-
a18fa3c1
by Cheng Shao at 2026-03-14T05:12:14-04:00
configure: make $LLVMAS default to $CC when $CcLlvmBackend is YES
This patch changes the $LLVMAS detection logic in configure so that
when it's not manually specified by the user, it defaults to $CC if
$CcLlvmBackend is YES. It's a more sensible default than auto-detected
clang from the environment, especially when cross-compiling, $CC as
the cross target's LLVM assembler is more compatible with the use case
than the system-wide clang. Fixes #26769.
-
3774086e
by Matthew Pickering at 2026-03-14T05:13:00-04:00
exceptions: annotate onException continuation with WhileHandling
Before this patch, an exception thrown in the `onException` handler
would loose track of where the original exception was thrown.
```
import Control.Exception
main :: IO ()
main = failingAction `onException` failingCleanup
where
failingAction = throwIO (ErrorCall "outer failure")
failingCleanup = throwIO (ErrorCall "cleanup failure")
```
would report
```
T28399: Uncaught exception ghc-internal:GHC.Internal.Exception.ErrorCall:
cleanup failure
HasCallStack backtrace:
throwIO, called at T28399.hs:<line>:<column> in <package-id>:Main
```
notice that the "outer failure" exception is not present in the error
message.
With this patch, any exception thrown is in the handler is annotated
with WhileHandling. The resulting message looks like
```
T28399: Uncaught exception ghc-internal:GHC.Internal.Exception.ErrorCall:
cleanup failure
While handling outer failure
HasCallStack backtrace:
throwIO, called at T28399.hs:7:22 in main:Main
```
CLC Proposal: https://github.com/haskell/core-libraries-committee/issues/397
Fixes #26759
-
63ae8eb3
by Andreas Klebinger at 2026-03-14T05:13:43-04:00
Fix missing profiling header for origin_thunk frame.
Fixes #27007
-
213d2c0e
by Cheng Shao at 2026-03-14T05:14:28-04:00
ci: fix ci-images revision
The current ci-images revision was a commit on the WIP branch of
https://gitlab.haskell.org/ghc/ci-images/-/merge_requests/183, and
it's not on the current ci-images master branch. This patch fixes the
image revision to use the current tip of ci-images master.
-
fc2b083f
by Andreas Klebinger at 2026-03-14T05:15:14-04:00
Revert "hadrian/build-cabal: Better respect and utilize -j"
This reverts commit eab3dbba79650e6046efca79133b4c0a5257613d.
While it's neat this currently isn't well supported on all platforms.
It's time will come, but for now I'm reverting this to avoid issues for
users on slightly unconvential platforms.
This will be tracked at #26977.
-
12a706cf
by Cheng Shao at 2026-03-14T16:37:54-04:00
base: fix redundant imports in GHC.Internal.Weak.Finalize
This patch fixes redundant imports in GHC.Internal.Weak.Finalize that
causes a regression in bootstrapping head from 9.14 with validate
flavours. Fixes #27026.
-
b5d39cad
by Matthew Pickering at 2026-03-14T16:38:37-04:00
Use explicit syntax rather than pure
-
43638643
by Andreas Klebinger at 2026-03-15T18:15:48-04:00
Configure: Fix check for --target support in stage0 CC
The check FP_PROG_CC_LINKER_TARGET used $CC unconditionally to check for
--target support. However this fails for the stage0 config where the C
compiler used is not $CC but $CC_STAGE0.
Since we already pass the compiler under test into the macro I simply
changed it to use that instead.
Fixes #26999
-
18fd0df6
by Simon Hengel at 2026-03-15T18:16:33-04:00
Fix typo in recursive_do.rst
-
86bd9bfc
by fendor at 2026-03-17T23:46:09-04:00
Introduce `-fimport-loaded-targets` GHCi flag
This new flag automatically adds all loaded targets to the GHCi session
by adding an `InteractiveImport` for the loaded targets.
By default, this flag is disabled, as it potentially increases memory-usage.
This interacts with the flag `-fno-load-initial-targets` as follows:
* If no module is loaded, no module is added as an interactive import.
* If a reload loads up to a module, all loaded modules are added as
interactive imports.
* Unloading modules removes them from the interactive context.
Fixes #26866 by rendering the use of a `-ghci-script` to achieve the
same thing redundant.
-
e3d4c1bb
by mniip at 2026-03-17T23:47:03-04:00
ghc-internal: Remove GHC.Internal.Data.Eq
It served no purpose other than being a re-export.
-
6f4f6cf0
by mniip at 2026-03-17T23:47:03-04:00
ghc-internal: Refine GHC.Internal.Base imports
Removed re-exports from GHC.Internal.Base. This reveals some modules
that don't actually use anything *defined* in GHC.Internal.Base, and
that can be pushed down a little in the import graph.
Replaced most imports of GHC.Internal.Base with non-wildcard imports
from modules where the identifiers are actually defined.
Part of #26834
Metric Decrease:
T5321FD
-
7fb51f54
by mangoiv at 2026-03-17T23:48:00-04:00
ci: clone, don't copy when creating the cabal cache
Also removed WINDOWS_HOST variable detected via uname - we now just
check whether the CI job has windows in its name. This works because we
only ever care about it if the respective job is not a cross job. We
also statically detect darwin cross jobs in the same way. We only ever have
darwin -> darwin cross jobs so this is enough to detect the host
reliably.
-
f8817879
by mangoiv at 2026-03-17T23:48:44-04:00
ci: mark size_hello_artifact fragile on darwin x86
The size of the x86_64 hello artifact is not stable which results in flaky testruns.
Resolves #26814
-
e34cb6da
by Adam Gundry at 2026-03-20T12:20:00-04:00
ghci: Mention active language edition in startup banner
Per GHC proposal 632, this makes the GHCi startup banner include
the active language edition, plus an indication of whether this
was the default (as opposed to being explicitly selected via an
option such as `-XGHC2024`). For example:
```
$ ghci
GHCi, version 9.14.1: https://www.haskell.org/ghc/ :? for help
Using default language edition: GHC2024
ghci>
```
Fixes #26037.
-
52c3e6ba
by sheaf at 2026-03-20T12:21:09-04:00
Improve incomplete record selector warnings
This commit stops GHC from emitting spurious incomplete record selector
warnings for bare selectors/projections such as .fld
There are two places we currently emit incomplete record selector
warnings:
1. In the desugarer, when we see a record selector or an occurrence
of 'getField'. Here, we can use pattern matching information to
ensure we don't give false positives.
2. In the typechecker, which might sometimes give false positives but
can emit warnings in cases that the pattern match checker would
otherwise miss.
This is explained in Note [Detecting incomplete record selectors]
in GHC.HsToCore.Pmc.
Now, we obviously don't want to emit the same error twice, and generally
we prefer (1), as those messages contain fewer false positives. So we
suppress (2) when we are sure we are going to emit (1); the logic for
doing so is in GHC.Tc.Instance.Class.warnIncompleteRecSel,
and works by looking at the CtOrigin.
Now, the issue was that this logic handled explicit record selectors as
well as overloaded record field selectors such as "x.r" (which turns
into a simple GetFieldOrigin CtOrigin), but it didn't properly handle
record projectors like ".fld" or ".fld1.fld2" (which result in other
CtOrigins such as 'RecordFieldProjectionOrigin').
To solve this problem, we re-use the 'isHasFieldOrigin' introduced in
fbdc623a (slightly adjusted).
On the way, we also had to update the desugarer with special handling
for the 'ExpandedThingTc' case in 'ds_app', to make sure that
'ds_app_var' sees all the type arguments to 'getField' in order for it
to indeed emit warnings like in (1).
Fixes #26686
-
309d7e87
by Cheng Shao at 2026-03-20T12:21:53-04:00
rts: opportunistically grow the MutableByteArray# in-place in resizeMutableByteArray#
Following !15234, this patch improves `resizeMutableByteArray#` memory
efficiency by growing the `MutableByteArray#` in-place if possible,
addressing an old todo comment here. Also adds a new test case
`resizeMutableByteArrayInPlace` that stresses this behavior.
-
7d4ef162
by Matthew Craven at 2026-03-20T12:22:47-04:00
Change representation of floating point literals
This commit changes the representation of floating point literals
throughough the compiler, in particular in Core and Cmm.
The Rational type is deficient for this purpose, dealing poorly
with NaN, +/-Infinity, and negative zero. Instead, the new module
GHC.Types.Literal.Floating uses the host Float/Double type to represent
NaNs, infinities and negative zero. It also contains a Rational
constructor, for the benefit of -fexcess-precision.
Other changes:
- Remove Note [negative zero] and related code
This also removes the restrictions on constant-folding of division
by zero, and should make any problems with NaN/Infinity more obvious.
- Use -0.0 as the additive identity for Core constant folding rules
for floating-point addition, fixing #21227.
- Manual worker-wrapper for GHC.Float.rationalToDouble. This is
intended to prevent the compiler's WW on this function from
interfering with constant-folding. This change means that we now
avoid allocating a box for the result of a 'realToFrac' call in
T10359.
- Combine floatDecodeOp and doubleDecodeOp.
This change also fixes a bug in doubleDecodeOp wherein it
would incorrectly produce an Int# instead of an Int64#
literal for the mantissa component with 64-bit targets.
- Use Float/Double for assembly immediates, and update the X86 and
PowerPC backends to properly handle special values such as NaN and
infinity.
- Allow 'rational_to' to handle zero denominators, fixing a
TODO in GHC.Core.Opt.ConstantFold.
Fixes #8364 #9811 #18897 #21227
Progress towards #26919
Metric Decrease:
T10359
Co-authored-by: sheaf <sam.derbyshire@gmail.com>
-------------------------
Metric Decrease:
T1969
T5321FD
-------------------------
-
80e2dd4f
by Zubin Duggal at 2026-03-20T12:23:33-04:00
compiler/ffi: Collapse void pointer chains in capi wrappers
New gcc/clang treat -Wincompatible-pointer-types as an error by
default. Since C only allows implicit conversion from void*, not void**,
capi wrappers for functions taking e.g. abstract** would fail to compile
when the Haskell type Ptr (Ptr Abstract) was naively translated to void**.
Collapse nested void pointers to a single void* when the pointee type
has no known C representation.
Fixes #26852
-
1c50bd7b
by Luite Stegeman at 2026-03-20T12:24:37-04:00
Move some functions related to pointer tagging to a separate module
-
bfd7aafd
by Luite Stegeman at 2026-03-20T12:24:37-04:00
Branchless unpacking for enumeration types
Change unpacking for enumeration types to go to Word8#/Word16#/Word#
directly instead of going through an intermediate unboxed sum. This
allows us to do a branchless conversion using DataToTag and TagToEnum.
Fixes #26970
-
72b20fc0
by Luite Stegeman at 2026-03-20T12:25:30-04:00
bytecode: Carefully SLIDE off the end of a stack chunk
The SLIDE bytecode instruction was not checking for stack chunk
boundaries and could corrupt the stack underflow frame, leading
to crashes.
We add a check to use safe writes if we cross the chunk boundary
and also handle stack underflow if Sp is advanced past the underflow
frame.
fix #27001
-
2e22b43c
by Cheng Shao at 2026-03-20T12:26:14-04:00
ghci: serialize BCOByteArray buffer directly when possible
This patch changes the `Binary` instances of `BCOByteArray` to
directly serialize the underlying buffer when possible, while also
taking into account the issue of host-dependent `Word` width. See
added comments and amended `Note [BCOByteArray serialization]` for
detailed explanation. Closes #27020.
-
89d9ba37
by Sylvain Henry at 2026-03-20T12:27:34-04:00
JS: replace BigInt with Number arithmetic for 32/64-bit quot/rem (#23597)
Replace BigInt-based implementations of quotWord32, remWord32,
quotRemWord32, quotRem2Word32, quotWord64, remWord64, quotInt64, and
remInt64 with pure Number (double/integer) arithmetic to avoid the
overhead of BigInt promotion.
-
ae4ddd60
by Sylvain Henry at 2026-03-20T12:28:28-04:00
Core: add constant-folding rules for Addr# eq/ne (#18032)
-
3e767f98
by Matthew Pickering at 2026-03-20T12:29:11-04:00
Use OsPath rather than FilePath in Downsweep cache
This gets us one step closure to uniformly using `OsPath` in the
compiler.
-
2c57de29
by Cheng Shao at 2026-03-20T12:29:55-04:00
hadrian: fix ghc-in-ghci flavour stage0 shared libraries
This patch fixes missing stage0 shared libraries in hadrian
ghc-in-ghci flavour, which was accidentally dropped in
669d09f950a6e88b903d9fd8a7571531774d4d5d and resulted in a regression
in HLS support on linux/macos. Fixes #27057.
-
5b1be555
by Sylvain Henry at 2026-03-20T12:30:48-04:00
JS: install rts/Types.h header file (#27033)
It was an omission, making HsFFI.h not usable with GHC using the JS
backend.
-
b883f08f
by Cheng Shao at 2026-03-20T12:31:33-04:00
hadrian: don't compile RTS with -Winline
This patch removes `-Winline` from cflags when compiling the RTS,
given that:
1. It generates a huge pile of spam and hurts developer experience
2. Whether inlining happens is highly dependent on toolchains,
flavours, etc, and it's not really an issue to fix if inlining
doesn't happen; it's a hint to the C compiler anyway.
Fixes #27060.
-
333387d6
by Cheng Shao at 2026-03-20T12:31:33-04:00
hadrian: compile libffi-clib with -Wno-deprecated-declarations
This patch adds `-Wno-deprecated-declarations` to cflags of
`libffi-clib`, given that it produces noise at compile-time that
aren't really our issue to fix anyway, it's from vendored libffi
source code.
-
67c47771
by Rodrigo Mesquita at 2026-03-20T12:32:17-04:00
Expose decodeStackWithIpe from ghc-experimental
This decoding is useful to the debugger and it wasn't originally
exported as an oversight.
-
18513365
by Matthew Pickering at 2026-03-21T04:43:26-04:00
Add support for custom external interpreter commands
It can be useful for GHC API clients to implement their own external
interpreter commands.
For example, the debugger may want an efficient way to inspect the
stacks of the running threads in the external interpreter.
-
4636d906
by mangoiv at 2026-03-21T04:44:10-04:00
ci: remove obsolete fallback for old debian and ubuntu versions
-
2e3a2805
by mangoiv at 2026-03-21T04:44:10-04:00
ci: drop ubuntu 18 and 20
Ubuntu 18 EOL: May 2023
Ubuntu 20 EOL: May 2025
We should probably not make another major release supporting these platforms.
Also updates the generator script.
Resolves #25876
-
de54e264
by Cheng Shao at 2026-03-21T17:52:08+01:00
rts: fix -Wcompare-distinct-pointer-types errors
This commit fixes `-Wcompare-distinct-pointer-types` errors in the RTS
which should have been caught by the `validate` flavour but was
warnings in CI due to the recent `+werror` regression.
-
b9bd73de
by Cheng Shao at 2026-03-21T17:52:08+01:00
ghc-internal: fix unused imports
This commit fixes unused imports in `ghc-internal` which should have
been caught by the `validate` flavour but was warnings in CI due to
the recent `+werror` regression. Fixes #26987 #27059.
-
da946a16
by Cheng Shao at 2026-03-21T17:03:51+00:00
ghci: fix unused imports
This commit fixes unused imports in `ghci` which should have been
caught by the `validate` flavour but was warnings in CI due to the
recent `+werror` regression. Fixes #26987 #27059.
-
955b1cf8
by Cheng Shao at 2026-03-21T17:03:51+00:00
compiler: fix unused imports in GHC.Tc.Types.Origin
This commit fixes unused imports in `GHC.Tc.Types.Origin` which should
have been caught by the `validate` flavour but was warnings in CI due
to the recent `+werror` regression. Fixes #27059.
-
3b1aeb50
by Cheng Shao at 2026-03-21T17:03:51+00:00
hadrian: fix missing +werror in validate flavour
This patch fixes missing `+werror` in validate flavour, which was an
oversight in bb3a2ba1eefadf0b2ef4f39b31337a23eec67f29. Fixes #27066.
-
44f118f0
by Cheng Shao at 2026-03-22T04:54:01-04:00
ci: bump CACHE_REV and add the missing reminder
This patch bumps `CACHE_REV` to address recent `[Cabal-7159]` CI
errors due to stale cabal cache on some runners, and also adds a
reminder to remind future maintainers. Fixes #27075.
-
2a218737
by ARATA Mizuki at 2026-03-23T11:11:39-04:00
Add 128-bit SIMD support to AArch64 NCG
Changes:
- Add `Format` field to vector-capable instructions.
These instructions will emit `vN.4s` (for example) as a operand.
- Additional constructors for `Operand`:
`OpVecLane` represents a vector lane and will be emitted as `vN.<width>[<index>]` (`vN.s[3]` for example).
`OpScalarAsVec` represents a scalar, but printed as a vector lane like `vN.<width>[0]` (`vN.s[0]` for example).
- Integer quot/rem are implemented in C, like x86.
Closes #26536
Metric Increase:
T3294
-
5d6e2be9
by ARATA Mizuki at 2026-03-23T11:11:39-04:00
AArch64 NCG: Improve code generation for floating-point and vector constants
Some floating-point constants can be directly encoded using the FMOV instruction.
Similarly, a class of vectors with same values can be encoded using FMOV, MOVI, or MVNI.
-
c6d262aa
by Simon Jakobi at 2026-03-23T11:12:22-04:00
Add regression test for #13729
Closes #13729.
-
aa5dfe67
by Sylvain Henry at 2026-03-26T03:48:56-04:00
Check that shift values are valid
In GHC's codebase in non-DEBUG builds we silently substitute shiftL/R
with unsafeShiftL/R for performance reasons. However we were not
checking that the shift value was valid for unsafeShiftL/R, leading to
wrong computations, but only in non-DEBUG builds.
This patch adds the necessary checks and reports an error when a wrong
shift value is passed.
-
c8a7b588
by Sylvain Henry at 2026-03-26T03:48:56-04:00
Implement basic value range analysis (#25718)
Perform basic value range analysis to try to determine at compile time
the result of the application of some comparison primops (ltWord#, etc.).
This subsumes the built-in rewrite rules used previously to check if one
of the comparison argument was a bound (e.g. (x :: Word8) <= 255 is
always True). Our analysis is more powerful and handles type
conversions: e.g. word8ToWord x <= 255 is now detected as always True too.
We also use value range analysis to filter unreachable alternatives in
case-expressions. To support this, we had to allow case-expressions for
primitive types to not have a DEFAULT alternative (as was assumed before
and checked in Core lint).
-
a5ec467e
by ARATA Mizuki at 2026-03-26T03:49:49-04:00
rts: Align stack to 64-byte boundary in StgRun on x86
When LLVM spills AVX/AVX-512 vector registers to the stack, it requires
32-byte (__m256) or 64-byte (__m512) alignment. If the stack is not
sufficiently aligned, LLVM inserts a realignment prologue that reserves
%rbp as a frame pointer, conflicting with GHC's use of %rbp as an STG
callee-saved register and breaking the tail-call-based calling convention.
Previously, GHC worked around this by lying to LLVM about the stack
alignment and rewriting aligned vector loads/stores (VMOVDQA, VMOVAPS)
to unaligned ones (VMOVDQU, VMOVUPS) in the LLVM Mangler. This had two
problems:
- It did not extend to AVX-512, which requires 64-byte alignment. (#26595)
- When Haskell calls a C function that takes __m256/__m512 arguments on
the stack, the callee requires genuine alignment, which could cause a
segfault. (#26822)
This patch genuinely aligns the stack to 64 bytes in StgRun by saving
the original stack pointer before alignment and restoring it in
StgReturn. We now unconditionally advertise 64-byte stack alignment to
LLVM for all x86 targets, making rewriteAVX in the LLVM Mangler
unnecessary. STG_RUN_STACK_FRAME_SIZE is increased from 48 to 56 bytes
on non-Windows x86-64 to store the saved stack pointer.
Closes #26595 and #26822
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
-
661da815
by Teo Camarasu at 2026-03-26T03:50:33-04:00
ghc-internal: Float Generics to near top of module graph
We remove GHC.Internal.Generics from the critical path of the
`ghc-internal` module graph. GHC.Internal.Generics used to be in the
middle of the module graph, but now it is nearer the top (built later).
This change thins out the module graph and allows us to get rid of the
ByteOrder hs-boot file.
We implement this by moving Generics instances from the module where the
datatype is defined to the GHC.Internal.Generics module. This trades off
increasing the compiled size of GHC.Internal.Generics with reducing the
dependency footprint of datatype modules.
Not all instances are moved to GHC.Internal.Generics. For instance,
`GHC.Internal.Control.Monad.Fix` keeps its instance as it is one of the
very last modules compiled in `ghc-internal` and so inverting the
relationship here would risk adding GHC.Internal.Generics back onto the
critical path.
We also don't change modules that are re-exported from the `template-haskell` or `ghc-heap`.
This is done to make it easy to eventually move `Generics` to `base`
once something like #26657 is implemented.
Resolves #26930
Metric Decrease:
T21839c
-
45428f88
by sheaf at 2026-03-26T03:51:31-04:00
Avoid infinite loop in deep subsumption
This commit ensures we only unify after we recur in the deep subsumption
code in the FunTy vs non-FunTy case of GHC.Tc.Utils.Unify.tc_sub_type_deep,
to avoid falling into an infinite loop.
See the new Wrinkle [Avoiding a loop in tc_sub_type_deep] in
Note [FunTy vs non-FunTy case in tc_sub_type_deep] in GHC.Tc.Utils.Unify.
Fixes #26823
Co-authored-by: simonpj <simon.peytonjones@gmail.com>
-
2823b039
by Ian Duncan at 2026-03-26T03:52:21-04:00
AArch64: fix MOVK regUsageOfInstr to mark dst as both read and written
MOVK (move with keep) modifies only a 16-bit slice of the destination
register, so the destination is both read and written. The register
allocator must know this to avoid clobbering live values. Update
regUsageOfInstr to list the destination in both src and dst sets.
No regression test: triggering the misallocation requires specific
register pressure around a MOVK sequence, which is difficult to
reliably provoke from Haskell source.
-
57b7878d
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #12002
Closes #12002.
-
c8f9df2d
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #12046
Closes #12046.
Co-authored-by: Andreas Klebinger <klebinger.andreas@gmx.at>
-
615d72ac
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #13180
Closes #13180.
-
423eebcf
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #11141
Closes #11141.
-
286849a4
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #11505
Closes #11505.
-
7db149d9
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression perf test for #13820
Closes #13820.
-
e73c4adb
by Simon Jakobi at 2026-03-26T03:53:07-04:00
Add regression test for #10381
Closes #10381.
-
5ebcfb57
by Benjamin Maurer at 2026-03-26T03:54:02-04:00
Generate assembly on x86 for word2float (#22252)
We used to emit C function call for MO_UF_Conv primitive.
Now emits direct assembly instead.
Co-Authored-By: Sylvain Henry <sylvain@haskus.fr>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
-
5b550754
by Matthew Pickering at 2026-03-26T03:54:51-04:00
rts: forward clone-stack messages after TSO migration
MSG_CLONE_STACK assumed that the target TSO was still owned by the
capability that received the message. This is not always true: the TSO
can migrate before the inbox entry is handled.
When that happened, handleCloneStackMessage could clone a live stack from
the wrong capability and use the wrong capability for allocation and
performTryPutMVar, leading to stack sanity failures such as
checkStackFrame: weird activation record found on stack.
Fix this by passing the current capability into
handleCloneStackMessage, rechecking msg->tso->cap at handling time, and
forwarding the message if the TSO has migrated. Once ownership matches,
use the executing capability consistently for cloneStack, rts_apply, and
performTryPutMVar.
Fixes #27008
-
ef0a1bd2
by mangoiv at 2026-03-26T03:55:34-04:00
release tracking: adopt release tracking ticket from #16816
-
a7f40fd9
by mangoiv at 2026-03-26T03:55:34-04:00
release tracking: add a release tracking ticket
Brings the information in the release tracking ticket up to date with
https://gitlab.haskell.org/ghc/ghc-hq/-/blob/main/release-management.mkd
Resolves #26691
-
161d3285
by Teo Camarasu at 2026-03-26T03:56:18-04:00
Revert "Set default eventlog-flush-interval to 5s"
Flushing the eventlog forces a synchronisation of all the capabilities
and there was a worry that this might lead to a performance cost for
some highly parallel workloads.
This reverts commit 66b96e2a591d8e3d60e74af3671344dfe4061cf2.
-
36eed985
by Cheng Shao at 2026-03-26T03:57:03-04:00
ghc-boot: move GHC.Data.SmallArray to ghc-boot
This commit moves `GHC.Data.SmallArray` from the `ghc` library to
`ghc-boot`, so that it can be used by `ghci` as well:
- The `Binary` (from `ghc`) instance of `SmallArray` is moved to
`GHC.Utils.Binary`
- Util functions `replicateSmallArrayIO`, `mapSmallArrayIO`,
`mapSmallArrayM_`, `imapSmallArrayM_` , `smallArrayFromList` and
`smallArrayToList` are added
- The `Show` instance is added
- The `Binary` (from `binary`) instance is added
-
fdf828ae
by Cheng Shao at 2026-03-26T03:57:03-04:00
compiler: use `Binary` instance of `BCOByteArray` for bytecode objects
This commit defines `Binary` (from `compiler`) instance of
`BCOByteArray` which serializes the underlying buffer directly, and
uses it directly in bytecode object serialization. Previously we reuse
the `Binary` (from `binary`) instance, and this change allows us to
avoid double-copying via an intermediate `ByteString` when using
`put`/`get` in `binnary`. Also see added comment for explanation.
-
3bf62d0a
by Cheng Shao at 2026-03-26T03:57:03-04:00
ghci: use SmallArray directly in ResolvedBCO
This patch makes ghci use `SmallArray` directly in `ResolvedBCO` when
applicable, making the memory representation more compact and reducing
marshaling overhead. Closes #27058.
-
3d6492ce
by Wen Kokke at 2026-03-26T03:57:53-04:00
Fix race condition between flushEventLog and start/endEventLogging.
This commit changes `flushEventLog` to acquire/release the `state_change` mutex to prevent interleaving with `startEventLogging` and `endEventLogging`. In the current RTS, `flushEventLog` _does not_ acquire this mutex, which may lead to eventlog corruption on the following interleaving:
- `startEventLogging` writes the new `EventLogWriter` to `event_log_writer`.
- `flushEventLog` flushes some events to `event_log_writer`.
- `startEventLogging` writes the eventlog header to `event_log_writer`.
This causes the eventlog to be written out in an unreadable state, with one or more events preceding the eventlog header.
This commit renames the old function to `flushEventLog_` and defines `flushEventLog` simply as:
```c
void flushEventLog(Capability **cap USED_IF_THREADS)
{
ACQUIRE_LOCK(&state_change_mutex);
flushEventLog_(cap);
RELEASE_LOCK(&state_change_mutex);
}
```
The old function is still needed internally within the compilation unit, where it is used in `endEventLogging` in a context where the `state_change` mutex has already been acquired. I've chosen to mark `flushEventLog_` as static and let other uses of `flushEventLog` within the RTS refer to the new version. There is one use in `hs_init_ghc` via `flushTrace`, where the new locking behaviour should be harmless, and one use in `handle_tick`, which I believe was likely vulnerable to the same race condition, so the new locking behaviour is desirable.
I have not added a test. The behaviour is highly non-deterministic and requires a program that concurrently calls `flushEventLog` and `startEventLogging`/`endEventLogging`. I encountered the issue while developing `eventlog-socket` and within that context have verified that my patch likely addresses the issue: a test that used to fail within the first dozen or so runs now has been running on repeat for several hours.
-
7b9a75f0
by Phil Hazelden at 2026-03-26T03:58:37-04:00
Fix build with werror on glibc 2.43.
We've been defining `_XOPEN_SOURCE` and `_POSIX_C_SOURCE` to the same
values as defined in glibc prior to 2.43. But in 2.43, glibc changes
them to new values, which means we get a warning when redefining them.
By `#undef`ing them first, we no longer get a warning.
Closes #27076.
-
fe6e76c5
by Tobias Haslop at 2026-03-26T03:59:30-04:00
Fix broken Haddock link to Bifunctor class in description of Functor class
-
404b71c1
by Luite Stegeman at 2026-03-27T04:40:49-04:00
Fix assert in Interpreter.c
If we skip exactly the number of words on the stack we end up on
the first word in the next chunk.
-
a85bd503
by Luite Stegeman at 2026-03-27T04:40:49-04:00
Support arbitrary size unboxed tuples in bytecode
This stores the size (number of words on the stack) of the next
expected tuple in the TSO, ctoi_spill_size field, eliminating
the need of stg_ctoi_tN frames for each size.
Note: On 32 bit platform there is still a bytecode tuple size
limit of 255 words on the stack.
Fixes #26946
-
e2209031
by Luite Stegeman at 2026-03-27T04:40:49-04:00
Add specialized frames for small tuples
Small tuples are now returned more efficiently to the interpreter.
They use one less word of stack space and don't need manipulation
of the TSO anymore.
-
b26bb2ea
by VeryMilkyJoe at 2026-03-27T04:41:38-04:00
Remove backwards compatibility pattern synonym `ModLocation`
Fixes #24932
-
66e5e324
by Vladislav Zavialov at 2026-03-27T04:42:25-04:00
Extend HsExpr with the StarIsType syntax (#26587, #26967)
This patch allows kinds of the form `k -> *` and `* -> k` to occur in
expression syntax, i.e. to be used as required type arguments.
For example:
{-# LANGUAGE RequiredTypeArguments, StarIsType #-}
x1 = f (* -> * -> *)
x2 = f (forall k. k -> *)
x3 = f ((* -> *) -> Constraint)
Summary of the changes:
* Introduce the HsStar constructor of HsExpr and its extension field XStar.
It is analogous to HsStarTy in HsType.
* Refactor HsStarTy to store the unicode flag as TokStar, defined as
type TokStar = EpUniToken "*" "★" -- similar to TokForall, TokRArrow, etc.
The token is stored in the extension field and replaces the Bool field.
* Extend the `infixexp2` nonterminal to parse `*` as a direct argument of `->`.
This is more limited than the full StarIsType syntax, but has the nice
property of not conflicting with the multiplication operator `a * b`.
Test case: T26967 T26967_tyop
-
f8de456f
by Sylvain Henry at 2026-03-27T04:43:22-04:00
STM: don't create a transaction in the rhs of catchRetry# (#26028)
We don't need to create a transaction for the rhs of (catchRetry#)
because contrary to the lhs we don't need to abort it on retry. Moreover
it is particularly harmful if we have code such as (#26028):
let cN = readTVar vN >> retry
tree = c1 `orElse` (c2 `orElse` (c3 `orElse` ...))
atomically tree
Because it will stack transactions for the rhss and the read-sets of all
the transactions will be iteratively merged in O(n^2) after the
execution of the most nested retry.
This is the second attempt at implementing this. The first attempt
triggered segfaults (#26291) and has been reverted.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
-
fcf092dd
by Luite Stegeman at 2026-03-27T04:44:17-04:00
Windows: remove StgAsyncIOResult and fix crash/leaks
In stg_block_async{_void}, a stack slot was reserved for
an StgAsyncIOResult. This slot would be filled by the IO
manager upon completion of the async call.
However, if the blocked thread was interrupted by an async
exception, we would end up in an invalid state:
- If the blocked computation was never re-entered, the
StgAsyncIOResult would never be freed.
- If the blocked computation was re-entered, the thread would
find an unitialized stack slot for the StgAsyncIOResult,
leading to a crash reading its fields, or freeing the pointer.
We fix this by removing the StgAsyncIOResult altogether and writing
the result directly to the stack.
Fixes #26341
-
05094993
by Luite Stegeman at 2026-03-27T04:45:12-04:00
Don't refine DEFAULT alt for unary typeclasses
A non-DEFAULT data alt for a unary typeclass dictionary would
interfere with Unary Class Magic, leading to segfaults.
fixes #27071
-
4ee260cf
by sheaf at 2026-03-27T04:46:06-04:00
Fix several oversights in hsExprType
This commit fixes several oversights in GHC.Hs.Syn.Type.hsExprType:
- The 'RecordCon' case was returning the type of the constructor,
instead of the constructor application. This is fixed by using
'splitFunTys'.
- The 'ExplicitTuple' case failed to take into account tuple sections,
and was also incorrectly handling 1-tuples (e.g. 'Solo') which can
be constructed using Template Haskell.
- The 'NegApp' case was returning the type of the negation operator,
again failing to apply it to the argument. Fixed by using
'funResultTy'.
- The 'HsProc' case was computing the result type of the arrow proc
block, without taking into account the argument type. Fix that by
adding a new field to 'CmdTopTc' that stores the arrow type, so that
we can construct the correct result type `arr a b` for
`proc (pat :: a) -> (cmd :: b)`.
- The 'ArithSeq' and 'NegApp' cases were failing to take into account
the result 'HsWrapper', which could e.g. silently drop casts.
This is fixed by introducing 'syntaxExpr_wrappedFunResTy' which, on
top of taking the result type, applies the result 'HsWrapper'.
These fixes are validated by the new GHC API test T26910.
Fixes #26910
-
e97232ce
by Hai at 2026-03-27T04:47:04-04:00
Parser.y: avoid looking at token with QualifiedDo
This changes the behavior of 'hintQualifiedDo' so that the supplied
token is not inspected when the QualifiedDo language extension bit is
set.
-
9831385b
by Vladislav Zavialov at 2026-03-27T17:22:30-04:00
Infix holes in types (#11107)
This patch introduces several improvements that follow naturally from
refactoring HsOpTy to represent the operator as an HsType, aligning it
with the approach taken by OpApp and HsExpr.
User-facing changes:
1. Infix holes (t1 `_` t2) are now permitted in types, following the
precedent set by term-level expressions.
Test case: T11107
2. Error messages for illegal promotion ticks are now reported at more
precise source locations.
Test case: T17865
Internal changes:
* The definition of HsOpTy now mirrors that of OpApp:
| HsOpTy (XOpTy p) (LHsType p) (LHsType p) (LHsType p)
| OpApp (XOpApp p) (LHsExpr p) (LHsExpr p) (LHsExpr p)
This moves us one step closer to unifying HsType and HsExpr.
* Ignoring locations,
the old pattern match (HsOpTy x prom lhs op rhs)
is now written as (HsOpTy x lhs (HsTyVar x' prom op) rhs)
but we also handle (HsOpTy x lhs (HsWildCardTy x') rhs)
Constructors other than HsTyVar and HsWildCardTy never appear
in the operator position.
* The various definitions across the compiler have been updated to work
with the new representation, drawing inspiration from the term-level
pipeline where appropriate. For example,
ppr_infix_ty <=> ppr_infix_expr
get_tyop <=> get_op
lookupTypeFixityRn <=> lookupExprFixityRn
(the latter is factored out from rnExpr)
Test cases: T11107 T17865
-
5b6757d7
by mangoiv at 2026-03-27T17:23:19-04:00
ci: build i386 non-validate for deb12
This is a small fix that will unlock ghcup metadata to run, i386 debian
12 was missing as a job.
-
cf942119
by Cheng Shao at 2026-03-30T15:24:37-04:00
ghc-boot: remove unused SizedSeq instances and functions
This commit removes unused `SizedSeq` instances and functions, only
keeping the bits we need for hpc tick sequence for now.
-
22c5b7cc
by Cheng Shao at 2026-03-30T15:24:38-04:00
ghci: remove unused GHCi.BinaryArray
This patch removes the unused `GHCi.BinaryArray` module from `ghci`.
Closes #27108.
-
77abb4ab
by Cheng Shao at 2026-03-30T15:25:21-04:00
testsuite: mark T17912 as fragile on Windows
T17912 is still fragile on Windows, it sometimes unexpectedly pass in
CI. This especially strains our already scarce Windows CI runner
resources. Mark it as fragile on Windows for the time being.
-
d741a6cc
by Andreas Klebinger at 2026-03-31T04:39:33-04:00
Bump minimum shake version for hadrian.
We also add the shake version we want to stack.yaml
Fixes #26884
-
5e556f9e
by Vladislav Zavialov at 2026-03-31T04:40:16-04:00
Status check for the HsType~HsExpr refactoring (#25121)
Add a test case to track the status of a refactoring project within GHC
whose goal is to arrive at the following declaration:
type HsType = HsExpr
The rationale for this is to increase code reuse between the term- and
type-level code in the compiler front-end (AST, parser, renamer, type checker).
The status report is saved to testsuite/tests/ghc-api/T25121_status.stdout
and provides useful insights into what needs to happen to make progress on
the ticket.
-
acffb1b1
by fendor at 2026-03-31T04:41:02-04:00
Extract Binary instances to `GHC.ByteCode.Binary`
-
e2ea8e25
by fendor at 2026-03-31T04:41:02-04:00
Add `seqNonEmpty` for evaluating `NonEmpty a`
-
048b00b7
by fendor at 2026-03-31T04:41:02-04:00
Record `LinkableUsage` instead of `Linkable` in `LoaderState`
Retaining a ByteCode `Linkable` after it has been loaded retains its
`UnlinkedBCO`, keeping it alive for the remainder of the program.
This starts accumulating a lot of `UnlinkedBCO` and memory over time.
However, the `Linkable` is merely used to later record its usage in
`mkObjectUsage`, which is used for recompilation checking.
However, this is incorrect, as the interface file and bytecode objects
could be in different states, e.g. the interface changes, but the
bytecode library hasn't changed so we don't need to recompile and vice
versa.
By computing a `Fingerprint` for the `ModuleByteCode`, and recording it
in the `LinkableUsage`, we know precisely whether the `ByteCode` object
on disk is outdated.
Thus, parts of this commit just makes sure that we efficiently compute a
`Fingerprint` for `ModuleByteCode` and store it in the on-disk
representation of `ModuleByteCode`.
We change the `LoaderState` to retain `LinkableUsage`, which is smaller
representation of a `Linkable`. This allows us to free the unneeded
fields of `Linkable` after linking them.
We declare the following memory invariants that this commit implements:
* No `LinkablePart` should be retained from `LoaderState`.
* `Linkable`s should be unloaded after they have been loaded.
These invariants are unfortunately tricky to automatically uphold, so we
are simply documenting our assumptions for now.
We introduce the `linkable-space` test which makes sure that after
loading, no `DotGBC` or `UnlinkedBCO` is retained.
-------------------------
Metric Increase:
MultiLayerModulesTH_OneShot
-------------------------
We allocate a bit more, but the peak number of bytes doesn't change.
While a bit unfortunate, accepting the metric increase.
We add multiple new performance measurements where we were able to
observe the desired memory invariants. Further, we add regression tests
to validate that the recompilation checker behaves more correct than
before.
-
2d1c1997
by Simon Jakobi at 2026-03-31T04:41:46-04:00
Eliminate dictionary-passing in ListMap operations
Mark the ListMap helpers 'INLINABLE' so importing modules can specialise
the 'TrieMap (ListMap m)' methods and avoid recursive dictionary-passing.
See Note [Making ListMap operations specialisable].
Fixes #27097
-
ed2c6570
by Cheng Shao at 2026-03-31T04:42:33-04:00
testsuite: fix testdir cleanup logic on Windows
testdir cleanup is unreliable on Windows (#13162) and despite existing
hacks in the driver, new failure mode has occurred. This patch makes
it print the warning and carry on when failed to clean up a testdir,
instead of reporting a spurious framework failure. See added comment
for detailed explanation.
-
d9388e29
by Simon Jakobi at 2026-03-31T13:14:59-04:00
Add regression test for #18177
Closes #18177.
Assisted-by: Codex
-
6a10045c
by mangoiv at 2026-03-31T13:15:43-04:00
ci: allow metric decrease for two tests on i386
There has been a nightly failure on i386 due to a compiler runtime
improvement on i386 debian 12. We allow that.
Metric Decrease (test_env='i386-linux-deb12'):
T12707 T8095
-
7fbb4fcb
by Rodrigo Mesquita at 2026-04-01T12:16:33+00:00
Bump default language edition to GHC2024
As per the accepted ghc-proposal#632
Fixes #26039
-
5ae43275
by Peng Fan at 2026-04-01T19:01:06-04:00
NCG/LA64: add cmpxchg and xchg primops
And append some new instructions for LA664 uarch.
Apply fix to cmpxchg-prim by Andreas Klebinger.
Suggestions in https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15515
-
8f95534a
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove signal-based ticker implementations
Fixes issue #27073
All supported platforms should work with the pthreads + nanosleep based
ticker implementation. This avoids all the problems with using signals.
In practice, all supported platforms were probably using the non-signal
tickers already, which is probably why we do not get lots of reports
about deadlocks and other weirdness: we were definately using functions
that are not async signal safe in the tick handler (such as fflush to
flussh the eventlog).
Only Solaris was explicitly using the timer_create ticker impl, and even
Solaris could probably use the pthreads one (if anyone cared: Solaris is
no longer a Teir 3 supported platform).
Plausibly the only supported platform that this will change will be AIX,
which should now use the pthreads impl.
-
51b32b0d
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Tidy up some timer/ticker comments elsewhere
-
7562bcd7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove now-unused install_vtalrm_handler
Support function used by both of the signal-based ticker
implementations.
-
6da127c7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
No longer probe for timer_create in rts/configure
It was only used by the TimerCreate.c ticker impl.
-
3fd490fa
by Duncan Coutts at 2026-04-01T19:01:53-04:00
Note that rtsTimerSignal is deprecated.
-
63099b0f
by Simon Jakobi at 2026-04-01T19:02:39-04:00
Add perf test for #13960
Closes #13960.
-
58009c14
by Apoorv Ingle at 2026-04-02T09:51:24+01:00
Streamline expansions using HsExpansion (#25001)
Notes added [Error Context Stack] [Typechecking by expansion: overview]
Notes updated Note [Expanding HsDo with XXExprGhcRn] [tcApp: typechecking applications]
-------------------------
Metric Decrease:
T9020
-------------------------
There are 2 key changes:
1. `HsExpand` datatype mediates between expansions
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
This has some consequences detailed below:
1. `HsExpand` datatype mediates between expansions
* Simplifies the implementations of `tcExpr` to work on `XExpr`
* Removes `VACtxt` (and its associated `VAExpansion` and `VACall`) datatype, it is subsumed by simply a `SrcSpan`.
* Removes the function `addHeadCtxt` as it is now mearly setting a location
* The function `tcValArgs` does its own argument number management
* move `splitHsTypes` out of `tcApp`
* Removes special case of tcBody from `tcLambdaMatches`
* Removes special case of `dsExpr` for `ExpandedThingTc`
* Renames `tcMonoExpr` -> `tcMonoLExpr`, `tcMonoExprNC` -> `tcMonoLExpr`
* Renames `EValArg`, `EValArgQL` fields: `ea_ctxt` -> `ea_loc_span` and `eaql_ctx` -> `eaql_loc_span`
* Remove `PopErrCtxt` from `XXExprGhcRn`
* `fun_orig` in tcInstFun depends on the SrcSpan of the head of the application chain (similar to addArgCtxt)
- it references the application chain head if it is user located, or
uses the error context stack as a fallback if it's a generated
location
* Make a new variant `GeneratedSrcSpan` in `SrcSpan` for HIEAst Nodes
- Expressions wrapped around `GeneratedSrcSpan` are ignored and never added to the error context stack
- In Explicit list expansion `fromListN` is wrapped with a `GeneratedSrcSpan` with `GeneratedSrcSpanDetails` field to store the original srcspan
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
* Merge `HsThingRn` to `HsCtxt`
* Landmark Error messages are now just computed on the fly
* Make HsExpandedRn and HsExpandedTc payload a located HsExpr GhcRn
* `HsCtxt` are tidied and zonked at the end right before printing
Co-authored-by: simonpj <simon.peytonjones@gmail.com>
-
bc4b4487
by Zubin Duggal at 2026-04-03T14:22:27-04:00
driver: recognise .dyn_o as a valid object file to link if passed on the command line.
This allows plugins compiled with this suffix to run.
Fixes #24486
-
5ebb9121
by Simon Jakobi at 2026-04-03T14:23:11-04:00
Add regression test for #16145
Closes #16145.
-
c1fc1c44
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Refactor eta-expansion in Prep
The Prep pass does eta-expansion but I found cases where it was
doing bad things. So I refactored and simplified it quite a bit.
In the new design
* There is no distinction between `rhs` and `body`; in particular,
lambdas can now appear anywhere, rather than just as the RHS of
a let-binding.
* This change led to a significant simplification of Prep, and
a more straightforward explanation of eta-expansion. See the new
Note [Eta expansion]
* The consequences is that CoreToStg needs to handle naked lambdas.
This is very easy; but it does need a unique supply, which forces
some simple refactoring. Having a unique supply to hand is probably
a good thing anyway.
-
21beda2c
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Clarify Note [Interesting dictionary arguments]
Ticket #26831 ended up concluding that the code for
GHC.Core.Opt.Specialise.interestingDict was good, but the
commments were a bit inadequate.
This commit improves the comments slightly.
-
3eaac1f2
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Make inlining a bit more eager for overloaded functions
If we have
f d = ... (class-op d x y) ...
we should be eager to inline `f`, because that may change the
higher order call (class-op d x y) into a call to a statically
known function.
See the discussion on #26831.
Even though this does a bit /more/ inlining, compile times
decrease by an average of 0.4%.
Compile time changes:
DsIncompleteRecSel3(normal) 431,786,104 -2.2%
ManyAlternatives(normal) 670,883,768 -1.6%
ManyConstructors(normal) 3,758,493,832 -2.6% GOOD
MultilineStringsPerf(normal) 29,900,576 -2.8%
T14052Type(ghci) 1,047,600,848 -1.2%
T17836(normal) 392,852,328 -5.2%
T18478(normal) 442,785,768 -1.4%
T21839c(normal) 341,536,992 -14.1% GOOD
T3064(normal) 174,086,152 +5.3% BAD
T5631(normal) 506,867,800 +1.0%
hard_hole_fits(normal) 209,530,736 -1.3%
info_table_map_perf(normal) 19,523,093,184 -1.2%
parsing001(normal) 377,810,528 -1.1%
pmcOrPats(normal) 60,075,264 -0.5%
geo. mean -0.4%
minimum -14.1%
maximum +5.3%
Runtime changes
haddock.Cabal(normal) 27,351,988,792 -0.7%
haddock.base(normal) 26,997,212,560 -0.6%
haddock.compiler(normal) 219,531,332,960 -1.0%
Metric Decrease:
LinkableUsage01
ManyConstructors
T17949
T21839c
T13035
TcPlugin_RewritePerf
hard_hole_fits
Metric Increase:
T3064
-
5cbc2c82
by Matthew Pickering at 2026-04-03T19:57:02-04:00
bytecode: Add magic header/version to bytecode files
In order to avoid confusing errors when using stale interface files (ie
from an older compiler version), we add a simple header/version check
like the one for interface files.
Fixes #27068
-
d95a1936
by fendor at 2026-04-03T19:57:02-04:00
Add constants for bytecode in-memory buffer size
Introduce a common constant for the default size of the .gbc and
.bytecodelib binary buffer.
The buffer is by default set to 1 MB.
-
b822c30a
by mangoiv at 2026-04-03T19:57:49-04:00
testsuite: filter stderr for static001 on darwin
This reactivates the test on x86_64 darwin as this should have been done
long ago and ignores warnings emitted by ranlib on newer version of the
darwin toolchain since they are benign. (no symbols for stub libraries)
Fixes #27116
-
28ce1f8a
by Andreas Klebinger at 2026-04-03T19:58:44-04:00
Give the Data instance for ModuleName a non-bottom toConstr implementation.
I've also taken the liberty to add Note [Data.Data instances for GHC AST Types]
describing some of the uses of Data.Data I could find.
Fixes #27129
-
8ca41ffe
by mangoiv at 2026-04-03T19:59:30-04:00
issue template: fix add bug label
-
3981db0c
by Sylvain Henry at 2026-04-03T20:00:33-04:00
Add more canned GC functions for common register patterns (#27142)
Based on analysis of heap-check sites across the GHC compiler and Cabal,
the following patterns were not covered by existing canned GC functions
but occurred frequently enough to warrant specialisation:
stg_gc_ppppp -- 5 GC pointers
stg_gc_ip -- unboxed word + GC pointer
stg_gc_pi -- GC pointer + unboxed word
stg_gc_ii -- two unboxed words
stg_gc_bpp -- byte (I8) + two GC pointers
Adding these reduces the fraction of heap-check sites falling back to
the generic GC path from ~1.4% to ~0.4% when compiling GHC itself.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
-
d17d1435
by Matthew Pickering at 2026-04-03T20:01:19-04:00
Make home unit dependencies stored as sets
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>
-
92a97015
by Simon Peyton Jones at 2026-04-05T00:58:57+01:00
Add Invariant (NoTypeShadowing) to Core
This commit addresses #26868, by adding
a new invariant (NoTypeShadowing) to Core.
See Note [No type-shadowing in Core] in GHC.Core
-
8b5a5020
by Simon Peyton Jones at 2026-04-05T00:58:57+01:00
Major refactor of free-variable functions
For some time we have had two free-variable mechanims for types:
* The "FV" mechanism, embodied in GHC.Utils.FV, which worked OK, but
was fragile where eta-expansion was concerned.
* The TyCoFolder mechanism, using a one-shot EndoOS accumulator
I finally got tired of this and refactored the whole thing, thereby
addressing #27080. Now we have
* `GHC.Types.Var.FV`, which has a composable free-variable result type,
very much in the spirit of the old `FV`, but much more robust.
(It uses the "one shot trick".)
* GHC.Core.TyCo.FVs now has just one technology for free variables.
All this led to a lot of renaming.
There are couple of error-message changes. The change in T18451
makes an already-poor error message even more mysterious. But
it really needs a separate look.
We also now traverse the AST in a different order leading to a different
but still deterministic order for FVs and test output has been adjusted
accordingly.
-
4bf040c6
by sheaf at 2026-04-05T14:56:29-04:00
Add utility pprTrace_ function
This function is useful for quick debugging, as it can be added to a
where clause to pretty-print debugging information:
fooBar x y
| cond = body1
| otherwise = body2
where
!_ = pprTrace_ "fooBar" $
vcat [ text "x:" <+> ppr x
, text "y:" <+> ppr y
, text "cond:" <+> ppr cond
]
-
502e6ffe
by Andrew Lelechenko at 2026-04-07T04:47:21-04:00
base: improve error message for Data.Char.chr
As per https://github.com/haskell/core-libraries-committee/issues/384
-
b21bd52e
by Simon Peyton Jones at 2026-04-07T04:48:07-04:00
Refactor FunResCtxt a bit
Fixes #27154
-
7fe84ea5
by Zubin Duggal at 2026-04-07T19:11:52+05:30
compiler: Warn when -finfo-table-map is used with -fllvm
These are currently not supported together.
Fixes #26435
-
4a45a7da
by Matthew Pickering at 2026-04-08T04:37:29-04:00
packaging: correctly propagate build/host/target to bindist configure script
At the moment the host and target which we will produce a compiler for
is fixed at the initial configure time. Therefore we need to persist
the choice made at this time into the installation bindist as well so we
look for the right tools, with the right prefixes at install time.
In the future, we want to provide a bit more control about what kind of
bindist we produce so the logic about what the host/target will have to
be written by hadrian rather than persisted by the configure script. In
particular with cross compilers we want to either build a normal stage 2
cross bindist or a stage 3 bindist, which creates a bindist which has a
native compiler for the target platform.
Fixes #21970
Co-authored-by: Sven Tennie <sven.tennie@gmail.com>
-
b0950df6
by Sven Tennie at 2026-04-08T04:37:29-04:00
Cross --host and --target no longer required for cross (#21970)
We set sane defaults in the configure script. Thus, these paramenters
aren't required any longer.
-
fef35216
by Sven Tennie at 2026-04-08T04:37:30-04:00
ci: Define USER_CONF_CC_OPTS_STAGE2 for aarch64/mingw
ghc-toolchain doesn't see $CONF_CC_OPTS_STAGE2 when the bindist gets
configured. So, the hack to override the compiler gets lost.
-
8dd6f453
by Cheng Shao at 2026-04-08T04:38:11-04:00
ghci: use ShortByteString for LookupSymbol/LookupSymbolInDLL/LookupClosure messages
This patch refactors ghci to use `ShortByteString` for
`LookupSymbol`/`LookupSymbolInDLL`/`LookupClosure` messages as the
first part of #27147.
Co-authored-by: Codex <codex@openai.com>
-
371ef200
by Cheng Shao at 2026-04-08T04:38:11-04:00
ghci: use ShortByteString for MkCostCentres message
This patch refactors ghci to use `ShortByteString` for `MkCostCentres`
messages as a first part of #27147. This also considerably lowers the
memory overhead of breakpoints when cost center profiling is enabled.
-------------------------
Metric Decrease:
interpreter_steplocal
-------------------------
Co-authored-by: Codex <codex@openai.com>
-
4a122bb6
by Phil Hazelden at 2026-04-08T20:49:42-04:00
Implement modifiers syntax.
The `%m` syntax of linear types is now accepted in more places, to allow
use by future extensions, though so far linear types is still the only
consumer.
This may break existing code where it
* Uses -XLinearTypes.
* Has code of the form `a %m -> b`, where `m` can't be inferred to be
kind Multiplicity.
The code can be fixed either by adding a kind annotation, or by setting
`-XLinearTypes -XNoModifiers`.
Proposal:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0370-modifiers.rst
-
07267f79
by Zubin Duggal at 2026-04-08T20:50:25-04:00
hadrian: Don't include the package hash in the haddock directory
Since GHC 9.8 and hash_unit_ids, haddock urls have looked like`ghc-9.10.3/doc/html/libraries/base-4.20.2.0-39f9/**/*.html`
The inclusion of the hash makes it hard for downstream non-boot packages to properly link to these files, as the hash is not
part of a standard cabal substitution.
Since we only build one version of each package, we don't need the hash to disambiguate anything, we can just remove it.
Fixes #26635
-
0a83b95b
by ARATA Mizuki at 2026-04-08T20:51:18-04:00
testsuite: Allow multiple ways to be run by setting multiple command-line options
This patch allows multiple `--test-way`s to take effect, like:
$ hadrian/build test --test-way=normal --test-way=llvm
Previously, only one way was run if the test speed was 'normal' or 'fast'.
Closes #26926
Co-authored-by: sheaf <sam.derbyshire@gmail.com>
-
e841931c
by Teo Camarasu at 2026-04-08T20:52:00-04:00
doc: improve eventlog-flush-interval flag documentation
We mention the performance cost and how this flag can be turned off.
Resolves #27056
-
e332db25
by Teo Camarasu at 2026-04-08T20:52:01-04:00
docs/user_guide: fix typo
-
5b82080a
by Simon Jakobi at 2026-04-08T20:52:44-04:00
Fix -dsuppress-uniques for free variables in demand signatures
Before: Str=b{sXyZ->S}
With this patch: Str=b{S}
T13143.stderr is updated accordingly.
Fixes #27106.
-
b7a084cc
by Simon Jakobi at 2026-04-08T20:53:27-04:00
Documentation fixes for demand signature notation
Fixes #27115.
-
59391132
by Simon Jakobi at 2026-04-08T20:54:08-04:00
Use upsert for non-deleting map updates
Some compiler functions were using `alter`, despite never removing
any entries: they only update an existing entry or insert a new one.
These functions are converted to using `upsert`:
alter :: (Maybe a -> Maybe a) -> Key -> Map a -> Map a
upsert :: (Maybe a -> a) -> Key -> Map a -> Map a
`upsert` variants are also added to APIs of the various Word64Map
wrapper types.
The precedent for this `upsert` operation is in the containers library:
see https://github.com/haskell/containers/pull/1145
Metrics: compile_time/bytes allocated
-------------------------------------
geo. mean: -0.1%
minimum: -0.5%
maximum: +0.0%
Resolves #27140.
-
da7e82f4
by Cheng Shao at 2026-04-08T20:54:49-04:00
testsuite: fix testsuite run for +ipe again
This patch makes the +ipe flavour transformer pass the entire
testsuite again by dropping stdout/stderr checks of certain tests that
are sensitive to stack layout changes with `+ipe`. Related: #26799.
-
b135a87d
by Zubin Duggal at 2026-04-09T19:36:50+05:30
Bump directory submodule to 1.3.11.0 (unreleased)
-
3a291d07
by Zubin Duggal at 2026-04-09T19:36:50+05:30
Bump file-io submodule to 0.2.0
-
e0ab606d
by Zubin Duggal at 2026-04-10T18:40:20+05:30
Release notes for GHC 10.0
-
e08b9b34
by Zubin Duggal at 2026-04-10T18:40:20+05:30
Bump ghc-prim version to 0.14.0
-
a92aac6e
by Zubin Duggal at 2026-04-10T18:40:20+05:30
Bump template-haskell to 2.25.0.0; update submodule exceptions for TH 2.25
-
f254d9e8
by Zubin Duggal at 2026-04-10T18:40:20+05:30
Bump GHC version to 10.0
-
6ce0368a
by Zubin Duggal at 2026-04-10T18:40:28+05:30
Bump base to 4.23.0.0; update submodules for base 4.24 upper bound
-
702fb8a5
by Zubin Duggal at 2026-04-10T18:40:28+05:30
Bump GHC version to 10.1; update submodules template-haskell-lift and template-haskell-quasiquoter for ghc-internal 10.200
-
75df1ca4
by Zubin Duggal at 2026-04-10T18:40:28+05:30
Use changelog.d for release notes (#26002)
GHC now uses a fragment-based changelog workflow using a custom script adapted from https://codeberg.org/fgaz/changelog-d.
Contributors add a file in changelog.d/ for each user-facing change.
At release time, these are assembled into release notes for sphinx (in RST) format, using
the tool.
New hadrian `changelog` target to generate changelogs
CI job to validate changelog entries for MRs unless skipped with ~"no-changelog" label
Teach sphinx about ghc-mr: extlink to link to MRs
Remove `ghc-package-list` from sphinx, and implement it in changelog-d instead (Fixes #26476).
(cherry picked from commit 989c07249978f418dfde1353abfad453f024d61a)
-
585d7450
by Luite Stegeman at 2026-04-11T02:17:13-04:00
tc: discard warnings in tcUserStmt Plan C
We typecheck let_stmt twice, but we don't want the warnings twice!
see #26233
-
2df604e9
by Sylvain Henry at 2026-04-11T02:19:30-04:00
Introduce TargetInt to represent target's Int (#15973)
GHC was using host 'Int' in several places to represent values that
live in the target machine's 'Int' type. This is silently wrong when
cross-compiling from a 32-bit host to a 64-bit target: the host Int
is 32 bits while the target Int is 64 bits.
See Note [TargetInt] in GHC.Platform.
Also used the opportunity to make DynTag = Word8.
Fixes #15973
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
-
d419e972
by Luite Stegeman at 2026-04-13T15:16:04-04:00
Suppress desugaring warnings in the pattern match checker
Avoid duplicating warnings from the actual desugaring pass.
fixes #25996
-
c5b80dd0
by Phil de Joux at 2026-04-13T15:16:51-04:00
Typo ~/ghc/arch-os-version/environments
-
71462fff
by Luite Stegeman at 2026-04-13T15:17:38-04:00
add changelog entry for #26233
-
d1ddfd4b
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
Add test for #25636
The existing test behaviour of "T23146_liftedeq" changed because the
simplifier now does a bit more inlining. We can restore the previous bad
behavior by using an OPAQUE pragma.
This test doubles as a test for #25636 when run in ghci, so we add it as
such.
-
b9df40ee
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
refactor: protoBCOName is always a Name
Simplifies the code by removing the unnecessary type argument to
ProtoBCO which was always 'Name'
-
5c2a179e
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
Allocate static constructors for bytecode
This commit adds support for static constructors when compiling and
linking ByteCode objects.
Top-level StgRhsCon get lowered to ProtoStaticCons rather than to
ProtoBCOs. A ProtoStaticCon gets allocated directly as a data con
application on the heap (using the new primop newConApp#).
Previously, we would allocate a ProtoBCO which, when evaluated, would
PACK and return the constructor.
A few more details are given in Note [Static constructors in Bytecode].
Secondly, this commit also fixes issue #25636 which was caused by
linking *unlifted* constructors in BCO instructions as
- (1) a thunk indexing the array of BCOs in a module
- (2) which evaluated to a BCO which still had to be evaluated to
return the unlifted constructor proper.
The (2) issue has been resolved by allocating the static constructors
directly. The (1) issue can be resolved by ensuring that we allocate all
unlifted top-level constructors eagerly, and leave the knot-tying for
the lifted BCOs and top-level constructors only.
The top-level unlifted constructors are never mutually recursive, so we
can allocate them all in one go as long as we do it in topological
order. Lifted fields of unlifted constructors can still be filled by the
knot-tied lifted variables since in those fields it is fine to keep
those thunks. See Note [Tying the knot in createBCOs] for more details.
Fixes #25636
-------------------------
Metric Decrease:
LinkableUsage01
-------------------------
-
cde47053
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
Revert "StgToByteCode: Assert that PUSH_G'd values are lifted"
This reverts commit ec26c54d818e0cd328276196930313f66b780905.
Ever since f7a22c0f4e9ae0dc767115d4c53fddbd8372b777, we now do support
and will link top-level unlifted constructors into evaluated and
properly tagged values which we can reference with PUSH_G.
This assertion is no longer true and triggered a failure in T25636
-
c7a7e5b8
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
refactor: Tag more remote Ptrs as RemotePtr
Pure refactor which improves the API of
- GHC.ByteCode.Linker
- GHC.Runtime.Interpreter
- GHC.Runtime.Interpreter.Types.SymbolCache
by using `RemotePtr` for more functions which used to return `Ptr`s that
could potentially be in a foreign process. E.g. `lookupIE`,
`lookupStaticPtr`, etc...
-
fc59494c
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
Add float# and subword tests for #25636
These tests cover that static constructors in bytecode work correctly
for Float# and subword values (Word8#, Word16#)
-
477f521b
by Rodrigo Mesquita at 2026-04-14T18:41:12-04:00
test: Validate topoSort logic in createBCOs
This test validates that the topological sorting and ordering of the
unlifted constructors and lifted constructors in `createBCOs` is
correct.
See `Note [Tying the knot in createBCOs]` for why tying the knot for the
created BCOs is slightly difficult and why the topological sorting is
necessary.
This test fails when `let topoSortedObjs = topSortObjs objs` is
substituted by `let topoSortedObjs = zip [0..] objs`, thus witnessing
the toposort logic is correct and necessary.
The test calls the ghci `createBCOs` directly because it is currently
impossible to construct in Source Haskell a situation where a top-level
static unlifted constructor depends on another (we don't have top-level
unlifted constructors except for nullary constructors like `Leaf ::
(UTree :: UnliftedType)`).
This is another test for fix for #25636
-
2d9c30be
by Simon Jakobi at 2026-04-14T18:42:00-04:00
Improve tests for `elem`
...in order to simplify the work on #27096.
* Improve T17752 by including the Core output in golden files, checking
both -O1 and -O2.
* Add tests for fusion and no-fusion cases.
Fixes #27101.
-
2dadf3b0
by sheaf at 2026-04-16T13:28:39-04:00
Simplify mkTick
This commit simplifies 'GHC.Core.Utils.mkTick', removing the
accumulating parameter 'rest' which was suspiciously treating a bunch of
different ticks as a group, and moving the group as a whole around the
AST, ignoring that the ticks in the group might have different placement
properties.
The most important change is that we revert the logic (added in 85b0aae2)
that allowed ticks to be placed around coercions, which caused serious
issues (e.g. #27121). It was just a mistake, as it doesn't make sense
to put a tick around a coercion.
Also adds Note [Pushing SCCs inwards] which clarifies the logic for
pushing SCCs into lambdas, constructor applications, and dropping SCCs
around non-function variables (in particular the treatment of splittable
ticks).
A few other changes are also implemented:
- simplify 'can_split' predicate (no functional change)
- combine profiling ticks into one when possible
Fixes #26878, #26941 and #27121
Co-authored-by: simonpj <simon.peytonjones@gmail.com>
-
a0d6f1f4
by Simon Jakobi at 2026-04-16T13:29:28-04:00
Add regression test for #9074
Closes #9074.
-
d178ee89
by Sylvain Henry at 2026-04-16T13:30:25-04:00
Add changelog for #15973
-
e8a196c6
by sheaf at 2026-04-16T13:31:19-04:00
Deal with 'noSpec' in 'coreExprToPmLit'
This commit makes two separate changes relating to
'GHC.HsToCore.Pmc.Solver.Types.coreExprAsPmLit':
1. Commit 7124e4ad mistakenly marked deferred errors as non-canonical,
which led to the introduction of 'nospec' wrappers in the
generated Core. This reverts that accident by declaring deferred
errors as being canonical, avoiding spurious 'nospec' wrapping.
2. Look through magic identity-like Ids such as 'nospec', 'inline' and
'lazy' in 'coreExprAsPmLit', just like Core Prep does.
There might genuinely be incoherent evidence, but that shouldn't
obstruct the pattern match checker. See test T27124a.
Fixes #25926 #27124
-------------------------
Metric Decrease:
T3294
-------------------------
-
8cb99552
by Sylvain Henry at 2026-04-16T19:22:43-04:00
hadrian: warn when package index is missing (#16484)
Since cabal-install 3.0 we can query the path of remote-repo-cache and
check if hackage package index is present.
Fixes #16484
-
d6ce7477
by Richard Eisenberg at 2026-04-16T19:23:25-04:00
Teach hadrian to --skip-test.
Fixes #27188.
This adds the --skip-test flag to `hadrian build`, as documented in the
patch.
-
7666f4a9
by Fendor at 2026-04-17T22:29:51-04:00
Migrate `ghc-pkg` to use `OsPath` and `file-io`
`ghc-pkg` should use UNC paths as much as possible to avoid MAX_PATH
issues on windows.
`file-io` uses UNC Paths by default on windows, ensuring we use the
correct APIs and that we finally are no longer plagued by MAX_PATH
issues in CI and private machines.
On top of it, the higher correctness of `OsPath` is appreciated in this
small codebase. Also, we improve memory usage very slightly, due to the
more efficient memory representation of `OsPath` over `FilePath`
Adds `ghc-pkg` regression test for MAX_PATH on windows
Make sure `ghc-pkg` behaves as expected when long paths (> 255) are
involved on windows.
Let's generate a testcase where we can actually observe that `ghc-pkg`
behaves as epxected.
See the documentation for windows on Maximum Path Length Limitation:
* `https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation`
Adds changelog entry for long path support in ghc-pkg.
-
78434e8c
by Simon Peyton Jones at 2026-04-17T22:30:38-04:00
Kill off the substitution in Lint
Now that we have invariant (NoTypeShadowing) we no longer
need Lint to carry an ambient substitution. This makes it
simpler and faster. A really worthwhile refactor.
There are some knock-on effects
* Linting join points after worker/wrapper. See
Note [Join points and beta redexes]
* Running a type substitution after the desugarer.
See Note [Substituting type-lets] in
the new module GHC.Core.SubstTypeLets
Implements #27078
Most perf tests don't use Lint so we won't see a perf incresae.
But T1969, which uses -O0 and Lint, gets 1.3% worse because it has
to run the SubstTypeLets pass which is a somewhat expensive no-op
Overall though compile-time allocations are down 0.1%.
Metric Increase:
T1969
-
86ca6c2c
by mangoiv at 2026-04-17T22:31:22-04:00
testsuite: inline elemCoreTest
Some weird (probably python scoping) rule caused elemCoreTest, a regex
being out of scope on ubuntu, presumably because of a newer python version.
This patch just inlines the regex, which fixes the issue.
Fixes #27193
-
72d6dc74
by aparker at 2026-04-20T20:15:44-04:00
NCG: Implement constant folding for vector simd ops (Issue #25030)
-
b9cab907
by sheaf at 2026-04-20T20:15:44-04:00
Mark some SIMD tests as broken on i386 optllvm
As seen in #25498, several SIMD tests are broken on i386 in the optllvm
way. This commit marks them as "expect_broken".
-
76528cc3
by Wolfgang Jeltsch at 2026-04-20T20:16:25-04:00
Move most of the `System.IO` implementation into `base`
This involves a rewrite of the `combine` helper function to avoid the
use of `last`, which would now be flagged as an error.
Metric Decrease:
LinkableUsage01
T3294
Metric Increase:
T12227
T12707
T5642
-
04d143c0
by Luite Stegeman at 2026-04-21T14:05:33-04:00
rts: add a few missing i386 relocations in the rts linker
-
014087e7
by Luite Stegeman at 2026-04-21T14:05:34-04:00
CodeOutput: Fix finalizers on multiple platforms
- ELF platforms: emit .fini_array section
- wasm32/Darwin: emit initializer with __cxa_atexit call
- Windows: use -Wl,--whole-archive to prevent dropping finalizer symbols
- rts linker: fix crash/assertion failure unloading objects with finalizers
fixes #27072
-
915bba6f
by Simon Jakobi at 2026-04-21T14:06:16-04:00
Add regression test for #10531
Closes #10531.
-
86a646a6
by Andreas Klebinger at 2026-04-22T13:00:05-04:00
Revert use of generic instances for compiler time perf reasons.
Revert "Derive Semigroup/Monoid for instances believed could be derived in #25871"
This reverts commit 11a04cbb221cc404fe00d65d7c951558ede4caa9.
Revert "add Ghc.Data.Pair deriving"
This reverts commit 15d9ce449e1be8c01b89fd39bdf1e700ea7d1dce.
-
bc9ee1cf
by Wen Kokke at 2026-04-22T13:00:51-04:00
hadrian: Fix docs to remove static flavour
In 638f6548, the static flavour was turned into into the fully_static
flavour transformer. However, this commit did not update flavours.md.
-
cc9cc6d5
by Cheng Shao at 2026-04-23T09:40:46+00:00
configure: bump LlvmMaxVersion to 23
This patch bumps `LlvmMaxVersion` to 23 to support LLVM 22.x releases.
-
2ea7ef8e
by Cheng Shao at 2026-04-23T09:46:26+00:00
changelog: add llvm 22.x support
-
5574ee10
by Cheng Shao at 2026-04-24T08:24:30-04:00
compiler: avoid unused temporary `appendFS` operands
This patch fixes unused temporary `appendFS` operands in the codebase
that are retained in the `FastString` table after concatenation.
Rewrite rules are added so that if an operand is
`fsLit`/`mkFastString`, the `appendFS` application is rewritten to
append the `ShortByteString` operands first. The patch also fixes
`sconcat` behavior to align with `mconcat` for the same reason. Fixes #27205.
-
4ed78760
by mangoiv at 2026-04-24T08:25:13-04:00
contributing: adjust MR template to be less verbose
- MR template only shows text that is relevant for submissiong
- MR template was rewritten so it's readable from a user's and reviewer's
perspective
Resolves #27165
Co-Authored-By: @sheaf
-
87db83e2
by Cheng Shao at 2026-04-24T14:37:21-04:00
ci: bump freebsd boot ghc to 9.10.3
This commit bumps freebsd boot ghc to 9.10.3 to align with other
platforms and prevent outdated boot libs in boot ghc to block the
freebsd job.
-
17e3a0b7
by Cheng Shao at 2026-04-24T14:37:21-04:00
compiler: improve Binary instance of Array
This patch improves the `Binary` instance of `Array`:
- We no longer allocate intermediate lists. When serializing an
`Array`, we iterate over the elements directly; when deserializing
it, we allocate the result `Array` and fill it in a loop.
- Now we only serialize the array bounds tuple; the length field is
not needed.
Closes #27109.
-
2d30f7d3
by sheaf at 2026-04-24T14:38:23-04:00
Vendor mini-QuickCheck for testsuite
This commit extracts the vendored QuickCheck implementation from the
foundation testsuite to make it more broadly available in the GHC
testsuite, and makes use of it in the simd006 test (which also used
a vendored QuickCheck implementation).
On the way, we update the linear congruential generator to avoid the
shortcoming of only generating 31 bit large numbers.
Fixes #25990 and #25969.
-
1350271b
by sheaf at 2026-04-27T09:32:53-04:00
Ensure TcM plugins are only initialised once
This commit ensures we keep TcM plugins (typechecker plugins,
defaulting plugins and hole fit plugins) running all the way through
desugaring, instead of stopping them at the end of typechecking.
To do this, the "stop" actions of TcPlugin and DefaultingPlugin are
split into two: one for the "post-typecheck" action, and one for the
final shutdown action (after desugaring).
This allows the plugins to be invoked by the pattern match checker
(during desugaring) without having to be repeatedly re-initialised and
stopped, fixing #26839.
In the process, this commit modifies 'initTc' and 'initTcInteractive',
adding an extra argument that describes whether to start/stop the 'TcM'
plugins.
See Note [Stop TcM plugins after desugaring] for an overview.
-
42549222
by sheaf at 2026-04-27T09:33:50-04:00
Hadrian: add --keep-response-files
This commit adds a Hadrian flag that allows response files to be
retained. This is useful for debugging a failing Hadrian command line.
-
40564e8d
by sheaf at 2026-04-27T09:34:46-04:00
hadrian/build-cabal.bat: fix build on Windows
Commit 8cb99552f6 introduced a warning for a missing package index.
However, the logic was faulty on Windows: the piping was broken, and
"remote-repo-cache:" was being interpreted as a (malformed) drive letter,
leading to the error:
The filename, directory name, or volume label syntax is incorrect.
This commit fixes that by using a temporary file instead of piping.
-
14bc71e4
by Sven Tennie at 2026-04-28T13:22:47-04:00
ghc: Distinguish between having an interpreter and having an internal one
Actually, these are related but different things:
- ghc can run an interpreter (either internal or external)
- ghc is compiled with an internal interpreter
Splitting the logic solves compiler warnings and expresses the intent
better.
-
df691563
by Vladislav Zavialov at 2026-04-28T13:23:29-04:00
Refactor HsWildCardTy to use HoleKind (#27111)
The payload of this patch is that the extension fields of HsWildCardTy
and HsHole now match:
type instance XWildCardTy Ghc{Ps,Rn} = HoleKind
type instance XHole Ghc{Ps,Rn} = HoleKind
This is progress towards unification of HsExpr and HsType.
Test case: T25121_status
In addition to that, exact-printing of infix holes is fixed.
Test case: PprInfixHole
-
f3485446
by fendor at 2026-04-28T13:24:12-04:00
Expose startupHpc as an rts symbol
-
28f07d70
by fendor at 2026-04-28T13:24:12-04:00
Make HPC work with bytecode interpreter
Add support to generate .tix files from bytecode objects and the
bytecode interpreter.
Conceptually, we insert HPC ticks into the bytecode similar to how we insert
breakpoints.
HPC and breakpoints do not share the same tick array but we use a separate
tick-array for hpc/breakpoint ticks during bytecode generation.
We teach the bytecode interpreter to handle hpc ticks.
The implementation is quite trivial, simply increment the counter in the
global hpc_ticks array for the respective module.
This hpc_ticks array is generated as part of the `CStub`, so we can rely
on it existing.
A tricky bit is "registering" a bytecode object for HPC instrumentation.
In the compiled case, this is achieved via CStub and initializer/finalizers
`.init` sections which are called when the executable is run.
After the initializers have been invoked, which is before `hs_init_ghc`,
we then call `startup_hpc` in `hs_init_ghc` iff any modules were "registered"
for hpc instrumentation via `hs_hpc_module`.
Since bytecode objects are loaded after starting up GHCi, this workflow
doesn't work for supporting `hpc` and the `hpc` run-time is never
started, even if a module is added for instrumentation.
We fix this issue by employing the same technique as is for `SptEntry`s:
* We introduce a new field to `CompiledByteCode`, called `ByteCodeHpcInfo`
which contains enough information to call `hs_hpc_module`, allowing us to
register the module for `hpc` instrumentation`.
* After registering the module, we unconditionally call `startupHpc`, to make
sure the .tix file is written.
Calling `startupHpc` multiple times is safe.
Calling `hs_hpc_module` multiple times for the same module is also safe.
If we didn't register the hpc module in this way, evaluating a bytecode object
instrumented with `-fhpc` without registering it in the `hpc` run-time will
simply not generate any `.tix` files for this bytecode object.
However, this shouldn't happen if everything is set up correctly.
Closes #27036
-
950879f0
by Vladislav Zavialov at 2026-04-28T13:24:55-04:00
Move NamespaceSpecifier from x-fields into the AST proper (#26678)
This refactoring moves NamespaceSpecifier out of extension fields and into the
AST proper, as it is part of the user-written source, and is not pass-specific.
Summary of changes:
* Move NamespaceSpecifier from GHC/Hs/Basic.hs to Language/Haskell/Syntax/ImpExp.hs
and parameterise it by the compiler pass, creating the necessary extension points
* Move NamespaceSpecifier out of XFixitySig into FixitySig
* Move NamespaceSpecifier out of XIEThingAll (IEThingAllExt) into IEThingAll
* Move NamespaceSpecifier out of XIEWholeNamespace (IEWholeNamespaceExt) into IEWholeNamespace
This is a pure refactoring with no change in behaviour.
-
9797052b
by Simon Peyton Jones at 2026-04-28T13:25:37-04:00
Fix assertion check in checkResultTy
As #27210 shows, the assertion was a little bit too eager.
I refactored a bit by moving some code from GHC.Tc.Gen.App
to GHC.Tc.Utils.Unify; see the new function tcSubTypeApp,
which replaces tcSubTypeDS
-
9f85f034
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Make cmm 'import "package" name;' syntax use consistent label types
There is a little-used syntactic form in cmm imports:
import "package" foo;
Which means to import foo from the given package (unit id, specified as
a string). This syntax is somewhat reminiscent of GHC's package import
extension.
This syntax form is not used in the rts cmm code, nor any of the boot
libraries. It may not be used at all. Unclear.
Change the kind of CLabel this syntax generates to be consistent with
the others. The other cmm imports use ForeignLabel with
ForeignLabelInExternalPackage. For some reason this form was using
CmmLabel. Change that to also be ForeignLabel but with
ForeignLabelInPackage. This specifies a specific package, rather
than an unnamed external package.
-
a811f68f
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Change default cmm import statements to be internal
Previously a cmm statement like:
import foo;
meant to expect the symbol from a different shared library than the
current one.
Now it means to expect the symbol from the same shared library as the
current one. We'll add explicit syntax to indicate that it's a foreign
import. Most existing uses are in fact intenal (rts to rts), so few
imports will need to be annotated foreign. Examples would include cmm
code in libraries (other than the rts) that need to access RTS APIs.
In practice, this makes no difference whatsoever at the moment on any
platform other than windows (where building Haskell libs as shared libs
does not fully work yet), since the 'labelDynamic' treats all such
labels as foreign, irrespective of the foreign label source.
-
17fe5d1d
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Add cmm import syntax 'import DATA foo;' as better name for CLOSURE
The existing syntax is:
import CLOSURE foo;
The new syntax is
import DATA foo;
This means to interpret the symbol foo as refering to data (i.e. a
global constant or variable) rather than to code (a function). The
historical syntax for this uses CLOSURE, which is rather misleading.
Presumably this was done to avoid introducing new reserved words.
Be less squemish about new reserved words and add DATA and use that.
Keep the existing CLOSURE syntax as an alias for compatibility.
-
3a530d68
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Add cmm 'import extern name;' syntax
Since the default for cmm imports is now for symbols within the same
shared object, we need a way to indicate we want a symbol from an
external shared object:
import extern foo; -- for a function
import extern DATA foo; -- for data
This adds a new reserved word 'extern'.
We don't expect to have to use this much. Most cmm imports are
intra-DSO.
This makes no difference currently on ELF and MachO platforms, but does
make a difference to the linking conventions on PE (Windows).
In future it's plausible we could take make distinctions on ELF or
MachO, so it's worth trying to get it right. Windows can be the guinea
pig.
-
2b8e44c7
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Add cmm syntax 'import "package" DATA foo;' for completeness
We already have:
import DATA foo; -- for data imports
import "package" foo; -- for imports from a given unitid
There's no reason not to have both at once:
import "package" DATA foo;
So add that.
-
ee05e5cc
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Improve the commentary for the cmm import grammar.
AFAIK, this is the only place where GHC-style Cmm syntax is documented.
-
b35946ad
by Duncan Coutts at 2026-04-30T04:52:42-04:00
Add a changelog.d entry for the .cmm import syntax changes
-
d59b7c71
by Wolfgang Jeltsch at 2026-04-30T04:53:25-04:00
Move code that uses `GHC.Internal.Text.Read` into `base`
This contribution serves to remove all dependencies on
`GHC.Internal.Text.Read` from within `ghc-internal`, so that the
implementation of `Text.Read` and ultimately more reading-related code
can be moved to `base` as well.
The following things are moved from `ghc-internal` to `base`:
* I/O-related `Read` instances
* Most of the `Numeric` implementation
* The instance `Read ByteOrder`
* The `parseVersion` operation
* The `readConstr` operation
Metric Increase:
LinkableUsage01
T9198
T12425
T13035
T13820
T18140
-
5bd6a964
by Rodrigo Mesquita at 2026-04-30T04:54:08-04:00
New rts Message to {set,unset} TSO flags
This commit introduces stg_MSG_SET_TSO_FLAG_info and
stg_MSG_UNSET_TSO_FLAG_info, which allows setting flags of a TSO other
than yourself.
This is especially useful/necessary to set breakpoints and toggle
breakpoints of different threads, which is needed to safely implement
features like pausing, toggling step-out, toggling step-in per thread,
etc.
Fixes #27131
-------------------------
Metric Decrease:
T3294
-------------------------
-
ce97fd3e
by Rodrigo Mesquita at 2026-04-30T04:54:08-04:00
test: Add test setting another TSO's flags
Introduces a test that runs on two capabilities. The main thread running
on Capability 0 sets the flags on a TSO running on Capability 1.
The TSO from Capability 1 itself checks whether its flags were set and
reports that back.
This validates that the RTS messages for setting TSO flags work, even if
it doesn't test a harsher scenario with race conditions to exercise why
the message passing is necessary for safely setting another TSO's flags.
Part of #27131
-
a4ff6315
by David Eichmann at 2026-04-30T04:54:51-04:00
Hadrian: withResponseFile outputs response file when verbodity is Verbose
At the Verbose verbosity, shake will display full commandlines. With the
use of response files, the full command is hidden. That makes it hard to run
the command manually. This commit outputs the contents of the response
file so that that full command can be recreated and also hints at the
use of the --keep-response-files hadrian flag.
-
cd732ee3
by Duncan Coutts at 2026-04-30T04:54:51-04:00
Use response files for hadrian linking with ghc (support long command lines)
In future support for windows dynamic linking, we expect long command
lines for linking dll files with ghc. Experiments with dynamic linking the
ghc-internal library yielded a link command well over 32kb. We did not
encounter this before for static libs, since we already use ar's @file
feature (if available, which it is for the llvm toolchain).
Co-authored-by: David Eichmann <davide@well-typed.com>
-
3d41368f
by Andreas Klebinger at 2026-04-30T04:55:32-04:00
Split GHC.Driver.Main.hs up into multiple components.
This commit splits GHC.Driver.Main into four components:
* GHC.Driver.Main.Compile
* GHC.Driver.Main.Hsc
* GHC.Driver.Main.Interactive
* GHC.Driver.Main.Passes
We might improve that separation further in the future but this should
hopefully make it easier to reason about and work with this part of the
code.
-
2128ba85
by Cheng Shao at 2026-04-30T04:56:14-04:00
compiler: avoid unique OccNames for internal Names in bytecode objects
This patch improves bytecode object serialization logic by avoiding
the construction of unique `OccName`s when serializing/deserializing
internal `Name`s. Closes #27213.
-------------------------
Metric Decrease:
LinkableUsage01
-------------------------
-
e16854c3
by Vladislav Zavialov at 2026-04-30T04:56:57-04:00
Replace GHC 9.16 references with GHC 10.0
-
39141343
by Alice Rixte at 2026-05-01T14:09:32+02:00
Add Bounded instances for Double, Float, CDouble and CFloat
-
5c4c3bf4
by Sylvain Henry at 2026-05-02T03:39:28-04:00
testsuite: fix flaky foundation Divisible / mulIntMayOflo# tests (#27222)
Since the LCG was widened to 64 bits and the seed randomised per CI run
(commit 2d30f7d3400 "Vendor mini-QuickCheck for testsuite"), two latent
bugs in the foundation test surface stochastically:
* The Divisible property `(x `div` y) * y + (x `mod` y) == x` raises
ArithException(Overflow) when (a, b) = (minBound, -1) for fixed-width
signed Integral types. Split testNumber/testDivisible into Bounded and
unbounded variants and skip just that one pair, gated by
`(minBound :: a) < 0` so unsigned types lose no coverage.
* The `mulIntMayOflo#` test compared raw Int# bit-for-bit, but the primop
is only specified to return 0/non-zero -- the exact non-zero indicator
legitimately differs between backends and inlining choices. Add a
dedicated `testPrimopMayOflo` helper that only compares zero / non-zero.
Also fix the long-standing typo "Dividible" -> "Divisible" in identifiers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
e242ce4f
by Sylvain Henry at 2026-05-02T03:39:28-04:00
testsuite: catch and display exceptions in MiniQuickCheck
Exceptions raised while evaluating a property are now caught and reported
as a normal failure (with arguments and seed), instead of aborting the
test.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
-
3b75cccd
by fendor at 2026-05-02T03:40:14-04:00
Fix name of Note [Structure of dep_boot_mods]
-
9a9ae4df
by Duncan Coutts at 2026-05-05T14:44:37-04:00
Use __attribute__((dllimport)) for external RTS symbol declarations
This is needed to be hygenic about DLL symbol imports and exports.
The attribute is ignored on platforms other than Windows.
Use of the attribute however means that external data symbols do not
have a compile-time constant address (they are loaded using an
indirection). This means we have to adjust the rtsSyms initial linker
table so that it is a local constant in a function, rather than a global
constant. We now define it within a function that pre-populates the
symbol table with the RTS symbols.
-
2ad3e01e
by Duncan Coutts at 2026-05-05T14:44:37-04:00
Fix the rts linker declarations for a few data symbols
and ensure that the (windows only) rts_IOManagerIsWin32Native data
symbol is marked as externally visible.
-
8ff4fdb5
by David Eichmann at 2026-05-05T14:44:37-04:00
Hadrian: Disable runtime pseudo relocations for RTS on windows hosts
-
96974723
by Teo Camarasu at 2026-05-05T14:45:20-04:00
ghci/TH: refactor to use IORef QState
This is a pure refactor and shouldn't modify semantics at all
-
eff6bfaf
by Teo Camarasu at 2026-05-05T14:45:20-04:00
iserv: recover/getQ/putQ should behave same as internal interpreter
The internal and external interpreter should behave the same when
handling `recover`, the exeception recovery method of Q.
In practice, they diverge. In case of failure, the internal interpreter
only restores error message state to before the computation, wheras the
external interperter restores error message state *and* the state of putQ/getQ.
As far as I can tell this is a simple mistake in the implementation.
Note [TH recover with -fexternal-interpreter] describes the correct
behaviour but the implementation doesn't mirror this.
This change restores the correct behaviour by keeping the effects of
putQ in the erroring computation.
This is a breaking change since it modifies the behaviour of programs
that rely on recover ignoring putQ from failling computations when used
with the external interpreter. Although I highly doubt anyone relies on
this behaviour.
This divergence was first introduced in d00c308633fe7d216d31a1087e00e63532d87d6d.
As far as I can tell this was unintentional and tha commit was trying to solve a different bug.
Resolves #27022
-
1cb1d672
by Wen Kokke at 2026-05-06T09:53:40-04:00
rts: Add dynamic trace flags API
This commit adds an API to the RTS (exposed via Rts.h) that allows users to dynamically change the trace flags.
Prior to this commit, users were able to stop and start the profiling and heap profiling timers (via startProfTimer/stopProfTimer and startHeapProfTimer/stopHeapProfTimer).
This extends that functionality to also cover the core event types.
The getTraceFlag/setTraceFlag functions read and write the values of the trace flag cache, which is allocated by Trace.c, rather than modifying the members of RtsFlags.TraceFlags.
This is done under the assumption that the members of RtsFlags should not be modified after RTS initialisation.
Consequently, if the user modifies the trace flags using setTraceFlag, the object returned by getTraceFlags (from base) will not reflect these changes.
The trace flags are not protected by locks of any sort.
Hence, these functions are not thread-safe.
However, the trace flags are not modified by the RTS after initialisation, only read, so the race conditions introduced by one user modifying them are most likely benign.
This PR also puts the trace flag cache in a single global struct, as opposed to a collection of global variables, and changes the types of the individual flags from uint8_t to bool, as these have the same size on both Clang and GCC and are a better semantic match.
Prior to the change to uint8_t, they had type int, see 42c47cd6.
Even with its deprecation in C23, I don't think there should be any issue depending on stdbool.h.
The TRACE_X macros are redefined to access the global struct, with values cast to const bool to ensure they are read-only.
-
9d54dc94
by Wen Kokke at 2026-05-06T09:53:40-04:00
rts: Ensure TRACE_X values are used in place of RtsFlags.TraceFlags.X
-
418d737b
by Wen Kokke at 2026-05-06T09:53:40-04:00
rts: Fix nonmoving-GC tracing
The current nonmoving-GC tracing functions were written in a different
style from the other tracing functions. They were directly implemented
as, e.g., a traceConcMarkEnd function that called postConcMarkEnd.
The other tracing functions are implemented as, e.g., traceThreadLabel_,
a function that posts the thread label event, and traceThreadLabel, a
macro that checks whether TRACE_scheduler is set. This commit fixes that
implementation, and ensures that the nonmoving-GC tracing functions only
emit events if nonmoving-GC tracing is enabled.
-
99f4afa4
by Wen Kokke at 2026-05-06T09:53:40-04:00
rts: Add SymI_HasProto for get/setTraceFlag
-
7e9eb8b9
by Wen Kokke at 2026-05-06T09:53:40-04:00
rts: Add SymI_HasProto for start/endEventLogging
-
3a3045fb
by Wen Kokke at 2026-05-06T09:53:41-04:00
rts: Add changelog entry
-
a3b339a4
by Teo Camarasu at 2026-05-06T09:54:25-04:00
interface-stability/base: don't distinguish ws-32
The interface of base is identical when the Word size is 32bits.
Therefore, there is no need to have another file for this case.
So, we delete it.
Step towards: #26752
-
eb922183
by Duncan Coutts at 2026-05-07T14:28:50+01:00
Add a rts posix FdWakup utility module
This will be used to implement wakeupIOManager for in-RTS I/O managers.
It provides a notification/wakeup mechanism using FDs, suitable for
situations when a thread is blocked on a set of fds anyway. It uses the
classic self-pipe trick, or equivalently eventfd on supported platforms.
This will initially be used to implement prompt interrupt or shutdown of
the posix ticker thread.
-
01b0e233
by Duncan Coutts at 2026-05-07T14:28:50+01:00
Add prompt shutdown to the pthread ticker implementation.
The Linux timerfd ticker monitors a pipe which is used by exitTicker to
ensure a prompt wakeup and shutdown. The pthread ticker lacked this and
so would only exit at the next ticker wakeup (10ms by default).
This patch adds the same mechanism to the pthread ticker.
This changes the pthread ticker from waiting by using nanosleep() to
waiting using either ppoll() or select(), so that it can wait on both
a time and a file descriptor. On Linux at least, a test program to
compare the timing jitter of these APIs shows that using nanpsleep,
ppoll or select makes no statistical difference to the maximum or
average jitter.
This is a step towards unifying the posix ticker implementations, so
that we can have just one portable one (albeit with some limited cpp).
It is also a step towards using the ticker as part of a more general
implementation of wakeUpRts, since this will require a method to wake
the rts from a signal handler context (ctl-c handler).
-
bc41d646
by Duncan Coutts at 2026-05-07T14:28:50+01:00
Update ticker header commentary
It was antique and didn't apply even to the previous implementation, and
certainly not to the updated one.
-
4ed9a386
by Duncan Coutts at 2026-05-07T14:28:50+01:00
Remove the timerfd-based ticker implementation
There does not appear to be any remaining advantage on Linux to using
the timerfd ticker implementation over the portable one (using ppoll on
Linux for precise timing).
The eventfd implementation was originally added at a time when Linux was
still using a signal based implementation. So it made sense at the time.
See (closed) issue #10840.
-
97504fa6
by Duncan Coutts at 2026-05-07T14:28:50+01:00
Consolidate to a single posix ticker implementation
Previously we had four implementations, two using signals and two using
threads. Having just one should make behaviour more consistent between
platforms, and should make maintenance easier.
-
1e60023b
by Facundo Domínguez at 2026-05-07T18:01:16-04:00
Generalize so_inline to specify which bindings should be preserved
This commit generalizes the so_inline option of the simple optimizer
so we can indicate with a predicate the specific bindings that should
be kept.
This feature is important for the LiquidHaskell plugin, which relies on the
simple optimizer to make core programs easier to read, but needs to preserve
bindings that are relevant for verification.
See https://gitlab.haskell.org/ghc/ghc/-/issues/24386 for the full discussion.
-
44cf9cd7
by Wolfgang Jeltsch at 2026-05-12T09:48:18-04:00
Move the `Text.Read` implementation into `base`
-
4ac3f7d6
by Vladislav Zavialov at 2026-05-12T09:49:03-04:00
EPA: Use AnnParen for tuples and sums
Summary of changes
* Do not use AnnParen in XListTy, replace it with EpToken "[" and "]"
* Specialise AnnParen to tuple/sums by dropping the AnnParensSquare
and keeping only AnnParens and AnnParensHash
* Use AnnParen in XExplicitTuple
* Use AnnParen in XExplicitTupleTy
* Use AnnParen in XTuplePat
* Use AnnParen in XExplicitSum (via AnnExplicitSum)
* Use AnnParen in XSumPat (via EpAnnSumPat)
This is a refactoring with no user-facing changes.
-
1bdcddec
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Add minimal dlltool support to ghc-toolchain
The dlltool is a tool that can create dll import libraries from .def
files. These .def files list the exported symbols of dlls. Its somewhat
like gnu linker scripts, but more limited.
We will need dlltool to build the rts and ghc-internal libraries as DLLs
on Windows. The rts and ghc-internal libraries have a recursive
dependency on each other. Import libraries can be used to resolve
recursive dependencies between dlls. We will use an import library for
the rts when linking the ghc-internal library.
-
f7fc3770
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Add minimal dlltool support into ./configure
Find dlltool, and hopefully support finding it within the bundled llvm
toolchain on windows.
-
e4e22bfb
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Update the default host and target files for dlltool support
-
5666c8f9
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Add dlltool as a hadrian builder
Optional except on windows.
-
5e14fe3f
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Update and generate libHSghc-internal.def from .def.in file
The only symbol that the rts imports from the ghc-internal package now
is init_ghc_hs_iface. So the rts only needs an import lib that defines
that one symbol.
Also, remove the libHSghc-prim.def because it is redundant. The rts no
longer imports anything from ghc-prim.
Keep libHSffi.def for now. We may yet need it once it is clear how
libffi is going to be built/used for ghc.
-
3d91e4a6
by Duncan Coutts at 2026-05-12T09:49:48-04:00
Add rule to build libHSghc-internal.dll.a and link into the rts
On windows only, with dynamic linking.
This is needed because on windows, all symbols in dlls must be resolved.
No dangling symbols allowed. References to external symbols must be
explicit. We resolve this with an import library. We create an import
library for ghc-internal, a .dll.a file. This is a static archive
containing .o files that define the symbols we need, and crucially have
".idata" sections that specifies the symbols the dll imports and from
where.
Note that we do not install this libHSghc-internal.dll.a, and it does
not need to list all the symbols exported by that package. We create a
special purpose import lib and only use it when linking the rts dll, so
it only has to list the symbols that the rts uses from ghc-internal
(which is exactly one symbol: init_ghc_hs_iface).
-
c8dae539
by Alice Rixte at 2026-05-12T09:50:52-04:00
Script for downloading and copying `base-exports` file
-
5fab2238
by Wolfgang Jeltsch at 2026-05-12T21:24:27+03:00
Introduce a cache of home module name providers
This contribution introduces to the module graph a cache that maps home
module names to sets of units providing them and changes the finder to
use that cache. This is a performance optimization, especially for
multi-home-unit builds.
The particular changes are as follows:
* In `GHC.Unit.Module.Graph`, `ModuleGraph` is extended with a new
field `mg_home_module_name_providers_map`, exposed as
`mgHomeModuleNameProvidersMap`. This is a cache that assigns to each
home module name the set of IDs of home units that define it.
Operations that construct module graphs are updated such that this
cache stays synchronized.
* In `GHC.Unit.Finder`, `findImportedModule` is changed to pull
`mgHomeModuleNameProvidersMap` from `hsc_mod_graph` and pass it to
`findImportedModuleNoHsc`, which now does not search home units in
arbitrary order but prioritizes those units that the cache mentions
as potential providers of the requested module.
In addition, this contribution adds variants of the two multi-component
compiler performance tests that use 100 units instead of 20, because
with just 20 units the benefits from caching of home module name
providers are still negligible.
The following table shows the total time needed for running both
multi-component tests before and after this contribution and with
different numbers of units:
| # of units | Before | After |
|-----------:|-------:|------:|
| 20 | 0:12 | 0:12 |
| 100 | 0:47 | 0:42 |
| 200 | 3:05 | 2:08 |
Note that there seems to be a general overhead of 12 seconds that is not
attributable to the actual tests, so that the real running times should
be 12 seconds smaller than shown above.
Resolves #27055.
Metric Decrease:
MultiComponentModules
MultiComponentModulesRecomp
Co-authored-by: Matthew Pickering <matthewtpickering@gmail.com>
Co-authored-by: Fendor <fendor@posteo.de>
-
38b76b2f
by Cheng Shao at 2026-05-13T17:48:48-04:00
testsuite: mark T22159 as fragile
This patch marks T22159 as fragile on Windows for issue described in #27248.
Before we get to the bottom of those failures, this unblocks newer
Windows runners.
-
50188615
by Ian Duncan at 2026-05-14T13:45:07+02:00
AArch64: use ASR not LSR for MO_U_Shr at W8/W16
The unsigned right shift (MO_U_Shr) for sub-word widths (W8, W16)
with a variable shift amount was emitting ASR (arithmetic/signed shift
right) after zero-extending with UXTB/UXTH. This should be LSR
(logical/unsigned shift right). After zero-extension the upper bits
happen to be 0 so ASR produces the same result, but it is semantically
wrong and would break if the zero-extension were ever optimized away.
Includes assembly output test (grep for lsr) and runtime test
verifying unsigned right shift of Word8 and Word16 values.
-
28666fbf
by Vladislav Zavialov at 2026-05-19T12:44:05-04:00
Add type families: Tuple, Constraints, Tuple#, Sum# (#27179)
These type families map tuples of types to the corresponding Tuple<N>,
Tuple<N>#, CTuple<N>, and Sum<N># types. Some examples at N=2:
Tuple (Int, Bool) = Tuple2 Int Bool
Constraints (Show a, Eq a) = CTuple2 (Show a) (Eq a)
Tuple# (Int#, Float#) = Tuple2# Int# Float#
Sum# (Int#, Float#) = Sum2# Int# Float#
See GHC Proposal #145 "Non-punning list and tuple syntax".
To make the Sum# instance at N=64 possible, this patch also introduces
the Sum64# constructor declaration and bumps mAX_SUM_SIZE from 63 to 64.
Metric Increase:
ghc_experimental_dir
-
41c2448b
by Wen Kokke at 2026-05-19T12:44:53-04:00
rts: Add IPE event class for -l
This commit adds a new IPE event class to the -l RTS flag.
Previously, IPE events were enabled unconditionally.
However, the IPE events can easily grow to hundreds or thousands of megabytes.
With the new event class you can pass, e.g., -l-I to disable IPE events.
-
62536551
by Wen Kokke at 2026-05-19T12:44:53-04:00
ghc-internal: Add TraceFlags.traceIPE
-
e45312d1
by Wen Kokke at 2026-05-19T12:44:53-04:00
testsuite: Add test for TraceFlags.traceIpe
-
4768d9aa
by Wen Kokke at 2026-05-19T12:44:53-04:00
ghc-internal: Add DebugFlags.ipe
-
bc1b5c69
by Wen Kokke at 2026-05-19T12:44:53-04:00
testsuite: Add test for DebugFlags.ipe
-
0da1543f
by Duncan Coutts at 2026-05-19T12:45:37-04:00
Document removal of the signal-based interval timer
Update mentions within the RTS section of the users guide.
Add a changelog entry.
-
b2911514
by Duncan Coutts at 2026-05-19T12:45:37-04:00
Fix section for an recent changelog entry
-
d6d76a7a
by David Eichmann at 2026-05-19T12:46:19-04:00
ghc-toolchain: implement llvm program versioning logic
-
2dd36fa3
by Wolfgang Jeltsch at 2026-05-20T04:49:52-04:00
Turn `Trustworthy` into `Safe` in `base` where possible
-
f4399dd1
by Wolfgang Jeltsch at 2026-05-20T04:50:37-04:00
Make the current `base` buildable with GHC 10.0
-
1a7de232
by Duncan Coutts at 2026-05-20T12:26:25-04:00
Hadrian: remove legacy rts .so symlinks
For compatibility with the old makefile based build system, hadrian had
rules to generate symlinks from unversioned to versioned names for the
rts .so/.dynlib file, like libHSrts-ghcx.y.so -> libHSrts-1.0.3-ghcx.y.so
We no longer need these symlinks since the makefile build system has
been retired some time ago. The need for these symlinks is awkward on
windows where we cannot (in practice) create symlinks. So rather than
make them conditional (non-windows), just remove them entirely.
-
286f1adf
by fendor at 2026-05-20T12:27:09-04:00
Fix regression T27202: `:load` and `:add` work in GHCi
To fix the regression there are conceptually two major things that we
fix:
* We don't remove the `importDirs` from `interactive-session`
* When `:add`ing a module, we don't try to find them via PackageImports
* The PackageImport is wrong as we can't know the package-name at
this stage in ghc/UI.hs
What does it mean to not remove the `importDirs` from
`interactive-session`?
It means that, given some initial `DynFlags`, we will use those
`importDirs` in `interactive-session`.
The initial `DynFlags`, however, depend on how you initialise the GHC
session.
For a simple session, initialised by
ghc -isrc -this-unit-id main
It is simple, just use the `DynFlags` given on the cli.
Thus, `main` and `interactive-session` will have the same `DynFlags`,
except for the `homeUnitId` and `interactive-session` depends on `main`
by construction of the GHCi session.
What about a multiple home unit session, though?
ghc -unit @unit1 -unit @unit2
What are the `DynFlags` in this cli invocation? It shouldn't be either
`@unti1` nor `@unit2`, as the order shouldn't matter or any other
implicit condition.
For consistency, we decide that the initial `DynFlags` are the top
`DynFlags` on the cli, ignoring `-unit` flags.
Thus, in this example, there are no `importsDirs` regardless of what we
might find in `@unit1` and `@unit2`.
But in this invocation:
ghc -isrc -unit @unit1 -unit @unit2
The `interactive-session` will have the `importsDirs` `src`.
Note, `-isrc` will be inherited in `@unit1` and `@unit2`, so you need to
explicitly use `-i` to clear the `importsDirs`, in order to avoid
accidentally adding `src` as an import directory to all other home
units.
This fix has been made possible by the improvements introduced in
!15888, which avoids ambiguity when a home unit shares the `importsDirs`
with the `interactive-session`, on top of being much faster for multiple
home units.
Adds regression tests for T27202 for `:load`ing and `:add`ing modules
that are located in import directories.
-
728662de
by fendor at 2026-05-20T12:27:09-04:00
Use home unit package db stacks in GHCi prompt and session unit
In order to import modules from home unit dependencies (e.g., `Data.Map`),
the ghci prompt unit needs to populate its `UnitState`.
This is tricky to handle correctly, which `PackageDBFlag`s should we use
to populate the `UnitState`?
We decide, the most intuitive solution for users is to depend on all
`PackageDBFlag`s, so that any dependency can be imported in GHCi.
This assumes consistency in the `PackageDBFlag`s, so no two home units
specify `PackageDBFlag`s that are inconsistent with each other.
We could simply concat all the `PackageDBFlag`s of the existing home
units, but later `PackageDBFlag`s shadow earlier ones, leading to the
last processed home units' `PackageDBFlag`s to shadow the earlier ones.
This is hard to fix, we need to give users the capability to provide ghc
options for the ghci prompt home unit.
However, as this is considerably more work, we decided on an
approximation that should work out most of the time.
Package Db stacks in cabal and stack follow a certain structure:
-no-user-package-db > -package-db $cabal-store > -package-db $local-db
The first two arguments are always the same, namely the
`-no-user-package-db` and `-package-db`.
We compute the longest common prefix over all home units, and use that
as the start of the package db stack. Then, over the rest of the
`PackageDBFlag`s, we simply take the union and append them to our
initial stack.
We assume, that the rest of package dbs only defines very few, "local"
units that are usually not shadowing each other.
This allows us to get a relatively consistent package database stack for
the ghci prompt home unit.
Similar reasoning applies to the session unit in order to add modules to
the session and have dependencies available in the module.
We do something similar for `-package` flags, to make sure only the
correct units are actually visible in the ghci session.
This time, we simply take the union of all `PackageFlag`s, allowing us
to import modules from the home unit dependencies.
In the future, it would be beneficial to allow the user to provide the
exact ghc options to control the visibilities. For now, this will have
to do.
-
740d89a0
by Simon Peyton Jones at 2026-05-20T17:20:44-04:00
Do not use mkCast during typechecking
This commit fixes #27219. The problem was that the typechecker was using
`mkCast`, whose assertion checks legitimately fail when applied to types
that contain unification variables.
-
a50fdb06
by Simon Peyton Jones at 2026-05-20T17:20:45-04:00
Major refactor of the Simplifier
The main payload of this patch is to refactor the Simplifer to avoid
repeated simplification when using Plan (AFTER) for rule rewrites.
The need for this was shown up by #26989.
See Note [Avoid repeated simplification] in GHC.Core.Opt.Simplify.Iteration.
Related refactoring:
* Refactor the two fields `sc_dup` and `sc_env` in `ApplyToVal` into one, `sc_env`.
Reason: the envt is irrelevant in the "simplified" case, so the data type describes
the possiblitiies much more accurately now.
* Some refactoring in `knownCon` to split off `wrapDataConFloats`.
* Refactor `lookupRule` and its auxiliary functions to return `RuleMatch`,
a new data type. See Note [data RuleMatch] in GHC.Core. Ditto for BuiltinRule.
This RuleMatch returns fragments of the target in rm_args and rm_floats,
leaving `rm_rhs` to be the stuff from the RULE itself.
Doing this has routine consequences in GHC.Core.Opt.ConstantFold. Many changes
there but all routine.
* When doing occurrence analysis on RULEs, make the occ-info on the rule
binders relate just to the RHS, not the LHS. See (OUR1) in
Note Note [OccInfo in unfoldings and rules]
This means that Lint must not complain about the fact that the patterns
in the RULE mentions binders that are marked dead.
See Note [Dead occurrences] in GHC.Core.Lint.
I changed the Core pretty-printer so that it didn't suppress dead binders,
else I can't see those binders in RULEs. That led to quite a lot of testsuite wibbles.
* Refactor FloatBinds, so that it is used both by
`exprIsConApp_mabye` and by `lookupRule`
* Move the definition of FloatBinds out of GHc.Core.Make, into GHC.Core.
* Add FloatTick as an extra constructor.
* Refactor `lookupRule` to use `FloatBinds` instead of `BindWrapper`.
This refactor just shares more code.
(Rename GHC.Core.Opt.FloatOut.FloatBinds to FloatLets, to avoid gratuitious
name clash with GHC.Core.FloatBinds.)
Corecion optimisation
* In simpleOpt, when composing coercions, call new function `optTransCo`.
This is much lighter weight than full blown coercion optimisation.
* Make `GHC.Core.Opt.Arity.pushCoValArg` and `pushCoTyArg` return the
coercionLKind of the coercion. This saves recomputing that coercionLKind
at the key call sites in GHC.Core.Opt.Simplify.Iteration.pushCast.
* Rename `addCoerce` in GHC.Core.Simplify.Iteration to become `pushCast`.
* In the `ApplyToVal` case of `pushCast` we had a very unsavoury call to `simplArg`.
I eliminated it by adding a field `sc_cast` to `ApplyToVal` that records any
pending casts. Much nicer now. See Note [The sc_cast field of ApplyToVal].
* Don't optimise coercions if the type-substitution is empty.
See Note [Optimising coercions] in GHC.Core.Opt.Simplify.Iteration.
The fix for #26838 is dramatic. For the test in perf/compiler/T26839 we have
Compiler allocs: Before: 7,363M
After: 688M
Compile time goes down generally. Here are compiler-alloc changes
over 0.5%:
CoOpt_Read(normal) 729,184,920 -0.7%
CoOpt_Singletons(normal) 666,916,960 -4.6% GOOD
LargeRecord(normal) 1,227,056,876 +1.1%
T12227(normal) 256,827,604 -4.6% GOOD
T12425(optasm) 76,879,410 -0.8%
T12545(normal) 787,826,918 -10.8% GOOD
T12707(normal) 775,186,464 -0.9%
T13253(normal) 318,599,596 -0.8%
T14766(normal) 685,857,320 -1.0%
T15304(normal) 1,123,333,422 -2.2%
T15630(normal) 123,142,330 -2.6%
T15630a(normal) 123,092,100 -2.6%
T15703(normal) 299,751,682 -2.9% GOOD
T17516(normal) 964,072,280 +1.0%
T18223(normal) 367,016,820 -6.2% GOOD
T18730(optasm) 130,643,770 -3.3% GOOD
T20261(normal) 535,608,584 -0.7%
T21839c(normal) 340,340,436 -0.9%
T24984(normal) 85,568,392 -1.9%
T3064(normal) 174,631,992 -1.2%
T3294(normal) 1,215,886,432 -0.7%
T5030(normal) 141,449,704 -17.2% GOOD
T5321Fun(normal) 258,484,744 -1.9%
T8095(normal) 770,532,232 -2.7%
T9630(normal) 858,423,408 -14.5% GOOD
T9872c(normal) 1,591,709,448 +0.7%
info_table_map_perf(normal) 19,700,614,458 -1.3%
geo. mean -0.7%
minimum -17.2%
maximum +1.1%
However, strangely there seems to be a 5.0% increase in CoOpt_Read in
the x86_64-linux-fedora43-validate+debug_info+ubsan job, although
there generally a /decrease/ in this test in other builds. The baseline
value looks strange. Anyway I'll just accept it.
Metric Decrease:
CoOpt_Singletons
T12227
T12545
T12707
T15703
T18223
T18730
T21839c
T5030
T9630
Metric Increase:
CoOpt_Read
-
834623d4
by Mrjtjmn at 2026-05-20T17:21:41-04:00
users-guide: Fix weird notation in "Summary of stolen syntax"
-
6f9d7c71
by Markus Läll at 2026-05-21T15:25:34-04:00
Use "grimily" instead of "grimly"
Fixes https://gitlab.haskell.org/ghc/ghc/-/issues/27221
-
50e999ca
by fendor at 2026-05-21T15:26:18-04:00
Speed up 'closure' computation in `ghc-pkg`
Cache the set of already seen `UnitId`s and use `Set` operations to
speed up 'closure' computation.
Further simplify the implementation of 'closure' to account for the
actual usage.
As a consequence, we rename 'closure' to 'brokenPackages' to reflect its
purpose better after the simplification.
-
7ecc6184
by sheaf at 2026-05-21T15:27:10-04:00
TcMPluginHandling: be more lenient when no plugins
This change ensures that, if a function such as 'typecheckModule' was
invoked with 'NoTcMPlugins', GHC doesn't spuriously complain about TcM
plugins having already been stopped, as there were none to start with.
-
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>
-
576987d0
by Simon Jakobi at 2026-06-02T04:53:36-04:00
compiler: use nubOrd from containers
Address #27103 by replacing GHC.Utils.Misc.ordNub[On] with
Data.Containers.ListUtils.nubOrd[On].
Note that nubOrd suffers from a small inefficiency, a fix for which
will be included in the next containers release:
https://github.com/haskell/containers/issues/1202
-
deea53c3
by David Eichmann at 2026-06-02T04:54:22-04:00
Hadrian: disable response files for GHC/Haddock builders on non-Windows
This makes debugging build errors easier on non-windows hosts.
See issue #27230
-
f2f5c6ba
by Nikita Efremov at 2026-06-02T16:04:54+00:00
fix typo : compete with performance, not complete
-
5524ea0e
by Wolfgang Jeltsch at 2026-06-03T08:01:26-04:00
Make the current `base` buildable with GHC 9.14
This comprises the following changes:
* Disable some imports into `GHC.Base` for GHC 9.14
* Disable some imports into `Prelude` for GHC 9.14
* Disable separate `ArrowLoop` import for GHC 9.14
* Disable `GHC.Internal.STM` import for GHC 9.14
* Disable `GHC.Internal.Unicode.Version` import for GHC 9.14
* Disable `GHC.Internal.TH.Monad` import for GHC 9.14
* Add alternative `fixIO` import for GHC 9.14
* Add alternative `unsafeCodeCoerce` import for GHC 9.14
* Disable hiding of imported SIMD operations for GHC 9.14
* Disable use of GHC 9.14’s `printToHandleFinalizerExceptionHandler`
* Enable use of `getFileHash` from `ghc-internal` for GHC 9.14
* Make `thenA` available for GHC 9.14
* Make `thenM` available for GHC 9.14
* Disable translation of `IoManagerFlagPoll` for GHC 9.14
* Add `hGetNewlineMode` for GHC 9.14
-
d3438055
by Enrico Maria De Angelis at 2026-06-03T08:02:17-04:00
Fix #27067 - Clarify haddocks on `minusNaturalMaybe`
-
f9bcfac2
by sheaf at 2026-06-03T14:47:19-04:00
Avoid mkTick in Core Prep breaking ANF
As discovered in #27182, mkTick can break ANF. This patch introduces a
variant of mkTick that skips the single optimisation that could break
ANF. This is preferrable over switching to the raw Tick constructor,
as the latter may introduce spurious cost centres in profiling reports.
This is a temporary measure until we more thoroughly refactor how
mkTick works (see #27141).
See Note [mkTick breaks ANF] in GHC.CoreToStg.Prep.
Fixes #27182
-
cf1fd661
by Artem Pelenitsyn at 2026-06-03T14:48:09-04:00
clarify comment for getSizeofMutableByteArray#: we get the size in bytes, not "elements"
-
a3b431f3
by David Eichmann at 2026-06-04T10:10:19+00:00
Hadrian: convert env variable ACLOCAL_PATH to unix paths.
Convert ACLOCAL_PATH to a unix style path when invoking autoreconf.
Autoreconf doesn't handle windows paths.
See Note [Autoreconf unix paths from ACLOCAL_PATH].
Fixes #27311
-
18f6138a
by Simon Jakobi at 2026-06-04T20:20:31-04:00
testsuite: Deduplicate --only test names
config.only is assumed to be a set, but supplying --only overwrote it
with the (list) argparse result, which can contain duplicates. When a
test ran, config.only.remove(name) dropped only the first occurrence,
so a duplicated name lingered and was later misreported as a
"test not found" framework failure. Store it as a set instead.
Fixes #27322
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
-
2f3cc9ff
by Simon Jakobi at 2026-06-08T07:55:49-04:00
testsuite: detect fast bignum via ghc-internal, not removed ghc-bignum
The ghc-bignum package was merged into ghc-internal, so the BIGNUM_GMP
probe in test.mk ran `ghc-pkg field ghc-bignum exposed-modules`, which
fails with "cannot find package ghc-bignum". That error went to stderr
and leaked into the captured stderr of every makefile_test, causing
spurious [bad stderr] failures across the suite. The probe also silently
returned empty, so config.have_fast_bignum was wrongly False even on GMP
builds.
Probe ghc-internal's extra-libraries for the gmp library instead: the
GMP backend module is an other-module (not exposed), but GMP_LIBS adds
gmp to extra-libraries only on a GMP build, so this distinguishes the
backends. Redirect stderr to keep any future missing-package error off
the harness's stderr.
This also removes a stale comment as per suggestion from hsyl20.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
-
eb3bf6e7
by Alan Zimmerman at 2026-06-08T07:56:32-04:00
EPA: Rename Transform.anchorEof to addModuleCommentOrigDeltas
This now matches what it actually does.
-
498bb21a
by David Eichmann at 2026-06-09T18:02:39-04:00
Hadrian: avoid response files when command line is short enough
This replaces the logic of always using response files on Windows.
With the new condition based on command line lenght, reponse files
can be avoided in many more cases (on windows).
Now that response files are only used in a small number of cases,
response files are always kept and the -r / --keep-response-files
command line options have been removed
The response file paths are nolonger randomized. They are placed in the
`_build/rsp` directory. This ensures they are ignored by git and we
that Hadrian reuses response file paths when rebuilding rather than
leaving stale response files around.
Update user guide putting response files in its own section
-
87f510a5
by Simon Hengel at 2026-06-09T18:03:25-04:00
Don't use non-breaking spaces
-
41a19379
by David Eichmann at 2026-06-09T18:04:11-04:00
Hadrian: remove unused wrapper scripts from windows bindist
These wrapper scripts are only installed on non-relocatable builds
which are not generally supported on windows.
-
ce01ccb6
by sheaf at 2026-06-10T05:08:48-04:00
Don't drop ticks around variables of type `IO ()`
GHC.Core.Utils.mkTick is responsible for placing a tick on a Core
expression. It contains logic for dropping SCCs (non-counting profiling
ticks) around non-function variables, as such variables cannot
meaningfully contribute to profiles. However, the logic for what counts
as a function was incorrect: it used `isFunTy` which returns 'False' for
types such as 'IO ()' where the function arrow is hidden under a
newtype.
We now use 'mightBeFunTy' instead of 'isFunTy'. This ensures we don't
drop ticks in cases we aren't sure.
On the way, we improve the documentation of 'isFunTy', 'isPiTy' and
'mightBeFunTy', and update the latter's implementation to consistently
handle unary classes.
Fixes #27225
-------------------------
Metric Decrease:
T5642
-------------------------
-
d311c4f1
by Simon Jakobi at 2026-06-10T05:09:32-04:00
testsuite: Add regression test for #4081
Check that a strict constructor field is unboxed once outside an
enclosing loop, not re-inspected each iteration (the float-out
case-floating from 9cb20b488). Uses simonpj's `data T a = T !a` example
from the ticket; T4081.stderr captures the expected Core.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
-
333df444
by sheaf at 2026-06-10T05:10:25-04:00
Check for cabal-install >= 3.12 upfront
Starting with commit 8cb99552f607f6bc4000e45ab32532d50c8bb996, Hadrian
requires cabal-install >= 3.12 in order to use the 'cabal path' command
that was introduced in version 3.12, as per
https://github.com/haskell/cabal/blob/a51c4ee1556d816ad86e90db7e6330dd51b0b6e7/release-notes/cabal-install-3.12.1.0.md?plain=1#L45
This was not reflected in the Hadrian build script, causing a delayed
build failure instead of enforcing the version requirement upfront,
which this patch does.
Fixes #27317
-
98c20394
by sheaf at 2026-06-10T05:11:09-04:00
Fix crash in Data.Data instance for HsCtxt
The Data.Data instance for HsCtxt contained an error for the 'toConstr'
method, which could trigger for example when looking at -ddump-tc-ast
traces. Replace it with the 'abstractConstr' pattern used in the rest of
the codebase.
-
5ac9ce7d
by Zubin Duggal at 2026-06-10T21:26:32+05:30
hadrian: Remove old package.conf files when generating new ones
Old package.conf files might exists with different hashes, causing issues like #26661
Fixes #26661
-
c9015f09
by sheaf at 2026-06-11T12:40:28-04:00
Fix AArch64 clobbering bug for MUL2
On AArch64, the code generator could clobber one of the input operands
when computing the lower bits of a MUL2 operation. This rendered invalid
the subsequent computation of the high bits.
This commit fixes that by using a temporary register. The register
allocator can remove the redundant move in the common case when the
registers do not conflict.
Fixes #27046
-
7ab90288
by Rodrigo Mesquita at 2026-06-11T12:41:11-04:00
fix: make T27131 less flaky
It seems that T27131 fails flakily in a race where we check the flag
before the capability had the chance to process the mailbox which sets
the flag. This seemingly should only happen if the capability ends up
being the same for setting and checking the flag.
-
8965cb76
by Marc Scholten at 2026-06-12T04:53:22-04:00
haddock: render modules concurrently
-
8cc0b64a
by Duncan Coutts at 2026-06-12T04:54:06-04:00
Promote HAVE_PREEMPTION from Timer.c to OSThreads.h
We will want to know about HAVE_PREEMPTION in more places.
HAVE_PREEMPTION tells us that we do have OS threads available,
irrespective of whether THREADED is defined. In particular,
HAVE_PREEMPTION is defined on all proper OSs, but not on WASM (and
hyopthetically may not be true on some other platforms like
micro-controllers, RTOSs, VM hypervisors etc).
-
cce574ed
by Duncan Coutts at 2026-06-12T04:54:06-04:00
Define ACQUIRE_LOCK_ALWAYS and friends
Fix issue #27335
Like the atomic _ALWAYS variants, these lock actions are always defined,
rather than being dependent on whether we are in the THREADED case. All
the "normal" LOCK macros are defined to be no-ops when !THREADED.
The use case for the _ALWAYS variants is where we are using OS threads
even in the non-threaded RTS. This includes everything to do with the
timer/ticker thread, which is used in the non-threaded RTS too.
In particular, we will want to use this for eventlog things, because the
timer thread performs eventlogging concurrently with the main
capability, even in the non-threaded RTS.
-
1f28d1f6
by Duncan Coutts at 2026-06-12T04:54:06-04:00
Use ACQUIRE/RELEASE_LOCK_ALWAYS with eventBufMutex
Even in the non-threaded RTS the eventBufMutex is needed by both the
main capability and the timer/ticker thread, so always use the mutex.
This should fix #25165 which is about the main capability and the timer
thread posting events to the eventlog buffer concurrently and thereby
corrupting the buffer data.
-
0ff29782
by Duncan Coutts at 2026-06-12T04:54:06-04:00
Expose eventBufMutex in the EventLog interface/header
We will need it in forkProcess to ensure we don't write to the global
eventlog buffer concurrently with trying to flush eventlog buffers and
do the fork().
-
7a688395
by Duncan Coutts at 2026-06-12T04:54:07-04:00
Split flushAllCapsEventsBufs into safe and unlocked version
Following the convention that unlocked versions have a trailing _
underscore in their name. This one requires the caller to hold the
eventlog global buffer mutex. We will need this in forkProcess.
-
341ed474
by Duncan Coutts at 2026-06-12T04:54:07-04:00
Remove redundant use of stopTimer in setNumCapabilities
Historically, the comment here was:
We must stop the interval timer while we are changing the
capabilities array lest handle_tick may try to context switch
an old capability. See #17289.
and
We must disable the timer while we do this since the tick handler may
call contextSwitchAllCapabilities, which may see the capabilities array
as we free it.
What this refers to is that historically, when changing the number of
capabilities, the array of capabilities was reallocated to a new size,
allocating new ones and freeing the old ones, thus invalidating all
existing capbility pointers.
Strangely, for good measure the code used to call stopTimer twice (hence
the two similar comments above).
However, since commit a3eccf06292dd666b24606251a52da2b466a9612, the
capabilities array is no longer reallocated. Instead the array is
allcoated once on RTS startup to the maximum size it could ever be
allowed to be, and then capabilities get enabled/disabled at runtime. So
the capability pointers never become invalid anymore. At worst, they may
point to capabilities that are disabled.
Thus we no longer need to stop the timer (twice) while we change the
number of enabled capabilities. This also partially solves issue #27105,
which notes that stopTimer is being used as if it were synchronous, when
it is not. At least for this case, the solution is that stopTimer is not
needed at all!
-
674858e3
by Duncan Coutts at 2026-06-12T04:54:07-04:00
Remove redundant use of stopTimer in forkProcess
but replace it with taking the eventlog buffer lock during the fork.
Fixes issue #27105
The original reason to block the timer during a fork was that
historically the timer was implemented using a periodic timer signal,
and the signal itself would interrupt the fork system call (returning
EINTR). For large processes (where fork() takes a while) this could
permanently livelock: the timer always would go off before the fork
could complete, which got retried in a loop forever.
The timer is no longer implemented as a unix signal, but uses threads.
Thus the original problem no longer exists. The only remaining reason to
block the timer tick is to prevent actions taken by the tick from
interfering with the delicate process involved in fork (taking a load of
locks and pausing everything).
The only thing we need to do is to prevent the eventlog from being
written to or flushed while the fork is taking place. To achieve this
all we need to do is hold the mutex for the global eventlog buffer.
This removes the last use of stopTimer that expects stopTimer to work
synchronously (which it was not) and thus solves issue #27105. To be
clear, we solve issue #27105 not by making stopTimer synchronous, but by
eliminating the use sites that expected it to be synchronous.
-
40764930
by sheaf at 2026-06-12T14:54:43-04:00
Add type family performance test for #26426
Some GHC versions produced large numbers of coercions after typechecking
and desugaring when compiling the program in #26426:
Version | Typechecker time | Typechecker allocations | Coercions
-------:|-----------------:|------------------------:|---------:
9.6 | 47 ms | 48 MB | 110k
9.8 | 1000 ms | 486 MB | 10,437k
9.10 | 922 ms | 489 MB | 10,436k
9.12 | 906 ms | 482 MB | 10,437k
9.14 | 63 ms | 55 MB | 333k
10.0 | 47 ms | 64 MB | 35k
The improvement 9.12 -> 9.14 was due to commit 22d11fa818fae2c95c494fc0fac1f8cb4c6e7cb6,
while the improvement 9.14 -> 10.0 was due to commit 0b7df6db9e46df40e86fbff1a66dc10440b99db5.
As the behaviour of GHC seems better than it's ever been on this program,
we declare victory, adding this performance test to ensure we don't
regress on this program.
On the way, we update Note [Combining equalities] in GHC.Tc.SolveR.Equality
with the explanation of the 9.12 -> 9.14 improvement (getting rid of an
exponential blowup in coercion sizes), and we update
Note [Exploiting closed type families] in GHC.Tc.Solver.FunDeps with
the explanation of the 9.14 -> 10.0 improvement (bringing down coercion
size growth from cubic to quadratic).
-
0f3d0a71
by Zubin Duggal at 2026-06-12T14:55:30-04:00
compiler: mark tool messages as errors/warnings depending on the exit code
Fixes #27370
-
d9ea2d76
by mangoiv at 2026-06-13T04:41:51-04:00
libraries/process: bump submodule to v1.6.30.0
- bump the submodule to the appropriate tag
- suppress benign warning resulting from the change
-
6ebaaba3
by David Eichmann at 2026-06-13T04:42:37-04:00
ghc-toolchain: don't throw when candidate executables are not found
Fixes #27369
-
6c65e1e1
by David Eichmann at 2026-06-13T04:43:23-04:00
CI: lint-changelog checks for no-changelog label in script instead of rules
-
bab37cc6
by konsumlamm at 2026-06-13T19:10:21+02:00
Implement CLC proposal #378
Add `Data.Double` and `Data.Float` modules
Document that GHC uses IEEE 754
-
fb5246ad
by fendor at 2026-06-15T18:07:23-04:00
Drop `preloadClosure` from `UnitState`
It is always hard-coded to the same value.
Backpack Unit instantiation isn't using it any more.
Allows us to simplify the API and get rid of `improveUnit`.
-
291ce3aa
by ARATA Mizuki at 2026-06-15T18:08:26-04:00
RISC-V NCG: Zero-extend the result of castFloatToWord32
According to the ISA manual, FMV.X.W sign-extends the result.
We need to truncate the result to avoid creating an exotic Word32 value.
Fixes #27300
-
011be91f
by ARATA Mizuki at 2026-06-15T18:08:26-04:00
RISC-V NCG: Treat d28-d31 (ft8-ft11) as caller-saved
According to the calling convention, the registers d28-d31 (ft8-ft11) are caller-saved.
Fixes #27306
-
e8a54713
by ARATA Mizuki at 2026-06-15T18:08:26-04:00
RISC-V NCG: Set rounding mode when emitting `truncate`
If we omit the rounding mode for `fcvt`, `dyn` will be used.
We do not want that for `truncate`, so we set `rtz`.
In other places, we set `rne` because we do not use the dynamic rounding mode.
Fixes #27303
-
9438bec7
by Zubin Duggal at 2026-06-15T18:09:11-04:00
rts: fix validate build with gcc 16. `__attribute__((regparm(1)))` is ignored on x86_64 and now
gcc warns that it is ignored:
rts/sm/Evac.h:35:1: error:
error: ‘regparm’ attribute ignored [-Werror=attributes]
See https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ccead81bbc39668376eb5cf47066acb446cc43f3
Fixes #27366
-
893e6133
by Andrew Lelechenko at 2026-06-15T23:55:36+01:00
base: more NonEmpty zips
CLC proposal: https://github.com/haskell/core-libraries-committee/issues/409
-
1314f2fd
by David Eichmann at 2026-06-16T05:46:52-04:00
Hadrian: fix ghc-internal .def file name
-
7f72bcb3
by mangoiv at 2026-06-16T05:47:39-04:00
compiler: ignore camelCase and Eta reduce hlint hints
These do not cohere with the style used in GHC. After disabling them,
hlint lints are much less noisy again.
-
842bef9f
by Alan Zimmerman at 2026-06-16T05:48:25-04:00
EPA: Use standard type family declaration for Anno
-
f6d30767
by Wolfgang Jeltsch at 2026-06-16T15:32:34-04:00
Fix two issues in the documentation of pipeline interruption
One issue is a typo (“interreuptible”), the other one the lack of an end
of a sentence, which has been reconstructed from the message of
633bbc1fd4762a2bb73ba1c5b9e0c279f1dd3c40, the commit that introduced
said documentation.
-
a3fa10e0
by Christian Georgii at 2026-06-16T15:33:26-04:00
Find plugins in sibling home units in multiple-home-unit sessions
In a multiple-home-unit session (e.g. `cabal repl --enable-multi-repl` or HLS), enabling a plugin with -fplugin that is defined in (or reexported by) another home unit failed with a "hidden package" error. The plugin module finder only searched the current home unit and the registered external packages, never the sibling home units.
findPluginModuleNoHsc now searches the home units that the current home unit depends on, following module reexports and respecting hidden modules, exactly as ordinary import resolution does in findImportedModuleNoHsc. To avoid two divergent copies of this logic, the shared home-unit search (the current home unit first, then its dependencies in priority order, with the accompanying ordering invariant) is extracted into findHomeModuleAmongDeps, which both findImportedModuleNoHsc and findPluginModuleNoHsc now call.
Add testsuite/tests/driver/multipleHomeUnits/plugin01, which loads a plugin as byte-code from a sibling home unit, and plugin02, in which the consumer enables a plugin reexported by a sibling home unit without depending on the plugin's own home unit directly.
Fixes #27349
-
d216412b
by Ian-Woo Kim at 2026-06-16T20:25:57-04:00
Make the order of usages deterministic
It has been observed that the ordering of usages can be non-determinstic
in parallel builds. Therefore, this contribution introduces sorting of
usages based on a platform- and race-independent sorting criterion.
Resolves #26877.
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>
-
8e1cc105
by Wolfgang Jeltsch at 2026-06-16T20:25:57-04:00
Change the descriptions of two existing changelog entries
The descriptions now describe the changes in a user-friendly manner, as
opposed to describing the contributions that led to these changes in a
developer-friendly manner.
-
636c1c7a
by Ian Duncan at 2026-06-16T20:26:50-04:00
AArch64: use SXTH, not SXTW, for W32 signExtendReg
signExtendReg was using SXTH (sign-extend halfword, 16-bit) for
W32-to-W64 sign extension. This should be SXTW (sign-extend word,
32-bit). SXTH only sign-extends the lower 16 bits, producing wrong
results for 32-bit values whose bit 15 differs from bit 31.
Other fixes:
- At sub-W64, code gen for MO_S_Mul2 should use W32 registers for
SMULL source operands as per the ARM spec (SMULL Xd, Wn, Wm),
and not W64.
- Ensure signExtendReg uses the source width for the source operand
in SXTW/SXTH/SXTB instructions. GNU as requires sxtw Xd,Wn (not
sxtw Xd,Xn), while LLVM's integrated assembler on macOS is lenient.
- Fix overflow flag computation for `MO_S_Mul2`. The overflow bit
was exactly inverted for sub-W64 operands.
Fixes #26978 and #27047
-
b734c75d
by Igor Ranieri at 2026-06-16T20:27:32-04:00
haddock: Update CONTRIBUTING with missing step, add missing test
dependency
-
7fe4f2ec
by Luite Stegeman at 2026-06-17T05:35:09-04:00
tag inference: don't confuse functions with their return values
inferTagRhs was mixing up taggedness for closures and return values
for function closures. We really shouldn't assign TagTuple to a
properly tagged function returning a tuple.
We fix this by keeping track of functions (TagFun) separately from
values (TagVal) and keeping track of their return value. TagFun is
also used for join points.
fixes #27005
-
4671c126
by Sebastian Graf at 2026-06-17T05:35:55-04:00
Seed the simplifier's in-scope set for open expressions
simplifyExpr simplifies expressions typed at the GHCi prompt and the
results of Template Haskell splices. Such an expression may be open: at a
GHCi debugger breakpoint its free variables include RuntimeUnk skolems
standing for as-yet-unknown types.
The simplifier began with an in-scope set holding only the wildcard
binder, so when it instantiated the unsafeCoerce# wrapper that GHCi
builds around a result, it formed a substitution whose range mentioned a
free skolem that was not in scope. That breaks the substitution invariant
and, in a compiler built with assertions, trips substTy's sanity check.
Seed the initial in-scope set with the free variables of the expression.
For a closed expression this adds nothing.
See Note [Seed the in-scope set for open expressions].
Fixes #17833 and its duplicate #21118.
-
67d41299
by Sebastian Graf at 2026-06-18T05:18:24-04:00
Desugar a `case` scrutinee only once (#27383, #20251)
In `dsExpr` for `HsCase` we desugared the scrutinee /twice/: once to
build the Core `case` itself, and again inside `matchWrapper`, which
re-desugared the source scrutinee (via `addHsScrutTmCs`) purely to
record long-distance information for the pattern-match checker.
For a single `case` that is merely wasteful. But for nested cases it
is catastrophic. Consider
case (case (case e of ... ) of ... ) of ...
Desugaring the outer scrutinee desugars the middle `case` twice, each
of which desugars the inner `case` twice, and so on. The work doubles
at every level, so desugaring takes O(2^n) time in the nesting depth.
That is the blowup reported in #27383; it is also what makes the
machine-generated program in #20251 take an age to compile.
The fix is simple. `matchWrapper` is handed the scrutinee anyway, so
we give it the Core expression we have /already/ desugared, and record
the long-distance term constraint with `addCoreScrutTmCs` instead of
re-desugaring from source. This is just what `matchSinglePatVar`
already does for single-pattern matches.
So:
* `matchWrapper` now takes `Maybe [CoreExpr]` rather than
`Maybe [LHsExpr GhcTc]`.
* The `HsCase` equation of `dsExpr` passes the already-desugared
`core_discrim`; the arrow desugarer passes its match variables.
* `addHsScrutTmCs` had no other use, so it is gone.
Desugaring is now linear in the nesting depth. (The coverage checker
still runs `simpleOptExpr` over each scrutinee, which leaves the total
at O(n^2); that is ample.) The long-distance information itself is
unchanged: the checker sees precisely the Core that backs the
generated code.
Test: deSugar/should_compile/T27383
-
fa5defde
by Rodrigo Mesquita at 2026-06-18T05:19:11-04:00
fix: Save FastStrings in the PMC
There is no point in adding the unique to the occurrence FastString we
create, since it is part of the Id anyway.
Adding it to the FastString, meant each FastString was unique
unnecessarily!
In a separate branch, running the compiler on test `InstanceMatching`
observed 30000 `FastString`s created by this code path.
Plus, `fsLit "pm"` follows the existing pattern in `mkPmId`.
-
4efb4a66
by Alan Zimmerman at 2026-06-18T14:41:14-04:00
TTG: Add extension points to HsConDetails
Extend HsConDetails as
data HsConDetails p arg rec
= PrefixCon !(XPrefixCon p) [arg] -- C @t1 @t2 p1 p2 p3
| RecCon !(XRecCon p) rec -- C { x = p1, y = p2 }
| InfixCon !(XInfixCon p) arg arg -- p1 `C` p2
| XHsConDetails !(XXHsConDetails p)
type family XPrefixCon p
type family XRecCon p
type family XInfixCon p
type family XXHsConDetails p
-
c8d27dd4
by Simon Jakobi at 2026-06-18T14:41:59-04:00
CI: quiet submodule clean output in after_script and setup
The clean and cleanup_submodules functions ran 'git submodule foreach
git clean -xdf', flooding the job log with 'Entering ...' and
'Removing ...' lines. Pass --quiet to 'git submodule' and -q to 'git
clean' to drop the success output; errors are still reported.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
-
09326ca6
by Matthew Pickering at 2026-06-20T23:41:12+02:00
Add missing req_interp modifier to T18441fail3 and T18441fail19
These tests require the interpreter but they were failing in a different
way with the javascript backend because the interpreter was disabled and
stderr is ignored by the test.
-
521e55bf
by Matthew Pickering at 2026-06-20T23:41:13+02:00
hadrian: Fill in more of the default.host toolchain file
When you are building a cross compiler this file will be used to build
stage1 and it's libraries, so we need enough information here to work
accurately. There is still more work to be done (see for example, word
size is still fixed).
-
23c9b6c3
by Matthew Pickering at 2026-06-20T23:42:52+02:00
hadrian: Build stage 2 cross compilers
* Most of hadrian is abstracted over the stage in order to remove the
assumption that the target of all stages is the same platform. This
allows the RTS to be built for two different targets for example.
* Abstracts the bindist creation logic to allow building either normal
or cross bindists. Normal bindists use stage 1 libraries and a stage 2
compiler. Cross bindists use stage 2 libararies and a stage 2
compiler.
* hadrian: Make binary-dist-dir the default build target. This allows us
to have the logic in one place about which libraries/stages to build
with cross compilers. Fixes #24192
New hadrian target:
* `binary-dist-dir-cross`: Build a cross compiler bindist (compiler =
stage 1, libraries = stage 2)
This commit also contains various changes to make stage2 compilers
feasible.
-------------------------
Metric Decrease:
LinkableUsage02
ManyAlternatives
ManyConstructors
MultiComponentModulesRecomp
MultiLayerModulesRecomp
RecordUpdPerf
T10421
T12150
T12227
T12425
T12707
T13035
T13379
T13820
T15703
T16577
T18140
T18282
T18698a
T18698b
T18923
T1969
T20049
T21839c
T3294
T4801
T5030
T5321FD
T5321Fun
T5631
T5642
T6048
T783
T9020
T9198
T9233
T9630
T9872d
T9961
parsing001
T3064
Metric Increase:
T26989
hard_hole_fits
-------------------------
Co-authored-by: Sven Tennie <sven.tennie@gmail.com>
-
26fed8ab
by Matthew Pickering at 2026-06-20T23:42:52+02:00
ci: Test cross bindists
We remove the special logic for testing in-tree cross
compilers and instead test cross compiler bindists, like we do for all
other platforms.
-
80c8910e
by Matthew Pickering at 2026-06-20T23:42:52+02:00
ci: Introduce CROSS_STAGE variable
In preparation for building and testing stage3 bindists we introduce the
CROSS_STAGE variable which is used by a CI job to determine what kind of
bindist the CI job should produce.
At the moment we are only using CROSS_STAGE=2 but in the future we will
have some jobs which set CROSS_STAGE=3 to produce native bindists for a
target, but produced by a cross compiler, which can be tested on by
another CI job on the native platform.
CROSS_STAGE=2: Build a normal cross compiler bindist
CROSS_STAGE=3: Build a stage 3 bindist, one which is a native compiler and library for the target
-
8215573d
by Sven Tennie at 2026-06-20T23:42:52+02:00
ci: Increase timeout for emulators
Test runs with emulators naturally take longer than on native machines.
Generate jobs.yml
-
5acb7dbc
by Matthew Pickering at 2026-06-20T23:42:52+02:00
ci: Javascript don't set CROSS_EMULATOR
There is no CROSS_EMULATOR needed to run javascript binaries, so we
don't set the CROSS_EMULATOR to some dummy value.
-
48345343
by Sven Tennie at 2026-06-20T23:42:52+02:00
Javascript skip T23697
See #22355 about how HSC2HS and the Javascript target don't play well
together.
-
5e44fd05
by Sven Tennie at 2026-06-20T23:42:52+02:00
Mark T24602 as fragile
It was skipped before (due to CROSS_EMULATOR being set, which changed
for JS), so we don't make things worse by marking it as fragile.
-
ab349ec2
by Sven Tennie at 2026-06-20T23:42:52+02:00
Fix T22744 for GHCJS
In fact, this test needs Template Haskell, not necessarily an
interpreter.
-
c73352d8
by Sven Tennie at 2026-06-20T23:42:52+02:00
haddock-test: fix GHCJS haddock test failures
Add --ghc-pkg-path flag support so haddock test runner can find
cross-prefixed ghc-pkg (e.g. javascript-unknown-ghcjs-ghc-pkg) which
is not on $PATH in cross install directories.
Skip haddockHtmlTest on GHCJS: Threaded.hs uses forkOS in a TH splice,
which GHCJS RTS doesn't support. Mark with js_skip in all.T.
-
5e814e76
by Andreas Klebinger at 2026-06-22T23:00:24-04:00
compiler: Deduplicate hscTidy
This function was accidentally duplicated during a refactor.
Fixes #27351
-
473b97eb
by sheaf at 2026-06-22T23:01:22-04:00
Avoid mkTick in Core Prep breaking ANF (part II)
Hotfix for 2f9579765f55b3920ceb2e04995ff41a9d0e2d4e fixing a small
oversight in the call to tickTickedExpr from mkTick, in which we
improperly recursively called mkTick without passing on the preserve_anf
flag.
Fixes #27386
-
9284a1f7
by Simon Hengel at 2026-06-23T05:55:33-04:00
Don't use global variables to address concurrency bugs! (fixes #27234)
This was originally introduce with
88f38b03025386f0f1e8f5861eed67d80495168a to address #17922.
In this specific case a better fix would have been to synchronize on
stderr:
withHandle_ "stderrSupportsAnsiColors" stderr $ \ _ -> do
...
But apparently the dependency on `terminfo` was removed in
32ab07bf3d6ce45e8ea5b55e8095174a6b42a7f0, preventing #17922 in the first
place.
-
44309cd3
by Alan Zimmerman at 2026-06-23T05:56:20-04:00
EPA: remove LocatedL / SrcSpanAnnL and LocatedLI / SrcSpanAnnLI
This is part of a refactor towards only having LocatedA / SrcSpanAnnA
It removes the stated items, but has to add back one for BooleanFormula,
LocatedBF / SrcSpanAnnBF
This commit also use the HsConDetails RecCon extension point to
capture the braces in a record constructor
-
2f6a5534
by Simon Jakobi at 2026-06-23T15:46:20+02:00
Add -dstable-core-dump-order for stable Core dump ordering (#27296)
The order of top-level bindings in Core dumps (-ddump-simpl etc.) is the
compiler's Unique-sensitive internal processing order, so an unrelated
upstream change can reorder them and defeat a textual diff of two dumps.
This adds an opt-in flag -dstable-core-dump-order that reorders the
top-level bindings of dumps routed through dumpPassResult into a stable,
Unique-independent order, so two dumps line up across rebuilds. See
Note [Stable Core dump order] in GHC.Core.Ppr for the sort key and its
rationale.
Adds tests T27296 (binders GHC emits in non-source order by default,
asserted to come out stably ordered under the flag) and T27296b (an
untidied -ddump-float-out dump pinning the ordering of the anonymous lvl
floats by literal value).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
-
141986e3
by mangoiv at 2026-06-24T15:51:14-04:00
compiler: refactor error reporting code for ExplicitLevelImports
Refactors error reporting code for ExplicitLevelImports to pass in a
RdrName and a GlobalReaderElt to be able to report errors that are
faithful to the source and to more precisely distinguish between names
that are in scope from different qualifications.
Fixes #27385 and #26616
-
aa7df6b6
by Simon Hengel at 2026-06-24T15:52:18-04:00
Set GHC_VERSION when calling custom pre-processors (see #25952)
(so that pre-processors can emit backwards compatible code)
-
a9e494f2
by Simon Hengel at 2026-06-24T15:54:08-04:00
Add a flag to control GHCi specific error hints (close #27409)
-
a805b2a2
by Simon Hengel at 2026-06-24T15:55:20-04:00
Reference correct package in error messages for reexported modules
(fixes #27417)
-
f235d183
by Simon Jakobi at 2026-06-25T05:51:18-04:00
Add explicit setBit/clearBit/complementBit for instance Bits Integer (#21176)
The default setBit, clearBit, and complementBit methods allocate
intermediate Integers per call. Define them explicitly via the new
integerSetBit[#], integerClearBit[#] and integerComplementBit[#], built
on the BigNat# primitives, which avoid those allocations. Allocation is not
eliminated entirely -- the negative (IN) cases would need in-place mutation,
which is left as future work.
The default methods constant-folded on literal arguments via the
integerOr/integerAnd/integerXor rules, which fold literal Integers of any
size. The explicit functions have no such rule, so they (their Word-argument
wrappers, and the Bits Integer methods) are marked INLINE to expose the
underlying primops to the simplifier; see Note [INLINE for constant folding
of bit operations]. This restores folding only on the small-int (IS) path --
large literal Integers (IP/IN) are no longer constant-folded, a minor
regression for that case. T8832 covers the IS-path folding.
The new golden-output test T21176 checks all three operations against the
default implementations across the sign/size boundaries, recording each
result plus its integerCheck validity. The base and ghc-bignum interface-
stability export goldens gain the new functions.
The main changelog entry lives in changelog.d under a new ghc-internal
section (renamed from ghc-prim).
CLC proposal: https://github.com/haskell/core-libraries-committee/issues/423
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
-
202ed264
by Marc Scholten at 2026-06-25T05:52:21-04:00
haddock: use Text in documentation pipeline
This patch moves Haddock's documentation pipeline from String to Text
where the data is already textual. It avoids repeated conversions while
keeping the existing decoding behavior for invalid UTF-8 docstring
chunks.
The main changes are:
* Render and carry docstrings as Text in Haddock-facing paths.
* Use the Binary Text instance from GHC.Utils.Binary for Haddock
interface files, and bump the Haddock binary interface version.
* Add a FastString HTML instance so XHTML rendering avoids
intermediate String allocation.
* Keep HsDocStringChunk decoding lenient, matching the previous
unpackHDSC behavior on invalid UTF-8 input.
* Update the xhtml submodule to 3000.4.1.0, which contains the
apostrophe escaping fix used by the Haddock test output.
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Assisted-by: Codex <codex@openai.com>
-
a72ff58f
by mangoiv at 2026-06-25T05:53:07-04:00
compiler: rename ZonkAny to UnusedType and add pretty printing logic
ZonkAny is a hard to understand name for users who do not know how the
compiler works internally. Additionally, it is confusing that ZonkAny,
while being a concrete type *represents* a meta variable, espeically in
the compiler output.
This patch changes the name of ZonkAny to UnusedType which is closer to
its intended semantics and adds special pretty printing logic to display
this type in the same fashion the compiler displays meta variables in
other places, whenever they leak from the implementation to the user.
It also exports the type from ghc-internal:GHC.Internal.Types in order
to expose documentation.
Fixes #27390
Co-Authored-By: Sam Derbyshire <sam.derbyshire@gmail.com>
-
6813f002
by Simon Jakobi at 2026-06-26T04:51:47-04:00
Reg.Linear: drop Platform argument from most FR (FreeRegs) methods
The FR class has one instance per CPU architecture, so any
architecture-constant information its methods derived from the Platform
argument can instead be baked into the instance. This removes the now
needless Platform argument from frAllocateReg, frGetFreeRegs and
frReleaseReg.
frInitFreeRegs keeps its Platform argument: the initial allocatable set is
genuinely platform-dependent, see Note [Aarch64 Register x18 at Darwin and
Windows].
Fixes #26665
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
-
3b2a9409
by Zubin Duggal at 2026-06-26T04:52:39-04:00
testsuite: Report fragile failures as skipped in JUnit output
-
27463426
by Rodrigo Mesquita at 2026-06-26T20:54:58-04:00
perf: Share Module in Iface Symbol Table
This commit modifies the structure of the serialized `SymbolTable Name`
to then re-use and share the `Module` (both on disk and in memory) across
all `Name`s from the same module.
The new structure looks like:
<total name count>
$modules.size
for (mod, names) in $modules:
$mod
$names.size
for table_ix, occ in $names
$table_ix
$occ
i.e. we put the module just once, followed by all names in that module.
When deserializing, we deserialize the module just once, and all the
following `Name`s are constructed with a pointer to that same decoded
`Module`.
In `hoogle-test`, we must use `DNameEnv` rather than `Map Name`,
otherwise the output fixities order was susceptible to changes in the
uniques assigned to each Names, which is not stable.
Fixes #27401
-------------------------
Metric Decrease:
InstanceMatching
LinkableUsage01
LinkableUsage02
hard_hole_fits
-------------------------
-
412f1675
by Simon Hengel at 2026-06-26T20:55:41-04:00
Rename `MCDiagnostic` to `InternalMCDiagnostic`
`MCDiagnostic` is meant to be used for compiler diagnostics.
Any code that creates `MCDiagnostic` directly, without going through
`GHC.Driver.Errors.printMessage`, sidesteps `-fdiagnostics-as-json` (see
e.g. !14616, !14475, !14492 !14548).
To avoid this in the future, this change more narrowly controls who
creates `MCDiagnostic` (see #24113).
-
6f212121
by Facundo Domínguez at 2026-06-26T20:56:27-04:00
Encapsulate options of occurAnalysePgm in a record
-
adfbb179
by Facundo Domínguez at 2026-06-26T20:56:27-04:00
Allow to configure the occurrence analyser to retain some dead bindings
This is needed by plugins that are the only consumers of a binding which
is otherwise unused in the program.
See Note [Controlling elimination of dead bindings in occurrence analysis]
added in this commit, or
https://gitlab.haskell.org/ghc/ghc/-/issues/27240 for more discussion.
-
c745b11f
by Copilot at 2026-06-26T20:56:27-04:00
Address documentation feedback
-
2c2a4a2a
by Copilot at 2026-06-26T20:56:27-04:00
Keep the imp_rules parameter of occurPgmAnalysePgm and add occ_opts to OccEnv
-
e2262b0e
by Copilot at 2026-06-26T20:56:27-04:00
Strengthen T27240.hs with a binding that should be removed
-
5f9d9268
by Copilot at 2026-06-26T20:56:27-04:00
Move the reference #27240 to a related paragraph
-
d86d2644
by Simon Hengel at 2026-06-26T20:57:10-04:00
Remove deprecated flag `-ddump-json` (see #24113)
This was first deprecated in 9.10.1.
-
3b15ff03
by Simon Jakobi at 2026-06-27T18:48:34+02:00
Tweak mk_mod_usage_info
* Use O(log n) `elemModuleEnv` instead of O(n) `elem` to filter the
direct imports.
* Use `nonDetModuleEnvKeys` to avoid sorting the ent_map keys twice.
* Prepend the presumably shorter list when creating all_mods with
`(++)`. Actually this eliminates the `(++)` entirely, as it seems to
fuse with the `filter` expression.
As a result there is a tiny speed-up when generating the .hi-files for
modules with many imports.
None of the changes affect compilation determinism as the module list
is explicitly sorted to ensure a canonical order.
-
2d0fd154
by Alan Zimmerman at 2026-06-29T11:44:00-04:00
EPA: Remove LocatedC / SrcSpanAnnC
This is part of a cleanup of the zoo of
SrcSpanAnnXXX types for exact print annotations.
This one removes SrcSpanAnnC used for storing exact print annotations
for contexts. It replaces it with an explicit `HsContext` data type
that carries the annotations and the context.
So, replace
type HsContext pass = [LHsType pass]
with
type HsContext pass = HsContextDetails pass (LHsType pass)
data HsContextDetails pass arg
= HsContext
{ hsc_ext :: !(XHsContext pass)
, hsc_ctxt :: [arg]
}
| XHsContextDetails !(XXHsContextDetails pass)
We need the parameterised HsContextDetails because it is used both for
HsQual carrying 'LHsExpr p' and "normal" contexts carrying 'LHsType p'.
-
cca0d589
by Luite Stegeman at 2026-06-30T13:33:40-04:00
rts: handle large AP closures in compacting GC
The function update_fwd_large in the compacting GC could run into
an unexpected object with the following error:
internal error: update_fwd_large: unknown/strange object 24
Closure type 24 is the AP closure, which was not handled in
upd_fwd_large. This patch adds handling them.
fixes #27434
-
42935858
by Luite Stegeman at 2026-06-30T13:33:40-04:00
testsuite: use compacting_gc way instead of hardcoding +RTS -c
-
bf7b5ce6
by Alan Zimmerman at 2026-06-30T13:34:23-04:00
EPA: Remove LocatedLW from LStmtLR
HsDo already had its XDo extension point for an
AnnList, which also appeared in LocatedLW.
So we remove the redundant one and use the one inside HsDo
as originally intended.
Also delete LocatedLC/LocatedLS as they were unused
-
d7cfea49
by Recursion Ninja at 2026-06-30T21:37:12-04:00
Decoupling 'L.H.S' from 'GHC.Types.SourceText'
* Migrated 'IntegralLit' to 'L.H.S.Lit'.
* Migrated 'FractionalLit' to 'L.H.S.Lit'.
* Migrated 'StringLiteral' to 'L.H.S.Lit'.
* Added TTG extension points to the types above.
* Added nice export list to 'GHC.Hs.Lit'.
* Added 'rnOverLitVal' and 'tcOverLitVal' functions to 'GHC.Hs.Lit'.
* Added instance 'Anno (StringLiteral (GhcPass p)) = SrcSpanAnnN'
* Moved [Notes] about 'SourceText' from 'L.H.S.*' to 'GHC.*'.
* Removed all references to 'SourceText' from 'L.H.S'.
* Removed the trailing comma record field from 'StringLiteral'
* Renamed exported functions for nomenclature consistency.
* Deprecated the renamed functions
Fixes #26953
-
a1f2558b
by Recursion Ninja at 2026-06-30T21:37:12-04:00
Monomorphising GHC pass parameters where appropriate
-
7bf9e3c5
by Teo Camarasu at 2026-06-30T21:38:03-04:00
Make Q abstract
This patch aims to clearly demarcate the internal and external interfaces
of Q.
In the past the `Quasi` typeclass was both part of the external,
public-facing interface, and was used to give the implementation of `Q`.
Now we separate out these two distinct roles. `Quasi` continues to exist
in the public interface, but we introduce a new `MetaHandlers` type,
which is equivalent to `Dict Quasi`.
`Q a` is now defined to be `MetaHandlers -> IO a`, and, crucially,
the constructor and the new `MetaHandlers` type are not exposed from the
public interface.
This gives us the ability to vary the interface on the GHC side without
forcing a breaking change on the `template-haskell` side.
Similarly `template-haskell` has more freedom to change the `Quasi`
typeclass without needing any changes in `lib:ghc`.
Implements https://github.com/ghc-proposals/ghc-proposals/pull/700
Resolves #27341
-
4262af36
by L0neGamer at 2026-06-30T21:38:56-04:00
generically defines mconcat in terms of internal type's Semigroup instance
add changelog entry
use simpler definition for mconcat
`nonEmpty` isn't available yet; inline branches in case
add test case
fixup generically defines mconcat in terms of internal type's Semigroup instance
add comment on Generically and deriving mishaps
swap mconcat to foldr version
add some strictness testing for mconcat
add to `base` changelog entry
-
e22ad997
by Cheng Shao at 2026-06-30T21:39:43-04:00
hadrian/rts: fix unregisterised build for gcc 15+
This patch fixes unregisterised build for gcc 15+:
- Pass -optc-Wno-error in hadrian when +werror enables -optc-Werror,
see added comment for details.
- For RTS functions that the codegen would emit calls, ensure their
real prototype is hidden when the header is included in .hc fies
(IN_STG_CODE), and the dummy prototype is provided to match the EFF_
convention.
In the future we should get rid of EFF_ (#14647) and remove these
hacks, but for now this patch makes unregisterised work again on newer
toolchains. Fixes #27404.
Co-authored-by: Codex <codex@openai.com>
-
3f00f234
by Cheng Shao at 2026-06-30T21:40:32-04:00
compiler: fix missing handling of CmmUnsafeForeignCall node in LayoutStack
This patch fixes missing handling of `CmmUnsafeForeignCall` middle
node in the `LayoutStack` pass.
Before proc-points splitting, this pass computes liveliness of local
registers, and spills those alive across a Cmm native call onto the
stack. It need to traverse all middle nodes in each block and check
whether a local register is an assignee, if so then the previous
mapping in `sm_regs` is invalidated and needs to be dropped. However,
it didn't handle `CmmUnsafeForeignCall` node which may also assign to
a local register. When proc-points splitting is enabled, this can
produce an invalid basic block that doesn't properly backup the
updated local register to the stack before doing a Cmm call, resulting
in completely invalid runtime behavior.
The patch also adds a `T27447` regression test. With no-TNTC or with
LLVM backend, without the fix the test case would output a stale
0x1111111111111111 value, instead of the expected 0x2222222222222222
output.
Fixes #27447.
Co-authored-by: Codex <codex@openai.com>
-
701088db
by Ben Gamari at 2026-07-01T10:34:03-04:00
gitlab-ci: Drop vestigial references to make build system
-
62d54a53
by Ben Gamari at 2026-07-01T10:34:03-04:00
gitlab-ci: Add support for running specifying a job's testsuite ways
-
7f97ac2c
by Ben Gamari at 2026-07-01T10:34:03-04:00
gitlab-ci: Run llvm testsuite ways in llvm jobs
Addresses #25762.
-
7ea75116
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Add normalise_ddump_deriv setup function
Some tests check the result of -ddump-deriv, which may contain INLINE pragmas depending on optimization flags.
With normalise_ddump_deriv setup function, INLINE pragmas are stripped off.
-
c7a8199f
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Use -dsuppress-idinfo to make tests more robust
Previously, T18052a and T21755 were failing on 'optasm' and 'optllvm' ways because of visibility of unfoldings.
-
a12122e5
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Use a trick to keep large objects alive
Previously, T17574 and T19381 were failing on 'optasm' and 'optllvm' ways because of compiler optimizations.
Change them to use NOINLINE to prevent unwanted optimizations.
-
1a95b327
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Only run T24224 in 'normal' way
This test is a frontend-only one and breaks if optimizations are enabled.
-
8abea737
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Ignore T18118's stderr
When optimizations are enabled, the compiler emits a warning (You cannot SPECIALISE ...).
The message is not important, so ignore it.
-
9453a722
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Mark T816 and tc216 broken with optimizations
These tests are about type checking, so we should not care too much if they are broken with optimizations.
See #26952
-
0aef9ec0
by Ben Gamari at 2026-07-01T10:34:03-04:00
testsuite: ds014 is not longer broken
It now appears to pass in the ways it was marked as broken in.
Closes #14901.
-
4692d1e4
by Ben Gamari at 2026-07-01T10:34:03-04:00
testsuite: Only run stack cloning tests in the normal way
These are too dependent upon code generation specifics to pass in most
other ways.
-
c154df26
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Update options_ghc_fbyte-code
The `-fbyte-code` option used to be overriden by `-fllvm` but it is no longer true since !14872 was merged.
I updated the test to accept the new behavior.
Closes #27049
-
5d8bb7b5
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Only run T22744 in 'normal' way
This test takes a long time on optimized ways.
-
d1e74c8e
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Disable tests that use -finfo-table-map on llvm ways
Currently, -finfo-table-map does not work with -fllvm. See #26435
-
3bf38c84
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Don't run T24726 on optimized ways
If optimizations are enabled, the rewrite rule just fires and -drule-check will report nothing.
-
e4eef116
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Use -fno-unoptimized-core-for-interpreter when running LinkableUsage01/02
Optimizations for the bytecode interpreter are considered experimental, and need a flag to be enabled.
-
234a9872
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Suppress unwanted optimizations on T25284
-
99a2af2f
by ARATA Mizuki at 2026-07-01T10:34:03-04:00
testsuite: Don't run stack_big_ret with optimizations
Stack layout may change with optimizations enabled.
-
04c836df
by ARATA Mizuki at 2026-07-01T10:34:04-04:00
testsuite: Mark memo001 broken on optimized ways
See #27396
-
1a8a24f4
by ARATA Mizuki at 2026-07-01T10:34:04-04:00
testsuite: Mark syn-perf broken on optimized ways
See #27398
-
40412093
by Duncan Coutts at 2026-07-01T10:34:50-04:00
Add a test for thread scheduler fairness
It also tests that the interval timer and context switching works.
We also test that fairness is lost when the context switching interval
is too coarse for the duration of the test.
We add this test before doing surgery on the interval timer, so we have
decent coverage.
-
3f34d557
by Duncan Coutts at 2026-07-01T10:34:50-04:00
Make exported stop/startTimer no-ops, and rename internal functions
Specifically, internally rename:
stop/startTimer to pause/unpauseTimer
stop/startTicker to pause/unpauseTicker
and keep stop/startTimer as exported functions, but now as no-ops.
In the past the stop/startTicker actions were used incorrectly as if
they were synchronous, which they are not. See issue #27105. We now
document pause/unpackTicker as being async and not to be used for the
purpose of concurrency safety.
The existing stop/startTimer (note Timer not Ticker, the Timer calls the
Ticker!) are also exported from the RTS as a public API. This was
historically because the ticker used signals and it was important to
suspend the timer signel over a process fork. So these functions were
exported to be used by the process and unix libraries.
We cannot just remove the RTS exports, but we now make them no-ops, and
they can be removed from the process and unix library later. This
was already documented in a changelog.d entry no-more-timer-signal but
due to changes during the MR process the change to make stop/startTicker
into no-ops didn't make it into the earlier MR.
-
02e84e5f
by Duncan Coutts at 2026-07-01T10:34:51-04:00
Make exitTicker/exitTimer unconditionally synchronous
We never use them asynchronously, and we should never need to do so.
And update some related comments.
-
13db6a72
by Duncan Coutts at 2026-07-01T10:34:51-04:00
posix ticker: update and improve comments on (un)pause and exit
Clarify what is async vs sync.
-
43d9a07d
by Duncan Coutts at 2026-07-01T10:34:51-04:00
posix ticker: split out ppoll/select helper functions
Move the #ifdefs out of the main code body by introducing local helper
functions and types, which themselves have two implementations (with a
common API) based on ppoll or select.
This helps improve clarity/readability.
-
a5491baa
by Duncan Coutts at 2026-07-01T10:34:51-04:00
posix ticker: improve the implementation
The existing implementation supported pausing and exiting, with the
implementation of pausing reling on a mutex and condition variable.
It needed to check the pause and stop shared variables on every
iteration. It relies on ppoll or select, to wait on the timeout and also
wait on an interrupt fd. The interrupt fd was only used for prompt
exit/shutdown, and not for pausing or other notification. The pause only
needed a lock and a memory operation, but the pause was not prompt. The
resume used a lock, and signaling a cond var.
The new implementation uses a somewhat more regular design: every
notification is done by setting a shared variable and
interrupting/notifying the ticker via the fd. The ticker thread does not
need to check any shared variables on normal timer expiry, only when it
recevies notification. This may be a micro-optimisation, but the tick
occurs 100 times a second by default so any improvements in the hot path
are amplified. When the ticker thread does receive notification it can
check the various shared variables and update its local state. The
blocking relies on using ppoll/select but without a timeout. This avoids
the condition var and also allows further notifications when paused
(also used for unpausing).
This design can be extended with further notification types if needed by
using and checking further shared vars (or making existing shared vars
an enum or counter). This may be used in future for additional
notifications to the ticker thread. This will likely be used to proxy
wakeUpRts from a single handler context for example. And this approach,
avoiding mutexes, is compatible with use from signal handlers.
So overall, it's:
* slightly simpler / more regular;
* easier to extend with additional notifications;
* probably slightly more efficient (but a micro-optimisation);
* and supports calling notification from signal handlers
-
5b20821e
by Duncan Coutts at 2026-07-01T10:34:51-04:00
posix ticker: further minor local renaming for code clarity
Improve the clarity with better choice of names for several local vars
and function.
-
1f3ec5e0
by Duncan Coutts at 2026-07-01T10:34:51-04:00
win32 ticker: split out local helper functions
-
596e7307
by Duncan Coutts at 2026-07-01T10:34:51-04:00
win32 ticker: provide guarantee about concurrency and idempotency
Use a lock to ensure pause/unpause can be used concurrently. Use a
paused variable, protected by the lock, to ensure that pause and unpause
are both idempotent. This is what the portable API expects.
-
1870edd7
by Duncan Coutts at 2026-07-01T10:34:51-04:00
win32 ticker: make the initial tick be after one wait interval
There is no need to tick immediately. This is consistent with the
posix implementation.
-
7c15ab5b
by Duncan Coutts at 2026-07-01T10:34:51-04:00
ticker: remove now-unnecessary layer of enable/disable
There was an atomic variable used to block *part* of the actions of the
tick handler. This still did not make stopTimer synchronous, even for
the part of the the handle_tick actions it covered. It also added a more
expensive (sequentuially consistent) atomic operation in the hot path
for the handle_tick action, whereas our new design requires no atomic
ops at all.
Now that we have eliminate the need for synchronous stop/startTicker,
we don't need this not-quite-working-anyway atomic protocol. The new
pause/unpauseTicker is explicitly asynchronous and idempotent.
-
8585f8cb
by Duncan Coutts at 2026-07-01T10:34:51-04:00
ticker: add TODOs about issue #27250: too much being done from handle_tick
The handle_tick should not perform I/O, block, perform long-running
operations or call arbitrary user code. Unfortunately, everything to
do with the eventlog (at the moment) falls into all those categories.
-
6e381626
by Duncan Coutts at 2026-07-01T22:29:55+01:00
Adjust releaseCapability_ precondition to allow cap->running_task == NULL
There are two use cases for releaseCapability_:
1. The current Task (cap->running_task) releases the Capability.
The Capability is marked free, and if there is any work to do,
an appropriate Task is woken up.
2. There is no current task (cap->task == NULL), and thus the
Capability is idle, and we want to wake up an idle Task to animate
the Capability. This case uses always_wakeup.
Currently, the precondition for releaseCapability_ is
cap->running_task != NULL
and so the 2nd use cases have to set cap->running_task (which is then
immediately overwritten) just to satisfy the precondition. See the
use cases in sendMessage and prodCapability.
So we can relax the precondition to be:
cap->running_task != NULL || always_wakeup
so that in the always_wakeup case, we say it is ok for the
cap->running_task to be NULL.
This lets us simplify sendMessage and prodCapability. In particular it
will allow prodCapability to not need a Task parameter.
The ulterior motive for all this is that I want to be able to call
prodCapability from an OS thread that is not itself a Task, in persuit
of issue #27086: disentangle I/O managers from wakeUpRts. The most
straightforward way to wake the RTS is using prodCapability, but the
context in which we will need to do that are threads that are not Tasks.
-
89404ebc
by Duncan Coutts at 2026-07-01T22:29:55+01:00
prodCapability no longer needs to take a Task param
Now that releaseCapability_ can accept cap->running_task == NULL then it
is no longer necessary for prodCapability to require a Task.
-
4e60c5f6
by Duncan Coutts at 2026-07-01T22:29:56+01:00
Define prodOneCapability
There was an existing declaration for this in the header file, but no
definition.
Similarly, there is a declaration for prodAllCapabilities but no
definition, and we don't need it, so remove the declaration.
-
2527026f
by Duncan Coutts at 2026-07-01T22:29:56+01:00
Add a wakeUpRtsViaTicker feature to the posix ticker
It proxies a call to wakeUpRts, but crucially, this can be called from
a signal handler context. It will be used for ctl-c handling.
-
aa5a03a5
by Duncan Coutts at 2026-07-01T22:29:56+01:00
Change how wakeUpRts works
Previously it would call wakeupIOManager to get a capability to wake up
and run. This works but it entangles the I/O managers with unrelated
features: ctl-c handling and idle gc (the two features that use wakeUpRts).
The reason it used wakeupIOManager is that this action is safe to use
from a posix signal handler, since it just posts bytes to a pipe.
Otherwise the more direct approach (used e.g. by sendMessage when the
target capability is idle) is to use releaseCapability. But that uses
condition variables and mutexes, which are not safe to use from within a
signal handler.
So instead of entangling the (multiple) I/O managers with this, we make
wakeUpRts use the direct approach (using prodOneCapability). On win32
the ctl-c console handler can call wakeUpRts directly, since it is
called in a proper thread. On posix, to deal with the signal handler
problem, we make the signal handler ask the ticker thread to proxy the
call to wakeUpRts, since the ticker thread is also a proper thread.
This will allow the I/O managers to no longer be concerned with this.
This is good because there are many I/O managers (and they're
complicated), but there is (on posix) only one ticker implementation. So
this is an overall reduction in coupling and complexity.
Fixes issue #27086
-
c6d53c16
by sheaf at 2026-07-02T21:35:44-04:00
Test driver: normalise line numbers into libraries
When comparing the stdout of tests that print out callstacks, we can't
rely on the stability of exact line:column spans pointing into libraries
(e.g. ghc-internal), as any change (such as adding a comment) can change
them.
This commit addresses this by normalising away line:column in callstacks,
but only when those point into internal libraries. We don't do this in
general, as the exact span might be important to the test (e.g. for a
span within the test module itself).
Fixes #27387
-
81ee62e0
by Alan Zimmerman at 2026-07-02T21:36:33-04:00
EPA: Remove LocatedLW from MatchGroup
This is the last usage of LocatedLW / SrcSpanAnnLW
-
925959db
by Recursion Ninja at 2026-07-04T04:14:12-04:00
Decoupling 'L.H.S' from 'GHC.Hs.Doc'
* Migrated 'GHC.Hs.Doc' and 'GHC.Hs.DocString' AST defintions from 'GHC.*' namespace,
to new 'Language.Haskell.Syntax.Doc' module in the 'L.H.S' "namespace."
* Updated 'HsDocString to be TTG-parameterised as 'HsDocString pass'.
* Added 'GHC.Hs.Extension.Pass': splits 'GhcPass'/'Pass' and all 'HsDocString'
TTG instances out of 'GHC.Hs.Extension', which re-exports it unchanged
(this is backwards compatible and prevents the introduction of a boot file).
* Deleted 'GHC.Hs.Doc.hs-boot'; removed all 'L.H.S.*' imports of 'GHC.Hs.Doc'.
* Updated 'GHC.Hs.DocString' to be TTG pass-parameterised throughout; moved
'mkHsDocStringChunk'/'unpackHDSC' here (require 'GHC.Utils.Encoding').
* Split 'GHC.Rename.Doc.rnHsDoc' from 'rnHsDocIdentifiersOnly'.
* Updated parser, renamer, typechecker, HIE, and exact-print for new types.
* Added 'HsDocString' TTG instances for 'DocNameI' to 'Haddock.Types'.
* Killed the last module loop between GHC.* and LHS.*.
- Only edges from LHS.* to GHC.Data.FastString now!
Resolves #26971
-
b7e24044
by mangoiv at 2026-07-04T04:14:56-04:00
ci: retry fetching test metrics
Retry fetching test metrics to make the CI not fail if the services is
temporarily unavailable
-
4180af3f
by Zubin Duggal at 2026-07-04T04:15:38-04:00
Bump semaphore-compat submodule to 2.0.1
This versions includes some cruicial fixes for darwin
-
242d4317
by sheaf at 2026-07-04T04:16:19-04:00
Remove outdated comment in GHC.Data.ShortText
There was a long comment in GHC.Data.ShortText about a workaround that
was necessary when bootstrapping with GHC 9.2 and below. The actual
logic has since been dropped, but the comment remained. This commit
removes the vestigial comment.
-
9b714c4c
by Zubin Duggal at 2026-07-05T09:40:36+05:30
CorePrep: Don't speculatively evaluate bindings that we have already discovered to be absent
In #25924, we segfault because speculation forces a projection out of a RUBBISH dictionary
(which we generated because it absent).
Solution: Don't speculate on bindings we already know are absent.
Fixes 25924
-
4a59b3ee
by Zubin Duggal at 2026-07-05T09:40:36+05:30
Don't make absent fillers for terminating types
In #25924 we discovered that we could speculatively evaluate an absent filler
for a dictionary, and project a field (a superclass selector) out of it,
resulting in segfaults.
Solution: Never make an absent filler or rubbish literal for a terminating type
like a dictionary. mkAbsentFiller returns Nothing for isTerminatingType, so
worker/wrapper and the specialiser keep the real argument instead.
Some small metric decreases because we do a little less work in the
simplifier now.
Metric Decrease:
T9872a
T9872b
T9872c
TcPlugin_RewritePerf
-
383ddcd4
by Alan Zimmerman at 2026-07-06T07:08:16-04:00
EPA: Move the 'where' annotation for PatSynBind
This allows us to move it out of the MatchGroup exact print annotation
too
-
66d1a5d5
by fendor at 2026-07-07T16:57:56-04:00
Add 'backendInfoTableMapValidity' backend predicate
Check whether the backend supports the `-finfo-table-map` flag and
ignore it otherwise.
Improve by-design documentation of `backendCodeOutput`.
`Backend` is **abstract by design**. Make this clearer in
`backendCodeOutput` which is incorrectly being used as a proxy for
`Backend`.
Instead, define the desired property predicates in GHC.Driver.Backend
In the process, make `backendCodeOutput` total.
-
74f1071d
by fendor at 2026-07-07T16:57:56-04:00
Add failing test for `-finfo-table-map` and bytecode backend
If you compile a module using the bytecode backend, with
-finfo-table-map, then the info table map doesn't get populated for the
module.
This is because the -finfo-table-map code path is implemented mostly in
the StgToCmm phase which isn't run when creating bytecode.
Ticket #27039
-
28d63bca
by mangoiv at 2026-07-07T16:59:16-04:00
ci: don't fail nightly if there have been no changes that night
Fixes #27127
-
4ebfc478
by Rodrigo Mesquita at 2026-07-08T04:47:53-04:00
ttg: Using ShortText over FastString in the AST
To make the AST independent of GHC, this commit replaces usages of
`FastString` with `HText` in the AST, killing the last edge from
Language.Haskell.* to GHC.* modules.
Even though we /do/ want to use FastStrings in general -- critically in
Names or Ids -- there is no particular reason for the FastStrings that
occur in the AST proper to be FastStrings. Strings in the AST are
typically unique and don't benefit particularly from being interned
FastStrings with Uniques for fast comparison.
`HText` is a type synonym for `ShortText` which uses GHC's Modified
UTF-8 encoding exclusively.
Modified UTF-8 must be used to represent the Haskell AST because the
Haskell Report allows surrogate code points. `Data.Text.Text` functions
use Standard UTF-8 which replace surrogates with a placeholder value,
thus `Data.Text.Text` is unsuitable for AST strings. See the
`Language.Haskell.Syntax.Text` module header for more details.
Final progress towards #21592
Closes #21628
-
d910b353
by Simon Peyton Jones at 2026-07-08T04:48:36-04:00
Update equality-type documenation in GHC.Builtin.Types.Prim
Fix #27466
-
b2530542
by Simon Peyton Jones at 2026-07-08T04:48:36-04:00
Honour -dsuppress-coercions in GHC.Core.TyCo.pprCo
Fixes #27467
-
9a73179a
by Facundo Domínguez at 2026-07-08T04:49:26-04:00
Add item to MR checklist asking to squash fixup commits after approval
The checklist has an item that reads
All commits are either individually buildable or squashed.
This item could be checked immediately after sending the merge request
though. If reviewers ask for amends later on, and the author amends
the merge request, there was no item that would remind the contributors
to squash the fixup commits before landing.
This commit adds a new item
After all approvals and before landing: all fixup commits are squashed with their originating commits.
which should be harder to mark as done before approvals have been given.
-
ed09895d
by Andreas Klebinger at 2026-07-08T16:53:27-04:00
Fix a profiling race condition resulting in segfaults.
StgToCmm: Don't assume tagged FUN closures in closureCodeBody.
When entering a closure the self/node pointer might not be tagged in
some situations when a thunk is evaluated by multiple threads.
So we most AND away the tag bits rather than subtracting an expected tag.
Apply.cmm: Fix a race condition occuring when a thunk is mutated during GC.
In stg_ap_0_fast when might need to run GC before entering a thunk. If this happens
another thread or the GC itself might mutate the closure making entering it no longer
valid. We now check for this.
Add test and changelog for #27123 fixes.
-
67c03eb2
by Cheng Shao at 2026-07-08T16:54:09-04:00
ghc-heap: fix invalid srtlen returned by peekItbl when no-TNTC
This patch fixes the no-TNTC code path of `peekItbl` so that it looks
at the right memory address when reading the `srt` field from the
`StgInfoTable_` struct. Also adds a `T27465` regression test that
reproduces the bug on no-TNTC builds before the fix. Fixes #27465.
Co-authored-by: Codex <codex@openai.com>
-
2ecabb4f
by Zubin Duggal at 2026-07-09T09:23:25-04:00
hadrian: binary-dist-dir should not be the default target
Revert behaviour to pre 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
In 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2, we applied the following behaviour change:
```
hadrian: Build stage 2 cross compilers
...
* hadrian: Make binary-dist-dir the default build target. This allows us
to have the logic in one place about which libraries/stages to build
with cross compilers. Fixes #24192
```
This is a major regression to development experience, a plain hadrian/build
--freeze1 now takes ages because we rebuild all docs (which need to go in the
binary dist dir).
`binary-dist-dir` is the wrong default target for regular GHC development work
Fixes #27445
-
e16388e3
by Zubin Duggal at 2026-07-09T09:23:25-04:00
.gitignore: Add the hadrian system.config introduced by commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
Since
commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
Author: Matthew Pickering <matthewtpickering@gmail.com>
Date: Thu Dec 21 16:17:41 2023 +0000
hadrian: Build stage 2 cross compilers
./configure produces /hadrian/cfg/system.config.{host,target}
Add these to .gitignore
-
7e8abf41
by Alan Zimmerman at 2026-07-09T09:24:12-04:00
EPA: Replace AnnListItem with simply [TrailingAnn]
Remove the unnecessary wrapper around a single field.
-
29032f17
by Zubin Duggal at 2026-07-09T09:24:58-04:00
testsuite: Keep real reason for fragile test failures
-
c34e03a7
by Zubin Duggal at 2026-07-09T09:24:58-04:00
testsuite: Fall back to the failure reason for empty JUnit bodies
-
409d40f0
by Zubin Duggal at 2026-07-09T09:24:58-04:00
testsuite: Show output diffs in JUnit output
Also refactor compare_outputs to return essentially a `Maybe Diff`
(`CompareOutput`) instead of a bool, but more pythonic. This
allows us to pass the diff through nice.
-
06fee1ab
by Zubin Duggal at 2026-07-09T09:24:58-04:00
perf notes: include stat deviation and acceptance window in notes so they show up in gitlab
-
57c0f32c
by mangoiv at 2026-07-10T11:08:38-04:00
driver: enable -finter-module-far-jumps by default
this fixes a compatibility bug with certain binutils/gcc versions where
we were seeing jump offset overflow errors.
This commit can probably reverted if we stop supporting the problematic
binutils/gcc verions (2.44 and 14.2, respectively)
Reolves #26994
-
4396a6f2
by Andrea Vezzosi at 2026-07-10T11:09:25-04:00
[Fix #27287] preserve ModBreaks in ModIface
-
b76d9b9e
by Cheng Shao at 2026-07-13T08:09:03+00:00
bindist: Fix make install -j race condition on macos/freebsd
This patch fixes make install -j race condition on macos/freebsd. BSD
install fails with EEXIST when multiple install processes concurrently
create the same prefix directory. So we add an `install_dirs`
prerequisite job that sequentially creates the directories for
subsequent jobs to work with. Fixes #27499.
Co-authored-by: Codex <codex@openai.com>
-
2fa76a94
by Cheng Shao at 2026-07-13T08:09:03+00:00
ci: run bindist make install with -j
This patch makes the ci scripts run `make install` with `-j` to reduce
wall clock time when installing the bindist, see related issue for
benchmark numbers. This only affects ghc ci logic, the user-facing
default is up to distributors and is still `-j1`. Closes #27029.