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, isGoodSrcSpan, 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"),
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 thing_inside
378 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
379 | otherwise = thing_inside -- Don't overwrite useful info with useless
381 addLocM :: (a -> TcM b) -> Located a -> TcM b
382 addLocM fn (L loc a) = addSrcSpan loc $ fn a
384 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
385 wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
387 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
388 wrapLocFstM fn (L loc a) =
393 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
394 wrapLocSndM fn (L loc a) =
402 getErrsVar :: TcRn (TcRef Messages)
403 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
405 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
406 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
408 addErr :: Message -> TcRn ()
409 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
411 addLocErr :: Located e -> (e -> Message) -> TcRn ()
412 addLocErr (L loc e) fn = addErrAt loc (fn e)
414 addErrAt :: SrcSpan -> Message -> TcRn ()
415 addErrAt loc msg = addLongErrAt loc msg empty
417 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
418 addLongErrAt loc msg extra
419 = do { errs_var <- getErrsVar ;
420 rdr_env <- getGlobalRdrEnv ;
421 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
422 (warns, errs) <- readMutVar errs_var ;
423 writeMutVar errs_var (warns, errs `snocBag` err) }
425 addErrs :: [(SrcSpan,Message)] -> TcRn ()
426 addErrs msgs = mappM_ add msgs
428 add (loc,msg) = addErrAt loc msg
430 addReport :: Message -> TcRn ()
431 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
433 addReportAt :: SrcSpan -> Message -> TcRn ()
435 = do { errs_var <- getErrsVar ;
436 rdr_env <- getGlobalRdrEnv ;
437 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
438 (warns, errs) <- readMutVar errs_var ;
439 writeMutVar errs_var (warns `snocBag` warn, errs) }
441 addWarn :: Message -> TcRn ()
442 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
444 addWarnAt :: SrcSpan -> Message -> TcRn ()
445 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
447 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
448 addLocWarn (L loc e) fn = addReportAt loc (fn e)
450 checkErr :: Bool -> Message -> TcRn ()
451 -- Add the error if the bool is False
452 checkErr ok msg = checkM ok (addErr msg)
454 warnIf :: Bool -> Message -> TcRn ()
455 warnIf True msg = addWarn msg
456 warnIf False msg = return ()
458 addMessages :: Messages -> TcRn ()
459 addMessages (m_warns, m_errs)
460 = do { errs_var <- getErrsVar ;
461 (warns, errs) <- readMutVar errs_var ;
462 writeMutVar errs_var (warns `unionBags` m_warns,
463 errs `unionBags` m_errs) }
465 discardWarnings :: TcRn a -> TcRn a
466 -- Ignore warnings inside the thing inside;
467 -- used to ignore-unused-variable warnings inside derived code
468 -- With -dppr-debug, the effects is switched off, so you can still see
469 -- what warnings derived code would give
470 discardWarnings thing_inside
471 | opt_PprStyle_Debug = thing_inside
473 = do { errs_var <- newMutVar emptyMessages
474 ; result <- setErrsVar errs_var thing_inside
475 ; (_warns, errs) <- readMutVar errs_var
476 ; addMessages (emptyBag, errs)
482 recoverM :: TcRn r -- Recovery action; do this if the main one fails
483 -> TcRn r -- Main action: do this first
485 recoverM recover thing
486 = do { mb_res <- try_m thing ;
489 Right res -> returnM res }
491 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
492 -- (tryTc m) executes m, and returns
493 -- Just r, if m succeeds (returning r) and caused no errors
494 -- Nothing, if m fails, or caused errors
495 -- It also returns all the errors accumulated by m
496 -- (even in the Just case, there might be warnings)
498 -- It always succeeds (never raises an exception)
500 = do { errs_var <- newMutVar emptyMessages ;
502 mb_r <- try_m (setErrsVar errs_var m) ;
504 new_errs <- readMutVar errs_var ;
511 Right r | errorsFound dflags new_errs -> Nothing
512 | otherwise -> Just r)
515 try_m :: TcRn r -> TcRn (Either Exception r)
516 -- Does try_m, with a debug-trace on failure
518 = do { mb_r <- tryM thing ;
520 Left exn -> do { traceTc (exn_msg exn); return mb_r }
521 Right r -> return mb_r }
523 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
525 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
526 -- Just like tryTc, except that it ensures that the LIE
527 -- for the thing is propagated only if there are no errors
528 -- Hence it's restricted to the type-check monad
529 tryTcLIE thing_inside
530 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
531 ifM (isJust mb_r) (extendLIEs lie) ;
532 return (errs, mb_r) }
534 tryTcLIE_ :: TcM r -> TcM r -> TcM r
535 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
536 -- otherwise it returns r. Any error messages added by m are discarded,
537 -- whether or not m succeeds.
538 tryTcLIE_ recover main
539 = do { (_msgs, mb_res) <- tryTcLIE main ;
541 Just res -> return res
544 checkNoErrs :: TcM r -> TcM r
545 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
546 -- If m fails then (checkNoErrsTc m) fails.
547 -- If m succeeds, it checks whether m generated any errors messages
548 -- (it might have recovered internally)
549 -- If so, it fails too.
550 -- Regardless, any errors generated by m are propagated to the enclosing context.
552 = do { (msgs, mb_res) <- tryTcLIE main ;
559 ifErrsM :: TcRn r -> TcRn r -> TcRn r
560 -- ifErrsM bale_out main
561 -- does 'bale_out' if there are errors in errors collection
562 -- otherwise does 'main'
563 ifErrsM bale_out normal
564 = do { errs_var <- getErrsVar ;
565 msgs <- readMutVar errs_var ;
567 if errorsFound dflags msgs then
572 failIfErrsM :: TcRn ()
573 -- Useful to avoid error cascades
574 failIfErrsM = ifErrsM failM (return ())
578 %************************************************************************
580 Context management and error message generation
583 %************************************************************************
586 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
587 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
588 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
590 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
591 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
592 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
594 popErrCtxt :: TcM a -> TcM a
595 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
597 getErrCtxt :: TcM ErrCtxt
598 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
600 -- Helper function for the above
601 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
602 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
603 env { tcl_ctxt = upd ctxt })
605 getInstLoc :: InstOrigin -> TcM InstLoc
607 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
608 return (InstLoc origin loc (tcl_ctxt env)) }
610 addInstCtxt :: InstLoc -> TcM a -> TcM a
611 -- Add the SrcSpan and context from the first Inst in the list
612 -- (they all have similar locations)
613 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
614 = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
617 The addErrTc functions add an error message, but do not cause failure.
618 The 'M' variants pass a TidyEnv that has already been used to
619 tidy up the message; we then use it to tidy the context messages
622 addErrTc :: Message -> TcM ()
623 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
625 addErrsTc :: [Message] -> TcM ()
626 addErrsTc err_msgs = mappM_ addErrTc err_msgs
628 addErrTcM :: (TidyEnv, Message) -> TcM ()
629 addErrTcM (tidy_env, err_msg)
630 = do { ctxt <- getErrCtxt ;
632 add_err_tcm tidy_env err_msg loc ctxt }
635 The failWith functions add an error message and cause failure
638 failWithTc :: Message -> TcM a -- Add an error message and fail
640 = addErrTc err_msg >> failM
642 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
643 failWithTcM local_and_msg
644 = addErrTcM local_and_msg >> failM
646 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
647 checkTc True err = returnM ()
648 checkTc False err = failWithTc err
651 Warnings have no 'M' variant, nor failure
654 addWarnTc :: Message -> TcM ()
656 = do { ctxt <- getErrCtxt ;
657 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
658 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
660 warnTc :: Bool -> Message -> TcM ()
661 warnTc warn_if_true warn_msg
662 | warn_if_true = addWarnTc warn_msg
663 | otherwise = return ()
669 add_err_tcm tidy_env err_msg loc ctxt
670 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
671 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
675 do_ctxt tidy_env (c:cs)
676 = do { (tidy_env', m) <- c tidy_env ;
677 ms <- do_ctxt tidy_env' cs ;
680 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
681 | otherwise = take 3 ctxt
684 %************************************************************************
686 Type constraints (the so-called LIE)
688 %************************************************************************
691 getLIEVar :: TcM (TcRef LIE)
692 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
694 setLIEVar :: TcRef LIE -> TcM a -> TcM a
695 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
697 getLIE :: TcM a -> TcM (a, [Inst])
698 -- (getLIE m) runs m, and returns the type constraints it generates
700 = do { lie_var <- newMutVar emptyLIE ;
701 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
703 lie <- readMutVar lie_var ;
704 return (res, lieToList lie) }
706 extendLIE :: Inst -> TcM ()
708 = do { lie_var <- getLIEVar ;
709 lie <- readMutVar lie_var ;
710 writeMutVar lie_var (inst `consLIE` lie) }
712 extendLIEs :: [Inst] -> TcM ()
716 = do { lie_var <- getLIEVar ;
717 lie <- readMutVar lie_var ;
718 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
722 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
723 -- Set the local type envt, but do *not* disturb other fields,
724 -- notably the lie_var
725 setLclTypeEnv lcl_env thing_inside
726 = updLclEnv upd thing_inside
728 upd env = env { tcl_env = tcl_env lcl_env,
729 tcl_tyvars = tcl_tyvars lcl_env }
733 %************************************************************************
735 Template Haskell context
737 %************************************************************************
740 recordThUse :: TcM ()
741 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
743 getStage :: TcM ThStage
744 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
746 setStage :: ThStage -> TcM a -> TcM a
747 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
751 %************************************************************************
755 %************************************************************************
758 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
760 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
762 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
763 = ASSERT( not (curr_lvl `elem` banned) )
764 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
766 getBannedProcLevels :: TcM [ProcLevel]
767 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
769 incProcLevel :: TcM a -> TcM a
771 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
773 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
777 %************************************************************************
779 Stuff for the renamer's local env
781 %************************************************************************
784 getLocalRdrEnv :: RnM LocalRdrEnv
785 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
787 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
788 setLocalRdrEnv rdr_env thing_inside
789 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
793 %************************************************************************
795 Stuff for interface decls
797 %************************************************************************
800 initIfaceTcRn :: IfG a -> TcRn a
801 initIfaceTcRn thing_inside
802 = do { tcg_env <- getGblEnv
803 ; let { if_env = IfGblEnv {
804 if_rec_types = Just (tcg_mod tcg_env, get_type_env),
805 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
806 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
807 ; setEnvs (if_env, ()) thing_inside }
809 initIfaceExtCore :: IfL a -> TcRn a
810 initIfaceExtCore thing_inside
811 = do { tcg_env <- getGblEnv
812 ; let { mod = tcg_mod tcg_env
813 ; if_env = IfGblEnv {
814 if_rec_types = Just (mod, return (tcg_type_env tcg_env)),
815 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
816 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
817 if_tv_env = emptyOccEnv,
818 if_id_env = emptyOccEnv }
820 ; setEnvs (if_env, if_lenv) thing_inside }
822 initIfaceCheck :: HscEnv -> IfG a -> IO a
823 -- Used when checking the up-to-date-ness of the old Iface
824 -- Initialise the environment with no useful info at all
825 initIfaceCheck hsc_env do_this
826 = do { let { gbl_env = IfGblEnv { if_is_boot = emptyModuleEnv,
827 if_rec_types = Nothing } ;
829 ; initTcRnIf 'i' hsc_env gbl_env () do_this
832 initIfaceTc :: HscEnv -> ModIface
833 -> (TcRef TypeEnv -> IfL a) -> IO a
834 -- Used when type-checking checking an up-to-date interface file
835 -- No type envt from the current module, but we do know the module dependencies
836 initIfaceTc hsc_env iface do_this
837 = do { tc_env_var <- newIORef emptyTypeEnv
838 ; let { gbl_env = IfGblEnv { if_is_boot = mkModDeps (dep_mods (mi_deps iface)),
839 if_rec_types = Just (mod, readMutVar tc_env_var) } ;
840 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
841 if_tv_env = emptyOccEnv,
842 if_id_env = emptyOccEnv }
844 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
847 mod = mi_module iface
849 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
850 -- Used when sucking in new Rules in SimplCore
851 -- We have available the type envt of the module being compiled, and we must use it
852 initIfaceRules hsc_env guts do_this
854 is_boot = mkModDeps (dep_mods (mg_deps guts))
855 -- Urgh! But we do somehow need to get the info
856 -- on whether (for this particular compilation) we should
857 -- import a hi-boot file or not.
858 ; type_info = (mg_module guts, return (mg_types guts))
859 ; gbl_env = IfGblEnv { if_is_boot = is_boot,
860 if_rec_types = Just type_info } ;
863 -- Run the thing; any exceptions just bubble out from here
864 ; initTcRnIf 'i' hsc_env gbl_env () do_this
867 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
868 initIfaceLcl mod thing_inside
869 = setLclEnv (IfLclEnv { if_mod = mod,
870 if_tv_env = emptyOccEnv,
871 if_id_env = emptyOccEnv })
876 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
877 -- Run thing_inside in an interleaved thread.
878 -- It shares everything with the parent thread, so this is DANGEROUS.
880 -- It returns Nothing if the computation fails
882 -- It's used for lazily type-checking interface
883 -- signatures, which is pretty benign
885 forkM_maybe doc thing_inside
886 = do { unsafeInterleaveM $
887 do { traceIf (text "Starting fork {" <+> doc)
888 ; mb_res <- tryM thing_inside ;
890 Right r -> do { traceIf (text "} ending fork" <+> doc)
894 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
895 -- Otherwise we silently discard errors. Errors can legitimately
896 -- happen when compiling interface signatures (see tcInterfaceSigs)
897 ifOptM Opt_D_dump_if_trace
898 (print_errs (hang (text "forkM failed:" <+> doc)
899 4 (text (show exn))))
901 ; traceIf (text "} ending fork (badly)" <+> doc)
905 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
907 forkM :: SDoc -> IfL a -> IfL a
908 forkM doc thing_inside
909 = do { mb_res <- forkM_maybe doc thing_inside
910 ; return (case mb_res of
911 Nothing -> pprPanic "forkM" doc