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 -fno-cse #-}
16 -- -fno-cse is needed for GLOBAL_VAR's to behave properly
18 module Linker ( HValue, getHValue, showLinkerState,
19 linkExpr, unload, withExtendedLinkEnv,
20 extendLinkEnv, deleteFromLinkEnv,
22 linkPackages,initDynLinker,
26 #include "HsVersions.h"
44 import qualified OccName
56 import qualified Maybes
60 import Config ( cProjectVersion )
70 import System.FilePath
72 import System.Directory
74 import Distribution.Package hiding (depends, PackageId)
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) $ ghcError (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 :: (MonadIO m, ExceptionMonad m) =>
288 [(Name,HValue)] -> m a -> m a
289 withExtendedLinkEnv new_env action
290 = gbracket set_new_env
291 (\_ -> reset_old_env)
293 where set_new_env = do
294 pls <- liftIO $ readIORef v_PersistentLinkerState
295 let new_closure_env = extendClosureEnv (closure_env pls) new_env
296 new_pls = pls { closure_env = new_closure_env }
297 liftIO $ writeIORef v_PersistentLinkerState new_pls
300 -- Remember that the linker state might be side-effected
301 -- during the execution of the IO action, and we don't want to
302 -- lose those changes (we might have linked a new module or
303 -- package), so the reset action only removes the names we
305 reset_old_env = liftIO $ do
306 modifyIORef v_PersistentLinkerState $ \pls ->
307 let cur = closure_env pls
308 new = delListFromNameEnv cur (map fst new_env)
310 pls{ closure_env = new }
312 -- filterNameMap removes from the environment all entries except
313 -- those for a given set of modules;
314 -- Note that this removes all *local* (i.e. non-isExternal) names too
315 -- (these are the temporary bindings from the command line).
316 -- Used to filter both the ClosureEnv and ItblEnv
318 filterNameMap :: [Module] -> NameEnv (Name, a) -> NameEnv (Name, a)
319 filterNameMap mods env
320 = filterNameEnv keep_elt env
322 keep_elt (n,_) = isExternalName n
323 && (nameModule n `elem` mods)
328 showLinkerState :: IO ()
329 -- Display the persistent linker state
331 = do pls <- readIORef v_PersistentLinkerState
332 printDump (vcat [text "----- Linker state -----",
333 text "Pkgs:" <+> ppr (pkgs_loaded pls),
334 text "Objs:" <+> ppr (objs_loaded pls),
335 text "BCOs:" <+> ppr (bcos_loaded pls)])
341 %************************************************************************
343 \subsection{Initialisation}
345 %************************************************************************
347 We initialise the dynamic linker by
349 a) calling the C initialisation procedure
351 b) Loading any packages specified on the command line,
353 c) Loading any packages specified on the command line,
354 now held in the -l options in v_Opt_l
356 d) Loading any .o/.dll files specified on the command line,
357 now held in v_Ld_inputs
359 e) Loading any MacOS frameworks
362 initDynLinker :: DynFlags -> IO ()
363 -- This function is idempotent; if called more than once, it does nothing
364 -- This is useful in Template Haskell, where we call it before trying to link
366 = do { done <- readIORef v_InitLinkerDone
367 ; if done then return ()
368 else do { writeIORef v_InitLinkerDone True
369 ; reallyInitDynLinker dflags }
372 reallyInitDynLinker :: DynFlags -> IO ()
373 reallyInitDynLinker dflags
374 = do { -- Initialise the linker state
375 ; writeIORef v_PersistentLinkerState (emptyPLS dflags)
377 -- (a) initialise the C dynamic linker
380 -- (b) Load packages from the command-line
381 ; linkPackages dflags (preloadPackages (pkgState dflags))
383 -- (c) Link libraries from the command-line
384 ; let optl = getOpts dflags opt_l
385 ; let minus_ls = [ lib | '-':'l':lib <- optl ]
387 -- (d) Link .o files from the command-line
388 ; let lib_paths = libraryPaths dflags
389 ; cmdline_ld_inputs <- readIORef v_Ld_inputs
391 ; classified_ld_inputs <- mapM classifyLdInput cmdline_ld_inputs
393 -- (e) Link any MacOS frameworks
394 ; let framework_paths
395 | isDarwinTarget = frameworkPaths dflags
398 | isDarwinTarget = cmdlineFrameworks dflags
400 -- Finally do (c),(d),(e)
401 ; let cmdline_lib_specs = [ l | Just l <- classified_ld_inputs ]
403 ++ map Framework frameworks
404 ; if null cmdline_lib_specs then return ()
407 { mapM_ (preloadLib dflags lib_paths framework_paths) cmdline_lib_specs
408 ; maybePutStr dflags "final link ... "
411 ; if succeeded ok then maybePutStrLn dflags "done"
412 else ghcError (ProgramError "linking extra libraries/objects failed")
415 classifyLdInput :: FilePath -> IO (Maybe LibrarySpec)
417 | isObjectFilename f = return (Just (Object f))
418 | isDynLibFilename f = return (Just (DLLPath f))
420 hPutStrLn stderr ("Warning: ignoring unrecognised input `" ++ f ++ "'")
423 preloadLib :: DynFlags -> [String] -> [String] -> LibrarySpec -> IO ()
424 preloadLib dflags lib_paths framework_paths lib_spec
425 = do maybePutStr dflags ("Loading object " ++ showLS lib_spec ++ " ... ")
428 -> do b <- preload_static lib_paths static_ish
429 maybePutStrLn dflags (if b then "done"
433 -> do maybe_errstr <- loadDynamic lib_paths dll_unadorned
435 Nothing -> maybePutStrLn dflags "done"
436 Just mm -> preloadFailed mm lib_paths lib_spec
439 -> do maybe_errstr <- loadDLL dll_path
441 Nothing -> maybePutStrLn dflags "done"
442 Just mm -> preloadFailed mm lib_paths lib_spec
446 -> do maybe_errstr <- loadFramework framework_paths framework
448 Nothing -> maybePutStrLn dflags "done"
449 Just mm -> preloadFailed mm framework_paths lib_spec
450 | otherwise -> panic "preloadLib Framework"
453 preloadFailed :: String -> [String] -> LibrarySpec -> IO ()
454 preloadFailed sys_errmsg paths spec
455 = do maybePutStr dflags "failed.\n"
458 "user specified .o/.so/.DLL could not be loaded ("
459 ++ sys_errmsg ++ ")\nWhilst trying to load: "
460 ++ showLS spec ++ "\nAdditional directories searched:"
461 ++ (if null paths then " (none)" else
462 (concat (intersperse "\n" (map (" "++) paths)))))
464 -- Not interested in the paths in the static case.
465 preload_static _paths name
466 = do b <- doesFileExist name
467 if not b then return False
468 else loadObj name >> return True
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 ghcError (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 = ghcError (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 ghcError (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 = adjust_linkable (Maybes.expectJust "getLinkDeps" (hm_linkable mod_info))
638 = do -- It's not in the HPT because we are in one shot mode,
639 -- so use the Finder to get a ModLocation...
640 mb_stuff <- findHomeModule hsc_env mod_name
642 Found loc mod -> found loc mod
646 -- ...and then find the linkable for it
647 mb_lnk <- findObjectLinkableMaybe mod loc ;
649 Nothing -> no_obj mod ;
650 Just lnk -> adjust_linkable lnk
654 | Just osuf <- maybe_normal_osuf = do
655 new_uls <- mapM (adjust_ul osuf) (linkableUnlinked lnk)
656 return lnk{ linkableUnlinked=new_uls }
660 adjust_ul osuf (DotO file) = do
661 let new_file = replaceExtension file osuf
662 ok <- doesFileExist new_file
665 ptext (sLit "cannot find normal object file ")
666 <> quotes (text new_file) $$ while_linking_expr
667 else return (DotO new_file)
668 adjust_ul _ _ = panic "adjust_ul"
672 %************************************************************************
675 The linkables may consist of a mixture of
676 byte-code modules and object modules
678 %************************************************************************
681 linkModules :: DynFlags -> [Linkable] -> IO SuccessFlag
682 linkModules dflags linkables
683 = block $ do -- don't want to be interrupted by ^C in here
685 let (objs, bcos) = partition isObjectLinkable
686 (concatMap partitionLinkable linkables)
688 -- Load objects first; they can't depend on BCOs
689 ok_flag <- dynLinkObjs dflags objs
691 if failed ok_flag then
698 -- HACK to support f-x-dynamic in the interpreter; no other purpose
699 partitionLinkable :: Linkable -> [Linkable]
701 = let li_uls = linkableUnlinked li
702 li_uls_obj = filter isObject li_uls
703 li_uls_bco = filter isInterpretable li_uls
705 case (li_uls_obj, li_uls_bco) of
706 (_:_, _:_) -> [li {linkableUnlinked=li_uls_obj},
707 li {linkableUnlinked=li_uls_bco}]
710 findModuleLinkable_maybe :: [Linkable] -> Module -> Maybe Linkable
711 findModuleLinkable_maybe lis mod
712 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
715 _ -> pprPanic "findModuleLinkable" (ppr mod)
717 linkableInSet :: Linkable -> [Linkable] -> Bool
718 linkableInSet l objs_loaded =
719 case findModuleLinkable_maybe objs_loaded (linkableModule l) of
721 Just m -> linkableTime l == linkableTime m
725 %************************************************************************
727 \subsection{The object-code linker}
729 %************************************************************************
732 dynLinkObjs :: DynFlags -> [Linkable] -> IO SuccessFlag
733 -- Side-effects the PersistentLinkerState
735 dynLinkObjs dflags objs
736 = do pls <- readIORef v_PersistentLinkerState
738 -- Load the object files and link them
739 let (objs_loaded', new_objs) = rmDupLinkables (objs_loaded pls) objs
740 pls1 = pls { objs_loaded = objs_loaded' }
741 unlinkeds = concatMap linkableUnlinked new_objs
743 mapM_ loadObj (map nameOfObject unlinkeds)
745 -- Link the all together
748 -- If resolving failed, unload all our
749 -- object modules and carry on
750 if succeeded ok then do
751 writeIORef v_PersistentLinkerState pls1
754 pls2 <- unload_wkr dflags [] pls1
755 writeIORef v_PersistentLinkerState pls2
759 rmDupLinkables :: [Linkable] -- Already loaded
760 -> [Linkable] -- New linkables
761 -> ([Linkable], -- New loaded set (including new ones)
762 [Linkable]) -- New linkables (excluding dups)
763 rmDupLinkables already ls
766 go already extras [] = (already, extras)
767 go already extras (l:ls)
768 | linkableInSet l already = go already extras ls
769 | otherwise = go (l:already) (l:extras) ls
772 %************************************************************************
774 \subsection{The byte-code linker}
776 %************************************************************************
779 dynLinkBCOs :: [Linkable] -> IO ()
780 -- Side-effects the persistent linker state
782 = do pls <- readIORef v_PersistentLinkerState
784 let (bcos_loaded', new_bcos) = rmDupLinkables (bcos_loaded pls) bcos
785 pls1 = pls { bcos_loaded = bcos_loaded' }
786 unlinkeds :: [Unlinked]
787 unlinkeds = concatMap linkableUnlinked new_bcos
789 cbcs :: [CompiledByteCode]
790 cbcs = map byteCodeOfObject unlinkeds
793 ul_bcos = [b | ByteCode bs _ <- cbcs, b <- bs]
794 ies = [ie | ByteCode _ ie <- cbcs]
795 gce = closure_env pls
796 final_ie = foldr plusNameEnv (itbl_env pls) ies
798 (final_gce, _linked_bcos) <- linkSomeBCOs True final_ie gce ul_bcos
799 -- XXX What happens to these linked_bcos?
801 let pls2 = pls1 { closure_env = final_gce,
802 itbl_env = final_ie }
804 writeIORef v_PersistentLinkerState pls2
807 -- Link a bunch of BCOs and return them + updated closure env.
808 linkSomeBCOs :: Bool -- False <=> add _all_ BCOs to returned closure env
809 -- True <=> add only toplevel BCOs to closure env
813 -> IO (ClosureEnv, [HValue])
814 -- The returned HValues are associated 1-1 with
815 -- the incoming unlinked BCOs. Each gives the
816 -- value of the corresponding unlinked BCO
818 linkSomeBCOs toplevs_only ie ce_in ul_bcos
819 = do let nms = map unlinkedBCOName ul_bcos
821 ( \ hvs -> let ce_out = extendClosureEnv ce_in (zipLazy nms hvs)
822 in mapM (linkBCO ie ce_out) ul_bcos )
823 let ce_all_additions = zip nms hvals
824 ce_top_additions = filter (isExternalName.fst) ce_all_additions
825 ce_additions = if toplevs_only then ce_top_additions
826 else ce_all_additions
827 ce_out = -- make sure we're not inserting duplicate names into the
828 -- closure environment, which leads to trouble.
829 ASSERT (all (not . (`elemNameEnv` ce_in)) (map fst ce_additions))
830 extendClosureEnv ce_in ce_additions
831 return (ce_out, hvals)
836 %************************************************************************
838 Unload some object modules
840 %************************************************************************
843 -- ---------------------------------------------------------------------------
844 -- Unloading old objects ready for a new compilation sweep.
846 -- The compilation manager provides us with a list of linkables that it
847 -- considers "stable", i.e. won't be recompiled this time around. For
848 -- each of the modules current linked in memory,
850 -- * if the linkable is stable (and it's the same one - the
851 -- user may have recompiled the module on the side), we keep it,
853 -- * otherwise, we unload it.
855 -- * we also implicitly unload all temporary bindings at this point.
857 unload :: DynFlags -> [Linkable] -> IO ()
858 -- The 'linkables' are the ones to *keep*
860 unload dflags linkables
861 = block $ do -- block, so we're safe from Ctrl-C in here
863 -- Initialise the linker (if it's not been done already)
866 pls <- readIORef v_PersistentLinkerState
867 new_pls <- unload_wkr dflags linkables pls
868 writeIORef v_PersistentLinkerState new_pls
870 debugTraceMsg dflags 3 (text "unload: retaining objs" <+> ppr (objs_loaded new_pls))
871 debugTraceMsg dflags 3 (text "unload: retaining bcos" <+> ppr (bcos_loaded new_pls))
874 unload_wkr :: DynFlags
875 -> [Linkable] -- stable linkables
876 -> PersistentLinkerState
877 -> IO PersistentLinkerState
878 -- Does the core unload business
879 -- (the wrapper blocks exceptions and deals with the PLS get and put)
881 unload_wkr _ linkables pls
882 = do let (objs_to_keep, bcos_to_keep) = partition isObjectLinkable linkables
884 objs_loaded' <- filterM (maybeUnload objs_to_keep) (objs_loaded pls)
885 bcos_loaded' <- filterM (maybeUnload bcos_to_keep) (bcos_loaded pls)
887 let bcos_retained = map linkableModule bcos_loaded'
888 itbl_env' = filterNameMap bcos_retained (itbl_env pls)
889 closure_env' = filterNameMap bcos_retained (closure_env pls)
890 new_pls = pls { itbl_env = itbl_env',
891 closure_env = closure_env',
892 bcos_loaded = bcos_loaded',
893 objs_loaded = objs_loaded' }
897 maybeUnload :: [Linkable] -> Linkable -> IO Bool
898 maybeUnload keep_linkables lnk
899 | linkableInSet lnk keep_linkables = return True
901 = do mapM_ unloadObj [f | DotO f <- linkableUnlinked lnk]
902 -- The components of a BCO linkable may contain
903 -- dot-o files. Which is very confusing.
905 -- But the BCO parts can be unlinked just by
906 -- letting go of them (plus of course depopulating
907 -- the symbol table which is done in the main body)
912 %************************************************************************
916 %************************************************************************
921 = Object FilePath -- Full path name of a .o file, including trailing .o
922 -- For dynamic objects only, try to find the object
923 -- file in all the directories specified in
924 -- v_Library_paths before giving up.
926 | DLL String -- "Unadorned" name of a .DLL/.so
927 -- e.g. On unix "qt" denotes "libqt.so"
928 -- On WinDoze "burble" denotes "burble.DLL"
929 -- loadDLL is platform-specific and adds the lib/.so/.DLL
930 -- suffixes platform-dependently
932 | DLLPath FilePath -- Absolute or relative pathname to a dynamic library
933 -- (ends with .dll or .so).
935 | Framework String -- Only used for darwin, but does no harm
937 -- If this package is already part of the GHCi binary, we'll already
938 -- have the right DLLs for this package loaded, so don't try to
941 -- But on Win32 we must load them 'again'; doing so is a harmless no-op
942 -- as far as the loader is concerned, but it does initialise the list
943 -- of DLL handles that rts/Linker.c maintains, and that in turn is
944 -- used by lookupSymbol. So we must call addDLL for each library
945 -- just to get the DLL handle into the list.
946 partOfGHCi :: [PackageName]
948 | isWindowsTarget || isDarwinTarget = []
949 | otherwise = map PackageName
950 ["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 = ghcError (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 (packageName 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 ghcError (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 -> ghcError (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 -> ghcError (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 dyn_lib_name)
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 dyn_lib_name = lib ++ "-ghc" ++ cProjectVersion
1098 mk_dyn_lib_path dir = dir </> mkSOName dyn_lib_name
1100 -- ----------------------------------------------------------------------------
1101 -- Loading a dyanmic library (dlopen()-ish on Unix, LoadLibrary-ish on Win32)
1103 -- return Nothing == success, else Just error message from dlopen
1104 loadDynamic :: [FilePath] -> FilePath -> IO (Maybe String)
1105 loadDynamic paths rootname
1106 = do { mb_dll <- findFile mk_dll_path paths
1108 Just dll -> loadDLL dll
1109 Nothing -> loadDLL (mkSOName rootname) }
1110 -- Tried all our known library paths, so let
1111 -- dlopen() search its own builtin paths now.
1113 mk_dll_path dir = dir </> mkSOName rootname
1115 mkSOName :: FilePath -> FilePath
1117 | isDarwinTarget = ("lib" ++ root) <.> "dylib"
1118 | isWindowsTarget = -- Win32 DLLs have no .dll extension here, because
1119 -- addDLL tries both foo.dll and foo.drv
1121 | otherwise = ("lib" ++ root) <.> "so"
1123 -- Darwin / MacOS X only: load a framework
1124 -- a framework is a dynamic library packaged inside a directory of the same
1125 -- name. They are searched for in different paths than normal libraries.
1126 loadFramework :: [FilePath] -> FilePath -> IO (Maybe String)
1127 loadFramework extraPaths rootname
1128 = do { either_dir <- tryIO getHomeDirectory
1129 ; let homeFrameworkPath = case either_dir of
1131 Right dir -> [dir ++ "/Library/Frameworks"]
1132 ps = extraPaths ++ homeFrameworkPath ++ defaultFrameworkPaths
1133 ; mb_fwk <- findFile mk_fwk ps
1135 Just fwk_path -> loadDLL fwk_path
1136 Nothing -> return (Just "not found") }
1137 -- Tried all our known library paths, but dlopen()
1138 -- has no built-in paths for frameworks: give up
1140 mk_fwk dir = dir </> (rootname ++ ".framework/" ++ rootname)
1141 -- sorry for the hardcoded paths, I hope they won't change anytime soon:
1142 defaultFrameworkPaths = ["/Library/Frameworks", "/System/Library/Frameworks"]
1145 %************************************************************************
1149 %************************************************************************
1152 findFile :: (FilePath -> FilePath) -- Maps a directory path to a file path
1153 -> [FilePath] -- Directories to look in
1154 -> IO (Maybe FilePath) -- The first file path to match
1157 findFile mk_file_path (dir:dirs)
1158 = do { let file_path = mk_file_path dir
1159 ; b <- doesFileExist file_path
1161 return (Just file_path)
1163 findFile mk_file_path dirs }
1167 maybePutStr :: DynFlags -> String -> IO ()
1168 maybePutStr dflags s | verbosity dflags > 0 = putStr s
1169 | otherwise = return ()
1171 maybePutStrLn :: DynFlags -> String -> IO ()
1172 maybePutStrLn dflags s | verbosity dflags > 0 = putStrLn s
1173 | otherwise = return ()