-
e757591a
by Simon Hengel at 2026-07-27T15:14:26+05:30
Reference correct package in error messages for reexported modules
(fixes #27417)
(cherry picked from commit a805b2a25021606b30d250e084d4beecbfac0d0a)
-
fba13ef3
by Luite Stegeman at 2026-07-27T15:14:33+05:30
rts: handle large AP closures in compacting GC
The function update_fwd_large in the compacting GC could run into
an unexpected object with the following error:
internal error: update_fwd_large: unknown/strange object 24
Closure type 24 is the AP closure, which was not handled in
upd_fwd_large. This patch adds handling them.
fixes #27434
(cherry picked from commit cca0d58963f802a8b2e43aa2dbc58592f8ad07bb)
-
0500851f
by Cheng Shao at 2026-07-27T15:14:33+05:30
compiler: fix missing handling of CmmUnsafeForeignCall node in LayoutStack
This patch fixes missing handling of `CmmUnsafeForeignCall` middle
node in the `LayoutStack` pass.
Before proc-points splitting, this pass computes liveliness of local
registers, and spills those alive across a Cmm native call onto the
stack. It need to traverse all middle nodes in each block and check
whether a local register is an assignee, if so then the previous
mapping in `sm_regs` is invalidated and needs to be dropped. However,
it didn't handle `CmmUnsafeForeignCall` node which may also assign to
a local register. When proc-points splitting is enabled, this can
produce an invalid basic block that doesn't properly backup the
updated local register to the stack before doing a Cmm call, resulting
in completely invalid runtime behavior.
The patch also adds a `T27447` regression test. With no-TNTC or with
LLVM backend, without the fix the test case would output a stale
0x1111111111111111 value, instead of the expected 0x2222222222222222
output.
Fixes #27447.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 3f00f234d0d5b3b3b2a23a5dc70ce372eb9bbdb4)
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31af42e7
by Cheng Shao at 2026-07-27T15:14:33+05:30
ci: use treeless fetch for perf notes
This patch improves the ci logic for fetching perf notes by using
treeless fetch
(https://github.blog/open-source/git/get-up-to-speed-with-partial-clone-and-shallow-clone),
to avoid downloading all blobs of the perf notes repo at once, and
only fetch the actually required blobs on-demand when needed. This
makes the initial `test-metrics.sh pull` operation much faster, and
also more robust, since we are seeing an increasing rate of 504 errors
in CI when fetching all perf notes at once, which is a major source of
CI flakiness at this point.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 3c0013778b4459c1f8e56cd0dc2600f5bb3769d2)
-
a56fcdee
by mangoiv at 2026-07-27T15:14:33+05:30
ci: retry fetching test metrics
Retry fetching test metrics to make the CI not fail if the services is
temporarily unavailable
(cherry picked from commit b7e24044fde064cb3f0d44c36872a86d024cd7d4)
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03e870e1
by Zubin Duggal at 2026-07-27T15:14:33+05:30
Bump semaphore-compat submodule to 2.0.1
This versions includes some cruicial fixes for darwin
(cherry picked from commit 4180af3f71754472dbd49b85179b25fd29bd9998)
-
1eb8f64b
by Zubin Duggal at 2026-07-27T15:14:33+05:30
CorePrep: Don't speculatively evaluate bindings that we have already discovered to be absent
In #25924, we segfault because speculation forces a projection out of a RUBBISH dictionary
(which we generated because it absent).
Solution: Don't speculate on bindings we already know are absent.
Fixes 25924
(cherry picked from commit 9b714c4c833461c621f0a050680848d7248aa57e)
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843e7885
by Zubin Duggal at 2026-07-27T15:14:33+05:30
Don't make absent fillers for terminating types
In #25924 we discovered that we could speculatively evaluate an absent filler
for a dictionary, and project a field (a superclass selector) out of it,
resulting in segfaults.
Solution: Never make an absent filler or rubbish literal for a terminating type
like a dictionary. mkAbsentFiller returns Nothing for isTerminatingType, so
worker/wrapper and the specialiser keep the real argument instead.
Some small metric decreases because we do a little less work in the
simplifier now.
Metric Decrease:
T9872a
T9872b
T9872c
TcPlugin_RewritePerf
(cherry picked from commit 4a59b3eece9b7106fcbe73d2d06a49755be4ea8f)
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e8f1b190
by Andreas Klebinger at 2026-07-27T15:14:33+05:30
Fix a profiling race condition resulting in segfaults.
StgToCmm: Don't assume tagged FUN closures in closureCodeBody.
When entering a closure the self/node pointer might not be tagged in
some situations when a thunk is evaluated by multiple threads.
So we most AND away the tag bits rather than subtracting an expected tag.
Apply.cmm: Fix a race condition occuring when a thunk is mutated during GC.
In stg_ap_0_fast when might need to run GC before entering a thunk. If this happens
another thread or the GC itself might mutate the closure making entering it no longer
valid. We now check for this.
Add test and changelog for #27123 fixes.
(cherry picked from commit ed09895d7de1ca116a561868c151fd825a16ad0c)
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f1cfd0f4
by Cheng Shao at 2026-07-27T15:14:33+05:30
ghc-heap: fix invalid srtlen returned by peekItbl when no-TNTC
This patch fixes the no-TNTC code path of `peekItbl` so that it looks
at the right memory address when reading the `srt` field from the
`StgInfoTable_` struct. Also adds a `T27465` regression test that
reproduces the bug on no-TNTC builds before the fix. Fixes #27465.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 67c03eb2c762fdfeb646eb8345341173dd4268b2)
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ed840c99
by Cheng Shao at 2026-07-27T15:14:33+05:30
compiler: fix miscompiled %load_relaxed, add missing %store_relaxed
This patch fixes the %load_relaxed cmm primop compilation logic to
correctly use relaxed memory ordering, and adds the missing
%store_relaxed primop. Parsing logic of %load/%store with explicit
ordering is covered in the AtomicFetch test case. Fixes #27483.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit eee8ec5b25ef0f83ba4822e7a0a941df7b0bec5f)
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fc129385
by Cheng Shao at 2026-07-27T15:14:33+05:30
rts: fix missing UNTAG in stg_readTVarIOzh
This patch fixes missing UNTAG on the current value closure read from
StgTVar. UNTAG is a no-op when it's stg_TREC_HEADER_info which is word
aligned; it may be a tagged closure, and reading info table from the
tagged address is an unaligned load which may cause issues on
platforms with strict alignment requirements.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit d377e83e51d39a06e1f0bf2e35a923a3210b21a2)
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2e023223
by Cheng Shao at 2026-07-27T15:14:33+05:30
rts: fix missing UNTAG in stg_control0zh_ll
This patch fixes missing UNTAG on the cont closure returned by
captureContinuationAndAbort. In case it's not NULL,
captureContinuationAndAbort returns a tagged StgContinuation closure,
in which case it must be untagged before accessing the
apply_mask_frame field.
In the past it worked out of luck: when apply_mask_frame was NULL then
mask_frame_offset is also 0 so the control flow didn't diverge to a
wrong path. Still, this is horribly wrong and will crash once
StgContinuation struct is refactored and fields are shuffled around.
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 8ed038421a20e3e4e681973b2f5098e5bd2144b5)
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a52c471f
by Cheng Shao at 2026-07-27T15:14:33+05:30
compiler: fix redundant AP thunk codegen when not using -ticky-ap-thunk
This patch fixes a double negation confusion in !7525 that results in
some redundant AP thunk code generation when not using
-ticky-ap-thunk. Now, we use `stgToCmmUseStdApThunk` to indicate
whether precomputed AP thunks in the RTS should be used, which
defaults to `True`, unless `-ticky-ap-thunk` is passed.
`-finfo-table-map` now also implies `-ticky-ap-thunk`, since when
doing IPE profiling we want the generated AP thunks to be unique.
Fixes #27502.
-------------------------
Metric Decrease:
T3064
-------------------------
Co-authored-by: Codex <codex@openai.com>
(cherry picked from commit 5aa7000ae246ae6a706437799338295b5801a629)
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d26793ae
by sheaf at 2026-07-27T15:14:33+05:30
Avoid mkTick in Core Prep breaking ANF
As discovered in #27182, mkTick can break ANF. This patch introduces a
variant of mkTick that skips the single optimisation that could break
ANF. This is preferrable over switching to the raw Tick constructor,
as the latter may introduce spurious cost centres in profiling reports.
This is a temporary measure until we more thoroughly refactor how
mkTick works (see #27141).
See Note [mkTick breaks ANF] in GHC.CoreToStg.Prep.
Fixes #27182
(cherry picked from commit f9bcfac2e92457128f5c82dea181edcd0baf7eef)
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34061ece
by sheaf at 2026-07-27T15:14:33+05:30
Don't drop ticks around variables of type `IO ()`
GHC.Core.Utils.mkTick is responsible for placing a tick on a Core
expression. It contains logic for dropping SCCs (non-counting profiling
ticks) around non-function variables, as such variables cannot
meaningfully contribute to profiles. However, the logic for what counts
as a function was incorrect: it used `isFunTy` which returns 'False' for
types such as 'IO ()' where the function arrow is hidden under a
newtype.
We now use 'mightBeFunTy' instead of 'isFunTy'. This ensures we don't
drop ticks in cases we aren't sure.
On the way, we improve the documentation of 'isFunTy', 'isPiTy' and
'mightBeFunTy', and update the latter's implementation to consistently
handle unary classes.
Fixes #27225
-------------------------
Metric Decrease:
T5642
-------------------------
(cherry picked from commit ce01ccb625514a09e76aded549691da4dfe87de7)
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e908040d
by sheaf at 2026-07-27T15:14:33+05:30
Avoid mkTick in Core Prep breaking ANF (part II)
Hotfix for 2f9579765f55b3920ceb2e04995ff41a9d0e2d4e fixing a small
oversight in the call to tickTickedExpr from mkTick, in which we
improperly recursively called mkTick without passing on the preserve_anf
flag.
Fixes #27386
(cherry picked from commit 473b97ebc742305f56e30d5b1bbf95b7681312f0)
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6bdf75ab
by Ian-Woo Kim at 2026-07-27T15:14:33+05:30
Make the order of usages deterministic
It has been observed that the ordering of usages can be non-determinstic
in parallel builds. Therefore, this contribution introduces sorting of
usages based on a platform- and race-independent sorting criterion.
Resolves #26877.
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>
(cherry picked from commit d216412babfd5b5746365f0686ec370fb0892ec7)
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6382e45c
by Wolfgang Jeltsch at 2026-07-27T15:14:33+05:30
Change the descriptions of two existing changelog entries
The descriptions now describe the changes in a user-friendly manner, as
opposed to describing the contributions that led to these changes in a
developer-friendly manner.
(cherry picked from commit 8e1cc105acae69b1fabd1a9b89e2d1823861f518)
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a8cb9679
by Andrea Vezzosi at 2026-07-27T15:14:33+05:30
[Fix #27287] preserve ModBreaks in ModIface
(cherry picked from commit 4396a6f2a4c7799908e1e0b88a218a51d063fdca)
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14691377
by mangoiv at 2026-07-27T15:14:33+05:30
compiler: refactor error reporting code for ExplicitLevelImports
Refactors error reporting code for ExplicitLevelImports to pass in a
RdrName and a GlobalReaderElt to be able to report errors that are
faithful to the source and to more precisely distinguish between names
that are in scope from different qualifications.
Fixes #27385 and #26616
(cherry picked from commit 141986e3680a24b76e21a7ad4ce6290a7413c7f5)
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d3099986
by mangoiv at 2026-07-27T15:14:33+05:30
compiler: rename ZonkAny to UnusedType and add pretty printing logic
ZonkAny is a hard to understand name for users who do not know how the
compiler works internally. Additionally, it is confusing that ZonkAny,
while being a concrete type *represents* a meta variable, espeically in
the compiler output.
This patch changes the name of ZonkAny to UnusedType which is closer to
its intended semantics and adds special pretty printing logic to display
this type in the same fashion the compiler displays meta variables in
other places, whenever they leak from the implementation to the user.
It also exports the type from ghc-internal:GHC.Internal.Types in order
to expose documentation.
Fixes #27390
Co-Authored-By: Sam Derbyshire <sam.derbyshire@gmail.com>
(cherry picked from commit a72ff58fa86172b1557e405f7246d27914fdae6e)
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8ad5f8f7
by Zubin Duggal at 2026-07-27T15:14:33+05:30
hadrian: Remove old package.conf files when generating new ones
Old package.conf files might exists with different hashes, causing issues like #26661
Fixes #26661
(cherry picked from commit 5ac9ce7d3821c75e2d2cc17fae00b9e865a02987)
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1b612594
by Zubin Duggal at 2026-07-27T15:14:33+05:30
testsuite: disable git auto-gc when fetching perf notes
Otherwise the message it prints breaks the parsing
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d1651dfd
by Zubin Duggal at 2026-07-27T15:14:54+05:30
UniqueDFM: alter should preserve insertion order
Before it always inserting new elements at the end.
This is problematic because instances get inserted into the map with
`alterF`, which can change ordering of how instances are printed
with `:info` depending on the order in which we consult interfaces
I expect `alter id k = id` and `alter (fmap f) k = adjust f k`. Moving keys to
the end breaks that (`adjust` already preserves position).
Fixes #27532
(cherry picked from commit f6f2343fbbfdfd8aaed9babf5983e3e24c08ca85)
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391df98b
by Zubin Duggal at 2026-07-27T15:14:54+05:30
Prepare 9.14.2
Bump filpath submodule to 1.5.5.0
Bump Win32 submodule to 2.14.2.2
Metric Increase:
T4029
T13379
Metric Decrease:
T5030