2 % (c) The University of Glasgow, 2000
4 \section[CmLink]{Linker for GHCI}
7 module CmLink ( Linkable(..), Unlinked(..),
9 findModuleLinkable_maybe,
13 PersistentLinkerState{-abstractly!-}, emptyPLS,
23 import CmStaticInfo ( GhciMode(..) )
24 import Outputable ( SDoc )
25 import Digraph ( SCC(..), flattenSCC )
26 import Module ( ModuleName )
29 import ErrUtils ( showPass )
30 import CmdLineOpts ( DynFlags(..) )
31 import Panic ( panic, GhcException(..) )
38 #include "HsVersions.h"
42 data PersistentLinkerState
43 = PersistentLinkerState {
47 -- Current global mapping from RdrNames to closure addresses
48 closure_env :: ClosureEnv,
50 -- the current global mapping from RdrNames of DataCons to
51 -- info table addresses.
52 -- When a new Unlinked is linked into the running image, or an existing
53 -- module in the image is replaced, the itbl_env must be updated
57 -- list of objects we've loaded (we'll need to unload them again
58 -- before re-loading the same module), together with the ClockTime
59 -- of the linkable they were loaded from.
60 objects_loaded :: [Linkable]
62 -- notionally here, but really lives in the C part of the linker:
63 -- object_symtab :: FiniteMap String Addr
65 dummy :: () -- sigh, can't have an empty record
71 = LinkOK PersistentLinkerState
72 | LinkErrs PersistentLinkerState [SDoc]
74 findModuleLinkable_maybe :: [Linkable] -> ModuleName -> Maybe Linkable
75 findModuleLinkable_maybe lis mod
76 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
79 many -> pprPanic "findModuleLinkable" (ppr mod)
82 emptyPLS :: IO PersistentLinkerState
84 emptyPLS = return (PersistentLinkerState { closure_env = emptyFM,
86 objects_loaded = [] })
88 emptyPLS = return (PersistentLinkerState {})
91 -----------------------------------------------------------------------------
92 -- Unloading old objects ready for a new compilation sweep.
94 -- The compilation manager provides us with a list of linkables that it
95 -- considers "stable", i.e. won't be recompiled this time around. For
96 -- each of the modules current linked in memory,
98 -- * if the linkable is stable (and it's the same one - the
99 -- user may have recompiled the module on the side), we keep it,
101 -- * otherwise, we unload it.
106 -> [Linkable] -- stable linkables
107 -> PersistentLinkerState
108 -> IO PersistentLinkerState
111 unload Batch dflags linkables pls = return pls
112 unload Interactive dflags linkables pls
113 = do new_loaded <- filterM maybeUnload (objects_loaded pls)
114 let mods_retained = map linkableModName new_loaded
115 itbl_env' = filterNameMap mods_retained (itbl_env pls)
116 closure_env' = filterNameMap mods_retained (closure_env pls)
118 let verb = verbosity dflags
119 when (verb >= 3) $ do
120 hPutStrLn stderr (showSDoc
121 (text "CmLink.unload: retaining" <+> ppr mods_retained))
123 return pls{ objects_loaded = new_loaded,
124 itbl_env = itbl_env',
125 closure_env = closure_env' }
127 maybeUnload :: Linkable -> IO Bool
128 maybeUnload (LM time mod objs) = do
129 case findModuleLinkable_maybe linkables mod of
130 Nothing -> do unloadObjs; return False
131 Just l | linkableTime l /= time -> do unloadObjs; return False
132 | otherwise -> return True
134 unloadObjs = mapM unloadObj [ f | DotO f <- objs ]
136 unload = panic "CmLink.unload: no interpreter"
138 -----------------------------------------------------------------------------
141 link :: GhciMode -- interactive or batch
142 -> DynFlags -- dynamic flags
143 -> Bool -- attempt linking in batch mode?
145 -> PersistentLinkerState
148 -- For the moment, in the batch linker, we don't bother to tell doLink
149 -- which packages to link -- it just tries all that are available.
150 -- batch_attempt_linking should only be *looked at* in batch mode. It
151 -- should only be True if the upsweep was successful and someone
152 -- exports main, i.e., we have good reason to believe that linking
155 -- There will be (ToDo: are) two lists passed to link. These
158 -- 1. The list of all linkables in the current home package. This is
159 -- used by the batch linker to link the program, and by the interactive
160 -- linker to decide which modules from the previous link it can
162 -- 2. The list of modules on which we just called "compile". This list
163 -- is used by the interactive linker to decide which modules need
164 -- to be actually linked this time around (or unlinked and re-linked
165 -- if the module was recompiled).
167 link mode dflags batch_attempt_linking linkables pls1
168 = do let verb = verbosity dflags
169 when (verb >= 3) $ do
170 hPutStrLn stderr "CmLink.link: linkables are ..."
171 hPutStrLn stderr (showSDoc (vcat (map ppr linkables)))
172 res <- link' mode dflags batch_attempt_linking linkables pls1
174 hPutStrLn stderr "CmLink.link: done"
177 link' Batch dflags batch_attempt_linking linkables pls1
178 | batch_attempt_linking
179 = do let o_files = concatMap getOfiles linkables
181 hPutStrLn stderr "ghc: linking ..."
182 -- don't showPass in Batch mode; doLink will do that for us.
184 -- doLink only returns if it succeeds
187 = do when (verb >= 3) $ do
188 hPutStrLn stderr "CmLink.link(batch): upsweep (partially) failed OR"
189 hPutStrLn stderr " Main.main not exported; not linking."
192 verb = verbosity dflags
193 getOfiles (LM _ _ us) = map nameOfObject (filter isObject us)
195 link' Interactive dflags batch_attempt_linking linkables pls
196 = do showPass dflags "Linking"
197 let (objs, bcos) = partition (isObject.head.linkableUnlinked) linkables
198 linkObjs (objs ++ bcos) pls
199 -- get the objects first
201 ppLinkableSCC :: SCC Linkable -> SDoc
202 ppLinkableSCC = ppr . flattenSCC
204 filterModuleLinkables :: (ModuleName -> Bool) -> [Linkable] -> [Linkable]
205 filterModuleLinkables p [] = []
206 filterModuleLinkables p (li:lis)
208 LM _ modnm _ -> if p modnm then retain else dump
210 dump = filterModuleLinkables p lis
213 -----------------------------------------------------------------------------
214 -- Linker for interactive mode
217 linkObjs = panic "CmLink.linkObjs: no interpreter"
218 lookupClosure = panic "CmLink.lookupClosure: no interpreter"
220 linkObjs [] pls = linkFinish pls []
221 linkObjs (l@(LM _ m uls) : ls) pls
222 | all isObject uls = do
223 if isLoaded l pls then linkObjs ls pls else do
224 let objs = [ file | DotO file <- uls ]
226 linkObjs ls pls{objects_loaded = l : objects_loaded pls}
227 | all isInterpretable uls = linkInterpretedCode (l:ls) [] pls
228 | otherwise = invalidLinkable
230 isLoaded :: Linkable -> PersistentLinkerState -> Bool
232 case findModuleLinkable_maybe (objects_loaded pls) (linkableModName l) of
234 Just m -> linkableTime l == linkableTime m
236 linkInterpretedCode [] ul_trees pls = linkFinish pls ul_trees
237 linkInterpretedCode (l@(LM _ m uls) : ls) ul_trees pls
238 | all isInterpretable uls =
239 if isLoaded l pls then linkInterpretedCode ls ul_trees pls else
240 linkInterpretedCode ls (uls++ul_trees)
241 pls{objects_loaded = l : objects_loaded pls}
243 = throwDyn (OtherError
244 "can't link object code that depends on interpreted code")
245 | otherwise = invalidLinkable
247 invalidLinkable = panic "CmLink: linkable doesn't contain entirely objects or interpreted code"
250 -- link all the interpreted code in one go.
251 linkFinish pls ul_bcos = do
254 let stuff = [ (bcos,itbls) | BCOs bcos itbls <- ul_bcos ]
256 (ibinds, new_itbl_env, new_closure_env) <-
257 linkIModules (itbl_env pls) (closure_env pls) stuff
259 let new_pls = pls { closure_env = new_closure_env,
260 itbl_env = new_itbl_env
262 return (LinkOK new_pls)
264 linkExpr :: PersistentLinkerState -> UnlinkedBCOExpr -> IO HValue
265 linkExpr PersistentLinkerState{ itbl_env = ie, closure_env = ce } bcos
266 = linkIExpr ie ce bcos