations)
	data HsTyVarBndr flag = HsTvb flag HsBndrVar HsBndrKind
	data HsBndrVar  = HsBndrVar Name | HsBndrWildCard
	data HsBndrKind = HsBndrNoKind | HsBndrKind LHsKind

The rest of the patch is downstream from this change.

To avoid a breaking change to the TH AST, we generate fresh
names to replace wildcard binders instead of adding a dedicated
representation for them (as discussed in #641).

And to put a cherry on top of the cake, we now allow wildcards in
kind-polymorphic type variable binders in constructor patterns,
see Note [Type patterns: binders and unifiers] and the tyPatToBndr
function in GHC.Tc.Gen.HsType; example:

	fn (MkT @(_ :: forall k. k -> Type) _ _) = ...

(Test case: testsuite/tests/typecheck/should_compile/T23501b.hs)

- - - - -
ff2bdca2 by Matthew Pickering at 2024-09-27T16:27:08+05:30
ci: Push perf notes from wasm jobs

It was observed in #25299 that we were failing to push performance
numbers from the wasm jobs.

In future we might want to remove this ad-hoc check but for now it's
easier to add another special case.

Towards #25299

- - - - -
4c76f75c by Zubin Duggal at 2024-09-27T16:44:00+05:30
Bump GHC version to 9.12

- - - - -
e4ac1b0d by Zubin Duggal at 2024-09-27T19:12:24+05:30
Bump GHC version to 9.13

- - - - -
28c0f9a4 by Ben Gamari at 2024-10-01T09:32:49-04:00
base: Introduce Data.Bounded

As proposed in [CLC#208] but unfortunately `Data.Enum` was already
incorrectly introduced in the `ghc-internal` refactor.

[CLC#208]: https://github.com/haskell/core-libraries-committee/issues/208

- - - - -
4aaf553b by Ben Gamari at 2024-10-01T09:37:40-04:00
base: Deprecate export of Bounded from Data.Enum

This begins the process of bringing us into compliance with
[CLC#208].

[CLC#208]: https://github.com/haskell/core-libraries-committee/issues/208

- - - - -


23 changed files:

- .gitignore
- .gitlab-ci.yml
- .gitlab/ci.sh
- .gitlab/generate-ci/flake.lock
- .gitlab/generate-ci/gen_ci.hs
- .gitlab/jobs.yaml
- .gitmodules
- CODEOWNERS
- compiler/CodeGen.Platform.h
- compiler/GHC/Builtin/Names.hs
- compiler/GHC/Builtin/Types.hs
- compiler/GHC/Builtin/Types/Literals.hs
- compiler/GHC/Builtin/primops.txt.pp
- compiler/GHC/ByteCode/Asm.hs
- compiler/GHC/ByteCode/Types.hs
- compiler/GHC/Cmm.hs
- compiler/GHC/Cmm/BlockId.hs
- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Cmm/CallConv.hs
- compiler/GHC/Cmm/Dataflow.hs
- compiler/GHC/Cmm/Dataflow/Graph.hs
- compiler/GHC/Cmm/Graph.hs
- compiler/GHC/Cmm/Info.hs


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9204fd6804ce649c2f5aef449874a8a5203867d7...4aaf553b3d97ca031a7fcb21630470e7976b151a

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9204fd6804ce649c2f5aef449874a8a5203867d7...4aaf553b3d97ca031a7fcb21630470e7976b151a
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