1 -- -----------------------------------------------------------------------------
3 -- (c) The University of Glasgow, 2005
7 -- -----------------------------------------------------------------------------
13 defaultCleanupHandler,
17 -- * Flags and settings
18 DynFlags(..), DynFlag(..), Severity(..), GhcMode(..), HscTarget(..), dopt,
25 Target(..), TargetId(..), Phase,
32 -- * Loading\/compiling the program
34 load, LoadHowMuch(..), SuccessFlag(..), -- also does depanal
35 workingDirectoryChanged,
36 checkModule, CheckedModule(..),
37 TypecheckedSource, ParsedSource, RenamedSource,
39 -- * Inspecting the module structure of the program
40 ModuleGraph, ModSummary(..),
45 -- * Inspecting modules
50 modInfoPrintUnqualified,
53 modInfoIsExportedName,
58 PrintUnqualified, alwaysQualify,
60 -- * Interactive evaluation
61 getBindings, getPrintUnqual,
63 setContext, getContext,
77 -- * Abstract syntax elements
80 Module, mkModule, pprModule,
84 nameModule, nameParent_maybe, pprParenSymName, nameSrcLoc,
89 isImplicitId, isDeadBinder,
90 isExportedId, isLocalId, isGlobalId,
92 isPrimOpId, isFCallId, isClassOpId_maybe,
93 isDataConWorkId, idDataCon,
94 isBottomingId, isDictonaryId,
95 recordSelectorFieldLabel,
97 -- ** Type constructors
99 tyConTyVars, tyConDataCons, tyConArity,
100 isClassTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
107 -- ** Data constructors
109 dataConSig, dataConType, dataConTyCon, dataConFieldLabels,
110 dataConIsInfix, isVanillaDataCon,
112 StrictnessMark(..), isMarkedStrict,
116 classMethods, classSCTheta, classTvsFds,
121 instanceDFunId, pprInstance, pprInstanceHdr,
123 -- ** Types and Kinds
124 Type, dropForAlls, splitForAllTys, funResultTy, pprParendType,
127 ThetaType, pprThetaArrow,
133 module HsSyn, -- ToDo: remove extraneous bits
137 defaultFixity, maxPrecedence,
141 -- ** Source locations
145 GhcException(..), showGhcException,
155 * inline bits of HscMain here to simplify layering: hscTcExpr, hscStmt.
156 * we need to expose DynFlags, so should parseDynamicFlags really be
157 part of this interface?
158 * what StaticFlags should we expose, if any?
161 #include "HsVersions.h"
164 import qualified Linker
165 import Linker ( HValue, extendLinkEnv )
166 import TcRnDriver ( tcRnLookupRdrName, tcRnGetInfo,
167 tcRnLookupName, getModuleExports )
168 import RdrName ( plusGlobalRdrEnv, Provenance(..),
169 ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
170 emptyGlobalRdrEnv, mkGlobalRdrEnv )
171 import HscMain ( hscParseIdentifier, hscStmt, hscTcExpr, hscKcType )
172 import Type ( tidyType )
173 import VarEnv ( emptyTidyEnv )
174 import GHC.Exts ( unsafeCoerce# )
177 import Packages ( initPackages )
178 import NameSet ( NameSet, nameSetToList, elemNameSet )
179 import RdrName ( GlobalRdrEnv, GlobalRdrElt(..), RdrName,
182 import Type ( Kind, Type, dropForAlls, PredType, ThetaType,
183 pprThetaArrow, pprParendType, splitForAllTys,
185 import Id ( Id, idType, isImplicitId, isDeadBinder,
186 isExportedId, isLocalId, isGlobalId,
187 isRecordSelector, recordSelectorFieldLabel,
188 isPrimOpId, isFCallId, isClassOpId_maybe,
189 isDataConWorkId, idDataCon,
192 import TysPrim ( alphaTyVars )
193 import TyCon ( TyCon, isClassTyCon, isSynTyCon, isNewTyCon,
194 isPrimTyCon, tyConArity,
195 tyConTyVars, tyConDataCons, getSynTyConDefn )
196 import Class ( Class, classSCTheta, classTvsFds, classMethods )
197 import FunDeps ( pprFundeps )
198 import DataCon ( DataCon, dataConWrapId, dataConSig, dataConTyCon,
199 dataConFieldLabels, dataConStrictMarks,
200 dataConIsInfix, isVanillaDataCon )
201 import Name ( Name, nameModule, NamedThing(..), nameParent_maybe,
203 import OccName ( parenSymOcc )
204 import NameEnv ( nameEnvElts )
205 import InstEnv ( Instance, instanceDFunId, pprInstance, pprInstanceHdr )
207 import DriverPipeline
208 import DriverPhases ( Phase(..), isHaskellSrcFilename, startPhase )
209 import GetImports ( getImports )
210 import Packages ( isHomePackage )
212 import HscMain ( newHscEnv, hscFileCheck, HscResult(..) )
216 import SysTools ( initSysTools, cleanTempFiles )
221 import Bag ( unitBag )
222 import ErrUtils ( Severity(..), showPass, Messages, fatalErrorMsg, debugTraceMsg,
223 mkPlainErrMsg, printBagOfErrors, printErrorsAndWarnings )
224 import qualified ErrUtils
225 import PrelNames ( mAIN )
227 import StringBuffer ( StringBuffer, hGetStringBuffer )
229 import SysTools ( cleanTempFilesExcept )
231 import TcType ( tcSplitSigmaTy, isDictTy )
232 import FastString ( mkFastString )
234 import Directory ( getModificationTime, doesFileExist )
235 import Maybe ( isJust, isNothing, fromJust )
236 import Maybes ( orElse, expectJust, mapCatMaybes )
237 import List ( partition, nub )
238 import qualified List
239 import Monad ( unless, when )
240 import System ( exitWith, ExitCode(..) )
241 import Time ( ClockTime )
242 import EXCEPTION as Exception hiding (handle)
245 import Prelude hiding (init)
247 -- -----------------------------------------------------------------------------
248 -- Exception handlers
250 -- | Install some default exception handlers and run the inner computation.
251 -- Unless you want to handle exceptions yourself, you should wrap this around
252 -- the top level of your program. The default handlers output the error
253 -- message(s) to stderr and exit cleanly.
254 defaultErrorHandler :: DynFlags -> IO a -> IO a
255 defaultErrorHandler dflags inner =
256 -- top-level exception handler: any unrecognised exception is a compiler bug.
257 handle (\exception -> do
260 -- an IO exception probably isn't our fault, so don't panic
262 fatalErrorMsg dflags (text (show exception))
263 AsyncException StackOverflow ->
264 fatalErrorMsg dflags (text "stack overflow: use +RTS -K<size> to increase it")
266 fatalErrorMsg dflags (text (show (Panic (show exception))))
267 exitWith (ExitFailure 1)
270 -- program errors: messages with locations attached. Sometimes it is
271 -- convenient to just throw these as exceptions.
272 handleDyn (\dyn -> do printBagOfErrors dflags (unitBag dyn)
273 exitWith (ExitFailure 1)) $
275 -- error messages propagated as exceptions
276 handleDyn (\dyn -> do
279 PhaseFailed _ code -> exitWith code
280 Interrupted -> exitWith (ExitFailure 1)
281 _ -> do fatalErrorMsg dflags (text (show (dyn :: GhcException)))
282 exitWith (ExitFailure 1)
286 -- | Install a default cleanup handler to remove temporary files
287 -- deposited by a GHC run. This is seperate from
288 -- 'defaultErrorHandler', because you might want to override the error
289 -- handling, but still get the ordinary cleanup behaviour.
290 defaultCleanupHandler :: DynFlags -> IO a -> IO a
291 defaultCleanupHandler dflags inner =
292 -- make sure we clean up after ourselves
293 later (unless (dopt Opt_KeepTmpFiles dflags) $
294 cleanTempFiles dflags)
295 -- exceptions will be blocked while we clean the temporary files,
296 -- so there shouldn't be any difficulty if we receive further
301 -- | Initialises GHC. This must be done /once/ only. Takes the
302 -- command-line arguments. All command-line arguments which aren't
303 -- understood by GHC will be returned.
305 init :: [String] -> IO [String]
308 installSignalHandlers
310 -- Grab the -B option if there is one
311 let (minusB_args, argv1) = partition (prefixMatch "-B") args
312 dflags0 <- initSysTools minusB_args defaultDynFlags
313 writeIORef v_initDynFlags dflags0
315 -- Parse the static flags
316 argv2 <- parseStaticFlags argv1
319 GLOBAL_VAR(v_initDynFlags, error "initDynFlags", DynFlags)
320 -- stores the DynFlags between the call to init and subsequent
321 -- calls to newSession.
323 -- | Starts a new session. A session consists of a set of loaded
324 -- modules, a set of options (DynFlags), and an interactive context.
325 -- ToDo: GhcMode should say "keep typechecked code" and\/or "keep renamed
327 newSession :: GhcMode -> IO Session
329 dflags0 <- readIORef v_initDynFlags
330 dflags <- initDynFlags dflags0
331 env <- newHscEnv dflags{ ghcMode=mode }
335 -- tmp: this breaks the abstraction, but required because DriverMkDepend
336 -- needs to call the Finder. ToDo: untangle this.
337 sessionHscEnv :: Session -> IO HscEnv
338 sessionHscEnv (Session ref) = readIORef ref
340 withSession :: Session -> (HscEnv -> IO a) -> IO a
341 withSession (Session ref) f = do h <- readIORef ref; f h
343 modifySession :: Session -> (HscEnv -> HscEnv) -> IO ()
344 modifySession (Session ref) f = do h <- readIORef ref; writeIORef ref $! f h
346 -- -----------------------------------------------------------------------------
349 -- | Grabs the DynFlags from the Session
350 getSessionDynFlags :: Session -> IO DynFlags
351 getSessionDynFlags s = withSession s (return . hsc_dflags)
353 -- | Updates the DynFlags in a Session
354 setSessionDynFlags :: Session -> DynFlags -> IO ()
355 setSessionDynFlags s dflags = modifySession s (\h -> h{ hsc_dflags = dflags })
357 -- | If there is no -o option, guess the name of target executable
358 -- by using top-level source file name as a base.
359 guessOutputFile :: Session -> IO ()
360 guessOutputFile s = modifySession s $ \env ->
361 let dflags = hsc_dflags env
362 mod_graph = hsc_mod_graph env
363 mainModuleSrcPath, guessedName :: Maybe String
364 mainModuleSrcPath = do
365 let isMain = (== mainModIs dflags) . ms_mod
366 [ms] <- return (filter isMain mod_graph)
367 ml_hs_file (ms_location ms)
368 guessedName = fmap basenameOf mainModuleSrcPath
370 case outputFile dflags of
372 Nothing -> env { hsc_dflags = dflags { outputFile = guessedName } }
374 -- -----------------------------------------------------------------------------
377 -- ToDo: think about relative vs. absolute file paths. And what
378 -- happens when the current directory changes.
380 -- | Sets the targets for this session. Each target may be a module name
381 -- or a filename. The targets correspond to the set of root modules for
382 -- the program\/library. Unloading the current program is achieved by
383 -- setting the current set of targets to be empty, followed by load.
384 setTargets :: Session -> [Target] -> IO ()
385 setTargets s targets = modifySession s (\h -> h{ hsc_targets = targets })
387 -- | returns the current set of targets
388 getTargets :: Session -> IO [Target]
389 getTargets s = withSession s (return . hsc_targets)
391 -- | Add another target
392 addTarget :: Session -> Target -> IO ()
394 = modifySession s (\h -> h{ hsc_targets = target : hsc_targets h })
397 removeTarget :: Session -> TargetId -> IO ()
398 removeTarget s target_id
399 = modifySession s (\h -> h{ hsc_targets = filter (hsc_targets h) })
401 filter targets = [ t | t@(Target id _) <- targets, id /= target_id ]
403 -- Attempts to guess what Target a string refers to. This function implements
404 -- the --make/GHCi command-line syntax for filenames:
406 -- - if the string looks like a Haskell source filename, then interpret
408 -- - if adding a .hs or .lhs suffix yields the name of an existing file,
410 -- - otherwise interpret the string as a module name
412 guessTarget :: String -> Maybe Phase -> IO Target
413 guessTarget file (Just phase)
414 = return (Target (TargetFile file (Just phase)) Nothing)
415 guessTarget file Nothing
416 | isHaskellSrcFilename file
417 = return (Target (TargetFile file Nothing) Nothing)
419 = do exists <- doesFileExist hs_file
421 then return (Target (TargetFile hs_file Nothing) Nothing)
423 exists <- doesFileExist lhs_file
425 then return (Target (TargetFile lhs_file Nothing) Nothing)
427 return (Target (TargetModule (mkModule file)) Nothing)
429 hs_file = file `joinFileExt` "hs"
430 lhs_file = file `joinFileExt` "lhs"
432 -- -----------------------------------------------------------------------------
433 -- Loading the program
435 -- Perform a dependency analysis starting from the current targets
436 -- and update the session with the new module graph.
437 depanal :: Session -> [Module] -> Bool -> IO (Maybe ModuleGraph)
438 depanal (Session ref) excluded_mods allow_dup_roots = do
439 hsc_env <- readIORef ref
441 dflags = hsc_dflags hsc_env
442 gmode = ghcMode (hsc_dflags hsc_env)
443 targets = hsc_targets hsc_env
444 old_graph = hsc_mod_graph hsc_env
446 showPass dflags "Chasing dependencies"
447 when (gmode == BatchCompile) $
448 debugTraceMsg dflags 1 (hcat [
449 text "Chasing modules from: ",
450 hcat (punctuate comma (map pprTarget targets))])
452 r <- downsweep hsc_env old_graph excluded_mods allow_dup_roots
454 Just mod_graph -> writeIORef ref hsc_env{ hsc_mod_graph = mod_graph }
459 -- | The result of load.
461 = LoadOk Errors -- ^ all specified targets were loaded successfully.
462 | LoadFailed Errors -- ^ not all modules were loaded.
464 type Errors = [String]
466 data ErrMsg = ErrMsg {
467 errMsgSeverity :: Severity, -- warning, error, etc.
468 errMsgSpans :: [SrcSpan],
469 errMsgShortDoc :: Doc,
470 errMsgExtraInfo :: Doc
477 | LoadDependenciesOf Module
479 -- | Try to load the program. If a Module is supplied, then just
480 -- attempt to load up to this target. If no Module is supplied,
481 -- then try to load all targets.
482 load :: Session -> LoadHowMuch -> IO SuccessFlag
483 load s@(Session ref) how_much
485 -- Dependency analysis first. Note that this fixes the module graph:
486 -- even if we don't get a fully successful upsweep, the full module
487 -- graph is still retained in the Session. We can tell which modules
488 -- were successfully loaded by inspecting the Session's HPT.
489 mb_graph <- depanal s [] False
491 Just mod_graph -> load2 s how_much mod_graph
492 Nothing -> return Failed
494 load2 s@(Session ref) how_much mod_graph = do
496 hsc_env <- readIORef ref
498 let hpt1 = hsc_HPT hsc_env
499 let dflags = hsc_dflags hsc_env
500 let ghci_mode = ghcMode dflags -- this never changes
502 -- The "bad" boot modules are the ones for which we have
503 -- B.hs-boot in the module graph, but no B.hs
504 -- The downsweep should have ensured this does not happen
506 let all_home_mods = [ms_mod s | s <- mod_graph, not (isBootSummary s)]
508 bad_boot_mods = [s | s <- mod_graph, isBootSummary s,
509 not (ms_mod s `elem` all_home_mods)]
511 ASSERT( null bad_boot_mods ) return ()
513 -- mg2_with_srcimps drops the hi-boot nodes, returning a
514 -- graph with cycles. Among other things, it is used for
515 -- backing out partially complete cycles following a failed
516 -- upsweep, and for removing from hpt all the modules
517 -- not in strict downwards closure, during calls to compile.
518 let mg2_with_srcimps :: [SCC ModSummary]
519 mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing
521 -- check the stability property for each module.
522 stable_mods@(stable_obj,stable_bco)
523 | BatchCompile <- ghci_mode = ([],[])
524 | otherwise = checkStability hpt1 mg2_with_srcimps all_home_mods
526 -- prune bits of the HPT which are definitely redundant now,
528 pruned_hpt = pruneHomePackageTable hpt1
529 (flattenSCCs mg2_with_srcimps)
534 debugTraceMsg dflags 2 (text "Stable obj:" <+> ppr stable_obj $$
535 text "Stable BCO:" <+> ppr stable_bco)
537 -- Unload any modules which are going to be re-linked this time around.
538 let stable_linkables = [ linkable
539 | m <- stable_obj++stable_bco,
540 Just hmi <- [lookupModuleEnv pruned_hpt m],
541 Just linkable <- [hm_linkable hmi] ]
542 unload hsc_env stable_linkables
544 -- We could at this point detect cycles which aren't broken by
545 -- a source-import, and complain immediately, but it seems better
546 -- to let upsweep_mods do this, so at least some useful work gets
547 -- done before the upsweep is abandoned.
548 --hPutStrLn stderr "after tsort:\n"
549 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
551 -- Now do the upsweep, calling compile for each module in
552 -- turn. Final result is version 3 of everything.
554 -- Topologically sort the module graph, this time including hi-boot
555 -- nodes, and possibly just including the portion of the graph
556 -- reachable from the module specified in the 2nd argument to load.
557 -- This graph should be cycle-free.
558 -- If we're restricting the upsweep to a portion of the graph, we
559 -- also want to retain everything that is still stable.
560 let full_mg :: [SCC ModSummary]
561 full_mg = topSortModuleGraph False mod_graph Nothing
563 maybe_top_mod = case how_much of
565 LoadDependenciesOf m -> Just m
568 partial_mg0 :: [SCC ModSummary]
569 partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod
571 -- LoadDependenciesOf m: we want the upsweep to stop just
572 -- short of the specified module (unless the specified module
575 | LoadDependenciesOf mod <- how_much
576 = ASSERT( case last partial_mg0 of
577 AcyclicSCC ms -> ms_mod ms == mod; _ -> False )
578 List.init partial_mg0
584 | AcyclicSCC ms <- full_mg,
585 ms_mod ms `elem` stable_obj++stable_bco,
586 ms_mod ms `notElem` [ ms_mod ms' |
587 AcyclicSCC ms' <- partial_mg ] ]
589 mg = stable_mg ++ partial_mg
591 -- clean up between compilations
592 let cleanup = cleanTempFilesExcept dflags
593 (ppFilesFromSummaries (flattenSCCs mg2_with_srcimps))
595 (upsweep_ok, hsc_env1, modsUpswept)
596 <- upsweep (hsc_env { hsc_HPT = emptyHomePackageTable })
597 pruned_hpt stable_mods cleanup mg
599 -- Make modsDone be the summaries for each home module now
600 -- available; this should equal the domain of hpt3.
601 -- Get in in a roughly top .. bottom order (hence reverse).
603 let modsDone = reverse modsUpswept
605 -- Try and do linking in some form, depending on whether the
606 -- upsweep was completely or only partially successful.
608 if succeeded upsweep_ok
611 -- Easy; just relink it all.
612 do debugTraceMsg dflags 2 (text "Upsweep completely successful.")
614 -- Clean up after ourselves
615 cleanTempFilesExcept dflags (ppFilesFromSummaries modsDone)
617 -- Issue a warning for the confusing case where the user
618 -- said '-o foo' but we're not going to do any linking.
619 -- We attempt linking if either (a) one of the modules is
620 -- called Main, or (b) the user said -no-hs-main, indicating
621 -- that main() is going to come from somewhere else.
623 let ofile = outputFile dflags
624 let no_hs_main = dopt Opt_NoHsMain dflags
626 main_mod = mainModIs dflags
627 a_root_is_Main = any ((==main_mod).ms_mod) mod_graph
628 do_linking = a_root_is_Main || no_hs_main
630 when (ghci_mode == BatchCompile && isJust ofile && not do_linking) $
631 debugTraceMsg dflags 1 (text ("Warning: output was redirected with -o, " ++
632 "but no output will be generated\n" ++
633 "because there is no " ++ moduleUserString main_mod ++ " module."))
635 -- link everything together
636 linkresult <- link ghci_mode dflags do_linking (hsc_HPT hsc_env1)
638 loadFinish Succeeded linkresult ref hsc_env1
641 -- Tricky. We need to back out the effects of compiling any
642 -- half-done cycles, both so as to clean up the top level envs
643 -- and to avoid telling the interactive linker to link them.
644 do debugTraceMsg dflags 2 (text "Upsweep partially successful.")
647 = map ms_mod modsDone
648 let mods_to_zap_names
649 = findPartiallyCompletedCycles modsDone_names
652 = filter ((`notElem` mods_to_zap_names).ms_mod)
655 let hpt4 = retainInTopLevelEnvs (map ms_mod mods_to_keep)
658 -- Clean up after ourselves
659 cleanTempFilesExcept dflags (ppFilesFromSummaries mods_to_keep)
661 -- there should be no Nothings where linkables should be, now
662 ASSERT(all (isJust.hm_linkable)
663 (moduleEnvElts (hsc_HPT hsc_env))) do
665 -- Link everything together
666 linkresult <- link ghci_mode dflags False hpt4
668 let hsc_env4 = hsc_env1{ hsc_HPT = hpt4 }
669 loadFinish Failed linkresult ref hsc_env4
671 -- Finish up after a load.
673 -- If the link failed, unload everything and return.
674 loadFinish all_ok Failed ref hsc_env
675 = do unload hsc_env []
676 writeIORef ref $! discardProg hsc_env
679 -- Empty the interactive context and set the module context to the topmost
680 -- newly loaded module, or the Prelude if none were loaded.
681 loadFinish all_ok Succeeded ref hsc_env
682 = do writeIORef ref $! hsc_env{ hsc_IC = emptyInteractiveContext }
686 -- Forget the current program, but retain the persistent info in HscEnv
687 discardProg :: HscEnv -> HscEnv
689 = hsc_env { hsc_mod_graph = emptyMG,
690 hsc_IC = emptyInteractiveContext,
691 hsc_HPT = emptyHomePackageTable }
693 -- used to fish out the preprocess output files for the purposes of
694 -- cleaning up. The preprocessed file *might* be the same as the
695 -- source file, but that doesn't do any harm.
696 ppFilesFromSummaries summaries = [ fn | Just fn <- map ms_hspp_file summaries ]
698 -- -----------------------------------------------------------------------------
702 CheckedModule { parsedSource :: ParsedSource,
703 renamedSource :: Maybe RenamedSource,
704 typecheckedSource :: Maybe TypecheckedSource,
705 checkedModuleInfo :: Maybe ModuleInfo
707 -- ToDo: improvements that could be made here:
708 -- if the module succeeded renaming but not typechecking,
709 -- we can still get back the GlobalRdrEnv and exports, so
710 -- perhaps the ModuleInfo should be split up into separate
711 -- fields within CheckedModule.
713 type ParsedSource = Located (HsModule RdrName)
714 type RenamedSource = HsGroup Name
715 type TypecheckedSource = LHsBinds Id
718 -- - things that aren't in the output of the renamer:
721 -- - things that aren't in the output of the typechecker right now:
725 -- - type/data/newtype declarations
726 -- - class declarations
728 -- - extra things in the typechecker's output:
729 -- - default methods are turned into top-level decls.
730 -- - dictionary bindings
733 -- | This is the way to get access to parsed and typechecked source code
734 -- for a module. 'checkModule' loads all the dependencies of the specified
735 -- module in the Session, and then attempts to typecheck the module. If
736 -- successful, it returns the abstract syntax for the module.
737 checkModule :: Session -> Module -> IO (Maybe CheckedModule)
738 checkModule session@(Session ref) mod = do
739 -- load up the dependencies first
740 r <- load session (LoadDependenciesOf mod)
741 if (failed r) then return Nothing else do
743 -- now parse & typecheck the module
744 hsc_env <- readIORef ref
745 let mg = hsc_mod_graph hsc_env
746 case [ ms | ms <- mg, ms_mod ms == mod ] of
749 -- Add in the OPTIONS from the source file This is nasty:
750 -- we've done this once already, in the compilation manager
751 -- It might be better to cache the flags in the
752 -- ml_hspp_file field, say
753 let dflags0 = hsc_dflags hsc_env
754 hspp_buf = expectJust "GHC.checkModule" (ms_hspp_buf ms)
755 filename = fromJust (ml_hs_file (ms_location ms))
756 opts = getOptionsFromStringBuffer hspp_buf filename
757 (dflags1,leftovers) <- parseDynamicFlags dflags0 (map snd opts)
758 if (not (null leftovers))
759 then do printErrorsAndWarnings dflags1 (optionsErrorMsgs leftovers opts filename)
763 r <- hscFileCheck hsc_env{hsc_dflags=dflags1} ms
767 HscChecked parsed renamed Nothing ->
768 return (Just (CheckedModule {
769 parsedSource = parsed,
770 renamedSource = renamed,
771 typecheckedSource = Nothing,
772 checkedModuleInfo = Nothing }))
773 HscChecked parsed renamed
774 (Just (tc_binds, rdr_env, details)) -> do
775 let minf = ModuleInfo {
776 minf_type_env = md_types details,
777 minf_exports = md_exports details,
778 minf_rdr_env = Just rdr_env,
779 minf_instances = md_insts details
781 return (Just (CheckedModule {
782 parsedSource = parsed,
783 renamedSource = renamed,
784 typecheckedSource = Just tc_binds,
785 checkedModuleInfo = Just minf }))
789 -- ---------------------------------------------------------------------------
792 unload :: HscEnv -> [Linkable] -> IO ()
793 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
794 = case ghcMode (hsc_dflags hsc_env) of
795 BatchCompile -> return ()
796 JustTypecheck -> return ()
798 Interactive -> Linker.unload (hsc_dflags hsc_env) stable_linkables
800 Interactive -> panic "unload: no interpreter"
802 other -> panic "unload: strange mode"
804 -- -----------------------------------------------------------------------------
808 Stability tells us which modules definitely do not need to be recompiled.
809 There are two main reasons for having stability:
811 - avoid doing a complete upsweep of the module graph in GHCi when
812 modules near the bottom of the tree have not changed.
814 - to tell GHCi when it can load object code: we can only load object code
815 for a module when we also load object code fo all of the imports of the
816 module. So we need to know that we will definitely not be recompiling
817 any of these modules, and we can use the object code.
819 NB. stability is of no importance to BatchCompile at all, only Interactive.
820 (ToDo: what about JustTypecheck?)
822 The stability check is as follows. Both stableObject and
823 stableBCO are used during the upsweep phase later.
826 stable m = stableObject m || stableBCO m
829 all stableObject (imports m)
830 && old linkable does not exist, or is == on-disk .o
831 && date(on-disk .o) > date(.hs)
834 all stable (imports m)
835 && date(BCO) > date(.hs)
838 These properties embody the following ideas:
840 - if a module is stable:
841 - if it has been compiled in a previous pass (present in HPT)
842 then it does not need to be compiled or re-linked.
843 - if it has not been compiled in a previous pass,
844 then we only need to read its .hi file from disk and
845 link it to produce a ModDetails.
847 - if a modules is not stable, we will definitely be at least
848 re-linking, and possibly re-compiling it during the upsweep.
849 All non-stable modules can (and should) therefore be unlinked
852 - Note that objects are only considered stable if they only depend
853 on other objects. We can't link object code against byte code.
857 :: HomePackageTable -- HPT from last compilation
858 -> [SCC ModSummary] -- current module graph (cyclic)
859 -> [Module] -- all home modules
860 -> ([Module], -- stableObject
861 [Module]) -- stableBCO
863 checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
865 checkSCC (stable_obj, stable_bco) scc0
866 | stableObjects = (scc_mods ++ stable_obj, stable_bco)
867 | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
868 | otherwise = (stable_obj, stable_bco)
870 scc = flattenSCC scc0
871 scc_mods = map ms_mod scc
872 home_module m = m `elem` all_home_mods && m `notElem` scc_mods
874 scc_allimps = nub (filter home_module (concatMap ms_allimps scc))
875 -- all imports outside the current SCC, but in the home pkg
877 stable_obj_imps = map (`elem` stable_obj) scc_allimps
878 stable_bco_imps = map (`elem` stable_bco) scc_allimps
885 and (zipWith (||) stable_obj_imps stable_bco_imps)
889 | Just t <- ms_obj_date ms = t >= ms_hs_date ms
893 same_as_prev t = case lookupModuleEnv hpt (ms_mod ms) of
894 Just hmi | Just l <- hm_linkable hmi
895 -> isObjectLinkable l && t == linkableTime l
897 -- why '>=' rather than '>' above? If the filesystem stores
898 -- times to the nearset second, we may occasionally find that
899 -- the object & source have the same modification time,
900 -- especially if the source was automatically generated
901 -- and compiled. Using >= is slightly unsafe, but it matches
905 = case lookupModuleEnv hpt (ms_mod ms) of
906 Just hmi | Just l <- hm_linkable hmi ->
907 not (isObjectLinkable l) &&
908 linkableTime l >= ms_hs_date ms
911 ms_allimps :: ModSummary -> [Module]
912 ms_allimps ms = map unLoc (ms_srcimps ms ++ ms_imps ms)
914 -- -----------------------------------------------------------------------------
915 -- Prune the HomePackageTable
917 -- Before doing an upsweep, we can throw away:
919 -- - For non-stable modules:
920 -- - all ModDetails, all linked code
921 -- - all unlinked code that is out of date with respect to
924 -- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
925 -- space at the end of the upsweep, because the topmost ModDetails of the
926 -- old HPT holds on to the entire type environment from the previous
929 pruneHomePackageTable
932 -> ([Module],[Module])
935 pruneHomePackageTable hpt summ (stable_obj, stable_bco)
936 = mapModuleEnv prune hpt
938 | is_stable modl = hmi'
939 | otherwise = hmi'{ hm_details = emptyModDetails }
941 modl = mi_module (hm_iface hmi)
942 hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
943 = hmi{ hm_linkable = Nothing }
946 where ms = expectJust "prune" (lookupModuleEnv ms_map modl)
948 ms_map = mkModuleEnv [(ms_mod ms, ms) | ms <- summ]
950 is_stable m = m `elem` stable_obj || m `elem` stable_bco
952 -- -----------------------------------------------------------------------------
954 -- Return (names of) all those in modsDone who are part of a cycle
955 -- as defined by theGraph.
956 findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
957 findPartiallyCompletedCycles modsDone theGraph
961 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
962 chew ((CyclicSCC vs):rest)
963 = let names_in_this_cycle = nub (map ms_mod vs)
965 = nub ([done | done <- modsDone,
966 done `elem` names_in_this_cycle])
967 chewed_rest = chew rest
969 if notNull mods_in_this_cycle
970 && length mods_in_this_cycle < length names_in_this_cycle
971 then mods_in_this_cycle ++ chewed_rest
974 -- -----------------------------------------------------------------------------
977 -- This is where we compile each module in the module graph, in a pass
978 -- from the bottom to the top of the graph.
980 -- There better had not be any cyclic groups here -- we check for them.
983 :: HscEnv -- Includes initially-empty HPT
984 -> HomePackageTable -- HPT from last time round (pruned)
985 -> ([Module],[Module]) -- stable modules (see checkStability)
986 -> IO () -- How to clean up unwanted tmp files
987 -> [SCC ModSummary] -- Mods to do (the worklist)
989 HscEnv, -- With an updated HPT
990 [ModSummary]) -- Mods which succeeded
992 upsweep hsc_env old_hpt stable_mods cleanup mods
993 = upsweep' hsc_env old_hpt stable_mods cleanup mods 1 (length mods)
995 upsweep' hsc_env old_hpt stable_mods cleanup
997 = return (Succeeded, hsc_env, [])
999 upsweep' hsc_env old_hpt stable_mods cleanup
1000 (CyclicSCC ms:_) _ _
1001 = do fatalErrorMsg (hsc_dflags hsc_env) (cyclicModuleErr ms)
1002 return (Failed, hsc_env, [])
1004 upsweep' hsc_env old_hpt stable_mods cleanup
1005 (AcyclicSCC mod:mods) mod_index nmods
1006 = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
1007 -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
1008 -- (moduleEnvElts (hsc_HPT hsc_env)))
1010 mb_mod_info <- upsweep_mod hsc_env old_hpt stable_mods mod
1013 cleanup -- Remove unwanted tmp files between compilations
1016 Nothing -> return (Failed, hsc_env, [])
1018 { let this_mod = ms_mod mod
1020 -- Add new info to hsc_env
1021 hpt1 = extendModuleEnv (hsc_HPT hsc_env)
1023 hsc_env1 = hsc_env { hsc_HPT = hpt1 }
1025 -- Space-saving: delete the old HPT entry
1026 -- for mod BUT if mod is a hs-boot
1027 -- node, don't delete it. For the
1028 -- interface, the HPT entry is probaby for the
1029 -- main Haskell source file. Deleting it
1030 -- would force .. (what?? --SDM)
1031 old_hpt1 | isBootSummary mod = old_hpt
1032 | otherwise = delModuleEnv old_hpt this_mod
1034 ; (restOK, hsc_env2, modOKs)
1035 <- upsweep' hsc_env1 old_hpt1 stable_mods cleanup
1036 mods (mod_index+1) nmods
1037 ; return (restOK, hsc_env2, mod:modOKs)
1041 -- Compile a single module. Always produce a Linkable for it if
1042 -- successful. If no compilation happened, return the old Linkable.
1043 upsweep_mod :: HscEnv
1045 -> ([Module],[Module])
1047 -> Int -- index of module
1048 -> Int -- total number of modules
1049 -> IO (Maybe HomeModInfo) -- Nothing => Failed
1051 upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) summary mod_index nmods
1054 this_mod = ms_mod summary
1055 mb_obj_date = ms_obj_date summary
1056 obj_fn = ml_obj_file (ms_location summary)
1057 hs_date = ms_hs_date summary
1059 compile_it :: Maybe Linkable -> IO (Maybe HomeModInfo)
1060 compile_it = upsweep_compile hsc_env old_hpt this_mod
1061 summary mod_index nmods
1063 case ghcMode (hsc_dflags hsc_env) of
1066 -- Batch-compilating is easy: just check whether we have
1067 -- an up-to-date object file. If we do, then the compiler
1068 -- needs to do a recompilation check.
1069 _ | Just obj_date <- mb_obj_date, obj_date >= hs_date -> do
1071 findObjectLinkable this_mod obj_fn obj_date
1072 compile_it (Just linkable)
1079 _ | is_stable_obj, isJust old_hmi ->
1081 -- object is stable, and we have an entry in the
1082 -- old HPT: nothing to do
1084 | is_stable_obj, isNothing old_hmi -> do
1086 findObjectLinkable this_mod obj_fn
1087 (expectJust "upseep1" mb_obj_date)
1088 compile_it (Just linkable)
1089 -- object is stable, but we need to load the interface
1090 -- off disk to make a HMI.
1093 ASSERT(isJust old_hmi) -- must be in the old_hpt
1095 -- BCO is stable: nothing to do
1097 | Just hmi <- old_hmi,
1098 Just l <- hm_linkable hmi, not (isObjectLinkable l),
1099 linkableTime l >= ms_hs_date summary ->
1101 -- we have an old BCO that is up to date with respect
1102 -- to the source: do a recompilation check as normal.
1106 -- no existing code at all: we must recompile.
1108 is_stable_obj = this_mod `elem` stable_obj
1109 is_stable_bco = this_mod `elem` stable_bco
1111 old_hmi = lookupModuleEnv old_hpt this_mod
1113 -- Run hsc to compile a module
1114 upsweep_compile hsc_env old_hpt this_mod summary
1116 mb_old_linkable = do
1118 -- The old interface is ok if it's in the old HPT
1119 -- a) we're compiling a source file, and the old HPT
1120 -- entry is for a source file
1121 -- b) we're compiling a hs-boot file
1122 -- Case (b) allows an hs-boot file to get the interface of its
1123 -- real source file on the second iteration of the compilation
1124 -- manager, but that does no harm. Otherwise the hs-boot file
1125 -- will always be recompiled
1128 = case lookupModuleEnv old_hpt this_mod of
1130 Just hm_info | isBootSummary summary -> Just iface
1131 | not (mi_boot iface) -> Just iface
1132 | otherwise -> Nothing
1134 iface = hm_iface hm_info
1136 compresult <- compile hsc_env summary mb_old_linkable mb_old_iface
1140 -- Compilation failed. Compile may still have updated the PCS, tho.
1141 CompErrs -> return Nothing
1143 -- Compilation "succeeded", and may or may not have returned a new
1144 -- linkable (depending on whether compilation was actually performed
1146 CompOK new_details new_iface new_linkable
1147 -> do let new_info = HomeModInfo { hm_iface = new_iface,
1148 hm_details = new_details,
1149 hm_linkable = new_linkable }
1150 return (Just new_info)
1153 -- Filter modules in the HPT
1154 retainInTopLevelEnvs :: [Module] -> HomePackageTable -> HomePackageTable
1155 retainInTopLevelEnvs keep_these hpt
1156 = mkModuleEnv [ (mod, expectJust "retain" mb_mod_info)
1158 , let mb_mod_info = lookupModuleEnv hpt mod
1159 , isJust mb_mod_info ]
1161 -- ---------------------------------------------------------------------------
1162 -- Topological sort of the module graph
1165 :: Bool -- Drop hi-boot nodes? (see below)
1169 -- Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
1170 -- The resulting list of strongly-connected-components is in topologically
1171 -- sorted order, starting with the module(s) at the bottom of the
1172 -- dependency graph (ie compile them first) and ending with the ones at
1175 -- Drop hi-boot nodes (first boolean arg)?
1177 -- False: treat the hi-boot summaries as nodes of the graph,
1178 -- so the graph must be acyclic
1180 -- True: eliminate the hi-boot nodes, and instead pretend
1181 -- the a source-import of Foo is an import of Foo
1182 -- The resulting graph has no hi-boot nodes, but can by cyclic
1184 topSortModuleGraph drop_hs_boot_nodes summaries Nothing
1185 = stronglyConnComp (fst (moduleGraphNodes drop_hs_boot_nodes summaries))
1186 topSortModuleGraph drop_hs_boot_nodes summaries (Just mod)
1187 = stronglyConnComp (map vertex_fn (reachable graph root))
1189 -- restrict the graph to just those modules reachable from
1190 -- the specified module. We do this by building a graph with
1191 -- the full set of nodes, and determining the reachable set from
1192 -- the specified node.
1193 (nodes, lookup_key) = moduleGraphNodes drop_hs_boot_nodes summaries
1194 (graph, vertex_fn, key_fn) = graphFromEdges' nodes
1196 | Just key <- lookup_key HsSrcFile mod, Just v <- key_fn key = v
1197 | otherwise = throwDyn (ProgramError "module does not exist")
1199 moduleGraphNodes :: Bool -> [ModSummary]
1200 -> ([(ModSummary, Int, [Int])], HscSource -> Module -> Maybe Int)
1201 moduleGraphNodes drop_hs_boot_nodes summaries = (nodes, lookup_key)
1203 -- Drop hs-boot nodes by using HsSrcFile as the key
1204 hs_boot_key | drop_hs_boot_nodes = HsSrcFile
1205 | otherwise = HsBootFile
1207 -- We use integers as the keys for the SCC algorithm
1208 nodes :: [(ModSummary, Int, [Int])]
1209 nodes = [(s, expectJust "topSort" (lookup_key (ms_hsc_src s) (ms_mod s)),
1210 out_edge_keys hs_boot_key (map unLoc (ms_srcimps s)) ++
1211 out_edge_keys HsSrcFile (map unLoc (ms_imps s)) )
1213 , not (isBootSummary s && drop_hs_boot_nodes) ]
1214 -- Drop the hi-boot ones if told to do so
1216 key_map :: NodeMap Int
1217 key_map = listToFM ([(ms_mod s, ms_hsc_src s) | s <- summaries]
1220 lookup_key :: HscSource -> Module -> Maybe Int
1221 lookup_key hs_src mod = lookupFM key_map (mod, hs_src)
1223 out_edge_keys :: HscSource -> [Module] -> [Int]
1224 out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
1225 -- If we want keep_hi_boot_nodes, then we do lookup_key with
1226 -- the IsBootInterface parameter True; else False
1229 type NodeKey = (Module, HscSource) -- The nodes of the graph are
1230 type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
1232 msKey :: ModSummary -> NodeKey
1233 msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (mod,boot)
1235 mkNodeMap :: [ModSummary] -> NodeMap ModSummary
1236 mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
1238 nodeMapElts :: NodeMap a -> [a]
1239 nodeMapElts = eltsFM
1241 -----------------------------------------------------------------------------
1242 -- Downsweep (dependency analysis)
1244 -- Chase downwards from the specified root set, returning summaries
1245 -- for all home modules encountered. Only follow source-import
1248 -- We pass in the previous collection of summaries, which is used as a
1249 -- cache to avoid recalculating a module summary if the source is
1252 -- The returned list of [ModSummary] nodes has one node for each home-package
1253 -- module, plus one for any hs-boot files. The imports of these nodes
1254 -- are all there, including the imports of non-home-package modules.
1257 -> [ModSummary] -- Old summaries
1258 -> [Module] -- Ignore dependencies on these; treat
1259 -- them as if they were package modules
1260 -> Bool -- True <=> allow multiple targets to have
1261 -- the same module name; this is
1262 -- very useful for ghc -M
1263 -> IO (Maybe [ModSummary])
1264 -- The elts of [ModSummary] all have distinct
1265 -- (Modules, IsBoot) identifiers, unless the Bool is true
1266 -- in which case there can be repeats
1267 downsweep hsc_env old_summaries excl_mods allow_dup_roots
1268 = -- catch error messages and return them
1269 handleDyn (\err_msg -> printBagOfErrors (hsc_dflags hsc_env) (unitBag err_msg) >> return Nothing) $ do
1270 rootSummaries <- mapM getRootSummary roots
1271 let root_map = mkRootMap rootSummaries
1272 checkDuplicates root_map
1273 summs <- loop (concatMap msDeps rootSummaries) root_map
1276 roots = hsc_targets hsc_env
1278 old_summary_map :: NodeMap ModSummary
1279 old_summary_map = mkNodeMap old_summaries
1281 getRootSummary :: Target -> IO ModSummary
1282 getRootSummary (Target (TargetFile file mb_phase) maybe_buf)
1283 = do exists <- doesFileExist file
1285 then summariseFile hsc_env old_summaries file mb_phase maybe_buf
1286 else throwDyn $ mkPlainErrMsg noSrcSpan $
1287 text "can't find file:" <+> text file
1288 getRootSummary (Target (TargetModule modl) maybe_buf)
1289 = do maybe_summary <- summariseModule hsc_env old_summary_map False
1290 (L rootLoc modl) maybe_buf excl_mods
1291 case maybe_summary of
1292 Nothing -> packageModErr modl
1295 rootLoc = mkGeneralSrcSpan FSLIT("<command line>")
1297 -- In a root module, the filename is allowed to diverge from the module
1298 -- name, so we have to check that there aren't multiple root files
1299 -- defining the same module (otherwise the duplicates will be silently
1300 -- ignored, leading to confusing behaviour).
1301 checkDuplicates :: NodeMap [ModSummary] -> IO ()
1302 checkDuplicates root_map
1303 | allow_dup_roots = return ()
1304 | null dup_roots = return ()
1305 | otherwise = multiRootsErr (head dup_roots)
1307 dup_roots :: [[ModSummary]] -- Each at least of length 2
1308 dup_roots = filterOut isSingleton (nodeMapElts root_map)
1310 loop :: [(Located Module,IsBootInterface)]
1311 -- Work list: process these modules
1312 -> NodeMap [ModSummary]
1313 -- Visited set; the range is a list because
1314 -- the roots can have the same module names
1315 -- if allow_dup_roots is True
1317 -- The result includes the worklist, except
1318 -- for those mentioned in the visited set
1319 loop [] done = return (concat (nodeMapElts done))
1320 loop ((wanted_mod, is_boot) : ss) done
1321 | Just summs <- lookupFM done key
1322 = if isSingleton summs then
1325 do { multiRootsErr summs; return [] }
1326 | otherwise = do { mb_s <- summariseModule hsc_env old_summary_map
1327 is_boot wanted_mod Nothing excl_mods
1329 Nothing -> loop ss done
1330 Just s -> loop (msDeps s ++ ss)
1331 (addToFM done key [s]) }
1333 key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
1335 mkRootMap :: [ModSummary] -> NodeMap [ModSummary]
1336 mkRootMap summaries = addListToFM_C (++) emptyFM
1337 [ (msKey s, [s]) | s <- summaries ]
1339 msDeps :: ModSummary -> [(Located Module, IsBootInterface)]
1340 -- (msDeps s) returns the dependencies of the ModSummary s.
1341 -- A wrinkle is that for a {-# SOURCE #-} import we return
1342 -- *both* the hs-boot file
1343 -- *and* the source file
1344 -- as "dependencies". That ensures that the list of all relevant
1345 -- modules always contains B.hs if it contains B.hs-boot.
1346 -- Remember, this pass isn't doing the topological sort. It's
1347 -- just gathering the list of all relevant ModSummaries
1349 concat [ [(m,True), (m,False)] | m <- ms_srcimps s ]
1350 ++ [ (m,False) | m <- ms_imps s ]
1352 -----------------------------------------------------------------------------
1353 -- Summarising modules
1355 -- We have two types of summarisation:
1357 -- * Summarise a file. This is used for the root module(s) passed to
1358 -- cmLoadModules. The file is read, and used to determine the root
1359 -- module name. The module name may differ from the filename.
1361 -- * Summarise a module. We are given a module name, and must provide
1362 -- a summary. The finder is used to locate the file in which the module
1367 -> [ModSummary] -- old summaries
1368 -> FilePath -- source file name
1369 -> Maybe Phase -- start phase
1370 -> Maybe (StringBuffer,ClockTime)
1373 summariseFile hsc_env old_summaries file mb_phase maybe_buf
1374 -- we can use a cached summary if one is available and the
1375 -- source file hasn't changed, But we have to look up the summary
1376 -- by source file, rather than module name as we do in summarise.
1377 | Just old_summary <- findSummaryBySourceFile old_summaries file
1379 let location = ms_location old_summary
1381 -- return the cached summary if the source didn't change
1382 src_timestamp <- case maybe_buf of
1383 Just (_,t) -> return t
1384 Nothing -> getModificationTime file
1385 -- The file exists; we checked in getRootSummary above.
1386 -- If it gets removed subsequently, then this
1387 -- getModificationTime may fail, but that's the right
1390 if ms_hs_date old_summary == src_timestamp
1391 then do -- update the object-file timestamp
1392 obj_timestamp <- getObjTimestamp location False
1393 return old_summary{ ms_obj_date = obj_timestamp }
1401 let dflags = hsc_dflags hsc_env
1403 (dflags', hspp_fn, buf)
1404 <- preprocessFile dflags file mb_phase maybe_buf
1406 (srcimps,the_imps, L _ mod) <- getImports dflags' buf hspp_fn
1408 -- Make a ModLocation for this file
1409 location <- mkHomeModLocation dflags mod file
1411 -- Tell the Finder cache where it is, so that subsequent calls
1412 -- to findModule will find it, even if it's not on any search path
1413 addHomeModuleToFinder hsc_env mod location
1415 src_timestamp <- case maybe_buf of
1416 Just (_,t) -> return t
1417 Nothing -> getModificationTime file
1418 -- getMofificationTime may fail
1420 obj_timestamp <- modificationTimeIfExists (ml_obj_file location)
1422 return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
1423 ms_location = location,
1424 ms_hspp_file = Just hspp_fn,
1425 ms_hspp_buf = Just buf,
1426 ms_srcimps = srcimps, ms_imps = the_imps,
1427 ms_hs_date = src_timestamp,
1428 ms_obj_date = obj_timestamp })
1430 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
1431 findSummaryBySourceFile summaries file
1432 = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
1433 fromJust (ml_hs_file (ms_location ms)) == file ] of
1437 -- Summarise a module, and pick up source and timestamp.
1440 -> NodeMap ModSummary -- Map of old summaries
1441 -> IsBootInterface -- True <=> a {-# SOURCE #-} import
1442 -> Located Module -- Imported module to be summarised
1443 -> Maybe (StringBuffer, ClockTime)
1444 -> [Module] -- Modules to exclude
1445 -> IO (Maybe ModSummary) -- Its new summary
1447 summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod) maybe_buf excl_mods
1448 | wanted_mod `elem` excl_mods
1451 | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
1452 = do -- Find its new timestamp; all the
1453 -- ModSummaries in the old map have valid ml_hs_files
1454 let location = ms_location old_summary
1455 src_fn = expectJust "summariseModule" (ml_hs_file location)
1457 -- check the modification time on the source file, and
1458 -- return the cached summary if it hasn't changed. If the
1459 -- file has disappeared, we need to call the Finder again.
1461 Just (_,t) -> check_timestamp old_summary location src_fn t
1463 m <- IO.try (getModificationTime src_fn)
1465 Right t -> check_timestamp old_summary location src_fn t
1466 Left e | isDoesNotExistError e -> find_it
1467 | otherwise -> ioError e
1469 | otherwise = find_it
1471 dflags = hsc_dflags hsc_env
1473 hsc_src = if is_boot then HsBootFile else HsSrcFile
1475 check_timestamp old_summary location src_fn src_timestamp
1476 | ms_hs_date old_summary == src_timestamp = do
1477 -- update the object-file timestamp
1478 obj_timestamp <- getObjTimestamp location is_boot
1479 return (Just old_summary{ ms_obj_date = obj_timestamp })
1481 -- source changed: find and re-summarise. We call the finder
1482 -- again, because the user may have moved the source file.
1483 new_summary location src_fn src_timestamp
1486 -- Don't use the Finder's cache this time. If the module was
1487 -- previously a package module, it may have now appeared on the
1488 -- search path, so we want to consider it to be a home module. If
1489 -- the module was previously a home module, it may have moved.
1490 uncacheModule hsc_env wanted_mod
1491 found <- findModule hsc_env wanted_mod True {-explicit-}
1494 | not (isHomePackage pkg) -> return Nothing
1495 -- Drop external-pkg
1496 | isJust (ml_hs_file location) -> just_found location
1498 err -> noModError dflags loc wanted_mod err
1501 just_found location = do
1502 -- Adjust location to point to the hs-boot source file,
1503 -- hi file, object file, when is_boot says so
1504 let location' | is_boot = addBootSuffixLocn location
1505 | otherwise = location
1506 src_fn = expectJust "summarise2" (ml_hs_file location')
1508 -- Check that it exists
1509 -- It might have been deleted since the Finder last found it
1510 maybe_t <- modificationTimeIfExists src_fn
1512 Nothing -> noHsFileErr loc src_fn
1513 Just t -> new_summary location' src_fn t
1516 new_summary location src_fn src_timestamp
1518 -- Preprocess the source file and get its imports
1519 -- The dflags' contains the OPTIONS pragmas
1520 (dflags', hspp_fn, buf) <- preprocessFile dflags src_fn Nothing maybe_buf
1521 (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn
1523 when (mod_name /= wanted_mod) $
1524 throwDyn $ mkPlainErrMsg mod_loc $
1525 text "file name does not match module name"
1526 <+> quotes (ppr mod_name)
1528 -- Find the object timestamp, and return the summary
1529 obj_timestamp <- getObjTimestamp location is_boot
1531 return (Just ( ModSummary { ms_mod = wanted_mod,
1532 ms_hsc_src = hsc_src,
1533 ms_location = location,
1534 ms_hspp_file = Just hspp_fn,
1535 ms_hspp_buf = Just buf,
1536 ms_srcimps = srcimps,
1538 ms_hs_date = src_timestamp,
1539 ms_obj_date = obj_timestamp }))
1542 getObjTimestamp location is_boot
1543 = if is_boot then return Nothing
1544 else modificationTimeIfExists (ml_obj_file location)
1547 preprocessFile :: DynFlags -> FilePath -> Maybe Phase -> Maybe (StringBuffer,ClockTime)
1548 -> IO (DynFlags, FilePath, StringBuffer)
1549 preprocessFile dflags src_fn mb_phase Nothing
1551 (dflags', hspp_fn) <- preprocess dflags (src_fn, mb_phase)
1552 buf <- hGetStringBuffer hspp_fn
1553 return (dflags', hspp_fn, buf)
1555 preprocessFile dflags src_fn mb_phase (Just (buf, time))
1557 -- case we bypass the preprocessing stage?
1559 local_opts = getOptionsFromStringBuffer buf src_fn
1561 (dflags', errs) <- parseDynamicFlags dflags (map snd local_opts)
1565 | Just (Unlit _) <- mb_phase = True
1566 | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
1567 -- note: local_opts is only required if there's no Unlit phase
1568 | dopt Opt_Cpp dflags' = True
1569 | dopt Opt_Pp dflags' = True
1572 when needs_preprocessing $
1573 ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
1575 return (dflags', src_fn, buf)
1578 -----------------------------------------------------------------------------
1580 -----------------------------------------------------------------------------
1582 noModError :: DynFlags -> SrcSpan -> Module -> FindResult -> IO ab
1583 -- ToDo: we don't have a proper line number for this error
1584 noModError dflags loc wanted_mod err
1585 = throwDyn $ mkPlainErrMsg loc $ cantFindError dflags wanted_mod err
1587 noHsFileErr loc path
1588 = throwDyn $ mkPlainErrMsg loc $ text "Can't find" <+> text path
1591 = throwDyn $ mkPlainErrMsg noSrcSpan $
1592 text "module" <+> quotes (ppr mod) <+> text "is a package module"
1594 multiRootsErr :: [ModSummary] -> IO ()
1595 multiRootsErr summs@(summ1:_)
1596 = throwDyn $ mkPlainErrMsg noSrcSpan $
1597 text "module" <+> quotes (ppr mod) <+>
1598 text "is defined in multiple files:" <+>
1599 sep (map text files)
1602 files = map (expectJust "checkDup" . ml_hs_file . ms_location) summs
1604 cyclicModuleErr :: [ModSummary] -> SDoc
1606 = hang (ptext SLIT("Module imports form a cycle for modules:"))
1607 2 (vcat (map show_one ms))
1609 show_one ms = sep [ show_mod (ms_hsc_src ms) (ms_mod ms),
1610 nest 2 $ ptext SLIT("imports:") <+>
1611 (pp_imps HsBootFile (ms_srcimps ms)
1612 $$ pp_imps HsSrcFile (ms_imps ms))]
1613 show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
1614 pp_imps src mods = fsep (map (show_mod src) mods)
1617 -- | Inform GHC that the working directory has changed. GHC will flush
1618 -- its cache of module locations, since it may no longer be valid.
1619 -- Note: if you change the working directory, you should also unload
1620 -- the current program (set targets to empty, followed by load).
1621 workingDirectoryChanged :: Session -> IO ()
1622 workingDirectoryChanged s = withSession s $ \hsc_env ->
1623 flushFinderCache (hsc_FC hsc_env)
1625 -- -----------------------------------------------------------------------------
1626 -- inspecting the session
1628 -- | Get the module dependency graph.
1629 getModuleGraph :: Session -> IO ModuleGraph -- ToDo: DiGraph ModSummary
1630 getModuleGraph s = withSession s (return . hsc_mod_graph)
1632 isLoaded :: Session -> Module -> IO Bool
1633 isLoaded s m = withSession s $ \hsc_env ->
1634 return $! isJust (lookupModuleEnv (hsc_HPT hsc_env) m)
1636 getBindings :: Session -> IO [TyThing]
1637 getBindings s = withSession s (return . nameEnvElts . ic_type_env . hsc_IC)
1639 getPrintUnqual :: Session -> IO PrintUnqualified
1640 getPrintUnqual s = withSession s (return . icPrintUnqual . hsc_IC)
1642 -- | Container for information about a 'Module'.
1643 data ModuleInfo = ModuleInfo {
1644 minf_type_env :: TypeEnv,
1645 minf_exports :: NameSet,
1646 minf_rdr_env :: Maybe GlobalRdrEnv, -- Nothing for a compiled/package mod
1647 minf_instances :: [Instance]
1648 -- ToDo: this should really contain the ModIface too
1650 -- We don't want HomeModInfo here, because a ModuleInfo applies
1651 -- to package modules too.
1653 -- | Request information about a loaded 'Module'
1654 getModuleInfo :: Session -> Module -> IO (Maybe ModuleInfo)
1655 getModuleInfo s mdl = withSession s $ \hsc_env -> do
1656 let mg = hsc_mod_graph hsc_env
1657 if mdl `elem` map ms_mod mg
1658 then getHomeModuleInfo hsc_env mdl
1660 {- if isHomeModule (hsc_dflags hsc_env) mdl
1662 else -} getPackageModuleInfo hsc_env mdl
1663 -- getPackageModuleInfo will attempt to find the interface, so
1664 -- we don't want to call it for a home module, just in case there
1665 -- was a problem loading the module and the interface doesn't
1666 -- exist... hence the isHomeModule test here. (ToDo: reinstate)
1668 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
1669 getPackageModuleInfo hsc_env mdl = do
1671 (_msgs, mb_names) <- getModuleExports hsc_env mdl
1673 Nothing -> return Nothing
1675 eps <- readIORef (hsc_EPS hsc_env)
1678 n_list = nameSetToList names
1679 tys = [ ty | name <- n_list,
1680 Just ty <- [lookupTypeEnv pte name] ]
1682 return (Just (ModuleInfo {
1683 minf_type_env = mkTypeEnv tys,
1684 minf_exports = names,
1685 minf_rdr_env = Just $! nameSetToGlobalRdrEnv names mdl,
1686 minf_instances = error "getModuleInfo: instances for package module unimplemented"
1689 -- bogusly different for non-GHCI (ToDo)
1693 getHomeModuleInfo hsc_env mdl =
1694 case lookupModuleEnv (hsc_HPT hsc_env) mdl of
1695 Nothing -> return Nothing
1697 let details = hm_details hmi
1698 return (Just (ModuleInfo {
1699 minf_type_env = md_types details,
1700 minf_exports = md_exports details,
1701 minf_rdr_env = mi_globals $! hm_iface hmi,
1702 minf_instances = md_insts details
1705 -- | The list of top-level entities defined in a module
1706 modInfoTyThings :: ModuleInfo -> [TyThing]
1707 modInfoTyThings minf = typeEnvElts (minf_type_env minf)
1709 modInfoTopLevelScope :: ModuleInfo -> Maybe [Name]
1710 modInfoTopLevelScope minf
1711 = fmap (map gre_name . globalRdrEnvElts) (minf_rdr_env minf)
1713 modInfoExports :: ModuleInfo -> [Name]
1714 modInfoExports minf = nameSetToList $! minf_exports minf
1716 -- | Returns the instances defined by the specified module.
1717 -- Warning: currently unimplemented for package modules.
1718 modInfoInstances :: ModuleInfo -> [Instance]
1719 modInfoInstances = minf_instances
1721 modInfoIsExportedName :: ModuleInfo -> Name -> Bool
1722 modInfoIsExportedName minf name = elemNameSet name (minf_exports minf)
1724 modInfoPrintUnqualified :: ModuleInfo -> Maybe PrintUnqualified
1725 modInfoPrintUnqualified minf = fmap unQualInScope (minf_rdr_env minf)
1727 modInfoLookupName :: Session -> ModuleInfo -> Name -> IO (Maybe TyThing)
1728 modInfoLookupName s minf name = withSession s $ \hsc_env -> do
1729 case lookupTypeEnv (minf_type_env minf) name of
1730 Just tyThing -> return (Just tyThing)
1732 eps <- readIORef (hsc_EPS hsc_env)
1733 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1735 isDictonaryId :: Id -> Bool
1737 = case tcSplitSigmaTy (idType id) of { (tvs, theta, tau) -> isDictTy tau }
1739 -- | Looks up a global name: that is, any top-level name in any
1740 -- visible module. Unlike 'lookupName', lookupGlobalName does not use
1741 -- the interactive context, and therefore does not require a preceding
1743 lookupGlobalName :: Session -> Name -> IO (Maybe TyThing)
1744 lookupGlobalName s name = withSession s $ \hsc_env -> do
1745 eps <- readIORef (hsc_EPS hsc_env)
1746 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1748 -- -----------------------------------------------------------------------------
1749 -- Misc exported utils
1751 dataConType :: DataCon -> Type
1752 dataConType dc = idType (dataConWrapId dc)
1754 -- | print a 'NamedThing', adding parentheses if the name is an operator.
1755 pprParenSymName :: NamedThing a => a -> SDoc
1756 pprParenSymName a = parenSymOcc (getOccName a) (ppr (getName a))
1758 -- ----------------------------------------------------------------------------
1763 -- - Data and Typeable instances for HsSyn.
1765 -- ToDo: check for small transformations that happen to the syntax in
1766 -- the typechecker (eg. -e ==> negate e, perhaps for fromIntegral)
1768 -- ToDo: maybe use TH syntax instead of IfaceSyn? There's already a way
1769 -- to get from TyCons, Ids etc. to TH syntax (reify).
1771 -- :browse will use either lm_toplev or inspect lm_interface, depending
1772 -- on whether the module is interpreted or not.
1774 -- This is for reconstructing refactored source code
1775 -- Calls the lexer repeatedly.
1776 -- ToDo: add comment tokens to token stream
1777 getTokenStream :: Session -> Module -> IO [Located Token]
1780 -- -----------------------------------------------------------------------------
1781 -- Interactive evaluation
1785 -- | Set the interactive evaluation context.
1787 -- Setting the context doesn't throw away any bindings; the bindings
1788 -- we've built up in the InteractiveContext simply move to the new
1789 -- module. They always shadow anything in scope in the current context.
1790 setContext :: Session
1791 -> [Module] -- entire top level scope of these modules
1792 -> [Module] -- exports only of these modules
1794 setContext (Session ref) toplevs exports = do
1795 hsc_env <- readIORef ref
1796 let old_ic = hsc_IC hsc_env
1797 hpt = hsc_HPT hsc_env
1799 mapM_ (checkModuleExists hsc_env hpt) exports
1800 export_env <- mkExportEnv hsc_env exports
1801 toplev_envs <- mapM (mkTopLevEnv hpt) toplevs
1802 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
1803 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplevs,
1804 ic_exports = exports,
1805 ic_rn_gbl_env = all_env }}
1808 -- Make a GlobalRdrEnv based on the exports of the modules only.
1809 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
1810 mkExportEnv hsc_env mods = do
1811 stuff <- mapM (getModuleExports hsc_env) mods
1813 (_msgs, mb_name_sets) = unzip stuff
1814 gres = [ nameSetToGlobalRdrEnv name_set mod
1815 | (Just name_set, mod) <- zip mb_name_sets mods ]
1817 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
1819 nameSetToGlobalRdrEnv :: NameSet -> Module -> GlobalRdrEnv
1820 nameSetToGlobalRdrEnv names mod =
1821 mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod }
1822 | name <- nameSetToList names ]
1824 vanillaProv :: Module -> Provenance
1825 -- We're building a GlobalRdrEnv as if the user imported
1826 -- all the specified modules into the global interactive module
1827 vanillaProv mod = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
1829 decl = ImpDeclSpec { is_mod = mod, is_as = mod,
1831 is_dloc = srcLocSpan interactiveSrcLoc }
1833 checkModuleExists :: HscEnv -> HomePackageTable -> Module -> IO ()
1834 checkModuleExists hsc_env hpt mod =
1835 case lookupModuleEnv hpt mod of
1836 Just mod_info -> return ()
1837 _not_a_home_module -> do
1838 res <- findPackageModule hsc_env mod True
1840 Found _ _ -> return ()
1841 err -> let msg = cantFindError (hsc_dflags hsc_env) mod err in
1842 throwDyn (CmdLineError (showSDoc msg))
1844 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
1845 mkTopLevEnv hpt modl
1846 = case lookupModuleEnv hpt modl of
1848 throwDyn (ProgramError ("mkTopLevEnv: not a home module "
1849 ++ showSDoc (pprModule modl)))
1851 case mi_globals (hm_iface details) of
1853 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
1854 ++ showSDoc (pprModule modl)))
1855 Just env -> return env
1857 -- | Get the interactive evaluation context, consisting of a pair of the
1858 -- set of modules from which we take the full top-level scope, and the set
1859 -- of modules from which we take just the exports respectively.
1860 getContext :: Session -> IO ([Module],[Module])
1861 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
1862 return (ic_toplev_scope ic, ic_exports ic))
1864 -- | Returns 'True' if the specified module is interpreted, and hence has
1865 -- its full top-level scope available.
1866 moduleIsInterpreted :: Session -> Module -> IO Bool
1867 moduleIsInterpreted s modl = withSession s $ \h ->
1868 case lookupModuleEnv (hsc_HPT h) modl of
1869 Just details -> return (isJust (mi_globals (hm_iface details)))
1870 _not_a_home_module -> return False
1872 -- | Looks up an identifier in the current interactive context (for :info)
1873 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
1874 getInfo s name = withSession s $ \hsc_env -> tcRnGetInfo hsc_env name
1876 -- | Returns all names in scope in the current interactive context
1877 getNamesInScope :: Session -> IO [Name]
1878 getNamesInScope s = withSession s $ \hsc_env -> do
1879 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
1881 -- | Parses a string as an identifier, and returns the list of 'Name's that
1882 -- the identifier can refer to in the current interactive context.
1883 parseName :: Session -> String -> IO [Name]
1884 parseName s str = withSession s $ \hsc_env -> do
1885 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
1886 case maybe_rdr_name of
1887 Nothing -> return []
1888 Just (L _ rdr_name) -> do
1889 mb_names <- tcRnLookupRdrName hsc_env rdr_name
1891 Nothing -> return []
1892 Just ns -> return ns
1893 -- ToDo: should return error messages
1895 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
1896 -- entity known to GHC, including 'Name's defined using 'runStmt'.
1897 lookupName :: Session -> Name -> IO (Maybe TyThing)
1898 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
1900 -- -----------------------------------------------------------------------------
1901 -- Getting the type of an expression
1903 -- | Get the type of an expression
1904 exprType :: Session -> String -> IO (Maybe Type)
1905 exprType s expr = withSession s $ \hsc_env -> do
1906 maybe_stuff <- hscTcExpr hsc_env expr
1908 Nothing -> return Nothing
1909 Just ty -> return (Just tidy_ty)
1911 tidy_ty = tidyType emptyTidyEnv ty
1913 -- -----------------------------------------------------------------------------
1914 -- Getting the kind of a type
1916 -- | Get the kind of a type
1917 typeKind :: Session -> String -> IO (Maybe Kind)
1918 typeKind s str = withSession s $ \hsc_env -> do
1919 maybe_stuff <- hscKcType hsc_env str
1921 Nothing -> return Nothing
1922 Just kind -> return (Just kind)
1924 -----------------------------------------------------------------------------
1925 -- cmCompileExpr: compile an expression and deliver an HValue
1927 compileExpr :: Session -> String -> IO (Maybe HValue)
1928 compileExpr s expr = withSession s $ \hsc_env -> do
1929 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
1931 Nothing -> return Nothing
1932 Just (new_ic, names, hval) -> do
1934 hvals <- (unsafeCoerce# hval) :: IO [HValue]
1936 case (names,hvals) of
1937 ([n],[hv]) -> return (Just hv)
1938 _ -> panic "compileExpr"
1940 -- -----------------------------------------------------------------------------
1941 -- running a statement interactively
1944 = RunOk [Name] -- ^ names bound by this evaluation
1945 | RunFailed -- ^ statement failed compilation
1946 | RunException Exception -- ^ statement raised an exception
1948 -- | Run a statement in the current interactive context. Statemenet
1949 -- may bind multple values.
1950 runStmt :: Session -> String -> IO RunResult
1951 runStmt (Session ref) expr
1953 hsc_env <- readIORef ref
1955 -- Turn off -fwarn-unused-bindings when running a statement, to hide
1956 -- warnings about the implicit bindings we introduce.
1957 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
1958 hsc_env' = hsc_env{ hsc_dflags = dflags' }
1960 maybe_stuff <- hscStmt hsc_env' expr
1963 Nothing -> return RunFailed
1964 Just (new_hsc_env, names, hval) -> do
1966 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
1967 either_hvals <- sandboxIO thing_to_run
1969 case either_hvals of
1971 -- on error, keep the *old* interactive context,
1972 -- so that 'it' is not bound to something
1973 -- that doesn't exist.
1974 return (RunException e)
1977 -- Get the newly bound things, and bind them.
1978 -- Don't need to delete any shadowed bindings;
1979 -- the new ones override the old ones.
1980 extendLinkEnv (zip names hvals)
1982 writeIORef ref new_hsc_env
1983 return (RunOk names)
1986 -- We run the statement in a "sandbox" to protect the rest of the
1987 -- system from anything the expression might do. For now, this
1988 -- consists of just wrapping it in an exception handler, but see below
1989 -- for another version.
1991 sandboxIO :: IO a -> IO (Either Exception a)
1992 sandboxIO thing = Exception.try thing
1995 -- This version of sandboxIO runs the expression in a completely new
1996 -- RTS main thread. It is disabled for now because ^C exceptions
1997 -- won't be delivered to the new thread, instead they'll be delivered
1998 -- to the (blocked) GHCi main thread.
2000 -- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
2002 sandboxIO :: IO a -> IO (Either Int (Either Exception a))
2003 sandboxIO thing = do
2004 st_thing <- newStablePtr (Exception.try thing)
2005 alloca $ \ p_st_result -> do
2006 stat <- rts_evalStableIO st_thing p_st_result
2007 freeStablePtr st_thing
2009 then do st_result <- peek p_st_result
2010 result <- deRefStablePtr st_result
2011 freeStablePtr st_result
2012 return (Right result)
2014 return (Left (fromIntegral stat))
2016 foreign import "rts_evalStableIO" {- safe -}
2017 rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
2018 -- more informative than the C type!
2021 -----------------------------------------------------------------------------
2022 -- show a module and it's source/object filenames
2024 showModule :: Session -> ModSummary -> IO String
2025 showModule s mod_summary = withSession s $ \hsc_env -> do
2026 case lookupModuleEnv (hsc_HPT hsc_env) (ms_mod mod_summary) of
2027 Nothing -> panic "missing linkable"
2028 Just mod_info -> return (showModMsg obj_linkable mod_summary)
2030 obj_linkable = isObjectLinkable (fromJust (hm_linkable mod_info))