8 #include "HsVersions.h"
10 import TcRnTypes -- Re-export all
11 import IOEnv -- Re-export all
13 import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
14 TyThing, Dependencies(..), TypeEnv, emptyTypeEnv,
15 ExternalPackageState(..), HomePackageTable,
16 ModDetails(..), HomeModInfo(..),
17 Deprecs(..), FixityEnv, FixItem,
18 GhciMode, lookupType, unQualInScope )
19 import Module ( Module, ModuleName, unitModuleEnv, foldModuleEnv, emptyModuleEnv )
20 import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
21 LocalRdrEnv, emptyLocalRdrEnv )
22 import Name ( Name, isInternalName )
24 import NameEnv ( extendNameEnvList )
25 import InstEnv ( InstEnv, emptyInstEnv, extendInstEnv )
27 import VarSet ( emptyVarSet )
28 import VarEnv ( TidyEnv, emptyTidyEnv )
29 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
30 mkErrMsg, mkWarnMsg, printErrorsAndWarnings )
31 import SrcLoc ( mkGeneralSrcSpan, SrcSpan, Located(..) )
32 import NameEnv ( emptyNameEnv )
33 import NameSet ( emptyDUs, emptyNameSet )
34 import OccName ( emptyOccEnv )
35 import Module ( moduleName )
36 import Bag ( emptyBag )
38 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
39 import Unique ( Unique )
40 import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug, dopt_set )
41 import Bag ( snocBag, unionBags )
42 import Panic ( showException )
44 import Maybe ( isJust )
46 import DATA_IOREF ( newIORef, readIORef )
47 import EXCEPTION ( Exception )
52 %************************************************************************
56 %************************************************************************
59 ioToTcRn :: IO r -> TcRn r
68 -- Nothing => error thrown by the thing inside
69 -- (error messages should have been printed already)
71 initTc hsc_env mod do_this
72 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
73 tvs_var <- newIORef emptyVarSet ;
74 type_env_var <- newIORef emptyNameEnv ;
75 dfuns_var <- newIORef emptyNameSet ;
80 tcg_rdr_env = emptyGlobalRdrEnv,
81 tcg_fix_env = emptyNameEnv,
82 tcg_default = Nothing,
83 tcg_type_env = emptyNameEnv,
84 tcg_type_env_var = type_env_var,
85 tcg_inst_env = mkImpInstEnv hsc_env,
86 tcg_inst_uses = dfuns_var,
88 tcg_imports = init_imports,
91 tcg_deprecs = NoDeprecs,
95 tcg_keep = emptyNameSet
99 tcl_loc = mkGeneralSrcSpan FSLIT("Top level of module"),
101 tcl_rdr = emptyLocalRdrEnv,
102 tcl_th_ctxt = topStage,
103 tcl_arrow_ctxt = topArrowCtxt,
104 tcl_env = emptyNameEnv,
105 tcl_tyvars = tvs_var,
106 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
110 -- OK, here's the business end!
111 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
112 do { r <- tryM do_this
114 Right res -> return (Just res)
115 Left _ -> return Nothing } ;
117 -- Print any error messages
118 msgs <- readIORef errs_var ;
119 printErrorsAndWarnings msgs ;
121 let { dflags = hsc_dflags hsc_env
122 ; final_res | errorsFound dflags msgs = Nothing
123 | otherwise = maybe_res } ;
128 init_imports = emptyImportAvails { imp_qual = unitModuleEnv mod emptyAvailEnv }
129 -- Initialise tcg_imports with an empty set of bindings for
130 -- this module, so that if we see 'module M' in the export
131 -- list, and there are no bindings in M, we don't bleat
132 -- "unknown module M".
134 mkImpInstEnv :: HscEnv -> InstEnv
135 -- At the moment we (wrongly) build an instance environment from all the
136 -- home-package modules we have already compiled.
137 -- We should really only get instances from modules below us in the
138 -- module import tree.
139 mkImpInstEnv (HscEnv {hsc_dflags = dflags, hsc_HPT = hpt})
140 = foldModuleEnv (add . md_insts . hm_details) emptyInstEnv hpt
142 add dfuns inst_env = foldl extendInstEnv inst_env dfuns
144 -- mkImpTypeEnv makes the imported symbol table
145 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
146 -> Name -> Maybe TyThing
147 mkImpTypeEnv pcs hpt = lookup
150 lookup name | isInternalName name = Nothing
151 | otherwise = lookupType hpt pte name
155 %************************************************************************
159 %************************************************************************
163 initTcRnIf :: Char -- Tag for unique supply
168 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
169 = do { us <- mkSplitUniqSupply uniq_tag ;
170 ; us_var <- newIORef us ;
172 ; let { env = Env { env_top = hsc_env,
175 env_lcl = lcl_env } }
177 ; runIOEnv env thing_inside
181 %************************************************************************
185 %************************************************************************
188 getTopEnv :: TcRnIf gbl lcl HscEnv
189 getTopEnv = do { env <- getEnv; return (env_top env) }
191 getGblEnv :: TcRnIf gbl lcl gbl
192 getGblEnv = do { env <- getEnv; return (env_gbl env) }
194 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
195 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
196 env { env_gbl = upd gbl })
198 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
199 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
201 getLclEnv :: TcRnIf gbl lcl lcl
202 getLclEnv = do { env <- getEnv; return (env_lcl env) }
204 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
205 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
206 env { env_lcl = upd lcl })
208 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
209 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
211 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
212 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
214 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
215 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
222 getDOpts :: TcRnIf gbl lcl DynFlags
223 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
225 doptM :: DynFlag -> TcRnIf gbl lcl Bool
226 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
228 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
229 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
230 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
232 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
233 ifOptM flag thing_inside = do { b <- doptM flag;
234 if b then thing_inside else return () }
236 getGhciMode :: TcRnIf gbl lcl GhciMode
237 getGhciMode = do { env <- getTopEnv; return (hsc_mode env) }
241 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
242 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
244 getEps :: TcRnIf gbl lcl ExternalPackageState
245 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
247 setEps :: ExternalPackageState -> TcRnIf gbl lcl ()
248 setEps eps = do { env <- getTopEnv; writeMutVar (hsc_EPS env) eps }
250 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
252 updateEps upd_fn = do { eps_var <- getEpsVar
253 ; eps <- readMutVar eps_var
254 ; let { (eps', val) = upd_fn eps }
255 ; writeMutVar eps_var eps'
258 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
260 updateEps_ upd_fn = do { eps_var <- getEpsVar
261 ; updMutVar eps_var upd_fn }
263 getHpt :: TcRnIf gbl lcl HomePackageTable
264 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
267 %************************************************************************
271 %************************************************************************
274 newUnique :: TcRnIf gbl lcl Unique
275 newUnique = do { us <- newUniqueSupply ;
276 return (uniqFromSupply us) }
278 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
280 = do { env <- getEnv ;
281 let { u_var = env_us env } ;
282 us <- readMutVar u_var ;
283 let { (us1, us2) = splitUniqSupply us } ;
284 writeMutVar u_var us1 ;
289 %************************************************************************
293 %************************************************************************
296 traceTc, traceRn :: SDoc -> TcRn ()
297 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
298 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
299 traceSplice = dumpOptTcRn Opt_D_dump_splices
302 traceIf :: SDoc -> TcRnIf m n ()
303 traceIf = dumpOptIf Opt_D_dump_if_trace
304 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
307 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
308 dumpOptIf flag doc = ifOptM flag $
309 ioToIOEnv (printForUser stderr alwaysQualify doc)
311 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
312 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
314 dumpTcRn :: SDoc -> TcRn ()
315 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
316 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
320 %************************************************************************
322 Typechecker global environment
324 %************************************************************************
327 getModule :: TcRn Module
328 getModule = do { env <- getGblEnv; return (tcg_mod env) }
330 getGlobalRdrEnv :: TcRn GlobalRdrEnv
331 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
333 getImports :: TcRn ImportAvails
334 getImports = do { env <- getGblEnv; return (tcg_imports env) }
336 getFixityEnv :: TcRn FixityEnv
337 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
339 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
340 extendFixityEnv new_bit
341 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
342 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
344 getDefaultTys :: TcRn (Maybe [Type])
345 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
348 %************************************************************************
352 %************************************************************************
355 getSrcSpanM :: TcRn SrcSpan
356 -- Avoid clash with Name.getSrcLoc
357 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
359 addSrcSpan :: SrcSpan -> TcRn a -> TcRn a
360 addSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc })
362 addLocM :: (a -> TcM b) -> Located a -> TcM b
363 addLocM fn (L loc a) = addSrcSpan loc $ fn a
365 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
366 wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
368 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
369 wrapLocFstM fn (L loc a) =
374 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
375 wrapLocSndM fn (L loc a) =
383 getErrsVar :: TcRn (TcRef Messages)
384 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
386 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
387 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
389 addErr :: Message -> TcRn ()
390 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
392 addLocErr :: Located e -> (e -> Message) -> TcRn ()
393 addLocErr (L loc e) fn = addErrAt loc (fn e)
395 addErrAt :: SrcSpan -> Message -> TcRn ()
397 = do { errs_var <- getErrsVar ;
398 rdr_env <- getGlobalRdrEnv ;
399 let { err = mkErrMsg loc (unQualInScope rdr_env) msg } ;
400 (warns, errs) <- readMutVar errs_var ;
401 writeMutVar errs_var (warns, errs `snocBag` err) }
403 addErrs :: [(SrcSpan,Message)] -> TcRn ()
404 addErrs msgs = mappM_ add msgs
406 add (loc,msg) = addErrAt loc msg
408 addReport :: Message -> TcRn ()
409 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
411 addReportAt :: SrcSpan -> Message -> TcRn ()
413 = do { errs_var <- getErrsVar ;
414 rdr_env <- getGlobalRdrEnv ;
415 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
416 (warns, errs) <- readMutVar errs_var ;
417 writeMutVar errs_var (warns `snocBag` warn, errs) }
419 addWarn :: Message -> TcRn ()
420 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
422 addWarnAt :: SrcSpan -> Message -> TcRn ()
423 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
425 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
426 addLocWarn (L loc e) fn = addReportAt loc (fn e)
428 checkErr :: Bool -> Message -> TcRn ()
429 -- Add the error if the bool is False
430 checkErr ok msg = checkM ok (addErr msg)
432 warnIf :: Bool -> Message -> TcRn ()
433 warnIf True msg = addWarn msg
434 warnIf False msg = return ()
436 addMessages :: Messages -> TcRn ()
437 addMessages (m_warns, m_errs)
438 = do { errs_var <- getErrsVar ;
439 (warns, errs) <- readMutVar errs_var ;
440 writeMutVar errs_var (warns `unionBags` m_warns,
441 errs `unionBags` m_errs) }
443 discardWarnings :: TcRn a -> TcRn a
444 -- Ignore warnings inside the thing inside;
445 -- used to ignore-unused-variable warnings inside derived code
446 -- With -dppr-debug, the effects is switched off, so you can still see
447 -- what warnings derived code would give
448 discardWarnings thing_inside
449 | opt_PprStyle_Debug = thing_inside
451 = do { errs_var <- newMutVar emptyMessages
452 ; result <- setErrsVar errs_var thing_inside
453 ; (_warns, errs) <- readMutVar errs_var
454 ; addMessages (emptyBag, errs)
460 recoverM :: TcRn r -- Recovery action; do this if the main one fails
461 -> TcRn r -- Main action: do this first
463 recoverM recover thing
464 = do { mb_res <- try_m thing ;
467 Right res -> returnM res }
469 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
470 -- (tryTc m) executes m, and returns
471 -- Just r, if m succeeds (returning r) and caused no errors
472 -- Nothing, if m fails, or caused errors
473 -- It also returns all the errors accumulated by m
474 -- (even in the Just case, there might be warnings)
476 -- It always succeeds (never raises an exception)
478 = do { errs_var <- newMutVar emptyMessages ;
480 mb_r <- try_m (setErrsVar errs_var m) ;
482 new_errs <- readMutVar errs_var ;
489 Right r | errorsFound dflags new_errs -> Nothing
490 | otherwise -> Just r)
493 try_m :: TcRn r -> TcRn (Either Exception r)
494 -- Does try_m, with a debug-trace on failure
496 = do { mb_r <- tryM thing ;
498 Left exn -> do { traceTc (exn_msg exn); return mb_r }
499 Right r -> return mb_r }
501 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
503 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
504 -- Just like tryTc, except that it ensures that the LIE
505 -- for the thing is propagated only if there are no errors
506 -- Hence it's restricted to the type-check monad
507 tryTcLIE thing_inside
508 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
509 ifM (isJust mb_r) (extendLIEs lie) ;
510 return (errs, mb_r) }
512 tryTcLIE_ :: TcM r -> TcM r -> TcM r
513 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
514 -- otherwise it returns r. Any error messages added by m are discarded,
515 -- whether or not m succeeds.
516 tryTcLIE_ recover main
517 = do { (_msgs, mb_res) <- tryTcLIE main ;
519 Just res -> return res
522 checkNoErrs :: TcM r -> TcM r
523 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
524 -- If m fails then (checkNoErrsTc m) fails.
525 -- If m succeeds, it checks whether m generated any errors messages
526 -- (it might have recovered internally)
527 -- If so, it fails too.
528 -- Regardless, any errors generated by m are propagated to the enclosing context.
530 = do { (msgs, mb_res) <- tryTcLIE main ;
537 ifErrsM :: TcRn r -> TcRn r -> TcRn r
538 -- ifErrsM bale_out main
539 -- does 'bale_out' if there are errors in errors collection
540 -- otherwise does 'main'
541 ifErrsM bale_out normal
542 = do { errs_var <- getErrsVar ;
543 msgs <- readMutVar errs_var ;
545 if errorsFound dflags msgs then
550 failIfErrsM :: TcRn ()
551 -- Useful to avoid error cascades
552 failIfErrsM = ifErrsM failM (return ())
556 %************************************************************************
558 Context management and error message generation
561 %************************************************************************
564 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
565 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
566 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
568 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
569 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
570 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
572 popErrCtxt :: TcM a -> TcM a
573 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
575 getErrCtxt :: TcM ErrCtxt
576 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
578 -- Helper function for the above
579 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
580 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
581 env { tcl_ctxt = upd ctxt })
583 getInstLoc :: InstOrigin -> TcM InstLoc
585 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
586 return (InstLoc origin loc (tcl_ctxt env)) }
588 addInstCtxt :: InstLoc -> TcM a -> TcM a
589 -- Add the SrcSpan and context from the first Inst in the list
590 -- (they all have similar locations)
591 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
592 = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
595 The addErrTc functions add an error message, but do not cause failure.
596 The 'M' variants pass a TidyEnv that has already been used to
597 tidy up the message; we then use it to tidy the context messages
600 addErrTc :: Message -> TcM ()
601 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
603 addErrsTc :: [Message] -> TcM ()
604 addErrsTc err_msgs = mappM_ addErrTc err_msgs
606 addErrTcM :: (TidyEnv, Message) -> TcM ()
607 addErrTcM (tidy_env, err_msg)
608 = do { ctxt <- getErrCtxt ;
610 add_err_tcm tidy_env err_msg loc ctxt }
613 The failWith functions add an error message and cause failure
616 failWithTc :: Message -> TcM a -- Add an error message and fail
618 = addErrTc err_msg >> failM
620 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
621 failWithTcM local_and_msg
622 = addErrTcM local_and_msg >> failM
624 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
625 checkTc True err = returnM ()
626 checkTc False err = failWithTc err
629 Warnings have no 'M' variant, nor failure
632 addWarnTc :: Message -> TcM ()
634 = do { ctxt <- getErrCtxt ;
635 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
636 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
638 warnTc :: Bool -> Message -> TcM ()
639 warnTc warn_if_true warn_msg
640 | warn_if_true = addWarnTc warn_msg
641 | otherwise = return ()
647 add_err_tcm tidy_env err_msg loc ctxt
648 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
649 addErrAt loc (vcat (err_msg : ctxt_to_use ctxt_msgs)) }
653 do_ctxt tidy_env (c:cs)
654 = do { (tidy_env', m) <- c tidy_env ;
655 ms <- do_ctxt tidy_env' cs ;
658 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
659 | otherwise = take 3 ctxt
662 %************************************************************************
664 Type constraints (the so-called LIE)
666 %************************************************************************
669 getLIEVar :: TcM (TcRef LIE)
670 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
672 setLIEVar :: TcRef LIE -> TcM a -> TcM a
673 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
675 getLIE :: TcM a -> TcM (a, [Inst])
676 -- (getLIE m) runs m, and returns the type constraints it generates
678 = do { lie_var <- newMutVar emptyLIE ;
679 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
681 lie <- readMutVar lie_var ;
682 return (res, lieToList lie) }
684 extendLIE :: Inst -> TcM ()
686 = do { lie_var <- getLIEVar ;
687 lie <- readMutVar lie_var ;
688 writeMutVar lie_var (inst `consLIE` lie) }
690 extendLIEs :: [Inst] -> TcM ()
694 = do { lie_var <- getLIEVar ;
695 lie <- readMutVar lie_var ;
696 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
700 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
701 -- Set the local type envt, but do *not* disturb other fields,
702 -- notably the lie_var
703 setLclTypeEnv lcl_env thing_inside
704 = updLclEnv upd thing_inside
706 upd env = env { tcl_env = tcl_env lcl_env,
707 tcl_tyvars = tcl_tyvars lcl_env }
711 %************************************************************************
713 Template Haskell context
715 %************************************************************************
718 getStage :: TcM ThStage
719 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
721 setStage :: ThStage -> TcM a -> TcM a
722 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
726 %************************************************************************
730 %************************************************************************
733 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
735 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
737 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
738 = ASSERT( not (curr_lvl `elem` banned) )
739 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
741 getBannedProcLevels :: TcM [ProcLevel]
742 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
744 incProcLevel :: TcM a -> TcM a
746 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
748 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
752 %************************************************************************
754 Stuff for the renamer's local env
756 %************************************************************************
759 getLocalRdrEnv :: RnM LocalRdrEnv
760 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
762 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
763 setLocalRdrEnv rdr_env thing_inside
764 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
768 %************************************************************************
770 Stuff for interface decls
772 %************************************************************************
775 initIfaceTcRn :: IfG a -> TcRn a
776 initIfaceTcRn thing_inside
777 = do { tcg_env <- getGblEnv
778 ; let { if_env = IfGblEnv {
779 if_rec_types = Just (tcg_mod tcg_env, get_type_env),
780 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
781 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
782 ; setEnvs (if_env, ()) thing_inside }
784 initIfaceExtCore :: IfL a -> TcRn a
785 initIfaceExtCore thing_inside
786 = do { tcg_env <- getGblEnv
787 ; let { mod = tcg_mod tcg_env
788 ; if_env = IfGblEnv {
789 if_rec_types = Just (mod, return (tcg_type_env tcg_env)),
790 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
791 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
792 if_tv_env = emptyOccEnv,
793 if_id_env = emptyOccEnv }
795 ; setEnvs (if_env, if_lenv) thing_inside }
797 initIfaceCheck :: HscEnv -> IfG a -> IO a
798 -- Used when checking the up-to-date-ness of the old Iface
799 -- Initialise the environment with no useful info at all
800 initIfaceCheck hsc_env do_this
801 = do { let { gbl_env = IfGblEnv { if_is_boot = emptyModuleEnv,
802 if_rec_types = Nothing } ;
804 ; initTcRnIf 'i' hsc_env gbl_env () do_this
807 initIfaceTc :: HscEnv -> ModIface
808 -> (TcRef TypeEnv -> IfL a) -> IO a
809 -- Used when type-checking checking an up-to-date interface file
810 -- No type envt from the current module, but we do know the module dependencies
811 initIfaceTc hsc_env iface do_this
812 = do { tc_env_var <- newIORef emptyTypeEnv
813 ; let { gbl_env = IfGblEnv { if_is_boot = mkModDeps (dep_mods (mi_deps iface)),
814 if_rec_types = Just (mod, readMutVar tc_env_var) } ;
815 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
816 if_tv_env = emptyOccEnv,
817 if_id_env = emptyOccEnv }
819 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
822 mod = mi_module iface
824 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
825 -- Used when sucking in new Rules in SimplCore
826 -- We have available the type envt of the module being compiled, and we must use it
827 initIfaceRules hsc_env guts do_this
829 is_boot = mkModDeps (dep_mods (mg_deps guts))
830 -- Urgh! But we do somehow need to get the info
831 -- on whether (for this particular compilation) we should
832 -- import a hi-boot file or not.
833 ; type_info = (mg_module guts, return (mg_types guts))
834 ; gbl_env = IfGblEnv { if_is_boot = is_boot,
835 if_rec_types = Just type_info } ;
838 -- Run the thing; any exceptions just bubble out from here
839 ; initTcRnIf 'i' hsc_env gbl_env () do_this
842 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
843 initIfaceLcl mod thing_inside
844 = setLclEnv (IfLclEnv { if_mod = mod,
845 if_tv_env = emptyOccEnv,
846 if_id_env = emptyOccEnv })
851 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
852 -- Run thing_inside in an interleaved thread.
853 -- It shares everything with the parent thread, so this is DANGEROUS.
855 -- It returns Nothing if the computation fails
857 -- It's used for lazily type-checking interface
858 -- signatures, which is pretty benign
860 forkM_maybe doc thing_inside
861 = do { unsafeInterleaveM $
862 do { traceIf (text "Starting fork {" <+> doc)
863 ; mb_res <- tryM thing_inside ;
865 Right r -> do { traceIf (text "} ending fork" <+> doc)
869 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
870 -- Otherwise we silently discard errors. Errors can legitimately
871 -- happen when compiling interface signatures (see tcInterfaceSigs)
872 ifOptM Opt_D_dump_if_trace
873 (print_errs (hang (text "forkM failed:" <+> doc)
874 4 (text (show exn))))
876 ; traceIf (text "} ending fork (badly)" <+> doc)
880 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
882 forkM :: SDoc -> IfL a -> IfL a
883 forkM doc thing_inside
884 = do { mb_res <- forkM_maybe doc thing_inside
885 ; return (case mb_res of
886 Nothing -> pprPanic "forkM" doc