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(..),
16 isHsBoot, ModSummary(..),
17 ExternalPackageState(..), HomePackageTable,
18 Deprecs(..), FixityEnv, FixItem,
19 lookupType, unQualInScope )
20 import Module ( Module, unitModuleEnv )
21 import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
22 LocalRdrEnv, emptyLocalRdrEnv )
23 import Name ( Name, isInternalName, mkInternalName, getOccName, getSrcLoc )
25 import NameEnv ( extendNameEnvList )
26 import InstEnv ( emptyInstEnv )
28 import VarSet ( emptyVarSet )
29 import VarEnv ( TidyEnv, emptyTidyEnv, emptyVarEnv )
30 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
31 mkWarnMsg, printErrorsAndWarnings,
32 mkLocMessage, mkLongErrMsg )
33 import Packages ( mkHomeModules )
34 import SrcLoc ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
35 import NameEnv ( emptyNameEnv )
36 import NameSet ( NameSet, emptyDUs, emptyNameSet, unionNameSets, addOneToNameSet )
37 import OccName ( emptyOccEnv )
38 import Bag ( emptyBag )
40 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
41 import Unique ( Unique )
42 import DynFlags ( DynFlags(..), DynFlag(..), dopt, dopt_set, GhcMode )
43 import StaticFlags ( opt_PprStyle_Debug )
44 import Bag ( snocBag, unionBags )
45 import Panic ( showException )
48 import DATA_IOREF ( newIORef, readIORef )
49 import EXCEPTION ( Exception )
54 %************************************************************************
58 %************************************************************************
61 ioToTcRn :: IO r -> TcRn r
70 -> IO (Messages, Maybe r)
71 -- Nothing => error thrown by the thing inside
72 -- (error messages should have been printed already)
74 initTc hsc_env hsc_src mod do_this
75 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
76 tvs_var <- newIORef emptyVarSet ;
77 type_env_var <- newIORef emptyNameEnv ;
78 dfuns_var <- newIORef emptyNameSet ;
79 keep_var <- newIORef emptyNameSet ;
80 th_var <- newIORef False ;
81 dfun_n_var <- newIORef 1 ;
87 tcg_rdr_env = emptyGlobalRdrEnv,
88 tcg_fix_env = emptyNameEnv,
89 tcg_default = Nothing,
90 tcg_type_env = emptyNameEnv,
91 tcg_type_env_var = type_env_var,
92 tcg_inst_env = emptyInstEnv,
93 tcg_inst_uses = dfuns_var,
95 tcg_exports = emptyNameSet,
96 tcg_imports = init_imports,
97 tcg_home_mods = home_mods,
99 tcg_rn_decls = Nothing,
100 tcg_binds = emptyLHsBinds,
101 tcg_deprecs = NoDeprecs,
105 tcg_dfun_n = dfun_n_var,
110 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
112 tcl_rdr = emptyLocalRdrEnv,
113 tcl_th_ctxt = topStage,
114 tcl_arrow_ctxt = NoArrowCtxt,
115 tcl_env = emptyNameEnv,
116 tcl_tyvars = tvs_var,
117 tcl_lie = panic "initTc:LIE", -- LIE only valid inside a getLIE
118 tcl_gadt = emptyVarEnv
122 -- OK, here's the business end!
123 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
124 do { r <- tryM do_this
126 Right res -> return (Just res)
127 Left _ -> return Nothing } ;
129 -- Collect any error messages
130 msgs <- readIORef errs_var ;
132 let { dflags = hsc_dflags hsc_env
133 ; final_res | errorsFound dflags msgs = Nothing
134 | otherwise = maybe_res } ;
136 return (msgs, final_res)
139 home_mods = mkHomeModules (map ms_mod (hsc_mod_graph hsc_env))
140 -- A guess at the home modules. This will be correct in
141 -- --make and GHCi modes, but in one-shot mode we need to
142 -- fix it up after we know the real dependencies of the current
143 -- module (see tcRnModule).
144 -- Setting it here is necessary for the typechecker entry points
145 -- other than tcRnModule: tcRnGetInfo, for example. These are
146 -- all called via the GHC module, so hsc_mod_graph will contain
147 -- something sensible.
149 init_imports = emptyImportAvails {imp_env = unitModuleEnv mod emptyNameSet}
150 -- Initialise tcg_imports with an empty set of bindings for
151 -- this module, so that if we see 'module M' in the export
152 -- list, and there are no bindings in M, we don't bleat
153 -- "unknown module M".
155 initTcPrintErrors -- Used from the interactive loop only
160 initTcPrintErrors env mod todo = do
161 (msgs, res) <- initTc env HsSrcFile mod todo
162 printErrorsAndWarnings (hsc_dflags env) msgs
165 -- mkImpTypeEnv makes the imported symbol table
166 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
167 -> Name -> Maybe TyThing
168 mkImpTypeEnv pcs hpt = lookup
171 lookup name | isInternalName name = Nothing
172 | otherwise = lookupType hpt pte name
176 %************************************************************************
180 %************************************************************************
184 initTcRnIf :: Char -- Tag for unique supply
189 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
190 = do { us <- mkSplitUniqSupply uniq_tag ;
191 ; us_var <- newIORef us ;
193 ; let { env = Env { env_top = hsc_env,
196 env_lcl = lcl_env } }
198 ; runIOEnv env thing_inside
202 %************************************************************************
206 %************************************************************************
209 getTopEnv :: TcRnIf gbl lcl HscEnv
210 getTopEnv = do { env <- getEnv; return (env_top env) }
212 getGblEnv :: TcRnIf gbl lcl gbl
213 getGblEnv = do { env <- getEnv; return (env_gbl env) }
215 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
216 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
217 env { env_gbl = upd gbl })
219 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
220 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
222 getLclEnv :: TcRnIf gbl lcl lcl
223 getLclEnv = do { env <- getEnv; return (env_lcl env) }
225 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
226 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
227 env { env_lcl = upd lcl })
229 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
230 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
232 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
233 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
235 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
236 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
243 getDOpts :: TcRnIf gbl lcl DynFlags
244 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
246 doptM :: DynFlag -> TcRnIf gbl lcl Bool
247 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
249 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
250 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
251 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
253 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
254 ifOptM flag thing_inside = do { b <- doptM flag;
255 if b then thing_inside else return () }
257 getGhciMode :: TcRnIf gbl lcl GhcMode
258 getGhciMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
262 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
263 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
265 getEps :: TcRnIf gbl lcl ExternalPackageState
266 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
268 -- Updating the EPS. This should be an atomic operation.
269 -- Note the delicate 'seq' which forces the EPS before putting it in the
270 -- variable. Otherwise what happens is that we get
271 -- write eps_var (....(unsafeRead eps_var)....)
272 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
273 -- we make the unsafeRead happen before we update the variable.
275 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
277 updateEps upd_fn = do { traceIf (text "updating EPS")
278 ; eps_var <- getEpsVar
279 ; eps <- readMutVar eps_var
280 ; let { (eps', val) = upd_fn eps }
281 ; seq eps' (writeMutVar eps_var eps')
284 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
286 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
287 ; eps_var <- getEpsVar
288 ; eps <- readMutVar eps_var
289 ; let { eps' = upd_fn eps }
290 ; seq eps' (writeMutVar eps_var eps') }
292 getHpt :: TcRnIf gbl lcl HomePackageTable
293 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
295 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
296 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
297 ; return (eps, hsc_HPT env) }
300 %************************************************************************
304 %************************************************************************
307 newUnique :: TcRnIf gbl lcl Unique
308 newUnique = do { us <- newUniqueSupply ;
309 return (uniqFromSupply us) }
311 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
313 = do { env <- getEnv ;
314 let { u_var = env_us env } ;
315 us <- readMutVar u_var ;
316 let { (us1, us2) = splitUniqSupply us } ;
317 writeMutVar u_var us1 ;
320 newLocalName :: Name -> TcRnIf gbl lcl Name
321 newLocalName name -- Make a clone
322 = newUnique `thenM` \ uniq ->
323 returnM (mkInternalName uniq (getOccName name) (getSrcLoc name))
327 %************************************************************************
331 %************************************************************************
334 traceTc, traceRn :: SDoc -> TcRn ()
335 traceRn = traceOptTcRn Opt_D_dump_rn_trace
336 traceTc = traceOptTcRn Opt_D_dump_tc_trace
337 traceSplice = traceOptTcRn Opt_D_dump_splices
340 traceIf :: SDoc -> TcRnIf m n ()
341 traceIf = traceOptIf Opt_D_dump_if_trace
342 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
345 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
346 traceOptIf flag doc = ifOptM flag $
347 ioToIOEnv (printForUser stderr alwaysQualify doc)
349 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
350 traceOptTcRn flag doc = ifOptM flag $ do
353 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
354 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
355 ; dumpTcRn real_doc }
357 dumpTcRn :: SDoc -> TcRn ()
358 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
359 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
361 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
362 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
366 %************************************************************************
368 Typechecker global environment
370 %************************************************************************
373 getModule :: TcRn Module
374 getModule = do { env <- getGblEnv; return (tcg_mod env) }
376 setModule :: Module -> TcRn a -> TcRn a
377 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
379 tcIsHsBoot :: TcRn Bool
380 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
382 getGlobalRdrEnv :: TcRn GlobalRdrEnv
383 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
385 getImports :: TcRn ImportAvails
386 getImports = do { env <- getGblEnv; return (tcg_imports env) }
388 getFixityEnv :: TcRn FixityEnv
389 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
391 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
392 extendFixityEnv new_bit
393 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
394 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
396 getDefaultTys :: TcRn (Maybe [Type])
397 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
400 %************************************************************************
404 %************************************************************************
407 getSrcSpanM :: TcRn SrcSpan
408 -- Avoid clash with Name.getSrcLoc
409 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
411 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
412 setSrcSpan loc thing_inside
413 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
414 | otherwise = thing_inside -- Don't overwrite useful info with useless
416 addLocM :: (a -> TcM b) -> Located a -> TcM b
417 addLocM fn (L loc a) = setSrcSpan loc $ fn a
419 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
420 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
422 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
423 wrapLocFstM fn (L loc a) =
428 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
429 wrapLocSndM fn (L loc a) =
437 getErrsVar :: TcRn (TcRef Messages)
438 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
440 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
441 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
443 addErr :: Message -> TcRn ()
444 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
446 addLocErr :: Located e -> (e -> Message) -> TcRn ()
447 addLocErr (L loc e) fn = addErrAt loc (fn e)
449 addErrAt :: SrcSpan -> Message -> TcRn ()
450 addErrAt loc msg = addLongErrAt loc msg empty
452 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
453 addLongErrAt loc msg extra
454 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
456 errs_var <- getErrsVar ;
457 rdr_env <- getGlobalRdrEnv ;
458 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
459 (warns, errs) <- readMutVar errs_var ;
460 writeMutVar errs_var (warns, errs `snocBag` err) }
462 addErrs :: [(SrcSpan,Message)] -> TcRn ()
463 addErrs msgs = mappM_ add msgs
465 add (loc,msg) = addErrAt loc msg
467 addReport :: Message -> TcRn ()
468 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
470 addReportAt :: SrcSpan -> Message -> TcRn ()
472 = do { errs_var <- getErrsVar ;
473 rdr_env <- getGlobalRdrEnv ;
474 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
475 (warns, errs) <- readMutVar errs_var ;
476 writeMutVar errs_var (warns `snocBag` warn, errs) }
478 addWarn :: Message -> TcRn ()
479 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
481 addWarnAt :: SrcSpan -> Message -> TcRn ()
482 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
484 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
485 addLocWarn (L loc e) fn = addReportAt loc (fn e)
487 checkErr :: Bool -> Message -> TcRn ()
488 -- Add the error if the bool is False
489 checkErr ok msg = checkM ok (addErr msg)
491 warnIf :: Bool -> Message -> TcRn ()
492 warnIf True msg = addWarn msg
493 warnIf False msg = return ()
495 addMessages :: Messages -> TcRn ()
496 addMessages (m_warns, m_errs)
497 = do { errs_var <- getErrsVar ;
498 (warns, errs) <- readMutVar errs_var ;
499 writeMutVar errs_var (warns `unionBags` m_warns,
500 errs `unionBags` m_errs) }
502 discardWarnings :: TcRn a -> TcRn a
503 -- Ignore warnings inside the thing inside;
504 -- used to ignore-unused-variable warnings inside derived code
505 -- With -dppr-debug, the effects is switched off, so you can still see
506 -- what warnings derived code would give
507 discardWarnings thing_inside
508 | opt_PprStyle_Debug = thing_inside
510 = do { errs_var <- newMutVar emptyMessages
511 ; result <- setErrsVar errs_var thing_inside
512 ; (_warns, errs) <- readMutVar errs_var
513 ; addMessages (emptyBag, errs)
519 try_m :: TcRn r -> TcRn (Either Exception r)
520 -- Does try_m, with a debug-trace on failure
522 = do { mb_r <- tryM thing ;
524 Left exn -> do { traceTc (exn_msg exn); return mb_r }
525 Right r -> return mb_r }
527 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
529 -----------------------
530 recoverM :: TcRn r -- Recovery action; do this if the main one fails
531 -> TcRn r -- Main action: do this first
533 -- Errors in 'thing' are retained
534 recoverM recover thing
535 = do { mb_res <- try_m thing ;
538 Right res -> returnM res }
540 -----------------------
541 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
542 -- (tryTc m) executes m, and returns
543 -- Just r, if m succeeds (returning r)
544 -- Nothing, if m fails
545 -- It also returns all the errors and warnings accumulated by m
546 -- It always succeeds (never raises an exception)
548 = do { errs_var <- newMutVar emptyMessages ;
549 res <- try_m (setErrsVar errs_var m) ;
550 msgs <- readMutVar errs_var ;
551 return (msgs, case res of
553 Right val -> Just val)
554 -- The exception is always the IOEnv built-in
555 -- in exception; see IOEnv.failM
558 -----------------------
559 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
560 -- Run the thing, returning
561 -- Just r, if m succceeds with no error messages
562 -- Nothing, if m fails, or if it succeeds but has error messages
563 -- Either way, the messages are returned; even in the Just case
564 -- there might be warnings
566 = do { (msgs, res) <- tryTc thing
568 ; let errs_found = errorsFound dflags msgs
569 ; return (msgs, case res of
571 Just val | errs_found -> Nothing
572 | otherwise -> Just val)
575 -----------------------
576 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
577 -- Just like tryTcErrs, except that it ensures that the LIE
578 -- for the thing is propagated only if there are no errors
579 -- Hence it's restricted to the type-check monad
580 tryTcLIE thing_inside
581 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
583 Nothing -> return (msgs, Nothing)
584 Just val -> do { extendLIEs lie; return (msgs, Just val) }
587 -----------------------
588 tryTcLIE_ :: TcM r -> TcM r -> TcM r
589 -- (tryTcLIE_ r m) tries m;
590 -- if m succeeds with no error messages, it's the answer
591 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
592 tryTcLIE_ recover main
593 = do { (msgs, mb_res) <- tryTcLIE main
595 Just val -> do { addMessages msgs -- There might be warnings
597 Nothing -> recover -- Discard all msgs
600 -----------------------
601 checkNoErrs :: TcM r -> TcM r
602 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
603 -- If m fails then (checkNoErrsTc m) fails.
604 -- If m succeeds, it checks whether m generated any errors messages
605 -- (it might have recovered internally)
606 -- If so, it fails too.
607 -- Regardless, any errors generated by m are propagated to the enclosing context.
609 = do { (msgs, mb_res) <- tryTcLIE main
613 Just val -> return val
616 ifErrsM :: TcRn r -> TcRn r -> TcRn r
617 -- ifErrsM bale_out main
618 -- does 'bale_out' if there are errors in errors collection
619 -- otherwise does 'main'
620 ifErrsM bale_out normal
621 = do { errs_var <- getErrsVar ;
622 msgs <- readMutVar errs_var ;
624 if errorsFound dflags msgs then
629 failIfErrsM :: TcRn ()
630 -- Useful to avoid error cascades
631 failIfErrsM = ifErrsM failM (return ())
635 %************************************************************************
637 Context management and error message generation
640 %************************************************************************
643 getErrCtxt :: TcM ErrCtxt
644 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
646 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
647 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
649 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
650 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
652 addErrCtxt :: Message -> TcM a -> TcM a
653 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
655 -- Helper function for the above
656 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
657 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
658 env { tcl_ctxt = upd ctxt })
660 -- Conditionally add an error context
661 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
662 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
663 maybeAddErrCtxt Nothing thing_inside = thing_inside
665 popErrCtxt :: TcM a -> TcM a
666 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
668 getInstLoc :: InstOrigin -> TcM InstLoc
670 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
671 return (InstLoc origin loc (tcl_ctxt env)) }
673 addInstCtxt :: InstLoc -> TcM a -> TcM a
674 -- Add the SrcSpan and context from the first Inst in the list
675 -- (they all have similar locations)
676 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
677 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
680 The addErrTc functions add an error message, but do not cause failure.
681 The 'M' variants pass a TidyEnv that has already been used to
682 tidy up the message; we then use it to tidy the context messages
685 addErrTc :: Message -> TcM ()
686 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
688 addErrsTc :: [Message] -> TcM ()
689 addErrsTc err_msgs = mappM_ addErrTc err_msgs
691 addErrTcM :: (TidyEnv, Message) -> TcM ()
692 addErrTcM (tidy_env, err_msg)
693 = do { ctxt <- getErrCtxt ;
695 add_err_tcm tidy_env err_msg loc ctxt }
698 The failWith functions add an error message and cause failure
701 failWithTc :: Message -> TcM a -- Add an error message and fail
703 = addErrTc err_msg >> failM
705 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
706 failWithTcM local_and_msg
707 = addErrTcM local_and_msg >> failM
709 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
710 checkTc True err = returnM ()
711 checkTc False err = failWithTc err
714 Warnings have no 'M' variant, nor failure
717 addWarnTc :: Message -> TcM ()
719 = do { ctxt <- getErrCtxt ;
720 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
721 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
723 warnTc :: Bool -> Message -> TcM ()
724 warnTc warn_if_true warn_msg
725 | warn_if_true = addWarnTc warn_msg
726 | otherwise = return ()
732 add_err_tcm tidy_env err_msg loc ctxt
733 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
734 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
738 do_ctxt tidy_env (c:cs)
739 = do { (tidy_env', m) <- c tidy_env ;
740 ms <- do_ctxt tidy_env' cs ;
743 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
744 | otherwise = take 3 ctxt
747 debugTc is useful for monadi debugging code
750 debugTc :: TcM () -> TcM ()
752 debugTc thing = thing
754 debugTc thing = return ()
758 %************************************************************************
760 Type constraints (the so-called LIE)
762 %************************************************************************
765 nextDFunIndex :: TcM Int -- Get the next dfun index
766 nextDFunIndex = do { env <- getGblEnv
767 ; let dfun_n_var = tcg_dfun_n env
768 ; n <- readMutVar dfun_n_var
769 ; writeMutVar dfun_n_var (n+1)
772 getLIEVar :: TcM (TcRef LIE)
773 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
775 setLIEVar :: TcRef LIE -> TcM a -> TcM a
776 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
778 getLIE :: TcM a -> TcM (a, [Inst])
779 -- (getLIE m) runs m, and returns the type constraints it generates
781 = do { lie_var <- newMutVar emptyLIE ;
782 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
784 lie <- readMutVar lie_var ;
785 return (res, lieToList lie) }
787 extendLIE :: Inst -> TcM ()
789 = do { lie_var <- getLIEVar ;
790 lie <- readMutVar lie_var ;
791 writeMutVar lie_var (inst `consLIE` lie) }
793 extendLIEs :: [Inst] -> TcM ()
797 = do { lie_var <- getLIEVar ;
798 lie <- readMutVar lie_var ;
799 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
803 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
804 -- Set the local type envt, but do *not* disturb other fields,
805 -- notably the lie_var
806 setLclTypeEnv lcl_env thing_inside
807 = updLclEnv upd thing_inside
809 upd env = env { tcl_env = tcl_env lcl_env,
810 tcl_tyvars = tcl_tyvars lcl_env }
814 %************************************************************************
816 Template Haskell context
818 %************************************************************************
821 recordThUse :: TcM ()
822 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
824 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
825 keepAliveTc n = do { env <- getGblEnv;
826 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
828 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
829 keepAliveSetTc ns = do { env <- getGblEnv;
830 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
832 getStage :: TcM ThStage
833 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
835 setStage :: ThStage -> TcM a -> TcM a
836 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
840 %************************************************************************
842 Stuff for the renamer's local env
844 %************************************************************************
847 getLocalRdrEnv :: RnM LocalRdrEnv
848 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
850 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
851 setLocalRdrEnv rdr_env thing_inside
852 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
856 %************************************************************************
858 Stuff for interface decls
860 %************************************************************************
863 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
864 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
866 if_tv_env = emptyOccEnv,
867 if_id_env = emptyOccEnv }
869 initIfaceTcRn :: IfG a -> TcRn a
870 initIfaceTcRn thing_inside
871 = do { tcg_env <- getGblEnv
872 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
873 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
874 ; setEnvs (if_env, ()) thing_inside }
876 initIfaceExtCore :: IfL a -> TcRn a
877 initIfaceExtCore thing_inside
878 = do { tcg_env <- getGblEnv
879 ; let { mod = tcg_mod tcg_env
880 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
881 ; if_env = IfGblEnv {
882 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
883 ; if_lenv = mkIfLclEnv mod doc
885 ; setEnvs (if_env, if_lenv) thing_inside }
887 initIfaceCheck :: HscEnv -> IfG a -> IO a
888 -- Used when checking the up-to-date-ness of the old Iface
889 -- Initialise the environment with no useful info at all
890 initIfaceCheck hsc_env do_this
891 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
892 ; initTcRnIf 'i' hsc_env gbl_env () do_this
895 initIfaceTc :: ModIface
896 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
897 -- Used when type-checking checking an up-to-date interface file
898 -- No type envt from the current module, but we do know the module dependencies
899 initIfaceTc iface do_this
900 = do { tc_env_var <- newMutVar emptyTypeEnv
901 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
902 ; if_lenv = mkIfLclEnv mod doc
904 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
907 mod = mi_module iface
908 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
910 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
911 -- Used when sucking in new Rules in SimplCore
912 -- We have available the type envt of the module being compiled, and we must use it
913 initIfaceRules hsc_env guts do_this
915 type_info = (mg_module guts, return (mg_types guts))
916 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
919 -- Run the thing; any exceptions just bubble out from here
920 ; initTcRnIf 'i' hsc_env gbl_env () do_this
923 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
924 initIfaceLcl mod loc_doc thing_inside
925 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
927 getIfModule :: IfL Module
928 getIfModule = do { env <- getLclEnv; return (if_mod env) }
931 failIfM :: Message -> IfL a
932 -- The Iface monad doesn't have a place to accumulate errors, so we
933 -- just fall over fast if one happens; it "shouldnt happen".
934 -- We use IfL here so that we can get context info out of the local env
936 = do { env <- getLclEnv
937 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
938 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
942 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
943 -- Run thing_inside in an interleaved thread.
944 -- It shares everything with the parent thread, so this is DANGEROUS.
946 -- It returns Nothing if the computation fails
948 -- It's used for lazily type-checking interface
949 -- signatures, which is pretty benign
951 forkM_maybe doc thing_inside
952 = do { unsafeInterleaveM $
953 do { traceIf (text "Starting fork {" <+> doc)
954 ; mb_res <- tryM thing_inside ;
956 Right r -> do { traceIf (text "} ending fork" <+> doc)
960 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
961 -- Otherwise we silently discard errors. Errors can legitimately
962 -- happen when compiling interface signatures (see tcInterfaceSigs)
963 ifOptM Opt_D_dump_if_trace
964 (print_errs (hang (text "forkM failed:" <+> doc)
965 4 (text (show exn))))
967 ; traceIf (text "} ending fork (badly)" <+> doc)
971 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
973 forkM :: SDoc -> IfL a -> IfL a
974 forkM doc thing_inside
975 = do { mb_res <- forkM_maybe doc thing_inside
976 ; return (case mb_res of
977 Nothing -> pgmError "Cannot continue after interface file error"
978 -- pprPanic "forkM" doc
982 %************************************************************************
986 %************************************************************************
989 getTypeRefinement :: TcM GadtRefinement
990 getTypeRefinement = do { lcl_env <- getLclEnv; return (tcl_gadt lcl_env) }
992 setTypeRefinement :: GadtRefinement -> TcM a -> TcM a
993 setTypeRefinement gadt = updLclEnv (\env -> env { tcl_gadt = gadt })