diff --git a/Demo/Main.hs b/Demo/Main.hs new file mode 100644 --- /dev/null +++ b/Demo/Main.hs @@ -0,0 +1,11 @@ +module Main where + +import System.Plugin +import Unsafe.Coerce + +main = do + val <- pdynload ("Prelude", "reverse") ("", "String -> String") + let str = case val of + Just v -> (unsafeCoerce v :: String -> String) "hello" + Nothing -> "Load failed." + print str diff --git a/Demo/Makefile b/Demo/Makefile new file mode 100644 --- /dev/null +++ b/Demo/Makefile @@ -0,0 +1,13 @@ + +PROGS = main +SOURCES = Main.hs + +all : $(PROGS) + +main : Main.hs + $(HC) --make $< -o $@ $(HCFLAGS) + +clean: + rm -f $(SOURCES:.hs=.hi) $(SOURCES:.hs=.o) $(PROGS) + +HC=ghc diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,676 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. + + diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,3 @@ +import Distribution.Simple + +main = defaultMain diff --git a/System/Plugin.hs b/System/Plugin.hs new file mode 100644 --- /dev/null +++ b/System/Plugin.hs @@ -0,0 +1,407 @@ +module System.Plugin ( +-- * Methods + pdynload + ) where + +import Control.Exception +import Control.Monad (when, liftM) +import Data.IORef +import Data.List (partition) +import GHC.Paths (libdir, ghc) +import MonadUtils (liftIO) +import System.Directory +import System.Exit +import System.IO +import System.Process +import System.Time +import Unsafe.Coerce +import qualified DynFlags +import qualified Exception +import qualified GHC +import qualified HscTypes +import qualified IOEnv +import qualified Linker +import qualified LoadIface +import qualified Maybes +import qualified Module +import qualified Name +import qualified OccName +import qualified Outputable +import qualified PackageConfig +import qualified Packages +import qualified SrcLoc +import qualified TcRnTypes +import qualified UniqSupply +import qualified Unique + +-- | The status of type check. +data TypeCheckStatus = TypeMatch + | TypeMismatch String + deriving (Show, Eq, Ord) + +-- | Polymorphic dynamic loading. +-- +-- Resolves the specified symbol to any given type. This means linking the package +-- containing it if it is not already linked, extracting the value of that symbol, +-- and returning that value. +-- +-- Here has simplest demo for test: +-- +-- > module Main where +-- > +-- > import System.Plugin +-- > import Unsafe.Coerce +-- > +-- > main = do +-- > val <- pdynload ("Prelude", "reverse") ("", "String -> String") +-- > let str = case val of +-- > Just v -> (unsafeCoerce v :: String -> String) "hello" +-- > Nothing -> "Load failed." +-- > print str +-- +-- Because 'pdynload' check type at runtime, so don't afraid 'unsafeCoerce', +-- it is perfect safety. +-- +pdynload :: (String, String) + -- ^ A tuple (@symbolModule@, @symbol@), specifying a symbol in module + -- + -- @symbolModule@ is a fully-qualified module name, ie @\"Data.List\"@ + -- + -- @symbol@ is an unqualified symbol name, ie @\"reverse\"@. + -> (String, String) + -- ^ A tuple (@typModule@, @typ@), specifying a type in module + -- + -- @typModule@ is a fully-qualified module name, ie @\"Prelude\"@ , + -- you can empty this string if type define in 'Prelude'. + -- + -- @typ@ is an unqualified type name, ie @\"String -> String\"@. + -> IO (Maybe a) + -- ^ If the specified symbol is found, 'Just' its value. Otherwise, 'Nothing'. +pdynload (symbolModule, symbol) (typModule, typ) = do + putStr "* Check type ... " + status <- typeCheck (symbolModule, symbol) (typModule, typ) + case status of + TypeMismatch error -> do + putStrLn "failed : " + putStrLn error + return Nothing + TypeMatch -> do + putStrLn "done." + GHC.defaultErrorHandler DynFlags.defaultDynFlags $ + GHC.runGhc (Just libdir) $ do + -- Update the DynFlags of current session. + flags <- GHC.getSessionDynFlags + GHC.setSessionDynFlags flags + -- Initialise package information. + (flags, _) <- liftIO $ Packages.initPackages flags + -- Initialise the dynamic linker. + liftIO $ Linker.initDynLinker flags + + -- Get package name for loading. + pName <- liftIO $ do + -- Search package in ghc database. + putStrLn $ "* Lookup package of module " ++ symbolModule + lookupPackageName flags symbolModule + + -- Try linking. + case pName of + -- Try linking symbol when found match package name. + Just pn -> + do + let pId = Module.stringToPackageId pn + hscEnv <- GHC.getSession + -- Because symbol perhaps re-export from external module. + -- So we need parse symbol to find define location. + name <- liftIO $ parseSymbol (pn, symbolModule, symbol) hscEnv flags + case name of + Just n -> load n pId flags + Nothing -> return Nothing + Nothing -> return Nothing + +-- | Type check at runtime. +-- +-- Instead of using any form of user-land dynamic types for runtime type checking, +-- We simply invoke the regular type checker on the test module at runtime. +-- This approach has the advantage that it is entirely independent of any extensions +-- of type type system supported by the underlying implementation. +-- It does not require any extension, but it also does not inhibit the use of any features +-- of the type system. +-- +-- Example +-- +-- > typecheck ("Data.List", "reverse") ("Prelude", "String -> String") +-- +-- will generate test module like below: +-- +-- > module TypeCheck where +-- > +-- > import qualified Data.List +-- > import Prelude +-- > +-- > typecheck = Data.List.reverse :: String -> String +-- +-- Then call \"ghc -e typecheck TypeCheck.hs\" for type-check. +-- If evaluate successful, then return 'TypeMatch', otherwise return 'TypeMismatch' with error. +-- +typeCheck :: (String, String) + -- ^ A tuple (@symbolModule@, @symbol@), specifying a symbol in module + -- + -- @symbolModule@ is a fully-qualified module name, ie @\"Data.List\"@ + -- + -- @symbol@ is an unqualified symbol name, ie @\"reverse\"@. + -> (String, String) + -- ^ A tuple (@typModule@, @typ@), specifying a type in module + -- + -- @typModule@ is a fully-qualified module name, ie @\"Prelude\"@ , + -- you can empty this string if type define in Prelude. + -- + -- @typ@ is an unqualified type name, ie @\"String -> String\"@. + -> IO TypeCheckStatus + -- ^ If type match return 'TypeMatch', otherwise return 'TypeMismatch' with error. +typeCheck (symbolModule, symbol) (typModule, typ) = do + -- Get unique id. + uniqueId <- getPicoseconds + + -- Initialise. + let tempDir = "/tmp/" + tempModule = "TypeCheck" ++ show uniqueId + tempFile = tempDir ++ tempModule ++ ".hs" + errFile = tempDir ++ tempModule ++ ".log" + checkExpression = "typecheck" + + -- Try compile temp module. + -- Redirect error to errFile if compile failed. + result <- bracket (openFile errFile WriteMode) hClose $ \errHandle -> do + -- Build source code. + let sourceCode = + -- Module name. + "module " ++ tempModule ++ " where" ++ "\n" + -- Import symbol module qualified. + ++ "import qualified " ++ symbolModule ++ "\n" + -- Import type module qualified. + ++ (if null typModule + then "import Prelude\n" + else "import " ++ typModule ++ "\n") + -- typecheck = SymbolModule.symbol :: TypeModule.Type + ++ checkExpression ++ " = " ++ (symbolModule ++ "." ++ symbol) -- symbol expression + ++ " :: " ++ typ -- type expression + + -- Write source code to temp haskell file. + handle <- openFile tempFile WriteMode + hWrite handle sourceCode + + -- Evaluate 'typecheck' in temp haskell file. + let ghcOpts = ["-e", checkExpression, tempFile] + ghcProc <- runProcess ghc ghcOpts (Just tempDir) Nothing Nothing Nothing (Just errHandle) + + -- If type mismatch or other runtime error, return ExitFailure. + waitForProcess ghcProc + + -- Get status. + status <- if result == ExitSuccess + -- Type match if compile haskell file successfully. + then return TypeMatch + -- Otherwise read error information. + else liftM TypeMismatch $ readFile errFile + + -- Clean temporary and error file. + tryRemoveFile tempFile + tryRemoveFile errFile + + -- Return status. + return status + +-- | Internal load function for pdynload. +load :: (GHC.GhcMonad m) + => (String, String, String) + -> Module.PackageId + -> GHC.DynFlags + -> m (Maybe a) +load (packageName, moduleName, symbolName) packageId flags = + Exception.ghandle + (\(GHC.CmdLineError _) -> do + -- Catch package error. + liftIO $ putStrLn $ "Unknown package " ++ packageName + return Nothing) + (do + -- Link exactly the specified packages, and their dependents + -- (unless of course they are already linked). + -- The dependents are linked automatically, + -- and it doesn't matter what order you specify the input packages. + liftIO $ Linker.linkPackages flags [packageId] + + Exception.ghandle + (\(GHC.ProgramError string) -> do + if hasPrefix string "Failed to load interface " + -- Catch module error + then liftIO $ putStrLn $ "Unknown module '" ++ moduleName ++ "'" + ++ " in package '" ++ packageName ++ "'" + -- Catch symbol error. + else liftIO $ putStrLn $ "Unknown symbol '" ++ symbolName ++ "'" + ++ " in module '" ++ moduleName ++ "'" + ++ " in package '" ++ packageName ++ "'" + return Nothing) + (do + liftIO $ putStrLn $ "* Linking " ++ packageName ++ ":" ++ moduleName ++ "." ++ symbolName ++ " ..." + -- Get current session. + session <- GHC.getSession + -- Create a name which definitely originates in the given module. + let name = Name.mkExternalName + (Unique.mkBuiltinUnique 0) + (Module.mkModule packageId + (Module.mkModuleName moduleName)) + (OccName.mkVarOcc symbolName) + SrcLoc.noSrcSpan + + -- Get the HValue associated with the given name. + -- May cause loading the module that contains the name. + result <- liftIO $ Linker.getHValue session name + -- Use unsafeCoerce convert to user specify type. + return $ Just $ unsafeCoerce result)) + +-- | Lookup package name from ghc database. +lookupPackageName :: DynFlags.DynFlags -> String -> IO (Maybe String) +lookupPackageName flags moduleName + -- Return Nothing when no package found. + | packageNum == 0 + = do + putStrLn $ "Can't found module " ++ show moduleName + return Nothing + | packageNum == 1 + = do + let (packageConfig, isExpose) = head packages + pName = packageConfigIdString packageConfig + if isExpose + -- Return package name when package expose module. + then return $ Just pName + -- Return Nothing if module hide in package. + else do + putStrLn $ "Module " ++ show moduleName ++ " hide in package " ++ pName + return Nothing + -- Return Nothing if no package expose module. + | null exposePackages + = do + putStrLn $ "Can't found module " ++ show moduleName + return Nothing + -- Return first match package when found module in multiple packages. + | otherwise + = do + let firstPackageIdString = packageConfigIdString $ fst $ head exposePackages + putStrLn $ "Module " ++ show moduleName ++ " expose in multiple packages :" + ++ concatMap (\ (packageConfig, _) -> + "\n " ++ packageConfigIdString packageConfig) exposePackages + putStrLn $ "# Use package '" ++ firstPackageIdString ++ "' (Maybe you need specify package name)" + return $ Just firstPackageIdString + where packages -- search package that *contain* module. + = Packages.lookupModuleInAllPackages flags (Module.mkModuleName moduleName) + packageNum -- length of package list + = length packages + exposePackages -- filter package that *export* module + = filter snd packages + +-- | Parse symbol whether defined in current module. +-- If symbol is re-export other module, parse recursively, +-- until found the define location of symbol. +parseSymbol :: (String, String, String) + -> HscTypes.HscEnv + -> GHC.DynFlags + -> IO (Maybe (String, String, String)) +parseSymbol (packageName, moduleName, symbolName) hscEnv flags = do + putStrLn $ "* Parse " ++ packageName ++ ":" ++ moduleName ++ "." ++ symbolName ++ " ..." + -- Build unique supply to build environment. + uniqueSupply <- UniqSupply.mkSplitUniqSupply 'a' + uniqueSupplyIORef <- newIORef uniqueSupply + -- Initialise. + let packageId = Module.stringToPackageId packageName + module' = Module.mkModule packageId $ Module.mkModuleName moduleName + environment = TcRnTypes.Env { + TcRnTypes.env_top = hscEnv, + TcRnTypes.env_us = uniqueSupplyIORef, + TcRnTypes.env_gbl = (), + TcRnTypes.env_lcl = ()} + -- Find and read interface file. + iface <- IOEnv.runIOEnv environment + $ LoadIface.findAndReadIface Outputable.empty module' False + case iface of + -- Return Nothing if can't found interface file. + Maybes.Failed _ -> do + putStrLn $ "Can't found interface file of " ++ packageName ++ ":" ++ moduleName ++ "." ++ symbolName + return Nothing + -- Parse symbol. + Maybes.Succeeded (moduleInterface, hiFile) -> do + putStrLn $ "Scan interface file " ++ hiFile ++ " ..." + -- Export list of current module + let ifaceExport = HscTypes.mi_exports moduleInterface + -- [(ModuleName, [type])] + exports = map (\ (mod, items) -> + (Module.moduleNameString $ Module.moduleName mod + ,concatMap (\item -> + case item of + HscTypes.Avail name -> [OccName.occNameString name] + HscTypes.AvailTC _ list -> + map OccName.occNameString list + ) items) + ) ifaceExport + -- Partition current module and external module. + (currentExports, otherExports) = partition (\ (mName, _) -> mName == moduleName) exports + case findSymbolInExportList currentExports symbolName of + -- Return current module if found symbol in export list of current module. + Just _ -> do + putStrLn $ "'" ++ symbolName ++ "' defined in " ++ packageName ++ ":" ++ moduleName + return $ Just (packageName, moduleName, symbolName) + Nothing -> + -- Parse recursively if symbol is re-export from external module. + case findSymbolInExportList otherExports symbolName of + Just mn -> do + putStrLn $ "'" ++ symbolName ++ "' is re-export from module " ++ mn + -- Lookup new package of external module. + newPackageName <- do + putStrLn $ "* Lookup package of module " ++ mn + lookupPackageName flags mn + case newPackageName of + -- Parse symbol in new package. + Just npn -> parseSymbol (npn, mn, symbolName) hscEnv flags + -- Return Nothing if package not found. + Nothing -> return Nothing + -- Return Nothing if can't found symbol in interface file. + -- If reach this, interface file is incorrect. + Nothing -> do + putStrLn $ "Can't found symbol " ++ symbolName ++ " in " ++ hiFile + return Nothing + +-- | Get PackageConfig id string. +packageConfigIdString :: Packages.PackageConfig -> String +packageConfigIdString = Module.packageIdString . PackageConfig.packageConfigId + +-- | Has prefix? +hasPrefix :: String -> String -> Bool +hasPrefix string prefix = + take (length prefix) string == prefix + +-- | Find symbol in export list of module. +-- Return module name when found symbol in export list. +-- Otherwise return Nothing. +findSymbolInExportList :: Eq b => [(a, [b])] -> b -> Maybe a +findSymbolInExportList [] _ = Nothing +findSymbolInExportList ((moduleName, symList) :xs) sym + | sym `elem` symList + = Just moduleName + | otherwise + = findSymbolInExportList xs sym + +-- | Get picoseconds for build unique haskell file. +getPicoseconds :: IO Integer +getPicoseconds = do + (TOD second picosecond) <- getClockTime + return (second * (10 ^ 12) + picosecond) + +-- | Write file. +hWrite :: Handle -> String -> IO () +hWrite hdl src = + hPutStr hdl src >> hClose hdl >> return () + +-- | Try remove file if file exist. +tryRemoveFile :: FilePath -> IO () +tryRemoveFile filepath = do + isExist <- doesFileExist filepath + when isExist $ removeFile filepath diff --git a/pdynload.cabal b/pdynload.cabal new file mode 100644 --- /dev/null +++ b/pdynload.cabal @@ -0,0 +1,33 @@ +name: pdynload +version: 0.0.1 +Cabal-Version: >= 1.6 +license: GPL-3 +license-file: LICENSE +copyright: (c) 2009 ~ 2010 Andy Stewart +synopsis: pdynload is polymorphic dynamic linking library. +description: This package use GHC-API implement polymorphic dynamic loading function -- pdynload. + Because pdynload invoke the regular type checker at runtime, + so pdynload is perfectly safety and does not inhibit the use of any features of the type system. +author: Andy Stewart +maintainer: Andy Stewart +stability: provisional +category: Development, Other + +tested-with: GHC==6.12.3 +build-type: Simple + +Data-Dir: Demo +Data-Files: Main.hs + Makefile + +Library + build-depends: base >= 4 && < 5, + ghc-paths >= 0.1.0.6, + directory >= 1.0.1.1, + process >= 1.0.1.3, + old-time >= 1.0.0.5, + ghc >= 6.12 + exposed-modules: + System.Plugin + other-modules: + ghc-options: -fwarn-unused-matches -fwarn-unused-binds -fwarn-unused-imports -fwarn-overlapping-patterns -fwarn-duplicate-exports -fwarn-unrecognised-pragmas -fwarn-hi-shadowing