-
ea5abf55
by sheaf at 2025-07-16T18:18:32+05:30
Don't cache solved [W] HasCallStack constraints
This commit ensures we do not add solved Wanted constraints that mention
HasCallStack or HasExceptionContext constraints to the set of solved
Wanted dictionary constraints: caching them is invalid, because re-using
such cached dictionaries means using an old call-stack instead of
constructing a new one, as was reported in #25529.
Fixes #25529.
(cherry picked from commit 256ac29c8df4f17a1d50ea243408d506ebf395d6)
-
ea4dcccc
by sheaf at 2025-07-16T18:18:32+05:30
LLVM: fix typo in padLiveArgs
This commit fixes a serious bug in the padLiveArgs function, which
was incorrectly computing too many padding registers. This caused
segfaults, e.g. in the UnboxedTuples test.
Fixes #25770
Fixes #25773
(cherry picked from commit 044a6e08c2aee23ef18c60a036e01d3b77168830)
-
56ff1301
by sheaf at 2025-07-16T18:18:32+05:30
GHC settings: always unescape escaped spaces
In #25204, it was noted that GHC didn't properly deal with having
spaces in its executable path, as it would compute an invalid path
for the C compiler.
The original fix in 31bf85ee49fe2ca0b17eaee0774e395f017a9373 used a
trick: escape spaces before splitting up flags into a list. This fixed
the behaviour with extra flags (e.g. -I), but forgot to also unescape
for non-flags, e.g. for an executable path (such as the C compiler).
This commit rectifies this oversight by consistently unescaping the
spaces that were introduced in order to split up argument lists.
Fixes #25204
(cherry picked from commit aa1e3b8b5c9a92592b6a49783083da37dfc69375)
-
5de74fc4
by Ben Gamari at 2025-07-16T18:18:32+05:30
llvmGen: Fix built-in variable predicate
Previously the predicate to identify LLVM builtin global variables was
checking for `$llvm` rather than `@llvm` as it should.
(cherry picked from commit 6e67fa083a50684e1cfae546e07cab4d4250e871)
-
240a483f
by Ben Gamari at 2025-07-16T18:18:32+05:30
llvmGen: Fix linkage of built-in arrays
LLVM now insists that built-in arrays use Appending linkage, not
Internal.
Fixes #25769.
(cherry picked from commit a9d0a22c0777de18446f7f1e31ec0f575d53b290)
-
25d60542
by Zubin Duggal at 2025-07-16T18:18:32+05:30
get-win32-tarballs.py: List tarball files to be downloaded if we cannot find them
Fixes #25929
(cherry picked from commit aba2a4a5913a347f7e11623ac3e6f528cf8d8c39)
-
c7ae9292
by Matthew Pickering at 2025-07-16T18:18:32+05:30
perf: Replace uses of genericLength with strictGenericLength
genericLength is a recursive function and marked NOINLINE. It is not
going to specialise. In profiles, it can be seen that 3% of total compilation
time when computing bytecode is spend calling this non-specialised
function.
In addition, we can simplify `addListToSS` to avoid traversing the input
list twice and also allocating an intermediate list (after the call to
reverse).
Overall these changes reduce the time spend in 'assembleBCOs' from 5.61s
to 3.88s. Allocations drop from 8GB to 5.3G.
Fixes #25706
-
64d40516
by Matthew Craven at 2025-07-16T18:18:32+05:30
Fix bytecode generation for `tagToEnum# <LITERAL>`
Fixes #25975.
(cherry picked from commit a00eeaec8f0b98ec2b8c4630f359fdeb3a6ce04e)
-
0e65b30b
by sheaf at 2025-07-16T18:18:32+05:30
Use mkTrAppChecked in ds_ev_typeable
This change avoids violating the invariant of mkTrApp according to which
the argument should not be a fully saturated function type.
This ensures we don't return false negatives for type equality
involving function types.
Fixes #25998
(cherry picked from commit 9c6d2b1bf54310b6d9755aa2ba67fbe38feeac51)
-
1e2d82a8
by Ben Gamari at 2025-07-16T18:18:32+05:30
rts/linker: Don't fail due to RTLD_NOW
In !12264 we started using the NativeObj machinery introduced some time
ago for loading of shared objects. One of the side-effects of this
change is shared objects are now loaded eagerly (i.e. with `RTLD_NOW`).
This is needed by NativeObj to ensure full visibility of the mappings of
the loaded object, which is in turn needed for safe shared object
unloading.
Unfortunately, this change subtly regressed, causing compilation
failures in some programs. Specifically, shared objects which refer to
undefined symbols (e.g. which may be usually provided by either the
executable image or libraries loaded via `dlopen`) will fail to load
with eager binding. This is problematic as GHC loads all package
dependencies while, e.g., evaluating TemplateHaskell splices. This
results in compilation failures in programs depending upon (but not
using at compile-time) packages with undefined symbol references.
To mitigate this NativeObj now first attempts to load an object via
eager binding, reverting to lazy binding (and disabling unloading) on
failure.
See Note [Don't fail due to RTLD_NOW].
Fixes #25943.
(cherry picked from commit ce6cf240f4b39371777d484b4de30d746b7abd62)
-
a2c55f0a
by Ben Gamari at 2025-07-16T18:18:32+05:30
base: Note strictness changes made in 4.16.0.0
Addresses #25886.
(cherry picked from commit 7722232c6f8f0b57db03d0439d77896d38191bf9)
-
d21b6e67
by kwxm at 2025-07-16T18:18:33+05:30
Fix bugs in `integerRecipMod` and `integerPowMod`
This fixes #26017.
* `integerRecipMod x 1` now returns `(# 1 | #)` for all x; previously it
incorrectly returned `(# | () #)`, indicating failure.
* `integerPowMod 0 e m` now returns `(# | () #)` for e<0 and m>1, indicating
failure; previously it incorrectly returned `(# 0 | #)`.
(cherry picked from commit 8ded23300367c6e032b3c5a635fd506b8915374b)
-
c81a805f
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker: Factor out ProddableBlocks machinery
-
58fe2d79
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker: Improve efficiency of proddable blocks structure
Previously the linker's "proddable blocks" check relied on a simple
linked list of spans. This resulted in extremely poor complexity while
linking objects with lots of small sections (e.g. objects built with
split sections).
Rework the mechanism to instead use a simple interval set implemented
via binary search.
Fixes #26009.
-
9f4c6d8b
by Ben Gamari at 2025-07-16T18:18:33+05:30
testsuite: Add simple functional test for ProddableBlockSet
-
caf15939
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker/PEi386: Drop check for LOAD_LIBRARY_SEARCH_*_DIRS
The `LOAD_LIBRARY_SEARCH_USER_DIRS` and
`LOAD_LIBRARY_SEARCH_DEFAULT_DIRS` were introduced in Windows Vista and
have been available every since. As we no longer support Windows XP we
can drop this check.
Addresses #26009.
-
152daa3d
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker/PEi386: Clean up code style
-
d1d1a867
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/Hash: Factor out hashBuffer
This is a useful helper which can be used for non-strings as well.
-
7320f9c2
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker/PEi386: Fix incorrect use of break in nested for
Previously the happy path of PEi386 used `break` in a double-`for` loop
resulting in redundant calls to `LoadLibraryEx`.
Fixes #26052.
-
bcef0f58
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts: Correctly mark const arguments
-
59225e43
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker/PEi386: Don't repeatedly load DLLs
Previously every DLL-imported symbol would result in a call to
`LoadLibraryEx`. This ended up constituting over 40% of the runtime of
`ghc --interactive -e 42` on Windows. Avoid this by maintaining a
hash-set of loaded DLL names, skipping the call if we have already
loaded the requested DLL.
Addresses #26009.
-
0482675b
by Ben Gamari at 2025-07-16T18:18:33+05:30
rts/linker: Expand comment describing ProddableBlockSet
-
62112832
by Cheng Shao at 2025-07-16T18:18:33+05:30
rts: fix rts_clearMemory logic when sanity checks are enabled
This commit fixes an RTS assertion failure when invoking
rts_clearMemory with +RTS -DS. -DS implies -DZ which asserts that free
blocks contain 0xaa as the designated garbage value. Also adds the
sanity way to rts_clearMemory test to prevent future regression.
Closes #26011.
ChatGPT Codex automatically diagnosed the issue and proposed the
initial patch in a single shot, given a GHC checkout and the following
prompt:
---
Someone is reporting the following error when attempting to use `rts_clearMemory` with the RTS option `-DS`:
```
test.wasm: internal error: ASSERTION FAILED: file rts/sm/Storage.c, line 1216
(GHC version 9.12.2.20250327 for wasm32_unknown_wasi)
Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
```
What's the culprit? How do I look into this issue?
---
I manually reviewed & revised the patch, tested and submitted it.
(cherry picked from commit 86406f48659a5ab61ce1fd2a2d427faba2dcdb09)
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309c717a
by Hécate Kleidukos at 2025-07-16T18:18:33+05:30
Expose all of Backtraces' internals for ghc-internal
Closes #26049
(cherry picked from commit 16014bf84afa0d009b6254b103033bceca42233a)
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361d39e3
by ARATA Mizuki at 2025-07-16T18:18:33+05:30
AArch64 NCG: Fix sub-word arithmetic right shift
As noted in Note [Signed arithmetic on AArch64], we should zero-extend sub-word values.
Fixes #26061
(cherry picked from commit 265d0024abc95be941f8e4769f24af128eedaa10)
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96bf5522
by Ben Gamari at 2025-07-16T18:18:33+05:30
base: Expose Backtraces constructor and fields
This was specified in the proposal (CLC #199) yet somehow didn't make it
into the implementation.
Fixes #26049.
(cherry picked from commit 17db44c5b32fff82ea988fa4f1a233d1a27bdf57)
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693de35d
by ARATA Mizuki at 2025-07-16T18:18:33+05:30
x86 NCG: Fix code generation of bswap64 on i386
Co-authored-by: sheaf <sam.derbyshire@gmail.com>
Fix #25601
(cherry picked from commit bfa6b70f27dc2ce7fc890ec71103c40f66497c77)
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e16d6ba5
by Cheng Shao at 2025-07-16T18:18:33+05:30
testsuite: add T26120 marked as broken
(cherry picked from commit 44b8cee2d5c114b238898ce4ee7b44ecaa0bf491)
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f2bfe159
by Cheng Shao at 2025-07-16T18:18:33+05:30
compiler: fix GHC.SysTools.Ar archive member size writing logic
This patch fixes a long-standing bug in `GHC.SysTools.Ar` that emits
the wrong archive member size in each archive header. It should encode
the exact length of the member payload, excluding any padding byte,
otherwise malformed archive that extracts a broken object with an
extra trailing byte could be created.
Apart from the in-tree `T26120` test, I've also created an out-of-tree
testsuite at https://github.com/TerrorJack/ghc-ar-quickcheck that
contains QuickCheck roundtrip tests for `GHC.SysTools.Ar`. With this
fix, simple roundtrip tests and `writeGNUAr`/GNU `ar` roundtrip test
passes. There might be more bugs lurking in here, but this patch is
still a critical bugfix already.
Fixes #26120 #22586.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 894a04f3a82dd39ecef71619e2032c4dfead556e)
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81066df0
by Vladislav Zavialov at 2025-07-16T18:18:33+05:30
Error message with EmptyCase and RequiredTypeArguments (#25004)
Fix a panic triggered by a combination of \case{} and forall t ->
ghci> let f :: forall (xs :: Type) -> (); f = \case {}
panic! (the 'impossible' happened)
GHC version 9.10.1:
Util: only
The new error message looks like this:
ghci> let f :: forall (xs :: Type) -> (); f = \case {}
<interactive>:5:41: error: [GHC-48010]
• Empty list of alternatives in \case expression
checked against a forall-type: forall xs -> ...
This is achieved as follows:
* A new data type, BadEmptyCaseReason, is now used to describe
why an empty case has been rejected. Used in TcRnEmptyCase.
* HsMatchContextRn is passed to tcMatches, so that the type checker
can attach the syntactic context to the error message.
* tcMatches now rejects type arguments if the list of alternatives is
empty. This is what fixes the bug.
(cherry picked from commit cce869ea2439bb16c284ce7ed71a173d54a8c9ad)
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61d237b5
by Vladislav Zavialov at 2025-07-16T18:18:33+05:30
Fix EmptyCase panic in tcMatches (#25960)
Due to faulty reasoning in Note [Pattern types for EmptyCase],
tcMatches was too keen to panic.
* Old (incorrect) assumption: pat_tys is a singleton list.
This does not hold when \case{} is checked against a function type
preceded by invisible forall. See the new T25960 test case.
* New (hopefully correct) assumption: vis_pat_tys is a singleton list.
This should follow from:
checkArgCounts :: MatchGroup GhcRn ... -> TcM VisArity
checkArgCounts (MG { mg_alts = L _ [] })
= return 1
...
(cherry picked from commit b34890c7d4803041caff060391eec298e2b0a098)
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0e28647d
by Vladislav Zavialov at 2025-07-16T18:20:06+05:30
Take subordinate 'type' specifiers into account
This patch fixes multiple bugs (#22581, #25983, #25984, #25991)
in name resolution of subordinate import lists.
Bug #22581
----------
In subordinate import lists, the use of the `type` namespace specifier
used to be ignored. For example, this import statement was incorrectly
accepted:
import Prelude (Bool(type True))
Now it results in an error message:
<interactive>:2:17: error: [GHC-51433]
In the import of ‘Prelude’:
a data type called ‘Bool’ is exported,
but its subordinate item ‘True’ is not in the type namespace.
Bug #25983
----------
In subordinate import lists within a `hiding` clause, non-existent
items led to a poor warning message with -Wdodgy-imports. Consider:
import Prelude hiding (Bool(X))
The warning message for this import statement used to misreport the
cause of the problem:
<interactive>:3:24: warning: [GHC-56449] [-Wdodgy-imports]
In the import of ‘Prelude’:
an item called ‘Bool’ is exported, but it is a type.
Now the warning message is correct:
<interactive>:2:24: warning: [GHC-10237] [-Wdodgy-imports]
In the import of ‘Prelude’:
a data type called ‘Bool’ is exported, but it does not export
any constructors or record fields called ‘X’.
Bug #25984
----------
In subordinate import lists within a `hiding` clause, non-existent
items resulted in the entire import declaration being discarded.
For example, this program was incorrectly accepted:
import Prelude hiding (Bool(True,X))
t = True
Now it results in an error message:
<interactive>:2:5: error: [GHC-88464]
Data constructor not in scope: True
Bug #25991
----------
In subordinate import lists, it was not possible to refer to a class
method if there was an associated type of the same name:
module M_helper where
class C a b where
type a # b
(#) :: a -> b -> ()
module M where
import M_helper (C((#)))
This import declaration failed with:
M.hs:2:28: error: [GHC-10237]
In the import of ‘M_helper’:
an item called ‘C’ is exported, but it does not export any children
(constructors, class methods or field names) called ‘#’.
Now it is accepted.
Summary
-------
The changes required to fix these bugs are almost entirely confined to
GHC.Rename.Names. Other than that, there is a new error constructor
BadImportNonTypeSubordinates with error code [GHC-51433].
Test cases:
T22581a T22581b T22581c T22581d
T25983a T25983b T25983c T25983d T25983e T25983f T25983g
T25984a T25984b
T25991a T25991b1 T25991b2
(cherry picked from commit 282df90570fa9c777c914ae543fea291f7158482)
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45c1be7c
by Andreas Klebinger at 2025-07-16T18:20:06+05:30
Add since tag and more docs for do-clever-arg-eta-expansion
Fixes #26113
(cherry picked from commit 699deef58bf89ef2f111b35f72d303a3624d219d)