{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE CPP #-} ----------------------------------------------------------------------------- -- | -- Module : Distribution.Simple.GHC -- Copyright : Isaac Jones 2003-2007 -- License : BSD3 -- -- Maintainer : cabal-devel@haskell.org -- Portability : portable -- -- This is a fairly large module. It contains most of the GHC-specific code for -- configuring, building and installing packages. It also exports a function -- for finding out what packages are already installed. Configuring involves -- finding the @ghc@ and @ghc-pkg@ programs, finding what language extensions -- this version of ghc supports and returning a 'Compiler' value. -- -- 'getInstalledPackages' involves calling the @ghc-pkg@ program to find out -- what packages are installed. -- -- Building is somewhat complex as there is quite a bit of information to take -- into account. We have to build libs and programs, possibly for profiling and -- shared libs. We have to support building libraries that will be usable by -- GHCi and also ghc's @-split-objs@ feature. We have to compile any C files -- using ghc. Linking, especially for @split-objs@ is remarkably complex, -- partly because there tend to be 1,000's of @.o@ files and this can often be -- more than we can pass to the @ld@ or @ar@ programs in one go. -- -- Installing for libs and exes involves finding the right files and copying -- them to the right places. One of the more tricky things about this module is -- remembering the layout of files in the build directory (which is not -- explicitly documented) and thus what search dirs are used for various kinds -- of files. module Distribution.Simple.GHC ( getGhcInfo, configure, getInstalledPackages, getInstalledPackagesMonitorFiles, getPackageDBContents, buildLib, buildFLib, buildExe, replLib, replFLib, replExe, startInterpreter, installLib, installFLib, installExe, libAbiHash, hcPkgInfo, registerPackage, componentGhcOptions, componentCcGhcOptions, getLibDir, isDynamic, getGlobalPackageDB, pkgRoot, -- * Constructing GHC environment files Internal.GhcEnvironmentFileEntry(..), Internal.simpleGhcEnvironmentFile, Internal.writeGhcEnvironmentFile, -- * Version-specific implementation quirks getImplInfo, GhcImplInfo(..) ) where import Prelude () import Distribution.Compat.Prelude import qualified Distribution.Simple.GHC.IPI642 as IPI642 import qualified Distribution.Simple.GHC.Internal as Internal import Distribution.Simple.GHC.ImplInfo import Distribution.PackageDescription.Utils (cabalBug) import Distribution.PackageDescription as PD import Distribution.InstalledPackageInfo (InstalledPackageInfo) import qualified Distribution.InstalledPackageInfo as InstalledPackageInfo import Distribution.Simple.PackageIndex (InstalledPackageIndex) import qualified Distribution.Simple.PackageIndex as PackageIndex import Distribution.Simple.LocalBuildInfo import Distribution.Types.ComponentLocalBuildInfo import qualified Distribution.Simple.Hpc as Hpc import Distribution.Simple.BuildPaths import Distribution.Simple.Utils import Distribution.Package import qualified Distribution.ModuleName as ModuleName import Distribution.ModuleName (ModuleName) import Distribution.Simple.Program import Distribution.Simple.Program.Builtin (runghcProgram) import qualified Distribution.Simple.Program.HcPkg as HcPkg import qualified Distribution.Simple.Program.Ar as Ar import qualified Distribution.Simple.Program.Ld as Ld import qualified Distribution.Simple.Program.Strip as Strip import Distribution.Simple.Program.GHC import Distribution.Simple.Setup import qualified Distribution.Simple.Setup as Cabal import Distribution.Simple.Compiler hiding (Flag) import Distribution.Version import Distribution.System import Distribution.Verbosity import Distribution.Text import Distribution.Types.ForeignLib import Distribution.Types.ForeignLibType import Distribution.Types.ForeignLibOption import Distribution.Types.UnqualComponentName import Distribution.Utils.NubList import Language.Haskell.Extension import Control.Monad (msum) import Data.Char (isLower) import qualified Data.Map as Map import System.Directory ( doesFileExist, getAppUserDataDirectory, createDirectoryIfMissing , canonicalizePath, removeFile, renameFile ) import System.FilePath ( (), (<.>), takeExtension , takeDirectory, replaceExtension ,isRelative ) import qualified System.Info #ifndef mingw32_HOST_OS import System.Posix (createSymbolicLink) #endif /* mingw32_HOST_OS */ -- ----------------------------------------------------------------------------- -- Configuring configure :: Verbosity -> Maybe FilePath -> Maybe FilePath -> ProgramDb -> IO (Compiler, Maybe Platform, ProgramDb) configure verbosity hcPath hcPkgPath conf0 = do (ghcProg, ghcVersion, progdb1) <- requireProgramVersion verbosity ghcProgram (orLaterVersion (mkVersion [6,11])) (userMaybeSpecifyPath "ghc" hcPath conf0) let implInfo = ghcVersionImplInfo ghcVersion -- Cabal 2.2 supports ghc >= 6.11 && < 8.5 unless (ghcVersion < mkVersion [8,5]) $ warn verbosity $ "Unknown/unsupported 'ghc' version detected " ++ "(Cabal " ++ display cabalVersion ++ " supports 'ghc' version < 8.5): " ++ programPath ghcProg ++ " is version " ++ display ghcVersion -- This is slightly tricky, we have to configure ghc first, then we use the -- location of ghc to help find ghc-pkg in the case that the user did not -- specify the location of ghc-pkg directly: (ghcPkgProg, ghcPkgVersion, progdb2) <- requireProgramVersion verbosity ghcPkgProgram { programFindLocation = guessGhcPkgFromGhcPath ghcProg } anyVersion (userMaybeSpecifyPath "ghc-pkg" hcPkgPath progdb1) when (ghcVersion /= ghcPkgVersion) $ die' verbosity $ "Version mismatch between ghc and ghc-pkg: " ++ programPath ghcProg ++ " is version " ++ display ghcVersion ++ " " ++ programPath ghcPkgProg ++ " is version " ++ display ghcPkgVersion -- Likewise we try to find the matching hsc2hs and haddock programs. let hsc2hsProgram' = hsc2hsProgram { programFindLocation = guessHsc2hsFromGhcPath ghcProg } haddockProgram' = haddockProgram { programFindLocation = guessHaddockFromGhcPath ghcProg } hpcProgram' = hpcProgram { programFindLocation = guessHpcFromGhcPath ghcProg } runghcProgram' = runghcProgram { programFindLocation = guessRunghcFromGhcPath ghcProg } progdb3 = addKnownProgram haddockProgram' $ addKnownProgram hsc2hsProgram' $ addKnownProgram hpcProgram' $ addKnownProgram runghcProgram' progdb2 languages <- Internal.getLanguages verbosity implInfo ghcProg extensions0 <- Internal.getExtensions verbosity implInfo ghcProg ghcInfo <- Internal.getGhcInfo verbosity implInfo ghcProg let ghcInfoMap = Map.fromList ghcInfo extensions = -- workaround https://ghc.haskell.org/ticket/11214 filterExt JavaScriptFFI $ -- see 'filterExtTH' comment below filterExtTH $ extensions0 -- starting with GHC 8.0, `TemplateHaskell` will be omitted from -- `--supported-extensions` when it's not available. -- for older GHCs we can use the "Have interpreter" property to -- filter out `TemplateHaskell` filterExtTH | ghcVersion < mkVersion [8] , Just "NO" <- Map.lookup "Have interpreter" ghcInfoMap = filterExt TemplateHaskell | otherwise = id filterExt ext = filter ((/= EnableExtension ext) . fst) let comp = Compiler { compilerId = CompilerId GHC ghcVersion, compilerAbiTag = NoAbiTag, compilerCompat = [], compilerLanguages = languages, compilerExtensions = extensions, compilerProperties = ghcInfoMap } compPlatform = Internal.targetPlatform ghcInfo -- configure gcc and ld progdb4 = Internal.configureToolchain implInfo ghcProg ghcInfoMap progdb3 return (comp, compPlatform, progdb4) -- | Given something like /usr/local/bin/ghc-6.6.1(.exe) we try and find -- the corresponding tool; e.g. if the tool is ghc-pkg, we try looking -- for a versioned or unversioned ghc-pkg in the same dir, that is: -- -- > /usr/local/bin/ghc-pkg-ghc-6.6.1(.exe) -- > /usr/local/bin/ghc-pkg-6.6.1(.exe) -- > /usr/local/bin/ghc-pkg(.exe) -- guessToolFromGhcPath :: Program -> ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessToolFromGhcPath tool ghcProg verbosity searchpath = do let toolname = programName tool given_path = programPath ghcProg given_dir = takeDirectory given_path real_path <- canonicalizePath given_path let real_dir = takeDirectory real_path versionSuffix path = takeVersionSuffix (dropExeExtension path) given_suf = versionSuffix given_path real_suf = versionSuffix real_path guessNormal dir = dir toolname <.> exeExtension guessGhcVersioned dir suf = dir (toolname ++ "-ghc" ++ suf) <.> exeExtension guessVersioned dir suf = dir (toolname ++ suf) <.> exeExtension mkGuesses dir suf | null suf = [guessNormal dir] | otherwise = [guessGhcVersioned dir suf, guessVersioned dir suf, guessNormal dir] guesses = mkGuesses given_dir given_suf ++ if real_path == given_path then [] else mkGuesses real_dir real_suf info verbosity $ "looking for tool " ++ toolname ++ " near compiler in " ++ given_dir debug verbosity $ "candidate locations: " ++ show guesses exists <- traverse doesFileExist guesses case [ file | (file, True) <- zip guesses exists ] of -- If we can't find it near ghc, fall back to the usual -- method. [] -> programFindLocation tool verbosity searchpath (fp:_) -> do info verbosity $ "found " ++ toolname ++ " in " ++ fp let lookedAt = map fst . takeWhile (\(_file, exist) -> not exist) $ zip guesses exists return (Just (fp, lookedAt)) where takeVersionSuffix :: FilePath -> String takeVersionSuffix = takeWhileEndLE isSuffixChar isSuffixChar :: Char -> Bool isSuffixChar c = isDigit c || c == '.' || c == '-' -- | Given something like /usr/local/bin/ghc-6.6.1(.exe) we try and find a -- corresponding ghc-pkg, we try looking for both a versioned and unversioned -- ghc-pkg in the same dir, that is: -- -- > /usr/local/bin/ghc-pkg-ghc-6.6.1(.exe) -- > /usr/local/bin/ghc-pkg-6.6.1(.exe) -- > /usr/local/bin/ghc-pkg(.exe) -- guessGhcPkgFromGhcPath :: ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessGhcPkgFromGhcPath = guessToolFromGhcPath ghcPkgProgram -- | Given something like /usr/local/bin/ghc-6.6.1(.exe) we try and find a -- corresponding hsc2hs, we try looking for both a versioned and unversioned -- hsc2hs in the same dir, that is: -- -- > /usr/local/bin/hsc2hs-ghc-6.6.1(.exe) -- > /usr/local/bin/hsc2hs-6.6.1(.exe) -- > /usr/local/bin/hsc2hs(.exe) -- guessHsc2hsFromGhcPath :: ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessHsc2hsFromGhcPath = guessToolFromGhcPath hsc2hsProgram -- | Given something like /usr/local/bin/ghc-6.6.1(.exe) we try and find a -- corresponding haddock, we try looking for both a versioned and unversioned -- haddock in the same dir, that is: -- -- > /usr/local/bin/haddock-ghc-6.6.1(.exe) -- > /usr/local/bin/haddock-6.6.1(.exe) -- > /usr/local/bin/haddock(.exe) -- guessHaddockFromGhcPath :: ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessHaddockFromGhcPath = guessToolFromGhcPath haddockProgram guessHpcFromGhcPath :: ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessHpcFromGhcPath = guessToolFromGhcPath hpcProgram guessRunghcFromGhcPath :: ConfiguredProgram -> Verbosity -> ProgramSearchPath -> IO (Maybe (FilePath, [FilePath])) guessRunghcFromGhcPath = guessToolFromGhcPath runghcProgram getGhcInfo :: Verbosity -> ConfiguredProgram -> IO [(String, String)] getGhcInfo verbosity ghcProg = Internal.getGhcInfo verbosity implInfo ghcProg where Just version = programVersion ghcProg implInfo = ghcVersionImplInfo version -- | Given a single package DB, return all installed packages. getPackageDBContents :: Verbosity -> PackageDB -> ProgramDb -> IO InstalledPackageIndex getPackageDBContents verbosity packagedb progdb = do pkgss <- getInstalledPackages' verbosity [packagedb] progdb toPackageIndex verbosity pkgss progdb -- | Given a package DB stack, return all installed packages. getInstalledPackages :: Verbosity -> Compiler -> PackageDBStack -> ProgramDb -> IO InstalledPackageIndex getInstalledPackages verbosity comp packagedbs progdb = do checkPackageDbEnvVar verbosity checkPackageDbStack verbosity comp packagedbs pkgss <- getInstalledPackages' verbosity packagedbs progdb index <- toPackageIndex verbosity pkgss progdb return $! hackRtsPackage index where hackRtsPackage index = case PackageIndex.lookupPackageName index (mkPackageName "rts") of [(_,[rts])] -> PackageIndex.insert (removeMingwIncludeDir rts) index _ -> index -- No (or multiple) ghc rts package is registered!! -- Feh, whatever, the ghc test suite does some crazy stuff. -- | Given a list of @(PackageDB, InstalledPackageInfo)@ pairs, produce a -- @PackageIndex@. Helper function used by 'getPackageDBContents' and -- 'getInstalledPackages'. toPackageIndex :: Verbosity -> [(PackageDB, [InstalledPackageInfo])] -> ProgramDb -> IO InstalledPackageIndex toPackageIndex verbosity pkgss progdb = do -- On Windows, various fields have $topdir/foo rather than full -- paths. We need to substitute the right value in so that when -- we, for example, call gcc, we have proper paths to give it. topDir <- getLibDir' verbosity ghcProg let indices = [ PackageIndex.fromList (map (Internal.substTopDir topDir) pkgs) | (_, pkgs) <- pkgss ] return $! mconcat indices where Just ghcProg = lookupProgram ghcProgram progdb getLibDir :: Verbosity -> LocalBuildInfo -> IO FilePath getLibDir verbosity lbi = dropWhileEndLE isSpace `fmap` getDbProgramOutput verbosity ghcProgram (withPrograms lbi) ["--print-libdir"] getLibDir' :: Verbosity -> ConfiguredProgram -> IO FilePath getLibDir' verbosity ghcProg = dropWhileEndLE isSpace `fmap` getProgramOutput verbosity ghcProg ["--print-libdir"] -- | Return the 'FilePath' to the global GHC package database. getGlobalPackageDB :: Verbosity -> ConfiguredProgram -> IO FilePath getGlobalPackageDB verbosity ghcProg = dropWhileEndLE isSpace `fmap` getProgramOutput verbosity ghcProg ["--print-global-package-db"] -- | Return the 'FilePath' to the per-user GHC package database. getUserPackageDB :: Verbosity -> ConfiguredProgram -> Platform -> NoCallStackIO FilePath getUserPackageDB _verbosity ghcProg platform = do -- It's rather annoying that we have to reconstruct this, because ghc -- hides this information from us otherwise. But for certain use cases -- like change monitoring it really can't remain hidden. appdir <- getAppUserDataDirectory "ghc" return (appdir platformAndVersion packageConfFileName) where platformAndVersion = Internal.ghcPlatformAndVersionString platform ghcVersion packageConfFileName | ghcVersion >= mkVersion [6,12] = "package.conf.d" | otherwise = "package.conf" Just ghcVersion = programVersion ghcProg checkPackageDbEnvVar :: Verbosity -> IO () checkPackageDbEnvVar verbosity = Internal.checkPackageDbEnvVar verbosity "GHC" "GHC_PACKAGE_PATH" checkPackageDbStack :: Verbosity -> Compiler -> PackageDBStack -> IO () checkPackageDbStack verbosity comp = if flagPackageConf implInfo then checkPackageDbStackPre76 verbosity else checkPackageDbStackPost76 verbosity where implInfo = ghcVersionImplInfo (compilerVersion comp) checkPackageDbStackPost76 :: Verbosity -> PackageDBStack -> IO () checkPackageDbStackPost76 _ (GlobalPackageDB:rest) | GlobalPackageDB `notElem` rest = return () checkPackageDbStackPost76 verbosity rest | GlobalPackageDB `elem` rest = die' verbosity $ "If the global package db is specified, it must be " ++ "specified first and cannot be specified multiple times" checkPackageDbStackPost76 _ _ = return () checkPackageDbStackPre76 :: Verbosity -> PackageDBStack -> IO () checkPackageDbStackPre76 _ (GlobalPackageDB:rest) | GlobalPackageDB `notElem` rest = return () checkPackageDbStackPre76 verbosity rest | GlobalPackageDB `notElem` rest = die' verbosity $ "With current ghc versions the global package db is always used " ++ "and must be listed first. This ghc limitation is lifted in GHC 7.6," ++ "see http://hackage.haskell.org/trac/ghc/ticket/5977" checkPackageDbStackPre76 verbosity _ = die' verbosity $ "If the global package db is specified, it must be " ++ "specified first and cannot be specified multiple times" -- GHC < 6.10 put "$topdir/include/mingw" in rts's installDirs. This -- breaks when you want to use a different gcc, so we need to filter -- it out. removeMingwIncludeDir :: InstalledPackageInfo -> InstalledPackageInfo removeMingwIncludeDir pkg = let ids = InstalledPackageInfo.includeDirs pkg ids' = filter (not . ("mingw" `isSuffixOf`)) ids in pkg { InstalledPackageInfo.includeDirs = ids' } -- | Get the packages from specific PackageDBs, not cumulative. -- getInstalledPackages' :: Verbosity -> [PackageDB] -> ProgramDb -> IO [(PackageDB, [InstalledPackageInfo])] getInstalledPackages' verbosity packagedbs progdb | ghcVersion >= mkVersion [6,9] = sequenceA [ do pkgs <- HcPkg.dump (hcPkgInfo progdb) verbosity packagedb return (packagedb, pkgs) | packagedb <- packagedbs ] where Just ghcProg = lookupProgram ghcProgram progdb Just ghcVersion = programVersion ghcProg getInstalledPackages' verbosity packagedbs progdb = do str <- getDbProgramOutput verbosity ghcPkgProgram progdb ["list"] let pkgFiles = [ init line | line <- lines str, last line == ':' ] dbFile packagedb = case (packagedb, pkgFiles) of (GlobalPackageDB, global:_) -> return $ Just global (UserPackageDB, _global:user:_) -> return $ Just user (UserPackageDB, _global:_) -> return $ Nothing (SpecificPackageDB specific, _) -> return $ Just specific _ -> die' verbosity "cannot read ghc-pkg package listing" pkgFiles' <- traverse dbFile packagedbs sequenceA [ withFileContents file $ \content -> do pkgs <- readPackages file content return (db, pkgs) | (db , Just file) <- zip packagedbs pkgFiles' ] where -- Depending on the version of ghc we use a different type's Read -- instance to parse the package file and then convert. -- It's a bit yuck. But that's what we get for using Read/Show. readPackages | ghcVersion >= mkVersion [6,4,2] = \file content -> case reads content of [(pkgs, _)] -> return (map IPI642.toCurrent pkgs) _ -> failToRead file -- We dropped support for 6.4.2 and earlier. | otherwise = \file _ -> failToRead file Just ghcProg = lookupProgram ghcProgram progdb Just ghcVersion = programVersion ghcProg failToRead file = die' verbosity $ "cannot read ghc package database " ++ file getInstalledPackagesMonitorFiles :: Verbosity -> Platform -> ProgramDb -> [PackageDB] -> IO [FilePath] getInstalledPackagesMonitorFiles verbosity platform progdb = traverse getPackageDBPath where getPackageDBPath :: PackageDB -> IO FilePath getPackageDBPath GlobalPackageDB = selectMonitorFile =<< getGlobalPackageDB verbosity ghcProg getPackageDBPath UserPackageDB = selectMonitorFile =<< getUserPackageDB verbosity ghcProg platform getPackageDBPath (SpecificPackageDB path) = selectMonitorFile path -- GHC has old style file dbs, and new style directory dbs. -- Note that for dir style dbs, we only need to monitor the cache file, not -- the whole directory. The ghc program itself only reads the cache file -- so it's safe to only monitor this one file. selectMonitorFile path = do isFileStyle <- doesFileExist path if isFileStyle then return path else return (path "package.cache") Just ghcProg = lookupProgram ghcProgram progdb -- ----------------------------------------------------------------------------- -- Building a library buildLib, replLib :: Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription -> LocalBuildInfo -> Library -> ComponentLocalBuildInfo -> IO () buildLib = buildOrReplLib False replLib = buildOrReplLib True buildOrReplLib :: Bool -> Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription -> LocalBuildInfo -> Library -> ComponentLocalBuildInfo -> IO () buildOrReplLib forRepl verbosity numJobs pkg_descr lbi lib clbi = do let uid = componentUnitId clbi libTargetDir = componentBuildDir lbi clbi whenVanillaLib forceVanilla = when (forceVanilla || withVanillaLib lbi) whenProfLib = when (withProfLib lbi) whenSharedLib forceShared = when (forceShared || withSharedLib lbi) whenStaticLib forceStatic = when (forceStatic || withStaticLib lbi) whenGHCiLib = when (withGHCiLib lbi && withVanillaLib lbi) ifReplLib = when forRepl comp = compiler lbi ghcVersion = compilerVersion comp implInfo = getImplInfo comp platform@(Platform _hostArch hostOS) = hostPlatform lbi has_code = not (componentIsIndefinite clbi) (ghcProg, _) <- requireProgram verbosity ghcProgram (withPrograms lbi) let runGhcProg = runGHC verbosity ghcProg comp platform libBi <- hackThreadedFlag verbosity comp (withProfLib lbi) (libBuildInfo lib) let isGhcDynamic = isDynamic comp dynamicTooSupported = supportsDynamicToo comp doingTH = usesTemplateHaskellOrQQ libBi forceVanillaLib = doingTH && not isGhcDynamic forceSharedLib = doingTH && isGhcDynamic -- TH always needs default libs, even when building for profiling -- Determine if program coverage should be enabled and if so, what -- '-hpcdir' should be. let isCoverageEnabled = libCoverage lbi -- TODO: Historically HPC files have been put into a directory which -- has the package name. I'm going to avoid changing this for -- now, but it would probably be better for this to be the -- component ID instead... pkg_name = display (PD.package pkg_descr) distPref = fromFlag $ configDistPref $ configFlags lbi hpcdir way | forRepl = mempty -- HPC is not supported in ghci | isCoverageEnabled = toFlag $ Hpc.mixDir distPref way pkg_name | otherwise = mempty createDirectoryIfMissingVerbose verbosity True libTargetDir -- TODO: do we need to put hs-boot files into place for mutually recursive -- modules? let cLikeFiles = fromNubListR $ toNubListR (cSources libBi) <> toNubListR (cxxSources libBi) cObjs = map (`replaceExtension` objExtension) cLikeFiles baseOpts = componentGhcOptions verbosity lbi libBi clbi libTargetDir vanillaOpts = baseOpts `mappend` mempty { ghcOptMode = toFlag GhcModeMake, ghcOptNumJobs = numJobs, ghcOptInputModules = toNubListR $ allLibModules lib clbi, ghcOptHPCDir = hpcdir Hpc.Vanilla } profOpts = vanillaOpts `mappend` mempty { ghcOptProfilingMode = toFlag True, ghcOptProfilingAuto = Internal.profDetailLevelFlag True (withProfLibDetail lbi), ghcOptHiSuffix = toFlag "p_hi", ghcOptObjSuffix = toFlag "p_o", ghcOptExtra = toNubListR $ hcProfOptions GHC libBi, ghcOptHPCDir = hpcdir Hpc.Prof } sharedOpts = vanillaOpts `mappend` mempty { ghcOptDynLinkMode = toFlag GhcDynamicOnly, ghcOptFPic = toFlag True, ghcOptHiSuffix = toFlag "dyn_hi", ghcOptObjSuffix = toFlag "dyn_o", ghcOptExtra = toNubListR $ hcSharedOptions GHC libBi, ghcOptHPCDir = hpcdir Hpc.Dyn } linkerOpts = mempty { ghcOptLinkOptions = toNubListR $ PD.ldOptions libBi, ghcOptLinkLibs = toNubListR $ extraLibs libBi, ghcOptLinkLibPath = toNubListR $ extraLibDirs libBi, ghcOptLinkFrameworks = toNubListR $ PD.frameworks libBi, ghcOptLinkFrameworkDirs = toNubListR $ PD.extraFrameworkDirs libBi, ghcOptInputFiles = toNubListR [libTargetDir x | x <- cObjs] } replOpts = vanillaOpts { ghcOptExtra = overNubListR Internal.filterGhciFlags $ ghcOptExtra vanillaOpts, ghcOptNumJobs = mempty } `mappend` linkerOpts `mappend` mempty { ghcOptMode = toFlag GhcModeInteractive, ghcOptOptimisation = toFlag GhcNoOptimisation } vanillaSharedOpts = vanillaOpts `mappend` mempty { ghcOptDynLinkMode = toFlag GhcStaticAndDynamic, ghcOptDynHiSuffix = toFlag "dyn_hi", ghcOptDynObjSuffix = toFlag "dyn_o", ghcOptHPCDir = hpcdir Hpc.Dyn } unless (forRepl || null (allLibModules lib clbi)) $ do let vanilla = whenVanillaLib forceVanillaLib (runGhcProg vanillaOpts) shared = whenSharedLib forceSharedLib (runGhcProg sharedOpts) useDynToo = dynamicTooSupported && (forceVanillaLib || withVanillaLib lbi) && (forceSharedLib || withSharedLib lbi) && null (hcSharedOptions GHC libBi) if not has_code then vanilla else if useDynToo then do runGhcProg vanillaSharedOpts case (hpcdir Hpc.Dyn, hpcdir Hpc.Vanilla) of (Cabal.Flag dynDir, Cabal.Flag vanillaDir) -> -- When the vanilla and shared library builds are done -- in one pass, only one set of HPC module interfaces -- are generated. This set should suffice for both -- static and dynamically linked executables. We copy -- the modules interfaces so they are available under -- both ways. copyDirectoryRecursive verbosity dynDir vanillaDir _ -> return () else if isGhcDynamic then do shared; vanilla else do vanilla; shared whenProfLib (runGhcProg profOpts) -- build any C++ sources seperately unless (not has_code || null (cxxSources libBi)) $ do info verbosity "Building C++ Sources..." sequence_ [ do let baseCxxOpts = Internal.componentCxxGhcOptions verbosity implInfo lbi libBi clbi libTargetDir filename vanillaCxxOpts = if isGhcDynamic then baseCxxOpts { ghcOptFPic = toFlag True } else baseCxxOpts profCxxOpts = vanillaCxxOpts `mappend` mempty { ghcOptProfilingMode = toFlag True, ghcOptObjSuffix = toFlag "p_o" } sharedCxxOpts = vanillaCxxOpts `mappend` mempty { ghcOptFPic = toFlag True, ghcOptDynLinkMode = toFlag GhcDynamicOnly, ghcOptObjSuffix = toFlag "dyn_o" } odir = fromFlag (ghcOptObjDir vanillaCxxOpts) createDirectoryIfMissingVerbose verbosity True odir let runGhcProgIfNeeded cxxOpts = do needsRecomp <- checkNeedsRecompilation filename cxxOpts when needsRecomp $ runGhcProg cxxOpts runGhcProgIfNeeded vanillaCxxOpts unless forRepl $ whenSharedLib forceSharedLib (runGhcProgIfNeeded sharedCxxOpts) unless forRepl $ whenProfLib (runGhcProgIfNeeded profCxxOpts) | filename <- cxxSources libBi] when has_code . ifReplLib $ do when (null (allLibModules lib clbi)) $ warn verbosity "No exposed modules" ifReplLib (runGhcProg replOpts) -- build any C sources -- TODO: Add support for S and CMM files. unless (not has_code || null (cSources libBi)) $ do info verbosity "Building C Sources..." sequence_ [ do let baseCcOpts = Internal.componentCcGhcOptions verbosity implInfo lbi libBi clbi libTargetDir filename vanillaCcOpts = if isGhcDynamic -- Dynamic GHC requires C sources to be built -- with -fPIC for REPL to work. See #2207. then baseCcOpts { ghcOptFPic = toFlag True } else baseCcOpts profCcOpts = vanillaCcOpts `mappend` mempty { ghcOptProfilingMode = toFlag True, ghcOptObjSuffix = toFlag "p_o" } sharedCcOpts = vanillaCcOpts `mappend` mempty { ghcOptFPic = toFlag True, ghcOptDynLinkMode = toFlag GhcDynamicOnly, ghcOptObjSuffix = toFlag "dyn_o" } odir = fromFlag (ghcOptObjDir vanillaCcOpts) createDirectoryIfMissingVerbose verbosity True odir let runGhcProgIfNeeded ccOpts = do needsRecomp <- checkNeedsRecompilation filename ccOpts when needsRecomp $ runGhcProg ccOpts runGhcProgIfNeeded vanillaCcOpts unless forRepl $ whenSharedLib forceSharedLib (runGhcProgIfNeeded sharedCcOpts) unless forRepl $ whenProfLib (runGhcProgIfNeeded profCcOpts) | filename <- cSources libBi] -- TODO: problem here is we need the .c files built first, so we can load them -- with ghci, but .c files can depend on .h files generated by ghc by ffi -- exports. -- link: when has_code . unless forRepl $ do info verbosity "Linking..." let cProfObjs = map (`replaceExtension` ("p_" ++ objExtension)) (cSources libBi ++ cxxSources libBi) cSharedObjs = map (`replaceExtension` ("dyn_" ++ objExtension)) (cSources libBi ++ cxxSources libBi) compiler_id = compilerId (compiler lbi) vanillaLibFilePath = libTargetDir mkLibName uid profileLibFilePath = libTargetDir mkProfLibName uid sharedLibFilePath = libTargetDir mkSharedLibName compiler_id uid staticLibFilePath = libTargetDir mkStaticLibName compiler_id uid ghciLibFilePath = libTargetDir Internal.mkGHCiLibName uid libInstallPath = libdir $ absoluteComponentInstallDirs pkg_descr lbi uid NoCopyDest sharedLibInstallPath = libInstallPath mkSharedLibName compiler_id uid stubObjs <- catMaybes <$> sequenceA [ findFileWithExtension [objExtension] [libTargetDir] (ModuleName.toFilePath x ++"_stub") | ghcVersion < mkVersion [7,2] -- ghc-7.2+ does not make _stub.o files , x <- allLibModules lib clbi ] stubProfObjs <- catMaybes <$> sequenceA [ findFileWithExtension ["p_" ++ objExtension] [libTargetDir] (ModuleName.toFilePath x ++"_stub") | ghcVersion < mkVersion [7,2] -- ghc-7.2+ does not make _stub.o files , x <- allLibModules lib clbi ] stubSharedObjs <- catMaybes <$> sequenceA [ findFileWithExtension ["dyn_" ++ objExtension] [libTargetDir] (ModuleName.toFilePath x ++"_stub") | ghcVersion < mkVersion [7,2] -- ghc-7.2+ does not make _stub.o files , x <- allLibModules lib clbi ] hObjs <- Internal.getHaskellObjects implInfo lib lbi clbi libTargetDir objExtension True hProfObjs <- if withProfLib lbi then Internal.getHaskellObjects implInfo lib lbi clbi libTargetDir ("p_" ++ objExtension) True else return [] hSharedObjs <- if withSharedLib lbi then Internal.getHaskellObjects implInfo lib lbi clbi libTargetDir ("dyn_" ++ objExtension) False else return [] unless (null hObjs && null cObjs && null stubObjs) $ do rpaths <- getRPaths lbi clbi let staticObjectFiles = hObjs ++ map (libTargetDir ) cObjs ++ stubObjs profObjectFiles = hProfObjs ++ map (libTargetDir ) cProfObjs ++ stubProfObjs ghciObjFiles = hObjs ++ map (libTargetDir ) cObjs ++ stubObjs dynamicObjectFiles = hSharedObjs ++ map (libTargetDir ) cSharedObjs ++ stubSharedObjs -- After the relocation lib is created we invoke ghc -shared -- with the dependencies spelled out as -package arguments -- and ghc invokes the linker with the proper library paths ghcSharedLinkArgs = mempty { ghcOptShared = toFlag True, ghcOptDynLinkMode = toFlag GhcDynamicOnly, ghcOptInputFiles = toNubListR dynamicObjectFiles, ghcOptOutputFile = toFlag sharedLibFilePath, ghcOptExtra = toNubListR $ hcSharedOptions GHC libBi, -- For dynamic libs, Mac OS/X needs to know the install location -- at build time. This only applies to GHC < 7.8 - see the -- discussion in #1660. ghcOptDylibName = if hostOS == OSX && ghcVersion < mkVersion [7,8] then toFlag sharedLibInstallPath else mempty, ghcOptHideAllPackages = toFlag True, ghcOptNoAutoLinkPackages = toFlag True, ghcOptPackageDBs = withPackageDB lbi, ghcOptThisUnitId = case clbi of LibComponentLocalBuildInfo { componentCompatPackageKey = pk } -> toFlag pk _ -> mempty, ghcOptThisComponentId = case clbi of LibComponentLocalBuildInfo { componentInstantiatedWith = insts } -> if null insts then mempty else toFlag (componentComponentId clbi) _ -> mempty, ghcOptInstantiatedWith = case clbi of LibComponentLocalBuildInfo { componentInstantiatedWith = insts } -> insts _ -> [], ghcOptPackages = toNubListR $ Internal.mkGhcOptPackages clbi , ghcOptLinkLibs = toNubListR $ extraLibs libBi, ghcOptLinkLibPath = toNubListR $ extraLibDirs libBi, ghcOptLinkFrameworks = toNubListR $ PD.frameworks libBi, ghcOptLinkFrameworkDirs = toNubListR $ PD.extraFrameworkDirs libBi, ghcOptRPaths = rpaths } ghcStaticLinkArgs = mempty { ghcOptStaticLib = toFlag True, ghcOptInputFiles = toNubListR staticObjectFiles, ghcOptOutputFile = toFlag staticLibFilePath, ghcOptExtra = toNubListR $ hcStaticOptions GHC libBi, ghcOptHideAllPackages = toFlag True, ghcOptNoAutoLinkPackages = toFlag True, ghcOptPackageDBs = withPackageDB lbi, ghcOptThisUnitId = case clbi of LibComponentLocalBuildInfo { componentCompatPackageKey = pk } -> toFlag pk _ -> mempty, ghcOptThisComponentId = case clbi of LibComponentLocalBuildInfo { componentInstantiatedWith = insts } -> if null insts then mempty else toFlag (componentComponentId clbi) _ -> mempty, ghcOptInstantiatedWith = case clbi of LibComponentLocalBuildInfo { componentInstantiatedWith = insts } -> insts _ -> [], ghcOptPackages = toNubListR $ Internal.mkGhcOptPackages clbi , ghcOptLinkLibs = toNubListR $ extraLibs libBi, ghcOptLinkLibPath = toNubListR $ extraLibDirs libBi } info verbosity (show (ghcOptPackages ghcSharedLinkArgs)) whenVanillaLib False $ Ar.createArLibArchive verbosity lbi vanillaLibFilePath staticObjectFiles whenProfLib $ Ar.createArLibArchive verbosity lbi profileLibFilePath profObjectFiles whenGHCiLib $ do (ldProg, _) <- requireProgram verbosity ldProgram (withPrograms lbi) Ld.combineObjectFiles verbosity lbi ldProg ghciLibFilePath ghciObjFiles whenSharedLib False $ runGhcProg ghcSharedLinkArgs whenStaticLib False $ runGhcProg ghcStaticLinkArgs -- | Start a REPL without loading any source files. startInterpreter :: Verbosity -> ProgramDb -> Compiler -> Platform -> PackageDBStack -> IO () startInterpreter verbosity progdb comp platform packageDBs = do let replOpts = mempty { ghcOptMode = toFlag GhcModeInteractive, ghcOptPackageDBs = packageDBs } checkPackageDbStack verbosity comp packageDBs (ghcProg, _) <- requireProgram verbosity ghcProgram progdb runGHC verbosity ghcProg comp platform replOpts -- ----------------------------------------------------------------------------- -- Building an executable or foreign library -- | Build a foreign library buildFLib, replFLib :: Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription -> LocalBuildInfo -> ForeignLib -> ComponentLocalBuildInfo -> IO () buildFLib v njobs pkg lbi = gbuild v njobs pkg lbi . GBuildFLib replFLib v njobs pkg lbi = gbuild v njobs pkg lbi . GReplFLib -- | Build an executable with GHC. -- buildExe, replExe :: Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription -> LocalBuildInfo -> Executable -> ComponentLocalBuildInfo -> IO () buildExe v njobs pkg lbi = gbuild v njobs pkg lbi . GBuildExe replExe v njobs pkg lbi = gbuild v njobs pkg lbi . GReplExe -- | Building an executable, starting the REPL, and building foreign -- libraries are all very similar and implemented in 'gbuild'. The -- 'GBuildMode' distinguishes between the various kinds of operation. data GBuildMode = GBuildExe Executable | GReplExe Executable | GBuildFLib ForeignLib | GReplFLib ForeignLib gbuildInfo :: GBuildMode -> BuildInfo gbuildInfo (GBuildExe exe) = buildInfo exe gbuildInfo (GReplExe exe) = buildInfo exe gbuildInfo (GBuildFLib flib) = foreignLibBuildInfo flib gbuildInfo (GReplFLib flib) = foreignLibBuildInfo flib gbuildName :: GBuildMode -> String gbuildName (GBuildExe exe) = unUnqualComponentName $ exeName exe gbuildName (GReplExe exe) = unUnqualComponentName $ exeName exe gbuildName (GBuildFLib flib) = unUnqualComponentName $ foreignLibName flib gbuildName (GReplFLib flib) = unUnqualComponentName $ foreignLibName flib gbuildTargetName :: LocalBuildInfo -> GBuildMode -> String gbuildTargetName _lbi (GBuildExe exe) = exeTargetName exe gbuildTargetName _lbi (GReplExe exe) = exeTargetName exe gbuildTargetName lbi (GBuildFLib flib) = flibTargetName lbi flib gbuildTargetName lbi (GReplFLib flib) = flibTargetName lbi flib exeTargetName :: Executable -> String exeTargetName exe = unUnqualComponentName (exeName exe) `withExt` exeExtension -- | Target name for a foreign library (the actual file name) -- -- We do not use mkLibName and co here because the naming for foreign libraries -- is slightly different (we don't use "_p" or compiler version suffices, and we -- don't want the "lib" prefix on Windows). -- -- TODO: We do use `dllExtension` and co here, but really that's wrong: they -- use the OS used to build cabal to determine which extension to use, rather -- than the target OS (but this is wrong elsewhere in Cabal as well). flibTargetName :: LocalBuildInfo -> ForeignLib -> String flibTargetName lbi flib = case (os, foreignLibType flib) of (Windows, ForeignLibNativeShared) -> nm <.> "dll" (Windows, ForeignLibNativeStatic) -> nm <.> "lib" (Linux, ForeignLibNativeShared) -> "lib" ++ nm <.> versionedExt (_other, ForeignLibNativeShared) -> "lib" ++ nm <.> dllExtension (_other, ForeignLibNativeStatic) -> "lib" ++ nm <.> staticLibExtension (_any, ForeignLibTypeUnknown) -> cabalBug "unknown foreign lib type" where nm :: String nm = unUnqualComponentName $ foreignLibName flib os :: OS os = let (Platform _ os') = hostPlatform lbi in os' -- If a foreign lib foo has lib-version-info 5:1:2 or -- lib-version-linux 3.2.1, it should be built as libfoo.so.3.2.1 -- Libtool's version-info data is translated into library versions in a -- nontrivial way: so refer to libtool documentation. versionedExt :: String versionedExt = let nums = foreignLibVersion flib os in foldl (<.>) "so" (map show nums) -- | Name for the library when building. -- -- If the `lib-version-info` field or the `lib-version-linux` field of -- a foreign library target is set, we need to incorporate that -- version into the SONAME field. -- -- If a foreign library foo has lib-version-info 5:1:2, it should be -- built as libfoo.so.3.2.1. We want it to get soname libfoo.so.3. -- However, GHC does not allow overriding soname by setting linker -- options, as it sets a soname of its own (namely the output -- filename), after the user-supplied linker options. Hence, we have -- to compile the library with the soname as its filename. We rename -- the compiled binary afterwards. -- -- This method allows to adjust the name of the library at build time -- such that the correct soname can be set. flibBuildName :: LocalBuildInfo -> ForeignLib -> String flibBuildName lbi flib -- On linux, if a foreign-library has version data, the first digit is used -- to produce the SONAME. | (os, foreignLibType flib) == (Linux, ForeignLibNativeShared) = let nums = foreignLibVersion flib os in "lib" ++ nm <.> foldl (<.>) "so" (map show (take 1 nums)) | otherwise = flibTargetName lbi flib where os :: OS os = let (Platform _ os') = hostPlatform lbi in os' nm :: String nm = unUnqualComponentName $ foreignLibName flib gbuildIsRepl :: GBuildMode -> Bool gbuildIsRepl (GBuildExe _) = False gbuildIsRepl (GReplExe _) = True gbuildIsRepl (GBuildFLib _) = False gbuildIsRepl (GReplFLib _) = True gbuildNeedDynamic :: LocalBuildInfo -> GBuildMode -> Bool gbuildNeedDynamic lbi bm = case bm of GBuildExe _ -> withDynExe lbi GReplExe _ -> withDynExe lbi GBuildFLib flib -> withDynFLib flib GReplFLib flib -> withDynFLib flib where withDynFLib flib = case foreignLibType flib of ForeignLibNativeShared -> ForeignLibStandalone `notElem` foreignLibOptions flib ForeignLibNativeStatic -> False ForeignLibTypeUnknown -> cabalBug "unknown foreign lib type" gbuildModDefFiles :: GBuildMode -> [FilePath] gbuildModDefFiles (GBuildExe _) = [] gbuildModDefFiles (GReplExe _) = [] gbuildModDefFiles (GBuildFLib flib) = foreignLibModDefFile flib gbuildModDefFiles (GReplFLib flib) = foreignLibModDefFile flib -- | "Main" module name when overridden by @ghc-options: -main-is ...@ -- or 'Nothing' if no @-main-is@ flag could be found. -- -- In case of 'Nothing', 'Distribution.ModuleName.main' can be assumed. exeMainModuleName :: Executable -> Maybe ModuleName exeMainModuleName Executable{buildInfo = bnfo} = -- GHC honors the last occurence of a module name updated via -main-is -- -- Moreover, -main-is when parsed left-to-right can update either -- the "Main" module name, or the "main" function name, or both, -- see also 'decodeMainIsArg'. msum $ reverse $ map decodeMainIsArg $ findIsMainArgs ghcopts where ghcopts = hcOptions GHC bnfo findIsMainArgs [] = [] findIsMainArgs ("-main-is":arg:rest) = arg : findIsMainArgs rest findIsMainArgs (_:rest) = findIsMainArgs rest -- | Decode argument to '-main-is' -- -- Returns 'Nothing' if argument set only the function name. -- -- This code has been stolen/refactored from GHC's DynFlags.setMainIs -- function. The logic here is deliberately imperfect as it is -- intended to be bug-compatible with GHC's parser. See discussion in -- https://github.com/haskell/cabal/pull/4539#discussion_r118981753. decodeMainIsArg :: String -> Maybe ModuleName decodeMainIsArg arg | not (null main_fn) && isLower (head main_fn) -- The arg looked like "Foo.Bar.baz" = Just (ModuleName.fromString main_mod) | isUpper (head arg) -- The arg looked like "Foo" or "Foo.Bar" = Just (ModuleName.fromString arg) | otherwise -- The arg looked like "baz" = Nothing where (main_mod, main_fn) = splitLongestPrefix arg (== '.') splitLongestPrefix :: String -> (Char -> Bool) -> (String,String) splitLongestPrefix str pred' | null r_pre = (str, []) | otherwise = (reverse (tail r_pre), reverse r_suf) -- 'tail' drops the char satisfying 'pred' where (r_suf, r_pre) = break pred' (reverse str) -- | Return C sources, GHC input files and GHC input modules gbuildSources :: Verbosity -> Version -- ^ specVersion -> FilePath -> GBuildMode -> IO ([FilePath], [FilePath], [ModuleName]) gbuildSources verbosity specVer tmpDir bm = case bm of GBuildExe exe -> exeSources exe GReplExe exe -> exeSources exe GBuildFLib flib -> return $ flibSources flib GReplFLib flib -> return $ flibSources flib where exeSources :: Executable -> IO ([FilePath], [FilePath], [ModuleName]) exeSources exe@Executable{buildInfo = bnfo, modulePath = modPath} = do main <- findFile (tmpDir : hsSourceDirs bnfo) modPath let mainModName = fromMaybe ModuleName.main $ exeMainModuleName exe otherModNames = exeModules exe if isHaskell main then if specVer < mkVersion [2] && (mainModName `elem` otherModNames) then do -- The cabal manual clearly states that `other-modules` is -- intended for non-main modules. However, there's at least one -- important package on Hackage (happy-1.19.5) which -- violates this. We workaround this here so that we don't -- invoke GHC with e.g. 'ghc --make Main src/Main.hs' which -- would result in GHC complaining about duplicate Main -- modules. -- -- Finally, we only enable this workaround for -- specVersion < 2, as 'cabal-version:>=2.0' cabal files -- have no excuse anymore to keep doing it wrong... ;-) warn verbosity $ "Enabling workaround for Main module '" ++ display mainModName ++ "' listed in 'other-modules' illegally!" return (cSources bnfo, [main], filter (/= mainModName) (exeModules exe)) else return (cSources bnfo, [main], exeModules exe) else return (main : cSources bnfo, [], exeModules exe) flibSources :: ForeignLib -> ([FilePath], [FilePath], [ModuleName]) flibSources flib@ForeignLib{foreignLibBuildInfo = bnfo} = (cSources bnfo, [], foreignLibModules flib) isHaskell :: FilePath -> Bool isHaskell fp = elem (takeExtension fp) [".hs", ".lhs"] -- | Generic build function. See comment for 'GBuildMode'. gbuild :: Verbosity -> Cabal.Flag (Maybe Int) -> PackageDescription -> LocalBuildInfo -> GBuildMode -> ComponentLocalBuildInfo -> IO () gbuild verbosity numJobs pkg_descr lbi bm clbi = do (ghcProg, _) <- requireProgram verbosity ghcProgram (withPrograms lbi) let comp = compiler lbi platform = hostPlatform lbi implInfo = getImplInfo comp runGhcProg = runGHC verbosity ghcProg comp platform bnfo <- hackThreadedFlag verbosity comp (withProfExe lbi) (gbuildInfo bm) -- the name that GHC really uses (e.g., with .exe on Windows for executables) let targetName = gbuildTargetName lbi bm let targetDir = buildDir lbi (gbuildName bm) let tmpDir = targetDir (gbuildName bm ++ "-tmp") createDirectoryIfMissingVerbose verbosity True targetDir createDirectoryIfMissingVerbose verbosity True tmpDir -- TODO: do we need to put hs-boot files into place for mutually recursive -- modules? FIX: what about exeName.hi-boot? -- Determine if program coverage should be enabled and if so, what -- '-hpcdir' should be. let isCoverageEnabled = exeCoverage lbi distPref = fromFlag $ configDistPref $ configFlags lbi hpcdir way | gbuildIsRepl bm = mempty -- HPC is not supported in ghci | isCoverageEnabled = toFlag $ Hpc.mixDir distPref way (gbuildName bm) | otherwise = mempty rpaths <- getRPaths lbi clbi (cSrcs, inputFiles, inputModules) <- gbuildSources verbosity (specVersion pkg_descr) tmpDir bm let isGhcDynamic = isDynamic comp dynamicTooSupported = supportsDynamicToo comp cObjs = map (`replaceExtension` objExtension) cSrcs needDynamic = gbuildNeedDynamic lbi bm needProfiling = withProfExe lbi -- build executables baseOpts = (componentGhcOptions verbosity lbi bnfo clbi tmpDir) `mappend` mempty { ghcOptMode = toFlag GhcModeMake, ghcOptInputFiles = toNubListR inputFiles, ghcOptInputModules = toNubListR inputModules } staticOpts = baseOpts `mappend` mempty { ghcOptDynLinkMode = toFlag GhcStaticOnly, ghcOptHPCDir = hpcdir Hpc.Vanilla } profOpts = baseOpts `mappend` mempty { ghcOptProfilingMode = toFlag True, ghcOptProfilingAuto = Internal.profDetailLevelFlag False (withProfExeDetail lbi), ghcOptHiSuffix = toFlag "p_hi", ghcOptObjSuffix = toFlag "p_o", ghcOptExtra = toNubListR (hcProfOptions GHC bnfo), ghcOptHPCDir = hpcdir Hpc.Prof } dynOpts = baseOpts `mappend` mempty { ghcOptDynLinkMode = toFlag GhcDynamicOnly, -- TODO: Does it hurt to set -fPIC for executables? ghcOptFPic = toFlag True, ghcOptHiSuffix = toFlag "dyn_hi", ghcOptObjSuffix = toFlag "dyn_o", ghcOptExtra = toNubListR $ hcSharedOptions GHC bnfo, ghcOptHPCDir = hpcdir Hpc.Dyn } dynTooOpts = staticOpts `mappend` mempty { ghcOptDynLinkMode = toFlag GhcStaticAndDynamic, ghcOptDynHiSuffix = toFlag "dyn_hi", ghcOptDynObjSuffix = toFlag "dyn_o", ghcOptHPCDir = hpcdir Hpc.Dyn } linkerOpts = mempty { ghcOptLinkOptions = toNubListR $ PD.ldOptions bnfo, ghcOptLinkLibs = toNubListR $ extraLibs bnfo, ghcOptLinkLibPath = toNubListR $ extraLibDirs bnfo, ghcOptLinkFrameworks = toNubListR $ PD.frameworks bnfo, ghcOptLinkFrameworkDirs = toNubListR $ PD.extraFrameworkDirs bnfo, ghcOptInputFiles = toNubListR [tmpDir x | x <- cObjs] } dynLinkerOpts = mempty { ghcOptRPaths = rpaths } replOpts = baseOpts { ghcOptExtra = overNubListR Internal.filterGhciFlags (ghcOptExtra baseOpts) } -- For a normal compile we do separate invocations of ghc for -- compiling as for linking. But for repl we have to do just -- the one invocation, so that one has to include all the -- linker stuff too, like -l flags and any .o files from C -- files etc. `mappend` linkerOpts `mappend` mempty { ghcOptMode = toFlag GhcModeInteractive, ghcOptOptimisation = toFlag GhcNoOptimisation } commonOpts | needProfiling = profOpts | needDynamic = dynOpts | otherwise = staticOpts compileOpts | useDynToo = dynTooOpts | otherwise = commonOpts withStaticExe = not needProfiling && not needDynamic -- For building exe's that use TH with -prof or -dynamic we actually have -- to build twice, once without -prof/-dynamic and then again with -- -prof/-dynamic. This is because the code that TH needs to run at -- compile time needs to be the vanilla ABI so it can be loaded up and run -- by the compiler. -- With dynamic-by-default GHC the TH object files loaded at compile-time -- need to be .dyn_o instead of .o. doingTH = usesTemplateHaskellOrQQ bnfo -- Should we use -dynamic-too instead of compiling twice? useDynToo = dynamicTooSupported && isGhcDynamic && doingTH && withStaticExe && null (hcSharedOptions GHC bnfo) compileTHOpts | isGhcDynamic = dynOpts | otherwise = staticOpts compileForTH | gbuildIsRepl bm = False | useDynToo = False | isGhcDynamic = doingTH && (needProfiling || withStaticExe) | otherwise = doingTH && (needProfiling || needDynamic) -- Build static/dynamic object files for TH, if needed. when compileForTH $ runGhcProg compileTHOpts { ghcOptNoLink = toFlag True , ghcOptNumJobs = numJobs } -- Do not try to build anything if there are no input files. -- This can happen if the cabal file ends up with only cSrcs -- but no Haskell modules. unless ((null inputFiles && null inputModules) || gbuildIsRepl bm) $ runGhcProg compileOpts { ghcOptNoLink = toFlag True , ghcOptNumJobs = numJobs } -- build any C sources unless (null cSrcs) $ do info verbosity "Building C Sources..." sequence_ [ do let baseCcOpts = Internal.componentCcGhcOptions verbosity implInfo lbi bnfo clbi tmpDir filename vanillaCcOpts = if isGhcDynamic -- Dynamic GHC requires C sources to be built -- with -fPIC for REPL to work. See #2207. then baseCcOpts { ghcOptFPic = toFlag True } else baseCcOpts profCcOpts = vanillaCcOpts `mappend` mempty { ghcOptProfilingMode = toFlag True } sharedCcOpts = vanillaCcOpts `mappend` mempty { ghcOptFPic = toFlag True, ghcOptDynLinkMode = toFlag GhcDynamicOnly } opts | needProfiling = profCcOpts | needDynamic = sharedCcOpts | otherwise = vanillaCcOpts odir = fromFlag (ghcOptObjDir opts) createDirectoryIfMissingVerbose verbosity True odir needsRecomp <- checkNeedsRecompilation filename opts when needsRecomp $ runGhcProg opts | filename <- cSrcs ] -- TODO: problem here is we need the .c files built first, so we can load them -- with ghci, but .c files can depend on .h files generated by ghc by ffi -- exports. case bm of GReplExe _ -> runGhcProg replOpts GReplFLib _ -> runGhcProg replOpts GBuildExe _ -> do let linkOpts = commonOpts `mappend` linkerOpts `mappend` mempty { ghcOptLinkNoHsMain = toFlag (null inputFiles) } `mappend` (if withDynExe lbi then dynLinkerOpts else mempty) info verbosity "Linking..." -- Work around old GHCs not relinking in this -- situation, see #3294 let target = targetDir targetName when (compilerVersion comp < mkVersion [7,7]) $ do e <- doesFileExist target when e (removeFile target) runGhcProg linkOpts { ghcOptOutputFile = toFlag target } GBuildFLib flib -> do let rtsInfo = extractRtsInfo lbi linkOpts = case foreignLibType flib of ForeignLibNativeShared -> commonOpts `mappend` linkerOpts `mappend` dynLinkerOpts `mappend` mempty { ghcOptLinkNoHsMain = toFlag True, ghcOptShared = toFlag True, ghcOptLinkLibs = toNubListR [ if needDynamic then rtsDynamicLib rtsInfo else rtsStaticLib rtsInfo ], ghcOptLinkLibPath = toNubListR $ rtsLibPaths rtsInfo, ghcOptFPic = toFlag True, ghcOptLinkModDefFiles = toNubListR $ gbuildModDefFiles bm } -- See Note [RPATH] `mappend` ifNeedsRPathWorkaround lbi mempty { ghcOptLinkOptions = toNubListR ["-Wl,--no-as-needed"] , ghcOptLinkLibs = toNubListR ["ffi"] } ForeignLibNativeStatic -> -- this should be caught by buildFLib -- (and if we do implement tihs, we probably don't even want to call -- ghc here, but rather Ar.createArLibArchive or something) cabalBug "static libraries not yet implemented" ForeignLibTypeUnknown -> cabalBug "unknown foreign lib type" -- We build under a (potentially) different filename to set a -- soname on supported platforms. See also the note for -- @flibBuildName@. info verbosity "Linking..." let buildName = flibBuildName lbi flib runGhcProg linkOpts { ghcOptOutputFile = toFlag (targetDir buildName) } renameFile (targetDir buildName) (targetDir targetName) {- Note [RPATH] ~~~~~~~~~~~~ Suppose that the dynamic library depends on `base`, but not (directly) on `integer-gmp` (which, however, is a dependency of `base`). We will link the library as gcc ... -lHSbase-4.7.0.2-ghc7.8.4 -lHSinteger-gmp-0.5.1.0-ghc7.8.4 ... However, on systems (like Ubuntu) where the linker gets called with `-as-needed` by default, the linker will notice that `integer-gmp` isn't actually a direct dependency and hence omit the link. Then when we attempt to link a C program against this dynamic library, the _static_ linker will attempt to verify that all symbols can be resolved. The dynamic library itself does not require any symbols from `integer-gmp`, but `base` does. In order to verify that the symbols used by `base` can be resolved, the static linker needs to be able to _find_ integer-gmp. Finding the `base` dependency is simple, because the dynamic elf header (`readelf -d`) for the library that we have created looks something like (NEEDED) Shared library: [libHSbase-4.7.0.2-ghc7.8.4.so] (RPATH) Library rpath: [/path/to/base-4.7.0.2:...] However, when it comes to resolving the dependency on `integer-gmp`, it needs to look at the dynamic header for `base`. On modern ghc (7.8 and higher) this looks something like (NEEDED) Shared library: [libHSinteger-gmp-0.5.1.0-ghc7.8.4.so] (RPATH) Library rpath: [$ORIGIN/../integer-gmp-0.5.1.0:...] This specifies the location of `integer-gmp` _in terms of_ the location of base (using the `$ORIGIN`) variable. But here's the crux: when the static linker attempts to verify that all symbols can be resolved, [**IT DOES NOT RESOLVE `$ORIGIN`**](http://stackoverflow.com/questions/6323603/ld-using-rpath-origin-inside-a-shared-library-recursive). As a consequence, it will not be able to resolve the symbols and report the missing symbols as errors, _even though the dynamic linker **would** be able to resolve these symbols_. We can tell the static linker not to report these errors by using `--unresolved-symbols=ignore-all` and all will be fine when we run the program ([(indeed, this is what the gold linker does)](https://sourceware.org/ml/binutils/2013-05/msg00038.html), but it makes the resulting library more difficult to use. Instead what we can do is make sure that the generated dynamic library has explicit top-level dependencies on these libraries. This means that the static linker knows where to find them, and when we have transitive dependencies on the same libraries the linker will only load them once, so we avoid needing to look at the `RPATH` of our dependencies. We can do this by passing `--no-as-needed` to the linker, so that it doesn't omit any libraries. Note that on older ghc (7.6 and before) the Haskell libraries don't have an RPATH set at all, which makes it even more important that we make these top-level dependencies. Finally, we have to explicitly link against `libffi` for the same reason. For newer ghc this _happens_ to be unnecessary on many systems because `libffi` is a library which is not specific to GHC, and when the static linker verifies that all symbols can be resolved it will find the `libffi` that is globally installed (completely independent from ghc). Of course, this may well be the _wrong_ version of `libffi`, but it's quite possible that symbol resolution happens to work. This is of course the wrong approach, which is why we link explicitly against `libffi` so that we will find the _right_ version of `libffi`. -} -- | Do we need the RPATH workaround? -- -- See Note [RPATH]. ifNeedsRPathWorkaround :: Monoid a => LocalBuildInfo -> a -> a ifNeedsRPathWorkaround lbi a = case hostPlatform lbi of Platform _ Linux -> a _otherwise -> mempty data RtsInfo = RtsInfo { rtsDynamicLib :: FilePath , rtsStaticLib :: FilePath , rtsLibPaths :: [FilePath] } -- | Extract (and compute) information about the RTS library -- -- TODO: This hardcodes the name as @HSrts-ghc@. I don't know if we can -- find this information somewhere. We can lookup the 'hsLibraries' field of -- 'InstalledPackageInfo' but it will tell us @["HSrts", "Cffi"]@, which -- doesn't really help. extractRtsInfo :: LocalBuildInfo -> RtsInfo extractRtsInfo lbi = case PackageIndex.lookupPackageName (installedPkgs lbi) (mkPackageName "rts") of [(_, [rts])] -> aux rts _otherwise -> error "No (or multiple) ghc rts package is registered" where aux :: InstalledPackageInfo -> RtsInfo aux rts = RtsInfo { rtsDynamicLib = "HSrts-ghc" ++ display ghcVersion , rtsStaticLib = "HSrts" , rtsLibPaths = InstalledPackageInfo.libraryDirs rts } ghcVersion :: Version ghcVersion = compilerVersion (compiler lbi) -- | Returns True if the modification date of the given source file is newer than -- the object file we last compiled for it, or if no object file exists yet. checkNeedsRecompilation :: FilePath -> GhcOptions -> NoCallStackIO Bool checkNeedsRecompilation filename opts = filename `moreRecentFile` oname where oname = getObjectFileName filename opts -- | Finds the object file name of the given source file getObjectFileName :: FilePath -> GhcOptions -> FilePath getObjectFileName filename opts = oname where odir = fromFlag (ghcOptObjDir opts) oext = fromFlagOrDefault "o" (ghcOptObjSuffix opts) oname = odir replaceExtension filename oext -- | Calculate the RPATHs for the component we are building. -- -- Calculates relative RPATHs when 'relocatable' is set. getRPaths :: LocalBuildInfo -> ComponentLocalBuildInfo -- ^ Component we are building -> NoCallStackIO (NubListR FilePath) getRPaths lbi clbi | supportRPaths hostOS = do libraryPaths <- depLibraryPaths False (relocatable lbi) lbi clbi let hostPref = case hostOS of OSX -> "@loader_path" _ -> "$ORIGIN" relPath p = if isRelative p then hostPref p else p rpaths = toNubListR (map relPath libraryPaths) return rpaths where (Platform _ hostOS) = hostPlatform lbi compid = compilerId . compiler $ lbi -- The list of RPath-supported operating systems below reflects the -- platforms on which Cabal's RPATH handling is tested. It does _NOT_ -- reflect whether the OS supports RPATH. -- E.g. when this comment was written, the *BSD operating systems were -- untested with regards to Cabal RPATH handling, and were hence set to -- 'False', while those operating systems themselves do support RPATH. supportRPaths Linux   = True supportRPaths Windows = False supportRPaths OSX   = True supportRPaths FreeBSD   = case compid of CompilerId GHC ver | ver >= mkVersion [7,10,2] -> True _ -> False supportRPaths OpenBSD   = False supportRPaths NetBSD   = False supportRPaths DragonFly = False supportRPaths Solaris = False supportRPaths AIX = False supportRPaths HPUX = False supportRPaths IRIX = False supportRPaths HaLVM = False supportRPaths IOS = False supportRPaths Android = False supportRPaths Ghcjs = False supportRPaths Hurd = False supportRPaths (OtherOS _) = False -- Do _not_ add a default case so that we get a warning here when a new OS -- is added. getRPaths _ _ = return mempty -- | Filter the "-threaded" flag when profiling as it does not -- work with ghc-6.8 and older. hackThreadedFlag :: Verbosity -> Compiler -> Bool -> BuildInfo -> IO BuildInfo hackThreadedFlag verbosity comp prof bi | not mustFilterThreaded = return bi | otherwise = do warn verbosity $ "The ghc flag '-threaded' is not compatible with " ++ "profiling in ghc-6.8 and older. It will be disabled." return bi { options = filterHcOptions (/= "-threaded") (options bi) } where mustFilterThreaded = prof && compilerVersion comp < mkVersion [6, 10] && "-threaded" `elem` hcOptions GHC bi filterHcOptions p hcoptss = [ (hc, if hc == GHC then filter p opts else opts) | (hc, opts) <- hcoptss ] -- | Extracts a String representing a hash of the ABI of a built -- library. It can fail if the library has not yet been built. -- libAbiHash :: Verbosity -> PackageDescription -> LocalBuildInfo -> Library -> ComponentLocalBuildInfo -> IO String libAbiHash verbosity _pkg_descr lbi lib clbi = do libBi <- hackThreadedFlag verbosity (compiler lbi) (withProfLib lbi) (libBuildInfo lib) let comp = compiler lbi platform = hostPlatform lbi vanillaArgs0 = (componentGhcOptions verbosity lbi libBi clbi (componentBuildDir lbi clbi)) `mappend` mempty { ghcOptMode = toFlag GhcModeAbiHash, ghcOptInputModules = toNubListR $ exposedModules lib } vanillaArgs = -- Package DBs unnecessary, and break ghc-cabal. See #3633 -- BUT, put at least the global database so that 7.4 doesn't -- break. vanillaArgs0 { ghcOptPackageDBs = [GlobalPackageDB] , ghcOptPackages = mempty } sharedArgs = vanillaArgs `mappend` mempty { ghcOptDynLinkMode = toFlag GhcDynamicOnly, ghcOptFPic = toFlag True, ghcOptHiSuffix = toFlag "dyn_hi", ghcOptObjSuffix = toFlag "dyn_o", ghcOptExtra = toNubListR $ hcSharedOptions GHC libBi } profArgs = vanillaArgs `mappend` mempty { ghcOptProfilingMode = toFlag True, ghcOptProfilingAuto = Internal.profDetailLevelFlag True (withProfLibDetail lbi), ghcOptHiSuffix = toFlag "p_hi", ghcOptObjSuffix = toFlag "p_o", ghcOptExtra = toNubListR $ hcProfOptions GHC libBi } ghcArgs | withVanillaLib lbi = vanillaArgs | withSharedLib lbi = sharedArgs | withProfLib lbi = profArgs | otherwise = error "libAbiHash: Can't find an enabled library way" (ghcProg, _) <- requireProgram verbosity ghcProgram (withPrograms lbi) hash <- getProgramInvocationOutput verbosity (ghcInvocation ghcProg comp platform ghcArgs) return (takeWhile (not . isSpace) hash) componentGhcOptions :: Verbosity -> LocalBuildInfo -> BuildInfo -> ComponentLocalBuildInfo -> FilePath -> GhcOptions componentGhcOptions verbosity lbi = Internal.componentGhcOptions verbosity implInfo lbi where comp = compiler lbi implInfo = getImplInfo comp componentCcGhcOptions :: Verbosity -> LocalBuildInfo -> BuildInfo -> ComponentLocalBuildInfo -> FilePath -> FilePath -> GhcOptions componentCcGhcOptions verbosity lbi = Internal.componentCcGhcOptions verbosity implInfo lbi where comp = compiler lbi implInfo = getImplInfo comp -- ----------------------------------------------------------------------------- -- Installing -- |Install executables for GHC. installExe :: Verbosity -> LocalBuildInfo -> FilePath -- ^Where to copy the files to -> FilePath -- ^Build location -> (FilePath, FilePath) -- ^Executable (prefix,suffix) -> PackageDescription -> Executable -> IO () installExe verbosity lbi binDir buildPref (progprefix, progsuffix) _pkg exe = do createDirectoryIfMissingVerbose verbosity True binDir let exeName' = unUnqualComponentName $ exeName exe exeFileName = exeTargetName exe fixedExeBaseName = progprefix ++ exeName' ++ progsuffix installBinary dest = do installExecutableFile verbosity (buildPref exeName' exeFileName) (dest <.> exeExtension) when (stripExes lbi) $ Strip.stripExe verbosity (hostPlatform lbi) (withPrograms lbi) (dest <.> exeExtension) installBinary (binDir fixedExeBaseName) -- |Install foreign library for GHC. installFLib :: Verbosity -> LocalBuildInfo -> FilePath -- ^install location -> FilePath -- ^Build location -> PackageDescription -> ForeignLib -> IO () installFLib verbosity lbi targetDir builtDir _pkg flib = install (foreignLibIsShared flib) builtDir targetDir (flibTargetName lbi flib) where install isShared srcDir dstDir name = do let src = srcDir name dst = dstDir name createDirectoryIfMissingVerbose verbosity True targetDir -- TODO: Should we strip? (stripLibs lbi) if isShared then installExecutableFile verbosity src dst else installOrdinaryFile verbosity src dst -- Now install appropriate symlinks if library is versioned let (Platform _ os) = hostPlatform lbi when (not (null (foreignLibVersion flib os))) $ do when (os /= Linux) $ die' verbosity -- It should be impossible to get here. "Can't install foreign-library symlink on non-Linux OS" #ifndef mingw32_HOST_OS -- 'createSymbolicLink file1 file2' creates a symbolic link -- named 'file2' which points to the file 'file1'. -- Note that we do want a symlink to 'name' rather than -- 'dst', because the symlink will be relative to the -- directory it's created in. -- Finally, we first create the symlinks in a temporary -- directory and then rename to simulate 'ln --force'. withTempDirectory verbosity dstDir nm $ \tmpDir -> do let link1 = flibBuildName lbi flib link2 = "lib" ++ nm <.> "so" createSymbolicLink name (tmpDir link1) renameFile (tmpDir link1) (dstDir link1) createSymbolicLink name (tmpDir link2) renameFile (tmpDir link2) (dstDir link2) where nm :: String nm = unUnqualComponentName $ foreignLibName flib #endif /* mingw32_HOST_OS */ -- |Install for ghc, .hi, .a and, if --with-ghci given, .o installLib :: Verbosity -> LocalBuildInfo -> FilePath -- ^install location -> FilePath -- ^install location for dynamic libraries -> FilePath -- ^Build location -> PackageDescription -> Library -> ComponentLocalBuildInfo -> IO () installLib verbosity lbi targetDir dynlibTargetDir _builtDir _pkg lib clbi = do -- copy .hi files over: whenVanilla $ copyModuleFiles "hi" whenProf $ copyModuleFiles "p_hi" whenShared $ copyModuleFiles "dyn_hi" -- copy the built library files over: whenHasCode $ do whenVanilla $ do sequence_ [ installOrdinary builtDir targetDir (mkGenericStaticLibName (l ++ f)) | l <- getHSLibraryName (componentUnitId clbi):(extraBundledLibs (libBuildInfo lib)) , f <- "":extraLibFlavours (libBuildInfo lib) ] whenProf $ installOrdinary builtDir targetDir profileLibName whenGHCi $ installOrdinary builtDir targetDir ghciLibName whenShared $ installShared builtDir dynlibTargetDir sharedLibName where builtDir = componentBuildDir lbi clbi install isShared srcDir dstDir name = do let src = srcDir name dst = dstDir name createDirectoryIfMissingVerbose verbosity True dstDir if isShared then installExecutableFile verbosity src dst else installOrdinaryFile verbosity src dst when (stripLibs lbi) $ Strip.stripLib verbosity (hostPlatform lbi) (withPrograms lbi) dst installOrdinary = install False installShared = install True copyModuleFiles ext = findModuleFiles [builtDir] [ext] (allLibModules lib clbi) >>= installOrdinaryFiles verbosity targetDir compiler_id = compilerId (compiler lbi) uid = componentUnitId clbi profileLibName = mkProfLibName uid ghciLibName = Internal.mkGHCiLibName uid sharedLibName = (mkSharedLibName compiler_id) uid hasLib = not $ null (allLibModules lib clbi) && null (cSources (libBuildInfo lib)) has_code = not (componentIsIndefinite clbi) whenHasCode = when has_code whenVanilla = when (hasLib && withVanillaLib lbi) whenProf = when (hasLib && withProfLib lbi && has_code) whenGHCi = when (hasLib && withGHCiLib lbi && has_code) whenShared = when (hasLib && withSharedLib lbi && has_code) -- ----------------------------------------------------------------------------- -- Registering hcPkgInfo :: ProgramDb -> HcPkg.HcPkgInfo hcPkgInfo progdb = HcPkg.HcPkgInfo { HcPkg.hcPkgProgram = ghcPkgProg , HcPkg.noPkgDbStack = v < [6,9] , HcPkg.noVerboseFlag = v < [6,11] , HcPkg.flagPackageConf = v < [7,5] , HcPkg.supportsDirDbs = v >= [6,8] , HcPkg.requiresDirDbs = v >= [7,10] , HcPkg.nativeMultiInstance = v >= [7,10] , HcPkg.recacheMultiInstance = v >= [6,12] , HcPkg.suppressFilesCheck = v >= [6,6] } where v = versionNumbers ver Just ghcPkgProg = lookupProgram ghcPkgProgram progdb Just ver = programVersion ghcPkgProg registerPackage :: Verbosity -> ProgramDb -> PackageDBStack -> InstalledPackageInfo -> HcPkg.RegisterOptions -> IO () registerPackage verbosity progdb packageDbs installedPkgInfo registerOptions = HcPkg.register (hcPkgInfo progdb) verbosity packageDbs installedPkgInfo registerOptions pkgRoot :: Verbosity -> LocalBuildInfo -> PackageDB -> IO FilePath pkgRoot verbosity lbi = pkgRoot' where pkgRoot' GlobalPackageDB = let Just ghcProg = lookupProgram ghcProgram (withPrograms lbi) in fmap takeDirectory (getGlobalPackageDB verbosity ghcProg) pkgRoot' UserPackageDB = do appDir <- getAppUserDataDirectory "ghc" let ver = compilerVersion (compiler lbi) subdir = System.Info.arch ++ '-':System.Info.os ++ '-':display ver rootDir = appDir subdir -- We must create the root directory for the user package database if it -- does not yet exists. Otherwise '${pkgroot}' will resolve to a -- directory at the time of 'ghc-pkg register', and registration will -- fail. createDirectoryIfMissing True rootDir return rootDir pkgRoot' (SpecificPackageDB fp) = return (takeDirectory fp) -- ----------------------------------------------------------------------------- -- Utils isDynamic :: Compiler -> Bool isDynamic = Internal.ghcLookupProperty "GHC Dynamic" supportsDynamicToo :: Compiler -> Bool supportsDynamicToo = Internal.ghcLookupProperty "Support dynamic-too" withExt :: FilePath -> String -> FilePath withExt fp ext = fp <.> if takeExtension fp /= ('.':ext) then ext else ""