Brandon Chinn pushed to branch wip/T26503 at Glasgow Haskell Compiler / GHC Commits: c56567ec by Simon Peyton Jones at 2026-01-15T23:19:04+00:00 Add evals for strict data-con args in worker-functions This fixes #26722, by adding an eval in a worker for arguments of strict data constructors, even if the function body uses them strictly. See (WIS1) in Note [Which Ids should be strictified] I took the opportunity to make substantial improvements in the documentation for call-by-value functions. See especially Note [CBV Function Ids: overview] in GHC.Types.Id.Info Note [Which Ids should be CBV candidates?] ditto Note [EPT enforcement] in GHC.Stg.EnforceEpt among others. - - - - - 9719ce5d by Simon Peyton Jones at 2026-01-15T23:19:04+00:00 Improve `interestingArg` This function analyses a function's argument to see if it is interesting enough to deserve an inlining discount. Improvements for * LitRubbish arguments * exprIsExpandable arguments See Note [Interesting arguments] which is substantially rewritten. - - - - - 7b616b9f by Cheng Shao at 2026-01-16T06:45:00-05:00 compiler: fix regression when compiling foreign stubs in the rts unit This patch fixes a regression when compiling foreign stubs in the rts unit introduced in 05e25647f72bc102061af3f20478aa72bff6ff6e. A simple revert would fix it, but it's better to implement a proper fix with comment for better understanding of the underlying problem, see the added comment for explanation. Co-authored-by: Codex <codex@openai.com> - - - - - c343ef64 by Sylvain Henry at 2026-01-16T06:45:51-05:00 base: remove GHC.JS.Prim.Internal.Build (#23432) See accepted CLC proposal https://github.com/haskell/core-libraries-committee/issues/329 - - - - - 29c0aceb by Simon Peyton Jones at 2026-01-16T17:18:11-05:00 Improve newtype unwrapping Ticket #26746 describes several relatively-minor shortcomings of newtype unwrapping. This MR addresses them, while also (arguably) simplifying the code a bit. See new Note [Solving newtype equalities: overview] and Note [Decomposing newtype equalities] and Note [Eager newtype decomposition] and Note [Even more eager newtype decomposition] For some reason, on Windows only, runtime allocations decrease for test T5205 (from 52k to 48k). I have not idea why. No change at all on Linux. I'm just going to accept the change. (I saw this same effect in another MR so I think it's a fault in the baseline.) Metric Decrease: T5205 - - - - - 8b59e62c by Andreas Klebinger at 2026-01-16T17:18:52-05:00 testsuite: Widen acceptance window for T5205. Fixes #26782 - - - - - 9e5e0234 by mangoiv at 2026-01-17T06:03:03-05:00 add a new issue template for getting verified To reduce spam created by new users, we will in future not grant any rights but reporting issues to new users. That is why we will have to be able to verify them. The added issue template serves that purpose. - - - - - b18b2c42 by Cheng Shao at 2026-01-17T06:03:44-05:00 llvm: fix split sections for llvm backend This patch fixes split sections for llvm backend: - Pass missing `--data-sections`/`--function-sections` flags to llc/opt. - Use `@llvm.compiler.used` instead of `@llvm.used` to avoid sections being unnecessarily retained at link-time. Fixes #26770. ------------------------- Metric Decrease: libdir size_hello_artifact size_hello_unicode ------------------------- Co-authored-by: Codex <codex@openai.com> - - - - - ebf66f67 by Cheng Shao at 2026-01-17T13:16:50-05:00 Update autoconf scripts Scripts taken from autoconf a2287c3041a3f2a204eb942e09c015eab00dc7dd - - - - - 598624b9 by Andreas Klebinger at 2026-01-17T13:17:32-05:00 CString.hs: Update incorrect comment. Fixes #26322 - - - - - eea2036b by Cheng Shao at 2026-01-18T10:00:49-05:00 libraries: bump haskeline submodule to 0.8.4.1 This patch bumps the haskeline submodule to 0.8.4.1 which includes an important fix for an ANSI handling bug on Windows (https://github.com/haskell/haskeline/pull/126). - - - - - 87d8f6c2 by Cheng Shao at 2026-01-18T10:01:30-05:00 hadrian: replace default -H32m/-H64m with -O64M to improve mutator productivity Most hadrian build flavours pass `-H32m`/`-H64m` to GHC as conventional wisdom to improve mutator productivity and reduce GC overhead. They were inherited from the legacy Make build system, and there used to be make flags to instrument a build process with `-Rghc-timing` option to collect GC stats of each GHC run from stderr. It's time to revisit whether there are better defaults for `-H32m`/`-H64m`, and this patch changes it to `-O64M` which indeed improves mutator productivity based on real statistics. `-O64M` is more aggressive than `-H64m`; it allows the old generation to grow to at least 64M before triggering major GC and reduces major GC runs. The stats of a clean build with `validate` flavour and `-H64m`: ``` h64m.log matched RTS stat lines: 5499 sum MUT cpu : 2400.808 s sum GC cpu : 1378.292 s sum MUT elapsed : 2788.253 s sum GC elapsed : 1389.233 s GC/MUT cpu ratio : 0.574 (GC is 57.4% of MUT) GC/MUT elapsed ratio : 0.498 (GC is 49.8% of MUT) GC fraction of (MUT+GC) cpu : 36.5% GC fraction of (MUT+GC) elapsed : 33.3% per-line GC/MUT cpu ratio: median 0.691, p90 1.777 per-line GC/MUT elapsed ratio: median 0.519, p90 1.081 ``` The stats of a clean build with `validate` flavour and `-O64M`: ``` o64m.log matched RTS stat lines: 5499 sum MUT cpu : 2377.383 s sum GC cpu : 1127.146 s sum MUT elapsed : 2758.857 s sum GC elapsed : 1135.587 s GC/MUT cpu ratio : 0.474 (GC is 47.4% of MUT) GC/MUT elapsed ratio : 0.412 (GC is 41.2% of MUT) GC fraction of (MUT+GC) cpu : 32.2% GC fraction of (MUT+GC) elapsed : 29.2% per-line GC/MUT cpu ratio: median 0.489, p90 1.099 per-line GC/MUT elapsed ratio: median 0.367, p90 0.806 ``` Mutator time is roughly in the same ballpark, but GC CPU time has reduced by 18.22%, and mutator productivity has increased from 63.5% to 67.8%. - - - - - 8372e13d by Cheng Shao at 2026-01-18T10:02:12-05:00 rts: remove unused .def files from rts/win32 This patch removes unused .def files from `rts/win32`, given we don't build .dll files for rts/ghc-internal/ghc-prim at all. Even when we resurrect win32 dll support at some point in the future, these .def files still contain incorrect symbols anyway and won't be of any use. - - - - - f6af485d by Cheng Shao at 2026-01-18T10:03:19-05:00 .gitmodules: use gitlab mirror for the libffi-clib submodule This patch fixes .gitmodules to use the gitlab mirror for the libffi-clib submodule, to make it coherent with other submodules that allow ghc developers to experiment with wip branches in submodules for ghc patches. Fixes #26783. - - - - - 41432d25 by Cheng Shao at 2026-01-18T10:05:13-05:00 hadrian: remove the horrible i386 speedHack When hadrian builds certain rts objects for i386, there's a horrible speedHack that forces -fno-PIC even for dynamic ways of those objects. This is not compatible with newer versions of gcc/binutils as well as clang/lld, and this patch removes it. Fixes #26792. - - - - - 323eb8f0 by Cheng Shao at 2026-01-18T21:48:19-05:00 hadrian: enable split sections for cross stage0 This patch fixes a minor issue with `splitSectionsArgs` in hadrian: previously, it's unconditionally disabled for stage0 libraries because it's not going to be shipped in the final bindists. But it's only true when not cross compiling. So for now we also need to enable it for cross stage0 as well. - - - - - 3fadfefe by Andreas Klebinger at 2026-01-18T21:49:01-05:00 RTS: Document -K behaviour better - - - - - 30f442a9 by Teo Camarasu at 2026-01-20T13:57:26-05:00 base: don't expose GHC.Num.{BigNat, Integer, Natural} We no longer expose GHC.Num.{BigNat, Integer, Natural} from base instead users should get these modules from ghc-bignum. We make this change to insulate end users from changes to GHC's implementation of big numbers. Implements CLC proposal 359: https://github.com/haskell/core-libraries-committee/issues/359 - - - - - 75a9053d by Teo Camarasu at 2026-01-20T13:58:07-05:00 base: deprecate GHC internals in GHC.Num Implements CLC proposal: https://github.com/haskell/core-libraries-committee/issues/360 - - - - - 9534b032 by Andreas Klebinger at 2026-01-20T13:58:50-05:00 ghc-experimental: Update Changelog I tried to reconstruct a high level overview of the changes and when they were made since we introduced it. Fixes #26506 Co-authored-by: Teo Camarasu <teofilcamarasu@gmail.com> - - - - - 346f2f5a by Cheng Shao at 2026-01-20T13:59:30-05:00 hadrian: remove RTS options in ghc-in-ghci flavour This patch removes the RTS options passed to ghc in ghc-in-ghci flavour, to workaround command line argument handling issue in hls/hie-boot that results in `-O64M` instead of `+RTS -O64M -RTS` being passed to ghc. It's not a hadrian bug per se, since ghc's own ghc-in-ghci multi repl works fine, but we should still make sure HLS works. Closes #26801. - - - - - 759fd15a by Andreas Klebinger at 2026-01-21T16:05:28-05:00 Don't build GHC with -Wcompat Without bumping the boot compiler the warnings it produces are often not actionable leading to pointless noise. Fixes #26800 - - - - - 3172db94 by Torsten Schmits at 2026-01-21T16:06:11-05:00 Use the correct field of ModOrigin when formatting error message listing hidden reexports - - - - - 485c12b2 by Cheng Shao at 2026-01-21T16:06:54-05:00 Revert "hadrian: handle findExecutable "" gracefully" This reverts commit 1e5752f64a522c4025365856d92f78073a7b3bba. The underlying issue has been fixed in https://github.com/haskell/directory/commit/75828696e7145adc09179111a0d631b9... and present since 1.3.9.0, and hadrian directory lower bound is 1.3.9.0, so we can revert our own in house hack now. - - - - - 5efb58dc by Cheng Shao at 2026-01-21T16:07:36-05:00 rts: fix typo in TICK_ALLOC_RTS This patch fixes a typo in the `TICK_ALLOC_RTS` macro, the original `bytes` argument was silently dropped. The Cmm code has its own version of `TICK_ALLOC_RTS` not affected by this typo, it affected the C RTS, and went unnoticed because the variable `n` happened to also be available at its call site. But the number was incorrect. Also fixes its call site since `WDS()` is not available in C. - - - - - c406ea69 by Cheng Shao at 2026-01-21T16:07:36-05:00 rts: remove broken & unused ALLOC_P_TICKY This patch removes the `ALLOC_P_TICKY` macro from the rts, it's unused, and its expanded code is already broken. - - - - - 34a27e20 by Simon Peyton Jones at 2026-01-21T16:08:17-05:00 Make the implicit-parameter class have representational role This MR addresses #26737, by making the built-in class IP have a representational role for its second parameter. See Note [IP: implicit parameter class] in ghc-internal:GHC.Internal.Classes.IP In fact, IP is (unfortunately, currently) exposed by base:GHC.Base, so we ran a quick CLC proposal to agree the change: https://github.com/haskell/core-libraries-committee/issues/385 Some (small) compilations get faster because they only need to load (small) interface file GHC.Internal.Classes.IP.hi, rather than (large) GHC.Internal.Classes.hi. Metric Decrease: T10421 T12150 T12425 T24582 T5837 T5030 - - - - - ca79475f by Cheng Shao at 2026-01-21T16:09:00-05:00 testsuite: avoid re.sub in favor of simple string replacements This patch refactors the testsuite driver and avoids the usage of re.sub in favor of simple string replacements when possible. The changes are not comprehensive, and there are still a lot of re.sub usages lingering around the tree, but this already addresses a major performance bottleneck in the testsuite driver that might has to do with quadratic or worse slowdown in cpython's regular expression engine when handling certain regex patterns with large strings. Especially on i386, and i386 jobs are the bottlenecks of all full-ci validate pipelines! Here are the elapsed times of testing x86_64/i386 with -j48 before this patch: x86_64: `Build completed in 6m06s` i386: `Build completed in 1h36m` And with this patch: x86_64: `Build completed in 4m55s` i386: `Build completed in 4m23s` Fixes #26786. Co-authored-by: Codex <codex@openai.com> - - - - - 88c93796 by Zubin Duggal at 2026-01-21T16:09:42-05:00 ghc-toolchain: Also configure windres on non-windows platforms. It may be needed for cross compilation. Fixes #24588 - - - - - 9788c0ec by Cheng Shao at 2026-01-21T16:10:24-05:00 ghci: print external interpreter trace messages to stderr instead of stdout This patch makes ghci print external interpreter trace messages to stderr instead of stdout, which is a much saner choice for diagnostic information. Closes #26807. - - - - - bc4d948a by Brandon Chinn at 2026-01-21T19:52:29-08:00 Unify HsString + HsMultilineString - - - - - c32aefd9 by Brandon Chinn at 2026-01-22T22:29:24-08:00 Implement QualifiedStrings (#26503) See Note [Implementation of QualifiedStrings] - - - - - 173 changed files: - + .gitlab/issue_templates/get-verified.md - .gitmodules - compiler/GHC/Builtin/Names.hs - compiler/GHC/Builtin/Names/TH.hs - compiler/GHC/Builtin/Types.hs - compiler/GHC/CmmToLlvm.hs - compiler/GHC/CmmToLlvm/Base.hs - compiler/GHC/Core/FamInstEnv.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Opt/WorkWrap/Utils.hs - compiler/GHC/Core/Tidy.hs - compiler/GHC/Core/Unfold.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/CoreToStg/Prep.hs - compiler/GHC/Driver/CodeOutput.hs - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/Lexer.x - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/Lint.hs - compiler/GHC/StgToCmm/Closure.hs - compiler/GHC/StgToCmm/Expr.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Id.hs - compiler/GHC/Types/Id/Info.hs - compiler/GHC/Types/Id/Make.hs - + compiler/GHC/Types/StringMeta.hs - compiler/GHC/Unit/State.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/ghc.cabal.in - config.guess - config.sub - docs/users_guide/9.16.1-notes.rst - + docs/users_guide/exts/qualified_strings.rst - docs/users_guide/runtime_control.rst - hadrian/doc/flavours.md - hadrian/src/Hadrian/Utilities.hs - hadrian/src/Rules/Docspec.hs - hadrian/src/Rules/Lint.hs - hadrian/src/Settings/Builders/Ghc.hs - hadrian/src/Settings/Builders/RunTest.hs - hadrian/src/Settings/Builders/SplitSections.hs - hadrian/src/Settings/Default.hs - hadrian/src/Settings/Flavours/Benchmark.hs - hadrian/src/Settings/Flavours/Development.hs - hadrian/src/Settings/Flavours/GhcInGhci.hs - hadrian/src/Settings/Flavours/Performance.hs - hadrian/src/Settings/Flavours/Quick.hs - hadrian/src/Settings/Flavours/QuickCross.hs - hadrian/src/Settings/Flavours/Quickest.hs - hadrian/src/Settings/Flavours/Validate.hs - hadrian/src/Settings/Packages.hs - libraries/base/base.cabal.in - libraries/base/changelog.md - libraries/base/src/Data/Array/Byte.hs - − libraries/base/src/GHC/JS/Prim/Internal/Build.hs - libraries/base/src/GHC/Num.hs - − libraries/base/src/GHC/Num/BigNat.hs - − libraries/base/src/GHC/Num/Integer.hs - − libraries/base/src/GHC/Num/Natural.hs - libraries/base/src/System/CPUTime/Utils.hs - libraries/ghc-bignum/ghc-bignum.cabal - libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs - libraries/ghc-experimental/CHANGELOG.md - libraries/ghc-experimental/ghc-experimental.cabal.in - libraries/ghc-experimental/src/GHC/TypeNats/Experimental.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/CString.hs - libraries/ghc-internal/src/GHC/Internal/Classes.hs - + libraries/ghc-internal/src/GHC/Internal/Classes/IP.hs - libraries/ghc-internal/src/GHC/Internal/LanguageExtensions.hs - libraries/ghc-internal/src/GHC/Internal/TH/Lib.hs - libraries/ghc-internal/src/GHC/Internal/TH/Syntax.hs - libraries/ghci/GHCi/Server.hs - libraries/haskeline - libraries/template-haskell/Language/Haskell/TH/Lib.hs - rts/include/Cmm.h - rts/include/stg/Ticky.h - rts/sm/Storage.c - − rts/win32/libHSffi.def - − rts/win32/libHSghc-internal.def - − rts/win32/libHSghc-prim.def - testsuite/driver/runtests.py - testsuite/driver/testlib.py - testsuite/driver/testutil.py - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/deriving/should_fail/T8984.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail4.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail5.stderr - testsuite/tests/driver/T4437.hs - testsuite/tests/ghc-api/annotations-literals/literals.stdout - testsuite/tests/ghc-api/annotations-literals/parsed.hs - testsuite/tests/ghc-api/annotations-literals/parsed.stdout - 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/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/interface-stability/ghc-prim-exports.stdout - testsuite/tests/interface-stability/ghc-prim-exports.stdout-mingw32 - testsuite/tests/interface-stability/template-haskell-exports.stdout - 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/DumpTypecheckedAst.stderr - testsuite/tests/perf/should_run/all.T - + testsuite/tests/qualified-strings/Makefile - + testsuite/tests/qualified-strings/should_compile/Example/Length.hs - + testsuite/tests/qualified-strings/should_compile/all.T - + testsuite/tests/qualified-strings/should_compile/qstrings_redundant_pattern.hs - + testsuite/tests/qualified-strings/should_compile/qstrings_redundant_pattern.stderr - + testsuite/tests/qualified-strings/should_fail/Example/Length.hs - + testsuite/tests/qualified-strings/should_fail/Makefile - + testsuite/tests/qualified-strings/should_fail/all.T - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_expr.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_expr.stderr - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_pat.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_bad_pat.stderr - + testsuite/tests/qualified-strings/should_fail/qstrings_multiline_no_ext.hs - + testsuite/tests/qualified-strings/should_fail/qstrings_multiline_no_ext.stderr - + testsuite/tests/qualified-strings/should_run/Example/ByteStringAscii.hs - + testsuite/tests/qualified-strings/should_run/Example/ByteStringUtf8.hs - + testsuite/tests/qualified-strings/should_run/Example/Text.hs - + testsuite/tests/qualified-strings/should_run/Makefile - + testsuite/tests/qualified-strings/should_run/all.T - + testsuite/tests/qualified-strings/should_run/qstrings_expr.hs - + testsuite/tests/qualified-strings/should_run/qstrings_expr.stdout - + testsuite/tests/qualified-strings/should_run/qstrings_pat.hs - + testsuite/tests/qualified-strings/should_run/qstrings_pat.stdout - + testsuite/tests/qualified-strings/should_run/qstrings_th.hs - + testsuite/tests/qualified-strings/should_run/qstrings_th.stdout - testsuite/tests/simplCore/should_compile/T18013.stderr - + testsuite/tests/simplCore/should_compile/T26722.hs - + testsuite/tests/simplCore/should_compile/T26722.stderr - testsuite/tests/simplCore/should_compile/all.T - testsuite/tests/th/TH_implicitParams.stdout - + testsuite/tests/typecheck/should_compile/T26737.hs - + testsuite/tests/typecheck/should_compile/T26746.hs - testsuite/tests/typecheck/should_compile/all.T - testsuite/tests/typecheck/should_fail/T15801.stderr - testsuite/tests/typecheck/should_fail/T22924b.stderr - testsuite/tests/typecheck/should_fail/TcCoercibleFail.hs - testsuite/tests/typecheck/should_fail/TcCoercibleFail.stderr - testsuite/tests/typecheck/should_fail/all.T - utils/check-exact/ExactPrint.hs - utils/ghc-toolchain/exe/Main.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hyperlinker/Parser.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/6dfed3a3d0b444bc6b971a6e32ba9ef... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/6dfed3a3d0b444bc6b971a6e32ba9ef... You're receiving this email because of your account on gitlab.haskell.org.