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,
60 PrintUnqualified, alwaysQualify,
62 -- * Interactive evaluation
63 getBindings, getPrintUnqual,
65 setContext, getContext,
68 getInfo, GetInfoResult,
80 -- * Abstract syntax elements
83 Module, mkModule, pprModule,
90 isImplicitId, isDeadBinder,
91 isSpecPragmaId, isExportedId, isLocalId, isGlobalId,
93 isPrimOpId, isFCallId,
94 isDataConWorkId, idDataCon,
95 isBottomingId, isDictonaryId,
97 -- ** Type constructors
99 isClassTyCon, isSynTyCon, isNewTyCon,
101 -- ** Data constructors
106 classSCTheta, classTvsFds,
111 -- ** Types and Kinds
119 module HsSyn, -- ToDo: remove extraneous bits
122 GhcException(..), showGhcException,
132 * inline bits of HscMain here to simplify layering: hscGetInfo,
134 * we need to expose DynFlags, so should parseDynamicFlags really be
135 part of this interface?
136 * what StaticFlags should we expose, if any?
139 #include "HsVersions.h"
142 import qualified Linker
143 import Linker ( HValue, extendLinkEnv )
144 import TcRnDriver ( getModuleContents, tcRnLookupRdrName,
146 import RdrName ( plusGlobalRdrEnv, Provenance(..),
147 ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
148 emptyGlobalRdrEnv, mkGlobalRdrEnv )
149 import HscMain ( hscGetInfo, GetInfoResult, hscParseIdentifier,
150 hscStmt, hscTcExpr, hscKcType )
151 import Type ( tidyType )
152 import VarEnv ( emptyTidyEnv )
153 import GHC.Exts ( unsafeCoerce# )
154 import IfaceSyn ( IfaceDecl )
157 import Packages ( initPackages, isHomeModule )
158 import NameSet ( NameSet, nameSetToList, elemNameSet )
159 import RdrName ( GlobalRdrEnv, GlobalRdrElt(..), RdrName,
162 import Type ( Kind, Type, dropForAlls )
163 import Id ( Id, idType, isImplicitId, isDeadBinder,
164 isSpecPragmaId, isExportedId, isLocalId, isGlobalId,
166 isPrimOpId, isFCallId,
167 isDataConWorkId, idDataCon,
169 import TyCon ( TyCon, isClassTyCon, isSynTyCon, isNewTyCon )
170 import Class ( Class, classSCTheta, classTvsFds )
171 import DataCon ( DataCon )
172 import Name ( Name, nameModule )
173 import NameEnv ( nameEnvElts )
174 import InstEnv ( Instance )
176 import DriverPipeline
177 import DriverPhases ( Phase(..), isHaskellSrcFilename, startPhase )
178 import GetImports ( getImports )
179 import Packages ( isHomePackage )
181 import HscMain ( newHscEnv, hscFileCheck, HscResult(..) )
185 import SysTools ( initSysTools, cleanTempFiles )
190 import Bag ( unitBag, emptyBag )
191 import ErrUtils ( showPass, Messages, putMsg, debugTraceMsg,
192 mkPlainErrMsg, pprBagOfErrors )
193 import qualified ErrUtils
195 import StringBuffer ( StringBuffer, hGetStringBuffer )
197 import SysTools ( cleanTempFilesExcept )
198 import BasicTypes ( SuccessFlag(..), succeeded, failed )
199 import TcType ( tcSplitSigmaTy, isDictTy )
200 import FastString ( mkFastString )
202 import Directory ( getModificationTime, doesFileExist )
203 import Maybe ( isJust, isNothing, fromJust )
204 import Maybes ( orElse, expectJust, mapCatMaybes )
205 import List ( partition, nub )
206 import qualified List
207 import Monad ( unless, when )
208 import System ( exitWith, ExitCode(..) )
209 import Time ( ClockTime )
210 import EXCEPTION as Exception hiding (handle)
213 import Prelude hiding (init)
215 -- -----------------------------------------------------------------------------
216 -- Exception handlers
218 -- | Install some default exception handlers and run the inner computation.
219 -- Unless you want to handle exceptions yourself, you should wrap this around
220 -- the top level of your program. The default handlers output the error
221 -- message(s) to stderr and exit cleanly.
222 defaultErrorHandler :: IO a -> IO a
223 defaultErrorHandler inner =
224 -- top-level exception handler: any unrecognised exception is a compiler bug.
225 handle (\exception -> do
228 -- an IO exception probably isn't our fault, so don't panic
229 IOException _ -> putMsg (show exception)
230 AsyncException StackOverflow ->
231 putMsg "stack overflow: use +RTS -K<size> to increase it"
232 _other -> putMsg (show (Panic (show exception)))
233 exitWith (ExitFailure 1)
236 -- program errors: messages with locations attached. Sometimes it is
237 -- convenient to just throw these as exceptions.
238 handleDyn (\dyn -> do printErrs (pprBagOfErrors (unitBag dyn))
239 exitWith (ExitFailure 1)) $
241 -- error messages propagated as exceptions
242 handleDyn (\dyn -> do
245 PhaseFailed _ code -> exitWith code
246 Interrupted -> exitWith (ExitFailure 1)
247 _ -> do putMsg (show (dyn :: GhcException))
248 exitWith (ExitFailure 1)
252 -- | Install a default cleanup handler to remove temporary files
253 -- deposited by a GHC run. This is seperate from
254 -- 'defaultErrorHandler', because you might want to override the error
255 -- handling, but still get the ordinary cleanup behaviour.
256 defaultCleanupHandler :: DynFlags -> IO a -> IO a
257 defaultCleanupHandler dflags inner =
258 -- make sure we clean up after ourselves
259 later (unless (dopt Opt_KeepTmpFiles dflags) $
260 cleanTempFiles dflags)
261 -- exceptions will be blocked while we clean the temporary files,
262 -- so there shouldn't be any difficulty if we receive further
267 -- | Initialises GHC. This must be done /once/ only. Takes the
268 -- command-line arguments. All command-line arguments which aren't
269 -- understood by GHC will be returned.
271 init :: [String] -> IO [String]
274 installSignalHandlers
276 -- Grab the -B option if there is one
277 let (minusB_args, argv1) = partition (prefixMatch "-B") args
278 dflags0 <- initSysTools minusB_args defaultDynFlags
279 writeIORef v_initDynFlags dflags0
281 -- Parse the static flags
282 argv2 <- parseStaticFlags argv1
285 GLOBAL_VAR(v_initDynFlags, error "initDynFlags", DynFlags)
286 -- stores the DynFlags between the call to init and subsequent
287 -- calls to newSession.
289 -- | Starts a new session. A session consists of a set of loaded
290 -- modules, a set of options (DynFlags), and an interactive context.
291 -- ToDo: GhcMode should say "keep typechecked code" and\/or "keep renamed
293 newSession :: GhcMode -> IO Session
295 dflags0 <- readIORef v_initDynFlags
296 dflags <- initDynFlags dflags0
297 env <- newHscEnv dflags{ ghcMode=mode }
301 -- tmp: this breaks the abstraction, but required because DriverMkDepend
302 -- needs to call the Finder. ToDo: untangle this.
303 sessionHscEnv :: Session -> IO HscEnv
304 sessionHscEnv (Session ref) = readIORef ref
306 withSession :: Session -> (HscEnv -> IO a) -> IO a
307 withSession (Session ref) f = do h <- readIORef ref; f h
309 modifySession :: Session -> (HscEnv -> HscEnv) -> IO ()
310 modifySession (Session ref) f = do h <- readIORef ref; writeIORef ref $! f h
312 -- -----------------------------------------------------------------------------
315 -- | Grabs the DynFlags from the Session
316 getSessionDynFlags :: Session -> IO DynFlags
317 getSessionDynFlags s = withSession s (return . hsc_dflags)
319 -- | Updates the DynFlags in a Session
320 setSessionDynFlags :: Session -> DynFlags -> IO ()
321 setSessionDynFlags s dflags = modifySession s (\h -> h{ hsc_dflags = dflags })
323 -- | Messages during compilation (eg. warnings and progress messages)
324 -- are reported using this callback. By default, these messages are
325 -- printed to stderr.
326 setMsgHandler :: (String -> IO ()) -> IO ()
327 setMsgHandler = ErrUtils.setMsgHandler
329 -- -----------------------------------------------------------------------------
332 -- ToDo: think about relative vs. absolute file paths. And what
333 -- happens when the current directory changes.
335 -- | Sets the targets for this session. Each target may be a module name
336 -- or a filename. The targets correspond to the set of root modules for
337 -- the program\/library. Unloading the current program is achieved by
338 -- setting the current set of targets to be empty, followed by load.
339 setTargets :: Session -> [Target] -> IO ()
340 setTargets s targets = modifySession s (\h -> h{ hsc_targets = targets })
342 -- | returns the current set of targets
343 getTargets :: Session -> IO [Target]
344 getTargets s = withSession s (return . hsc_targets)
346 -- | Add another target
347 addTarget :: Session -> Target -> IO ()
349 = modifySession s (\h -> h{ hsc_targets = target : hsc_targets h })
352 removeTarget :: Session -> TargetId -> IO ()
353 removeTarget s target_id
354 = modifySession s (\h -> h{ hsc_targets = filter (hsc_targets h) })
356 filter targets = [ t | t@(Target id _) <- targets, id /= target_id ]
358 -- Attempts to guess what Target a string refers to. This function implements
359 -- the --make/GHCi command-line syntax for filenames:
361 -- - if the string looks like a Haskell source filename, then interpret
363 -- - if adding a .hs or .lhs suffix yields the name of an existing file,
365 -- - otherwise interpret the string as a module name
367 guessTarget :: String -> Maybe Phase -> IO Target
368 guessTarget file (Just phase)
369 = return (Target (TargetFile file (Just phase)) Nothing)
370 guessTarget file Nothing
371 | isHaskellSrcFilename file
372 = return (Target (TargetFile file Nothing) Nothing)
374 = do exists <- doesFileExist hs_file
376 then return (Target (TargetFile hs_file Nothing) Nothing)
378 exists <- doesFileExist lhs_file
380 then return (Target (TargetFile lhs_file Nothing) Nothing)
382 return (Target (TargetModule (mkModule file)) Nothing)
384 hs_file = file `joinFileExt` "hs"
385 lhs_file = file `joinFileExt` "lhs"
387 -- -----------------------------------------------------------------------------
388 -- Loading the program
390 -- Perform a dependency analysis starting from the current targets
391 -- and update the session with the new module graph.
392 depanal :: Session -> [Module] -> IO (Either Messages ModuleGraph)
393 depanal (Session ref) excluded_mods = do
394 hsc_env <- readIORef ref
396 dflags = hsc_dflags hsc_env
397 gmode = ghcMode (hsc_dflags hsc_env)
398 targets = hsc_targets hsc_env
399 old_graph = hsc_mod_graph hsc_env
401 showPass dflags "Chasing dependencies"
402 when (gmode == BatchCompile) $
403 debugTraceMsg dflags 1 (showSDoc (hcat [
404 text "Chasing modules from: ",
405 hcat (punctuate comma (map pprTarget targets))]))
407 r <- downsweep hsc_env old_graph excluded_mods
409 Right mod_graph -> writeIORef ref hsc_env{ hsc_mod_graph = mod_graph }
414 -- | The result of load.
416 = LoadOk Errors -- ^ all specified targets were loaded successfully.
417 | LoadFailed Errors -- ^ not all modules were loaded.
419 type Errors = [String]
421 data ErrMsg = ErrMsg {
422 errMsgSeverity :: Severity, -- warning, error, etc.
423 errMsgSpans :: [SrcSpan],
424 errMsgShortDoc :: Doc,
425 errMsgExtraInfo :: Doc
432 | LoadDependenciesOf Module
434 -- | Try to load the program. If a Module is supplied, then just
435 -- attempt to load up to this target. If no Module is supplied,
436 -- then try to load all targets.
437 load :: Session -> LoadHowMuch -> IO SuccessFlag
438 load session how_much =
439 loadMsgs session how_much ErrUtils.printErrorsAndWarnings
441 -- | Version of 'load' that takes a callback function to be invoked
442 -- on compiler errors and warnings as they occur during compilation.
443 loadMsgs :: Session -> LoadHowMuch -> (Messages-> IO ()) -> IO SuccessFlag
444 loadMsgs s@(Session ref) how_much msg_act
446 -- Dependency analysis first. Note that this fixes the module graph:
447 -- even if we don't get a fully successful upsweep, the full module
448 -- graph is still retained in the Session. We can tell which modules
449 -- were successfully loaded by inspecting the Session's HPT.
450 mb_graph <- depanal s []
452 Left msgs -> do msg_act msgs; return Failed
453 Right mod_graph -> loadMsgs2 s how_much msg_act mod_graph
455 loadMsgs2 s@(Session ref) how_much msg_act mod_graph = do
456 hsc_env <- readIORef ref
458 let hpt1 = hsc_HPT hsc_env
459 let dflags = hsc_dflags hsc_env
460 let ghci_mode = ghcMode dflags -- this never changes
462 -- The "bad" boot modules are the ones for which we have
463 -- B.hs-boot in the module graph, but no B.hs
464 -- The downsweep should have ensured this does not happen
466 let all_home_mods = [ms_mod s | s <- mod_graph, not (isBootSummary s)]
468 bad_boot_mods = [s | s <- mod_graph, isBootSummary s,
469 not (ms_mod s `elem` all_home_mods)]
471 ASSERT( null bad_boot_mods ) return ()
473 -- mg2_with_srcimps drops the hi-boot nodes, returning a
474 -- graph with cycles. Among other things, it is used for
475 -- backing out partially complete cycles following a failed
476 -- upsweep, and for removing from hpt all the modules
477 -- not in strict downwards closure, during calls to compile.
478 let mg2_with_srcimps :: [SCC ModSummary]
479 mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing
481 -- check the stability property for each module.
482 stable_mods@(stable_obj,stable_bco)
483 | BatchCompile <- ghci_mode = ([],[])
484 | otherwise = checkStability hpt1 mg2_with_srcimps all_home_mods
486 -- prune bits of the HPT which are definitely redundant now,
488 pruned_hpt = pruneHomePackageTable hpt1
489 (flattenSCCs mg2_with_srcimps)
494 debugTraceMsg dflags 2 (showSDoc (text "Stable obj:" <+> ppr stable_obj $$
495 text "Stable BCO:" <+> ppr stable_bco))
497 -- Unload any modules which are going to be re-linked this time around.
498 let stable_linkables = [ linkable
499 | m <- stable_obj++stable_bco,
500 Just hmi <- [lookupModuleEnv pruned_hpt m],
501 Just linkable <- [hm_linkable hmi] ]
502 unload hsc_env stable_linkables
504 -- We could at this point detect cycles which aren't broken by
505 -- a source-import, and complain immediately, but it seems better
506 -- to let upsweep_mods do this, so at least some useful work gets
507 -- done before the upsweep is abandoned.
508 --hPutStrLn stderr "after tsort:\n"
509 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
511 -- Now do the upsweep, calling compile for each module in
512 -- turn. Final result is version 3 of everything.
514 -- Topologically sort the module graph, this time including hi-boot
515 -- nodes, and possibly just including the portion of the graph
516 -- reachable from the module specified in the 2nd argument to load.
517 -- This graph should be cycle-free.
518 -- If we're restricting the upsweep to a portion of the graph, we
519 -- also want to retain everything that is still stable.
520 let full_mg :: [SCC ModSummary]
521 full_mg = topSortModuleGraph False mod_graph Nothing
523 maybe_top_mod = case how_much of
525 LoadDependenciesOf m -> Just m
528 partial_mg0 :: [SCC ModSummary]
529 partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod
531 -- LoadDependenciesOf m: we want the upsweep to stop just
532 -- short of the specified module (unless the specified module
535 | LoadDependenciesOf mod <- how_much
536 = ASSERT( case last partial_mg0 of
537 AcyclicSCC ms -> ms_mod ms == mod; _ -> False )
538 List.init partial_mg0
544 | AcyclicSCC ms <- full_mg,
545 ms_mod ms `elem` stable_obj++stable_bco,
546 ms_mod ms `notElem` [ ms_mod ms' |
547 AcyclicSCC ms' <- partial_mg ] ]
549 mg = stable_mg ++ partial_mg
551 -- clean up between compilations
552 let cleanup = cleanTempFilesExcept dflags
553 (ppFilesFromSummaries (flattenSCCs mg2_with_srcimps))
555 (upsweep_ok, hsc_env1, modsUpswept)
556 <- upsweep (hsc_env { hsc_HPT = emptyHomePackageTable })
557 pruned_hpt stable_mods cleanup msg_act mg
559 -- Make modsDone be the summaries for each home module now
560 -- available; this should equal the domain of hpt3.
561 -- Get in in a roughly top .. bottom order (hence reverse).
563 let modsDone = reverse modsUpswept
565 -- Try and do linking in some form, depending on whether the
566 -- upsweep was completely or only partially successful.
568 if succeeded upsweep_ok
571 -- Easy; just relink it all.
572 do debugTraceMsg dflags 2 "Upsweep completely successful."
574 -- Clean up after ourselves
575 cleanTempFilesExcept dflags (ppFilesFromSummaries modsDone)
577 -- Issue a warning for the confusing case where the user
578 -- said '-o foo' but we're not going to do any linking.
579 -- We attempt linking if either (a) one of the modules is
580 -- called Main, or (b) the user said -no-hs-main, indicating
581 -- that main() is going to come from somewhere else.
583 let ofile = outputFile dflags
584 let no_hs_main = dopt Opt_NoHsMain dflags
585 let mb_main_mod = mainModIs dflags
587 main_mod = mb_main_mod `orElse` "Main"
589 = any ((==main_mod).moduleUserString.ms_mod)
591 do_linking = a_root_is_Main || no_hs_main
593 when (ghci_mode == BatchCompile && isJust ofile && not do_linking) $
594 debugTraceMsg dflags 1 ("Warning: output was redirected with -o, " ++
595 "but no output will be generated\n" ++
596 "because there is no " ++ main_mod ++ " module.")
598 -- link everything together
599 linkresult <- link ghci_mode dflags do_linking (hsc_HPT hsc_env1)
601 loadFinish Succeeded linkresult ref hsc_env1
604 -- Tricky. We need to back out the effects of compiling any
605 -- half-done cycles, both so as to clean up the top level envs
606 -- and to avoid telling the interactive linker to link them.
607 do debugTraceMsg dflags 2 "Upsweep partially successful."
610 = map ms_mod modsDone
611 let mods_to_zap_names
612 = findPartiallyCompletedCycles modsDone_names
615 = filter ((`notElem` mods_to_zap_names).ms_mod)
618 let hpt4 = retainInTopLevelEnvs (map ms_mod mods_to_keep)
621 -- Clean up after ourselves
622 cleanTempFilesExcept dflags (ppFilesFromSummaries mods_to_keep)
624 -- there should be no Nothings where linkables should be, now
625 ASSERT(all (isJust.hm_linkable)
626 (moduleEnvElts (hsc_HPT hsc_env))) do
628 -- Link everything together
629 linkresult <- link ghci_mode dflags False hpt4
631 let hsc_env4 = hsc_env1{ hsc_HPT = hpt4 }
632 loadFinish Failed linkresult ref hsc_env4
634 -- Finish up after a load.
636 -- If the link failed, unload everything and return.
637 loadFinish all_ok Failed ref hsc_env
638 = do unload hsc_env []
639 writeIORef ref $! discardProg hsc_env
642 -- Empty the interactive context and set the module context to the topmost
643 -- newly loaded module, or the Prelude if none were loaded.
644 loadFinish all_ok Succeeded ref hsc_env
645 = do writeIORef ref $! hsc_env{ hsc_IC = emptyInteractiveContext }
649 -- Forget the current program, but retain the persistent info in HscEnv
650 discardProg :: HscEnv -> HscEnv
652 = hsc_env { hsc_mod_graph = emptyMG,
653 hsc_IC = emptyInteractiveContext,
654 hsc_HPT = emptyHomePackageTable }
656 -- used to fish out the preprocess output files for the purposes of
657 -- cleaning up. The preprocessed file *might* be the same as the
658 -- source file, but that doesn't do any harm.
659 ppFilesFromSummaries summaries = [ fn | Just fn <- map ms_hspp_file summaries ]
661 -- -----------------------------------------------------------------------------
665 CheckedModule { parsedSource :: ParsedSource,
666 renamedSource :: Maybe RenamedSource,
667 typecheckedSource :: Maybe TypecheckedSource,
668 checkedModuleInfo :: Maybe ModuleInfo
670 -- ToDo: improvements that could be made here:
671 -- if the module succeeded renaming but not typechecking,
672 -- we can still get back the GlobalRdrEnv and exports, so
673 -- perhaps the ModuleInfo should be split up into separate
674 -- fields within CheckedModule.
676 type ParsedSource = Located (HsModule RdrName)
677 type RenamedSource = HsGroup Name
678 type TypecheckedSource = LHsBinds Id
680 -- | This is the way to get access to parsed and typechecked source code
681 -- for a module. 'checkModule' loads all the dependencies of the specified
682 -- module in the Session, and then attempts to typecheck the module. If
683 -- successful, it returns the abstract syntax for the module.
684 checkModule :: Session -> Module -> (Messages -> IO ())
685 -> IO (Maybe CheckedModule)
686 checkModule session@(Session ref) mod msg_act = do
687 -- load up the dependencies first
688 r <- loadMsgs session (LoadDependenciesOf mod) msg_act
689 if (failed r) then return Nothing else do
691 -- now parse & typecheck the module
692 hsc_env <- readIORef ref
693 let mg = hsc_mod_graph hsc_env
694 case [ ms | ms <- mg, ms_mod ms == mod ] of
697 -- Add in the OPTIONS from the source file This is nasty:
698 -- we've done this once already, in the compilation manager
699 -- It might be better to cache the flags in the
700 -- ml_hspp_file field, say
701 let dflags0 = hsc_dflags hsc_env
702 hspp_buf = expectJust "GHC.checkModule" (ms_hspp_buf ms)
703 opts = getOptionsFromStringBuffer hspp_buf
704 (dflags1,leftovers) <- parseDynamicFlags dflags0 (map snd opts)
705 if (not (null leftovers))
706 then do let filename = fromJust (ml_hs_file (ms_location ms))
707 msg_act (optionsErrorMsgs leftovers opts filename)
711 r <- hscFileCheck hsc_env{hsc_dflags=dflags1} msg_act ms
715 HscChecked parsed renamed Nothing ->
716 return (Just (CheckedModule {
717 parsedSource = parsed,
718 renamedSource = renamed,
719 typecheckedSource = Nothing,
720 checkedModuleInfo = Nothing }))
721 HscChecked parsed renamed
722 (Just (tc_binds, rdr_env, details)) -> do
723 let minf = ModuleInfo {
724 minf_type_env = md_types details,
725 minf_exports = md_exports details,
726 minf_rdr_env = Just rdr_env,
727 minf_instances = md_insts details
729 return (Just (CheckedModule {
730 parsedSource = parsed,
731 renamedSource = renamed,
732 typecheckedSource = Just tc_binds,
733 checkedModuleInfo = Just minf }))
737 -- ---------------------------------------------------------------------------
740 unload :: HscEnv -> [Linkable] -> IO ()
741 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
742 = case ghcMode (hsc_dflags hsc_env) of
743 BatchCompile -> return ()
744 JustTypecheck -> return ()
746 Interactive -> Linker.unload (hsc_dflags hsc_env) stable_linkables
748 Interactive -> panic "unload: no interpreter"
750 other -> panic "unload: strange mode"
752 -- -----------------------------------------------------------------------------
756 Stability tells us which modules definitely do not need to be recompiled.
757 There are two main reasons for having stability:
759 - avoid doing a complete upsweep of the module graph in GHCi when
760 modules near the bottom of the tree have not changed.
762 - to tell GHCi when it can load object code: we can only load object code
763 for a module when we also load object code fo all of the imports of the
764 module. So we need to know that we will definitely not be recompiling
765 any of these modules, and we can use the object code.
767 NB. stability is of no importance to BatchCompile at all, only Interactive.
768 (ToDo: what about JustTypecheck?)
770 The stability check is as follows. Both stableObject and
771 stableBCO are used during the upsweep phase later.
774 stable m = stableObject m || stableBCO m
777 all stableObject (imports m)
778 && old linkable does not exist, or is == on-disk .o
779 && date(on-disk .o) > date(.hs)
782 all stable (imports m)
783 && date(BCO) > date(.hs)
786 These properties embody the following ideas:
788 - if a module is stable:
789 - if it has been compiled in a previous pass (present in HPT)
790 then it does not need to be compiled or re-linked.
791 - if it has not been compiled in a previous pass,
792 then we only need to read its .hi file from disk and
793 link it to produce a ModDetails.
795 - if a modules is not stable, we will definitely be at least
796 re-linking, and possibly re-compiling it during the upsweep.
797 All non-stable modules can (and should) therefore be unlinked
800 - Note that objects are only considered stable if they only depend
801 on other objects. We can't link object code against byte code.
805 :: HomePackageTable -- HPT from last compilation
806 -> [SCC ModSummary] -- current module graph (cyclic)
807 -> [Module] -- all home modules
808 -> ([Module], -- stableObject
809 [Module]) -- stableBCO
811 checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
813 checkSCC (stable_obj, stable_bco) scc0
814 | stableObjects = (scc_mods ++ stable_obj, stable_bco)
815 | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
816 | otherwise = (stable_obj, stable_bco)
818 scc = flattenSCC scc0
819 scc_mods = map ms_mod scc
820 home_module m = m `elem` all_home_mods && m `notElem` scc_mods
822 scc_allimps = nub (filter home_module (concatMap ms_allimps scc))
823 -- all imports outside the current SCC, but in the home pkg
825 stable_obj_imps = map (`elem` stable_obj) scc_allimps
826 stable_bco_imps = map (`elem` stable_bco) scc_allimps
833 and (zipWith (||) stable_obj_imps stable_bco_imps)
837 | Just t <- ms_obj_date ms = t >= ms_hs_date ms
841 same_as_prev t = case lookupModuleEnv hpt (ms_mod ms) of
842 Just hmi | Just l <- hm_linkable hmi
843 -> isObjectLinkable l && t == linkableTime l
845 -- why '>=' rather than '>' above? If the filesystem stores
846 -- times to the nearset second, we may occasionally find that
847 -- the object & source have the same modification time,
848 -- especially if the source was automatically generated
849 -- and compiled. Using >= is slightly unsafe, but it matches
853 = case lookupModuleEnv hpt (ms_mod ms) of
854 Just hmi | Just l <- hm_linkable hmi ->
855 not (isObjectLinkable l) &&
856 linkableTime l >= ms_hs_date ms
859 ms_allimps :: ModSummary -> [Module]
860 ms_allimps ms = map unLoc (ms_srcimps ms ++ ms_imps ms)
862 -- -----------------------------------------------------------------------------
863 -- Prune the HomePackageTable
865 -- Before doing an upsweep, we can throw away:
867 -- - For non-stable modules:
868 -- - all ModDetails, all linked code
869 -- - all unlinked code that is out of date with respect to
872 -- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
873 -- space at the end of the upsweep, because the topmost ModDetails of the
874 -- old HPT holds on to the entire type environment from the previous
877 pruneHomePackageTable
880 -> ([Module],[Module])
883 pruneHomePackageTable hpt summ (stable_obj, stable_bco)
884 = mapModuleEnv prune hpt
886 | is_stable modl = hmi'
887 | otherwise = hmi'{ hm_details = emptyModDetails }
889 modl = mi_module (hm_iface hmi)
890 hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
891 = hmi{ hm_linkable = Nothing }
894 where ms = expectJust "prune" (lookupModuleEnv ms_map modl)
896 ms_map = mkModuleEnv [(ms_mod ms, ms) | ms <- summ]
898 is_stable m = m `elem` stable_obj || m `elem` stable_bco
900 -- -----------------------------------------------------------------------------
902 -- Return (names of) all those in modsDone who are part of a cycle
903 -- as defined by theGraph.
904 findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
905 findPartiallyCompletedCycles modsDone theGraph
909 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
910 chew ((CyclicSCC vs):rest)
911 = let names_in_this_cycle = nub (map ms_mod vs)
913 = nub ([done | done <- modsDone,
914 done `elem` names_in_this_cycle])
915 chewed_rest = chew rest
917 if notNull mods_in_this_cycle
918 && length mods_in_this_cycle < length names_in_this_cycle
919 then mods_in_this_cycle ++ chewed_rest
922 -- -----------------------------------------------------------------------------
925 -- This is where we compile each module in the module graph, in a pass
926 -- from the bottom to the top of the graph.
928 -- There better had not be any cyclic groups here -- we check for them.
931 :: HscEnv -- Includes initially-empty HPT
932 -> HomePackageTable -- HPT from last time round (pruned)
933 -> ([Module],[Module]) -- stable modules (see checkStability)
934 -> IO () -- How to clean up unwanted tmp files
935 -> (Messages -> IO ()) -- Compiler error message callback
936 -> [SCC ModSummary] -- Mods to do (the worklist)
938 HscEnv, -- With an updated HPT
939 [ModSummary]) -- Mods which succeeded
941 upsweep hsc_env old_hpt stable_mods cleanup msg_act mods
942 = upsweep' hsc_env old_hpt stable_mods cleanup msg_act mods 1 (length mods)
944 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
946 = return (Succeeded, hsc_env, [])
948 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
950 = do putMsg (showSDoc (cyclicModuleErr ms))
951 return (Failed, hsc_env, [])
953 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
954 (AcyclicSCC mod:mods) mod_index nmods
955 = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
956 -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
957 -- (moduleEnvElts (hsc_HPT hsc_env)))
959 mb_mod_info <- upsweep_mod hsc_env old_hpt stable_mods msg_act mod
962 cleanup -- Remove unwanted tmp files between compilations
965 Nothing -> return (Failed, hsc_env, [])
967 { let this_mod = ms_mod mod
969 -- Add new info to hsc_env
970 hpt1 = extendModuleEnv (hsc_HPT hsc_env)
972 hsc_env1 = hsc_env { hsc_HPT = hpt1 }
974 -- Space-saving: delete the old HPT entry
975 -- for mod BUT if mod is a hs-boot
976 -- node, don't delete it. For the
977 -- interface, the HPT entry is probaby for the
978 -- main Haskell source file. Deleting it
979 -- would force .. (what?? --SDM)
980 old_hpt1 | isBootSummary mod = old_hpt
981 | otherwise = delModuleEnv old_hpt this_mod
983 ; (restOK, hsc_env2, modOKs)
984 <- upsweep' hsc_env1 old_hpt1 stable_mods cleanup
985 msg_act mods (mod_index+1) nmods
986 ; return (restOK, hsc_env2, mod:modOKs)
990 -- Compile a single module. Always produce a Linkable for it if
991 -- successful. If no compilation happened, return the old Linkable.
992 upsweep_mod :: HscEnv
994 -> ([Module],[Module])
995 -> (Messages -> IO ())
997 -> Int -- index of module
998 -> Int -- total number of modules
999 -> IO (Maybe HomeModInfo) -- Nothing => Failed
1001 upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) msg_act summary mod_index nmods
1004 this_mod = ms_mod summary
1005 mb_obj_date = ms_obj_date summary
1006 obj_fn = ml_obj_file (ms_location summary)
1007 hs_date = ms_hs_date summary
1009 compile_it :: Maybe Linkable -> IO (Maybe HomeModInfo)
1010 compile_it = upsweep_compile hsc_env old_hpt this_mod
1011 msg_act summary mod_index nmods
1013 case ghcMode (hsc_dflags hsc_env) of
1016 -- Batch-compilating is easy: just check whether we have
1017 -- an up-to-date object file. If we do, then the compiler
1018 -- needs to do a recompilation check.
1019 _ | Just obj_date <- mb_obj_date, obj_date >= hs_date -> do
1021 findObjectLinkable this_mod obj_fn obj_date
1022 compile_it (Just linkable)
1029 _ | is_stable_obj, isJust old_hmi ->
1031 -- object is stable, and we have an entry in the
1032 -- old HPT: nothing to do
1034 | is_stable_obj, isNothing old_hmi -> do
1036 findObjectLinkable this_mod obj_fn
1037 (expectJust "upseep1" mb_obj_date)
1038 compile_it (Just linkable)
1039 -- object is stable, but we need to load the interface
1040 -- off disk to make a HMI.
1043 ASSERT(isJust old_hmi) -- must be in the old_hpt
1045 -- BCO is stable: nothing to do
1047 | Just hmi <- old_hmi,
1048 Just l <- hm_linkable hmi, not (isObjectLinkable l),
1049 linkableTime l >= ms_hs_date summary ->
1051 -- we have an old BCO that is up to date with respect
1052 -- to the source: do a recompilation check as normal.
1056 -- no existing code at all: we must recompile.
1058 is_stable_obj = this_mod `elem` stable_obj
1059 is_stable_bco = this_mod `elem` stable_bco
1061 old_hmi = lookupModuleEnv old_hpt this_mod
1063 -- Run hsc to compile a module
1064 upsweep_compile hsc_env old_hpt this_mod msg_act summary
1066 mb_old_linkable = do
1068 -- The old interface is ok if it's in the old HPT
1069 -- a) we're compiling a source file, and the old HPT
1070 -- entry is for a source file
1071 -- b) we're compiling a hs-boot file
1072 -- Case (b) allows an hs-boot file to get the interface of its
1073 -- real source file on the second iteration of the compilation
1074 -- manager, but that does no harm. Otherwise the hs-boot file
1075 -- will always be recompiled
1078 = case lookupModuleEnv old_hpt this_mod of
1080 Just hm_info | isBootSummary summary -> Just iface
1081 | not (mi_boot iface) -> Just iface
1082 | otherwise -> Nothing
1084 iface = hm_iface hm_info
1086 compresult <- compile hsc_env msg_act summary mb_old_linkable mb_old_iface
1090 -- Compilation failed. Compile may still have updated the PCS, tho.
1091 CompErrs -> return Nothing
1093 -- Compilation "succeeded", and may or may not have returned a new
1094 -- linkable (depending on whether compilation was actually performed
1096 CompOK new_details new_iface new_linkable
1097 -> do let new_info = HomeModInfo { hm_iface = new_iface,
1098 hm_details = new_details,
1099 hm_linkable = new_linkable }
1100 return (Just new_info)
1103 -- Filter modules in the HPT
1104 retainInTopLevelEnvs :: [Module] -> HomePackageTable -> HomePackageTable
1105 retainInTopLevelEnvs keep_these hpt
1106 = mkModuleEnv [ (mod, expectJust "retain" mb_mod_info)
1108 , let mb_mod_info = lookupModuleEnv hpt mod
1109 , isJust mb_mod_info ]
1111 -- ---------------------------------------------------------------------------
1112 -- Topological sort of the module graph
1115 :: Bool -- Drop hi-boot nodes? (see below)
1119 -- Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
1120 -- The resulting list of strongly-connected-components is in topologically
1121 -- sorted order, starting with the module(s) at the bottom of the
1122 -- dependency graph (ie compile them first) and ending with the ones at
1125 -- Drop hi-boot nodes (first boolean arg)?
1127 -- False: treat the hi-boot summaries as nodes of the graph,
1128 -- so the graph must be acyclic
1130 -- True: eliminate the hi-boot nodes, and instead pretend
1131 -- the a source-import of Foo is an import of Foo
1132 -- The resulting graph has no hi-boot nodes, but can by cyclic
1134 topSortModuleGraph drop_hs_boot_nodes summaries Nothing
1135 = stronglyConnComp (fst (moduleGraphNodes drop_hs_boot_nodes summaries))
1136 topSortModuleGraph drop_hs_boot_nodes summaries (Just mod)
1137 = stronglyConnComp (map vertex_fn (reachable graph root))
1139 -- restrict the graph to just those modules reachable from
1140 -- the specified module. We do this by building a graph with
1141 -- the full set of nodes, and determining the reachable set from
1142 -- the specified node.
1143 (nodes, lookup_key) = moduleGraphNodes drop_hs_boot_nodes summaries
1144 (graph, vertex_fn, key_fn) = graphFromEdges' nodes
1146 | Just key <- lookup_key HsSrcFile mod, Just v <- key_fn key = v
1147 | otherwise = throwDyn (ProgramError "module does not exist")
1149 moduleGraphNodes :: Bool -> [ModSummary]
1150 -> ([(ModSummary, Int, [Int])], HscSource -> Module -> Maybe Int)
1151 moduleGraphNodes drop_hs_boot_nodes summaries = (nodes, lookup_key)
1153 -- Drop hs-boot nodes by using HsSrcFile as the key
1154 hs_boot_key | drop_hs_boot_nodes = HsSrcFile
1155 | otherwise = HsBootFile
1157 -- We use integers as the keys for the SCC algorithm
1158 nodes :: [(ModSummary, Int, [Int])]
1159 nodes = [(s, expectJust "topSort" (lookup_key (ms_hsc_src s) (ms_mod s)),
1160 out_edge_keys hs_boot_key (map unLoc (ms_srcimps s)) ++
1161 out_edge_keys HsSrcFile (map unLoc (ms_imps s)) )
1163 , not (isBootSummary s && drop_hs_boot_nodes) ]
1164 -- Drop the hi-boot ones if told to do so
1166 key_map :: NodeMap Int
1167 key_map = listToFM ([(ms_mod s, ms_hsc_src s) | s <- summaries]
1170 lookup_key :: HscSource -> Module -> Maybe Int
1171 lookup_key hs_src mod = lookupFM key_map (mod, hs_src)
1173 out_edge_keys :: HscSource -> [Module] -> [Int]
1174 out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
1175 -- If we want keep_hi_boot_nodes, then we do lookup_key with
1176 -- the IsBootInterface parameter True; else False
1179 type NodeKey = (Module, HscSource) -- The nodes of the graph are
1180 type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
1182 msKey :: ModSummary -> NodeKey
1183 msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (mod,boot)
1185 mkNodeMap :: [ModSummary] -> NodeMap ModSummary
1186 mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
1188 nodeMapElts :: NodeMap a -> [a]
1189 nodeMapElts = eltsFM
1191 -----------------------------------------------------------------------------
1192 -- Downsweep (dependency analysis)
1194 -- Chase downwards from the specified root set, returning summaries
1195 -- for all home modules encountered. Only follow source-import
1198 -- We pass in the previous collection of summaries, which is used as a
1199 -- cache to avoid recalculating a module summary if the source is
1202 -- The returned list of [ModSummary] nodes has one node for each home-package
1203 -- module, plus one for any hs-boot files. The imports of these nodes
1204 -- are all there, including the imports of non-home-package modules.
1207 -> [ModSummary] -- Old summaries
1208 -> [Module] -- Ignore dependencies on these; treat them as
1209 -- if they were package modules
1210 -> IO (Either Messages [ModSummary])
1211 downsweep hsc_env old_summaries excl_mods
1212 = -- catch error messages and return them
1213 handleDyn (\err_msg -> return (Left (emptyBag, unitBag err_msg))) $ do
1214 rootSummaries <- mapM getRootSummary roots
1215 checkDuplicates rootSummaries
1216 summs <- loop (concatMap msDeps rootSummaries) (mkNodeMap rootSummaries)
1217 return (Right summs)
1219 roots = hsc_targets hsc_env
1221 old_summary_map :: NodeMap ModSummary
1222 old_summary_map = mkNodeMap old_summaries
1224 getRootSummary :: Target -> IO ModSummary
1225 getRootSummary (Target (TargetFile file mb_phase) maybe_buf)
1226 = do exists <- doesFileExist file
1228 then summariseFile hsc_env old_summaries file mb_phase maybe_buf
1229 else throwDyn $ mkPlainErrMsg noSrcSpan $
1230 text "can't find file:" <+> text file
1231 getRootSummary (Target (TargetModule modl) maybe_buf)
1232 = do maybe_summary <- summariseModule hsc_env old_summary_map False
1233 (L rootLoc modl) maybe_buf excl_mods
1234 case maybe_summary of
1235 Nothing -> packageModErr modl
1238 rootLoc = mkGeneralSrcSpan FSLIT("<command line>")
1240 -- In a root module, the filename is allowed to diverge from the module
1241 -- name, so we have to check that there aren't multiple root files
1242 -- defining the same module (otherwise the duplicates will be silently
1243 -- ignored, leading to confusing behaviour).
1244 checkDuplicates :: [ModSummary] -> IO ()
1245 checkDuplicates summaries = mapM_ check summaries
1250 many -> multiRootsErr modl many
1251 where modl = ms_mod summ
1253 [ expectJust "checkDup" (ml_hs_file (ms_location summ'))
1254 | summ' <- summaries, ms_mod summ' == modl ]
1256 loop :: [(Located Module,IsBootInterface)]
1257 -- Work list: process these modules
1258 -> NodeMap ModSummary
1261 -- The result includes the worklist, except
1262 -- for those mentioned in the visited set
1263 loop [] done = return (nodeMapElts done)
1264 loop ((wanted_mod, is_boot) : ss) done
1265 | key `elemFM` done = loop ss done
1266 | otherwise = do { mb_s <- summariseModule hsc_env old_summary_map
1267 is_boot wanted_mod Nothing excl_mods
1269 Nothing -> loop ss done
1270 Just s -> loop (msDeps s ++ ss)
1271 (addToFM done key s) }
1273 key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
1275 msDeps :: ModSummary -> [(Located Module, IsBootInterface)]
1276 -- (msDeps s) returns the dependencies of the ModSummary s.
1277 -- A wrinkle is that for a {-# SOURCE #-} import we return
1278 -- *both* the hs-boot file
1279 -- *and* the source file
1280 -- as "dependencies". That ensures that the list of all relevant
1281 -- modules always contains B.hs if it contains B.hs-boot.
1282 -- Remember, this pass isn't doing the topological sort. It's
1283 -- just gathering the list of all relevant ModSummaries
1285 concat [ [(m,True), (m,False)] | m <- ms_srcimps s ]
1286 ++ [ (m,False) | m <- ms_imps s ]
1288 -----------------------------------------------------------------------------
1289 -- Summarising modules
1291 -- We have two types of summarisation:
1293 -- * Summarise a file. This is used for the root module(s) passed to
1294 -- cmLoadModules. The file is read, and used to determine the root
1295 -- module name. The module name may differ from the filename.
1297 -- * Summarise a module. We are given a module name, and must provide
1298 -- a summary. The finder is used to locate the file in which the module
1303 -> [ModSummary] -- old summaries
1304 -> FilePath -- source file name
1305 -> Maybe Phase -- start phase
1306 -> Maybe (StringBuffer,ClockTime)
1309 summariseFile hsc_env old_summaries file mb_phase maybe_buf
1310 -- we can use a cached summary if one is available and the
1311 -- source file hasn't changed, But we have to look up the summary
1312 -- by source file, rather than module name as we do in summarise.
1313 | Just old_summary <- findSummaryBySourceFile old_summaries file
1315 let location = ms_location old_summary
1317 -- return the cached summary if the source didn't change
1318 src_timestamp <- case maybe_buf of
1319 Just (_,t) -> return t
1320 Nothing -> getModificationTime file
1322 if ms_hs_date old_summary == src_timestamp
1323 then do -- update the object-file timestamp
1324 obj_timestamp <- getObjTimestamp location False
1325 return old_summary{ ms_obj_date = obj_timestamp }
1333 let dflags = hsc_dflags hsc_env
1335 (dflags', hspp_fn, buf)
1336 <- preprocessFile dflags file mb_phase maybe_buf
1338 (srcimps,the_imps, L _ mod) <- getImports dflags' buf hspp_fn
1340 -- Make a ModLocation for this file
1341 location <- mkHomeModLocation dflags mod file
1343 -- Tell the Finder cache where it is, so that subsequent calls
1344 -- to findModule will find it, even if it's not on any search path
1345 addHomeModuleToFinder hsc_env mod location
1347 src_timestamp <- case maybe_buf of
1348 Just (_,t) -> return t
1349 Nothing -> getModificationTime file
1351 obj_timestamp <- modificationTimeIfExists (ml_obj_file location)
1353 return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
1354 ms_location = location,
1355 ms_hspp_file = Just hspp_fn,
1356 ms_hspp_buf = Just buf,
1357 ms_srcimps = srcimps, ms_imps = the_imps,
1358 ms_hs_date = src_timestamp,
1359 ms_obj_date = obj_timestamp })
1361 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
1362 findSummaryBySourceFile summaries file
1363 = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
1364 fromJust (ml_hs_file (ms_location ms)) == file ] of
1368 -- Summarise a module, and pick up source and timestamp.
1371 -> NodeMap ModSummary -- Map of old summaries
1372 -> IsBootInterface -- True <=> a {-# SOURCE #-} import
1373 -> Located Module -- Imported module to be summarised
1374 -> Maybe (StringBuffer, ClockTime)
1375 -> [Module] -- Modules to exclude
1376 -> IO (Maybe ModSummary) -- Its new summary
1378 summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod) maybe_buf excl_mods
1379 | wanted_mod `elem` excl_mods
1382 | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
1383 = do -- Find its new timestamp; all the
1384 -- ModSummaries in the old map have valid ml_hs_files
1385 let location = ms_location old_summary
1386 src_fn = expectJust "summariseModule" (ml_hs_file location)
1388 -- return the cached summary if the source didn't change
1389 src_timestamp <- case maybe_buf of
1390 Just (_,t) -> return t
1391 Nothing -> getModificationTime src_fn
1393 if ms_hs_date old_summary == src_timestamp
1394 then do -- update the object-file timestamp
1395 obj_timestamp <- getObjTimestamp location is_boot
1396 return (Just old_summary{ ms_obj_date = obj_timestamp })
1398 -- source changed: re-summarise
1399 new_summary location src_fn maybe_buf src_timestamp
1402 = do found <- findModule hsc_env wanted_mod True {-explicit-}
1405 | not (isHomePackage pkg) -> return Nothing
1406 -- Drop external-pkg
1407 | isJust (ml_hs_file location) -> just_found location
1409 err -> noModError dflags loc wanted_mod err
1412 dflags = hsc_dflags hsc_env
1414 hsc_src = if is_boot then HsBootFile else HsSrcFile
1416 just_found location = do
1417 -- Adjust location to point to the hs-boot source file,
1418 -- hi file, object file, when is_boot says so
1419 let location' | is_boot = addBootSuffixLocn location
1420 | otherwise = location
1421 src_fn = expectJust "summarise2" (ml_hs_file location')
1423 -- Check that it exists
1424 -- It might have been deleted since the Finder last found it
1425 maybe_t <- modificationTimeIfExists src_fn
1427 Nothing -> noHsFileErr loc src_fn
1428 Just t -> new_summary location' src_fn Nothing t
1431 new_summary location src_fn maybe_bug src_timestamp
1433 -- Preprocess the source file and get its imports
1434 -- The dflags' contains the OPTIONS pragmas
1435 (dflags', hspp_fn, buf) <- preprocessFile dflags src_fn Nothing maybe_buf
1436 (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn
1438 when (mod_name /= wanted_mod) $
1439 throwDyn $ mkPlainErrMsg mod_loc $
1440 text "file name does not match module name"
1441 <+> quotes (ppr mod_name)
1443 -- Find the object timestamp, and return the summary
1444 obj_timestamp <- getObjTimestamp location is_boot
1446 return (Just ( ModSummary { ms_mod = wanted_mod,
1447 ms_hsc_src = hsc_src,
1448 ms_location = location,
1449 ms_hspp_file = Just hspp_fn,
1450 ms_hspp_buf = Just buf,
1451 ms_srcimps = srcimps,
1453 ms_hs_date = src_timestamp,
1454 ms_obj_date = obj_timestamp }))
1457 getObjTimestamp location is_boot
1458 = if is_boot then return Nothing
1459 else modificationTimeIfExists (ml_obj_file location)
1462 preprocessFile :: DynFlags -> FilePath -> Maybe Phase -> Maybe (StringBuffer,ClockTime)
1463 -> IO (DynFlags, FilePath, StringBuffer)
1464 preprocessFile dflags src_fn mb_phase Nothing
1466 (dflags', hspp_fn) <- preprocess dflags (src_fn, mb_phase)
1467 buf <- hGetStringBuffer hspp_fn
1468 return (dflags', hspp_fn, buf)
1470 preprocessFile dflags src_fn mb_phase (Just (buf, time))
1472 -- case we bypass the preprocessing stage?
1474 local_opts = getOptionsFromStringBuffer buf
1476 (dflags', errs) <- parseDynamicFlags dflags (map snd local_opts)
1480 | Just (Unlit _) <- mb_phase = True
1481 | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
1482 -- note: local_opts is only required if there's no Unlit phase
1483 | dopt Opt_Cpp dflags' = True
1484 | dopt Opt_Pp dflags' = True
1487 when needs_preprocessing $
1488 ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
1490 return (dflags', src_fn, buf)
1493 -----------------------------------------------------------------------------
1495 -----------------------------------------------------------------------------
1497 noModError :: DynFlags -> SrcSpan -> Module -> FindResult -> IO ab
1498 -- ToDo: we don't have a proper line number for this error
1499 noModError dflags loc wanted_mod err
1500 = throwDyn $ mkPlainErrMsg loc $ cantFindError dflags wanted_mod err
1502 noHsFileErr loc path
1503 = throwDyn $ mkPlainErrMsg loc $ text "Can't find" <+> text path
1506 = throwDyn $ mkPlainErrMsg noSrcSpan $
1507 text "module" <+> quotes (ppr mod) <+> text "is a package module"
1509 multiRootsErr mod files
1510 = throwDyn $ mkPlainErrMsg noSrcSpan $
1511 text "module" <+> quotes (ppr mod) <+>
1512 text "is defined in multiple files:" <+>
1513 sep (map text files)
1515 cyclicModuleErr :: [ModSummary] -> SDoc
1517 = hang (ptext SLIT("Module imports form a cycle for modules:"))
1518 2 (vcat (map show_one ms))
1520 show_one ms = sep [ show_mod (ms_hsc_src ms) (ms_mod ms),
1521 nest 2 $ ptext SLIT("imports:") <+>
1522 (pp_imps HsBootFile (ms_srcimps ms)
1523 $$ pp_imps HsSrcFile (ms_imps ms))]
1524 show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
1525 pp_imps src mods = fsep (map (show_mod src) mods)
1528 -- | Inform GHC that the working directory has changed. GHC will flush
1529 -- its cache of module locations, since it may no longer be valid.
1530 -- Note: if you change the working directory, you should also unload
1531 -- the current program (set targets to empty, followed by load).
1532 workingDirectoryChanged :: Session -> IO ()
1533 workingDirectoryChanged s = withSession s $ \hsc_env ->
1534 flushFinderCache (hsc_FC hsc_env)
1536 -- -----------------------------------------------------------------------------
1537 -- inspecting the session
1539 -- | Get the module dependency graph.
1540 getModuleGraph :: Session -> IO ModuleGraph -- ToDo: DiGraph ModSummary
1541 getModuleGraph s = withSession s (return . hsc_mod_graph)
1543 isLoaded :: Session -> Module -> IO Bool
1544 isLoaded s m = withSession s $ \hsc_env ->
1545 return $! isJust (lookupModuleEnv (hsc_HPT hsc_env) m)
1547 getBindings :: Session -> IO [TyThing]
1548 getBindings s = withSession s (return . nameEnvElts . ic_type_env . hsc_IC)
1550 getPrintUnqual :: Session -> IO PrintUnqualified
1551 getPrintUnqual s = withSession s (return . icPrintUnqual . hsc_IC)
1553 -- | Container for information about a 'Module'.
1554 data ModuleInfo = ModuleInfo {
1555 minf_type_env :: TypeEnv,
1556 minf_exports :: NameSet,
1557 minf_rdr_env :: Maybe GlobalRdrEnv, -- Nothing for a compiled/package mod
1558 minf_instances :: [Instance]
1559 -- ToDo: this should really contain the ModIface too
1561 -- We don't want HomeModInfo here, because a ModuleInfo applies
1562 -- to package modules too.
1564 -- | Request information about a loaded 'Module'
1565 getModuleInfo :: Session -> Module -> IO (Maybe ModuleInfo)
1566 getModuleInfo s mdl = withSession s $ \hsc_env -> do
1567 let mg = hsc_mod_graph hsc_env
1568 if mdl `elem` map ms_mod mg
1569 then getHomeModuleInfo hsc_env mdl
1571 if isHomeModule (hsc_dflags hsc_env) mdl
1573 else getPackageModuleInfo hsc_env mdl
1574 -- getPackageModuleInfo will attempt to find the interface, so
1575 -- we don't want to call it for a home module, just in case there
1576 -- was a problem loading the module and the interface doesn't
1577 -- exist... hence the isHomeModule test here.
1579 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
1580 getPackageModuleInfo hsc_env mdl = do
1582 (_msgs, mb_names) <- getModuleExports hsc_env mdl
1584 Nothing -> return Nothing
1586 eps <- readIORef (hsc_EPS hsc_env)
1589 n_list = nameSetToList names
1590 tys = [ ty | name <- n_list,
1591 Just ty <- [lookupTypeEnv pte name] ]
1593 return (Just (ModuleInfo {
1594 minf_type_env = mkTypeEnv tys,
1595 minf_exports = names,
1596 minf_rdr_env = Just $! nameSetToGlobalRdrEnv names mdl,
1597 minf_instances = error "getModuleInfo: instances for package module unimplemented"
1600 -- bogusly different for non-GHCI (ToDo)
1604 getHomeModuleInfo hsc_env mdl =
1605 case lookupModuleEnv (hsc_HPT hsc_env) mdl of
1606 Nothing -> return Nothing
1608 let details = hm_details hmi
1609 return (Just (ModuleInfo {
1610 minf_type_env = md_types details,
1611 minf_exports = md_exports details,
1612 minf_rdr_env = mi_globals $! hm_iface hmi,
1613 minf_instances = md_insts details
1616 -- | The list of top-level entities defined in a module
1617 modInfoTyThings :: ModuleInfo -> [TyThing]
1618 modInfoTyThings minf = typeEnvElts (minf_type_env minf)
1620 modInfoTopLevelScope :: ModuleInfo -> Maybe [Name]
1621 modInfoTopLevelScope minf
1622 = fmap (map gre_name . globalRdrEnvElts) (minf_rdr_env minf)
1624 modInfoExports :: ModuleInfo -> [Name]
1625 modInfoExports minf = nameSetToList $! minf_exports minf
1627 -- | Returns the instances defined by the specified module.
1628 -- Warning: currently unimplemented for package modules.
1629 modInfoInstances :: ModuleInfo -> [Instance]
1630 modInfoInstances = minf_instances
1632 modInfoIsExportedName :: ModuleInfo -> Name -> Bool
1633 modInfoIsExportedName minf name = elemNameSet name (minf_exports minf)
1635 modInfoPrintUnqualified :: ModuleInfo -> Maybe PrintUnqualified
1636 modInfoPrintUnqualified minf = fmap unQualInScope (minf_rdr_env minf)
1638 modInfoLookupName :: Session -> ModuleInfo -> Name -> IO (Maybe TyThing)
1639 modInfoLookupName s minf name = withSession s $ \hsc_env -> do
1640 case lookupTypeEnv (minf_type_env minf) name of
1641 Just tyThing -> return (Just tyThing)
1643 eps <- readIORef (hsc_EPS hsc_env)
1644 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1646 isDictonaryId :: Id -> Bool
1648 = case tcSplitSigmaTy (idType id) of { (tvs, theta, tau) -> isDictTy tau }
1650 -- | Looks up a global name: that is, any top-level name in any
1651 -- visible module. Unlike 'lookupName', lookupGlobalName does not use
1652 -- the interactive context, and therefore does not require a preceding
1654 lookupGlobalName :: Session -> Name -> IO (Maybe TyThing)
1655 lookupGlobalName s name = withSession s $ \hsc_env -> do
1656 eps <- readIORef (hsc_EPS hsc_env)
1657 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1663 | BinaryCode FilePath
1665 -- ToDo: typechecks abstract syntax or renamed abstract syntax. Issues:
1666 -- - typechecked syntax includes extra dictionary translation and
1667 -- AbsBinds which need to be translated back into something closer to
1668 -- the original source.
1671 -- - Data and Typeable instances for HsSyn.
1674 -- - things that aren't in the output of the renamer:
1675 -- - the export list
1679 -- - things that aren't in the output of the typechecker right now:
1680 -- - the export list
1682 -- - type signatures
1683 -- - type/data/newtype declarations
1684 -- - class declarations
1686 -- - extra things in the typechecker's output:
1687 -- - default methods are turned into top-level decls.
1688 -- - dictionary bindings
1690 -- ToDo: check for small transformations that happen to the syntax in
1691 -- the typechecker (eg. -e ==> negate e, perhaps for fromIntegral)
1693 -- ToDo: maybe use TH syntax instead of IfaceSyn? There's already a way
1694 -- to get from TyCons, Ids etc. to TH syntax (reify).
1696 -- :browse will use either lm_toplev or inspect lm_interface, depending
1697 -- on whether the module is interpreted or not.
1699 -- This is for reconstructing refactored source code
1700 -- Calls the lexer repeatedly.
1701 -- ToDo: add comment tokens to token stream
1702 getTokenStream :: Session -> Module -> IO [Located Token]
1705 -- -----------------------------------------------------------------------------
1706 -- Interactive evaluation
1710 -- | Set the interactive evaluation context.
1712 -- Setting the context doesn't throw away any bindings; the bindings
1713 -- we've built up in the InteractiveContext simply move to the new
1714 -- module. They always shadow anything in scope in the current context.
1715 setContext :: Session
1716 -> [Module] -- entire top level scope of these modules
1717 -> [Module] -- exports only of these modules
1719 setContext (Session ref) toplevs exports = do
1720 hsc_env <- readIORef ref
1721 let old_ic = hsc_IC hsc_env
1722 hpt = hsc_HPT hsc_env
1724 mapM_ (checkModuleExists hsc_env hpt) exports
1725 export_env <- mkExportEnv hsc_env exports
1726 toplev_envs <- mapM (mkTopLevEnv hpt) toplevs
1727 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
1728 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplevs,
1729 ic_exports = exports,
1730 ic_rn_gbl_env = all_env } }
1732 -- Make a GlobalRdrEnv based on the exports of the modules only.
1733 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
1734 mkExportEnv hsc_env mods = do
1735 stuff <- mapM (getModuleExports hsc_env) mods
1737 (_msgs, mb_name_sets) = unzip stuff
1738 gres = [ nameSetToGlobalRdrEnv name_set mod
1739 | (Just name_set, mod) <- zip mb_name_sets mods ]
1741 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
1743 nameSetToGlobalRdrEnv :: NameSet -> Module -> GlobalRdrEnv
1744 nameSetToGlobalRdrEnv names mod =
1745 mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod }
1746 | name <- nameSetToList names ]
1748 vanillaProv :: Module -> Provenance
1749 -- We're building a GlobalRdrEnv as if the user imported
1750 -- all the specified modules into the global interactive module
1751 vanillaProv mod = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
1753 decl = ImpDeclSpec { is_mod = mod, is_as = mod,
1755 is_dloc = srcLocSpan interactiveSrcLoc }
1757 checkModuleExists :: HscEnv -> HomePackageTable -> Module -> IO ()
1758 checkModuleExists hsc_env hpt mod =
1759 case lookupModuleEnv hpt mod of
1760 Just mod_info -> return ()
1761 _not_a_home_module -> do
1762 res <- findPackageModule hsc_env mod True
1764 Found _ _ -> return ()
1765 err -> let msg = cantFindError (hsc_dflags hsc_env) mod err in
1766 throwDyn (CmdLineError (showSDoc msg))
1768 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
1769 mkTopLevEnv hpt modl
1770 = case lookupModuleEnv hpt modl of
1772 throwDyn (ProgramError ("mkTopLevEnv: not a home module "
1773 ++ showSDoc (pprModule modl)))
1775 case mi_globals (hm_iface details) of
1777 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
1778 ++ showSDoc (pprModule modl)))
1779 Just env -> return env
1781 -- | Get the interactive evaluation context, consisting of a pair of the
1782 -- set of modules from which we take the full top-level scope, and the set
1783 -- of modules from which we take just the exports respectively.
1784 getContext :: Session -> IO ([Module],[Module])
1785 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
1786 return (ic_toplev_scope ic, ic_exports ic))
1788 -- | Returns 'True' if the specified module is interpreted, and hence has
1789 -- its full top-level scope available.
1790 moduleIsInterpreted :: Session -> Module -> IO Bool
1791 moduleIsInterpreted s modl = withSession s $ \h ->
1792 case lookupModuleEnv (hsc_HPT h) modl of
1793 Just details -> return (isJust (mi_globals (hm_iface details)))
1794 _not_a_home_module -> return False
1796 -- | Looks up an identifier in the current interactive context (for :info)
1797 {-# DEPRECATED getInfo "we should be using parseName/lookupName instead" #-}
1798 getInfo :: Session -> String -> IO [GetInfoResult]
1799 getInfo s id = withSession s $ \hsc_env -> hscGetInfo hsc_env id
1801 -- | Returns all names in scope in the current interactive context
1802 getNamesInScope :: Session -> IO [Name]
1803 getNamesInScope s = withSession s $ \hsc_env -> do
1804 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
1806 -- | Parses a string as an identifier, and returns the list of 'Name's that
1807 -- the identifier can refer to in the current interactive context.
1808 parseName :: Session -> String -> IO [Name]
1809 parseName s str = withSession s $ \hsc_env -> do
1810 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
1811 case maybe_rdr_name of
1812 Nothing -> return []
1813 Just (L _ rdr_name) -> do
1814 mb_names <- tcRnLookupRdrName hsc_env rdr_name
1816 Nothing -> return []
1817 Just ns -> return ns
1818 -- ToDo: should return error messages
1820 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
1821 -- entity known to GHC, including 'Name's defined using 'runStmt'.
1822 lookupName :: Session -> Name -> IO (Maybe TyThing)
1823 lookupName s name = withSession s $ \hsc_env -> do
1824 case lookupTypeEnv (ic_type_env (hsc_IC hsc_env)) name of
1825 Just tt -> return (Just tt)
1827 eps <- readIORef (hsc_EPS hsc_env)
1828 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1830 -- -----------------------------------------------------------------------------
1831 -- Getting the type of an expression
1833 -- | Get the type of an expression
1834 exprType :: Session -> String -> IO (Maybe Type)
1835 exprType s expr = withSession s $ \hsc_env -> do
1836 maybe_stuff <- hscTcExpr hsc_env expr
1838 Nothing -> return Nothing
1839 Just ty -> return (Just tidy_ty)
1841 tidy_ty = tidyType emptyTidyEnv ty
1843 -- -----------------------------------------------------------------------------
1844 -- Getting the kind of a type
1846 -- | Get the kind of a type
1847 typeKind :: Session -> String -> IO (Maybe Kind)
1848 typeKind s str = withSession s $ \hsc_env -> do
1849 maybe_stuff <- hscKcType hsc_env str
1851 Nothing -> return Nothing
1852 Just kind -> return (Just kind)
1854 -----------------------------------------------------------------------------
1855 -- cmCompileExpr: compile an expression and deliver an HValue
1857 compileExpr :: Session -> String -> IO (Maybe HValue)
1858 compileExpr s expr = withSession s $ \hsc_env -> do
1859 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
1861 Nothing -> return Nothing
1862 Just (new_ic, names, hval) -> do
1864 hvals <- (unsafeCoerce# hval) :: IO [HValue]
1866 case (names,hvals) of
1867 ([n],[hv]) -> return (Just hv)
1868 _ -> panic "compileExpr"
1870 -- -----------------------------------------------------------------------------
1871 -- running a statement interactively
1874 = RunOk [Name] -- ^ names bound by this evaluation
1875 | RunFailed -- ^ statement failed compilation
1876 | RunException Exception -- ^ statement raised an exception
1878 -- | Run a statement in the current interactive context. Statemenet
1879 -- may bind multple values.
1880 runStmt :: Session -> String -> IO RunResult
1881 runStmt (Session ref) expr
1883 hsc_env <- readIORef ref
1885 -- Turn off -fwarn-unused-bindings when running a statement, to hide
1886 -- warnings about the implicit bindings we introduce.
1887 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
1888 hsc_env' = hsc_env{ hsc_dflags = dflags' }
1890 maybe_stuff <- hscStmt hsc_env' expr
1893 Nothing -> return RunFailed
1894 Just (new_hsc_env, names, hval) -> do
1896 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
1897 either_hvals <- sandboxIO thing_to_run
1899 case either_hvals of
1901 -- on error, keep the *old* interactive context,
1902 -- so that 'it' is not bound to something
1903 -- that doesn't exist.
1904 return (RunException e)
1907 -- Get the newly bound things, and bind them.
1908 -- Don't need to delete any shadowed bindings;
1909 -- the new ones override the old ones.
1910 extendLinkEnv (zip names hvals)
1912 writeIORef ref new_hsc_env
1913 return (RunOk names)
1916 -- We run the statement in a "sandbox" to protect the rest of the
1917 -- system from anything the expression might do. For now, this
1918 -- consists of just wrapping it in an exception handler, but see below
1919 -- for another version.
1921 sandboxIO :: IO a -> IO (Either Exception a)
1922 sandboxIO thing = Exception.try thing
1925 -- This version of sandboxIO runs the expression in a completely new
1926 -- RTS main thread. It is disabled for now because ^C exceptions
1927 -- won't be delivered to the new thread, instead they'll be delivered
1928 -- to the (blocked) GHCi main thread.
1930 -- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
1932 sandboxIO :: IO a -> IO (Either Int (Either Exception a))
1933 sandboxIO thing = do
1934 st_thing <- newStablePtr (Exception.try thing)
1935 alloca $ \ p_st_result -> do
1936 stat <- rts_evalStableIO st_thing p_st_result
1937 freeStablePtr st_thing
1939 then do st_result <- peek p_st_result
1940 result <- deRefStablePtr st_result
1941 freeStablePtr st_result
1942 return (Right result)
1944 return (Left (fromIntegral stat))
1946 foreign import "rts_evalStableIO" {- safe -}
1947 rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
1948 -- more informative than the C type!
1951 -- ---------------------------------------------------------------------------
1952 -- cmBrowseModule: get all the TyThings defined in a module
1954 {-# DEPRECATED browseModule "we should be using getModuleInfo instead" #-}
1955 browseModule :: Session -> Module -> Bool -> IO [IfaceDecl]
1956 browseModule s modl exports_only = withSession s $ \hsc_env -> do
1957 mb_decls <- getModuleContents hsc_env modl exports_only
1959 Nothing -> return [] -- An error of some kind
1960 Just ds -> return ds
1963 -----------------------------------------------------------------------------
1964 -- show a module and it's source/object filenames
1966 showModule :: Session -> ModSummary -> IO String
1967 showModule s mod_summary = withSession s $ \hsc_env -> do
1968 case lookupModuleEnv (hsc_HPT hsc_env) (ms_mod mod_summary) of
1969 Nothing -> panic "missing linkable"
1970 Just mod_info -> return (showModMsg obj_linkable mod_summary)
1972 obj_linkable = isObjectLinkable (fromJust (hm_linkable mod_info))