-
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
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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
-
313e31eb
by Wolfgang Jeltsch at 2026-04-29T16:59:41+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.
Resolves #27055.
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>