-
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
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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`.
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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
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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.
-
8e82a065
by Cheng Shao at 2025-08-19T18:05:10+02:00
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>