-
ce2d62fb
by Jessica Clarke at 2026-01-29T19:48:51-05:00
PPC NCG: Use libcall for 64-bit cmpxchg on 32-bit PowerPC
There is no native instruction for this, and even if there were a
register pair version we could use, the implementation here is assuming
the values fit in a single register, and we end up only using / defining
the low halves of the registers.
Fixes: b4d39adbb5 ("PrimOps: Add CAS op for all int sizes")
Fixes: #23969
-
43d97761
by Michael Karcher at 2026-01-29T19:49:43-05:00
NCG for PPC: add pattern for CmmRegOff to iselExpr64
Closes #26828
-
aeeb4a20
by Matthew Pickering at 2026-01-30T11:42:47-05:00
determinism: Use deterministic map for Strings in TyLitMap
When generating typeable evidence the types we need evidence for all
cached in a TypeMap, the order terms are retrieved from a type map
determines the order the bindings appear in the program.
A TypeMap is quite diligent to use deterministic maps, apart from in the
TyLitMap, which uses a UniqFM for storing strings, whose ordering
depends on the Unique of the FastString.
This can cause non-deterministic .hi and .o files.
An unexpected side-effect is the error message but RecordDotSyntaxFail8
changing. I looked into this with Sam and this change caused the
constraints to be solved in a different order which results in a
slightly different error message. I have accepted the new test, since
the output before was non-deterministic and the new output is consistent
with the other messages in that file.
Fixes #26846
-
9e4d70c2
by Andrew Lelechenko at 2026-01-30T11:43:29-05:00
Upgrade text submodule to 2.1.4
-
631fa5ae
by Recursion Ninja at 2026-01-31T22:30:11+00:00
Decouple `L.S.H.Decls` from importing `GHC.Types.Basic`
Data-types within `GHC.Types.Basic` which describe components of
the AST are migrated to `Language.Haskell.Syntax.Basic`. Related
function definitions are also moved.
Types moved to L.H.S. because they are part of the AST:
* TopLevelFlag
* RuleName
Types moved from L.H.S. to GHC.Hs. because they are not needed in the AST:
* TyConFlavour
* TypeOrData
* NewOrData
Migrated instances:
* `Outputable` instances moved to in `GHC.Utils.Outputable`
* `Binary` instance of `Boxity` moved to to `GHC.Utils.Binary`
* Other `Binary` instances are orphans to be migrated later.
The `OverlapMode` data-type is given a TTG extension point.
The `OverlapFlag` data-type, which depends on `OverlapMode`,
is updated to support `OverlapMode` with a GHC "pass" type paramerter.
In order to avoid module import cycles, `OverlapMode` and `OverlapFlag`
are migrated to new modules (no way around this).
* Migrated `OverlapMode` to new module `Language.Haskell.Syntax.Overlap`
* Migrated `OverlapFlag` to new module `GHC.Hs.Decls.Overlap`
-
9769cc03
by Simon Hengel at 2026-02-01T04:21:03-05:00
Update the documentation for MultiWayIf (fixes #25376)
(so that it matches the implementation)
-
5fc9442a
by Peter Trommler at 2026-02-01T04:21:44-05:00
hadrian: Fix dependency generation for assembler
Assembler files allow # for comments unless in column 1. A modern
cpp for C treats those a preprocessor directives. We tell gcc that
a .S file is assembler with cpp and not C.
Fixes #26819
-
269c4087
by Simon Peyton Jones at 2026-02-01T19:38:10-05:00
Include current phase in the range for rule/unfoldings
This MR fixes a bad loop in the compiler: #26826.
The fix is to add (WAR2) to
Note [What is active in the RHS of a RULE or unfolding?]
in GHC.Core.Opt.Simplify.Utils
-
ddf1434f
by Vladislav Zavialov at 2026-02-01T19:38:52-05:00
Refactor: merge HsMultilineString into HsString (#26860)
Before this patch, HsLit defined two separate constructors to represent
single-line and multi-line strings:
data HsLit x
...
| HsString (XHsString x) FastString
| HsMultilineString (XHsMultilineString x) FastString
I found this to be an unnecessary complication and an obstacle to unifying
HsLit with HsTyLit. Now we use HsString for both kinds of literals.
One user-facing change here is `ppr (HsString st s)` behaving differently for
single-line strings containing newlines:
x = "first line \
\asdf\n\
\second line"
Previously, the literal was fed to `ftext` with its newlines, producing an
ill-formed SDoc. This issue is now addressed by using `split` for both
single-line and multi-line strings:
vcat $ map text $ split '\n' (unpackFS src)
See the parser/should_fail/T26860ppr test.
In addition (and unrelatedly to the main payload of this patch),
drop the unused pmPprHsLit helper.
-
2b4f463c
by Simon Peyton Jones at 2026-02-02T17:32:32+00:00
Remove exprIsCheap from doFloatFromRhs
See #26854 and Note [Float when expandable]
This patch simplifies the code, by removing an extra unnecessary test.
-
9db7f21f
by Brandon Chinn at 2026-02-03T09:15:10-05:00
Refactor: make function patterns exhaustive
Also added missing (==) logic for:
* HsMultilineString
* HsInt{8,16,32}
* HsWord{8,16,32}
-
aa9c5e2c
by Hécate Kleidukos at 2026-02-03T15:58:35-05:00
driver: Hide source paths at verbosity level 1 by default
-
c64cca1e
by mangoiv at 2026-02-03T15:59:29-05:00
ExplicitLevelImports: check staging for types just like for values
Previously, imported types were entirely exempted from staging checks as
the implicit stage persistance assumed to be all imported types to be
well staged. ExplicitLevelImports' change specification, however, does
not do such an exemption. Thus we want to introduce such a check, just
like we have for values.
ExplicitLevelImports does not, however, talk about local names - from
its perspective, we could theoretically keep treating locally introduced
types specially - e.g. an ill-staged used in a quote would only emit a
warning, not an error. To allow for a potential future migration away
from such wrinkles as the staging check in notFound
(see Note [Out of scope might be a staging error]) we consistently do
the strict staging check that we also do for value if ExplicitLevelImports
is on.
Closes #26098
-
5f0dbeb6
by Simon Hengel at 2026-02-03T16:00:12-05:00
Use Haddock formatting in deprecation message of `initNameCache`
-
01ecb612
by Andreas Klebinger at 2026-02-04T09:56:25-05:00
testsuite: Explicitly use utf-8 encoding in rts-includes linter.
Not doing so caused failures on windows, as python failed to pick a
reasonable encoding even with locale set.
Fixes #26850
-
ea0d1317
by Zubin Duggal at 2026-02-04T09:57:06-05:00
Bump transformers submodule to 0.6.3.0
Fixes #26790
-
cbe4300e
by Simon Peyton Jones at 2026-02-05T04:31:04-05:00
Fix subtle bug in GHC.Core.Utils.mkTick
This patch fixes a decade-old bug in `mkTick`, which
could generate type-incorrect code! See the diagnosis
in #26772.
The new code is simpler and easier to understand.
(As #26772 says, I think it could be improved further.)
-
a193a8da
by Simon Peyton Jones at 2026-02-05T04:31:04-05:00
Modify a debug-trace in the Simplifier
...just to show a bit more information.
-
b579dfdc
by Simon Peyton Jones at 2026-02-05T04:31:04-05:00
Fix long-standing interaction between ticks and casts
The code for Note [Eliminate Identity Cases] was simply wrong when
ticks and casts interacted. This patch fixes the interaction.
It was shown up when validating #26772, although it's not the exactly
the bug that's reported by #26772. Nor is it easy to reproduce, hence
no regression test.
-
fac0de1e
by Cheng Shao at 2026-02-05T04:31:49-05:00
libraries: bump Cabal submodule to 3.16.1.0
-
00589122
by Cheng Shao at 2026-02-05T04:31:49-05:00
libraries: bump deepseq submodule to 1.5.2.0
Also:
- Get rid of usage of deprecated `NFData` function instance in the
compiler
- `T21391` still relies on `NFData` function instance, add
`-Wno-deprecations` for the time being.
-
84474c71
by Cheng Shao at 2026-02-05T04:31:50-05:00
libraries: bump directory submodule to 1.3.10.1
-
1a9f4662
by Cheng Shao at 2026-02-05T04:31:50-05:00
libraries: bump exceptions submodule to 0.10.12
-
2e39a340
by Peng Fan at 2026-02-07T03:42:01-05:00
NCG/LA64: adjust register usage to avoid src-register being clobbered
-
9faf1b35
by Teo Camarasu at 2026-02-07T03:42:43-05:00
ghc-internal: Delete unnecessary GHC.Internal.Data.Ix
This module merely re-exports GHC.Internal.Ix. It was copied from
`base` when `ghc-internal` was split, but there is no reason to have
this now. So, let's delete it.
Resolves #26848
-
d112b440
by Sven Tennie at 2026-02-07T10:47:56-05:00
Add cabal.project file to generate-ci
This fixes the HLS setup for our CI code generation script
(generate-ci).
The project file simply makes `generate-ci` of the cabal file
discoverable.
-
5339f6f0
by Andreas Klebinger at 2026-02-07T10:48:40-05:00
CI: Don't collapse test results.
This puts test output back into the primary test log instead of a
subsection removing the need to expand a section to see test results.
While the intention was good in practice the old behaviour mostly wastes time
by requiring expansion of the section.
Fixes #26882
-
0e1cd2e0
by Evan Piro at 2026-02-08T10:35:16-08:00
Linker.MacOS reduce dynflags import
-
1c79a4cd
by Michael Alan Dorman at 2026-02-09T08:11:51-05:00
Remove `extra_src_files` variable from `testsuite/driver/testlib.py`
While reading through the test harness code, I noticed this variable
with a TODO attached that referenced #12223. Although that bug is
closed, it strongly implied that this special-case variable that only
affected a single test was expected to be removed at some point.
I also looked at 3415bcaa0b1903b5e12dfaadb5b774718e406eab---where it
was added---whose commit message suggested that it would have been
desirable to remove it, but that there were special circumstances that
meant it had to remain (though it doesn't elucidate what those special
circumstances are).
However, the special circumstances were mentioned as if the test was
in a different location than is currently is, so I decided to try
changing the test to use the standard `extra_files` mechanism, which
works in local testing.
This also seems like a reasonable time to remove the script that was
originally used in the transition, since it doesn't really serve a
purpose anymore.
-
0020e38a
by Matthew Pickering at 2026-02-09T17:29:14-05:00
determinism: Use a stable sort in WithHsDocIdentifiers binary instance
`WithHsDocIdentifiers` is defined as
```
71 data WithHsDocIdentifiers a pass = WithHsDocIdentifiers
72 { hsDocString :: !a
73 , hsDocIdentifiers :: ![Located (IdP pass)]
74 }
```
This list of names is populated from `rnHsDocIdentifiers`, which calls
`lookupGRE`, which calls `lookupOccEnv_AllNameSpaces`, which calls
`nonDetEltsUFM` and returns the results in an order depending on
uniques.
Sorting the list with a stable sort before returning the interface makes
the output deterministic and follows the approach taken by other fields
in `Docs`.
Fixes #26858
-
89898ce6
by echoumcp1 at 2026-02-09T17:30:01-05:00
Replace putstrln with logMsg in handleSeqHValueStatus
Fixes #26549
-
7c52c4f9
by John Paul Adrian Glaubitz at 2026-02-10T13:52:43-05:00
rts: Switch prim to use modern atomic compiler builtins
The __sync_*() atomic compiler builtins have been deprecated in GCC
for a while now and also don't provide variants for 64-bit values
such as __sync_fetch_and_add_8().
Thus, replace them with the modern __atomic_*() compiler builtins and
while we're at it, also drop the helper macro CAS_NAND() which is now
no longer needed since we stopped using the __sync_*() compiler builtins
altogether.
Co-authored-by: Ilias Tsitsimpis <iliastsi@debian.org>
Fixes #26729
-
cf60850a
by Recursion Ninja at 2026-02-10T13:53:27-05:00
Decoupling L.H.S.Decls from GHC.Types.ForeignCall
- Adding TTG extension point for 'CCallTarget'
- Adding TTG extension point for 'CType'
- Adding TTG extension point for 'Header'
- Moving ForeignCall types that do not need extension
to new L.H.S.Decls.Foreign module
- Replacing 'Bool' parameters with descriptive data-types
to increase clairty and prevent "Boolean Blindness"
-
11a04cbb
by Eric Lee at 2026-02-11T09:20:46-05:00
Derive Semigroup/Monoid for instances believed could be derived in #25871
-
15d9ce44
by Eric Lee at 2026-02-11T09:20:46-05:00
add Ghc.Data.Pair deriving
-
c85dc170
by Evan Piro at 2026-02-11T09:21:45-05:00
Linker.MacOS reduce options import
-
a541dd83
by Chris Wendt at 2026-02-11T16:06:41-05:00
Initialize plugins for `:set +c` in GHCi
Fixes #23110.
-
0f5a73bc
by Cheng Shao at 2026-02-11T16:07:27-05:00
compiler: add Binary Text instance
This patch adds `Binary` instance for strict `Text`, in preparation of
making `Text` usable in certain GHC API use cases (e.g. haddock). This
also introduces `text` as a direct dependency of the `ghc` package.
-
9e58b8a1
by Cheng Shao at 2026-02-11T16:08:10-05:00
ghc-toolchain: add C11 check
This patch partially reverts commit
b8307eab80c5809df5405d76c822bf86877f5960 that removed C99 check in
autoconf/ghc-toolchain. Now we:
- No longer re-implement `FP_SET_CFLAGS_C11` similar to
`FP_SET_CFLAGS_C99` in the past, since autoconf doesn't provide a
convenient `AC_PROG_CC_C11` function. ghc-toolchain will handle it
anyway.
- The Cmm CPP C99 check is relanded and repurposed for C11.
- The C99 logic in ghc-toolchain is relanded and repurposed for C11.
- The C99 check in Stg.h is corrected to check for C11. The obsolete
_ISOC99_SOURCE trick is dropped.
- Usages of `-std=gnu99` in the testsuite are corrected to use
`-std=gnu11`.
Closes #26908.
-
4df0adf6
by Simon Peyton Jones at 2026-02-11T21:50:13-05:00
Simplify the treatment of static forms
This MR implements GHC proposal 732: simplify static forms,
https://github.com/ghc-proposals/ghc-proposals/pull/732
thereby addressing #26556.
See `Note [Grand plan for static forms]` in GHC.Iface.Tidy.StaticPtrTable
The main changes are:
* There is a new, simple rule for (static e), namely that the free
term variables of `e` must be bound at top level. The check is
done in the `HsStatic` case of `GHC.Rename.Expr.rnExpr`
* That in turn substantially simplifies the info that the typechecker
carries around in its type environment. Hooray.
* The desugarer emits static bindings to top level directly; see the
`HsStatic` case of `dsExpr`.
* There is no longer any special static-related magic in the FloatOut
pass. And the main Simplifier pipeline no longer needs a special case
to run FloatOut even with -O0. Hooray.
All this forced an unexpected change to the pattern match checker. It
recursively invokes the main Hs desugarer when it wants to take a look
at a term to spot some special cases (notably constructor applications).
We don't want to emit any nested (static e) bindings to top level a
second time! Yikes.
That forced a modest refactor in GHC.HsToCore.Pmc:
* The `dsl_nablas` field of `DsLclEnv` now has a `NoPmc` case, which says
"I'm desugaring just for pattern-match checking purposes".
* When that flag is set we don't emit static binds.
That in turn forces a cascade of refactoring, but the net effect is an
improvement; less risk of duplicated (even exponential?) work.
See Note [Desugaring HsExpr during pattern-match checking].
10% metric decrease, on some architectures, of compile-time max-bytes-used on T15304.
Metric Decrease:
T15304
-
7922f728
by Teo Camarasu at 2026-02-11T21:50:58-05:00
ghc-internal: avoid depending on GHC.Internal.Exts
This module is mostly just re-exports. It made sense as a user-facing
module, but there's no good reason ghc-internal modules should depend on
it and doing so linearises the module graph
- move considerAccessible to GHC.Internal.Magic
Previously it lived in GHC.Internal.Exts, but it really deserves to live
along with the other magic function, which are already re-exported from .Exts
- move maxTupleSize to GHC.Internal.Tuple
This previously lived in GHC.Internal.Exts but a comment already said it
should be moved to .Tuple
Resolves #26832
-
b6a4a29b
by Eric Lee at 2026-02-11T21:51:55-05:00
Remove unused Semigroup imports to fix GHC 9.14 bootstrapping
-
99d8c146
by Simon Peyton Jones at 2026-02-12T17:36:59+00:00
Fix subtle bug in cast worker/wrapper
See (CWw4) in Note [Cast worker/wrapper].
The true payload is in the change to the definition of
GHC.Types.Id.Info.hasInlineUnfolding
Everthing else is just documentation.
There is a 2% compile time decrease for T13056;
I'll take the win!
Metric Decrease:
T13056
-
530e8e58
by Simon Peyton Jones at 2026-02-12T20:17:23-05:00
Add regression tests for four StaticPtr bugs
Tickets #26545, #24464, #24773, #16981 are all solved by the
recently-landed MR
commit 318ee13bcffa6aa8df42ba442ccd92aa0f7e210c
Author: Simon Peyton Jones <simon.peytonjones@gmail.com>
Date: Mon Oct 20 23:07:20 2025 +0100
Simplify the treatment of static forms
This MR just adds regression tests for them.
-
4157160f
by Cheng Shao at 2026-02-13T06:27:04-05:00
ci: remove unused hlint-ghc-and-base job definition
This patch removes the unused `hlint-ghc-and-base` job definition,
it's never run since !9806. Note that hadrian lint rules still work
locally, so anyone that wishes to run hlint on the codebase can
continue to do so in their local worktree.
-
039f1977
by Cheng Shao at 2026-02-13T06:27:47-05:00
wasm: use import.meta.main for proper distinction of nodejs main modules
This patch uses `import.meta.main` for proper distinction of nodejs
main modules, especially when the main module might be installed as a
symlink. Fixes #26916.
-
14f485ee
by ARATA Mizuki at 2026-02-17T09:09:24+09:00
Support more x86 extensions: AVX-512 {BW,DQ,VL} and GFNI
Also, mark AVX-512 ER and PF as deprecated.
AVX-512 instructions can be used for certain 64-bit integer vector operations.
GFNI can be used to implement bitReverse (currently not used by NCG, but LLVM may use it).
Closes #26406
Addresses #26509
-
016f79d5
by fendor at 2026-02-17T09:16:16-05:00
Hide implementation details from base exception stack traces
Ensure we hide the implementation details of the exception throwing mechanisms:
* `undefined`
* `throwSTM`
* `throw`
* `throwIO`
* `error`
The `HasCallStackBacktrace` should always have a length of exactly 1,
not showing internal implementation details in the stack trace, as these
are vastly distracting to end users.
CLC proposal [#387](https://github.com/haskell/core-libraries-committee/issues/387)
-
4f2840f2
by Brian J. Cardiff at 2026-02-17T17:04:08-05:00
configure: Accept happy-2.2
In Jan 2026 happy-2.2 was released. The most sensible change is https://github.com/haskell/happy/issues/335 which didn't trigger in a fresh build
-
10b4d364
by Duncan Coutts at 2026-02-17T17:04:52-05:00
Fix errors in the documentation of the eventlog STOP_THREAD status codes
Fix the code for BlockedOnMsgThrowTo.
Document all the known historical warts.
Fixes issue #26867
-
c5e15b8b
by Phil de Joux at 2026-02-18T05:07:36-05:00
haddock: use snippets for all list examples
- generate snippet output for docs
- reduce font size to better fit snippets
- Use only directive to guard html snippets
- Add latex snippets for lists
-
d388bac1
by Phil de Joux at 2026-02-18T05:07:36-05:00
haddock: Place the snippet input and output together
- Put the output seemingly inside the example box
-
016fa306
by Samuel Thibault at 2026-02-18T05:08:35-05:00
Fix linking against libm by moving the -lm option
For those systems that need -lm for getting math functions, this is
currently added on the link line very early, before the object files being
linked together. Newer toolchains enable --as-needed by default, which means
-lm is ignored at that point because no object requires a math function
yet. With such toolchains, we thus have to add -lm after the objects, so the
linker actually includes libm in the link.
-
68bd0805
by Teo Camarasu at 2026-02-18T05:09:19-05:00
ghc-internal: Move GHC.Internal.Data.Bool to base
This is a tiny module that only defines bool :: Bool -> a -> a -> a. We can just move this to base and delete it from ghc-internal. If we want this functionality there we can just use a case statement or if-then expression.
Resolves 26865
-
4c40df3d
by fendor at 2026-02-20T10:24:48-05:00
Add optional `SrcLoc` to `StackAnnotation` class
`StackAnnotation`s give access to an optional `SrcLoc` field that
user-added stack annotations can use to provide better backtraces in both error
messages and when decoding the callstack.
We update builtin stack annotations such as `StringAnnotation` and
`ShowAnnotation` to also capture the `SrcLoc` of the current `CallStack`
to improve backtraces by default (if stack annotations are used).
This change is backwards compatible with GHC 9.14.1.
-
fd9aaa28
by Simon Hengel at 2026-02-20T10:25:33-05:00
docs: Fix grammar in explicit_namespaces.rst
-
44354255
by Vo Minh Thu at 2026-02-20T18:53:06-05:00
GHCi: add a :version command.
This looks like:
ghci> :version
GHCi, version 9.11.20240322
This closes #24576.
Co-Author: Markus Läll <markus.l2ll@gmail.com>
-
eab3dbba
by Andreas Klebinger at 2026-02-20T18:53:51-05:00
hadrian/build-cabal: Better respect and utilize -j
* We now respect -j<n> for the cabal invocation to build hadrian rather
than hardcoding -j
* We use the --semaphore flag to ensure cabal/ghc build the hadrian
executable in parallel using the -jsem mechanism.
Saves 10-15s on fresh builds for me.
Fixes #26876
-
17839248
by Teo Camarasu at 2026-02-24T08:36:03-05:00
ghc-internal: avoid depending on GHC.Internal.Control.Monad.Fix
This module contains the definition of MonadFix, since we want an
instance for IO, that instance requires a lot of machinery and we want
to avoid an orphan instance, this will naturally be quite high up in the
dependency graph.
So we want to avoid other modules depending on it as far as possible.
On Windows, the IO manager depends on the RTSFlags type, which
transtively depends on MonadFix. We refactor things to avoid this
dependency, which would have caused a regression.
Resolves #26875
Metric Decrease:
T12227
-
fa88d09a
by Wolfgang Jeltsch at 2026-02-24T08:36:47-05:00
Refine the imports of `System.IO.OS`
Commit 68bd08055594b8cbf6148a72d108786deb6c12a1 replaced the
`GHC.Internal.Data.Bool` import by a `GHC.Internal.Base` import.
However, while the `GHC.Internal.Data.Bool` import was conditional and
partial, the `GHC.Internal.Base` import is unconditional and total. As a
result, the import list is not tuned to import only the necessary bits
anymore, and furthermore GHC emits a lot of warnings about redundant
imports.
This commit makes the `GHC.Internal.Base` import conditional and partial
in the same way that the `GHC.Internal.Data.Bool` import was.
-
c951fef1
by Cheng Shao at 2026-02-25T20:58:28+00:00
wasm: add /assets endpoint to serve user-specified assets
This patch adds an `/assets` endpoint to the wasm dyld http server, so
that users can also fetch assets from the same host with sensible
default MIME types, without needing a separate http server for assets
that also introduces CORS headaches:
- A `-fghci-browser-assets-dir` driver flag is added to specify the
assets root directory (defaults to `$PWD`)
- The dyld http server fetches `mime-db` on demand and uses it as
source of truth for mime types.
Closes #26951.
-
dde22f97
by Sylvain Henry at 2026-02-26T13:14:03-05:00
Fix -fcheck-prim-bounds for non constant args (#26958)
Previously we were only checking bounds for constant (literal)
arguments!
I've refactored the code to simplify the generation of out-of-line Cmm
code for the primop composed of some inline code + some call to an
external Cmm function.
-
bd3eba86
by Vladislav Zavialov at 2026-02-27T05:48:01-05:00
Check for negative type literals in the type checker (#26861)
GHC disallows negative type literals (e.g., -1), as tested by T8306 and
T8412. This check is currently performed in the renamer:
rnHsTyLit tyLit@(HsNumTy x i) = do
when (i < 0) $
addErr $ TcRnNegativeNumTypeLiteral tyLit
However, this check can be bypassed using RequiredTypeArguments
(see the new test case T26861). Prior to this patch, such programs
caused the compiler to hang instead of reporting a proper error.
This patch addresses the issue by adding an equivalent check in
the type checker, namely in tcHsType.
The diff is deliberately minimal to facilitate backporting. A more
comprehensive rework of HsTyLit is planned for a separate commit.
-
faf14e0c
by Vladislav Zavialov at 2026-02-27T05:48:45-05:00
Consistent pretty-printing of HsString, HsIsString, HsStrTy
Factor out a helper to pretty-print string literals, thus fixing newline
handling for overloaded string literals and type literals.
Test cases: T26860ppr T26860ppr_overloaded T26860ppr_tylit
Follow up to ddf1434ff9bb08cfef3c93f23de6b83ec698aa27
-
f108a972
by Arnaud Spiwack at 2026-02-27T12:53:01-05:00
Make list comprehension completely non-linear
Fixes #25081
From the note:
The usefulness of list comprehension in conjunction with linear types is dubious.
After all, statements are made to be run many times, for instance in
```haskell
[u | y <- [0,1], stmts]
```
both `u` and `stmts` are going to be run several times.
In principle, though, there are some position in a monad comprehension
expression which could be considered linear. We could try and make it so that
these positions are considered linear by the typechecker, but in practice the
desugarer doesn't take enough care to ensure that these are indeed desugared to
linear sites. We tried in the past, and it turned out that we'd miss a
desugaring corner case (#25772).
Until there's a demand for this very specific improvement, let's instead be
conservative, and consider list comprehension to be completely non-linear.
-
ae799cab
by Simon Jakobi at 2026-02-27T12:53:54-05:00
PmAltConSet: Use Data.Set instead of Data.Map
...to store `PmLit`s.
The Map was only used to map keys to themselves.
Changing the Map to a Set saves a Word of memory per entry.
Resolves #26756.
-
dcd7819c
by Vladislav Zavialov at 2026-02-27T18:46:03-05:00
Drop HsTyLit in favor of HsLit (#26862, #25121)
This patch is a small step towards unification of HsExpr and HsType,
taking care of literals (HsLit) and type literals (HsTyLit).
Additionally, it improves error messages for unsupported type literals,
such as unboxed or fractional literals (test cases: T26862, T26862_th).
Changes to the AST:
* Use HsLit where HsTyLit was previously used
* Use HsChar where HsCharTy was previously used
* Use HsString where HsStrTy was previously used
* Use HsNatural (NEW) where HsNumTy was previously used
* Use HsDouble (NEW) to represent unsupported fractional type literals
Changes to logic:
* Parse unboxed and fractional type literals (to be rejected later)
* Drop the check for negative literals in the renamer (rnHsTyLit)
in favor of checking in the type checker (tc_hs_lit_ty)
* Check for invalid type literals in TH (repTyLit) and report
unrepresentable literals with ThUnsupportedTyLit
* Allow negative type literals in TH (numTyLit). This is fine as
these will be taken care of at splice time (test case: T8306_th)
-
c927954f
by Vladislav Zavialov at 2026-02-27T18:46:50-05:00
Increase test coverage of diagnostics
Add test cases for the previously untested diagnostics:
[GHC-01239] PsErrIfInFunAppExpr
[GHC-04807] PsErrProcInFunAppExpr
[GHC-08195] PsErrInvalidRecordCon
[GHC-16863] PsErrUnsupportedBoxedSumPat
[GHC-18910] PsErrSemiColonsInCondCmd
[GHC-24737] PsErrInvalidWhereBindInPatSynDecl
[GHC-25037] PsErrCaseInFunAppExpr
[GHC-25078] PsErrPrecedenceOutOfRange
[GHC-28021] PsErrRecordSyntaxInPatSynDecl
[GHC-35827] TcRnNonOverloadedSpecialisePragma
[GHC-40845] PsErrUnpackDataCon
[GHC-45106] PsErrInvalidInfixHole
[GHC-50396] PsErrInvalidRuleActivationMarker
[GHC-63930] MultiWayIfWithoutAlts
[GHC-65536] PsErrNoSingleWhereBindInPatSynDecl
[GHC-67630] PsErrMDoInFunAppExpr
[GHC-70526] PsErrLetCmdInFunAppCmd
[GHC-77808] PsErrDoCmdInFunAppCmd
[GHC-86934] ClassPE
[GHC-90355] PsErrLetInFunAppExpr
[GHC-91745] CasesExprWithoutAlts
[GHC-92971] PsErrCaseCmdInFunAppCmd
[GHC-95644] PsErrBangPatWithoutSpace
[GHC-97005] PsErrIfCmdInFunAppCmd
Remove unused error constructors:
[GHC-44524] PsErrExpectedHyphen
[GHC-91382] TcRnIllegalKindSignature
-
3a9470fd
by Torsten Schmits at 2026-02-27T18:47:34-05:00
Avoid expensive computation for debug logging in `mergeDatabases` when log level is low
This computed and traversed a set intersection for every single
dependency unconditionally.
-
81fa469f
by Joseph Fourment at 2026-02-28T12:47:12+00:00
Add type-lets into Core
The plan for #20264 is to introduce let-bound types to have observable sharing in types.
To avoid the need to carry an environment when dealing with occurrences of these type variables,
we embed the types they're bound to (if any) in a `tv_unfolding :: Maybe Type` attribute.
This way, one can look through let-bound type variables using `coreView` and friends.
In particular, definitional equality looks through unfoldings.
simple-opt: don't inline type-lets
specialise: fix type-lets in DFun unfoldings
During specialisation, a dictionary being specialised gets a new unfolding by turning
`DFun \ bndrs -> MkD @<T1> ... @<Tm> <op1> ... <opn>` into
`DFun \ spec_bndrs -> MkD @((\ bndrs -> TYPE: <T1>) spec_args) ... ((\ bndrs -> <opn>) spec_args)`
which in turns gets beta-reduced into
`DFun \ spec_bndrs -> MkD (let { bndrs = spec_args } in TYPE: <T1>) ... (let { bndrs = spec_args } in <opn>)`.
Previously, such let binders would immediately be substituted into the type so it didn't cause any issue,
but now we want to avoid inlining.
Arguments of the form `let { bndrs = spec_args } in TYPE: <T1>` are not considered as type arguments since they're
not of the canonical form `TYPE: something`.
This commit restores the previous behavior of substituting the specialised type arguments.
Alternatively, we could attach some floated type bindings to `DFun`s.
occur-anal: implement occurence analysis for type variables
In order to find out let-bound type variables that are used only once, in the hope of inlining them,
we need to track type variables as well in the occurrence analiser. Just like Id's, we attach an
`OccInfo` to each (immutable) type variable, and we walk into types and coercions to accurately gather
occurrences.
simplifier: don't inline type-lets
Keep propagating type-lets further down the pipeline, in the simplifier.
We also update CallArity, CprAnal, DmdAnal, WorkWrap, and Specialise to ignore type-lets.
prep: make type-lets pass through CorePrep
As a first attempt, ignore type-lets in CorePrep to avoid crashes.
However, this is not enough: CorePrep also does some let-floating.
If we don't float type-lets along with value-level let-bindings,
the latter can float out of the scope of a type variable in use.
simple-opt: fix simple_type_bind
Also:
- Inline small types using a new typeIsSmallEnoughToInline predicate
- Inline single-occurrence variables
simple-opt: make beta-reduction use simple_bind_type
iface: add IfaceTypeLetBndr to represent non-top-level type-let binders
IfaceLetBndr isn't fit to represent type-let binders, as it includes a
bunch of vacuous flags for Ids only.
Instead of putting squares in circles, I added a new constructor for type binders.
The downside is that it breaks existing iface files, so since we can't bootstrap
yet so we have to bootstrap a cherry-picked branch and then checkout again to build
with --freeze1.
To avoid similar issues in the future, IfaceTyVarInfoItem serialises with a tag
despite there being only one constructor for now.
dmd-anal: prefix unused variable with _ to avoid warning
type: inline unfoldView in sORTKind_maybe
tidy: deal with type-lets
notes: add Note [Type and coercion lets]
notes: update Note [Comparing nullary type synonyms] to account for type variables
While updating backlinks, I noticed the optimisation for type variables
could be performed in more places.
simplifier: inline single-occurring type-lets
cleanup: remove NOINLINE on tyVarOccInfo
Wibbles
Wibbles
Progress
Progress
More progress
Progress
...doesn't compile though
Mostly working now
Aggressively create type-lets
more progress
More progress
Temp debug printing
Remove bogus assert
Fix anoher couple of bugs
in SimpleOpt and exprIsTrivial
Improve zonking of foreign decls to avoid TcTyVars escaping
Wibbles
Some small wibbles
Improvements
Rmmove trace
Wibbles
Use lambda, not let, in WorkWrap
Using type let did not work right with type lets and shadowing
Requires Lint to be OK join points under beta redexes -- but it is!
Needs better documentation
Wibbles
More improvements
More improvements
* Less cloning in SpecConstr
* Lint checks RULES for imported binders
Comments only
Wibble
Wibbles
Wibbles
.. getting Lint errors when compiling GHC.Internal.Classes
Wibbles
More improvements
..now getting to the back end an interface file generation
Wibbles
Wibble unsed var
Missing case in tyThingEntityInfo
Add IfaceExtTyVar
Wibbles
Start to make OccAnal count TyCoVars properly [skip ci]
Proper occurrence analysis for TyCoVars
Wibble imports
Wibble imports again
Fix two tricky buglets
More small fixes
Add missing mkAbsCoreApps
...which caused bad Lint errors
More wibbles
More wibbles exp around mkPolyAbsLams
-
edb80662
by Simon Peyton Jones at 2026-02-28T12:47:12+00:00
Make it compile again
-
d5f0983b
by Simon Peyton Jones at 2026-02-28T12:47:12+00:00
Simplify mkcoreAbsLams a bit
..Needs documentation
-
e25403b7
by Simon Peyton Jones at 2026-02-28T12:47:12+00:00
Fix build
Several important fixes, need better docs
-
90e7da0d
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Wibbles
-
57533888
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Make it compile
-
1c226b9e
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Improve Lint error message slightly
-
9a8e4f5d
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Wibble lint rules
-
b0ad947b
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Wibbles
-
4c91f804
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Wibbles
-
693257bb
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Expand tyvars in Specialise
Pretty important!
-
0a216ee9
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Comments only
-
66675343
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
More wibbles
* `bindAuxiliaryTyVars` in Specialise
* `trivial_expr_fold` needs to accept big coercions in CoreToStg
because the binder-swap can duplicate big coercions (boo)
Plus renaming in Specialise
-
c405723a
by Simon Peyton Jones at 2026-02-28T12:47:13+00:00
Onward