2 % (c) The University of Glasgow, 2000
4 \section[CompManager]{The Compilation Manager}
7 module CompManager ( cmInit, cmLoadModule, cmUnload,
11 CmState, emptyCmState -- abstract
15 #include "HsVersions.h"
20 import Module ( Module, ModuleName, moduleName, isHomeModule,
21 mkModuleName, moduleNameUserString )
22 import CmStaticInfo ( GhciMode(..) )
25 import HscTypes ( HomeSymbolTable, HomeIfaceTable,
26 PersistentCompilerState, ModDetails(..) )
27 import HscMain ( initPersistentCompilerState )
29 import UniqFM ( emptyUFM, lookupUFM, addToUFM, delListFromUFM,
31 import Unique ( Uniquable )
32 import Digraph ( SCC(..), stronglyConnComp, flattenSCC )
33 import DriverFlags ( getDynFlags )
35 import DriverUtil ( splitFilename3 )
36 import ErrUtils ( showPass )
41 import CmdLineOpts ( DynFlags(..) )
45 import Interpreter ( HValue )
46 import HscMain ( hscExpr )
48 import PrelGHC ( unsafeCoerce# )
52 import Exception ( throwDyn )
55 import Time ( ClockTime )
56 import Directory ( getModificationTime, doesFileExist )
60 import Maybe ( catMaybes, fromMaybe, isJust, fromJust )
65 cmInit :: GhciMode -> IO CmState
72 -> Bool -- True <=> wrap in 'print' to get an IO-typed result
75 -> IO (CmState, Maybe (HValue, PrintUnqualified, Type))
76 cmGetExpr cmstate dflags wrap_io mod expr
77 = do (new_pcs, maybe_stuff) <-
78 hscExpr dflags wrap_io hst hit pcs mod expr
80 Nothing -> return (cmstate{ pcs=new_pcs }, Nothing)
81 Just (bcos, print_unqual, ty) -> do
82 hValue <- linkExpr pls bcos
83 return (cmstate{ pcs=new_pcs },
84 Just (hValue, print_unqual, ty))
86 -- ToDo: check that the module we passed in is sane/exists?
88 CmState{ hst=hst, hit=hit, pcs=pcs, pls=pls } = cmstate
90 -- The HValue should represent a value of type IO () (Perhaps IO a?)
91 cmRunExpr :: HValue -> IO ()
93 = do unsafeCoerce# hval :: IO ()
97 emptyHIT :: HomeIfaceTable
99 emptyHST :: HomeSymbolTable
102 -- Persistent state for the entire system
105 hst :: HomeSymbolTable, -- home symbol table
106 hit :: HomeIfaceTable, -- home interface table
107 ui :: UnlinkedImage, -- the unlinked images
108 mg :: ModuleGraph, -- the module graph
109 gmode :: GhciMode, -- NEVER CHANGES
111 pcs :: PersistentCompilerState, -- compile's persistent state
112 pls :: PersistentLinkerState -- link's persistent state
115 emptyCmState :: GhciMode -> IO CmState
117 = do pcs <- initPersistentCompilerState
119 return (CmState { hst = emptyHST,
128 type UnlinkedImage = [Linkable] -- the unlinked images (should be a set, really)
129 emptyUI :: UnlinkedImage
132 type ModuleGraph = [ModSummary] -- the module graph, topologically sorted
133 emptyMG :: ModuleGraph
138 Unload the compilation manager's state: everything it knows about the
139 current collection of modules in the Home package.
142 cmUnload :: CmState -> IO CmState
144 = do -- Throw away the old home dir cache
146 -- Throw away the HIT and the HST
147 return state{ hst=new_hst, hit=new_hit, ui=emptyUI }
149 CmState{ hst=hst, hit=hit } = state
150 (new_hst, new_hit) = retainInTopLevelEnvs [] (hst,hit)
153 The real business of the compilation manager: given a system state and
154 a module name, try and bring the module up to date, probably changing
155 the system state at the same time.
158 cmLoadModule :: CmState
160 -> IO (CmState, -- new state
161 Bool, -- was successful
162 [Module]) -- list of modules loaded
164 cmLoadModule cmstate1 rootname
165 = do -- version 1's are the original, before downsweep
166 let pls1 = pls cmstate1
167 let pcs1 = pcs cmstate1
168 let hst1 = hst cmstate1
169 let hit1 = hit cmstate1
170 -- similarly, ui1 is the (complete) set of linkables from
171 -- the previous pass, if any.
172 let ui1 = ui cmstate1
173 let mg1 = mg cmstate1
175 let ghci_mode = gmode cmstate1 -- this never changes
177 -- Do the downsweep to reestablish the module graph
178 -- then generate version 2's by retaining in HIT,HST,UI a
179 -- stable set S of modules, as defined below.
181 dflags <- getDynFlags
182 let verb = verbosity dflags
184 showPass dflags "Chasing dependencies"
185 when (verb >= 1 && ghci_mode == Batch) $
186 hPutStrLn stderr (progName ++ ": chasing modules from: " ++ rootname)
188 (mg2unsorted, a_root_is_Main) <- downsweep [rootname] mg1
189 let mg2unsorted_names = map name_of_summary mg2unsorted
191 -- reachable_from follows source as well as normal imports
192 let reachable_from :: ModuleName -> [ModuleName]
193 reachable_from = downwards_closure_of_module mg2unsorted
195 -- should be cycle free; ignores 'import source's
196 let mg2 = topological_sort False mg2unsorted
197 -- ... whereas this takes them into account. Used for
198 -- backing out partially complete cycles following a failed
199 -- upsweep, and for removing from hst/hit all the modules
200 -- not in strict downwards closure, during calls to compile.
201 let mg2_with_srcimps = topological_sort True mg2unsorted
203 -- Sort out which linkables we wish to keep in the unlinked image.
204 -- See getValidLinkables below for details.
205 valid_linkables <- getValidLinkables ui1 mg2unsorted_names
208 -- Figure out a stable set of modules which can be retained
209 -- the top level envs, to avoid upsweeping them. Goes to a
210 -- bit of trouble to avoid upsweeping module cycles.
212 -- Construct a set S of stable modules like this:
213 -- Travel upwards, over the sccified graph. For each scc
214 -- of modules ms, add ms to S only if:
215 -- 1. All home imports of ms are either in ms or S
216 -- 2. A valid linkable exists for each module in ms
219 <- preUpsweep valid_linkables ui1 mg2unsorted_names
223 = concatMap (findInSummaries mg2unsorted) stable_mods
226 = filter (\m -> linkableModName m `elem` stable_mods)
230 putStrLn (showSDoc (text "STABLE MODULES:"
231 <+> sep (map (text.moduleNameUserString) stable_mods)))
233 -- unload any modules which aren't going to be re-linked this
235 pls2 <- unload ghci_mode dflags stable_linkables pls1
237 -- We could at this point detect cycles which aren't broken by
238 -- a source-import, and complain immediately, but it seems better
239 -- to let upsweep_mods do this, so at least some useful work gets
240 -- done before the upsweep is abandoned.
242 = filter (\scc -> any (`notElem` stable_mods)
243 (map name_of_summary (flattenSCC scc)))
246 --hPutStrLn stderr "after tsort:\n"
247 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
249 -- Because we don't take into account source imports when doing
250 -- the topological sort, there shouldn't be any cycles in mg2.
251 -- If there is, we complain and give up -- the user needs to
252 -- break the cycle using a boot file.
254 -- Now do the upsweep, calling compile for each module in
255 -- turn. Final result is version 3 of everything.
257 let threaded2 = CmThreaded pcs1 hst1 hit1
259 (upsweep_complete_success, threaded3, modsUpswept, newLis)
260 <- upsweep_mods ghci_mode dflags valid_linkables reachable_from
261 threaded2 upsweep_these
263 let ui3 = add_to_ui valid_linkables newLis
264 let (CmThreaded pcs3 hst3 hit3) = threaded3
266 -- At this point, modsUpswept and newLis should have the same
267 -- length, so there is one new (or old) linkable for each
268 -- mod which was processed (passed to compile).
270 -- Make modsDone be the summaries for each home module now
271 -- available; this should equal the domains of hst3 and hit3.
272 -- (NOT STRICTLY TRUE if an interactive session was started
273 -- with some object on disk ???)
274 -- Get in in a roughly top .. bottom order (hence reverse).
276 let modsDone = reverse modsUpswept ++ stable_summaries
278 -- Try and do linking in some form, depending on whether the
279 -- upsweep was completely or only partially successful.
281 if upsweep_complete_success
284 -- Easy; just relink it all.
285 do when (verb >= 2) $
286 hPutStrLn stderr "Upsweep completely successful."
288 <- link ghci_mode dflags a_root_is_Main ui3 pls2
291 -> panic "cmLoadModule: link failed (1)"
294 = CmState { hst=hst3, hit=hit3,
298 return (cmstate3, True,
302 -- Tricky. We need to back out the effects of compiling any
303 -- half-done cycles, both so as to clean up the top level envs
304 -- and to avoid telling the interactive linker to link them.
305 do when (verb >= 2) $
306 hPutStrLn stderr "Upsweep partially successful."
309 = map name_of_summary modsDone
310 let mods_to_zap_names
311 = findPartiallyCompletedCycles modsDone_names mg2_with_srcimps
312 let (hst4, hit4, ui4)
313 = removeFromTopLevelEnvs mods_to_zap_names (hst3,hit3,ui3)
315 = filter ((`notElem` mods_to_zap_names).name_of_summary) modsDone
316 let mods_to_keep_names
317 = map name_of_summary mods_to_keep
318 -- we could get the relevant linkables by filtering newLis, but
319 -- it seems easier to drag them out of the updated, cleaned-up UI
320 let linkables_to_link
321 = map (unJust "linkables_to_link" . findModuleLinkable_maybe ui4)
324 linkresult <- link ghci_mode dflags False linkables_to_link pls2
327 -> panic "cmLoadModule: link failed (2)"
330 = CmState { hst=hst4, hit=hit4,
331 ui=ui4, mg=mods_to_keep,
332 gmode=ghci_mode, pcs=pcs3, pls=pls3 }
333 return (cmstate4, False,
334 map ms_mod mods_to_keep)
337 -----------------------------------------------------------------------------
340 -- For each module (or SCC of modules), we take:
342 -- - the old in-core linkable, if available
343 -- - an on-disk linkable, if available
345 -- and we take the youngest of these, provided it is younger than the
346 -- source file. We ignore the on-disk linkables unless all of the
347 -- dependents of this SCC also have on-disk linkables.
349 -- If a module has a valid linkable, then it may be STABLE (see below),
350 -- and it is classified as SOURCE UNCHANGED for the purposes of calling
353 -- ToDo: this pass could be merged with the preUpsweep.
356 :: [Linkable] -- old linkables
357 -> [ModuleName] -- all home modules
358 -> [SCC ModSummary] -- all modules in the program, dependency order
359 -> IO [Linkable] -- still-valid linkables
361 getValidLinkables old_linkables all_home_mods module_graph
362 = foldM (getValidLinkablesSCC old_linkables all_home_mods) [] module_graph
364 getValidLinkablesSCC old_linkables all_home_mods new_linkables scc0
366 scc = flattenSCC scc0
367 scc_names = map name_of_summary scc
368 home_module m = m `elem` all_home_mods && m `notElem` scc_names
369 scc_allhomeimps = nub (filter home_module (concatMap ms_allimps scc))
371 has_object m = case findModuleLinkable_maybe new_linkables m of
373 Just l -> isObjectLinkable l
375 objects_allowed = all has_object scc_allhomeimps
379 <- foldM (getValidLinkable old_linkables objects_allowed) [] scc
381 -- since an scc can contain only all objects or no objects at all,
382 -- we have to check whether we got all objects or not, and re-do
383 -- the linkable check if not.
385 <- if objects_allowed && not (all isObjectLinkable these_linkables)
386 then foldM (getValidLinkable old_linkables False) [] scc
387 else return these_linkables
389 return (adjusted_linkables ++ new_linkables)
392 getValidLinkable :: [Linkable] -> Bool -> [Linkable] -> ModSummary
394 getValidLinkable old_linkables objects_allowed new_linkables summary
396 let mod_name = name_of_summary summary
399 <- if (not objects_allowed)
401 else case ml_obj_file (ms_location summary) of
402 Just obj_fn -> maybe_getFileLinkable mod_name obj_fn
403 Nothing -> return Nothing
405 -- find an old in-core linkable if we have one. (forget about
406 -- on-disk linkables for now, we'll check again whether there's
407 -- one here below, just in case a new one has popped up recently).
408 let old_linkable = findModuleLinkable_maybe old_linkables mod_name
411 Just (LM _ _ ls) | all isInterpretable ls -> old_linkable
414 -- The most recent of the old UI linkable or whatever we could
415 -- find on disk is returned as the linkable if compile
416 -- doesn't think we need to recompile.
418 = case (maybe_old_linkable, maybe_disk_linkable) of
419 (Nothing, Nothing) -> []
420 (Nothing, Just di) -> [di]
421 (Just ui, Nothing) -> [ui]
423 | linkableTime ui >= linkableTime di -> [ui]
426 -- only linkables newer than the source code are valid
427 let maybe_src_date = ms_hs_date summary
430 = case maybe_src_date of
431 Nothing -> panic "valid_linkable_list"
433 -> filter (\li -> linkableTime li > src_date) linkable_list
435 return (valid_linkable_list ++ new_linkables)
438 maybe_getFileLinkable :: ModuleName -> FilePath -> IO (Maybe Linkable)
439 maybe_getFileLinkable mod_name obj_fn
440 = do obj_exist <- doesFileExist obj_fn
444 do let stub_fn = case splitFilename3 obj_fn of
445 (dir, base, ext) -> dir ++ "/" ++ base ++ ".stub_o"
446 stub_exist <- doesFileExist stub_fn
447 obj_time <- getModificationTime obj_fn
449 then return (Just (LM obj_time mod_name [DotO obj_fn, DotO stub_fn]))
450 else return (Just (LM obj_time mod_name [DotO obj_fn]))
453 -----------------------------------------------------------------------------
454 -- Do a pre-upsweep without use of "compile", to establish a
455 -- (downward-closed) set of stable modules for which we won't call compile.
457 preUpsweep :: [Linkable] -- new valid linkables
458 -> [Linkable] -- old linkables
459 -> [ModuleName] -- names of all mods encountered in downsweep
460 -> [ModuleName] -- accumulating stable modules
461 -> [SCC ModSummary] -- scc-ified mod graph, including src imps
462 -> IO [ModuleName] -- stable modules
464 preUpsweep valid_lis old_lis all_home_mods stable []
466 preUpsweep valid_lis old_lis all_home_mods stable (scc0:sccs)
467 = do let scc = flattenSCC scc0
468 scc_allhomeimps :: [ModuleName]
470 = nub (filter (`elem` all_home_mods) (concatMap ms_allimps scc))
471 all_imports_in_scc_or_stable
472 = all in_stable_or_scc scc_allhomeimps
474 = map name_of_summary scc
476 = m `elem` scc_names || m `elem` stable
478 -- now we check for valid linkables: each module in the SCC must
479 -- have a valid linkable (see getValidLinkables above), and the
480 -- newest linkable must be the same as the previous linkable for
481 -- this module (if one exists).
482 has_valid_linkable new_summary
483 = case findModuleLinkable_maybe valid_lis modname of
485 Just l -> case findModuleLinkable_maybe old_lis modname of
487 Just m -> linkableTime l == linkableTime m
488 where modname = name_of_summary new_summary
490 scc_is_stable = all_imports_in_scc_or_stable
491 && all has_valid_linkable scc
494 then preUpsweep valid_lis old_lis all_home_mods
495 (scc_names++stable) sccs
496 else preUpsweep valid_lis old_lis all_home_mods
502 -- Helper for preUpsweep. Assuming that new_summary's imports are all
503 -- stable (in the sense of preUpsweep), determine if new_summary is itself
504 -- stable, and, if so, in batch mode, return its linkable.
505 findInSummaries :: [ModSummary] -> ModuleName -> [ModSummary]
506 findInSummaries old_summaries mod_name
507 = [s | s <- old_summaries, name_of_summary s == mod_name]
509 findModInSummaries :: [ModSummary] -> Module -> Maybe ModSummary
510 findModInSummaries old_summaries mod
511 = case [s | s <- old_summaries, ms_mod s == mod] of
515 -- Return (names of) all those in modsDone who are part of a cycle
516 -- as defined by theGraph.
517 findPartiallyCompletedCycles :: [ModuleName] -> [SCC ModSummary] -> [ModuleName]
518 findPartiallyCompletedCycles modsDone theGraph
522 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
523 chew ((CyclicSCC vs):rest)
524 = let names_in_this_cycle = nub (map name_of_summary vs)
526 = nub ([done | done <- modsDone,
527 done `elem` names_in_this_cycle])
528 chewed_rest = chew rest
530 if not (null mods_in_this_cycle)
531 && length mods_in_this_cycle < length names_in_this_cycle
532 then mods_in_this_cycle ++ chewed_rest
536 -- Add the given (LM-form) Linkables to the UI, overwriting previous
537 -- versions if they exist.
538 add_to_ui :: UnlinkedImage -> [Linkable] -> UnlinkedImage
540 = filter (not_in lis) ui ++ lis
542 not_in :: [Linkable] -> Linkable -> Bool
544 = all (\l -> linkableModName l /= mod) lis
545 where mod = linkableModName li
548 data CmThreaded -- stuff threaded through individual module compilations
549 = CmThreaded PersistentCompilerState HomeSymbolTable HomeIfaceTable
552 -- Compile multiple modules, stopping as soon as an error appears.
553 -- There better had not be any cyclic groups here -- we check for them.
554 upsweep_mods :: GhciMode
556 -> UnlinkedImage -- valid linkables
557 -> (ModuleName -> [ModuleName]) -- to construct downward closures
558 -> CmThreaded -- PCS & HST & HIT
559 -> [SCC ModSummary] -- mods to do (the worklist)
560 -- ...... RETURNING ......
561 -> IO (Bool{-complete success?-},
563 [ModSummary], -- mods which succeeded
564 [Linkable]) -- new linkables
566 upsweep_mods ghci_mode dflags oldUI reachable_from threaded
568 = return (True, threaded, [], [])
570 upsweep_mods ghci_mode dflags oldUI reachable_from threaded
572 = do hPutStrLn stderr ("Module imports form a cycle for modules:\n\t" ++
573 unwords (map (moduleNameUserString.name_of_summary) ms))
574 return (False, threaded, [], [])
576 upsweep_mods ghci_mode dflags oldUI reachable_from threaded
577 ((AcyclicSCC mod):mods)
578 = do --case threaded of
579 -- CmThreaded pcsz hstz hitz
580 -- -> putStrLn ("UPSWEEP_MOD: hit = " ++ show (map (moduleNameUserString.moduleName.mi_module) (eltsUFM hitz)))
582 (threaded1, maybe_linkable)
583 <- upsweep_mod ghci_mode dflags oldUI threaded mod
584 (reachable_from (name_of_summary mod))
585 case maybe_linkable of
587 -> -- No errors; do the rest
588 do (restOK, threaded2, modOKs, linkables)
589 <- upsweep_mods ghci_mode dflags oldUI reachable_from
591 return (restOK, threaded2, mod:modOKs, linkable:linkables)
592 Nothing -- we got a compilation error; give up now
593 -> return (False, threaded1, [], [])
596 -- Compile a single module. Always produce a Linkable for it if
597 -- successful. If no compilation happened, return the old Linkable.
598 upsweep_mod :: GhciMode
604 -> IO (CmThreaded, Maybe Linkable)
606 upsweep_mod ghci_mode dflags oldUI threaded1 summary1 reachable_from_here
608 let mod_name = name_of_summary summary1
609 let verb = verbosity dflags
612 if (ghci_mode == Batch)
613 then hPutStr stderr (progName ++ ": module "
614 ++ moduleNameUserString mod_name
616 else hPutStr stderr ("Compiling "
617 ++ moduleNameUserString mod_name
620 let (CmThreaded pcs1 hst1 hit1) = threaded1
621 let old_iface = lookupUFM hit1 mod_name
623 let maybe_old_linkable = findModuleLinkable_maybe oldUI mod_name
625 source_unchanged = isJust maybe_old_linkable
627 (hst1_strictDC, hit1_strictDC)
628 = retainInTopLevelEnvs
629 (filter (/= (name_of_summary summary1)) reachable_from_here)
633 = unJust "upsweep_mod:old_linkable" maybe_old_linkable
635 compresult <- compile ghci_mode summary1 source_unchanged
636 old_iface hst1_strictDC hit1_strictDC pcs1
640 -- Compilation "succeeded", but didn't return a new
641 -- linkable, meaning that compilation wasn't needed, and the
642 -- new details were manufactured from the old iface.
643 CompOK pcs2 new_details new_iface Nothing
644 -> do let hst2 = addToUFM hst1 mod_name new_details
645 hit2 = addToUFM hit1 mod_name new_iface
646 threaded2 = CmThreaded pcs2 hst2 hit2
648 if ghci_mode == Interactive && verb >= 1 then
649 -- if we're using an object file, tell the user
651 (LM _ _ objs@(DotO _:_))
652 -> do hPutStrLn stderr (showSDoc (space <>
653 parens (hsep (text "using":
655 [ text o | DotO o <- objs ]))))
660 return (threaded2, Just old_linkable)
662 -- Compilation really did happen, and succeeded. A new
663 -- details, iface and linkable are returned.
664 CompOK pcs2 new_details new_iface (Just new_linkable)
665 -> do let hst2 = addToUFM hst1 mod_name new_details
666 hit2 = addToUFM hit1 mod_name new_iface
667 threaded2 = CmThreaded pcs2 hst2 hit2
669 return (threaded2, Just new_linkable)
671 -- Compilation failed. compile may still have updated
674 -> do let threaded2 = CmThreaded pcs2 hst1 hit1
675 return (threaded2, Nothing)
677 -- Remove unwanted modules from the top level envs (HST, HIT, UI).
678 removeFromTopLevelEnvs :: [ModuleName]
679 -> (HomeSymbolTable, HomeIfaceTable, UnlinkedImage)
680 -> (HomeSymbolTable, HomeIfaceTable, UnlinkedImage)
681 removeFromTopLevelEnvs zap_these (hst, hit, ui)
682 = (delListFromUFM hst zap_these,
683 delListFromUFM hit zap_these,
684 filterModuleLinkables (`notElem` zap_these) ui
687 retainInTopLevelEnvs :: [ModuleName]
688 -> (HomeSymbolTable, HomeIfaceTable)
689 -> (HomeSymbolTable, HomeIfaceTable)
690 retainInTopLevelEnvs keep_these (hst, hit)
691 = (retainInUFM hst keep_these,
692 retainInUFM hit keep_these
695 retainInUFM :: Uniquable key => UniqFM elt -> [key] -> UniqFM elt
696 retainInUFM ufm keys_to_keep
697 = listToUFM (concatMap (maybeLookupUFM ufm) keys_to_keep)
699 = case lookupUFM ufm u of Nothing -> []; Just val -> [(u, val)]
701 -- Needed to clean up HIT and HST so that we don't get duplicates in inst env
702 downwards_closure_of_module :: [ModSummary] -> ModuleName -> [ModuleName]
703 downwards_closure_of_module summaries root
704 = let toEdge :: ModSummary -> (ModuleName,[ModuleName])
705 toEdge summ = (name_of_summary summ, ms_allimps summ)
706 res = simple_transitive_closure (map toEdge summaries) [root]
708 --trace (showSDoc (text "DC of mod" <+> ppr root
709 -- <+> text "=" <+> ppr res)) (
713 -- Calculate transitive closures from a set of roots given an adjacency list
714 simple_transitive_closure :: Eq a => [(a,[a])] -> [a] -> [a]
715 simple_transitive_closure graph set
716 = let set2 = nub (concatMap dsts set ++ set)
717 dsts node = fromMaybe [] (lookup node graph)
719 if length set == length set2
721 else simple_transitive_closure graph set2
724 -- Calculate SCCs of the module graph, with or without taking into
725 -- account source imports.
726 topological_sort :: Bool -> [ModSummary] -> [SCC ModSummary]
727 topological_sort include_source_imports summaries
729 toEdge :: ModSummary -> (ModSummary,ModuleName,[ModuleName])
731 = (summ, name_of_summary summ,
732 (if include_source_imports
733 then ms_srcimps summ else []) ++ ms_imps summ)
735 mash_edge :: (ModSummary,ModuleName,[ModuleName]) -> (ModSummary,Int,[Int])
736 mash_edge (summ, m, m_imports)
737 = case lookup m key_map of
738 Nothing -> panic "reverse_topological_sort"
739 Just mk -> (summ, mk,
740 -- ignore imports not from the home package
741 catMaybes (map (flip lookup key_map) m_imports))
743 edges = map toEdge summaries
744 key_map = zip [nm | (s,nm,imps) <- edges] [1 ..] :: [(ModuleName,Int)]
745 scc_input = map mash_edge edges
746 sccs = stronglyConnComp scc_input
751 -- Chase downwards from the specified root set, returning summaries
752 -- for all home modules encountered. Only follow source-import
753 -- links. Also returns a Bool to indicate whether any of the roots
755 downsweep :: [FilePath] -> [ModSummary] -> IO ([ModSummary], Bool)
756 downsweep rootNm old_summaries
757 = do rootSummaries <- mapM getRootSummary rootNm
759 = any ((=="Main").moduleNameUserString.name_of_summary)
762 <- loop (concat (map ms_imps rootSummaries))
763 (filter (isHomeModule.ms_mod) rootSummaries)
764 return (all_summaries, a_root_is_Main)
766 getRootSummary :: FilePath -> IO ModSummary
768 | haskellish_file file
769 = do exists <- doesFileExist file
770 if exists then summariseFile file else do
771 throwDyn (OtherError ("can't find file `" ++ file ++ "'"))
773 = do exists <- doesFileExist hs_file
774 if exists then summariseFile hs_file else do
775 exists <- doesFileExist lhs_file
776 if exists then summariseFile lhs_file else do
777 getSummary (mkModuleName file)
779 hs_file = file ++ ".hs"
780 lhs_file = file ++ ".lhs"
782 getSummary :: ModuleName -> IO ModSummary
784 = do found <- findModule nm
786 Just (mod, location) -> do
787 let old_summary = findModInSummaries old_summaries mod
788 new_summary <- summarise mod location old_summary
790 Nothing -> return (fromJust old_summary)
793 Nothing -> throwDyn (OtherError
794 ("can't find module `"
795 ++ showSDoc (ppr nm) ++ "'"))
797 -- loop invariant: home_summaries doesn't contain package modules
798 loop :: [ModuleName] -> [ModSummary] -> IO [ModSummary]
799 loop [] home_summaries = return home_summaries
800 loop imps home_summaries
801 = do -- all modules currently in homeSummaries
802 let all_home = map (moduleName.ms_mod) home_summaries
804 -- imports for modules we don't already have
805 let needed_imps = nub (filter (`notElem` all_home) imps)
808 needed_summaries <- mapM getSummary needed_imps
810 -- get just the "home" modules
811 let new_home_summaries
812 = filter (isHomeModule.ms_mod) needed_summaries
814 -- loop, checking the new imports
815 let new_imps = concat (map ms_imps new_home_summaries)
816 loop new_imps (new_home_summaries ++ home_summaries)
818 -----------------------------------------------------------------------------
819 -- Summarising modules
821 -- We have two types of summarisation:
823 -- * Summarise a file. This is used for the root module passed to
824 -- cmLoadModule. The file is read, and used to determine the root
825 -- module name. The module name may differ from the filename.
827 -- * Summarise a module. We are given a module name, and must provide
828 -- a summary. The finder is used to locate the file in which the module
831 summariseFile :: FilePath -> IO ModSummary
833 = do hspp_fn <- preprocess file
834 modsrc <- readFile hspp_fn
836 let (srcimps,imps,mod_name) = getImports modsrc
837 (path, basename, ext) = splitFilename3 file
840 <- mkHomeModuleLocn mod_name (path ++ '/':basename) file
843 <- case ml_hs_file location of
844 Nothing -> return Nothing
845 Just src_fn -> maybe_getModificationTime src_fn
847 return (ModSummary mod
848 location{ml_hspp_file=Just hspp_fn}
852 -- Summarise a module, and pick up source and timestamp.
853 summarise :: Module -> ModuleLocation -> Maybe ModSummary
854 -> IO (Maybe ModSummary)
855 summarise mod location old_summary
857 = do let hs_fn = unJust "summarise" (ml_hs_file location)
860 <- case ml_hs_file location of
861 Nothing -> return Nothing
862 Just src_fn -> maybe_getModificationTime src_fn
864 -- return the cached summary if the source didn't change
865 case old_summary of {
866 Just s | ms_hs_date s == maybe_src_timestamp -> return Nothing;
869 hspp_fn <- preprocess hs_fn
870 modsrc <- readFile hspp_fn
871 let (srcimps,imps,mod_name) = getImports modsrc
874 <- case ml_hs_file location of
875 Nothing -> return Nothing
876 Just src_fn -> maybe_getModificationTime src_fn
878 when (mod_name /= moduleName mod) $
880 (showSDoc (text "file name does not match module name: "
881 <+> ppr (moduleName mod) <+> text "vs"
884 return (Just (ModSummary mod location{ml_hspp_file=Just hspp_fn}
886 maybe_src_timestamp))
890 = return (Just (ModSummary mod location [] [] Nothing))
892 maybe_getModificationTime :: FilePath -> IO (Maybe ClockTime)
893 maybe_getModificationTime fn
894 = (do time <- getModificationTime fn
897 (\err -> return Nothing)