2 % (c) The University of Glasgow 2005-2006
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
15 {-# OPTIONS -optc-DNON_POSIX_SOURCE -#include "Linker.h" #-}
18 -- The above warning supression flag is a temporary kludge.
19 -- While working on this module you are encouraged to remove it and fix
20 -- any warnings in the module. See
21 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
24 module Linker ( HValue, getHValue, showLinkerState,
25 linkExpr, unload, withExtendedLinkEnv,
26 extendLinkEnv, deleteFromLinkEnv,
28 linkPackages,initDynLinker,
32 #include "HsVersions.h"
50 import qualified OccName
64 import qualified Maybes
68 import Config ( cProjectVersion )
78 import System.FilePath
80 import System.Directory
82 import Control.Exception
87 %************************************************************************
91 %************************************************************************
93 The persistent linker state *must* match the actual state of the
94 C dynamic linker at all times, so we keep it in a private global variable.
97 The PersistentLinkerState maps Names to actual closures (for
98 interpreted code only), for use during linking.
101 GLOBAL_VAR(v_PersistentLinkerState, panic "Dynamic linker not initialised", PersistentLinkerState)
102 GLOBAL_VAR(v_InitLinkerDone, False, Bool) -- Set True when dynamic linker is initialised
104 data PersistentLinkerState
105 = PersistentLinkerState {
107 -- Current global mapping from Names to their true values
108 closure_env :: ClosureEnv,
110 -- The current global mapping from RdrNames of DataCons to
111 -- info table addresses.
112 -- When a new Unlinked is linked into the running image, or an existing
113 -- module in the image is replaced, the itbl_env must be updated
117 -- The currently loaded interpreted modules (home package)
118 bcos_loaded :: [Linkable],
120 -- And the currently-loaded compiled modules (home package)
121 objs_loaded :: [Linkable],
123 -- The currently-loaded packages; always object code
124 -- Held, as usual, in dependency order; though I am not sure if
125 -- that is really important
126 pkgs_loaded :: [PackageId]
129 emptyPLS :: DynFlags -> PersistentLinkerState
130 emptyPLS dflags = PersistentLinkerState {
131 closure_env = emptyNameEnv,
132 itbl_env = emptyNameEnv,
133 pkgs_loaded = init_pkgs,
137 -- Packages that don't need loading, because the compiler
138 -- shares them with the interpreted program.
140 -- The linker's symbol table is populated with RTS symbols using an
141 -- explicit list. See rts/Linker.c for details.
142 where init_pkgs = [rtsPackageId]
146 extendLoadedPkgs :: [PackageId] -> IO ()
147 extendLoadedPkgs pkgs
148 = modifyIORef v_PersistentLinkerState (\s -> s{pkgs_loaded = pkgs ++ pkgs_loaded s})
150 extendLinkEnv :: [(Name,HValue)] -> IO ()
151 -- Automatically discards shadowed bindings
152 extendLinkEnv new_bindings
153 = do pls <- readIORef v_PersistentLinkerState
154 let new_closure_env = extendClosureEnv (closure_env pls) new_bindings
155 new_pls = pls { closure_env = new_closure_env }
156 writeIORef v_PersistentLinkerState new_pls
158 deleteFromLinkEnv :: [Name] -> IO ()
159 deleteFromLinkEnv to_remove
160 = do pls <- readIORef v_PersistentLinkerState
161 let new_closure_env = delListFromNameEnv (closure_env pls) to_remove
162 new_pls = pls { closure_env = new_closure_env }
163 writeIORef v_PersistentLinkerState new_pls
165 -- | Given a data constructor in the heap, find its Name.
166 -- The info tables for data constructors have a field which records
167 -- the source name of the constructor as a Ptr Word8 (UTF-8 encoded
168 -- string). The format is:
170 -- Package:Module.Name
172 -- We use this string to lookup the interpreter's internal representation of the name
173 -- using the lookupOrig.
175 dataConInfoPtrToName :: Ptr () -> TcM (Either String Name)
176 dataConInfoPtrToName x = do
177 theString <- liftIO $ do
178 let ptr = castPtr x :: Ptr StgInfoTable
179 conDescAddress <- getConDescAddress ptr
180 peekArray0 0 conDescAddress
181 let (pkg, mod, occ) = parse theString
182 pkgFS = mkFastStringByteList pkg
183 modFS = mkFastStringByteList mod
184 occFS = mkFastStringByteList occ
185 occName = mkOccNameFS OccName.dataName occFS
186 modName = mkModule (fsToPackageId pkgFS) (mkModuleNameFS modFS)
187 return (Left$ showSDoc$ ppr modName <> dot <> ppr occName )
188 `recoverM` (Right `fmap` lookupOrig modName occName)
192 {- To find the string in the constructor's info table we need to consider
193 the layout of info tables relative to the entry code for a closure.
195 An info table can be next to the entry code for the closure, or it can
196 be separate. The former (faster) is used in registerised versions of ghc,
197 and the latter (portable) is for non-registerised versions.
199 The diagrams below show where the string is to be found relative to
200 the normal info table of the closure.
202 1) Code next to table:
205 | | <- pointer to the start of the string
207 | | <- the (start of the) info table structure
214 In this case the pointer to the start of the string can be found in
215 the memory location _one word before_ the first entry in the normal info
218 2) Code NOT next to table:
221 info table structure -> | *------------------> --------------
225 ptr to start of str -> | |
228 In this case the pointer to the start of the string can be found
229 in the memory location: info_table_ptr + info_table_size
232 getConDescAddress :: Ptr StgInfoTable -> IO (Ptr Word8)
233 getConDescAddress ptr
234 | ghciTablesNextToCode = do
235 offsetToString <- peek $ ptr `plusPtr` (- wORD_SIZE)
236 return $ (ptr `plusPtr` stdInfoTableSizeB) `plusPtr` (fromIntegral (offsetToString :: StgWord))
238 peek $ intPtrToPtr $ (ptrToIntPtr ptr) + fromIntegral stdInfoTableSizeB
240 -- parsing names is a little bit fiddly because we have a string in the form:
241 -- pkg:A.B.C.foo, and we want to split it into three parts: ("pkg", "A.B.C", "foo").
242 -- Thus we split at the leftmost colon and the rightmost occurrence of the dot.
243 -- It would be easier if the string was in the form pkg:A.B.C:foo, but alas
244 -- this is not the conventional way of writing Haskell names. We stick with
245 -- convention, even though it makes the parsing code more troublesome.
246 -- Warning: this code assumes that the string is well formed.
247 parse :: [Word8] -> ([Word8], [Word8], [Word8])
249 = ASSERT (all (>0) (map length [pkg, mod, occ])) (pkg, mod, occ)
251 dot = fromIntegral (ord '.')
252 (pkg, rest1) = break (== fromIntegral (ord ':')) input
254 = (concat $ intersperse [dot] $ reverse modWords, occWord)
256 (modWords, occWord) = ASSERT (length rest1 > 0) (parseModOcc [] (tail rest1))
257 parseModOcc :: [[Word8]] -> [Word8] -> ([[Word8]], [Word8])
259 = case break (== dot) str of
260 (top, []) -> (acc, top)
261 (top, _:bot) -> parseModOcc (top : acc) bot
264 getHValue :: HscEnv -> Name -> IO HValue
265 getHValue hsc_env name = do
266 when (isExternalName name) $ do
267 ok <- linkDependencies hsc_env noSrcSpan [nameModule name]
268 when (failed ok) $ throwDyn (ProgramError "")
269 pls <- readIORef v_PersistentLinkerState
270 lookupName (closure_env pls) name
272 linkDependencies :: HscEnv -> SrcSpan -> [Module] -> IO SuccessFlag
273 linkDependencies hsc_env span needed_mods = do
274 let hpt = hsc_HPT hsc_env
275 dflags = hsc_dflags hsc_env
276 -- The interpreter and dynamic linker can only handle object code built
277 -- the "normal" way, i.e. no non-std ways like profiling or ticky-ticky.
278 -- So here we check the build tag: if we're building a non-standard way
279 -- then we need to find & link object files built the "normal" way.
280 maybe_normal_osuf <- checkNonStdWay dflags span
282 -- Find what packages and linkables are required
283 eps <- readIORef (hsc_EPS hsc_env)
284 (lnks, pkgs) <- getLinkDeps hsc_env hpt (eps_PIT eps)
285 maybe_normal_osuf span needed_mods
287 -- Link the packages and modules required
288 linkPackages dflags pkgs
289 linkModules dflags lnks
292 -- | Temporarily extend the linker state.
294 withExtendedLinkEnv :: [(Name,HValue)] -> IO a -> IO a
295 withExtendedLinkEnv new_env action
296 = bracket set_new_env
299 where set_new_env = do
300 pls <- readIORef v_PersistentLinkerState
301 let new_closure_env = extendClosureEnv (closure_env pls) new_env
302 new_pls = pls { closure_env = new_closure_env }
303 writeIORef v_PersistentLinkerState new_pls
304 return (closure_env pls)
306 -- Remember that the linker state might be side-effected
307 -- during the execution of the IO action, and we don't want to
308 -- lose those changes (we might have linked a new module or
309 -- package), so the reset action only removes the names we
311 reset_old_env env = do
312 modifyIORef v_PersistentLinkerState $ \pls ->
313 let cur = closure_env pls
314 new = delListFromNameEnv cur (map fst new_env)
316 pls{ closure_env = new }
318 -- filterNameMap removes from the environment all entries except
319 -- those for a given set of modules;
320 -- Note that this removes all *local* (i.e. non-isExternal) names too
321 -- (these are the temporary bindings from the command line).
322 -- Used to filter both the ClosureEnv and ItblEnv
324 filterNameMap :: [Module] -> NameEnv (Name, a) -> NameEnv (Name, a)
325 filterNameMap mods env
326 = filterNameEnv keep_elt env
328 keep_elt (n,_) = isExternalName n
329 && (nameModule n `elem` mods)
334 showLinkerState :: IO ()
335 -- Display the persistent linker state
337 = do pls <- readIORef v_PersistentLinkerState
338 printDump (vcat [text "----- Linker state -----",
339 text "Pkgs:" <+> ppr (pkgs_loaded pls),
340 text "Objs:" <+> ppr (objs_loaded pls),
341 text "BCOs:" <+> ppr (bcos_loaded pls)])
347 %************************************************************************
349 \subsection{Initialisation}
351 %************************************************************************
353 We initialise the dynamic linker by
355 a) calling the C initialisation procedure
357 b) Loading any packages specified on the command line,
359 c) Loading any packages specified on the command line,
360 now held in the -l options in v_Opt_l
362 d) Loading any .o/.dll files specified on the command line,
363 now held in v_Ld_inputs
365 e) Loading any MacOS frameworks
368 initDynLinker :: DynFlags -> IO ()
369 -- This function is idempotent; if called more than once, it does nothing
370 -- This is useful in Template Haskell, where we call it before trying to link
372 = do { done <- readIORef v_InitLinkerDone
373 ; if done then return ()
374 else do { writeIORef v_InitLinkerDone True
375 ; reallyInitDynLinker dflags }
378 reallyInitDynLinker dflags
379 = do { -- Initialise the linker state
380 ; writeIORef v_PersistentLinkerState (emptyPLS dflags)
382 -- (a) initialise the C dynamic linker
385 -- (b) Load packages from the command-line
386 ; linkPackages dflags (preloadPackages (pkgState dflags))
388 -- (c) Link libraries from the command-line
389 ; let optl = getOpts dflags opt_l
390 ; let minus_ls = [ lib | '-':'l':lib <- optl ]
392 -- (d) Link .o files from the command-line
393 ; let lib_paths = libraryPaths dflags
394 ; cmdline_ld_inputs <- readIORef v_Ld_inputs
396 ; classified_ld_inputs <- mapM classifyLdInput cmdline_ld_inputs
398 -- (e) Link any MacOS frameworks
399 ; let framework_paths
400 | isDarwinTarget = frameworkPaths dflags
403 | isDarwinTarget = cmdlineFrameworks dflags
405 -- Finally do (c),(d),(e)
406 ; let cmdline_lib_specs = [ l | Just l <- classified_ld_inputs ]
408 ++ map Framework frameworks
409 ; if null cmdline_lib_specs then return ()
412 { mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs
413 ; maybePutStr dflags "final link ... "
416 ; if succeeded ok then maybePutStrLn dflags "done"
417 else throwDyn (InstallationError "linking extra libraries/objects failed")
420 classifyLdInput :: FilePath -> IO (Maybe LibrarySpec)
422 | isObjectFilename f = return (Just (Object f))
423 | isDynLibFilename f = return (Just (DLLPath f))
425 hPutStrLn stderr ("Warning: ignoring unrecognised input `" ++ f ++ "'")
428 preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO ()
429 preloadLib dflags lib_paths framework_paths lib_spec
430 = do maybePutStr dflags ("Loading object " ++ showLS lib_spec ++ " ... ")
433 -> do b <- preload_static lib_paths static_ish
434 maybePutStrLn dflags (if b then "done"
438 -> do maybe_errstr <- loadDynamic lib_paths dll_unadorned
440 Nothing -> maybePutStrLn dflags "done"
441 Just mm -> preloadFailed mm lib_paths lib_spec
444 -> do maybe_errstr <- loadDLL dll_path
446 Nothing -> maybePutStrLn dflags "done"
447 Just mm -> preloadFailed mm lib_paths lib_spec
451 -> do maybe_errstr <- loadFramework framework_paths framework
453 Nothing -> maybePutStrLn dflags "done"
454 Just mm -> preloadFailed mm framework_paths lib_spec
455 | otherwise -> panic "preloadLib Framework"
458 preloadFailed :: String -> [String] -> LibrarySpec -> IO ()
459 preloadFailed sys_errmsg paths spec
460 = do maybePutStr dflags
461 ("failed.\nDynamic linker error message was:\n "
462 ++ sys_errmsg ++ "\nWhilst trying to load: "
463 ++ showLS spec ++ "\nDirectories to search are:\n"
464 ++ unlines (map (" "++) paths) )
467 -- Not interested in the paths in the static case.
468 preload_static paths name
469 = do b <- doesFileExist name
470 if not b then return False
471 else loadObj name >> return True
474 CmdLineError "user specified .o/.so/.DLL could not be loaded."
478 %************************************************************************
480 Link a byte-code expression
482 %************************************************************************
485 linkExpr :: HscEnv -> SrcSpan -> UnlinkedBCO -> IO HValue
487 -- Link a single expression, *including* first linking packages and
488 -- modules that this expression depends on.
490 -- Raises an IO exception if it can't find a compiled version of the
491 -- dependents to link.
493 -- Note: This function side-effects the linker state (Pepe)
495 linkExpr hsc_env span root_ul_bco
497 -- Initialise the linker (if it's not been done already)
498 let dflags = hsc_dflags hsc_env
499 ; initDynLinker dflags
501 -- Link the packages and modules required
502 ; ok <- linkDependencies hsc_env span needed_mods
504 throwDyn (ProgramError "")
507 -- Link the expression itself
508 pls <- readIORef v_PersistentLinkerState
509 ; let ie = itbl_env pls
512 -- Link the necessary packages and linkables
513 ; (_, (root_hval:_)) <- linkSomeBCOs False ie ce [root_ul_bco]
517 free_names = nameSetToList (bcoFreeNames root_ul_bco)
519 needed_mods :: [Module]
520 needed_mods = [ nameModule n | n <- free_names,
521 isExternalName n, -- Names from other modules
522 not (isWiredInName n) -- Exclude wired-in names
523 ] -- (see note below)
524 -- Exclude wired-in names because we may not have read
525 -- their interface files, so getLinkDeps will fail
526 -- All wired-in names are in the base package, which we link
527 -- by default, so we can safely ignore them here.
529 dieWith span msg = throwDyn (ProgramError (showSDoc (mkLocMessage span msg)))
532 checkNonStdWay :: DynFlags -> SrcSpan -> IO (Maybe String)
533 checkNonStdWay dflags srcspan = do
534 tag <- readIORef v_Build_tag
535 if null tag then return Nothing else do
536 let default_osuf = phaseInputExt StopLn
537 if objectSuf dflags == default_osuf
538 then failNonStd srcspan
539 else return (Just default_osuf)
541 failNonStd srcspan = dieWith srcspan $
542 ptext (sLit "Dynamic linking required, but this is a non-standard build (eg. prof).") $$
543 ptext (sLit "You need to build the program twice: once the normal way, and then") $$
544 ptext (sLit "in the desired way using -osuf to set the object file suffix.")
547 getLinkDeps :: HscEnv -> HomePackageTable -> PackageIfaceTable
548 -> Maybe String -- the "normal" object suffix
549 -> SrcSpan -- for error messages
550 -> [Module] -- If you need these
551 -> IO ([Linkable], [PackageId]) -- ... then link these first
552 -- Fails with an IO exception if it can't find enough files
554 getLinkDeps hsc_env hpt pit maybe_normal_osuf span mods
555 -- Find all the packages and linkables that a set of modules depends on
556 = do { pls <- readIORef v_PersistentLinkerState ;
557 -- 1. Find the dependent home-pkg-modules/packages from each iface
558 (mods_s, pkgs_s) <- follow_deps mods emptyUniqSet emptyUniqSet;
561 -- 2. Exclude ones already linked
562 -- Main reason: avoid findModule calls in get_linkable
563 mods_needed = mods_s `minusList` linked_mods ;
564 pkgs_needed = pkgs_s `minusList` pkgs_loaded pls ;
566 linked_mods = map (moduleName.linkableModule)
567 (objs_loaded pls ++ bcos_loaded pls)
570 -- putStrLn (showSDoc (ppr mods_s)) ;
571 -- 3. For each dependent module, find its linkable
572 -- This will either be in the HPT or (in the case of one-shot
573 -- compilation) we may need to use maybe_getFileLinkable
574 lnks_needed <- mapM (get_linkable maybe_normal_osuf) mods_needed ;
576 return (lnks_needed, pkgs_needed) }
578 dflags = hsc_dflags hsc_env
579 this_pkg = thisPackage dflags
581 -- The ModIface contains the transitive closure of the module dependencies
582 -- within the current package, *except* for boot modules: if we encounter
583 -- a boot module, we have to find its real interface and discover the
584 -- dependencies of that. Hence we need to traverse the dependency
585 -- tree recursively. See bug #936, testcase ghci/prog007.
586 follow_deps :: [Module] -- modules to follow
587 -> UniqSet ModuleName -- accum. module dependencies
588 -> UniqSet PackageId -- accum. package dependencies
589 -> IO ([ModuleName], [PackageId]) -- result
590 follow_deps [] acc_mods acc_pkgs
591 = return (uniqSetToList acc_mods, uniqSetToList acc_pkgs)
592 follow_deps (mod:mods) acc_mods acc_pkgs
594 mb_iface <- initIfaceCheck hsc_env $
595 loadInterface msg mod (ImportByUser False)
596 iface <- case mb_iface of
597 Maybes.Failed err -> ghcError (ProgramError (showSDoc err))
598 Maybes.Succeeded iface -> return iface
600 when (mi_boot iface) $ link_boot_mod_error mod
603 pkg = modulePackageId mod
606 pkg_deps = dep_pkgs deps
607 (boot_deps, mod_deps) = partitionWith is_boot (dep_mods deps)
608 where is_boot (m,True) = Left m
609 is_boot (m,False) = Right m
611 boot_deps' = filter (not . (`elementOfUniqSet` acc_mods)) boot_deps
612 acc_mods' = addListToUniqSet acc_mods (moduleName mod : mod_deps)
613 acc_pkgs' = addListToUniqSet acc_pkgs pkg_deps
616 then follow_deps mods acc_mods (addOneToUniqSet acc_pkgs' pkg)
617 else follow_deps (map (mkModule this_pkg) boot_deps' ++ mods)
620 msg = text "need to link module" <+> ppr mod <+>
621 text "due to use of Template Haskell"
624 link_boot_mod_error mod =
625 throwDyn (ProgramError (showSDoc (
626 text "module" <+> ppr mod <+>
627 text "cannot be linked; it is only available as a boot module")))
629 no_obj mod = dieWith span $
630 ptext (sLit "cannot find object file for module ") <>
634 while_linking_expr = ptext (sLit "while linking an interpreted expression")
636 -- This one is a build-system bug
638 get_linkable maybe_normal_osuf mod_name -- A home-package module
639 | Just mod_info <- lookupUFM hpt mod_name
640 = ASSERT(isJust (hm_linkable mod_info))
641 adjust_linkable (fromJust (hm_linkable mod_info))
643 = do -- It's not in the HPT because we are in one shot mode,
644 -- so use the Finder to get a ModLocation...
645 mb_stuff <- findHomeModule hsc_env mod_name
647 Found loc mod -> found loc mod
651 -- ...and then find the linkable for it
652 mb_lnk <- findObjectLinkableMaybe mod loc ;
654 Nothing -> no_obj mod ;
655 Just lnk -> adjust_linkable lnk
659 | Just osuf <- maybe_normal_osuf = do
660 new_uls <- mapM (adjust_ul osuf) (linkableUnlinked lnk)
661 return lnk{ linkableUnlinked=new_uls }
665 adjust_ul osuf (DotO file) = do
666 let new_file = replaceExtension file osuf
667 ok <- doesFileExist new_file
670 ptext (sLit "cannot find normal object file ")
671 <> quotes (text new_file) $$ while_linking_expr
672 else return (DotO new_file)
676 %************************************************************************
679 The linkables may consist of a mixture of
680 byte-code modules and object modules
682 %************************************************************************
685 linkModules :: DynFlags -> [Linkable] -> IO SuccessFlag
686 linkModules dflags linkables
687 = block $ do -- don't want to be interrupted by ^C in here
689 let (objs, bcos) = partition isObjectLinkable
690 (concatMap partitionLinkable linkables)
692 -- Load objects first; they can't depend on BCOs
693 ok_flag <- dynLinkObjs dflags objs
695 if failed ok_flag then
702 -- HACK to support f-x-dynamic in the interpreter; no other purpose
703 partitionLinkable :: Linkable -> [Linkable]
705 = let li_uls = linkableUnlinked li
706 li_uls_obj = filter isObject li_uls
707 li_uls_bco = filter isInterpretable li_uls
709 case (li_uls_obj, li_uls_bco) of
710 (objs@(_:_), bcos@(_:_))
711 -> [li{linkableUnlinked=li_uls_obj}, li{linkableUnlinked=li_uls_bco}]
715 findModuleLinkable_maybe :: [Linkable] -> Module -> Maybe Linkable
716 findModuleLinkable_maybe lis mod
717 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
720 many -> pprPanic "findModuleLinkable" (ppr mod)
722 linkableInSet :: Linkable -> [Linkable] -> Bool
723 linkableInSet l objs_loaded =
724 case findModuleLinkable_maybe objs_loaded (linkableModule l) of
726 Just m -> linkableTime l == linkableTime m
730 %************************************************************************
732 \subsection{The object-code linker}
734 %************************************************************************
737 dynLinkObjs :: DynFlags -> [Linkable] -> IO SuccessFlag
738 -- Side-effects the PersistentLinkerState
740 dynLinkObjs dflags objs
741 = do pls <- readIORef v_PersistentLinkerState
743 -- Load the object files and link them
744 let (objs_loaded', new_objs) = rmDupLinkables (objs_loaded pls) objs
745 pls1 = pls { objs_loaded = objs_loaded' }
746 unlinkeds = concatMap linkableUnlinked new_objs
748 mapM loadObj (map nameOfObject unlinkeds)
750 -- Link the all together
753 -- If resolving failed, unload all our
754 -- object modules and carry on
755 if succeeded ok then do
756 writeIORef v_PersistentLinkerState pls1
759 pls2 <- unload_wkr dflags [] pls1
760 writeIORef v_PersistentLinkerState pls2
764 rmDupLinkables :: [Linkable] -- Already loaded
765 -> [Linkable] -- New linkables
766 -> ([Linkable], -- New loaded set (including new ones)
767 [Linkable]) -- New linkables (excluding dups)
768 rmDupLinkables already ls
771 go already extras [] = (already, extras)
772 go already extras (l:ls)
773 | linkableInSet l already = go already extras ls
774 | otherwise = go (l:already) (l:extras) ls
777 %************************************************************************
779 \subsection{The byte-code linker}
781 %************************************************************************
784 dynLinkBCOs :: [Linkable] -> IO ()
785 -- Side-effects the persistent linker state
787 = do pls <- readIORef v_PersistentLinkerState
789 let (bcos_loaded', new_bcos) = rmDupLinkables (bcos_loaded pls) bcos
790 pls1 = pls { bcos_loaded = bcos_loaded' }
791 unlinkeds :: [Unlinked]
792 unlinkeds = concatMap linkableUnlinked new_bcos
794 cbcs :: [CompiledByteCode]
795 cbcs = map byteCodeOfObject unlinkeds
798 ul_bcos = [b | ByteCode bs _ <- cbcs, b <- bs]
799 ies = [ie | ByteCode _ ie <- cbcs]
800 gce = closure_env pls
801 final_ie = foldr plusNameEnv (itbl_env pls) ies
803 (final_gce, linked_bcos) <- linkSomeBCOs True final_ie gce ul_bcos
804 -- What happens to these linked_bcos?
806 let pls2 = pls1 { closure_env = final_gce,
807 itbl_env = final_ie }
809 writeIORef v_PersistentLinkerState pls2
812 -- Link a bunch of BCOs and return them + updated closure env.
813 linkSomeBCOs :: Bool -- False <=> add _all_ BCOs to returned closure env
814 -- True <=> add only toplevel BCOs to closure env
818 -> IO (ClosureEnv, [HValue])
819 -- The returned HValues are associated 1-1 with
820 -- the incoming unlinked BCOs. Each gives the
821 -- value of the corresponding unlinked BCO
823 linkSomeBCOs toplevs_only ie ce_in ul_bcos
824 = do let nms = map unlinkedBCOName ul_bcos
826 ( \ hvs -> let ce_out = extendClosureEnv ce_in (zipLazy nms hvs)
827 in mapM (linkBCO ie ce_out) ul_bcos )
828 let ce_all_additions = zip nms hvals
829 ce_top_additions = filter (isExternalName.fst) ce_all_additions
830 ce_additions = if toplevs_only then ce_top_additions
831 else ce_all_additions
832 ce_out = -- make sure we're not inserting duplicate names into the
833 -- closure environment, which leads to trouble.
834 ASSERT (all (not . (`elemNameEnv` ce_in)) (map fst ce_additions))
835 extendClosureEnv ce_in ce_additions
836 return (ce_out, hvals)
841 %************************************************************************
843 Unload some object modules
845 %************************************************************************
848 -- ---------------------------------------------------------------------------
849 -- Unloading old objects ready for a new compilation sweep.
851 -- The compilation manager provides us with a list of linkables that it
852 -- considers "stable", i.e. won't be recompiled this time around. For
853 -- each of the modules current linked in memory,
855 -- * if the linkable is stable (and it's the same one - the
856 -- user may have recompiled the module on the side), we keep it,
858 -- * otherwise, we unload it.
860 -- * we also implicitly unload all temporary bindings at this point.
862 unload :: DynFlags -> [Linkable] -> IO ()
863 -- The 'linkables' are the ones to *keep*
865 unload dflags linkables
866 = block $ do -- block, so we're safe from Ctrl-C in here
868 -- Initialise the linker (if it's not been done already)
871 pls <- readIORef v_PersistentLinkerState
872 new_pls <- unload_wkr dflags linkables pls
873 writeIORef v_PersistentLinkerState new_pls
875 debugTraceMsg dflags 3 (text "unload: retaining objs" <+> ppr (objs_loaded new_pls))
876 debugTraceMsg dflags 3 (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls))
879 unload_wkr :: DynFlags
880 -> [Linkable] -- stable linkables
881 -> PersistentLinkerState
882 -> IO PersistentLinkerState
883 -- Does the core unload business
884 -- (the wrapper blocks exceptions and deals with the PLS get and put)
886 unload_wkr dflags linkables pls
887 = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables
889 objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls)
890 bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls)
892 let bcos_retained = map linkableModule bcos_loaded'
893 itbl_env' = filterNameMap bcos_retained (itbl_env pls)
894 closure_env' = filterNameMap bcos_retained (closure_env pls)
895 new_pls = pls { itbl_env = itbl_env',
896 closure_env = closure_env',
897 bcos_loaded = bcos_loaded',
898 objs_loaded = objs_loaded' }
902 maybeUnload :: [Linkable] -> Linkable -> IO Bool
903 maybeUnload keep_linkables lnk
904 | linkableInSet lnk linkables = return True
906 = do mapM_ unloadObj [f | DotO f <- linkableUnlinked lnk]
907 -- The components of a BCO linkable may contain
908 -- dot-o files. Which is very confusing.
910 -- But the BCO parts can be unlinked just by
911 -- letting go of them (plus of course depopulating
912 -- the symbol table which is done in the main body)
917 %************************************************************************
921 %************************************************************************
926 = Object FilePath -- Full path name of a .o file, including trailing .o
927 -- For dynamic objects only, try to find the object
928 -- file in all the directories specified in
929 -- v_Library_paths before giving up.
931 | DLL String -- "Unadorned" name of a .DLL/.so
932 -- e.g. On unix "qt" denotes "libqt.so"
933 -- On WinDoze "burble" denotes "burble.DLL"
934 -- loadDLL is platform-specific and adds the lib/.so/.DLL
935 -- suffixes platform-dependently
937 | DLLPath FilePath -- Absolute or relative pathname to a dynamic library
938 -- (ends with .dll or .so).
940 | Framework String -- Only used for darwin, but does no harm
942 -- If this package is already part of the GHCi binary, we'll already
943 -- have the right DLLs for this package loaded, so don't try to
946 -- But on Win32 we must load them 'again'; doing so is a harmless no-op
947 -- as far as the loader is concerned, but it does initialise the list
948 -- of DLL handles that rts/Linker.c maintains, and that in turn is
949 -- used by lookupSymbol. So we must call addDLL for each library
950 -- just to get the DLL handle into the list.
952 | isWindowsTarget || isDarwinTarget = []
953 | otherwise = [ "base", "haskell98", "template-haskell", "editline" ]
955 showLS (Object nm) = "(static) " ++ nm
956 showLS (DLL nm) = "(dynamic) " ++ nm
957 showLS (DLLPath nm) = "(dynamic) " ++ nm
958 showLS (Framework nm) = "(framework) " ++ nm
960 linkPackages :: DynFlags -> [PackageId] -> IO ()
961 -- Link exactly the specified packages, and their dependents
962 -- (unless of course they are already linked)
963 -- The dependents are linked automatically, and it doesn't matter
964 -- what order you specify the input packages.
966 -- NOTE: in fact, since each module tracks all the packages it depends on,
967 -- we don't really need to use the package-config dependencies.
968 -- However we do need the package-config stuff (to find aux libs etc),
969 -- and following them lets us load libraries in the right order, which
970 -- perhaps makes the error message a bit more localised if we get a link
971 -- failure. So the dependency walking code is still here.
973 linkPackages dflags new_pkgs
974 = do { pls <- readIORef v_PersistentLinkerState
975 ; let pkg_map = pkgIdMap (pkgState dflags)
977 ; pkgs' <- link pkg_map (pkgs_loaded pls) new_pkgs
979 ; writeIORef v_PersistentLinkerState (pls { pkgs_loaded = pkgs' })
982 link :: PackageConfigMap -> [PackageId] -> [PackageId] -> IO [PackageId]
983 link pkg_map pkgs new_pkgs
984 = foldM (link_one pkg_map) pkgs new_pkgs
986 link_one pkg_map pkgs new_pkg
987 | new_pkg `elem` pkgs -- Already linked
990 | Just pkg_cfg <- lookupPackage pkg_map new_pkg
991 = do { -- Link dependents first
992 pkgs' <- link pkg_map pkgs (map mkPackageId (depends pkg_cfg))
993 -- Now link the package itself
994 ; linkPackage dflags pkg_cfg
995 ; return (new_pkg : pkgs') }
998 = throwDyn (CmdLineError ("unknown package: " ++ packageIdString new_pkg))
1001 linkPackage :: DynFlags -> PackageConfig -> IO ()
1002 linkPackage dflags pkg
1004 let dirs = Packages.libraryDirs pkg
1006 let libs = Packages.hsLibraries pkg
1007 -- Because of slight differences between the GHC dynamic linker and
1008 -- the native system linker some packages have to link with a
1009 -- different list of libraries when using GHCi. Examples include: libs
1010 -- that are actually gnu ld scripts, and the possability that the .a
1011 -- libs do not exactly match the .so/.dll equivalents. So if the
1012 -- package file provides an "extra-ghci-libraries" field then we use
1013 -- that instead of the "extra-libraries" field.
1014 ++ (if null (Packages.extraGHCiLibraries pkg)
1015 then Packages.extraLibraries pkg
1016 else Packages.extraGHCiLibraries pkg)
1017 ++ [ lib | '-':'l':lib <- Packages.ldOptions pkg ]
1018 classifieds <- mapM (locateOneObj dirs) libs
1020 -- Complication: all the .so's must be loaded before any of the .o's.
1021 let dlls = [ dll | DLL dll <- classifieds ]
1022 objs = [ obj | Object obj <- classifieds ]
1024 maybePutStr dflags ("Loading package " ++ display (package pkg) ++ " ... ")
1026 -- See comments with partOfGHCi
1027 when (pkgName (package pkg) `notElem` partOfGHCi) $ do
1029 -- When a library A needs symbols from a library B, the order in
1030 -- extra_libraries/extra_ld_opts is "-lA -lB", because that's the
1031 -- way ld expects it for static linking. Dynamic linking is a
1032 -- different story: When A has no dependency information for B,
1033 -- dlopen-ing A with RTLD_NOW (see addDLL in Linker.c) will fail
1034 -- when B has not been loaded before. In a nutshell: Reverse the
1035 -- order of DLLs for dynamic linking.
1036 -- This fixes a problem with the HOpenGL package (see "Compiling
1037 -- HOpenGL under recent versions of GHC" on the HOpenGL list).
1038 mapM_ (load_dyn dirs) (reverse dlls)
1040 -- After loading all the DLLs, we can load the static objects.
1041 -- Ordering isn't important here, because we do one final link
1042 -- step to resolve everything.
1045 maybePutStr dflags "linking ... "
1047 if succeeded ok then maybePutStrLn dflags "done."
1048 else throwDyn (InstallationError ("unable to load package `" ++ display (package pkg) ++ "'"))
1050 load_dyn dirs dll = do r <- loadDynamic dirs dll
1052 Nothing -> return ()
1053 Just err -> throwDyn (CmdLineError ("can't load .so/.DLL for: "
1054 ++ dll ++ " (" ++ err ++ ")" ))
1057 | isDarwinTarget = mapM_ load frameworks
1058 | otherwise = return ()
1060 fw_dirs = Packages.frameworkDirs pkg
1061 frameworks = Packages.frameworks pkg
1063 load fw = do r <- loadFramework fw_dirs fw
1065 Nothing -> return ()
1066 Just err -> throwDyn (CmdLineError ("can't load framework: "
1067 ++ fw ++ " (" ++ err ++ ")" ))
1069 -- Try to find an object file for a given library in the given paths.
1070 -- If it isn't present, we assume it's a dynamic library.
1072 -- When the GHC package was not compiled as dynamic library (=__PIC__ not set),
1073 -- we search for .o libraries first.
1074 locateOneObj :: [FilePath] -> String -> IO LibrarySpec
1075 locateOneObj dirs lib
1076 = do { mb_obj_path <- findFile mk_obj_path dirs
1077 ; case mb_obj_path of
1078 Just obj_path -> return (Object obj_path)
1080 do { mb_lib_path <- findFile mk_dyn_lib_path dirs
1081 ; case mb_lib_path of
1082 Just lib_path -> return (DLL (lib ++ "-ghc" ++ cProjectVersion))
1083 Nothing -> return (DLL lib) }} -- We assume
1085 mk_obj_path dir = dir </> lib <.> "o"
1086 mk_dyn_lib_path dir = dir </> mkSOName (lib ++ "-ghc" ++ cProjectVersion)
1088 -- When the GHC package was compiled as dynamic library (=__PIC__ set),
1089 -- we search for .so libraries first.
1090 locateOneObj :: [FilePath] -> String -> IO LibrarySpec
1091 locateOneObj dirs lib
1092 = do { mb_lib_path <- findFile mk_dyn_lib_path dirs
1093 ; case mb_lib_path of
1094 Just lib_path -> return (DLL (lib ++ "-ghc" ++ cProjectVersion))
1096 do { mb_obj_path <- findFile mk_obj_path dirs
1097 ; case mb_obj_path of
1098 Just obj_path -> return (Object obj_path)
1099 Nothing -> return (DLL lib) }} -- We assume
1101 mk_obj_path dir = dir </> (lib <.> "o")
1102 mk_dyn_lib_path dir = dir </> mkSOName (lib ++ "-ghc" ++ cProjectVersion)
1105 -- ----------------------------------------------------------------------------
1106 -- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32)
1108 -- return Nothing == success, else Just error message from dlopen
1109 loadDynamic paths rootname
1110 = do { mb_dll <- findFile mk_dll_path paths
1112 Just dll -> loadDLL dll
1113 Nothing -> loadDLL (mkSOName rootname) }
1114 -- Tried all our known library paths, so let
1115 -- dlopen() search its own builtin paths now.
1117 mk_dll_path dir = dir </> mkSOName rootname
1120 | isDarwinTarget = ("lib" ++ root) <.> "dylib"
1121 | isWindowsTarget = -- Win32 DLLs have no .dll extension here, because
1122 -- addDLL tries both foo.dll and foo.drv
1124 | otherwise = ("lib" ++ root) <.> "so"
1126 -- Darwin / MacOS X only: load a framework
1127 -- a framework is a dynamic library packaged inside a directory of the same
1128 -- name. They are searched for in different paths than normal libraries.
1129 loadFramework extraPaths rootname
1130 = do { either_dir <- Control.Exception.try getHomeDirectory
1131 ; let homeFrameworkPath = case either_dir of
1133 Right dir -> [dir ++ "/Library/Frameworks"]
1134 ps = extraPaths ++ homeFrameworkPath ++ defaultFrameworkPaths
1135 ; mb_fwk <- findFile mk_fwk ps
1137 Just fwk_path -> loadDLL fwk_path
1138 Nothing -> return (Just "not found") }
1139 -- Tried all our known library paths, but dlopen()
1140 -- has no built-in paths for frameworks: give up
1142 mk_fwk dir = dir </> (rootname ++ ".framework/" ++ rootname)
1143 -- sorry for the hardcoded paths, I hope they won't change anytime soon:
1144 defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"]
1147 %************************************************************************
1151 %************************************************************************
1154 findFile :: (FilePath -> FilePath) -- Maps a directory path to a file path
1155 -> [FilePath] -- Directories to look in
1156 -> IO (Maybe FilePath) -- The first file path to match
1157 findFile mk_file_path []
1159 findFile mk_file_path (dir:dirs)
1160 = do { let file_path = mk_file_path dir
1161 ; b <- doesFileExist file_path
1163 return (Just file_path)
1165 findFile mk_file_path dirs }
1169 maybePutStr dflags s | verbosity dflags > 0 = putStr s
1170 | otherwise = return ()
1172 maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s
1173 | otherwise = return ()