%
-% (c) The University of Glasgow, 2000
+% (c) The University of Glasgow 2000
%
-\section[Linker]{The In-Memory Object File Linker}
+
+-- --------------------------------------
+-- 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 -#include "Linker.h" #-}
-module Linker (
- initLinker, -- :: IO ()
- loadObj, -- :: String -> IO ()
- unloadObj, -- :: String -> IO ()
- lookupSymbol, -- :: String -> IO (Maybe (Ptr a))
- resolveObjs -- :: IO Bool
- ) where
+{-# OPTIONS -optc-DNON_POSIX_SOURCE -#include "Linker.h" #-}
-import Monad ( when )
+module Linker ( HValue, showLinkerState,
+ linkExpr, unload, extendLinkEnv,
+ linkPackages,
+ ) where
-import Foreign.C
-import Foreign ( Ptr, nullPtr )
-import Panic ( panic )
-import DriverUtil ( prefixUnderscore )
+#include "../includes/ghcconfig.h"
+#include "HsVersions.h"
--- ---------------------------------------------------------------------------
--- RTS Linker Interface
--- ---------------------------------------------------------------------------
+import ObjLink ( loadDLL, loadObj, unloadObj, resolveObjs, initObjLinker )
+import ByteCodeLink ( HValue, ClosureEnv, extendClosureEnv, linkBCO )
+import ByteCodeItbls ( ItblEnv )
+import ByteCodeAsm ( CompiledByteCode(..), bcoFreeNames, UnlinkedBCO(..))
-lookupSymbol :: String -> IO (Maybe (Ptr a))
-lookupSymbol str_in = do
- let str = prefixUnderscore str_in
- withCString str $ \c_str -> do
- addr <- c_lookupSymbol c_str
- if addr == nullPtr
- then return Nothing
- else return (Just addr)
-
-loadObj :: String -> IO ()
-loadObj str =
- withCString str $ \c_str -> do
- r <- c_loadObj c_str
- when (r == 0) (panic "loadObj: failed")
-
-unloadObj :: String -> IO ()
-unloadObj str =
- withCString str $ \c_str -> do
- r <- c_unloadObj c_str
- when (r == 0) (panic "unloadObj: failed")
-
-resolveObjs :: IO Bool
-resolveObjs = do
- r <- c_resolveObjs
- return (r /= 0) -- returns True <=> success
+import Packages
+import DriverState ( v_Library_paths, v_Opt_l, v_Ld_inputs, getStaticOpts )
+import DriverPhases ( isObjectFilename, isDynLibFilename )
+import DriverUtil ( getFileSuffix )
+#ifdef darwin_TARGET_OS
+import DriverState ( v_Cmdline_frameworks, v_Framework_paths )
+#endif
+import Finder ( findModule, findLinkable, FindResult(..) )
+import HscTypes
+import Name ( Name, nameModule, isExternalName, isWiredInName )
+import NameEnv
+import NameSet ( nameSetToList )
+import Module
+import ListSetOps ( minusList )
+import CmdLineOpts ( DynFlags(..) )
+import BasicTypes ( SuccessFlag(..), succeeded, failed )
+import Outputable
+import Panic ( GhcException(..) )
+import Util ( zipLazy, global )
+-- Standard libraries
+import Control.Monad ( when, filterM, foldM )
+
+import Data.IORef ( IORef, readIORef, writeIORef )
+import Data.List ( partition, nub )
+
+import System.IO ( putStr, putStrLn, hPutStrLn, stderr, fixIO )
+import System.Directory ( doesFileExist )
+
+import Control.Exception ( block, throwDyn )
+
+#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
+ | Just rts_id <- rtsPackageId (pkgState dflags) = [rts_id]
+ | otherwise = []
+
+\end{code}
+
+\begin{code}
+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
+
+-- 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
+ ; opt_l <- getStaticOpts v_Opt_l
+ ; let minus_ls = [ lib | '-':'l':lib <- opt_l ]
+
+ -- (d) Link .o files from the command-line
+ ; lib_paths <- readIORef v_Library_paths
+ ; cmdline_ld_inputs <- readIORef v_Ld_inputs
+
+ ; classified_ld_inputs <- mapM classifyLdInput cmdline_ld_inputs
+
+ -- (e) Link any MacOS frameworks
+#ifdef darwin_TARGET_OS
+ ; framework_paths <- readIORef v_Framework_paths
+ ; frameworks <- readIORef v_Cmdline_frameworks
+#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 dflags 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 :: DynFlags -> 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 dflags 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
+ | ExternalPackage 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
+ = return (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 dflags 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 <- findLinkable 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}
-- ---------------------------------------------------------------------------
--- Foreign declaractions to RTS entry points which does the real work;
--- ---------------------------------------------------------------------------
+-- 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
+
+ pls <- readIORef v_PersistentLinkerState
+ new_pls <- unload_wkr dflags linkables pls
+ writeIORef v_PersistentLinkerState new_pls
-foreign import "initLinker" unsafe
- initLinker :: IO ()
+ let verb = verbosity dflags
+ when (verb >= 3) $ do
+ hPutStrLn stderr (showSDoc
+ (text "unload: retaining objs" <+> ppr (objs_loaded new_pls)))
+ hPutStrLn stderr (showSDoc
+ (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls)))
-foreign import "lookupSymbol" unsafe
- c_lookupSymbol :: CString -> IO (Ptr a)
+ return ()
-foreign import "loadObj" unsafe
- c_loadObj :: CString -> IO Int
+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)
-foreign import "unloadObj" unsafe
- c_unloadObj :: CString -> IO Int
+unload_wkr dflags linkables pls
+ = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables
-foreign import "resolveObjs" unsafe
- c_resolveObjs :: IO Int
+ 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 ++ Packages.extraLibraries pkg
+ ++ [ lib | '-':'l':lib <- Packages.extraLdOpts 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.extraFrameworks 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 ++ '/':lib ++ ".o"
+ mk_dyn_lib_path dir = dir ++ '/':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 ++ '/':mkSOName rootname
+
+#if defined(darwin_TARGET_OS)
+mkSOName root = "lib" ++ root ++ ".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 ++ ".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 ++ '/' : 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}
projects / ghc-hetmet.git / blobdiff