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 )
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, pprBagOfErrors,
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, unitBag )
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 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 ;
322 %************************************************************************
326 %************************************************************************
329 traceTc, traceRn :: SDoc -> TcRn ()
330 traceRn = traceOptTcRn Opt_D_dump_rn_trace
331 traceTc = traceOptTcRn Opt_D_dump_tc_trace
332 traceSplice = traceOptTcRn Opt_D_dump_splices
335 traceIf :: SDoc -> TcRnIf m n ()
336 traceIf = traceOptIf Opt_D_dump_if_trace
337 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
340 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
341 traceOptIf flag doc = ifOptM flag $
342 ioToIOEnv (printForUser stderr alwaysQualify doc)
344 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
345 traceOptTcRn flag doc = ifOptM flag $ do
348 ; ctxt_msgs <- do_ctxt emptyTidyEnv ctxt
349 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
350 ; dumpTcRn real_doc }
352 dumpTcRn :: SDoc -> TcRn ()
353 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
354 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
356 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
357 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
361 %************************************************************************
363 Typechecker global environment
365 %************************************************************************
368 getModule :: TcRn Module
369 getModule = do { env <- getGblEnv; return (tcg_mod env) }
371 tcIsHsBoot :: TcRn Bool
372 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
374 getGlobalRdrEnv :: TcRn GlobalRdrEnv
375 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
377 getImports :: TcRn ImportAvails
378 getImports = do { env <- getGblEnv; return (tcg_imports env) }
380 getFixityEnv :: TcRn FixityEnv
381 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
383 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
384 extendFixityEnv new_bit
385 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
386 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
388 getDefaultTys :: TcRn (Maybe [Type])
389 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
392 %************************************************************************
396 %************************************************************************
399 getSrcSpanM :: TcRn SrcSpan
400 -- Avoid clash with Name.getSrcLoc
401 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
403 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
404 setSrcSpan loc thing_inside
405 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
406 | otherwise = thing_inside -- Don't overwrite useful info with useless
408 addLocM :: (a -> TcM b) -> Located a -> TcM b
409 addLocM fn (L loc a) = setSrcSpan loc $ fn a
411 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
412 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
414 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
415 wrapLocFstM fn (L loc a) =
420 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
421 wrapLocSndM fn (L loc a) =
429 getErrsVar :: TcRn (TcRef Messages)
430 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
432 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
433 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
435 addErr :: Message -> TcRn ()
436 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
438 addLocErr :: Located e -> (e -> Message) -> TcRn ()
439 addLocErr (L loc e) fn = addErrAt loc (fn e)
441 addErrAt :: SrcSpan -> Message -> TcRn ()
442 addErrAt loc msg = addLongErrAt loc msg empty
444 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
445 addLongErrAt loc msg extra
446 = do { errs_var <- getErrsVar ;
447 rdr_env <- getGlobalRdrEnv ;
448 let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
449 (warns, errs) <- readMutVar errs_var ;
450 traceTc (ptext SLIT("Adding error:") <+> \ _ -> pprBagOfErrors (unitBag err)) ;
451 -- Ugh! traceTc is too specific; unitBag is horrible
452 writeMutVar errs_var (warns, errs `snocBag` err) }
454 addErrs :: [(SrcSpan,Message)] -> TcRn ()
455 addErrs msgs = mappM_ add msgs
457 add (loc,msg) = addErrAt loc msg
459 addReport :: Message -> TcRn ()
460 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
462 addReportAt :: SrcSpan -> Message -> TcRn ()
464 = do { errs_var <- getErrsVar ;
465 rdr_env <- getGlobalRdrEnv ;
466 let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
467 (warns, errs) <- readMutVar errs_var ;
468 writeMutVar errs_var (warns `snocBag` warn, errs) }
470 addWarn :: Message -> TcRn ()
471 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
473 addWarnAt :: SrcSpan -> Message -> TcRn ()
474 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
476 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
477 addLocWarn (L loc e) fn = addReportAt loc (fn e)
479 checkErr :: Bool -> Message -> TcRn ()
480 -- Add the error if the bool is False
481 checkErr ok msg = checkM ok (addErr msg)
483 warnIf :: Bool -> Message -> TcRn ()
484 warnIf True msg = addWarn msg
485 warnIf False msg = return ()
487 addMessages :: Messages -> TcRn ()
488 addMessages (m_warns, m_errs)
489 = do { errs_var <- getErrsVar ;
490 (warns, errs) <- readMutVar errs_var ;
491 writeMutVar errs_var (warns `unionBags` m_warns,
492 errs `unionBags` m_errs) }
494 discardWarnings :: TcRn a -> TcRn a
495 -- Ignore warnings inside the thing inside;
496 -- used to ignore-unused-variable warnings inside derived code
497 -- With -dppr-debug, the effects is switched off, so you can still see
498 -- what warnings derived code would give
499 discardWarnings thing_inside
500 | opt_PprStyle_Debug = thing_inside
502 = do { errs_var <- newMutVar emptyMessages
503 ; result <- setErrsVar errs_var thing_inside
504 ; (_warns, errs) <- readMutVar errs_var
505 ; addMessages (emptyBag, errs)
511 try_m :: TcRn r -> TcRn (Either Exception r)
512 -- Does try_m, with a debug-trace on failure
514 = do { mb_r <- tryM thing ;
516 Left exn -> do { traceTc (exn_msg exn); return mb_r }
517 Right r -> return mb_r }
519 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
521 -----------------------
522 recoverM :: TcRn r -- Recovery action; do this if the main one fails
523 -> TcRn r -- Main action: do this first
525 -- Errors in 'thing' are retained
526 recoverM recover thing
527 = do { mb_res <- try_m thing ;
530 Right res -> returnM res }
532 -----------------------
533 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
534 -- (tryTc m) executes m, and returns
535 -- Just r, if m succeeds (returning r)
536 -- Nothing, if m fails
537 -- It also returns all the errors and warnings accumulated by m
538 -- It always succeeds (never raises an exception)
540 = do { errs_var <- newMutVar emptyMessages ;
541 res <- try_m (setErrsVar errs_var m) ;
542 msgs <- readMutVar errs_var ;
543 return (msgs, case res of
545 Right val -> Just val)
546 -- The exception is always the IOEnv built-in
547 -- in exception; see IOEnv.failM
550 -----------------------
551 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
552 -- Run the thing, returning
553 -- Just r, if m succceeds with no error messages
554 -- Nothing, if m fails, or if it succeeds but has error messages
555 -- Either way, the messages are returned; even in the Just case
556 -- there might be warnings
558 = do { (msgs, res) <- tryTc thing
560 ; let errs_found = errorsFound dflags msgs
561 ; return (msgs, case res of
563 Just val | errs_found -> Nothing
564 | otherwise -> Just val)
567 -----------------------
568 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
569 -- Just like tryTcErrs, except that it ensures that the LIE
570 -- for the thing is propagated only if there are no errors
571 -- Hence it's restricted to the type-check monad
572 tryTcLIE thing_inside
573 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
575 Nothing -> return (msgs, Nothing)
576 Just val -> do { extendLIEs lie; return (msgs, Just val) }
579 -----------------------
580 tryTcLIE_ :: TcM r -> TcM r -> TcM r
581 -- (tryTcLIE_ r m) tries m;
582 -- if m succeeds with no error messages, it's the answer
583 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
584 tryTcLIE_ recover main
585 = do { (msgs, mb_res) <- tryTcLIE main
587 Just val -> do { addMessages msgs -- There might be warnings
589 Nothing -> recover -- Discard all msgs
592 -----------------------
593 checkNoErrs :: TcM r -> TcM r
594 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
595 -- If m fails then (checkNoErrsTc m) fails.
596 -- If m succeeds, it checks whether m generated any errors messages
597 -- (it might have recovered internally)
598 -- If so, it fails too.
599 -- Regardless, any errors generated by m are propagated to the enclosing context.
601 = do { (msgs, mb_res) <- tryTcLIE main
605 Just val -> return val
608 ifErrsM :: TcRn r -> TcRn r -> TcRn r
609 -- ifErrsM bale_out main
610 -- does 'bale_out' if there are errors in errors collection
611 -- otherwise does 'main'
612 ifErrsM bale_out normal
613 = do { errs_var <- getErrsVar ;
614 msgs <- readMutVar errs_var ;
616 if errorsFound dflags msgs then
621 failIfErrsM :: TcRn ()
622 -- Useful to avoid error cascades
623 failIfErrsM = ifErrsM failM (return ())
627 %************************************************************************
629 Context management and error message generation
632 %************************************************************************
635 getErrCtxt :: TcM ErrCtxt
636 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
638 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
639 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
641 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
642 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
644 addErrCtxt :: Message -> TcM a -> TcM a
645 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
647 -- Helper function for the above
648 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
649 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
650 env { tcl_ctxt = upd ctxt })
652 -- Conditionally add an error context
653 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
654 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
655 maybeAddErrCtxt Nothing thing_inside = thing_inside
657 popErrCtxt :: TcM a -> TcM a
658 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
660 getInstLoc :: InstOrigin -> TcM InstLoc
662 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
663 return (InstLoc origin loc (tcl_ctxt env)) }
665 addInstCtxt :: InstLoc -> TcM a -> TcM a
666 -- Add the SrcSpan and context from the first Inst in the list
667 -- (they all have similar locations)
668 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
669 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
672 The addErrTc functions add an error message, but do not cause failure.
673 The 'M' variants pass a TidyEnv that has already been used to
674 tidy up the message; we then use it to tidy the context messages
677 addErrTc :: Message -> TcM ()
678 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
680 addErrsTc :: [Message] -> TcM ()
681 addErrsTc err_msgs = mappM_ addErrTc err_msgs
683 addErrTcM :: (TidyEnv, Message) -> TcM ()
684 addErrTcM (tidy_env, err_msg)
685 = do { ctxt <- getErrCtxt ;
687 add_err_tcm tidy_env err_msg loc ctxt }
690 The failWith functions add an error message and cause failure
693 failWithTc :: Message -> TcM a -- Add an error message and fail
695 = addErrTc err_msg >> failM
697 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
698 failWithTcM local_and_msg
699 = addErrTcM local_and_msg >> failM
701 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
702 checkTc True err = returnM ()
703 checkTc False err = failWithTc err
706 Warnings have no 'M' variant, nor failure
709 addWarnTc :: Message -> TcM ()
711 = do { ctxt <- getErrCtxt ;
712 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
713 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
715 warnTc :: Bool -> Message -> TcM ()
716 warnTc warn_if_true warn_msg
717 | warn_if_true = addWarnTc warn_msg
718 | otherwise = return ()
724 add_err_tcm tidy_env err_msg loc ctxt
725 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
726 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
730 do_ctxt tidy_env (c:cs)
731 = do { (tidy_env', m) <- c tidy_env ;
732 ms <- do_ctxt tidy_env' cs ;
735 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
736 | otherwise = take 3 ctxt
739 debugTc is useful for monadi debugging code
742 debugTc :: TcM () -> TcM ()
744 debugTc thing = thing
746 debugTc thing = return ()
750 %************************************************************************
752 Type constraints (the so-called LIE)
754 %************************************************************************
757 nextDFunIndex :: TcM Int -- Get the next dfun index
758 nextDFunIndex = do { env <- getGblEnv
759 ; let dfun_n_var = tcg_dfun_n env
760 ; n <- readMutVar dfun_n_var
761 ; writeMutVar dfun_n_var (n+1)
764 getLIEVar :: TcM (TcRef LIE)
765 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
767 setLIEVar :: TcRef LIE -> TcM a -> TcM a
768 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
770 getLIE :: TcM a -> TcM (a, [Inst])
771 -- (getLIE m) runs m, and returns the type constraints it generates
773 = do { lie_var <- newMutVar emptyLIE ;
774 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
776 lie <- readMutVar lie_var ;
777 return (res, lieToList lie) }
779 extendLIE :: Inst -> TcM ()
781 = do { lie_var <- getLIEVar ;
782 lie <- readMutVar lie_var ;
783 writeMutVar lie_var (inst `consLIE` lie) }
785 extendLIEs :: [Inst] -> TcM ()
789 = do { lie_var <- getLIEVar ;
790 lie <- readMutVar lie_var ;
791 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
795 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
796 -- Set the local type envt, but do *not* disturb other fields,
797 -- notably the lie_var
798 setLclTypeEnv lcl_env thing_inside
799 = updLclEnv upd thing_inside
801 upd env = env { tcl_env = tcl_env lcl_env,
802 tcl_tyvars = tcl_tyvars lcl_env }
806 %************************************************************************
808 Template Haskell context
810 %************************************************************************
813 recordThUse :: TcM ()
814 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
816 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
817 keepAliveTc n = do { env <- getGblEnv;
818 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
820 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
821 keepAliveSetTc ns = do { env <- getGblEnv;
822 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
824 getStage :: TcM ThStage
825 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
827 setStage :: ThStage -> TcM a -> TcM a
828 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
832 %************************************************************************
834 Stuff for the renamer's local env
836 %************************************************************************
839 getLocalRdrEnv :: RnM LocalRdrEnv
840 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
842 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
843 setLocalRdrEnv rdr_env thing_inside
844 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
848 %************************************************************************
850 Stuff for interface decls
852 %************************************************************************
855 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
856 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
858 if_tv_env = emptyOccEnv,
859 if_id_env = emptyOccEnv }
861 initIfaceTcRn :: IfG a -> TcRn a
862 initIfaceTcRn thing_inside
863 = do { tcg_env <- getGblEnv
864 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
865 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
866 ; setEnvs (if_env, ()) thing_inside }
868 initIfaceExtCore :: IfL a -> TcRn a
869 initIfaceExtCore thing_inside
870 = do { tcg_env <- getGblEnv
871 ; let { mod = tcg_mod tcg_env
872 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
873 ; if_env = IfGblEnv {
874 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
875 ; if_lenv = mkIfLclEnv mod doc
877 ; setEnvs (if_env, if_lenv) thing_inside }
879 initIfaceCheck :: HscEnv -> IfG a -> IO a
880 -- Used when checking the up-to-date-ness of the old Iface
881 -- Initialise the environment with no useful info at all
882 initIfaceCheck hsc_env do_this
883 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
884 ; initTcRnIf 'i' hsc_env gbl_env () do_this
887 initIfaceTc :: ModIface
888 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
889 -- Used when type-checking checking an up-to-date interface file
890 -- No type envt from the current module, but we do know the module dependencies
891 initIfaceTc iface do_this
892 = do { tc_env_var <- newMutVar emptyTypeEnv
893 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
894 ; if_lenv = mkIfLclEnv mod doc
896 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
899 mod = mi_module iface
900 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
902 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
903 -- Used when sucking in new Rules in SimplCore
904 -- We have available the type envt of the module being compiled, and we must use it
905 initIfaceRules hsc_env guts do_this
907 type_info = (mg_module guts, return (mg_types guts))
908 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
911 -- Run the thing; any exceptions just bubble out from here
912 ; initTcRnIf 'i' hsc_env gbl_env () do_this
915 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
916 initIfaceLcl mod loc_doc thing_inside
917 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
919 getIfModule :: IfL Module
920 getIfModule = do { env <- getLclEnv; return (if_mod env) }
923 failIfM :: Message -> IfL a
924 -- The Iface monad doesn't have a place to accumulate errors, so we
925 -- just fall over fast if one happens; it "shouldnt happen".
926 -- We use IfL here so that we can get context info out of the local env
928 = do { env <- getLclEnv
929 ; let full_msg = if_loc env $$ nest 2 msg
930 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
934 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
935 -- Run thing_inside in an interleaved thread.
936 -- It shares everything with the parent thread, so this is DANGEROUS.
938 -- It returns Nothing if the computation fails
940 -- It's used for lazily type-checking interface
941 -- signatures, which is pretty benign
943 forkM_maybe doc thing_inside
944 = do { unsafeInterleaveM $
945 do { traceIf (text "Starting fork {" <+> doc)
946 ; mb_res <- tryM thing_inside ;
948 Right r -> do { traceIf (text "} ending fork" <+> doc)
952 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
953 -- Otherwise we silently discard errors. Errors can legitimately
954 -- happen when compiling interface signatures (see tcInterfaceSigs)
955 ifOptM Opt_D_dump_if_trace
956 (print_errs (hang (text "forkM failed:" <+> doc)
957 4 (text (show exn))))
959 ; traceIf (text "} ending fork (badly)" <+> doc)
963 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
965 forkM :: SDoc -> IfL a -> IfL a
966 forkM doc thing_inside
967 = do { mb_res <- forkM_maybe doc thing_inside
968 ; return (case mb_res of
969 Nothing -> pprPanic "forkM" doc
973 %************************************************************************
977 %************************************************************************
980 getTypeRefinement :: TcM GadtRefinement
981 getTypeRefinement = do { lcl_env <- getLclEnv; return (tcl_gadt lcl_env) }
983 setTypeRefinement :: GadtRefinement -> TcM a -> TcM a
984 setTypeRefinement gadt = updLclEnv (\env -> env { tcl_gadt = gadt })