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 ;
81 tcg_rdr_env = emptyGlobalRdrEnv,
82 tcg_fix_env = emptyNameEnv,
83 tcg_default = Nothing,
84 tcg_type_env = emptyNameEnv,
85 tcg_type_env_var = type_env_var,
86 tcg_inst_env = mkImpInstEnv hsc_env,
87 tcg_inst_uses = dfuns_var,
88 tcg_exports = emptyNameSet,
89 tcg_imports = init_imports,
92 tcg_deprecs = NoDeprecs,
96 tcg_keep = emptyNameSet
100 tcl_loc = mkGeneralSrcSpan FSLIT("Top level of module"),
102 tcl_rdr = emptyLocalRdrEnv,
103 tcl_th_ctxt = topStage,
104 tcl_arrow_ctxt = topArrowCtxt,
105 tcl_env = emptyNameEnv,
106 tcl_tyvars = tvs_var,
107 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
111 -- OK, here's the business end!
112 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
113 do { r <- tryM do_this
115 Right res -> return (Just res)
116 Left _ -> return Nothing } ;
118 -- Collect any error messages
119 msgs <- readIORef errs_var ;
121 let { dflags = hsc_dflags hsc_env
122 ; final_res | errorsFound dflags msgs = Nothing
123 | otherwise = maybe_res } ;
125 return (msgs, final_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".
139 initTcPrintErrors env mod todo = do
140 (msgs, res) <- initTc env mod todo
141 printErrorsAndWarnings msgs
144 mkImpInstEnv :: HscEnv -> InstEnv
145 -- At the moment we (wrongly) build an instance environment from all the
146 -- home-package modules we have already compiled.
147 -- We should really only get instances from modules below us in the
148 -- module import tree.
149 mkImpInstEnv (HscEnv {hsc_dflags = dflags, hsc_HPT = hpt})
150 = foldModuleEnv (add . md_insts . hm_details) emptyInstEnv hpt
152 add dfuns inst_env = foldl extendInstEnv inst_env dfuns
154 -- mkImpTypeEnv makes the imported symbol table
155 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
156 -> Name -> Maybe TyThing
157 mkImpTypeEnv pcs hpt = lookup
160 lookup name | isInternalName name = Nothing
161 | otherwise = lookupType hpt pte name
165 %************************************************************************
169 %************************************************************************
173 initTcRnIf :: Char -- Tag for unique supply
178 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
179 = do { us <- mkSplitUniqSupply uniq_tag ;
180 ; us_var <- newIORef us ;
182 ; let { env = Env { env_top = hsc_env,
185 env_lcl = lcl_env } }
187 ; runIOEnv env thing_inside
191 %************************************************************************
195 %************************************************************************
198 getTopEnv :: TcRnIf gbl lcl HscEnv
199 getTopEnv = do { env <- getEnv; return (env_top env) }
201 getGblEnv :: TcRnIf gbl lcl gbl
202 getGblEnv = do { env <- getEnv; return (env_gbl env) }
204 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
205 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
206 env { env_gbl = upd gbl })
208 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
209 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
211 getLclEnv :: TcRnIf gbl lcl lcl
212 getLclEnv = do { env <- getEnv; return (env_lcl env) }
214 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
215 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
216 env { env_lcl = upd lcl })
218 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
219 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
221 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
222 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
224 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
225 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
232 getDOpts :: TcRnIf gbl lcl DynFlags
233 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
235 doptM :: DynFlag -> TcRnIf gbl lcl Bool
236 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
238 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
239 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
240 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
242 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
243 ifOptM flag thing_inside = do { b <- doptM flag;
244 if b then thing_inside else return () }
246 getGhciMode :: TcRnIf gbl lcl GhciMode
247 getGhciMode = do { env <- getTopEnv; return (hsc_mode env) }
251 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
252 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
254 getEps :: TcRnIf gbl lcl ExternalPackageState
255 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
257 setEps :: ExternalPackageState -> TcRnIf gbl lcl ()
258 setEps eps = do { env <- getTopEnv; writeMutVar (hsc_EPS env) eps }
260 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
262 updateEps upd_fn = do { eps_var <- getEpsVar
263 ; eps <- readMutVar eps_var
264 ; let { (eps', val) = upd_fn eps }
265 ; writeMutVar eps_var eps'
268 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
270 updateEps_ upd_fn = do { eps_var <- getEpsVar
271 ; updMutVar eps_var upd_fn }
273 getHpt :: TcRnIf gbl lcl HomePackageTable
274 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
277 %************************************************************************
281 %************************************************************************
284 newUnique :: TcRnIf gbl lcl Unique
285 newUnique = do { us <- newUniqueSupply ;
286 return (uniqFromSupply us) }
288 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
290 = do { env <- getEnv ;
291 let { u_var = env_us env } ;
292 us <- readMutVar u_var ;
293 let { (us1, us2) = splitUniqSupply us } ;
294 writeMutVar u_var us1 ;
299 %************************************************************************
303 %************************************************************************
306 traceTc, traceRn :: SDoc -> TcRn ()
307 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
308 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
309 traceSplice = dumpOptTcRn Opt_D_dump_splices
312 traceIf :: SDoc -> TcRnIf m n ()
313 traceIf = dumpOptIf Opt_D_dump_if_trace
314 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
317 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
318 dumpOptIf flag doc = ifOptM flag $
319 ioToIOEnv (printForUser stderr alwaysQualify doc)
321 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
322 dumpOptTcRn flag doc = ifOptM flag $ do
325 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
326 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
327 ; dumpTcRn real_doc }
329 dumpTcRn :: SDoc -> TcRn ()
330 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
331 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
335 %************************************************************************
337 Typechecker global environment
339 %************************************************************************
342 getModule :: TcRn Module
343 getModule = do { env <- getGblEnv; return (tcg_mod env) }
345 getGlobalRdrEnv :: TcRn GlobalRdrEnv
346 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
348 getImports :: TcRn ImportAvails
349 getImports = do { env <- getGblEnv; return (tcg_imports env) }
351 getFixityEnv :: TcRn FixityEnv
352 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
354 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
355 extendFixityEnv new_bit
356 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
357 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
359 getDefaultTys :: TcRn (Maybe [Type])
360 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
363 %************************************************************************
367 %************************************************************************
370 getSrcSpanM :: TcRn SrcSpan
371 -- Avoid clash with Name.getSrcLoc
372 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
374 addSrcSpan :: SrcSpan -> TcRn a -> TcRn a
375 addSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc })
377 addLocM :: (a -> TcM b) -> Located a -> TcM b
378 addLocM fn (L loc a) = addSrcSpan loc $ fn a
380 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
381 wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
383 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
384 wrapLocFstM fn (L loc a) =
389 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
390 wrapLocSndM fn (L loc a) =
398 getErrsVar :: TcRn (TcRef Messages)
399 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
401 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
402 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
404 addErr :: Message -> TcRn ()
405 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
407 addLocErr :: Located e -> (e -> Message) -> TcRn ()
408 addLocErr (L loc e) fn = addErrAt loc (fn e)
410 addErrAt :: SrcSpan -> Message -> TcRn ()
411 addErrAt loc msg = addLongErrAt loc msg empty
413 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
414 addLongErrAt loc msg extra
415 = do { errs_var <- getErrsVar ;
416 rdr_env <- getGlobalRdrEnv ;
417 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
418 (warns, errs) <- readMutVar errs_var ;
419 writeMutVar errs_var (warns, errs `snocBag` err) }
421 addErrs :: [(SrcSpan,Message)] -> TcRn ()
422 addErrs msgs = mappM_ add msgs
424 add (loc,msg) = addErrAt loc msg
426 addReport :: Message -> TcRn ()
427 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
429 addReportAt :: SrcSpan -> Message -> TcRn ()
431 = do { errs_var <- getErrsVar ;
432 rdr_env <- getGlobalRdrEnv ;
433 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
434 (warns, errs) <- readMutVar errs_var ;
435 writeMutVar errs_var (warns `snocBag` warn, errs) }
437 addWarn :: Message -> TcRn ()
438 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
440 addWarnAt :: SrcSpan -> Message -> TcRn ()
441 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
443 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
444 addLocWarn (L loc e) fn = addReportAt loc (fn e)
446 checkErr :: Bool -> Message -> TcRn ()
447 -- Add the error if the bool is False
448 checkErr ok msg = checkM ok (addErr msg)
450 warnIf :: Bool -> Message -> TcRn ()
451 warnIf True msg = addWarn msg
452 warnIf False msg = return ()
454 addMessages :: Messages -> TcRn ()
455 addMessages (m_warns, m_errs)
456 = do { errs_var <- getErrsVar ;
457 (warns, errs) <- readMutVar errs_var ;
458 writeMutVar errs_var (warns `unionBags` m_warns,
459 errs `unionBags` m_errs) }
461 discardWarnings :: TcRn a -> TcRn a
462 -- Ignore warnings inside the thing inside;
463 -- used to ignore-unused-variable warnings inside derived code
464 -- With -dppr-debug, the effects is switched off, so you can still see
465 -- what warnings derived code would give
466 discardWarnings thing_inside
467 | opt_PprStyle_Debug = thing_inside
469 = do { errs_var <- newMutVar emptyMessages
470 ; result <- setErrsVar errs_var thing_inside
471 ; (_warns, errs) <- readMutVar errs_var
472 ; addMessages (emptyBag, errs)
478 recoverM :: TcRn r -- Recovery action; do this if the main one fails
479 -> TcRn r -- Main action: do this first
481 recoverM recover thing
482 = do { mb_res <- try_m thing ;
485 Right res -> returnM res }
487 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
488 -- (tryTc m) executes m, and returns
489 -- Just r, if m succeeds (returning r) and caused no errors
490 -- Nothing, if m fails, or caused errors
491 -- It also returns all the errors accumulated by m
492 -- (even in the Just case, there might be warnings)
494 -- It always succeeds (never raises an exception)
496 = do { errs_var <- newMutVar emptyMessages ;
498 mb_r <- try_m (setErrsVar errs_var m) ;
500 new_errs <- readMutVar errs_var ;
507 Right r | errorsFound dflags new_errs -> Nothing
508 | otherwise -> Just r)
511 try_m :: TcRn r -> TcRn (Either Exception r)
512 -- Does try_m, with a debug-trace on failure
514 = do { mb_r <- tryM thing ;
516 Left exn -> do { traceTc (exn_msg exn); return mb_r }
517 Right r -> return mb_r }
519 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
521 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
522 -- Just like tryTc, except that it ensures that the LIE
523 -- for the thing is propagated only if there are no errors
524 -- Hence it's restricted to the type-check monad
525 tryTcLIE thing_inside
526 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
527 ifM (isJust mb_r) (extendLIEs lie) ;
528 return (errs, mb_r) }
530 tryTcLIE_ :: TcM r -> TcM r -> TcM r
531 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
532 -- otherwise it returns r. Any error messages added by m are discarded,
533 -- whether or not m succeeds.
534 tryTcLIE_ recover main
535 = do { (_msgs, mb_res) <- tryTcLIE main ;
537 Just res -> return res
540 checkNoErrs :: TcM r -> TcM r
541 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
542 -- If m fails then (checkNoErrsTc m) fails.
543 -- If m succeeds, it checks whether m generated any errors messages
544 -- (it might have recovered internally)
545 -- If so, it fails too.
546 -- Regardless, any errors generated by m are propagated to the enclosing context.
548 = do { (msgs, mb_res) <- tryTcLIE main ;
555 ifErrsM :: TcRn r -> TcRn r -> TcRn r
556 -- ifErrsM bale_out main
557 -- does 'bale_out' if there are errors in errors collection
558 -- otherwise does 'main'
559 ifErrsM bale_out normal
560 = do { errs_var <- getErrsVar ;
561 msgs <- readMutVar errs_var ;
563 if errorsFound dflags msgs then
568 failIfErrsM :: TcRn ()
569 -- Useful to avoid error cascades
570 failIfErrsM = ifErrsM failM (return ())
574 %************************************************************************
576 Context management and error message generation
579 %************************************************************************
582 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
583 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
584 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
586 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
587 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
588 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
590 popErrCtxt :: TcM a -> TcM a
591 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
593 getErrCtxt :: TcM ErrCtxt
594 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
596 -- Helper function for the above
597 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
598 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
599 env { tcl_ctxt = upd ctxt })
601 getInstLoc :: InstOrigin -> TcM InstLoc
603 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
604 return (InstLoc origin loc (tcl_ctxt env)) }
606 addInstCtxt :: InstLoc -> TcM a -> TcM a
607 -- Add the SrcSpan and context from the first Inst in the list
608 -- (they all have similar locations)
609 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
610 = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
613 The addErrTc functions add an error message, but do not cause failure.
614 The 'M' variants pass a TidyEnv that has already been used to
615 tidy up the message; we then use it to tidy the context messages
618 addErrTc :: Message -> TcM ()
619 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
621 addErrsTc :: [Message] -> TcM ()
622 addErrsTc err_msgs = mappM_ addErrTc err_msgs
624 addErrTcM :: (TidyEnv, Message) -> TcM ()
625 addErrTcM (tidy_env, err_msg)
626 = do { ctxt <- getErrCtxt ;
628 add_err_tcm tidy_env err_msg loc ctxt }
631 The failWith functions add an error message and cause failure
634 failWithTc :: Message -> TcM a -- Add an error message and fail
636 = addErrTc err_msg >> failM
638 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
639 failWithTcM local_and_msg
640 = addErrTcM local_and_msg >> failM
642 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
643 checkTc True err = returnM ()
644 checkTc False err = failWithTc err
647 Warnings have no 'M' variant, nor failure
650 addWarnTc :: Message -> TcM ()
652 = do { ctxt <- getErrCtxt ;
653 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
654 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
656 warnTc :: Bool -> Message -> TcM ()
657 warnTc warn_if_true warn_msg
658 | warn_if_true = addWarnTc warn_msg
659 | otherwise = return ()
665 add_err_tcm tidy_env err_msg loc ctxt
666 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
667 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
671 do_ctxt tidy_env (c:cs)
672 = do { (tidy_env', m) <- c tidy_env ;
673 ms <- do_ctxt tidy_env' cs ;
676 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
677 | otherwise = take 3 ctxt
680 %************************************************************************
682 Type constraints (the so-called LIE)
684 %************************************************************************
687 getLIEVar :: TcM (TcRef LIE)
688 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
690 setLIEVar :: TcRef LIE -> TcM a -> TcM a
691 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
693 getLIE :: TcM a -> TcM (a, [Inst])
694 -- (getLIE m) runs m, and returns the type constraints it generates
696 = do { lie_var <- newMutVar emptyLIE ;
697 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
699 lie <- readMutVar lie_var ;
700 return (res, lieToList lie) }
702 extendLIE :: Inst -> TcM ()
704 = do { lie_var <- getLIEVar ;
705 lie <- readMutVar lie_var ;
706 writeMutVar lie_var (inst `consLIE` lie) }
708 extendLIEs :: [Inst] -> TcM ()
712 = do { lie_var <- getLIEVar ;
713 lie <- readMutVar lie_var ;
714 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
718 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
719 -- Set the local type envt, but do *not* disturb other fields,
720 -- notably the lie_var
721 setLclTypeEnv lcl_env thing_inside
722 = updLclEnv upd thing_inside
724 upd env = env { tcl_env = tcl_env lcl_env,
725 tcl_tyvars = tcl_tyvars lcl_env }
729 %************************************************************************
731 Template Haskell context
733 %************************************************************************
736 getStage :: TcM ThStage
737 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
739 setStage :: ThStage -> TcM a -> TcM a
740 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
744 %************************************************************************
748 %************************************************************************
751 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
753 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
755 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
756 = ASSERT( not (curr_lvl `elem` banned) )
757 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
759 getBannedProcLevels :: TcM [ProcLevel]
760 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
762 incProcLevel :: TcM a -> TcM a
764 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
766 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
770 %************************************************************************
772 Stuff for the renamer's local env
774 %************************************************************************
777 getLocalRdrEnv :: RnM LocalRdrEnv
778 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
780 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
781 setLocalRdrEnv rdr_env thing_inside
782 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
786 %************************************************************************
788 Stuff for interface decls
790 %************************************************************************
793 initIfaceTcRn :: IfG a -> TcRn a
794 initIfaceTcRn thing_inside
795 = do { tcg_env <- getGblEnv
796 ; let { if_env = IfGblEnv {
797 if_rec_types = Just (tcg_mod tcg_env, get_type_env),
798 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
799 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
800 ; setEnvs (if_env, ()) thing_inside }
802 initIfaceExtCore :: IfL a -> TcRn a
803 initIfaceExtCore thing_inside
804 = do { tcg_env <- getGblEnv
805 ; let { mod = tcg_mod tcg_env
806 ; if_env = IfGblEnv {
807 if_rec_types = Just (mod, return (tcg_type_env tcg_env)),
808 if_is_boot = imp_dep_mods (tcg_imports tcg_env) }
809 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
810 if_tv_env = emptyOccEnv,
811 if_id_env = emptyOccEnv }
813 ; setEnvs (if_env, if_lenv) thing_inside }
815 initIfaceCheck :: HscEnv -> IfG a -> IO a
816 -- Used when checking the up-to-date-ness of the old Iface
817 -- Initialise the environment with no useful info at all
818 initIfaceCheck hsc_env do_this
819 = do { let { gbl_env = IfGblEnv { if_is_boot = emptyModuleEnv,
820 if_rec_types = Nothing } ;
822 ; initTcRnIf 'i' hsc_env gbl_env () do_this
825 initIfaceTc :: HscEnv -> ModIface
826 -> (TcRef TypeEnv -> IfL a) -> IO a
827 -- Used when type-checking checking an up-to-date interface file
828 -- No type envt from the current module, but we do know the module dependencies
829 initIfaceTc hsc_env iface do_this
830 = do { tc_env_var <- newIORef emptyTypeEnv
831 ; let { gbl_env = IfGblEnv { if_is_boot = mkModDeps (dep_mods (mi_deps iface)),
832 if_rec_types = Just (mod, readMutVar tc_env_var) } ;
833 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
834 if_tv_env = emptyOccEnv,
835 if_id_env = emptyOccEnv }
837 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
840 mod = mi_module iface
842 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
843 -- Used when sucking in new Rules in SimplCore
844 -- We have available the type envt of the module being compiled, and we must use it
845 initIfaceRules hsc_env guts do_this
847 is_boot = mkModDeps (dep_mods (mg_deps guts))
848 -- Urgh! But we do somehow need to get the info
849 -- on whether (for this particular compilation) we should
850 -- import a hi-boot file or not.
851 ; type_info = (mg_module guts, return (mg_types guts))
852 ; gbl_env = IfGblEnv { if_is_boot = is_boot,
853 if_rec_types = Just type_info } ;
856 -- Run the thing; any exceptions just bubble out from here
857 ; initTcRnIf 'i' hsc_env gbl_env () do_this
860 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
861 initIfaceLcl mod thing_inside
862 = setLclEnv (IfLclEnv { if_mod = mod,
863 if_tv_env = emptyOccEnv,
864 if_id_env = emptyOccEnv })
869 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
870 -- Run thing_inside in an interleaved thread.
871 -- It shares everything with the parent thread, so this is DANGEROUS.
873 -- It returns Nothing if the computation fails
875 -- It's used for lazily type-checking interface
876 -- signatures, which is pretty benign
878 forkM_maybe doc thing_inside
879 = do { unsafeInterleaveM $
880 do { traceIf (text "Starting fork {" <+> doc)
881 ; mb_res <- tryM thing_inside ;
883 Right r -> do { traceIf (text "} ending fork" <+> doc)
887 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
888 -- Otherwise we silently discard errors. Errors can legitimately
889 -- happen when compiling interface signatures (see tcInterfaceSigs)
890 ifOptM Opt_D_dump_if_trace
891 (print_errs (hang (text "forkM failed:" <+> doc)
892 4 (text (show exn))))
894 ; traceIf (text "} ending fork (badly)" <+> doc)
898 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
900 forkM :: SDoc -> IfL a -> IfL a
901 forkM doc thing_inside
902 = do { mb_res <- forkM_maybe doc thing_inside
903 ; return (case mb_res of
904 Nothing -> pprPanic "forkM" doc