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Diffstat (limited to 'compiler/ghci/Linker.lhs')
| -rw-r--r-- | compiler/ghci/Linker.lhs | 927 |
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diff --git a/compiler/ghci/Linker.lhs b/compiler/ghci/Linker.lhs new file mode 100644 index 0000000000..3a5ecf8a6d --- /dev/null +++ b/compiler/ghci/Linker.lhs @@ -0,0 +1,927 @@ +% +% (c) The University of Glasgow 2005 +% + +-- -------------------------------------- +-- 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. + + +\begin{code} + +{-# OPTIONS -optc-DNON_POSIX_SOURCE -#include "Linker.h" #-} + +module Linker ( HValue, showLinkerState, + linkExpr, unload, extendLinkEnv, withExtendedLinkEnv, + extendLoadedPkgs, + linkPackages,initDynLinker + ) where + +#include "HsVersions.h" + +import ObjLink ( loadDLL, loadObj, unloadObj, resolveObjs, initObjLinker ) +import ByteCodeLink ( HValue, ClosureEnv, extendClosureEnv, linkBCO ) +import ByteCodeItbls ( ItblEnv ) +import ByteCodeAsm ( CompiledByteCode(..), bcoFreeNames, UnlinkedBCO(..)) + +import Packages +import DriverPhases ( isObjectFilename, isDynLibFilename ) +import Finder ( findModule, findObjectLinkableMaybe, FindResult(..) ) +import HscTypes +import Name ( Name, nameModule, isExternalName, isWiredInName ) +import NameEnv +import NameSet ( nameSetToList ) +import Module +import ListSetOps ( minusList ) +import DynFlags ( DynFlags(..), getOpts ) +import BasicTypes ( SuccessFlag(..), succeeded, failed ) +import Outputable +import Panic ( GhcException(..) ) +import Util ( zipLazy, global, joinFileExt, joinFileName, suffixOf ) +import StaticFlags ( v_Ld_inputs ) +import ErrUtils ( debugTraceMsg ) + +-- Standard libraries +import Control.Monad ( when, filterM, foldM ) + +import Data.IORef ( IORef, readIORef, writeIORef, modifyIORef ) +import Data.List ( partition, nub ) + +import System.IO ( putStr, putStrLn, hPutStrLn, stderr, fixIO ) +import System.Directory ( doesFileExist ) + +import Control.Exception ( block, throwDyn, bracket ) +import Maybe ( isJust, fromJust ) + +#if __GLASGOW_HASKELL__ >= 503 +import GHC.IOBase ( IO(..) ) +#else +import PrelIOBase ( IO(..) ) +#endif +\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_VAR(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 dflags = 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 + | ExtPackage rts_id <- rtsPackageId (pkgState dflags) = [rts_id] + | otherwise = [] +\end{code} + +\begin{code} +extendLoadedPkgs :: [PackageId] -> IO () +extendLoadedPkgs pkgs + = modifyIORef v_PersistentLinkerState (\s -> s{pkgs_loaded = pkgs ++ pkgs_loaded s}) + +extendLinkEnv :: [(Name,HValue)] -> IO () +-- Automatically discards shadowed bindings +extendLinkEnv new_bindings + = do pls <- readIORef v_PersistentLinkerState + let new_closure_env = extendClosureEnv (closure_env pls) new_bindings + new_pls = pls { closure_env = new_closure_env } + writeIORef v_PersistentLinkerState new_pls + +withExtendedLinkEnv :: [(Name,HValue)] -> IO a -> IO a +withExtendedLinkEnv new_env action + = bracket set_new_env + reset_old_env + (const action) + where set_new_env = do pls <- readIORef v_PersistentLinkerState + let new_closure_env = extendClosureEnv (closure_env pls) new_env + new_pls = pls { closure_env = new_closure_env } + writeIORef v_PersistentLinkerState new_pls + return pls + reset_old_env pls = writeIORef v_PersistentLinkerState pls + +-- 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} +showLinkerState :: IO () +-- Display the persistent linker state +showLinkerState + = do pls <- readIORef 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} +%* * +%************************************************************************ + +We initialise the dynamic linker by + +a) calling the C initialisation procedure + +b) Loading any packages specified on the command line, + now held in v_ExplicitPackages + +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 + +\begin{code} +initDynLinker :: DynFlags -> IO () +-- 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 dflags + = do { done <- readIORef v_InitLinkerDone + ; if done then return () + else do { writeIORef v_InitLinkerDone True + ; reallyInitDynLinker dflags } + } + +reallyInitDynLinker dflags + = do { -- Initialise the linker state + ; writeIORef v_PersistentLinkerState (emptyPLS dflags) + + -- (a) initialise the C dynamic linker + ; initObjLinker + + -- (b) Load packages from the command-line + ; linkPackages dflags (explicitPackages (pkgState dflags)) + + -- (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 +#ifdef darwin_TARGET_OS + ; let framework_paths = frameworkPaths dflags + ; let frameworks = cmdlineFrameworks dflags +#else + ; let frameworks = [] + ; let framework_paths = [] +#endif + -- 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 () + 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 throwDyn (InstallationError "linking extra libraries/objects failed") + }} + +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") + + 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 + +#ifdef darwin_TARGET_OS + Framework framework + -> do maybe_errstr <- loadFramework framework_paths framework + case maybe_errstr of + Nothing -> maybePutStrLn dflags "done" + Just mm -> preloadFailed mm framework_paths lib_spec +#endif + where + preloadFailed :: String -> [String] -> LibrarySpec -> IO () + preloadFailed sys_errmsg paths spec + = do maybePutStr dflags + ("failed.\nDynamic linker error message was:\n " + ++ sys_errmsg ++ "\nWhilst trying to load: " + ++ showLS spec ++ "\nDirectories to search are:\n" + ++ unlines (map (" "++) paths) ) + give_up + + -- 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 + + give_up = throwDyn $ + CmdLineError "user specified .o/.so/.DLL could not be loaded." +\end{code} + + +%************************************************************************ +%* * + Link a byte-code expression +%* * +%************************************************************************ + +\begin{code} +linkExpr :: HscEnv -> UnlinkedBCO -> IO HValue + +-- Link a single expression, *including* first linking packages and +-- modules that this expression depends on. +-- +-- Raises an IO exception if it can't find a compiled version of the +-- dependents to link. + +linkExpr hsc_env root_ul_bco + = do { + -- Initialise the linker (if it's not been done already) + let dflags = hsc_dflags hsc_env + ; initDynLinker dflags + + -- Find what packages and linkables are required + ; eps <- readIORef (hsc_EPS hsc_env) + ; (lnks, pkgs) <- getLinkDeps hsc_env hpt (eps_PIT eps) needed_mods + + -- Link the packages and modules required + ; linkPackages dflags pkgs + ; ok <- linkModules dflags lnks + ; if failed ok then + dieWith empty + else do { + + -- Link the expression itself + pls <- readIORef v_PersistentLinkerState + ; 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 root_hval + }} + where + hpt = hsc_HPT hsc_env + dflags = hsc_dflags hsc_env + 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 msg = throwDyn (ProgramError (showSDoc msg)) + +getLinkDeps :: HscEnv -> HomePackageTable -> PackageIfaceTable + -> [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 pit mods +-- Find all the packages and linkables that a set of modules depends on + = do { pls <- readIORef v_PersistentLinkerState ; + let { + -- 1. Find the dependent home-pkg-modules/packages from each iface + (mods_s, pkgs_s) = unzip (map get_deps mods) ; + + -- 2. Exclude ones already linked + -- Main reason: avoid findModule calls in get_linkable + mods_needed = nub (concat mods_s) `minusList` linked_mods ; + pkgs_needed = nub (concat pkgs_s) `minusList` pkgs_loaded pls ; + + linked_mods = map linkableModule (objs_loaded pls ++ bcos_loaded pls) + } ; + + -- 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 mods_needed ; + + return (lnks_needed, pkgs_needed) } + where + get_deps :: Module -> ([Module],[PackageId]) + -- Get the things needed for the specified module + -- This is rather similar to the code in RnNames.importsFromImportDecl + get_deps mod + | ExtPackage p <- mi_package iface + = ([], p : dep_pkgs deps) + | otherwise + = (mod : [m | (m,_) <- dep_mods deps], dep_pkgs deps) + where + iface = get_iface mod + deps = mi_deps iface + + get_iface mod = case lookupIface hpt pit mod of + Just iface -> iface + Nothing -> pprPanic "getLinkDeps" (no_iface mod) + no_iface mod = ptext SLIT("No iface for") <+> ppr mod + -- This one is a GHC bug + + no_obj mod = dieWith (ptext SLIT("No compiled code for") <+> ppr mod) + -- This one is a build-system bug + + get_linkable mod_name -- A home-package module + | Just mod_info <- lookupModuleEnv hpt mod_name + = ASSERT(isJust (hm_linkable mod_info)) + return (fromJust (hm_linkable mod_info)) + | otherwise + = -- It's not in the HPT because we are in one shot mode, + -- so use the Finder to get a ModLocation... + do { mb_stuff <- findModule hsc_env mod_name False ; + case mb_stuff of { + Found loc _ -> found loc mod_name ; + _ -> no_obj mod_name + }} + + found loc mod_name = do { + -- ...and then find the linkable for it + mb_lnk <- findObjectLinkableMaybe mod_name loc ; + case mb_lnk of { + Nothing -> no_obj mod_name ; + Just lnk -> return lnk + }} +\end{code} + + +%************************************************************************ +%* * + Link some linkables + The linkables may consist of a mixture of + byte-code modules and object modules +%* * +%************************************************************************ + +\begin{code} +linkModules :: DynFlags -> [Linkable] -> IO SuccessFlag +linkModules dflags linkables + = block $ 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 + ok_flag <- dynLinkObjs dflags objs + + if failed ok_flag then + return Failed + else do + dynLinkBCOs bcos + return 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 + (objs@(_:_), bcos@(_:_)) + -> [li{linkableUnlinked=li_uls_obj}, li{linkableUnlinked=li_uls_bco}] + other + -> [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 + many -> 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 -> [Linkable] -> IO SuccessFlag + -- Side-effects the PersistentLinkerState + +dynLinkObjs dflags objs + = do pls <- readIORef v_PersistentLinkerState + + -- 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 + writeIORef v_PersistentLinkerState pls1 + return Succeeded + else do + pls2 <- unload_wkr dflags [] pls1 + writeIORef v_PersistentLinkerState pls2 + return 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 :: [Linkable] -> IO () + -- Side-effects the persistent linker state +dynLinkBCOs bcos + = do pls <- readIORef v_PersistentLinkerState + + 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 + -- What happens to these linked_bcos? + + let pls2 = pls1 { closure_env = final_gce, + itbl_env = final_ie } + + writeIORef v_PersistentLinkerState pls2 + return () + +-- 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] -> IO () +-- The 'linkables' are the ones to *keep* + +unload dflags linkables + = block $ do -- block, so we're safe from Ctrl-C in here + + -- Initialise the linker (if it's not been done already) + initDynLinker dflags + + pls <- readIORef v_PersistentLinkerState + new_pls <- unload_wkr dflags linkables pls + writeIORef v_PersistentLinkerState new_pls + + 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 dflags 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 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. + + | 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 +# if defined(mingw32_TARGET_OS) || defined(darwin_TARGET_OS) + = [ ] +# else + = [ "base", "haskell98", "template-haskell", "readline" ] +# endif + +showLS (Object nm) = "(static) " ++ nm +showLS (DLL nm) = "(dynamic) " ++ nm +showLS (DLLPath nm) = "(dynamic) " ++ nm +showLS (Framework nm) = "(framework) " ++ nm + +linkPackages :: DynFlags -> [PackageId] -> IO () +-- 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. +-- +-- 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 { pls <- readIORef v_PersistentLinkerState + ; let pkg_map = pkgIdMap (pkgState dflags) + + ; pkgs' <- link pkg_map (pkgs_loaded pls) new_pkgs + + ; writeIORef v_PersistentLinkerState (pls { pkgs_loaded = pkgs' }) + } + where + link :: PackageConfigMap -> [PackageId] -> [PackageId] -> IO [PackageId] + link pkg_map pkgs new_pkgs + = foldM (link_one pkg_map) pkgs new_pkgs + + link_one pkg_map 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 pkg_map pkgs (map mkPackageId (depends pkg_cfg)) + -- Now link the package itself + ; linkPackage dflags pkg_cfg + ; return (new_pkg : pkgs') } + + | otherwise + = throwDyn (CmdLineError ("unknown package: " ++ packageIdString new_pkg)) + + +linkPackage :: DynFlags -> PackageConfig -> IO () +linkPackage dflags pkg + = do + let dirs = Packages.libraryDirs pkg + + let libs = Packages.hsLibraries pkg + -- 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 dlls = [ dll | DLL dll <- classifieds ] + objs = [ obj | Object obj <- classifieds ] + + maybePutStr dflags ("Loading package " ++ showPackageId (package pkg) ++ " ... ") + + -- See comments with partOfGHCi + when (pkgName (package pkg) `notElem` partOfGHCi) $ do + loadFrameworks pkg + -- When a library A needs symbols from a library B, the order in + -- extra_libraries/extra_ld_opts is "-lA -lB", because that's the + -- way ld expects it for static linking. Dynamic linking is a + -- different story: When A has no dependency information for B, + -- dlopen-ing A with RTLD_NOW (see addDLL in Linker.c) will fail + -- when B has not been loaded before. In a nutshell: Reverse the + -- order of DLLs for dynamic linking. + -- This fixes a problem with the HOpenGL package (see "Compiling + -- HOpenGL under recent versions of GHC" on the HOpenGL list). + mapM_ (load_dyn dirs) (reverse 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 + + maybePutStr dflags "linking ... " + ok <- resolveObjs + if succeeded ok then maybePutStrLn dflags "done." + else throwDyn (InstallationError ("unable to load package `" ++ showPackageId (package pkg) ++ "'")) + +load_dyn dirs dll = do r <- loadDynamic dirs dll + case r of + Nothing -> return () + Just err -> throwDyn (CmdLineError ("can't load .so/.DLL for: " + ++ dll ++ " (" ++ err ++ ")" )) +#ifndef darwin_TARGET_OS +loadFrameworks pkg = return () +#else +loadFrameworks pkg = mapM_ load frameworks + 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 -> throwDyn (CmdLineError ("can't load framework: " + ++ fw ++ " (" ++ err ++ ")" )) +#endif + +-- 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 + = do { mb_obj_path <- findFile mk_obj_path dirs + ; case mb_obj_path of + Just obj_path -> return (Object obj_path) + Nothing -> + do { mb_lib_path <- findFile mk_dyn_lib_path dirs + ; case mb_lib_path of + Just lib_path -> return (DLL (lib ++ "_dyn")) + Nothing -> return (DLL lib) }} -- We assume + where + mk_obj_path dir = dir `joinFileName` (lib `joinFileExt` "o") + mk_dyn_lib_path dir = dir `joinFileName` mkSOName (lib ++ "_dyn") + + +-- ---------------------------------------------------------------------------- +-- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32) + +-- return Nothing == success, else Just error message from dlopen +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 `joinFileName` mkSOName rootname + +#if defined(darwin_TARGET_OS) +mkSOName root = ("lib" ++ root) `joinFileExt` "dylib" +#elif defined(mingw32_TARGET_OS) +-- Win32 DLLs have no .dll extension here, because addDLL tries +-- both foo.dll and foo.drv +mkSOName root = root +#else +mkSOName root = ("lib" ++ root) `joinFileExt` "so" +#endif + +-- 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. +#ifdef darwin_TARGET_OS +loadFramework extraPaths rootname + = do { mb_fwk <- findFile mk_fwk (extraPaths ++ defaultFrameworkPaths) + ; 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 `joinFileName` (rootname ++ ".framework/" ++ rootname) + -- sorry for the hardcoded paths, I hope they won't change anytime soon: + defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"] +#endif +\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 mk_file_path [] + = 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 dflags s | verbosity dflags > 0 = putStr s + | otherwise = return () + +maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s + | otherwise = return () +\end{code} |