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" #-}
17 module Linker ( HValue, getHValue, showLinkerState,
18 linkExpr, unload, withExtendedLinkEnv,
19 extendLinkEnv, deleteFromLinkEnv,
21 linkPackages,initDynLinker,
25 #include "HsVersions.h"
43 import qualified OccName
57 import qualified Maybes
61 import Config ( cProjectVersion )
71 import System.FilePath
73 import System.Directory
75 import Control.Exception
80 %************************************************************************
84 %************************************************************************
86 The persistent linker state *must* match the actual state of the
87 C dynamic linker at all times, so we keep it in a private global variable.
90 The PersistentLinkerState maps Names to actual closures (for
91 interpreted code only), for use during linking.
94 GLOBAL_VAR(v_PersistentLinkerState, panic "Dynamic linker not initialised", PersistentLinkerState)
95 GLOBAL_VAR(v_InitLinkerDone, False, Bool) -- Set True when dynamic linker is initialised
97 data PersistentLinkerState
98 = PersistentLinkerState {
100 -- Current global mapping from Names to their true values
101 closure_env :: ClosureEnv,
103 -- The current global mapping from RdrNames of DataCons to
104 -- info table addresses.
105 -- When a new Unlinked is linked into the running image, or an existing
106 -- module in the image is replaced, the itbl_env must be updated
110 -- The currently loaded interpreted modules (home package)
111 bcos_loaded :: [Linkable],
113 -- And the currently-loaded compiled modules (home package)
114 objs_loaded :: [Linkable],
116 -- The currently-loaded packages; always object code
117 -- Held, as usual, in dependency order; though I am not sure if
118 -- that is really important
119 pkgs_loaded :: [PackageId]
122 emptyPLS :: DynFlags -> PersistentLinkerState
123 emptyPLS _ = PersistentLinkerState {
124 closure_env = emptyNameEnv,
125 itbl_env = emptyNameEnv,
126 pkgs_loaded = init_pkgs,
130 -- Packages that don't need loading, because the compiler
131 -- shares them with the interpreted program.
133 -- The linker's symbol table is populated with RTS symbols using an
134 -- explicit list. See rts/Linker.c for details.
135 where init_pkgs = [rtsPackageId]
139 extendLoadedPkgs :: [PackageId] -> IO ()
140 extendLoadedPkgs pkgs
141 = modifyIORef v_PersistentLinkerState (\s -> s{pkgs_loaded = pkgs ++ pkgs_loaded s})
143 extendLinkEnv :: [(Name,HValue)] -> IO ()
144 -- Automatically discards shadowed bindings
145 extendLinkEnv new_bindings
146 = do pls <- readIORef v_PersistentLinkerState
147 let new_closure_env = extendClosureEnv (closure_env pls) new_bindings
148 new_pls = pls { closure_env = new_closure_env }
149 writeIORef v_PersistentLinkerState new_pls
151 deleteFromLinkEnv :: [Name] -> IO ()
152 deleteFromLinkEnv to_remove
153 = do pls <- readIORef v_PersistentLinkerState
154 let new_closure_env = delListFromNameEnv (closure_env pls) to_remove
155 new_pls = pls { closure_env = new_closure_env }
156 writeIORef v_PersistentLinkerState new_pls
158 -- | Given a data constructor in the heap, find its Name.
159 -- The info tables for data constructors have a field which records
160 -- the source name of the constructor as a Ptr Word8 (UTF-8 encoded
161 -- string). The format is:
163 -- Package:Module.Name
165 -- We use this string to lookup the interpreter's internal representation of the name
166 -- using the lookupOrig.
168 dataConInfoPtrToName :: Ptr () -> TcM (Either String Name)
169 dataConInfoPtrToName x = do
170 theString <- liftIO $ do
171 let ptr = castPtr x :: Ptr StgInfoTable
172 conDescAddress <- getConDescAddress ptr
173 peekArray0 0 conDescAddress
174 let (pkg, mod, occ) = parse theString
175 pkgFS = mkFastStringByteList pkg
176 modFS = mkFastStringByteList mod
177 occFS = mkFastStringByteList occ
178 occName = mkOccNameFS OccName.dataName occFS
179 modName = mkModule (fsToPackageId pkgFS) (mkModuleNameFS modFS)
180 return (Left$ showSDoc$ ppr modName <> dot <> ppr occName )
181 `recoverM` (Right `fmap` lookupOrig modName occName)
185 {- To find the string in the constructor's info table we need to consider
186 the layout of info tables relative to the entry code for a closure.
188 An info table can be next to the entry code for the closure, or it can
189 be separate. The former (faster) is used in registerised versions of ghc,
190 and the latter (portable) is for non-registerised versions.
192 The diagrams below show where the string is to be found relative to
193 the normal info table of the closure.
195 1) Code next to table:
198 | | <- pointer to the start of the string
200 | | <- the (start of the) info table structure
207 In this case the pointer to the start of the string can be found in
208 the memory location _one word before_ the first entry in the normal info
211 2) Code NOT next to table:
214 info table structure -> | *------------------> --------------
218 ptr to start of str -> | |
221 In this case the pointer to the start of the string can be found
222 in the memory location: info_table_ptr + info_table_size
225 getConDescAddress :: Ptr StgInfoTable -> IO (Ptr Word8)
226 getConDescAddress ptr
227 | ghciTablesNextToCode = do
228 offsetToString <- peek $ ptr `plusPtr` (- wORD_SIZE)
229 return $ (ptr `plusPtr` stdInfoTableSizeB) `plusPtr` (fromIntegral (offsetToString :: StgWord))
231 peek $ intPtrToPtr $ (ptrToIntPtr ptr) + fromIntegral stdInfoTableSizeB
233 -- parsing names is a little bit fiddly because we have a string in the form:
234 -- pkg:A.B.C.foo, and we want to split it into three parts: ("pkg", "A.B.C", "foo").
235 -- Thus we split at the leftmost colon and the rightmost occurrence of the dot.
236 -- It would be easier if the string was in the form pkg:A.B.C:foo, but alas
237 -- this is not the conventional way of writing Haskell names. We stick with
238 -- convention, even though it makes the parsing code more troublesome.
239 -- Warning: this code assumes that the string is well formed.
240 parse :: [Word8] -> ([Word8], [Word8], [Word8])
242 = ASSERT (all (>0) (map length [pkg, mod, occ])) (pkg, mod, occ)
244 dot = fromIntegral (ord '.')
245 (pkg, rest1) = break (== fromIntegral (ord ':')) input
247 = (concat $ intersperse [dot] $ reverse modWords, occWord)
249 (modWords, occWord) = ASSERT (length rest1 > 0) (parseModOcc [] (tail rest1))
250 parseModOcc :: [[Word8]] -> [Word8] -> ([[Word8]], [Word8])
252 = case break (== dot) str of
253 (top, []) -> (acc, top)
254 (top, _:bot) -> parseModOcc (top : acc) bot
257 getHValue :: HscEnv -> Name -> IO HValue
258 getHValue hsc_env name = do
259 when (isExternalName name) $ do
260 ok <- linkDependencies hsc_env noSrcSpan [nameModule name]
261 when (failed ok) $ throwDyn (ProgramError "")
262 pls <- readIORef v_PersistentLinkerState
263 lookupName (closure_env pls) name
265 linkDependencies :: HscEnv -> SrcSpan -> [Module] -> IO SuccessFlag
266 linkDependencies hsc_env span needed_mods = do
267 let hpt = hsc_HPT hsc_env
268 dflags = hsc_dflags hsc_env
269 -- The interpreter and dynamic linker can only handle object code built
270 -- the "normal" way, i.e. no non-std ways like profiling or ticky-ticky.
271 -- So here we check the build tag: if we're building a non-standard way
272 -- then we need to find & link object files built the "normal" way.
273 maybe_normal_osuf <- checkNonStdWay dflags span
275 -- Find what packages and linkables are required
276 eps <- readIORef (hsc_EPS hsc_env)
277 (lnks, pkgs) <- getLinkDeps hsc_env hpt (eps_PIT eps)
278 maybe_normal_osuf span needed_mods
280 -- Link the packages and modules required
281 linkPackages dflags pkgs
282 linkModules dflags lnks
285 -- | Temporarily extend the linker state.
287 withExtendedLinkEnv :: [(Name,HValue)] -> IO a -> IO a
288 withExtendedLinkEnv new_env action
289 = bracket_ set_new_env
292 where set_new_env = do
293 pls <- readIORef v_PersistentLinkerState
294 let new_closure_env = extendClosureEnv (closure_env pls) new_env
295 new_pls = pls { closure_env = new_closure_env }
296 writeIORef v_PersistentLinkerState new_pls
299 -- Remember that the linker state might be side-effected
300 -- during the execution of the IO action, and we don't want to
301 -- lose those changes (we might have linked a new module or
302 -- package), so the reset action only removes the names we
305 modifyIORef v_PersistentLinkerState $ \pls ->
306 let cur = closure_env pls
307 new = delListFromNameEnv cur (map fst new_env)
309 pls{ closure_env = new }
311 -- filterNameMap removes from the environment all entries except
312 -- those for a given set of modules;
313 -- Note that this removes all *local* (i.e. non-isExternal) names too
314 -- (these are the temporary bindings from the command line).
315 -- Used to filter both the ClosureEnv and ItblEnv
317 filterNameMap :: [Module] -> NameEnv (Name, a) -> NameEnv (Name, a)
318 filterNameMap mods env
319 = filterNameEnv keep_elt env
321 keep_elt (n,_) = isExternalName n
322 && (nameModule n `elem` mods)
327 showLinkerState :: IO ()
328 -- Display the persistent linker state
330 = do pls <- readIORef v_PersistentLinkerState
331 printDump (vcat [text "----- Linker state -----",
332 text "Pkgs:" <+> ppr (pkgs_loaded pls),
333 text "Objs:" <+> ppr (objs_loaded pls),
334 text "BCOs:" <+> ppr (bcos_loaded pls)])
340 %************************************************************************
342 \subsection{Initialisation}
344 %************************************************************************
346 We initialise the dynamic linker by
348 a) calling the C initialisation procedure
350 b) Loading any packages specified on the command line,
352 c) Loading any packages specified on the command line,
353 now held in the -l options in v_Opt_l
355 d) Loading any .o/.dll files specified on the command line,
356 now held in v_Ld_inputs
358 e) Loading any MacOS frameworks
361 initDynLinker :: DynFlags -> IO ()
362 -- This function is idempotent; if called more than once, it does nothing
363 -- This is useful in Template Haskell, where we call it before trying to link
365 = do { done <- readIORef v_InitLinkerDone
366 ; if done then return ()
367 else do { writeIORef v_InitLinkerDone True
368 ; reallyInitDynLinker dflags }
371 reallyInitDynLinker :: DynFlags -> IO ()
372 reallyInitDynLinker dflags
373 = do { -- Initialise the linker state
374 ; writeIORef v_PersistentLinkerState (emptyPLS dflags)
376 -- (a) initialise the C dynamic linker
379 -- (b) Load packages from the command-line
380 ; linkPackages dflags (preloadPackages (pkgState dflags))
382 -- (c) Link libraries from the command-line
383 ; let optl = getOpts dflags opt_l
384 ; let minus_ls = [ lib | '-':'l':lib <- optl ]
386 -- (d) Link .o files from the command-line
387 ; let lib_paths = libraryPaths dflags
388 ; cmdline_ld_inputs <- readIORef v_Ld_inputs
390 ; classified_ld_inputs <- mapM classifyLdInput cmdline_ld_inputs
392 -- (e) Link any MacOS frameworks
393 ; let framework_paths
394 | isDarwinTarget = frameworkPaths dflags
397 | isDarwinTarget = cmdlineFrameworks dflags
399 -- Finally do (c),(d),(e)
400 ; let cmdline_lib_specs = [ l | Just l <- classified_ld_inputs ]
402 ++ map Framework frameworks
403 ; if null cmdline_lib_specs then return ()
406 { mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs
407 ; maybePutStr dflags "final link ... "
410 ; if succeeded ok then maybePutStrLn dflags "done"
411 else throwDyn (InstallationError "linking extra libraries/objects failed")
414 classifyLdInput :: FilePath -> IO (Maybe LibrarySpec)
416 | isObjectFilename f = return (Just (Object f))
417 | isDynLibFilename f = return (Just (DLLPath f))
419 hPutStrLn stderr ("Warning: ignoring unrecognised input `" ++ f ++ "'")
422 preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO ()
423 preloadLib dflags lib_paths framework_paths lib_spec
424 = do maybePutStr dflags ("Loading object " ++ showLS lib_spec ++ " ... ")
427 -> do b <- preload_static lib_paths static_ish
428 maybePutStrLn dflags (if b then "done"
432 -> do maybe_errstr <- loadDynamic lib_paths dll_unadorned
434 Nothing -> maybePutStrLn dflags "done"
435 Just mm -> preloadFailed mm lib_paths lib_spec
438 -> do maybe_errstr <- loadDLL dll_path
440 Nothing -> maybePutStrLn dflags "done"
441 Just mm -> preloadFailed mm lib_paths lib_spec
445 -> do maybe_errstr <- loadFramework framework_paths framework
447 Nothing -> maybePutStrLn dflags "done"
448 Just mm -> preloadFailed mm framework_paths lib_spec
449 | otherwise -> panic "preloadLib Framework"
452 preloadFailed :: String -> [String] -> LibrarySpec -> IO ()
453 preloadFailed sys_errmsg paths spec
454 = do maybePutStr dflags
455 ("failed.\nDynamic linker error message was:\n "
456 ++ sys_errmsg ++ "\nWhilst trying to load: "
457 ++ showLS spec ++ "\nDirectories to search are:\n"
458 ++ unlines (map (" "++) paths) )
461 -- Not interested in the paths in the static case.
462 preload_static _paths name
463 = do b <- doesFileExist name
464 if not b then return False
465 else loadObj name >> return True
468 CmdLineError "user specified .o/.so/.DLL could not be loaded."
472 %************************************************************************
474 Link a byte-code expression
476 %************************************************************************
479 linkExpr :: HscEnv -> SrcSpan -> UnlinkedBCO -> IO HValue
481 -- Link a single expression, *including* first linking packages and
482 -- modules that this expression depends on.
484 -- Raises an IO exception if it can't find a compiled version of the
485 -- dependents to link.
487 -- Note: This function side-effects the linker state (Pepe)
489 linkExpr hsc_env span root_ul_bco
491 -- Initialise the linker (if it's not been done already)
492 let dflags = hsc_dflags hsc_env
493 ; initDynLinker dflags
495 -- Link the packages and modules required
496 ; ok <- linkDependencies hsc_env span needed_mods
498 throwDyn (ProgramError "")
501 -- Link the expression itself
502 pls <- readIORef v_PersistentLinkerState
503 ; let ie = itbl_env pls
506 -- Link the necessary packages and linkables
507 ; (_, (root_hval:_)) <- linkSomeBCOs False ie ce [root_ul_bco]
511 free_names = nameSetToList (bcoFreeNames root_ul_bco)
513 needed_mods :: [Module]
514 needed_mods = [ nameModule n | n <- free_names,
515 isExternalName n, -- Names from other modules
516 not (isWiredInName n) -- Exclude wired-in names
517 ] -- (see note below)
518 -- Exclude wired-in names because we may not have read
519 -- their interface files, so getLinkDeps will fail
520 -- All wired-in names are in the base package, which we link
521 -- by default, so we can safely ignore them here.
523 dieWith :: SrcSpan -> Message -> IO a
524 dieWith span msg = throwDyn (ProgramError (showSDoc (mkLocMessage span msg)))
527 checkNonStdWay :: DynFlags -> SrcSpan -> IO (Maybe String)
528 checkNonStdWay dflags srcspan = do
529 tag <- readIORef v_Build_tag
530 if null tag then return Nothing else do
531 let default_osuf = phaseInputExt StopLn
532 if objectSuf dflags == default_osuf
533 then failNonStd srcspan
534 else return (Just default_osuf)
536 failNonStd :: SrcSpan -> IO (Maybe String)
537 failNonStd srcspan = dieWith srcspan $
538 ptext (sLit "Dynamic linking required, but this is a non-standard build (eg. prof).") $$
539 ptext (sLit "You need to build the program twice: once the normal way, and then") $$
540 ptext (sLit "in the desired way using -osuf to set the object file suffix.")
543 getLinkDeps :: HscEnv -> HomePackageTable -> PackageIfaceTable
544 -> Maybe String -- the "normal" object suffix
545 -> SrcSpan -- for error messages
546 -> [Module] -- If you need these
547 -> IO ([Linkable], [PackageId]) -- ... then link these first
548 -- Fails with an IO exception if it can't find enough files
550 getLinkDeps hsc_env hpt _ maybe_normal_osuf span mods
551 -- Find all the packages and linkables that a set of modules depends on
552 = do { pls <- readIORef v_PersistentLinkerState ;
553 -- 1. Find the dependent home-pkg-modules/packages from each iface
554 (mods_s, pkgs_s) <- follow_deps mods emptyUniqSet emptyUniqSet;
557 -- 2. Exclude ones already linked
558 -- Main reason: avoid findModule calls in get_linkable
559 mods_needed = mods_s `minusList` linked_mods ;
560 pkgs_needed = pkgs_s `minusList` pkgs_loaded pls ;
562 linked_mods = map (moduleName.linkableModule)
563 (objs_loaded pls ++ bcos_loaded pls)
566 -- putStrLn (showSDoc (ppr mods_s)) ;
567 -- 3. For each dependent module, find its linkable
568 -- This will either be in the HPT or (in the case of one-shot
569 -- compilation) we may need to use maybe_getFileLinkable
570 lnks_needed <- mapM (get_linkable maybe_normal_osuf) mods_needed ;
572 return (lnks_needed, pkgs_needed) }
574 dflags = hsc_dflags hsc_env
575 this_pkg = thisPackage dflags
577 -- The ModIface contains the transitive closure of the module dependencies
578 -- within the current package, *except* for boot modules: if we encounter
579 -- a boot module, we have to find its real interface and discover the
580 -- dependencies of that. Hence we need to traverse the dependency
581 -- tree recursively. See bug #936, testcase ghci/prog007.
582 follow_deps :: [Module] -- modules to follow
583 -> UniqSet ModuleName -- accum. module dependencies
584 -> UniqSet PackageId -- accum. package dependencies
585 -> IO ([ModuleName], [PackageId]) -- result
586 follow_deps [] acc_mods acc_pkgs
587 = return (uniqSetToList acc_mods, uniqSetToList acc_pkgs)
588 follow_deps (mod:mods) acc_mods acc_pkgs
590 mb_iface <- initIfaceCheck hsc_env $
591 loadInterface msg mod (ImportByUser False)
592 iface <- case mb_iface of
593 Maybes.Failed err -> ghcError (ProgramError (showSDoc err))
594 Maybes.Succeeded iface -> return iface
596 when (mi_boot iface) $ link_boot_mod_error mod
599 pkg = modulePackageId mod
602 pkg_deps = dep_pkgs deps
603 (boot_deps, mod_deps) = partitionWith is_boot (dep_mods deps)
604 where is_boot (m,True) = Left m
605 is_boot (m,False) = Right m
607 boot_deps' = filter (not . (`elementOfUniqSet` acc_mods)) boot_deps
608 acc_mods' = addListToUniqSet acc_mods (moduleName mod : mod_deps)
609 acc_pkgs' = addListToUniqSet acc_pkgs pkg_deps
612 then follow_deps mods acc_mods (addOneToUniqSet acc_pkgs' pkg)
613 else follow_deps (map (mkModule this_pkg) boot_deps' ++ mods)
616 msg = text "need to link module" <+> ppr mod <+>
617 text "due to use of Template Haskell"
620 link_boot_mod_error mod =
621 throwDyn (ProgramError (showSDoc (
622 text "module" <+> ppr mod <+>
623 text "cannot be linked; it is only available as a boot module")))
625 no_obj mod = dieWith span $
626 ptext (sLit "cannot find object file for module ") <>
630 while_linking_expr = ptext (sLit "while linking an interpreted expression")
632 -- This one is a build-system bug
634 get_linkable maybe_normal_osuf mod_name -- A home-package module
635 | Just mod_info <- lookupUFM hpt mod_name
636 = ASSERT(isJust (hm_linkable mod_info))
637 adjust_linkable (fromJust (hm_linkable mod_info))
639 = do -- It's not in the HPT because we are in one shot mode,
640 -- so use the Finder to get a ModLocation...
641 mb_stuff <- findHomeModule hsc_env mod_name
643 Found loc mod -> found loc mod
647 -- ...and then find the linkable for it
648 mb_lnk <- findObjectLinkableMaybe mod loc ;
650 Nothing -> no_obj mod ;
651 Just lnk -> adjust_linkable lnk
655 | Just osuf <- maybe_normal_osuf = do
656 new_uls <- mapM (adjust_ul osuf) (linkableUnlinked lnk)
657 return lnk{ linkableUnlinked=new_uls }
661 adjust_ul osuf (DotO file) = do
662 let new_file = replaceExtension file osuf
663 ok <- doesFileExist new_file
666 ptext (sLit "cannot find normal object file ")
667 <> quotes (text new_file) $$ while_linking_expr
668 else return (DotO new_file)
669 adjust_ul _ _ = panic "adjust_ul"
673 %************************************************************************
676 The linkables may consist of a mixture of
677 byte-code modules and object modules
679 %************************************************************************
682 linkModules :: DynFlags -> [Linkable] -> IO SuccessFlag
683 linkModules dflags linkables
684 = block $ do -- don't want to be interrupted by ^C in here
686 let (objs, bcos) = partition isObjectLinkable
687 (concatMap partitionLinkable linkables)
689 -- Load objects first; they can't depend on BCOs
690 ok_flag <- dynLinkObjs dflags objs
692 if failed ok_flag then
699 -- HACK to support f-x-dynamic in the interpreter; no other purpose
700 partitionLinkable :: Linkable -> [Linkable]
702 = let li_uls = linkableUnlinked li
703 li_uls_obj = filter isObject li_uls
704 li_uls_bco = filter isInterpretable li_uls
706 case (li_uls_obj, li_uls_bco) of
707 (_:_, _:_) -> [li {linkableUnlinked=li_uls_obj},
708 li {linkableUnlinked=li_uls_bco}]
711 findModuleLinkable_maybe :: [Linkable] -> Module -> Maybe Linkable
712 findModuleLinkable_maybe lis mod
713 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
716 _ -> pprPanic "findModuleLinkable" (ppr mod)
718 linkableInSet :: Linkable -> [Linkable] -> Bool
719 linkableInSet l objs_loaded =
720 case findModuleLinkable_maybe objs_loaded (linkableModule l) of
722 Just m -> linkableTime l == linkableTime m
726 %************************************************************************
728 \subsection{The object-code linker}
730 %************************************************************************
733 dynLinkObjs :: DynFlags -> [Linkable] -> IO SuccessFlag
734 -- Side-effects the PersistentLinkerState
736 dynLinkObjs dflags objs
737 = do pls <- readIORef v_PersistentLinkerState
739 -- Load the object files and link them
740 let (objs_loaded', new_objs) = rmDupLinkables (objs_loaded pls) objs
741 pls1 = pls { objs_loaded = objs_loaded' }
742 unlinkeds = concatMap linkableUnlinked new_objs
744 mapM loadObj (map nameOfObject unlinkeds)
746 -- Link the all together
749 -- If resolving failed, unload all our
750 -- object modules and carry on
751 if succeeded ok then do
752 writeIORef v_PersistentLinkerState pls1
755 pls2 <- unload_wkr dflags [] pls1
756 writeIORef v_PersistentLinkerState pls2
760 rmDupLinkables :: [Linkable] -- Already loaded
761 -> [Linkable] -- New linkables
762 -> ([Linkable], -- New loaded set (including new ones)
763 [Linkable]) -- New linkables (excluding dups)
764 rmDupLinkables already ls
767 go already extras [] = (already, extras)
768 go already extras (l:ls)
769 | linkableInSet l already = go already extras ls
770 | otherwise = go (l:already) (l:extras) ls
773 %************************************************************************
775 \subsection{The byte-code linker}
777 %************************************************************************
780 dynLinkBCOs :: [Linkable] -> IO ()
781 -- Side-effects the persistent linker state
783 = do pls <- readIORef v_PersistentLinkerState
785 let (bcos_loaded', new_bcos) = rmDupLinkables (bcos_loaded pls) bcos
786 pls1 = pls { bcos_loaded = bcos_loaded' }
787 unlinkeds :: [Unlinked]
788 unlinkeds = concatMap linkableUnlinked new_bcos
790 cbcs :: [CompiledByteCode]
791 cbcs = map byteCodeOfObject unlinkeds
794 ul_bcos = [b | ByteCode bs _ <- cbcs, b <- bs]
795 ies = [ie | ByteCode _ ie <- cbcs]
796 gce = closure_env pls
797 final_ie = foldr plusNameEnv (itbl_env pls) ies
799 (final_gce, _linked_bcos) <- linkSomeBCOs True final_ie gce ul_bcos
800 -- XXX What happens to these linked_bcos?
802 let pls2 = pls1 { closure_env = final_gce,
803 itbl_env = final_ie }
805 writeIORef v_PersistentLinkerState pls2
808 -- Link a bunch of BCOs and return them + updated closure env.
809 linkSomeBCOs :: Bool -- False <=> add _all_ BCOs to returned closure env
810 -- True <=> add only toplevel BCOs to closure env
814 -> IO (ClosureEnv, [HValue])
815 -- The returned HValues are associated 1-1 with
816 -- the incoming unlinked BCOs. Each gives the
817 -- value of the corresponding unlinked BCO
819 linkSomeBCOs toplevs_only ie ce_in ul_bcos
820 = do let nms = map unlinkedBCOName ul_bcos
822 ( \ hvs -> let ce_out = extendClosureEnv ce_in (zipLazy nms hvs)
823 in mapM (linkBCO ie ce_out) ul_bcos )
824 let ce_all_additions = zip nms hvals
825 ce_top_additions = filter (isExternalName.fst) ce_all_additions
826 ce_additions = if toplevs_only then ce_top_additions
827 else ce_all_additions
828 ce_out = -- make sure we're not inserting duplicate names into the
829 -- closure environment, which leads to trouble.
830 ASSERT (all (not . (`elemNameEnv` ce_in)) (map fst ce_additions))
831 extendClosureEnv ce_in ce_additions
832 return (ce_out, hvals)
837 %************************************************************************
839 Unload some object modules
841 %************************************************************************
844 -- ---------------------------------------------------------------------------
845 -- Unloading old objects ready for a new compilation sweep.
847 -- The compilation manager provides us with a list of linkables that it
848 -- considers "stable", i.e. won't be recompiled this time around. For
849 -- each of the modules current linked in memory,
851 -- * if the linkable is stable (and it's the same one - the
852 -- user may have recompiled the module on the side), we keep it,
854 -- * otherwise, we unload it.
856 -- * we also implicitly unload all temporary bindings at this point.
858 unload :: DynFlags -> [Linkable] -> IO ()
859 -- The 'linkables' are the ones to *keep*
861 unload dflags linkables
862 = block $ do -- block, so we're safe from Ctrl-C in here
864 -- Initialise the linker (if it's not been done already)
867 pls <- readIORef v_PersistentLinkerState
868 new_pls <- unload_wkr dflags linkables pls
869 writeIORef v_PersistentLinkerState new_pls
871 debugTraceMsg dflags 3 (text "unload: retaining objs" <+> ppr (objs_loaded new_pls))
872 debugTraceMsg dflags 3 (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls))
875 unload_wkr :: DynFlags
876 -> [Linkable] -- stable linkables
877 -> PersistentLinkerState
878 -> IO PersistentLinkerState
879 -- Does the core unload business
880 -- (the wrapper blocks exceptions and deals with the PLS get and put)
882 unload_wkr _ linkables pls
883 = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables
885 objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls)
886 bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls)
888 let bcos_retained = map linkableModule bcos_loaded'
889 itbl_env' = filterNameMap bcos_retained (itbl_env pls)
890 closure_env' = filterNameMap bcos_retained (closure_env pls)
891 new_pls = pls { itbl_env = itbl_env',
892 closure_env = closure_env',
893 bcos_loaded = bcos_loaded',
894 objs_loaded = objs_loaded' }
898 maybeUnload :: [Linkable] -> Linkable -> IO Bool
899 maybeUnload keep_linkables lnk
900 | linkableInSet lnk keep_linkables = return True
902 = do mapM_ unloadObj [f | DotO f <- linkableUnlinked lnk]
903 -- The components of a BCO linkable may contain
904 -- dot-o files. Which is very confusing.
906 -- But the BCO parts can be unlinked just by
907 -- letting go of them (plus of course depopulating
908 -- the symbol table which is done in the main body)
913 %************************************************************************
917 %************************************************************************
922 = Object FilePath -- Full path name of a .o file, including trailing .o
923 -- For dynamic objects only, try to find the object
924 -- file in all the directories specified in
925 -- v_Library_paths before giving up.
927 | DLL String -- "Unadorned" name of a .DLL/.so
928 -- e.g. On unix "qt" denotes "libqt.so"
929 -- On WinDoze "burble" denotes "burble.DLL"
930 -- loadDLL is platform-specific and adds the lib/.so/.DLL
931 -- suffixes platform-dependently
933 | DLLPath FilePath -- Absolute or relative pathname to a dynamic library
934 -- (ends with .dll or .so).
936 | Framework String -- Only used for darwin, but does no harm
938 -- If this package is already part of the GHCi binary, we'll already
939 -- have the right DLLs for this package loaded, so don't try to
942 -- But on Win32 we must load them 'again'; doing so is a harmless no-op
943 -- as far as the loader is concerned, but it does initialise the list
944 -- of DLL handles that rts/Linker.c maintains, and that in turn is
945 -- used by lookupSymbol. So we must call addDLL for each library
946 -- just to get the DLL handle into the list.
947 partOfGHCi :: [String]
949 | isWindowsTarget || isDarwinTarget = []
950 | otherwise = [ "base", "haskell98", "template-haskell", "editline" ]
952 showLS :: LibrarySpec -> String
953 showLS (Object nm) = "(static) " ++ nm
954 showLS (DLL nm) = "(dynamic) " ++ nm
955 showLS (DLLPath nm) = "(dynamic) " ++ nm
956 showLS (Framework nm) = "(framework) " ++ nm
958 linkPackages :: DynFlags -> [PackageId] -> IO ()
959 -- Link exactly the specified packages, and their dependents
960 -- (unless of course they are already linked)
961 -- The dependents are linked automatically, and it doesn't matter
962 -- what order you specify the input packages.
964 -- NOTE: in fact, since each module tracks all the packages it depends on,
965 -- we don't really need to use the package-config dependencies.
966 -- However we do need the package-config stuff (to find aux libs etc),
967 -- and following them lets us load libraries in the right order, which
968 -- perhaps makes the error message a bit more localised if we get a link
969 -- failure. So the dependency walking code is still here.
971 linkPackages dflags new_pkgs
972 = do { pls <- readIORef v_PersistentLinkerState
973 ; let pkg_map = pkgIdMap (pkgState dflags)
975 ; pkgs' <- link pkg_map (pkgs_loaded pls) new_pkgs
977 ; writeIORef v_PersistentLinkerState (pls { pkgs_loaded = pkgs' })
980 link :: PackageConfigMap -> [PackageId] -> [PackageId] -> IO [PackageId]
981 link pkg_map pkgs new_pkgs
982 = foldM (link_one pkg_map) pkgs new_pkgs
984 link_one pkg_map pkgs new_pkg
985 | new_pkg `elem` pkgs -- Already linked
988 | Just pkg_cfg <- lookupPackage pkg_map new_pkg
989 = do { -- Link dependents first
990 pkgs' <- link pkg_map pkgs (map mkPackageId (depends pkg_cfg))
991 -- Now link the package itself
992 ; linkPackage dflags pkg_cfg
993 ; return (new_pkg : pkgs') }
996 = throwDyn (CmdLineError ("unknown package: " ++ packageIdString new_pkg))
999 linkPackage :: DynFlags -> PackageConfig -> IO ()
1000 linkPackage dflags pkg
1002 let dirs = Packages.libraryDirs pkg
1004 let libs = Packages.hsLibraries pkg
1005 -- Because of slight differences between the GHC dynamic linker and
1006 -- the native system linker some packages have to link with a
1007 -- different list of libraries when using GHCi. Examples include: libs
1008 -- that are actually gnu ld scripts, and the possability that the .a
1009 -- libs do not exactly match the .so/.dll equivalents. So if the
1010 -- package file provides an "extra-ghci-libraries" field then we use
1011 -- that instead of the "extra-libraries" field.
1012 ++ (if null (Packages.extraGHCiLibraries pkg)
1013 then Packages.extraLibraries pkg
1014 else Packages.extraGHCiLibraries pkg)
1015 ++ [ lib | '-':'l':lib <- Packages.ldOptions pkg ]
1016 classifieds <- mapM (locateOneObj dirs) libs
1018 -- Complication: all the .so's must be loaded before any of the .o's.
1019 let dlls = [ dll | DLL dll <- classifieds ]
1020 objs = [ obj | Object obj <- classifieds ]
1022 maybePutStr dflags ("Loading package " ++ display (package pkg) ++ " ... ")
1024 -- See comments with partOfGHCi
1025 when (pkgName (package pkg) `notElem` partOfGHCi) $ do
1027 -- When a library A needs symbols from a library B, the order in
1028 -- extra_libraries/extra_ld_opts is "-lA -lB", because that's the
1029 -- way ld expects it for static linking. Dynamic linking is a
1030 -- different story: When A has no dependency information for B,
1031 -- dlopen-ing A with RTLD_NOW (see addDLL in Linker.c) will fail
1032 -- when B has not been loaded before. In a nutshell: Reverse the
1033 -- order of DLLs for dynamic linking.
1034 -- This fixes a problem with the HOpenGL package (see "Compiling
1035 -- HOpenGL under recent versions of GHC" on the HOpenGL list).
1036 mapM_ (load_dyn dirs) (reverse dlls)
1038 -- After loading all the DLLs, we can load the static objects.
1039 -- Ordering isn't important here, because we do one final link
1040 -- step to resolve everything.
1043 maybePutStr dflags "linking ... "
1045 if succeeded ok then maybePutStrLn dflags "done."
1046 else throwDyn (InstallationError ("unable to load package `" ++ display (package pkg) ++ "'"))
1048 load_dyn :: [FilePath] -> FilePath -> IO ()
1049 load_dyn dirs dll = do r <- loadDynamic dirs dll
1051 Nothing -> return ()
1052 Just err -> throwDyn (CmdLineError ("can't load .so/.DLL for: "
1053 ++ dll ++ " (" ++ err ++ ")" ))
1055 loadFrameworks :: InstalledPackageInfo_ ModuleName -> IO ()
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.
1071 locateOneObj :: [FilePath] -> String -> IO LibrarySpec
1072 locateOneObj dirs lib
1074 -- When the GHC package was not compiled as dynamic library
1075 -- (=__PIC__ not set), we search for .o libraries first.
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 _ -> return (DLL (lib ++ "-ghc" ++ cProjectVersion))
1083 Nothing -> return (DLL lib) }} -- We assume
1085 -- When the GHC package was compiled as dynamic library (=__PIC__ set),
1086 -- we search for .so libraries first.
1087 = do { mb_lib_path <- findFile mk_dyn_lib_path dirs
1088 ; case mb_lib_path of
1089 Just _ -> return (DLL (lib ++ "-ghc" ++ cProjectVersion))
1091 do { mb_obj_path <- findFile mk_obj_path dirs
1092 ; case mb_obj_path of
1093 Just obj_path -> return (Object obj_path)
1094 Nothing -> return (DLL lib) }} -- We assume
1096 mk_obj_path dir = dir </> (lib <.> "o")
1097 mk_dyn_lib_path dir = dir </> mkSOName (lib ++ "-ghc" ++ cProjectVersion)
1099 -- ----------------------------------------------------------------------------
1100 -- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32)
1102 -- return Nothing == success, else Just error message from dlopen
1103 loadDynamic :: [FilePath] -> FilePath -> IO (Maybe String)
1104 loadDynamic paths rootname
1105 = do { mb_dll <- findFile mk_dll_path paths
1107 Just dll -> loadDLL dll
1108 Nothing -> loadDLL (mkSOName rootname) }
1109 -- Tried all our known library paths, so let
1110 -- dlopen() search its own builtin paths now.
1112 mk_dll_path dir = dir </> mkSOName rootname
1114 mkSOName :: FilePath -> FilePath
1116 | isDarwinTarget = ("lib" ++ root) <.> "dylib"
1117 | isWindowsTarget = -- Win32 DLLs have no .dll extension here, because
1118 -- addDLL tries both foo.dll and foo.drv
1120 | otherwise = ("lib" ++ root) <.> "so"
1122 -- Darwin / MacOS X only: load a framework
1123 -- a framework is a dynamic library packaged inside a directory of the same
1124 -- name. They are searched for in different paths than normal libraries.
1125 loadFramework :: [FilePath] -> FilePath -> IO (Maybe String)
1126 loadFramework extraPaths rootname
1127 = do { either_dir <- Control.Exception.try getHomeDirectory
1128 ; let homeFrameworkPath = case either_dir of
1130 Right dir -> [dir ++ "/Library/Frameworks"]
1131 ps = extraPaths ++ homeFrameworkPath ++ defaultFrameworkPaths
1132 ; mb_fwk <- findFile mk_fwk ps
1134 Just fwk_path -> loadDLL fwk_path
1135 Nothing -> return (Just "not found") }
1136 -- Tried all our known library paths, but dlopen()
1137 -- has no built-in paths for frameworks: give up
1139 mk_fwk dir = dir </> (rootname ++ ".framework/" ++ rootname)
1140 -- sorry for the hardcoded paths, I hope they won't change anytime soon:
1141 defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"]
1144 %************************************************************************
1148 %************************************************************************
1151 findFile :: (FilePath -> FilePath) -- Maps a directory path to a file path
1152 -> [FilePath] -- Directories to look in
1153 -> IO (Maybe FilePath) -- The first file path to match
1156 findFile mk_file_path (dir:dirs)
1157 = do { let file_path = mk_file_path dir
1158 ; b <- doesFileExist file_path
1160 return (Just file_path)
1162 findFile mk_file_path dirs }
1166 maybePutStr :: DynFlags -> String -> IO ()
1167 maybePutStr dflags s | verbosity dflags > 0 = putStr s
1168 | otherwise = return ()
1170 maybePutStrLn :: DynFlags -> String -> IO ()
1171 maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s
1172 | otherwise = return ()