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[Git][ghc/ghc][wip/fix-hadrian-hls] hadrian: fix HLS support
by Cheng Shao (＠TerrorJack) 08 Jul '26

08 Jul '26

Cheng Shao pushed to branch wip/fix-hadrian-hls at Glasgow Haskell Compiler / GHC Commits: d645779f by Cheng Shao at 2026-07-08T09:48:49+00:00 hadrian: fix HLS support This patch fixes hadrian's HLS support so one can rely on HLS when working on the hadrian codebase. Fixes #27480. Not building/linking shared libraries for hadrian is a severely premature optimization; this top-level setting in `cabal.project` only affects home packages while the dependencies in the cabal store are built with vanilla/dynamic anyway, and even adding dynamic builds to home packages would not be costly due to cabal's usage of `-dynamic-too`. - - - - - 1 changed file: - hadrian/cabal.project Changes: ===================================== hadrian/cabal.project ===================================== @@ -12,7 +12,3 @@ index-state: 2026-03-10T17:36:36Z -- and the Cabal takes nearly twice as long to build with -O1. See #16817. package Cabal optimization: False - --- Build static linked, vanilla libraries to reduce build time. -shared: False -executable-dynamic: False View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d645779f9c3c02a6feb34d0a7a6b083… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d645779f9c3c02a6feb34d0a7a6b083… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/fix-hadrian-hls
by Cheng Shao (＠TerrorJack) 08 Jul '26

08 Jul '26

Cheng Shao pushed new branch wip/fix-hadrian-hls at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/fix-hadrian-hls You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/dcoutts/capability-yield
by Duncan Coutts (＠dcoutts) 08 Jul '26

08 Jul '26

Duncan Coutts pushed new branch wip/dcoutts/capability-yield at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/dcoutts/capability-yield You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 6 commits: ttg: Using ShortText over FastString in the AST
by Marge Bot (＠marge-bot) 08 Jul '26

08 Jul '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 4ebfc478 by Rodrigo Mesquita at 2026-07-08T04:47:53-04:00 ttg: Using ShortText over FastString in the AST To make the AST independent of GHC, this commit replaces usages of `FastString` with `HText` in the AST, killing the last edge from Language.Haskell.* to GHC.* modules. Even though we /do/ want to use FastStrings in general -- critically in Names or Ids -- there is no particular reason for the FastStrings that occur in the AST proper to be FastStrings. Strings in the AST are typically unique and don't benefit particularly from being interned FastStrings with Uniques for fast comparison. `HText` is a type synonym for `ShortText` which uses GHC's Modified UTF-8 encoding exclusively. Modified UTF-8 must be used to represent the Haskell AST because the Haskell Report allows surrogate code points. `Data.Text.Text` functions use Standard UTF-8 which replace surrogates with a placeholder value, thus `Data.Text.Text` is unsuitable for AST strings. See the `Language.Haskell.Syntax.Text` module header for more details. Final progress towards #21592 Closes #21628 - - - - - d910b353 by Simon Peyton Jones at 2026-07-08T04:48:36-04:00 Update equality-type documenation in GHC.Builtin.Types.Prim Fix #27466 - - - - - b2530542 by Simon Peyton Jones at 2026-07-08T04:48:36-04:00 Honour -dsuppress-coercions in GHC.Core.TyCo.pprCo Fixes #27467 - - - - - 9a73179a by Facundo Domínguez at 2026-07-08T04:49:26-04:00 Add item to MR checklist asking to squash fixup commits after approval The checklist has an item that reads All commits are either individually buildable or squashed. This item could be checked immediately after sending the merge request though. If reviewers ask for amends later on, and the author amends the merge request, there was no item that would remind the contributors to squash the fixup commits before landing. This commit adds a new item After all approvals and before landing: all fixup commits are squashed with their originating commits. which should be harder to mark as done before approvals have been given. - - - - - ae9c944a by Andreas Klebinger at 2026-07-08T05:22:46-04:00 Fix a profiling race condition resulting in segfaults. StgToCmm: Don't assume tagged FUN closures in closureCodeBody. When entering a closure the self/node pointer might not be tagged in some situations when a thunk is evaluated by multiple threads. So we most AND away the tag bits rather than subtracting an expected tag. Apply.cmm: Fix a race condition occuring when a thunk is mutated during GC. In stg_ap_0_fast when might need to run GC before entering a thunk. If this happens another thread or the GC itself might mutate the closure making entering it no longer valid. We now check for this. Add test and changelog for #27123 fixes. - - - - - 59b6942d by Cheng Shao at 2026-07-08T05:22:47-04:00 ghc-heap: fix invalid srtlen returned by peekItbl when no-TNTC This patch fixes the no-TNTC code path of `peekItbl` so that it looks at the right memory address when reading the `srt` field from the `StgInfoTable_` struct. Also adds a `T27465` regression test that reproduces the bug on no-TNTC builds before the fix. Fixes #27465. Co-authored-by: Codex <codex(a)openai.com> - - - - - 118 changed files: - .gitlab/merge_request_templates/Default.md - + changelog.d/T21628 - + changelog.d/T27123.md - + changelog.d/fix-peekitbl-no-tntc - compiler/GHC/Builtin/Types/Prim.hs - compiler/GHC/Builtin/Utils.hs - compiler/GHC/Cmm/CLabel.hs - compiler/GHC/Core/Ppr.hs - compiler/GHC/Core/TyCo/Ppr.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCon.hs - compiler/GHC/Data/FastString.hs - compiler/GHC/Data/StringBuffer.hs - compiler/GHC/Driver/Errors/Ppr.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Foreign/C.hs - compiler/GHC/HsToCore/Foreign/JavaScript.hs - compiler/GHC/HsToCore/Foreign/Wasm.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Pmc/Solver/Types.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/HaddockLex.x - compiler/GHC/Parser/Lexer.x - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Env.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/StgToCmm/Bind.hs - compiler/GHC/StgToCmm/Foreign.hs - compiler/GHC/StgToCmm/Prim.hs - compiler/GHC/StgToJS/FFI.hs - compiler/GHC/Tc/Deriv/Generate.hs - compiler/GHC/Tc/Deriv/Generics.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Instance/Class.hs - compiler/GHC/Tc/Solver/Dict.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Validity.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/Error.hs - compiler/GHC/Types/FieldLabel.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Types/Literal.hs - compiler/GHC/Unit/Module/Warnings.hs - compiler/GHC/Utils/Binary.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Basic.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Decls/Foreign.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Module/Name.hs - + compiler/Language/Haskell/Syntax/Text.hs - compiler/Language/Haskell/Syntax/Type.hs - compiler/ghc.cabal.in - libraries/ghc-boot/GHC/Data/ShortText.hs - + libraries/ghc-heap/tests/T27465.hs - + libraries/ghc-heap/tests/T27465.stdout - libraries/ghc-heap/tests/all.T - libraries/ghc-internal/src/GHC/Internal/Heap/InfoTable.hsc - libraries/ghc-internal/src/GHC/Internal/Heap/InfoTableProf.hsc - rts/Apply.cmm - testsuite/tests/codeGen/should_compile/T25177.stderr - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/ghc-api/annotations-literals/parsed.hs - testsuite/tests/numeric/should_compile/T15547.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/DumpTypecheckedAst.stderr - + testsuite/tests/parser/should_run/StringStartsWithNull.hs - + testsuite/tests/parser/should_run/StringStartsWithNull.stdout - testsuite/tests/parser/should_run/all.T - testsuite/tests/perf/compiler/hard_hole_fits.stderr - + testsuite/tests/rts/T27123.hs - testsuite/tests/rts/all.T - testsuite/tests/simplCore/should_compile/DataToTagFamilyScrut.stderr - testsuite/tests/simplCore/should_compile/T14978.stdout - testsuite/tests/simplCore/should_compile/T18013.stderr - testsuite/tests/simplCore/should_compile/T24229a.stderr - testsuite/tests/simplCore/should_compile/T24229b.stderr - utils/check-exact/ExactPrint.hs - utils/check-exact/check-exact.cabal - utils/haddock/haddock-api/haddock-api.cabal - utils/haddock/haddock-api/src/Haddock/Backends/Hyperlinker/Parser.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/Interface/Create.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/d990626ecd9d9c064519fed1fc94d2… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/d990626ecd9d9c064519fed1fc94d2… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Add item to MR checklist asking to squash fixup commits after approval
by Marge Bot (＠marge-bot) 08 Jul '26

08 Jul '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 9a73179a by Facundo Domínguez at 2026-07-08T04:49:26-04:00 Add item to MR checklist asking to squash fixup commits after approval The checklist has an item that reads All commits are either individually buildable or squashed. This item could be checked immediately after sending the merge request though. If reviewers ask for amends later on, and the author amends the merge request, there was no item that would remind the contributors to squash the fixup commits before landing. This commit adds a new item After all approvals and before landing: all fixup commits are squashed with their originating commits. which should be harder to mark as done before approvals have been given. - - - - - 1 changed file: - .gitlab/merge_request_templates/Default.md Changes: ===================================== .gitlab/merge_request_templates/Default.md ===================================== @@ -27,6 +27,7 @@ https://gitlab.haskell.org/ghc/ghc/-/wikis/Contributing-a-Patch - [ ] If this MR has the potential to break user programs, the ~"user-facing" label was applied to test against head.hackage. - [ ] All commits are either individually buildable or squashed. +- [ ] After all approvals and before landing: all fixup commits are squashed with their originating commits. - [ ] Commit messages describe *what they do*, referring to tickets using `#NNNNN` syntax. - [ ] Source comments describing the change were added. For larger changes [notes][notes] and cross-references from the relevant places were added (as applicable). View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9a73179ad3244d0bc00f84c61cda90e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/9a73179ad3244d0bc00f84c61cda90e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] 2 commits: Update equality-type documenation in GHC.Builtin.Types.Prim
by Marge Bot (＠marge-bot) 08 Jul '26

08 Jul '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: d910b353 by Simon Peyton Jones at 2026-07-08T04:48:36-04:00 Update equality-type documenation in GHC.Builtin.Types.Prim Fix #27466 - - - - - b2530542 by Simon Peyton Jones at 2026-07-08T04:48:36-04:00 Honour -dsuppress-coercions in GHC.Core.TyCo.pprCo Fixes #27467 - - - - - 11 changed files: - compiler/GHC/Builtin/Types/Prim.hs - compiler/GHC/Core/Ppr.hs - compiler/GHC/Core/TyCo/Ppr.hs - compiler/GHC/Core/TyCo/Rep.hs - testsuite/tests/codeGen/should_compile/T25177.stderr - testsuite/tests/numeric/should_compile/T15547.stderr - testsuite/tests/simplCore/should_compile/DataToTagFamilyScrut.stderr - testsuite/tests/simplCore/should_compile/T14978.stdout - testsuite/tests/simplCore/should_compile/T18013.stderr - testsuite/tests/simplCore/should_compile/T24229a.stderr - testsuite/tests/simplCore/should_compile/T24229b.stderr Changes: ===================================== compiler/GHC/Builtin/Types/Prim.hs ===================================== @@ -1002,26 +1002,29 @@ doublePrimTyCon = pcPrimTyCon0 doublePrimTyConName doubleRepDataConTy Note [The equality types story] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -GHC sports a veritable menagerie of equality types: - - Type or Lifted? Hetero? Role Built in Defining module - class? L/U TyCon ------------------------------------------------------------------------------------------ -~# T U hetero nominal eqPrimTyCon GHC.Prim -~~ C L hetero nominal heqTyCon GHC.Types -~ C L homo nominal eqTyCon GHC.Types -:~: T L homo nominal (not built-in) Data.Type.Equality -:~~: T L hetero nominal (not built-in) Data.Type.Equality - -~R# T U hetero repr eqReprPrimTy GHC.Prim -Coercible C L homo repr coercibleTyCon GHC.Types -Coercion T L homo repr (not built-in) Data.Type.Coercion -~P# T U hetero phantom eqPhantPrimTyCon GHC.Prim +GHC sports a veritable menagerie of equality types. + + Result kind Hetero? Role Built in Defining module +--------------------------------------------------------------------------------- +~# Constraint# hetero nominal eqPrimTyCon GHC.Prim +~~ Constraint hetero nominal heqTyCon GHC.Types +~ Constraint homo nominal eqTyCon GHC.Types +:~: Type homo nominal (not built-in) Data.Type.Equality +:~~: Type hetero nominal (not built-in) Data.Type.Equality + +~R# Constraint# hetero repr eqReprPrimTy GHC.Prim +Coercible Constraint homo repr coercibleTyCon GHC.Types +Coercion Type homo repr (not built-in) Data.Type.Coercion +~P# Constraint# hetero phantom eqPhantPrimTyCon GHC.Prim + +Here `Constraint#` means `CONSTRAINT (TupleRep [])`, a constraint kind that is +represented by a zero-width tuple. Recall that "hetero" means the equality can related types of different kinds. Knowing that (t1 ~# t2) or (t1 ~R# t2) or even that (t1 ~P# t2) also means that (k1 ~# k2), where (t1 :: k1) and (t2 :: k2). + To produce less confusion for end users, when not dumping and without -fprint-equality-relations, each of these groups is printed as the bottommost listed equality. That is, (~#) and (~~) are both rendered as (~) in @@ -1030,7 +1033,7 @@ error messages, and (~R#) is rendered as Coercible. Let's take these one at a time: -------------------------- - (~#) :: forall k1 k2. k1 -> k2 -> TYPE (TupleRep '[]) + (~#) :: forall k1 k2. k1 -> k2 -> CONSTRAINT (TupleRep '[]) -------------------------- This is The Type Of Equality in GHC. It classifies nominal coercions. This type is used in the solver for recording equality constraints. @@ -1054,8 +1057,6 @@ This is (almost) an ordinary class, defined as if by Here's what's unusual about it: * We can't actually declare it that way because we don't have syntax for ~#. - And ~# isn't a constraint, so even if we could write it, it wouldn't kind - check. * Users cannot write instances of it. @@ -1112,7 +1113,7 @@ They are not defined within GHC at all. -------------------------- - (~R#) :: forall k1 k2. k1 -> k2 -> TYPE (TupleRep '[]) + (~R#) :: forall k1 k2. k1 -> k2 -> CONSTRAINT (TupleRep '[]) -------------------------- The is the representational analogue of ~#. This is the type of representational equalities that the solver works on. All wanted constraints of this type are @@ -1147,7 +1148,7 @@ within GHC at all. -------------------------- - (~P#) :: forall k1 k2. k1 -> k2 -> TYPE (TupleRep '[]) + (~P#) :: forall k1 k2. k1 -> k2 -> CONSTRAINT (TupleRep '[]) -------------------------- This is the phantom analogue of ~# and it is barely used at all. (The solver has no idea about this one.) Here is the motivation: ===================================== compiler/GHC/Core/Ppr.hs ===================================== @@ -292,14 +292,14 @@ noParens :: SDoc -> SDoc noParens pp = pp pprOptCo :: Coercion -> SDoc --- Print a coercion optionally; i.e. honouring -dsuppress-coercions -pprOptCo co = sdocOption sdocSuppressCoercions $ \case - True -> angleBrackets (text "Co:" <> int (coercionSize co)) <+> dcolon <+> co_type - False -> parens $ sep [ppr co, dcolon <+> co_type] - where - co_type = sdocOption sdocSuppressCoercionTypes $ \case - True -> ellipsis - False -> ppr (coercionType co) +-- Print a coercion with its type (unless suppressed by -dsuppress-coercion-types) +-- Honour -dsuppress-coercions +-- Placed here because it needs GHC.Core.Coercion.coercionType +pprOptCo co = sdocOption sdocSuppressCoercionTypes $ \case + True -> pprParendCo co + False -> parens (sep [pprCo co, dcolon <+> pp_co_type]) + where + pp_co_type = ppr (coercionType co) ppr_id_occ :: (SDoc -> SDoc) -> Id -> SDoc ppr_id_occ add_par id ===================================== compiler/GHC/Core/TyCo/Ppr.hs ===================================== @@ -132,8 +132,14 @@ tidyToIfaceTypeX env ty = toIfaceTypeX (mkVarSet free_tcvs) (tidyType env' ty) ------------ pprCo, pprParendCo :: Coercion -> SDoc -pprCo co = getPprStyle $ \ sty -> pprIfaceCoercion (tidyToIfaceCoSty co sty) -pprParendCo co = getPprStyle $ \ sty -> pprParendIfaceCoercion (tidyToIfaceCoSty co sty) +-- Print a coercion without its type +-- Honour -dsuppress-coercions +pprCo co = sdocOption sdocSuppressCoercions $ \case + True -> angleBrackets (text "Co:" <> int (coercionSize co)) + False -> getPprStyle $ \ sty -> pprIfaceCoercion (tidyToIfaceCoSty co sty) +pprParendCo co = sdocOption sdocSuppressCoercions $ \case + True -> angleBrackets (text "Co:" <> int (coercionSize co)) + False -> getPprStyle $ \ sty -> pprParendIfaceCoercion (tidyToIfaceCoSty co sty) tidyToIfaceCoSty :: Coercion -> PprStyle -> IfaceCoercion tidyToIfaceCoSty co sty ===================================== compiler/GHC/Core/TyCo/Rep.hs ===================================== @@ -1640,7 +1640,7 @@ Here, co3 = UnivCo ProofIrrelProv Nominal (CoercionTy co1) (CoercionTy co2) [co5] where co5 :: (a1 ~# Bool) ~# (a2 ~# Bool) - co5 = TyConAppCo Nominal (~#) [<Consraint#>, <Constraint#>, co4, <Bool>] + co5 = TyConAppCo Nominal (~#) [<Constraint#>, <Constraint#>, co4, <Bool>] Note [The importance of tracking UnivCo dependencies] ===================================== testsuite/tests/codeGen/should_compile/T25177.stderr ===================================== @@ -11,7 +11,7 @@ lvl = foo d bar1 = \ x eta -> case lvl of { W# ipv -> (# eta, () #) } -bar = bar1 `cast` <Co:6> :: ... +bar = bar1 `cast` <Co:6> ===================================== testsuite/tests/numeric/should_compile/T15547.stderr ===================================== @@ -5,25 +5,25 @@ Result size of Tidy Core nat2Word# = \ @n $dKnownNat p1 -> - naturalToWord# ((natSing $dKnownNat) `cast` <Co:2> :: ...) + naturalToWord# ((natSing $dKnownNat) `cast` <Co:2>) foo = \ ds -> 18## fd = \ @n $dKnownNat ds -> - naturalToWord# ((natSing $dKnownNat) `cast` <Co:6> :: ...) + naturalToWord# ((natSing $dKnownNat) `cast` <Co:6>) d = \ ds -> 3## fm = \ @n $dKnownNat ds -> - naturalToWord# ((natSing $dKnownNat) `cast` <Co:8> :: ...) + naturalToWord# ((natSing $dKnownNat) `cast` <Co:8>) m = \ ds -> 9## fp = \ @n $dKnownNat ds -> - naturalToWord# ((natSing $dKnownNat) `cast` <Co:10> :: ...) + naturalToWord# ((natSing $dKnownNat) `cast` <Co:10>) p = \ ds -> 512## ===================================== testsuite/tests/simplCore/should_compile/DataToTagFamilyScrut.stderr ===================================== @@ -5,7 +5,7 @@ Result size of Tidy Core testFun = \ @x v -> - case v `cast` <Co:2> :: ... of { + case v `cast` <Co:2> of { __DEFAULT -> 47#; C0 ipv -> -3#; C2 -> 13#; ===================================== testsuite/tests/simplCore/should_compile/T14978.stdout ===================================== @@ -1,2 +1,2 @@ foo :: Goof Int -foo = T14978.Goof @Int @~<Co:1> :: Int GHC.Internal.Prim.~# Int +foo = T14978.Goof @Int @~(<Co:1> :: Int GHC.Internal.Prim.~# Int) ===================================== testsuite/tests/simplCore/should_compile/T18013.stderr ===================================== @@ -161,11 +161,11 @@ T18013.$wmapMaybeRule @s @(Maybe b) ww2 (GHC.Internal.Maybe.Nothing @b) #); Just x -> case ((wild s2 x) - `cast` <Co:4> :: IO (Result s b) - ~R# (GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld - -> (# GHC.Internal.Prim.State# - GHC.Internal.Prim.RealWorld, - Result s b #))) + `cast` (<Co:4> + :: IO (Result s b) + ~R# (GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld + -> (# GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld, + Result s b #)))) s1 of { (# ipv, ipv1 #) -> @@ -175,12 +175,13 @@ T18013.$wmapMaybeRule } } }) - `cast` <Co:13> :: (s - -> Maybe a - -> GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld - -> (# GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld, - Result s (Maybe b) #)) - ~R# (s -> Maybe a -> IO (Result s (Maybe b)))) + `cast` (<Co:13> + :: (s + -> Maybe a + -> GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld + -> (# GHC.Internal.Prim.State# GHC.Internal.Prim.RealWorld, + Result s (Maybe b) #)) + ~R# (s -> Maybe a -> IO (Result s (Maybe b))))) } } ===================================== testsuite/tests/simplCore/should_compile/T24229a.stderr ===================================== @@ -15,8 +15,8 @@ foo = \ @a ds ds1 -> case ds of { I# ww -> case ww of ds2 { - __DEFAULT -> case ds1 `cast` <Co:4> :: ... of { (x, y) -> case foo_$s$wfoo (-# ds2 1#) y x of { (# ww1 #) -> Just ww1 } }; - 0# -> Just (ds1 `cast` <Co:4> :: ...) + __DEFAULT -> case ds1 `cast` <Co:4> of { (x, y) -> case foo_$s$wfoo (-# ds2 1#) y x of { (# ww1 #) -> Just ww1 } }; + 0# -> Just (ds1 `cast` <Co:4>) } } ===================================== testsuite/tests/simplCore/should_compile/T24229b.stderr ===================================== @@ -15,8 +15,8 @@ foo = \ @a ds ds1 -> case ds of { I# ww -> case ww of ds2 { - __DEFAULT -> case ds1 `cast` <Co:4> :: ... of { (x, y) -> case foo_$s$wfoo (-# ds2 1#) y x of { (# ww1 #) -> Just ww1 } }; - 0# -> Just (ds1 `cast` <Co:4> :: ...) + __DEFAULT -> case ds1 `cast` <Co:4> of { (x, y) -> case foo_$s$wfoo (-# ds2 1#) y x of { (# ww1 #) -> Just ww1 } }; + 0# -> Just (ds1 `cast` <Co:4>) } } View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4ebfc47842229a94a28c459806d9d8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4ebfc47842229a94a28c459806d9d8… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] ttg: Using ShortText over FastString in the AST
by Marge Bot (＠marge-bot) 08 Jul '26

08 Jul '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 4ebfc478 by Rodrigo Mesquita at 2026-07-08T04:47:53-04:00 ttg: Using ShortText over FastString in the AST To make the AST independent of GHC, this commit replaces usages of `FastString` with `HText` in the AST, killing the last edge from Language.Haskell.* to GHC.* modules. Even though we /do/ want to use FastStrings in general -- critically in Names or Ids -- there is no particular reason for the FastStrings that occur in the AST proper to be FastStrings. Strings in the AST are typically unique and don't benefit particularly from being interned FastStrings with Uniques for fast comparison. `HText` is a type synonym for `ShortText` which uses GHC's Modified UTF-8 encoding exclusively. Modified UTF-8 must be used to represent the Haskell AST because the Haskell Report allows surrogate code points. `Data.Text.Text` functions use Standard UTF-8 which replace surrogates with a placeholder value, thus `Data.Text.Text` is unsuitable for AST strings. See the `Language.Haskell.Syntax.Text` module header for more details. Final progress towards #21592 Closes #21628 - - - - - 96 changed files: - + changelog.d/T21628 - compiler/GHC/Builtin/Utils.hs - compiler/GHC/Cmm/CLabel.hs - compiler/GHC/Core/Ppr.hs - compiler/GHC/Core/TyCon.hs - compiler/GHC/Data/FastString.hs - compiler/GHC/Data/StringBuffer.hs - compiler/GHC/Driver/Errors/Ppr.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Foreign/C.hs - compiler/GHC/HsToCore/Foreign/JavaScript.hs - compiler/GHC/HsToCore/Foreign/Wasm.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Pmc/Solver/Types.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/HaddockLex.x - compiler/GHC/Parser/Lexer.x - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Env.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/StgToCmm/Foreign.hs - compiler/GHC/StgToCmm/Prim.hs - compiler/GHC/StgToJS/FFI.hs - compiler/GHC/Tc/Deriv/Generate.hs - compiler/GHC/Tc/Deriv/Generics.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Instance/Class.hs - compiler/GHC/Tc/Solver/Dict.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Validity.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/Error.hs - compiler/GHC/Types/FieldLabel.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Types/Literal.hs - compiler/GHC/Unit/Module/Warnings.hs - compiler/GHC/Utils/Binary.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Basic.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Decls/Foreign.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Module/Name.hs - + compiler/Language/Haskell/Syntax/Text.hs - compiler/Language/Haskell/Syntax/Type.hs - compiler/ghc.cabal.in - libraries/ghc-boot/GHC/Data/ShortText.hs - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/ghc-api/annotations-literals/parsed.hs - 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/parser/should_run/StringStartsWithNull.hs - + testsuite/tests/parser/should_run/StringStartsWithNull.stdout - testsuite/tests/parser/should_run/all.T - testsuite/tests/perf/compiler/hard_hole_fits.stderr - utils/check-exact/ExactPrint.hs - utils/check-exact/check-exact.cabal - utils/haddock/haddock-api/haddock-api.cabal - utils/haddock/haddock-api/src/Haddock/Backends/Hyperlinker/Parser.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/Interface/Create.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4ebfc47842229a94a28c459806d9d8b… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/4ebfc47842229a94a28c459806d9d8b… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/junit-diffs] perf notes: include stat deviation and acceptance window in notes so they show up in gitlab
by Zubin (＠wz1000) 08 Jul '26

08 Jul '26

Zubin pushed to branch wip/junit-diffs at Glasgow Haskell Compiler / GHC Commits: b555b20b by Zubin Duggal at 2026-07-08T12:09:23+05:30 perf notes: include stat deviation and acceptance window in notes so they show up in gitlab - - - - - 1 changed file: - testsuite/driver/perf_notes.py Changes: ===================================== testsuite/driver/perf_notes.py ===================================== @@ -653,7 +653,11 @@ def check_stats_change(actual: PerfStat, error = str(change) + ' from ' + baseline.perfStat.test_env + \ ' baseline @ %s' % baseline.commit print(actual.metric, error + ':') - result = failBecause('stat ' + error, tag='stat') + dev = 100.0 if expected_val == 0 else round(((float(actual.value) * 100) / int(expected_val)) - 100, 1) + change_line = (f'{actual.metric} {change.value} from {baseline.perfStat.test_env} ' + f'baseline @ {baseline.commit[:7]}: {expected_val} -> {actual.value} ' + f'({dev:+g}%, allowed {acceptance_window.describe()})') + result = failBecause('stat ' + change_line, tag='stat') if not change_allowed or force_print: length = max(len(str(x)) for x in [expected_val, lowerBound, upperBound, actual.value]) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b555b20bb89ad38e8831810896bd3f7… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b555b20bb89ad38e8831810896bd3f7… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/junit-diffs] perf notes: include stat deviation and acceptance window in notes so they show up in gitlab
by Zubin (＠wz1000) 08 Jul '26

08 Jul '26

Zubin pushed to branch wip/junit-diffs at Glasgow Haskell Compiler / GHC Commits: e0c95b19 by Zubin Duggal at 2026-07-08T12:09:13+05:30 perf notes: include stat deviation and acceptance window in notes so they show up in gitlab - - - - - 1 changed file: - testsuite/driver/perf_notes.py Changes: ===================================== testsuite/driver/perf_notes.py ===================================== @@ -653,7 +653,11 @@ def check_stats_change(actual: PerfStat, error = str(change) + ' from ' + baseline.perfStat.test_env + \ ' baseline @ %s' % baseline.commit print(actual.metric, error + ':') - result = failBecause('stat ' + error, tag='stat') + dev = 100.0 if expected_val == 0 else round(((float(actual.value) * 100) / int(expected_val)) - 100, 1) + change_line = (f'{actual.metric} {change.value} from {baseline.perfStat.test_env} ' + f'baseline @ {baseline.commit[:7]}: {expected_val} -> {actual.value} ' + f'({dev:+g}%, allowed {acceptance_window.describe()})') + result = failBecause('stat ' + change_line, tag='stat') if not change_allowed or force_print: length = max(len(str(x)) for x in [expected_val, lowerBound, upperBound, actual.value]) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/e0c95b196e59f6b1693cc199fbf2e20… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/e0c95b196e59f6b1693cc199fbf2e20… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/sjakobi/udfm-placement] UDFM: don't INLINE udfmToList (fixes T17836 alloc regression)
by Simon Jakobi (＠sjakobi2) 08 Jul '26

08 Jul '26

Simon Jakobi pushed to branch wip/sjakobi/udfm-placement at Glasgow Haskell Compiler / GHC Commits: 966e260a by Simon Jakobi at 2026-07-08T07:00:19+02:00 UDFM: don't INLINE udfmToList (fixes T17836 alloc regression) Commit 6990e63f made udfmToList INLINE so its n <= 1 case would fuse with its consumer. But udfmToList's one hot consumer -- traverseUSDFM in the pattern-match checker -- doesn't fuse, and inlining the size dispatch into it regressed the T17836 ghc/alloc perf test. Unlike eltsUDFM, which is called on ~2M singleton maps by fusing consumers in T13719, udfmToList fuses too rarely (~60k singleton calls) to earn its INLINE. Assisted-by: Claude Opus 4.8 - - - - - 1 changed file: - compiler/GHC/Types/Unique/DFM.hs Changes: ===================================== compiler/GHC/Types/Unique/DFM.hs ===================================== @@ -504,12 +504,13 @@ udfmRestrictKeysSet (UDFM val_set i) set = -- as this already incurs most of the cost of returning the full list. -- See Note [Cost of deterministic iteration]. udfmToList :: UniqDFM key elt -> [(Unique, elt)] -{-# INLINE udfmToList #-} -- so the small case is a good producer +-- NB: no INLINE, unlike eltsUDFM. udfmToList's one hot consumer is +-- traverseUSDFM in the pattern-match checker, which doesn't fuse. Inlining +-- the size dispatch into it regresses T17836. udfmToList (UDFM m ub) -- n <= 1: any order is trivially tag order, so read straight off the map | M.compareSize m 1 /= GT = - build (\c n -> - M.foldrWithKey (\k tv r -> c (mkUniqueGrimily k, taggedFst tv) r) n m) + M.foldrWithKey (\k tv r -> (mkUniqueGrimily k, taggedFst tv) : r) [] m | otherwise = to_list_nonempty m ub -- Precondition: m is non-empty View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/966e260a14667b5f21f73088356e88e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/966e260a14667b5f21f73088356e88e… You're receiving this email because of your account on gitlab.haskell.org.

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