-
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
-
866b8060
by Rodrigo Mesquita at 2026-04-14T14:13:27+01:00
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
-
86a28284
by Rodrigo Mesquita at 2026-04-14T14:13:27+01:00
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