8 #include "HsVersions.h"
10 import TcRnTypes -- Re-export all
11 import IOEnv -- Re-export all
13 import HsSyn ( emptyLHsBinds )
14 import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
15 TyThing, TypeEnv, emptyTypeEnv, HscSource(..), isHsBoot,
16 ExternalPackageState(..), HomePackageTable,
17 Deprecs(..), FixityEnv, FixItem,
18 lookupType, unQualInScope )
19 import Module ( Module, unitModuleEnv )
20 import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
21 LocalRdrEnv, emptyLocalRdrEnv )
22 import Name ( Name, isInternalName )
24 import NameEnv ( extendNameEnvList )
25 import InstEnv ( emptyInstEnv )
27 import VarSet ( emptyVarSet )
28 import VarEnv ( TidyEnv, emptyTidyEnv, emptyVarEnv )
29 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
30 mkWarnMsg, printErrorsAndWarnings,
31 mkLocMessage, mkLongErrMsg )
32 import SrcLoc ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
33 import NameEnv ( emptyNameEnv )
34 import NameSet ( NameSet, emptyDUs, emptyNameSet, unionNameSets, addOneToNameSet )
35 import OccName ( emptyOccEnv )
36 import Bag ( emptyBag )
38 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
39 import Unique ( Unique )
40 import DynFlags ( DynFlags(..), DynFlag(..), dopt, dopt_set, GhcMode )
41 import StaticFlags ( opt_PprStyle_Debug )
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
69 -> IO (Messages, Maybe r)
70 -- Nothing => error thrown by the thing inside
71 -- (error messages should have been printed already)
73 initTc hsc_env hsc_src mod do_this
74 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
75 tvs_var <- newIORef emptyVarSet ;
76 type_env_var <- newIORef emptyNameEnv ;
77 dfuns_var <- newIORef emptyNameSet ;
78 keep_var <- newIORef emptyNameSet ;
79 th_var <- newIORef False ;
85 tcg_rdr_env = emptyGlobalRdrEnv,
86 tcg_fix_env = emptyNameEnv,
87 tcg_default = Nothing,
88 tcg_type_env = emptyNameEnv,
89 tcg_type_env_var = type_env_var,
90 tcg_inst_env = emptyInstEnv,
91 tcg_inst_uses = dfuns_var,
93 tcg_exports = emptyNameSet,
94 tcg_imports = init_imports,
96 tcg_rn_decls = Nothing,
97 tcg_binds = emptyLHsBinds,
98 tcg_deprecs = NoDeprecs,
106 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
108 tcl_rdr = emptyLocalRdrEnv,
109 tcl_th_ctxt = topStage,
110 tcl_env = emptyNameEnv,
111 tcl_tyvars = tvs_var,
112 tcl_lie = panic "initTc:LIE", -- LIE only valid inside a getLIE
113 tcl_gadt = emptyVarEnv
117 -- OK, here's the business end!
118 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
119 do { r <- tryM do_this
121 Right res -> return (Just res)
122 Left _ -> return Nothing } ;
124 -- Collect any error messages
125 msgs <- readIORef errs_var ;
127 let { dflags = hsc_dflags hsc_env
128 ; final_res | errorsFound dflags msgs = Nothing
129 | otherwise = maybe_res } ;
131 return (msgs, final_res)
134 init_imports = emptyImportAvails { imp_env = unitModuleEnv mod emptyNameSet }
135 -- Initialise tcg_imports with an empty set of bindings for
136 -- this module, so that if we see 'module M' in the export
137 -- list, and there are no bindings in M, we don't bleat
138 -- "unknown module M".
140 initTcPrintErrors -- Used from the interactive loop only
145 initTcPrintErrors env mod todo = do
146 (msgs, res) <- initTc env HsSrcFile mod todo
147 printErrorsAndWarnings msgs
150 -- mkImpTypeEnv makes the imported symbol table
151 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
152 -> Name -> Maybe TyThing
153 mkImpTypeEnv pcs hpt = lookup
156 lookup name | isInternalName name = Nothing
157 | otherwise = lookupType hpt pte name
161 %************************************************************************
165 %************************************************************************
169 initTcRnIf :: Char -- Tag for unique supply
174 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
175 = do { us <- mkSplitUniqSupply uniq_tag ;
176 ; us_var <- newIORef us ;
178 ; let { env = Env { env_top = hsc_env,
181 env_lcl = lcl_env } }
183 ; runIOEnv env thing_inside
187 %************************************************************************
191 %************************************************************************
194 getTopEnv :: TcRnIf gbl lcl HscEnv
195 getTopEnv = do { env <- getEnv; return (env_top env) }
197 getGblEnv :: TcRnIf gbl lcl gbl
198 getGblEnv = do { env <- getEnv; return (env_gbl env) }
200 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
201 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
202 env { env_gbl = upd gbl })
204 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
205 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
207 getLclEnv :: TcRnIf gbl lcl lcl
208 getLclEnv = do { env <- getEnv; return (env_lcl env) }
210 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
211 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
212 env { env_lcl = upd lcl })
214 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
215 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
217 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
218 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
220 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
221 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
228 getDOpts :: TcRnIf gbl lcl DynFlags
229 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
231 doptM :: DynFlag -> TcRnIf gbl lcl Bool
232 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
234 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
235 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
236 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
238 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
239 ifOptM flag thing_inside = do { b <- doptM flag;
240 if b then thing_inside else return () }
242 getGhciMode :: TcRnIf gbl lcl GhcMode
243 getGhciMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
247 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
248 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
250 getEps :: TcRnIf gbl lcl ExternalPackageState
251 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
253 -- Updating the EPS. This should be an atomic operation.
254 -- Note the delicate 'seq' which forces the EPS before putting it in the
255 -- variable. Otherwise what happens is that we get
256 -- write eps_var (....(unsafeRead eps_var)....)
257 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
258 -- we make the unsafeRead happen before we update the variable.
260 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
262 updateEps upd_fn = do { traceIf (text "updating EPS")
263 ; eps_var <- getEpsVar
264 ; eps <- readMutVar eps_var
265 ; let { (eps', val) = upd_fn eps }
266 ; seq eps' (writeMutVar eps_var eps')
269 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
271 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
272 ; eps_var <- getEpsVar
273 ; eps <- readMutVar eps_var
274 ; let { eps' = upd_fn eps }
275 ; seq eps' (writeMutVar eps_var eps') }
277 getHpt :: TcRnIf gbl lcl HomePackageTable
278 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
280 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
281 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
282 ; return (eps, hsc_HPT env) }
285 %************************************************************************
289 %************************************************************************
292 newUnique :: TcRnIf gbl lcl Unique
293 newUnique = do { us <- newUniqueSupply ;
294 return (uniqFromSupply us) }
296 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
298 = do { env <- getEnv ;
299 let { u_var = env_us env } ;
300 us <- readMutVar u_var ;
301 let { (us1, us2) = splitUniqSupply us } ;
302 writeMutVar u_var us1 ;
307 %************************************************************************
311 %************************************************************************
314 traceTc, traceRn :: SDoc -> TcRn ()
315 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
316 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
317 traceSplice = dumpOptTcRn Opt_D_dump_splices
320 traceIf :: SDoc -> TcRnIf m n ()
321 traceIf = dumpOptIf Opt_D_dump_if_trace
322 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
325 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
326 dumpOptIf flag doc = ifOptM flag $
327 ioToIOEnv (printForUser stderr alwaysQualify doc)
329 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
330 dumpOptTcRn flag doc = ifOptM flag $ do
333 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
334 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
335 ; dumpTcRn real_doc }
337 dumpTcRn :: SDoc -> TcRn ()
338 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
339 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
343 %************************************************************************
345 Typechecker global environment
347 %************************************************************************
350 getModule :: TcRn Module
351 getModule = do { env <- getGblEnv; return (tcg_mod env) }
353 tcIsHsBoot :: TcRn Bool
354 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
356 getGlobalRdrEnv :: TcRn GlobalRdrEnv
357 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
359 getImports :: TcRn ImportAvails
360 getImports = do { env <- getGblEnv; return (tcg_imports env) }
362 getFixityEnv :: TcRn FixityEnv
363 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
365 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
366 extendFixityEnv new_bit
367 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
368 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
370 getDefaultTys :: TcRn (Maybe [Type])
371 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
374 %************************************************************************
378 %************************************************************************
381 getSrcSpanM :: TcRn SrcSpan
382 -- Avoid clash with Name.getSrcLoc
383 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
385 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
386 setSrcSpan loc thing_inside
387 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
388 | otherwise = thing_inside -- Don't overwrite useful info with useless
390 addLocM :: (a -> TcM b) -> Located a -> TcM b
391 addLocM fn (L loc a) = setSrcSpan loc $ fn a
393 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
394 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
396 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
397 wrapLocFstM fn (L loc a) =
402 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
403 wrapLocSndM fn (L loc a) =
411 getErrsVar :: TcRn (TcRef Messages)
412 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
414 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
415 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
417 addErr :: Message -> TcRn ()
418 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
420 addLocErr :: Located e -> (e -> Message) -> TcRn ()
421 addLocErr (L loc e) fn = addErrAt loc (fn e)
423 addErrAt :: SrcSpan -> Message -> TcRn ()
424 addErrAt loc msg = addLongErrAt loc msg empty
426 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
427 addLongErrAt loc msg extra
428 = do { errs_var <- getErrsVar ;
429 rdr_env <- getGlobalRdrEnv ;
430 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
431 (warns, errs) <- readMutVar errs_var ;
432 writeMutVar errs_var (warns, errs `snocBag` err) }
434 addErrs :: [(SrcSpan,Message)] -> TcRn ()
435 addErrs msgs = mappM_ add msgs
437 add (loc,msg) = addErrAt loc msg
439 addReport :: Message -> TcRn ()
440 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
442 addReportAt :: SrcSpan -> Message -> TcRn ()
444 = do { errs_var <- getErrsVar ;
445 rdr_env <- getGlobalRdrEnv ;
446 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
447 (warns, errs) <- readMutVar errs_var ;
448 writeMutVar errs_var (warns `snocBag` warn, errs) }
450 addWarn :: Message -> TcRn ()
451 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
453 addWarnAt :: SrcSpan -> Message -> TcRn ()
454 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
456 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
457 addLocWarn (L loc e) fn = addReportAt loc (fn e)
459 checkErr :: Bool -> Message -> TcRn ()
460 -- Add the error if the bool is False
461 checkErr ok msg = checkM ok (addErr msg)
463 warnIf :: Bool -> Message -> TcRn ()
464 warnIf True msg = addWarn msg
465 warnIf False msg = return ()
467 addMessages :: Messages -> TcRn ()
468 addMessages (m_warns, m_errs)
469 = do { errs_var <- getErrsVar ;
470 (warns, errs) <- readMutVar errs_var ;
471 writeMutVar errs_var (warns `unionBags` m_warns,
472 errs `unionBags` m_errs) }
474 discardWarnings :: TcRn a -> TcRn a
475 -- Ignore warnings inside the thing inside;
476 -- used to ignore-unused-variable warnings inside derived code
477 -- With -dppr-debug, the effects is switched off, so you can still see
478 -- what warnings derived code would give
479 discardWarnings thing_inside
480 | opt_PprStyle_Debug = thing_inside
482 = do { errs_var <- newMutVar emptyMessages
483 ; result <- setErrsVar errs_var thing_inside
484 ; (_warns, errs) <- readMutVar errs_var
485 ; addMessages (emptyBag, errs)
491 recoverM :: TcRn r -- Recovery action; do this if the main one fails
492 -> TcRn r -- Main action: do this first
494 recoverM recover thing
495 = do { mb_res <- try_m thing ;
498 Right res -> returnM res }
500 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
501 -- (tryTc m) executes m, and returns
502 -- Just r, if m succeeds (returning r) and caused no errors
503 -- Nothing, if m fails, or caused errors
504 -- It also returns all the errors accumulated by m
505 -- (even in the Just case, there might be warnings)
507 -- It always succeeds (never raises an exception)
509 = do { errs_var <- newMutVar emptyMessages ;
511 mb_r <- try_m (setErrsVar errs_var m) ;
513 new_errs <- readMutVar errs_var ;
520 Right r | errorsFound dflags new_errs -> Nothing
521 | otherwise -> Just r)
524 try_m :: TcRn r -> TcRn (Either Exception r)
525 -- Does try_m, with a debug-trace on failure
527 = do { mb_r <- tryM thing ;
529 Left exn -> do { traceTc (exn_msg exn); return mb_r }
530 Right r -> return mb_r }
532 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
534 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
535 -- Just like tryTc, except that it ensures that the LIE
536 -- for the thing is propagated only if there are no errors
537 -- Hence it's restricted to the type-check monad
538 tryTcLIE thing_inside
539 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
540 ifM (isJust mb_r) (extendLIEs lie) ;
541 return (errs, mb_r) }
543 tryTcLIE_ :: TcM r -> TcM r -> TcM r
544 -- (tryTcLIE_ r m) tries m; if it succeeds it returns it,
545 -- otherwise it returns r. Any error messages added by m are discarded,
546 -- whether or not m succeeds.
547 tryTcLIE_ recover main
548 = do { (_msgs, mb_res) <- tryTcLIE main ;
550 Just res -> return res
553 checkNoErrs :: TcM r -> TcM r
554 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
555 -- If m fails then (checkNoErrsTc m) fails.
556 -- If m succeeds, it checks whether m generated any errors messages
557 -- (it might have recovered internally)
558 -- If so, it fails too.
559 -- Regardless, any errors generated by m are propagated to the enclosing context.
561 = do { (msgs, mb_res) <- tryTcLIE main ;
568 ifErrsM :: TcRn r -> TcRn r -> TcRn r
569 -- ifErrsM bale_out main
570 -- does 'bale_out' if there are errors in errors collection
571 -- otherwise does 'main'
572 ifErrsM bale_out normal
573 = do { errs_var <- getErrsVar ;
574 msgs <- readMutVar errs_var ;
576 if errorsFound dflags msgs then
581 failIfErrsM :: TcRn ()
582 -- Useful to avoid error cascades
583 failIfErrsM = ifErrsM failM (return ())
587 %************************************************************************
589 Context management and error message generation
592 %************************************************************************
595 getErrCtxt :: TcM ErrCtxt
596 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
598 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
599 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
601 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
602 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
604 addErrCtxt :: Message -> TcM a -> TcM a
605 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
607 -- Helper function for the above
608 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
609 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
610 env { tcl_ctxt = upd ctxt })
612 -- Conditionally add an error context
613 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
614 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
615 maybeAddErrCtxt Nothing thing_inside = thing_inside
617 popErrCtxt :: TcM a -> TcM a
618 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
620 getInstLoc :: InstOrigin -> TcM InstLoc
622 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
623 return (InstLoc origin loc (tcl_ctxt env)) }
625 addInstCtxt :: InstLoc -> TcM a -> TcM a
626 -- Add the SrcSpan and context from the first Inst in the list
627 -- (they all have similar locations)
628 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
629 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
632 The addErrTc functions add an error message, but do not cause failure.
633 The 'M' variants pass a TidyEnv that has already been used to
634 tidy up the message; we then use it to tidy the context messages
637 addErrTc :: Message -> TcM ()
638 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
640 addErrsTc :: [Message] -> TcM ()
641 addErrsTc err_msgs = mappM_ addErrTc err_msgs
643 addErrTcM :: (TidyEnv, Message) -> TcM ()
644 addErrTcM (tidy_env, err_msg)
645 = do { ctxt <- getErrCtxt ;
647 add_err_tcm tidy_env err_msg loc ctxt }
650 The failWith functions add an error message and cause failure
653 failWithTc :: Message -> TcM a -- Add an error message and fail
655 = addErrTc err_msg >> failM
657 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
658 failWithTcM local_and_msg
659 = addErrTcM local_and_msg >> failM
661 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
662 checkTc True err = returnM ()
663 checkTc False err = failWithTc err
666 Warnings have no 'M' variant, nor failure
669 addWarnTc :: Message -> TcM ()
671 = do { ctxt <- getErrCtxt ;
672 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
673 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
675 warnTc :: Bool -> Message -> TcM ()
676 warnTc warn_if_true warn_msg
677 | warn_if_true = addWarnTc warn_msg
678 | otherwise = return ()
684 add_err_tcm tidy_env err_msg loc ctxt
685 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
686 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
690 do_ctxt tidy_env (c:cs)
691 = do { (tidy_env', m) <- c tidy_env ;
692 ms <- do_ctxt tidy_env' cs ;
695 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
696 | otherwise = take 3 ctxt
699 debugTc is useful for monadi debugging code
702 debugTc :: TcM () -> TcM ()
704 debugTc thing = thing
706 debugTc thing = return ()
710 %************************************************************************
712 Type constraints (the so-called LIE)
714 %************************************************************************
717 getLIEVar :: TcM (TcRef LIE)
718 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
720 setLIEVar :: TcRef LIE -> TcM a -> TcM a
721 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
723 getLIE :: TcM a -> TcM (a, [Inst])
724 -- (getLIE m) runs m, and returns the type constraints it generates
726 = do { lie_var <- newMutVar emptyLIE ;
727 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
729 lie <- readMutVar lie_var ;
730 return (res, lieToList lie) }
732 extendLIE :: Inst -> TcM ()
734 = do { lie_var <- getLIEVar ;
735 lie <- readMutVar lie_var ;
736 writeMutVar lie_var (inst `consLIE` lie) }
738 extendLIEs :: [Inst] -> TcM ()
742 = do { lie_var <- getLIEVar ;
743 lie <- readMutVar lie_var ;
744 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
748 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
749 -- Set the local type envt, but do *not* disturb other fields,
750 -- notably the lie_var
751 setLclTypeEnv lcl_env thing_inside
752 = updLclEnv upd thing_inside
754 upd env = env { tcl_env = tcl_env lcl_env,
755 tcl_tyvars = tcl_tyvars lcl_env }
759 %************************************************************************
761 Template Haskell context
763 %************************************************************************
766 recordThUse :: TcM ()
767 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
769 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
770 keepAliveTc n = do { env <- getGblEnv;
771 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
773 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
774 keepAliveSetTc ns = do { env <- getGblEnv;
775 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
777 getStage :: TcM ThStage
778 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
780 setStage :: ThStage -> TcM a -> TcM a
781 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
785 %************************************************************************
787 Stuff for the renamer's local env
789 %************************************************************************
792 getLocalRdrEnv :: RnM LocalRdrEnv
793 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
795 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
796 setLocalRdrEnv rdr_env thing_inside
797 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
801 %************************************************************************
803 Stuff for interface decls
805 %************************************************************************
808 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
809 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
811 if_tv_env = emptyOccEnv,
812 if_id_env = emptyOccEnv }
814 initIfaceTcRn :: IfG a -> TcRn a
815 initIfaceTcRn thing_inside
816 = do { tcg_env <- getGblEnv
817 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
818 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
819 ; setEnvs (if_env, ()) thing_inside }
821 initIfaceExtCore :: IfL a -> TcRn a
822 initIfaceExtCore thing_inside
823 = do { tcg_env <- getGblEnv
824 ; let { mod = tcg_mod tcg_env
825 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
826 ; if_env = IfGblEnv {
827 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
828 ; if_lenv = mkIfLclEnv mod doc
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 }
837 ; initTcRnIf 'i' hsc_env gbl_env () do_this
840 initIfaceTc :: ModIface
841 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
842 -- Used when type-checking checking an up-to-date interface file
843 -- No type envt from the current module, but we do know the module dependencies
844 initIfaceTc iface do_this
845 = do { tc_env_var <- newMutVar emptyTypeEnv
846 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
847 ; if_lenv = mkIfLclEnv mod doc
849 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
852 mod = mi_module iface
853 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
855 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
856 -- Used when sucking in new Rules in SimplCore
857 -- We have available the type envt of the module being compiled, and we must use it
858 initIfaceRules hsc_env guts do_this
860 type_info = (mg_module guts, return (mg_types guts))
861 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
864 -- Run the thing; any exceptions just bubble out from here
865 ; initTcRnIf 'i' hsc_env gbl_env () do_this
868 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
869 initIfaceLcl mod loc_doc thing_inside
870 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
872 getIfModule :: IfL Module
873 getIfModule = do { env <- getLclEnv; return (if_mod env) }
876 failIfM :: Message -> IfL a
877 -- The Iface monad doesn't have a place to accumulate errors, so we
878 -- just fall over fast if one happens; it "shouldnt happen".
879 -- We use IfL here so that we can get context info out of the local env
881 = do { env <- getLclEnv
882 ; let full_msg = if_loc env $$ nest 2 msg
883 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
887 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
888 -- Run thing_inside in an interleaved thread.
889 -- It shares everything with the parent thread, so this is DANGEROUS.
891 -- It returns Nothing if the computation fails
893 -- It's used for lazily type-checking interface
894 -- signatures, which is pretty benign
896 forkM_maybe doc thing_inside
897 = do { unsafeInterleaveM $
898 do { traceIf (text "Starting fork {" <+> doc)
899 ; mb_res <- tryM thing_inside ;
901 Right r -> do { traceIf (text "} ending fork" <+> doc)
905 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
906 -- Otherwise we silently discard errors. Errors can legitimately
907 -- happen when compiling interface signatures (see tcInterfaceSigs)
908 ifOptM Opt_D_dump_if_trace
909 (print_errs (hang (text "forkM failed:" <+> doc)
910 4 (text (show exn))))
912 ; traceIf (text "} ending fork (badly)" <+> doc)
916 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
918 forkM :: SDoc -> IfL a -> IfL a
919 forkM doc thing_inside
920 = do { mb_res <- forkM_maybe doc thing_inside
921 ; return (case mb_res of
922 Nothing -> pprPanic "forkM" doc
926 %************************************************************************
930 %************************************************************************
933 getTypeRefinement :: TcM GadtRefinement
934 getTypeRefinement = do { lcl_env <- getLclEnv; return (tcl_gadt lcl_env) }
936 setTypeRefinement :: GadtRefinement -> TcM a -> TcM a
937 setTypeRefinement gadt = updLclEnv (\env -> env { tcl_gadt = gadt })