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 -- Updating the EPS. This should be an atomic operation.
260 -- Note the delicate 'seq' which forces the EPS before putting it in the
261 -- variable. Otherwise what happens is that we get
262 -- write eps_var (....(unsafeRead eps_var)....)
263 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
264 -- we make the unsafeRead happen before we update the variable.
266 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
268 updateEps upd_fn = do { traceIf (text "updating EPS")
269 ; eps_var <- getEpsVar
270 ; eps <- readMutVar eps_var
271 ; let { (eps', val) = upd_fn eps }
272 ; seq eps' (writeMutVar eps_var eps')
275 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
277 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
278 ; eps_var <- getEpsVar
279 ; eps <- readMutVar eps_var
280 ; let { eps' = upd_fn eps }
281 ; seq eps' (writeMutVar eps_var eps') }
283 getHpt :: TcRnIf gbl lcl HomePackageTable
284 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
286 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
287 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
288 ; return (eps, hsc_HPT env) }
291 %************************************************************************
295 %************************************************************************
298 newUnique :: TcRnIf gbl lcl Unique
299 newUnique = do { us <- newUniqueSupply ;
300 return (uniqFromSupply us) }
302 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
304 = do { env <- getEnv ;
305 let { u_var = env_us env } ;
306 us <- readMutVar u_var ;
307 let { (us1, us2) = splitUniqSupply us } ;
308 writeMutVar u_var us1 ;
313 %************************************************************************
317 %************************************************************************
320 traceTc, traceRn :: SDoc -> TcRn ()
321 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
322 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
323 traceSplice = dumpOptTcRn Opt_D_dump_splices
326 traceIf :: SDoc -> TcRnIf m n ()
327 traceIf = dumpOptIf Opt_D_dump_if_trace
328 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
331 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
332 dumpOptIf flag doc = ifOptM flag $
333 ioToIOEnv (printForUser stderr alwaysQualify doc)
335 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
336 dumpOptTcRn flag doc = ifOptM flag $ do
339 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
340 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
341 ; dumpTcRn real_doc }
343 dumpTcRn :: SDoc -> TcRn ()
344 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
345 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
349 %************************************************************************
351 Typechecker global environment
353 %************************************************************************
356 getModule :: TcRn Module
357 getModule = do { env <- getGblEnv; return (tcg_mod env) }
359 getGlobalRdrEnv :: TcRn GlobalRdrEnv
360 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
362 getImports :: TcRn ImportAvails
363 getImports = do { env <- getGblEnv; return (tcg_imports env) }
365 getFixityEnv :: TcRn FixityEnv
366 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
368 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
369 extendFixityEnv new_bit
370 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
371 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
373 getDefaultTys :: TcRn (Maybe [Type])
374 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
377 %************************************************************************
381 %************************************************************************
384 getSrcSpanM :: TcRn SrcSpan
385 -- Avoid clash with Name.getSrcLoc
386 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
388 addSrcSpan :: SrcSpan -> TcRn a -> TcRn a
389 addSrcSpan loc thing_inside
390 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
391 | otherwise = thing_inside -- Don't overwrite useful info with useless
393 addLocM :: (a -> TcM b) -> Located a -> TcM b
394 addLocM fn (L loc a) = addSrcSpan loc $ fn a
396 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
397 wrapLocM fn (L loc a) = addSrcSpan loc $ do b <- fn a; return (L loc b)
399 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
400 wrapLocFstM fn (L loc a) =
405 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
406 wrapLocSndM fn (L loc a) =
414 getErrsVar :: TcRn (TcRef Messages)
415 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
417 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
418 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
420 addErr :: Message -> TcRn ()
421 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
423 addLocErr :: Located e -> (e -> Message) -> TcRn ()
424 addLocErr (L loc e) fn = addErrAt loc (fn e)
426 addErrAt :: SrcSpan -> Message -> TcRn ()
427 addErrAt loc msg = addLongErrAt loc msg empty
429 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
430 addLongErrAt loc msg extra
431 = do { errs_var <- getErrsVar ;
432 rdr_env <- getGlobalRdrEnv ;
433 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
434 (warns, errs) <- readMutVar errs_var ;
435 writeMutVar errs_var (warns, errs `snocBag` err) }
437 addErrs :: [(SrcSpan,Message)] -> TcRn ()
438 addErrs msgs = mappM_ add msgs
440 add (loc,msg) = addErrAt loc msg
442 addReport :: Message -> TcRn ()
443 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
445 addReportAt :: SrcSpan -> Message -> TcRn ()
447 = do { errs_var <- getErrsVar ;
448 rdr_env <- getGlobalRdrEnv ;
449 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
450 (warns, errs) <- readMutVar errs_var ;
451 writeMutVar errs_var (warns `snocBag` warn, errs) }
453 addWarn :: Message -> TcRn ()
454 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
456 addWarnAt :: SrcSpan -> Message -> TcRn ()
457 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
459 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
460 addLocWarn (L loc e) fn = addReportAt loc (fn e)
462 checkErr :: Bool -> Message -> TcRn ()
463 -- Add the error if the bool is False
464 checkErr ok msg = checkM ok (addErr msg)
466 warnIf :: Bool -> Message -> TcRn ()
467 warnIf True msg = addWarn msg
468 warnIf False msg = return ()
470 addMessages :: Messages -> TcRn ()
471 addMessages (m_warns, m_errs)
472 = do { errs_var <- getErrsVar ;
473 (warns, errs) <- readMutVar errs_var ;
474 writeMutVar errs_var (warns `unionBags` m_warns,
475 errs `unionBags` m_errs) }
477 discardWarnings :: TcRn a -> TcRn a
478 -- Ignore warnings inside the thing inside;
479 -- used to ignore-unused-variable warnings inside derived code
480 -- With -dppr-debug, the effects is switched off, so you can still see
481 -- what warnings derived code would give
482 discardWarnings thing_inside
483 | opt_PprStyle_Debug = thing_inside
485 = do { errs_var <- newMutVar emptyMessages
486 ; result <- setErrsVar errs_var thing_inside
487 ; (_warns, errs) <- readMutVar errs_var
488 ; addMessages (emptyBag, errs)
494 recoverM :: TcRn r -- Recovery action; do this if the main one fails
495 -> TcRn r -- Main action: do this first
497 recoverM recover thing
498 = do { mb_res <- try_m thing ;
501 Right res -> returnM res }
503 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
504 -- (tryTc m) executes m, and returns
505 -- Just r, if m succeeds (returning r) and caused no errors
506 -- Nothing, if m fails, or caused errors
507 -- It also returns all the errors accumulated by m
508 -- (even in the Just case, there might be warnings)
510 -- It always succeeds (never raises an exception)
512 = do { errs_var <- newMutVar emptyMessages ;
514 mb_r <- try_m (setErrsVar errs_var m) ;
516 new_errs <- readMutVar errs_var ;
523 Right r | errorsFound dflags new_errs -> Nothing
524 | otherwise -> Just r)
527 try_m :: TcRn r -> TcRn (Either Exception r)
528 -- Does try_m, with a debug-trace on failure
530 = do { mb_r <- tryM thing ;
532 Left exn -> do { traceTc (exn_msg exn); return mb_r }
533 Right r -> return mb_r }
535 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
537 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
538 -- Just like tryTc, except that it ensures that the LIE
539 -- for the thing is propagated only if there are no errors
540 -- Hence it's restricted to the type-check monad
541 tryTcLIE thing_inside
542 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
543 ifM (isJust mb_r) (extendLIEs lie) ;
544 return (errs, mb_r) }
546 tryTcLIE_ :: TcM r -> TcM r -> TcM r
547 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
548 -- otherwise it returns r. Any error messages added by m are discarded,
549 -- whether or not m succeeds.
550 tryTcLIE_ recover main
551 = do { (_msgs, mb_res) <- tryTcLIE main ;
553 Just res -> return res
556 checkNoErrs :: TcM r -> TcM r
557 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
558 -- If m fails then (checkNoErrsTc m) fails.
559 -- If m succeeds, it checks whether m generated any errors messages
560 -- (it might have recovered internally)
561 -- If so, it fails too.
562 -- Regardless, any errors generated by m are propagated to the enclosing context.
564 = do { (msgs, mb_res) <- tryTcLIE main ;
571 ifErrsM :: TcRn r -> TcRn r -> TcRn r
572 -- ifErrsM bale_out main
573 -- does 'bale_out' if there are errors in errors collection
574 -- otherwise does 'main'
575 ifErrsM bale_out normal
576 = do { errs_var <- getErrsVar ;
577 msgs <- readMutVar errs_var ;
579 if errorsFound dflags msgs then
584 failIfErrsM :: TcRn ()
585 -- Useful to avoid error cascades
586 failIfErrsM = ifErrsM failM (return ())
590 %************************************************************************
592 Context management and error message generation
595 %************************************************************************
598 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
599 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
600 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
602 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
603 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
604 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
606 popErrCtxt :: TcM a -> TcM a
607 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
609 getErrCtxt :: TcM ErrCtxt
610 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
612 -- Helper function for the above
613 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
614 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
615 env { tcl_ctxt = upd ctxt })
617 getInstLoc :: InstOrigin -> TcM InstLoc
619 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
620 return (InstLoc origin loc (tcl_ctxt env)) }
622 addInstCtxt :: InstLoc -> TcM a -> TcM a
623 -- Add the SrcSpan and context from the first Inst in the list
624 -- (they all have similar locations)
625 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
626 = addSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
629 The addErrTc functions add an error message, but do not cause failure.
630 The 'M' variants pass a TidyEnv that has already been used to
631 tidy up the message; we then use it to tidy the context messages
634 addErrTc :: Message -> TcM ()
635 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
637 addErrsTc :: [Message] -> TcM ()
638 addErrsTc err_msgs = mappM_ addErrTc err_msgs
640 addErrTcM :: (TidyEnv, Message) -> TcM ()
641 addErrTcM (tidy_env, err_msg)
642 = do { ctxt <- getErrCtxt ;
644 add_err_tcm tidy_env err_msg loc ctxt }
647 The failWith functions add an error message and cause failure
650 failWithTc :: Message -> TcM a -- Add an error message and fail
652 = addErrTc err_msg >> failM
654 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
655 failWithTcM local_and_msg
656 = addErrTcM local_and_msg >> failM
658 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
659 checkTc True err = returnM ()
660 checkTc False err = failWithTc err
663 Warnings have no 'M' variant, nor failure
666 addWarnTc :: Message -> TcM ()
668 = do { ctxt <- getErrCtxt ;
669 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
670 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
672 warnTc :: Bool -> Message -> TcM ()
673 warnTc warn_if_true warn_msg
674 | warn_if_true = addWarnTc warn_msg
675 | otherwise = return ()
681 add_err_tcm tidy_env err_msg loc ctxt
682 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
683 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
687 do_ctxt tidy_env (c:cs)
688 = do { (tidy_env', m) <- c tidy_env ;
689 ms <- do_ctxt tidy_env' cs ;
692 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
693 | otherwise = take 3 ctxt
696 %************************************************************************
698 Type constraints (the so-called LIE)
700 %************************************************************************
703 getLIEVar :: TcM (TcRef LIE)
704 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
706 setLIEVar :: TcRef LIE -> TcM a -> TcM a
707 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
709 getLIE :: TcM a -> TcM (a, [Inst])
710 -- (getLIE m) runs m, and returns the type constraints it generates
712 = do { lie_var <- newMutVar emptyLIE ;
713 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
715 lie <- readMutVar lie_var ;
716 return (res, lieToList lie) }
718 extendLIE :: Inst -> TcM ()
720 = do { lie_var <- getLIEVar ;
721 lie <- readMutVar lie_var ;
722 writeMutVar lie_var (inst `consLIE` lie) }
724 extendLIEs :: [Inst] -> TcM ()
728 = do { lie_var <- getLIEVar ;
729 lie <- readMutVar lie_var ;
730 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
734 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
735 -- Set the local type envt, but do *not* disturb other fields,
736 -- notably the lie_var
737 setLclTypeEnv lcl_env thing_inside
738 = updLclEnv upd thing_inside
740 upd env = env { tcl_env = tcl_env lcl_env,
741 tcl_tyvars = tcl_tyvars lcl_env }
745 %************************************************************************
747 Template Haskell context
749 %************************************************************************
752 recordThUse :: TcM ()
753 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
755 getStage :: TcM ThStage
756 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
758 setStage :: ThStage -> TcM a -> TcM a
759 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
763 %************************************************************************
767 %************************************************************************
770 popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
772 = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
774 pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
775 = ASSERT( not (curr_lvl `elem` banned) )
776 ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
778 getBannedProcLevels :: TcM [ProcLevel]
779 = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
781 incProcLevel :: TcM a -> TcM a
783 = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
785 inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
789 %************************************************************************
791 Stuff for the renamer's local env
793 %************************************************************************
796 getLocalRdrEnv :: RnM LocalRdrEnv
797 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
799 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
800 setLocalRdrEnv rdr_env thing_inside
801 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
805 %************************************************************************
807 Stuff for interface decls
809 %************************************************************************
812 initIfaceTcRn :: IfG a -> TcRn a
813 initIfaceTcRn thing_inside
814 = do { tcg_env <- getGblEnv
815 ; let { if_env = IfGblEnv {
816 if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
817 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
818 ; setEnvs (if_env, ()) thing_inside }
820 initIfaceExtCore :: IfL a -> TcRn a
821 initIfaceExtCore thing_inside
822 = do { tcg_env <- getGblEnv
823 ; let { mod = tcg_mod tcg_env
824 ; if_env = IfGblEnv {
825 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
826 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
827 if_tv_env = emptyOccEnv,
828 if_id_env = emptyOccEnv }
830 ; setEnvs (if_env, if_lenv) thing_inside }
832 initIfaceCheck :: HscEnv -> IfG a -> IO a
833 -- Used when checking the up-to-date-ness of the old Iface
834 -- Initialise the environment with no useful info at all
835 initIfaceCheck hsc_env do_this
836 = do { let { gbl_env = IfGblEnv { if_rec_types = Nothing } ;
838 ; initTcRnIf 'i' hsc_env gbl_env () do_this
841 initIfaceTc :: HscEnv -> ModIface
842 -> (TcRef TypeEnv -> IfL a) -> IO a
843 -- Used when type-checking checking an up-to-date interface file
844 -- No type envt from the current module, but we do know the module dependencies
845 initIfaceTc hsc_env iface do_this
846 = do { tc_env_var <- newIORef emptyTypeEnv
847 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
848 ; if_lenv = IfLclEnv { if_mod = moduleName mod,
849 if_tv_env = emptyOccEnv,
850 if_id_env = emptyOccEnv }
852 ; initTcRnIf 'i' hsc_env gbl_env if_lenv (do_this tc_env_var)
855 mod = mi_module iface
857 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
858 -- Used when sucking in new Rules in SimplCore
859 -- We have available the type envt of the module being compiled, and we must use it
860 initIfaceRules hsc_env guts do_this
862 type_info = (mg_module guts, return (mg_types guts))
863 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
866 -- Run the thing; any exceptions just bubble out from here
867 ; initTcRnIf 'i' hsc_env gbl_env () do_this
870 initIfaceLcl :: ModuleName -> IfL a -> IfM lcl a
871 initIfaceLcl mod thing_inside
872 = setLclEnv (IfLclEnv { if_mod = mod,
873 if_tv_env = emptyOccEnv,
874 if_id_env = emptyOccEnv })
879 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
880 -- Run thing_inside in an interleaved thread.
881 -- It shares everything with the parent thread, so this is DANGEROUS.
883 -- It returns Nothing if the computation fails
885 -- It's used for lazily type-checking interface
886 -- signatures, which is pretty benign
888 forkM_maybe doc thing_inside
889 = do { unsafeInterleaveM $
890 do { traceIf (text "Starting fork {" <+> doc)
891 ; mb_res <- tryM thing_inside ;
893 Right r -> do { traceIf (text "} ending fork" <+> doc)
897 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
898 -- Otherwise we silently discard errors. Errors can legitimately
899 -- happen when compiling interface signatures (see tcInterfaceSigs)
900 ifOptM Opt_D_dump_if_trace
901 (print_errs (hang (text "forkM failed:" <+> doc)
902 4 (text (show exn))))
904 ; traceIf (text "} ending fork (badly)" <+> doc)
908 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
910 forkM :: SDoc -> IfL a -> IfL a
911 forkM doc thing_inside
912 = do { mb_res <- forkM_maybe doc thing_inside
913 ; return (case mb_res of
914 Nothing -> pprPanic "forkM" doc