{-# LANGUAGE CPP #-} {-# LANGUAGE MultiWayIf #-} {-# LANGUAGE DerivingVia #-} {-# LANGUAGE NamedFieldPuns #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE GADTs #-} {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-} #include {- Functions for providing the default interpretation of the 'TPhase' actions -} module GHC.Driver.Pipeline.Execute where import GHC.Prelude import Control.Monad import Control.Monad.IO.Class import Control.Monad.Catch import GHC.Driver.Hooks import Control.Monad.Trans.Reader import GHC.Driver.Pipeline.Monad import GHC.Driver.Pipeline.Phases import GHC.Driver.Env hiding (Hsc) import GHC.Unit.Module.Location import GHC.Driver.Phases import GHC.Unit.Types import GHC.Types.SourceFile import GHC.Unit.Module.Status import GHC.Unit.Module.ModIface import GHC.Driver.Backend import GHC.Driver.Session import GHC.Driver.CmdLine import GHC.Unit.Module.ModSummary import qualified GHC.LanguageExtensions as LangExt import GHC.Types.SrcLoc import GHC.Driver.Main import GHC.Tc.Types import GHC.Types.Error import GHC.Driver.Errors.Types import GHC.Fingerprint import GHC.Utils.Logger import GHC.Utils.TmpFs import GHC.Platform import Data.List (intercalate, isInfixOf) import GHC.Unit.Env import GHC.Utils.Error import Data.Maybe import GHC.CmmToLlvm.Mangler import GHC.SysTools import GHC.SysTools.Cpp import GHC.Utils.Panic.Plain import System.Directory import System.FilePath import GHC.Utils.Misc import GHC.Utils.Outputable import GHC.Unit.Info import GHC.Unit.State import GHC.Unit.Home import GHC.Data.Maybe import GHC.Iface.Make import GHC.Driver.Config.Parser import GHC.Parser.Header import GHC.Data.StringBuffer import GHC.Types.SourceError import GHC.Unit.Finder import GHC.Runtime.Loader import Data.IORef import GHC.Types.Name.Env import GHC.Platform.Ways import GHC.Driver.LlvmConfigCache (readLlvmConfigCache) import GHC.CmmToLlvm.Config (LlvmTarget (..), LlvmConfig (..)) import {-# SOURCE #-} GHC.Driver.Pipeline (compileForeign, compileEmptyStub) import GHC.Settings import System.IO import GHC.Linker.ExtraObj import GHC.Linker.Dynamic import GHC.Utils.Panic import GHC.Unit.Module.Env import GHC.Driver.Env.KnotVars import GHC.Driver.Config.Finder import GHC.Rename.Names import GHC.StgToJS.Linker.Linker (embedJsFile) import Language.Haskell.Syntax.Module.Name import GHC.Unit.Home.ModInfo newtype HookedUse a = HookedUse { runHookedUse :: (Hooks, PhaseHook) -> IO a } deriving (Functor, Applicative, Monad, MonadIO, MonadThrow, MonadCatch) via (ReaderT (Hooks, PhaseHook) IO) instance MonadUse TPhase HookedUse where use fa = HookedUse $ \(hooks, (PhaseHook k)) -> case runPhaseHook hooks of Nothing -> k fa Just (PhaseHook h) -> h fa -- | The default mechanism to run a pipeline, see Note [The Pipeline Monad] runPipeline :: Hooks -> HookedUse a -> IO a runPipeline hooks pipeline = runHookedUse pipeline (hooks, PhaseHook runPhase) -- | Default interpretation of each phase, in terms of IO. runPhase :: TPhase out -> IO out runPhase (T_Unlit pipe_env hsc_env inp_path) = do out_path <- phaseOutputFilenameNew (Cpp HsSrcFile) pipe_env hsc_env Nothing runUnlitPhase hsc_env inp_path out_path runPhase (T_FileArgs hsc_env inp_path) = getFileArgs hsc_env inp_path runPhase (T_Cpp pipe_env hsc_env inp_path) = do out_path <- phaseOutputFilenameNew (HsPp HsSrcFile) pipe_env hsc_env Nothing runCppPhase hsc_env inp_path out_path runPhase (T_HsPp pipe_env hsc_env origin_path inp_path) = do out_path <- phaseOutputFilenameNew (Hsc HsSrcFile) pipe_env hsc_env Nothing runHsPpPhase hsc_env origin_path inp_path out_path runPhase (T_HscRecomp pipe_env hsc_env fp hsc_src) = do runHscPhase pipe_env hsc_env fp hsc_src runPhase (T_Hsc hsc_env mod_sum) = runHscTcPhase hsc_env mod_sum runPhase (T_HscPostTc hsc_env ms fer m mfi) = runHscPostTcPhase hsc_env ms fer m mfi runPhase (T_HscBackend pipe_env hsc_env mod_name hsc_src location x) = do runHscBackendPhase pipe_env hsc_env mod_name hsc_src location x runPhase (T_CmmCpp pipe_env hsc_env input_fn) = do output_fn <- phaseOutputFilenameNew Cmm pipe_env hsc_env Nothing doCpp (hsc_logger hsc_env) (hsc_tmpfs hsc_env) (hsc_dflags hsc_env) (hsc_unit_env hsc_env) (CppOpts { cppUseCc = True , cppLinePragmas = True }) input_fn output_fn return output_fn runPhase (T_Js pipe_env hsc_env location js_src) = runJsPhase pipe_env hsc_env location js_src runPhase (T_ForeignJs pipe_env hsc_env location js_src) = runForeignJsPhase pipe_env hsc_env location js_src runPhase (T_Cmm pipe_env hsc_env input_fn) = do let dflags = hsc_dflags hsc_env let next_phase = hscPostBackendPhase HsSrcFile (backend dflags) output_fn <- phaseOutputFilenameNew next_phase pipe_env hsc_env Nothing mstub <- hscCompileCmmFile hsc_env (src_filename pipe_env) input_fn output_fn stub_o <- mapM (compileStub hsc_env) mstub let foreign_os = maybeToList stub_o return (foreign_os, output_fn) runPhase (T_Cc phase pipe_env hsc_env location input_fn) = runCcPhase phase pipe_env hsc_env location input_fn runPhase (T_As cpp pipe_env hsc_env location input_fn) = do runAsPhase cpp pipe_env hsc_env location input_fn runPhase (T_LlvmOpt pipe_env hsc_env input_fn) = runLlvmOptPhase pipe_env hsc_env input_fn runPhase (T_LlvmLlc pipe_env hsc_env input_fn) = runLlvmLlcPhase pipe_env hsc_env input_fn runPhase (T_LlvmMangle pipe_env hsc_env input_fn) = runLlvmManglePhase pipe_env hsc_env input_fn runPhase (T_MergeForeign pipe_env hsc_env input_fn fos) = runMergeForeign pipe_env hsc_env input_fn fos runLlvmManglePhase :: PipeEnv -> HscEnv -> FilePath -> IO [Char] runLlvmManglePhase pipe_env hsc_env input_fn = do let next_phase = As False output_fn <- phaseOutputFilenameNew next_phase pipe_env hsc_env Nothing let dflags = hsc_dflags hsc_env llvmFixupAsm (targetPlatform dflags) input_fn output_fn return output_fn runMergeForeign :: PipeEnv -> HscEnv -> FilePath -> [FilePath] -> IO FilePath runMergeForeign _pipe_env hsc_env input_fn foreign_os = do if null foreign_os then return input_fn else do -- Work around a binutil < 2.31 bug where you can't merge objects if the output file -- is one of the inputs new_o <- newTempName (hsc_logger hsc_env) (hsc_tmpfs hsc_env) (tmpDir (hsc_dflags hsc_env)) TFL_CurrentModule "o" copyFile input_fn new_o joinObjectFiles hsc_env (new_o : foreign_os) input_fn return input_fn runLlvmLlcPhase :: PipeEnv -> HscEnv -> FilePath -> IO FilePath runLlvmLlcPhase pipe_env hsc_env input_fn = do -- Note [Clamping of llc optimizations] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- See #13724 -- -- we clamp the llc optimization between [1,2]. This is because passing -O0 -- to llc 3.9 or llc 4.0, the naive register allocator can fail with -- -- Error while trying to spill R1 from class GPR: Cannot scavenge register -- without an emergency spill slot! -- -- Observed at least with target 'arm-unknown-linux-gnueabihf'. -- -- -- With LLVM4, llc -O3 crashes when ghc-stage1 tries to compile -- rts/HeapStackCheck.cmm -- -- llc -O3 '-mtriple=arm-unknown-linux-gnueabihf' -enable-tbaa /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_6.bc -o /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_7.lm_s -- 0 llc 0x0000000102ae63e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40 -- 1 llc 0x0000000102ae69a6 SignalHandler(int) + 358 -- 2 libsystem_platform.dylib 0x00007fffc23f4b3a _sigtramp + 26 -- 3 libsystem_c.dylib 0x00007fffc226498b __vfprintf + 17876 -- 4 llc 0x00000001029d5123 llvm::SelectionDAGISel::LowerArguments(llvm::Function const&) + 5699 -- 5 llc 0x0000000102a21a35 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) + 3381 -- 6 llc 0x0000000102a202b1 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 1457 -- 7 llc 0x0000000101bdc474 (anonymous namespace)::ARMDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 20 -- 8 llc 0x00000001025573a6 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) + 134 -- 9 llc 0x000000010274fb12 llvm::FPPassManager::runOnFunction(llvm::Function&) + 498 -- 10 llc 0x000000010274fd23 llvm::FPPassManager::runOnModule(llvm::Module&) + 67 -- 11 llc 0x00000001027501b8 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 920 -- 12 llc 0x000000010195f075 compileModule(char**, llvm::LLVMContext&) + 12133 -- 13 llc 0x000000010195bf0b main + 491 -- 14 libdyld.dylib 0x00007fffc21e5235 start + 1 -- Stack dump: -- 0. Program arguments: llc -O3 -mtriple=arm-unknown-linux-gnueabihf -enable-tbaa /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_6.bc -o /var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_7.lm_s -- 1. Running pass 'Function Pass Manager' on module '/var/folders/fv/xqjrpfj516n5xq_m_ljpsjx00000gn/T/ghc33674_0/ghc_6.bc'. -- 2. Running pass 'ARM Instruction Selection' on function '@"stg_gc_f1$def"' -- -- Observed at least with -mtriple=arm-unknown-linux-gnueabihf -enable-tbaa -- llvm_config <- readLlvmConfigCache (hsc_llvm_config hsc_env) let dflags = hsc_dflags hsc_env logger = hsc_logger hsc_env llvmOpts = case llvmOptLevel dflags of 0 -> "-O1" -- required to get the non-naive reg allocator. Passing -regalloc=greedy is not sufficient. 1 -> "-O1" _ -> "-O2" defaultOptions = map GHC.SysTools.Option . concatMap words . snd $ unzip (llvmOptions llvm_config dflags) optFlag = if null (getOpts dflags opt_lc) then map GHC.SysTools.Option $ words llvmOpts else [] next_phase <- if -- hidden debugging flag '-dno-llvm-mangler' to skip mangling | gopt Opt_NoLlvmMangler dflags -> return (As False) | otherwise -> return LlvmMangle output_fn <- phaseOutputFilenameNew next_phase pipe_env hsc_env Nothing GHC.SysTools.runLlvmLlc logger dflags ( optFlag ++ defaultOptions ++ [ GHC.SysTools.FileOption "" input_fn , GHC.SysTools.Option "-o" , GHC.SysTools.FileOption "" output_fn ] ) return output_fn runLlvmOptPhase :: PipeEnv -> HscEnv -> FilePath -> IO FilePath runLlvmOptPhase pipe_env hsc_env input_fn = do let dflags = hsc_dflags hsc_env logger = hsc_logger hsc_env llvm_config <- readLlvmConfigCache (hsc_llvm_config hsc_env) let -- we always (unless -optlo specified) run Opt since we rely on it to -- fix up some pretty big deficiencies in the code we generate optIdx = max 0 $ min 2 $ llvmOptLevel dflags -- ensure we're in [0,2] llvmOpts = case lookup optIdx $ llvmPasses llvm_config of Just passes -> passes Nothing -> panic ("runPhase LlvmOpt: llvm-passes file " ++ "is missing passes for level " ++ show optIdx) defaultOptions = map GHC.SysTools.Option . concat . fmap words . fst $ unzip (llvmOptions llvm_config dflags) -- don't specify anything if user has specified commands. We do this -- for opt but not llc since opt is very specifically for optimisation -- passes only, so if the user is passing us extra options we assume -- they know what they are doing and don't get in the way. optFlag = if null (getOpts dflags opt_lo) then map GHC.SysTools.Option $ words llvmOpts else [] output_fn <- phaseOutputFilenameNew LlvmLlc pipe_env hsc_env Nothing GHC.SysTools.runLlvmOpt logger dflags ( optFlag ++ defaultOptions ++ [ GHC.SysTools.FileOption "" input_fn , GHC.SysTools.Option "-o" , GHC.SysTools.FileOption "" output_fn] ) return output_fn runAsPhase :: Bool -> PipeEnv -> HscEnv -> Maybe ModLocation -> FilePath -> IO FilePath runAsPhase with_cpp pipe_env hsc_env location input_fn = do let dflags = hsc_dflags hsc_env let logger = hsc_logger hsc_env let unit_env = hsc_unit_env hsc_env let platform = ue_platform unit_env -- LLVM from version 3.0 onwards doesn't support the OS X system -- assembler, so we use clang as the assembler instead. (#5636) let (as_prog, get_asm_info) = ( applyAssemblerProg $ backendAssemblerProg (backend dflags) , applyAssemblerInfoGetter $ backendAssemblerInfoGetter (backend dflags) ) asmInfo <- get_asm_info logger dflags platform let cmdline_include_paths = includePaths dflags let pic_c_flags = picCCOpts dflags output_fn <- phaseOutputFilenameNew StopLn pipe_env hsc_env location -- we create directories for the object file, because it -- might be a hierarchical module. createDirectoryIfMissing True (takeDirectory output_fn) let global_includes = [ GHC.SysTools.Option ("-I" ++ p) | p <- includePathsGlobal cmdline_include_paths ] let local_includes = [ GHC.SysTools.Option ("-iquote" ++ p) | p <- includePathsQuote cmdline_include_paths ++ includePathsQuoteImplicit cmdline_include_paths] let runAssembler inputFilename outputFilename = withAtomicRename outputFilename $ \temp_outputFilename -> as_prog logger dflags platform (local_includes ++ global_includes -- See Note [-fPIC for assembler] ++ map GHC.SysTools.Option pic_c_flags -- See Note [Produce big objects on Windows] ++ [ GHC.SysTools.Option "-Wa,-mbig-obj" | platformOS (targetPlatform dflags) == OSMinGW32 , not $ target32Bit (targetPlatform dflags) ] -- See Note [-Wa,--no-type-check on wasm32] ++ [ GHC.SysTools.Option "-Wa,--no-type-check" | platformArch (targetPlatform dflags) == ArchWasm32] ++ (if any (asmInfo ==) [Clang, AppleClang, AppleClang51] then [GHC.SysTools.Option "-Qunused-arguments"] else []) ++ [ GHC.SysTools.Option "-x" , if with_cpp then GHC.SysTools.Option "assembler-with-cpp" else GHC.SysTools.Option "assembler" , GHC.SysTools.Option "-c" , GHC.SysTools.FileOption "" inputFilename , GHC.SysTools.Option "-o" , GHC.SysTools.FileOption "" temp_outputFilename ]) debugTraceMsg logger 4 (text "Running the assembler") runAssembler input_fn output_fn return output_fn -- Note [JS Backend .o file procedure] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- -- The JS backend breaks some of the assumptions on file generation order -- because it directly produces .o files. This violation breaks some of the -- assumptions on file timestamps, particularly in the postHsc phase. The -- postHsc phase for the JS backend is performed in 'runJsPhase'. Consider -- what the NCG does: -- -- With other NCG backends we have the following order: -- 1. The backend produces a .s file -- 2. Then we write the interface file, .hi -- 3. Then we generate a .o file in a postHsc phase (calling the asm phase etc.) -- -- For the JS Backend this order is different -- 1. The JS Backend _directly_ produces .o files -- 2. Then we write the interface file. Notice that this breaks the ordering -- of .hi > .o (step 2 and step 3 in the NCG above). -- -- This violation results in timestamp checks which pass on the NCG but fail -- in the JS backend. In particular, checks that compare 'ms_obj_date', and -- 'ms_iface_date' in 'GHC.Unit.Module.ModSummary'. -- -- Thus to fix this ordering we touch the object files we generated earlier -- to ensure these timestamps abide by the proper ordering. -- | Run the JS Backend postHsc phase. runJsPhase :: PipeEnv -> HscEnv -> Maybe ModLocation -> FilePath -> IO FilePath runJsPhase _pipe_env hsc_env _location input_fn = do let dflags = hsc_dflags hsc_env let logger = hsc_logger hsc_env -- The object file is already generated. We only touch it to ensure the -- timestamp is refreshed, see Note [JS Backend .o file procedure]. touchObjectFile logger dflags input_fn return input_fn -- | Deal with foreign JS files (embed them into .o files) runForeignJsPhase :: PipeEnv -> HscEnv -> Maybe ModLocation -> FilePath -> IO FilePath runForeignJsPhase pipe_env hsc_env _location input_fn = do let dflags = hsc_dflags hsc_env let logger = hsc_logger hsc_env let tmpfs = hsc_tmpfs hsc_env let unit_env = hsc_unit_env hsc_env output_fn <- phaseOutputFilenameNew StopLn pipe_env hsc_env Nothing embedJsFile logger dflags tmpfs unit_env input_fn output_fn return output_fn applyAssemblerInfoGetter :: DefunctionalizedAssemblerInfoGetter -> Logger -> DynFlags -> Platform -> IO CompilerInfo applyAssemblerInfoGetter StandardAssemblerInfoGetter logger dflags _platform = getAssemblerInfo logger dflags applyAssemblerInfoGetter JSAssemblerInfoGetter _ _ _ = pure Emscripten applyAssemblerInfoGetter DarwinClangAssemblerInfoGetter logger dflags platform = if platformOS platform == OSDarwin then pure Clang else getAssemblerInfo logger dflags applyAssemblerProg :: DefunctionalizedAssemblerProg -> Logger -> DynFlags -> Platform -> [Option] -> IO () applyAssemblerProg StandardAssemblerProg logger dflags _platform = runAs logger dflags applyAssemblerProg JSAssemblerProg logger dflags _platform = runEmscripten logger dflags applyAssemblerProg DarwinClangAssemblerProg logger dflags platform = if platformOS platform == OSDarwin then runClang logger dflags else runAs logger dflags runCcPhase :: Phase -> PipeEnv -> HscEnv -> Maybe ModLocation -> FilePath -> IO FilePath runCcPhase cc_phase pipe_env hsc_env location input_fn = do let dflags = hsc_dflags hsc_env let logger = hsc_logger hsc_env let unit_env = hsc_unit_env hsc_env let home_unit = hsc_home_unit hsc_env let tmpfs = hsc_tmpfs hsc_env let platform = ue_platform unit_env let hcc = cc_phase `eqPhase` HCc let cmdline_include_paths = offsetIncludePaths dflags (includePaths dflags) -- HC files have the dependent packages stamped into them pkgs <- if hcc then getHCFilePackages input_fn else return [] -- add package include paths even if we're just compiling .c -- files; this is the Value Add(TM) that using ghc instead of -- gcc gives you :) ps <- mayThrowUnitErr (preloadUnitsInfo' unit_env pkgs) let pkg_include_dirs = collectIncludeDirs ps let include_paths_global = foldr (\ x xs -> ("-I" ++ x) : xs) [] (includePathsGlobal cmdline_include_paths ++ pkg_include_dirs) let include_paths_quote = foldr (\ x xs -> ("-iquote" ++ x) : xs) [] (includePathsQuote cmdline_include_paths ++ includePathsQuoteImplicit cmdline_include_paths) let include_paths = include_paths_quote ++ include_paths_global -- pass -D or -optP to preprocessor when compiling foreign C files -- (#16737). Doing it in this way is simpler and also enable the C -- compiler to perform preprocessing and parsing in a single pass, -- but it may introduce inconsistency if a different pgm_P is specified. let opts = getOpts dflags opt_P aug_imports = augmentImports dflags opts more_preprocessor_opts = concat [ ["-Xpreprocessor", i] | not hcc , i <- aug_imports ] let gcc_extra_viac_flags = extraGccViaCFlags dflags let pic_c_flags = picCCOpts dflags let verbFlags = getVerbFlags dflags -- cc-options are not passed when compiling .hc files. Our -- hc code doesn't not #include any header files anyway, so these -- options aren't necessary. let pkg_extra_cc_opts | hcc = [] | otherwise = collectExtraCcOpts ps let framework_paths | platformUsesFrameworks platform = let pkgFrameworkPaths = collectFrameworksDirs ps cmdlineFrameworkPaths = frameworkPaths dflags in map ("-F"++) (cmdlineFrameworkPaths ++ pkgFrameworkPaths) | otherwise = [] let cc_opt | llvmOptLevel dflags >= 2 = [ "-O2" ] | llvmOptLevel dflags >= 1 = [ "-O" ] | otherwise = [] output_fn <- phaseOutputFilenameNew StopLn pipe_env hsc_env location -- we create directories for the object file, because it -- might be a hierarchical module. createDirectoryIfMissing True (takeDirectory output_fn) let more_hcc_opts = -- on x86 the floating point regs have greater precision -- than a double, which leads to unpredictable results. -- By default, we turn this off with -ffloat-store unless -- the user specified -fexcess-precision. (if platformArch platform == ArchX86 && not (gopt Opt_ExcessPrecision dflags) then [ "-ffloat-store" ] else []) ++ -- gcc's -fstrict-aliasing allows two accesses to memory -- to be considered non-aliasing if they have different types. -- This interacts badly with the C code we generate, which is -- very weakly typed, being derived from C--. ["-fno-strict-aliasing"] ghcVersionH <- getGhcVersionPathName dflags unit_env withAtomicRename output_fn $ \temp_outputFilename -> GHC.SysTools.runCc (phaseForeignLanguage cc_phase) logger tmpfs dflags ( [ GHC.SysTools.Option "-c" , GHC.SysTools.FileOption "" input_fn , GHC.SysTools.Option "-o" , GHC.SysTools.FileOption "" temp_outputFilename ] ++ map GHC.SysTools.Option ( pic_c_flags -- See Note [Produce big objects on Windows] ++ [ "-Wa,-mbig-obj" | platformOS (targetPlatform dflags) == OSMinGW32 , not $ target32Bit (targetPlatform dflags) ] -- Stub files generated for foreign exports references the runIO_closure -- and runNonIO_closure symbols, which are defined in the base package. -- These symbols are imported into the stub.c file via RtsAPI.h, and the -- way we do the import depends on whether we're currently compiling -- the base package or not. ++ (if platformOS platform == OSMinGW32 && isHomeUnitId home_unit baseUnitId then [ "-DCOMPILING_BASE_PACKAGE" ] else []) -- GCC 4.6+ doesn't like -Wimplicit when compiling C++. ++ (if (cc_phase /= Ccxx && cc_phase /= Cobjcxx) then ["-Wimplicit"] else []) ++ (if hcc then gcc_extra_viac_flags ++ more_hcc_opts else []) ++ verbFlags ++ cc_opt ++ [ "-include", ghcVersionH ] ++ framework_paths ++ include_paths ++ more_preprocessor_opts ++ pkg_extra_cc_opts )) return output_fn -- This is where all object files get written from, for hs-boot and hsig files as well. runHscBackendPhase :: PipeEnv -> HscEnv -> ModuleName -> HscSource -> ModLocation -> HscBackendAction -> IO ([FilePath], ModIface, HomeModLinkable, FilePath) runHscBackendPhase pipe_env hsc_env mod_name src_flavour location result = do let dflags = hsc_dflags hsc_env logger = hsc_logger hsc_env o_file = if dynamicNow dflags then ml_dyn_obj_file location else ml_obj_file location -- The real object file next_phase = hscPostBackendPhase src_flavour (backend dflags) case result of HscUpdate iface -> do case src_flavour of HsigFile -> do -- We need to create a REAL but empty .o file -- because we are going to attempt to put it in a library let input_fn = expectJust "runPhase" (ml_hs_file location) basename = dropExtension input_fn compileEmptyStub dflags hsc_env basename location mod_name -- In the case of hs-boot files, generate a dummy .o-boot -- stamp file for the benefit of Make HsBootFile -> touchObjectFile logger dflags o_file HsSrcFile -> panic "HscUpdate not relevant for HscSrcFile" return ([], iface, emptyHomeModInfoLinkable, o_file) HscRecomp { hscs_guts = cgguts, hscs_mod_location = mod_location, hscs_partial_iface = partial_iface, hscs_old_iface_hash = mb_old_iface_hash } -> if not (backendGeneratesCode (backend dflags)) then panic "HscRecomp not relevant for NoBackend" else if backendWritesFiles (backend dflags) then do output_fn <- phaseOutputFilenameNew next_phase pipe_env hsc_env (Just location) (outputFilename, mStub, foreign_files, stg_infos, cg_infos) <- hscGenHardCode hsc_env cgguts mod_location output_fn final_iface <- mkFullIface hsc_env partial_iface stg_infos cg_infos -- See Note [Writing interface files] hscMaybeWriteIface logger dflags False final_iface mb_old_iface_hash mod_location mlinkable <- if backendGeneratesCode (backend dflags) && gopt Opt_ByteCodeAndObjectCode dflags then do bc <- generateFreshByteCode hsc_env mod_name (mkCgInteractiveGuts cgguts) mod_location return $ emptyHomeModInfoLinkable { homeMod_bytecode = Just bc } else return emptyHomeModInfoLinkable stub_o <- mapM (compileStub hsc_env) mStub foreign_os <- mapM (uncurry (compileForeign hsc_env)) foreign_files let fos = (maybe [] return stub_o ++ foreign_os) -- This is awkward, no linkable is produced here because we still -- have some way to do before the object file is produced -- In future we can split up the driver logic more so that this function -- is in TPipeline and in this branch we can invoke the rest of the backend phase. return (fos, final_iface, mlinkable, outputFilename) else -- In interpreted mode the regular codeGen backend is not run so we -- generate a interface without codeGen info. do final_iface <- mkFullIface hsc_env partial_iface Nothing Nothing hscMaybeWriteIface logger dflags True final_iface mb_old_iface_hash location bc <- generateFreshByteCode hsc_env mod_name (mkCgInteractiveGuts cgguts) mod_location return ([], final_iface, emptyHomeModInfoLinkable { homeMod_bytecode = Just bc } , panic "interpreter") runUnlitPhase :: HscEnv -> FilePath -> FilePath -> IO FilePath runUnlitPhase hsc_env input_fn output_fn = do let -- escape the characters \, ", and ', but don't try to escape -- Unicode or anything else (so we don't use Util.charToC -- here). If we get this wrong, then in -- GHC.HsToCore.Ticks.isGoodTickSrcSpan where we check that the filename in -- a SrcLoc is the same as the source filename, the two will -- look bogusly different. See test: -- libraries/hpc/tests/function/subdir/tough2.hs escape ('\\':cs) = '\\':'\\': escape cs escape ('\"':cs) = '\\':'\"': escape cs escape ('\'':cs) = '\\':'\'': escape cs escape (c:cs) = c : escape cs escape [] = [] let flags = [ -- The -h option passes the file name for unlit to -- put in a #line directive GHC.SysTools.Option "-h" -- See Note [Don't normalise input filenames]. , GHC.SysTools.Option $ escape input_fn , GHC.SysTools.FileOption "" input_fn , GHC.SysTools.FileOption "" output_fn ] let dflags = hsc_dflags hsc_env logger = hsc_logger hsc_env GHC.SysTools.runUnlit logger dflags flags return output_fn getFileArgs :: HscEnv -> FilePath -> IO ((DynFlags, Messages PsMessage, [Warn])) getFileArgs hsc_env input_fn = do let dflags0 = hsc_dflags hsc_env parser_opts = initParserOpts dflags0 (warns0, src_opts) <- getOptionsFromFile parser_opts input_fn (dflags1, unhandled_flags, warns) <- parseDynamicFilePragma dflags0 src_opts checkProcessArgsResult unhandled_flags return (dflags1, warns0, warns) runCppPhase :: HscEnv -> FilePath -> FilePath -> IO FilePath runCppPhase hsc_env input_fn output_fn = do doCpp (hsc_logger hsc_env) (hsc_tmpfs hsc_env) (hsc_dflags hsc_env) (hsc_unit_env hsc_env) (CppOpts { cppUseCc = False , cppLinePragmas = True }) input_fn output_fn return output_fn runHscPhase :: PipeEnv -> HscEnv -> FilePath -> HscSource -> IO (HscEnv, ModSummary, HscRecompStatus) runHscPhase pipe_env hsc_env0 input_fn src_flavour = do let dflags0 = hsc_dflags hsc_env0 PipeEnv{ src_basename=basename, src_suffix=suff } = pipe_env -- we add the current directory (i.e. the directory in which -- the .hs files resides) to the include path, since this is -- what gcc does, and it's probably what you want. let current_dir = takeDirectory basename new_includes = addImplicitQuoteInclude paths [current_dir] paths = includePaths dflags0 dflags = dflags0 { includePaths = new_includes } hsc_env = hscSetFlags dflags hsc_env0 -- gather the imports and module name (hspp_buf,mod_name,imps,src_imps, ghc_prim_imp) <- do buf <- hGetStringBuffer input_fn let imp_prelude = xopt LangExt.ImplicitPrelude dflags popts = initParserOpts dflags rn_pkg_qual = renameRawPkgQual (hsc_unit_env hsc_env) rn_imps = fmap (\(rpk, lmn@(L _ mn)) -> (rn_pkg_qual mn rpk, lmn)) eimps <- getImports popts imp_prelude buf input_fn (basename <.> suff) case eimps of Left errs -> throwErrors (GhcPsMessage <$> errs) Right (src_imps,imps, ghc_prim_imp, L _ mod_name) -> return (Just buf, mod_name, rn_imps imps, rn_imps src_imps, ghc_prim_imp) -- Take -o into account if present -- Very like -ohi, but we must *only* do this if we aren't linking -- (If we're linking then the -o applies to the linked thing, not to -- the object file for one module.) -- Note the nasty duplication with the same computation in compileFile above location <- mkOneShotModLocation pipe_env dflags src_flavour mod_name let o_file = ml_obj_file location -- The real object file hi_file = ml_hi_file location hie_file = ml_hie_file location dyn_o_file = ml_dyn_obj_file location src_hash <- getFileHash (basename <.> suff) hi_date <- modificationTimeIfExists hi_file hie_date <- modificationTimeIfExists hie_file o_mod <- modificationTimeIfExists o_file dyn_o_mod <- modificationTimeIfExists dyn_o_file -- Tell the finder cache about this module mod <- do let home_unit = hsc_home_unit hsc_env let fc = hsc_FC hsc_env addHomeModuleToFinder fc home_unit mod_name location -- Make the ModSummary to hand to hscMain let mod_summary = ModSummary { ms_mod = mod, ms_hsc_src = src_flavour, ms_hspp_file = input_fn, ms_hspp_opts = dflags, ms_hspp_buf = hspp_buf, ms_location = location, ms_hs_hash = src_hash, ms_obj_date = o_mod, ms_dyn_obj_date = dyn_o_mod, ms_parsed_mod = Nothing, ms_iface_date = hi_date, ms_hie_date = hie_date, ms_ghc_prim_import = ghc_prim_imp, ms_textual_imps = imps, ms_srcimps = src_imps } -- run the compiler! let msg :: Messager msg hsc_env _ what _ = oneShotMsg (hsc_logger hsc_env) what plugin_hsc_env' <- initializePlugins hsc_env -- Need to set the knot-tying mutable variable for interface -- files. See GHC.Tc.Utils.TcGblEnv.tcg_type_env_var. -- See also Note [hsc_type_env_var hack] type_env_var <- newIORef emptyNameEnv let plugin_hsc_env = plugin_hsc_env' { hsc_type_env_vars = knotVarsFromModuleEnv (mkModuleEnv [(mod, type_env_var)]) } status <- hscRecompStatus (Just msg) plugin_hsc_env mod_summary Nothing emptyHomeModInfoLinkable (1, 1) return (plugin_hsc_env, mod_summary, status) -- | Calculate the ModLocation from the provided DynFlags. This function is only used -- in one-shot mode and therefore takes into account the effect of -o/-ohi flags -- (which do nothing in --make mode) mkOneShotModLocation :: PipeEnv -> DynFlags -> HscSource -> ModuleName -> IO ModLocation mkOneShotModLocation pipe_env dflags src_flavour mod_name = do let PipeEnv{ src_basename=basename, src_suffix=suff } = pipe_env let location1 = mkHomeModLocation2 fopts mod_name basename suff -- Boot-ify it if necessary let location2 | HsBootFile <- src_flavour = addBootSuffixLocnOut location1 | otherwise = location1 -- Take -ohi into account if present -- This can't be done in mkHomeModuleLocation because -- it only applies to the module being compiles let ohi = outputHi dflags location3 | Just fn <- ohi = location2{ ml_hi_file = fn } | otherwise = location2 let dynohi = dynOutputHi dflags location4 | Just fn <- dynohi = location3{ ml_dyn_hi_file = fn } | otherwise = location3 -- Take -o into account if present -- Very like -ohi, but we must *only* do this if we aren't linking -- (If we're linking then the -o applies to the linked thing, not to -- the object file for one module.) -- Note the nasty duplication with the same computation in compileFile -- above let expl_o_file = outputFile_ dflags expl_dyn_o_file = dynOutputFile_ dflags location5 | Just ofile <- expl_o_file , let dyn_ofile = fromMaybe (ofile -<.> dynObjectSuf_ dflags) expl_dyn_o_file , isNoLink (ghcLink dflags) = location4 { ml_obj_file = ofile , ml_dyn_obj_file = dyn_ofile } | Just dyn_ofile <- expl_dyn_o_file = location4 { ml_dyn_obj_file = dyn_ofile } | otherwise = location4 return location5 where fopts = initFinderOpts dflags runHscTcPhase :: HscEnv -> ModSummary -> IO (FrontendResult, Messages GhcMessage) runHscTcPhase = hscTypecheckAndGetWarnings runHscPostTcPhase :: HscEnv -> ModSummary -> FrontendResult -> Messages GhcMessage -> Maybe Fingerprint -> IO HscBackendAction runHscPostTcPhase hsc_env mod_summary tc_result tc_warnings mb_old_hash = do runHsc hsc_env $ do hscDesugarAndSimplify mod_summary tc_result tc_warnings mb_old_hash runHsPpPhase :: HscEnv -> FilePath -> FilePath -> FilePath -> IO FilePath runHsPpPhase hsc_env orig_fn input_fn output_fn = do let dflags = hsc_dflags hsc_env let logger = hsc_logger hsc_env GHC.SysTools.runPp logger dflags ( [ GHC.SysTools.Option orig_fn , GHC.SysTools.Option input_fn , GHC.SysTools.FileOption "" output_fn ] ) return output_fn phaseOutputFilenameNew :: Phase -- ^ The next phase -> PipeEnv -> HscEnv -> Maybe ModLocation -- ^ A ModLocation, if we are compiling a Haskell source file -> IO FilePath phaseOutputFilenameNew next_phase pipe_env hsc_env maybe_loc = do let PipeEnv{stop_phase, src_basename, output_spec} = pipe_env let dflags = hsc_dflags hsc_env logger = hsc_logger hsc_env tmpfs = hsc_tmpfs hsc_env getOutputFilename logger tmpfs (stopPhaseToPhase stop_phase) output_spec src_basename dflags next_phase maybe_loc -- | Computes the next output filename for something in the compilation -- pipeline. This is controlled by several variables: -- -- 1. 'Phase': the last phase to be run (e.g. 'stopPhase'). This -- is used to tell if we're in the last phase or not, because -- in that case flags like @-o@ may be important. -- 2. 'PipelineOutput': is this intended to be a 'Temporary' or -- 'Persistent' build output? Temporary files just go in -- a fresh temporary name. -- 3. 'String': what was the basename of the original input file? -- 4. 'DynFlags': the obvious thing -- 5. 'Phase': the phase we want to determine the output filename of. -- 6. @Maybe ModLocation@: the 'ModLocation' of the module we're -- compiling; this can be used to override the default output -- of an object file. (TODO: do we actually need this?) getOutputFilename :: Logger -> TmpFs -> Phase -> PipelineOutput -> String -> DynFlags -> Phase -- next phase -> Maybe ModLocation -> IO FilePath getOutputFilename logger tmpfs stop_phase output basename dflags next_phase maybe_location -- 1. If we are generating object files for a .hs file, then return the odir as the ModLocation -- will have been modified to point to the accurate locations | StopLn <- next_phase, Just loc <- maybe_location = return $ if dynamicNow dflags then ml_dyn_obj_file loc else ml_obj_file loc -- 2. If output style is persistent then | is_last_phase, Persistent <- output = persistent_fn -- 3. Specific file is only set when outputFile is set by -o -- If we are in dynamic mode but -dyno is not set then write to the same path as -- -o with a .dyn_* extension. This case is not triggered for object files which -- are always handled by the ModLocation. | is_last_phase, SpecificFile <- output = return $ if dynamicNow dflags then case dynOutputFile_ dflags of Nothing -> let ofile = getOutputFile_ dflags new_ext = case takeExtension ofile of "" -> "dyn" ext -> "dyn_" ++ tail ext in replaceExtension ofile new_ext Just fn -> fn else getOutputFile_ dflags | keep_this_output = persistent_fn | Temporary lifetime <- output = newTempName logger tmpfs (tmpDir dflags) lifetime suffix | otherwise = newTempName logger tmpfs (tmpDir dflags) TFL_CurrentModule suffix where getOutputFile_ dflags = case outputFile_ dflags of Nothing -> pprPanic "SpecificFile: No filename" (ppr (dynamicNow dflags) $$ text (fromMaybe "-" (dynOutputFile_ dflags))) Just fn -> fn hcsuf = hcSuf dflags odir = objectDir dflags osuf = objectSuf dflags keep_hc = gopt Opt_KeepHcFiles dflags keep_hscpp = gopt Opt_KeepHscppFiles dflags keep_s = gopt Opt_KeepSFiles dflags keep_bc = gopt Opt_KeepLlvmFiles dflags myPhaseInputExt HCc = hcsuf myPhaseInputExt MergeForeign = osuf myPhaseInputExt StopLn = osuf myPhaseInputExt other = phaseInputExt other is_last_phase = next_phase `eqPhase` stop_phase -- sometimes, we keep output from intermediate stages keep_this_output = case next_phase of As _ | keep_s -> True LlvmOpt | keep_bc -> True HCc | keep_hc -> True HsPp _ | keep_hscpp -> True -- See #10869 _other -> False suffix = myPhaseInputExt next_phase -- persistent object files get put in odir persistent_fn | StopLn <- next_phase = return odir_persistent | otherwise = return persistent persistent = basename <.> suffix odir_persistent | Just d <- odir = (d persistent) | otherwise = persistent -- | LLVM Options. These are flags to be passed to opt and llc, to ensure -- consistency we list them in pairs, so that they form groups. llvmOptions :: LlvmConfig -> DynFlags -> [(String, String)] -- ^ pairs of (opt, llc) arguments llvmOptions llvm_config dflags = [("-enable-tbaa -tbaa", "-enable-tbaa") | gopt Opt_LlvmTBAA dflags ] ++ [("-relocation-model=" ++ rmodel ,"-relocation-model=" ++ rmodel) | not (null rmodel)] ++ [("-stack-alignment=" ++ (show align) ,"-stack-alignment=" ++ (show align)) | align > 0 ] -- Additional llc flags ++ [("", "-mcpu=" ++ mcpu) | not (null mcpu) , not (any (isInfixOf "-mcpu") (getOpts dflags opt_lc)) ] ++ [("", "-mattr=" ++ attrs) | not (null attrs) ] ++ [("", "-target-abi=" ++ abi) | not (null abi) ] where target = platformMisc_llvmTarget $ platformMisc dflags Just (LlvmTarget _ mcpu mattr) = lookup target (llvmTargets llvm_config) -- Relocation models rmodel | gopt Opt_PIC dflags = "pic" | positionIndependent dflags = "pic" | ways dflags `hasWay` WayDyn = "dynamic-no-pic" | otherwise = "static" platform = targetPlatform dflags align :: Int align = case platformArch platform of ArchX86_64 | isAvxEnabled dflags -> 32 _ -> 0 attrs :: String attrs = intercalate "," $ mattr ++ ["+sse42" | isSse4_2Enabled dflags ] ++ ["+sse2" | isSse2Enabled platform ] ++ ["+sse" | isSseEnabled platform ] ++ ["+avx512f" | isAvx512fEnabled dflags ] ++ ["+avx2" | isAvx2Enabled dflags ] ++ ["+avx" | isAvxEnabled dflags ] ++ ["+avx512cd"| isAvx512cdEnabled dflags ] ++ ["+avx512er"| isAvx512erEnabled dflags ] ++ ["+avx512pf"| isAvx512pfEnabled dflags ] ++ ["+bmi" | isBmiEnabled dflags ] ++ ["+bmi2" | isBmi2Enabled dflags ] abi :: String abi = case platformArch (targetPlatform dflags) of ArchRISCV64 -> "lp64d" ArchLoongArch64 -> "lp64d" _ -> "" -- | What phase to run after one of the backend code generators has run hscPostBackendPhase :: HscSource -> Backend -> Phase hscPostBackendPhase HsBootFile _ = StopLn hscPostBackendPhase HsigFile _ = StopLn hscPostBackendPhase _ bcknd = backendNormalSuccessorPhase bcknd compileStub :: HscEnv -> FilePath -> IO FilePath compileStub hsc_env stub_c = compileForeign hsc_env LangC stub_c -- --------------------------------------------------------------------------- -- join object files into a single relocatable object file, using ld -r {- Note [Produce big objects on Windows] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The Windows Portable Executable object format has a limit of 32k sections, which we tend to blow through pretty easily. Thankfully, there is a "big object" extension, which raises this limit to 2^32. However, it must be explicitly enabled in the toolchain: * the assembler accepts the -mbig-obj flag, which causes it to produce a bigobj-enabled COFF object. * the linker accepts the --oformat pe-bigobj-x86-64 flag. Despite what the name suggests, this tells the linker to produce a bigobj-enabled COFF object, no a PE executable. Previously when we used ld.bfd we had to enable bigobj output in a few places: * When merging object files (GHC.Driver.Pipeline.Execute.joinObjectFiles) * When assembling (GHC.Driver.Pipeline.runPhase (RealPhase As ...)) However, this is no longer necessary with ld.lld, which detects that the object is large on its own. Unfortunately the big object format is not supported on 32-bit targets so none of this can be used in that case. Note [Object merging] ~~~~~~~~~~~~~~~~~~~~~ On most platforms one can "merge" a set of relocatable object files into a new, partially-linked-but-still-relocatable object. In a typical UNIX-style linker, this is accomplished with the `ld -r` command. We rely on this for two ends: * We rely on `ld -r` to squash together split sections, making GHCi loading more efficient. See Note [Merging object files for GHCi]. * We use merging to combine a module's object code (e.g. produced by the NCG) with its foreign stubs (typically produced by a C compiler). The command used for object linking is set using the -pgmlm and -optlm command-line options. Sadly, the LLD linker that we use on Windows does not support the `-r` flag needed to support object merging (see #21068). For this reason on Windows we do not support GHCi objects. To deal with foreign stubs we build a static archive of all of a module's object files instead merging them. Consequently, we can end up producing `.o` files which are in fact static archives. However, toolchains generally don't have a problem with this as they use file headers, not the filename, to determine the nature of inputs. Note that this has somewhat non-obvious consequences when producing initializers and finalizers. See Note [Initializers and finalizers in Cmm] in GHC.Cmm.InitFini for details. Note [Merging object files for GHCi] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GHCi can usually loads standard linkable object files using GHC's linker implementation. However, most users build their projects with -split-sections, meaning that such object files can have an extremely high number of sections. As the linker must map each of these sections individually, loading such object files is very inefficient. To avoid this inefficiency, we use the linker's `-r` flag and a linker script to produce a merged relocatable object file. This file will contain a singe text section section and can consequently be mapped far more efficiently. As gcc tends to do unpredictable things to our linker command line, we opt to invoke ld directly in this case, in contrast to our usual strategy of linking via gcc. -} -- | See Note [Object merging]. joinObjectFiles :: HscEnv -> [FilePath] -> FilePath -> IO () joinObjectFiles hsc_env o_files output_fn | can_merge_objs && not dashLSupported = do let toolSettings' = toolSettings dflags ldIsGnuLd = toolSettings_ldIsGnuLd toolSettings' ld_r args = GHC.SysTools.runMergeObjects (hsc_logger hsc_env) (hsc_tmpfs hsc_env) (hsc_dflags hsc_env) ( [ GHC.SysTools.Option "-o", GHC.SysTools.FileOption "" output_fn ] ++ args) if ldIsGnuLd then do script <- newTempName logger tmpfs (tmpDir dflags) TFL_CurrentModule "ldscript" cwd <- getCurrentDirectory let o_files_abs = map (\x -> "\"" ++ (cwd x) ++ "\"") o_files writeFile script $ "INPUT(" ++ unwords o_files_abs ++ ")" ld_r [GHC.SysTools.FileOption "" script] else if toolSettings_ldSupportsFilelist toolSettings' then do filelist <- newTempName logger tmpfs (tmpDir dflags) TFL_CurrentModule "filelist" writeFile filelist $ unlines o_files ld_r [GHC.SysTools.Option "-filelist", GHC.SysTools.FileOption "" filelist] else ld_r (map (GHC.SysTools.FileOption "") o_files) | otherwise = do withAtomicRename output_fn $ \tmp_ar -> liftIO $ runAr logger dflags Nothing $ map Option $ ["qc" ++ dashL, tmp_ar] ++ o_files where dashLSupported = sArSupportsDashL (settings dflags) dashL = if dashLSupported then "L" else "" can_merge_objs = isJust (pgm_lm (hsc_dflags hsc_env)) dflags = hsc_dflags hsc_env tmpfs = hsc_tmpfs hsc_env logger = hsc_logger hsc_env ----------------------------------------------------------------------------- -- Look for the /* GHC_PACKAGES ... */ comment at the top of a .hc file getHCFilePackages :: FilePath -> IO [UnitId] getHCFilePackages filename = withFile filename ReadMode $ \h -> do l <- hGetLine h case l of '/':'*':' ':'G':'H':'C':'_':'P':'A':'C':'K':'A':'G':'E':'S':rest -> return (map stringToUnitId (words rest)) _other -> return [] linkDynLibCheck :: Logger -> TmpFs -> DynFlags -> UnitEnv -> [String] -> [UnitId] -> IO () linkDynLibCheck logger tmpfs dflags unit_env o_files dep_units = do when (haveRtsOptsFlags dflags) $ logMsg logger MCInfo noSrcSpan $ withPprStyle defaultUserStyle (text "Warning: -rtsopts and -with-rtsopts have no effect with -shared." $$ text " Call hs_init_ghc() from your main() function to set these options.") linkDynLib logger tmpfs dflags unit_env o_files dep_units -- ----------------------------------------------------------------------------- -- Misc. touchObjectFile :: Logger -> DynFlags -> FilePath -> IO () touchObjectFile logger dflags path = do createDirectoryIfMissing True $ takeDirectory path GHC.SysTools.touch logger dflags "Touching object file" path -- Note [-fPIC for assembler] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~ -- When compiling .c source file GHC's driver pipeline basically -- does the following two things: -- 1. ${CC} -S 'PIC_CFLAGS' source.c -- 2. ${CC} -x assembler -c 'PIC_CFLAGS' source.S -- -- Why do we need to pass 'PIC_CFLAGS' both to C compiler and assembler? -- Because on some architectures (at least sparc32) assembler also chooses -- the relocation type! -- Consider the following C module: -- -- /* pic-sample.c */ -- int v; -- void set_v (int n) { v = n; } -- int get_v (void) { return v; } -- -- $ gcc -S -fPIC pic-sample.c -- $ gcc -c pic-sample.s -o pic-sample.no-pic.o # incorrect binary -- $ gcc -c -fPIC pic-sample.s -o pic-sample.pic.o # correct binary -- -- $ objdump -r -d pic-sample.pic.o > pic-sample.pic.o.od -- $ objdump -r -d pic-sample.no-pic.o > pic-sample.no-pic.o.od -- $ diff -u pic-sample.pic.o.od pic-sample.no-pic.o.od -- -- Most of architectures won't show any difference in this test, but on sparc32 -- the following assembly snippet: -- -- sethi %hi(_GLOBAL_OFFSET_TABLE_-8), %l7 -- -- generates two kinds or relocations, only 'R_SPARC_PC22' is correct: -- -- 3c: 2f 00 00 00 sethi %hi(0), %l7 -- - 3c: R_SPARC_PC22 _GLOBAL_OFFSET_TABLE_-0x8 -- + 3c: R_SPARC_HI22 _GLOBAL_OFFSET_TABLE_-0x8 {- Note [Don't normalise input filenames] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Summary We used to normalise input filenames when starting the unlit phase. This broke hpc in `--make` mode with imported literate modules (#2991). Introduction 1) --main When compiling a module with --main, GHC scans its imports to find out which other modules it needs to compile too. It turns out that there is a small difference between saying `ghc --make A.hs`, when `A` imports `B`, and specifying both modules on the command line with `ghc --make A.hs B.hs`. In the former case, the filename for B is inferred to be './B.hs' instead of 'B.hs'. 2) unlit When GHC compiles a literate haskell file, the source code first needs to go through unlit, which turns it into normal Haskell source code. At the start of the unlit phase, in `Driver.Pipeline.runPhase`, we call unlit with the option `-h` and the name of the original file. We used to normalise this filename using System.FilePath.normalise, which among other things removes an initial './'. unlit then uses that filename in #line directives that it inserts in the transformed source code. 3) SrcSpan A SrcSpan represents a portion of a source code file. It has fields linenumber, start column, end column, and also a reference to the file it originated from. The SrcSpans for a literate haskell file refer to the filename that was passed to unlit -h. 4) -fhpc At some point during compilation with -fhpc, in the function `GHC.HsToCore.Ticks.isGoodTickSrcSpan`, we compare the filename that a `SrcSpan` refers to with the name of the file we are currently compiling. For some reason I don't yet understand, they can sometimes legitimately be different, and then hpc ignores that SrcSpan. Problem When running `ghc --make -fhpc A.hs`, where `A.hs` imports the literate module `B.lhs`, `B` is inferred to be in the file `./B.lhs` (1). At the start of the unlit phase, the name `./B.lhs` is normalised to `B.lhs` (2). Therefore the SrcSpans of `B` refer to the file `B.lhs` (3), but we are still compiling `./B.lhs`. Hpc thinks these two filenames are different (4), doesn't include ticks for B, and we have unhappy customers (#2991). Solution Do not normalise `input_fn` when starting the unlit phase. Alternative solution Another option would be to not compare the two filenames on equality, but to use System.FilePath.equalFilePath. That function first normalises its arguments. The problem is that by the time we need to do the comparison, the filenames have been turned into FastStrings, probably for performance reasons, so System.FilePath.equalFilePath can not be used directly. Archeology The call to `normalise` was added in a commit called "Fix slash direction on Windows with the new filePath code" (c9b6b5e8). The problem that commit was addressing has since been solved in a different manner, in a commit called "Fix the filename passed to unlit" (1eedbc6b). So the `normalise` is no longer necessary. -} {- Note [-Wa,--no-type-check on wasm32] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Wasm32 has a type system and corresponding validation rules, so it's possible to produce syntactically valid object code that doesn't pass validation. We have no problem with that, but we do have a problem with clang. When clang takes an assembly input for wasm32, it uses its internal type-checker, which is a huge source of trouble (see llvm ticket #56935 #58438): it may reject valid assembly, and even worse, it may silently alter the output object code!!! The worsest of all, is the person that added the wasm32 asm typechecker logic has moved on from Google/LLVM, and while other LLVM devs may be knowledgable enough to fix this mess, they likely got tons of other stuff on their table and don't care enough. We do have an escape hatch, just pass -Wa,--no-type-check to clang to bypass the entire wasm32 asm typechecking logic. There's little point in type-checking object code at compile-time anyway, the wasm engines will do type-checking at run-time. And even if we want to add some linting flag to do compile-time checks, we should just rely on battle-tested external tools instead of a completely broken horror story. -}