-
bcdec657
by Zubin Duggal at 2025-08-05T10:37:29+05:30
compiler: Export a version of `newNameCache` that is not prone to footguns.
`newNameCache` must be initialized with both a non-"reserved" unique tag, as well
as a list of known key names. Failing to do so results in hard to debug unique conflicts.
It is difficult for API users to tell which unique tags are safe to use. So instead of leaving
this up to the user to decide, we now export a version of `newNameCache` which uses a guaranteed
non-reserved unique tag. In fact, this is now the way the unique tag is initialized for all invocations
of the compiler.
The original version of `newNameCache` is now exported as `newNameCache'` for advanced users.
We also deprecate `initNameCache` as it is also prone to footguns and is completely subsumed in
functionality by `newNameCache` and `newNameCache'`.
Fixes #26135 and #26055
-
57d3b4a8
by Andrew Lelechenko at 2025-08-05T18:36:31-04:00
hadrian: bump Stackage snapshot to LTS 24.2 / GHC 9.10.2
In line with #25693 we should use GHC 9.10 as a boot compiler,
while Hadrian stack.yaml was stuck on GHC 9.6.
-
c2a78cea
by Peng Fan at 2025-08-05T18:37:27-04:00
NCG/LA64: implement atomic write with finer-grained DBAR hints
Signed-off-by: Peng Fan <fanpeng@loongson.cn>
-
95231c8e
by Teo Camarasu at 2025-08-06T08:35:58-04:00
CODEOWNERS: add CLC as codeowner of base
We also remove hvr, since I think he is no longer active
-
77df0ded
by Andrew Lelechenko at 2025-08-06T08:36:39-04:00
Bump submodule text to 2.1.3
-
8af260d0
by Nikolaos Chatzikonstantinou at 2025-08-06T08:37:23-04:00
docs: fix internal import in getopt examples
This external-facing doc example shouldn't mention GHC internals when
using 'fromMaybe'.
-
69cc16ca
by Marc Scholten at 2025-08-06T15:51:28-04:00
README: Add note on ghc.nix
-
93a2f450
by Daniel Díaz at 2025-08-06T15:52:14-04:00
Link to the "Strict Bindings" docs from the linear types docs
Strict Bidings are relevant for the kinds of multiplicity annotations
linear lets support.
-
246b7853
by Matthew Pickering at 2025-08-07T06:58:30-04:00
level imports: Check the level of exported identifiers
The level imports specification states that exported identifiers have to
be at level 0. This patch adds the requird level checks that all
explicitly mentioned identifiers occur at level 0.
For implicit export specifications (T(..) and module B), only level 0
identifiers are selected for re-export.
ghc-proposal: https://github.com/ghc-proposals/ghc-proposals/pull/705
Fixes #26090
-
358bc4fc
by fendor at 2025-08-07T06:59:12-04:00
Bump GHC on darwin CI to 9.10.1
-
1903ae35
by Matthew Pickering at 2025-08-07T12:21:10+01:00
ipe: Place strings and metadata into specific .ipe section
By placing the .ipe metadata into a specific section it can be stripped
from the final binary if desired.
```
objcopy --remove-section .ipe <binary>
upx <binary>
```
Towards #21766
-
c80dd91c
by Matthew Pickering at 2025-08-07T12:22:42+01:00
ipe: Place magic word at the start of entries in the .ipe section
The magic word "IPE\nIPE\n" is placed at the start of .ipe sections,
then if the section is stripped, we can check whether the section starts
with the magic word or not to determine whether there is metadata
present or not.
Towards #21766
-
cab42666
by Matthew Pickering at 2025-08-07T12:22:42+01:00
ipe: Use stable IDs for IPE entries
IPEs have historically been indexed and reported by their address.
This makes it impossible to compare profiles between runs, since the
addresses may change (due to ASLR) and also makes it tricky to separate
out the IPE map from the binary.
This small patch adds a stable identifier for each IPE entry.
The stable identifier is a single 64 bit word. The high-bits are a
per-module identifier and the low bits identify which entry in each
module.
1. When a node is added into the IPE buffer it is assigned a unique
identifier from an incrementing global counter.
2. Each entry already has an index by it's position in the
`IpeBufferListNode`.
The two are combined together by the `IPE_ENTRY_KEY` macro.
Info table profiling uses the stable identifier rather than the address
of the info table.
The benefits of this change are:
* Profiles from different runs can be easily compared
* The metadata can be extracted from the binary (via the eventlog for
example) and then stripped from the executable.
Fixes #21766
-
2860a9a5
by Simon Peyton Jones at 2025-08-07T20:29:18-04:00
In TcSShortCut, typechecker plugins should get empty Givens
Solving in TcShortCut mode means /ignoring the Givens/. So we
should not pass them to typechecker plugins!
Fixes #26258.
This is a fixup to the earlier MR:
commit 1bd12371feacc52394a0e660ef9349f9e8ee1c06
Author: Simon Peyton Jones <simon.peytonjones@gmail.com>
Date: Mon Jul 21 10:04:49 2025 +0100
Improve treatment of SPECIALISE pragmas -- again!
-
2157db2d
by sterni at 2025-08-08T15:32:39-04:00
hadrian: enable terminfo if --with-curses-* flags are given
The GHC make build system used to support WITH_TERMINFO in ghc.mk which
allowed controlling whether to build GHC with terminfo or not. hadrian
has replaced this with a system where this is effectively controlled by
the cross-compiling setting (the default WITH_TERMINFO value was bassed
on CrossCompiling, iirc).
This behavior is undesireable in some cases and there is not really a
good way to work around it. Especially for downstream packagers,
modifying this via UserSettings is not really feasible since such a
source file has to be kept in sync with Settings/Default.hs manually
since it can't import Settings.Default or any predefined Flavour
definitions.
To avoid having to add a new setting to cfg/system.config and/or a new
configure flag (though I'm happy to implement both if required), I've
chosen to take --with-curses-* being set explicitly as an indication
that the user wants to have terminfo enabled. This would work for
Nixpkgs which sets these flags [1] as well as haskell.nix [2] (which
goes to some extreme measures [3] [4] to force terminfo in all scenarios).
In general, I'm an advocate for making the GHC build be the same for
native and cross insofar it is possible since it makes packaging GHC and
Haskell related things while still supporting cross much less
compilicated. A more minimal GHC with reduced dependencies should
probably be a specific flavor, not the default.
Partially addresses #26288 by forcing terminfo to be built if the user
explicitly passes configure flags related to it. However, it isn't built
by default when cross-compiling yet nor is there an explicit way to
control the package being built.
[1]: https://github.com/NixOS/nixpkgs/blob/3a7266fcefcb9ce353df49ba3f292d06443760bb/pkgs/development/compilers/ghc/common-hadrian.nix#L513-L515
[2]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L185
[3]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L678-L682
[4]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L772-L773
-
b3c31488
by David Feuer at 2025-08-08T15:33:21-04:00
Add default QuasiQuoters
Add `defaultQuasiQuoter` and `namedDefaultQuasiQuoter` to make it easier
to write `QuasiQuoters` that give helpful error messages when they're
used in inappropriate contexts.
Closes #24434.
-
03555ed8
by Sylvain Henry at 2025-08-10T22:20:57-04:00
Handle non-fractional CmmFloats in Cmm's CBE (#26229)
Since f8d9d016305be355f518c141f6c6d4826f2de9a2, toRational for Float and
Double converts float's infinity and NaN into Rational's infinity and
NaN (respectively 1%0 and 0%0).
Cmm CommonBlockEliminator hashing function needs to take these values
into account as they can appear as literals now. See added testcase.
-
6c956af3
by J. Ryan Stinnett at 2025-08-10T22:21:42-04:00
Fix extensions list in `DoAndIfThenElse` docs
-
6dc420b1
by J. Ryan Stinnett at 2025-08-10T22:21:42-04:00
Document status of `RelaxedPolyRec` extension
This adds a brief extension page explaining the status of the
`RelaxedPolyRec` extension. The behaviour of this mode is already
explained elsewhere, so this page is mainly for completeness so that
various lists of extensions have somewhere to point to for this flag.
Fixes #18630
-
18036d52
by Simon Peyton Jones at 2025-08-11T11:31:20-04:00
Take more care in zonkEqTypes on AppTy/AppTy
This patch fixes #26256.
See Note [zonkEqTypes and the PKTI] in GHC.Tc.Solver.Equality
-
c8d76a29
by Zubin Duggal at 2025-08-11T11:32:02-04:00
ci: upgrade bootstrap compiler on windows to 9.10.1
-
34fc50c1
by Ben Gamari at 2025-08-11T13:36:25-04:00
Kill IOPort#
This type is unnecessary, having been superceded by `MVar` and a rework
of WinIO's blocking logic.
See #20947.
See https://github.com/haskell/core-libraries-committee/issues/213.
-
56b32c5a
by sheaf at 2025-08-12T10:00:19-04:00
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.
For example, we now are properly able to prove the subtyping relationship
((∀ a. a->a) -> Int) -> Bool <= β[tau] Bool
for an unfilled metavariable β. In this case (with an AppTy on the right),
we used to fall back to unification. No longer: now, given that the LHS
is a FunTy and that the RHS is a deep rho type (does not need any instantiation),
we try to make the RHS into a FunTy, viz.
β := (->) γ
We can then continue using covariance & contravariance of the function
arrow, which allows us to prove the subtyping relationship, instead of
trying to unify which would cause us to error out with:
Couldn't match expected type ‘β’ with actual type ‘(->) ((∀ a. a -> a) -> Int)
See Note [FunTy vs non-FunTy case in tc_sub_type_deep] in GHC.Tc.Utils.Unify.
The other main improvement in this patch concerns type inference.
The main subsumption logic happens (before & after this patch) in
GHC.Tc.Gen.App.checkResultTy. However, before this patch, all of the
DeepSubsumption logic only kicked in in 'check' mode, not in 'infer' mode.
This patch adds deep instantiation in the 'infer' mode of checkResultTy
when we are doing deep subsumption, which allows us to accept programs
such as:
f :: Int -> (forall a. a->a)
g :: Int -> Bool -> Bool
test1 b =
case b of
True -> f
False -> g
test2 b =
case b of
True -> g
False -> f
See Note [Deeply instantiate in checkResultTy when inferring].
Finally, we add representation-polymorphism checks to ensure that the
lambda abstractions we introduce when doing subsumption obey the
representation polymorphism invariants of Note [Representation polymorphism invariants]
in GHC.Core. See Note [FunTy vs FunTy case in tc_sub_type_deep].
This is accompanied by a courtesy change to `(<.>) :: HsWrapper -> HsWrapper -> HsWrapper`,
adding the equation:
WpCast c1 <.> WpCast c2 = WpCast (c1 `mkTransCo` c2)
This is useful because mkWpFun does not introduce an eta-expansion when
both of the argument & result wrappers are casts; so this change allows
us to avoid introducing lambda abstractions when casts suffice.
Fixes #26225
-
d175aff8
by Sylvain Henry at 2025-08-12T10:01:31-04:00
Add regression test for #18619
-
a3983a26
by Sylvain Henry at 2025-08-12T10:02:20-04:00
RTS: remove some TSAN annotations (#20464)
Use RELAXED_LOAD_ALWAYS macro instead.
-
0434af81
by Ben Gamari at 2025-08-12T10:03:02-04:00
Bump time submodule to 1.15
Also required bumps of Cabal, directory, and hpc.
-
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