July 2026 - ghc-commits

[Git][ghc/ghc][wip/dcoutts/io-manager-selectbis] 26 commits: Coercion optimisation: avoid double-Sym for InstCo
by Duncan Coutts (＠dcoutts) 18 Jul '26

18 Jul '26

Duncan Coutts pushed to branch wip/dcoutts/io-manager-selectbis at Glasgow Haskell Compiler / GHC Commits: 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(a)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. - - - - - af228f98 by Duncan Coutts at 2026-07-18T21:16:32+01:00 Add a new I/O manager based on select() Yes, this is the second such I/O manager, but it is a modern re-implementation based on the new in-RTS I/O manager infrastructure. So it is cleaner and faster than the old select I/O manager. Why do we need another I/O manager based on select? Why isn't the poll() one good enough as a baseline portable unix I/O manager? Because macOS. Apple Inc. is why we cannot have nice things. The man page for poll on macOS documents the fact that it does not work. At least, it does not work for all files. Specifically, it does not work for device files. Whereas macOS select() does work for device files. Aaaaarg! We _do_ want to deprecate and remove the old select I/O manager, but due to macOS we cannot do that until we have a replacement. This is that replacement. Until of course a nice new k-queue I/O manager arrives, which could become the new default for macOS and FreeBSD. Interestingly, this select I/O manager is actually faster than the poll one, on Linix, in some circumstances: specifically when many Haskell threads are waiting on the same fd. The poll I/O manager does O(n) work for n threads waiting on I/O, whereas the select one does O(fds) work for the number of fds that threads are waiting on. Usually this is 1:1, so it's not noticable, but one can concoct extreme benchmarks to show the difference. - - - - - 9f34b5fa by Duncan Coutts at 2026-07-18T21:16:32+01:00 Document the new select I/O manager in the user guide in the RTS section about I/O managers. And add a changelog entry. - - - - - 1423e247 by Duncan Coutts at 2026-07-18T21:16:32+01:00 Update the "location" for blockedOnBadFD exception This exception is thrown by the select, selectbis and poll I/O managers in rare circumstances. The existing location for the error was "awaitEvent" which is an old name that was internal to the RTS. The Haskell functions which this gets thrown from are the functions threadWaitRead / threadWaitWrite. So this is a more appropriate loction string. - - - - - 3222607b by Duncan Coutts at 2026-07-18T21:16:32+01:00 Minor updates in the poll I/O manager to keep in sync This keeps it in sync with select one. The changes are based on code review while implementing the new select I/O manager. The two I/O managers are so similar in structure that it makes sense to try to minimise the diff between them. This should aid understanding, and fixes to both in future. - - - - - 7860dd93 by Duncan Coutts at 2026-07-18T21:16:32+01:00 Use selectbis I/O manager by default for CI coverage This should not be committed to master. It would be nice however to get better CI coverage of non-default I/O managers. - - - - - 55 changed files: - + changelog.d/T27374 - + changelog.d/select-io-manager - compiler/GHC/Core/Coercion/Opt.hs - docs/users_guide/runtime_control.rst - libraries/base/src/GHC/RTS/Flags.hs - 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/Thread.hs - libraries/ghc-internal/src/GHC/Internal/Event/TimerManager.hs - libraries/ghc-internal/src/GHC/Internal/RTS/Flags.hsc - rts/Capability.c - rts/Capability.h - rts/IOManager.c - rts/IOManager.h - rts/IOManagerInternals.h - rts/PrimOps.cmm - rts/RaiseAsync.c - rts/RtsStartup.c - rts/RtsSymbols.c - rts/Schedule.c - rts/Schedule.h - rts/configure.ac - rts/include/rts/Flags.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/SelectBis.c - + rts/posix/SelectBis.h - rts/posix/Signals.c - rts/posix/Signals.h - rts/posix/Timeout.c - rts/posix/Timeout.h - rts/rts.cabal - 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/tests/corelint/T27374.hs - testsuite/tests/corelint/all.T - testsuite/tests/interface-stability/ghc-experimental-exports.stdout - testsuite/tests/interface-stability/ghc-experimental-exports.stdout-mingw32 - utils/deriveConstants/Main.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/c3af2a9db4a4c9f841988dc449de41… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/c3af2a9db4a4c9f841988dc449de41… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 23 commits: Coercion optimisation: avoid double-Sym for InstCo
by Marge Bot (＠marge-bot) 18 Jul '26

18 Jul '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 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(a)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. - - - - - 6b5603b8 by Brian McKenna at 2026-07-18T13:48:03-04:00 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 - - - - - 093125f2 by Mrjtjmn at 2026-07-18T13:48:17-04:00 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 - - - - - 59 changed files: - + changelog.d/T26532 - + changelog.d/T27314.md - + changelog.d/T27374 - compiler/GHC/Core/Coercion/Opt.hs - compiler/GHC/HsToCore/Pmc/Solver.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Instance/Typeable.hs - 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 - rts/Capability.c - rts/Capability.h - rts/IOManager.c - rts/IOManager.h - rts/IOManagerInternals.h - rts/PrimOps.cmm - rts/RaiseAsync.c - rts/RtsStartup.c - rts/RtsSymbols.c - rts/Schedule.c - rts/Schedule.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/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/tests/corelint/T27374.hs - testsuite/tests/corelint/all.T - + testsuite/tests/pmcheck/should_compile/T27314.hs - testsuite/tests/pmcheck/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/T9858b.stderr - testsuite/tests/typecheck/should_fail/TcStaticPointersFail02.stderr - testsuite/tests/typecheck/should_fail/all.T - utils/deriveConstants/Main.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/429363015bee4467102357e3c718db… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/429363015bee4467102357e3c718db… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][wip/sjakobi/T16720] 2 commits: testsuite: Put rerun hint after result details
by Simon Jakobi (＠sjakobi2) 18 Jul '26

18 Jul '26

Simon Jakobi pushed to branch wip/sjakobi/T16720 at Glasgow Haskell Compiler / GHC Commits: 47d04b79 by Simon Jakobi at 2026-07-18T16:29:46+02:00 testsuite: Put rerun hint after result details Keep detailed unexpected-result sections together and emit the TEST rerun command as the final item before SUMMARY. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 4933f5aa by Simon Jakobi at 2026-07-18T18:54:23+02:00 testsuite: Reword omitted failure output heading Put the excessive-result threshold before the omitted-output explanation to make the heading easier to scan. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 1 changed file: - testsuite/driver/testlib.py Changes: ===================================== testsuite/driver/testlib.py ===================================== @@ -3569,15 +3569,11 @@ def summary(t: TestRun, file: TextIO, color=False, junit_path: Optional[Path]=No printTestOutputSummary(file, t.unexpected_failures, color, junit_path) else: where = '; see {}'.format(junit_path) if junit_path else '' - header = ('Unexpected failures (output omitted, more than {}{}):' + header = ('Unexpected failures (more than {}, output omitted{}):' .format(MAX_SUMMARY_OUTPUT_TESTS, where)) file.write(colored_if(color, Color.RED, header) + '\n') printTestInfosSummary(file, t.unexpected_failures) - printUnexpectedTests(file, - [t.unexpected_passes, t.unexpected_failures, - t.unexpected_stat_failures, t.framework_failures], color) - if t.unexpected_passes: header = 'Unexpected passes:' file.write(colored_if(color, Color.RED, header) + '\n') @@ -3602,6 +3598,10 @@ def summary(t: TestRun, file: TextIO, color=False, junit_path: Optional[Path]=No warning = 'WARNING: Testsuite run was terminated early' file.write(colored_if(color, Color.YELLOW, warning) + '\n') + printUnexpectedTests(file, + [t.unexpected_passes, t.unexpected_failures, + t.unexpected_stat_failures, t.framework_failures], color) + if len(t.unexpected_failures) > 0 or \ len(t.unexpected_stat_failures) > 0 or \ len(t.unexpected_passes) > 0 or \ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9b495cba96fe8077f12a6228590f54… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9b495cba96fe8077f12a6228590f54… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][master] 19 commits: Move THREADED_RTS-conditional struct members to end of Capability
by Marge Bot (＠marge-bot) 18 Jul '26

18 Jul '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 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. - - - - - 40 changed files: - 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 - rts/Capability.c - rts/Capability.h - rts/IOManager.c - rts/IOManager.h - rts/IOManagerInternals.h - rts/PrimOps.cmm - rts/RaiseAsync.c - rts/RtsStartup.c - rts/RtsSymbols.c - rts/Schedule.c - rts/Schedule.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/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 - utils/deriveConstants/Main.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ff70fc752a44cab602defd5164a565… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ff70fc752a44cab602defd5164a565… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][wip/sjakobi/T16720] 3 commits: testsuite: Put detailed results before summary
by Simon Jakobi (＠sjakobi2) 18 Jul '26

18 Jul '26

Simon Jakobi pushed to branch wip/sjakobi/T16720 at Glasgow Haskell Compiler / GHC Commits: 11815846 by Simon Jakobi at 2026-07-18T14:16:27+02:00 testsuite: Put detailed results before summary Report unexpected passes, stat failures, framework results, and early termination before the aggregate SUMMARY so the summary consistently concludes the test report. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - dd3f8c8a by Simon Jakobi at 2026-07-18T14:44:02+02:00 testsuite: Color detailed result headings Highlight unsuccessful result headings in red and non-fatal warnings in yellow, including the output-omitted and early-termination messages. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 9b495cba by Simon Jakobi at 2026-07-18T14:46:41+02:00 testsuite: Factor conditional color rendering Centralize the per-output color switch in term_color and use it throughout testsuite summary rendering. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 2 changed files: - testsuite/driver/term_color.py - testsuite/driver/testlib.py Changes: ===================================== testsuite/driver/term_color.py ===================================== @@ -18,3 +18,5 @@ def colored(color: Color, s: str) -> str: else: return s +def colored_if(enabled: bool, color: Color, s: str) -> str: + return colored(color, s) if enabled else s ===================================== testsuite/driver/testlib.py ===================================== @@ -27,7 +27,7 @@ from testutil import strip_quotes, lndir, link_or_copy_file, passed, \ failBecause, testing_metrics, residency_testing_metrics, \ stable_perf_counters, \ PassFail, badResult, str_warn, str_removeprefix -from term_color import Color, colored +from term_color import Color, colored_if import testutil from cpu_features import have_cpu_feature import perf_notes as Perf @@ -3569,13 +3569,38 @@ def summary(t: TestRun, file: TextIO, color=False, junit_path: Optional[Path]=No printTestOutputSummary(file, t.unexpected_failures, color, junit_path) else: where = '; see {}'.format(junit_path) if junit_path else '' - file.write('Unexpected failures (output omitted, more than {}{}):\n' - .format(MAX_SUMMARY_OUTPUT_TESTS, where)) + header = ('Unexpected failures (output omitted, more than {}{}):' + .format(MAX_SUMMARY_OUTPUT_TESTS, where)) + file.write(colored_if(color, Color.RED, header) + '\n') printTestInfosSummary(file, t.unexpected_failures) printUnexpectedTests(file, [t.unexpected_passes, t.unexpected_failures, - t.unexpected_stat_failures, t.framework_failures]) + t.unexpected_stat_failures, t.framework_failures], color) + + if t.unexpected_passes: + header = 'Unexpected passes:' + file.write(colored_if(color, Color.RED, header) + '\n') + printTestInfosSummary(file, t.unexpected_passes) + + if t.unexpected_stat_failures: + header = 'Unexpected stat failures:' + file.write(colored_if(color, Color.RED, header) + '\n') + printTestInfosSummary(file, t.unexpected_stat_failures) + + if t.framework_failures: + header = 'Framework failures:' + file.write(colored_if(color, Color.RED, header) + '\n') + printTestInfosSummary(file, t.framework_failures) + + if t.framework_warnings: + header = 'Framework warnings:' + file.write(colored_if(color, Color.YELLOW, header) + '\n') + printTestInfosSummary(file, t.framework_warnings) + + if stopping(): + warning = 'WARNING: Testsuite run was terminated early' + file.write(colored_if(color, Color.YELLOW, warning) + '\n') if len(t.unexpected_failures) > 0 or \ len(t.unexpected_stat_failures) > 0 or \ @@ -3586,7 +3611,7 @@ def summary(t: TestRun, file: TextIO, color=False, junit_path: Optional[Path]=No summary_color = Color.GREEN assert t.start_time is not None - summary_header = colored(summary_color, 'SUMMARY') if color else 'SUMMARY' + summary_header = colored_if(color, summary_color, 'SUMMARY') file.write(summary_header + ' for test run started at ' + t.start_time.strftime("%c %Z") + '\n' + str(datetime.datetime.now() - t.start_time).rjust(8) @@ -3619,32 +3644,14 @@ def summary(t: TestRun, file: TextIO, color=False, junit_path: Optional[Path]=No + ' fragile tests\n' + '\n') - if t.unexpected_passes: - file.write('Unexpected passes:\n') - printTestInfosSummary(file, t.unexpected_passes) - - if t.unexpected_stat_failures: - file.write('Unexpected stat failures:\n') - printTestInfosSummary(file, t.unexpected_stat_failures) - - if t.framework_failures: - file.write('Framework failures:\n') - printTestInfosSummary(file, t.framework_failures) - - if t.framework_warnings: - file.write('Framework warnings:\n') - printTestInfosSummary(file, t.framework_warnings) - - if stopping(): - file.write('WARNING: Testsuite run was terminated early\n') - -def printUnexpectedTests(file: TextIO, testInfoss): +def printUnexpectedTests(file: TextIO, testInfoss, color=False): unexpected = set(result.testname for testInfos in testInfoss for result in testInfos if not result.testname.endswith('.T')) if unexpected: - file.write('Unexpected results from:\n') + header = 'Unexpected results from:' + file.write(colored_if(color, Color.RED, header) + '\n') file.write('TEST="' + ' '.join(sorted(unexpected)) + '"\n') file.write('\n') @@ -3661,9 +3668,7 @@ def printTestOutputSummary(file: TextIO, testInfos, color: bool=False, # Repeat failing tests' captured output in the summary, so one needn't # hunt for it earlier in a possibly very long log; see #16720. header = '=====> Unexpected failures output summary' - if color: - header = colored(Color.RED, header) - file.write(header + '\n\n') + file.write(colored_if(color, Color.RED, header) + '\n\n') where = ', see {}'.format(junit_path) if junit_path else '' # Tests that fail identically in several ways (e.g. normal and g1) share one @@ -3675,28 +3680,23 @@ def printTestOutputSummary(file: TextIO, testInfos, color: bool=False, for result, ways in groups.values(): header = '=====> {}({}) ({}) [{}]'.format( result.testname, ', '.join(ways), result.directory + os.sep, result.reason) - if color: - header = colored(Color.RED, header) - file.write(header + '\n') + file.write(colored_if(color, Color.RED, header) + '\n') for stream_name, contents in [('stdout', result.stdout), ('stderr', result.stderr)]: if contents and contents.strip(): label = 'Captured {}:'.format(stream_name) - if color: - label = colored(Color.CYAN, label) lines = contents.rstrip('\n').split('\n') if len(lines) > MAX_SUMMARY_OUTPUT_LINES: omitted = len(lines) - MAX_SUMMARY_OUTPUT_LINES lines = lines[:MAX_SUMMARY_OUTPUT_LINES] \ + ['... ({} more lines omitted{})'.format(omitted, where)] - s = label + '\n' + ''.join(l + '\n' for l in lines) + s = colored_if(color, Color.CYAN, label) + '\n' \ + + ''.join(l + '\n' for l in lines) # Test output can contain characters that file's encoding # cannot represent; replace rather than crash (cf safe_print). enc = getattr(file, 'encoding', None) or 'utf-8' file.write(s.encode(enc, errors='replace').decode(enc)) footer = '<===== end of unexpected failures output summary' - if color: - footer = colored(Color.RED, footer) - file.write(footer + '\n\n') + file.write(colored_if(color, Color.RED, footer) + '\n\n') def printTestInfosSummary(file: TextIO, testInfos): for result in sorted(testInfos, key=lambda r: (r.testname.lower(), r.way, r.directory)): View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0c3b23edb050fa3bc3968fdb17e2b2… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0c3b23edb050fa3bc3968fdb17e2b2… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][master] 2 commits: Coercion optimisation: avoid double-Sym for InstCo
by Marge Bot (＠marge-bot) 18 Jul '26

18 Jul '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 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(a)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. - - - - - 4 changed files: - + changelog.d/T27374 - compiler/GHC/Core/Coercion/Opt.hs - + testsuite/tests/corelint/T27374.hs - testsuite/tests/corelint/all.T Changes: ===================================== changelog.d/T27374 ===================================== @@ -0,0 +1,9 @@ +section: compiler +issues: #27374 +mrs: !16207 +synopsis: + Fix optimisation of InstCo coercions +description: + Fixes a bug in which the coercion optimiser would incorrectly optimise certain + InstCo coercions, incorrectly changing their kinds. + ===================================== compiler/GHC/Core/Coercion/Opt.hs ===================================== @@ -274,10 +274,11 @@ opt_co4, opt_co4' :: LiftingContext -> SwapFlag -> ReprFlag -- Precondition: In every call (opt_co4 lc sym rep role co) -- we should have role = coercionRole co -- Precondition: role is not Phantom --- Postcondition: The resulting coercion is equivalant to --- wrapsub (wrapsym (mksub co) --- where wrapsym is SymCo if sym=True --- wrapsub is SubCo if rep=True +-- Postcondition: The resulting coercion is equivalent to +-- wrapSub (wrapSym (substCo co)) +-- where substCo applies the LiftingContext substitution +-- wrapSym wraps in SymCo when the ambient Sym is IsSwapped +-- wrapSub wraps in SubCo when rep=True -- opt_co4 is there just to support tracing, when debugging -- Usually it just goes straight to opt_co4' @@ -327,7 +328,10 @@ opt_co4' env sym rep r (GRefl _r ty (MCo kco)) text "Type:" <+> ppr ty) $ if isReflKindCo kco || isReflKindCo kco' then wrapSym sym ty_co - else wrapSym sym $ mk_coherence_right_co r' (coercionRKind ty_co) kco' ty_co + else + -- Keep 'sym' on the outside instead of trying to push it in, to avoid + -- duplicating 'k_co' in 'GRefl r (ty |> kco) (MCo (sym kco))' + wrapSym sym $ mk_coherence_right_co r' (coercionRKind ty_co) kco' ty_co -- ty :: k1 -- kco :: k1 ~ k2 -- Desired result coercion: ty ~ ty |> co @@ -534,25 +538,36 @@ opt_co4' env sym rep r (InstCo fun_co arg_co) , let s2' = coercionRKind arg_co' tv_co = mk_coherence_right_co Nominal s2' (mkSymCo k_co') arg_co' env' = extendLiftingContext (zapLiftingContext env) tv' tv_co - = opt_co4 env' NotSwapped False r' body_co' + = opt_co4 env' sym False r' body_co' -- See Note [Forall over coercion] | Just (cv', _visL, _visR, _kind_co', body_co') <- splitForAllCo_co_maybe fun_co' , CoercionTy h1' <- coercionLKind arg_co' , let env' = extendLiftingContextCvSubst (zapLiftingContext env) cv' h1' - = opt_co4 env' NotSwapped False r' body_co' + = opt_co4 env' sym False r' body_co' -- Those cases didn't work either, so rebuild the InstCo - -- Push Sym into /both/ function /and/ arg_coument - | otherwise = InstCo fun_co' arg_co' + | otherwise = InstCo sym_fun_co' sym_arg_co' where - -- fun_co' arg_co' are both optimised, /and/ we have pushed `sym` into both - -- So no more sym'ing on th results of fun_co' arg_co' - fun_co' = opt_co4 env sym rep r fun_co - arg_co' = opt_co4 env sym False Nominal arg_co r' = chooseRole rep r + -- Optimised versions of fun_co & arg_co. + -- NB: we do /not/ push in `sym` (hence using `NotSwappped`), + -- in order to respect (LC2) in Note [The LiftingContext in optCoercion]. + fun_co' = opt_co4 env NotSwapped rep r fun_co + arg_co' = opt_co4 env NotSwapped False Nominal arg_co + + -- Like fun_co'/arg_co', except we /have/ pushed in `sym`. + -- We use 'mkDeepSymCo' to push in 'sym' without re-optimising. + -- See Note [Pushing Sym without re-optimising] + sym_fun_co' + | isSwapped sym = mkDeepSymCo fun_co' + | otherwise = fun_co' + sym_arg_co' + | isSwapped sym = mkDeepSymCo arg_co' + | otherwise = arg_co' + opt_co4' env sym _rep r (KindCo co) = assert (r == Nominal) $ let kco' = promoteCoercion co in @@ -575,6 +590,83 @@ We do so here in optCoercion, not in mkCoVarCo; see Note [mkCoVarCo] in GHC.Core.Coercion. -} +{- Note [Pushing Sym without re-optimising] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +To optimise (InstCo fun_co arg_co) we must first optimise fun_co and arg_co +/without/ the ambient Sym, as required by (LC2) of +Note [The LiftingContext in optCoercion]. + +But in the fallback case (when the optimised fun_co is not a ForAllCo), we need +to push the ambient Sym into both components when rebuilding the InstCo. + + Re-running the optimiser with sym=IsSwapped would optimise each component twice. + As the components can themselves contain 'InstCo's, this has the potential to + trigger exponential behaviour. + + Simply wrapping 'sym' on the outside would fail to push 'sym' deeply into the + coercion, which would be in tension with the rest of the coercion optimiser + which relies on 'sym' being pushed into the leaves to expose cancellation + opportunities. + +To solve this, we define 'mkDeepSymCo': it pushes a Sym into an already +optimised coercion. This is much simpler than full coercion optimisation, as it +doesn't need to do coercion lifting nor downgrade roles. +-} + +-- | Push 'Sym' deeply into an already-optimised coercion. +-- +-- Morally the same as re-optimising the coercion with @sym=IsSwapped@, but +-- more efficient. +-- +-- See Note [Pushing Sym without re-optimising] +mkDeepSymCo :: NormalCo -> NormalCo +mkDeepSymCo = go + where + go :: NormalCo -> NormalCo + -- Straightforward cases + go (SymCo co) = co + go co@(UnivCo { uco_lty = t1, uco_rty = t2 }) = co { uco_lty = t2, uco_rty = t1 } + go (TyConAppCo r tc cos) = TyConAppCo r tc $ map go cos + go (AppCo co1 co2) = AppCo (go co1) (go co2) + go (FunCo r afl afr cow co1 co2) = FunCo r afr afl (go cow) (go co1) (go co2) + go (TransCo co1 co2) = TransCo (go co2) (go co1) + go (SelCo cs co) = SelCo cs $ go co + go (LRCo lr co) = LRCo lr $ go co + go (InstCo fun_co arg_co) = InstCo (go fun_co) (go arg_co) + go (KindCo co) = KindCo $ go co + go (SubCo co) = SubCo $ go co + go co@(CoVarCo {}) = SymCo co + go co@(Refl {}) = co + go co@(GRefl _ _ MRefl) = co + go co@(GRefl _ _ (MCo {})) = SymCo co + -- keep the sym outside, like the GRefl case of opt_co4' does, instead of + -- GRefl r (ty |> kco) (MCo (sym kco)) + -- as that duplicates 'kco' + go co@(AxiomCo {}) = SymCo co + -- Same as in opt_co4': do *not* push sym inside top-level axioms. + + go co@(ForAllCo { fco_tcv = tcv, fco_visL = visL, fco_visR = visR + , fco_kind = k_mco, fco_body = body_co }) + = case k_mco of + MRefl -> ForAllCo tcv visR visL k_mco (go body_co) + MCo {} -> + -- Pushing 'sym' into the kind coercion would require threading a + -- substitution through, as per Note [Optimising ForAllCo]. + -- This wouldn't be difficult (see commented out code below), but + -- for now we prefer to keep 'mkDeepSymCo' as simple as possible. + SymCo co + + -- Pushing 'sym' into the kind coercion, threading 'Subst' through: + -- + -- = ForAllCo tcv' visR visL k_mco' (go subst' body_co) + -- where + -- k_mco' = case k_mco of + -- MRefl -> MRefl + -- MCo co -> MCo (go subst co) + -- (subst', tcv') = forAllCoBndrSubst IsSwapped tcv k_mco' subst + + go (HoleCo h) = pprPanic "mkDeepSymCo: HoleCo" (ppr h) + ------------- -- | Optimize a phantom coercion. The input coercion may not necessarily -- be a phantom, but the output sure will be. @@ -1450,6 +1542,9 @@ But if sym=Swapped, things are trickier. Here is an identity that helps: of tv:k1 in bodyco by (tv:k2 |> Sym kco) This mirrors what happens in the typing rule for ForAllCo See Note [ForAllCo] in GHC.Core.TyCo.Rep + NB: doing so inlines 'kco' at all occurrences of tv, duplicating it. This is + inconsistent with how we optimise GRefl, where we keep the 'Sym' on the + outside to avoid duplicating the kind coercion. -} optForAllCoBndr :: LiftingContext -> SwapFlag @@ -1464,13 +1559,20 @@ optForAllCoBndr env sym tcv k_mco MRefl -> MRefl MCo co -> MCo (opt_co4 env sym False Nominal co) - (env', tcv') = updateLCSubst env upd_subst - - upd_subst :: Subst -> (Subst, TyCoVar) - upd_subst subst - | isTyVar tcv = upd_subst_tv subst - | otherwise = upd_subst_cv subst - + (env', tcv') = updateLCSubst env (forAllCoBndrSubst sym tcv k_mco') + +-- | Substitute a 'ForAllCo' binder, returning the body substitution. +-- +-- See Note [Optimising ForAllCo]. +forAllCoBndrSubst + :: SwapFlag + -> TyCoVar -- ^ the ForAllCo binder + -> MCoercionN -- ^ its kind coercion, with the ambient Sym already pushed into it + -> Subst -> (Subst, TyCoVar) +forAllCoBndrSubst sym tcv k_mco' + | isTyVar tcv = upd_subst_tv + | otherwise = upd_subst_cv + where upd_subst_tv subst = case k_mco' of MCo k_co' | isSwapped sym -> (subst2, tv2) ===================================== testsuite/tests/corelint/T27374.hs ===================================== @@ -0,0 +1,201 @@ +{-# LANGUAGE BlockArguments #-} + +-- | Regression test for #27374: +-- +-- - manually construct some coercions that are not InstCo but become InstCo +-- after optimisation +-- - check that the coercion optimiser properly optimises these by running +-- Core Lint on the output + +module Main (main) where + +-- base +import Control.Monad.IO.Class + ( liftIO ) +import Data.Foldable + ( for_ ) +import System.Environment + ( getArgs ) + +-- ghc +import GHC + ( runGhc, getSessionDynFlags, getLogger ) +import GHC.Builtin.Types + ( maybeTyCon, tupleTyCon, mkBoxedTupleTy ) +import GHC.Core + ( Expr(Coercion) ) +import GHC.Core.Coercion + ( Coercion, CoVar, MCoercion(..) + , Role(..), CoSel(..), FunSel(..) + , mkCoercionType + , mkCoVar, mkCoVarCo, mkForAllCo, mkInstCo, mkReflCo, mkNomReflCo + , mkSelCo, mkSymCo, mkTransCo, mkTyConAppCo + , tyCoVarsOfCo + ) +import GHC.Core.Coercion.Opt + ( OptCoercionOpts(..), optCoercion ) +import GHC.Core.Lint + ( lintExpr ) +import GHC.Core.Predicate + ( mkNomEqPred ) +import GHC.Core.TyCo.FVs + ( tyCoVarsOfCoList ) +import GHC.Core.TyCo.Rep + ( Type(CoercionTy) ) +import GHC.Core.Type + +import GHC.Data.FastString + ( fsLit ) + +import GHC.Driver.Config.Core.Lint + ( initLintConfig ) + +import GHC.Types.Basic + ( Boxity(Boxed) ) +import GHC.Types.Var + ( mkTyVar, coreTyLamForAllTyFlag ) +import GHC.Types.Var.Env + ( mkInScopeSet ) +import GHC.Types.Name + ( mkInternalName ) +import GHC.Types.Name.Occurrence + ( mkTyVarOccFS, mkVarOccFS ) +import GHC.Types.SrcLoc + ( noSrcSpan ) +import GHC.Types.Unique + ( mkUniqueGrimily ) + +import GHC.Utils.Error + ( pprMessageBag, putMsg ) +import GHC.Utils.Outputable + ( (<+>), text, vcat ) + +-------------------------------------------------------------------------------- +-- Helpers for building fresh variables +-------------------------------------------------------------------------------- + +mkTv :: Int -> String -> Kind -> TyVar +mkTv i s = + mkTyVar $ + mkInternalName + ( mkUniqueGrimily (fromIntegral i) ) + ( mkTyVarOccFS (fsLit s) ) + noSrcSpan + +mkCv :: Int -> String -> Type -> CoVar +mkCv i s = + mkCoVar $ + mkInternalName + ( mkUniqueGrimily (fromIntegral i) ) + ( mkVarOccFS (fsLit s) ) + noSrcSpan + +-------------------------------------------------------------------------------- +-- ForAllCo-over-type +-------------------------------------------------------------------------------- + +co1 :: Coercion +co1 = + -- Use mkTransCo to get a coercion that is not InstCo but optimises to InstCo + lhs `mkTransCo` rhs + where + p = mkTv 21 "p" liftedTypeKind + q = mkTv 22 "q" liftedTypeKind + a = mkTv 23 "a" liftedTypeKind + b = mkTv 24 "b" liftedTypeKind + + tup2 = tupleTyCon Boxed 2 + + -- cv :: p ~# q + cv = mkCoVarCo $ + mkCv 25 "cv" $ + mkCoercionType Nominal (mkTyVarTy p) (mkTyVarTy q) + + -- arg :: Maybe q ~ Maybe p + arg = mkSymCo (mkTyConAppCo Nominal maybeTyCon [cv]) + + -- forallCo = <forall a b. (a, b) -> a>_N + forallCo = + mkReflCo Nominal $ + mkSpecForAllTys [a, b] $ + mkVisFunTyMany + (mkBoxedTupleTy [mkTyVarTy a, mkTyVarTy b]) + (mkTyVarTy a) + + -- forallCo @arg @arg + inst_co = mkInstCo (mkInstCo forallCo arg) arg + + rhs = mkSymCo (mkSelCo (SelFun SelArg) inst_co) + lhs = mkTyConAppCo Nominal tup2 [arg, arg] + +-------------------------------------------------------------------------------- +-- ForAllCo-over-coercion +-------------------------------------------------------------------------------- + +co2 :: Coercion +co2 = + -- This outer 'sym' was necessary to trigger the specific bug + mkSymCo $ + mkInstCo ( mkSymCo g ) arg + where + k1 = mkTyVarTy $ mkTv 11 "k1" liftedTypeKind + k2 = mkTyVarTy $ mkTv 12 "k2" liftedTypeKind + + x = mkTv 13 "x" k1 + + -- cv :: k1 ~# Type + cv_ty = mkNomEqPred k1 liftedTypeKind + cv = mkCv 14 "cv" cv_ty + + -- hk :: (k1 ~# Type) ~# (k2 ~# Type) + hk = mkCoVarCo (mkCv 15 "hk" (mkNomEqPred cv_ty (mkNomEqPred k2 liftedTypeKind))) + + -- body :: (x |> cv) ~# (x |> cv) + body = mkNomReflCo (mkCastTy (mkTyVarTy x) (mkCoVarCo cv)) + + -- g :: (forall (cv :: k1 ~# Type). x |> cv) + -- ~# (forall (cv' :: k2 ~# Type). x |> (sel 2 hk ; cv' ; sym (sel 3 hk))) + g = mkForAllCo cv vis vis (MCo hk) body + vis = coreTyLamForAllTyFlag + + -- two distinct coercions to instantiate at + coL = mkCoVarCo (mkCv 16 "coL" (mkNomEqPred k1 liftedTypeKind)) + coR = mkCoVarCo (mkCv 17 "coR" (mkNomEqPred k2 liftedTypeKind)) + arg = mkCoVarCo (mkCv 18 "arg" (mkNomEqPred (CoercionTy coL) (CoercionTy coR))) + +-------------------------------------------------------------------------------- +-- Test runner +-------------------------------------------------------------------------------- + +test_cos :: [ ( String, Coercion ) ] +test_cos = + [ ( "InstCo (TyVar)", co1 ) + , ( "InstCo (CoVar)", co2 ) + ] + +opt_co :: Coercion -> Coercion +opt_co co = + let in_scope = mkInScopeSet $ tyCoVarsOfCo co + in + optCoercion + ( OptCoercionOpts { optCoercionEnabled = True } ) + ( mkEmptySubst in_scope ) + co + +main :: IO () +main = do + [libdir] <- getArgs + runGhc ( Just libdir ) do + dflags <- getSessionDynFlags + logger <- getLogger + liftIO $ for_ test_cos \ ( name, co ) -> do + -- Optimise each test coercion and run the result through Core Lint. + let + co' = opt_co co + in_scope = tyCoVarsOfCoList co' + lint_cfg = initLintConfig dflags in_scope + for_ ( lintExpr lint_cfg ( Coercion co' ) ) \ errs -> + putMsg logger $ + vcat [ text "Core Lint error for" <+> text name + , pprMessageBag errs + ] ===================================== testsuite/tests/corelint/all.T ===================================== @@ -9,5 +9,6 @@ setTestOpts(extra_hc_opts('-package ghc')) setTestOpts(extra_run_opts('"' + config.libdir + '"')) test('LintEtaExpand', normal, compile_and_run, ['']) +test('T27374', normal, compile_and_run, ['']) ## These tests use the GHC API. ## Test cases which don't use the GHC API should be added nearer the top. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fe3b059c714be22dac658a620a2b5a… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fe3b059c714be22dac658a620a2b5a… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc] Pushed new branch wip/andreask/fix-notes
by Andreas Klebinger (＠AndreasK) 18 Jul '26

18 Jul '26

Andreas Klebinger pushed new branch wip/andreask/fix-notes at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/andreask/fix-notes You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][wip/az/exactprint-annotation-rationalisation] 23 commits: Strip ticks when desugaring bool guards
by Alan Zimmerman (＠alanz) 18 Jul '26

18 Jul '26

Alan Zimmerman pushed to branch wip/az/exactprint-annotation-rationalisation at Glasgow Haskell Compiler / GHC Commits: 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(a)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 - - - - - 57ec828f by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Keep decls together in ClassDecl Similar to 1718230f4d3d19d8c49c0e5d496cb0fb6f399528 for HsValBindsLR, this commit updates ClassDecl so that it no longer splits out the assorted `LHsDecl GhcPs` until the renamer. It does this by inserting a type family (separate from the classic TTG one) for this. So data TyClDecl ... | ClassDecl { ... tcdDecls :: XClassDecls pass with type instance XClassDecls GhcPs = [LHsDecl GhcPs] type instance XClassDecls GhcRn = ClassDeclX GhcRn type instance XClassDecls GhcTc = ClassDeclX GhcTc data ClassDeclX pass = ClassDeclX { tcdSigs :: [LSig pass], -- ^ Methods' signatures tcdMeths :: LHsBinds pass, -- ^ Default methods tcdATs :: [LFamilyDecl pass], -- ^ Associated types; tcdATDefs :: [LTyFamDefltDecl pass], -- ^ Associated type defaults tcdDocs :: [LDocDecl pass] -- ^ Haddock docs } - - - - - 34d3536a by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: ClsInstDecl as list in GhcPs - - - - - be5a6400 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedP from OverlapMode - - - - - fbdc0b05 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedP from CType - - - - - 32a98fe7 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedP, last use in WarningTxt - - - - - 28a45308 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedE from WarningCategory - - - - - dcc85bbf by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocateE from XCImport and XCExport - - - - - e07491a3 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedE from HsRecFields dot - - - - - da65d94c by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedE completely, last usage for pats - - - - - 179ec156 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove AnnList (EpToken "where") usages This is moving toward removing the parameter from AnnList completely - - - - - a0ad69ea by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA remove AnnList (EpToken "rec") usages - - - - - 5f79214c by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove last parameterised AnnList usage (EpaLocation) Also remove the parameter - - - - - 5cc06df4 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 TTG: Add extension points to BooleanFormula They are currently unused, but will be used for exact print annotations next - - - - - da7db0e7 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Remove LocatedBC / SrcSpanBF - - - - - eb4f8caa by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: remove unused addTrailingAnnToL. Squash appropriately - - - - - 96504da1 by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPS: Remove NoEpTok/NoEpUniTok, using an unhelpful SrcSpan instead Also introduce helper functions noEpTok and noEpUniTok to serve as simple replacements in code inserting an token annotation without location information. - - - - - 151 changed files: - .gitlab-ci.yml - .gitlab/ci.sh - + changelog.d/T27329 - + changelog.d/T27360 - + changelog.d/T27456 - + changelog.d/fix-make-install-j - compiler/GHC/Builtin/Utils.hs - compiler/GHC/Core/Class.hs - compiler/GHC/CoreToIface.hs - compiler/GHC/Data/BooleanFormula.hs - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Stats.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Warnings.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Class.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/Types/Rank.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Unit/Module/Warnings.hs - compiler/Language/Haskell/Syntax/Binds.hs - compiler/Language/Haskell/Syntax/BooleanFormula.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Extension.hs - docs/users_guide/expected-undocumented-flags.txt - docs/users_guide/exts/rank_polymorphism.rst - docs/users_guide/exts/static_pointers.rst - hadrian/bindist/Makefile - 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/Exception/Type.hs - libraries/ghc-internal/tests/backtraces/T14532b.stdout - testsuite/tests/backpack/should_compile/T13149.bkp - testsuite/tests/codeGen/should_run/cgrun025.stderr - 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/haddock/haddock_examples/haddock.Test.stderr - 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/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/T15279.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/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/rts/ipe/IpeStats/Fold.hs - testsuite/tests/runghc/T7859.stderr-mingw32 - 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/T18920.hs - testsuite/tests/typecheck/should_compile/T2595.hs - testsuite/tests/typecheck/should_compile/T7541.hs - testsuite/tests/typecheck/should_fail/T6069.stderr - testsuite/tests/typecheck/should_fail/T7368a.hs - 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/Parsers.hs - utils/check-exact/Transform.hs - utils/check-exact/Utils.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Backends/LaTeX.hs - utils/haddock/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/GhcUtils.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/72da7aff710e37719e52238f88d472… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/72da7aff710e37719e52238f88d472… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc][wip/az/epa-tidy-locatedxxx-8] 6 commits: ci: add missing docker permission workaround in abi-test job
by Alan Zimmerman (＠alanz) 18 Jul '26

18 Jul '26

Alan Zimmerman pushed to branch wip/az/epa-tidy-locatedxxx-8 at Glasgow Haskell Compiler / GHC Commits: 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(a)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 - - - - - 57ec828f by Alan Zimmerman at 2026-07-18T11:47:17+01:00 EPA: Keep decls together in ClassDecl Similar to 1718230f4d3d19d8c49c0e5d496cb0fb6f399528 for HsValBindsLR, this commit updates ClassDecl so that it no longer splits out the assorted `LHsDecl GhcPs` until the renamer. It does this by inserting a type family (separate from the classic TTG one) for this. So data TyClDecl ... | ClassDecl { ... tcdDecls :: XClassDecls pass with type instance XClassDecls GhcPs = [LHsDecl GhcPs] type instance XClassDecls GhcRn = ClassDeclX GhcRn type instance XClassDecls GhcTc = ClassDeclX GhcTc data ClassDeclX pass = ClassDeclX { tcdSigs :: [LSig pass], -- ^ Methods' signatures tcdMeths :: LHsBinds pass, -- ^ Default methods tcdATs :: [LFamilyDecl pass], -- ^ Associated types; tcdATDefs :: [LTyFamDefltDecl pass], -- ^ Associated type defaults tcdDocs :: [LDocDecl pass] -- ^ Haddock docs } - - - - - 91 changed files: - .gitlab-ci.yml - .gitlab/ci.sh - + changelog.d/T27329 - + changelog.d/fix-make-install-j - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Stats.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Class.hs - compiler/GHC/Tc/Types/Rank.hs - compiler/GHC/ThToHs.hs - compiler/Language/Haskell/Syntax/Binds.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Extension.hs - docs/users_guide/expected-undocumented-flags.txt - docs/users_guide/exts/rank_polymorphism.rst - docs/users_guide/exts/static_pointers.rst - hadrian/bindist/Makefile - libraries/base/changelog.md - libraries/base/src/System/Environment.hs - libraries/ghc-internal/ghc-internal.cabal.in - testsuite/tests/backpack/should_compile/T13149.bkp - testsuite/tests/determinism/determ017/A.hs - testsuite/tests/ghci/scripts/T12005.script - testsuite/tests/haddock/haddock_examples/haddock.Test.stderr - 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/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/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/DumpSemis.stderr - + testsuite/tests/parser/should_compile/T13087.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/parser/should_fail/T8431.stderr - testsuite/tests/parser/should_fail/readFail038.stderr - testsuite/tests/perf/compiler/T3064.hs - testsuite/tests/polykinds/T7594.hs - testsuite/tests/printer/Test24533.stdout - testsuite/tests/programs/thurston-modular-arith/Main.hs - testsuite/tests/rts/ipe/IpeStats/Fold.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/T18920.hs - testsuite/tests/typecheck/should_compile/T2595.hs - testsuite/tests/typecheck/should_compile/T7541.hs - testsuite/tests/typecheck/should_fail/T6069.stderr - testsuite/tests/typecheck/should_fail/T7368a.hs - 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/Utils.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Backends/LaTeX.hs - utils/haddock/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/GhcUtils.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ebc758f69f3da634ba9411e5b9ca32… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ebc758f69f3da634ba9411e5b9ca32… You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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[Git][ghc/ghc] Pushed new branch wip/sjakobi/T24471-flaky-peak
by Simon Jakobi (＠sjakobi2) 18 Jul '26

18 Jul '26

Simon Jakobi pushed new branch wip/sjakobi/T24471-flaky-peak at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/sjakobi/T24471-flaky-peak You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help

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