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 ;
80 dfun_n_var <- newIORef 1 ;
86 tcg_rdr_env = emptyGlobalRdrEnv,
87 tcg_fix_env = emptyNameEnv,
88 tcg_default = Nothing,
89 tcg_type_env = emptyNameEnv,
90 tcg_type_env_var = type_env_var,
91 tcg_inst_env = emptyInstEnv,
92 tcg_inst_uses = dfuns_var,
94 tcg_exports = emptyNameSet,
95 tcg_imports = init_imports,
97 tcg_rn_decls = Nothing,
98 tcg_binds = emptyLHsBinds,
99 tcg_deprecs = NoDeprecs,
103 tcg_dfun_n = dfun_n_var,
108 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
110 tcl_rdr = emptyLocalRdrEnv,
111 tcl_th_ctxt = topStage,
112 tcl_arrow_ctxt = NoArrowCtxt,
113 tcl_env = emptyNameEnv,
114 tcl_tyvars = tvs_var,
115 tcl_lie = panic "initTc:LIE", -- LIE only valid inside a getLIE
116 tcl_gadt = emptyVarEnv
120 -- OK, here's the business end!
121 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
122 do { r <- tryM do_this
124 Right res -> return (Just res)
125 Left _ -> return Nothing } ;
127 -- Collect any error messages
128 msgs <- readIORef errs_var ;
130 let { dflags = hsc_dflags hsc_env
131 ; final_res | errorsFound dflags msgs = Nothing
132 | otherwise = maybe_res } ;
134 return (msgs, final_res)
137 init_imports = emptyImportAvails { imp_env = unitModuleEnv mod emptyNameSet }
138 -- Initialise tcg_imports with an empty set of bindings for
139 -- this module, so that if we see 'module M' in the export
140 -- list, and there are no bindings in M, we don't bleat
141 -- "unknown module M".
143 initTcPrintErrors -- Used from the interactive loop only
148 initTcPrintErrors env mod todo = do
149 (msgs, res) <- initTc env HsSrcFile mod todo
150 printErrorsAndWarnings msgs
153 -- mkImpTypeEnv makes the imported symbol table
154 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
155 -> Name -> Maybe TyThing
156 mkImpTypeEnv pcs hpt = lookup
159 lookup name | isInternalName name = Nothing
160 | otherwise = lookupType hpt pte name
164 %************************************************************************
168 %************************************************************************
172 initTcRnIf :: Char -- Tag for unique supply
177 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
178 = do { us <- mkSplitUniqSupply uniq_tag ;
179 ; us_var <- newIORef us ;
181 ; let { env = Env { env_top = hsc_env,
184 env_lcl = lcl_env } }
186 ; runIOEnv env thing_inside
190 %************************************************************************
194 %************************************************************************
197 getTopEnv :: TcRnIf gbl lcl HscEnv
198 getTopEnv = do { env <- getEnv; return (env_top env) }
200 getGblEnv :: TcRnIf gbl lcl gbl
201 getGblEnv = do { env <- getEnv; return (env_gbl env) }
203 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
204 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
205 env { env_gbl = upd gbl })
207 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
208 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
210 getLclEnv :: TcRnIf gbl lcl lcl
211 getLclEnv = do { env <- getEnv; return (env_lcl env) }
213 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
214 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
215 env { env_lcl = upd lcl })
217 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
218 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
220 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
221 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
223 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
224 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
231 getDOpts :: TcRnIf gbl lcl DynFlags
232 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
234 doptM :: DynFlag -> TcRnIf gbl lcl Bool
235 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
237 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
238 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
239 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
241 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
242 ifOptM flag thing_inside = do { b <- doptM flag;
243 if b then thing_inside else return () }
245 getGhciMode :: TcRnIf gbl lcl GhcMode
246 getGhciMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
250 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
251 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
253 getEps :: TcRnIf gbl lcl ExternalPackageState
254 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
256 -- Updating the EPS. This should be an atomic operation.
257 -- Note the delicate 'seq' which forces the EPS before putting it in the
258 -- variable. Otherwise what happens is that we get
259 -- write eps_var (....(unsafeRead eps_var)....)
260 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
261 -- we make the unsafeRead happen before we update the variable.
263 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
265 updateEps upd_fn = do { traceIf (text "updating EPS")
266 ; eps_var <- getEpsVar
267 ; eps <- readMutVar eps_var
268 ; let { (eps', val) = upd_fn eps }
269 ; seq eps' (writeMutVar eps_var eps')
272 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
274 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
275 ; eps_var <- getEpsVar
276 ; eps <- readMutVar eps_var
277 ; let { eps' = upd_fn eps }
278 ; seq eps' (writeMutVar eps_var eps') }
280 getHpt :: TcRnIf gbl lcl HomePackageTable
281 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
283 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
284 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
285 ; return (eps, hsc_HPT env) }
288 %************************************************************************
292 %************************************************************************
295 newUnique :: TcRnIf gbl lcl Unique
296 newUnique = do { us <- newUniqueSupply ;
297 return (uniqFromSupply us) }
299 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
301 = do { env <- getEnv ;
302 let { u_var = env_us env } ;
303 us <- readMutVar u_var ;
304 let { (us1, us2) = splitUniqSupply us } ;
305 writeMutVar u_var us1 ;
310 %************************************************************************
314 %************************************************************************
317 traceTc, traceRn :: SDoc -> TcRn ()
318 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
319 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
320 traceSplice = dumpOptTcRn Opt_D_dump_splices
323 traceIf :: SDoc -> TcRnIf m n ()
324 traceIf = dumpOptIf Opt_D_dump_if_trace
325 traceHiDiffs = dumpOptIf Opt_D_dump_hi_diffs
328 dumpOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
329 dumpOptIf flag doc = ifOptM flag $
330 ioToIOEnv (printForUser stderr alwaysQualify doc)
332 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
333 dumpOptTcRn flag doc = ifOptM flag $ do
336 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
337 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
338 ; dumpTcRn real_doc }
340 dumpTcRn :: SDoc -> TcRn ()
341 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
342 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
346 %************************************************************************
348 Typechecker global environment
350 %************************************************************************
353 getModule :: TcRn Module
354 getModule = do { env <- getGblEnv; return (tcg_mod env) }
356 tcIsHsBoot :: TcRn Bool
357 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src 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 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
389 setSrcSpan 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) = setSrcSpan loc $ fn a
396 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
397 wrapLocM fn (L loc a) = setSrcSpan 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 getErrCtxt :: TcM ErrCtxt
599 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
601 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
602 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
604 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
605 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
607 addErrCtxt :: Message -> TcM a -> TcM a
608 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
610 -- Helper function for the above
611 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
612 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
613 env { tcl_ctxt = upd ctxt })
615 -- Conditionally add an error context
616 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
617 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
618 maybeAddErrCtxt Nothing thing_inside = thing_inside
620 popErrCtxt :: TcM a -> TcM a
621 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
623 getInstLoc :: InstOrigin -> TcM InstLoc
625 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
626 return (InstLoc origin loc (tcl_ctxt env)) }
628 addInstCtxt :: InstLoc -> TcM a -> TcM a
629 -- Add the SrcSpan and context from the first Inst in the list
630 -- (they all have similar locations)
631 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
632 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
635 The addErrTc functions add an error message, but do not cause failure.
636 The 'M' variants pass a TidyEnv that has already been used to
637 tidy up the message; we then use it to tidy the context messages
640 addErrTc :: Message -> TcM ()
641 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
643 addErrsTc :: [Message] -> TcM ()
644 addErrsTc err_msgs = mappM_ addErrTc err_msgs
646 addErrTcM :: (TidyEnv, Message) -> TcM ()
647 addErrTcM (tidy_env, err_msg)
648 = do { ctxt <- getErrCtxt ;
650 add_err_tcm tidy_env err_msg loc ctxt }
653 The failWith functions add an error message and cause failure
656 failWithTc :: Message -> TcM a -- Add an error message and fail
658 = addErrTc err_msg >> failM
660 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
661 failWithTcM local_and_msg
662 = addErrTcM local_and_msg >> failM
664 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
665 checkTc True err = returnM ()
666 checkTc False err = failWithTc err
669 Warnings have no 'M' variant, nor failure
672 addWarnTc :: Message -> TcM ()
674 = do { ctxt <- getErrCtxt ;
675 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
676 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
678 warnTc :: Bool -> Message -> TcM ()
679 warnTc warn_if_true warn_msg
680 | warn_if_true = addWarnTc warn_msg
681 | otherwise = return ()
687 add_err_tcm tidy_env err_msg loc ctxt
688 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
689 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
693 do_ctxt tidy_env (c:cs)
694 = do { (tidy_env', m) <- c tidy_env ;
695 ms <- do_ctxt tidy_env' cs ;
698 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
699 | otherwise = take 3 ctxt
702 debugTc is useful for monadi debugging code
705 debugTc :: TcM () -> TcM ()
707 debugTc thing = thing
709 debugTc thing = return ()
713 %************************************************************************
715 Type constraints (the so-called LIE)
717 %************************************************************************
720 nextDFunIndex :: TcM Int -- Get the next dfun index
721 nextDFunIndex = do { env <- getGblEnv
722 ; let dfun_n_var = tcg_dfun_n env
723 ; n <- readMutVar dfun_n_var
724 ; writeMutVar dfun_n_var (n+1)
727 getLIEVar :: TcM (TcRef LIE)
728 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
730 setLIEVar :: TcRef LIE -> TcM a -> TcM a
731 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
733 getLIE :: TcM a -> TcM (a, [Inst])
734 -- (getLIE m) runs m, and returns the type constraints it generates
736 = do { lie_var <- newMutVar emptyLIE ;
737 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
739 lie <- readMutVar lie_var ;
740 return (res, lieToList lie) }
742 extendLIE :: Inst -> TcM ()
744 = do { lie_var <- getLIEVar ;
745 lie <- readMutVar lie_var ;
746 writeMutVar lie_var (inst `consLIE` lie) }
748 extendLIEs :: [Inst] -> TcM ()
752 = do { lie_var <- getLIEVar ;
753 lie <- readMutVar lie_var ;
754 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
758 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
759 -- Set the local type envt, but do *not* disturb other fields,
760 -- notably the lie_var
761 setLclTypeEnv lcl_env thing_inside
762 = updLclEnv upd thing_inside
764 upd env = env { tcl_env = tcl_env lcl_env,
765 tcl_tyvars = tcl_tyvars lcl_env }
769 %************************************************************************
771 Template Haskell context
773 %************************************************************************
776 recordThUse :: TcM ()
777 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
779 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
780 keepAliveTc n = do { env <- getGblEnv;
781 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
783 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
784 keepAliveSetTc ns = do { env <- getGblEnv;
785 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
787 getStage :: TcM ThStage
788 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
790 setStage :: ThStage -> TcM a -> TcM a
791 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
795 %************************************************************************
797 Stuff for the renamer's local env
799 %************************************************************************
802 getLocalRdrEnv :: RnM LocalRdrEnv
803 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
805 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
806 setLocalRdrEnv rdr_env thing_inside
807 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
811 %************************************************************************
813 Stuff for interface decls
815 %************************************************************************
818 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
819 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
821 if_tv_env = emptyOccEnv,
822 if_id_env = emptyOccEnv }
824 initIfaceTcRn :: IfG a -> TcRn a
825 initIfaceTcRn thing_inside
826 = do { tcg_env <- getGblEnv
827 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
828 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
829 ; setEnvs (if_env, ()) thing_inside }
831 initIfaceExtCore :: IfL a -> TcRn a
832 initIfaceExtCore thing_inside
833 = do { tcg_env <- getGblEnv
834 ; let { mod = tcg_mod tcg_env
835 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
836 ; if_env = IfGblEnv {
837 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
838 ; if_lenv = mkIfLclEnv mod doc
840 ; setEnvs (if_env, if_lenv) thing_inside }
842 initIfaceCheck :: HscEnv -> IfG a -> IO a
843 -- Used when checking the up-to-date-ness of the old Iface
844 -- Initialise the environment with no useful info at all
845 initIfaceCheck hsc_env do_this
846 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
847 ; initTcRnIf 'i' hsc_env gbl_env () do_this
850 initIfaceTc :: ModIface
851 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
852 -- Used when type-checking checking an up-to-date interface file
853 -- No type envt from the current module, but we do know the module dependencies
854 initIfaceTc iface do_this
855 = do { tc_env_var <- newMutVar emptyTypeEnv
856 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
857 ; if_lenv = mkIfLclEnv mod doc
859 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
862 mod = mi_module iface
863 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
865 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
866 -- Used when sucking in new Rules in SimplCore
867 -- We have available the type envt of the module being compiled, and we must use it
868 initIfaceRules hsc_env guts do_this
870 type_info = (mg_module guts, return (mg_types guts))
871 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
874 -- Run the thing; any exceptions just bubble out from here
875 ; initTcRnIf 'i' hsc_env gbl_env () do_this
878 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
879 initIfaceLcl mod loc_doc thing_inside
880 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
882 getIfModule :: IfL Module
883 getIfModule = do { env <- getLclEnv; return (if_mod env) }
886 failIfM :: Message -> IfL a
887 -- The Iface monad doesn't have a place to accumulate errors, so we
888 -- just fall over fast if one happens; it "shouldnt happen".
889 -- We use IfL here so that we can get context info out of the local env
891 = do { env <- getLclEnv
892 ; let full_msg = if_loc env $$ nest 2 msg
893 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
897 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
898 -- Run thing_inside in an interleaved thread.
899 -- It shares everything with the parent thread, so this is DANGEROUS.
901 -- It returns Nothing if the computation fails
903 -- It's used for lazily type-checking interface
904 -- signatures, which is pretty benign
906 forkM_maybe doc thing_inside
907 = do { unsafeInterleaveM $
908 do { traceIf (text "Starting fork {" <+> doc)
909 ; mb_res <- tryM thing_inside ;
911 Right r -> do { traceIf (text "} ending fork" <+> doc)
915 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
916 -- Otherwise we silently discard errors. Errors can legitimately
917 -- happen when compiling interface signatures (see tcInterfaceSigs)
918 ifOptM Opt_D_dump_if_trace
919 (print_errs (hang (text "forkM failed:" <+> doc)
920 4 (text (show exn))))
922 ; traceIf (text "} ending fork (badly)" <+> doc)
926 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
928 forkM :: SDoc -> IfL a -> IfL a
929 forkM doc thing_inside
930 = do { mb_res <- forkM_maybe doc thing_inside
931 ; return (case mb_res of
932 Nothing -> pprPanic "forkM" doc
936 %************************************************************************
940 %************************************************************************
943 getTypeRefinement :: TcM GadtRefinement
944 getTypeRefinement = do { lcl_env <- getLclEnv; return (tcl_gadt lcl_env) }
946 setTypeRefinement :: GadtRefinement -> TcM a -> TcM a
947 setTypeRefinement gadt = updLclEnv (\env -> env { tcl_gadt = gadt })