1 -- -----------------------------------------------------------------------------
3 -- (c) The University of Glasgow, 2005
7 -- -----------------------------------------------------------------------------
13 defaultCleanupHandler,
17 -- * Flags and settings
18 DynFlags(..), DynFlag(..), GhcMode(..), HscTarget(..), dopt,
26 Target(..), TargetId(..), Phase,
33 -- * Loading\/compiling the program
35 load, LoadHowMuch(..), SuccessFlag(..), -- also does depanal
37 workingDirectoryChanged,
38 checkModule, CheckedModule(..),
39 TypecheckedSource, ParsedSource, RenamedSource,
41 -- * Inspecting the module structure of the program
42 ModuleGraph, ModSummary(..),
47 -- * Inspecting modules
52 modInfoPrintUnqualified,
55 modInfoIsExportedName,
59 -- * Interactive evaluation
60 getBindings, getPrintUnqual,
62 setContext, getContext,
65 getInfo, GetInfoResult,
77 -- * Abstract syntax elements
80 Module, mkModule, pprModule,
87 isImplicitId, isDeadBinder,
88 isSpecPragmaId, isExportedId, isLocalId, isGlobalId,
90 isPrimOpId, isFCallId,
91 isDataConWorkId, idDataCon,
92 isBottomingId, isDictonaryId,
94 -- ** Type constructors
96 isClassTyCon, isSynTyCon, isNewTyCon,
98 -- ** Data constructors
103 classSCTheta, classTvsFds,
108 -- ** Types and Kinds
116 module HsSyn, -- ToDo: remove extraneous bits
119 GhcException(..), showGhcException,
129 * inline bits of HscMain here to simplify layering: hscGetInfo,
131 * we need to expose DynFlags, so should parseDynamicFlags really be
132 part of this interface?
133 * what StaticFlags should we expose, if any?
136 #include "HsVersions.h"
139 import qualified Linker
140 import Linker ( HValue, extendLinkEnv )
141 import TcRnDriver ( getModuleContents, tcRnLookupRdrName,
143 import RdrName ( plusGlobalRdrEnv, Provenance(..),
144 ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
145 emptyGlobalRdrEnv, mkGlobalRdrEnv )
146 import HscMain ( hscGetInfo, GetInfoResult, hscParseIdentifier,
147 hscStmt, hscTcExpr, hscKcType )
148 import Type ( tidyType )
149 import VarEnv ( emptyTidyEnv )
150 import GHC.Exts ( unsafeCoerce# )
151 import IfaceSyn ( IfaceDecl )
152 import SrcLoc ( srcLocSpan, interactiveSrcLoc )
155 import Packages ( initPackages, isHomeModule )
156 import NameSet ( NameSet, nameSetToList, elemNameSet )
157 import RdrName ( GlobalRdrEnv, GlobalRdrElt(..), RdrName,
160 import Type ( Kind, Type, dropForAlls )
161 import Id ( Id, idType, isImplicitId, isDeadBinder,
162 isSpecPragmaId, isExportedId, isLocalId, isGlobalId,
164 isPrimOpId, isFCallId,
165 isDataConWorkId, idDataCon,
167 import TyCon ( TyCon, isClassTyCon, isSynTyCon, isNewTyCon )
168 import Class ( Class, classSCTheta, classTvsFds )
169 import DataCon ( DataCon )
170 import Name ( Name, nameModule )
171 import NameEnv ( nameEnvElts )
172 import InstEnv ( Instance )
173 import SrcLoc ( Located(..), mkGeneralSrcSpan, SrcSpan, unLoc )
174 import DriverPipeline
175 import DriverPhases ( Phase(..), isHaskellSrcFilename, startPhase )
176 import GetImports ( getImports )
177 import Packages ( isHomePackage )
179 import HscMain ( newHscEnv, hscFileCheck, HscResult(..) )
183 import SysTools ( initSysTools, cleanTempFiles )
188 import Bag ( unitBag, emptyBag )
189 import ErrUtils ( showPass, Messages, putMsg, debugTraceMsg,
190 mkPlainErrMsg, pprBagOfErrors )
191 import qualified ErrUtils
193 import StringBuffer ( StringBuffer, hGetStringBuffer )
195 import SysTools ( cleanTempFilesExcept )
196 import BasicTypes ( SuccessFlag(..), succeeded, failed )
197 import TcType ( tcSplitSigmaTy, isDictTy )
198 import FastString ( mkFastString )
200 import Directory ( getModificationTime, doesFileExist )
201 import Maybe ( isJust, isNothing, fromJust )
202 import Maybes ( orElse, expectJust, mapCatMaybes )
203 import List ( partition, nub )
204 import qualified List
205 import Monad ( unless, when )
206 import System ( exitWith, ExitCode(..) )
207 import Time ( ClockTime )
208 import EXCEPTION as Exception hiding (handle)
211 import Prelude hiding (init)
213 -- -----------------------------------------------------------------------------
214 -- Exception handlers
216 -- | Install some default exception handlers and run the inner computation.
217 -- Unless you want to handle exceptions yourself, you should wrap this around
218 -- the top level of your program. The default handlers output the error
219 -- message(s) to stderr and exit cleanly.
220 defaultErrorHandler :: IO a -> IO a
221 defaultErrorHandler inner =
222 -- top-level exception handler: any unrecognised exception is a compiler bug.
223 handle (\exception -> do
226 -- an IO exception probably isn't our fault, so don't panic
227 IOException _ -> putMsg (show exception)
228 AsyncException StackOverflow ->
229 putMsg "stack overflow: use +RTS -K<size> to increase it"
230 _other -> putMsg (show (Panic (show exception)))
231 exitWith (ExitFailure 1)
234 -- program errors: messages with locations attached. Sometimes it is
235 -- convenient to just throw these as exceptions.
236 handleDyn (\dyn -> do printErrs (pprBagOfErrors (unitBag dyn))
237 exitWith (ExitFailure 1)) $
239 -- error messages propagated as exceptions
240 handleDyn (\dyn -> do
243 PhaseFailed _ code -> exitWith code
244 Interrupted -> exitWith (ExitFailure 1)
245 _ -> do putMsg (show (dyn :: GhcException))
246 exitWith (ExitFailure 1)
250 -- | Install a default cleanup handler to remove temporary files
251 -- deposited by a GHC run. This is seperate from
252 -- 'defaultErrorHandler', because you might want to override the error
253 -- handling, but still get the ordinary cleanup behaviour.
254 defaultCleanupHandler :: DynFlags -> IO a -> IO a
255 defaultCleanupHandler dflags inner =
256 -- make sure we clean up after ourselves
257 later (unless (dopt Opt_KeepTmpFiles dflags) $
258 cleanTempFiles dflags)
259 -- exceptions will be blocked while we clean the temporary files,
260 -- so there shouldn't be any difficulty if we receive further
265 -- | Initialises GHC. This must be done /once/ only. Takes the
266 -- command-line arguments. All command-line arguments which aren't
267 -- understood by GHC will be returned.
269 init :: [String] -> IO [String]
272 installSignalHandlers
274 -- Grab the -B option if there is one
275 let (minusB_args, argv1) = partition (prefixMatch "-B") args
276 dflags0 <- initSysTools minusB_args defaultDynFlags
277 writeIORef v_initDynFlags dflags0
279 -- Parse the static flags
280 argv2 <- parseStaticFlags argv1
283 GLOBAL_VAR(v_initDynFlags, error "initDynFlags", DynFlags)
284 -- stores the DynFlags between the call to init and subsequent
285 -- calls to newSession.
287 -- | Starts a new session. A session consists of a set of loaded
288 -- modules, a set of options (DynFlags), and an interactive context.
289 -- ToDo: GhcMode should say "keep typechecked code" and\/or "keep renamed
291 newSession :: GhcMode -> IO Session
293 dflags0 <- readIORef v_initDynFlags
294 dflags <- initDynFlags dflags0
295 env <- newHscEnv dflags{ ghcMode=mode }
299 -- tmp: this breaks the abstraction, but required because DriverMkDepend
300 -- needs to call the Finder. ToDo: untangle this.
301 sessionHscEnv :: Session -> IO HscEnv
302 sessionHscEnv (Session ref) = readIORef ref
304 withSession :: Session -> (HscEnv -> IO a) -> IO a
305 withSession (Session ref) f = do h <- readIORef ref; f h
307 modifySession :: Session -> (HscEnv -> HscEnv) -> IO ()
308 modifySession (Session ref) f = do h <- readIORef ref; writeIORef ref $! f h
310 -- -----------------------------------------------------------------------------
313 -- | Grabs the DynFlags from the Session
314 getSessionDynFlags :: Session -> IO DynFlags
315 getSessionDynFlags s = withSession s (return . hsc_dflags)
317 -- | Updates the DynFlags in a Session
318 setSessionDynFlags :: Session -> DynFlags -> IO ()
319 setSessionDynFlags s dflags = modifySession s (\h -> h{ hsc_dflags = dflags })
321 -- | Messages during compilation (eg. warnings and progress messages)
322 -- are reported using this callback. By default, these messages are
323 -- printed to stderr.
324 setMsgHandler :: (String -> IO ()) -> IO ()
325 setMsgHandler = ErrUtils.setMsgHandler
327 -- -----------------------------------------------------------------------------
330 -- ToDo: think about relative vs. absolute file paths. And what
331 -- happens when the current directory changes.
333 -- | Sets the targets for this session. Each target may be a module name
334 -- or a filename. The targets correspond to the set of root modules for
335 -- the program\/library. Unloading the current program is achieved by
336 -- setting the current set of targets to be empty, followed by load.
337 setTargets :: Session -> [Target] -> IO ()
338 setTargets s targets = modifySession s (\h -> h{ hsc_targets = targets })
340 -- | returns the current set of targets
341 getTargets :: Session -> IO [Target]
342 getTargets s = withSession s (return . hsc_targets)
344 -- | Add another target
345 addTarget :: Session -> Target -> IO ()
347 = modifySession s (\h -> h{ hsc_targets = target : hsc_targets h })
350 removeTarget :: Session -> TargetId -> IO ()
351 removeTarget s target_id
352 = modifySession s (\h -> h{ hsc_targets = filter (hsc_targets h) })
354 filter targets = [ t | t@(Target id _) <- targets, id /= target_id ]
356 -- Attempts to guess what Target a string refers to. This function implements
357 -- the --make/GHCi command-line syntax for filenames:
359 -- - if the string looks like a Haskell source filename, then interpret
361 -- - if adding a .hs or .lhs suffix yields the name of an existing file,
363 -- - otherwise interpret the string as a module name
365 guessTarget :: String -> Maybe Phase -> IO Target
366 guessTarget file (Just phase)
367 = return (Target (TargetFile file (Just phase)) Nothing)
368 guessTarget file Nothing
369 | isHaskellSrcFilename file
370 = return (Target (TargetFile file Nothing) Nothing)
372 = do exists <- doesFileExist hs_file
374 then return (Target (TargetFile hs_file Nothing) Nothing)
376 exists <- doesFileExist lhs_file
378 then return (Target (TargetFile lhs_file Nothing) Nothing)
380 return (Target (TargetModule (mkModule file)) Nothing)
382 hs_file = file `joinFileExt` "hs"
383 lhs_file = file `joinFileExt` "lhs"
385 -- -----------------------------------------------------------------------------
386 -- Loading the program
388 -- Perform a dependency analysis starting from the current targets
389 -- and update the session with the new module graph.
390 depanal :: Session -> [Module] -> IO (Either Messages ModuleGraph)
391 depanal (Session ref) excluded_mods = do
392 hsc_env <- readIORef ref
394 dflags = hsc_dflags hsc_env
395 gmode = ghcMode (hsc_dflags hsc_env)
396 targets = hsc_targets hsc_env
397 old_graph = hsc_mod_graph hsc_env
399 showPass dflags "Chasing dependencies"
400 when (gmode == BatchCompile) $
401 debugTraceMsg dflags 1 (showSDoc (hcat [
402 text "Chasing modules from: ",
403 hcat (punctuate comma (map pprTarget targets))]))
405 downsweep hsc_env old_graph excluded_mods
408 -- | The result of load.
410 = LoadOk Errors -- ^ all specified targets were loaded successfully.
411 | LoadFailed Errors -- ^ not all modules were loaded.
413 type Errors = [String]
415 data ErrMsg = ErrMsg {
416 errMsgSeverity :: Severity, -- warning, error, etc.
417 errMsgSpans :: [SrcSpan],
418 errMsgShortDoc :: Doc,
419 errMsgExtraInfo :: Doc
426 | LoadDependenciesOf Module
428 -- | Try to load the program. If a Module is supplied, then just
429 -- attempt to load up to this target. If no Module is supplied,
430 -- then try to load all targets.
431 load :: Session -> LoadHowMuch -> IO SuccessFlag
432 load session how_much =
433 loadMsgs session how_much ErrUtils.printErrorsAndWarnings
435 -- | Version of 'load' that takes a callback function to be invoked
436 -- on compiler errors and warnings as they occur during compilation.
437 loadMsgs :: Session -> LoadHowMuch -> (Messages-> IO ()) -> IO SuccessFlag
438 loadMsgs s@(Session ref) how_much msg_act
440 -- Dependency analysis first. Note that this fixes the module graph:
441 -- even if we don't get a fully successful upsweep, the full module
442 -- graph is still retained in the Session. We can tell which modules
443 -- were successfully loaded by inspecting the Session's HPT.
444 mb_graph <- depanal s []
446 Left msgs -> do msg_act msgs; return Failed
447 Right mod_graph -> do
448 hsc_env <- readIORef ref
449 writeIORef ref hsc_env{ hsc_mod_graph = mod_graph }
450 loadMsgs2 s how_much msg_act mod_graph
452 loadMsgs2 s@(Session ref) how_much msg_act mod_graph = do
453 hsc_env <- readIORef ref
455 let hpt1 = hsc_HPT hsc_env
456 let dflags = hsc_dflags hsc_env
457 let ghci_mode = ghcMode dflags -- this never changes
458 let verb = verbosity dflags
460 -- The "bad" boot modules are the ones for which we have
461 -- B.hs-boot in the module graph, but no B.hs
462 -- The downsweep should have ensured this does not happen
464 let all_home_mods = [ms_mod s | s <- mod_graph, not (isBootSummary s)]
465 bad_boot_mods = [s | s <- mod_graph, isBootSummary s,
466 not (ms_mod s `elem` all_home_mods)]
467 ASSERT( null bad_boot_mods ) return ()
469 -- mg2_with_srcimps drops the hi-boot nodes, returning a
470 -- graph with cycles. Among other things, it is used for
471 -- backing out partially complete cycles following a failed
472 -- upsweep, and for removing from hpt all the modules
473 -- not in strict downwards closure, during calls to compile.
474 let mg2_with_srcimps :: [SCC ModSummary]
475 mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing
477 -- check the stability property for each module.
478 stable_mods@(stable_obj,stable_bco)
479 | BatchCompile <- ghci_mode = ([],[])
480 | otherwise = checkStability hpt1 mg2_with_srcimps all_home_mods
482 -- prune bits of the HPT which are definitely redundant now,
484 pruned_hpt = pruneHomePackageTable hpt1
485 (flattenSCCs mg2_with_srcimps)
490 debugTraceMsg dflags 2 (showSDoc (text "Stable obj:" <+> ppr stable_obj $$
491 text "Stable BCO:" <+> ppr stable_bco))
493 -- Unload any modules which are going to be re-linked this time around.
494 let stable_linkables = [ linkable
495 | m <- stable_obj++stable_bco,
496 Just hmi <- [lookupModuleEnv pruned_hpt m],
497 Just linkable <- [hm_linkable hmi] ]
498 unload hsc_env stable_linkables
500 -- We could at this point detect cycles which aren't broken by
501 -- a source-import, and complain immediately, but it seems better
502 -- to let upsweep_mods do this, so at least some useful work gets
503 -- done before the upsweep is abandoned.
504 --hPutStrLn stderr "after tsort:\n"
505 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
507 -- Now do the upsweep, calling compile for each module in
508 -- turn. Final result is version 3 of everything.
510 -- Topologically sort the module graph, this time including hi-boot
511 -- nodes, and possibly just including the portion of the graph
512 -- reachable from the module specified in the 2nd argument to load.
513 -- This graph should be cycle-free.
514 -- If we're restricting the upsweep to a portion of the graph, we
515 -- also want to retain everything that is still stable.
516 let full_mg :: [SCC ModSummary]
517 full_mg = topSortModuleGraph False mod_graph Nothing
519 maybe_top_mod = case how_much of
521 LoadDependenciesOf m -> Just m
524 partial_mg0 :: [SCC ModSummary]
525 partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod
527 -- LoadDependenciesOf m: we want the upsweep to stop just
528 -- short of the specified module (unless the specified module
531 | LoadDependenciesOf mod <- how_much
532 = ASSERT( case last partial_mg0 of
533 AcyclicSCC ms -> ms_mod ms == mod; _ -> False )
534 List.init partial_mg0
540 | AcyclicSCC ms <- full_mg,
541 ms_mod ms `elem` stable_obj++stable_bco,
542 ms_mod ms `notElem` [ ms_mod ms' |
543 AcyclicSCC ms' <- partial_mg ] ]
545 mg = stable_mg ++ partial_mg
547 -- clean up between compilations
548 let cleanup = cleanTempFilesExcept dflags
549 (ppFilesFromSummaries (flattenSCCs mg2_with_srcimps))
551 (upsweep_ok, hsc_env1, modsUpswept)
552 <- upsweep (hsc_env { hsc_HPT = emptyHomePackageTable })
553 pruned_hpt stable_mods cleanup msg_act mg
555 -- Make modsDone be the summaries for each home module now
556 -- available; this should equal the domain of hpt3.
557 -- Get in in a roughly top .. bottom order (hence reverse).
559 let modsDone = reverse modsUpswept
561 -- Try and do linking in some form, depending on whether the
562 -- upsweep was completely or only partially successful.
564 if succeeded upsweep_ok
567 -- Easy; just relink it all.
568 do debugTraceMsg dflags 2 "Upsweep completely successful."
570 -- Clean up after ourselves
571 cleanTempFilesExcept dflags (ppFilesFromSummaries modsDone)
573 -- Issue a warning for the confusing case where the user
574 -- said '-o foo' but we're not going to do any linking.
575 -- We attempt linking if either (a) one of the modules is
576 -- called Main, or (b) the user said -no-hs-main, indicating
577 -- that main() is going to come from somewhere else.
579 let ofile = outputFile dflags
580 let no_hs_main = dopt Opt_NoHsMain dflags
581 let mb_main_mod = mainModIs dflags
583 main_mod = mb_main_mod `orElse` "Main"
585 = any ((==main_mod).moduleUserString.ms_mod)
587 do_linking = a_root_is_Main || no_hs_main
589 when (ghci_mode == BatchCompile && isJust ofile && not do_linking) $
590 debugTraceMsg dflags 1 ("Warning: output was redirected with -o, " ++
591 "but no output will be generated\n" ++
592 "because there is no " ++ main_mod ++ " module.")
594 -- link everything together
595 linkresult <- link ghci_mode dflags do_linking (hsc_HPT hsc_env1)
597 loadFinish Succeeded linkresult ref hsc_env1
600 -- Tricky. We need to back out the effects of compiling any
601 -- half-done cycles, both so as to clean up the top level envs
602 -- and to avoid telling the interactive linker to link them.
603 do debugTraceMsg dflags 2 "Upsweep partially successful."
606 = map ms_mod modsDone
607 let mods_to_zap_names
608 = findPartiallyCompletedCycles modsDone_names
611 = filter ((`notElem` mods_to_zap_names).ms_mod)
614 let hpt4 = retainInTopLevelEnvs (map ms_mod mods_to_keep)
617 -- Clean up after ourselves
618 cleanTempFilesExcept dflags (ppFilesFromSummaries mods_to_keep)
620 -- there should be no Nothings where linkables should be, now
621 ASSERT(all (isJust.hm_linkable)
622 (moduleEnvElts (hsc_HPT hsc_env))) do
624 -- Link everything together
625 linkresult <- link ghci_mode dflags False hpt4
627 let hsc_env4 = hsc_env1{ hsc_HPT = hpt4 }
628 loadFinish Failed linkresult ref hsc_env4
630 -- Finish up after a load.
632 -- If the link failed, unload everything and return.
633 loadFinish all_ok Failed ref hsc_env
634 = do unload hsc_env []
635 writeIORef ref $! discardProg hsc_env
638 -- Empty the interactive context and set the module context to the topmost
639 -- newly loaded module, or the Prelude if none were loaded.
640 loadFinish all_ok Succeeded ref hsc_env
641 = do writeIORef ref $! hsc_env{ hsc_IC = emptyInteractiveContext }
645 -- Forget the current program, but retain the persistent info in HscEnv
646 discardProg :: HscEnv -> HscEnv
648 = hsc_env { hsc_mod_graph = emptyMG,
649 hsc_IC = emptyInteractiveContext,
650 hsc_HPT = emptyHomePackageTable }
652 -- used to fish out the preprocess output files for the purposes of
653 -- cleaning up. The preprocessed file *might* be the same as the
654 -- source file, but that doesn't do any harm.
655 ppFilesFromSummaries summaries = [ fn | Just fn <- map ms_hspp_file summaries ]
657 -- -----------------------------------------------------------------------------
661 CheckedModule { parsedSource :: ParsedSource,
662 renamedSource :: Maybe RenamedSource,
663 typecheckedSource :: Maybe TypecheckedSource,
664 checkedModuleInfo :: Maybe ModuleInfo
666 -- ToDo: improvements that could be made here:
667 -- if the module succeeded renaming but not typechecking,
668 -- we can still get back the GlobalRdrEnv and exports, so
669 -- perhaps the ModuleInfo should be split up into separate
670 -- fields within CheckedModule.
672 type ParsedSource = Located (HsModule RdrName)
673 type RenamedSource = HsGroup Name
674 type TypecheckedSource = LHsBinds Id
676 -- | This is the way to get access to parsed and typechecked source code
677 -- for a module. 'checkModule' loads all the dependencies of the specified
678 -- module in the Session, and then attempts to typecheck the module. If
679 -- successful, it returns the abstract syntax for the module.
680 checkModule :: Session -> Module -> (Messages -> IO ())
681 -> IO (Maybe CheckedModule)
682 checkModule session@(Session ref) mod msg_act = do
683 -- load up the dependencies first
684 r <- loadMsgs session (LoadDependenciesOf mod) msg_act
685 if (failed r) then return Nothing else do
687 -- now parse & typecheck the module
688 hsc_env <- readIORef ref
689 let mg = hsc_mod_graph hsc_env
690 case [ ms | ms <- mg, ms_mod ms == mod ] of
693 -- Add in the OPTIONS from the source file This is nasty:
694 -- we've done this once already, in the compilation manager
695 -- It might be better to cache the flags in the
696 -- ml_hspp_file field, say
697 let dflags0 = hsc_dflags hsc_env
698 hspp_buf = expectJust "GHC.checkModule" (ms_hspp_buf ms)
699 opts = getOptionsFromStringBuffer hspp_buf
700 (dflags1,leftovers) <- parseDynamicFlags dflags0 (map snd opts)
701 if (not (null leftovers))
702 then do let filename = fromJust (ml_hs_file (ms_location ms))
703 msg_act (optionsErrorMsgs leftovers opts filename)
707 r <- hscFileCheck hsc_env{hsc_dflags=dflags1} msg_act ms
711 HscChecked parsed renamed Nothing ->
712 return (Just (CheckedModule {
713 parsedSource = parsed,
714 renamedSource = renamed,
715 typecheckedSource = Nothing,
716 checkedModuleInfo = Nothing }))
717 HscChecked parsed renamed
718 (Just (tc_binds, rdr_env, details)) -> do
719 let minf = ModuleInfo {
720 minf_type_env = md_types details,
721 minf_exports = md_exports details,
722 minf_rdr_env = Just rdr_env,
723 minf_instances = md_insts details
725 return (Just (CheckedModule {
726 parsedSource = parsed,
727 renamedSource = renamed,
728 typecheckedSource = Just tc_binds,
729 checkedModuleInfo = Just minf }))
731 -- ---------------------------------------------------------------------------
734 unload :: HscEnv -> [Linkable] -> IO ()
735 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
736 = case ghcMode (hsc_dflags hsc_env) of
737 BatchCompile -> return ()
738 JustTypecheck -> return ()
740 Interactive -> Linker.unload (hsc_dflags hsc_env) stable_linkables
742 Interactive -> panic "unload: no interpreter"
744 other -> panic "unload: strange mode"
746 -- -----------------------------------------------------------------------------
750 Stability tells us which modules definitely do not need to be recompiled.
751 There are two main reasons for having stability:
753 - avoid doing a complete upsweep of the module graph in GHCi when
754 modules near the bottom of the tree have not changed.
756 - to tell GHCi when it can load object code: we can only load object code
757 for a module when we also load object code fo all of the imports of the
758 module. So we need to know that we will definitely not be recompiling
759 any of these modules, and we can use the object code.
761 NB. stability is of no importance to BatchCompile at all, only Interactive.
762 (ToDo: what about JustTypecheck?)
764 The stability check is as follows. Both stableObject and
765 stableBCO are used during the upsweep phase later.
768 stable m = stableObject m || stableBCO m
771 all stableObject (imports m)
772 && old linkable does not exist, or is == on-disk .o
773 && date(on-disk .o) > date(.hs)
776 all stable (imports m)
777 && date(BCO) > date(.hs)
780 These properties embody the following ideas:
782 - if a module is stable:
783 - if it has been compiled in a previous pass (present in HPT)
784 then it does not need to be compiled or re-linked.
785 - if it has not been compiled in a previous pass,
786 then we only need to read its .hi file from disk and
787 link it to produce a ModDetails.
789 - if a modules is not stable, we will definitely be at least
790 re-linking, and possibly re-compiling it during the upsweep.
791 All non-stable modules can (and should) therefore be unlinked
794 - Note that objects are only considered stable if they only depend
795 on other objects. We can't link object code against byte code.
799 :: HomePackageTable -- HPT from last compilation
800 -> [SCC ModSummary] -- current module graph (cyclic)
801 -> [Module] -- all home modules
802 -> ([Module], -- stableObject
803 [Module]) -- stableBCO
805 checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
807 checkSCC (stable_obj, stable_bco) scc0
808 | stableObjects = (scc_mods ++ stable_obj, stable_bco)
809 | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
810 | otherwise = (stable_obj, stable_bco)
812 scc = flattenSCC scc0
813 scc_mods = map ms_mod scc
814 home_module m = m `elem` all_home_mods && m `notElem` scc_mods
816 scc_allimps = nub (filter home_module (concatMap ms_allimps scc))
817 -- all imports outside the current SCC, but in the home pkg
819 stable_obj_imps = map (`elem` stable_obj) scc_allimps
820 stable_bco_imps = map (`elem` stable_bco) scc_allimps
827 and (zipWith (||) stable_obj_imps stable_bco_imps)
831 | Just t <- ms_obj_date ms = t >= ms_hs_date ms
835 same_as_prev t = case lookupModuleEnv hpt (ms_mod ms) of
837 Just hmi | Just l <- hm_linkable hmi
838 -> isObjectLinkable l && t == linkableTime l
839 -- why '>=' rather than '>' above? If the filesystem stores
840 -- times to the nearset second, we may occasionally find that
841 -- the object & source have the same modification time,
842 -- especially if the source was automatically generated
843 -- and compiled. Using >= is slightly unsafe, but it matches
847 = case lookupModuleEnv hpt (ms_mod ms) of
849 Just hmi | Just l <- hm_linkable hmi ->
850 not (isObjectLinkable l) &&
851 linkableTime l >= ms_hs_date ms
853 ms_allimps :: ModSummary -> [Module]
854 ms_allimps ms = map unLoc (ms_srcimps ms ++ ms_imps ms)
856 -- -----------------------------------------------------------------------------
857 -- Prune the HomePackageTable
859 -- Before doing an upsweep, we can throw away:
861 -- - For non-stable modules:
862 -- - all ModDetails, all linked code
863 -- - all unlinked code that is out of date with respect to
866 -- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
867 -- space at the end of the upsweep, because the topmost ModDetails of the
868 -- old HPT holds on to the entire type environment from the previous
871 pruneHomePackageTable
874 -> ([Module],[Module])
877 pruneHomePackageTable hpt summ (stable_obj, stable_bco)
878 = mapModuleEnv prune hpt
880 | is_stable modl = hmi'
881 | otherwise = hmi'{ hm_details = emptyModDetails }
883 modl = mi_module (hm_iface hmi)
884 hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
885 = hmi{ hm_linkable = Nothing }
888 where ms = expectJust "prune" (lookupModuleEnv ms_map modl)
890 ms_map = mkModuleEnv [(ms_mod ms, ms) | ms <- summ]
892 is_stable m = m `elem` stable_obj || m `elem` stable_bco
894 -- -----------------------------------------------------------------------------
896 -- Return (names of) all those in modsDone who are part of a cycle
897 -- as defined by theGraph.
898 findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
899 findPartiallyCompletedCycles modsDone theGraph
903 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
904 chew ((CyclicSCC vs):rest)
905 = let names_in_this_cycle = nub (map ms_mod vs)
907 = nub ([done | done <- modsDone,
908 done `elem` names_in_this_cycle])
909 chewed_rest = chew rest
911 if notNull mods_in_this_cycle
912 && length mods_in_this_cycle < length names_in_this_cycle
913 then mods_in_this_cycle ++ chewed_rest
916 -- -----------------------------------------------------------------------------
919 -- This is where we compile each module in the module graph, in a pass
920 -- from the bottom to the top of the graph.
922 -- There better had not be any cyclic groups here -- we check for them.
925 :: HscEnv -- Includes initially-empty HPT
926 -> HomePackageTable -- HPT from last time round (pruned)
927 -> ([Module],[Module]) -- stable modules (see checkStability)
928 -> IO () -- How to clean up unwanted tmp files
929 -> (Messages -> IO ()) -- Compiler error message callback
930 -> [SCC ModSummary] -- Mods to do (the worklist)
932 HscEnv, -- With an updated HPT
933 [ModSummary]) -- Mods which succeeded
935 upsweep hsc_env old_hpt stable_mods cleanup msg_act mods
936 = upsweep' hsc_env old_hpt stable_mods cleanup msg_act mods 1 (length mods)
938 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
940 = return (Succeeded, hsc_env, [])
942 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
944 = do putMsg (showSDoc (cyclicModuleErr ms))
945 return (Failed, hsc_env, [])
947 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
948 (AcyclicSCC mod:mods) mod_index nmods
949 = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
950 -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
951 -- (moduleEnvElts (hsc_HPT hsc_env)))
953 mb_mod_info <- upsweep_mod hsc_env old_hpt stable_mods msg_act mod
956 cleanup -- Remove unwanted tmp files between compilations
959 Nothing -> return (Failed, hsc_env, [])
961 { let this_mod = ms_mod mod
963 -- Add new info to hsc_env
964 hpt1 = extendModuleEnv (hsc_HPT hsc_env)
966 hsc_env1 = hsc_env { hsc_HPT = hpt1 }
968 -- Space-saving: delete the old HPT entry
969 -- for mod BUT if mod is a hs-boot
970 -- node, don't delete it. For the
971 -- interface, the HPT entry is probaby for the
972 -- main Haskell source file. Deleting it
973 -- would force .. (what?? --SDM)
974 old_hpt1 | isBootSummary mod = old_hpt
975 | otherwise = delModuleEnv old_hpt this_mod
977 ; (restOK, hsc_env2, modOKs)
978 <- upsweep' hsc_env1 old_hpt1 stable_mods cleanup
979 msg_act mods (mod_index+1) nmods
980 ; return (restOK, hsc_env2, mod:modOKs)
984 -- Compile a single module. Always produce a Linkable for it if
985 -- successful. If no compilation happened, return the old Linkable.
986 upsweep_mod :: HscEnv
988 -> ([Module],[Module])
989 -> (Messages -> IO ())
991 -> Int -- index of module
992 -> Int -- total number of modules
993 -> IO (Maybe HomeModInfo) -- Nothing => Failed
995 upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) msg_act summary mod_index nmods
998 this_mod = ms_mod summary
999 mb_obj_date = ms_obj_date summary
1000 obj_fn = ml_obj_file (ms_location summary)
1001 hs_date = ms_hs_date summary
1003 compile_it :: Maybe Linkable -> IO (Maybe HomeModInfo)
1004 compile_it = upsweep_compile hsc_env old_hpt this_mod
1005 msg_act summary mod_index nmods
1007 case ghcMode (hsc_dflags hsc_env) of
1010 -- Batch-compilating is easy: just check whether we have
1011 -- an up-to-date object file. If we do, then the compiler
1012 -- needs to do a recompilation check.
1013 _ | Just obj_date <- mb_obj_date, obj_date >= hs_date -> do
1015 findObjectLinkable this_mod obj_fn obj_date
1016 compile_it (Just linkable)
1023 _ | is_stable_obj, isJust old_hmi ->
1025 -- object is stable, and we have an entry in the
1026 -- old HPT: nothing to do
1028 | is_stable_obj, isNothing old_hmi -> do
1030 findObjectLinkable this_mod obj_fn
1031 (expectJust "upseep1" mb_obj_date)
1032 compile_it (Just linkable)
1033 -- object is stable, but we need to load the interface
1034 -- off disk to make a HMI.
1037 ASSERT(isJust old_hmi) -- must be in the old_hpt
1039 -- BCO is stable: nothing to do
1041 | Just hmi <- old_hmi,
1042 Just l <- hm_linkable hmi, not (isObjectLinkable l),
1043 linkableTime l >= ms_hs_date summary ->
1045 -- we have an old BCO that is up to date with respect
1046 -- to the source: do a recompilation check as normal.
1050 -- no existing code at all: we must recompile.
1052 is_stable_obj = this_mod `elem` stable_obj
1053 is_stable_bco = this_mod `elem` stable_bco
1055 old_hmi = lookupModuleEnv old_hpt this_mod
1057 -- Run hsc to compile a module
1058 upsweep_compile hsc_env old_hpt this_mod msg_act summary
1060 mb_old_linkable = do
1062 -- The old interface is ok if it's in the old HPT
1063 -- a) we're compiling a source file, and the old HPT
1064 -- entry is for a source file
1065 -- b) we're compiling a hs-boot file
1066 -- Case (b) allows an hs-boot file to get the interface of its
1067 -- real source file on the second iteration of the compilation
1068 -- manager, but that does no harm. Otherwise the hs-boot file
1069 -- will always be recompiled
1072 = case lookupModuleEnv old_hpt this_mod of
1074 Just hm_info | isBootSummary summary -> Just iface
1075 | not (mi_boot iface) -> Just iface
1076 | otherwise -> Nothing
1078 iface = hm_iface hm_info
1080 compresult <- compile hsc_env msg_act summary mb_old_linkable mb_old_iface
1084 -- Compilation failed. Compile may still have updated the PCS, tho.
1085 CompErrs -> return Nothing
1087 -- Compilation "succeeded", and may or may not have returned a new
1088 -- linkable (depending on whether compilation was actually performed
1090 CompOK new_details new_iface new_linkable
1091 -> do let new_info = HomeModInfo { hm_iface = new_iface,
1092 hm_details = new_details,
1093 hm_linkable = new_linkable }
1094 return (Just new_info)
1097 -- Filter modules in the HPT
1098 retainInTopLevelEnvs :: [Module] -> HomePackageTable -> HomePackageTable
1099 retainInTopLevelEnvs keep_these hpt
1100 = mkModuleEnv [ (mod, expectJust "retain" mb_mod_info)
1102 , let mb_mod_info = lookupModuleEnv hpt mod
1103 , isJust mb_mod_info ]
1105 -- ---------------------------------------------------------------------------
1106 -- Topological sort of the module graph
1109 :: Bool -- Drop hi-boot nodes? (see below)
1113 -- Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
1114 -- The resulting list of strongly-connected-components is in topologically
1115 -- sorted order, starting with the module(s) at the bottom of the
1116 -- dependency graph (ie compile them first) and ending with the ones at
1119 -- Drop hi-boot nodes (first boolean arg)?
1121 -- False: treat the hi-boot summaries as nodes of the graph,
1122 -- so the graph must be acyclic
1124 -- True: eliminate the hi-boot nodes, and instead pretend
1125 -- the a source-import of Foo is an import of Foo
1126 -- The resulting graph has no hi-boot nodes, but can by cyclic
1128 topSortModuleGraph drop_hs_boot_nodes summaries Nothing
1129 = stronglyConnComp (fst (moduleGraphNodes drop_hs_boot_nodes summaries))
1130 topSortModuleGraph drop_hs_boot_nodes summaries (Just mod)
1131 = stronglyConnComp (map vertex_fn (reachable graph root))
1133 -- restrict the graph to just those modules reachable from
1134 -- the specified module. We do this by building a graph with
1135 -- the full set of nodes, and determining the reachable set from
1136 -- the specified node.
1137 (nodes, lookup_key) = moduleGraphNodes drop_hs_boot_nodes summaries
1138 (graph, vertex_fn, key_fn) = graphFromEdges' nodes
1140 | Just key <- lookup_key HsSrcFile mod, Just v <- key_fn key = v
1141 | otherwise = throwDyn (ProgramError "module does not exist")
1143 moduleGraphNodes :: Bool -> [ModSummary]
1144 -> ([(ModSummary, Int, [Int])], HscSource -> Module -> Maybe Int)
1145 moduleGraphNodes drop_hs_boot_nodes summaries = (nodes, lookup_key)
1147 -- Drop hs-boot nodes by using HsSrcFile as the key
1148 hs_boot_key | drop_hs_boot_nodes = HsSrcFile
1149 | otherwise = HsBootFile
1151 -- We use integers as the keys for the SCC algorithm
1152 nodes :: [(ModSummary, Int, [Int])]
1153 nodes = [(s, expectJust "topSort" (lookup_key (ms_hsc_src s) (ms_mod s)),
1154 out_edge_keys hs_boot_key (map unLoc (ms_srcimps s)) ++
1155 out_edge_keys HsSrcFile (map unLoc (ms_imps s)) )
1157 , not (isBootSummary s && drop_hs_boot_nodes) ]
1158 -- Drop the hi-boot ones if told to do so
1160 key_map :: NodeMap Int
1161 key_map = listToFM ([(ms_mod s, ms_hsc_src s) | s <- summaries]
1164 lookup_key :: HscSource -> Module -> Maybe Int
1165 lookup_key hs_src mod = lookupFM key_map (mod, hs_src)
1167 out_edge_keys :: HscSource -> [Module] -> [Int]
1168 out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
1169 -- If we want keep_hi_boot_nodes, then we do lookup_key with
1170 -- the IsBootInterface parameter True; else False
1173 type NodeKey = (Module, HscSource) -- The nodes of the graph are
1174 type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
1176 msKey :: ModSummary -> NodeKey
1177 msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (mod,boot)
1179 emptyNodeMap :: NodeMap a
1180 emptyNodeMap = emptyFM
1182 mkNodeMap :: [ModSummary] -> NodeMap ModSummary
1183 mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
1185 nodeMapElts :: NodeMap a -> [a]
1186 nodeMapElts = eltsFM
1188 -- -----------------------------------------------------------------
1189 -- The unlinked image
1191 -- The compilation manager keeps a list of compiled, but as-yet unlinked
1192 -- binaries (byte code or object code). Even when it links bytecode
1193 -- it keeps the unlinked version so it can re-link it later without
1196 type UnlinkedImage = [Linkable] -- the unlinked images (should be a set, really)
1198 findModuleLinkable_maybe :: [Linkable] -> Module -> Maybe Linkable
1199 findModuleLinkable_maybe lis mod
1200 = case [LM time nm us | LM time nm us <- lis, nm == mod] of
1203 many -> pprPanic "findModuleLinkable" (ppr mod)
1205 delModuleLinkable :: [Linkable] -> Module -> [Linkable]
1206 delModuleLinkable ls mod = [ l | l@(LM _ nm _) <- ls, nm /= mod ]
1208 -----------------------------------------------------------------------------
1209 -- Downsweep (dependency analysis)
1211 -- Chase downwards from the specified root set, returning summaries
1212 -- for all home modules encountered. Only follow source-import
1215 -- We pass in the previous collection of summaries, which is used as a
1216 -- cache to avoid recalculating a module summary if the source is
1219 -- The returned list of [ModSummary] nodes has one node for each home-package
1220 -- module, plus one for any hs-boot files. The imports of these nodes
1221 -- are all there, including the imports of non-home-package modules.
1224 -> [ModSummary] -- Old summaries
1225 -> [Module] -- Ignore dependencies on these; treat them as
1226 -- if they were package modules
1227 -> IO (Either Messages [ModSummary])
1228 downsweep hsc_env old_summaries excl_mods
1229 = -- catch error messages and return them
1230 handleDyn (\err_msg -> return (Left (emptyBag, unitBag err_msg))) $ do
1231 rootSummaries <- mapM getRootSummary roots
1232 checkDuplicates rootSummaries
1233 summs <- loop (concatMap msDeps rootSummaries) (mkNodeMap rootSummaries)
1234 return (Right summs)
1236 roots = hsc_targets hsc_env
1238 old_summary_map :: NodeMap ModSummary
1239 old_summary_map = mkNodeMap old_summaries
1241 getRootSummary :: Target -> IO ModSummary
1242 getRootSummary (Target (TargetFile file mb_phase) maybe_buf)
1243 = do exists <- doesFileExist file
1245 then summariseFile hsc_env old_summaries file mb_phase maybe_buf
1247 throwDyn (CmdLineError ("can't find file: " ++ file))
1248 getRootSummary (Target (TargetModule modl) maybe_buf)
1249 = do maybe_summary <- summariseModule hsc_env old_summary_map False
1250 (L rootLoc modl) maybe_buf excl_mods
1251 case maybe_summary of
1252 Nothing -> packageModErr modl
1255 rootLoc = mkGeneralSrcSpan FSLIT("<command line>")
1257 -- In a root module, the filename is allowed to diverge from the module
1258 -- name, so we have to check that there aren't multiple root files
1259 -- defining the same module (otherwise the duplicates will be silently
1260 -- ignored, leading to confusing behaviour).
1261 checkDuplicates :: [ModSummary] -> IO ()
1262 checkDuplicates summaries = mapM_ check summaries
1267 many -> multiRootsErr modl many
1268 where modl = ms_mod summ
1270 [ expectJust "checkDup" (ml_hs_file (ms_location summ'))
1271 | summ' <- summaries, ms_mod summ' == modl ]
1273 loop :: [(Located Module,IsBootInterface)]
1274 -- Work list: process these modules
1275 -> NodeMap ModSummary
1278 -- The result includes the worklist, except
1279 -- for those mentioned in the visited set
1280 loop [] done = return (nodeMapElts done)
1281 loop ((wanted_mod, is_boot) : ss) done
1282 | key `elemFM` done = loop ss done
1283 | otherwise = do { mb_s <- summariseModule hsc_env old_summary_map
1284 is_boot wanted_mod Nothing excl_mods
1286 Nothing -> loop ss done
1287 Just s -> loop (msDeps s ++ ss)
1288 (addToFM done key s) }
1290 key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
1292 msDeps :: ModSummary -> [(Located Module, IsBootInterface)]
1293 -- (msDeps s) returns the dependencies of the ModSummary s.
1294 -- A wrinkle is that for a {-# SOURCE #-} import we return
1295 -- *both* the hs-boot file
1296 -- *and* the source file
1297 -- as "dependencies". That ensures that the list of all relevant
1298 -- modules always contains B.hs if it contains B.hs-boot.
1299 -- Remember, this pass isn't doing the topological sort. It's
1300 -- just gathering the list of all relevant ModSummaries
1302 concat [ [(m,True), (m,False)] | m <- ms_srcimps s ]
1303 ++ [ (m,False) | m <- ms_imps s ]
1305 -----------------------------------------------------------------------------
1306 -- Summarising modules
1308 -- We have two types of summarisation:
1310 -- * Summarise a file. This is used for the root module(s) passed to
1311 -- cmLoadModules. The file is read, and used to determine the root
1312 -- module name. The module name may differ from the filename.
1314 -- * Summarise a module. We are given a module name, and must provide
1315 -- a summary. The finder is used to locate the file in which the module
1320 -> [ModSummary] -- old summaries
1321 -> FilePath -- source file name
1322 -> Maybe Phase -- start phase
1323 -> Maybe (StringBuffer,ClockTime)
1326 summariseFile hsc_env old_summaries file mb_phase maybe_buf
1327 -- we can use a cached summary if one is available and the
1328 -- source file hasn't changed, But we have to look up the summary
1329 -- by source file, rather than module name as we do in summarise.
1330 | Just old_summary <- findSummaryBySourceFile old_summaries file
1332 let location = ms_location old_summary
1334 -- return the cached summary if the source didn't change
1335 src_timestamp <- case maybe_buf of
1336 Just (_,t) -> return t
1337 Nothing -> getModificationTime file
1339 if ms_hs_date old_summary == src_timestamp
1340 then do -- update the object-file timestamp
1341 obj_timestamp <- getObjTimestamp location False
1342 return old_summary{ ms_obj_date = obj_timestamp }
1350 let dflags = hsc_dflags hsc_env
1352 (dflags', hspp_fn, buf)
1353 <- preprocessFile dflags file mb_phase maybe_buf
1355 (srcimps,the_imps, L _ mod) <- getImports dflags' buf hspp_fn
1357 -- Make a ModLocation for this file
1358 location <- mkHomeModLocation dflags mod file
1360 -- Tell the Finder cache where it is, so that subsequent calls
1361 -- to findModule will find it, even if it's not on any search path
1362 addHomeModuleToFinder hsc_env mod location
1364 src_timestamp <- case maybe_buf of
1365 Just (_,t) -> return t
1366 Nothing -> getModificationTime file
1368 obj_timestamp <- modificationTimeIfExists (ml_obj_file location)
1370 return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
1371 ms_location = location,
1372 ms_hspp_file = Just hspp_fn,
1373 ms_hspp_buf = Just buf,
1374 ms_srcimps = srcimps, ms_imps = the_imps,
1375 ms_hs_date = src_timestamp,
1376 ms_obj_date = obj_timestamp })
1378 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
1379 findSummaryBySourceFile summaries file
1380 = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
1381 fromJust (ml_hs_file (ms_location ms)) == file ] of
1385 -- Summarise a module, and pick up source and timestamp.
1388 -> NodeMap ModSummary -- Map of old summaries
1389 -> IsBootInterface -- True <=> a {-# SOURCE #-} import
1390 -> Located Module -- Imported module to be summarised
1391 -> Maybe (StringBuffer, ClockTime)
1392 -> [Module] -- Modules to exclude
1393 -> IO (Maybe ModSummary) -- Its new summary
1395 summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod) maybe_buf excl_mods
1396 | wanted_mod `elem` excl_mods
1399 | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
1400 = do -- Find its new timestamp; all the
1401 -- ModSummaries in the old map have valid ml_hs_files
1402 let location = ms_location old_summary
1403 src_fn = expectJust "summariseModule" (ml_hs_file location)
1405 -- return the cached summary if the source didn't change
1406 src_timestamp <- case maybe_buf of
1407 Just (_,t) -> return t
1408 Nothing -> getModificationTime src_fn
1410 if ms_hs_date old_summary == src_timestamp
1411 then do -- update the object-file timestamp
1412 obj_timestamp <- getObjTimestamp location is_boot
1413 return (Just old_summary{ ms_obj_date = obj_timestamp })
1415 -- source changed: re-summarise
1416 new_summary location src_fn maybe_buf src_timestamp
1419 = do found <- findModule hsc_env wanted_mod True {-explicit-}
1422 | not (isHomePackage pkg) -> return Nothing
1423 -- Drop external-pkg
1424 | isJust (ml_hs_file location) -> just_found location
1426 err -> noModError dflags loc wanted_mod err
1429 dflags = hsc_dflags hsc_env
1431 hsc_src = if is_boot then HsBootFile else HsSrcFile
1433 just_found location = do
1434 -- Adjust location to point to the hs-boot source file,
1435 -- hi file, object file, when is_boot says so
1436 let location' | is_boot = addBootSuffixLocn location
1437 | otherwise = location
1438 src_fn = expectJust "summarise2" (ml_hs_file location')
1440 -- Check that it exists
1441 -- It might have been deleted since the Finder last found it
1442 maybe_t <- modificationTimeIfExists src_fn
1444 Nothing -> noHsFileErr loc src_fn
1445 Just t -> new_summary location' src_fn Nothing t
1448 new_summary location src_fn maybe_bug src_timestamp
1450 -- Preprocess the source file and get its imports
1451 -- The dflags' contains the OPTIONS pragmas
1452 (dflags', hspp_fn, buf) <- preprocessFile dflags src_fn Nothing maybe_buf
1453 (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn
1455 when (mod_name /= wanted_mod) $
1456 throwDyn $ mkPlainErrMsg mod_loc $
1457 text "file name does not match module name"
1458 <+> quotes (ppr mod_name)
1460 -- Find the object timestamp, and return the summary
1461 obj_timestamp <- getObjTimestamp location is_boot
1463 return (Just ( ModSummary { ms_mod = wanted_mod,
1464 ms_hsc_src = hsc_src,
1465 ms_location = location,
1466 ms_hspp_file = Just hspp_fn,
1467 ms_hspp_buf = Just buf,
1468 ms_srcimps = srcimps,
1470 ms_hs_date = src_timestamp,
1471 ms_obj_date = obj_timestamp }))
1474 getObjTimestamp location is_boot
1475 = if is_boot then return Nothing
1476 else modificationTimeIfExists (ml_obj_file location)
1479 preprocessFile :: DynFlags -> FilePath -> Maybe Phase -> Maybe (StringBuffer,ClockTime)
1480 -> IO (DynFlags, FilePath, StringBuffer)
1481 preprocessFile dflags src_fn mb_phase Nothing
1483 (dflags', hspp_fn) <- preprocess dflags (src_fn, mb_phase)
1484 buf <- hGetStringBuffer hspp_fn
1485 return (dflags', hspp_fn, buf)
1487 preprocessFile dflags src_fn mb_phase (Just (buf, time))
1489 -- case we bypass the preprocessing stage?
1491 local_opts = getOptionsFromStringBuffer buf
1493 (dflags', errs) <- parseDynamicFlags dflags (map snd local_opts)
1497 | Just (Unlit _) <- mb_phase = True
1498 | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
1499 -- note: local_opts is only required if there's no Unlit phase
1500 | dopt Opt_Cpp dflags' = True
1501 | dopt Opt_Pp dflags' = True
1504 when needs_preprocessing $
1505 ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
1507 return (dflags', src_fn, buf)
1510 -----------------------------------------------------------------------------
1512 -----------------------------------------------------------------------------
1514 noModError :: DynFlags -> SrcSpan -> Module -> FindResult -> IO ab
1515 -- ToDo: we don't have a proper line number for this error
1516 noModError dflags loc wanted_mod err
1517 = throwDyn $ mkPlainErrMsg loc $ cantFindError dflags wanted_mod err
1519 noHsFileErr loc path
1520 = throwDyn $ mkPlainErrMsg loc $ text "Can't find" <+> text path
1523 = throwDyn (CmdLineError (showSDoc (text "module" <+>
1524 quotes (ppr mod) <+>
1525 text "is a package module")))
1527 multiRootsErr mod files
1528 = throwDyn (ProgramError (showSDoc (
1529 text "module" <+> quotes (ppr mod) <+>
1530 text "is defined in multiple files:" <+>
1531 sep (map text files))))
1533 cyclicModuleErr :: [ModSummary] -> SDoc
1535 = hang (ptext SLIT("Module imports form a cycle for modules:"))
1536 2 (vcat (map show_one ms))
1538 show_one ms = sep [ show_mod (ms_hsc_src ms) (ms_mod ms),
1539 nest 2 $ ptext SLIT("imports:") <+>
1540 (pp_imps HsBootFile (ms_srcimps ms)
1541 $$ pp_imps HsSrcFile (ms_imps ms))]
1542 show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
1543 pp_imps src mods = fsep (map (show_mod src) mods)
1546 -- | Inform GHC that the working directory has changed. GHC will flush
1547 -- its cache of module locations, since it may no longer be valid.
1548 -- Note: if you change the working directory, you should also unload
1549 -- the current program (set targets to empty, followed by load).
1550 workingDirectoryChanged :: Session -> IO ()
1551 workingDirectoryChanged s = withSession s $ \hsc_env ->
1552 flushFinderCache (hsc_FC hsc_env)
1554 -- -----------------------------------------------------------------------------
1555 -- inspecting the session
1557 -- | Get the module dependency graph.
1558 getModuleGraph :: Session -> IO ModuleGraph -- ToDo: DiGraph ModSummary
1559 getModuleGraph s = withSession s (return . hsc_mod_graph)
1561 isLoaded :: Session -> Module -> IO Bool
1562 isLoaded s m = withSession s $ \hsc_env ->
1563 return $! isJust (lookupModuleEnv (hsc_HPT hsc_env) m)
1565 getBindings :: Session -> IO [TyThing]
1566 getBindings s = withSession s (return . nameEnvElts . ic_type_env . hsc_IC)
1568 getPrintUnqual :: Session -> IO PrintUnqualified
1569 getPrintUnqual s = withSession s (return . icPrintUnqual . hsc_IC)
1571 -- | Container for information about a 'Module'.
1572 data ModuleInfo = ModuleInfo {
1573 minf_type_env :: TypeEnv,
1574 minf_exports :: NameSet,
1575 minf_rdr_env :: Maybe GlobalRdrEnv, -- Nothing for a compiled/package mod
1576 minf_instances :: [Instance]
1577 -- ToDo: this should really contain the ModIface too
1579 -- We don't want HomeModInfo here, because a ModuleInfo applies
1580 -- to package modules too.
1582 -- | Request information about a loaded 'Module'
1583 getModuleInfo :: Session -> Module -> IO (Maybe ModuleInfo)
1584 getModuleInfo s mdl = withSession s $ \hsc_env -> do
1585 let mg = hsc_mod_graph hsc_env
1586 if mdl `elem` map ms_mod mg
1587 then getHomeModuleInfo hsc_env mdl
1589 if isHomeModule (hsc_dflags hsc_env) mdl
1591 else getPackageModuleInfo hsc_env mdl
1592 -- getPackageModuleInfo will attempt to find the interface, so
1593 -- we don't want to call it for a home module, just in case there
1594 -- was a problem loading the module and the interface doesn't
1595 -- exist... hence the isHomeModule test here.
1597 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
1598 getPackageModuleInfo hsc_env mdl = do
1600 (_msgs, mb_names) <- getModuleExports hsc_env mdl
1602 Nothing -> return Nothing
1604 eps <- readIORef (hsc_EPS hsc_env)
1607 n_list = nameSetToList names
1608 tys = [ ty | name <- n_list,
1609 Just ty <- [lookupTypeEnv pte name] ]
1611 return (Just (ModuleInfo {
1612 minf_type_env = mkTypeEnv tys,
1613 minf_exports = names,
1614 minf_rdr_env = Just $! nameSetToGlobalRdrEnv names mdl,
1615 minf_instances = error "getModuleInfo: instances for package module unimplemented"
1618 -- bogusly different for non-GHCI (ToDo)
1622 getHomeModuleInfo hsc_env mdl =
1623 case lookupModuleEnv (hsc_HPT hsc_env) mdl of
1624 Nothing -> return Nothing
1626 let details = hm_details hmi
1627 return (Just (ModuleInfo {
1628 minf_type_env = md_types details,
1629 minf_exports = md_exports details,
1630 minf_rdr_env = mi_globals $! hm_iface hmi,
1631 minf_instances = md_insts details
1634 -- | The list of top-level entities defined in a module
1635 modInfoTyThings :: ModuleInfo -> [TyThing]
1636 modInfoTyThings minf = typeEnvElts (minf_type_env minf)
1638 modInfoTopLevelScope :: ModuleInfo -> Maybe [Name]
1639 modInfoTopLevelScope minf
1640 = fmap (map gre_name . globalRdrEnvElts) (minf_rdr_env minf)
1642 modInfoExports :: ModuleInfo -> [Name]
1643 modInfoExports minf = nameSetToList $! minf_exports minf
1645 -- | Returns the instances defined by the specified module.
1646 -- Warning: currently unimplemented for package modules.
1647 modInfoInstances :: ModuleInfo -> [Instance]
1648 modInfoInstances = minf_instances
1650 modInfoIsExportedName :: ModuleInfo -> Name -> Bool
1651 modInfoIsExportedName minf name = elemNameSet name (minf_exports minf)
1653 modInfoPrintUnqualified :: ModuleInfo -> Maybe PrintUnqualified
1654 modInfoPrintUnqualified minf = fmap unQualInScope (minf_rdr_env minf)
1656 modInfoLookupName :: Session -> ModuleInfo -> Name -> IO (Maybe TyThing)
1657 modInfoLookupName s minf name = withSession s $ \hsc_env -> do
1658 case lookupTypeEnv (minf_type_env minf) name of
1659 Just tyThing -> return (Just tyThing)
1661 eps <- readIORef (hsc_EPS hsc_env)
1662 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1664 isDictonaryId :: Id -> Bool
1666 = case tcSplitSigmaTy (idType id) of { (tvs, theta, tau) -> isDictTy tau }
1668 -- | Looks up a global name: that is, any top-level name in any
1669 -- visible module. Unlike 'lookupName', lookupGlobalName does not use
1670 -- the interactive context, and therefore does not require a preceding
1672 lookupGlobalName :: Session -> Name -> IO (Maybe TyThing)
1673 lookupGlobalName s name = withSession s $ \hsc_env -> do
1674 eps <- readIORef (hsc_EPS hsc_env)
1675 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1681 | BinaryCode FilePath
1683 -- ToDo: typechecks abstract syntax or renamed abstract syntax. Issues:
1684 -- - typechecked syntax includes extra dictionary translation and
1685 -- AbsBinds which need to be translated back into something closer to
1686 -- the original source.
1689 -- - Data and Typeable instances for HsSyn.
1692 -- - things that aren't in the output of the renamer:
1693 -- - the export list
1697 -- - things that aren't in the output of the typechecker right now:
1698 -- - the export list
1700 -- - type signatures
1701 -- - type/data/newtype declarations
1702 -- - class declarations
1704 -- - extra things in the typechecker's output:
1705 -- - default methods are turned into top-level decls.
1706 -- - dictionary bindings
1708 -- ToDo: check for small transformations that happen to the syntax in
1709 -- the typechecker (eg. -e ==> negate e, perhaps for fromIntegral)
1711 -- ToDo: maybe use TH syntax instead of IfaceSyn? There's already a way
1712 -- to get from TyCons, Ids etc. to TH syntax (reify).
1714 -- :browse will use either lm_toplev or inspect lm_interface, depending
1715 -- on whether the module is interpreted or not.
1717 -- This is for reconstructing refactored source code
1718 -- Calls the lexer repeatedly.
1719 -- ToDo: add comment tokens to token stream
1720 getTokenStream :: Session -> Module -> IO [Located Token]
1723 -- -----------------------------------------------------------------------------
1724 -- Interactive evaluation
1728 -- | Set the interactive evaluation context.
1730 -- Setting the context doesn't throw away any bindings; the bindings
1731 -- we've built up in the InteractiveContext simply move to the new
1732 -- module. They always shadow anything in scope in the current context.
1733 setContext :: Session
1734 -> [Module] -- entire top level scope of these modules
1735 -> [Module] -- exports only of these modules
1737 setContext (Session ref) toplevs exports = do
1738 hsc_env <- readIORef ref
1739 let old_ic = hsc_IC hsc_env
1740 hpt = hsc_HPT hsc_env
1742 mapM_ (checkModuleExists hsc_env hpt) exports
1743 export_env <- mkExportEnv hsc_env exports
1744 toplev_envs <- mapM (mkTopLevEnv hpt) toplevs
1745 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
1746 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplevs,
1747 ic_exports = exports,
1748 ic_rn_gbl_env = all_env } }
1750 -- Make a GlobalRdrEnv based on the exports of the modules only.
1751 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
1752 mkExportEnv hsc_env mods = do
1753 stuff <- mapM (getModuleExports hsc_env) mods
1755 (_msgs, mb_name_sets) = unzip stuff
1756 gres = [ nameSetToGlobalRdrEnv name_set mod
1757 | (Just name_set, mod) <- zip mb_name_sets mods ]
1759 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
1761 nameSetToGlobalRdrEnv :: NameSet -> Module -> GlobalRdrEnv
1762 nameSetToGlobalRdrEnv names mod =
1763 mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod }
1764 | name <- nameSetToList names ]
1766 vanillaProv :: Module -> Provenance
1767 -- We're building a GlobalRdrEnv as if the user imported
1768 -- all the specified modules into the global interactive module
1769 vanillaProv mod = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
1771 decl = ImpDeclSpec { is_mod = mod, is_as = mod,
1773 is_dloc = srcLocSpan interactiveSrcLoc }
1775 checkModuleExists :: HscEnv -> HomePackageTable -> Module -> IO ()
1776 checkModuleExists hsc_env hpt mod =
1777 case lookupModuleEnv hpt mod of
1778 Just mod_info -> return ()
1779 _not_a_home_module -> do
1780 res <- findPackageModule hsc_env mod True
1782 Found _ _ -> return ()
1783 err -> let msg = cantFindError (hsc_dflags hsc_env) mod err in
1784 throwDyn (CmdLineError (showSDoc msg))
1786 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
1787 mkTopLevEnv hpt modl
1788 = case lookupModuleEnv hpt modl of
1790 throwDyn (ProgramError ("mkTopLevEnv: not a home module "
1791 ++ showSDoc (pprModule modl)))
1793 case mi_globals (hm_iface details) of
1795 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
1796 ++ showSDoc (pprModule modl)))
1797 Just env -> return env
1799 -- | Get the interactive evaluation context, consisting of a pair of the
1800 -- set of modules from which we take the full top-level scope, and the set
1801 -- of modules from which we take just the exports respectively.
1802 getContext :: Session -> IO ([Module],[Module])
1803 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
1804 return (ic_toplev_scope ic, ic_exports ic))
1806 -- | Returns 'True' if the specified module is interpreted, and hence has
1807 -- its full top-level scope available.
1808 moduleIsInterpreted :: Session -> Module -> IO Bool
1809 moduleIsInterpreted s modl = withSession s $ \h ->
1810 case lookupModuleEnv (hsc_HPT h) modl of
1811 Just details -> return (isJust (mi_globals (hm_iface details)))
1812 _not_a_home_module -> return False
1814 -- | Looks up an identifier in the current interactive context (for :info)
1815 {-# DEPRECATED getInfo "we should be using parseName/lookupName instead" #-}
1816 getInfo :: Session -> String -> IO [GetInfoResult]
1817 getInfo s id = withSession s $ \hsc_env -> hscGetInfo hsc_env id
1819 -- | Returns all names in scope in the current interactive context
1820 getNamesInScope :: Session -> IO [Name]
1821 getNamesInScope s = withSession s $ \hsc_env -> do
1822 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
1824 -- | Parses a string as an identifier, and returns the list of 'Name's that
1825 -- the identifier can refer to in the current interactive context.
1826 parseName :: Session -> String -> IO [Name]
1827 parseName s str = withSession s $ \hsc_env -> do
1828 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
1829 case maybe_rdr_name of
1830 Nothing -> return []
1831 Just (L _ rdr_name) -> do
1832 mb_names <- tcRnLookupRdrName hsc_env rdr_name
1834 Nothing -> return []
1835 Just ns -> return ns
1836 -- ToDo: should return error messages
1838 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
1839 -- entity known to GHC, including 'Name's defined using 'runStmt'.
1840 lookupName :: Session -> Name -> IO (Maybe TyThing)
1841 lookupName s name = withSession s $ \hsc_env -> do
1842 case lookupTypeEnv (ic_type_env (hsc_IC hsc_env)) name of
1843 Just tt -> return (Just tt)
1845 eps <- readIORef (hsc_EPS hsc_env)
1846 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1848 -- -----------------------------------------------------------------------------
1849 -- Getting the type of an expression
1851 -- | Get the type of an expression
1852 exprType :: Session -> String -> IO (Maybe Type)
1853 exprType s expr = withSession s $ \hsc_env -> do
1854 maybe_stuff <- hscTcExpr hsc_env expr
1856 Nothing -> return Nothing
1857 Just ty -> return (Just tidy_ty)
1859 tidy_ty = tidyType emptyTidyEnv ty
1860 dflags = hsc_dflags hsc_env
1862 -- -----------------------------------------------------------------------------
1863 -- Getting the kind of a type
1865 -- | Get the kind of a type
1866 typeKind :: Session -> String -> IO (Maybe Kind)
1867 typeKind s str = withSession s $ \hsc_env -> do
1868 maybe_stuff <- hscKcType hsc_env str
1870 Nothing -> return Nothing
1871 Just kind -> return (Just kind)
1873 -----------------------------------------------------------------------------
1874 -- cmCompileExpr: compile an expression and deliver an HValue
1876 compileExpr :: Session -> String -> IO (Maybe HValue)
1877 compileExpr s expr = withSession s $ \hsc_env -> do
1878 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
1880 Nothing -> return Nothing
1881 Just (new_ic, names, hval) -> do
1883 hvals <- (unsafeCoerce# hval) :: IO [HValue]
1885 case (names,hvals) of
1886 ([n],[hv]) -> return (Just hv)
1887 _ -> panic "compileExpr"
1889 -- -----------------------------------------------------------------------------
1890 -- running a statement interactively
1893 = RunOk [Name] -- ^ names bound by this evaluation
1894 | RunFailed -- ^ statement failed compilation
1895 | RunException Exception -- ^ statement raised an exception
1897 -- | Run a statement in the current interactive context. Statemenet
1898 -- may bind multple values.
1899 runStmt :: Session -> String -> IO RunResult
1900 runStmt (Session ref) expr
1902 hsc_env <- readIORef ref
1904 -- Turn off -fwarn-unused-bindings when running a statement, to hide
1905 -- warnings about the implicit bindings we introduce.
1906 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
1907 hsc_env' = hsc_env{ hsc_dflags = dflags' }
1909 maybe_stuff <- hscStmt hsc_env' expr
1912 Nothing -> return RunFailed
1913 Just (new_hsc_env, names, hval) -> do
1915 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
1916 either_hvals <- sandboxIO thing_to_run
1918 case either_hvals of
1920 -- on error, keep the *old* interactive context,
1921 -- so that 'it' is not bound to something
1922 -- that doesn't exist.
1923 return (RunException e)
1926 -- Get the newly bound things, and bind them.
1927 -- Don't need to delete any shadowed bindings;
1928 -- the new ones override the old ones.
1929 extendLinkEnv (zip names hvals)
1931 writeIORef ref new_hsc_env
1932 return (RunOk names)
1935 -- We run the statement in a "sandbox" to protect the rest of the
1936 -- system from anything the expression might do. For now, this
1937 -- consists of just wrapping it in an exception handler, but see below
1938 -- for another version.
1940 sandboxIO :: IO a -> IO (Either Exception a)
1941 sandboxIO thing = Exception.try thing
1944 -- This version of sandboxIO runs the expression in a completely new
1945 -- RTS main thread. It is disabled for now because ^C exceptions
1946 -- won't be delivered to the new thread, instead they'll be delivered
1947 -- to the (blocked) GHCi main thread.
1949 -- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
1951 sandboxIO :: IO a -> IO (Either Int (Either Exception a))
1952 sandboxIO thing = do
1953 st_thing <- newStablePtr (Exception.try thing)
1954 alloca $ \ p_st_result -> do
1955 stat <- rts_evalStableIO st_thing p_st_result
1956 freeStablePtr st_thing
1958 then do st_result <- peek p_st_result
1959 result <- deRefStablePtr st_result
1960 freeStablePtr st_result
1961 return (Right result)
1963 return (Left (fromIntegral stat))
1965 foreign import "rts_evalStableIO" {- safe -}
1966 rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
1967 -- more informative than the C type!
1970 -- ---------------------------------------------------------------------------
1971 -- cmBrowseModule: get all the TyThings defined in a module
1973 {-# DEPRECATED browseModule "we should be using getModuleInfo instead" #-}
1974 browseModule :: Session -> Module -> Bool -> IO [IfaceDecl]
1975 browseModule s modl exports_only = withSession s $ \hsc_env -> do
1976 mb_decls <- getModuleContents hsc_env modl exports_only
1978 Nothing -> return [] -- An error of some kind
1979 Just ds -> return ds
1982 -----------------------------------------------------------------------------
1983 -- show a module and it's source/object filenames
1985 showModule :: Session -> ModSummary -> IO String
1986 showModule s mod_summary = withSession s $ \hsc_env -> do
1987 case lookupModuleEnv (hsc_HPT hsc_env) (ms_mod mod_summary) of
1988 Nothing -> panic "missing linkable"
1989 Just mod_info -> return (showModMsg obj_linkable mod_summary)
1991 obj_linkable = isObjectLinkable (fromJust (hm_linkable mod_info))