% % (c) The University of Glasgow 2005-2006 % \begin{code} -- | The dynamic linker for GHCi. -- -- This module deals with the top-level issues of dynamic linking, -- calling the object-code linker and the byte-code linker where -- necessary. {-# OPTIONS -fno-cse #-} -- -fno-cse is needed for GLOBAL_VAR's to behave properly module Linker ( HValue, getHValue, showLinkerState, linkExpr, unload, withExtendedLinkEnv, extendLinkEnv, deleteFromLinkEnv, extendLoadedPkgs, linkPackages,initDynLinker,linkModule, dataConInfoPtrToName, lessUnsafeCoerce ) where #include "HsVersions.h" import LoadIface import ObjLink import ByteCodeLink import ByteCodeItbls import ByteCodeAsm import CgInfoTbls import SMRep import IfaceEnv import TcRnMonad import Packages import DriverPhases import Finder import HscTypes import Name import NameEnv import NameSet import qualified OccName import UniqFM import Module import ListSetOps import DynFlags import BasicTypes import Outputable import Panic import Util import StaticFlags import ErrUtils import SrcLoc import qualified Maybes import UniqSet import Constants import FastString import Config import GHC.Exts (unsafeCoerce#) -- Standard libraries import Control.Monad import Data.Char import Data.IORef import Data.List import qualified Data.Map as Map import Foreign import Control.Concurrent.MVar import System.FilePath import System.IO import System.Directory import Distribution.Package hiding (depends, PackageId) import Exception \end{code} %************************************************************************ %* * The Linker's state %* * %************************************************************************ The persistent linker state *must* match the actual state of the C dynamic linker at all times, so we keep it in a private global variable. The PersistentLinkerState maps Names to actual closures (for interpreted code only), for use during linking. \begin{code} GLOBAL_MVAR(v_PersistentLinkerState, panic "Dynamic linker not initialised", PersistentLinkerState) GLOBAL_VAR(v_InitLinkerDone, False, Bool) -- Set True when dynamic linker is initialised data PersistentLinkerState = PersistentLinkerState { -- Current global mapping from Names to their true values closure_env :: ClosureEnv, -- The current global mapping from RdrNames of DataCons to -- info table addresses. -- When a new Unlinked is linked into the running image, or an existing -- module in the image is replaced, the itbl_env must be updated -- appropriately. itbl_env :: !ItblEnv, -- The currently loaded interpreted modules (home package) bcos_loaded :: ![Linkable], -- And the currently-loaded compiled modules (home package) objs_loaded :: ![Linkable], -- The currently-loaded packages; always object code -- Held, as usual, in dependency order; though I am not sure if -- that is really important pkgs_loaded :: ![PackageId] } emptyPLS :: DynFlags -> PersistentLinkerState emptyPLS _ = PersistentLinkerState { closure_env = emptyNameEnv, itbl_env = emptyNameEnv, pkgs_loaded = init_pkgs, bcos_loaded = [], objs_loaded = [] } -- Packages that don't need loading, because the compiler -- shares them with the interpreted program. -- -- The linker's symbol table is populated with RTS symbols using an -- explicit list. See rts/Linker.c for details. where init_pkgs = [rtsPackageId] \end{code} \begin{code} extendLoadedPkgs :: [PackageId] -> IO () extendLoadedPkgs pkgs = modifyMVar_ v_PersistentLinkerState $ \s -> return s{ pkgs_loaded = pkgs ++ pkgs_loaded s } extendLinkEnv :: [(Name,HValue)] -> IO () -- Automatically discards shadowed bindings extendLinkEnv new_bindings = modifyMVar_ v_PersistentLinkerState $ \pls -> let new_closure_env = extendClosureEnv (closure_env pls) new_bindings in return pls{ closure_env = new_closure_env } deleteFromLinkEnv :: [Name] -> IO () deleteFromLinkEnv to_remove = modifyMVar_ v_PersistentLinkerState $ \pls -> let new_closure_env = delListFromNameEnv (closure_env pls) to_remove in return pls{ closure_env = new_closure_env } -- | Given a data constructor in the heap, find its Name. -- The info tables for data constructors have a field which records -- the source name of the constructor as a Ptr Word8 (UTF-8 encoded -- string). The format is: -- -- > Package:Module.Name -- -- We use this string to lookup the interpreter's internal representation of the name -- using the lookupOrig. -- dataConInfoPtrToName :: Ptr () -> TcM (Either String Name) dataConInfoPtrToName x = do theString <- liftIO $ do let ptr = castPtr x :: Ptr StgInfoTable conDescAddress <- getConDescAddress ptr peekArray0 0 conDescAddress let (pkg, mod, occ) = parse theString pkgFS = mkFastStringByteList pkg modFS = mkFastStringByteList mod occFS = mkFastStringByteList occ occName = mkOccNameFS OccName.dataName occFS modName = mkModule (fsToPackageId pkgFS) (mkModuleNameFS modFS) return (Left$ showSDoc$ ppr modName <> dot <> ppr occName ) `recoverM` (Right `fmap` lookupOrig modName occName) where {- To find the string in the constructor's info table we need to consider the layout of info tables relative to the entry code for a closure. An info table can be next to the entry code for the closure, or it can be separate. The former (faster) is used in registerised versions of ghc, and the latter (portable) is for non-registerised versions. The diagrams below show where the string is to be found relative to the normal info table of the closure. 1) Code next to table: -------------- | | <- pointer to the start of the string -------------- | | <- the (start of the) info table structure | | | | -------------- | entry code | | .... | In this case the pointer to the start of the string can be found in the memory location _one word before_ the first entry in the normal info table. 2) Code NOT next to table: -------------- info table structure -> | *------------------> -------------- | | | entry code | | | | .... | -------------- ptr to start of str -> | | -------------- In this case the pointer to the start of the string can be found in the memory location: info_table_ptr + info_table_size -} getConDescAddress :: Ptr StgInfoTable -> IO (Ptr Word8) getConDescAddress ptr | ghciTablesNextToCode = do offsetToString <- peek $ ptr `plusPtr` (- wORD_SIZE) return $ (ptr `plusPtr` stdInfoTableSizeB) `plusPtr` (fromIntegral (offsetToString :: StgWord)) | otherwise = peek $ intPtrToPtr $ (ptrToIntPtr ptr) + fromIntegral stdInfoTableSizeB -- parsing names is a little bit fiddly because we have a string in the form: -- pkg:A.B.C.foo, and we want to split it into three parts: ("pkg", "A.B.C", "foo"). -- Thus we split at the leftmost colon and the rightmost occurrence of the dot. -- It would be easier if the string was in the form pkg:A.B.C:foo, but alas -- this is not the conventional way of writing Haskell names. We stick with -- convention, even though it makes the parsing code more troublesome. -- Warning: this code assumes that the string is well formed. parse :: [Word8] -> ([Word8], [Word8], [Word8]) parse input = ASSERT (all (>0) (map length [pkg, mod, occ])) (pkg, mod, occ) where dot = fromIntegral (ord '.') (pkg, rest1) = break (== fromIntegral (ord ':')) input (mod, occ) = (concat $ intersperse [dot] $ reverse modWords, occWord) where (modWords, occWord) = ASSERT (length rest1 > 0) (parseModOcc [] (tail rest1)) parseModOcc :: [[Word8]] -> [Word8] -> ([[Word8]], [Word8]) -- We only look for dots if str could start with a module name, -- i.e. if it starts with an upper case character. -- Otherwise we might think that "X.:->" is the module name in -- "X.:->.+", whereas actually "X" is the module name and -- ":->.+" is a constructor name. parseModOcc acc str@(c : _) | isUpper $ chr $ fromIntegral c = case break (== dot) str of (top, []) -> (acc, top) (top, _ : bot) -> parseModOcc (top : acc) bot parseModOcc acc str = (acc, str) -- | Get the 'HValue' associated with the given name. -- -- May cause loading the module that contains the name. -- -- Throws a 'ProgramError' if loading fails or the name cannot be found. getHValue :: HscEnv -> Name -> IO HValue getHValue hsc_env name = do initDynLinker (hsc_dflags hsc_env) pls <- modifyMVar v_PersistentLinkerState $ \pls -> do if (isExternalName name) then do (pls', ok) <- linkDependencies hsc_env pls noSrcSpan [nameModule name] if (failed ok) then ghcError (ProgramError "") else return (pls', pls') else return (pls, pls) lookupName (closure_env pls) name linkDependencies :: HscEnv -> PersistentLinkerState -> SrcSpan -> [Module] -> IO (PersistentLinkerState, SuccessFlag) linkDependencies hsc_env pls span needed_mods = do -- initDynLinker (hsc_dflags hsc_env) let hpt = hsc_HPT hsc_env dflags = hsc_dflags hsc_env -- The interpreter and dynamic linker can only handle object code built -- the "normal" way, i.e. no non-std ways like profiling or ticky-ticky. -- So here we check the build tag: if we're building a non-standard way -- then we need to find & link object files built the "normal" way. maybe_normal_osuf <- checkNonStdWay dflags span -- Find what packages and linkables are required (lnks, pkgs) <- getLinkDeps hsc_env hpt pls maybe_normal_osuf span needed_mods -- Link the packages and modules required pls1 <- linkPackages' dflags pkgs pls linkModules dflags pls1 lnks -- | Temporarily extend the linker state. withExtendedLinkEnv :: (MonadIO m, ExceptionMonad m) => [(Name,HValue)] -> m a -> m a withExtendedLinkEnv new_env action = gbracket (liftIO $ extendLinkEnv new_env) (\_ -> reset_old_env) (\_ -> action) where -- Remember that the linker state might be side-effected -- during the execution of the IO action, and we don't want to -- lose those changes (we might have linked a new module or -- package), so the reset action only removes the names we -- added earlier. reset_old_env = liftIO $ do modifyMVar_ v_PersistentLinkerState $ \pls -> let cur = closure_env pls new = delListFromNameEnv cur (map fst new_env) in return pls{ closure_env = new } -- filterNameMap removes from the environment all entries except -- those for a given set of modules; -- Note that this removes all *local* (i.e. non-isExternal) names too -- (these are the temporary bindings from the command line). -- Used to filter both the ClosureEnv and ItblEnv filterNameMap :: [Module] -> NameEnv (Name, a) -> NameEnv (Name, a) filterNameMap mods env = filterNameEnv keep_elt env where keep_elt (n,_) = isExternalName n && (nameModule n `elem` mods) \end{code} \begin{code} -- | Display the persistent linker state. showLinkerState :: IO () showLinkerState = do pls <- readMVar v_PersistentLinkerState printDump (vcat [text "----- Linker state -----", text "Pkgs:" <+> ppr (pkgs_loaded pls), text "Objs:" <+> ppr (objs_loaded pls), text "BCOs:" <+> ppr (bcos_loaded pls)]) \end{code} %************************************************************************ %* * \subsection{Initialisation} %* * %************************************************************************ \begin{code} -- | Initialise the dynamic linker. This entails -- -- a) Calling the C initialisation procedure, -- -- b) Loading any packages specified on the command line, -- -- c) Loading any packages specified on the command line, now held in the -- @-l@ options in @v_Opt_l@, -- -- d) Loading any @.o\/.dll@ files specified on the command line, now held -- in @v_Ld_inputs@, -- -- e) Loading any MacOS frameworks. -- -- NOTE: This function is idempotent; if called more than once, it does -- nothing. This is useful in Template Haskell, where we call it before -- trying to link. -- initDynLinker :: DynFlags -> IO () initDynLinker dflags = modifyMVar_ v_PersistentLinkerState $ \pls0 -> do done <- readIORef v_InitLinkerDone if done then return pls0 else do writeIORef v_InitLinkerDone True reallyInitDynLinker dflags reallyInitDynLinker :: DynFlags -> IO PersistentLinkerState reallyInitDynLinker dflags = do { -- Initialise the linker state let pls0 = emptyPLS dflags -- (a) initialise the C dynamic linker ; initObjLinker -- (b) Load packages from the command-line ; pls <- linkPackages' dflags (preloadPackages (pkgState dflags)) pls0 -- (c) Link libraries from the command-line ; let optl = getOpts dflags opt_l ; let minus_ls = [ lib | '-':'l':lib <- optl ] -- (d) Link .o files from the command-line ; let lib_paths = libraryPaths dflags ; cmdline_ld_inputs <- readIORef v_Ld_inputs ; classified_ld_inputs <- mapM classifyLdInput cmdline_ld_inputs -- (e) Link any MacOS frameworks ; let framework_paths | isDarwinTarget = frameworkPaths dflags | otherwise = [] ; let frameworks | isDarwinTarget = cmdlineFrameworks dflags | otherwise = [] -- Finally do (c),(d),(e) ; let cmdline_lib_specs = [ l | Just l <- classified_ld_inputs ] ++ map DLL minus_ls ++ map Framework frameworks ; if null cmdline_lib_specs then return pls else do { mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs ; maybePutStr dflags "final link ... " ; ok <- resolveObjs ; if succeeded ok then maybePutStrLn dflags "done" else ghcError (ProgramError "linking extra libraries/objects failed") ; return pls }} classifyLdInput :: FilePath -> IO (Maybe LibrarySpec) classifyLdInput f | isObjectFilename f = return (Just (Object f)) | isDynLibFilename f = return (Just (DLLPath f)) | otherwise = do hPutStrLn stderr ("Warning: ignoring unrecognised input `" ++ f ++ "'") return Nothing preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO () preloadLib dflags lib_paths framework_paths lib_spec = do maybePutStr dflags ("Loading object " ++ showLS lib_spec ++ " ... ") case lib_spec of Object static_ish -> do b <- preload_static lib_paths static_ish maybePutStrLn dflags (if b then "done" else "not found") Archive static_ish -> do b <- preload_static_archive lib_paths static_ish maybePutStrLn dflags (if b then "done" else "not found") DLL dll_unadorned -> do maybe_errstr <- loadDynamic lib_paths dll_unadorned case maybe_errstr of Nothing -> maybePutStrLn dflags "done" Just mm -> preloadFailed mm lib_paths lib_spec DLLPath dll_path -> do maybe_errstr <- loadDLL dll_path case maybe_errstr of Nothing -> maybePutStrLn dflags "done" Just mm -> preloadFailed mm lib_paths lib_spec Framework framework | isDarwinTarget -> do maybe_errstr <- loadFramework framework_paths framework case maybe_errstr of Nothing -> maybePutStrLn dflags "done" Just mm -> preloadFailed mm framework_paths lib_spec | otherwise -> panic "preloadLib Framework" where preloadFailed :: String -> [String] -> LibrarySpec -> IO () preloadFailed sys_errmsg paths spec = do maybePutStr dflags "failed.\n" ghcError $ CmdLineError ( "user specified .o/.so/.DLL could not be loaded (" ++ sys_errmsg ++ ")\nWhilst trying to load: " ++ showLS spec ++ "\nAdditional directories searched:" ++ (if null paths then " (none)" else (concat (intersperse "\n" (map (" "++) paths))))) -- Not interested in the paths in the static case. preload_static _paths name = do b <- doesFileExist name if not b then return False else loadObj name >> return True preload_static_archive _paths name = do b <- doesFileExist name if not b then return False else loadArchive name >> return True \end{code} %************************************************************************ %* * Link a byte-code expression %* * %************************************************************************ \begin{code} -- | Link a single expression, /including/ first linking packages and -- modules that this expression depends on. -- -- Raises an IO exception ('ProgramError') if it can't find a compiled -- version of the dependents to link. -- linkExpr :: HscEnv -> SrcSpan -> UnlinkedBCO -> IO HValue linkExpr hsc_env span root_ul_bco = do { -- Initialise the linker (if it's not been done already) let dflags = hsc_dflags hsc_env ; initDynLinker dflags -- Take lock for the actual work. ; modifyMVar v_PersistentLinkerState $ \pls0 -> do { -- Link the packages and modules required ; (pls, ok) <- linkDependencies hsc_env pls0 span needed_mods ; if failed ok then ghcError (ProgramError "") else do { -- Link the expression itself let ie = itbl_env pls ce = closure_env pls -- Link the necessary packages and linkables ; (_, (root_hval:_)) <- linkSomeBCOs False ie ce [root_ul_bco] ; return (pls, root_hval) }}} where free_names = nameSetToList (bcoFreeNames root_ul_bco) needed_mods :: [Module] needed_mods = [ nameModule n | n <- free_names, isExternalName n, -- Names from other modules not (isWiredInName n) -- Exclude wired-in names ] -- (see note below) -- Exclude wired-in names because we may not have read -- their interface files, so getLinkDeps will fail -- All wired-in names are in the base package, which we link -- by default, so we can safely ignore them here. dieWith :: SrcSpan -> Message -> IO a dieWith span msg = ghcError (ProgramError (showSDoc (mkLocMessage span msg))) checkNonStdWay :: DynFlags -> SrcSpan -> IO (Maybe String) checkNonStdWay dflags srcspan = do let tag = buildTag dflags if null tag {- || tag == "dyn" -} then return Nothing else do -- see #3604: object files compiled for way "dyn" need to link to the -- dynamic packages, so we can't load them into a statically-linked GHCi. -- we have to treat "dyn" in the same way as "prof". -- -- In the future when GHCi is dynamically linked we should be able to relax -- this, but they we may have to make it possible to load either ordinary -- .o files or -dynamic .o files into GHCi (currently that's not possible -- because the dynamic objects contain refs to e.g. __stginit_base_Prelude_dyn -- whereas we have __stginit_base_Prelude_. let default_osuf = phaseInputExt StopLn if objectSuf dflags == default_osuf then failNonStd srcspan else return (Just default_osuf) failNonStd :: SrcSpan -> IO (Maybe String) failNonStd srcspan = dieWith srcspan $ ptext (sLit "Dynamic linking required, but this is a non-standard build (eg. prof).") $$ ptext (sLit "You need to build the program twice: once the normal way, and then") $$ ptext (sLit "in the desired way using -osuf to set the object file suffix.") getLinkDeps :: HscEnv -> HomePackageTable -> PersistentLinkerState -> Maybe String -- the "normal" object suffix -> SrcSpan -- for error messages -> [Module] -- If you need these -> IO ([Linkable], [PackageId]) -- ... then link these first -- Fails with an IO exception if it can't find enough files getLinkDeps hsc_env hpt pls maybe_normal_osuf span mods -- Find all the packages and linkables that a set of modules depends on = do { -- 1. Find the dependent home-pkg-modules/packages from each iface (mods_s, pkgs_s) <- follow_deps mods emptyUniqSet emptyUniqSet; let { -- 2. Exclude ones already linked -- Main reason: avoid findModule calls in get_linkable mods_needed = mods_s `minusList` linked_mods ; pkgs_needed = pkgs_s `minusList` pkgs_loaded pls ; linked_mods = map (moduleName.linkableModule) (objs_loaded pls ++ bcos_loaded pls) } ; -- putStrLn (showSDoc (ppr mods_s)) ; -- 3. For each dependent module, find its linkable -- This will either be in the HPT or (in the case of one-shot -- compilation) we may need to use maybe_getFileLinkable lnks_needed <- mapM (get_linkable maybe_normal_osuf) mods_needed ; return (lnks_needed, pkgs_needed) } where dflags = hsc_dflags hsc_env this_pkg = thisPackage dflags -- The ModIface contains the transitive closure of the module dependencies -- within the current package, *except* for boot modules: if we encounter -- a boot module, we have to find its real interface and discover the -- dependencies of that. Hence we need to traverse the dependency -- tree recursively. See bug #936, testcase ghci/prog007. follow_deps :: [Module] -- modules to follow -> UniqSet ModuleName -- accum. module dependencies -> UniqSet PackageId -- accum. package dependencies -> IO ([ModuleName], [PackageId]) -- result follow_deps [] acc_mods acc_pkgs = return (uniqSetToList acc_mods, uniqSetToList acc_pkgs) follow_deps (mod:mods) acc_mods acc_pkgs = do mb_iface <- initIfaceCheck hsc_env $ loadInterface msg mod (ImportByUser False) iface <- case mb_iface of Maybes.Failed err -> ghcError (ProgramError (showSDoc err)) Maybes.Succeeded iface -> return iface when (mi_boot iface) $ link_boot_mod_error mod let pkg = modulePackageId mod deps = mi_deps iface pkg_deps = dep_pkgs deps (boot_deps, mod_deps) = partitionWith is_boot (dep_mods deps) where is_boot (m,True) = Left m is_boot (m,False) = Right m boot_deps' = filter (not . (`elementOfUniqSet` acc_mods)) boot_deps acc_mods' = addListToUniqSet acc_mods (moduleName mod : mod_deps) acc_pkgs' = addListToUniqSet acc_pkgs $ map fst pkg_deps -- if pkg /= this_pkg then follow_deps mods acc_mods (addOneToUniqSet acc_pkgs' pkg) else follow_deps (map (mkModule this_pkg) boot_deps' ++ mods) acc_mods' acc_pkgs' where msg = text "need to link module" <+> ppr mod <+> text "due to use of Template Haskell" link_boot_mod_error mod = ghcError (ProgramError (showSDoc ( text "module" <+> ppr mod <+> text "cannot be linked; it is only available as a boot module"))) no_obj :: Outputable a => a -> IO b no_obj mod = dieWith span $ ptext (sLit "cannot find object file for module ") <> quotes (ppr mod) $$ while_linking_expr while_linking_expr = ptext (sLit "while linking an interpreted expression") -- This one is a build-system bug get_linkable maybe_normal_osuf mod_name -- A home-package module | Just mod_info <- lookupUFM hpt mod_name = adjust_linkable (Maybes.expectJust "getLinkDeps" (hm_linkable mod_info)) | otherwise = do -- It's not in the HPT because we are in one shot mode, -- so use the Finder to get a ModLocation... mb_stuff <- findHomeModule hsc_env mod_name case mb_stuff of Found loc mod -> found loc mod _ -> no_obj mod_name where found loc mod = do { -- ...and then find the linkable for it mb_lnk <- findObjectLinkableMaybe mod loc ; case mb_lnk of { Nothing -> no_obj mod ; Just lnk -> adjust_linkable lnk }} adjust_linkable lnk | Just osuf <- maybe_normal_osuf = do new_uls <- mapM (adjust_ul osuf) (linkableUnlinked lnk) return lnk{ linkableUnlinked=new_uls } | otherwise = return lnk adjust_ul osuf (DotO file) = do let new_file = replaceExtension file osuf ok <- doesFileExist new_file if (not ok) then dieWith span $ ptext (sLit "cannot find normal object file ") <> quotes (text new_file) $$ while_linking_expr else return (DotO new_file) adjust_ul _ _ = panic "adjust_ul" \end{code} %************************************************************************ %* * Loading a single module %* * %************************************************************************ \begin{code} -- | Link a single module linkModule :: HscEnv -> Module -> IO () linkModule hsc_env mod = do initDynLinker (hsc_dflags hsc_env) modifyMVar v_PersistentLinkerState $ \pls -> do (pls', ok) <- linkDependencies hsc_env pls noSrcSpan [mod] if (failed ok) then ghcError (ProgramError "could not link module") else return (pls',()) -- | Coerce a value as usual, but: -- -- 1) Evaluate it immediately to get a segfault early if the coercion was wrong -- -- 2) Wrap it in some debug messages at verbosity 3 or higher so we can see what happened -- if it /does/ segfault lessUnsafeCoerce :: DynFlags -> String -> a -> IO b lessUnsafeCoerce dflags context what = do debugTraceMsg dflags 3 $ (ptext $ sLit "Coercing a value in") <+> (text context) <> (ptext $ sLit "...") output <- evaluate (unsafeCoerce# what) debugTraceMsg dflags 3 $ ptext $ sLit "Successfully evaluated coercion" return output \end{code} %************************************************************************ %* * Link some linkables The linkables may consist of a mixture of byte-code modules and object modules %* * %************************************************************************ \begin{code} linkModules :: DynFlags -> PersistentLinkerState -> [Linkable] -> IO (PersistentLinkerState, SuccessFlag) linkModules dflags pls linkables = mask_ $ do -- don't want to be interrupted by ^C in here let (objs, bcos) = partition isObjectLinkable (concatMap partitionLinkable linkables) -- Load objects first; they can't depend on BCOs (pls1, ok_flag) <- dynLinkObjs dflags pls objs if failed ok_flag then return (pls1, Failed) else do pls2 <- dynLinkBCOs pls1 bcos return (pls2, Succeeded) -- HACK to support f-x-dynamic in the interpreter; no other purpose partitionLinkable :: Linkable -> [Linkable] partitionLinkable li = let li_uls = linkableUnlinked li li_uls_obj = filter isObject li_uls li_uls_bco = filter isInterpretable li_uls in case (li_uls_obj, li_uls_bco) of (_:_, _:_) -> [li {linkableUnlinked=li_uls_obj}, li {linkableUnlinked=li_uls_bco}] _ -> [li] findModuleLinkable_maybe :: [Linkable] -> Module -> Maybe Linkable findModuleLinkable_maybe lis mod = case [LM time nm us | LM time nm us <- lis, nm == mod] of [] -> Nothing [li] -> Just li _ -> pprPanic "findModuleLinkable" (ppr mod) linkableInSet :: Linkable -> [Linkable] -> Bool linkableInSet l objs_loaded = case findModuleLinkable_maybe objs_loaded (linkableModule l) of Nothing -> False Just m -> linkableTime l == linkableTime m \end{code} %************************************************************************ %* * \subsection{The object-code linker} %* * %************************************************************************ \begin{code} dynLinkObjs :: DynFlags -> PersistentLinkerState -> [Linkable] -> IO (PersistentLinkerState, SuccessFlag) dynLinkObjs dflags pls objs = do -- Load the object files and link them let (objs_loaded', new_objs) = rmDupLinkables (objs_loaded pls) objs pls1 = pls { objs_loaded = objs_loaded' } unlinkeds = concatMap linkableUnlinked new_objs mapM_ loadObj (map nameOfObject unlinkeds) -- Link the all together ok <- resolveObjs -- If resolving failed, unload all our -- object modules and carry on if succeeded ok then do return (pls1, Succeeded) else do pls2 <- unload_wkr dflags [] pls1 return (pls2, Failed) rmDupLinkables :: [Linkable] -- Already loaded -> [Linkable] -- New linkables -> ([Linkable], -- New loaded set (including new ones) [Linkable]) -- New linkables (excluding dups) rmDupLinkables already ls = go already [] ls where go already extras [] = (already, extras) go already extras (l:ls) | linkableInSet l already = go already extras ls | otherwise = go (l:already) (l:extras) ls \end{code} %************************************************************************ %* * \subsection{The byte-code linker} %* * %************************************************************************ \begin{code} dynLinkBCOs :: PersistentLinkerState -> [Linkable] -> IO PersistentLinkerState dynLinkBCOs pls bcos = do let (bcos_loaded', new_bcos) = rmDupLinkables (bcos_loaded pls) bcos pls1 = pls { bcos_loaded = bcos_loaded' } unlinkeds :: [Unlinked] unlinkeds = concatMap linkableUnlinked new_bcos cbcs :: [CompiledByteCode] cbcs = map byteCodeOfObject unlinkeds ul_bcos = [b | ByteCode bs _ <- cbcs, b <- bs] ies = [ie | ByteCode _ ie <- cbcs] gce = closure_env pls final_ie = foldr plusNameEnv (itbl_env pls) ies (final_gce, _linked_bcos) <- linkSomeBCOs True final_ie gce ul_bcos -- XXX What happens to these linked_bcos? let pls2 = pls1 { closure_env = final_gce, itbl_env = final_ie } return pls2 -- Link a bunch of BCOs and return them + updated closure env. linkSomeBCOs :: Bool -- False <=> add _all_ BCOs to returned closure env -- True <=> add only toplevel BCOs to closure env -> ItblEnv -> ClosureEnv -> [UnlinkedBCO] -> IO (ClosureEnv, [HValue]) -- The returned HValues are associated 1-1 with -- the incoming unlinked BCOs. Each gives the -- value of the corresponding unlinked BCO linkSomeBCOs toplevs_only ie ce_in ul_bcos = do let nms = map unlinkedBCOName ul_bcos hvals <- fixIO ( \ hvs -> let ce_out = extendClosureEnv ce_in (zipLazy nms hvs) in mapM (linkBCO ie ce_out) ul_bcos ) let ce_all_additions = zip nms hvals ce_top_additions = filter (isExternalName.fst) ce_all_additions ce_additions = if toplevs_only then ce_top_additions else ce_all_additions ce_out = -- make sure we're not inserting duplicate names into the -- closure environment, which leads to trouble. ASSERT (all (not . (`elemNameEnv` ce_in)) (map fst ce_additions)) extendClosureEnv ce_in ce_additions return (ce_out, hvals) \end{code} %************************************************************************ %* * Unload some object modules %* * %************************************************************************ \begin{code} -- --------------------------------------------------------------------------- -- | Unloading old objects ready for a new compilation sweep. -- -- The compilation manager provides us with a list of linkables that it -- considers \"stable\", i.e. won't be recompiled this time around. For -- each of the modules current linked in memory, -- -- * if the linkable is stable (and it's the same one -- the user may have -- recompiled the module on the side), we keep it, -- -- * otherwise, we unload it. -- -- * we also implicitly unload all temporary bindings at this point. -- unload :: DynFlags -> [Linkable] -- ^ The linkables to *keep*. -> IO () unload dflags linkables = mask_ $ do -- mask, so we're safe from Ctrl-C in here -- Initialise the linker (if it's not been done already) initDynLinker dflags new_pls <- modifyMVar v_PersistentLinkerState $ \pls -> do pls1 <- unload_wkr dflags linkables pls return (pls1, pls1) debugTraceMsg dflags 3 (text "unload: retaining objs" <+> ppr (objs_loaded new_pls)) debugTraceMsg dflags 3 (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls)) return () unload_wkr :: DynFlags -> [Linkable] -- stable linkables -> PersistentLinkerState -> IO PersistentLinkerState -- Does the core unload business -- (the wrapper blocks exceptions and deals with the PLS get and put) unload_wkr _ linkables pls = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls) bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls) let bcos_retained = map linkableModule bcos_loaded' itbl_env' = filterNameMap bcos_retained (itbl_env pls) closure_env' = filterNameMap bcos_retained (closure_env pls) new_pls = pls { itbl_env = itbl_env', closure_env = closure_env', bcos_loaded = bcos_loaded', objs_loaded = objs_loaded' } return new_pls where maybeUnload :: [Linkable] -> Linkable -> IO Bool maybeUnload keep_linkables lnk | linkableInSet lnk keep_linkables = return True | otherwise = do mapM_ unloadObj [f | DotO f <- linkableUnlinked lnk] -- The components of a BCO linkable may contain -- dot-o files. Which is very confusing. -- -- But the BCO parts can be unlinked just by -- letting go of them (plus of course depopulating -- the symbol table which is done in the main body) return False \end{code} %************************************************************************ %* * Loading packages %* * %************************************************************************ \begin{code} data LibrarySpec = Object FilePath -- Full path name of a .o file, including trailing .o -- For dynamic objects only, try to find the object -- file in all the directories specified in -- v_Library_paths before giving up. | Archive FilePath -- Full path name of a .a file, including trailing .a | DLL String -- "Unadorned" name of a .DLL/.so -- e.g. On unix "qt" denotes "libqt.so" -- On WinDoze "burble" denotes "burble.DLL" -- loadDLL is platform-specific and adds the lib/.so/.DLL -- suffixes platform-dependently | DLLPath FilePath -- Absolute or relative pathname to a dynamic library -- (ends with .dll or .so). | Framework String -- Only used for darwin, but does no harm -- If this package is already part of the GHCi binary, we'll already -- have the right DLLs for this package loaded, so don't try to -- load them again. -- -- But on Win32 we must load them 'again'; doing so is a harmless no-op -- as far as the loader is concerned, but it does initialise the list -- of DLL handles that rts/Linker.c maintains, and that in turn is -- used by lookupSymbol. So we must call addDLL for each library -- just to get the DLL handle into the list. partOfGHCi :: [PackageName] partOfGHCi | isWindowsTarget || isDarwinTarget = [] | otherwise = map PackageName ["base", "template-haskell", "editline"] showLS :: LibrarySpec -> String showLS (Object nm) = "(static) " ++ nm showLS (Archive nm) = "(static archive) " ++ nm showLS (DLL nm) = "(dynamic) " ++ nm showLS (DLLPath nm) = "(dynamic) " ++ nm showLS (Framework nm) = "(framework) " ++ nm -- | 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. -- linkPackages :: DynFlags -> [PackageId] -> IO () -- NOTE: in fact, since each module tracks all the packages it depends on, -- we don't really need to use the package-config dependencies. -- -- However we do need the package-config stuff (to find aux libs etc), -- and following them lets us load libraries in the right order, which -- perhaps makes the error message a bit more localised if we get a link -- failure. So the dependency walking code is still here. linkPackages dflags new_pkgs = do -- It's probably not safe to try to load packages concurrently, so we take -- a lock. initDynLinker dflags modifyMVar_ v_PersistentLinkerState $ \pls -> do linkPackages' dflags new_pkgs pls linkPackages' :: DynFlags -> [PackageId] -> PersistentLinkerState -> IO PersistentLinkerState linkPackages' dflags new_pks pls = do pkgs' <- link (pkgs_loaded pls) new_pks return $! pls { pkgs_loaded = pkgs' } where pkg_map = pkgIdMap (pkgState dflags) ipid_map = installedPackageIdMap (pkgState dflags) link :: [PackageId] -> [PackageId] -> IO [PackageId] link pkgs new_pkgs = foldM link_one pkgs new_pkgs link_one pkgs new_pkg | new_pkg `elem` pkgs -- Already linked = return pkgs | Just pkg_cfg <- lookupPackage pkg_map new_pkg = do { -- Link dependents first pkgs' <- link pkgs [ Maybes.expectJust "link_one" $ Map.lookup ipid ipid_map | ipid <- depends pkg_cfg ] -- Now link the package itself ; linkPackage dflags pkg_cfg ; return (new_pkg : pkgs') } | otherwise = ghcError (CmdLineError ("unknown package: " ++ packageIdString new_pkg)) linkPackage :: DynFlags -> PackageConfig -> IO () linkPackage dflags pkg = do let dirs = Packages.libraryDirs pkg let libs = Packages.hsLibraries pkg -- The FFI GHCi import lib isn't needed as -- compiler/ghci/Linker.lhs + rts/Linker.c link the -- interpreted references to FFI to the compiled FFI. -- We therefore filter it out so that we don't get -- duplicate symbol errors. libs' = filter ("HSffi" /=) libs -- Because of slight differences between the GHC dynamic linker and -- the native system linker some packages have to link with a -- different list of libraries when using GHCi. Examples include: libs -- that are actually gnu ld scripts, and the possability that the .a -- libs do not exactly match the .so/.dll equivalents. So if the -- package file provides an "extra-ghci-libraries" field then we use -- that instead of the "extra-libraries" field. ++ (if null (Packages.extraGHCiLibraries pkg) then Packages.extraLibraries pkg else Packages.extraGHCiLibraries pkg) ++ [ lib | '-':'l':lib <- Packages.ldOptions pkg ] classifieds <- mapM (locateOneObj dirs) libs' -- Complication: all the .so's must be loaded before any of the .o's. let known_dlls = [ dll | DLLPath dll <- classifieds ] dlls = [ dll | DLL dll <- classifieds ] objs = [ obj | Object obj <- classifieds ] archs = [ arch | Archive arch <- classifieds ] maybePutStr dflags ("Loading package " ++ display (sourcePackageId pkg) ++ " ... ") -- See comments with partOfGHCi when (packageName pkg `notElem` partOfGHCi) $ do loadFrameworks pkg mapM_ load_dyn (known_dlls ++ map mkSOName dlls) -- After loading all the DLLs, we can load the static objects. -- Ordering isn't important here, because we do one final link -- step to resolve everything. mapM_ loadObj objs mapM_ loadArchive archs maybePutStr dflags "linking ... " ok <- resolveObjs if succeeded ok then maybePutStrLn dflags "done." else ghcError (InstallationError ("unable to load package `" ++ display (sourcePackageId pkg) ++ "'")) -- we have already searched the filesystem; the strings passed to load_dyn -- can be passed directly to loadDLL. They are either fully-qualified -- ("/usr/lib/libfoo.so"), or unqualified ("libfoo.so"). In the latter case, -- loadDLL is going to search the system paths to find the library. -- load_dyn :: FilePath -> IO () load_dyn dll = do r <- loadDLL dll case r of Nothing -> return () Just err -> ghcError (CmdLineError ("can't load .so/.DLL for: " ++ dll ++ " (" ++ err ++ ")" )) loadFrameworks :: InstalledPackageInfo_ ModuleName -> IO () loadFrameworks pkg | isDarwinTarget = mapM_ load frameworks | otherwise = return () where fw_dirs = Packages.frameworkDirs pkg frameworks = Packages.frameworks pkg load fw = do r <- loadFramework fw_dirs fw case r of Nothing -> return () Just err -> ghcError (CmdLineError ("can't load framework: " ++ fw ++ " (" ++ err ++ ")" )) -- Try to find an object file for a given library in the given paths. -- If it isn't present, we assume it's a dynamic library. locateOneObj :: [FilePath] -> String -> IO LibrarySpec locateOneObj dirs lib | not ("HS" `isPrefixOf` lib) -- For non-Haskell libraries (e.g. gmp, iconv) we assume dynamic library = assumeDll | not isDynamicGhcLib -- When the GHC package was not compiled as dynamic library -- (=DYNAMIC not set), we search for .o libraries or, if they -- don't exist, .a libraries. = findObject `orElse` findArchive `orElse` assumeDll | otherwise -- When the GHC package was compiled as dynamic library (=DYNAMIC set), -- we search for .so libraries first. = findDll `orElse` findObject `orElse` findArchive `orElse` assumeDll where mk_obj_path dir = dir (lib <.> "o") mk_arch_path dir = dir ("lib" ++ lib <.> "a") dyn_lib_name = lib ++ "-ghc" ++ cProjectVersion mk_dyn_lib_path dir = dir mkSOName dyn_lib_name findObject = liftM (fmap Object) $ findFile mk_obj_path dirs findArchive = liftM (fmap Archive) $ findFile mk_arch_path dirs findDll = liftM (fmap DLLPath) $ findFile mk_dyn_lib_path dirs assumeDll = return (DLL lib) infixr `orElse` f `orElse` g = do m <- f case m of Just x -> return x Nothing -> g -- ---------------------------------------------------------------------------- -- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32) -- return Nothing == success, else Just error message from dlopen loadDynamic :: [FilePath] -> FilePath -> IO (Maybe String) loadDynamic paths rootname = do { mb_dll <- findFile mk_dll_path paths ; case mb_dll of Just dll -> loadDLL dll Nothing -> loadDLL (mkSOName rootname) } -- Tried all our known library paths, so let -- dlopen() search its own builtin paths now. where mk_dll_path dir = dir mkSOName rootname mkSOName :: FilePath -> FilePath mkSOName root | isDarwinTarget = ("lib" ++ root) <.> "dylib" | isWindowsTarget = -- Win32 DLLs have no .dll extension here, because -- addDLL tries both foo.dll and foo.drv root | otherwise = ("lib" ++ root) <.> "so" -- Darwin / MacOS X only: load a framework -- a framework is a dynamic library packaged inside a directory of the same -- name. They are searched for in different paths than normal libraries. loadFramework :: [FilePath] -> FilePath -> IO (Maybe String) loadFramework extraPaths rootname = do { either_dir <- tryIO getHomeDirectory ; let homeFrameworkPath = case either_dir of Left _ -> [] Right dir -> [dir ++ "/Library/Frameworks"] ps = extraPaths ++ homeFrameworkPath ++ defaultFrameworkPaths ; mb_fwk <- findFile mk_fwk ps ; case mb_fwk of Just fwk_path -> loadDLL fwk_path Nothing -> return (Just "not found") } -- Tried all our known library paths, but dlopen() -- has no built-in paths for frameworks: give up where mk_fwk dir = dir (rootname ++ ".framework/" ++ rootname) -- sorry for the hardcoded paths, I hope they won't change anytime soon: defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"] \end{code} %************************************************************************ %* * Helper functions %* * %************************************************************************ \begin{code} findFile :: (FilePath -> FilePath) -- Maps a directory path to a file path -> [FilePath] -- Directories to look in -> IO (Maybe FilePath) -- The first file path to match findFile _ [] = return Nothing findFile mk_file_path (dir:dirs) = do { let file_path = mk_file_path dir ; b <- doesFileExist file_path ; if b then return (Just file_path) else findFile mk_file_path dirs } \end{code} \begin{code} maybePutStr :: DynFlags -> String -> IO () maybePutStr dflags s | verbosity dflags > 0 = putStr s | otherwise = return () maybePutStrLn :: DynFlags -> String -> IO () maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s | otherwise = return () \end{code}