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[Git][ghc/ghc][wip/sand-witch/27423-gadt-parens] Parentheses in prefix GADT constructors (#27423)
by Andrei Borzenkov (＠sand-witch) 10 Jul '26

10 Jul '26

Andrei Borzenkov pushed to branch wip/sand-witch/27423-gadt-parens at Glasgow Haskell Compiler / GHC Commits: 3a32ebde by Andrei Borzenkov at 2026-07-10T11:45:31+04:00 Parentheses in prefix GADT constructors (#27423) Updated `splitLHsGadtTy` to allow looking through the parentheses for inner binders. General example of a code pattern that's allowed now: data S a where MkS :: (forall a. S a) That should work now with any combination of nested foralls and parentheses. We don't perform parenthesis unwrapping for record GADT constructors in accordance with GHC Proposal #402. Updated `pprConDecl` to improve the `parse == parse . ppr . parse` property of GADT pretty-printing. The pretty printer can now output code that's similar to this: data T a where MkT1 :: (forall a. T a) MkT2 :: forall . forall a. T a These are special cases of inner forall binders for prefix GADT constructors, when we have either implicit or zero explicit outer binders. - - - - - 13 changed files: - + changelog.d/allow-gadt-prefx-con-parens - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Type.hs - − testsuite/tests/gadt/T14320.stderr - testsuite/tests/gadt/T18191.hs - testsuite/tests/gadt/T18191.stderr - + testsuite/tests/gadt/T27423a.hs - + testsuite/tests/gadt/T27423b.hs - + testsuite/tests/gadt/T27423b.stderr - testsuite/tests/gadt/all.T - testsuite/tests/printer/Makefile - + testsuite/tests/printer/T27423c.hs - testsuite/tests/printer/all.T Changes: ===================================== changelog.d/allow-gadt-prefx-con-parens ===================================== @@ -0,0 +1,16 @@ +section: language +synopsis: Allow parentheses in prefix GADT constructor declarations, as specified + by GHC Proposal #402 "Stable GADT constructor syntax". +issues: #27423 +mrs: !16321 + +description: { + Parenthesized types are now accepted in prefix GADT constructor declarations, + even when they contain explicit ``forall`` quantifiers. For example: + + data T where + MkT :: (forall a. a -> b -> T) + + This is equivalent to ``MkT :: forall {b}. (forall a. a -> b -> T)``, so the + forall-or-nothing rule continues to be respected. +} ===================================== compiler/GHC/Hs/Decls.hs ===================================== @@ -910,13 +910,28 @@ pprConDecl (ConDeclGADT { con_names = cons , con_res_ty = res_ty, con_modifiers = mods, con_doc = doc }) = pprMaybeWithDoc doc $ pprLHsModifiers mods <+> ppr_con_names (toList cons) <+> dcolon <+> (sep [pprHsOuterSigTyVarBndrs outer_bndrs + <+> inner_bndrs_lguard <+> hsep (map pprHsForAllTelescope inner_bndrs) <+> pprLHsContext mcxt, - sep (ppr_args args ++ [ppr res_ty]) ]) + sep (ppr_args args ++ [ppr res_ty]), + inner_bndrs_rguard ]) where ppr_args (PrefixConGADT _ args) = map (pprHsConDeclFieldWith (\arr tyDoc -> tyDoc <+> pprHsModifiedFunArr arr)) args ppr_args (RecConGADT _ fields) = [pprHsConDeclRecFields (unLoc fields) <+> arrow] + -- We may have inner binders without outer ones, for example: + -- data D a where MkD :: forall. forall a. D a + -- and + -- data D a where MkD :: (forall a. D a) + -- These cases have different outer_bndrs: explicit or implicit. + -- We want to add an empty `forall.` or wrap type into parentheses + -- to highlight the fact that binds in the question are indeed inner. + (inner_bndrs_lguard, inner_bndrs_rguard) + | null inner_bndrs = (empty, empty) + | HsOuterImplicit{} <- outer_bndrs = (lparen, rparen) + | HsOuterExplicit{hso_bndrs=[]} <- outer_bndrs = (text "forall" <+> text ".", empty) + | otherwise = (empty, empty) + ppr_con_names :: (OutputableBndr a) => [GenLocated l a] -> SDoc ppr_con_names = pprWithCommas (pprPrefixOcc . unLoc) ===================================== compiler/GHC/Hs/Type.hs ===================================== @@ -898,12 +898,11 @@ splitLHsGadtTy (L _ sig_ty) | (outer_bndrs, sigma_ty) <- split_outer_bndrs sig_ty , (inner_bndrs, phi_ty) <- split_inner_bndrs sigma_ty , (mb_ctxt, rho_ty) <- splitLHsQualTy_KP phi_ty - = case rho_ty of - L _ (HsFunTy _ _ (L _ (XHsType HsRecTy{})) _) | not (null inner_bndrs) + = if is_gadt_rec_ty rho_ty && not (null inner_bndrs) -- Bad! Record GADTs are not allowed to have inner_bndrs, -- undo the split to get a proper error message later - -> (outer_bndrs, [], Nothing, sigma_ty) - _ -> (outer_bndrs, inner_bndrs, mb_ctxt, rho_ty) + then (outer_bndrs, [], Nothing, sigma_ty) + else (outer_bndrs, inner_bndrs, mb_ctxt, rho_ty) where split_outer_bndrs :: HsSigType GhcPs -> (HsOuterSigTyVarBndrs GhcPs, LHsType GhcPs) split_outer_bndrs (HsSig{sig_bndrs = outer_bndrs, sig_body = body_ty}) = @@ -914,8 +913,17 @@ splitLHsGadtTy (L _ sig_ty) , hst_body = body }) = let ~(teles, t) = split_inner_bndrs body in (tele:teles, t) + split_inner_bndrs t@(L _ (HsParTy _ ty)) + | not (is_gadt_rec_ty ty) + = split_inner_bndrs ty + | otherwise + = ([], t) split_inner_bndrs t = ([], t) + -- type of form {fld :: ty, ...} -> ResTy + is_gadt_rec_ty (L _ (HsFunTy _ _ (L _ (XHsType HsRecTy{})) _)) = True + is_gadt_rec_ty _ = False + -- | Decompose a type of the form @forall <tvs>. body@ into its constituent -- parts. Only splits type variable binders that -- were quantified invisibly (e.g., @forall a.@, with a dot). ===================================== testsuite/tests/gadt/T14320.stderr deleted ===================================== @@ -1,4 +0,0 @@ - -T14320.hs:17:14: error: [GHC-71492] - GADT constructor type signature cannot contain nested ‘forall’s or contexts - In the definition of data constructor ‘TEBad’ ===================================== testsuite/tests/gadt/T18191.hs ===================================== @@ -2,15 +2,6 @@ {-# LANGUAGE RankNTypes #-} module T18191 where -data T where - MkT :: (forall a. a -> b -> T) - -data S a where - MkS :: (forall a. S a) - -data U a where - MkU :: (Show a => U a) - data Z a where MkZ1 :: forall a. forall b. { unZ1 :: (a, b) } -> Z (a, b) MkZ2 :: Eq a => Eq b => { unZ1 :: (a, b) } -> Z (a, b) ===================================== testsuite/tests/gadt/T18191.stderr ===================================== @@ -1,28 +1,16 @@ - -T18191.hs:6:11: error: [GHC-71492] - • GADT constructor type signature cannot contain nested ‘forall’s or contexts - • In the definition of data constructor ‘MkT’ - -T18191.hs:9:11: error: [GHC-71492] - • GADT constructor type signature cannot contain nested ‘forall’s or contexts - • In the definition of data constructor ‘MkS’ - -T18191.hs:12:11: error: [GHC-71492] - • GADT constructor type signature cannot contain nested ‘forall’s or contexts - • In the definition of data constructor ‘MkU’ - -T18191.hs:15:21: error: [GHC-71492] +T18191.hs:6:21: error: [GHC-71492] • GADT constructor type signature cannot contain nested ‘forall’s or contexts • In the definition of data constructor ‘MkZ1’ -T18191.hs:15:31: error: [GHC-89246] +T18191.hs:6:31: error: [GHC-89246] • Record syntax is illegal here: {unZ1 :: (a, b)} • In the definition of data constructor ‘MkZ1’ -T18191.hs:16:19: error: [GHC-71492] +T18191.hs:7:19: error: [GHC-71492] • GADT constructor type signature cannot contain nested ‘forall’s or contexts • In the definition of data constructor ‘MkZ2’ -T18191.hs:16:27: error: [GHC-89246] +T18191.hs:7:27: error: [GHC-89246] • Record syntax is illegal here: {unZ1 :: (a, b)} • In the definition of data constructor ‘MkZ2’ + ===================================== testsuite/tests/gadt/T27423a.hs ===================================== @@ -0,0 +1,31 @@ +{-# LANGUAGE GADTs #-} +module T27423a where + +data G a where + MkG1 :: a -> G a + MkG2 :: (a -> G a) + MkG3 :: forall a. a -> G a + MkG4 :: forall a. (a -> G a) + +-- this is equivalent to `forall {b}. (forall a. a -> b -> T)`. +data T where + MkT2 :: (forall a. a -> b -> T) + +-- this is equivalent to `forall. (forall a. S a)`. +data S a where + MkS :: (forall a. S a) + +-- A forall and a context combined inside the same parentheses, with no +-- outer forall at all. +data Y a where + MkY :: (forall a. Show a => a -> Y a) + +-- Multiple, redundant nested parentheses around the whole type should +-- be accepted. +data H a where + MkH :: ((a -> H a)) + +-- An unparenthesised outer forall together with an independent, +-- parenthesised inner forall. +data I a where + MkI :: forall a. (forall b. I (b, a)) ===================================== testsuite/tests/gadt/T27423b.hs ===================================== @@ -0,0 +1,16 @@ +{-# LANGUAGE GADTs #-} +module T27423b where + +-- Record-style GADT constructors must remain unparenthesisable, per +-- GHC Proposal #402: this is out of scope for #27423 and should +-- continue to be rejected. +data T1 a where + MkT1 :: ({ fld :: a } -> T1 a) + +data T2 a where + MkT2 :: (forall a. { fld :: a } -> T2 a) + +-- Without parentheses, forall-or-nothing applies to the whole type, so +-- `b` is not implicitly quantified and this must be rejected. +data T3 where + MkT3 :: forall a. a -> b -> T3 ===================================== testsuite/tests/gadt/T27423b.stderr ===================================== @@ -0,0 +1,15 @@ +T27423b.hs:8:12: error: [GHC-89246] + • Record syntax is illegal here: {fld :: a} + • In the definition of data constructor ‘MkT1’ + +T27423b.hs:11:12: error: [GHC-71492] + • GADT constructor type signature cannot contain nested ‘forall’s or contexts + • In the definition of data constructor ‘MkT2’ + +T27423b.hs:11:22: error: [GHC-89246] + • Record syntax is illegal here: {fld :: a} + • In the definition of data constructor ‘MkT2’ + +T27423b.hs:16:26: error: [GHC-76037] + Not in scope: type variable ‘b’ + ===================================== testsuite/tests/gadt/all.T ===================================== @@ -114,7 +114,7 @@ test('T7558', normal, compile, ['']) test('T9380', normal, compile_and_run, ['']) test('T12087', normal, compile_fail, ['']) test('T12468', normal, compile_fail, ['']) -test('T14320', normal, compile_fail, ['']) +test('T14320', normal, compile, ['']) test('T14719', normal, compile_fail, ['-fdiagnostics-show-caret']) test('T14808', normal, compile, ['']) test('T15009', normal, compile, ['']) @@ -132,3 +132,6 @@ test('T19847b', normal, compile, ['']) test('T23022', normal, compile, ['-dcore-lint']) test('T23023', normal, compile_fail, ['-O -dcore-lint']) # todo: move this test? test('T23298', normal, compile_fail, ['']) + +test('T27423a', normal, compile, ['']) +test('T27423b', normal, compile_fail, ['']) ===================================== testsuite/tests/printer/Makefile ===================================== @@ -932,3 +932,8 @@ PprModifiers: PprQualifiedStrings: $(CHECK_PPR) $(LIBDIR) PprQualifiedStrings.hs $(CHECK_EXACT) $(LIBDIR) PprQualifiedStrings.hs + +.PHONY: T27423c +T27423c: + $(CHECK_PPR) $(LIBDIR) T27423c.hs + $(CHECK_EXACT) $(LIBDIR) T27423c.hs ===================================== testsuite/tests/printer/T27423c.hs ===================================== @@ -0,0 +1,26 @@ +{-# LANGUAGE GADTs #-} +module T27423c where + +-- Exact-printing regression test +-- Not every declaration there would pass renamer without errors +data G a where + MkG1 :: a -> G a + MkG2 :: (a -> G a) + MkG3 :: forall a. a -> G a + MkG4 :: forall a. (a -> G a) + +data T where + MkT1 :: forall a. a -> b -> T + MkT2 :: (forall a. a -> b -> T) + +data S a where + MkS :: (forall a. S a) + +data U a where + MkU :: (Show a => U a) + +data V a where + MkV1 :: ((a -> V a)) + MkV2 :: forall a. (forall b. V (b, a)) + MkV3 :: (forall a. Show a => a -> V a) + MkV4 :: forall a. ((forall b. (Show a => a -> (b -> V a)))) ===================================== testsuite/tests/printer/all.T ===================================== @@ -223,3 +223,5 @@ test('TestLevelImports', [ignore_stderr, req_ppr_deps], makefile_test, ['TestLev test('TestNamedDefaults', [ignore_stderr, req_ppr_deps], makefile_test, ['TestNamedDefaults']) test('PprModifiers', [ignore_stderr,req_ppr_deps], makefile_test, ['PprModifiers']) test('PprQualifiedStrings', [ignore_stderr,req_ppr_deps], makefile_test, ['PprQualifiedStrings']) + +test('T27423c', [ignore_stderr,req_ppr_deps], makefile_test, ['T27423c']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/3a32ebdea1a458a0a606f59a5404673… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/3a32ebdea1a458a0a606f59a5404673… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/TTG-No-Orphans] First pass of orphan instance removal.
by recursion-ninja (＠recursion-ninja) 10 Jul '26

10 Jul '26

recursion-ninja pushed to branch wip/TTG-No-Orphans at Glasgow Haskell Compiler / GHC Commits: 69607e46 by Recursion Ninja at 2026-07-09T19:34:49-04:00 First pass of orphan instance removal. This is part of a technical debt removal effort made possible now that seperating out the AST via TTG comes to a close. As the AST in 'L.H.S' has been incrementally separated from the GHC internals, there are many accumulated orphan instance of 'Binary', 'Outputable', 'Uniquable', etc. The orphan instance of data-types from within 'L.H.S' are having thier orphan instances moved to the module which defined the type-class; i.e. moving an orphan 'Binary' instance to 'GHC.Utils.Binary'. Orphan instances resolved (57): | Data-type | Resolved instance(s) | Former orphan module(s) | | -------------------- | -------------------------- | ------------------------- | | Role | Binary, NFData, Outputable | GHC.Core.Coercion.Axiom | | SrcStrictness | Binary, NFData, Outputable | GHC.Core.DataCon | | SrcUnpackedness | Binary, NFData, Outputable | GHC.Core.DataCon | | Fixity | Binary, Outputable | GHC.Hs.Basic | | FixityDirection | Binary, Outputable | GHC.Hs.Basic | | LexicalFixity | Outputable | GHC.Hs.Basic | | CCallTarget | NFData | GHC.Hs.Decls.Foreign | | CType | NFData | GHC.Hs.Decls.Foreign | | Header | NFData | GHC.Hs.Decls.Foreign | | OverlapMode | Binary, NFData | GHC.Hs.Decls.Overlap | | WithHsDocIdentifiers | Eq, NFData, Outputable | GHC.Hs.Doc | | HsDocString | Eq, NFData, Show | GHC.Hs.DocString | | HsDocStringChunk | Binary, Outputable | GHC.Hs.DocString | | HsDocStringDecorator | Binary, Outputable | GHC.Hs.DocString | | IEWrappedName | Eq, Outputable | GHC.Hs.ImpExp | | NamespaceSpecifier | Eq, Outputable | GHC.Hs.ImpExp | | IE | Eq | GHC.Hs.Instances | | HsLit | Eq | GHC.Hs.Lit | | HsOverLit | Eq | GHC.Hs.Lit | | OverLitVal | Eq | GHC.Hs.Lit | | HsQualLit | Eq | GHC.Hs.Lit | | QualLitVal | Eq | GHC.Hs.Lit | | FractionalLit | Eq, Show | GHC.Hs.Lit | | IntegralLit | Eq, Show | GHC.Hs.Lit | | StringLiteral | Eq, Show | GHC.Hs.Lit | | ForAllTyFlag | Binary, NFData, Outputable | GHC.Hs.Specificity | | Specificity | Binary, NFData | GHC.Hs.Specificity | | PromotionFlag | Binary, Outputable | GHC.Types.Basic | | FieldLabelString | Outputable, Uniquable | GHC.Types.FieldLabel | | CCallTarget | Eq | GHC.Types.ForeignCall | | Header | Eq | GHC.Types.ForeignCall | | InlinePragma | Binary | GHC.Types.InlinePragma | | InWarningCategory | Eq | GHC.Unit.Module.Warnings | | WarningTxt | Eq | GHC.Unit.Module.Warnings | Closes #21262, #27469 Resolving more orphan 'Eq' instances - - - - - 31 changed files: - compiler/GHC/Core/Coercion/Axiom.hs - compiler/GHC/Core/DataCon.hs - compiler/GHC/Hs/Basic.hs - compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Doc.hs - compiler/GHC/Hs/DocString.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Lit.hs - − compiler/GHC/Hs/Specificity.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/FieldLabel.hs - compiler/GHC/Types/Fixity.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Types/InlinePragma.hs - compiler/GHC/Types/Unique.hs - compiler/GHC/Types/Var.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/Doc.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Specificity.hs - compiler/ghc.cabal.in - testsuite/tests/count-deps/CountDepsParser.stdout The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/69607e46000eaf0cbb31002247f5fb3… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/69607e46000eaf0cbb31002247f5fb3… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/getFullArgs] base: re-export GHC.Environment.getFullArgs from System.Environment
by Bodigrim (＠Bodigrim) 10 Jul '26

10 Jul '26

Bodigrim pushed to branch wip/getFullArgs at Glasgow Haskell Compiler / GHC Commits: 5d1f7f5b by Andrew Lelechenko at 2026-07-09T23:08:10+01:00 base: re-export GHC.Environment.getFullArgs from System.Environment CLC proposal https://github.com/haskell/core-libraries-committee/issues/431 - - - - - 5 changed files: - libraries/base/changelog.md - libraries/base/src/System/Environment.hs - 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 Changes: ===================================== libraries/base/changelog.md ===================================== @@ -2,6 +2,7 @@ ## 4.24.0.0 *TBA* * Give `setBit`, `clearBit` and `complementBit` explicit definitions in `instance Bits Integer`, reducing intermediate allocations. ([CLC proposal #423](https://github.com/haskell/core-libraries-committee/issues/423)) + * Export `GHC.Environment.getFullArgs` from `System.Environment`. ([CLC proposal #431](https://github.com/haskell/core-libraries-committee/issues/431)) * Add `Bounded` instances for `Double`, `Float`, `CDouble` and `CFloat`. ([CLC proposal #402](https://github.com/haskell/core-libraries-committee/issues/402)) * Add `Data.List.NonEmpty.{zip{3..7},zipWith{3..7},unzip{3..7}}` ([CLC proposal #409)(https://github.com/haskell/core-libraries-committee/issues/409)) * Ensure that `Data.List.elem` and `notElem` can be specialized even when no list fusion happens. ([CLC proposal #412)(https://github.com/haskell/core-libraries-committee/issues/412)) ===================================== libraries/base/src/System/Environment.hs ===================================== @@ -15,6 +15,7 @@ module System.Environment ( getArgs, + getFullArgs, getProgName, executablePath, getExecutablePath, @@ -27,4 +28,5 @@ module System.Environment getEnvironment, ) where +import GHC.Internal.Environment (getFullArgs) import GHC.Internal.System.Environment ===================================== testsuite/tests/interface-stability/base-exports.stdout ===================================== @@ -9885,6 +9885,7 @@ module System.Environment where getEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO GHC.Internal.Base.String getEnvironment :: GHC.Internal.Types.IO [(GHC.Internal.Base.String, GHC.Internal.Base.String)] getExecutablePath :: GHC.Internal.Types.IO GHC.Internal.IO.FilePath + getFullArgs :: GHC.Internal.Types.IO [GHC.Internal.Base.String] getProgName :: GHC.Internal.Types.IO GHC.Internal.Base.String lookupEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) setEnv :: GHC.Internal.Base.String -> GHC.Internal.Base.String -> GHC.Internal.Types.IO () ===================================== testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs ===================================== @@ -9923,6 +9923,7 @@ module System.Environment where getEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO GHC.Internal.Base.String getEnvironment :: GHC.Internal.Types.IO [(GHC.Internal.Base.String, GHC.Internal.Base.String)] getExecutablePath :: GHC.Internal.Types.IO GHC.Internal.IO.FilePath + getFullArgs :: GHC.Internal.Types.IO [GHC.Internal.Base.String] getProgName :: GHC.Internal.Types.IO GHC.Internal.Base.String lookupEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) setEnv :: GHC.Internal.Base.String -> GHC.Internal.Base.String -> GHC.Internal.Types.IO () ===================================== testsuite/tests/interface-stability/base-exports.stdout-mingw32 ===================================== @@ -10165,6 +10165,7 @@ module System.Environment where getEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO GHC.Internal.Base.String getEnvironment :: GHC.Internal.Types.IO [(GHC.Internal.Base.String, GHC.Internal.Base.String)] getExecutablePath :: GHC.Internal.Types.IO GHC.Internal.IO.FilePath + getFullArgs :: GHC.Internal.Types.IO [GHC.Internal.Base.String] getProgName :: GHC.Internal.Types.IO GHC.Internal.Base.String lookupEnv :: GHC.Internal.Base.String -> GHC.Internal.Types.IO (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) setEnv :: GHC.Internal.Base.String -> GHC.Internal.Base.String -> GHC.Internal.Types.IO () View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5d1f7f5b03dd1947d84dcffea17eed3… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5d1f7f5b03dd1947d84dcffea17eed3… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/TTG-No-Orphans] 10 commits: Fix a profiling race condition resulting in segfaults.
by recursion-ninja (＠recursion-ninja) 10 Jul '26

10 Jul '26

recursion-ninja pushed to branch wip/TTG-No-Orphans at Glasgow Haskell Compiler / GHC Commits: ed09895d by Andreas Klebinger at 2026-07-08T16:53:27-04:00 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. - - - - - 67c03eb2 by Cheng Shao at 2026-07-08T16:54:09-04:00 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> - - - - - 2ecabb4f by Zubin Duggal at 2026-07-09T09:23:25-04:00 hadrian: binary-dist-dir should not be the default target Revert behaviour to pre 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 In 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2, we applied the following behaviour change: ``` hadrian: Build stage 2 cross compilers ... * hadrian: Make binary-dist-dir the default build target. This allows us to have the logic in one place about which libraries/stages to build with cross compilers. Fixes #24192 ``` This is a major regression to development experience, a plain hadrian/build --freeze1 now takes ages because we rebuild all docs (which need to go in the binary dist dir). `binary-dist-dir` is the wrong default target for regular GHC development work Fixes #27445 - - - - - e16388e3 by Zubin Duggal at 2026-07-09T09:23:25-04:00 .gitignore: Add the hadrian system.config introduced by commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 Since commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 Author: Matthew Pickering <matthewtpickering(a)gmail.com> Date: Thu Dec 21 16:17:41 2023 +0000 hadrian: Build stage 2 cross compilers ./configure produces /hadrian/cfg/system.config.{host,target} Add these to .gitignore - - - - - 7e8abf41 by Alan Zimmerman at 2026-07-09T09:24:12-04:00 EPA: Replace AnnListItem with simply [TrailingAnn] Remove the unnecessary wrapper around a single field. - - - - - 29032f17 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Keep real reason for fragile test failures - - - - - c34e03a7 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Fall back to the failure reason for empty JUnit bodies - - - - - 409d40f0 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Show output diffs in JUnit output Also refactor compare_outputs to return essentially a `Maybe Diff` (`CompareOutput`) instead of a bool, but more pythonic. This allows us to pass the diff through nice. - - - - - 06fee1ab by Zubin Duggal at 2026-07-09T09:24:58-04:00 perf notes: include stat deviation and acceptance window in notes so they show up in gitlab - - - - - 91520d2f by Recursion Ninja at 2026-07-09T17:07:21-04:00 First pass of orphan instance removal. This is part of a technical debt removal effort made possible now that seperating out the AST via TTG comes to a close. As the AST in 'L.H.S' has been incrementally separated from the GHC internals, there are many accumulated orphan instance of 'Binary', 'Outputable', 'Uniquable', etc. The orphan instance of data-types from within 'L.H.S' are having thier orphan instances moved to the module which defined the type-class; i.e. moving an orphan 'Binary' instance to 'GHC.Utils.Binary'. Orphan instances resolved (49): | Data-type | Resolved instance(s) | Former orphan module(s) | | -------------------- | -------------------------- | ----------------------- | | Role | Binary, NFData, Outputable | GHC.Core.Coercion.Axiom | | SrcStrictness | Binary, NFData, Outputable | GHC.Core.DataCon | | SrcUnpackedness | Binary, NFData, Outputable | GHC.Core.DataCon | | Fixity | Binary, Outputable | GHC.Hs.Basic | | FixityDirection | Binary, Outputable | GHC.Hs.Basic | | LexicalFixity | Outputable | GHC.Hs.Basic | | CCallTarget | NFData | GHC.Hs.Decls.Foreign | | CType | NFData | GHC.Hs.Decls.Foreign | | Header | NFData | GHC.Hs.Decls.Foreign | | OverlapMode | Binary, NFData | GHC.Hs.Decls.Overlap | | WithHsDocIdentifiers | NFData, Outputable | GHC.Hs.Doc | | HsDocString | Eq, NFData, Show | GHC.Hs.DocString | | HsDocStringChunk | Binary, Outputable | GHC.Hs.DocString | | HsDocStringDecorator | Binary, Outputable | GHC.Hs.DocString | | NamespaceSpecifier | Outputable | GHC.Hs.ImpExp | | HsLit | Eq | GHC.Hs.Lit | | HsOverLit | Eq | GHC.Hs.Lit | | OverLitVal | Eq | GHC.Hs.Lit | | HsQualLit | Eq | GHC.Hs.Lit | | QualLitVal | Eq | GHC.Hs.Lit | | FractionalLit | Eq, Show | GHC.Hs.Lit | | IntegralLit | Eq, Show | GHC.Hs.Lit | | StringLiteral | Eq, Show | GHC.Hs.Lit | | ForAllTyFlag | Binary, NFData, Outputable | GHC.Hs.Specificity | | Specificity | Binary, NFData | GHC.Hs.Specificity | | PromotionFlag | Binary, Outputable | GHC.Types.Basic | | FieldLabelString | Outputable, Uniquable | GHC.Types.FieldLabel | | InlinePragma | Binary | GHC.Types.InlinePragma | Closes #21262, #27469 - - - - - 80 changed files: - .gitignore - + changelog.d/T27123.md - + changelog.d/fix-peekitbl-no-tntc - compiler/GHC/Core/Coercion/Axiom.hs - compiler/GHC/Core/DataCon.hs - compiler/GHC/Hs/Basic.hs - compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Doc.hs - compiler/GHC/Hs/DocString.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Lit.hs - − compiler/GHC/Hs/Specificity.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/StgToCmm/Bind.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/FieldLabel.hs - compiler/GHC/Types/Fixity.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Types/InlinePragma.hs - compiler/GHC/Types/Unique.hs - compiler/GHC/Types/Var.hs - compiler/GHC/Utils/Binary.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Basic.hs - compiler/Language/Haskell/Syntax/Decls/Foreign.hs - compiler/Language/Haskell/Syntax/Doc.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/Language/Haskell/Syntax/Specificity.hs - compiler/ghc.cabal.in - hadrian/src/Rules.hs - hadrian/src/Rules/BinaryDist.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/driver/junit.py - testsuite/driver/perf_notes.py - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/driver/testutil.py - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/ghc-api/T25121_status.stdout - testsuite/tests/ghc-api/exactprint/T22919.stderr - testsuite/tests/ghc-api/exactprint/Test20239.stderr - testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T24221.stderr - testsuite/tests/module/mod185.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/DumpSemis.stderr - testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_compile/T15323.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/parser/should_compile/T20718.stderr - testsuite/tests/parser/should_compile/T20718b.stderr - testsuite/tests/parser/should_compile/T20846.stderr - testsuite/tests/parser/should_compile/T23315/T23315.stderr - testsuite/tests/printer/AnnotationNoListTuplePuns.stdout - testsuite/tests/printer/T18791.stderr - testsuite/tests/printer/Test20297.stdout - testsuite/tests/printer/Test24533.stdout - + testsuite/tests/rts/T27123.hs - testsuite/tests/rts/all.T - testsuite/tests/typecheck/should_compile/T15242.stderr - testsuite/tests/typecheck/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/check-exact/Transform.hs - utils/check-exact/Utils.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3d8477c757209b44e3da36ecc8a28e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3d8477c757209b44e3da36ecc8a28e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/getFullArgs
by Bodigrim (＠Bodigrim) 09 Jul '26

09 Jul '26

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

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[Git][ghc/ghc][wip/az/exactprint-annotation-rationalisation] 24 commits: Fix a profiling race condition resulting in segfaults.
by Alan Zimmerman (＠alanz) 09 Jul '26

09 Jul '26

Alan Zimmerman pushed to branch wip/az/exactprint-annotation-rationalisation at Glasgow Haskell Compiler / GHC Commits: ed09895d by Andreas Klebinger at 2026-07-08T16:53:27-04:00 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. - - - - - 67c03eb2 by Cheng Shao at 2026-07-08T16:54:09-04:00 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> - - - - - 2ecabb4f by Zubin Duggal at 2026-07-09T09:23:25-04:00 hadrian: binary-dist-dir should not be the default target Revert behaviour to pre 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 In 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2, we applied the following behaviour change: ``` hadrian: Build stage 2 cross compilers ... * hadrian: Make binary-dist-dir the default build target. This allows us to have the logic in one place about which libraries/stages to build with cross compilers. Fixes #24192 ``` This is a major regression to development experience, a plain hadrian/build --freeze1 now takes ages because we rebuild all docs (which need to go in the binary dist dir). `binary-dist-dir` is the wrong default target for regular GHC development work Fixes #27445 - - - - - e16388e3 by Zubin Duggal at 2026-07-09T09:23:25-04:00 .gitignore: Add the hadrian system.config introduced by commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 Since commit 23c9b6c392f52ec9d7a8618b204ff6b885f5fba2 Author: Matthew Pickering <matthewtpickering(a)gmail.com> Date: Thu Dec 21 16:17:41 2023 +0000 hadrian: Build stage 2 cross compilers ./configure produces /hadrian/cfg/system.config.{host,target} Add these to .gitignore - - - - - 7e8abf41 by Alan Zimmerman at 2026-07-09T09:24:12-04:00 EPA: Replace AnnListItem with simply [TrailingAnn] Remove the unnecessary wrapper around a single field. - - - - - 29032f17 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Keep real reason for fragile test failures - - - - - c34e03a7 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Fall back to the failure reason for empty JUnit bodies - - - - - 409d40f0 by Zubin Duggal at 2026-07-09T09:24:58-04:00 testsuite: Show output diffs in JUnit output Also refactor compare_outputs to return essentially a `Maybe Diff` (`CompareOutput`) instead of a bool, but more pythonic. This allows us to pass the diff through nice. - - - - - 06fee1ab by Zubin Duggal at 2026-07-09T09:24:58-04:00 perf notes: include stat deviation and acceptance window in notes so they show up in gitlab - - - - - 3a4a66b6 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Keep binds and sigs together in HsValBindsLR We combine them into a single list for GhcPs, wrapped in the ValBind data type, which is the bind equivalent of ValD, having constructors for binds and sigs. This simplifies exact print processing, especially when using it to update the contents of local binds, as we no longer need AnnSortKey BindTag - - - - - cc4ddb5a by Alan Zimmerman at 2026-07-09T20:19:33+01:00 Keep decls together in ClassDecl - - - - - 253bcf62 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: ClsInstDecl as list in GhcPs - - - - - 9e0f416a by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedP from OverlapMode - - - - - c34d11a4 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedP from CType - - - - - 6a59c189 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedP, last use in WarningTxt - - - - - c1083835 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedE from WarningCategory - - - - - edf7464d by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocateE from XCImport and XCExport - - - - - 7a49677b by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedE from HsRecFields dot - - - - - d648cd22 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedE completely, last usage for pats - - - - - 5d91cd73 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove AnnList (EpToken "where") usages This is moving toward removing the parameter from AnnList completely - - - - - 79d06d30 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA remove AnnList (EpToken "rec") usages - - - - - 1c0baaf0 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove last parameterised AnnList usage (EpaLocation) Also remove the parameter - - - - - 58f8a373 by Alan Zimmerman at 2026-07-09T20:19:33+01:00 TTG: Add extension points to BooleanFormula They are currently unused, but will be used for exact print annotations next - - - - - ba591aff by Alan Zimmerman at 2026-07-09T20:19:33+01:00 EPA: Remove LocatedBC / SrcSpanBF - - - - - 106 changed files: - .gitignore - + changelog.d/T27123.md - + changelog.d/fix-peekitbl-no-tntc - compiler/GHC/Builtin/Utils.hs - compiler/GHC/Core/Class.hs - compiler/GHC/CoreToIface.hs - compiler/GHC/Data/BooleanFormula.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Stats.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Warnings.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/Runtime/Eval.hs - compiler/GHC/StgToCmm/Bind.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Class.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/ForeignCall.hs - compiler/GHC/Unit/Module/Warnings.hs - compiler/Language/Haskell/Syntax/Binds.hs - compiler/Language/Haskell/Syntax/BooleanFormula.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Extension.hs - ghc/GHCi/UI.hs - hadrian/src/Rules.hs - hadrian/src/Rules/BinaryDist.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/driver/junit.py - testsuite/driver/perf_notes.py - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/driver/testutil.py - testsuite/tests/ghc-api/T25121_status.stdout - testsuite/tests/ghc-api/exactprint/T22919.stderr - testsuite/tests/ghc-api/exactprint/Test20239.stderr - testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr - testsuite/tests/haddock/haddock_examples/haddock.Test.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T24221.stderr - testsuite/tests/module/mod185.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/DumpSemis.stderr - testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_compile/T15279.stderr - testsuite/tests/parser/should_compile/T15323.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/parser/should_compile/T20718.stderr - testsuite/tests/parser/should_compile/T20718b.stderr - testsuite/tests/parser/should_compile/T20846.stderr - testsuite/tests/parser/should_compile/T23315/T23315.stderr - testsuite/tests/printer/AnnotationNoListTuplePuns.stdout - testsuite/tests/printer/T18791.stderr - testsuite/tests/printer/Test20297.stdout - testsuite/tests/printer/Test24533.stdout - + testsuite/tests/rts/T27123.hs - testsuite/tests/rts/all.T - testsuite/tests/typecheck/should_compile/T15242.stderr - testsuite/tests/typecheck/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/check-exact/Main.hs - utils/check-exact/Transform.hs - utils/check-exact/Utils.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.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/GhcUtils.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/65a8a867afb1ce642a95a58f09adfb… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/65a8a867afb1ce642a95a58f09adfb… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/az/epa-tidy-locatedxxx-7
by Alan Zimmerman (＠alanz) 09 Jul '26

09 Jul '26

Alan Zimmerman pushed new branch wip/az/epa-tidy-locatedxxx-7 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/az/epa-tidy-locatedxxx-7 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/jeltsch/textual-bytecode-output] Remove obsolete import of `(&&)`
by Wolfgang Jeltsch (＠jeltsch) 09 Jul '26

09 Jul '26

Wolfgang Jeltsch pushed to branch wip/jeltsch/textual-bytecode-output at Glasgow Haskell Compiler / GHC Commits: 45ac6cc4 by Wolfgang Jeltsch at 2026-07-09T20:58:24+03:00 Remove obsolete import of `(&&)` - - - - - 1 changed file: - compiler/GHC/ByteCode/Show.hs Changes: ===================================== compiler/GHC/ByteCode/Show.hs ===================================== @@ -13,7 +13,7 @@ import Data.Ord ((<=)) import Data.Bits (FiniteBits, finiteBitSize) import Data.Function (($), id, (.)) import Data.Tuple (fst, snd, uncurry) -import Data.Bool (Bool, otherwise, not, (&&)) +import Data.Bool (Bool, otherwise, not) import Data.Int (Int) import Data.Word (Word) import Data.Maybe (Maybe (Nothing, Just), maybe) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/45ac6cc4b361d5fc3e32266c98400e0… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/45ac6cc4b361d5fc3e32266c98400e0… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/jeltsch/ghc-9-14-building-base] Add CI job `base-build-with-released-ghcs`
by Wolfgang Jeltsch (＠jeltsch) 09 Jul '26

09 Jul '26

Wolfgang Jeltsch pushed to branch wip/jeltsch/ghc-9-14-building-base at Glasgow Haskell Compiler / GHC Commits: 98cc92bd by Wolfgang Jeltsch at 2026-07-09T21:03:43+03:00 Add CI job `base-build-with-released-ghcs` - - - - - 1 changed file: - .gitlab-ci.yml Changes: ===================================== .gitlab-ci.yml ===================================== @@ -65,7 +65,7 @@ stages: - quick-build # A very quick smoke-test to weed out broken commits - full-build # Build all the things - packaging # Source distribution, etc. - - testing # head.hackage correctness and compiler performance testing + - testing # Various tests - deploy # push documentation # Note [The CI Story] @@ -1142,6 +1142,48 @@ ghc-wasm-meta-unreg: UPSTREAM_GHC_FLAVOUR: unreg UPSTREAM_GHC_JOB_NAME: x86_64-linux-alpine3_23-wasm-unreg-cross_wasm32-wasi-release+host_fully_static+text_simdutf +############################################################ +# Building `base` with released GHC versions +############################################################ + +base-build-with-released-ghcs: + stage: testing + needs: + - job: x86_64-linux-deb13-validate + optional: true + - job: nightly-x86_64-linux-deb13-validate + optional: true + - job: release-x86_64-linux-deb13-release + optional: true + dependencies: null + image: "registry.gitlab.haskell.org/ghc/ci-images/x86_64-linux-deb12:$DOCKER_REV" + tags: + - x86_64-linux + script: + - | + # The GHC versions to build `base` with are specified below as a + # whitespace-separated list between apostrophes. + ghc_versions='9.14.1' + sed -E -e 's/^( *ghc-internal)[^[:alnum:]-].*(,|$)/\1\2/' \ + < libraries/base/base.cabal.in \ + > libraries/base/base.cabal + for ghc_version in ${ghc_versions} + do + url=https://downloads.haskell.org/~ghc/${ghc_version}/ghc-${ghc_version}-x8… + curl "$url" >ghc-${ghc_version}.tar.xz + tar -xJf ghc-${ghc_version}.tar.xz + cd ghc-${ghc_version}-x86_64-unknown-linux + ./configure --prefix "$PWD/../ghc-${ghc_version}-installed" + make install + cd ../libraries/base + cabal build --with-compiler ../../ghc-${ghc_version}-installed/bin/ghc \ + --allow-boot-library-installs \ + -O0 + cd .. + done + rules: + - *full-ci + ############################################################ # Documentation deployment via GitLab Pages ############################################################ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/98cc92bd201dd1d3218e198add845fa… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/98cc92bd201dd1d3218e198add845fa… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/sjakobi/udfm-placement] 2 commits: WIP: UDFM: fold foldUDFM directly over the placement array
by Simon Jakobi (＠sjakobi2) 09 Jul '26

09 Jul '26

Simon Jakobi pushed to branch wip/sjakobi/udfm-placement at Glasgow Haskell Compiler / GHC Commits: cb32b775 by Simon Jakobi at 2026-07-09T19:31:05+02:00 WIP: UDFM: fold foldUDFM directly over the placement array foldUDFM was foldr k z (eltsUDFM m); on the non-empty path eltsUDFM calls the out-of-line elts_nonempty, which returns a real list, so every non-singleton fold materialised the sorted [elt] before consuming it. Make placementSort emit its readout as a build, and route foldUDFM's non-empty case through an out-of-line fold_elts_nonempty that does foldr k z (placementSort ...). placementSort's INLINE lets foldr/build fuse once inside the worker, so the combiner is threaded straight into the array readout with no intermediate list -- and without inlining the sort machinery into every consumer. eltsUDFM's list-producing path is unchanged (the unfused build reduces to cons/nil). See Note [Sorting a UDFM]. Assisted-by: Claude Opus 4.8 - - - - - 26f30aa1 by Simon Jakobi at 2026-07-09T19:31:11+02:00 UDFM: use a static sentinel for placement-sort holes placementSort seeds the array with a sentinel (tag -1) in slots that no element's tag ever hits. TaggedVal's value field is strict, so the sentinel needs a value in WHNF. Borrowing one from the map via findMin allocates a thunk per call that also retains the whole source map until the holes are read. Use `unsafeCoerce ()` instead: () is a static, already-evaluated nullary constructor, so the sentinel is a single shared top-level value -- no per-call allocation and it retains nothing. The value is never read (the readout skips tag < 0) and r is always a lifted, boxed type, so this is safe; see Note [Sorting a UDFM]. Measured (perf+no_profiled_libs, 80 compiler perf tests): bytes allocated drops slightly on every affected test versus the findMin sentinel, with no residency change. Assisted-by: Claude Opus 4.8 - - - - - 1 changed file: - compiler/GHC/Types/Unique/DFM.hs Changes: ===================================== compiler/GHC/Types/Unique/DFM.hs ===================================== @@ -347,8 +347,21 @@ elemUDFM k (UDFM m _i) = M.member (getKey $ getUnique k) m -- See Note [Cost of deterministic iteration]. foldUDFM :: (elt -> a -> a) -> a -> UniqDFM key elt -> a {-# INLINE foldUDFM #-} --- This INLINE prevents a regression in !10568 -foldUDFM k z m = foldr k z (eltsUDFM m) +-- The INLINE prevents a regression in !10568 and, together with the placement +-- sort's build form, lets the non-empty path fold directly over the sorted +-- readout with no intermediate list. See Note [Sorting a UDFM]. +foldUDFM k z (UDFM m ub) + -- n <= 1: any order is trivially tag order, so fold straight over the map + | M.compareSize m 1 /= GT = M.foldr (k . taggedFst) z m + | otherwise = fold_elts_nonempty k z m ub + +-- Precondition: m is non-empty. Out of line (like elts_nonempty) so foldUDFM's +-- consumers don't inline the sort machinery; but placementSort's build fuses +-- with the foldr here, so the placement path folds without building a list. +fold_elts_nonempty :: (elt -> a -> a) -> a -> M.Word64Map (TaggedVal elt) -> Int -> a +fold_elts_nonempty k z m ub + | usePlacement m ub = foldr k z (placementSort ub (\_ tv -> tv) m) + | otherwise = foldr k z (map taggedFst (sort_it m)) -- | Like 'foldUDFM' but the function also receives a key. -- @@ -420,13 +433,29 @@ O(ub) -- with no comparisons. The readout is lazy, so consumers that demand only a prefix pay almost nothing beyond the fill (but the fill itself is unavoidable; see Note [Cost of deterministic iteration]). +placementSort emits the readout as a 'build', so foldr/build fusion applies. +An eltsUDFM consumer materialises the list (build reduces to cons/nil); a +foldUDFM consumer instead has its combiner threaded straight into the readout, +folding the sorted elements with no intermediate list. foldUDFM is INLINE and +dispatches through the out-of-line fold_elts_nonempty, where the fusion happens +once -- so the fold is list-free without inlining the sort into every consumer. + Holes: slots whose tag never occurs keep the initial sentinel, a TaggedVal -with tag -1. Real tags are non-negative, so the readout skips on tag < 0. -The sentinel's value field is never read, but something must fill it: not a -panic thunk -- TaggedVal's strict value field would force it as soon as the -readout inspects a hole's tag -- so we borrow the value of an arbitrary map -element. (Safe: the callers' guards send maps of size < 2 down a different -path, so the map is never empty here.) +with tag -1. Real tags are non-negative, so the readout skips on tag < 0 and +never reads the sentinel's value field. But that field is strict, so the +sentinel still needs a value in WHNF: a panic thunk is out (it would be forced +-- and crash -- the moment the readout inspects a hole's tag). We use +@unsafeCoerce ()@: () is a static, already-evaluated nullary constructor, so +the sentinel is one shared top-level value -- no per-call allocation, and it +retains nothing. + +The unsafeCoerce is safe here because r is always a lifted, boxed (pointer) +type -- it comes from the map's elements -- so a pointer to () has the right +representation. The GC only ever traces that pointer (() is a valid closure); +the value is never evaluated or used as an r, since the readout takes values +only from filled slots. Borrowing a real element instead would also type-check +but costs a per-call thunk that retains the whole source map until the holes +are read. This sorting method loses when ub is much larger than n = M.size m: ub never shrinks (overwrites keep bumping it, delete/filter shrink n but not ub). We @@ -453,19 +482,15 @@ placementSort :: forall e r. Int -> (M.Key -> TaggedVal e -> TaggedVal r) -> M.Word64Map (TaggedVal e) -> [r] -{-# INLINE placementSort #-} -- specializes mk into the fill loop -placementSort ub mk m = runST (ST (\s0 -> - case newSmallArray ub hole s0 of - (# s1, marr #) -> case fill marr s1 of - (# s2, () #) -> case unsafeFreezeSmallArray marr s2 of - (# s3, arr #) -> (# s3, readout arr 0 #))) +{-# INLINE placementSort #-} -- specializes mk into the fill loop; makes the + -- readout a good producer that fuses with a + -- consuming fold. See Note [Sorting a UDFM]. +placementSort ub mk m = build gen where - -- The tag -1 marks unfilled slots; the value field is never read, but - -- it is strict, so it needs a real value of type r -- borrow one from - -- the map. See Note [Sorting a UDFM]. + -- The tag -1 marks unfilled slots; the value field is never read, but it + -- is strict, so it needs a WHNF value of type r. See Note [Sorting a UDFM]. hole :: TaggedVal r - hole = case M.findMin m of - (k, tv) -> TaggedVal (taggedFst (mk k tv)) (-1) + hole = TaggedVal (unsafeCoerce ()) (-1) fill :: SmallMutableArray s (TaggedVal r) -> State# s -> (# State# s, () #) fill marr s = case M.traverseWithKey_ write m of ST st -> st s @@ -473,12 +498,22 @@ placementSort ub mk m = runST (ST (\s0 -> write k tv = ST (\s' -> (# writeSmallArray marr (taggedSnd tv) (mk k tv) s', () #)) - readout :: SmallArray (TaggedVal r) -> Int -> [r] - readout arr j - | j >= ub = [] - | t < 0 = readout arr (j + 1) - | otherwise = v : readout arr (j + 1) - where TaggedVal v t = indexSmallArray arr j + -- Written as a build so that foldr/build fusion lets a consuming fold + -- (foldUDFM) apply its combiner during readout, with no cons cells. + -- Unfused (eltsUDFM), build reduces to cons/nil and yields the list. + gen :: forall b. (r -> b -> b) -> b -> b + gen cons nil = runST (ST (\s0 -> + case newSmallArray ub hole s0 of + (# s1, marr #) -> case fill marr s1 of + (# s2, () #) -> case unsafeFreezeSmallArray marr s2 of + (# s3, arr #) -> (# s3, readout arr 0 #))) + where + readout :: SmallArray (TaggedVal r) -> Int -> b + readout arr j + | j >= ub = nil + | t < 0 = readout arr (j + 1) + | otherwise = cons v (readout arr (j + 1)) + where TaggedVal v t = indexSmallArray arr j filterUDFM :: (elt -> Bool) -> UniqDFM key elt -> UniqDFM key elt filterUDFM p (UDFM m i) = UDFM (M.filter (\(TaggedVal v _) -> p v) m) i View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/966e260a14667b5f21f73088356e88… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/966e260a14667b5f21f73088356e88… You're receiving this email because of your account on gitlab.haskell.org.

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