-
62899117
by Florian Ragwitz at 2025-08-13T21:01:34-04:00
Extend record-selector usage ticking to all binds using a record field
This extends the previous handling of ticking for RecordWildCards and
NamedFieldPuns to all var bindings that involve record selectors.
Note that certain patterns such as `Foo{foo = 42}` will currently not tick the
`foo` selector, as ticking is triggered by `HsVar`s.
Closes #26191.
-
b37b3af7
by Florian Ragwitz at 2025-08-13T21:01:34-04:00
Add release notes for 9.16.1 and move description of latest HPC changes there.
-
a5e4b7d9
by Ben Gamari at 2025-08-13T21:02:18-04:00
rts: Clarify rationale for undefined atomic wrappers
Since c06e3f46d24ef69f3a3d794f5f604cb8c2a40cbc the RTS has declared
various atomic operation wrappers defined by ghc-internal as undefined.
While the rationale for this isn't clear from the commit message, I
believe that this is necessary due to the unregisterised backend.
Specifically, the code generator will reference these symbols when
compiling RTS Cmm sources.
-
50842f83
by Andreas Klebinger at 2025-08-13T21:03:01-04:00
Make unexpected LLVM versions a warning rather than an error.
Typically a newer LLVM version *will* work so erroring out if
a user uses a newer LLVM version is too aggressive.
Fixes #25915
-
c91e2650
by fendor at 2025-08-13T21:03:43-04:00
Store `StackTrace` and `StackSnapshot` in `Backtraces`
Instead of decoding the stack traces when collecting the `Backtraces`,
defer this decoding until actually showing the `Backtraces`.
This allows users to customise how `Backtraces` are displayed by
using a custom implementation of `displayExceptionWithInfo`, overwriting
the default implementation for `Backtraces` (`displayBacktraces`).
-
dee28cdd
by fendor at 2025-08-13T21:03:43-04:00
Allow users to customise the collection of exception annotations
Add a global `CollectExceptionAnnotationMechanism` which determines how
`ExceptionAnnotation`s are collected upon throwing an `Exception`.
This API is exposed via `ghc-experimental`.
By overriding how we collect `Backtraces`, we can control how the
`Backtraces` are displayed to the user by newtyping `Backtraces` and
giving a different instance for `ExceptionAnnotation`.
A concrete use-case for this feature is allowing us to experiment with
alternative stack decoders, without having to modify `base`, which take
additional information from the stack frames.
This commit does not modify how `Backtraces` are currently
collected or displayed.
-
66024722
by fendor at 2025-08-13T21:03:43-04:00
Expose Backtraces internals from ghc-experimental
Additionally, expose the same API `base:Control.Exception.Backtrace`
to make it easier to use as a drop-in replacement.
-
a766286f
by Reed Mullanix at 2025-08-13T21:04:36-04:00
ghc-internal: Fix naturalAndNot for NB/NS case
When the first argument to `naturalAndNot` is larger than a `Word` and the second is `Word`-sized, `naturalAndNot` will truncate the
result:
```
>>> naturalAndNot ((2 ^ 65) .|. (2 ^ 3)) (2 ^ 3)
0
```
In contrast, `naturalAndNot` does not truncate when both arguments are larger than a `Word`, so this appears to be a bug.
Luckily, the fix is pretty easy: we just need to call `bigNatAndNotWord#` instead of truncating.
Fixes #26230
-
3506fa7d
by Simon Hengel at 2025-08-13T21:05:18-04:00
Report -pgms as a deprecated flag
(instead of reporting an unspecific warning)
Before:
on the commandline: warning:
Object splitting was removed in GHC 8.8
After:
on the commandline: warning: [GHC-53692] [-Wdeprecated-flags]
-pgms is deprecated: Object splitting was removed in GHC 8.8
-
51c701fe
by Zubin Duggal at 2025-08-13T21:06:00-04:00
testsuite: Be more permissive when filtering out GNU_PROPERTY_TYPE linker warnings
The warning text is slightly different with ld.bfd.
Fixes #26249
-
dfe6f464
by Simon Hengel at 2025-08-13T21:06:43-04:00
Refactoring: Don't misuse `MCDiagnostic` for lint messages
`MCDiagnostic` is meant to be used for compiler diagnostics.
Any code that creates `MCDiagnostic` directly, without going through
`GHC.Driver.Errors.printMessage`, side steps `-fdiagnostics-as-json`
(see e.g. !14475, !14492 !14548).
To avoid this in the future I want to control more narrowly who creates
`MCDiagnostic` (see #24113).
Some parts of the compiler use `MCDiagnostic` purely for formatting
purposes, without creating any real compiler diagnostics. This change
introduces a helper function, `formatDiagnostic`, that can be used in
such cases instead of constructing `MCDiagnostic`.
-
a8b2fbae
by Teo Camarasu at 2025-08-13T21:07:24-04:00
rts: ensure MessageBlackHole.link is always a valid closure
We turn a MessageBlackHole into an StgInd in wakeBlockingQueue().
Therefore it's important that the link field, which becomes the
indirection field, always points to a valid closure.
It's unclear whether it's currently possible for the previous behaviour
to lead to a crash, but it's good to be consistent about this invariant nonetheless.
Co-authored-by: Andreas Klebinger <klebinger.andreas@gmx.at>
-
4021181e
by Teo Camarasu at 2025-08-13T21:07:24-04:00
rts: spin if we see a WHITEHOLE in messageBlackHole
When a BLACKHOLE gets cancelled in raiseAsync, we indirect to a THUNK.
GC can then shortcut this, replacing our BLACKHOLE with a fresh THUNK.
This THUNK is not guaranteed to have a valid indirectee field.
If at the same time, a message intended for the previous BLACKHOLE is
processed and concurrently we BLACKHOLE the THUNK, thus temporarily
turning it into a WHITEHOLE, we can get a segfault, since we look at the
undefined indirectee field of the THUNK
The fix is simple: spin if we see a WHITEHOLE, and it will soon be
replaced with a valid BLACKHOLE.
Resolves #26205
-
1107af89
by Oleg Grenrus at 2025-08-13T21:08:06-04:00
Allow defining HasField instances for naughty fields
Resolves #26295
... as HasField solver doesn't solve for fields with "naughty"
selectors, we could as well allow defining HasField instances for these
fields.
-
020e7587
by Sylvain Henry at 2025-08-13T21:09:00-04:00
Fix Data.List unqualified import warning
-
fd811ded
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Make injecting implicit bindings into its own pass
Previously we were injecting "impliicit bindings" (data constructor
worker and wrappers etc)
- both at the end of CoreTidy,
- and at the start of CorePrep
This is unpleasant and confusing. This patch puts it it its own pass,
addImplicitBinds, which runs between the two.
The function `GHC.CoreToStg.AddImplicitBinds.addImplicitBinds` now takes /all/
TyCons, not just the ones for algebraic data types. That change ripples
through to
- corePrepPgm
- doCodeGen
- byteCodeGen
All take [TyCon] which includes all TyCons
-
9bd7fcc5
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Implement unary classes
The big change is described exhaustively in
Note [Unary class magic] in GHC.Core.TyCon
Other changes
* We never unbox class dictionaries in worker/wrapper. This has been true for some
time now, but the logic is now centralised in functions in
GHC.Core.Opt.WorkWrap.Utils, namely `canUnboxTyCon`, and `canUnboxArg`
See Note [Do not unbox class dictionaries] in GHC.Core.Opt.WorkWrap.Utils.
* Refactored the `notWorthFloating` logic in GHc.Core.Opt.SetLevels.
I can't remember if I actually changed any behaviour here, but if so it's
only in a corner cases.
* Fixed a bug in `GHC.Core.TyCon.isEnumerationTyCon`, which was wrongly returning
True for (##).
* Remove redundant Role argument to `liftCoSubstWithEx`. It was always
Representational.
* I refactored evidence generation in the constraint solver:
* Made GHC.Tc.Types.Evidence contain better abstactions for evidence
generation.
* I deleted the file `GHC.Tc.Types.EvTerm` and merged its (small) contents
elsewhere. It wasn't paying its way.
* Made evidence for implicit parameters go via a proper abstraction.
* Fix inlineBoringOk; see (IB6) in Note [inlineBoringOk]
This fixes a slowdown in `countdownEffectfulDynLocal`
in the `effectful` library.
Smaller things
* Rename `isDataTyCon` to `isBoxedDataTyCon`.
* GHC.Core.Corecion.liftCoSubstWithEx was only called with Representational role,
so I baked that into the function and removed the argument.
* Get rid of `GHC.Core.TyCon.tyConSingleAlgDataCon_maybe` in favour of calling
`not isNewTyCon` at the call sites; more explicit.
* Refatored `GHC.Core.TyCon.isInjectiveTyCon`; but I don't think I changed its
behaviour
* Moved `decomposeIPPred` to GHC.Core.Predicate
Compile time performance changes:
geo. mean +0.1%
minimum -6.8%
maximum +14.4%
The +14% one is in T21839c, where it seems that a bit more inlining
is taking place. That seems acceptable; and the average change is small
Metric Decrease:
LargeRecord
T12227
T12707
T16577
T21839r
T5642
Metric Increase:
T15164
T21839c
T3294
T5321FD
T5321Fun
WWRec
-
b4075d71
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Slight improvement to pre/postInlineUnconditionally
Avoids an extra simplifier iteration
-
9e443596
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Fix a long-standing assertion error in normSplitTyConApp_maybe
-
91310ad0
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Add comment to coercion optimiser
-
5b841d82
by Teo Camarasu at 2025-08-14T17:57:56-04:00
template-haskell: move some identifiers from ghc-internal to template-haskell
These identifiers are not used internally by the compiler. Therefore we
have no reason for them to be in ghc-internal.
By moving them to template-haskell, we benefit from it being easier to
change them and we avoid having to build them in stage0.
Resolves #26048
-
33e2c7e5
by Teo Camarasu at 2025-08-14T17:57:56-04:00
template-haskell: transfer $infix note to public module
This Haddock note should be in the public facing module
-
2a411fc4
by Sylvain Henry at 2025-08-14T17:59:09-04:00
JS: export HEAP8 symbol (#26290)
Newer Emscripten requires this.
-
248f78ca
by Ben Gamari at 2025-08-14T17:59:51-04:00
users-guide: Drop the THREAD_RUNNABLE event
As of f361281c89fbce42865d8b8b27b0957205366186 it is no longer emitted.
-
706d33e3
by Recursion Ninja at 2025-08-15T04:12:12-04:00
Resolving issues #20645 and #26109
Correctly sign extending and casting smaller bit width types for LLVM operations:
- bitReverse8#
- bitReverse16#
- bitReverse32#
- byteSwap16#
- byteSwap32#
- pdep8#
- pdep16#
- pext8#
- pext16#
-
1cdc6f46
by Cheng Shao at 2025-08-15T04:12:56-04:00
hadrian: enforce have_llvm=False for wasm32/js
This patch fixes hadrian to always pass have_llvm=False to the
testsuite driver for wasm32/js targets. These targets don't really
support the LLVM backend, and the optllvm test way doesn't work. We
used to special-case wasm32/js to avoid auto-adding optllvm way in
testsuite/config/ghc, but this is still problematic if someone writes
a new LLVM-related test and uses something like when(have_llvm(),
extra_ways(["optllvm"])). So better just enforce have_llvm=False for
these targets here.
-
ca03226d
by Ben Gamari at 2025-08-18T13:43:20+00:00
configure: Allow use of LLVM 20
-
783cd7d6
by Cheng Shao at 2025-08-18T20:13:14-04:00
compiler: use `UniqMap` instead of `Map` for `BCEnv` in bytecode compiler
The bytecode compiler maintains a `BCEnv` which was previously `Map Id
StackDepth`. Given `Id` is `Uniquable`, we might as well use `UniqMap`
here as a more efficient data structure, hence this patch.
Co-authored-by: Codex <codex@openai.com>
-
58e46da9
by fendor at 2025-08-18T20:13:56-04:00
rts: Strip lower three bits when hashing Word instead of lower eight bits
-
45dbfa23
by Cheng Shao at 2025-08-18T20:14:37-04:00
libffi: update to 3.5.2
Bumps libffi submodule.
-
54be78ef
by Ben Gamari at 2025-08-19T16:28:05-04:00
testsuite: Fix T20006b
This test is supposed to fail for non-threaded ways yet it
was previously marked as only failing in `normal`.
Fix this.
-
f4bac607
by Simon Peyton Jones at 2025-08-19T16:28:47-04:00
Take yet more care with reporting redundant constraints
This small patch fixes #25992, which relates to reporting redundant
constraints on default-method declarations.
See (TRC5) in Note [Tracking redundant constraints]
-
ab130fec
by fendor at 2025-08-19T16:29:29-04:00
Bump dependencies of hadrian-bootstrap-gen to use GHC 9.6.7
-
6d02ac6f
by fendor at 2025-08-19T16:29:29-04:00
Bump required GHC version for test-bootstrap jobs to 9.10.1
Include test-bootstrap job for GHC 9.12.2.
Update hadrian bootstrap plans use GHC 9.10 and 9.12
Remove older GHC bootstrap configurations.
We require at least GHC 9.10.1 to build GHC.
Adds plans for:
* 9.10.1
* 9.10.2
* 9.12.1
* 9.12.2
-
9e857171
by Brandon Chinn at 2025-08-20T11:47:46-04:00
Don't warn unused-imports with used generated imports
Fixes #21730
* The old notion of "implicit" import has been renamed to "generated". See Note [Generated imports] in GHC.Hs.ImpExp.
* ImportMap now keeps track of generated and user-written imports separately. This avoids the fake SrcSpan we used to give the implicit Prelude import, and the hack that went with it.
* -ddump-minimal-imports now considers generated imports (but still only
warns on + prints user-written imports)
* bestImport considers generated imports to take priority over user-written imports.
-
9fb3bad4
by Ben Gamari at 2025-08-20T11:48:31-04:00
mailmap: Use ben@well-typed.com more liberally
Nearly all of this work was done while working for Well-Typed.
-
774fec37
by Ben Gamari at 2025-08-20T11:49:15-04:00
Add primop to annotate the call stack with arbitrary data
We introduce a new primop `annotateStack#` which allows us to push
arbitrary data onto the call-stack.
This allows us to extract the data later when decoding the stack, for
example when an exception is thrown, showing more information to the
user without having to annotate the full call-stack with `HasCallStack`
constraints.
A new stack frame value is introduced `AnnFrame`, which consists of
nothing but a generic payload.
The primop has a small wrapper API that allows users to annotate their
call-stack in programs.
There is a pure API and an IO-based one. The former is a little bit
dubious, as it affects the evaluation of a program, so use with care.
The latter is "safe", as it doesn't change the evaluation of the
program.
The stack annotation mechanism is similarly implemented to the
`ExceptionAnnotation` and `Exception`, there is a typeclass to indicate
something can be pushed onto the call-stack and all values are wrapped
in the existential `SomeStackAnnotation`, which recover the type of the
annotation payload.
There is currently no builtin way to show the stack annotations when
`Backtraces` are displayed (i.e., when showing stack traces to the user),
which we will address in a follow-up MR.
-------------------------
Metric Increase:
ghc_experimental_so
-------------------------
We increase the size of the package, so this is not unreasonable.
Co-Authored-By: fendor <fendor@posteo.de>
Co-Authored-By: Ben Gamari <bgamari.foss@gmail.com>
-
fdfa3892
by Ben Gamari at 2025-08-20T11:49:57-04:00
testsuite: Add regression test for #24606
-
39b2e382
by Cheng Shao at 2025-08-20T11:50:40-04:00
compiler: only use `Name` instead of `Id` in `SptEntry`
As a part of #26298, this patch refactors `SptEntry` to only carry a
`Name` instead of `Id`: we do not care about extra information like
caffyness or type at all in any static pointer related codegen logic.
This is necessary to make `SptEntry` serializable, as a part of the
grand plan of serializable bytecode.
Co-authored-by: Codex <codex@openai.com>
-
276f8ea8
by Vekhir -- at 2025-08-20T11:51:35-04:00
Bump Cabal dependency
-
0b9c7437
by Zubin Duggal at 2025-08-20T11:52:18-04:00
ci: Teach ci.sh to fetch FreeBSD artifacts from ghcup unofficial bindists and bootstrap compiler on FreeBSD to 9.10.1
Also refactor fetch_ghc logic in ci.sh, renaming the GHC_VERSION enviorment configuration variable to FETCH_GHC_VERSION,
making it clear that it is intended for use on platforms like Windows and FreeBSD where we don't want to use the GHC
excecutable from the platform environment and instead need to download and install GHC-$FETCH_GHC_VERSION from a release
bindist.
Fixes #26296
-
b2914797
by Cheng Shao at 2025-08-20T11:53:00-04:00
driver: use UniqSet for hiddenModules in DynFlags/FinderOpts
This patch replaces Set ModuleName with UniqSet ModuleName in
DynFlags.hiddenModules and FinderOpts.finder_hiddenModules for
improved efficiency.
Co-authored-by: Codex <codex@openai.com>
-
0335d899
by Cheng Shao at 2025-08-20T11:53:00-04:00
driver: use UniqMap ModuleName in the finder
This patch replaces Map ModuleName with UniqMap ModuleName in the
finder for improved efficiency.
Co-authored-by: Codex <codex@openai.com>
-
91f4faaa
by Cheng Shao at 2025-08-20T11:53:43-04:00
configure: check python3 version and require minimal 3.7
Since !9515, the testsuite driver requires python3 version to be at
least 3.7, though this has never been checked by configure logic. This
patch implements the version check. Fixes #23234.
Co-authored-by: Codex <codex@openai.com>
-
df4ee9b4
by Cheng Shao at 2025-08-20T11:54:25-04:00
compiler: use zero cost coerce in GHC.CmmToAsm.CFG.loopInfo
This patch refactors GHC.CmmToAsm.CFG.loopInfo to use zero cost coerce
and thus addresses the TODO. For coerce to work, constructors of
Label/LabelMap/LabelSet from GHC.Cmm.Dataflow.Label are exposed,
though I believe it's a worthy tradeoff to avoid unnecessary runtime
cost without using unsafeCoerce, since the latter could be a landmine
for future refactoring.
Co-authored-by: Codex <codex@openai.com>
-
ccda188d
by Simon Peyton Jones at 2025-08-20T11:55:07-04:00
Start with empty inerts in shortcut solving
When short-cut solving we were starting with an inert set that had
unsolved Wanteds. This caused an infinite loop (#26314), because a
typechecker plugin kept being given that unsolved Wanted.
It's better just to start with an empty inert set
-
c8882ed7
by Ben Gamari at 2025-08-20T11:55:49-04:00
configure: Bump minimal bootstrap GHC version to 9.8
-
f0a19d74
by fendor at 2025-08-20T19:55:00-04:00
Remove deprecated functions from the ghci package
-
ebeb991b
by fendor at 2025-08-20T19:55:00-04:00
base: Remove unstable heap representation details from GHC.Exts
-
e368e247
by Rodrigo Mesquita at 2025-08-20T19:55:42-04:00
bytecode: Use 32bits for breakpoint index
Fixes #26325
-
42724462
by Simon Hengel at 2025-08-21T17:52:11-04:00
Serialize wired-in names as external names when creating HIE files
Note that the domain of de-serialized names stays the same.
Specifically, for known-key names, before `lookupKnownKeyName` was used,
while now this is handled by `lookupOrigNameCache` which captures the
same range provided that the OrigNameCache has been initialized with
`knownKeyNames` (which is the case by default).
(fixes #26238)
-
6a43f8ec
by Cheng Shao at 2025-08-21T17:52:52-04:00
compiler: fix closure C type in SPT init code
This patch fixes the closure C type in SPT init code to StgClosure,
instead of the previously incorrect StgPtr. Having an incorrect C type
makes SPT init code not compatible with other foreign stub generation
logic, which may also emit their own extern declarations for the same
closure symbols and thus will clash with the incorrect prototypes in
SPT init code.
-
5b5d9d47
by Ben Gamari at 2025-08-25T14:29:35-04:00
Revert "STM: don't create a transaction in the rhs of catchRetry# (#26028)"
This reverts commit 0a5836891ca29836a24c306d2a364c2e4b5377fd
-
10f06163
by Cheng Shao at 2025-08-25T14:30:16-04:00
wasm: ensure setKeepCAFs() is called in ghci
This patch is a critical bugfix for #26106, see comment and linked
issue for details.
-
bedc1004
by Cheng Shao at 2025-08-26T09:31:18-04:00
compiler: use zero cost coerce in hoopl setElems/mapToList
This patch is a follow-up of !14680 and changes setElems/mapToList in
GHC/Cmm/Dataflow/Label to use coerce instead of mapping mkHooplLabel
over the keys.
-
13250d97
by Ryan Scott at 2025-08-26T09:31:59-04:00
Reject infix promoted data constructors without DataKinds
In the rename, make sure to apply the same `DataKinds` checks for both
`HsTyVar` (for prefix promoted data constructors) and `HsOpTy` (for infix
promoted data constructors) alike.
Fixes #26318.
-
37655c46
by Teo Camarasu at 2025-08-26T15:24:51-04:00
tests: disable T22859 under LLVM
This test was failing under the LLVM backend since the allocations
differ from the NCG.
Resolves #26282
-
2cbba9d6
by Teo Camarasu at 2025-08-26T15:25:33-04:00
base-exports: update version numbers
As the version of the compiler has been bumped, a lot of the embedded
version numbers will need to be updated if we ever run this test with
`--test-accept` so let's just update them now, and keep future diffs
clean.
-
f9f2ffcf
by Alexandre Esteves at 2025-08-27T07:19:14-04:00
Import new name for 'utimbuf' on windows to fix #26337
Fixes an `-Wincompatible-pointer-types` instance that turns into an error on
recent toolchains and surfaced as such on nixpkgs when doing linux->ucrt cross.
This long-standing warning has been present at least since 9.4:
```
C:\GitLabRunner\builds\0\1709189\tmp\ghc16652_0\ghc_4.c:26:115: error:
warning: incompatible pointer types passing 'struct utimbuf *' to parameter of type 'struct _utimbuf *' [-Wincompatible-pointer-types]
|
26 | HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);}
| ^
HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);}
^~
C:\GitLabRunner\builds\0\1709189\_build\stage0\lib\..\..\mingw\x86_64-w64-mingw32\include\sys\utime.h:109:72: error:
note: passing argument to parameter '_Utimbuf' here
|
109 | __CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) {
| ^
__CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) {
```
-
ae89f000
by Hassan Al-Awwadi at 2025-08-27T07:19:56-04:00
Adds the fucnction addDependentDirectory to Q, resolving issue #26148.
This function adds a new directory to the list of things a module depends upon. That means that when the contents of the directory change, the recompilation checker will notice this and the module will be recompiled. Documentation has also been added for addDependentFunction and addDependentDirectory in the user guide.
-
00478944
by Simon Peyton Jones at 2025-08-27T16:48:30+01:00
Comments only
-
a7884589
by Simon Peyton Jones at 2025-08-28T11:08:23+01:00
Type-family occurs check in unification
The occurs check in `GHC.Core.Unify.uVarOrFam` was inadequate in dealing
with type families.
Better now. See Note [The occurs check in the Core unifier].
As I did this I realised that the whole apartness thing is trickier than I
thought: see the new Note [Shortcomings of the apartness test]
-
8adfc222
by sheaf at 2025-08-28T19:47:17-04:00
Fix orientation in HsWrapper composition (<.>)
This commit fixes the order in which WpCast HsWrappers are composed,
fixing a bug introduced in commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1.
Fixes #26350
-
eb2ab1e2
by Oleg Grenrus at 2025-08-29T11:00:53-04:00
Generalise thNameToGhcName by adding HasHscEnv
There were multiple single monad-specific `getHscEnv` across codebase.
HasHscEnv is modelled on HasDynFlags.
My first idea was to simply add thNameToGhcNameHsc and
thNameToGhcNameTc, but those would been exactly the same
as thNameToGhcName already.
Also add an usage example to thNameToGhcName and mention that it's
recommended way of looking up names in GHC plugins
-
2d575a7f
by fendor at 2025-08-29T11:01:36-04:00
configure: Bump minimal bootstrap GHC version to 9.10
-
716274a5
by Simon Peyton Jones at 2025-08-29T17:27:12-04:00
Fix deep subsumption again
This commit fixed #26255:
commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1
Author: sheaf <sam.derbyshire@gmail.com>
Date: Mon Aug 11 15:50:47 2025 +0200
Improve deep subsumption
This commit improves the DeepSubsumption sub-typing implementation
in GHC.Tc.Utils.Unify.tc_sub_type_deep by being less eager to fall back
to unification.
But alas it still wasn't quite right for view patterns: #26331
This MR does a generalisation to fix it. A bit of a sledgehammer to crack
a nut, but nice.
* Add a field `ir_inst :: InferInstFlag` to `InferResult`, where
```
data InferInstFlag = IIF_Sigma | IIF_ShallowRho | IIF_DeepRho
```
* The flag says exactly how much `fillInferResult` should instantiate
before filling the hole.
* We can also use this to replace the previous very ad-hoc `tcInferSigma`
that was used to implement GHCi's `:type` command.
-
27206c5e
by sheaf at 2025-08-29T17:28:14-04:00
Back-compat for TH SpecialiseP data-con of Pragma
This commit improves the backwards-compatibility story for the
SpecialiseP constructor of the Template Haskell 'Pragma' datatype.
Instead of keeping the constructor but deprecating it, this commit makes
it into a bundled pattern synonym of the Pragma datatype. We no longer
deprecate it; it's useful for handling old-form specialise pragmas.
-
26dbcf61
by fendor at 2025-08-30T05:10:08-04:00
Move stack decoding logic from ghc-heap to ghc-internal
The stack decoding logic in `ghc-heap` is more sophisticated than the one
currently employed in `CloneStack`. We want to use the stack decoding
implementation from `ghc-heap` in `base`.
We cannot simply depend on `ghc-heap` in `base` due do bootstrapping
issues.
Thus, we move the code that is necessary to implement stack decoding to
`ghc-internal`. This is the right location, as we don't want to add a
new API to `base`.
Moving the stack decoding logic and re-exposing it in ghc-heap is
insufficient, though, as we have a dependency cycle between.
* ghc-heap depends on stage1:ghc-internal
* stage0:ghc depends on stage0:ghc-heap
To fix this, we remove ghc-heap from the set of `stage0` dependencies.
This is not entirely straight-forward, as a couple of boot dependencies,
such as `ghci` depend on `ghc-heap`.
Luckily, the boot compiler of GHC is now >=9.10, so we can migrate `ghci`
to use `ghc-internal` instead of `ghc-heap`, which already exports the
relevant modules.
However, we cannot 100% remove ghc's dependency on `ghc-heap`, since
when we compile `stage0:ghc`, `stage1:ghc-internal` is not yet
available.
Thus, when we compile with the boot-compiler, we still depend on an
older version of `ghc-heap`, and only use the modules from `ghc-internal`,
if the `ghc-internal` version is recent enough.
-------------------------
Metric Increase:
T24602_perf_size
T25046_perf_size_gzip
T25046_perf_size_unicode
T25046_perf_size_unicode_gzip
size_hello_artifact
size_hello_artifact_gzip
size_hello_unicode
size_hello_unicode_gzip
-------------------------
These metric increases are unfortunate, they are most likely caused by
the larger (literally in terms of lines of code) stack decoder implementation
that are now linked into hello-word binaries.
On linux, it is almost a 10% increase, which is considerable.
-
bd80bb70
by fendor at 2025-08-30T05:10:08-04:00
Implement `decode` in terms of `decodeStackWithIpe`
Uses the more efficient stack decoder implementation.
-
24441165
by fendor at 2025-08-30T05:10:08-04:00
Remove stg_decodeStackzh
-
fb9cc882
by Simon Peyton Jones at 2025-08-30T05:10:51-04:00
Fix a long standing bug in the coercion optimiser
We were mis-optimising ForAllCo, leading to #26345
Part of the poblem was the tricky tower of abstractions leading to
the dreadful
GHC.Core.TyCo.Subst.substForAllCoTyVarBndrUsing
This function was serving two masters: regular substitution, but also
coercion optimsation. So tricky was it that it did so wrong.
In this MR I locate all the fancy footwork for coercion optimisation
in GHC.Core.Coercion.Opt, where it belongs. That leaves substitution
free to be much simpler.
-
01387c66
by Luite Stegeman at 2025-08-31T12:36:39+02:00
Support larger unboxed sums
Change known constructor encoding for sums in interfaces to use
11 bits for both the arity and the alternative (up from 8 and 6,
respectively)
-
b606b177
by Luite Stegeman at 2025-08-31T12:36:39+02:00
Use slots smaller than word as tag for smaller unboxed sums
This packs unboxed sums more efficiently by allowing
Word8, Word16 and Word32 for the tag field if the number of
constructors is small enough
-
02ab9cf4
by Luite Stegeman at 2025-08-31T12:36:39+02:00
reduce compile time/memory for testcase