-
72c8de5c
by Simon Jakobi at 2026-05-23T18:41:42-04:00
Implement List.elem via foldr
...in order to allow specialization to Eq instances.
The implementation of notElem is updated for consistency.`
Corresponding CLC proposal:
https://github.com/haskell/core-libraries-committee/issues/412
Addresses #27096.
-
3268c610
by Alan Zimmerman at 2026-05-23T18:42:30-04:00
EPA: Fix span for qualified multiline string
Fix the span for a qualified multiline string like
Text."""
I'm a multiline
Text value
!
"""
to extend to the end of the entire string, not just the first line.
Closes #27274
-
1f096790
by Alan Zimmerman at 2026-05-23T18:43:20-04:00
EPA: Fix exact printing namespace-specified wildcards
Ensures correct printing of imports of the form
import Data.Bool (data True(data ..))
import Data.Bool (data True(type ..))
Closes #27291
-
56ada7c0
by Mrjtjmn at 2026-05-23T18:44:19-04:00
Fix ambiguous syntax of BangPatterns in users guide
Update documentation for the BangPatterns extension to specify
how surrounding whitespace affects interpretation of `!`.
* Only when there is whitespace before `!` and no whitespace after,
it is recognized as a BangPattern.
* Other cases `⟨varid⟩!⟨varid⟩`, `⟨varid⟩ ! ⟨varid⟩`, `⟨varid⟩! ⟨varid⟩`
are treated as infix operators.
-
579aa0b7
by Simon Jakobi at 2026-05-25T16:31:26-04:00
Ensure that SetOps.{minusList,unionListsOrd} can be specialized
...by marking them INLINABLE. Haddock allocates 0.1–0.3% less as a
result.
This also removes some redundant constraints on unionListsOrd.
-
cccf45da
by Cheng Shao at 2026-05-25T16:32:13-04:00
wasm: ensure post-linker output is synchronous ESM
This patch fixes wasm backend's post-linker output script to ensure
it's synchronous ESM and doesn't use top-level await, which doesn't
work in ServiceWorkers. Fixes #27257.
-
8db331a3
by Zubin Duggal at 2026-05-26T04:54:03-04:00
Update to semaphore-compat 2.0.0 using v2 of the protocol
On Linux and other POSIX platforms, GHC's -jsem jobserver client now
speaks v2 of the semaphore-compat protocol, which uses Unix domain
sockets in place of POSIX named semaphores. This avoids the libc-ABI
issues that affected the old implementation. Windows is unaffected
and continues to use the v1 protocol (Win32 named semaphores); its
reported protocol version remains v1.
When GHC receives a -jsem name whose protocol version it does not
support, it emits a -Wsemaphore-version-mismatch warning and falls
back to -j<N> rather than crashing. ghc --info exposes the supported
version in a new "Semaphore version" entry so cabal-install can detect
a mismatch before invoking GHC.
Users on a cabal-install that predates the v2 update will continue to
build successfully on Linux/POSIX, but will lose the cross-process
-jsem coordination and fall back to -j<N> per GHC invocation. Users
must upgrade to a cabal-install that supports protocol v2 to recover
full parallelism.
Also fix a leak in cleanupSem (#27253): cleanupSem used to snapshot
heldTokens and release them before killing the loop, while the loop's
in-flight acquire/release children could still be mutating it.
Cleanup now runs inside the loop's own exit handler, after draining
the active child via a new activeChild TVar, so the snapshot has no
concurrent mutator.
See also:
- GHC proposal amendment: https://github.com/ghc-proposals/ghc-proposals/pull/673
- cabal-install patch: https://github.com/haskell/cabal/pull/11628
- semaphore-compat MR: https://gitlab.haskell.org/ghc/semaphore-compat/-/merge_requests/8
Bump semaphore-compat submodule to 2.0.0
Fixes #25087 and #27253
-
17be4f1f
by Alan Zimmerman at 2026-05-26T04:54:52-04:00
EPA: Record semicolons in HsModifier
Ensure the semi colons are captured in the ParsedSource for code like
%True;; %False;
instance C D
It makes HsModifier (and hence HsModifierOf) LocatedA, so the semi
colons can be recorded as [TrailingAnn]
Also rename pprHsModifiers to pprLHsModifiers to match.
Closes #27294
-
8f991755
by fendor at 2026-05-26T11:02:52-04:00
Revert prog003 acceptance
We thought the commit 286f1adff3e78d775ff325caff71d0cee25d710b fixed the
test, but due to changes to ghci, modules loaded during the GHCi
session, the test was actually no longer testing what it set out to do,
"fixing" the broken test.
As modules are added to the `interactive-session` home unit, the object code needs
to be compiled with `-this-unit-id interactive-session`, otherwise the
object code won't be used.
Once this has been fixed in the test, the test fails as expected again.
-
277a3687
by mangoiv at 2026-05-26T11:03:40-04:00
libraries/process: bump submodule to v1.6.29.0
This submodule bump resolves a segfault on macos 15.
Fixes #27144
-
6779bb0c
by mangoiv at 2026-05-26T11:03:40-04:00
libraries/unix: in submodule, don't pick branch 2.7
The 2.7 branch is outdated and the module has been advanced far beyond
it anyway, so remove that line.
-
4a645683
by Simon Peyton Jones at 2026-05-27T21:41:59-04:00
Trim the continuation in mkDupableContWithDmds
When there are no remaining argument demands, it means the application
is bottoming. In this case, we can trim the continuation to avoid the
panic that was observed in #27261.
See Note [Trimming the continuation for bottoming functions] in
GHC.Core.Opt.Simplify.Iteration.
-
8ab506ff
by Cheng Shao at 2026-05-27T21:42:47-04:00
ghci: fix module name string lifetime in hs_hpc_module invocation
This patch makes hpcAddModule pass a properly malloced module name
string to hs_hpc_module, instead of using useAsCString which causes
use-after-free of module name string. Fixes #27297.
Co-authored-by: Codex <codex@openai.com>
-
b0233814
by sheaf at 2026-05-27T21:43:31-04:00
Relax acceptance threshold for T10421
As seen in #27289, the 1% acceptance threshold for this text was
overly narrow, resulting in spurious test failures. This commit widens
the acceptance threshold to 2%. Fixes #27289.
-
63ce5770
by Luite Stegeman at 2026-05-28T12:23:35-04:00
Fixes for black holes
- suspend duplicate work for eager black holes
- detect eager black holes in checkBlockingQueues
- don't overwrite existing black holes even if they're not
in an eager blackhole frame
- don't deadlock on self when thunk is already blackholed
Fixes #26936
-
037a80dc
by Tom McLaughlin at 2026-05-28T12:24:36-04:00
Event/Windows.hsc: rethrow exceptions in overlapped IO
This prevents the WinIO manager from swallowing exceptions in overlapped IO. It
was added to make WinIO support possible in the `network` library. See
https://gitlab.haskell.org/ghc/ghc/-/issues/27283.
We also bump __IO_MANAGER_WINIO__ to 2 so libraries can gate on this using CPP.
-
2d53bcdb
by Wolfgang Jeltsch at 2026-05-28T12:25:21-04:00
Allow `downsweep` to use nodes of an existing module graph
To this end, `downsweep` has not been able to use the nodes of a module
graph obtained from a previous downsweeping round. In some GHC API
applications, downsweeping is performed somewhat incrementally and
therefore could profit from reusing such existing results. This
contribution makes this possible.
Resolves #27054.
Co-authored-by: Matthew Pickering <matthewtpickering@gmail.com>
-
f4fbb583
by Simon Jakobi at 2026-05-28T12:26:04-04:00
Add regression test for T11226
Closes #11226.
-
ed29a5e6
by Sven Tennie at 2026-05-28T17:30:36-04:00
Add optional config setting for LibDir (#19174)
Previously, the `libDir` was derived from `topDir`. This won't work for
inplace stage2 cross-compilers where binaries and libraries are in
different stage dirs (`_build/stage1/` for executables and
`_build/stage2` for libraries).
`LibDir` is set in the inplace `settings` files. For bindists, we
generate a new `settings` file with no `LibDir` entry. GHC then defaults
to use `topDir` as `libDir` again. This keeps the bindist relocatable.
If `LibDir` is a relative path, it is interpreted relatively to
`topDir`.
The global package db is part of the `lib/` folder. If we want to point
for inplace cross-compilers to the succeeding stage's folder, this is
done by setting `LibDir`. Thus, the global package db must be found
relative to `libDir`` (which may default to `topDir` or be set by
`LibDir`).
The complexity of settings becomes scary. So, add a test to ensure
`LibDir` works as expected.
-
8339cf8f
by Sven Tennie at 2026-05-28T17:30:36-04:00
Add Haddock to FileSettings
Helping to understand the fields' meanings without deeper analyses.
-
4ce251e4
by Sylvain Henry at 2026-05-28T17:31:39-04:00
foundation test: skip signed minBound `quot` (-1) (#27222)
`minBound `quot` (-1)` for fixed-width signed integers is platform
dependent: the mathematical result -minBound is not representable in
the type. On x86, IDIV traps; LLVM's sdiv is undefined behaviour in
this case; on AArch64/RISC-V, SDIV wraps to minBound.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
b8ba7e61
by Simon Jakobi at 2026-05-28T17:32:23-04:00
Prevent dictionary-passing in checkTyEqRhs
...by pre-specializing it to TcM.
Previously, wherever checkTyEqRhs was used in other modules, the
Core showed dictionary passing ($fMonadIOEnv). The added SPECIALIZE
pragma prevents this.
-
d603477f
by David Eichmann at 2026-05-29T13:17:12-04:00
Hadrian: create a ghc-internal .def file per ghc-internal dll
The .def file generated from rts/win32/libHSghc-internal.def.in contains
the name of the ghc-internal dll. The correct dll name differs based
on if the dll is inplace/final and if using the Dynamic way. Previously,
this was not accounted for and inconsistent dlls names where used. That
led to failure when loading dlls at runtime in experiments with windows
dynamic linking.
-
1fc21753
by Sylvain Henry at 2026-05-29T13:18:14-04:00
ghc-bignum: copy backend interface haddocks to Native backend (#27305)
The haddock comments documenting the BigNat backend interface (function
contracts, expected MutableWordArray# sizes, return-value semantics, etc.)
were attached to the FFI backend module. Copy them to the Native backend
so they remain in tree once the FFI backend is removed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
717059df
by Sylvain Henry at 2026-05-29T13:18:14-04:00
ghc-bignum: remove FFI backend (#27305)
The FFI backend of ghc-bignum (now part of ghc-internal) had no known
users and is easy to recreate by relinking ghc-internal with a custom
backend. Remove the backend module, the bignum-ffi cabal flag, and the
ffi option from Hadrian's --bignum selector. The backend interface
documentation now lives in the Native backend module.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
4bb3b1d8
by Sylvain Henry at 2026-05-29T13:18:14-04:00
ghc-bignum: remove Check backend (#27305)
The Check backend of ghc-bignum (now part of ghc-internal) compared the
selected backend's output against the Native backend for validation.
It had no known users. Remove the backend module, the bignum-check
cabal flag, the bignumCheck Hadrian flavour field, and the check-
prefix in Hadrian's --bignum selector.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
6b3044a0
by David Eichmann at 2026-05-30T11:58:48-04:00
Add code comments to allocator code
-
f4e04210
by Matthew Pickering at 2026-05-30T11:59:34-04:00
hadrian: Refactor system-cxx-std-lib rules
I noticed a few things wrong with the hadrian rules for
`system-cxx-std-lib` rules.
* For `text` there is an ad-hoc check to depend on `system-cxx-std-lib`
outside of `configurePackage`.
* The `system-cxx-std-lib` dependency is not read from cabal files.
* Recache is not called on the packge database after the `.conf` file is
generated, a more natural place for this rule is `registerRules`.
Treating this uniformly like other packages is complicated by it not
having any source code or a cabal file. However we can do a bit better
by reporting the dependency firstly in `PackageData` and then needing
the `.conf` file in the same place as every other package in
`configurePackage`.
This commit increases the `shakeVersion`, to provide backwards
compatibility to previous builds with different PackageData.
Fixes #25303
Co-authored-by: Sven Tennie <sven.tennie@gmail.com>
-
b335fbdc
by Simon Jakobi at 2026-06-02T01:01:21+02:00
Add support for related locations in Diagnostic
* Convert TcRnBindingNameConflict to demonstrate this feature.
* Enable -fdiagnostics-show-caret in some tests to show what error
messages with multiple caret sections look like.
* Carry diagnostic related spans through MessageClass.
This prepares the ground for #22637. The diagnosticRelatedLocations
name is inspired by #23414.
-
335251cc
by Simon Jakobi at 2026-06-02T01:08:39+02:00
Add related locations to duplicate-declaration and duplicate-export errors
Attach diagnosticRelatedLocations (multi-caret) to:
* TcRnDuplicateDecls
* TcRnDuplicateExport
* TcRnDuplicateNamedDefaultExport
Enable -fdiagnostics-show-caret for the DuplicateExports and T25857
tests to exercise the new caret sections.
check_occs now threads LIE GhcPs so these export items can carry their
source spans. TcRnConflictingExports and TcRnDuplicateFieldExport were
also tried but reverted to IE GhcPs: their export items already appear
in the message text and name provenance is rendered too, so the carets
only duplicated the primary span.
Assisted-by: Claude Opus 4.8 <noreply@anthropic.com>