7 #include "HsVersions.h"
9 import HsSyn ( MonoBinds(..) )
10 import HscTypes ( HscEnv(..), PersistentCompilerState(..),
11 emptyFixityEnv, emptyGlobalRdrEnv, TyThing,
12 ExternalPackageState(..), HomePackageTable,
13 ModDetails(..), HomeModInfo(..), Deprecations(..),
14 GlobalRdrEnv, LocalRdrEnv, NameCache, FixityEnv,
15 GhciMode, lookupType, unQualInScope )
17 import Module ( Module, foldModuleEnv )
18 import Name ( Name, isInternalName )
20 import NameEnv ( extendNameEnvList )
21 import InstEnv ( InstEnv, extendInstEnv )
22 import TysWiredIn ( integerTy, doubleTy )
24 import VarSet ( emptyVarSet )
25 import VarEnv ( TidyEnv, emptyTidyEnv )
26 import RdrName ( emptyRdrEnv )
27 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
28 addShortErrLocLine, addShortWarnLocLine, printErrorsAndWarnings )
29 import SrcLoc ( SrcLoc, noSrcLoc )
30 import NameEnv ( emptyNameEnv )
31 import Bag ( emptyBag )
33 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
34 import Unique ( Unique )
35 import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug )
36 import BasicTypes ( FixitySig )
37 import Bag ( snocBag, unionBags )
39 import Maybe ( isJust )
41 import DATA_IOREF ( newIORef, readIORef )
44 %************************************************************************
46 Standard combinators, but specialised for this monad
49 6%************************************************************************
52 mappM :: (a -> TcRn m b) -> [a] -> TcRn m [b]
53 mappM_ :: (a -> TcRn m b) -> [a] -> TcRn m ()
54 -- Funny names to avoid clash with Prelude
55 sequenceM :: [TcRn m a] -> TcRn m [a]
56 foldlM :: (a -> b -> TcRn m a) -> a -> [b] -> TcRn m a
57 mapAndUnzipM :: (a -> TcRn m (b,c)) -> [a] -> TcRn m ([b],[c])
58 mapAndUnzip3M :: (a -> TcRn m (b,c,d)) -> [a] -> TcRn m ([b],[c],[d])
59 checkM :: Bool -> TcRn m () -> TcRn m () -- Perform arg if bool is False
60 ifM :: Bool -> TcRn m () -> TcRn m () -- Perform arg if bool is True
62 mappM f [] = return []
63 mappM f (x:xs) = do { r <- f x; rs <- mappM f xs; return (r:rs) }
65 mappM_ f [] = return ()
66 mappM_ f (x:xs) = f x >> mappM_ f xs
68 sequenceM [] = return []
69 sequenceM (x:xs) = do { r <- x; rs <- sequenceM xs; return (r:rs) }
71 foldlM k z [] = return z
72 foldlM k z (x:xs) = do { r <- k z x; foldlM k r xs }
74 mapAndUnzipM f [] = return ([],[])
75 mapAndUnzipM f (x:xs) = do { (r,s) <- f x;
76 (rs,ss) <- mapAndUnzipM f xs;
79 mapAndUnzip3M f [] = return ([],[], [])
80 mapAndUnzip3M f (x:xs) = do { (r,s,t) <- f x;
81 (rs,ss,ts) <- mapAndUnzip3M f xs;
82 return (r:rs, s:ss, t:ts) }
84 checkM True err = return ()
85 checkM False err = err
87 ifM True do_it = do_it
88 ifM False do_it = return ()
92 %************************************************************************
96 %************************************************************************
99 initTc :: HscEnv -> PersistentCompilerState
102 -> IO (PersistentCompilerState, Maybe r)
103 -- Nothing => error thrown by the thing inside
104 -- (error messages should have been printed already)
106 initTc (HscEnv { hsc_mode = ghci_mode,
108 hsc_dflags = dflags })
110 = do { us <- mkSplitUniqSupply 'a' ;
111 us_var <- newIORef us ;
112 errs_var <- newIORef (emptyBag, emptyBag) ;
113 tvs_var <- newIORef emptyVarSet ;
114 usg_var <- newIORef emptyUsages ;
115 nc_var <- newIORef (pcs_nc pcs) ;
116 eps_var <- newIORef eps ;
119 env = Env { env_top = top_env,
122 env_loc = noSrcLoc } ;
125 top_mode = ghci_mode,
131 top_errs = errs_var } ;
135 tcg_usages = usg_var,
136 tcg_rdr_env = emptyGlobalRdrEnv,
137 tcg_fix_env = emptyFixityEnv,
138 tcg_default = defaultDefaultTys,
139 tcg_type_env = emptyNameEnv,
140 tcg_ist = mkImpTypeEnv eps hpt,
141 tcg_inst_env = mkImpInstEnv dflags eps hpt,
143 tcg_imports = emptyImportAvails,
144 tcg_binds = EmptyMonoBinds,
145 tcg_deprecs = NoDeprecs,
152 tcl_level = topStage,
153 tcl_env = emptyNameEnv,
154 tcl_tyvars = tvs_var,
155 tcl_lie = panic "initTc:LIE" } ;
156 -- LIE only valid inside a getLIE
159 -- OK, here's the business end!
160 maybe_res <- catch (do { res <- runTcRn env do_this ;
162 (\_ -> return Nothing) ;
164 -- Print any error messages
165 msgs <- readIORef errs_var ;
166 printErrorsAndWarnings msgs ;
168 -- Get final PCS and return
169 eps' <- readIORef eps_var ;
170 nc' <- readIORef nc_var ;
171 let { pcs' = PCS { pcs_EPS = eps', pcs_nc = nc' } ;
172 final_res | errorsFound msgs = Nothing
173 | otherwise = maybe_res } ;
175 return (pcs', final_res)
180 defaultDefaultTys :: [Type]
181 defaultDefaultTys = [integerTy, doubleTy]
183 mkImpInstEnv :: DynFlags -> ExternalPackageState -> HomePackageTable -> InstEnv
184 mkImpInstEnv dflags eps hpt
185 = foldModuleEnv (add . md_insts . hm_details)
189 -- We shouldn't get instance conflict errors from
190 -- the package and home type envs
191 add dfuns inst_env = WARN( not (null errs), vcat (map snd errs) ) inst_env'
193 (inst_env', errs) = extendInstEnv dflags inst_env dfuns
195 -- mkImpTypeEnv makes the imported symbol table
196 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
197 -> Name -> Maybe TyThing
198 mkImpTypeEnv pcs hpt = lookup
201 lookup name | isInternalName name = Nothing
202 | otherwise = lookupType hpt pte name
206 %************************************************************************
210 %************************************************************************
213 getTopEnv :: TcRn m TopEnv
214 getTopEnv = do { env <- getEnv; return (env_top env) }
216 getGblEnv :: TcRn m TcGblEnv
217 getGblEnv = do { env <- getEnv; return (env_gbl env) }
219 updGblEnv :: (TcGblEnv -> TcGblEnv) -> TcRn m a -> TcRn m a
220 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
221 env { env_gbl = upd gbl })
223 setGblEnv :: TcGblEnv -> TcRn m a -> TcRn m a
224 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
226 getLclEnv :: TcRn m m
227 getLclEnv = do { env <- getEnv; return (env_lcl env) }
229 updLclEnv :: (m -> m) -> TcRn m a -> TcRn m a
230 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
231 env { env_lcl = upd lcl })
233 setLclEnv :: m -> TcRn m a -> TcRn n a
234 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
240 getDOpts :: TcRn m DynFlags
241 getDOpts = do { env <- getTopEnv; return (top_dflags env) }
243 doptM :: DynFlag -> TcRn m Bool
244 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
246 ifOptM :: DynFlag -> TcRn m () -> TcRn m () -- Do it flag is true
247 ifOptM flag thing_inside = do { b <- doptM flag;
248 if b then thing_inside else return () }
250 getGhciMode :: TcRn m GhciMode
251 getGhciMode = do { env <- getTopEnv; return (top_mode env) }
255 getSrcLocM :: TcRn m SrcLoc
256 -- Avoid clash with Name.getSrcLoc
257 getSrcLocM = do { env <- getEnv; return (env_loc env) }
259 addSrcLoc :: SrcLoc -> TcRn m a -> TcRn m a
260 addSrcLoc loc = updEnv (\env -> env { env_loc = loc })
264 getEps :: TcRn m ExternalPackageState
265 getEps = do { env <- getTopEnv; readMutVar (top_eps env) }
267 setEps :: ExternalPackageState -> TcRn m ()
268 setEps eps = do { env <- getTopEnv; writeMutVar (top_eps env) eps }
270 getHpt :: TcRn m HomePackageTable
271 getHpt = do { env <- getTopEnv; return (top_hpt env) }
273 getModule :: TcRn m Module
274 getModule = do { env <- getGblEnv; return (tcg_mod env) }
276 getGlobalRdrEnv :: TcRn m GlobalRdrEnv
277 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
279 getFixityEnv :: TcRn m FixityEnv
280 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
282 extendFixityEnv :: [(Name,FixitySig Name)] -> RnM a -> RnM a
283 extendFixityEnv new_bit
284 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
285 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
287 getDefaultTys :: TcRn m [Type]
288 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
292 getUsageVar :: TcRn m (TcRef Usages)
293 getUsageVar = do { env <- getGblEnv; return (tcg_usages env) }
295 getUsages :: TcRn m Usages
296 getUsages = do { usg_var <- getUsageVar; readMutVar usg_var }
298 updUsages :: (Usages -> Usages) -> TcRn m ()
299 updUsages upd = do { usg_var <- getUsageVar ;
300 usg <- readMutVar usg_var ;
301 writeMutVar usg_var (upd usg) }
305 %************************************************************************
309 %************************************************************************
312 getErrsVar :: TcRn m (TcRef Messages)
313 getErrsVar = do { env <- getTopEnv; return (top_errs env) }
315 setErrsVar :: TcRef Messages -> TcRn m a -> TcRn m a
316 setErrsVar v = updEnv (\ env@(Env { env_top = top_env }) ->
317 env { env_top = top_env { top_errs = v }})
319 addErr :: Message -> TcRn m ()
320 addErr msg = do { loc <- getSrcLocM ; addErrAt loc msg }
322 addErrAt :: SrcLoc -> Message -> TcRn m ()
324 = do { errs_var <- getErrsVar ;
325 rdr_env <- getGlobalRdrEnv ;
326 let { err = addShortErrLocLine loc (unQualInScope rdr_env) msg } ;
327 (warns, errs) <- readMutVar errs_var ;
328 writeMutVar errs_var (warns, errs `snocBag` err) }
330 addErrs :: [(SrcLoc,Message)] -> TcRn m ()
331 addErrs msgs = mappM_ add msgs
333 add (loc,msg) = addErrAt loc msg
335 addWarn :: Message -> TcRn m ()
337 = do { errs_var <- getErrsVar ;
339 rdr_env <- getGlobalRdrEnv ;
340 let { warn = addShortWarnLocLine loc (unQualInScope rdr_env) msg } ;
341 (warns, errs) <- readMutVar errs_var ;
342 writeMutVar errs_var (warns `snocBag` warn, errs) }
344 checkErr :: Bool -> Message -> TcRn m ()
345 -- Add the error if the bool is False
346 checkErr ok msg = checkM ok (addErr msg)
348 warnIf :: Bool -> Message -> TcRn m ()
349 warnIf True msg = addWarn msg
350 warnIf False msg = return ()
352 addMessages :: Messages -> TcRn m ()
353 addMessages (m_warns, m_errs)
354 = do { errs_var <- getErrsVar ;
355 (warns, errs) <- readMutVar errs_var ;
356 writeMutVar errs_var (warns `unionBags` m_warns,
357 errs `unionBags` m_errs) }
359 checkGHCI :: Message -> TcRn m () -- Check that GHCI is on
360 -- otherwise add the error message
362 checkGHCI m = returnM ()
364 checkGHCI m = addErr m
370 tryM :: TcRn m a -> TcRn m (Messages, Maybe a)
371 -- (try m) executes m, and returns
372 -- Just r, if m succeeds (returning r) and caused no errors
373 -- Nothing, if m fails, or caused errors
374 -- It also returns all the errors accumulated by m
375 -- (even in the Just case, there might be warnings)
377 -- It always succeeds (never raises an exception)
379 = do { errs_var <- newMutVar emptyMessages ;
381 mb_r <- recoverM (return Nothing)
382 (do { r <- setErrsVar errs_var m ;
385 new_errs <- readMutVar errs_var ;
390 Just r | errorsFound new_errs -> Nothing
391 | otherwise -> Just r)
394 tryTc :: TcM a -> TcM (Messages, Maybe a)
395 -- Just like tryM, except that it ensures that the LIE
396 -- for the thing is propagated only if there are no errors
397 -- Hence it's restricted to the type-check monad
399 = do { ((errs, mb_r), lie) <- getLIE (tryM thing_inside) ;
400 ifM (isJust mb_r) (extendLIEs lie) ;
401 return (errs, mb_r) }
403 tryTc_ :: TcM r -> TcM r -> TcM r
404 -- (tryM_ r m) tries m; if it succeeds it returns it,
405 -- otherwise it returns r. Any error messages added by m are discarded,
406 -- whether or not m succeeds.
408 = do { (_msgs, mb_res) <- tryTc main ;
410 Just res -> return res
413 checkNoErrs :: TcM r -> TcM r
414 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
415 -- If m fails then (checkNoErrsTc m) fails.
416 -- If m succeeds, it checks whether m generated any errors messages
417 -- (it might have recovered internally)
418 -- If so, it fails too.
419 -- Regardless, any errors generated by m are propagated to the enclosing context.
421 = do { (msgs, mb_res) <- tryTc main ;
428 ifErrsM :: TcRn m r -> TcRn m r -> TcRn m r
429 -- ifErrsM bale_out main
430 -- does 'bale_out' if there are errors in errors collection
431 -- otherwise does 'main'
432 ifErrsM bale_out normal
433 = do { errs_var <- getErrsVar ;
434 msgs <- readMutVar errs_var ;
435 if errorsFound msgs then
440 failIfErrsM :: TcRn m ()
441 -- Useful to avoid error cascades
442 failIfErrsM = ifErrsM failM (return ())
446 forkM :: SDoc -> TcM a -> TcM (Maybe a)
447 -- Run thing_inside in an interleaved thread. It gets a separate
450 -- but everything else is shared, so this is DANGEROUS.
452 -- It returns Nothing if the computation fails
454 -- It's used for lazily type-checking interface
455 -- signatures, which is pretty benign
457 forkM doc thing_inside
458 = do { us <- newUniqueSupply ;
460 do { us_var <- newMutVar us ;
461 (msgs, mb_res) <- tryTc (setUsVar us_var thing_inside) ;
463 Just r -> return (Just r)
465 -- Bleat about errors in the forked thread
466 ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
467 printErrorsAndWarnings msgs }) ;
471 hdr_doc = text "forkM failed:" <+> doc
475 %************************************************************************
479 %************************************************************************
482 getUsVar :: TcRn m (TcRef UniqSupply)
483 getUsVar = do { env <- getTopEnv; return (top_us env) }
485 setUsVar :: TcRef UniqSupply -> TcRn m a -> TcRn m a
486 setUsVar v = updEnv (\ env@(Env { env_top = top_env }) ->
487 env { env_top = top_env { top_us = v }})
489 newUnique :: TcRn m Unique
490 newUnique = do { us <- newUniqueSupply ;
491 return (uniqFromSupply us) }
493 newUniqueSupply :: TcRn m UniqSupply
495 = do { u_var <- getUsVar ;
496 us <- readMutVar u_var ;
497 let { (us1, us2) = splitUniqSupply us } ;
498 writeMutVar u_var us1 ;
504 getNameCache :: TcRn m NameCache
505 getNameCache = do { TopEnv { top_nc = nc_var } <- getTopEnv;
508 setNameCache :: NameCache -> TcRn m ()
509 setNameCache nc = do { TopEnv { top_nc = nc_var } <- getTopEnv;
510 writeMutVar nc_var nc }
514 %************************************************************************
518 %************************************************************************
521 traceTc, traceRn :: SDoc -> TcRn a ()
522 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
523 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
524 traceHiDiffs = dumpOptTcRn Opt_D_dump_hi_diffs
526 dumpOptTcRn :: DynFlag -> SDoc -> TcRn a ()
527 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
529 dumpTcRn :: SDoc -> TcRn a ()
530 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
531 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
535 %************************************************************************
537 Context management and error message generation
540 %************************************************************************
543 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
544 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
545 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
547 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
548 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
549 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
551 popErrCtxt :: TcM a -> TcM a
552 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
554 getErrCtxt :: TcM ErrCtxt
555 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
557 -- Helper function for the above
558 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
559 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
560 env { tcl_ctxt = upd ctxt })
562 getInstLoc :: InstOrigin -> TcM InstLoc
564 = do { loc <- getSrcLocM ; env <- getLclEnv ;
565 return (origin, loc, (tcl_ctxt env)) }
568 The addErrTc functions add an error message, but do not cause failure.
569 The 'M' variants pass a TidyEnv that has already been used to
570 tidy up the message; we then use it to tidy the context messages
573 addErrTc :: Message -> TcM ()
574 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
576 addErrsTc :: [Message] -> TcM ()
577 addErrsTc err_msgs = mappM_ addErrTc err_msgs
579 addErrTcM :: (TidyEnv, Message) -> TcM ()
580 addErrTcM (tidy_env, err_msg)
581 = do { ctxt <- getErrCtxt ;
583 add_err_tcm tidy_env err_msg loc ctxt }
585 addInstErrTcM :: InstLoc -> (TidyEnv, Message) -> TcM ()
586 addInstErrTcM inst_loc@(_, loc, ctxt) (tidy_env, err_msg)
587 = add_err_tcm tidy_env err_msg loc full_ctxt
589 full_ctxt = (\env -> returnM (env, pprInstLoc inst_loc)) : ctxt
592 The failWith functions add an error message and cause failure
595 failWithTc :: Message -> TcM a -- Add an error message and fail
597 = addErrTc err_msg >> failM
599 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
600 failWithTcM local_and_msg
601 = addErrTcM local_and_msg >> failM
603 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
604 checkTc True err = returnM ()
605 checkTc False err = failWithTc err
608 Warnings have no 'M' variant, nor failure
611 addWarnTc :: Message -> TcM ()
613 = do { ctxt <- getErrCtxt ;
614 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
615 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
617 warnTc :: Bool -> Message -> TcM ()
618 warnTc warn_if_true warn_msg
619 | warn_if_true = addWarnTc warn_msg
620 | otherwise = return ()
626 add_err_tcm tidy_env err_msg loc ctxt
627 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
628 addErrAt loc (vcat (err_msg : ctxt_to_use ctxt_msgs)) }
632 do_ctxt tidy_env (c:cs)
633 = do { (tidy_env', m) <- c tidy_env ;
634 ms <- do_ctxt tidy_env' cs ;
637 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
638 | otherwise = take 3 ctxt
641 %************************************************************************
643 Other stuff specific to type checker
645 %************************************************************************
648 getLIEVar :: TcM (TcRef LIE)
649 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
651 setLIEVar :: TcRef LIE -> TcM a -> TcM a
652 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
654 getLIE :: TcM a -> TcM (a, [Inst])
655 -- (getLIE m) runs m, and returns the type constraints it generates
657 = do { lie_var <- newMutVar emptyLIE ;
658 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
660 lie <- readMutVar lie_var ;
661 return (res, lieToList lie) }
663 extendLIE :: Inst -> TcM ()
665 = do { lie_var <- getLIEVar ;
666 lie <- readMutVar lie_var ;
667 writeMutVar lie_var (inst `consLIE` lie) }
669 extendLIEs :: [Inst] -> TcM ()
673 = do { lie_var <- getLIEVar ;
674 lie <- readMutVar lie_var ;
675 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
680 getStage :: TcM Stage
681 getStage = do { env <- getLclEnv; return (tcl_level env) }
683 setStage :: Stage -> TcM a -> TcM a
684 setStage s = updLclEnv (\ env -> env { tcl_level = s })
686 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
687 -- Set the local type envt, but do *not* disturb other fields,
688 -- notably the lie_var
689 setLclTypeEnv lcl_env thing_inside
690 = updLclEnv upd thing_inside
692 upd env = env { tcl_env = tcl_env lcl_env,
693 tcl_tyvars = tcl_tyvars lcl_env }
697 %************************************************************************
699 Stuff for the renamer's local env
701 %************************************************************************
704 initRn :: RnMode -> RnM a -> TcRn m a
705 initRn mode thing_inside
706 = do { env <- getGblEnv ;
707 let { lcl_env = RnLclEnv {
709 rn_lenv = emptyRdrEnv }} ;
710 setLclEnv lcl_env thing_inside }
714 getLocalRdrEnv :: RnM LocalRdrEnv
715 getLocalRdrEnv = do { env <- getLclEnv; return (rn_lenv env) }
717 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
718 setLocalRdrEnv rdr_env thing_inside
719 = updLclEnv (\env -> env {rn_lenv = rdr_env}) thing_inside
721 getModeRn :: RnM RnMode
722 getModeRn = do { env <- getLclEnv; return (rn_mode env) }