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 mkLocMessage, mkLongErrMsg )
32 import SrcLoc ( mkGeneralSrcSpan, SrcSpan, Located(..) )
33 import NameEnv ( emptyNameEnv )
34 import NameSet ( emptyDUs, emptyNameSet )
35 import OccName ( emptyOccEnv )
36 import Module ( moduleName )
37 import Bag ( emptyBag )
39 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
40 import Unique ( Unique )
41 import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug, dopt_set )
42 import Bag ( snocBag, unionBags )
43 import Panic ( showException )
45 import Maybe ( isJust )
47 import DATA_IOREF ( newIORef, readIORef )
48 import EXCEPTION ( Exception )
53 %************************************************************************
57 %************************************************************************
60 ioToTcRn :: IO r -> TcRn r
68 -> IO (Messages, Maybe r)
69 -- Nothing => error thrown by the thing inside
70 -- (error messages should have been printed already)
72 initTc hsc_env mod do_this
73 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
74 tvs_var <- newIORef emptyVarSet ;
75 type_env_var <- newIORef emptyNameEnv ;
76 dfuns_var <- newIORef emptyNameSet ;
77 th_var <- newIORef False ;
82 tcg_rdr_env = emptyGlobalRdrEnv,
83 tcg_fix_env = emptyNameEnv,
84 tcg_default = Nothing,
85 tcg_type_env = emptyNameEnv,
86 tcg_type_env_var = type_env_var,
87 tcg_inst_env = mkImpInstEnv hsc_env,
88 tcg_inst_uses = dfuns_var,
90 tcg_exports = emptyNameSet,
91 tcg_imports = init_imports,
94 tcg_deprecs = NoDeprecs,
98 tcg_keep = emptyNameSet
102 tcl_loc = mkGeneralSrcSpan FSLIT("Top level of module"),
104 tcl_rdr = emptyLocalRdrEnv,
105 tcl_th_ctxt = topStage,
106 tcl_arrow_ctxt = topArrowCtxt,
107 tcl_env = emptyNameEnv,
108 tcl_tyvars = tvs_var,
109 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
113 -- OK, here's the business end!
114 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
115 do { r <- tryM do_this
117 Right res -> return (Just res)
118 Left _ -> return Nothing } ;
120 -- Collect any error messages
121 msgs <- readIORef errs_var ;
123 let { dflags = hsc_dflags hsc_env
124 ; final_res | errorsFound dflags msgs = Nothing
125 | otherwise = maybe_res } ;
127 return (msgs, final_res)
130 init_imports = emptyImportAvails { imp_qual = unitModuleEnv mod emptyAvailEnv }
131 -- Initialise tcg_imports with an empty set of bindings for
132 -- this module, so that if we see 'module M' in the export
133 -- list, and there are no bindings in M, we don't bleat
134 -- "unknown module M".
141 initTcPrintErrors env mod todo = do
142 (msgs, res) <- initTc env mod todo
143 printErrorsAndWarnings msgs
146 mkImpInstEnv :: HscEnv -> InstEnv
147 -- At the moment we (wrongly) build an instance environment from all the
148 -- home-package modules we have already compiled.
149 -- We should really only get instances from modules below us in the
150 -- module import tree.
151 mkImpInstEnv (HscEnv {hsc_dflags = dflags, hsc_HPT = hpt})
152 = foldModuleEnv (add . md_insts . hm_details) emptyInstEnv hpt
154 add dfuns inst_env = foldl extendInstEnv inst_env dfuns
156 -- mkImpTypeEnv makes the imported symbol table
157 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
158 -> Name -> Maybe TyThing
159 mkImpTypeEnv pcs hpt = lookup
162 lookup name | isInternalName name = Nothing
163 | otherwise = lookupType hpt pte name
167 %************************************************************************
171 %************************************************************************
175 initTcRnIf :: Char -- Tag for unique supply
180 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
181 = do { us <- mkSplitUniqSupply uniq_tag ;
182 ; us_var <- newIORef us ;
184 ; let { env = Env { env_top = hsc_env,
187 env_lcl = lcl_env } }
189 ; runIOEnv env thing_inside
193 %************************************************************************
197 %************************************************************************
200 getTopEnv :: TcRnIf gbl lcl HscEnv
201 getTopEnv = do { env <- getEnv; return (env_top env) }
203 getGblEnv :: TcRnIf gbl lcl gbl
204 getGblEnv = do { env <- getEnv; return (env_gbl env) }
206 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
207 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
208 env { env_gbl = upd gbl })
210 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
211 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
213 getLclEnv :: TcRnIf gbl lcl lcl
214 getLclEnv = do { env <- getEnv; return (env_lcl env) }
216 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
217 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
218 env { env_lcl = upd lcl })
220 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
221 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
223 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
224 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
226 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
227 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
234 getDOpts :: TcRnIf gbl lcl DynFlags
235 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
237 doptM :: DynFlag -> TcRnIf gbl lcl Bool
238 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
240 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
241 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
242 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
244 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
245 ifOptM flag thing_inside = do { b <- doptM flag;
246 if b then thing_inside else return () }
248 getGhciMode :: TcRnIf gbl lcl GhciMode
249 getGhciMode = do { env <- getTopEnv; return (hsc_mode env) }
253 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
254 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
256 getEps :: TcRnIf gbl lcl ExternalPackageState
257 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
259 setEps :: ExternalPackageState -> TcRnIf gbl lcl ()
260 setEps eps = do { env <- getTopEnv; writeMutVar (hsc_EPS env) eps }
262 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
264 updateEps upd_fn = do { eps_var <- getEpsVar
265 ; eps <- readMutVar eps_var
266 ; let { (eps', val) = upd_fn eps }
267 ; writeMutVar eps_var eps'
270 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
272 updateEps_ upd_fn = do { eps_var <- getEpsVar
273 ; updMutVar eps_var upd_fn }
275 getHpt :: TcRnIf gbl lcl HomePackageTable
276 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
279 %************************************************************************
283 %************************************************************************
286 newUnique :: TcRnIf gbl lcl Unique
287 newUnique = do { us <- newUniqueSupply ;
288 return (uniqFromSupply us) }
290 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
292 = do { env <- getEnv ;
293 let { u_var = env_us env } ;
294 us <- readMutVar u_var ;
295 let { (us1, us2) = splitUniqSupply us } ;
296 writeMutVar u_var us1 ;
301 %************************************************************************
305 %************************************************************************
308 traceTc, traceRn :: SDoc -> TcRn ()
309 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
310 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
311 traceSplice = dumpOptTcRn Opt_D_dump_splices
314 traceIf :: SDoc -> TcRnIf m n ()
315 traceIf = dumpOptIf Opt_D_dump_if_trace
316 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
319 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
320 dumpOptIf flag doc = ifOptM flag $
321 ioToIOEnv (printForUser stderr alwaysQualify doc)
323 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
324 dumpOptTcRn flag doc = ifOptM flag $ do
327 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
328 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
329 ; dumpTcRn real_doc }
331 dumpTcRn :: SDoc -> TcRn ()
332 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
333 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
337 %************************************************************************
339 Typechecker global environment
341 %************************************************************************
344 getModule :: TcRn Module
345 getModule = do { env <- getGblEnv; return (tcg_mod env) }
347 getGlobalRdrEnv :: TcRn GlobalRdrEnv
348 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
350 getImports :: TcRn ImportAvails
351 getImports = do { env <- getGblEnv; return (tcg_imports env) }
353 getFixityEnv :: TcRn FixityEnv
354 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
356 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
357 extendFixityEnv new_bit
358 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
359 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
361 getDefaultTys :: TcRn (Maybe [Type])
362 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
365 %************************************************************************
369 %************************************************************************
372 getSrcSpanM :: TcRn SrcSpan
373 -- Avoid clash with Name.getSrcLoc
374 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
376 addSrcSpan :: SrcSpan -> TcRn a -> TcRn a
377 addSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc })
379 addLocM :: (a -> TcM b) -> Located a -> TcM b
380 addLocM fn (L loc a) = addSrcSpan loc $ fn a
382 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
383 wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
385 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
386 wrapLocFstM fn (L loc a) =
391 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
392 wrapLocSndM fn (L loc a) =
400 getErrsVar :: TcRn (TcRef Messages)
401 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
403 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
404 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
406 addErr :: Message -> TcRn ()
407 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
409 addLocErr :: Located e -> (e -> Message) -> TcRn ()
410 addLocErr (L loc e) fn = addErrAt loc (fn e)
412 addErrAt :: SrcSpan -> Message -> TcRn ()
413 addErrAt loc msg = addLongErrAt loc msg empty
415 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
416 addLongErrAt loc msg extra
417 = do { errs_var <- getErrsVar ;
418 rdr_env <- getGlobalRdrEnv ;
419 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
420 (warns, errs) <- readMutVar errs_var ;
421 writeMutVar errs_var (warns, errs `snocBag` err) }
423 addErrs :: [(SrcSpan,Message)] -> TcRn ()
424 addErrs msgs = mappM_ add msgs
426 add (loc,msg) = addErrAt loc msg
428 addReport :: Message -> TcRn ()
429 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
431 addReportAt :: SrcSpan -> Message -> TcRn ()
433 = do { errs_var <- getErrsVar ;
434 rdr_env <- getGlobalRdrEnv ;
435 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
436 (warns, errs) <- readMutVar errs_var ;
437 writeMutVar errs_var (warns `snocBag` warn, errs) }
439 addWarn :: Message -> TcRn ()
440 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
442 addWarnAt :: SrcSpan -> Message -> TcRn ()
443 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
445 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
446 addLocWarn (L loc e) fn = addReportAt loc (fn e)
448 checkErr :: Bool -> Message -> TcRn ()
449 -- Add the error if the bool is False
450 checkErr ok msg = checkM ok (addErr msg)
452 warnIf :: Bool -> Message -> TcRn ()
453 warnIf True msg = addWarn msg
454 warnIf False msg = return ()
456 addMessages :: Messages -> TcRn ()
457 addMessages (m_warns, m_errs)
458 = do { errs_var <- getErrsVar ;
459 (warns, errs) <- readMutVar errs_var ;
460 writeMutVar errs_var (warns `unionBags` m_warns,
461 errs `unionBags` m_errs) }
463 discardWarnings :: TcRn a -> TcRn a
464 -- Ignore warnings inside the thing inside;
465 -- used to ignore-unused-variable warnings inside derived code
466 -- With -dppr-debug, the effects is switched off, so you can still see
467 -- what warnings derived code would give
468 discardWarnings thing_inside
469 | opt_PprStyle_Debug = thing_inside
471 = do { errs_var <- newMutVar emptyMessages
472 ; result <- setErrsVar errs_var thing_inside
473 ; (_warns, errs) <- readMutVar errs_var
474 ; addMessages (emptyBag, errs)
480 recoverM :: TcRn r -- Recovery action; do this if the main one fails
481 -> TcRn r -- Main action: do this first
483 recoverM recover thing
484 = do { mb_res <- try_m thing ;
487 Right res -> returnM res }
489 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
490 -- (tryTc m) executes m, and returns
491 -- Just r, if m succeeds (returning r) and caused no errors
492 -- Nothing, if m fails, or caused errors
493 -- It also returns all the errors accumulated by m
494 -- (even in the Just case, there might be warnings)
496 -- It always succeeds (never raises an exception)
498 = do { errs_var <- newMutVar emptyMessages ;
500 mb_r <- try_m (setErrsVar errs_var m) ;
502 new_errs <- readMutVar errs_var ;
509 Right r | errorsFound dflags new_errs -> Nothing
510 | otherwise -> Just r)
513 try_m :: TcRn r -> TcRn (Either Exception r)
514 -- Does try_m, with a debug-trace on failure
516 = do { mb_r <- tryM thing ;
518 Left exn -> do { traceTc (exn_msg exn); return mb_r }
519 Right r -> return mb_r }
521 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
523 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
524 -- Just like tryTc, except that it ensures that the LIE
525 -- for the thing is propagated only if there are no errors
526 -- Hence it's restricted to the type-check monad
527 tryTcLIE thing_inside
528 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
529 ifM (isJust mb_r) (extendLIEs lie) ;
530 return (errs, mb_r) }
532 tryTcLIE_ :: TcM r -> TcM r -> TcM r
533 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
534 -- otherwise it returns r. Any error messages added by m are discarded,
535 -- whether or not m succeeds.
536 tryTcLIE_ recover main
537 = do { (_msgs, mb_res) <- tryTcLIE main ;
539 Just res -> return res
542 checkNoErrs :: TcM r -> TcM r
543 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
544 -- If m fails then (checkNoErrsTc m) fails.
545 -- If m succeeds, it checks whether m generated any errors messages
546 -- (it might have recovered internally)
547 -- If so, it fails too.
548 -- Regardless, any errors generated by m are propagated to the enclosing context.
550 = do { (msgs, mb_res) <- tryTcLIE main ;
557 ifErrsM :: TcRn r -> TcRn r -> TcRn r
558 -- ifErrsM bale_out main
559 -- does 'bale_out' if there are errors in errors collection
560 -- otherwise does 'main'
561 ifErrsM bale_out normal
562 = do { errs_var <- getErrsVar ;
563 msgs <- readMutVar errs_var ;
565 if errorsFound dflags msgs then
570 failIfErrsM :: TcRn ()
571 -- Useful to avoid error cascades
572 failIfErrsM = ifErrsM failM (return ())
576 %************************************************************************
578 Context management and error message generation
581 %************************************************************************
584 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
585 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
586 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
588 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
589 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
590 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
592 popErrCtxt :: TcM a -> TcM a
593 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
595 getErrCtxt :: TcM ErrCtxt
596 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
598 -- Helper function for the above
599 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
600 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
601 env { tcl_ctxt = upd ctxt })
603 getInstLoc :: InstOrigin -> TcM InstLoc
605 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
606 return (InstLoc origin loc (tcl_ctxt env)) }
608 addInstCtxt :: InstLoc -> TcM a -> TcM a
609 -- Add the SrcSpan and context from the first Inst in the list
610 -- (they all have similar locations)
611 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
612 = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
615 The addErrTc functions add an error message, but do not cause failure.
616 The 'M' variants pass a TidyEnv that has already been used to
617 tidy up the message; we then use it to tidy the context messages
620 addErrTc :: Message -> TcM ()
621 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
623 addErrsTc :: [Message] -> TcM ()
624 addErrsTc err_msgs = mappM_ addErrTc err_msgs
626 addErrTcM :: (TidyEnv, Message) -> TcM ()
627 addErrTcM (tidy_env, err_msg)
628 = do { ctxt <- getErrCtxt ;
630 add_err_tcm tidy_env err_msg loc ctxt }
633 The failWith functions add an error message and cause failure
636 failWithTc :: Message -> TcM a -- Add an error message and fail
638 = addErrTc err_msg >> failM
640 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
641 failWithTcM local_and_msg
642 = addErrTcM local_and_msg >> failM
644 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
645 checkTc True err = returnM ()
646 checkTc False err = failWithTc err
649 Warnings have no 'M' variant, nor failure
652 addWarnTc :: Message -> TcM ()
654 = do { ctxt <- getErrCtxt ;
655 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
656 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
658 warnTc :: Bool -> Message -> TcM ()
659 warnTc warn_if_true warn_msg
660 | warn_if_true = addWarnTc warn_msg
661 | otherwise = return ()
667 add_err_tcm tidy_env err_msg loc ctxt
668 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
669 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
673 do_ctxt tidy_env (c:cs)
674 = do { (tidy_env', m) <- c tidy_env ;
675 ms <- do_ctxt tidy_env' cs ;
678 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
679 | otherwise = take 3 ctxt
682 %************************************************************************
684 Type constraints (the so-called LIE)
686 %************************************************************************
689 getLIEVar :: TcM (TcRef LIE)
690 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
692 setLIEVar :: TcRef LIE -> TcM a -> TcM a
693 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
695 getLIE :: TcM a -> TcM (a, [Inst])
696 -- (getLIE m) runs m, and returns the type constraints it generates
698 = do { lie_var <- newMutVar emptyLIE ;
699 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
701 lie <- readMutVar lie_var ;
702 return (res, lieToList lie) }
704 extendLIE :: Inst -> TcM ()
706 = do { lie_var <- getLIEVar ;
707 lie <- readMutVar lie_var ;
708 writeMutVar lie_var (inst `consLIE` lie) }
710 extendLIEs :: [Inst] -> TcM ()
714 = do { lie_var <- getLIEVar ;
715 lie <- readMutVar lie_var ;
716 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
720 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
721 -- Set the local type envt, but do *not* disturb other fields,
722 -- notably the lie_var
723 setLclTypeEnv lcl_env thing_inside
724 = updLclEnv upd thing_inside
726 upd env = env { tcl_env = tcl_env lcl_env,
727 tcl_tyvars = tcl_tyvars lcl_env }
731 %************************************************************************
733 Template Haskell context
735 %************************************************************************
738 recordThUse :: TcM ()
739 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
741 getStage :: TcM ThStage
742 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
744 setStage :: ThStage -> TcM a -> TcM a
745 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
749 %************************************************************************
753 %************************************************************************
756 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
758 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
760 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
761 = ASSERT( not (curr_lvl `elem` banned) )
762 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
764 getBannedProcLevels :: TcM [ProcLevel]
765 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
767 incProcLevel :: TcM a -> TcM a
769 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
771 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
775 %************************************************************************
777 Stuff for the renamer's local env
779 %************************************************************************
782 getLocalRdrEnv :: RnM LocalRdrEnv
783 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
785 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
786 setLocalRdrEnv rdr_env thing_inside
787 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
791 %************************************************************************
793 Stuff for interface decls
795 %************************************************************************
798 initIfaceTcRn :: IfG a -> TcRn a
799 initIfaceTcRn thing_inside
800 = do { tcg_env <- getGblEnv
801 ; let { if_env = IfGblEnv {
802 if_rec_types = Just (tcg_mod tcg_env, get_type_env),
803 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
804 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
805 ; setEnvs (if_env, ()) thing_inside }
807 initIfaceExtCore :: IfL a -> TcRn a
808 initIfaceExtCore thing_inside
809 = do { tcg_env <- getGblEnv
810 ; let { mod = tcg_mod tcg_env
811 ; if_env = IfGblEnv {
812 if_rec_types = Just (mod, return (tcg_type_env tcg_env)),
813 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
814 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
815 if_tv_env = emptyOccEnv,
816 if_id_env = emptyOccEnv }
818 ; setEnvs (if_env, if_lenv) thing_inside }
820 initIfaceCheck :: HscEnv -> IfG a -> IO a
821 -- Used when checking the up-to-date-ness of the old Iface
822 -- Initialise the environment with no useful info at all
823 initIfaceCheck hsc_env do_this
824 = do { let { gbl_env = IfGblEnv { if_is_boot = emptyModuleEnv,
825 if_rec_types = Nothing } ;
827 ; initTcRnIf 'i' hsc_env gbl_env () do_this
830 initIfaceTc :: HscEnv -> ModIface
831 -> (TcRef TypeEnv -> IfL a) -> IO a
832 -- Used when type-checking checking an up-to-date interface file
833 -- No type envt from the current module, but we do know the module dependencies
834 initIfaceTc hsc_env iface do_this
835 = do { tc_env_var <- newIORef emptyTypeEnv
836 ; let { gbl_env = IfGblEnv { if_is_boot = mkModDeps (dep_mods (mi_deps iface)),
837 if_rec_types = Just (mod, readMutVar tc_env_var) } ;
838 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
839 if_tv_env = emptyOccEnv,
840 if_id_env = emptyOccEnv }
842 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
845 mod = mi_module iface
847 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
848 -- Used when sucking in new Rules in SimplCore
849 -- We have available the type envt of the module being compiled, and we must use it
850 initIfaceRules hsc_env guts do_this
852 is_boot = mkModDeps (dep_mods (mg_deps guts))
853 -- Urgh! But we do somehow need to get the info
854 -- on whether (for this particular compilation) we should
855 -- import a hi-boot file or not.
856 ; type_info = (mg_module guts, return (mg_types guts))
857 ; gbl_env = IfGblEnv { if_is_boot = is_boot,
858 if_rec_types = Just type_info } ;
861 -- Run the thing; any exceptions just bubble out from here
862 ; initTcRnIf 'i' hsc_env gbl_env () do_this
865 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
866 initIfaceLcl mod thing_inside
867 = setLclEnv (IfLclEnv { if_mod = mod,
868 if_tv_env = emptyOccEnv,
869 if_id_env = emptyOccEnv })
874 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
875 -- Run thing_inside in an interleaved thread.
876 -- It shares everything with the parent thread, so this is DANGEROUS.
878 -- It returns Nothing if the computation fails
880 -- It's used for lazily type-checking interface
881 -- signatures, which is pretty benign
883 forkM_maybe doc thing_inside
884 = do { unsafeInterleaveM $
885 do { traceIf (text "Starting fork {" <+> doc)
886 ; mb_res <- tryM thing_inside ;
888 Right r -> do { traceIf (text "} ending fork" <+> doc)
892 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
893 -- Otherwise we silently discard errors. Errors can legitimately
894 -- happen when compiling interface signatures (see tcInterfaceSigs)
895 ifOptM Opt_D_dump_if_trace
896 (print_errs (hang (text "forkM failed:" <+> doc)
897 4 (text (show exn))))
899 ; traceIf (text "} ending fork (badly)" <+> doc)
903 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
905 forkM :: SDoc -> IfL a -> IfL a
906 forkM doc thing_inside
907 = do { mb_res <- forkM_maybe doc thing_inside
908 ; return (case mb_res of
909 Nothing -> pprPanic "forkM" doc