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,
79 -- * Abstract syntax elements
82 Module, mkModule, pprModule,
86 nameModule, nameParent_maybe, pprParenSymName, nameSrcLoc,
91 isImplicitId, isDeadBinder,
92 isExportedId, isLocalId, isGlobalId,
94 isPrimOpId, isFCallId, isClassOpId_maybe,
95 isDataConWorkId, idDataCon,
96 isBottomingId, isDictonaryId,
97 recordSelectorFieldLabel,
99 -- ** Type constructors
101 tyConTyVars, tyConDataCons, tyConArity,
102 isClassTyCon, isSynTyCon, isNewTyCon, isPrimTyCon,
109 -- ** Data constructors
111 dataConSig, dataConType, dataConTyCon, dataConFieldLabels,
112 dataConIsInfix, isVanillaDataCon,
114 StrictnessMark(..), isMarkedStrict,
118 classMethods, classSCTheta, classTvsFds,
123 instanceDFunId, pprInstance, pprInstanceHdr,
125 -- ** Types and Kinds
126 Type, dropForAlls, splitForAllTys, funResultTy, pprParendType,
129 ThetaType, pprThetaArrow,
135 module HsSyn, -- ToDo: remove extraneous bits
139 defaultFixity, maxPrecedence,
143 -- ** Source locations
147 GhcException(..), showGhcException,
157 * inline bits of HscMain here to simplify layering: hscTcExpr, hscStmt.
158 * we need to expose DynFlags, so should parseDynamicFlags really be
159 part of this interface?
160 * what StaticFlags should we expose, if any?
163 #include "HsVersions.h"
166 import qualified Linker
167 import Linker ( HValue, extendLinkEnv )
168 import TcRnDriver ( tcRnLookupRdrName, tcRnGetInfo,
169 tcRnLookupName, getModuleExports )
170 import RdrName ( plusGlobalRdrEnv, Provenance(..),
171 ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
172 emptyGlobalRdrEnv, mkGlobalRdrEnv )
173 import HscMain ( hscParseIdentifier, hscStmt, hscTcExpr, hscKcType )
174 import Type ( tidyType )
175 import VarEnv ( emptyTidyEnv )
176 import GHC.Exts ( unsafeCoerce# )
179 import Packages ( initPackages )
180 import NameSet ( NameSet, nameSetToList, elemNameSet )
181 import RdrName ( GlobalRdrEnv, GlobalRdrElt(..), RdrName,
184 import Type ( Kind, Type, dropForAlls, PredType, ThetaType,
185 pprThetaArrow, pprParendType, splitForAllTys,
187 import Id ( Id, idType, isImplicitId, isDeadBinder,
188 isExportedId, isLocalId, isGlobalId,
189 isRecordSelector, recordSelectorFieldLabel,
190 isPrimOpId, isFCallId, isClassOpId_maybe,
191 isDataConWorkId, idDataCon,
194 import TysPrim ( alphaTyVars )
195 import TyCon ( TyCon, isClassTyCon, isSynTyCon, isNewTyCon,
196 isPrimTyCon, tyConArity,
197 tyConTyVars, tyConDataCons, getSynTyConDefn )
198 import Class ( Class, classSCTheta, classTvsFds, classMethods )
199 import FunDeps ( pprFundeps )
200 import DataCon ( DataCon, dataConWrapId, dataConSig, dataConTyCon,
201 dataConFieldLabels, dataConStrictMarks,
202 dataConIsInfix, isVanillaDataCon )
203 import Name ( Name, nameModule, NamedThing(..), nameParent_maybe,
205 import OccName ( parenSymOcc )
206 import NameEnv ( nameEnvElts )
207 import InstEnv ( Instance, instanceDFunId, pprInstance, pprInstanceHdr )
209 import DriverPipeline
210 import DriverPhases ( Phase(..), isHaskellSrcFilename, startPhase )
211 import GetImports ( getImports )
212 import Packages ( isHomePackage )
214 import HscMain ( newHscEnv, hscFileCheck, HscResult(..) )
218 import SysTools ( initSysTools, cleanTempFiles )
223 import Bag ( unitBag, emptyBag )
224 import ErrUtils ( showPass, Messages, putMsg, debugTraceMsg,
225 mkPlainErrMsg, pprBagOfErrors )
226 import qualified ErrUtils
228 import StringBuffer ( StringBuffer, hGetStringBuffer )
230 import SysTools ( cleanTempFilesExcept )
232 import TcType ( tcSplitSigmaTy, isDictTy )
233 import FastString ( mkFastString )
235 import Directory ( getModificationTime, doesFileExist )
236 import Maybe ( isJust, isNothing, fromJust )
237 import Maybes ( orElse, expectJust, mapCatMaybes )
238 import List ( partition, nub )
239 import qualified List
240 import Monad ( unless, when )
241 import System ( exitWith, ExitCode(..) )
242 import Time ( ClockTime )
243 import EXCEPTION as Exception hiding (handle)
246 import Prelude hiding (init)
248 -- -----------------------------------------------------------------------------
249 -- Exception handlers
251 -- | Install some default exception handlers and run the inner computation.
252 -- Unless you want to handle exceptions yourself, you should wrap this around
253 -- the top level of your program. The default handlers output the error
254 -- message(s) to stderr and exit cleanly.
255 defaultErrorHandler :: IO a -> IO a
256 defaultErrorHandler inner =
257 -- top-level exception handler: any unrecognised exception is a compiler bug.
258 handle (\exception -> do
261 -- an IO exception probably isn't our fault, so don't panic
262 IOException _ -> putMsg (show exception)
263 AsyncException StackOverflow ->
264 putMsg "stack overflow: use +RTS -K<size> to increase it"
265 _other -> putMsg (show (Panic (show exception)))
266 exitWith (ExitFailure 1)
269 -- program errors: messages with locations attached. Sometimes it is
270 -- convenient to just throw these as exceptions.
271 handleDyn (\dyn -> do printErrs (pprBagOfErrors (unitBag dyn))
272 exitWith (ExitFailure 1)) $
274 -- error messages propagated as exceptions
275 handleDyn (\dyn -> do
278 PhaseFailed _ code -> exitWith code
279 Interrupted -> exitWith (ExitFailure 1)
280 _ -> do putMsg (show (dyn :: GhcException))
281 exitWith (ExitFailure 1)
285 -- | Install a default cleanup handler to remove temporary files
286 -- deposited by a GHC run. This is seperate from
287 -- 'defaultErrorHandler', because you might want to override the error
288 -- handling, but still get the ordinary cleanup behaviour.
289 defaultCleanupHandler :: DynFlags -> IO a -> IO a
290 defaultCleanupHandler dflags inner =
291 -- make sure we clean up after ourselves
292 later (unless (dopt Opt_KeepTmpFiles dflags) $
293 cleanTempFiles dflags)
294 -- exceptions will be blocked while we clean the temporary files,
295 -- so there shouldn't be any difficulty if we receive further
300 -- | Initialises GHC. This must be done /once/ only. Takes the
301 -- command-line arguments. All command-line arguments which aren't
302 -- understood by GHC will be returned.
304 init :: [String] -> IO [String]
307 installSignalHandlers
309 -- Grab the -B option if there is one
310 let (minusB_args, argv1) = partition (prefixMatch "-B") args
311 dflags0 <- initSysTools minusB_args defaultDynFlags
312 writeIORef v_initDynFlags dflags0
314 -- Parse the static flags
315 argv2 <- parseStaticFlags argv1
318 GLOBAL_VAR(v_initDynFlags, error "initDynFlags", DynFlags)
319 -- stores the DynFlags between the call to init and subsequent
320 -- calls to newSession.
322 -- | Starts a new session. A session consists of a set of loaded
323 -- modules, a set of options (DynFlags), and an interactive context.
324 -- ToDo: GhcMode should say "keep typechecked code" and\/or "keep renamed
326 newSession :: GhcMode -> IO Session
328 dflags0 <- readIORef v_initDynFlags
329 dflags <- initDynFlags dflags0
330 env <- newHscEnv dflags{ ghcMode=mode }
334 -- tmp: this breaks the abstraction, but required because DriverMkDepend
335 -- needs to call the Finder. ToDo: untangle this.
336 sessionHscEnv :: Session -> IO HscEnv
337 sessionHscEnv (Session ref) = readIORef ref
339 withSession :: Session -> (HscEnv -> IO a) -> IO a
340 withSession (Session ref) f = do h <- readIORef ref; f h
342 modifySession :: Session -> (HscEnv -> HscEnv) -> IO ()
343 modifySession (Session ref) f = do h <- readIORef ref; writeIORef ref $! f h
345 -- -----------------------------------------------------------------------------
348 -- | Grabs the DynFlags from the Session
349 getSessionDynFlags :: Session -> IO DynFlags
350 getSessionDynFlags s = withSession s (return . hsc_dflags)
352 -- | Updates the DynFlags in a Session
353 setSessionDynFlags :: Session -> DynFlags -> IO ()
354 setSessionDynFlags s dflags = modifySession s (\h -> h{ hsc_dflags = dflags })
356 -- | Messages during compilation (eg. warnings and progress messages)
357 -- are reported using this callback. By default, these messages are
358 -- printed to stderr.
359 setMsgHandler :: (String -> IO ()) -> IO ()
360 setMsgHandler = ErrUtils.setMsgHandler
362 -- -----------------------------------------------------------------------------
365 -- ToDo: think about relative vs. absolute file paths. And what
366 -- happens when the current directory changes.
368 -- | Sets the targets for this session. Each target may be a module name
369 -- or a filename. The targets correspond to the set of root modules for
370 -- the program\/library. Unloading the current program is achieved by
371 -- setting the current set of targets to be empty, followed by load.
372 setTargets :: Session -> [Target] -> IO ()
373 setTargets s targets = modifySession s (\h -> h{ hsc_targets = targets })
375 -- | returns the current set of targets
376 getTargets :: Session -> IO [Target]
377 getTargets s = withSession s (return . hsc_targets)
379 -- | Add another target
380 addTarget :: Session -> Target -> IO ()
382 = modifySession s (\h -> h{ hsc_targets = target : hsc_targets h })
385 removeTarget :: Session -> TargetId -> IO ()
386 removeTarget s target_id
387 = modifySession s (\h -> h{ hsc_targets = filter (hsc_targets h) })
389 filter targets = [ t | t@(Target id _) <- targets, id /= target_id ]
391 -- Attempts to guess what Target a string refers to. This function implements
392 -- the --make/GHCi command-line syntax for filenames:
394 -- - if the string looks like a Haskell source filename, then interpret
396 -- - if adding a .hs or .lhs suffix yields the name of an existing file,
398 -- - otherwise interpret the string as a module name
400 guessTarget :: String -> Maybe Phase -> IO Target
401 guessTarget file (Just phase)
402 = return (Target (TargetFile file (Just phase)) Nothing)
403 guessTarget file Nothing
404 | isHaskellSrcFilename file
405 = return (Target (TargetFile file Nothing) Nothing)
407 = do exists <- doesFileExist hs_file
409 then return (Target (TargetFile hs_file Nothing) Nothing)
411 exists <- doesFileExist lhs_file
413 then return (Target (TargetFile lhs_file Nothing) Nothing)
415 return (Target (TargetModule (mkModule file)) Nothing)
417 hs_file = file `joinFileExt` "hs"
418 lhs_file = file `joinFileExt` "lhs"
420 -- -----------------------------------------------------------------------------
421 -- Loading the program
423 -- Perform a dependency analysis starting from the current targets
424 -- and update the session with the new module graph.
425 depanal :: Session -> [Module] -> Bool -> IO (Either Messages ModuleGraph)
426 depanal (Session ref) excluded_mods allow_dup_roots = do
427 hsc_env <- readIORef ref
429 dflags = hsc_dflags hsc_env
430 gmode = ghcMode (hsc_dflags hsc_env)
431 targets = hsc_targets hsc_env
432 old_graph = hsc_mod_graph hsc_env
434 showPass dflags "Chasing dependencies"
435 when (gmode == BatchCompile) $
436 debugTraceMsg dflags 1 (showSDoc (hcat [
437 text "Chasing modules from: ",
438 hcat (punctuate comma (map pprTarget targets))]))
440 r <- downsweep hsc_env old_graph excluded_mods allow_dup_roots
442 Right mod_graph -> writeIORef ref hsc_env{ hsc_mod_graph = mod_graph }
447 -- | The result of load.
449 = LoadOk Errors -- ^ all specified targets were loaded successfully.
450 | LoadFailed Errors -- ^ not all modules were loaded.
452 type Errors = [String]
454 data ErrMsg = ErrMsg {
455 errMsgSeverity :: Severity, -- warning, error, etc.
456 errMsgSpans :: [SrcSpan],
457 errMsgShortDoc :: Doc,
458 errMsgExtraInfo :: Doc
465 | LoadDependenciesOf Module
467 -- | Try to load the program. If a Module is supplied, then just
468 -- attempt to load up to this target. If no Module is supplied,
469 -- then try to load all targets.
470 load :: Session -> LoadHowMuch -> IO SuccessFlag
471 load session how_much =
472 loadMsgs session how_much ErrUtils.printErrorsAndWarnings
474 -- | Version of 'load' that takes a callback function to be invoked
475 -- on compiler errors and warnings as they occur during compilation.
476 loadMsgs :: Session -> LoadHowMuch -> (Messages-> IO ()) -> IO SuccessFlag
477 loadMsgs s@(Session ref) how_much msg_act
479 -- Dependency analysis first. Note that this fixes the module graph:
480 -- even if we don't get a fully successful upsweep, the full module
481 -- graph is still retained in the Session. We can tell which modules
482 -- were successfully loaded by inspecting the Session's HPT.
483 mb_graph <- depanal s [] False
485 Left msgs -> do msg_act msgs; return Failed
486 Right mod_graph -> loadMsgs2 s how_much msg_act mod_graph
488 loadMsgs2 s@(Session ref) how_much msg_act mod_graph = do
489 hsc_env <- readIORef ref
491 let hpt1 = hsc_HPT hsc_env
492 let dflags = hsc_dflags hsc_env
493 let ghci_mode = ghcMode dflags -- this never changes
495 -- The "bad" boot modules are the ones for which we have
496 -- B.hs-boot in the module graph, but no B.hs
497 -- The downsweep should have ensured this does not happen
499 let all_home_mods = [ms_mod s | s <- mod_graph, not (isBootSummary s)]
501 bad_boot_mods = [s | s <- mod_graph, isBootSummary s,
502 not (ms_mod s `elem` all_home_mods)]
504 ASSERT( null bad_boot_mods ) return ()
506 -- mg2_with_srcimps drops the hi-boot nodes, returning a
507 -- graph with cycles. Among other things, it is used for
508 -- backing out partially complete cycles following a failed
509 -- upsweep, and for removing from hpt all the modules
510 -- not in strict downwards closure, during calls to compile.
511 let mg2_with_srcimps :: [SCC ModSummary]
512 mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing
514 -- check the stability property for each module.
515 stable_mods@(stable_obj,stable_bco)
516 | BatchCompile <- ghci_mode = ([],[])
517 | otherwise = checkStability hpt1 mg2_with_srcimps all_home_mods
519 -- prune bits of the HPT which are definitely redundant now,
521 pruned_hpt = pruneHomePackageTable hpt1
522 (flattenSCCs mg2_with_srcimps)
527 debugTraceMsg dflags 2 (showSDoc (text "Stable obj:" <+> ppr stable_obj $$
528 text "Stable BCO:" <+> ppr stable_bco))
530 -- Unload any modules which are going to be re-linked this time around.
531 let stable_linkables = [ linkable
532 | m <- stable_obj++stable_bco,
533 Just hmi <- [lookupModuleEnv pruned_hpt m],
534 Just linkable <- [hm_linkable hmi] ]
535 unload hsc_env stable_linkables
537 -- We could at this point detect cycles which aren't broken by
538 -- a source-import, and complain immediately, but it seems better
539 -- to let upsweep_mods do this, so at least some useful work gets
540 -- done before the upsweep is abandoned.
541 --hPutStrLn stderr "after tsort:\n"
542 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
544 -- Now do the upsweep, calling compile for each module in
545 -- turn. Final result is version 3 of everything.
547 -- Topologically sort the module graph, this time including hi-boot
548 -- nodes, and possibly just including the portion of the graph
549 -- reachable from the module specified in the 2nd argument to load.
550 -- This graph should be cycle-free.
551 -- If we're restricting the upsweep to a portion of the graph, we
552 -- also want to retain everything that is still stable.
553 let full_mg :: [SCC ModSummary]
554 full_mg = topSortModuleGraph False mod_graph Nothing
556 maybe_top_mod = case how_much of
558 LoadDependenciesOf m -> Just m
561 partial_mg0 :: [SCC ModSummary]
562 partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod
564 -- LoadDependenciesOf m: we want the upsweep to stop just
565 -- short of the specified module (unless the specified module
568 | LoadDependenciesOf mod <- how_much
569 = ASSERT( case last partial_mg0 of
570 AcyclicSCC ms -> ms_mod ms == mod; _ -> False )
571 List.init partial_mg0
577 | AcyclicSCC ms <- full_mg,
578 ms_mod ms `elem` stable_obj++stable_bco,
579 ms_mod ms `notElem` [ ms_mod ms' |
580 AcyclicSCC ms' <- partial_mg ] ]
582 mg = stable_mg ++ partial_mg
584 -- clean up between compilations
585 let cleanup = cleanTempFilesExcept dflags
586 (ppFilesFromSummaries (flattenSCCs mg2_with_srcimps))
588 (upsweep_ok, hsc_env1, modsUpswept)
589 <- upsweep (hsc_env { hsc_HPT = emptyHomePackageTable })
590 pruned_hpt stable_mods cleanup msg_act mg
592 -- Make modsDone be the summaries for each home module now
593 -- available; this should equal the domain of hpt3.
594 -- Get in in a roughly top .. bottom order (hence reverse).
596 let modsDone = reverse modsUpswept
598 -- Try and do linking in some form, depending on whether the
599 -- upsweep was completely or only partially successful.
601 if succeeded upsweep_ok
604 -- Easy; just relink it all.
605 do debugTraceMsg dflags 2 "Upsweep completely successful."
607 -- Clean up after ourselves
608 cleanTempFilesExcept dflags (ppFilesFromSummaries modsDone)
610 -- Issue a warning for the confusing case where the user
611 -- said '-o foo' but we're not going to do any linking.
612 -- We attempt linking if either (a) one of the modules is
613 -- called Main, or (b) the user said -no-hs-main, indicating
614 -- that main() is going to come from somewhere else.
616 let ofile = outputFile dflags
617 let no_hs_main = dopt Opt_NoHsMain dflags
618 let mb_main_mod = mainModIs dflags
620 main_mod = mb_main_mod `orElse` "Main"
622 = any ((==main_mod).moduleUserString.ms_mod)
624 do_linking = a_root_is_Main || no_hs_main
626 when (ghci_mode == BatchCompile && isJust ofile && not do_linking) $
627 debugTraceMsg dflags 1 ("Warning: output was redirected with -o, " ++
628 "but no output will be generated\n" ++
629 "because there is no " ++ main_mod ++ " module.")
631 -- link everything together
632 linkresult <- link ghci_mode dflags do_linking (hsc_HPT hsc_env1)
634 loadFinish Succeeded linkresult ref hsc_env1
637 -- Tricky. We need to back out the effects of compiling any
638 -- half-done cycles, both so as to clean up the top level envs
639 -- and to avoid telling the interactive linker to link them.
640 do debugTraceMsg dflags 2 "Upsweep partially successful."
643 = map ms_mod modsDone
644 let mods_to_zap_names
645 = findPartiallyCompletedCycles modsDone_names
648 = filter ((`notElem` mods_to_zap_names).ms_mod)
651 let hpt4 = retainInTopLevelEnvs (map ms_mod mods_to_keep)
654 -- Clean up after ourselves
655 cleanTempFilesExcept dflags (ppFilesFromSummaries mods_to_keep)
657 -- there should be no Nothings where linkables should be, now
658 ASSERT(all (isJust.hm_linkable)
659 (moduleEnvElts (hsc_HPT hsc_env))) do
661 -- Link everything together
662 linkresult <- link ghci_mode dflags False hpt4
664 let hsc_env4 = hsc_env1{ hsc_HPT = hpt4 }
665 loadFinish Failed linkresult ref hsc_env4
667 -- Finish up after a load.
669 -- If the link failed, unload everything and return.
670 loadFinish all_ok Failed ref hsc_env
671 = do unload hsc_env []
672 writeIORef ref $! discardProg hsc_env
675 -- Empty the interactive context and set the module context to the topmost
676 -- newly loaded module, or the Prelude if none were loaded.
677 loadFinish all_ok Succeeded ref hsc_env
678 = do writeIORef ref $! hsc_env{ hsc_IC = emptyInteractiveContext }
682 -- Forget the current program, but retain the persistent info in HscEnv
683 discardProg :: HscEnv -> HscEnv
685 = hsc_env { hsc_mod_graph = emptyMG,
686 hsc_IC = emptyInteractiveContext,
687 hsc_HPT = emptyHomePackageTable }
689 -- used to fish out the preprocess output files for the purposes of
690 -- cleaning up. The preprocessed file *might* be the same as the
691 -- source file, but that doesn't do any harm.
692 ppFilesFromSummaries summaries = [ fn | Just fn <- map ms_hspp_file summaries ]
694 -- -----------------------------------------------------------------------------
698 CheckedModule { parsedSource :: ParsedSource,
699 renamedSource :: Maybe RenamedSource,
700 typecheckedSource :: Maybe TypecheckedSource,
701 checkedModuleInfo :: Maybe ModuleInfo
703 -- ToDo: improvements that could be made here:
704 -- if the module succeeded renaming but not typechecking,
705 -- we can still get back the GlobalRdrEnv and exports, so
706 -- perhaps the ModuleInfo should be split up into separate
707 -- fields within CheckedModule.
709 type ParsedSource = Located (HsModule RdrName)
710 type RenamedSource = HsGroup Name
711 type TypecheckedSource = LHsBinds Id
714 -- - things that aren't in the output of the renamer:
717 -- - things that aren't in the output of the typechecker right now:
721 -- - type/data/newtype declarations
722 -- - class declarations
724 -- - extra things in the typechecker's output:
725 -- - default methods are turned into top-level decls.
726 -- - dictionary bindings
729 -- | This is the way to get access to parsed and typechecked source code
730 -- for a module. 'checkModule' loads all the dependencies of the specified
731 -- module in the Session, and then attempts to typecheck the module. If
732 -- successful, it returns the abstract syntax for the module.
733 checkModule :: Session -> Module -> (Messages -> IO ())
734 -> IO (Maybe CheckedModule)
735 checkModule session@(Session ref) mod msg_act = do
736 -- load up the dependencies first
737 r <- loadMsgs session (LoadDependenciesOf mod) msg_act
738 if (failed r) then return Nothing else do
740 -- now parse & typecheck the module
741 hsc_env <- readIORef ref
742 let mg = hsc_mod_graph hsc_env
743 case [ ms | ms <- mg, ms_mod ms == mod ] of
746 -- Add in the OPTIONS from the source file This is nasty:
747 -- we've done this once already, in the compilation manager
748 -- It might be better to cache the flags in the
749 -- ml_hspp_file field, say
750 let dflags0 = hsc_dflags hsc_env
751 hspp_buf = expectJust "GHC.checkModule" (ms_hspp_buf ms)
752 opts = getOptionsFromStringBuffer hspp_buf
753 (dflags1,leftovers) <- parseDynamicFlags dflags0 (map snd opts)
754 if (not (null leftovers))
755 then do let filename = fromJust (ml_hs_file (ms_location ms))
756 msg_act (optionsErrorMsgs leftovers opts filename)
760 r <- hscFileCheck hsc_env{hsc_dflags=dflags1} msg_act ms
764 HscChecked parsed renamed Nothing ->
765 return (Just (CheckedModule {
766 parsedSource = parsed,
767 renamedSource = renamed,
768 typecheckedSource = Nothing,
769 checkedModuleInfo = Nothing }))
770 HscChecked parsed renamed
771 (Just (tc_binds, rdr_env, details)) -> do
772 let minf = ModuleInfo {
773 minf_type_env = md_types details,
774 minf_exports = md_exports details,
775 minf_rdr_env = Just rdr_env,
776 minf_instances = md_insts details
778 return (Just (CheckedModule {
779 parsedSource = parsed,
780 renamedSource = renamed,
781 typecheckedSource = Just tc_binds,
782 checkedModuleInfo = Just minf }))
786 -- ---------------------------------------------------------------------------
789 unload :: HscEnv -> [Linkable] -> IO ()
790 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
791 = case ghcMode (hsc_dflags hsc_env) of
792 BatchCompile -> return ()
793 JustTypecheck -> return ()
795 Interactive -> Linker.unload (hsc_dflags hsc_env) stable_linkables
797 Interactive -> panic "unload: no interpreter"
799 other -> panic "unload: strange mode"
801 -- -----------------------------------------------------------------------------
805 Stability tells us which modules definitely do not need to be recompiled.
806 There are two main reasons for having stability:
808 - avoid doing a complete upsweep of the module graph in GHCi when
809 modules near the bottom of the tree have not changed.
811 - to tell GHCi when it can load object code: we can only load object code
812 for a module when we also load object code fo all of the imports of the
813 module. So we need to know that we will definitely not be recompiling
814 any of these modules, and we can use the object code.
816 NB. stability is of no importance to BatchCompile at all, only Interactive.
817 (ToDo: what about JustTypecheck?)
819 The stability check is as follows. Both stableObject and
820 stableBCO are used during the upsweep phase later.
823 stable m = stableObject m || stableBCO m
826 all stableObject (imports m)
827 && old linkable does not exist, or is == on-disk .o
828 && date(on-disk .o) > date(.hs)
831 all stable (imports m)
832 && date(BCO) > date(.hs)
835 These properties embody the following ideas:
837 - if a module is stable:
838 - if it has been compiled in a previous pass (present in HPT)
839 then it does not need to be compiled or re-linked.
840 - if it has not been compiled in a previous pass,
841 then we only need to read its .hi file from disk and
842 link it to produce a ModDetails.
844 - if a modules is not stable, we will definitely be at least
845 re-linking, and possibly re-compiling it during the upsweep.
846 All non-stable modules can (and should) therefore be unlinked
849 - Note that objects are only considered stable if they only depend
850 on other objects. We can't link object code against byte code.
854 :: HomePackageTable -- HPT from last compilation
855 -> [SCC ModSummary] -- current module graph (cyclic)
856 -> [Module] -- all home modules
857 -> ([Module], -- stableObject
858 [Module]) -- stableBCO
860 checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
862 checkSCC (stable_obj, stable_bco) scc0
863 | stableObjects = (scc_mods ++ stable_obj, stable_bco)
864 | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
865 | otherwise = (stable_obj, stable_bco)
867 scc = flattenSCC scc0
868 scc_mods = map ms_mod scc
869 home_module m = m `elem` all_home_mods && m `notElem` scc_mods
871 scc_allimps = nub (filter home_module (concatMap ms_allimps scc))
872 -- all imports outside the current SCC, but in the home pkg
874 stable_obj_imps = map (`elem` stable_obj) scc_allimps
875 stable_bco_imps = map (`elem` stable_bco) scc_allimps
882 and (zipWith (||) stable_obj_imps stable_bco_imps)
886 | Just t <- ms_obj_date ms = t >= ms_hs_date ms
890 same_as_prev t = case lookupModuleEnv hpt (ms_mod ms) of
891 Just hmi | Just l <- hm_linkable hmi
892 -> isObjectLinkable l && t == linkableTime l
894 -- why '>=' rather than '>' above? If the filesystem stores
895 -- times to the nearset second, we may occasionally find that
896 -- the object & source have the same modification time,
897 -- especially if the source was automatically generated
898 -- and compiled. Using >= is slightly unsafe, but it matches
902 = case lookupModuleEnv hpt (ms_mod ms) of
903 Just hmi | Just l <- hm_linkable hmi ->
904 not (isObjectLinkable l) &&
905 linkableTime l >= ms_hs_date ms
908 ms_allimps :: ModSummary -> [Module]
909 ms_allimps ms = map unLoc (ms_srcimps ms ++ ms_imps ms)
911 -- -----------------------------------------------------------------------------
912 -- Prune the HomePackageTable
914 -- Before doing an upsweep, we can throw away:
916 -- - For non-stable modules:
917 -- - all ModDetails, all linked code
918 -- - all unlinked code that is out of date with respect to
921 -- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
922 -- space at the end of the upsweep, because the topmost ModDetails of the
923 -- old HPT holds on to the entire type environment from the previous
926 pruneHomePackageTable
929 -> ([Module],[Module])
932 pruneHomePackageTable hpt summ (stable_obj, stable_bco)
933 = mapModuleEnv prune hpt
935 | is_stable modl = hmi'
936 | otherwise = hmi'{ hm_details = emptyModDetails }
938 modl = mi_module (hm_iface hmi)
939 hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
940 = hmi{ hm_linkable = Nothing }
943 where ms = expectJust "prune" (lookupModuleEnv ms_map modl)
945 ms_map = mkModuleEnv [(ms_mod ms, ms) | ms <- summ]
947 is_stable m = m `elem` stable_obj || m `elem` stable_bco
949 -- -----------------------------------------------------------------------------
951 -- Return (names of) all those in modsDone who are part of a cycle
952 -- as defined by theGraph.
953 findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
954 findPartiallyCompletedCycles modsDone theGraph
958 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
959 chew ((CyclicSCC vs):rest)
960 = let names_in_this_cycle = nub (map ms_mod vs)
962 = nub ([done | done <- modsDone,
963 done `elem` names_in_this_cycle])
964 chewed_rest = chew rest
966 if notNull mods_in_this_cycle
967 && length mods_in_this_cycle < length names_in_this_cycle
968 then mods_in_this_cycle ++ chewed_rest
971 -- -----------------------------------------------------------------------------
974 -- This is where we compile each module in the module graph, in a pass
975 -- from the bottom to the top of the graph.
977 -- There better had not be any cyclic groups here -- we check for them.
980 :: HscEnv -- Includes initially-empty HPT
981 -> HomePackageTable -- HPT from last time round (pruned)
982 -> ([Module],[Module]) -- stable modules (see checkStability)
983 -> IO () -- How to clean up unwanted tmp files
984 -> (Messages -> IO ()) -- Compiler error message callback
985 -> [SCC ModSummary] -- Mods to do (the worklist)
987 HscEnv, -- With an updated HPT
988 [ModSummary]) -- Mods which succeeded
990 upsweep hsc_env old_hpt stable_mods cleanup msg_act mods
991 = upsweep' hsc_env old_hpt stable_mods cleanup msg_act mods 1 (length mods)
993 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
995 = return (Succeeded, hsc_env, [])
997 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
999 = do putMsg (showSDoc (cyclicModuleErr ms))
1000 return (Failed, hsc_env, [])
1002 upsweep' hsc_env old_hpt stable_mods cleanup msg_act
1003 (AcyclicSCC mod:mods) mod_index nmods
1004 = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
1005 -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
1006 -- (moduleEnvElts (hsc_HPT hsc_env)))
1008 mb_mod_info <- upsweep_mod hsc_env old_hpt stable_mods msg_act mod
1011 cleanup -- Remove unwanted tmp files between compilations
1014 Nothing -> return (Failed, hsc_env, [])
1016 { let this_mod = ms_mod mod
1018 -- Add new info to hsc_env
1019 hpt1 = extendModuleEnv (hsc_HPT hsc_env)
1021 hsc_env1 = hsc_env { hsc_HPT = hpt1 }
1023 -- Space-saving: delete the old HPT entry
1024 -- for mod BUT if mod is a hs-boot
1025 -- node, don't delete it. For the
1026 -- interface, the HPT entry is probaby for the
1027 -- main Haskell source file. Deleting it
1028 -- would force .. (what?? --SDM)
1029 old_hpt1 | isBootSummary mod = old_hpt
1030 | otherwise = delModuleEnv old_hpt this_mod
1032 ; (restOK, hsc_env2, modOKs)
1033 <- upsweep' hsc_env1 old_hpt1 stable_mods cleanup
1034 msg_act mods (mod_index+1) nmods
1035 ; return (restOK, hsc_env2, mod:modOKs)
1039 -- Compile a single module. Always produce a Linkable for it if
1040 -- successful. If no compilation happened, return the old Linkable.
1041 upsweep_mod :: HscEnv
1043 -> ([Module],[Module])
1044 -> (Messages -> IO ())
1046 -> Int -- index of module
1047 -> Int -- total number of modules
1048 -> IO (Maybe HomeModInfo) -- Nothing => Failed
1050 upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) msg_act summary mod_index nmods
1053 this_mod = ms_mod summary
1054 mb_obj_date = ms_obj_date summary
1055 obj_fn = ml_obj_file (ms_location summary)
1056 hs_date = ms_hs_date summary
1058 compile_it :: Maybe Linkable -> IO (Maybe HomeModInfo)
1059 compile_it = upsweep_compile hsc_env old_hpt this_mod
1060 msg_act summary mod_index nmods
1062 case ghcMode (hsc_dflags hsc_env) of
1065 -- Batch-compilating is easy: just check whether we have
1066 -- an up-to-date object file. If we do, then the compiler
1067 -- needs to do a recompilation check.
1068 _ | Just obj_date <- mb_obj_date, obj_date >= hs_date -> do
1070 findObjectLinkable this_mod obj_fn obj_date
1071 compile_it (Just linkable)
1078 _ | is_stable_obj, isJust old_hmi ->
1080 -- object is stable, and we have an entry in the
1081 -- old HPT: nothing to do
1083 | is_stable_obj, isNothing old_hmi -> do
1085 findObjectLinkable this_mod obj_fn
1086 (expectJust "upseep1" mb_obj_date)
1087 compile_it (Just linkable)
1088 -- object is stable, but we need to load the interface
1089 -- off disk to make a HMI.
1092 ASSERT(isJust old_hmi) -- must be in the old_hpt
1094 -- BCO is stable: nothing to do
1096 | Just hmi <- old_hmi,
1097 Just l <- hm_linkable hmi, not (isObjectLinkable l),
1098 linkableTime l >= ms_hs_date summary ->
1100 -- we have an old BCO that is up to date with respect
1101 -- to the source: do a recompilation check as normal.
1105 -- no existing code at all: we must recompile.
1107 is_stable_obj = this_mod `elem` stable_obj
1108 is_stable_bco = this_mod `elem` stable_bco
1110 old_hmi = lookupModuleEnv old_hpt this_mod
1112 -- Run hsc to compile a module
1113 upsweep_compile hsc_env old_hpt this_mod msg_act summary
1115 mb_old_linkable = do
1117 -- The old interface is ok if it's in the old HPT
1118 -- a) we're compiling a source file, and the old HPT
1119 -- entry is for a source file
1120 -- b) we're compiling a hs-boot file
1121 -- Case (b) allows an hs-boot file to get the interface of its
1122 -- real source file on the second iteration of the compilation
1123 -- manager, but that does no harm. Otherwise the hs-boot file
1124 -- will always be recompiled
1127 = case lookupModuleEnv old_hpt this_mod of
1129 Just hm_info | isBootSummary summary -> Just iface
1130 | not (mi_boot iface) -> Just iface
1131 | otherwise -> Nothing
1133 iface = hm_iface hm_info
1135 compresult <- compile hsc_env msg_act summary mb_old_linkable mb_old_iface
1139 -- Compilation failed. Compile may still have updated the PCS, tho.
1140 CompErrs -> return Nothing
1142 -- Compilation "succeeded", and may or may not have returned a new
1143 -- linkable (depending on whether compilation was actually performed
1145 CompOK new_details new_iface new_linkable
1146 -> do let new_info = HomeModInfo { hm_iface = new_iface,
1147 hm_details = new_details,
1148 hm_linkable = new_linkable }
1149 return (Just new_info)
1152 -- Filter modules in the HPT
1153 retainInTopLevelEnvs :: [Module] -> HomePackageTable -> HomePackageTable
1154 retainInTopLevelEnvs keep_these hpt
1155 = mkModuleEnv [ (mod, expectJust "retain" mb_mod_info)
1157 , let mb_mod_info = lookupModuleEnv hpt mod
1158 , isJust mb_mod_info ]
1160 -- ---------------------------------------------------------------------------
1161 -- Topological sort of the module graph
1164 :: Bool -- Drop hi-boot nodes? (see below)
1168 -- Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
1169 -- The resulting list of strongly-connected-components is in topologically
1170 -- sorted order, starting with the module(s) at the bottom of the
1171 -- dependency graph (ie compile them first) and ending with the ones at
1174 -- Drop hi-boot nodes (first boolean arg)?
1176 -- False: treat the hi-boot summaries as nodes of the graph,
1177 -- so the graph must be acyclic
1179 -- True: eliminate the hi-boot nodes, and instead pretend
1180 -- the a source-import of Foo is an import of Foo
1181 -- The resulting graph has no hi-boot nodes, but can by cyclic
1183 topSortModuleGraph drop_hs_boot_nodes summaries Nothing
1184 = stronglyConnComp (fst (moduleGraphNodes drop_hs_boot_nodes summaries))
1185 topSortModuleGraph drop_hs_boot_nodes summaries (Just mod)
1186 = stronglyConnComp (map vertex_fn (reachable graph root))
1188 -- restrict the graph to just those modules reachable from
1189 -- the specified module. We do this by building a graph with
1190 -- the full set of nodes, and determining the reachable set from
1191 -- the specified node.
1192 (nodes, lookup_key) = moduleGraphNodes drop_hs_boot_nodes summaries
1193 (graph, vertex_fn, key_fn) = graphFromEdges' nodes
1195 | Just key <- lookup_key HsSrcFile mod, Just v <- key_fn key = v
1196 | otherwise = throwDyn (ProgramError "module does not exist")
1198 moduleGraphNodes :: Bool -> [ModSummary]
1199 -> ([(ModSummary, Int, [Int])], HscSource -> Module -> Maybe Int)
1200 moduleGraphNodes drop_hs_boot_nodes summaries = (nodes, lookup_key)
1202 -- Drop hs-boot nodes by using HsSrcFile as the key
1203 hs_boot_key | drop_hs_boot_nodes = HsSrcFile
1204 | otherwise = HsBootFile
1206 -- We use integers as the keys for the SCC algorithm
1207 nodes :: [(ModSummary, Int, [Int])]
1208 nodes = [(s, expectJust "topSort" (lookup_key (ms_hsc_src s) (ms_mod s)),
1209 out_edge_keys hs_boot_key (map unLoc (ms_srcimps s)) ++
1210 out_edge_keys HsSrcFile (map unLoc (ms_imps s)) )
1212 , not (isBootSummary s && drop_hs_boot_nodes) ]
1213 -- Drop the hi-boot ones if told to do so
1215 key_map :: NodeMap Int
1216 key_map = listToFM ([(ms_mod s, ms_hsc_src s) | s <- summaries]
1219 lookup_key :: HscSource -> Module -> Maybe Int
1220 lookup_key hs_src mod = lookupFM key_map (mod, hs_src)
1222 out_edge_keys :: HscSource -> [Module] -> [Int]
1223 out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
1224 -- If we want keep_hi_boot_nodes, then we do lookup_key with
1225 -- the IsBootInterface parameter True; else False
1228 type NodeKey = (Module, HscSource) -- The nodes of the graph are
1229 type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
1231 msKey :: ModSummary -> NodeKey
1232 msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (mod,boot)
1234 mkNodeMap :: [ModSummary] -> NodeMap ModSummary
1235 mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
1237 nodeMapElts :: NodeMap a -> [a]
1238 nodeMapElts = eltsFM
1240 -----------------------------------------------------------------------------
1241 -- Downsweep (dependency analysis)
1243 -- Chase downwards from the specified root set, returning summaries
1244 -- for all home modules encountered. Only follow source-import
1247 -- We pass in the previous collection of summaries, which is used as a
1248 -- cache to avoid recalculating a module summary if the source is
1251 -- The returned list of [ModSummary] nodes has one node for each home-package
1252 -- module, plus one for any hs-boot files. The imports of these nodes
1253 -- are all there, including the imports of non-home-package modules.
1256 -> [ModSummary] -- Old summaries
1257 -> [Module] -- Ignore dependencies on these; treat
1258 -- them as if they were package modules
1259 -> Bool -- True <=> allow multiple targets to have
1260 -- the same module name; this is
1261 -- very useful for ghc -M
1262 -> IO (Either Messages [ModSummary])
1263 -- The elts of [ModSummary] all have distinct
1264 -- (Modules, IsBoot) identifiers, unless the Bool is true
1265 -- in which case there can be repeats
1266 downsweep hsc_env old_summaries excl_mods allow_dup_roots
1267 = -- catch error messages and return them
1268 handleDyn (\err_msg -> return (Left (emptyBag, unitBag err_msg))) $ do
1269 rootSummaries <- mapM getRootSummary roots
1270 let root_map = mkRootMap rootSummaries
1271 checkDuplicates root_map
1272 summs <- loop (concatMap msDeps rootSummaries) root_map
1273 return (Right summs)
1275 roots = hsc_targets hsc_env
1277 old_summary_map :: NodeMap ModSummary
1278 old_summary_map = mkNodeMap old_summaries
1280 getRootSummary :: Target -> IO ModSummary
1281 getRootSummary (Target (TargetFile file mb_phase) maybe_buf)
1282 = do exists <- doesFileExist file
1284 then summariseFile hsc_env old_summaries file mb_phase maybe_buf
1285 else throwDyn $ mkPlainErrMsg noSrcSpan $
1286 text "can't find file:" <+> text file
1287 getRootSummary (Target (TargetModule modl) maybe_buf)
1288 = do maybe_summary <- summariseModule hsc_env old_summary_map False
1289 (L rootLoc modl) maybe_buf excl_mods
1290 case maybe_summary of
1291 Nothing -> packageModErr modl
1294 rootLoc = mkGeneralSrcSpan FSLIT("<command line>")
1296 -- In a root module, the filename is allowed to diverge from the module
1297 -- name, so we have to check that there aren't multiple root files
1298 -- defining the same module (otherwise the duplicates will be silently
1299 -- ignored, leading to confusing behaviour).
1300 checkDuplicates :: NodeMap [ModSummary] -> IO ()
1301 checkDuplicates root_map
1302 | allow_dup_roots = return ()
1303 | null dup_roots = return ()
1304 | otherwise = multiRootsErr (head dup_roots)
1306 dup_roots :: [[ModSummary]] -- Each at least of length 2
1307 dup_roots = filterOut isSingleton (nodeMapElts root_map)
1309 loop :: [(Located Module,IsBootInterface)]
1310 -- Work list: process these modules
1311 -> NodeMap [ModSummary]
1312 -- Visited set; the range is a list because
1313 -- the roots can have the same module names
1314 -- if allow_dup_roots is True
1316 -- The result includes the worklist, except
1317 -- for those mentioned in the visited set
1318 loop [] done = return (concat (nodeMapElts done))
1319 loop ((wanted_mod, is_boot) : ss) done
1320 | Just summs <- lookupFM done key
1321 = if isSingleton summs then
1324 do { multiRootsErr summs; return [] }
1325 | otherwise = do { mb_s <- summariseModule hsc_env old_summary_map
1326 is_boot wanted_mod Nothing excl_mods
1328 Nothing -> loop ss done
1329 Just s -> loop (msDeps s ++ ss)
1330 (addToFM done key [s]) }
1332 key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
1334 mkRootMap :: [ModSummary] -> NodeMap [ModSummary]
1335 mkRootMap summaries = addListToFM_C (++) emptyFM
1336 [ (msKey s, [s]) | s <- summaries ]
1338 msDeps :: ModSummary -> [(Located Module, IsBootInterface)]
1339 -- (msDeps s) returns the dependencies of the ModSummary s.
1340 -- A wrinkle is that for a {-# SOURCE #-} import we return
1341 -- *both* the hs-boot file
1342 -- *and* the source file
1343 -- as "dependencies". That ensures that the list of all relevant
1344 -- modules always contains B.hs if it contains B.hs-boot.
1345 -- Remember, this pass isn't doing the topological sort. It's
1346 -- just gathering the list of all relevant ModSummaries
1348 concat [ [(m,True), (m,False)] | m <- ms_srcimps s ]
1349 ++ [ (m,False) | m <- ms_imps s ]
1351 -----------------------------------------------------------------------------
1352 -- Summarising modules
1354 -- We have two types of summarisation:
1356 -- * Summarise a file. This is used for the root module(s) passed to
1357 -- cmLoadModules. The file is read, and used to determine the root
1358 -- module name. The module name may differ from the filename.
1360 -- * Summarise a module. We are given a module name, and must provide
1361 -- a summary. The finder is used to locate the file in which the module
1366 -> [ModSummary] -- old summaries
1367 -> FilePath -- source file name
1368 -> Maybe Phase -- start phase
1369 -> Maybe (StringBuffer,ClockTime)
1372 summariseFile hsc_env old_summaries file mb_phase maybe_buf
1373 -- we can use a cached summary if one is available and the
1374 -- source file hasn't changed, But we have to look up the summary
1375 -- by source file, rather than module name as we do in summarise.
1376 | Just old_summary <- findSummaryBySourceFile old_summaries file
1378 let location = ms_location old_summary
1380 -- return the cached summary if the source didn't change
1381 src_timestamp <- case maybe_buf of
1382 Just (_,t) -> return t
1383 Nothing -> getModificationTime file
1384 -- The file exists; we checked in getRootSummary above.
1385 -- If it gets removed subsequently, then this
1386 -- getModificationTime may fail, but that's the right
1389 if ms_hs_date old_summary == src_timestamp
1390 then do -- update the object-file timestamp
1391 obj_timestamp <- getObjTimestamp location False
1392 return old_summary{ ms_obj_date = obj_timestamp }
1400 let dflags = hsc_dflags hsc_env
1402 (dflags', hspp_fn, buf)
1403 <- preprocessFile dflags file mb_phase maybe_buf
1405 (srcimps,the_imps, L _ mod) <- getImports dflags' buf hspp_fn
1407 -- Make a ModLocation for this file
1408 location <- mkHomeModLocation dflags mod file
1410 -- Tell the Finder cache where it is, so that subsequent calls
1411 -- to findModule will find it, even if it's not on any search path
1412 addHomeModuleToFinder hsc_env mod location
1414 src_timestamp <- case maybe_buf of
1415 Just (_,t) -> return t
1416 Nothing -> getModificationTime file
1417 -- getMofificationTime may fail
1419 obj_timestamp <- modificationTimeIfExists (ml_obj_file location)
1421 return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
1422 ms_location = location,
1423 ms_hspp_file = Just hspp_fn,
1424 ms_hspp_buf = Just buf,
1425 ms_srcimps = srcimps, ms_imps = the_imps,
1426 ms_hs_date = src_timestamp,
1427 ms_obj_date = obj_timestamp })
1429 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
1430 findSummaryBySourceFile summaries file
1431 = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
1432 fromJust (ml_hs_file (ms_location ms)) == file ] of
1436 -- Summarise a module, and pick up source and timestamp.
1439 -> NodeMap ModSummary -- Map of old summaries
1440 -> IsBootInterface -- True <=> a {-# SOURCE #-} import
1441 -> Located Module -- Imported module to be summarised
1442 -> Maybe (StringBuffer, ClockTime)
1443 -> [Module] -- Modules to exclude
1444 -> IO (Maybe ModSummary) -- Its new summary
1446 summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod) maybe_buf excl_mods
1447 | wanted_mod `elem` excl_mods
1450 | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
1451 = do -- Find its new timestamp; all the
1452 -- ModSummaries in the old map have valid ml_hs_files
1453 let location = ms_location old_summary
1454 src_fn = expectJust "summariseModule" (ml_hs_file location)
1456 -- check the modification time on the source file, and
1457 -- return the cached summary if it hasn't changed. If the
1458 -- file has disappeared, we need to call the Finder again.
1460 Just (_,t) -> check_timestamp old_summary location src_fn t
1462 m <- IO.try (getModificationTime src_fn)
1464 Right t -> check_timestamp old_summary location src_fn t
1465 Left e | isDoesNotExistError e -> find_it
1466 | otherwise -> ioError e
1468 | otherwise = find_it
1470 dflags = hsc_dflags hsc_env
1472 hsc_src = if is_boot then HsBootFile else HsSrcFile
1474 check_timestamp old_summary location src_fn src_timestamp
1475 | ms_hs_date old_summary == src_timestamp = do
1476 -- update the object-file timestamp
1477 obj_timestamp <- getObjTimestamp location is_boot
1478 return (Just old_summary{ ms_obj_date = obj_timestamp })
1480 -- source changed: find and re-summarise. We call the finder
1481 -- again, because the user may have moved the source file.
1482 new_summary location src_fn src_timestamp
1485 -- Don't use the Finder's cache this time. If the module was
1486 -- previously a package module, it may have now appeared on the
1487 -- search path, so we want to consider it to be a home module. If
1488 -- the module was previously a home module, it may have moved.
1489 uncacheModule hsc_env wanted_mod
1490 found <- findModule hsc_env wanted_mod True {-explicit-}
1493 | not (isHomePackage pkg) -> return Nothing
1494 -- Drop external-pkg
1495 | isJust (ml_hs_file location) -> just_found location
1497 err -> noModError dflags loc wanted_mod err
1500 just_found location = do
1501 -- Adjust location to point to the hs-boot source file,
1502 -- hi file, object file, when is_boot says so
1503 let location' | is_boot = addBootSuffixLocn location
1504 | otherwise = location
1505 src_fn = expectJust "summarise2" (ml_hs_file location')
1507 -- Check that it exists
1508 -- It might have been deleted since the Finder last found it
1509 maybe_t <- modificationTimeIfExists src_fn
1511 Nothing -> noHsFileErr loc src_fn
1512 Just t -> new_summary location' src_fn t
1515 new_summary location src_fn src_timestamp
1517 -- Preprocess the source file and get its imports
1518 -- The dflags' contains the OPTIONS pragmas
1519 (dflags', hspp_fn, buf) <- preprocessFile dflags src_fn Nothing maybe_buf
1520 (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn
1522 when (mod_name /= wanted_mod) $
1523 throwDyn $ mkPlainErrMsg mod_loc $
1524 text "file name does not match module name"
1525 <+> quotes (ppr mod_name)
1527 -- Find the object timestamp, and return the summary
1528 obj_timestamp <- getObjTimestamp location is_boot
1530 return (Just ( ModSummary { ms_mod = wanted_mod,
1531 ms_hsc_src = hsc_src,
1532 ms_location = location,
1533 ms_hspp_file = Just hspp_fn,
1534 ms_hspp_buf = Just buf,
1535 ms_srcimps = srcimps,
1537 ms_hs_date = src_timestamp,
1538 ms_obj_date = obj_timestamp }))
1541 getObjTimestamp location is_boot
1542 = if is_boot then return Nothing
1543 else modificationTimeIfExists (ml_obj_file location)
1546 preprocessFile :: DynFlags -> FilePath -> Maybe Phase -> Maybe (StringBuffer,ClockTime)
1547 -> IO (DynFlags, FilePath, StringBuffer)
1548 preprocessFile dflags src_fn mb_phase Nothing
1550 (dflags', hspp_fn) <- preprocess dflags (src_fn, mb_phase)
1551 buf <- hGetStringBuffer hspp_fn
1552 return (dflags', hspp_fn, buf)
1554 preprocessFile dflags src_fn mb_phase (Just (buf, time))
1556 -- case we bypass the preprocessing stage?
1558 local_opts = getOptionsFromStringBuffer buf
1560 (dflags', errs) <- parseDynamicFlags dflags (map snd local_opts)
1564 | Just (Unlit _) <- mb_phase = True
1565 | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
1566 -- note: local_opts is only required if there's no Unlit phase
1567 | dopt Opt_Cpp dflags' = True
1568 | dopt Opt_Pp dflags' = True
1571 when needs_preprocessing $
1572 ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
1574 return (dflags', src_fn, buf)
1577 -----------------------------------------------------------------------------
1579 -----------------------------------------------------------------------------
1581 noModError :: DynFlags -> SrcSpan -> Module -> FindResult -> IO ab
1582 -- ToDo: we don't have a proper line number for this error
1583 noModError dflags loc wanted_mod err
1584 = throwDyn $ mkPlainErrMsg loc $ cantFindError dflags wanted_mod err
1586 noHsFileErr loc path
1587 = throwDyn $ mkPlainErrMsg loc $ text "Can't find" <+> text path
1590 = throwDyn $ mkPlainErrMsg noSrcSpan $
1591 text "module" <+> quotes (ppr mod) <+> text "is a package module"
1593 multiRootsErr :: [ModSummary] -> IO ()
1594 multiRootsErr summs@(summ1:_)
1595 = throwDyn $ mkPlainErrMsg noSrcSpan $
1596 text "module" <+> quotes (ppr mod) <+>
1597 text "is defined in multiple files:" <+>
1598 sep (map text files)
1601 files = map (expectJust "checkDup" . ml_hs_file . ms_location) summs
1603 cyclicModuleErr :: [ModSummary] -> SDoc
1605 = hang (ptext SLIT("Module imports form a cycle for modules:"))
1606 2 (vcat (map show_one ms))
1608 show_one ms = sep [ show_mod (ms_hsc_src ms) (ms_mod ms),
1609 nest 2 $ ptext SLIT("imports:") <+>
1610 (pp_imps HsBootFile (ms_srcimps ms)
1611 $$ pp_imps HsSrcFile (ms_imps ms))]
1612 show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
1613 pp_imps src mods = fsep (map (show_mod src) mods)
1616 -- | Inform GHC that the working directory has changed. GHC will flush
1617 -- its cache of module locations, since it may no longer be valid.
1618 -- Note: if you change the working directory, you should also unload
1619 -- the current program (set targets to empty, followed by load).
1620 workingDirectoryChanged :: Session -> IO ()
1621 workingDirectoryChanged s = withSession s $ \hsc_env ->
1622 flushFinderCache (hsc_FC hsc_env)
1624 -- -----------------------------------------------------------------------------
1625 -- inspecting the session
1627 -- | Get the module dependency graph.
1628 getModuleGraph :: Session -> IO ModuleGraph -- ToDo: DiGraph ModSummary
1629 getModuleGraph s = withSession s (return . hsc_mod_graph)
1631 isLoaded :: Session -> Module -> IO Bool
1632 isLoaded s m = withSession s $ \hsc_env ->
1633 return $! isJust (lookupModuleEnv (hsc_HPT hsc_env) m)
1635 getBindings :: Session -> IO [TyThing]
1636 getBindings s = withSession s (return . nameEnvElts . ic_type_env . hsc_IC)
1638 getPrintUnqual :: Session -> IO PrintUnqualified
1639 getPrintUnqual s = withSession s (return . icPrintUnqual . hsc_IC)
1641 -- | Container for information about a 'Module'.
1642 data ModuleInfo = ModuleInfo {
1643 minf_type_env :: TypeEnv,
1644 minf_exports :: NameSet,
1645 minf_rdr_env :: Maybe GlobalRdrEnv, -- Nothing for a compiled/package mod
1646 minf_instances :: [Instance]
1647 -- ToDo: this should really contain the ModIface too
1649 -- We don't want HomeModInfo here, because a ModuleInfo applies
1650 -- to package modules too.
1652 -- | Request information about a loaded 'Module'
1653 getModuleInfo :: Session -> Module -> IO (Maybe ModuleInfo)
1654 getModuleInfo s mdl = withSession s $ \hsc_env -> do
1655 let mg = hsc_mod_graph hsc_env
1656 if mdl `elem` map ms_mod mg
1657 then getHomeModuleInfo hsc_env mdl
1659 {- if isHomeModule (hsc_dflags hsc_env) mdl
1661 else -} getPackageModuleInfo hsc_env mdl
1662 -- getPackageModuleInfo will attempt to find the interface, so
1663 -- we don't want to call it for a home module, just in case there
1664 -- was a problem loading the module and the interface doesn't
1665 -- exist... hence the isHomeModule test here. (ToDo: reinstate)
1667 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
1668 getPackageModuleInfo hsc_env mdl = do
1670 (_msgs, mb_names) <- getModuleExports hsc_env mdl
1672 Nothing -> return Nothing
1674 eps <- readIORef (hsc_EPS hsc_env)
1677 n_list = nameSetToList names
1678 tys = [ ty | name <- n_list,
1679 Just ty <- [lookupTypeEnv pte name] ]
1681 return (Just (ModuleInfo {
1682 minf_type_env = mkTypeEnv tys,
1683 minf_exports = names,
1684 minf_rdr_env = Just $! nameSetToGlobalRdrEnv names mdl,
1685 minf_instances = error "getModuleInfo: instances for package module unimplemented"
1688 -- bogusly different for non-GHCI (ToDo)
1692 getHomeModuleInfo hsc_env mdl =
1693 case lookupModuleEnv (hsc_HPT hsc_env) mdl of
1694 Nothing -> return Nothing
1696 let details = hm_details hmi
1697 return (Just (ModuleInfo {
1698 minf_type_env = md_types details,
1699 minf_exports = md_exports details,
1700 minf_rdr_env = mi_globals $! hm_iface hmi,
1701 minf_instances = md_insts details
1704 -- | The list of top-level entities defined in a module
1705 modInfoTyThings :: ModuleInfo -> [TyThing]
1706 modInfoTyThings minf = typeEnvElts (minf_type_env minf)
1708 modInfoTopLevelScope :: ModuleInfo -> Maybe [Name]
1709 modInfoTopLevelScope minf
1710 = fmap (map gre_name . globalRdrEnvElts) (minf_rdr_env minf)
1712 modInfoExports :: ModuleInfo -> [Name]
1713 modInfoExports minf = nameSetToList $! minf_exports minf
1715 -- | Returns the instances defined by the specified module.
1716 -- Warning: currently unimplemented for package modules.
1717 modInfoInstances :: ModuleInfo -> [Instance]
1718 modInfoInstances = minf_instances
1720 modInfoIsExportedName :: ModuleInfo -> Name -> Bool
1721 modInfoIsExportedName minf name = elemNameSet name (minf_exports minf)
1723 modInfoPrintUnqualified :: ModuleInfo -> Maybe PrintUnqualified
1724 modInfoPrintUnqualified minf = fmap unQualInScope (minf_rdr_env minf)
1726 modInfoLookupName :: Session -> ModuleInfo -> Name -> IO (Maybe TyThing)
1727 modInfoLookupName s minf name = withSession s $ \hsc_env -> do
1728 case lookupTypeEnv (minf_type_env minf) name of
1729 Just tyThing -> return (Just tyThing)
1731 eps <- readIORef (hsc_EPS hsc_env)
1732 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1734 isDictonaryId :: Id -> Bool
1736 = case tcSplitSigmaTy (idType id) of { (tvs, theta, tau) -> isDictTy tau }
1738 -- | Looks up a global name: that is, any top-level name in any
1739 -- visible module. Unlike 'lookupName', lookupGlobalName does not use
1740 -- the interactive context, and therefore does not require a preceding
1742 lookupGlobalName :: Session -> Name -> IO (Maybe TyThing)
1743 lookupGlobalName s name = withSession s $ \hsc_env -> do
1744 eps <- readIORef (hsc_EPS hsc_env)
1745 return $! lookupType (hsc_HPT hsc_env) (eps_PTE eps) name
1747 -- -----------------------------------------------------------------------------
1748 -- Misc exported utils
1750 dataConType :: DataCon -> Type
1751 dataConType dc = idType (dataConWrapId dc)
1753 -- | print a 'NamedThing', adding parentheses if the name is an operator.
1754 pprParenSymName :: NamedThing a => a -> SDoc
1755 pprParenSymName a = parenSymOcc (getOccName a) (ppr (getName a))
1757 -- ----------------------------------------------------------------------------
1762 -- - Data and Typeable instances for HsSyn.
1764 -- ToDo: check for small transformations that happen to the syntax in
1765 -- the typechecker (eg. -e ==> negate e, perhaps for fromIntegral)
1767 -- ToDo: maybe use TH syntax instead of IfaceSyn? There's already a way
1768 -- to get from TyCons, Ids etc. to TH syntax (reify).
1770 -- :browse will use either lm_toplev or inspect lm_interface, depending
1771 -- on whether the module is interpreted or not.
1773 -- This is for reconstructing refactored source code
1774 -- Calls the lexer repeatedly.
1775 -- ToDo: add comment tokens to token stream
1776 getTokenStream :: Session -> Module -> IO [Located Token]
1779 -- -----------------------------------------------------------------------------
1780 -- Interactive evaluation
1784 -- | Set the interactive evaluation context.
1786 -- Setting the context doesn't throw away any bindings; the bindings
1787 -- we've built up in the InteractiveContext simply move to the new
1788 -- module. They always shadow anything in scope in the current context.
1789 setContext :: Session
1790 -> [Module] -- entire top level scope of these modules
1791 -> [Module] -- exports only of these modules
1793 setContext (Session ref) toplevs exports = do
1794 hsc_env <- readIORef ref
1795 let old_ic = hsc_IC hsc_env
1796 hpt = hsc_HPT hsc_env
1798 mapM_ (checkModuleExists hsc_env hpt) exports
1799 export_env <- mkExportEnv hsc_env exports
1800 toplev_envs <- mapM (mkTopLevEnv hpt) toplevs
1801 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
1802 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplevs,
1803 ic_exports = exports,
1804 ic_rn_gbl_env = all_env }}
1807 -- Make a GlobalRdrEnv based on the exports of the modules only.
1808 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
1809 mkExportEnv hsc_env mods = do
1810 stuff <- mapM (getModuleExports hsc_env) mods
1812 (_msgs, mb_name_sets) = unzip stuff
1813 gres = [ nameSetToGlobalRdrEnv name_set mod
1814 | (Just name_set, mod) <- zip mb_name_sets mods ]
1816 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
1818 nameSetToGlobalRdrEnv :: NameSet -> Module -> GlobalRdrEnv
1819 nameSetToGlobalRdrEnv names mod =
1820 mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod }
1821 | name <- nameSetToList names ]
1823 vanillaProv :: Module -> Provenance
1824 -- We're building a GlobalRdrEnv as if the user imported
1825 -- all the specified modules into the global interactive module
1826 vanillaProv mod = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
1828 decl = ImpDeclSpec { is_mod = mod, is_as = mod,
1830 is_dloc = srcLocSpan interactiveSrcLoc }
1832 checkModuleExists :: HscEnv -> HomePackageTable -> Module -> IO ()
1833 checkModuleExists hsc_env hpt mod =
1834 case lookupModuleEnv hpt mod of
1835 Just mod_info -> return ()
1836 _not_a_home_module -> do
1837 res <- findPackageModule hsc_env mod True
1839 Found _ _ -> return ()
1840 err -> let msg = cantFindError (hsc_dflags hsc_env) mod err in
1841 throwDyn (CmdLineError (showSDoc msg))
1843 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
1844 mkTopLevEnv hpt modl
1845 = case lookupModuleEnv hpt modl of
1847 throwDyn (ProgramError ("mkTopLevEnv: not a home module "
1848 ++ showSDoc (pprModule modl)))
1850 case mi_globals (hm_iface details) of
1852 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
1853 ++ showSDoc (pprModule modl)))
1854 Just env -> return env
1856 -- | Get the interactive evaluation context, consisting of a pair of the
1857 -- set of modules from which we take the full top-level scope, and the set
1858 -- of modules from which we take just the exports respectively.
1859 getContext :: Session -> IO ([Module],[Module])
1860 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
1861 return (ic_toplev_scope ic, ic_exports ic))
1863 -- | Returns 'True' if the specified module is interpreted, and hence has
1864 -- its full top-level scope available.
1865 moduleIsInterpreted :: Session -> Module -> IO Bool
1866 moduleIsInterpreted s modl = withSession s $ \h ->
1867 case lookupModuleEnv (hsc_HPT h) modl of
1868 Just details -> return (isJust (mi_globals (hm_iface details)))
1869 _not_a_home_module -> return False
1871 -- | Looks up an identifier in the current interactive context (for :info)
1872 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
1873 getInfo s name = withSession s $ \hsc_env -> tcRnGetInfo hsc_env name
1875 -- | Returns all names in scope in the current interactive context
1876 getNamesInScope :: Session -> IO [Name]
1877 getNamesInScope s = withSession s $ \hsc_env -> do
1878 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
1880 -- | Parses a string as an identifier, and returns the list of 'Name's that
1881 -- the identifier can refer to in the current interactive context.
1882 parseName :: Session -> String -> IO [Name]
1883 parseName s str = withSession s $ \hsc_env -> do
1884 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
1885 case maybe_rdr_name of
1886 Nothing -> return []
1887 Just (L _ rdr_name) -> do
1888 mb_names <- tcRnLookupRdrName hsc_env rdr_name
1890 Nothing -> return []
1891 Just ns -> return ns
1892 -- ToDo: should return error messages
1894 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
1895 -- entity known to GHC, including 'Name's defined using 'runStmt'.
1896 lookupName :: Session -> Name -> IO (Maybe TyThing)
1897 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
1899 -- -----------------------------------------------------------------------------
1900 -- Getting the type of an expression
1902 -- | Get the type of an expression
1903 exprType :: Session -> String -> IO (Maybe Type)
1904 exprType s expr = withSession s $ \hsc_env -> do
1905 maybe_stuff <- hscTcExpr hsc_env expr
1907 Nothing -> return Nothing
1908 Just ty -> return (Just tidy_ty)
1910 tidy_ty = tidyType emptyTidyEnv ty
1912 -- -----------------------------------------------------------------------------
1913 -- Getting the kind of a type
1915 -- | Get the kind of a type
1916 typeKind :: Session -> String -> IO (Maybe Kind)
1917 typeKind s str = withSession s $ \hsc_env -> do
1918 maybe_stuff <- hscKcType hsc_env str
1920 Nothing -> return Nothing
1921 Just kind -> return (Just kind)
1923 -----------------------------------------------------------------------------
1924 -- cmCompileExpr: compile an expression and deliver an HValue
1926 compileExpr :: Session -> String -> IO (Maybe HValue)
1927 compileExpr s expr = withSession s $ \hsc_env -> do
1928 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
1930 Nothing -> return Nothing
1931 Just (new_ic, names, hval) -> do
1933 hvals <- (unsafeCoerce# hval) :: IO [HValue]
1935 case (names,hvals) of
1936 ([n],[hv]) -> return (Just hv)
1937 _ -> panic "compileExpr"
1939 -- -----------------------------------------------------------------------------
1940 -- running a statement interactively
1943 = RunOk [Name] -- ^ names bound by this evaluation
1944 | RunFailed -- ^ statement failed compilation
1945 | RunException Exception -- ^ statement raised an exception
1947 -- | Run a statement in the current interactive context. Statemenet
1948 -- may bind multple values.
1949 runStmt :: Session -> String -> IO RunResult
1950 runStmt (Session ref) expr
1952 hsc_env <- readIORef ref
1954 -- Turn off -fwarn-unused-bindings when running a statement, to hide
1955 -- warnings about the implicit bindings we introduce.
1956 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
1957 hsc_env' = hsc_env{ hsc_dflags = dflags' }
1959 maybe_stuff <- hscStmt hsc_env' expr
1962 Nothing -> return RunFailed
1963 Just (new_hsc_env, names, hval) -> do
1965 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
1966 either_hvals <- sandboxIO thing_to_run
1968 case either_hvals of
1970 -- on error, keep the *old* interactive context,
1971 -- so that 'it' is not bound to something
1972 -- that doesn't exist.
1973 return (RunException e)
1976 -- Get the newly bound things, and bind them.
1977 -- Don't need to delete any shadowed bindings;
1978 -- the new ones override the old ones.
1979 extendLinkEnv (zip names hvals)
1981 writeIORef ref new_hsc_env
1982 return (RunOk names)
1985 -- We run the statement in a "sandbox" to protect the rest of the
1986 -- system from anything the expression might do. For now, this
1987 -- consists of just wrapping it in an exception handler, but see below
1988 -- for another version.
1990 sandboxIO :: IO a -> IO (Either Exception a)
1991 sandboxIO thing = Exception.try thing
1994 -- This version of sandboxIO runs the expression in a completely new
1995 -- RTS main thread. It is disabled for now because ^C exceptions
1996 -- won't be delivered to the new thread, instead they'll be delivered
1997 -- to the (blocked) GHCi main thread.
1999 -- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
2001 sandboxIO :: IO a -> IO (Either Int (Either Exception a))
2002 sandboxIO thing = do
2003 st_thing <- newStablePtr (Exception.try thing)
2004 alloca $ \ p_st_result -> do
2005 stat <- rts_evalStableIO st_thing p_st_result
2006 freeStablePtr st_thing
2008 then do st_result <- peek p_st_result
2009 result <- deRefStablePtr st_result
2010 freeStablePtr st_result
2011 return (Right result)
2013 return (Left (fromIntegral stat))
2015 foreign import "rts_evalStableIO" {- safe -}
2016 rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
2017 -- more informative than the C type!
2020 -----------------------------------------------------------------------------
2021 -- show a module and it's source/object filenames
2023 showModule :: Session -> ModSummary -> IO String
2024 showModule s mod_summary = withSession s $ \hsc_env -> do
2025 case lookupModuleEnv (hsc_HPT hsc_env) (ms_mod mod_summary) of
2026 Nothing -> panic "missing linkable"
2027 Just mod_info -> return (showModMsg obj_linkable mod_summary)
2029 obj_linkable = isObjectLinkable (fromJust (hm_linkable mod_info))