Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: ac9fb269 by Simon Peyton Jones at 2025-05-20T09:19:04-04:00 Track rewriter sets more accurately in constraint solving This MR addresses #26003, by refactoring the arcane intricacies of Note [Equalities with incompatible kinds]. NB: now retitled to Note [Equalities with heterogeneous kinds]. and the main Note for this MR. In particular: * Abandon invariant (COERCION-HOLE) in Note [Unification preconditions] in GHC.Tc.Utils.Unify. * Abandon invariant (TyEq:CH)) in Note [Canonical equalities] in GHC.Tc.Types.Constraint. * Instead: add invariant (REWRITERS) to Note [Unification preconditions]: unify only if the constraint has an empty rewriter set. Implementation: * In canEqCanLHSFinish_try_unification, skip trying unification if there is a non-empty rewriter set. * To do this, make sure the rewriter set is zonked; do so in selectNextWorkItem, which also deals with prioritisation. * When a coercion hole is filled, kick out inert equalities that have that hole as a rewriter. It might now be unlocked and available to unify. * Remove the ad-hoc `ch_hetero_kind` field of `CoercionHole`. * In `selectNextWorkItem`, priorities equalities withan empty rewriter set. * Defaulting: see (DE6) in Note [Defaulting equalities] and Note [Limited defaulting in the ambiguity check] * Concreteness checks: there is some extra faff to try to get decent error messages when the FRR (representation-polymorphism) checks fail. In partiular, add a "When unifying..." explanation when the representation-polymorphism check arose from another constraint. - - - - - 86406f48 by Cheng Shao at 2025-05-20T09:19:47-04:00 rts: fix rts_clearMemory logic when sanity checks are enabled This commit fixes an RTS assertion failure when invoking rts_clearMemory with +RTS -DS. -DS implies -DZ which asserts that free blocks contain 0xaa as the designated garbage value. Also adds the sanity way to rts_clearMemory test to prevent future regression. Closes #26011. ChatGPT Codex automatically diagnosed the issue and proposed the initial patch in a single shot, given a GHC checkout and the following prompt: --- Someone is reporting the following error when attempting to use `rts_clearMemory` with the RTS option `-DS`: ``` test.wasm: internal error: ASSERTION FAILED: file rts/sm/Storage.c, line 1216 (GHC version 9.12.2.20250327 for wasm32_unknown_wasi) Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug ``` What's the culprit? How do I look into this issue? --- I manually reviewed & revised the patch, tested and submitted it. - - - - - 2b795c2f by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: do not allocate strings in bytecode assembler This patch refactors the compiler to avoid allocating iserv buffers for BCONPtrStr at assemble-time. Now BCONPtrStr ByteStrings are recorded as a part of CompiledByteCode, and actual allocation only happens at link-time. This refactoring is necessary for adding bytecode serialization functionality, as explained by the revised comments in this commit. - - - - - 2914d829 by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: make bc_strs serializable This commit makes the bc_strs field in CompiledByteCode serializable; similar to previous commit, we preserve the ByteString directly and defer the actual allocation to link-time, as mentioned in updated comment. - - - - - a6ec1765 by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: make bc_itbls serializable This commit makes bc_itbls in CompiledByteCode serializable. A dedicated ConInfoTable datatype has been added in ghci which is the recipe for dynamically making a datacon's info table, containing the payload of the MkConInfoTable iserv message. - - - - - a238a259 by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: remove FFIInfo bookkeeping in BCO This commit removes the bc_ffis field from CompiledByteCode completely, as well as all the related bookkeeping logic in GHC.StgToByteCode. bc_ffis is actually *unused* in the rest of GHC codebase! It is merely a list of FFIInfo, which is just a remote pointer of the libffi ffi_cif struct; once we allocate the ffi_cif struct and put its pointer in a CCALL instruction, we'll never free it anyway. So there is no point of bookkeeping. - - - - - 1f5cc26b by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: make FFIInfo serializable in BCO This commit makes all the FFIInfo needed in CCALL instructions serializable. Previously, when doing STG to BCO lowering, we would allocate a libffi ffi_cif struct and keep its remote pointer as FFIInfo; but actually we can just keep the type signature as FFIInfo and defer the actual allocation to link-time. - - - - - 20a60364 by Cheng Shao at 2025-05-20T09:51:24-04:00 ghci: remove redundant NewBreakModule message This commit removes the redundant NewBreakModule message from ghci: it just allocates two strings! This functionality can be implemented with existing MallocStrings in one iserv call. - - - - - bbfd5a5c by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: make breakpoint module name and unit id serializable This commit makes breakpoint module name and unit id serializable, in BRK_FUN instructions as well as ModBreaks. We can simply keep the module name and unit ids, and defer the buffer allocation to link time. - - - - - aaaf4576 by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: remove unused newModule This commit removes the now unused newModule function from GHC. - - - - - ea0f5482 by Cheng Shao at 2025-05-20T09:51:24-04:00 compiler: add BCONPtrFS for interned top level string literals in BCO This commit adds BCONPtrFS as a BCO non-pointer literal kind, which has the same semantics of BCONPtrStr, except it contains a FastString instead of a ByteString. By using BCONPtrFS to represent top level string literals that are already FastString in the compilation pipeline, we enjoy the FastString interning logic and avoid allocating a bunch of redundant ByteStrings for the same FastStrings, especially when we lower the BRK_FUN instruction. - - - - - 55b0dfd8 by Peng Fan at 2025-05-20T09:51:36-04:00 hadrian: enable GHCi for loongarch64 - - - - - 6c1c9110 by kwxm at 2025-05-20T09:51:45-04:00 Fix bugs in `integerRecipMod` and `integerPowMod` This fixes #26017. * `integerRecipMod x 1` now returns `(# 1 | #)` for all x; previously it incorrectly returned `(# | () #)`, indicating failure. * `integerPowMod 0 e m` now returns `(# | () #)` for e<0 and m>1, indicating failure; previously it incorrectly returned `(# 0 | #)`. - - - - - 0155f550 by Andreas Klebinger at 2025-05-20T09:51:46-04:00 Specialise: Don't float out constraint components. It was fairly complex to do so and it doesn't seem to improve anything. Nofib allocations were unaffected as well. See also Historical Note [Floating dictionaries out of cases] - - - - - 89 changed files: - compiler/GHC/ByteCode/Asm.hs - compiler/GHC/ByteCode/InfoTable.hs - compiler/GHC/ByteCode/Instr.hs - compiler/GHC/ByteCode/Linker.hs - compiler/GHC/ByteCode/Types.hs - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Predicate.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCo/Tidy.hs - compiler/GHC/HsToCore/Breakpoints.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Runtime/Interpreter.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Plugin.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/InertSet.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Types/Error/Codes.hs - hadrian/src/Oracles/Flag.hs - libraries/base/changelog.md - libraries/ghc-internal/src/GHC/Internal/Bignum/Integer.hs - libraries/ghci/GHCi/Message.hs - libraries/ghci/GHCi/Run.hs - rts/sm/Storage.h - testsuite/tests/bytecode/T22376/all.T - testsuite/tests/dependent/should_fail/T11471.stderr - testsuite/tests/diagnostic-codes/codes.stdout - testsuite/tests/ffi/should_run/all.T - testsuite/tests/indexed-types/should_fail/T8227.stderr - testsuite/tests/indexed-types/should_fail/T9662.stderr - + testsuite/tests/lib/integer/T26017.hs - + testsuite/tests/lib/integer/T26017.stdout - testsuite/tests/lib/integer/all.T - testsuite/tests/lib/integer/integerRecipMod.hs - testsuite/tests/lib/integer/integerRecipMod.stdout - testsuite/tests/partial-sigs/should_fail/T14040a.stderr - testsuite/tests/partial-sigs/should_fail/T14584.stderr - testsuite/tests/perf/should_run/ByteCodeAsm.hs - testsuite/tests/polykinds/T14172.stderr - testsuite/tests/polykinds/T14846.stderr - testsuite/tests/rep-poly/RepPolyArgument.stderr - testsuite/tests/rep-poly/RepPolyBackpack1.stderr - testsuite/tests/rep-poly/RepPolyBinder.stderr - testsuite/tests/rep-poly/RepPolyDoBind.stderr - testsuite/tests/rep-poly/RepPolyDoBody1.stderr - testsuite/tests/rep-poly/RepPolyDoBody2.stderr - testsuite/tests/rep-poly/RepPolyLeftSection2.stderr - testsuite/tests/rep-poly/RepPolyMagic.stderr - testsuite/tests/rep-poly/RepPolyMcBind.stderr - testsuite/tests/rep-poly/RepPolyMcBody.stderr - testsuite/tests/rep-poly/RepPolyMcGuard.stderr - testsuite/tests/rep-poly/RepPolyNPlusK.stderr - testsuite/tests/rep-poly/RepPolyPatBind.stderr - testsuite/tests/rep-poly/RepPolyRecordUpdate.stderr - testsuite/tests/rep-poly/RepPolyRightSection.stderr - testsuite/tests/rep-poly/RepPolyRule1.stderr - testsuite/tests/rep-poly/RepPolyTuple.stderr - testsuite/tests/rep-poly/RepPolyTuple4.stderr - testsuite/tests/rep-poly/RepPolyTupleSection.stderr - testsuite/tests/rep-poly/RepPolyWrappedVar.stderr - testsuite/tests/rep-poly/T11473.stderr - testsuite/tests/rep-poly/T12709.stderr - testsuite/tests/rep-poly/T12973.stderr - testsuite/tests/rep-poly/T13233.stderr - testsuite/tests/rep-poly/T13929.stderr - testsuite/tests/rep-poly/T14561.stderr - testsuite/tests/rep-poly/T14561b.stderr - testsuite/tests/rep-poly/T17817.stderr - testsuite/tests/rep-poly/T19615.stderr - testsuite/tests/rep-poly/T19709b.stderr - testsuite/tests/rep-poly/T21906.stderr - testsuite/tests/rep-poly/T23903.stderr - testsuite/tests/rep-poly/UnliftedNewtypesCoerceFail.stderr - testsuite/tests/typecheck/no_skolem_info/T14040.stderr - testsuite/tests/typecheck/should_compile/T25266a.stderr - testsuite/tests/typecheck/should_fail/T16204c.stderr - testsuite/tests/typecheck/should_fail/T7696.stderr - testsuite/tests/typecheck/should_fail/T8603.stderr The diff was not included because it is too large. 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