2 % (c) The University of Glasgow 2006
12 #include "HsVersions.h"
14 import TcRnTypes -- Re-export all
15 import IOEnv -- Re-export all
22 import {-#SOURCE#-} TcEnv
25 import HsSyn hiding (LIE)
54 import Control.Exception
59 %************************************************************************
63 %************************************************************************
66 ioToTcRn :: IO r -> TcRn r
76 -> IO (Messages, Maybe r)
77 -- Nothing => error thrown by the thing inside
78 -- (error messages should have been printed already)
80 initTc hsc_env hsc_src mod do_this
81 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
82 tvs_var <- newIORef emptyVarSet ;
83 type_env_var <- newIORef emptyNameEnv ;
84 dfuns_var <- newIORef emptyNameSet ;
85 keep_var <- newIORef emptyNameSet ;
86 th_var <- newIORef False ;
87 dfun_n_var <- newIORef 1 ;
92 tcg_rdr_env = hsc_global_rdr_env hsc_env,
93 tcg_fix_env = emptyNameEnv,
94 tcg_default = Nothing,
95 tcg_type_env = hsc_global_type_env hsc_env,
96 tcg_type_env_var = type_env_var,
97 tcg_inst_env = emptyInstEnv,
98 tcg_fam_inst_env = emptyFamInstEnv,
99 tcg_inst_uses = dfuns_var,
100 tcg_th_used = th_var,
102 tcg_imports = emptyImportAvails,
104 tcg_rn_imports = Nothing,
105 tcg_rn_exports = Nothing,
106 tcg_rn_decls = Nothing,
107 tcg_binds = emptyLHsBinds,
108 tcg_deprecs = NoDeprecs,
113 tcg_dfun_n = dfun_n_var,
116 tcg_hmi = HaddockModInfo Nothing Nothing Nothing Nothing
120 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
122 tcl_rdr = emptyLocalRdrEnv,
123 tcl_th_ctxt = topStage,
124 tcl_arrow_ctxt = NoArrowCtxt,
125 tcl_env = emptyNameEnv,
126 tcl_tyvars = tvs_var,
127 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
131 -- OK, here's the business end!
132 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
133 addBreakpointBindings $
134 do { r <- tryM do_this
136 Right res -> return (Just res)
137 Left _ -> return Nothing } ;
139 -- Collect any error messages
140 msgs <- readIORef errs_var ;
142 let { dflags = hsc_dflags hsc_env
143 ; final_res | errorsFound dflags msgs = Nothing
144 | otherwise = maybe_res } ;
146 return (msgs, final_res)
149 initTcPrintErrors -- Used from the interactive loop only
154 initTcPrintErrors env mod todo = do
155 (msgs, res) <- initTc env HsSrcFile mod todo
156 printErrorsAndWarnings (hsc_dflags env) msgs
161 addBreakpointBindings :: TcM a -> TcM a
162 addBreakpointBindings thing_inside
164 = do { unique <- newUnique
165 ; let { var = mkInternalName unique (mkOccName tvName "a") noSrcLoc;
166 tyvar = mkTyVar var liftedTypeKind;
167 basicType extra = (FunTy intTy
168 (FunTy (mkListTy unitTy)
172 (FunTy (TyVarTy tyvar)
173 (TyVarTy tyvar)))))));
175 = Id.mkGlobalId VanillaGlobal breakpointJumpName
176 (basicType id) vanillaIdInfo;
178 = Id.mkGlobalId VanillaGlobal breakpointCondJumpName
179 (basicType (FunTy boolTy)) vanillaIdInfo
181 ; tcExtendIdEnv [breakpointJumpId, breakpointCondJumpId] thing_inside}
187 %************************************************************************
191 %************************************************************************
195 initTcRnIf :: Char -- Tag for unique supply
200 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
201 = do { us <- mkSplitUniqSupply uniq_tag ;
202 ; us_var <- newIORef us ;
204 ; let { env = Env { env_top = hsc_env,
207 env_lcl = lcl_env } }
209 ; runIOEnv env thing_inside
213 %************************************************************************
217 %************************************************************************
220 getTopEnv :: TcRnIf gbl lcl HscEnv
221 getTopEnv = do { env <- getEnv; return (env_top env) }
223 getGblEnv :: TcRnIf gbl lcl gbl
224 getGblEnv = do { env <- getEnv; return (env_gbl env) }
226 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
227 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
228 env { env_gbl = upd gbl })
230 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
231 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
233 getLclEnv :: TcRnIf gbl lcl lcl
234 getLclEnv = do { env <- getEnv; return (env_lcl env) }
236 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
237 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
238 env { env_lcl = upd lcl })
240 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
241 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
243 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
244 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
246 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
247 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
254 getDOpts :: TcRnIf gbl lcl DynFlags
255 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
257 doptM :: DynFlag -> TcRnIf gbl lcl Bool
258 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
260 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
261 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
262 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
264 unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
265 unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
266 env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
268 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
269 ifOptM flag thing_inside = do { b <- doptM flag;
270 if b then thing_inside else return () }
272 getGhcMode :: TcRnIf gbl lcl GhcMode
273 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
277 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
278 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
280 getEps :: TcRnIf gbl lcl ExternalPackageState
281 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
283 -- Updating the EPS. This should be an atomic operation.
284 -- Note the delicate 'seq' which forces the EPS before putting it in the
285 -- variable. Otherwise what happens is that we get
286 -- write eps_var (....(unsafeRead eps_var)....)
287 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
288 -- we make the unsafeRead happen before we update the variable.
290 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
292 updateEps upd_fn = do { traceIf (text "updating EPS")
293 ; eps_var <- getEpsVar
294 ; eps <- readMutVar eps_var
295 ; let { (eps', val) = upd_fn eps }
296 ; seq eps' (writeMutVar eps_var eps')
299 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
301 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
302 ; eps_var <- getEpsVar
303 ; eps <- readMutVar eps_var
304 ; let { eps' = upd_fn eps }
305 ; seq eps' (writeMutVar eps_var eps') }
307 getHpt :: TcRnIf gbl lcl HomePackageTable
308 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
310 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
311 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
312 ; return (eps, hsc_HPT env) }
315 %************************************************************************
319 %************************************************************************
322 newUnique :: TcRnIf gbl lcl Unique
324 = do { env <- getEnv ;
325 let { u_var = env_us env } ;
326 us <- readMutVar u_var ;
327 case splitUniqSupply us of { (us1,_) -> do {
328 writeMutVar u_var us1 ;
329 return $! uniqFromSupply us }}}
330 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
331 -- a chain of unevaluated supplies behind.
332 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
333 -- throw away one half of the new split supply. This is safe because this
334 -- is the only place we use that unique. Using the other half of the split
335 -- supply is safer, but slower.
337 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
339 = do { env <- getEnv ;
340 let { u_var = env_us env } ;
341 us <- readMutVar u_var ;
342 case splitUniqSupply us of { (us1,us2) -> do {
343 writeMutVar u_var us1 ;
346 newLocalName :: Name -> TcRnIf gbl lcl Name
347 newLocalName name -- Make a clone
348 = do { uniq <- newUnique
349 ; return (mkInternalName uniq (nameOccName name) (getSrcLoc name)) }
351 newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
352 newSysLocalIds fs tys
353 = do { us <- newUniqueSupply
354 ; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
358 %************************************************************************
362 %************************************************************************
365 traceTc, traceRn :: SDoc -> TcRn ()
366 traceRn = traceOptTcRn Opt_D_dump_rn_trace
367 traceTc = traceOptTcRn Opt_D_dump_tc_trace
368 traceSplice = traceOptTcRn Opt_D_dump_splices
371 traceIf :: SDoc -> TcRnIf m n ()
372 traceIf = traceOptIf Opt_D_dump_if_trace
373 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
376 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
377 traceOptIf flag doc = ifOptM flag $
378 ioToIOEnv (printForUser stderr alwaysQualify doc)
380 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
381 traceOptTcRn flag doc = ifOptM flag $ do
384 ; env0 <- tcInitTidyEnv
385 ; ctxt_msgs <- do_ctxt env0 ctxt
386 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
387 ; dumpTcRn real_doc }
389 dumpTcRn :: SDoc -> TcRn ()
390 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
391 ioToTcRn (printForUser stderr (mkPrintUnqualified rdr_env) doc) }
393 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
394 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
398 %************************************************************************
400 Typechecker global environment
402 %************************************************************************
405 getModule :: TcRn Module
406 getModule = do { env <- getGblEnv; return (tcg_mod env) }
408 setModule :: Module -> TcRn a -> TcRn a
409 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
411 tcIsHsBoot :: TcRn Bool
412 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
414 getGlobalRdrEnv :: TcRn GlobalRdrEnv
415 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
417 getImports :: TcRn ImportAvails
418 getImports = do { env <- getGblEnv; return (tcg_imports env) }
420 getFixityEnv :: TcRn FixityEnv
421 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
423 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
424 extendFixityEnv new_bit
425 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
426 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
428 getDefaultTys :: TcRn (Maybe [Type])
429 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
432 %************************************************************************
436 %************************************************************************
439 getSrcSpanM :: TcRn SrcSpan
440 -- Avoid clash with Name.getSrcLoc
441 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
443 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
444 setSrcSpan loc thing_inside
445 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
446 | otherwise = thing_inside -- Don't overwrite useful info with useless
448 addLocM :: (a -> TcM b) -> Located a -> TcM b
449 addLocM fn (L loc a) = setSrcSpan loc $ fn a
451 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
452 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
454 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
455 wrapLocFstM fn (L loc a) =
460 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
461 wrapLocSndM fn (L loc a) =
469 getErrsVar :: TcRn (TcRef Messages)
470 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
472 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
473 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
475 addErr :: Message -> TcRn ()
476 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
478 addLocErr :: Located e -> (e -> Message) -> TcRn ()
479 addLocErr (L loc e) fn = addErrAt loc (fn e)
481 addErrAt :: SrcSpan -> Message -> TcRn ()
482 addErrAt loc msg = addLongErrAt loc msg empty
484 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
485 addLongErrAt loc msg extra
486 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
487 errs_var <- getErrsVar ;
488 rdr_env <- getGlobalRdrEnv ;
489 let { err = mkLongErrMsg loc (mkPrintUnqualified rdr_env) msg extra } ;
490 (warns, errs) <- readMutVar errs_var ;
491 writeMutVar errs_var (warns, errs `snocBag` err) }
493 addErrs :: [(SrcSpan,Message)] -> TcRn ()
494 addErrs msgs = mappM_ add msgs
496 add (loc,msg) = addErrAt loc msg
498 addReport :: Message -> TcRn ()
499 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
501 addReportAt :: SrcSpan -> Message -> TcRn ()
503 = do { errs_var <- getErrsVar ;
504 rdr_env <- getGlobalRdrEnv ;
505 let { warn = mkWarnMsg loc (mkPrintUnqualified rdr_env) msg } ;
506 (warns, errs) <- readMutVar errs_var ;
507 writeMutVar errs_var (warns `snocBag` warn, errs) }
509 addWarn :: Message -> TcRn ()
510 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
512 addWarnAt :: SrcSpan -> Message -> TcRn ()
513 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
515 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
516 addLocWarn (L loc e) fn = addReportAt loc (fn e)
518 checkErr :: Bool -> Message -> TcRn ()
519 -- Add the error if the bool is False
520 checkErr ok msg = checkM ok (addErr msg)
522 warnIf :: Bool -> Message -> TcRn ()
523 warnIf True msg = addWarn msg
524 warnIf False msg = return ()
526 addMessages :: Messages -> TcRn ()
527 addMessages (m_warns, m_errs)
528 = do { errs_var <- getErrsVar ;
529 (warns, errs) <- readMutVar errs_var ;
530 writeMutVar errs_var (warns `unionBags` m_warns,
531 errs `unionBags` m_errs) }
533 discardWarnings :: TcRn a -> TcRn a
534 -- Ignore warnings inside the thing inside;
535 -- used to ignore-unused-variable warnings inside derived code
536 -- With -dppr-debug, the effects is switched off, so you can still see
537 -- what warnings derived code would give
538 discardWarnings thing_inside
539 | opt_PprStyle_Debug = thing_inside
541 = do { errs_var <- newMutVar emptyMessages
542 ; result <- setErrsVar errs_var thing_inside
543 ; (_warns, errs) <- readMutVar errs_var
544 ; addMessages (emptyBag, errs)
550 try_m :: TcRn r -> TcRn (Either Exception r)
551 -- Does try_m, with a debug-trace on failure
553 = do { mb_r <- tryM thing ;
555 Left exn -> do { traceTc (exn_msg exn); return mb_r }
556 Right r -> return mb_r }
558 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
560 -----------------------
561 recoverM :: TcRn r -- Recovery action; do this if the main one fails
562 -> TcRn r -- Main action: do this first
564 -- Errors in 'thing' are retained
565 recoverM recover thing
566 = do { mb_res <- try_m thing ;
569 Right res -> returnM res }
571 -----------------------
572 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
573 -- (tryTc m) executes m, and returns
574 -- Just r, if m succeeds (returning r)
575 -- Nothing, if m fails
576 -- It also returns all the errors and warnings accumulated by m
577 -- It always succeeds (never raises an exception)
579 = do { errs_var <- newMutVar emptyMessages ;
580 res <- try_m (setErrsVar errs_var m) ;
581 msgs <- readMutVar errs_var ;
582 return (msgs, case res of
584 Right val -> Just val)
585 -- The exception is always the IOEnv built-in
586 -- in exception; see IOEnv.failM
589 -----------------------
590 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
591 -- Run the thing, returning
592 -- Just r, if m succceeds with no error messages
593 -- Nothing, if m fails, or if it succeeds but has error messages
594 -- Either way, the messages are returned; even in the Just case
595 -- there might be warnings
597 = do { (msgs, res) <- tryTc thing
599 ; let errs_found = errorsFound dflags msgs
600 ; return (msgs, case res of
602 Just val | errs_found -> Nothing
603 | otherwise -> Just val)
606 -----------------------
607 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
608 -- Just like tryTcErrs, except that it ensures that the LIE
609 -- for the thing is propagated only if there are no errors
610 -- Hence it's restricted to the type-check monad
611 tryTcLIE thing_inside
612 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
614 Nothing -> return (msgs, Nothing)
615 Just val -> do { extendLIEs lie; return (msgs, Just val) }
618 -----------------------
619 tryTcLIE_ :: TcM r -> TcM r -> TcM r
620 -- (tryTcLIE_ r m) tries m;
621 -- if m succeeds with no error messages, it's the answer
622 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
623 tryTcLIE_ recover main
624 = do { (msgs, mb_res) <- tryTcLIE main
626 Just val -> do { addMessages msgs -- There might be warnings
628 Nothing -> recover -- Discard all msgs
631 -----------------------
632 checkNoErrs :: TcM r -> TcM r
633 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
634 -- If m fails then (checkNoErrsTc m) fails.
635 -- If m succeeds, it checks whether m generated any errors messages
636 -- (it might have recovered internally)
637 -- If so, it fails too.
638 -- Regardless, any errors generated by m are propagated to the enclosing context.
640 = do { (msgs, mb_res) <- tryTcLIE main
644 Just val -> return val
647 ifErrsM :: TcRn r -> TcRn r -> TcRn r
648 -- ifErrsM bale_out main
649 -- does 'bale_out' if there are errors in errors collection
650 -- otherwise does 'main'
651 ifErrsM bale_out normal
652 = do { errs_var <- getErrsVar ;
653 msgs <- readMutVar errs_var ;
655 if errorsFound dflags msgs then
660 failIfErrsM :: TcRn ()
661 -- Useful to avoid error cascades
662 failIfErrsM = ifErrsM failM (return ())
666 %************************************************************************
668 Context management and error message generation
671 %************************************************************************
674 getErrCtxt :: TcM ErrCtxt
675 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
677 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
678 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
680 addErrCtxt :: Message -> TcM a -> TcM a
681 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
683 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
684 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
686 -- Helper function for the above
687 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
688 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
689 env { tcl_ctxt = upd ctxt })
691 -- Conditionally add an error context
692 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
693 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
694 maybeAddErrCtxt Nothing thing_inside = thing_inside
696 popErrCtxt :: TcM a -> TcM a
697 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
699 getInstLoc :: InstOrigin -> TcM InstLoc
701 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
702 return (InstLoc origin loc (tcl_ctxt env)) }
704 addInstCtxt :: InstLoc -> TcM a -> TcM a
705 -- Add the SrcSpan and context from the first Inst in the list
706 -- (they all have similar locations)
707 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
708 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
711 The addErrTc functions add an error message, but do not cause failure.
712 The 'M' variants pass a TidyEnv that has already been used to
713 tidy up the message; we then use it to tidy the context messages
716 addErrTc :: Message -> TcM ()
717 addErrTc err_msg = do { env0 <- tcInitTidyEnv
718 ; addErrTcM (env0, err_msg) }
720 addErrsTc :: [Message] -> TcM ()
721 addErrsTc err_msgs = mappM_ addErrTc err_msgs
723 addErrTcM :: (TidyEnv, Message) -> TcM ()
724 addErrTcM (tidy_env, err_msg)
725 = do { ctxt <- getErrCtxt ;
727 add_err_tcm tidy_env err_msg loc ctxt }
730 The failWith functions add an error message and cause failure
733 failWithTc :: Message -> TcM a -- Add an error message and fail
735 = addErrTc err_msg >> failM
737 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
738 failWithTcM local_and_msg
739 = addErrTcM local_and_msg >> failM
741 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
742 checkTc True err = returnM ()
743 checkTc False err = failWithTc err
746 Warnings have no 'M' variant, nor failure
749 addWarnTc :: Message -> TcM ()
751 = do { ctxt <- getErrCtxt ;
752 env0 <- tcInitTidyEnv ;
753 ctxt_msgs <- do_ctxt env0 ctxt ;
754 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
756 warnTc :: Bool -> Message -> TcM ()
757 warnTc warn_if_true warn_msg
758 | warn_if_true = addWarnTc warn_msg
759 | otherwise = return ()
762 -----------------------------------
765 We initialise the "tidy-env", used for tidying types before printing,
766 by building a reverse map from the in-scope type variables to the
767 OccName that the programmer originally used for them
770 tcInitTidyEnv :: TcM TidyEnv
772 = do { lcl_env <- getLclEnv
773 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
774 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
776 ; return (foldl add emptyTidyEnv nm_tv_prs) }
778 add (env,subst) (name, tyvar)
779 = case tidyOccName env (nameOccName name) of
780 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
782 tyvar' = setTyVarName tyvar name'
783 name' = tidyNameOcc name occ'
786 -----------------------------------
787 Other helper functions
790 add_err_tcm tidy_env err_msg loc ctxt
791 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
792 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
796 do_ctxt tidy_env (c:cs)
797 = do { (tidy_env', m) <- c tidy_env ;
798 ms <- do_ctxt tidy_env' cs ;
801 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
802 | otherwise = take 3 ctxt
805 debugTc is useful for monadic debugging code
808 debugTc :: TcM () -> TcM ()
810 debugTc thing = thing
812 debugTc thing = return ()
816 %************************************************************************
818 Type constraints (the so-called LIE)
820 %************************************************************************
823 nextDFunIndex :: TcM Int -- Get the next dfun index
824 nextDFunIndex = do { env <- getGblEnv
825 ; let dfun_n_var = tcg_dfun_n env
826 ; n <- readMutVar dfun_n_var
827 ; writeMutVar dfun_n_var (n+1)
830 getLIEVar :: TcM (TcRef LIE)
831 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
833 setLIEVar :: TcRef LIE -> TcM a -> TcM a
834 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
836 getLIE :: TcM a -> TcM (a, [Inst])
837 -- (getLIE m) runs m, and returns the type constraints it generates
839 = do { lie_var <- newMutVar emptyLIE ;
840 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
842 lie <- readMutVar lie_var ;
843 return (res, lieToList lie) }
845 extendLIE :: Inst -> TcM ()
847 = do { lie_var <- getLIEVar ;
848 lie <- readMutVar lie_var ;
849 writeMutVar lie_var (inst `consLIE` lie) }
851 extendLIEs :: [Inst] -> TcM ()
855 = do { lie_var <- getLIEVar ;
856 lie <- readMutVar lie_var ;
857 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
861 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
862 -- Set the local type envt, but do *not* disturb other fields,
863 -- notably the lie_var
864 setLclTypeEnv lcl_env thing_inside
865 = updLclEnv upd thing_inside
867 upd env = env { tcl_env = tcl_env lcl_env,
868 tcl_tyvars = tcl_tyvars lcl_env }
872 %************************************************************************
874 Template Haskell context
876 %************************************************************************
879 recordThUse :: TcM ()
880 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
882 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
883 keepAliveTc n = do { env <- getGblEnv;
884 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
886 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
887 keepAliveSetTc ns = do { env <- getGblEnv;
888 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
890 getStage :: TcM ThStage
891 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
893 setStage :: ThStage -> TcM a -> TcM a
894 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
898 %************************************************************************
900 Stuff for the renamer's local env
902 %************************************************************************
905 getLocalRdrEnv :: RnM LocalRdrEnv
906 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
908 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
909 setLocalRdrEnv rdr_env thing_inside
910 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
914 %************************************************************************
916 Stuff for interface decls
918 %************************************************************************
921 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
922 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
924 if_tv_env = emptyOccEnv,
925 if_id_env = emptyOccEnv }
927 initIfaceTcRn :: IfG a -> TcRn a
928 initIfaceTcRn thing_inside
929 = do { tcg_env <- getGblEnv
930 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
931 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
932 ; setEnvs (if_env, ()) thing_inside }
934 initIfaceExtCore :: IfL a -> TcRn a
935 initIfaceExtCore thing_inside
936 = do { tcg_env <- getGblEnv
937 ; let { mod = tcg_mod tcg_env
938 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
939 ; if_env = IfGblEnv {
940 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
941 ; if_lenv = mkIfLclEnv mod doc
943 ; setEnvs (if_env, if_lenv) thing_inside }
945 initIfaceCheck :: HscEnv -> IfG a -> IO a
946 -- Used when checking the up-to-date-ness of the old Iface
947 -- Initialise the environment with no useful info at all
948 initIfaceCheck hsc_env do_this
949 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
950 ; initTcRnIf 'i' hsc_env gbl_env () do_this
953 initIfaceTc :: ModIface
954 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
955 -- Used when type-checking checking an up-to-date interface file
956 -- No type envt from the current module, but we do know the module dependencies
957 initIfaceTc iface do_this
958 = do { tc_env_var <- newMutVar emptyTypeEnv
959 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
960 ; if_lenv = mkIfLclEnv mod doc
962 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
965 mod = mi_module iface
966 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
968 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
969 -- Used when sucking in new Rules in SimplCore
970 -- We have available the type envt of the module being compiled, and we must use it
971 initIfaceRules hsc_env guts do_this
973 type_info = (mg_module guts, return (mg_types guts))
974 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
977 -- Run the thing; any exceptions just bubble out from here
978 ; initTcRnIf 'i' hsc_env gbl_env () do_this
981 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
982 initIfaceLcl mod loc_doc thing_inside
983 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
985 getIfModule :: IfL Module
986 getIfModule = do { env <- getLclEnv; return (if_mod env) }
989 failIfM :: Message -> IfL a
990 -- The Iface monad doesn't have a place to accumulate errors, so we
991 -- just fall over fast if one happens; it "shouldnt happen".
992 -- We use IfL here so that we can get context info out of the local env
994 = do { env <- getLclEnv
995 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
996 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
1000 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1001 -- Run thing_inside in an interleaved thread.
1002 -- It shares everything with the parent thread, so this is DANGEROUS.
1004 -- It returns Nothing if the computation fails
1006 -- It's used for lazily type-checking interface
1007 -- signatures, which is pretty benign
1009 forkM_maybe doc thing_inside
1010 = do { unsafeInterleaveM $
1011 do { traceIf (text "Starting fork {" <+> doc)
1013 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1016 Right r -> do { traceIf (text "} ending fork" <+> doc)
1020 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1021 -- Otherwise we silently discard errors. Errors can legitimately
1022 -- happen when compiling interface signatures (see tcInterfaceSigs)
1023 ifOptM Opt_D_dump_if_trace
1024 (print_errs (hang (text "forkM failed:" <+> doc)
1025 4 (text (show exn))))
1027 ; traceIf (text "} ending fork (badly)" <+> doc)
1031 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
1033 forkM :: SDoc -> IfL a -> IfL a
1034 forkM doc thing_inside
1035 = do { mb_res <- forkM_maybe doc thing_inside
1036 ; return (case mb_res of
1037 Nothing -> pgmError "Cannot continue after interface file error"
1038 -- pprPanic "forkM" doc