Wen Kokke pushed to branch wip/wenkokke/trace-ipe at Glasgow Haskell Compiler / GHC Commits: eb922183 by Duncan Coutts at 2026-05-07T14:28:50+01:00 Add a rts posix FdWakup utility module This will be used to implement wakeupIOManager for in-RTS I/O managers. It provides a notification/wakeup mechanism using FDs, suitable for situations when a thread is blocked on a set of fds anyway. It uses the classic self-pipe trick, or equivalently eventfd on supported platforms. This will initially be used to implement prompt interrupt or shutdown of the posix ticker thread. - - - - - 01b0e233 by Duncan Coutts at 2026-05-07T14:28:50+01:00 Add prompt shutdown to the pthread ticker implementation. The Linux timerfd ticker monitors a pipe which is used by exitTicker to ensure a prompt wakeup and shutdown. The pthread ticker lacked this and so would only exit at the next ticker wakeup (10ms by default). This patch adds the same mechanism to the pthread ticker. This changes the pthread ticker from waiting by using nanosleep() to waiting using either ppoll() or select(), so that it can wait on both a time and a file descriptor. On Linux at least, a test program to compare the timing jitter of these APIs shows that using nanpsleep, ppoll or select makes no statistical difference to the maximum or average jitter. This is a step towards unifying the posix ticker implementations, so that we can have just one portable one (albeit with some limited cpp). It is also a step towards using the ticker as part of a more general implementation of wakeUpRts, since this will require a method to wake the rts from a signal handler context (ctl-c handler). - - - - - bc41d646 by Duncan Coutts at 2026-05-07T14:28:50+01:00 Update ticker header commentary It was antique and didn't apply even to the previous implementation, and certainly not to the updated one. - - - - - 4ed9a386 by Duncan Coutts at 2026-05-07T14:28:50+01:00 Remove the timerfd-based ticker implementation There does not appear to be any remaining advantage on Linux to using the timerfd ticker implementation over the portable one (using ppoll on Linux for precise timing). The eventfd implementation was originally added at a time when Linux was still using a signal based implementation. So it made sense at the time. See (closed) issue #10840. - - - - - 97504fa6 by Duncan Coutts at 2026-05-07T14:28:50+01:00 Consolidate to a single posix ticker implementation Previously we had four implementations, two using signals and two using threads. Having just one should make behaviour more consistent between platforms, and should make maintenance easier. - - - - - 1e60023b by Facundo Domínguez at 2026-05-07T18:01:16-04:00 Generalize so_inline to specify which bindings should be preserved This commit generalizes the so_inline option of the simple optimizer so we can indicate with a predicate the specific bindings that should be kept. This feature is important for the LiquidHaskell plugin, which relies on the simple optimizer to make core programs easier to read, but needs to preserve bindings that are relevant for verification. See https://gitlab.haskell.org/ghc/ghc/-/issues/24386 for the full discussion. - - - - - 44cf9cd7 by Wolfgang Jeltsch at 2026-05-12T09:48:18-04:00 Move the `Text.Read` implementation into `base` - - - - - 4ac3f7d6 by Vladislav Zavialov at 2026-05-12T09:49:03-04:00 EPA: Use AnnParen for tuples and sums Summary of changes * Do not use AnnParen in XListTy, replace it with EpToken "[" and "]" * Specialise AnnParen to tuple/sums by dropping the AnnParensSquare and keeping only AnnParens and AnnParensHash * Use AnnParen in XExplicitTuple * Use AnnParen in XExplicitTupleTy * Use AnnParen in XTuplePat * Use AnnParen in XExplicitSum (via AnnExplicitSum) * Use AnnParen in XSumPat (via EpAnnSumPat) This is a refactoring with no user-facing changes. - - - - - 1bdcddec by Duncan Coutts at 2026-05-12T09:49:48-04:00 Add minimal dlltool support to ghc-toolchain The dlltool is a tool that can create dll import libraries from .def files. These .def files list the exported symbols of dlls. Its somewhat like gnu linker scripts, but more limited. We will need dlltool to build the rts and ghc-internal libraries as DLLs on Windows. The rts and ghc-internal libraries have a recursive dependency on each other. Import libraries can be used to resolve recursive dependencies between dlls. We will use an import library for the rts when linking the ghc-internal library. - - - - - f7fc3770 by Duncan Coutts at 2026-05-12T09:49:48-04:00 Add minimal dlltool support into ./configure Find dlltool, and hopefully support finding it within the bundled llvm toolchain on windows. - - - - - e4e22bfb by Duncan Coutts at 2026-05-12T09:49:48-04:00 Update the default host and target files for dlltool support - - - - - 5666c8f9 by Duncan Coutts at 2026-05-12T09:49:48-04:00 Add dlltool as a hadrian builder Optional except on windows. - - - - - 5e14fe3f by Duncan Coutts at 2026-05-12T09:49:48-04:00 Update and generate libHSghc-internal.def from .def.in file The only symbol that the rts imports from the ghc-internal package now is init_ghc_hs_iface. So the rts only needs an import lib that defines that one symbol. Also, remove the libHSghc-prim.def because it is redundant. The rts no longer imports anything from ghc-prim. Keep libHSffi.def for now. We may yet need it once it is clear how libffi is going to be built/used for ghc. - - - - - 3d91e4a6 by Duncan Coutts at 2026-05-12T09:49:48-04:00 Add rule to build libHSghc-internal.dll.a and link into the rts On windows only, with dynamic linking. This is needed because on windows, all symbols in dlls must be resolved. No dangling symbols allowed. References to external symbols must be explicit. We resolve this with an import library. We create an import library for ghc-internal, a .dll.a file. This is a static archive containing .o files that define the symbols we need, and crucially have ".idata" sections that specifies the symbols the dll imports and from where. Note that we do not install this libHSghc-internal.dll.a, and it does not need to list all the symbols exported by that package. We create a special purpose import lib and only use it when linking the rts dll, so it only has to list the symbols that the rts uses from ghc-internal (which is exactly one symbol: init_ghc_hs_iface). - - - - - c8dae539 by Alice Rixte at 2026-05-12T09:50:52-04:00 Script for downloading and copying `base-exports` file - - - - - 5fab2238 by Wolfgang Jeltsch at 2026-05-12T21:24:27+03:00 Introduce a cache of home module name providers This contribution introduces to the module graph a cache that maps home module names to sets of units providing them and changes the finder to use that cache. This is a performance optimization, especially for multi-home-unit builds. The particular changes are as follows: * In `GHC.Unit.Module.Graph`, `ModuleGraph` is extended with a new field `mg_home_module_name_providers_map`, exposed as `mgHomeModuleNameProvidersMap`. This is a cache that assigns to each home module name the set of IDs of home units that define it. Operations that construct module graphs are updated such that this cache stays synchronized. * In `GHC.Unit.Finder`, `findImportedModule` is changed to pull `mgHomeModuleNameProvidersMap` from `hsc_mod_graph` and pass it to `findImportedModuleNoHsc`, which now does not search home units in arbitrary order but prioritizes those units that the cache mentions as potential providers of the requested module. In addition, this contribution adds variants of the two multi-component compiler performance tests that use 100 units instead of 20, because with just 20 units the benefits from caching of home module name providers are still negligible. The following table shows the total time needed for running both multi-component tests before and after this contribution and with different numbers of units: | # of units | Before | After | |-----------:|-------:|------:| | 20 | 0:12 | 0:12 | | 100 | 0:47 | 0:42 | | 200 | 3:05 | 2:08 | Note that there seems to be a general overhead of 12 seconds that is not attributable to the actual tests, so that the real running times should be 12 seconds smaller than shown above. Resolves #27055. Metric Decrease: MultiComponentModules MultiComponentModulesRecomp Co-authored-by: Matthew Pickering <matthewtpickering@gmail.com> Co-authored-by: Fendor <fendor@posteo.de> - - - - - 38b76b2f by Cheng Shao at 2026-05-13T17:48:48-04:00 testsuite: mark T22159 as fragile This patch marks T22159 as fragile on Windows for issue described in #27248. Before we get to the bottom of those failures, this unblocks newer Windows runners. - - - - - 4866321b by Wen Kokke at 2026-05-14T18:00:24+01:00 rts: Add IPE event class for -l This commit adds a new IPE event class to the -l RTS flag. Previously, IPE events were enabled unconditionally. However, the IPE events can easily grow to hundreds or thousands of megabytes. With the new event class you can pass, e.g., -l-I to disable IPE events. - - - - - 5fb731b7 by Wen Kokke at 2026-05-14T18:00:24+01:00 ghc-internal: Add traceIPE to TraceFlags - - - - - 309ea2a7 by Wen Kokke at 2026-05-14T18:00:24+01:00 testsuite: Add test for TraceFlags.traceIpe - - - - - d58886d5 by Wen Kokke at 2026-05-14T18:00:24+01:00 ghc-internal: Add @since to TraceFlags.traceIpe - - - - - 38d6a704 by Wen Kokke at 2026-05-14T18:00:24+01:00 ghc-internal: Add ipe to DebugFlags - - - - - 96aa6010 by Wen Kokke at 2026-05-14T18:00:24+01:00 testsuite: Add test for DebugFlags.ipe - - - - - 7d960125 by Wen Kokke at 2026-05-14T18:00:24+01:00 ghc-internal: Add @since to DebugFlags.ipe - - - - - 77 changed files: - + changelog.d/ghc-api-epa-parens - + changelog.d/ipe-event-class - + changelog.d/more-efficient-home-unit-imports-finding - + changelog.d/so_inline_is_a_predicate - compiler/GHC/Core/SimpleOpt.hs - compiler/GHC/Driver/Config.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Unit/Finder.hs - compiler/GHC/Unit/Module/Graph.hs - configure.ac - distrib/configure.ac.in - docs/users_guide/runtime_control.rst - hadrian/cfg/default.host.target.in - hadrian/cfg/default.target.in - hadrian/src/Builder.hs - hadrian/src/Rules/Generate.hs - hadrian/src/Rules/Library.hs - hadrian/src/Rules/Rts.hs - libraries/base/src/Data/Functor/Classes.hs - libraries/base/src/Data/Functor/Compose.hs - libraries/base/src/Prelude.hs - libraries/base/src/Text/Read.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/IO/Encoding.hs - libraries/ghc-internal/src/GHC/Internal/RTS/Flags.hsc - − libraries/ghc-internal/src/GHC/Internal/Text/Read.hs - m4/find_llvm_prog.m4 - m4/fp_setup_windows_toolchain.m4 - m4/ghc_toolchain.m4 - m4/prep_target_file.m4 - rts/.gitignore - rts/IPE.c - rts/RtsFlags.c - rts/Trace.c - rts/Trace.h - rts/include/rts/EventLogWriter.h - rts/include/rts/Flags.h - + rts/posix/FdWakeup.c - + rts/posix/FdWakeup.h - rts/posix/Ticker.c - − rts/posix/ticker/Pthread.c - − rts/posix/ticker/TimerFd.c - rts/rts.cabal - + rts/win32/libHSghc-internal.def.in - testsuite/tests/ffi/should_run/all.T - + testsuite/tests/ghc-api/T24386.hs - testsuite/tests/ghc-api/T25121_status.stdout - testsuite/tests/ghc-api/all.T - + testsuite/tests/interface-stability/.gitignore - testsuite/tests/interface-stability/README.mkd - + testsuite/tests/interface-stability/download-base-exports.sh - testsuite/tests/parser/should_compile/DumpParsedAst.stderr - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/perf/compiler/Makefile - testsuite/tests/perf/compiler/all.T - testsuite/tests/perf/compiler/genMultiComp.py - + testsuite/tests/rts/T25275/DebugIpe.hs - + testsuite/tests/rts/T25275/T25275_A.stdout - + testsuite/tests/rts/T25275/T25275_B.stdout - + testsuite/tests/rts/T25275/T25275_C.stdout - + testsuite/tests/rts/T25275/T25275_D.stdout - + testsuite/tests/rts/T25275/TraceIpe.hs - + testsuite/tests/rts/T25275/all.T - testsuite/tests/th/T24111.stdout - testsuite/tests/typecheck/should_compile/subsumption_sort_hole_fits.stderr - testsuite/tests/typecheck/should_fail/T21130.stderr - utils/check-exact/ExactPrint.hs - utils/ghc-toolchain/exe/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Target.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/97983c96d547549d65ea3703fdff858... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/97983c96d547549d65ea3703fdff858... You're receiving this email because of your account on gitlab.haskell.org.