-
cf942119
by Cheng Shao at 2026-03-30T15:24:37-04:00
ghc-boot: remove unused SizedSeq instances and functions
This commit removes unused `SizedSeq` instances and functions, only
keeping the bits we need for hpc tick sequence for now.
-
22c5b7cc
by Cheng Shao at 2026-03-30T15:24:38-04:00
ghci: remove unused GHCi.BinaryArray
This patch removes the unused `GHCi.BinaryArray` module from `ghci`.
Closes #27108.
-
77abb4ab
by Cheng Shao at 2026-03-30T15:25:21-04:00
testsuite: mark T17912 as fragile on Windows
T17912 is still fragile on Windows, it sometimes unexpectedly pass in
CI. This especially strains our already scarce Windows CI runner
resources. Mark it as fragile on Windows for the time being.
-
d741a6cc
by Andreas Klebinger at 2026-03-31T04:39:33-04:00
Bump minimum shake version for hadrian.
We also add the shake version we want to stack.yaml
Fixes #26884
-
5e556f9e
by Vladislav Zavialov at 2026-03-31T04:40:16-04:00
Status check for the HsType~HsExpr refactoring (#25121)
Add a test case to track the status of a refactoring project within GHC
whose goal is to arrive at the following declaration:
type HsType = HsExpr
The rationale for this is to increase code reuse between the term- and
type-level code in the compiler front-end (AST, parser, renamer, type checker).
The status report is saved to testsuite/tests/ghc-api/T25121_status.stdout
and provides useful insights into what needs to happen to make progress on
the ticket.
-
acffb1b1
by fendor at 2026-03-31T04:41:02-04:00
Extract Binary instances to `GHC.ByteCode.Binary`
-
e2ea8e25
by fendor at 2026-03-31T04:41:02-04:00
Add `seqNonEmpty` for evaluating `NonEmpty a`
-
048b00b7
by fendor at 2026-03-31T04:41:02-04:00
Record `LinkableUsage` instead of `Linkable` in `LoaderState`
Retaining a ByteCode `Linkable` after it has been loaded retains its
`UnlinkedBCO`, keeping it alive for the remainder of the program.
This starts accumulating a lot of `UnlinkedBCO` and memory over time.
However, the `Linkable` is merely used to later record its usage in
`mkObjectUsage`, which is used for recompilation checking.
However, this is incorrect, as the interface file and bytecode objects
could be in different states, e.g. the interface changes, but the
bytecode library hasn't changed so we don't need to recompile and vice
versa.
By computing a `Fingerprint` for the `ModuleByteCode`, and recording it
in the `LinkableUsage`, we know precisely whether the `ByteCode` object
on disk is outdated.
Thus, parts of this commit just makes sure that we efficiently compute a
`Fingerprint` for `ModuleByteCode` and store it in the on-disk
representation of `ModuleByteCode`.
We change the `LoaderState` to retain `LinkableUsage`, which is smaller
representation of a `Linkable`. This allows us to free the unneeded
fields of `Linkable` after linking them.
We declare the following memory invariants that this commit implements:
* No `LinkablePart` should be retained from `LoaderState`.
* `Linkable`s should be unloaded after they have been loaded.
These invariants are unfortunately tricky to automatically uphold, so we
are simply documenting our assumptions for now.
We introduce the `linkable-space` test which makes sure that after
loading, no `DotGBC` or `UnlinkedBCO` is retained.
-------------------------
Metric Increase:
MultiLayerModulesTH_OneShot
-------------------------
We allocate a bit more, but the peak number of bytes doesn't change.
While a bit unfortunate, accepting the metric increase.
We add multiple new performance measurements where we were able to
observe the desired memory invariants. Further, we add regression tests
to validate that the recompilation checker behaves more correct than
before.
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2d1c1997
by Simon Jakobi at 2026-03-31T04:41:46-04:00
Eliminate dictionary-passing in ListMap operations
Mark the ListMap helpers 'INLINABLE' so importing modules can specialise
the 'TrieMap (ListMap m)' methods and avoid recursive dictionary-passing.
See Note [Making ListMap operations specialisable].
Fixes #27097
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ed2c6570
by Cheng Shao at 2026-03-31T04:42:33-04:00
testsuite: fix testdir cleanup logic on Windows
testdir cleanup is unreliable on Windows (#13162) and despite existing
hacks in the driver, new failure mode has occurred. This patch makes
it print the warning and carry on when failed to clean up a testdir,
instead of reporting a spurious framework failure. See added comment
for detailed explanation.
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d9388e29
by Simon Jakobi at 2026-03-31T13:14:59-04:00
Add regression test for #18177
Closes #18177.
Assisted-by: Codex
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6a10045c
by mangoiv at 2026-03-31T13:15:43-04:00
ci: allow metric decrease for two tests on i386
There has been a nightly failure on i386 due to a compiler runtime
improvement on i386 debian 12. We allow that.
Metric Decrease (test_env='i386-linux-deb12'):
T12707 T8095
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7fbb4fcb
by Rodrigo Mesquita at 2026-04-01T12:16:33+00:00
Bump default language edition to GHC2024
As per the accepted ghc-proposal#632
Fixes #26039
-
5ae43275
by Peng Fan at 2026-04-01T19:01:06-04:00
NCG/LA64: add cmpxchg and xchg primops
And append some new instructions for LA664 uarch.
Apply fix to cmpxchg-prim by Andreas Klebinger.
Suggestions in https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15515
-
8f95534a
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove signal-based ticker implementations
Fixes issue #27073
All supported platforms should work with the pthreads + nanosleep based
ticker implementation. This avoids all the problems with using signals.
In practice, all supported platforms were probably using the non-signal
tickers already, which is probably why we do not get lots of reports
about deadlocks and other weirdness: we were definately using functions
that are not async signal safe in the tick handler (such as fflush to
flussh the eventlog).
Only Solaris was explicitly using the timer_create ticker impl, and even
Solaris could probably use the pthreads one (if anyone cared: Solaris is
no longer a Teir 3 supported platform).
Plausibly the only supported platform that this will change will be AIX,
which should now use the pthreads impl.
-
51b32b0d
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Tidy up some timer/ticker comments elsewhere
-
7562bcd7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove now-unused install_vtalrm_handler
Support function used by both of the signal-based ticker
implementations.
-
6da127c7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
No longer probe for timer_create in rts/configure
It was only used by the TimerCreate.c ticker impl.
-
3fd490fa
by Duncan Coutts at 2026-04-01T19:01:53-04:00
Note that rtsTimerSignal is deprecated.
-
63099b0f
by Simon Jakobi at 2026-04-01T19:02:39-04:00
Add perf test for #13960
Closes #13960.
-
58009c14
by Apoorv Ingle at 2026-04-02T09:51:24+01:00
Streamline expansions using HsExpansion (#25001)
Notes added [Error Context Stack] [Typechecking by expansion: overview]
Notes updated Note [Expanding HsDo with XXExprGhcRn] [tcApp: typechecking applications]
-------------------------
Metric Decrease:
T9020
-------------------------
There are 2 key changes:
1. `HsExpand` datatype mediates between expansions
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
This has some consequences detailed below:
1. `HsExpand` datatype mediates between expansions
* Simplifies the implementations of `tcExpr` to work on `XExpr`
* Removes `VACtxt` (and its associated `VAExpansion` and `VACall`) datatype, it is subsumed by simply a `SrcSpan`.
* Removes the function `addHeadCtxt` as it is now mearly setting a location
* The function `tcValArgs` does its own argument number management
* move `splitHsTypes` out of `tcApp`
* Removes special case of tcBody from `tcLambdaMatches`
* Removes special case of `dsExpr` for `ExpandedThingTc`
* Renames `tcMonoExpr` -> `tcMonoLExpr`, `tcMonoExprNC` -> `tcMonoLExpr`
* Renames `EValArg`, `EValArgQL` fields: `ea_ctxt` -> `ea_loc_span` and `eaql_ctx` -> `eaql_loc_span`
* Remove `PopErrCtxt` from `XXExprGhcRn`
* `fun_orig` in tcInstFun depends on the SrcSpan of the head of the application chain (similar to addArgCtxt)
- it references the application chain head if it is user located, or
uses the error context stack as a fallback if it's a generated
location
* Make a new variant `GeneratedSrcSpan` in `SrcSpan` for HIEAst Nodes
- Expressions wrapped around `GeneratedSrcSpan` are ignored and never added to the error context stack
- In Explicit list expansion `fromListN` is wrapped with a `GeneratedSrcSpan` with `GeneratedSrcSpanDetails` field to store the original srcspan
2. Replace `ErrCtxtM` to a simpler `HsCtxt` that does not depend on a `TidyEnv`
* Merge `HsThingRn` to `HsCtxt`
* Landmark Error messages are now just computed on the fly
* Make HsExpandedRn and HsExpandedTc payload a located HsExpr GhcRn
* `HsCtxt` are tidied and zonked at the end right before printing
Co-authored-by: simonpj <simon.peytonjones@gmail.com>
-
bc4b4487
by Zubin Duggal at 2026-04-03T14:22:27-04:00
driver: recognise .dyn_o as a valid object file to link if passed on the command line.
This allows plugins compiled with this suffix to run.
Fixes #24486
-
5ebb9121
by Simon Jakobi at 2026-04-03T14:23:11-04:00
Add regression test for #16145
Closes #16145.
-
c1fc1c44
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Refactor eta-expansion in Prep
The Prep pass does eta-expansion but I found cases where it was
doing bad things. So I refactored and simplified it quite a bit.
In the new design
* There is no distinction between `rhs` and `body`; in particular,
lambdas can now appear anywhere, rather than just as the RHS of
a let-binding.
* This change led to a significant simplification of Prep, and
a more straightforward explanation of eta-expansion. See the new
Note [Eta expansion]
* The consequences is that CoreToStg needs to handle naked lambdas.
This is very easy; but it does need a unique supply, which forces
some simple refactoring. Having a unique supply to hand is probably
a good thing anyway.
-
21beda2c
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Clarify Note [Interesting dictionary arguments]
Ticket #26831 ended up concluding that the code for
GHC.Core.Opt.Specialise.interestingDict was good, but the
commments were a bit inadequate.
This commit improves the comments slightly.
-
3eaac1f2
by Simon Peyton Jones at 2026-04-03T19:56:07-04:00
Make inlining a bit more eager for overloaded functions
If we have
f d = ... (class-op d x y) ...
we should be eager to inline `f`, because that may change the
higher order call (class-op d x y) into a call to a statically
known function.
See the discussion on #26831.
Even though this does a bit /more/ inlining, compile times
decrease by an average of 0.4%.
Compile time changes:
DsIncompleteRecSel3(normal) 431,786,104 -2.2%
ManyAlternatives(normal) 670,883,768 -1.6%
ManyConstructors(normal) 3,758,493,832 -2.6% GOOD
MultilineStringsPerf(normal) 29,900,576 -2.8%
T14052Type(ghci) 1,047,600,848 -1.2%
T17836(normal) 392,852,328 -5.2%
T18478(normal) 442,785,768 -1.4%
T21839c(normal) 341,536,992 -14.1% GOOD
T3064(normal) 174,086,152 +5.3% BAD
T5631(normal) 506,867,800 +1.0%
hard_hole_fits(normal) 209,530,736 -1.3%
info_table_map_perf(normal) 19,523,093,184 -1.2%
parsing001(normal) 377,810,528 -1.1%
pmcOrPats(normal) 60,075,264 -0.5%
geo. mean -0.4%
minimum -14.1%
maximum +5.3%
Runtime changes
haddock.Cabal(normal) 27,351,988,792 -0.7%
haddock.base(normal) 26,997,212,560 -0.6%
haddock.compiler(normal) 219,531,332,960 -1.0%
Metric Decrease:
LinkableUsage01
ManyConstructors
T17949
T21839c
T13035
TcPlugin_RewritePerf
hard_hole_fits
Metric Increase:
T3064
-
5cbc2c82
by Matthew Pickering at 2026-04-03T19:57:02-04:00
bytecode: Add magic header/version to bytecode files
In order to avoid confusing errors when using stale interface files (ie
from an older compiler version), we add a simple header/version check
like the one for interface files.
Fixes #27068
-
d95a1936
by fendor at 2026-04-03T19:57:02-04:00
Add constants for bytecode in-memory buffer size
Introduce a common constant for the default size of the .gbc and
.bytecodelib binary buffer.
The buffer is by default set to 1 MB.
-
b822c30a
by mangoiv at 2026-04-03T19:57:49-04:00
testsuite: filter stderr for static001 on darwin
This reactivates the test on x86_64 darwin as this should have been done
long ago and ignores warnings emitted by ranlib on newer version of the
darwin toolchain since they are benign. (no symbols for stub libraries)
Fixes #27116
-
28ce1f8a
by Andreas Klebinger at 2026-04-03T19:58:44-04:00
Give the Data instance for ModuleName a non-bottom toConstr implementation.
I've also taken the liberty to add Note [Data.Data instances for GHC AST Types]
describing some of the uses of Data.Data I could find.
Fixes #27129
-
8ca41ffe
by mangoiv at 2026-04-03T19:59:30-04:00
issue template: fix add bug label
-
3981db0c
by Sylvain Henry at 2026-04-03T20:00:33-04:00
Add more canned GC functions for common register patterns (#27142)
Based on analysis of heap-check sites across the GHC compiler and Cabal,
the following patterns were not covered by existing canned GC functions
but occurred frequently enough to warrant specialisation:
stg_gc_ppppp -- 5 GC pointers
stg_gc_ip -- unboxed word + GC pointer
stg_gc_pi -- GC pointer + unboxed word
stg_gc_ii -- two unboxed words
stg_gc_bpp -- byte (I8) + two GC pointers
Adding these reduces the fraction of heap-check sites falling back to
the generic GC path from ~1.4% to ~0.4% when compiling GHC itself.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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d17d1435
by Matthew Pickering at 2026-04-03T20:01:19-04:00
Make home unit dependencies stored as sets
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>
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92a97015
by Simon Peyton Jones at 2026-04-05T00:58:57+01:00
Add Invariant (NoTypeShadowing) to Core
This commit addresses #26868, by adding
a new invariant (NoTypeShadowing) to Core.
See Note [No type-shadowing in Core] in GHC.Core
-
8b5a5020
by Simon Peyton Jones at 2026-04-05T00:58:57+01:00
Major refactor of free-variable functions
For some time we have had two free-variable mechanims for types:
* The "FV" mechanism, embodied in GHC.Utils.FV, which worked OK, but
was fragile where eta-expansion was concerned.
* The TyCoFolder mechanism, using a one-shot EndoOS accumulator
I finally got tired of this and refactored the whole thing, thereby
addressing #27080. Now we have
* `GHC.Types.Var.FV`, which has a composable free-variable result type,
very much in the spirit of the old `FV`, but much more robust.
(It uses the "one shot trick".)
* GHC.Core.TyCo.FVs now has just one technology for free variables.
All this led to a lot of renaming.
There are couple of error-message changes. The change in T18451
makes an already-poor error message even more mysterious. But
it really needs a separate look.
We also now traverse the AST in a different order leading to a different
but still deterministic order for FVs and test output has been adjusted
accordingly.
-
4bf040c6
by sheaf at 2026-04-05T14:56:29-04:00
Add utility pprTrace_ function
This function is useful for quick debugging, as it can be added to a
where clause to pretty-print debugging information:
fooBar x y
| cond = body1
| otherwise = body2
where
!_ = pprTrace_ "fooBar" $
vcat [ text "x:" <+> ppr x
, text "y:" <+> ppr y
, text "cond:" <+> ppr cond
]
-
ed734539
by Matthew Pickering at 2026-04-07T05:36:42+00:00
packaging: correctly propagate build/host/target to bindist configure script
At the moment the host and target which we will produce a compiler for
is fixed at the initial configure time. Therefore we need to persist
the choice made at this time into the installation bindist as well so we
look for the right tools, with the right prefixes at install time.
In the future, we want to provide a bit more control about what kind of
bindist we produce so the logic about what the host/target will have to
be written by hadrian rather than persisted by the configure script. In
particular with cross compilers we want to either build a normal stage 2
cross bindist or a stage 3 bindist, which creates a bindist which has a
native compiler for the target platform.
Fixes #21970
Co-authored-by: Sven Tennie <sven.tennie@gmail.com>
-
1e1f4048
by Sven Tennie at 2026-04-07T05:36:42+00:00
Cross --host and --target no longer required for cross (#21970)
We set sane defaults in the configure script. Thus, these paramenters
aren't required any longer.
-
f9e70b7d
by Sven Tennie at 2026-04-07T05:36:42+00:00
ci: Define USER_CONF_CC_OPTS_STAGE2 for aarch64/mingw
ghc-toolchain doesn't see $CONF_CC_OPTS_STAGE2 when the bindist gets
configured. So, the hack to override the compiler gets lost.