\begin{code}
-{-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
+{-# OPTIONS -optc-DNON_POSIX_SOURCE -#include "Linker.h" #-}
-module Linker ( HValue, initLinker, showLinkerState,
- linkLibraries, linkExpr,
- unload, extendLinkEnv,
- LibrarySpec(..),
+module Linker ( HValue, showLinkerState,
+ linkExpr, unload, extendLinkEnv,
linkPackages,
) where
-#include "../includes/config.h"
+#include "../includes/ghcconfig.h"
#include "HsVersions.h"
-import ObjLink ( loadDLL, loadObj, unloadObj, resolveObjs, initLinker )
+import ObjLink ( loadDLL, loadObj, unloadObj, resolveObjs, initObjLinker )
import ByteCodeLink ( HValue, ClosureEnv, extendClosureEnv, linkBCO )
import ByteCodeItbls ( ItblEnv )
import ByteCodeAsm ( CompiledByteCode(..), bcoFreeNames, UnlinkedBCO(..))
import Packages
-import DriverState ( v_Library_paths, v_Opt_l,
- v_Cmdline_frameworks, v_Framework_paths, getStaticOpts )
+import DriverState ( v_Library_paths, v_Opt_l, v_Ld_inputs, getStaticOpts, v_ExplicitPackages )
+import DriverPhases ( isObjectFilename, isDynLibFilename )
+import DriverUtil ( getFileSuffix )
+#ifdef darwin_TARGET_OS
+import DriverState ( v_Cmdline_frameworks, v_Framework_paths )
+#endif
import Finder ( findModule, findLinkable )
import HscTypes
-import Name ( Name, nameModule, isExternalName )
+import Name ( Name, nameModule, nameModuleName, isExternalName, isWiredInName )
import NameEnv
import NameSet ( nameSetToList )
import Module
-import FastString ( FastString(..), unpackFS )
import ListSetOps ( minusList )
-import CmdLineOpts ( DynFlags(verbosity) )
+import CmdLineOpts ( DynFlags(verbosity), getDynFlags )
import BasicTypes ( SuccessFlag(..), succeeded, failed )
import Outputable
import Panic ( GhcException(..) )
interpreted code only), for use during linking.
\begin{code}
-GLOBAL_VAR(v_PersistentLinkerState, emptyPLS, PersistentLinkerState)
+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 {
-- 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.
init_pkgs_loaded = [ FSLIT("rts") ]
\end{code}
= filterNameEnv keep_elt env
where
keep_elt (n,_) = isExternalName n
- && (moduleName (nameModule n) `elem` mods)
+ && (nameModuleName n `elem` mods)
\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 :: 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
+ = do { done <- readIORef v_InitLinkerDone
+ ; if done then return ()
+ else do { writeIORef v_InitLinkerDone True
+ ; reallyInitDynLinker }
+ }
+
+reallyInitDynLinker
+ = do { dflags <- getDynFlags
+
+ -- Initialise the linker state
+ ; writeIORef v_PersistentLinkerState emptyPLS
+
+ -- (a) initialise the C dynamic linker
+ ; initObjLinker
+
+ -- (b) Load packages from the command-line
+ ; expl <- readIORef v_ExplicitPackages
+ ; linkPackages dflags expl
+
+ -- (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 -> PersistentCompilerState
- -> UnlinkedBCO -> IO HValue
+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 pcs root_ul_bco
+linkExpr hsc_env root_ul_bco
= do {
+ -- Initialise the linker (if it's not been done already)
+ initDynLinker
+
-- Find what packages and linkables are required
- (lnks, pkgs) <- getLinkDeps hpt pit needed_mods ;
+ ; eps <- readIORef (hsc_EPS hsc_env)
+ ; (lnks, pkgs) <- getLinkDeps hpt (eps_PIT eps) needed_mods
-- Link the packages and modules required
- linkPackages dflags pkgs
- ; ok <- linkModules dflags lnks
+ ; linkPackages dflags pkgs
+ ; ok <- linkModules dflags lnks
; if failed ok then
dieWith empty
else do {
; return root_hval
}}
where
- pit = eps_PIT (pcs_EPS pcs)
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 ]
+ 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 (UsageError (showSDoc msg))
+dieWith msg = throwDyn (ProgramError (showSDoc msg))
getLinkDeps :: HomePackageTable -> PackageIfaceTable
-> [Module] -- If you need these
-- so use the Finder to get a ModLocation...
do { mb_stuff <- findModule mod_name ;
case mb_stuff of {
- Nothing -> no_obj mod_name ;
- Just (_, loc) -> do {
+ Left _ -> no_obj mod_name ;
+ Right (_, loc) -> do {
-- ...and then find the linkable for it
mb_lnk <- findLinkable mod_name loc ;
Nothing -> no_obj mod_name ;
Just lnk -> return lnk
}}}}
-\end{code}
+\end{code}
%************************************************************************
[li] -> Just li
many -> pprPanic "findModuleLinkable" (ppr mod)
-filterModuleLinkables :: (ModuleName -> Bool) -> [Linkable] -> [Linkable]
-filterModuleLinkables p ls = filter (p . linkableModName) ls
-
linkableInSet :: Linkable -> [Linkable] -> Bool
linkableInSet l objs_loaded =
case findModuleLinkable_maybe objs_loaded (linkableModName l) of
| otherwise = go (l:already) (l:extras) ls
\end{code}
-
-\begin{code}
-linkLibraries :: DynFlags
- -> [String] -- foo.o files specified on command line
- -> IO ()
--- Used just at initialisation time to link in libraries
--- specified on the command line.
-linkLibraries dflags objs
- = do { lib_paths <- readIORef v_Library_paths
- ; opt_l <- getStaticOpts v_Opt_l
- ; let minus_ls = [ lib | '-':'l':lib <- opt_l ]
-#ifdef darwin_TARGET_OS
- ; framework_paths <- readIORef v_Framework_paths
- ; frameworks <- readIORef v_Cmdline_frameworks
-#endif
- ; let cmdline_lib_specs = map Object objs ++ map DLL minus_ls
-#ifdef darwin_TARGET_OS
- ++ map Framework frameworks
-#endif
- ; if (null cmdline_lib_specs) then return ()
- else do {
-
- -- Now link them
-#ifdef darwin_TARGET_OS
- ; mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs
-#else
- ; mapM_ (preloadLib dflags lib_paths) cmdline_lib_specs
-#endif
- ; maybePutStr dflags "final link ... "
- ; ok <- resolveObjs
- ; if succeeded ok then maybePutStrLn dflags "done."
- else throwDyn (InstallationError "linking extra libraries/objects failed")
- }}
- where
-#ifdef darwin_TARGET_OS
- preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO ()
- preloadLib dflags lib_paths framework_paths lib_spec
-#else
- preloadLib :: DynFlags -> [String] -> LibrarySpec -> IO ()
- preloadLib dflags lib_paths lib_spec
-#endif
- = 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 -> return ()
- Just mm -> preloadFailed mm lib_paths lib_spec
- maybePutStrLn dflags "done"
-#ifdef darwin_TARGET_OS
- Framework framework
- -> do maybe_errstr <- loadFramework framework_paths framework
- case maybe_errstr of
- Nothing -> return ()
- Just mm -> preloadFailed mm framework_paths lib_spec
- maybePutStrLn dflags "done"
-#endif
- 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}
-
-
%************************************************************************
%* *
\subsection{The byte-code linker}
objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls)
bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls)
- let objs_retained = map linkableModName objs_loaded'
- bcos_retained = map linkableModName bcos_loaded'
+ let bcos_retained = map linkableModName 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',
-- On WinDoze "burble" denotes "burble.DLL"
-- loadDLL is platform-specific and adds the lib/.so/.DLL
-- suffixes platform-dependently
-#ifdef darwin_TARGET_OS
- | Framework String
-#endif
+
+ | 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
# if defined(mingw32_TARGET_OS) || defined(darwin_TARGET_OS)
= [ ]
# else
- = [ "base", "haskell98", "haskell-src", "readline" ]
+ = [ "base", "haskell98", "template-haskell", "readline" ]
# endif
-showLS (Object nm) = "(static) " ++ nm
-showLS (DLL nm) = "(dynamic) " ++ nm
-#ifdef darwin_TARGET_OS
+showLS (Object nm) = "(static) " ++ nm
+showLS (DLL nm) = "(dynamic) " ++ nm
+showLS (DLLPath nm) = "(dynamic) " ++ nm
showLS (Framework nm) = "(framework) " ++ nm
-#endif
linkPackages :: DynFlags -> [PackageName] -> IO ()
-- Link exactly the specified packages, and their dependents
linkPackage :: DynFlags -> PackageConfig -> IO ()
linkPackage dflags pkg
= do
- let dirs = Packages.library_dirs pkg
- let libs = Packages.hs_libraries pkg ++ extra_libraries pkg
- ++ [ lib | '-':'l':lib <- extra_ld_opts pkg ]
+ let dirs = Packages.libraryDirs pkg
+ let libs = Packages.hsLibraries pkg ++ Packages.extraLibraries pkg
+ ++ [ lib | '-':'l':lib <- Packages.extraLdOpts pkg ]
classifieds <- mapM (locateOneObj dirs) libs
-#ifdef darwin_TARGET_OS
- let fwDirs = Packages.framework_dirs pkg
- let frameworks= Packages.extra_frameworks pkg
-#endif
-- 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 " ++ Packages.name pkg ++ " ... ")
+ maybePutStr dflags ("Loading package " ++ showPackageId (package pkg) ++ " ... ")
-- See comments with partOfGHCi
- when (Packages.name pkg `notElem` partOfGHCi) $ do
-#ifdef darwin_TARGET_OS
- loadFrameworks fwDirs frameworks
-#endif
- loadDynamics dirs dlls
+ 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 panic ("can't load package `" ++ name pkg ++ "'")
-
-loadDynamics dirs [] = return ()
-loadDynamics dirs (dll:dlls) = do
- r <- loadDynamic dirs dll
- case r of
- Nothing -> loadDynamics dirs dlls
- Just err -> throwDyn (CmdLineError ("can't load .so/.DLL for: "
- ++ dll ++ " (" ++ err ++ ")" ))
-#ifdef darwin_TARGET_OS
-loadFrameworks dirs [] = return ()
-loadFrameworks dirs (fw:fws) = do
- r <- loadFramework dirs fw
- case r of
- Nothing -> loadFrameworks dirs fws
- Just err -> throwDyn (CmdLineError ("can't load framework: "
- ++ fw ++ " (" ++ err ++ ")" ))
+ 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.framework_dirs pkg
+ frameworks = Packages.extra_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.
= do { mb_obj_path <- findFile mk_obj_path dirs
; case mb_obj_path of
Just obj_path -> return (Object obj_path)
- Nothing -> return (DLL lib) } -- we assume
+ Nothing -> return (DLL lib) } -- We assume
where
mk_obj_path dir = dir ++ '/':lib ++ ".o"