Wolfgang Jeltsch pushed to branch wip/jeltsch/ghc-9-14-building-base at Glasgow Haskell Compiler / GHC

Commits:

• 2ecabb4f
  by Zubin Duggal at 2026-07-09T09:23:25-04:00

  hadrian: binary-dist-dir should not be the default target
  
  Revert behaviour to pre 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
  
  In 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2, we applied the following behaviour change:
  
  ```
  hadrian: Build stage 2 cross compilers
  ...
  * hadrian: Make binary-dist-dir the default build target. This allows us
    to have the logic in one place about which libraries/stages to build
    with cross compilers. Fixes #24192
  ```
  
  This is a major regression to development experience, a plain hadrian/build
  --freeze1 now takes ages because we rebuild all docs (which need to go in the
  binary dist dir).
  
  `binary-dist-dir` is the wrong default target for regular GHC development work
  
  Fixes #27445
  

• e16388e3
  by Zubin Duggal at 2026-07-09T09:23:25-04:00

  .gitignore: Add the hadrian system.config introduced by commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
  
  Since
  
  commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2
  Author: Matthew Pickering <matthewtpickering@gmail.com>
  Date:   Thu Dec 21 16:17:41 2023 +0000
  
      hadrian: Build stage 2 cross compilers
  
  ./configure produces /hadrian/cfg/system.config.{host,target}
  
  Add these to .gitignore
  

• 7e8abf41
  by Alan Zimmerman at 2026-07-09T09:24:12-04:00

  EPA: Replace AnnListItem with simply [TrailingAnn]
  
  Remove the unnecessary wrapper around a single field.
  

• 29032f17
  by Zubin Duggal at 2026-07-09T09:24:58-04:00

  testsuite: Keep real reason for fragile test failures
  

• c34e03a7
  by Zubin Duggal at 2026-07-09T09:24:58-04:00

  testsuite: Fall back to the failure reason for empty JUnit bodies
  

• 409d40f0
  by Zubin Duggal at 2026-07-09T09:24:58-04:00

  testsuite: Show output diffs in JUnit output
  
  Also refactor compare_outputs to return essentially a `Maybe Diff`
  (`CompareOutput`) instead of a bool, but more pythonic. This
  allows us to pass the diff through nice.
  

• 06fee1ab
  by Zubin Duggal at 2026-07-09T09:24:58-04:00

  perf notes: include stat deviation and acceptance window in notes so they show up in gitlab
  

• 57c0f32c
  by mangoiv at 2026-07-10T11:08:38-04:00

  driver: enable -finter-module-far-jumps by default
  
  this fixes a compatibility bug with certain binutils/gcc versions where
  we were seeing jump offset overflow errors.
  This commit can probably reverted if we stop supporting the problematic
  binutils/gcc verions (2.44 and 14.2, respectively)
  
  Reolves #26994
  

• 4396a6f2
  by Andrea Vezzosi at 2026-07-10T11:09:25-04:00

  [Fix #27287] preserve ModBreaks in ModIface
  

• ed261a7e
  by Cheng Shao at 2026-07-14T17:59:38-04:00

  hadrian: fix HLS support
  
  This patch fixes hadrian's HLS support so one can rely on HLS when
  working on the hadrian codebase. Fixes #27480.
  
  Not building/linking shared libraries for hadrian is a severely
  premature optimization; this top-level setting in `cabal.project` only
  affects home packages while the dependencies in the cabal store are
  built with vanilla/dynamic anyway, and even adding dynamic builds to
  home packages would not be costly due to cabal's usage of
  `-dynamic-too`.
  

• eee8ec5b
  by Cheng Shao at 2026-07-14T18:00:20-04:00

  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>
  

• 1718230f
  by Alan Zimmerman at 2026-07-14T18:01:06-04:00

  EPA: Keep binds and sigs together in HsValBindsLR
  
  We combine them into a single list for GhcPs, wrapped in the
  ValBind data type, which is the bind equivalent of ValD, having
  constructors for binds and sigs.
  
  This simplifies exact print processing, especially when using it to
  update the contents of local binds, as we no longer need AnnSortKey
  BindTag
  

• 6bd1ad2a
  by Andreas Klebinger at 2026-07-14T18:01:49-04:00

  Bump nofib submodule to account for MonoLocalBinds.
  
  New versions of GHC enable MonoLocalBinds by default.
  This breaks some of the benchmarks. I've fixed this and
  this bump pulls in that fix.
  

• 7eb0f1c9
  by Cheng Shao at 2026-07-14T18:02:31-04:00

  testsuite: fix bytecodeIPE test under +ipe flavours
  
  This patch fixes the bytecodeIPE test under +ipe flavours. It used to
  fail under +ipe because the RTS is built with IPE info, then
  stg_AP_info in RTS carries IPE info, so whereFrom wouldn't return
  Nothing. Now the test checks IPE info of a datacon in the ghci-loaded
  module which is not affected by whether the RTS is built with IPE info
  or not. Fixes #27498.
  
  Co-authored-by: Codex <codex@openai.com>
  

• ef038aae
  by cydparser at 2026-07-15T04:35:41-04:00

  Reduce bytes allocated for `capabilities` in RTS (fixes #27487)
  
  In rts/Capability.c, `capabilities` is an array of pointers, but it was allocated as if it were an
  array of Capability's.
  

• d377e83e
  by Cheng Shao at 2026-07-15T04:36:27-04:00

  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>
  

• 8ed03842
  by Cheng Shao at 2026-07-15T04:36:27-04:00

  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>
  

• 5aa7000a
  by Cheng Shao at 2026-07-15T04:37:08-04:00

  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>
  

• d43a7b7a
  by Brian McKenna at 2026-07-15T20:10:04+02:00

  Strip ticks when desugaring bool guards
  
  The special `considerAccessible` pattern was broken when compiling
  with debug info. Compiling with debug info wraps expressions with
  `SourceNote` ticks, which broke the internals of the
  `desugarBoolGuard` function. Ticks are now ignored within this
  function.
  
  Fixes #27360
  

• ede4b17b
  by Ben Gamari at 2026-07-15T22:59:53-04:00

  base: Display ExceptionContext in WhileHandling's textual description
  
  As originally-implemented the implementation for
  `WhileHandling(displayExceptionAnnotation)` would display the
  `ExceptionContext` of the exception which it carries (as this was the
  behavior of `displayException`, in terms of which
  `displayExceptionAnnotation` was implemented).
  
  However, in 284ffab3 the definition of `SomeException(displayException)`
  was changed to exclude the `ExceptionContext`. This means that
  `WhileHandling(displayExceptionAnnotation)` fails to describe the
  provenance of the exception which it captures, greatly limiting its
  utility.
  
  Return the implementation to its originally-specified behavior by
  implementing `WhileHandling(displayExceptionAnnotation)` in terms of
  `displayExceptionWithInfo`.
  
  Fixes #27456.
  

• 0f64f348
  by Cheng Shao at 2026-07-16T15:41:08+00:00

  ci: add missing docker permission workaround in abi-test job
  

• 660cb239
  by Cheng Shao at 2026-07-16T19:37:48+00:00

  bindist: Fix make install -j race condition on macos/freebsd
  
  This patch fixes make install -j race condition on macos/freebsd. BSD
  install fails with EEXIST when multiple install processes concurrently
  create the same prefix directory. So we add an `install_dirs`
  prerequisite job that sequentially creates the directories for
  subsequent jobs to work with. Fixes #27499.
  
  Co-authored-by: Codex <codex@openai.com>
  

• 08130257
  by Cheng Shao at 2026-07-16T19:37:48+00:00

  ci: run bindist make install with -j
  
  This patch makes the ci scripts run `make install` with `-j` to reduce
  wall clock time when installing the bindist, see related issue for
  benchmark numbers. This only affects ghc ci logic, the user-facing
  default is up to distributors and is still `-j1`. Closes #27029.
  

• d5ae6906
  by Adam Gundry at 2026-07-17T04:57:43-04:00

  Mark various language extension flags as deprecated (see #27329)
  
  The following language extensions are now deprecated:
  
   - AlternativeLayoutRule
   - AlternativeLayoutRuleTransitional
   - ParallelArrays
   - PolymorphicComponents
   - Rank2Types
  
  In addition, the warning `-Walternative-layout-rule-transitional`
  has been marked as deprecated, as it is emitted only under the
  deprecated extension `XAlternativeLayoutRuleTransitional`.
  

• fe3b059c
  by Andrew Lelechenko at 2026-07-17T04:58:26-04:00

  base: re-export GHC.Environment.getFullArgs from System.Environment
  
  CLC proposal https://github.com/haskell/core-libraries-committee/issues/431
  

• 722236dd
  by sheaf at 2026-07-18T08:48:31-04:00

  Coercion optimisation: avoid double-Sym for InstCo
  
  Ticket #27374 pointed out an issue with GHC.Core.Coercion.Opt.optCoercion's
  handling of InstCo: it contravened (LC2) in Note [The LiftingContext in optCoercion]
  because it applied the ambient 'sym' to a coercion that was then added
  to the lifting context substitution.
  
  Fixes #27374
  
  Co-authored-by: Simon Jakobi <simon.jakobi@gmail.com>
  

• ff70fc75
  by sheaf at 2026-07-18T08:48:31-04:00

  Coercion optimisation: avoid exponential behaviour
  
  The change to coercion optimisation of 'InstCo' in the previous commit
  introduces exponential behaviour to the coercion optimiser. To avoid
  this, this commit provides a way to push in 'Sym' of an already-optimised
  coercion: GHC.Core.Coercion.Opt.mkDeepSymCo.
  
  See Note [Pushing Sym without re-optimising] in GHC.Core.Coercion.Opt.
  

• dfef27f0
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Move THREADED_RTS-conditional struct members to end of Capability
  
  Accessing members of the Capability struct from CMM code rely on
  accessor macros. (The macros are generated by deriveConstants).
  
  These macros have a single definition. This means that the offsets of
  all struct members must *not* vary based on THREADED_RTS vs
  !THREADED_RTS. This requires that any struct members that are
  conditional on THREADED_RTS must occur after the unconditional struct
  members. Hence we move all the ones that are conditional on
  THREADED_RTS to the end.
  
  Add a deriveConstants entry for the iomgr member of the Capability
  struct, which was the motivation for this change.
  
  Add warning messages to help our future selves. Debugging this took me
  a couple hours in gdb!
  

• c254e022
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Make the IOManager API use CapIOManager rather than Capability
  
  This makes the API somewhat more self-contained and more consistent.
  Now the IOManager API and each of the backends takes just the I/O
  manager structure. Previously we had a bit of a mixture, depending on
  whether the function needed access to the Capability or just the
  CapIOManager.
  
  We still need access to the cap, so we introduce a back reference to
  reach the capability, via iomgr->cap.
  
  Convert all uses in select and poll backends, but not win32 ones.
  Convert callers in the scheduler and elsewhere.
  
  Also convert the three CMM primops that call IOManager APIs. They just
  need to use Capability_iomgr(MyCapability()).
  

• 4f3d8f31
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Split posix/MIO.c out of posix/Signals.c
  
  The MIO I/O manager was secretly living inside the Signals file.
  
  Now it gets its own file, like any other self-respecting I/O manager.
  

• 52ce04a9
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Rationalise some scheduler run queue utilities
  
  Move them all to the same place in the file.
  
  Make some static that were used only internally.
  
  Also remove a redundant assignment after calling truncateRunQueue that
  is already done within truncateRunQueue.
  

• 75bbdebc
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Rename initIOManager{AfterFork} to {re}startIOManager
  
  These are more accurate names, since these actions happen after
  initialisation and are really about starting (or restarting) background
  threads.
  

• 724c0517
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Free per-cap I/O managers during shutdown and forkProcess
  
  Historically this was not strictly necessary. The select and win32
  legacy I/O managers did not maintain any dynamically allocated
  resources. The new poll one does (an auxillary table), and so this
  should be freed.
  
  After forkProcess, all threads get deleted. This includes threads
  waiting on I/O or timers. So as of this patch, resetting the I/O
  manager is just about tidying things up. For example, for the poll
  I/O manager this will reset the size of the AIOP table (which
  otherwise grows but never shrinks).
  
  In future however the re-initialising will become neeecessary for
  functionality, since some I/O managers will need to re-initialise
  wakeup fds that are set CLOEXEC.
  

• c007d122
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Add a TODO to the MIO I/O manager
  
  The direction of travel is to make I/O managers per-capability and have
  all their state live in the struct CapIOManager. The MIO I/O manager
  however still has a number of global variables.
  
  It's not obvious how handle these globals however.
  

• b65ab7b3
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Add a FIXME note in the Poll I/O manager
  

• daf2bd6f
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Add missing updateRemembSetPushClosure in poll I/O manager
  
  For the non-moving GC.
  

• e33ca830
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Minor doc improvement to struct StgAsyncIOOp member outcome
  
  Mention the enumeration names, as well as their numeric values. The rest
  of the code uses the enum names.
  

• 4edd2579
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Minor doc improvements for StgTSOBlockInfo
  
  Clarify that certain union members are used only by certain legacy
  I/O managers. Hopefully we will be able to remove these at some point.
  

• 536bedbb
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Avoid exporting various win32-specific rts symbols
  
  The BeginPrivate.h / EndPrivate.h scheme works perfectly well on
  Windows, but all of the rts/win32/*.h files were not using it.
  

• 8139b5ac
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Remove wakeupIOManager, ioManagerWakeup and setIOManagerWakeupFd
  
  We no longer need wakeupIOManager for the threaded RTS case, so we can
  remove it and the bits only needed to support it. This includes the
  pipe/eventfd fd shared between the RTS and the in-library I/O manager
  used for waking up the I/O manager thread. The pipe/eventfd still
  exists, but it no longer has to be communicated to the RTS, since the
  RTS no longer needs to use it.
  
  So we remove the RTS API export setIOManagerWakeupFd, and remove uses of
  it within the I/O managers in ghc-internal.
  

• 74fe7c66
  by Duncan Coutts at 2026-07-18T08:49:12-04:00

  Add a new interruptIOManager API for the I/O managers
  
  It will be used to interrupt awaitCompletedTimeoutsOrIO. Also update the
  return type and docs for awaitCompletedTimeoutsOrIO to have it return
  false when it gets interrupted, and have no useful post condition in
  that case.
  

• 38792843
  by Duncan Coutts at 2026-07-18T08:49:13-04:00

  Add interruptIOManager support for select I/O manager
  
  Uses the FdWakup mechanism.
  

• 2f3b00aa
  by Duncan Coutts at 2026-07-18T08:49:13-04:00

  Add interruptIOManager support for poll I/O manager
  
  Uses the FdWakup mechanism.
  
  A quirk we have to cope with is that we now need to poll one more fd --
  the wakeup_fd_r -- but this fd has no corresponding entry in the
  aiop_table. This is awkward since we have set up our aiop_poll_table to
  be an auxilliary table with matching indicies.
  
  The solution this patch uses (and described in the comments) is to have
  two tables: struct pollfd *aiop_poll_table, *full_poll_table;
  and to have the aiop_poll_table alias the tail of the full_poll_table.
  The head entry in the full_poll_table is the extra fd. So we poll the
  full_poll_table, while the aiop_poll_table still has matching indicies
  with the aiop_table.
  
  Hurrah for C aliasing rules.
  

• cee50131
  by Duncan Coutts at 2026-07-18T08:49:13-04:00

  Add interruptIOManager support for win32 legacy I/O manager
  
  And remove unused related helper resetAbandonRequestWait. It is not
  called because the event is created in auto-reset mode, so never needs
  to be reset manually.
  

• cf453143
  by Duncan Coutts at 2026-07-18T08:49:13-04:00

  Note lack of interruptIOManager support for WinIO I/O manager
  
  Though there's a plausible design, we can't sanely test it at the moment
  due to related WinIO bugs. Filed as issue #27403.
  

• 1b74a0ad
  by Duncan Coutts at 2026-07-18T08:49:13-04:00

  Be more explicit about enum IOReadOrWrite values, and type within cmm
  
  Belt and braces.
  

• b388d093
  by Brian McKenna at 2026-07-18T17:51:50-04:00

  Ignore ticks in the pattern-match term oracle
  
  The term-oracle in the pattern-match checker is keyed by a canonical
  form of the scrutinee, computed by `makeDictsCoherent`. That canonical
  form was tick-sensitive: two occurrences of an otherwise identical
  expression that happened to carry different ticks were treated as
  distinct values, breaking long-distance information.
  
  This shows up in practice under `-finfo-table-map`, because the
  desugarer wraps every record-selector use site in a `SourceNote`
  carrying that site's span. For example:
  
       data Box = Box { unBox :: Maybe Int }
       f b = case unBox b of
         Nothing -> 0
         Just _  -> let Just x = unBox b in x
  
  The two `unBox b` expressionss carry different SourceNote spans, the
  pattern-match checker sees them as different, the long-distance
  information from the outer `Just _` branch never reaches the
  let-pattern, and `Just x = unBox b` is wrongly reported as
  non-exhaustive.
  
  We now strip all ticks in `makeDictsCoherent`.  This is documented as
  Wrinkle (UD1) of Note [Unique dictionaries in the TmOracle CoreMap].
  
  Fixes #27314
  

• c23e1acb
  by Mrjtjmn at 2026-07-18T17:52:45-04:00

  Add explanations for unsolved Typeable constraints
  
  This commit adds explanations for unsolved 'Typeable' constraints.
  
  GHC will now provide additional explanations for an unsolved constraint
  of the form 'Typeable ty', explain why GHC did not solve Typeable constraint.
  e.g.:
   - 'ty' is a polymorphic type (e.g. forall a. a -> a)
   - 'ty' is a qualified type (e.g. Eq Int => Int)
   - 'ty' is an unboxed sum type
   - 'ty' is an unreduced type family application
   - 'ty' whose kind is not typeable
  
  Fixes #26532
  

• cbef021e
  by Artem Pelenitsyn at 2026-07-19T07:49:55-04:00

  ghc-internal: Lock.hs: fix typo and indentation

• 42918646
  by Duncan Coutts at 2026-07-19T07:50:36-04:00

  Fix failing test GcStaticPointers for non-moving GC
  
  Minor mistake in asserting something before checking for that same
  thing.
  
  Specifically, Bdescr asserts HEAP_ALLOCED_GC, but Bdescr was being used
  prior to a guard that checks HEAP_ALLOCED_GC. The solution is just to
  move the use of Bdescr after the guard.
  
  Thanks to Simon Jakobi for identifying the problem.
  

• c2f6dcd4
  by Sasha Bogicevic at 2026-07-20T10:31:56+02:00

  Improve error messages for invalid record wildcards
  
  Record wildcard hints are now shown in more contexts and include
  constructor arity; matching with `..` on a fieldless constructor
  now produces a dedicated error message.
  
  Fixes #21101
  

• 4c02e76b
  by Duncan Coutts at 2026-07-21T10:37:21-04:00

  Mark test T27105 as fragile, citing issue #27522
  
  Scheduler fairness is fine, except when it isn't. And it isn't on CI
  machines surprisingly often! See the issue for details.
  

• 43dd2b15
  by Recursion Ninja at 2026-07-21T17:09:53-04:00

  Resolving many TTG related orphan type-class instances
  
  This is part a technical debt removal effort made possible now
  that separating out the AST via TTG has come to a close.
  
  As the AST in 'L.H.S' has been incrementally separated from the GHC internals,
  there are many accumulated orphan instance of 'Binary', 'NFData', 'Outputable',
  and 'Uniquable'. The orphan instance of data-types from within 'L.H.S' have had
  their orphan instances moved to either:
    1. The module which defines the data-type
    2. The module which defines the type-class;
       i.e. moving an orphan 'Binary' instance to 'GHC.Utils.Binary'
  
  Orphan instances resolved (37):
  
    | Data-type            | Resolved instance(s)       | Former orphan module(s)   |
    | -------------------- | -------------------------- | ------------------------- |
    | Role                 | Binary, NFData, Outputable | GHC.Core.Coercion.Axiom   |
    | SrcStrictness        | Binary, NFData, Outputable | GHC.Core.DataCon          |
    | SrcUnpackedness      | Binary, NFData, Outputable | GHC.Core.DataCon          |
    | Fixity               | Binary, Outputable         | GHC.Hs.Basic              |
    | FixityDirection      | Binary, Outputable         | GHC.Hs.Basic              |
    | LexicalFixity        | Outputable                 | GHC.Hs.Basic              |
    | CCallTarget          | NFData                     | GHC.Hs.Decls.Foreign      |
    | CType                | NFData                     | GHC.Hs.Decls.Foreign      |
    | Header               | NFData                     | GHC.Hs.Decls.Foreign      |
    | OverlapMode          | Binary, NFData             | GHC.Hs.Decls.Overlap      |
    | WithHsDocIdentifiers | NFData, Outputable         | GHC.Hs.Doc                |
    | HsDocString          | NFData                     | GHC.Hs.DocString          |
    | HsDocStringChunk     | Binary, Outputable         | GHC.Hs.DocString          |
    | HsDocStringDecorator | Binary, Outputable         | GHC.Hs.DocString          |
    | NamespaceSpecifier   | Outputable                 | GHC.Hs.ImpExp             |
    | ForAllTyFlag         | Binary, NFData, Outputable | GHC.Hs.Specificity        |
    | Specificity          | Binary, NFData             | GHC.Hs.Specificity        |
    | PromotionFlag        | Binary, Outputable         | GHC.Types.Basic           |
    | FieldLabelString     | Outputable, Uniquable      | GHC.Types.FieldLabel      |
    | InlinePragma         | Binary                     | GHC.Types.InlinePragma    |
  
  -------------------------
  Metric Decrease:
      hard_hole_fits
  -------------------------
  
  Closes #21262, #27469
  

• ab9ab895
  by Cheng Shao at 2026-07-21T17:10:53-04:00

  rts: always use StgInt to represent cost center id
  
  Currently cost center id is modeled as `Int` and it should be `StgInt`
  uniformly in the RTS, hence this patch. Fixes #27524.
  

• 94d8f83b
  by Cheng Shao at 2026-07-22T11:30:40-04:00

  hadrian: clean up stale cabal package flags in the tree
  
  This patch cleans up stale cabal package flags in the tree and related
  hadrian/autoconf logic. Closes #27474.
  
  Co-authored-by: Codex <codex@openai.com>
  

• 0bf1d8c9
  by Sasha Bogicevic at 2026-07-22T11:31:21-04:00

  parser: don't suggest ImportQualifiedPost when it is already enabled
  
  -Wprepositive-qualified-module unconditionally attached a hint to
  enable ImportQualifiedPost, even when the extension was already on
  (as it is by default under GHC2021). Record the extension's state in
  the PsWarnImportPreQualified diagnostic and drop the hint when it is
  already enabled.
  
  Fixes #27380
  

• 700a1dd1
  by Simon Jakobi at 2026-07-23T11:21:20-04:00

  ci: Reduce lint job setup costs
  
  Avoid fetching unnecessary history and submodules for lightweight lint
  jobs. Run changelog validation without Hadrian.
  
  Because the lint-author job is now based on the .lint template directly,
  we enhance it to allow Git to read from the runner-owned checkouts,
  In the previously used .lint-params template, this permissions issue was
  addressed via `chown`.
  
  Closes #27521.
  
  Assisted-by: gpt-5.6-sol via Codex CLI
  

• 26a44fb0
  by ARATA Mizuki at 2026-07-23T11:22:10-04:00

  testsuite: Fix memory issues of doublex2_* and simd010
  
  doublex2_* had reads from uninitialized memory.
  
  simd010 had out-of-bounds array access.
  
  Fixes #27544
  

• a5311a8b
  by Wolfgang Jeltsch at 2026-07-23T18:32:50+03:00

  Add test for `base` being buildable with released GHCs
  

293 changed files:

• .gitignore
• .gitlab-ci.yml
• + .gitlab/base-ci.sh
• .gitlab/ci.sh
• + changelog.d/21101
• + changelog.d/27380
• + changelog.d/T26532
• + changelog.d/T27314.md
• + changelog.d/T27329
• + changelog.d/T27360
• + changelog.d/T27374
• + changelog.d/T27456
• + changelog.d/fix-cmm-atomic-load-store
• + changelog.d/fix-make-install-j
• + changelog.d/fix-use-std-ap-thunk
• + changelog.d/inter-module-far-jumps-aarch64-default
• compiler/GHC/ByteCode/Breakpoints.hs
• compiler/GHC/ByteCode/Types.hs
• compiler/GHC/Cmm/Parser.y
• compiler/GHC/Core/Coercion/Axiom.hs
• compiler/GHC/Core/Coercion/Opt.hs
• compiler/GHC/Core/DataCon.hs
• compiler/GHC/Driver/Config/StgToCmm.hs
• compiler/GHC/Driver/DynFlags.hs
• compiler/GHC/Driver/Flags.hs
• compiler/GHC/Driver/Main/Compile.hs
• compiler/GHC/Driver/Main/Hsc.hs
• compiler/GHC/Driver/Main/Passes.hs
• compiler/GHC/Driver/Session.hs
• compiler/GHC/Hs/Basic.hs
• compiler/GHC/Hs/Binds.hs
• compiler/GHC/Hs/Decls/Overlap.hs
• compiler/GHC/Hs/Doc.hs
• compiler/GHC/Hs/DocString.hs
• compiler/GHC/Hs/Dump.hs
• compiler/GHC/Hs/ImpExp.hs
• compiler/GHC/Hs/Instances.hs
• − compiler/GHC/Hs/Specificity.hs
• compiler/GHC/Hs/Utils.hs
• compiler/GHC/HsToCore/Breakpoints.hs
• + compiler/GHC/HsToCore/Breakpoints/Types.hs
• compiler/GHC/HsToCore/Pmc/Desugar.hs
• compiler/GHC/HsToCore/Pmc/Solver.hs
• compiler/GHC/HsToCore/Quote.hs
• compiler/GHC/HsToCore/Ticks.hs
• compiler/GHC/Iface/Ext/Ast.hs
• compiler/GHC/Iface/Load.hs
• compiler/GHC/Iface/Make.hs
• compiler/GHC/Iface/Recomp.hs
• compiler/GHC/Parser.y
• compiler/GHC/Parser/Annotation.hs
• compiler/GHC/Parser/Errors/Ppr.hs
• compiler/GHC/Parser/Errors/Types.hs
• compiler/GHC/Parser/PostProcess.hs
• compiler/GHC/Platform/Ways.hs
• compiler/GHC/Rename/Bind.hs
• compiler/GHC/Rename/Env.hs
• compiler/GHC/Rename/Expr.hs
• compiler/GHC/Rename/Module.hs
• compiler/GHC/Rename/Names.hs
• compiler/GHC/Rename/Pat.hs
• compiler/GHC/Rename/Utils.hs
• compiler/GHC/Runtime/Eval.hs
• compiler/GHC/StgToCmm/Bind.hs
• compiler/GHC/StgToCmm/Config.hs
• compiler/GHC/Tc/Deriv.hs
• compiler/GHC/Tc/Errors.hs
• compiler/GHC/Tc/Errors/Ppr.hs
• compiler/GHC/Tc/Errors/Types.hs
• compiler/GHC/Tc/Gen/Head.hs
• compiler/GHC/Tc/Instance/Typeable.hs
• compiler/GHC/Tc/Types/Rank.hs
• compiler/GHC/ThToHs.hs
• compiler/GHC/Types/Basic.hs
• compiler/GHC/Types/FieldLabel.hs
• compiler/GHC/Types/Fixity.hs
• compiler/GHC/Types/ForeignCall.hs
• compiler/GHC/Types/GREInfo.hs
• compiler/GHC/Types/Hint.hs
• compiler/GHC/Types/Hint/Ppr.hs
• compiler/GHC/Types/InlinePragma.hs
• compiler/GHC/Types/Unique.hs
• compiler/GHC/Types/Var.hs
• compiler/GHC/Unit/Module/ModGuts.hs
• compiler/GHC/Unit/Module/ModIface.hs
• compiler/GHC/Unit/Module/WholeCoreBindings.hs
• compiler/GHC/Utils/Binary.hs
• compiler/GHC/Utils/Outputable.hs
• compiler/Language/Haskell/Syntax/Basic.hs
• compiler/Language/Haskell/Syntax/Binds.hs
• compiler/Language/Haskell/Syntax/Decls/Foreign.hs
• compiler/Language/Haskell/Syntax/Doc.hs
• compiler/Language/Haskell/Syntax/Extension.hs
• compiler/Language/Haskell/Syntax/ImpExp.hs
• compiler/Language/Haskell/Syntax/Specificity.hs
• compiler/ghc.cabal.in
• configure.ac
• distrib/configure.ac.in
• docs/users_guide/expected-undocumented-flags.txt
• docs/users_guide/exts/rank_polymorphism.rst
• docs/users_guide/exts/static_pointers.rst
• docs/users_guide/using-optimisation.rst
• ghc/GHCi/UI.hs
• hadrian/bindist/Makefile
• hadrian/cabal.project
• hadrian/cfg/system.config.host.in
• hadrian/cfg/system.config.target.in
• hadrian/src/Oracles/Flag.hs
• hadrian/src/Rules.hs
• hadrian/src/Rules/BinaryDist.hs
• hadrian/src/Rules/Generate.hs
• hadrian/src/Rules/Test.hs
• hadrian/src/Settings/Packages.hs
• libraries/base/changelog.md
• libraries/base/src/System/Environment.hs
• libraries/base/tests/T15349.stderr
• libraries/ghc-internal/ghc-internal.cabal.in
• libraries/ghc-internal/src/GHC/Internal/Event/Control.hs
• libraries/ghc-internal/src/GHC/Internal/Event/Manager.hs
• libraries/ghc-internal/src/GHC/Internal/Event/TimerManager.hs
• libraries/ghc-internal/src/GHC/Internal/Exception/Type.hs
• libraries/ghc-internal/src/GHC/Internal/IO/Handle/Lock.hs
• libraries/ghc-internal/tests/backtraces/T14532b.stdout
• m4/fp_check_pthreads.m4
• nofib
• rts/Capability.c
• rts/Capability.h
• rts/ContinuationOps.cmm
• rts/IOManager.c
• rts/IOManager.h
• rts/IOManagerInternals.h
• rts/PrimOps.cmm
• rts/Profiling.c
• rts/RaiseAsync.c
• rts/RtsStartup.c
• rts/RtsSymbols.c
• rts/Schedule.c
• rts/Schedule.h
• rts/Trace.c
• rts/Trace.h
• rts/eventlog/EventLog.c
• rts/eventlog/EventLog.h
• rts/include/rts/IOInterface.h
• rts/include/rts/storage/Closures.h
• rts/include/rts/storage/TSO.h
• rts/posix/FdWakeup.h
• + rts/posix/MIO.c
• + rts/posix/MIO.h
• rts/posix/Poll.c
• rts/posix/Poll.h
• rts/posix/Select.c
• rts/posix/Select.h
• rts/posix/Signals.c
• rts/posix/Signals.h
• rts/posix/Timeout.c
• rts/posix/Timeout.h
• rts/rts.cabal
• rts/sm/NonMovingMark.c
• rts/win32/AsyncMIO.c
• rts/win32/AsyncMIO.h
• rts/win32/AsyncWinIO.h
• rts/win32/AwaitEvent.c
• rts/win32/AwaitEvent.h
• rts/win32/ConsoleHandler.h
• rts/win32/MIOManager.h
• rts/win32/ThrIOManager.h
• rts/win32/WorkQueue.h
• rts/win32/veh_excn.h
• testsuite/driver/junit.py
• testsuite/driver/perf_notes.py
• testsuite/driver/testglobals.py
• testsuite/driver/testlib.py
• testsuite/driver/testutil.py
• testsuite/tests/backpack/should_compile/T13149.bkp
• testsuite/tests/cmm/should_run/AtomicFetch.hs
• testsuite/tests/cmm/should_run/AtomicFetch_cmm.cmm
• testsuite/tests/codeGen/should_run/cgrun025.stderr
• testsuite/tests/concurrent/should_run/T27105.hs
• testsuite/tests/concurrent/should_run/all.T
• + testsuite/tests/corelint/T27374.hs
• testsuite/tests/corelint/all.T
• testsuite/tests/count-deps/CountDepsParser.stdout
• testsuite/tests/determinism/determ017/A.hs
• testsuite/tests/exceptions/T26759.stderr
• testsuite/tests/ghc-api/T25121_status.stdout
• testsuite/tests/ghc-api/exactprint/T22919.stderr
• testsuite/tests/ghc-api/exactprint/Test20239.stderr
• testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr
• testsuite/tests/ghc-e/should_fail/T18441fail7.stderr
• testsuite/tests/ghci/scripts/T12005.script
• testsuite/tests/ghci/scripts/bytecodeIPE.hs
• testsuite/tests/ghci/should_run/Makefile
• + testsuite/tests/ghci/should_run/T27287.hs
• + testsuite/tests/ghci/should_run/T27287.stdout
• testsuite/tests/ghci/should_run/all.T
• testsuite/tests/haddock/perf/Fold.hs
• testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr
• testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr
• testsuite/tests/haddock/should_compile_flag_haddock/T24221.stderr
• testsuite/tests/indexed-types/should_fail/T7354.hs
• testsuite/tests/interface-stability/base-exports.stdout
• testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
• testsuite/tests/interface-stability/base-exports.stdout-mingw32
• testsuite/tests/layout/layout001.stdout
• testsuite/tests/layout/layout002.stdout
• testsuite/tests/layout/layout003.stdout
• testsuite/tests/layout/layout004.stdout
• testsuite/tests/layout/layout005.stdout
• testsuite/tests/layout/layout006.stdout
• testsuite/tests/layout/layout007.stdout
• testsuite/tests/layout/layout008.stdout
• testsuite/tests/layout/layout009.stdout
• testsuite/tests/linear/should_compile/T1735Min.hs
• testsuite/tests/mdo/should_fail/mdofail006.stderr
• + testsuite/tests/module/T27380.hs
• + testsuite/tests/module/T27380.stderr
• testsuite/tests/module/all.T
• testsuite/tests/module/mod184.stderr
• testsuite/tests/module/mod185.stderr
• testsuite/tests/parser/should_compile/DumpParsedAst.stderr
• testsuite/tests/parser/should_compile/DumpParsedAstComments.stderr
• testsuite/tests/parser/should_compile/DumpRenamedAst.stderr
• testsuite/tests/parser/should_compile/DumpSemis.stderr
• testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr
• testsuite/tests/parser/should_compile/KindSigs.stderr
• + testsuite/tests/parser/should_compile/T13087.stderr
• testsuite/tests/parser/should_compile/T14189.stderr
• testsuite/tests/parser/should_compile/T15323.stderr
• testsuite/tests/parser/should_compile/T20452.stderr
• testsuite/tests/parser/should_compile/T20718.stderr
• testsuite/tests/parser/should_compile/T20718b.stderr
• testsuite/tests/parser/should_compile/T20846.stderr
• testsuite/tests/parser/should_compile/T23315/T23315.stderr
• testsuite/tests/parser/should_fail/T8431.stderr
• testsuite/tests/parser/should_fail/readFail038.stderr
• testsuite/tests/perf/compiler/T3064.hs
• + testsuite/tests/pmcheck/should_compile/T27314.hs
• + testsuite/tests/pmcheck/should_compile/T27360.hs
• testsuite/tests/pmcheck/should_compile/all.T
• testsuite/tests/polykinds/T7594.hs
• testsuite/tests/printer/AnnotationNoListTuplePuns.stdout
• testsuite/tests/printer/T18791.stderr
• testsuite/tests/printer/Test20297.stdout
• testsuite/tests/printer/Test24533.stdout
• testsuite/tests/programs/thurston-modular-arith/Main.hs
• + testsuite/tests/rename/should_fail/T21101.hs
• + testsuite/tests/rename/should_fail/T21101.stderr
• testsuite/tests/rename/should_fail/T9815.stderr
• testsuite/tests/rename/should_fail/T9815b.stderr
• testsuite/tests/rename/should_fail/T9815bghci.stderr
• testsuite/tests/rename/should_fail/T9815ghci.stderr
• testsuite/tests/rename/should_fail/all.T
• testsuite/tests/rts/ipe/IpeStats/Fold.hs
• testsuite/tests/runghc/T7859.stderr-mingw32
• testsuite/tests/simd/should_run/doublex2_arith.hs
• testsuite/tests/simd/should_run/doublex2_arith.stdout
• testsuite/tests/simd/should_run/doublex2_arith_baseline.hs
• testsuite/tests/simd/should_run/doublex2_arith_baseline.stdout
• testsuite/tests/simd/should_run/doublex2_fma.hs
• testsuite/tests/simd/should_run/doublex2_fma.stdout
• testsuite/tests/simd/should_run/simd010.hs
• testsuite/tests/simplCore/should_compile/T11562.hs
• testsuite/tests/simplCore/should_run/T3591.hs
• testsuite/tests/typecheck/should_compile/DeepSubsumption02.hs
• testsuite/tests/typecheck/should_compile/T12507.hs
• testsuite/tests/typecheck/should_compile/T13951.hs
• testsuite/tests/typecheck/should_compile/T15242.stderr
• testsuite/tests/typecheck/should_compile/T18920.hs
• testsuite/tests/typecheck/should_compile/T2595.hs
• testsuite/tests/typecheck/should_compile/T7541.hs
• testsuite/tests/typecheck/should_compile/all.T
• testsuite/tests/typecheck/should_fail/T15067.stderr
• + testsuite/tests/typecheck/should_fail/T26532.hs
• + testsuite/tests/typecheck/should_fail/T26532.stderr
• testsuite/tests/typecheck/should_fail/T6069.stderr
• testsuite/tests/typecheck/should_fail/T7368a.hs
• testsuite/tests/typecheck/should_fail/T9858b.stderr
• testsuite/tests/typecheck/should_fail/TcStaticPointersFail02.stderr
• testsuite/tests/typecheck/should_fail/all.T
• testsuite/tests/typecheck/should_run/T1735_Help/Basics.hs
• testsuite/tests/typecheck/should_run/T3731-short.hs
• testsuite/tests/typecheck/should_run/T3731.hs
• testsuite/tests/typecheck/should_run/church.hs
• testsuite/tests/typecheck/should_run/tcrun008.hs
• testsuite/tests/typecheck/should_run/tcrun017.hs
• testsuite/tests/typecheck/should_run/tcrun026.hs
• testsuite/tests/typecheck/should_run/tcrun035.hs
• testsuite/tests/typecheck/should_run/tcrun036.hs
• utils/check-exact/ExactPrint.hs
• utils/check-exact/Main.hs
• utils/check-exact/Transform.hs
• utils/check-exact/Utils.hs
• utils/deriveConstants/Main.hs

The diff was not included because it is too large.