Rodrigo Mesquita pushed to branch wip/romes/exec-break-has-resume at Glasgow Haskell Compiler / GHC Commits: cc533b66 by Sasha Bogicevic at 2026-10-31T09:18:15-04:00 Don't report -XStrict-generated bangs under -Wredundant-bang-patterns The -XStrict flag causes the desugarer to insert bang patterns. These are not user-written, so -Wredundant-bang-patterns must not report them. To achieve this, the desugarer now tracks whether it is desugaring compiler-generated code (similar to the typechecker's 'tcl_in_gen_code'). Bangs inserted by -XStrict are given generated spans, which suppresses the "redundant bang" warnings without otherwise affecting pattern-match warnings. Fixes #27323 - - - - - 13d38047 by Luite Stegeman at 2026-10-31T09:19:11-04:00 rts: tombstone Weak# copies that lose an evacuation race (#23160) Mark the losing copy of a Weak# during an evacuation race in parallel GC with stg_DEAD_WEAK_info. This ensures that the nonmoving GC doesn't follow dangling pointers, leading to crashes. Fixes #23160 - - - - - 63347328 by Zubin Duggal at 2026-10-31T09:19:52-04:00 ghci: Drop GHCi's exception context when rethrowing in ghc -e Fixes #27847. - - - - - a85fef3f by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context in modifyIOError Fixes #27851. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/446 - - - - - 1d60b591 by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context in mapException Fixes #27851. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/446 - - - - - 3c029a1b by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context when rethrowing exceptions in Handle reads Fixes #27875. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/447 - - - - - ab2b317a by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context when rethrowing exceptions in hClose Fixes #27875. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/447 - - - - - f5abf277 by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context when rethrowing exceptions in Windows openFile Fixes #27875. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/447 - - - - - d842c672 by Zubin Duggal at 2026-10-31T09:19:52-04:00 base: Preserve exception context when rethrowing exceptions in executablePath Fixes #27875. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/447 - - - - - c5a8bb9f by Simon Peyton Jones at 2026-10-31T09:20:34-04:00 Simplify a tc-trace which could crash the compiler The trace formatted an error message, which prematurely read the ExpType in a FunResCtxt. Solution: don't put call the error message formatting when tc-tracing. - - - - - ab49b1d2 by Simon Peyton Jones at 2026-10-31T09:20:34-04:00 Tiny comment change to uniqAway - - - - - 6efe4ba3 by Simon Peyton Jones at 2026-10-31T09:20:34-04:00 Make niFixSubst idempotent I discovered (when fixing #27994) that `niFixSubst` didn't actually generate an idempotent subsitution despite its claims. It could return a substitution that mentions domain variables on in its range, when those variables are hidden inside the kind of a type variable occurrence. As a result it can generate ill-kinded types. Boo! The fix is simple, and uses deep substitution. See Note [Finding the substitution fixpoint] I don't think it actually /caused/ any bugs, so there is no regression test. - - - - - 3b60ae7e by Simon Peyton Jones at 2026-10-31T09:20:34-04:00 Fix a nasty bug in fundeps This MR fixes #27994, which turned out to be very tricky. See Note [Exploiting closed type famililes], especially (CF7). I was ending up with TyVars (not TcTyVars) in the solver, because the substitution computed in `getRelevantBranches` mixed the two. The code was just too clever. I ended up simplifying it quite a bit. For /closed/ families we no longer call `trimQtvs` (was `trim_qtvs`). Open families still do use `trimQtvs`. See Note [trimQTvs] This patch also fixes one other buglet in the same code. * Over-saturated type families were being mis-handled. See the new use of `saturatedFamApp_maybe`. - - - - - e4610f2d by Facundo Domínguez at 2026-10-31T09:21:24-04:00 Have haddock --incremental look for the module in -this-unit-id - - - - - bc6c0db6 by sheaf at 2026-10-31T09:22:20-04:00 mightBeFunTy: hotfix for #27979 ce01ccb6 refactored 'GHC.Types.RepType.mightBeFunTy' to look through unary classes. That change introduced the helper function 'unwrap_type' which was supposed to always return an unwrapped type, but its fallback equation mistakenly returned the original type. This caused the subsequent 'tyConAppTyCon_maybe' to fail in cases where it should succeed (e.g. looking through foralls). In this commit, we move all the unary class unwrapping logic into 'unwrapType' where it belonged from the start, and update the documentation of 'unwrapType' to better explain what it should be used for (#26695). Fixes #27979 #26695 ------------------------- Metric Increase: T5642 ------------------------- - - - - - 233cce46 by Alan Zimmerman at 2026-10-31T09:23:01-04:00 EPA: Tidy up ExactPrint.markAnnListA' It takes an action which can modify the AnnList, but this is never used. So remove it. - - - - - 3594a908 by Sylvain Henry at 2026-10-31T09:23:51-04:00 gitmodules: ignore dirty libffi-clib submodule (#26785) `./boot` runs autoreconf in libraries/libffi-clib, which leaves `configure~` behind and rewrites the tracked `aclocal.m4` whenever the local automake version differs from the one that generated it. Every checkout then looks dirty. Ignore working-tree changes in the submodule (`ignore = dirty`); a changed submodule commit is still reported. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> - - - - - 341223c0 by Rodrigo Mesquita at 2026-10-31T09:24:33-04:00 refactor: Keep the interactive Ids directly rather than Name Removes things like names <- map idName ids map (\i -> let id = find (\x -> i==idName x) names) idso and is more straightforward because there's less state going around (no more updating HscEnv as an output) It also kills `printTypeOfNames` completely, since now we just have the Ids. No longer `lookupName` names to get back the ids... ``` printTypeOfName :: GHC.GhcMonad m => Name -> m () printTypeOfName n = do maybe_tything <- GHC.lookupName n case maybe_tything of Nothing -> return () Just thing -> printTyThing thing ``` now is just `printTyThing . AnId` Also: ```diff - tythings <- catMaybes `liftM` mapM GHC.lookupName namesSorted - docs <- mapM pprTypeAndContents [i | AnId i <- tythings] + docs <- mapM pprTypeAndContents idsSorted ``` (and yes, in ExecBreaks there are only Ids, no TyThings, bc they are only constructed by the interpreter execution which can only bind ids. for TyThings use runDecls which doesn't return execBreaks.) There's some care to be had to make sure we use the "most refined" Ids, whereas when using `Name`s we'd always fetch the most refined Id from scratch. Fixes #28052 - - - - - 6b7a7364 by Rodrigo Mesquita at 2026-11-02T13:57:14+00:00 interp: Make resumeExec and ExecBreak use `Resume` directly Previously, `Resume` contexts were just put directly in the global interactive environment state, so they were only accessible through it. However, in the context of multi-threaded debugging, in that many threads may hit breakpoints, it no longer suffices to have a global linear list of breakpoints hit. We need a per-breakpoint Resume context and need to be able to wield it directly rather than going through a global context. The driving changes of this commit are: - Put the Resume data in ExecBreak - Make resumeExec receive a Resume as an argument This also simplifies the interpreter in that we no longer necessarily rely on the global interactive state to resume a thread. We can do it directly from the ExecBreak. The interactive context still maintains a stack of resumes, but `resumeExec` can no longer pop the resume it resumes off of the breakpoints stack, since it is no longer guaranteed to be resuming the first in that list. Hence, callers of `resumeExec` must update ic_resume on their own. - - - - - 84 changed files: - .gitmodules - + changelog.d/T27323 - + changelog.d/T27847 - + changelog.d/T27979 - + changelog.d/T27994 - + changelog.d/clc-446 - + changelog.d/clc-447 - + changelog.d/fix-nonmoving-weak-evacuation-race-23160 - + changelog.d/ghc-api-exec-break-resume - + changelog.d/ghc-api-interactive-ids - compiler/GHC/Core/Coercion/Axiom.hs - compiler/GHC/Core/Predicate.hs - compiler/GHC/Core/TyCo/FVs.hs - compiler/GHC/Core/TyCo/Subst.hs - compiler/GHC/Core/Type.hs - compiler/GHC/Core/Unify.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Monad.hs - compiler/GHC/HsToCore/Pmc.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Types.hs - compiler/GHC/HsToCore/Utils.hs - compiler/GHC/Runtime/Context.hs - compiler/GHC/Runtime/Debugger.hs - compiler/GHC/Runtime/Eval.hs - compiler/GHC/Runtime/Eval/Types.hs - compiler/GHC/Runtime/Heap/Inspect.hs - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Solver/FunDeps.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Types/RepType.hs - compiler/GHC/Types/Var/Env.hs - ghc/GHCi/UI.hs - ghc/GHCi/UI/Monad.hs - libraries/base/changelog.md - libraries/ghc-internal/src/GHC/Internal/Control/Exception/Base.hs - libraries/ghc-internal/src/GHC/Internal/IO/Handle/Internals.hs - libraries/ghc-internal/src/GHC/Internal/IO/Handle/Text.hs - libraries/ghc-internal/src/GHC/Internal/IO/Handle/Windows.hs - libraries/ghc-internal/src/GHC/Internal/System/Environment/ExecutablePath.hsc - libraries/ghc-internal/src/GHC/Internal/System/IO/Error.hs - rts/sm/Evac.c - + testsuite/tests/codeGen/should_compile/T27979.hs - + testsuite/tests/codeGen/should_compile/T27979.stderr - testsuite/tests/codeGen/should_compile/all.T - testsuite/tests/count-deps/CountDepsParser.stdout - + testsuite/tests/exceptions/T27851.hs - + testsuite/tests/exceptions/T27851.stderr - + testsuite/tests/exceptions/T27851b.hs - + testsuite/tests/exceptions/T27851b.stderr - + testsuite/tests/exceptions/T27851c.hs - + testsuite/tests/exceptions/T27851c.stdout - + testsuite/tests/exceptions/T27851d.hs - + testsuite/tests/exceptions/T27851d.stdout - + testsuite/tests/exceptions/T27851d.stdout-javascript-unknown-ghcjs - testsuite/tests/exceptions/all.T - testsuite/tests/ghc-e/should_fail/T18441fail7.stderr - testsuite/tests/ghc-e/should_run/ghc-e005.stderr - + testsuite/tests/ghci.debugger/scripts/RttiSharedTyVar.hs - + testsuite/tests/ghci.debugger/scripts/RttiSharedTyVar.script - + testsuite/tests/ghci.debugger/scripts/RttiSharedTyVar.stdout - testsuite/tests/ghci.debugger/scripts/all.T - + testsuite/tests/haddock/haddock_testsuite/IncrementalUnitId.hs - testsuite/tests/haddock/haddock_testsuite/Makefile - testsuite/tests/haddock/haddock_testsuite/all.T - + testsuite/tests/haddock/haddock_testsuite/haddockIncrementalUnitId.stdout - + testsuite/tests/pmcheck/should_compile/T27323.hs - + testsuite/tests/pmcheck/should_compile/T27323b.hs - testsuite/tests/pmcheck/should_compile/all.T - + testsuite/tests/rts/T23160.hs - + testsuite/tests/rts/T23160.stdout - testsuite/tests/rts/all.T - + testsuite/tests/typecheck/should_compile/T27994.hs - + testsuite/tests/typecheck/should_compile/T27994a.hs - + testsuite/tests/typecheck/should_compile/T27994b.hs - testsuite/tests/typecheck/should_compile/all.T - testsuite/tests/warnings/should_compile/Overflow.stderr-ws-32 - testsuite/tests/warnings/should_compile/Overflow.stderr-ws-64 - testsuite/tests/warnings/should_compile/T13256.stderr-ws-32 - testsuite/tests/warnings/should_compile/T13256.stderr-ws-64 - utils/check-exact/ExactPrint.hs - utils/haddock/CHANGES.md - utils/haddock/haddock-api/src/Haddock/Interface.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/02d460909a997e9ba4d24d320dccda5... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/02d460909a997e9ba4d24d320dccda5... 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