-
d4b1e353
by Simon Hengel at 2025-12-10T00:00:02-05:00
Fix syntax error in gadt_syntax.rst
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91cc8be6
by Cheng Shao at 2025-12-10T00:00:43-05:00
ci: fix "ci.sh clean" to address frequent out of space error on windows runners
This patch fixes the `ci.sh clean` logic to address frequent out of
space error on windows runners; previously it didn't clean up the
inplace mingw blobs, which is the largest source of space leak on
windows runners. See added comment for detailed explanation.
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fe2b79f4
by Recursion Ninja at 2025-12-10T08:34:18-05:00
Narrow before optimising MUL/DIV/REM into shifts
The MUL/DIV/REM operations can be optimised into shifts when one of the
operands is a constant power of 2. However, as literals in Cmm are
stored as 'Integer', for this to be correct we first need to narrow the
literal to the appropriate width before checking whether the literal is
a power of 2.
Fixes #25664
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06c2349c
by Recursion Ninja at 2025-12-10T08:34:58-05:00
Decouple 'Language.Haskell.Syntax.Type' from 'GHC.Utils.Panic'
- Remove the *original* defintion of 'hsQTvExplicit' defined within 'Language.Haskell.Syntax.Type'
- Redefine 'hsQTvExplicit' as 'hsq_explicit' specialized to 'GhcPass' exported by 'GHC.Utils.Panic'
- Define 'hsQTvExplicitBinders' as 'hsq_explicit' specialized to 'DocNameI' exported by 'Haddock.GhcUtils'.
- Replace all call sites of the original 'hsQTvExplicit' definition with either:
1. 'hsQTvExplicit' updated definition
2. 'hsQTvExplicitBinders'
All call sites never entered the 'XLHsQTyVars' constructor branch, but a call to 'panic' existed on this code path because the type system was not strong enought to guarantee that the 'XLHsQTyVars' construction was impossible.
These two specialized functions provide the type system with enough information to make that guarantee, and hence the dependancy on 'panic' can be removed.
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ac0815d5
by sheaf at 2025-12-10T23:39:57-05:00
Quantify arg before mult in function arrows
As noted in #23764, we expect quantification order to be left-to-right,
so that in a type such as
a %m -> b
the inferred quantification order should be [a, m, b] and not [m, a, b].
This was addressed in commit d31fbf6c, but that commit failed to update
some other functions such as GHC.Core.TyCo.FVs.tyCoFVsOfType.
This affects Haddock, as whether we print an explicit forall or not
depends on whether the inferred quantification order matches the actual
quantification order.
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2caf796e
by sheaf at 2025-12-10T23:39:57-05:00
Haddock: improvements to ty-var quantification
This commit makes several improvements to how Haddock deals with the
quantification of type variables:
1. In pattern synonyms, Haddock used to jumble up universal and
existential quantification. That is now fixed, fixing #26252.
Tested in the 'PatternSyns2' haddock-html test.
2. The logic for computing whether to use an explicit kind annotation
for a type variable quantified in a forall was not even wrong.
This commit improves the heuristic, but it will always remain an
imperfect heuristic (lest we actually run kind inference again).
In the future (#26271), we hope to avoid reliance on this heuristic.
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b14bdd59
by Teo Camarasu at 2025-12-10T23:40:38-05:00
Add explicit export list to GHC.Num
Let's make clear what this module exports to allow us to easily deprecate and remove some of these in the future. Resolves https://gitlab.haskell.org/ghc/ghc/-/issues/26625
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64553a1c
by Cheng Shao at 2025-12-11T15:10:41+01:00
configure: bump LlvmMaxVersion to 22
This commit bumps LlvmMaxVersion to 22; 21.x releases have been
available since Aug 26th, 2025 and there's no regressions with 21.x so
far. This bump is also required for updating fedora image to 43.
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c89f17c6
by Cheng Shao at 2025-12-11T16:17:07+01:00
hadrian: add support for building with UndefinedBehaviorSanitizer
This patch adds a +ubsan flavour transformer to hadrian to build all
stage1+ C/C++ code with UndefinedBehaviorSanitizer. This is
particularly useful to catch potential undefined behavior in the RTS
codebase.
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97b60f92
by Cheng Shao at 2025-12-11T16:17:11+01:00
ci: update alpine/fedora & add ubsan job
This patch updates alpine image to 3.23, fedora image to 43, and adds
a `x86_64-linux-fedora43-validate+debug_info+ubsan` job that's run in
validate/nightly pipelines to catch undefined behavior in the RTS
codebase.
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b65422e6
by Cheng Shao at 2025-12-11T16:17:11+01:00
rts: fix zero-length VLA undefined behavior in interpretBCO
This commit fixes a zero-length VLA undefined behavior in interpretBCO, caught by UBSan:
```
+rts/Interpreter.c:3133:19: runtime variable length array bound evaluates to non-positive value 0
```
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993054b2
by Cheng Shao at 2025-12-11T16:17:11+01:00
rts: fix unaligned ReadSpB in interpretBCO
This commit fixes unaligned ReadSpB in interpretBCO, caught by UBSan:
```
+rts/Interpreter.c:2174:64: runtime load of misaligned address 0x004202059dd1 for type 'StgWord', which requires 8 byte alignment
```
To perform proper unaligned read, we define StgUnalignedWord as a type
alias of StgWord with aligned(1) attribute, and load StgUnalignedWord
instead of StgWord in ReadSpB, so the C compiler is aware that we're
not loading with natural alignment.
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8870995f
by Cheng Shao at 2025-12-11T16:17:11+01:00
rts: fix signed integer overflow in subword arithmetic in interpretBCO
This commit fixes signed integer overflow in subword arithmetic in
interpretBCO, see added note for detailed explanation.