8 #include "HsVersions.h"
10 import TcRnTypes -- Re-export all
11 import IOEnv -- Re-export all
13 #if defined(GHCI) && defined(BREAKPOINT)
14 import TypeRep ( Type(..), liftedTypeKind )
15 import Var ( mkTyVar, mkGlobalId )
16 import IdInfo ( GlobalIdDetails(..), vanillaIdInfo )
17 import OccName ( mkOccName, tvName )
18 import SrcLoc ( noSrcLoc )
19 import TysWiredIn ( intTy, stringTy, mkListTy, unitTy, boolTy )
20 import PrelNames ( breakpointJumpName, breakpointCondJumpName )
21 import NameEnv ( mkNameEnv )
24 import HsSyn ( emptyLHsBinds )
25 import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
26 TypeEnv, emptyTypeEnv, HscSource(..), isHsBoot,
27 ExternalPackageState(..), HomePackageTable,
28 Deprecs(..), FixityEnv, FixItem,
30 import Module ( Module, moduleName )
31 import RdrName ( GlobalRdrEnv, LocalRdrEnv, emptyLocalRdrEnv )
32 import Name ( Name, mkInternalName, tidyNameOcc, nameOccName, getSrcLoc )
34 import TcType ( tcIsTyVarTy, tcGetTyVar )
35 import NameEnv ( extendNameEnvList, nameEnvElts )
36 import InstEnv ( emptyInstEnv )
38 import Var ( setTyVarName )
39 import VarSet ( emptyVarSet )
40 import VarEnv ( TidyEnv, emptyTidyEnv, extendVarEnv )
41 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
42 mkWarnMsg, printErrorsAndWarnings,
43 mkLocMessage, mkLongErrMsg )
44 import SrcLoc ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
45 import NameEnv ( emptyNameEnv )
46 import NameSet ( NameSet, emptyDUs, emptyNameSet, unionNameSets, addOneToNameSet )
47 import OccName ( emptyOccEnv, tidyOccName )
48 import Bag ( emptyBag )
50 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
51 import UniqFM ( unitUFM )
52 import Unique ( Unique )
53 import DynFlags ( DynFlags(..), DynFlag(..), dopt, dopt_set, GhcMode )
54 import StaticFlags ( opt_PprStyle_Debug )
55 import Bag ( snocBag, unionBags )
56 import Panic ( showException )
59 import DATA_IOREF ( newIORef, readIORef )
60 import EXCEPTION ( Exception )
65 %************************************************************************
69 %************************************************************************
72 ioToTcRn :: IO r -> TcRn r
81 -> IO (Messages, Maybe r)
82 -- Nothing => error thrown by the thing inside
83 -- (error messages should have been printed already)
85 initTc hsc_env hsc_src mod do_this
86 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
87 tvs_var <- newIORef emptyVarSet ;
88 type_env_var <- newIORef emptyNameEnv ;
89 dfuns_var <- newIORef emptyNameSet ;
90 keep_var <- newIORef emptyNameSet ;
91 th_var <- newIORef False ;
92 dfun_n_var <- newIORef 1 ;
97 tcg_rdr_env = hsc_global_rdr_env hsc_env,
98 tcg_fix_env = emptyNameEnv,
99 tcg_default = Nothing,
100 tcg_type_env = hsc_global_type_env hsc_env,
101 tcg_type_env_var = type_env_var,
102 tcg_inst_env = emptyInstEnv,
103 tcg_inst_uses = dfuns_var,
104 tcg_th_used = th_var,
105 tcg_exports = emptyNameSet,
106 tcg_imports = init_imports,
108 tcg_rn_imports = Nothing,
109 tcg_rn_exports = Nothing,
110 tcg_rn_decls = Nothing,
111 tcg_binds = emptyLHsBinds,
112 tcg_deprecs = NoDeprecs,
116 tcg_dfun_n = dfun_n_var,
121 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
123 tcl_rdr = emptyLocalRdrEnv,
124 tcl_th_ctxt = topStage,
125 tcl_arrow_ctxt = NoArrowCtxt,
126 tcl_env = emptyNameEnv,
127 tcl_tyvars = tvs_var,
128 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
132 -- OK, here's the business end!
133 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
135 #if defined(GHCI) && defined(BREAKPOINT)
136 unique <- newUnique ;
137 let { var = mkInternalName unique (mkOccName tvName "a") noSrcLoc;
138 tyvar = mkTyVar var liftedTypeKind;
139 basicType extra = (FunTy intTy
140 (FunTy (mkListTy unitTy)
144 (FunTy (TyVarTy tyvar)
145 (TyVarTy tyvar)))))));
147 = mkGlobalId VanillaGlobal breakpointJumpName
148 (basicType id) vanillaIdInfo;
149 breakpointCondJumpType
150 = mkGlobalId VanillaGlobal breakpointCondJumpName
151 (basicType (FunTy boolTy)) vanillaIdInfo;
152 new_env = mkNameEnv [(breakpointJumpName
153 , ATcId breakpointJumpType topLevel False)
154 ,(breakpointCondJumpName
155 , ATcId breakpointCondJumpType topLevel False)];
157 r <- tryM (updLclEnv (\gbl -> gbl{tcl_env=new_env}) do_this)
162 Right res -> return (Just res)
163 Left _ -> return Nothing } ;
165 -- Collect any error messages
166 msgs <- readIORef errs_var ;
168 let { dflags = hsc_dflags hsc_env
169 ; final_res | errorsFound dflags msgs = Nothing
170 | otherwise = maybe_res } ;
172 return (msgs, final_res)
175 init_imports = emptyImportAvails {imp_env =
176 unitUFM (moduleName mod) emptyNameSet}
177 -- Initialise tcg_imports with an empty set of bindings for
178 -- this module, so that if we see 'module M' in the export
179 -- list, and there are no bindings in M, we don't bleat
180 -- "unknown module M".
182 initTcPrintErrors -- Used from the interactive loop only
187 initTcPrintErrors env mod todo = do
188 (msgs, res) <- initTc env HsSrcFile mod todo
189 printErrorsAndWarnings (hsc_dflags env) msgs
194 %************************************************************************
198 %************************************************************************
202 initTcRnIf :: Char -- Tag for unique supply
207 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
208 = do { us <- mkSplitUniqSupply uniq_tag ;
209 ; us_var <- newIORef us ;
211 ; let { env = Env { env_top = hsc_env,
214 env_lcl = lcl_env } }
216 ; runIOEnv env thing_inside
220 %************************************************************************
224 %************************************************************************
227 getTopEnv :: TcRnIf gbl lcl HscEnv
228 getTopEnv = do { env <- getEnv; return (env_top env) }
230 getGblEnv :: TcRnIf gbl lcl gbl
231 getGblEnv = do { env <- getEnv; return (env_gbl env) }
233 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
234 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
235 env { env_gbl = upd gbl })
237 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
238 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
240 getLclEnv :: TcRnIf gbl lcl lcl
241 getLclEnv = do { env <- getEnv; return (env_lcl env) }
243 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
244 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
245 env { env_lcl = upd lcl })
247 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
248 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
250 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
251 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
253 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
254 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
261 getDOpts :: TcRnIf gbl lcl DynFlags
262 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
264 doptM :: DynFlag -> TcRnIf gbl lcl Bool
265 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
267 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
268 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
269 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
271 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
272 ifOptM flag thing_inside = do { b <- doptM flag;
273 if b then thing_inside else return () }
275 getGhcMode :: TcRnIf gbl lcl GhcMode
276 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
280 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
281 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
283 getEps :: TcRnIf gbl lcl ExternalPackageState
284 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
286 -- Updating the EPS. This should be an atomic operation.
287 -- Note the delicate 'seq' which forces the EPS before putting it in the
288 -- variable. Otherwise what happens is that we get
289 -- write eps_var (....(unsafeRead eps_var)....)
290 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
291 -- we make the unsafeRead happen before we update the variable.
293 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
295 updateEps upd_fn = do { traceIf (text "updating EPS")
296 ; eps_var <- getEpsVar
297 ; eps <- readMutVar eps_var
298 ; let { (eps', val) = upd_fn eps }
299 ; seq eps' (writeMutVar eps_var eps')
302 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
304 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
305 ; eps_var <- getEpsVar
306 ; eps <- readMutVar eps_var
307 ; let { eps' = upd_fn eps }
308 ; seq eps' (writeMutVar eps_var eps') }
310 getHpt :: TcRnIf gbl lcl HomePackageTable
311 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
313 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
314 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
315 ; return (eps, hsc_HPT env) }
318 %************************************************************************
322 %************************************************************************
325 newUnique :: TcRnIf gbl lcl Unique
327 = do { env <- getEnv ;
328 let { u_var = env_us env } ;
329 us <- readMutVar u_var ;
330 case splitUniqSupply us of { (us1,_) -> do {
331 writeMutVar u_var us1 ;
332 return $! uniqFromSupply us }}}
333 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
334 -- a chain of unevaluated supplies behind.
335 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
336 -- throw away one half of the new split supply. This is safe because this
337 -- is the only place we use that unique. Using the other half of the split
338 -- supply is safer, but slower.
340 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
342 = do { env <- getEnv ;
343 let { u_var = env_us env } ;
344 us <- readMutVar u_var ;
345 case splitUniqSupply us of { (us1,us2) -> do {
346 writeMutVar u_var us1 ;
349 newLocalName :: Name -> TcRnIf gbl lcl Name
350 newLocalName name -- Make a clone
351 = newUnique `thenM` \ uniq ->
352 returnM (mkInternalName uniq (nameOccName name) (getSrcLoc name))
356 %************************************************************************
360 %************************************************************************
363 traceTc, traceRn :: SDoc -> TcRn ()
364 traceRn = traceOptTcRn Opt_D_dump_rn_trace
365 traceTc = traceOptTcRn Opt_D_dump_tc_trace
366 traceSplice = traceOptTcRn Opt_D_dump_splices
369 traceIf :: SDoc -> TcRnIf m n ()
370 traceIf = traceOptIf Opt_D_dump_if_trace
371 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
374 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
375 traceOptIf flag doc = ifOptM flag $
376 ioToIOEnv (printForUser stderr alwaysQualify doc)
378 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
379 traceOptTcRn flag doc = ifOptM flag $ do
382 ; env0 <- tcInitTidyEnv
383 ; ctxt_msgs <- do_ctxt env0 ctxt
384 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
385 ; dumpTcRn real_doc }
387 dumpTcRn :: SDoc -> TcRn ()
388 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
389 ioToTcRn (printForUser stderr (mkPrintUnqualified rdr_env) doc) }
391 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
392 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
396 %************************************************************************
398 Typechecker global environment
400 %************************************************************************
403 getModule :: TcRn Module
404 getModule = do { env <- getGblEnv; return (tcg_mod env) }
406 setModule :: Module -> TcRn a -> TcRn a
407 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
409 tcIsHsBoot :: TcRn Bool
410 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
412 getGlobalRdrEnv :: TcRn GlobalRdrEnv
413 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
415 getImports :: TcRn ImportAvails
416 getImports = do { env <- getGblEnv; return (tcg_imports env) }
418 getFixityEnv :: TcRn FixityEnv
419 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
421 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
422 extendFixityEnv new_bit
423 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
424 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
426 getDefaultTys :: TcRn (Maybe [Type])
427 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
430 %************************************************************************
434 %************************************************************************
437 getSrcSpanM :: TcRn SrcSpan
438 -- Avoid clash with Name.getSrcLoc
439 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
441 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
442 setSrcSpan loc thing_inside
443 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
444 | otherwise = thing_inside -- Don't overwrite useful info with useless
446 addLocM :: (a -> TcM b) -> Located a -> TcM b
447 addLocM fn (L loc a) = setSrcSpan loc $ fn a
449 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
450 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
452 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
453 wrapLocFstM fn (L loc a) =
458 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
459 wrapLocSndM fn (L loc a) =
467 getErrsVar :: TcRn (TcRef Messages)
468 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
470 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
471 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
473 addErr :: Message -> TcRn ()
474 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
476 addLocErr :: Located e -> (e -> Message) -> TcRn ()
477 addLocErr (L loc e) fn = addErrAt loc (fn e)
479 addErrAt :: SrcSpan -> Message -> TcRn ()
480 addErrAt loc msg = addLongErrAt loc msg empty
482 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
483 addLongErrAt loc msg extra
484 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
485 errs_var <- getErrsVar ;
486 rdr_env <- getGlobalRdrEnv ;
487 let { err = mkLongErrMsg loc (mkPrintUnqualified rdr_env) msg extra } ;
488 (warns, errs) <- readMutVar errs_var ;
489 writeMutVar errs_var (warns, errs `snocBag` err) }
491 addErrs :: [(SrcSpan,Message)] -> TcRn ()
492 addErrs msgs = mappM_ add msgs
494 add (loc,msg) = addErrAt loc msg
496 addReport :: Message -> TcRn ()
497 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
499 addReportAt :: SrcSpan -> Message -> TcRn ()
501 = do { errs_var <- getErrsVar ;
502 rdr_env <- getGlobalRdrEnv ;
503 let { warn = mkWarnMsg loc (mkPrintUnqualified rdr_env) msg } ;
504 (warns, errs) <- readMutVar errs_var ;
505 writeMutVar errs_var (warns `snocBag` warn, errs) }
507 addWarn :: Message -> TcRn ()
508 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
510 addWarnAt :: SrcSpan -> Message -> TcRn ()
511 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
513 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
514 addLocWarn (L loc e) fn = addReportAt loc (fn e)
516 checkErr :: Bool -> Message -> TcRn ()
517 -- Add the error if the bool is False
518 checkErr ok msg = checkM ok (addErr msg)
520 warnIf :: Bool -> Message -> TcRn ()
521 warnIf True msg = addWarn msg
522 warnIf False msg = return ()
524 addMessages :: Messages -> TcRn ()
525 addMessages (m_warns, m_errs)
526 = do { errs_var <- getErrsVar ;
527 (warns, errs) <- readMutVar errs_var ;
528 writeMutVar errs_var (warns `unionBags` m_warns,
529 errs `unionBags` m_errs) }
531 discardWarnings :: TcRn a -> TcRn a
532 -- Ignore warnings inside the thing inside;
533 -- used to ignore-unused-variable warnings inside derived code
534 -- With -dppr-debug, the effects is switched off, so you can still see
535 -- what warnings derived code would give
536 discardWarnings thing_inside
537 | opt_PprStyle_Debug = thing_inside
539 = do { errs_var <- newMutVar emptyMessages
540 ; result <- setErrsVar errs_var thing_inside
541 ; (_warns, errs) <- readMutVar errs_var
542 ; addMessages (emptyBag, errs)
548 try_m :: TcRn r -> TcRn (Either Exception r)
549 -- Does try_m, with a debug-trace on failure
551 = do { mb_r <- tryM thing ;
553 Left exn -> do { traceTc (exn_msg exn); return mb_r }
554 Right r -> return mb_r }
556 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
558 -----------------------
559 recoverM :: TcRn r -- Recovery action; do this if the main one fails
560 -> TcRn r -- Main action: do this first
562 -- Errors in 'thing' are retained
563 recoverM recover thing
564 = do { mb_res <- try_m thing ;
567 Right res -> returnM res }
569 -----------------------
570 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
571 -- (tryTc m) executes m, and returns
572 -- Just r, if m succeeds (returning r)
573 -- Nothing, if m fails
574 -- It also returns all the errors and warnings accumulated by m
575 -- It always succeeds (never raises an exception)
577 = do { errs_var <- newMutVar emptyMessages ;
578 res <- try_m (setErrsVar errs_var m) ;
579 msgs <- readMutVar errs_var ;
580 return (msgs, case res of
582 Right val -> Just val)
583 -- The exception is always the IOEnv built-in
584 -- in exception; see IOEnv.failM
587 -----------------------
588 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
589 -- Run the thing, returning
590 -- Just r, if m succceeds with no error messages
591 -- Nothing, if m fails, or if it succeeds but has error messages
592 -- Either way, the messages are returned; even in the Just case
593 -- there might be warnings
595 = do { (msgs, res) <- tryTc thing
597 ; let errs_found = errorsFound dflags msgs
598 ; return (msgs, case res of
600 Just val | errs_found -> Nothing
601 | otherwise -> Just val)
604 -----------------------
605 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
606 -- Just like tryTcErrs, except that it ensures that the LIE
607 -- for the thing is propagated only if there are no errors
608 -- Hence it's restricted to the type-check monad
609 tryTcLIE thing_inside
610 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
612 Nothing -> return (msgs, Nothing)
613 Just val -> do { extendLIEs lie; return (msgs, Just val) }
616 -----------------------
617 tryTcLIE_ :: TcM r -> TcM r -> TcM r
618 -- (tryTcLIE_ r m) tries m;
619 -- if m succeeds with no error messages, it's the answer
620 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
621 tryTcLIE_ recover main
622 = do { (msgs, mb_res) <- tryTcLIE main
624 Just val -> do { addMessages msgs -- There might be warnings
626 Nothing -> recover -- Discard all msgs
629 -----------------------
630 checkNoErrs :: TcM r -> TcM r
631 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
632 -- If m fails then (checkNoErrsTc m) fails.
633 -- If m succeeds, it checks whether m generated any errors messages
634 -- (it might have recovered internally)
635 -- If so, it fails too.
636 -- Regardless, any errors generated by m are propagated to the enclosing context.
638 = do { (msgs, mb_res) <- tryTcLIE main
642 Just val -> return val
645 ifErrsM :: TcRn r -> TcRn r -> TcRn r
646 -- ifErrsM bale_out main
647 -- does 'bale_out' if there are errors in errors collection
648 -- otherwise does 'main'
649 ifErrsM bale_out normal
650 = do { errs_var <- getErrsVar ;
651 msgs <- readMutVar errs_var ;
653 if errorsFound dflags msgs then
658 failIfErrsM :: TcRn ()
659 -- Useful to avoid error cascades
660 failIfErrsM = ifErrsM failM (return ())
664 %************************************************************************
666 Context management and error message generation
669 %************************************************************************
672 getErrCtxt :: TcM ErrCtxt
673 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
675 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
676 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
678 addErrCtxt :: Message -> TcM a -> TcM a
679 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
681 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
682 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
684 -- Helper function for the above
685 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
686 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
687 env { tcl_ctxt = upd ctxt })
689 -- Conditionally add an error context
690 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
691 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
692 maybeAddErrCtxt Nothing thing_inside = thing_inside
694 popErrCtxt :: TcM a -> TcM a
695 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
697 getInstLoc :: InstOrigin -> TcM InstLoc
699 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
700 return (InstLoc origin loc (tcl_ctxt env)) }
702 addInstCtxt :: InstLoc -> TcM a -> TcM a
703 -- Add the SrcSpan and context from the first Inst in the list
704 -- (they all have similar locations)
705 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
706 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
709 The addErrTc functions add an error message, but do not cause failure.
710 The 'M' variants pass a TidyEnv that has already been used to
711 tidy up the message; we then use it to tidy the context messages
714 addErrTc :: Message -> TcM ()
715 addErrTc err_msg = do { env0 <- tcInitTidyEnv
716 ; addErrTcM (env0, err_msg) }
718 addErrsTc :: [Message] -> TcM ()
719 addErrsTc err_msgs = mappM_ addErrTc err_msgs
721 addErrTcM :: (TidyEnv, Message) -> TcM ()
722 addErrTcM (tidy_env, err_msg)
723 = do { ctxt <- getErrCtxt ;
725 add_err_tcm tidy_env err_msg loc ctxt }
728 The failWith functions add an error message and cause failure
731 failWithTc :: Message -> TcM a -- Add an error message and fail
733 = addErrTc err_msg >> failM
735 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
736 failWithTcM local_and_msg
737 = addErrTcM local_and_msg >> failM
739 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
740 checkTc True err = returnM ()
741 checkTc False err = failWithTc err
744 Warnings have no 'M' variant, nor failure
747 addWarnTc :: Message -> TcM ()
749 = do { ctxt <- getErrCtxt ;
750 env0 <- tcInitTidyEnv ;
751 ctxt_msgs <- do_ctxt env0 ctxt ;
752 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
754 warnTc :: Bool -> Message -> TcM ()
755 warnTc warn_if_true warn_msg
756 | warn_if_true = addWarnTc warn_msg
757 | otherwise = return ()
760 -----------------------------------
763 We initialise the "tidy-env", used for tidying types before printing,
764 by building a reverse map from the in-scope type variables to the
765 OccName that the programmer originally used for them
768 tcInitTidyEnv :: TcM TidyEnv
770 = do { lcl_env <- getLclEnv
771 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
772 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
774 ; return (foldl add emptyTidyEnv nm_tv_prs) }
776 add (env,subst) (name, tyvar)
777 = case tidyOccName env (nameOccName name) of
778 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
780 tyvar' = setTyVarName tyvar name'
781 name' = tidyNameOcc name occ'
784 -----------------------------------
785 Other helper functions
788 add_err_tcm tidy_env err_msg loc ctxt
789 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
790 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
794 do_ctxt tidy_env (c:cs)
795 = do { (tidy_env', m) <- c tidy_env ;
796 ms <- do_ctxt tidy_env' cs ;
799 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
800 | otherwise = take 3 ctxt
803 debugTc is useful for monadic debugging code
806 debugTc :: TcM () -> TcM ()
808 debugTc thing = thing
810 debugTc thing = return ()
814 %************************************************************************
816 Type constraints (the so-called LIE)
818 %************************************************************************
821 nextDFunIndex :: TcM Int -- Get the next dfun index
822 nextDFunIndex = do { env <- getGblEnv
823 ; let dfun_n_var = tcg_dfun_n env
824 ; n <- readMutVar dfun_n_var
825 ; writeMutVar dfun_n_var (n+1)
828 getLIEVar :: TcM (TcRef LIE)
829 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
831 setLIEVar :: TcRef LIE -> TcM a -> TcM a
832 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
834 getLIE :: TcM a -> TcM (a, [Inst])
835 -- (getLIE m) runs m, and returns the type constraints it generates
837 = do { lie_var <- newMutVar emptyLIE ;
838 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
840 lie <- readMutVar lie_var ;
841 return (res, lieToList lie) }
843 extendLIE :: Inst -> TcM ()
845 = do { lie_var <- getLIEVar ;
846 lie <- readMutVar lie_var ;
847 writeMutVar lie_var (inst `consLIE` lie) }
849 extendLIEs :: [Inst] -> TcM ()
853 = do { lie_var <- getLIEVar ;
854 lie <- readMutVar lie_var ;
855 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
859 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
860 -- Set the local type envt, but do *not* disturb other fields,
861 -- notably the lie_var
862 setLclTypeEnv lcl_env thing_inside
863 = updLclEnv upd thing_inside
865 upd env = env { tcl_env = tcl_env lcl_env,
866 tcl_tyvars = tcl_tyvars lcl_env }
870 %************************************************************************
872 Template Haskell context
874 %************************************************************************
877 recordThUse :: TcM ()
878 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
880 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
881 keepAliveTc n = do { env <- getGblEnv;
882 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
884 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
885 keepAliveSetTc ns = do { env <- getGblEnv;
886 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
888 getStage :: TcM ThStage
889 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
891 setStage :: ThStage -> TcM a -> TcM a
892 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
896 %************************************************************************
898 Stuff for the renamer's local env
900 %************************************************************************
903 getLocalRdrEnv :: RnM LocalRdrEnv
904 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
906 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
907 setLocalRdrEnv rdr_env thing_inside
908 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
912 %************************************************************************
914 Stuff for interface decls
916 %************************************************************************
919 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
920 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
922 if_tv_env = emptyOccEnv,
923 if_id_env = emptyOccEnv }
925 initIfaceTcRn :: IfG a -> TcRn a
926 initIfaceTcRn thing_inside
927 = do { tcg_env <- getGblEnv
928 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
929 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
930 ; setEnvs (if_env, ()) thing_inside }
932 initIfaceExtCore :: IfL a -> TcRn a
933 initIfaceExtCore thing_inside
934 = do { tcg_env <- getGblEnv
935 ; let { mod = tcg_mod tcg_env
936 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
937 ; if_env = IfGblEnv {
938 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
939 ; if_lenv = mkIfLclEnv mod doc
941 ; setEnvs (if_env, if_lenv) thing_inside }
943 initIfaceCheck :: HscEnv -> IfG a -> IO a
944 -- Used when checking the up-to-date-ness of the old Iface
945 -- Initialise the environment with no useful info at all
946 initIfaceCheck hsc_env do_this
947 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
948 ; initTcRnIf 'i' hsc_env gbl_env () do_this
951 initIfaceTc :: ModIface
952 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
953 -- Used when type-checking checking an up-to-date interface file
954 -- No type envt from the current module, but we do know the module dependencies
955 initIfaceTc iface do_this
956 = do { tc_env_var <- newMutVar emptyTypeEnv
957 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
958 ; if_lenv = mkIfLclEnv mod doc
960 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
963 mod = mi_module iface
964 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
966 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
967 -- Used when sucking in new Rules in SimplCore
968 -- We have available the type envt of the module being compiled, and we must use it
969 initIfaceRules hsc_env guts do_this
971 type_info = (mg_module guts, return (mg_types guts))
972 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
975 -- Run the thing; any exceptions just bubble out from here
976 ; initTcRnIf 'i' hsc_env gbl_env () do_this
979 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
980 initIfaceLcl mod loc_doc thing_inside
981 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
983 getIfModule :: IfL Module
984 getIfModule = do { env <- getLclEnv; return (if_mod env) }
987 failIfM :: Message -> IfL a
988 -- The Iface monad doesn't have a place to accumulate errors, so we
989 -- just fall over fast if one happens; it "shouldnt happen".
990 -- We use IfL here so that we can get context info out of the local env
992 = do { env <- getLclEnv
993 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
994 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
998 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
999 -- Run thing_inside in an interleaved thread.
1000 -- It shares everything with the parent thread, so this is DANGEROUS.
1002 -- It returns Nothing if the computation fails
1004 -- It's used for lazily type-checking interface
1005 -- signatures, which is pretty benign
1007 forkM_maybe doc thing_inside
1008 = do { unsafeInterleaveM $
1009 do { traceIf (text "Starting fork {" <+> doc)
1011 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1014 Right r -> do { traceIf (text "} ending fork" <+> doc)
1018 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1019 -- Otherwise we silently discard errors. Errors can legitimately
1020 -- happen when compiling interface signatures (see tcInterfaceSigs)
1021 ifOptM Opt_D_dump_if_trace
1022 (print_errs (hang (text "forkM failed:" <+> doc)
1023 4 (text (show exn))))
1025 ; traceIf (text "} ending fork (badly)" <+> doc)
1029 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
1031 forkM :: SDoc -> IfL a -> IfL a
1032 forkM doc thing_inside
1033 = do { mb_res <- forkM_maybe doc thing_inside
1034 ; return (case mb_res of
1035 Nothing -> pgmError "Cannot continue after interface file error"
1036 -- pprPanic "forkM" doc