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[Git][ghc/ghc][wip/int-index/no-multiline] Refactor: merge HsMultilineString into HsString (#26860)
by Vladislav Zavialov (＠int-index) 31 Jan '26

31 Jan '26

Vladislav Zavialov pushed to branch wip/int-index/no-multiline at Glasgow Haskell Compiler / GHC Commits: 2aeefaee by Vladislav Zavialov at 2026-01-31T15:56:45+03:00 Refactor: merge HsMultilineString into HsString (#26860) Before this patch, HsLit defined two separate constructors to represent single-line and multi-line strings: data HsLit x ... | HsString (XHsString x) FastString | HsMultilineString (XHsMultilineString x) FastString I found this to be an unnecessary complication and an obstacle to unifying HsLit with HsTyLit. Now we use HsString for both kinds of literals. One user-facing change here is `ppr (HsString st s)` behaving differently for single-line strings containing newlines: x = "first line \ \asdf\n\ \second line" Previously, the literal was fed to `ftext` with its newlines, producing an ill-formed SDoc. This issue is now addressed by using `split` for both single-line and multi-line strings: vcat $ map text $ split '\n' (unpackFS src) See the parser/should_fail/T26860ppr test. In addition (and unrelatedly to the main payload of this patch), drop the unused pmPprHsLit helper. - - - - - 14 changed files: - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - + testsuite/tests/parser/should_fail/T26860ppr.hs - + testsuite/tests/parser/should_fail/T26860ppr.stderr - testsuite/tests/parser/should_fail/all.T - utils/check-exact/ExactPrint.hs Changes: ===================================== compiler/GHC/Hs/Lit.hs ===================================== @@ -45,7 +45,6 @@ import Language.Haskell.Syntax.Lit type instance XHsChar (GhcPass _) = SourceText type instance XHsCharPrim (GhcPass _) = SourceText type instance XHsString (GhcPass _) = SourceText -type instance XHsMultilineString (GhcPass _) = SourceText type instance XHsStringPrim (GhcPass _) = SourceText type instance XHsInt (GhcPass _) = NoExtField type instance XHsIntPrim (GhcPass _) = SourceText @@ -147,7 +146,6 @@ hsLitNeedsParens p = go go (HsChar {}) = False go (HsCharPrim {}) = False go (HsString {}) = False - go (HsMultilineString {}) = False go (HsStringPrim {}) = False go (HsInt _ x) = p > topPrec && il_neg x go (HsFloatPrim {}) = False @@ -177,7 +175,6 @@ convertLit :: XXLit (GhcPass p)~DataConCantHappen => HsLit (GhcPass p) -> HsLit convertLit (HsChar a x) = HsChar a x convertLit (HsCharPrim a x) = HsCharPrim a x convertLit (HsString a x) = HsString a x -convertLit (HsMultilineString a x) = HsMultilineString a x convertLit (HsStringPrim a x) = HsStringPrim a x convertLit (HsInt a x) = HsInt a x convertLit (HsIntPrim a x) = HsIntPrim a x @@ -212,8 +209,7 @@ Equivalently it's True if instance IsPass p => Outputable (HsLit (GhcPass p)) where ppr (HsChar st c) = pprWithSourceText st (pprHsChar c) ppr (HsCharPrim st c) = pprWithSourceText st (pprPrimChar c) - ppr (HsString st s) = pprWithSourceText st (pprHsString s) - ppr (HsMultilineString st s) = + ppr (HsString st s) = case st of NoSourceText -> pprHsString s SourceText src -> vcat $ map text $ split '\n' (unpackFS src) @@ -248,36 +244,6 @@ instance Outputable OverLitVal where ppr (HsFractional f) = ppr f ppr (HsIsString st s) = pprWithSourceText st (pprHsString s) --- | pmPprHsLit pretty prints literals and is used when pretty printing pattern --- match warnings. All are printed the same (i.e., without hashes if they are --- primitive and not wrapped in constructors if they are boxed). This happens --- mainly for too reasons: --- * We do not want to expose their internal representation --- * The warnings become too messy -pmPprHsLit :: forall p. IsPass p => HsLit (GhcPass p) -> SDoc -pmPprHsLit (HsChar _ c) = pprHsChar c -pmPprHsLit (HsCharPrim _ c) = pprHsChar c -pmPprHsLit (HsString st s) = pprWithSourceText st (pprHsString s) -pmPprHsLit (HsMultilineString st s) = pprWithSourceText st (pprHsString s) -pmPprHsLit (HsStringPrim _ s) = pprHsBytes s -pmPprHsLit (HsInt _ i) = integer (il_value i) -pmPprHsLit (HsIntPrim _ i) = integer i -pmPprHsLit (HsWordPrim _ w) = integer w -pmPprHsLit (HsInt8Prim _ i) = integer i -pmPprHsLit (HsInt16Prim _ i) = integer i -pmPprHsLit (HsInt32Prim _ i) = integer i -pmPprHsLit (HsInt64Prim _ i) = integer i -pmPprHsLit (HsWord8Prim _ w) = integer w -pmPprHsLit (HsWord16Prim _ w) = integer w -pmPprHsLit (HsWord32Prim _ w) = integer w -pmPprHsLit (HsWord64Prim _ w) = integer w -pmPprHsLit (HsFloatPrim _ f) = ppr f -pmPprHsLit (HsDoublePrim _ d) = ppr d -pmPprHsLit (XLit x) = case ghcPass @p of - GhcTc -> case x of - (HsInteger _ i _) -> integer i - (HsRat f _) -> ppr f - negateOverLitVal :: OverLitVal -> OverLitVal negateOverLitVal (HsIntegral i) = HsIntegral (negateIntegralLit i) negateOverLitVal (HsFractional f) = HsFractional (negateFractionalLit f) ===================================== compiler/GHC/Hs/Syn/Type.hs ===================================== @@ -75,7 +75,6 @@ hsLitType :: forall p. IsPass p => HsLit (GhcPass p) -> Type hsLitType (HsChar _ _) = charTy hsLitType (HsCharPrim _ _) = charPrimTy hsLitType (HsString _ _) = stringTy -hsLitType (HsMultilineString _ _) = stringTy hsLitType (HsStringPrim _ _) = addrPrimTy hsLitType (HsInt _ _) = intTy hsLitType (HsIntPrim _ _) = intPrimTy ===================================== compiler/GHC/HsToCore/Match/Literal.hs ===================================== @@ -117,7 +117,6 @@ dsLit l = do HsDoublePrim _ fl -> return (Lit (LitDouble (rationalFromFractionalLit fl))) HsChar _ c -> return (mkCharExpr c) HsString _ str -> mkStringExprFS str - HsMultilineString _ str -> mkStringExprFS str HsInt _ i -> return (mkIntExpr platform (il_value i)) XLit x -> case ghcPass @p of GhcTc -> case x of @@ -463,7 +462,6 @@ getSimpleIntegralLit (XLit (HsInteger _ i ty)) = Just (i, ty) getSimpleIntegralLit HsChar{} = Nothing getSimpleIntegralLit HsCharPrim{} = Nothing getSimpleIntegralLit HsString{} = Nothing -getSimpleIntegralLit HsMultilineString{} = Nothing getSimpleIntegralLit HsStringPrim{} = Nothing getSimpleIntegralLit (XLit (HsRat{})) = Nothing getSimpleIntegralLit HsFloatPrim{} = Nothing ===================================== compiler/GHC/HsToCore/Quote.hs ===================================== @@ -3077,7 +3077,6 @@ repLiteral lit HsChar _ _ -> Just charLName HsCharPrim _ _ -> Just charPrimLName HsString _ _ -> Just stringLName - HsMultilineString _ _ -> Just stringLName _ -> Nothing mk_integer :: Integer -> MetaM (HsLit GhcTc) ===================================== compiler/GHC/Parser.y ===================================== @@ -4130,7 +4130,7 @@ literal :: { Located (HsLit GhcPs) } : CHAR { sL1 $1 $ HsChar (getCHARs $1) $ getCHAR $1 } | STRING { sL1 $1 $ HsString (getSTRINGs $1) $ getSTRING $1 } - | STRING_MULTI { sL1 $1 $ HsMultilineString (getSTRINGMULTIs $1) + | STRING_MULTI { sL1 $1 $ HsString (getSTRINGMULTIs $1) $ getSTRINGMULTI $1 } | PRIMINTEGER { sL1 $1 $ HsIntPrim (getPRIMINTEGERs $1) $ getPRIMINTEGER $1 } ===================================== compiler/GHC/Parser/String.hs ===================================== @@ -392,9 +392,9 @@ proposal: https://github.com/ghc-proposals/ghc-proposals/pull/569 Multiline string literals are syntax sugar for normal string literals, with an extra post processing step. This all happens in the Lexer; that -is, HsMultilineString will contain the post-processed string. This matches -the same behavior as HsString, which contains the normalized string -(see Note [Literal source text]). +is, the multi-line HsString will contain the post-processed string. +This matches the behavior of the single-line HsString, which contains +the normalized string too (see Note [Literal source text]). The canonical steps for post processing a multiline string are: 1. Collapse string gaps ===================================== compiler/GHC/Rename/Expr.hs ===================================== @@ -352,18 +352,13 @@ rnExpr (HsOverLabel src v) hs_ty_arg = mkEmptyWildCardBndrs $ wrapGenSpan $ HsTyLit noExtField (HsStrTy NoSourceText v) -rnExpr (HsLit x lit) | Just (src, s) <- stringLike lit +rnExpr (HsLit x lit) | HsString src s <- lit = do { opt_OverloadedStrings <- xoptM LangExt.OverloadedStrings ; if opt_OverloadedStrings then rnExpr (HsOverLit x (mkHsIsString src s)) else do { ; rnLit lit ; return (HsLit x (convertLit lit), emptyFVs) } } - where - stringLike = \case - HsString src s -> Just (src, s) - HsMultilineString src s -> Just (src, s) - _ -> Nothing rnExpr (HsLit x lit) = do { rnLit lit ===================================== compiler/GHC/Tc/Gen/HsType.hs ===================================== @@ -4786,7 +4786,6 @@ promotionErr name err tyLitFromLit :: HsLit GhcRn -> Maybe (HsTyLit GhcRn) tyLitFromLit (HsString x str) = Just (HsStrTy x str) -tyLitFromLit (HsMultilineString x str) = Just (HsStrTy x str) tyLitFromLit (HsChar x char) = Just (HsCharTy x char) tyLitFromLit _ = Nothing ===================================== compiler/Language/Haskell/Syntax/Extension.hs ===================================== @@ -604,7 +604,6 @@ type family XXParStmtBlock x x' type family XHsChar x type family XHsCharPrim x type family XHsString x -type family XHsMultilineString x type family XHsStringPrim x type family XHsInt x type family XHsIntPrim x ===================================== compiler/Language/Haskell/Syntax/Lit.hs ===================================== @@ -47,8 +47,6 @@ data HsLit x -- ^ Unboxed character | HsString (XHsString x) {- SourceText -} FastString -- ^ String - | HsMultilineString (XHsMultilineString x) {- SourceText -} FastString - -- ^ String | HsStringPrim (XHsStringPrim x) {- SourceText -} !ByteString -- ^ Packed bytes | HsInt (XHsInt x) IntegralLit ===================================== testsuite/tests/parser/should_fail/T26860ppr.hs ===================================== @@ -0,0 +1,11 @@ +{-# LANGUAGE NoOverloadedStrings #-} + +module T26860ppr where + +-- Test that the error message containing the string literal is well-formatted. +-- See also: parser/should_fail/MultilineStringsError +x :: Int +x = "first line \ + \asdf\n\ + \second line" + ===================================== testsuite/tests/parser/should_fail/T26860ppr.stderr ===================================== @@ -0,0 +1,13 @@ +T26860ppr.hs:8:5: error: [GHC-83865] + • Couldn't match type ‘[Char]’ with ‘Int’ + Expected: Int + Actual: String + • In the expression: + "first line \ + \asdf\n\ + \second line" + In an equation for ‘x’: + x = "first line \ + \asdf\n\ + \second line" + ===================================== testsuite/tests/parser/should_fail/all.T ===================================== @@ -244,3 +244,4 @@ test('T25530', normal, compile_fail, ['']) test('T26418', normal, compile_fail, ['']) test('T12488c', normal, compile_fail, ['']) test('T12488d', normal, compile_fail, ['']) +test('T26860ppr', normal, compile_fail, ['']) ===================================== utils/check-exact/ExactPrint.hs ===================================== @@ -4794,7 +4794,6 @@ hsLit2String lit = HsChar src v -> toSourceTextWithSuffix src v "" HsCharPrim src p -> toSourceTextWithSuffix src p "" HsString src v -> toSourceTextWithSuffix src v "" - HsMultilineString src v -> toSourceTextWithSuffix src v "" HsStringPrim src v -> toSourceTextWithSuffix src v "" HsInt _ (IL src _ v) -> toSourceTextWithSuffix src v "" HsIntPrim src v -> toSourceTextWithSuffix src v "" View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2aeefaee539e7cba900d1722d559c28… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/2aeefaee539e7cba900d1722d559c28… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26834] 12 commits: Invert Identity/Const Traversable instances
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed to branch wip/T26834 at Glasgow Haskell Compiler / GHC Commits: d99c7b3a by Teo Camarasu at 2026-01-31T11:37:17+00:00 Invert Identity/Const Traversable instances - - - - - 90f61ccd by Teo Camarasu at 2026-01-31T11:37:18+00:00 Refine imports of GHC.Internal.Control.Monad - - - - - 802d4adf by Teo Camarasu at 2026-01-31T11:37:19+00:00 Float up Generics - - - - - 2a542bf0 by Teo Camarasu at 2026-01-31T11:37:19+00:00 Refine imports of GHC.Internal.Stack - - - - - f0658571 by Teo Camarasu at 2026-01-31T11:38:09+00:00 Tidy up GHC.Internal.Stack - - - - - 95febc30 by Teo Camarasu at 2026-01-31T11:38:09+00:00 Switch MonadFix with Arrow - - - - - 625c1b1a by Teo Camarasu at 2026-01-31T11:38:09+00:00 Refine import of ForeignPtr - - - - - e4ee1d14 by Teo Camarasu at 2026-01-31T11:38:09+00:00 wip - - - - - 955465e9 by Teo Camarasu at 2026-01-31T11:38:10+00:00 Explicit imports - - - - - 87ffd839 by Teo Camarasu at 2026-01-31T11:38:10+00:00 Delete re-exports - - - - - e8428e16 by Teo Camarasu at 2026-01-31T11:38:10+00:00 Delete Imp modules - - - - - e14fec2d by Teo Camarasu at 2026-01-31T11:38:10+00:00 Move MonadFix instance of Q into MonadFix - - - - - 49 changed files: - libraries/base/src/Control/Monad/ST.hs - libraries/base/src/Control/Monad/ST/Lazy.hs - libraries/base/src/Control/Monad/ST/Lazy/Safe.hs - libraries/base/src/Control/Monad/ST/Lazy/Unsafe.hs - libraries/base/src/Control/Monad/ST/Safe.hs - libraries/base/src/Control/Monad/ST/Strict.hs - libraries/base/src/Control/Monad/ST/Unsafe.hs - libraries/base/src/Data/STRef/Lazy.hs - libraries/base/src/Data/Traversable.hs - libraries/base/src/Foreign/ForeignPtr.hs - libraries/base/src/Foreign/ForeignPtr/Safe.hs - libraries/base/src/Foreign/ForeignPtr/Unsafe.hs - libraries/base/src/GHC/Stack.hs - libraries/base/src/Numeric.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/Control/Arrow.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Fix.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/ST.hs - − libraries/ghc-internal/src/GHC/Internal/Control/Monad/ST/Imp.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/ST/Lazy.hs - − libraries/ghc-internal/src/GHC/Internal/Control/Monad/ST/Lazy/Imp.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Zip.hs - libraries/ghc-internal/src/GHC/Internal/Data/Foldable.hs - libraries/ghc-internal/src/GHC/Internal/Data/Functor/Const.hs - libraries/ghc-internal/src/GHC/Internal/Data/Functor/Identity.hs - libraries/ghc-internal/src/GHC/Internal/Data/Monoid.hs - libraries/ghc-internal/src/GHC/Internal/Data/Semigroup/Internal.hs - libraries/ghc-internal/src/GHC/Internal/Data/String.hs - libraries/ghc-internal/src/GHC/Internal/Data/Traversable.hs - libraries/ghc-internal/src/GHC/Internal/Debug/Trace.hs - libraries/ghc-internal/src/GHC/Internal/Exts.hs - libraries/ghc-internal/src/GHC/Internal/Foreign/ForeignPtr.hs - − libraries/ghc-internal/src/GHC/Internal/Foreign/ForeignPtr/Imp.hs - − libraries/ghc-internal/src/GHC/Internal/Foreign/ForeignPtr/Unsafe.hs - libraries/ghc-internal/src/GHC/Internal/Functor/ZipList.hs - libraries/ghc-internal/src/GHC/Internal/Generics.hs - libraries/ghc-internal/src/GHC/Internal/Heap/Closures.hs - libraries/ghc-internal/src/GHC/Internal/IO/Buffer.hs - libraries/ghc-internal/src/GHC/Internal/IO/Exception.hs - libraries/ghc-internal/src/GHC/Internal/IORef.hs - libraries/ghc-internal/src/GHC/Internal/Numeric.hs - libraries/ghc-internal/src/GHC/Internal/ResponseFile.hs - libraries/ghc-internal/src/GHC/Internal/STM.hs - libraries/ghc-internal/src/GHC/Internal/Stack.hs - libraries/ghc-internal/src/GHC/Internal/Stats.hsc - libraries/ghc-internal/src/GHC/Internal/System/Environment.hs - libraries/ghc-internal/src/GHC/Internal/System/Exit.hs - libraries/ghc-internal/src/GHC/Internal/System/IO/OS.hs - libraries/ghc-internal/src/GHC/Internal/TH/Monad.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/44b212a7813ef6781b3d461585b6de… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/44b212a7813ef6781b3d461585b6de… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26859] Deleted 1 commit: try no data instance
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed to branch wip/T26859 at Glasgow Haskell Compiler / GHC WARNING: The push did not contain any new commits, but force pushed to delete the commits and changes below. Deleted commits: a1a1fe26 by Teo Camarasu at 2026-01-31T02:11:59+00:00 try no data instance - - - - - 1 changed file: - libraries/base/src/Data/Ord.hs Changes: ===================================== libraries/base/src/Data/Ord.hs ===================================== @@ -41,7 +41,7 @@ import GHC.Internal.Generics import GHC.Internal.Data.Foldable import GHC.Internal.Data.Traversable import GHC.Internal.Control.Monad.Zip -import GHC.Internal.Data.Data +--import GHC.Internal.Data.Data -- $setup -- >>> import Prelude @@ -173,7 +173,7 @@ instance Monad Down where Down a >>= k = k a -- | @since base-4.12.0.0 -deriving instance Data a => Data (Down a) +--deriving instance Data a => Data (Down a) -- | -- > comparing p x y = compare (p x) (p y) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a1a1fe26970c4300dd6b0c4ee71e828… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a1a1fe26970c4300dd6b0c4ee71e828… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/sol/fix-docs
by Simon Hengel (＠sol) 31 Jan '26

31 Jan '26

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

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[Git][ghc/ghc][wip/T26859] try no data instance
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed to branch wip/T26859 at Glasgow Haskell Compiler / GHC Commits: a1a1fe26 by Teo Camarasu at 2026-01-31T02:11:59+00:00 try no data instance - - - - - 1 changed file: - libraries/base/src/Data/Ord.hs Changes: ===================================== libraries/base/src/Data/Ord.hs ===================================== @@ -41,7 +41,7 @@ import GHC.Internal.Generics import GHC.Internal.Data.Foldable import GHC.Internal.Data.Traversable import GHC.Internal.Control.Monad.Zip -import GHC.Internal.Data.Data +--import GHC.Internal.Data.Data -- $setup -- >>> import Prelude @@ -173,7 +173,7 @@ instance Monad Down where Down a >>= k = k a -- | @since base-4.12.0.0 -deriving instance Data a => Data (Down a) +--deriving instance Data a => Data (Down a) -- | -- > comparing p x y = compare (p x) (p y) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a1a1fe26970c4300dd6b0c4ee71e828… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a1a1fe26970c4300dd6b0c4ee71e828… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26859] ghc-internal: Move GHC.Internal.Data.Ord to base:Data.Ord
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed to branch wip/T26859 at Glasgow Haskell Compiler / GHC Commits: 54910a17 by Teo Camarasu at 2026-01-30T23:45:27+00:00 ghc-internal: Move GHC.Internal.Data.Ord to base:Data.Ord This module is just a re-export of Ord and the definition of some utilities. Nothing from this module is used in ghc-internal and none of it is known key or wiredin. Yet its presence linearises the module graph. Let's move it base. Resolves #26859 - - - - - 26 changed files: - libraries/base/src/Data/Foldable1.hs - libraries/base/src/Data/Functor/Classes.hs - libraries/base/src/Data/List.hs - libraries/base/src/Data/List/NonEmpty.hs - libraries/base/src/Data/List/NubOrdSet.hs - libraries/base/src/Data/Ord.hs - libraries/base/src/GHC/Exts.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/ClosureTypes.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Fix.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Zip.hs - libraries/ghc-internal/src/GHC/Internal/Data/Data.hs - libraries/ghc-internal/src/GHC/Internal/Data/Foldable.hs - − libraries/ghc-internal/src/GHC/Internal/Data/Ord.hs - libraries/ghc-internal/src/GHC/Internal/Data/Traversable.hs - libraries/ghc-internal/src/GHC/Internal/Data/Type/Ord.hs - libraries/ghc-internal/src/GHC/Internal/Data/Version.hs - libraries/ghc-internal/src/GHC/Internal/Exts.hs - libraries/ghc-internal/src/GHC/Internal/Generics.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 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/interface-stability/ghc-experimental-exports.stdout - testsuite/tests/interface-stability/ghc-experimental-exports.stdout-mingw32 - testsuite/tests/typecheck/should_fail/TcCoercibleFail.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/54910a1757ca494c842cdc0612896d2… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/54910a1757ca494c842cdc0612896d2… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26834] 17 commits: PPC NCG: Use libcall for 64-bit cmpxchg on 32-bit PowerPC
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed to branch wip/T26834 at Glasgow Haskell Compiler / GHC Commits: ce2d62fb by Jessica Clarke at 2026-01-29T19:48:51-05:00 PPC NCG: Use libcall for 64-bit cmpxchg on 32-bit PowerPC There is no native instruction for this, and even if there were a register pair version we could use, the implementation here is assuming the values fit in a single register, and we end up only using / defining the low halves of the registers. Fixes: b4d39adbb5 ("PrimOps: Add CAS op for all int sizes") Fixes: #23969 - - - - - 43d97761 by Michael Karcher at 2026-01-29T19:49:43-05:00 NCG for PPC: add pattern for CmmRegOff to iselExpr64 Closes #26828 - - - - - aeeb4a20 by Matthew Pickering at 2026-01-30T11:42:47-05:00 determinism: Use deterministic map for Strings in TyLitMap When generating typeable evidence the types we need evidence for all cached in a TypeMap, the order terms are retrieved from a type map determines the order the bindings appear in the program. A TypeMap is quite diligent to use deterministic maps, apart from in the TyLitMap, which uses a UniqFM for storing strings, whose ordering depends on the Unique of the FastString. This can cause non-deterministic .hi and .o files. An unexpected side-effect is the error message but RecordDotSyntaxFail8 changing. I looked into this with Sam and this change caused the constraints to be solved in a different order which results in a slightly different error message. I have accepted the new test, since the output before was non-deterministic and the new output is consistent with the other messages in that file. Fixes #26846 - - - - - 9e4d70c2 by Andrew Lelechenko at 2026-01-30T11:43:29-05:00 Upgrade text submodule to 2.1.4 - - - - - 5085d918 by Teo Camarasu at 2026-01-30T18:11:09+00:00 ghc-internal: refine imports of GHC.Internal.Data.Bool - - - - - 33505d95 by Teo Camarasu at 2026-01-30T18:11:09+00:00 Delete unecessary GHC.Internal.Data.Ix - - - - - 3f053e9d by Teo Camarasu at 2026-01-30T18:11:09+00:00 ghc-internal: refine List imports - - - - - 008d7ff2 by Teo Camarasu at 2026-01-30T18:11:10+00:00 Move MonadFix Identity into Monad.Fix - - - - - 6c06525c by Teo Camarasu at 2026-01-30T18:12:27+00:00 ghc-internal: Move GHC.Internal.Data.Ord to base:Data.Ord This module is just a re-export of Ord and the definition of some utilities. Nothing from this module is used in ghc-internal and none of it is known key or wiredin. Yet its presence linearises the module graph. Let's move it base. Resolves #26859 - - - - - d2f11069 by Teo Camarasu at 2026-01-30T18:31:51+00:00 Invert Identity/Const Traversable instances - - - - - be7ef54e by Teo Camarasu at 2026-01-30T18:34:17+00:00 Refine imports of GHC.Internal.Control.Monad - - - - - 48f8c975 by Teo Camarasu at 2026-01-30T20:22:05+00:00 Float up Generics - - - - - 45692c90 by Teo Camarasu at 2026-01-30T20:22:05+00:00 Refine imports of GHC.Internal.Stack - - - - - bb3ff50f by Teo Camarasu at 2026-01-30T20:22:05+00:00 Tidy up GHC.Internal.Stack - - - - - 91d1295c by Teo Camarasu at 2026-01-30T20:24:16+00:00 Switch MonadFix with Arrow - - - - - b7c5ad3d by Teo Camarasu at 2026-01-30T20:24:17+00:00 Refine import of ForeignPtr - - - - - 44b212a7 by Teo Camarasu at 2026-01-30T20:40:39+00:00 wip - - - - - 66 changed files: - compiler/GHC/CmmToAsm/PPC/CodeGen.hs - compiler/GHC/Core/Map/Type.hs - libraries/base/src/Data/Foldable1.hs - libraries/base/src/Data/Functor/Classes.hs - libraries/base/src/Data/Ix.hs - libraries/base/src/Data/List.hs - libraries/base/src/Data/List/NonEmpty.hs - libraries/base/src/Data/List/NubOrdSet.hs - libraries/base/src/Data/Ord.hs - libraries/base/src/Data/Traversable.hs - libraries/base/src/GHC/Exts.hs - libraries/base/src/GHC/Stack.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/ClosureTypes.hs - libraries/ghc-internal/src/GHC/Internal/Control/Arrow.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Fix.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad/Zip.hs - libraries/ghc-internal/src/GHC/Internal/Data/Data.hs - libraries/ghc-internal/src/GHC/Internal/Data/Foldable.hs - libraries/ghc-internal/src/GHC/Internal/Data/Function.hs - libraries/ghc-internal/src/GHC/Internal/Data/Functor/Const.hs - libraries/ghc-internal/src/GHC/Internal/Data/Functor/Identity.hs - − libraries/ghc-internal/src/GHC/Internal/Data/Ix.hs - libraries/ghc-internal/src/GHC/Internal/Data/List/NonEmpty.hs - libraries/ghc-internal/src/GHC/Internal/Data/Monoid.hs - − libraries/ghc-internal/src/GHC/Internal/Data/Ord.hs - libraries/ghc-internal/src/GHC/Internal/Data/Semigroup/Internal.hs - libraries/ghc-internal/src/GHC/Internal/Data/String.hs - libraries/ghc-internal/src/GHC/Internal/Data/Traversable.hs - libraries/ghc-internal/src/GHC/Internal/Data/Type/Bool.hs - libraries/ghc-internal/src/GHC/Internal/Data/Type/Ord.hs - libraries/ghc-internal/src/GHC/Internal/Data/Version.hs - libraries/ghc-internal/src/GHC/Internal/Debug/Trace.hs - libraries/ghc-internal/src/GHC/Internal/Event/Windows.hsc - libraries/ghc-internal/src/GHC/Internal/ExecutionStack/Internal.hsc - libraries/ghc-internal/src/GHC/Internal/Exts.hs - libraries/ghc-internal/src/GHC/Internal/Functor/ZipList.hs - libraries/ghc-internal/src/GHC/Internal/Generics.hs - libraries/ghc-internal/src/GHC/Internal/Heap/Closures.hs - libraries/ghc-internal/src/GHC/Internal/IO/Buffer.hs - libraries/ghc-internal/src/GHC/Internal/IO/Encoding/CodePage.hs - libraries/ghc-internal/src/GHC/Internal/IO/Exception.hs - libraries/ghc-internal/src/GHC/Internal/IORef.hs - + libraries/ghc-internal/src/GHC/Internal/Prim.hs - + libraries/ghc-internal/src/GHC/Internal/PrimopWrappers.hs - libraries/ghc-internal/src/GHC/Internal/ResponseFile.hs - libraries/ghc-internal/src/GHC/Internal/STM.hs - libraries/ghc-internal/src/GHC/Internal/Stack.hs - libraries/ghc-internal/src/GHC/Internal/Stack/Decode.hs - libraries/ghc-internal/src/GHC/Internal/Stats.hsc - libraries/ghc-internal/src/GHC/Internal/System/Environment.hs - libraries/ghc-internal/src/GHC/Internal/System/Environment/Blank.hsc - libraries/ghc-internal/src/GHC/Internal/System/Environment/ExecutablePath.hsc - libraries/ghc-internal/src/GHC/Internal/System/IO/OS.hs - libraries/ghc-internal/src/GHC/Internal/System/Posix/Internals.hs - libraries/ghc-internal/src/GHC/Internal/TypeError.hs - libraries/text - + testsuite/tests/ghc-api/TypeMapStringLiteral.hs - testsuite/tests/ghc-api/all.T - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/interface-stability/ghc-experimental-exports.stdout - testsuite/tests/interface-stability/ghc-experimental-exports.stdout-mingw32 - testsuite/tests/parser/should_fail/RecordDotSyntaxFail8.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/1dd155964e9baf4f58a5196b541e7e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/1dd155964e9baf4f58a5196b541e7e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/int-index/no-multiline] Refactor: merge HsMultilineString into HsString (#26860)
by Vladislav Zavialov (＠int-index) 31 Jan '26

31 Jan '26

Vladislav Zavialov pushed to branch wip/int-index/no-multiline at Glasgow Haskell Compiler / GHC Commits: 1d461f72 by Vladislav Zavialov at 2026-01-30T23:09:44+03:00 Refactor: merge HsMultilineString into HsString (#26860) Before this patch, HsLit defined two separate constructors to represent single-line and multi-line strings: data HsLit x ... | HsString (XHsString x) FastString | HsMultilineString (XHsMultilineString x) FastString I found this to be an unnecessary complication and an obstacle to unifying HsLit with HsTyLit. Now we use HsString for both kinds of literals. In addition (and unrelatedly to the main payload of this patch), drop the unused pmPprHsLit helper. - - - - - 11 changed files: - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - utils/check-exact/ExactPrint.hs Changes: ===================================== compiler/GHC/Hs/Lit.hs ===================================== @@ -45,7 +45,6 @@ import Language.Haskell.Syntax.Lit type instance XHsChar (GhcPass _) = SourceText type instance XHsCharPrim (GhcPass _) = SourceText type instance XHsString (GhcPass _) = SourceText -type instance XHsMultilineString (GhcPass _) = SourceText type instance XHsStringPrim (GhcPass _) = SourceText type instance XHsInt (GhcPass _) = NoExtField type instance XHsIntPrim (GhcPass _) = SourceText @@ -147,7 +146,6 @@ hsLitNeedsParens p = go go (HsChar {}) = False go (HsCharPrim {}) = False go (HsString {}) = False - go (HsMultilineString {}) = False go (HsStringPrim {}) = False go (HsInt _ x) = p > topPrec && il_neg x go (HsFloatPrim {}) = False @@ -177,7 +175,6 @@ convertLit :: XXLit (GhcPass p)~DataConCantHappen => HsLit (GhcPass p) -> HsLit convertLit (HsChar a x) = HsChar a x convertLit (HsCharPrim a x) = HsCharPrim a x convertLit (HsString a x) = HsString a x -convertLit (HsMultilineString a x) = HsMultilineString a x convertLit (HsStringPrim a x) = HsStringPrim a x convertLit (HsInt a x) = HsInt a x convertLit (HsIntPrim a x) = HsIntPrim a x @@ -212,8 +209,7 @@ Equivalently it's True if instance IsPass p => Outputable (HsLit (GhcPass p)) where ppr (HsChar st c) = pprWithSourceText st (pprHsChar c) ppr (HsCharPrim st c) = pprWithSourceText st (pprPrimChar c) - ppr (HsString st s) = pprWithSourceText st (pprHsString s) - ppr (HsMultilineString st s) = + ppr (HsString st s) = case st of NoSourceText -> pprHsString s SourceText src -> vcat $ map text $ split '\n' (unpackFS src) @@ -248,36 +244,6 @@ instance Outputable OverLitVal where ppr (HsFractional f) = ppr f ppr (HsIsString st s) = pprWithSourceText st (pprHsString s) --- | pmPprHsLit pretty prints literals and is used when pretty printing pattern --- match warnings. All are printed the same (i.e., without hashes if they are --- primitive and not wrapped in constructors if they are boxed). This happens --- mainly for too reasons: --- * We do not want to expose their internal representation --- * The warnings become too messy -pmPprHsLit :: forall p. IsPass p => HsLit (GhcPass p) -> SDoc -pmPprHsLit (HsChar _ c) = pprHsChar c -pmPprHsLit (HsCharPrim _ c) = pprHsChar c -pmPprHsLit (HsString st s) = pprWithSourceText st (pprHsString s) -pmPprHsLit (HsMultilineString st s) = pprWithSourceText st (pprHsString s) -pmPprHsLit (HsStringPrim _ s) = pprHsBytes s -pmPprHsLit (HsInt _ i) = integer (il_value i) -pmPprHsLit (HsIntPrim _ i) = integer i -pmPprHsLit (HsWordPrim _ w) = integer w -pmPprHsLit (HsInt8Prim _ i) = integer i -pmPprHsLit (HsInt16Prim _ i) = integer i -pmPprHsLit (HsInt32Prim _ i) = integer i -pmPprHsLit (HsInt64Prim _ i) = integer i -pmPprHsLit (HsWord8Prim _ w) = integer w -pmPprHsLit (HsWord16Prim _ w) = integer w -pmPprHsLit (HsWord32Prim _ w) = integer w -pmPprHsLit (HsWord64Prim _ w) = integer w -pmPprHsLit (HsFloatPrim _ f) = ppr f -pmPprHsLit (HsDoublePrim _ d) = ppr d -pmPprHsLit (XLit x) = case ghcPass @p of - GhcTc -> case x of - (HsInteger _ i _) -> integer i - (HsRat f _) -> ppr f - negateOverLitVal :: OverLitVal -> OverLitVal negateOverLitVal (HsIntegral i) = HsIntegral (negateIntegralLit i) negateOverLitVal (HsFractional f) = HsFractional (negateFractionalLit f) ===================================== compiler/GHC/Hs/Syn/Type.hs ===================================== @@ -75,7 +75,6 @@ hsLitType :: forall p. IsPass p => HsLit (GhcPass p) -> Type hsLitType (HsChar _ _) = charTy hsLitType (HsCharPrim _ _) = charPrimTy hsLitType (HsString _ _) = stringTy -hsLitType (HsMultilineString _ _) = stringTy hsLitType (HsStringPrim _ _) = addrPrimTy hsLitType (HsInt _ _) = intTy hsLitType (HsIntPrim _ _) = intPrimTy ===================================== compiler/GHC/HsToCore/Match/Literal.hs ===================================== @@ -117,7 +117,6 @@ dsLit l = do HsDoublePrim _ fl -> return (Lit (LitDouble (rationalFromFractionalLit fl))) HsChar _ c -> return (mkCharExpr c) HsString _ str -> mkStringExprFS str - HsMultilineString _ str -> mkStringExprFS str HsInt _ i -> return (mkIntExpr platform (il_value i)) XLit x -> case ghcPass @p of GhcTc -> case x of @@ -463,7 +462,6 @@ getSimpleIntegralLit (XLit (HsInteger _ i ty)) = Just (i, ty) getSimpleIntegralLit HsChar{} = Nothing getSimpleIntegralLit HsCharPrim{} = Nothing getSimpleIntegralLit HsString{} = Nothing -getSimpleIntegralLit HsMultilineString{} = Nothing getSimpleIntegralLit HsStringPrim{} = Nothing getSimpleIntegralLit (XLit (HsRat{})) = Nothing getSimpleIntegralLit HsFloatPrim{} = Nothing ===================================== compiler/GHC/HsToCore/Quote.hs ===================================== @@ -3077,7 +3077,6 @@ repLiteral lit HsChar _ _ -> Just charLName HsCharPrim _ _ -> Just charPrimLName HsString _ _ -> Just stringLName - HsMultilineString _ _ -> Just stringLName _ -> Nothing mk_integer :: Integer -> MetaM (HsLit GhcTc) ===================================== compiler/GHC/Parser.y ===================================== @@ -4130,7 +4130,7 @@ literal :: { Located (HsLit GhcPs) } : CHAR { sL1 $1 $ HsChar (getCHARs $1) $ getCHAR $1 } | STRING { sL1 $1 $ HsString (getSTRINGs $1) $ getSTRING $1 } - | STRING_MULTI { sL1 $1 $ HsMultilineString (getSTRINGMULTIs $1) + | STRING_MULTI { sL1 $1 $ HsString (getSTRINGMULTIs $1) $ getSTRINGMULTI $1 } | PRIMINTEGER { sL1 $1 $ HsIntPrim (getPRIMINTEGERs $1) $ getPRIMINTEGER $1 } ===================================== compiler/GHC/Parser/String.hs ===================================== @@ -392,9 +392,9 @@ proposal: https://github.com/ghc-proposals/ghc-proposals/pull/569 Multiline string literals are syntax sugar for normal string literals, with an extra post processing step. This all happens in the Lexer; that -is, HsMultilineString will contain the post-processed string. This matches -the same behavior as HsString, which contains the normalized string -(see Note [Literal source text]). +is, the multi-line HsString will contain the post-processed string. +This matches the behavior of the single-line HsString, which contains +the normalized string too (see Note [Literal source text]). The canonical steps for post processing a multiline string are: 1. Collapse string gaps ===================================== compiler/GHC/Rename/Expr.hs ===================================== @@ -352,18 +352,13 @@ rnExpr (HsOverLabel src v) hs_ty_arg = mkEmptyWildCardBndrs $ wrapGenSpan $ HsTyLit noExtField (HsStrTy NoSourceText v) -rnExpr (HsLit x lit) | Just (src, s) <- stringLike lit +rnExpr (HsLit x lit) | HsString src s <- lit = do { opt_OverloadedStrings <- xoptM LangExt.OverloadedStrings ; if opt_OverloadedStrings then rnExpr (HsOverLit x (mkHsIsString src s)) else do { ; rnLit lit ; return (HsLit x (convertLit lit), emptyFVs) } } - where - stringLike = \case - HsString src s -> Just (src, s) - HsMultilineString src s -> Just (src, s) - _ -> Nothing rnExpr (HsLit x lit) = do { rnLit lit ===================================== compiler/GHC/Tc/Gen/HsType.hs ===================================== @@ -4786,7 +4786,6 @@ promotionErr name err tyLitFromLit :: HsLit GhcRn -> Maybe (HsTyLit GhcRn) tyLitFromLit (HsString x str) = Just (HsStrTy x str) -tyLitFromLit (HsMultilineString x str) = Just (HsStrTy x str) tyLitFromLit (HsChar x char) = Just (HsCharTy x char) tyLitFromLit _ = Nothing ===================================== compiler/Language/Haskell/Syntax/Extension.hs ===================================== @@ -604,7 +604,6 @@ type family XXParStmtBlock x x' type family XHsChar x type family XHsCharPrim x type family XHsString x -type family XHsMultilineString x type family XHsStringPrim x type family XHsInt x type family XHsIntPrim x ===================================== compiler/Language/Haskell/Syntax/Lit.hs ===================================== @@ -47,8 +47,6 @@ data HsLit x -- ^ Unboxed character | HsString (XHsString x) {- SourceText -} FastString -- ^ String - | HsMultilineString (XHsMultilineString x) {- SourceText -} FastString - -- ^ String | HsStringPrim (XHsStringPrim x) {- SourceText -} !ByteString -- ^ Packed bytes | HsInt (XHsInt x) IntegralLit ===================================== utils/check-exact/ExactPrint.hs ===================================== @@ -4794,7 +4794,6 @@ hsLit2String lit = HsChar src v -> toSourceTextWithSuffix src v "" HsCharPrim src p -> toSourceTextWithSuffix src p "" HsString src v -> toSourceTextWithSuffix src v "" - HsMultilineString src v -> toSourceTextWithSuffix src v "" HsStringPrim src v -> toSourceTextWithSuffix src v "" HsInt _ (IL src _ v) -> toSourceTextWithSuffix src v "" HsIntPrim src v -> toSourceTextWithSuffix src v "" View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1d461f728d4e65726725f02e4dab854… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1d461f728d4e65726725f02e4dab854… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/T26859
by Teo Camarasu (＠teo) 31 Jan '26

31 Jan '26

Teo Camarasu pushed new branch wip/T26859 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/T26859 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T20264] 2 commits: Expand tyvars in Specialise
by Simon Peyton Jones (＠simonpj) 31 Jan '26

31 Jan '26

Simon Peyton Jones pushed to branch wip/T20264 at Glasgow Haskell Compiler / GHC Commits: 9be7029d by Simon Peyton Jones at 2026-01-30T13:03:27+00:00 Expand tyvars in Specialise Pretty important! - - - - - 1347e1f2 by Simon Peyton Jones at 2026-01-30T13:04:00+00:00 Comments only - - - - - 3 changed files: - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Utils.hs Changes: ===================================== compiler/GHC/Core/Opt/Simplify/Env.hs ===================================== @@ -823,8 +823,8 @@ andFF FltOkSpec _ = FltOkSpec andFF FltLifted flt = flt -doFloatFromRhs :: SimplEnv -> TopLevelFlag -> RecFlag -> Bool - -> [OutTyVar] -> SimplFloats -> OutExpr -> Bool +doFloatFromRhs :: SimplEnv -> TopLevelFlag -> RecFlag -> Bool -> [OutTyVar] + -> SimplFloats -> OutExpr -> Bool -- If you change this function look also at FloatIn.noFloatIntoRhs doFloatFromRhs env lvl rec strict_bind tvs (SimplFloats { sfLetFloats = LetFloats fs ff }) rhs = not (isNilOL fs) ===================================== compiler/GHC/Core/Opt/Specialise.hs ===================================== @@ -2626,17 +2626,23 @@ specHeader subst (bndr:bndrs) (SpecType ty : args) -- See (MP2) in Note [Specialising polymorphic dictionaries] let in_scope = Core.substInScopeSet subst not_in_scope tv = not (tv `elemInScopeSet` in_scope) + + expanded_ty = expandSomeTyVarUnfoldings not_in_scope ty + -- expanded_ty: consider f @(Maybe (a{=Int}) + -- We don't want to abstract over `a`! So, expand + -- unfoldings of any not-in-scope tyavars + free_tvs = scopedSort $ fvVarList $ filterFV not_in_scope $ - tyCoFVsOfType ty + tyCoFVsOfType expanded_ty subst1 = subst `Core.extendSubstInScopeList` free_tvs - ; let subst2 = Core.extendTvSubst subst1 bndr ty + ; let subst2 = Core.extendTvSubst subst1 bndr expanded_ty ; (useful, subst3, rule_bs, rule_args, spec_bs, dx, spec_args) <- specHeader subst2 bndrs args ; pure ( useful, subst3 - , free_tvs ++ rule_bs, Type ty : rule_args - , free_tvs ++ spec_bs, dx, Type ty : spec_args ) } + , free_tvs ++ rule_bs, Type expanded_ty : rule_args + , free_tvs ++ spec_bs, dx, Type expanded_ty : spec_args ) } -- Next we have a type that we don't want to specialise. We need to perform -- a substitution on it (in case the type refers to 'a'). Additionally, we need ===================================== compiler/GHC/Core/Utils.hs ===================================== @@ -1618,6 +1618,101 @@ in this (which it previously was): in g False -> \x. x in \w. v True + +Note [isCheapApp: bottoming functions] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +I'm not sure why we have a special case for bottoming +functions in isCheapApp. Maybe we don't need it. + +Note [exprIsExpandable] +~~~~~~~~~~~~~~~~~~~~~~~ +An expression is "expandable" if we are willing to duplicate it, if doing +so might make a RULE or case-of-constructor fire. Consider + let x = (a,b) + y = build g + in ....(case x of (p,q) -> rhs)....(foldr k z y).... + +We don't inline 'x' or 'y' (see Note [Lone variables] in GHC.Core.Unfold), +but we do want + + * the case-expression to simplify + (via exprIsConApp_maybe, exprIsLiteral_maybe) + + * the foldr/build RULE to fire + (by expanding the unfolding during rule matching) + +So we classify the unfolding of a let-binding as "expandable" (via the +uf_expandable field) if we want to do this kind of on-the-fly +expansion. Specifically: + +* True of constructor applications (K a b) + +* True of applications of a "CONLIKE" Id; see Note [CONLIKE pragma] in GHC.Types.Basic. + (NB: exprIsCheap might not be true of this) + +* False of case-expressions. If we have + let x = case ... in ...(case x of ...)... + we won't simplify. We have to inline x. See #14688. + +* False of let-expressions (same reason); and in any case we + float lets out of an RHS if doing so will reveal an expandable + application (see SimplEnv.doFloatFromRhs). + +* Take care: exprIsExpandable should /not/ be true of primops. I + found this in test T5623a: + let q = /\a. Ptr a (a +# b) + in case q @ Float of Ptr v -> ...q... + + q's inlining should not be expandable, else exprIsConApp_maybe will + say that (q @ Float) expands to (Ptr a (a +# b)), and that will + duplicate the (a +# b) primop, which we should not do lightly. + (It's quite hard to trigger this bug, but T13155 does so for GHC 8.0.) + +NB: exprIsWorkFree implies exprIsExpandable. + +Note [isExpandableApp: bottoming functions] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +It's important that isExpandableApp does not respond True to bottoming +functions. Recall undefined :: HasCallStack => a +Suppose isExpandableApp responded True to (undefined d), and we had: + + x = undefined <dict-expr> + +Then Simplify.prepareRhs would ANF the RHS: + + d = <dict-expr> + x = undefined d + +This is already bad: we gain nothing from having x bound to (undefined +var), unlike the case for data constructors. Worse, we get the +simplifier loop described in OccurAnal Note [Cascading inlines]. +Suppose x occurs just once; OccurAnal.occAnalNonRecRhs decides x will +certainly_inline; so we end up inlining d right back into x; but in +the end x doesn't inline because it is bottom (preInlineUnconditionally); +so the process repeats.. We could elaborate the certainly_inline logic +some more, but it's better just to treat bottoming bindings as +non-expandable, because ANFing them is a bad idea in the first place. + +Note [Record selection] +~~~~~~~~~~~~~~~~~~~~~~~~~~ +I'm experimenting with making record selection +look cheap, so we will substitute it inside a +lambda. Particularly for dictionary field selection. + +BUT: Take care with (sel d x)! The (sel d) might be cheap, but +there's no guarantee that (sel d x) will be too. Hence (n_val_args == 1) + +Note [Expandable overloadings] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Suppose the user wrote this + {-# RULE forall x. foo (negate x) = h x #-} + f x = ....(foo (negate x)).... +They'd expect the rule to fire. But since negate is overloaded, we might +get this: + f = \d -> let n = negate d in \x -> ...foo (n x)... +So we treat the application of a function (negate in this case) to a +*dictionary* as expandable. In effect, every function is CONLIKE when +it's applied only to dictionaries. -} ------------------------------------- @@ -1690,6 +1785,10 @@ isWorkFreeApp fn n_val_args _ -> False isCheapApp :: CheapAppFun +-- Like isWorkFreeApp, but add: +-- - bottoming applications +-- - cheap (rather than just work-free) primops +-- - record selectors applied to just the record isCheapApp fn n_val_args | isWorkFreeApp fn n_val_args = True | isDeadEndId fn = True -- See Note [isCheapApp: bottoming functions] @@ -1706,6 +1805,10 @@ isCheapApp fn n_val_args -- to bother to check the number of args isExpandableApp :: CheapAppFun +-- Like isWorkFreeApp, but add: +-- - record selectors applied to just the record +-- - ConLike Ids (if not bottoming) +-- - a function applied to dictionaries isExpandableApp fn n_val_args | isWorkFreeApp fn n_val_args = True | otherwise @@ -1737,101 +1840,6 @@ isExpandableApp fn n_val_args | otherwise = False -{- Note [isCheapApp: bottoming functions] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -I'm not sure why we have a special case for bottoming -functions in isCheapApp. Maybe we don't need it. - -Note [exprIsExpandable] -~~~~~~~~~~~~~~~~~~~~~~~ -An expression is "expandable" if we are willing to duplicate it, if doing -so might make a RULE or case-of-constructor fire. Consider - let x = (a,b) - y = build g - in ....(case x of (p,q) -> rhs)....(foldr k z y).... - -We don't inline 'x' or 'y' (see Note [Lone variables] in GHC.Core.Unfold), -but we do want - - * the case-expression to simplify - (via exprIsConApp_maybe, exprIsLiteral_maybe) - - * the foldr/build RULE to fire - (by expanding the unfolding during rule matching) - -So we classify the unfolding of a let-binding as "expandable" (via the -uf_expandable field) if we want to do this kind of on-the-fly -expansion. Specifically: - -* True of constructor applications (K a b) - -* True of applications of a "CONLIKE" Id; see Note [CONLIKE pragma] in GHC.Types.Basic. - (NB: exprIsCheap might not be true of this) - -* False of case-expressions. If we have - let x = case ... in ...(case x of ...)... - we won't simplify. We have to inline x. See #14688. - -* False of let-expressions (same reason); and in any case we - float lets out of an RHS if doing so will reveal an expandable - application (see SimplEnv.doFloatFromRhs). - -* Take care: exprIsExpandable should /not/ be true of primops. I - found this in test T5623a: - let q = /\a. Ptr a (a +# b) - in case q @ Float of Ptr v -> ...q... - - q's inlining should not be expandable, else exprIsConApp_maybe will - say that (q @ Float) expands to (Ptr a (a +# b)), and that will - duplicate the (a +# b) primop, which we should not do lightly. - (It's quite hard to trigger this bug, but T13155 does so for GHC 8.0.) - -NB: exprIsWorkFree implies exprIsExpandable. - -Note [isExpandableApp: bottoming functions] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -It's important that isExpandableApp does not respond True to bottoming -functions. Recall undefined :: HasCallStack => a -Suppose isExpandableApp responded True to (undefined d), and we had: - - x = undefined <dict-expr> - -Then Simplify.prepareRhs would ANF the RHS: - - d = <dict-expr> - x = undefined d - -This is already bad: we gain nothing from having x bound to (undefined -var), unlike the case for data constructors. Worse, we get the -simplifier loop described in OccurAnal Note [Cascading inlines]. -Suppose x occurs just once; OccurAnal.occAnalNonRecRhs decides x will -certainly_inline; so we end up inlining d right back into x; but in -the end x doesn't inline because it is bottom (preInlineUnconditionally); -so the process repeats.. We could elaborate the certainly_inline logic -some more, but it's better just to treat bottoming bindings as -non-expandable, because ANFing them is a bad idea in the first place. - -Note [Record selection] -~~~~~~~~~~~~~~~~~~~~~~~~~~ -I'm experimenting with making record selection -look cheap, so we will substitute it inside a -lambda. Particularly for dictionary field selection. - -BUT: Take care with (sel d x)! The (sel d) might be cheap, but -there's no guarantee that (sel d x) will be too. Hence (n_val_args == 1) - -Note [Expandable overloadings] -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Suppose the user wrote this - {-# RULE forall x. foo (negate x) = h x #-} - f x = ....(foo (negate x)).... -They'd expect the rule to fire. But since negate is overloaded, we might -get this: - f = \d -> let n = negate d in \x -> ...foo (n x)... -So we treat the application of a function (negate in this case) to a -*dictionary* as expandable. In effect, every function is CONLIKE when -it's applied only to dictionaries. --} isUnaryClassId :: Id -> Bool -- True of (a) the method selector (classop) @@ -3265,8 +3273,8 @@ So: * When we make an AbsVars list, we close over the free vars of the unfoldings of any tyvars in it. So if `b{=Maybe a}` is in the list then so is `a` -* `mkCoreAbsLams` (more generally `mkPolyAbsLams`) forms a lambda abstraction pushing - the tyvar bindings into the body: +* `mkCoreAbsLams` (more generally `mkPolyAbsLams`) forms a lambda abstraction + pushing the tyvar bindings into the body: mkCoreAbsLams [a, b=[a], x:b] body = \a. \(x:[a]). let @b = [a] in let x:b = x in -- See (AFV1) @@ -3301,8 +3309,10 @@ type TaggedAbsVars t = [TaggedBndr t] mkPolyAbsLams :: forall b. (b -> AbsVar, Var -> b -> b) -> [b] -> Expr b -> Expr b --- `mkPolyAbsLams` is polymorphic in (get,set) so that we can --- use it for both CoreExpr and LevelledExpr +-- `mkPolyAbsLams` is polymorphic in (get,set) so that we +-- can use it for both CoreExpr and LevelledExpr. See +-- - mkCoreAbsLams +-- - mkTaggedAbsLams {-# INLINE mkPolyAbsLams #-} mkPolyAbsLams (getter,setter) bndrs body = go emptyVarSet [] bndrs View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fdc5c34c4d36b1a0c7f4f3066b2bb7… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fdc5c34c4d36b1a0c7f4f3066b2bb7… You're receiving this email because of your account on gitlab.haskell.org.

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