2 % (c) The University of Glasgow 2000
5 -- --------------------------------------
6 -- The dynamic linker for GHCi
7 -- --------------------------------------
9 This module deals with the top-level issues of dynamic linking,
10 calling the object-code linker and the byte-code linker where
16 {-# OPTIONS -optc-DNON_POSIX_SOURCE -#include "Linker.h" #-}
18 module Linker ( HValue, initLinker, showLinkerState,
19 linkLibraries, linkExpr,
20 unload, extendLinkEnv,
25 #include "../includes/config.h"
26 #include "HsVersions.h"
28 import ObjLink ( loadDLL, loadObj, unloadObj, resolveObjs, initLinker )
29 import ByteCodeLink ( HValue, ClosureEnv, extendClosureEnv, linkBCO )
30 import ByteCodeItbls ( ItblEnv )
31 import ByteCodeAsm ( CompiledByteCode(..), bcoFreeNames, UnlinkedBCO(..))
34 import DriverState ( v_Library_paths, v_Opt_l, getStaticOpts )
35 #ifdef darwin_TARGET_OS
36 import DriverState ( v_Cmdline_frameworks, v_Framework_paths )
38 import Finder ( findModule, findLinkable )
40 import Name ( Name, nameModule, isExternalName )
42 import NameSet ( nameSetToList )
44 import FastString ( FastString(..), unpackFS )
45 import ListSetOps ( minusList )
46 import CmdLineOpts ( DynFlags(verbosity) )
47 import BasicTypes ( SuccessFlag(..), succeeded, failed )
49 import Panic ( GhcException(..) )
50 import Util ( zipLazy, global )
53 import Control.Monad ( when, filterM, foldM )
55 import Data.IORef ( IORef, readIORef, writeIORef )
56 import Data.List ( partition, nub )
58 import System.IO ( putStr, putStrLn, hPutStrLn, stderr, fixIO )
59 import System.Directory ( doesFileExist )
61 import Control.Exception ( block, throwDyn )
63 #if __GLASGOW_HASKELL__ >= 503
64 import GHC.IOBase ( IO(..) )
66 import PrelIOBase ( IO(..) )
71 %************************************************************************
75 %************************************************************************
77 The persistent linker state *must* match the actual state of the
78 C dynamic linker at all times, so we keep it in a private global variable.
81 The PersistentLinkerState maps Names to actual closures (for
82 interpreted code only), for use during linking.
85 GLOBAL_VAR(v_PersistentLinkerState, emptyPLS, PersistentLinkerState)
87 data PersistentLinkerState
88 = PersistentLinkerState {
90 -- Current global mapping from Names to their true values
91 closure_env :: ClosureEnv,
93 -- The current global mapping from RdrNames of DataCons to
94 -- info table addresses.
95 -- When a new Unlinked is linked into the running image, or an existing
96 -- module in the image is replaced, the itbl_env must be updated
100 -- The currently loaded interpreted modules (home package)
101 bcos_loaded :: [Linkable],
103 -- And the currently-loaded compiled modules (home package)
104 objs_loaded :: [Linkable],
106 -- The currently-loaded packages; always object code
107 -- Held, as usual, in dependency order; though I am not sure if
108 -- that is really important
109 pkgs_loaded :: [PackageName]
112 emptyPLS :: PersistentLinkerState
113 emptyPLS = PersistentLinkerState { closure_env = emptyNameEnv,
114 itbl_env = emptyNameEnv,
115 pkgs_loaded = init_pkgs_loaded,
119 -- Packages that don't need loading, because the compiler
120 -- shares them with the interpreted program.
121 init_pkgs_loaded = [ FSLIT("rts") ]
125 extendLinkEnv :: [(Name,HValue)] -> IO ()
126 -- Automatically discards shadowed bindings
127 extendLinkEnv new_bindings
128 = do pls <- readIORef v_PersistentLinkerState
129 let new_closure_env = extendClosureEnv (closure_env pls) new_bindings
130 new_pls = pls { closure_env = new_closure_env }
131 writeIORef v_PersistentLinkerState new_pls
133 -- filterNameMap removes from the environment all entries except
134 -- those for a given set of modules;
135 -- Note that this removes all *local* (i.e. non-isExternal) names too
136 -- (these are the temporary bindings from the command line).
137 -- Used to filter both the ClosureEnv and ItblEnv
139 filterNameMap :: [ModuleName] -> NameEnv (Name, a) -> NameEnv (Name, a)
140 filterNameMap mods env
141 = filterNameEnv keep_elt env
143 keep_elt (n,_) = isExternalName n
144 && (moduleName (nameModule n) `elem` mods)
149 showLinkerState :: IO ()
150 -- Display the persistent linker state
152 = do pls <- readIORef v_PersistentLinkerState
153 printDump (vcat [text "----- Linker state -----",
154 text "Pkgs:" <+> ppr (pkgs_loaded pls),
155 text "Objs:" <+> ppr (objs_loaded pls),
156 text "BCOs:" <+> ppr (bcos_loaded pls)])
161 %************************************************************************
163 Link a byte-code expression
165 %************************************************************************
168 linkExpr :: HscEnv -> PersistentCompilerState
169 -> UnlinkedBCO -> IO HValue
171 -- Link a single expression, *including* first linking packages and
172 -- modules that this expression depends on.
174 -- Raises an IO exception if it can't find a compiled version of the
175 -- dependents to link.
177 linkExpr hsc_env pcs root_ul_bco
179 -- Find what packages and linkables are required
180 (lnks, pkgs) <- getLinkDeps hpt pit needed_mods ;
182 -- Link the packages and modules required
183 linkPackages dflags pkgs
184 ; ok <- linkModules dflags lnks
189 -- Link the expression itself
190 pls <- readIORef v_PersistentLinkerState
191 ; let ie = itbl_env pls
194 -- Link the necessary packages and linkables
195 ; (_, (root_hval:_)) <- linkSomeBCOs False ie ce [root_ul_bco]
199 pit = eps_PIT (pcs_EPS pcs)
200 hpt = hsc_HPT hsc_env
201 dflags = hsc_dflags hsc_env
202 free_names = nameSetToList (bcoFreeNames root_ul_bco)
204 needed_mods :: [Module]
205 needed_mods = [ nameModule n | n <- free_names, isExternalName n ]
207 dieWith msg = throwDyn (ProgramError (showSDoc msg))
209 getLinkDeps :: HomePackageTable -> PackageIfaceTable
210 -> [Module] -- If you need these
211 -> IO ([Linkable], [PackageName]) -- ... then link these first
212 -- Fails with an IO exception if it can't find enough files
214 getLinkDeps hpt pit mods
215 -- Find all the packages and linkables that a set of modules depends on
216 = do { pls <- readIORef v_PersistentLinkerState ;
218 -- 1. Find the dependent home-pkg-modules/packages from each iface
219 (mods_s, pkgs_s) = unzip (map get_deps mods) ;
221 -- 2. Exclude ones already linked
222 -- Main reason: avoid findModule calls in get_linkable
223 mods_needed = nub (concat mods_s) `minusList` linked_mods ;
224 pkgs_needed = nub (concat pkgs_s) `minusList` pkgs_loaded pls ;
226 linked_mods = map linkableModName (objs_loaded pls ++ bcos_loaded pls)
229 -- 3. For each dependent module, find its linkable
230 -- This will either be in the HPT or (in the case of one-shot
231 -- compilation) we may need to use maybe_getFileLinkable
232 lnks_needed <- mapM get_linkable mods_needed ;
234 return (lnks_needed, pkgs_needed) }
236 get_deps :: Module -> ([ModuleName],[PackageName])
237 -- Get the things needed for the specified module
238 -- This is rather similar to the code in RnNames.importsFromImportDecl
240 | isHomeModule (mi_module iface)
241 = (moduleName mod : [m | (m,_) <- dep_mods deps], dep_pkgs deps)
243 = ([], mi_package iface : dep_pkgs deps)
245 iface = get_iface mod
248 get_iface mod = case lookupIface hpt pit mod of
250 Nothing -> pprPanic "getLinkDeps" (no_iface mod)
251 no_iface mod = ptext SLIT("No iface for") <+> ppr mod
252 -- This one is a GHC bug
254 no_obj mod = dieWith (ptext SLIT("No compiled code for") <+> ppr mod)
255 -- This one is a build-system bug
257 get_linkable mod_name -- A home-package module
258 | Just mod_info <- lookupModuleEnvByName hpt mod_name
259 = return (hm_linkable mod_info)
261 = -- It's not in the HPT because we are in one shot mode,
262 -- so use the Finder to get a ModLocation...
263 do { mb_stuff <- findModule mod_name ;
265 Left _ -> no_obj mod_name ;
266 Right (_, loc) -> do {
268 -- ...and then find the linkable for it
269 mb_lnk <- findLinkable mod_name loc ;
271 Nothing -> no_obj mod_name ;
272 Just lnk -> return lnk
277 %************************************************************************
280 The linkables may consist of a mixture of
281 byte-code modules and object modules
283 %************************************************************************
286 linkModules :: DynFlags -> [Linkable] -> IO SuccessFlag
287 linkModules dflags linkables
288 = block $ do -- don't want to be interrupted by ^C in here
290 let (objs, bcos) = partition isObjectLinkable
291 (concatMap partitionLinkable linkables)
293 -- Load objects first; they can't depend on BCOs
294 ok_flag <- dynLinkObjs dflags objs
296 if failed ok_flag then
303 -- HACK to support f-x-dynamic in the interpreter; no other purpose
304 partitionLinkable :: Linkable -> [Linkable]
306 = let li_uls = linkableUnlinked li
307 li_uls_obj = filter isObject li_uls
308 li_uls_bco = filter isInterpretable li_uls
310 case (li_uls_obj, li_uls_bco) of
311 (objs@(_:_), bcos@(_:_))
312 -> [li{linkableUnlinked=li_uls_obj}, li{linkableUnlinked=li_uls_bco}]
316 findModuleLinkable_maybe :: [Linkable] -> ModuleName -> Maybe Linkable
317 findModuleLinkable_maybe lis mod
318 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
321 many -> pprPanic "findModuleLinkable" (ppr mod)
323 filterModuleLinkables :: (ModuleName -> Bool) -> [Linkable] -> [Linkable]
324 filterModuleLinkables p ls = filter (p . linkableModName) ls
326 linkableInSet :: Linkable -> [Linkable] -> Bool
327 linkableInSet l objs_loaded =
328 case findModuleLinkable_maybe objs_loaded (linkableModName l) of
330 Just m -> linkableTime l == linkableTime m
334 %************************************************************************
336 \subsection{The object-code linker}
338 %************************************************************************
341 dynLinkObjs :: DynFlags -> [Linkable] -> IO SuccessFlag
342 -- Side-effects the PersistentLinkerState
344 dynLinkObjs dflags objs
345 = do pls <- readIORef v_PersistentLinkerState
347 -- Load the object files and link them
348 let (objs_loaded', new_objs) = rmDupLinkables (objs_loaded pls) objs
349 pls1 = pls { objs_loaded = objs_loaded' }
350 unlinkeds = concatMap linkableUnlinked new_objs
352 mapM loadObj (map nameOfObject unlinkeds)
354 -- Link the all together
357 -- If resolving failed, unload all our
358 -- object modules and carry on
359 if succeeded ok then do
360 writeIORef v_PersistentLinkerState pls1
363 pls2 <- unload_wkr dflags [] pls1
364 writeIORef v_PersistentLinkerState pls2
368 rmDupLinkables :: [Linkable] -- Already loaded
369 -> [Linkable] -- New linkables
370 -> ([Linkable], -- New loaded set (including new ones)
371 [Linkable]) -- New linkables (excluding dups)
372 rmDupLinkables already ls
375 go already extras [] = (already, extras)
376 go already extras (l:ls)
377 | linkableInSet l already = go already extras ls
378 | otherwise = go (l:already) (l:extras) ls
383 linkLibraries :: DynFlags
384 -> [String] -- foo.o files specified on command line
386 -- Used just at initialisation time to link in libraries
387 -- specified on the command line.
388 linkLibraries dflags objs
389 = do { lib_paths <- readIORef v_Library_paths
390 ; opt_l <- getStaticOpts v_Opt_l
391 ; let minus_ls = [ lib | '-':'l':lib <- opt_l ]
392 #ifdef darwin_TARGET_OS
393 ; framework_paths <- readIORef v_Framework_paths
394 ; frameworks <- readIORef v_Cmdline_frameworks
396 ; let cmdline_lib_specs = map Object objs ++ map DLL minus_ls
397 #ifdef darwin_TARGET_OS
398 ++ map Framework frameworks
400 ; if (null cmdline_lib_specs) then return ()
404 #ifdef darwin_TARGET_OS
405 ; mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs
407 ; mapM_ (preloadLib dflags lib_paths) cmdline_lib_specs
409 ; maybePutStr dflags "final link ... "
411 ; if succeeded ok then maybePutStrLn dflags "done."
412 else throwDyn (InstallationError "linking extra libraries/objects failed")
415 #ifdef darwin_TARGET_OS
416 preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO ()
417 preloadLib dflags lib_paths framework_paths lib_spec
419 preloadLib :: DynFlags -> [String] -> LibrarySpec -> IO ()
420 preloadLib dflags lib_paths lib_spec
422 = do maybePutStr dflags ("Loading object " ++ showLS lib_spec ++ " ... ")
425 -> do b <- preload_static lib_paths static_ish
426 maybePutStrLn dflags (if b then "done."
429 -> do maybe_errstr <- loadDynamic lib_paths dll_unadorned
432 Just mm -> preloadFailed mm lib_paths lib_spec
433 maybePutStrLn dflags "done"
434 #ifdef darwin_TARGET_OS
436 -> do maybe_errstr <- loadFramework framework_paths framework
439 Just mm -> preloadFailed mm framework_paths lib_spec
440 maybePutStrLn dflags "done"
442 preloadFailed :: String -> [String] -> LibrarySpec -> IO ()
443 preloadFailed sys_errmsg paths spec
444 = do maybePutStr dflags
445 ("failed.\nDynamic linker error message was:\n "
446 ++ sys_errmsg ++ "\nWhilst trying to load: "
447 ++ showLS spec ++ "\nDirectories to search are:\n"
448 ++ unlines (map (" "++) paths) )
451 -- not interested in the paths in the static case.
452 preload_static paths name
453 = do b <- doesFileExist name
454 if not b then return False
455 else loadObj name >> return True
458 = (throwDyn . CmdLineError)
459 "user specified .o/.so/.DLL could not be loaded."
463 %************************************************************************
465 \subsection{The byte-code linker}
467 %************************************************************************
470 dynLinkBCOs :: [Linkable] -> IO ()
471 -- Side-effects the persistent linker state
473 = do pls <- readIORef v_PersistentLinkerState
475 let (bcos_loaded', new_bcos) = rmDupLinkables (bcos_loaded pls) bcos
476 pls1 = pls { bcos_loaded = bcos_loaded' }
477 unlinkeds :: [Unlinked]
478 unlinkeds = concatMap linkableUnlinked new_bcos
480 cbcs :: [CompiledByteCode]
481 cbcs = map byteCodeOfObject unlinkeds
484 ul_bcos = [b | ByteCode bs _ <- cbcs, b <- bs]
485 ies = [ie | ByteCode _ ie <- cbcs]
486 gce = closure_env pls
487 final_ie = foldr plusNameEnv (itbl_env pls) ies
489 (final_gce, linked_bcos) <- linkSomeBCOs True final_ie gce ul_bcos
490 -- What happens to these linked_bcos?
492 let pls2 = pls1 { closure_env = final_gce,
493 itbl_env = final_ie }
495 writeIORef v_PersistentLinkerState pls2
498 -- Link a bunch of BCOs and return them + updated closure env.
499 linkSomeBCOs :: Bool -- False <=> add _all_ BCOs to returned closure env
500 -- True <=> add only toplevel BCOs to closure env
504 -> IO (ClosureEnv, [HValue])
505 -- The returned HValues are associated 1-1 with
506 -- the incoming unlinked BCOs. Each gives the
507 -- value of the corresponding unlinked BCO
510 linkSomeBCOs toplevs_only ie ce_in ul_bcos
511 = do let nms = map unlinkedBCOName ul_bcos
513 ( \ hvs -> let ce_out = extendClosureEnv ce_in (zipLazy nms hvs)
514 in mapM (linkBCO ie ce_out) ul_bcos )
516 let ce_all_additions = zip nms hvals
517 ce_top_additions = filter (isExternalName.fst) ce_all_additions
518 ce_additions = if toplevs_only then ce_top_additions
519 else ce_all_additions
520 ce_out = -- make sure we're not inserting duplicate names into the
521 -- closure environment, which leads to trouble.
522 ASSERT (all (not . (`elemNameEnv` ce_in)) (map fst ce_additions))
523 extendClosureEnv ce_in ce_additions
524 return (ce_out, hvals)
529 %************************************************************************
531 Unload some object modules
533 %************************************************************************
536 -- ---------------------------------------------------------------------------
537 -- Unloading old objects ready for a new compilation sweep.
539 -- The compilation manager provides us with a list of linkables that it
540 -- considers "stable", i.e. won't be recompiled this time around. For
541 -- each of the modules current linked in memory,
543 -- * if the linkable is stable (and it's the same one - the
544 -- user may have recompiled the module on the side), we keep it,
546 -- * otherwise, we unload it.
548 -- * we also implicitly unload all temporary bindings at this point.
550 unload :: DynFlags -> [Linkable] -> IO ()
551 -- The 'linkables' are the ones to *keep*
553 unload dflags linkables
554 = block $ do -- block, so we're safe from Ctrl-C in here
556 pls <- readIORef v_PersistentLinkerState
557 new_pls <- unload_wkr dflags linkables pls
558 writeIORef v_PersistentLinkerState new_pls
560 let verb = verbosity dflags
561 when (verb >= 3) $ do
562 hPutStrLn stderr (showSDoc
563 (text "unload: retaining objs" <+> ppr (objs_loaded new_pls)))
564 hPutStrLn stderr (showSDoc
565 (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls)))
569 unload_wkr :: DynFlags
570 -> [Linkable] -- stable linkables
571 -> PersistentLinkerState
572 -> IO PersistentLinkerState
573 -- Does the core unload business
574 -- (the wrapper blocks exceptions and deals with the PLS get and put)
576 unload_wkr dflags linkables pls
577 = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables
579 objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls)
580 bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls)
582 let objs_retained = map linkableModName objs_loaded'
583 bcos_retained = map linkableModName bcos_loaded'
584 itbl_env' = filterNameMap bcos_retained (itbl_env pls)
585 closure_env' = filterNameMap bcos_retained (closure_env pls)
586 new_pls = pls { itbl_env = itbl_env',
587 closure_env = closure_env',
588 bcos_loaded = bcos_loaded',
589 objs_loaded = objs_loaded' }
593 maybeUnload :: [Linkable] -> Linkable -> IO Bool
594 maybeUnload keep_linkables lnk
595 | linkableInSet lnk linkables = return True
597 = do mapM_ unloadObj [f | DotO f <- linkableUnlinked lnk]
598 -- The components of a BCO linkable may contain
599 -- dot-o files. Which is very confusing.
601 -- But the BCO parts can be unlinked just by
602 -- letting go of them (plus of course depopulating
603 -- the symbol table which is done in the main body)
608 %************************************************************************
612 %************************************************************************
617 = Object FilePath -- Full path name of a .o file, including trailing .o
618 -- For dynamic objects only, try to find the object
619 -- file in all the directories specified in
620 -- v_Library_paths before giving up.
622 | DLL String -- "Unadorned" name of a .DLL/.so
623 -- e.g. On unix "qt" denotes "libqt.so"
624 -- On WinDoze "burble" denotes "burble.DLL"
625 -- loadDLL is platform-specific and adds the lib/.so/.DLL
626 -- suffixes platform-dependently
627 #ifdef darwin_TARGET_OS
631 -- If this package is already part of the GHCi binary, we'll already
632 -- have the right DLLs for this package loaded, so don't try to
635 -- But on Win32 we must load them 'again'; doing so is a harmless no-op
636 -- as far as the loader is concerned, but it does initialise the list
637 -- of DLL handles that rts/Linker.c maintains, and that in turn is
638 -- used by lookupSymbol. So we must call addDLL for each library
639 -- just to get the DLL handle into the list.
641 # if defined(mingw32_TARGET_OS) || defined(darwin_TARGET_OS)
644 = [ "base", "haskell98", "haskell-src", "readline" ]
647 showLS (Object nm) = "(static) " ++ nm
648 showLS (DLL nm) = "(dynamic) " ++ nm
649 #ifdef darwin_TARGET_OS
650 showLS (Framework nm) = "(framework) " ++ nm
653 linkPackages :: DynFlags -> [PackageName] -> IO ()
654 -- Link exactly the specified packages, and their dependents
655 -- (unless of course they are already linked)
656 -- The dependents are linked automatically, and it doesn't matter
657 -- what order you specify the input packages.
659 -- NOTE: in fact, since each module tracks all the packages it depends on,
660 -- we don't really need to use the package-config dependencies.
661 -- However we do need the package-config stuff (to find aux libs etc),
662 -- and following them lets us load libraries in the right order, which
663 -- perhaps makes the error message a bit more localised if we get a link
664 -- failure. So the dependency walking code is still here.
666 linkPackages dflags new_pkgs
667 = do { pls <- readIORef v_PersistentLinkerState
668 ; pkg_map <- getPackageConfigMap
670 ; pkgs' <- link pkg_map (pkgs_loaded pls) new_pkgs
672 ; writeIORef v_PersistentLinkerState (pls { pkgs_loaded = pkgs' })
675 link :: PackageConfigMap -> [PackageName] -> [PackageName] -> IO [PackageName]
676 link pkg_map pkgs new_pkgs
677 = foldM (link_one pkg_map) pkgs new_pkgs
679 link_one pkg_map pkgs new_pkg
680 | new_pkg `elem` pkgs -- Already linked
683 | Just pkg_cfg <- lookupPkg pkg_map new_pkg
684 = do { -- Link dependents first
685 pkgs' <- link pkg_map pkgs (packageDependents pkg_cfg)
686 -- Now link the package itself
687 ; linkPackage dflags pkg_cfg
688 ; return (new_pkg : pkgs') }
691 = throwDyn (CmdLineError ("unknown package name: " ++ packageNameString new_pkg))
694 linkPackage :: DynFlags -> PackageConfig -> IO ()
695 linkPackage dflags pkg
697 let dirs = Packages.library_dirs pkg
698 let libs = Packages.hs_libraries pkg ++ extra_libraries pkg
699 ++ [ lib | '-':'l':lib <- extra_ld_opts pkg ]
700 classifieds <- mapM (locateOneObj dirs) libs
701 #ifdef darwin_TARGET_OS
702 let fwDirs = Packages.framework_dirs pkg
703 let frameworks= Packages.extra_frameworks pkg
706 -- Complication: all the .so's must be loaded before any of the .o's.
707 let dlls = [ dll | DLL dll <- classifieds ]
708 objs = [ obj | Object obj <- classifieds ]
710 maybePutStr dflags ("Loading package " ++ Packages.name pkg ++ " ... ")
712 -- See comments with partOfGHCi
713 when (Packages.name pkg `notElem` partOfGHCi) $ do
714 #ifdef darwin_TARGET_OS
715 loadFrameworks fwDirs frameworks
717 loadDynamics dirs dlls
719 -- After loading all the DLLs, we can load the static objects.
722 maybePutStr dflags "linking ... "
724 if succeeded ok then maybePutStrLn dflags "done."
725 else panic ("can't load package `" ++ name pkg ++ "'")
727 loadDynamics dirs [] = return ()
728 loadDynamics dirs (dll:dlls) = do
729 r <- loadDynamic dirs dll
731 Nothing -> loadDynamics dirs dlls
732 Just err -> throwDyn (CmdLineError ("can't load .so/.DLL for: "
733 ++ dll ++ " (" ++ err ++ ")" ))
734 #ifdef darwin_TARGET_OS
735 loadFrameworks dirs [] = return ()
736 loadFrameworks dirs (fw:fws) = do
737 r <- loadFramework dirs fw
739 Nothing -> loadFrameworks dirs fws
740 Just err -> throwDyn (CmdLineError ("can't load framework: "
741 ++ fw ++ " (" ++ err ++ ")" ))
744 -- Try to find an object file for a given library in the given paths.
745 -- If it isn't present, we assume it's a dynamic library.
746 locateOneObj :: [FilePath] -> String -> IO LibrarySpec
747 locateOneObj dirs lib
748 = do { mb_obj_path <- findFile mk_obj_path dirs
749 ; case mb_obj_path of
750 Just obj_path -> return (Object obj_path)
751 Nothing -> return (DLL lib) } -- we assume
753 mk_obj_path dir = dir ++ '/':lib ++ ".o"
756 -- ----------------------------------------------------------------------------
757 -- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32)
759 -- return Nothing == success, else Just error message from dlopen
760 loadDynamic paths rootname
761 = do { mb_dll <- findFile mk_dll_path paths
763 Just dll -> loadDLL dll
764 Nothing -> loadDLL (mkSOName rootname) }
765 -- Tried all our known library paths, so let
766 -- dlopen() search its own builtin paths now.
768 mk_dll_path dir = dir ++ '/':mkSOName rootname
770 #if defined(darwin_TARGET_OS)
771 mkSOName root = "lib" ++ root ++ ".dylib"
772 #elif defined(mingw32_TARGET_OS)
773 -- Win32 DLLs have no .dll extension here, because addDLL tries
774 -- both foo.dll and foo.drv
777 mkSOName root = "lib" ++ root ++ ".so"
780 -- Darwin / MacOS X only: load a framework
781 -- a framework is a dynamic library packaged inside a directory of the same
782 -- name. They are searched for in different paths than normal libraries.
783 #ifdef darwin_TARGET_OS
784 loadFramework extraPaths rootname
785 = do { mb_fwk <- findFile mk_fwk (extraPaths ++ defaultFrameworkPaths)
787 Just fwk_path -> loadDLL fwk_path
788 Nothing -> return (Just "not found") }
789 -- Tried all our known library paths, but dlopen()
790 -- has no built-in paths for frameworks: give up
792 mk_fwk dir = dir ++ '/' : rootname ++ ".framework/" ++ rootname
793 -- sorry for the hardcoded paths, I hope they won't change anytime soon:
794 defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"]
798 %************************************************************************
802 %************************************************************************
805 findFile :: (FilePath -> FilePath) -- Maps a directory path to a file path
806 -> [FilePath] -- Directories to look in
807 -> IO (Maybe FilePath) -- The first file path to match
808 findFile mk_file_path []
810 findFile mk_file_path (dir:dirs)
811 = do { let file_path = mk_file_path dir
812 ; b <- doesFileExist file_path
814 return (Just file_path)
816 findFile mk_file_path dirs }
820 maybePutStr dflags s | verbosity dflags > 0 = putStr s
821 | otherwise = return ()
823 maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s
824 | otherwise = return ()