Magnus pushed to branch wip/mangoiv/ghc-9.12-bp at Glasgow Haskell Compiler / GHC Commits: 46d50d5f by Andreas Klebinger at 2026-05-14T16:26:57+02:00 Configure: Fix check for --target support in stage0 CC The check FP_PROG_CC_LINKER_TARGET used $CC unconditionally to check for --target support. However this fails for the stage0 config where the C compiler used is not $CC but $CC_STAGE0. Since we already pass the compiler under test into the macro I simply changed it to use that instead. Fixes #26999 (cherry picked from commit 43638643adbe999de8d2288a40bdd15c602f6481) - - - - - 25b0b83a by Ian Duncan at 2026-05-14T16:27:32+02:00 AArch64: fix MOVK regUsageOfInstr to mark dst as both read and written MOVK (move with keep) modifies only a 16-bit slice of the destination register, so the destination is both read and written. The register allocator must know this to avoid clobbering live values. Update regUsageOfInstr to list the destination in both src and dst sets. No regression test: triggering the misallocation requires specific register pressure around a MOVK sequence, which is difficult to reliably provoke from Haskell source. (cherry picked from commit 2823b03966e495581f4695f07649c5885306b656) - - - - - 402e6861 by Zubin Duggal at 2026-05-14T16:33:28+02:00 compiler/ffi: Collapse void pointer chains in capi wrappers New gcc/clang treat -Wincompatible-pointer-types as an error by default. Since C only allows implicit conversion from void*, not void**, capi wrappers for functions taking e.g. abstract** would fail to compile when the Haskell type Ptr (Ptr Abstract) was naively translated to void**. Collapse nested void pointers to a single void* when the pointee type has no known C representation. Fixes #26852 (cherry picked from commit 80e2dd4f084eff9cc857b31daf9ea2e9e460c727) - - - - - ba9d5b97 by Zubin Duggal at 2026-05-14T16:34:02+02:00 hadrian: Don't include the package hash in the haddock directory Since GHC 9.8 and hash_unit_ids, haddock urls have looked like`ghc-9.10.3/doc/html/libraries/base-4.20.2.0-39f9/**/*.html` The inclusion of the hash makes it hard for downstream non-boot packages to properly link to these files, as the hash is not part of a standard cabal substitution. Since we only build one version of each package, we don't need the hash to disambiguate anything, we can just remove it. Fixes #26635 (cherry picked from commit 07267f79d91169f474cacc8bcd38d76a6e97887d) - - - - - 11 changed files: - compiler/GHC/CmmToAsm/AArch64/Instr.hs - compiler/GHC/HsToCore/Foreign/C.hs - hadrian/bindist/Makefile - hadrian/src/CommandLine.hs - hadrian/src/Context.hs - hadrian/src/Settings/Builders/Cabal.hs - m4/fp_prog_cc_linker_target.m4 - + testsuite/tests/ffi/should_compile/T26852.h - + testsuite/tests/ffi/should_compile/T26852.hs - + testsuite/tests/ffi/should_compile/T26852.stderr - testsuite/tests/ffi/should_compile/all.T Changes: ===================================== compiler/GHC/CmmToAsm/AArch64/Instr.hs ===================================== @@ -114,7 +114,7 @@ regUsageOfInstr platform instr = case instr of LSL dst src1 src2 -> usage (regOp src1 ++ regOp src2, regOp dst) LSR dst src1 src2 -> usage (regOp src1 ++ regOp src2, regOp dst) MOV dst src -> usage (regOp src, regOp dst) - MOVK dst src -> usage (regOp src, regOp dst) + MOVK dst src -> usage (regOp src ++ regOp dst, regOp dst) MOVZ dst src -> usage (regOp src, regOp dst) MVN dst src -> usage (regOp src, regOp dst) ORR dst src1 src2 -> usage (regOp src1 ++ regOp src2, regOp dst) ===================================== compiler/GHC/HsToCore/Foreign/C.hs ===================================== @@ -328,37 +328,68 @@ dsFCall fn_id co fcall mDeclHeader = do toCName :: Id -> String toCName i = showSDocOneLine defaultSDocContext (pprCode (ppr (idName i))) +{- Note [Collapsing void pointer chains] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +When translating Haskell types like (Ptr (Ptr Abstract)) to C types for capi +wrappers, where Abstract has no CType annotation, naively we would produce +"void**". This is problematic because in C, only void* has implicit conversion +to any pointer type. +Modern compilers (gcc, clang) treat -Wincompatible-pointer-types as an error +by default (#26852), causing compilation failures for capi wrappers. + +The fix is to collapse void pointer chains: whenever the inner type of a +Ptr/FunPtr resolves to void (i.e. the Haskell type has no known C +representation), we return void* instead of void**, void***, etc. +This works because void* implicitly converts to any pointer type in C. + +Examples: + Ptr Abstract => void* + Ptr (Ptr Abstract) => void* (used to be void**) + Ptr (Ptr (Ptr Abstract)) => void* + Ptr (Ptr CInt) => int** (CInt has CType "int", don't collapse) +-} + +-- | See Note [Collapsing void pointer chains] toCType :: Type -> (Maybe Header, SDoc) -toCType = f False - where f voidOK t - -- First, if we have (Ptr t) of (FunPtr t), then we need to +toCType t = case f False t of + (mh, _, cType) -> (mh, cType) + where + -- The Bool in the return type indicates whether the C type is + -- "void" due to an unknown Haskell type (True = void-based). + f :: Bool -> Type -> (Maybe Header, Bool, SDoc) + f voidOK t + -- First, if we have (Ptr t) or (FunPtr t), then we need to -- convert t to a C type and put a * after it. If we don't -- know a type for t, then "void" is fine, though. + -- If the inner type is void-based, we collapse the pointer + -- chain to just "void*". See Note [Collapsing void pointer chains]. | Just (ptr, [t']) <- splitTyConApp_maybe t , tyConName ptr `elem` [ptrTyConName, funPtrTyConName] = case f True t' of - (mh, cType') -> - (mh, cType' <> char '*') + (mh, True, _) -> + (mh, True, text "void*") + (mh, False, cType') -> + (mh, False, cType' <> char '*') -- Otherwise, if we have a type constructor application, then -- see if there is a C type associated with that constructor. -- Note that we aren't looking through type synonyms or -- anything, as it may be the synonym that is annotated. | Just tycon <- tyConAppTyConPicky_maybe t - , Just (CType _ mHeader (_,cType)) <- tyConCType_maybe tycon - = (mHeader, ftext cType) + , Just (CType _ mHeader (_, cType)) <- tyConCType_maybe tycon + = (mHeader, False, ftext cType) -- If we don't know a C type for this type, then try looking -- through one layer of type synonym etc. | Just t' <- coreView t = f voidOK t' - -- Handle 'UnliftedFFITypes' argument + -- Handle 'UnliftedFFITypes' argument | Just tyCon <- tyConAppTyConPicky_maybe t , isPrimTyCon tyCon , Just cType <- ppPrimTyConStgType tyCon - = (Nothing, text cType) + = (Nothing, False, text cType) -- Otherwise we don't know the C type. If we are allowing -- void then return that; otherwise something has gone wrong. - | voidOK = (Nothing, text "void") + | voidOK = (Nothing, True, text "void") | otherwise = pprPanic "toCType" (ppr t) ===================================== hadrian/bindist/Makefile ===================================== @@ -252,7 +252,7 @@ update_package_db: install_bin install_lib $(INSTALL_DATA) mk/system-cxx-std-lib-1.0.conf "$(DESTDIR)$(ActualLibsDir)/package.conf.d" @echo "Updating the package DB" $(foreach p, $(PKG_CONFS),\ - $(call patchpackageconf,$(shell echo $(notdir $p) | sed 's/-[0-9.]*-[0-9a-zA-Z]*\.conf//g'),$(shell echo "$p" | sed 's:\0xxx\0: :g'),$(docdir),$(shell mk/relpath.sh "$(ActualLibsDir)" "$(docdir)"),$(shell echo $(notdir $p) | sed 's/.conf//g'))) + $(call patchpackageconf,$(shell echo $(notdir $p) | sed 's/-[0-9.]*-[0-9a-zA-Z]*\.conf//g'),$(shell echo "$p" | sed 's:\0xxx\0: :g'),$(docdir),$(shell mk/relpath.sh "$(ActualLibsDir)" "$(docdir)"),$(shell echo $(notdir $p) | sed 's/-[0-9a-zA-Z]*\.conf$$//'))) '$(DESTDIR)$(ActualBinsDir)/$(CrossCompilePrefix)ghc-pkg' --global-package-db "$(DESTDIR)$(ActualLibsDir)/package.conf.d" recache .PHONY: install_mingw ===================================== hadrian/src/CommandLine.hs ===================================== @@ -113,7 +113,7 @@ data DocArgs = DocArgs } deriving (Eq, Show) defaultDocArgs :: DocArgs -defaultDocArgs = DocArgs { docsBaseUrl = "../%pkgid%" } +defaultDocArgs = DocArgs { docsBaseUrl = "../%pkg%" } readConfigure :: Either String (CommandLineArgs -> CommandLineArgs) readConfigure = Left "hadrian --configure has been deprecated (see #20167). Please run ./boot; ./configure manually" ===================================== hadrian/src/Context.hs ===================================== @@ -128,7 +128,9 @@ pkgSetupConfigFile context = pkgSetupConfigDir context <&> (-/- "setup-config") pkgHaddockFile :: Context -> Action FilePath pkgHaddockFile Context {..} = do root <- buildRoot - version <- pkgUnitId stage package + -- We don't want to use the hash in the html documentation because it + -- makes it harder for non-boot packages to link to boot packages, see #26635 + version <- pkgSimpleIdentifier package return $ root -/- "doc/html/libraries" -/- version -/- pkgName package <.> "haddock" -- | Path to the registered ghc-pkg library file of a given 'Context', e.g.: ===================================== hadrian/src/Settings/Builders/Cabal.hs ===================================== @@ -85,6 +85,9 @@ commonCabalArgs :: Stage -> Args commonCabalArgs stage = do pkg <- getPackage package_id <- expr $ pkgUnitId stage pkg + -- We don't want to use the hash in the html documentation because it + -- makes it harder for non-boot packages to link to boot packages, see #26635 + package_simple_id <- expr $ pkgSimpleIdentifier pkg let prefix = "${pkgroot}" ++ (if windowsHost then "" else "/..") mconcat [ -- Don't strip libraries when cross compiling. -- TODO: We need to set @--with-strip=(stripCmdPath :: Action FilePath)@, @@ -112,7 +115,7 @@ commonCabalArgs stage = do -- -- This doesn't hold if we move the @doc@ folder anywhere else. , arg "--htmldir" - , arg $ "${pkgroot}/../../doc/html/libraries/" ++ package_id + , arg $ "${pkgroot}/../../doc/html/libraries/" ++ package_simple_id -- These trigger a need on each dependency, so every important to need -- them in parallel or it linearises the build of Ghc and GhcPkg ===================================== m4/fp_prog_cc_linker_target.m4 ===================================== @@ -8,7 +8,7 @@ # a linker AC_DEFUN([FP_PROG_CC_LINKER_TARGET], [ - AC_MSG_CHECKING([whether $CC used as a linker understands --target]) + AC_MSG_CHECKING([whether $1 used as a linker understands --target]) echo 'int foo() { return 0; }' > conftest1.c echo 'int main() { return 0; }' > conftest2.c @@ -20,7 +20,7 @@ AC_DEFUN([FP_PROG_CC_LINKER_TARGET], # See Note [Don't pass --target to emscripten toolchain] in GHC.Toolchain.Program CONF_CC_SUPPORTS_TARGET=NO AC_MSG_RESULT([no]) - elif "$CC" $$3 --target=$LlvmTarget -o conftest conftest1.o conftest2.o; + elif "$1" $$3 --target=$LlvmTarget -o conftest conftest1.o conftest2.o; then $3="--target=$LlvmTarget $$3" AC_MSG_RESULT([yes]) ===================================== testsuite/tests/ffi/should_compile/T26852.h ===================================== @@ -0,0 +1,7 @@ +typedef struct abstract abstract; + +void blah(abstract** x); +abstract** get_abstract(void); +abstract*** get_abstract3(void); +abstract* get_simple(void); +int** get_int_pp(void); ===================================== testsuite/tests/ffi/should_compile/T26852.hs ===================================== @@ -0,0 +1,22 @@ +{-# LANGUAGE CApiFFI #-} +module T26852 where + +import Foreign.Ptr +import Foreign.C.Types + +data Abstract + +foreign import capi "T26852.h blah" + c_blah :: Ptr (Ptr Abstract) -> IO () + +foreign import capi "T26852.h get_abstract" + c_get_abstract :: IO (Ptr (Ptr Abstract)) + +foreign import capi "T26852.h get_abstract3" + c_get_abstract3 :: IO (Ptr (Ptr (Ptr Abstract))) + +foreign import capi "T26852.h get_simple" + c_get_simple :: IO (Ptr Abstract) + +foreign import capi "T26852.h get_int_pp" + c_get_int_pp :: IO (Ptr (Ptr CInt)) ===================================== testsuite/tests/ffi/should_compile/T26852.stderr ===================================== @@ -0,0 +1,18 @@ + +==================== Foreign export header file ==================== + + + +==================== Foreign export stubs ==================== +#include "T26852.h" +int** ghczuwrapperZC0ZCmainZCT26852ZCgetzuintzupp(void) {return get_int_pp();} +#include "T26852.h" +void* ghczuwrapperZC1ZCmainZCT26852ZCgetzusimple(void) {return get_simple();} +#include "T26852.h" +void* ghczuwrapperZC2ZCmainZCT26852ZCgetzuabstract3(void) {return get_abstract3();} +#include "T26852.h" +void* ghczuwrapperZC3ZCmainZCT26852ZCgetzuabstract(void) {return get_abstract();} +#include "T26852.h" +void ghczuwrapperZC4ZCmainZCT26852ZCblah(void* a1) {blah(a1);} + + ===================================== testsuite/tests/ffi/should_compile/all.T ===================================== @@ -43,3 +43,4 @@ test('T22774', unless(js_arch() or arch('wasm32'), expect_fail), compile, ['']) test('T24034', normal, compile, ['']) test('T25255', normal, compile, ['-dppr-debug']) +test('T26852', [when(js_arch(), skip), filter_stdout_lines(r'.*ghczuwrapper.*')], compile, ['-ddump-foreign']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/52c2ba8f55b6a862df6ff9fc5db5c84... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/52c2ba8f55b6a862df6ff9fc5db5c84... 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