2 % (c) The University of Glasgow 2006
12 #include "HsVersions.h"
14 import TcRnTypes -- Re-export all
15 import IOEnv -- Re-export all
17 #if defined(GHCI) && defined(BREAKPOINT)
29 import HsSyn hiding (LIE)
59 import Control.Exception
64 %************************************************************************
68 %************************************************************************
71 ioToTcRn :: IO r -> TcRn r
80 -> IO (Messages, Maybe r)
81 -- Nothing => error thrown by the thing inside
82 -- (error messages should have been printed already)
84 initTc hsc_env hsc_src mod do_this
85 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
86 tvs_var <- newIORef emptyVarSet ;
87 type_env_var <- newIORef emptyNameEnv ;
88 dfuns_var <- newIORef emptyNameSet ;
89 keep_var <- newIORef emptyNameSet ;
90 th_var <- newIORef False ;
91 dfun_n_var <- newIORef 1 ;
96 tcg_rdr_env = hsc_global_rdr_env hsc_env,
97 tcg_fix_env = emptyNameEnv,
98 tcg_default = Nothing,
99 tcg_type_env = hsc_global_type_env hsc_env,
100 tcg_type_env_var = type_env_var,
101 tcg_inst_env = emptyInstEnv,
102 tcg_fam_inst_env = emptyFamInstEnv,
103 tcg_inst_uses = dfuns_var,
104 tcg_th_used = th_var,
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,
117 tcg_dfun_n = dfun_n_var,
120 tcg_hmi = HaddockModInfo Nothing Nothing Nothing Nothing
124 tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
126 tcl_rdr = emptyLocalRdrEnv,
127 tcl_th_ctxt = topStage,
128 tcl_arrow_ctxt = NoArrowCtxt,
129 tcl_env = emptyNameEnv,
130 tcl_tyvars = tvs_var,
131 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
135 -- OK, here's the business end!
136 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
137 addBreakpointBindings $
138 do { r <- tryM do_this
140 Right res -> return (Just res)
141 Left _ -> return Nothing } ;
143 -- Collect any error messages
144 msgs <- readIORef errs_var ;
146 let { dflags = hsc_dflags hsc_env
147 ; final_res | errorsFound dflags msgs = Nothing
148 | otherwise = maybe_res } ;
150 return (msgs, final_res)
153 init_imports = emptyImportAvails {imp_env = unitUFM (moduleName mod) []}
154 -- Initialise tcg_imports with an empty set of bindings for
155 -- this module, so that if we see 'module M' in the export
156 -- list, and there are no bindings in M, we don't bleat
157 -- "unknown module M".
159 initTcPrintErrors -- Used from the interactive loop only
164 initTcPrintErrors env mod todo = do
165 (msgs, res) <- initTc env HsSrcFile mod todo
166 printErrorsAndWarnings (hsc_dflags env) msgs
171 addBreakpointBindings :: TcM a -> TcM a
172 addBreakpointBindings thing_inside
173 #if defined(GHCI) && defined(BREAKPOINT)
174 = do { unique <- newUnique
175 ; let { var = mkInternalName unique (mkOccName tvName "a") noSrcLoc;
176 tyvar = mkTyVar var liftedTypeKind;
177 basicType extra = (FunTy intTy
178 (FunTy (mkListTy unitTy)
182 (FunTy (TyVarTy tyvar)
183 (TyVarTy tyvar)))))));
185 = mkGlobalId VanillaGlobal breakpointJumpName
186 (basicType id) vanillaIdInfo;
188 = mkGlobalId VanillaGlobal breakpointCondJumpName
189 (basicType (FunTy boolTy)) vanillaIdInfo
191 ; tcExtendIdEnv [breakpointJumpId, breakpointCondJumpId] thing_inside}
197 %************************************************************************
201 %************************************************************************
205 initTcRnIf :: Char -- Tag for unique supply
210 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
211 = do { us <- mkSplitUniqSupply uniq_tag ;
212 ; us_var <- newIORef us ;
214 ; let { env = Env { env_top = hsc_env,
217 env_lcl = lcl_env } }
219 ; runIOEnv env thing_inside
223 %************************************************************************
227 %************************************************************************
230 getTopEnv :: TcRnIf gbl lcl HscEnv
231 getTopEnv = do { env <- getEnv; return (env_top env) }
233 getGblEnv :: TcRnIf gbl lcl gbl
234 getGblEnv = do { env <- getEnv; return (env_gbl env) }
236 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
237 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
238 env { env_gbl = upd gbl })
240 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
241 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
243 getLclEnv :: TcRnIf gbl lcl lcl
244 getLclEnv = do { env <- getEnv; return (env_lcl env) }
246 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
247 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
248 env { env_lcl = upd lcl })
250 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
251 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
253 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
254 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
256 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
257 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
264 getDOpts :: TcRnIf gbl lcl DynFlags
265 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
267 doptM :: DynFlag -> TcRnIf gbl lcl Bool
268 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
270 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
271 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
272 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
274 unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
275 unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
276 env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
278 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
279 ifOptM flag thing_inside = do { b <- doptM flag;
280 if b then thing_inside else return () }
282 getGhcMode :: TcRnIf gbl lcl GhcMode
283 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
287 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
288 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
290 getEps :: TcRnIf gbl lcl ExternalPackageState
291 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
293 -- Updating the EPS. This should be an atomic operation.
294 -- Note the delicate 'seq' which forces the EPS before putting it in the
295 -- variable. Otherwise what happens is that we get
296 -- write eps_var (....(unsafeRead eps_var)....)
297 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
298 -- we make the unsafeRead happen before we update the variable.
300 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
302 updateEps upd_fn = do { traceIf (text "updating EPS")
303 ; eps_var <- getEpsVar
304 ; eps <- readMutVar eps_var
305 ; let { (eps', val) = upd_fn eps }
306 ; seq eps' (writeMutVar eps_var eps')
309 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
311 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
312 ; eps_var <- getEpsVar
313 ; eps <- readMutVar eps_var
314 ; let { eps' = upd_fn eps }
315 ; seq eps' (writeMutVar eps_var eps') }
317 getHpt :: TcRnIf gbl lcl HomePackageTable
318 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
320 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
321 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
322 ; return (eps, hsc_HPT env) }
325 %************************************************************************
329 %************************************************************************
332 newUnique :: TcRnIf gbl lcl Unique
334 = do { env <- getEnv ;
335 let { u_var = env_us env } ;
336 us <- readMutVar u_var ;
337 case splitUniqSupply us of { (us1,_) -> do {
338 writeMutVar u_var us1 ;
339 return $! uniqFromSupply us }}}
340 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
341 -- a chain of unevaluated supplies behind.
342 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
343 -- throw away one half of the new split supply. This is safe because this
344 -- is the only place we use that unique. Using the other half of the split
345 -- supply is safer, but slower.
347 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
349 = do { env <- getEnv ;
350 let { u_var = env_us env } ;
351 us <- readMutVar u_var ;
352 case splitUniqSupply us of { (us1,us2) -> do {
353 writeMutVar u_var us1 ;
356 newLocalName :: Name -> TcRnIf gbl lcl Name
357 newLocalName name -- Make a clone
358 = do { uniq <- newUnique
359 ; return (mkInternalName uniq (nameOccName name) (getSrcLoc name)) }
361 newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
362 newSysLocalIds fs tys
363 = do { us <- newUniqueSupply
364 ; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
368 %************************************************************************
372 %************************************************************************
375 traceTc, traceRn :: SDoc -> TcRn ()
376 traceRn = traceOptTcRn Opt_D_dump_rn_trace
377 traceTc = traceOptTcRn Opt_D_dump_tc_trace
378 traceSplice = traceOptTcRn Opt_D_dump_splices
381 traceIf :: SDoc -> TcRnIf m n ()
382 traceIf = traceOptIf Opt_D_dump_if_trace
383 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
386 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
387 traceOptIf flag doc = ifOptM flag $
388 ioToIOEnv (printForUser stderr alwaysQualify doc)
390 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
391 traceOptTcRn flag doc = ifOptM flag $ do
394 ; env0 <- tcInitTidyEnv
395 ; ctxt_msgs <- do_ctxt env0 ctxt
396 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
397 ; dumpTcRn real_doc }
399 dumpTcRn :: SDoc -> TcRn ()
400 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
401 ioToTcRn (printForUser stderr (mkPrintUnqualified rdr_env) doc) }
403 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
404 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
408 %************************************************************************
410 Typechecker global environment
412 %************************************************************************
415 getModule :: TcRn Module
416 getModule = do { env <- getGblEnv; return (tcg_mod env) }
418 setModule :: Module -> TcRn a -> TcRn a
419 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
421 tcIsHsBoot :: TcRn Bool
422 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
424 getGlobalRdrEnv :: TcRn GlobalRdrEnv
425 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
427 getImports :: TcRn ImportAvails
428 getImports = do { env <- getGblEnv; return (tcg_imports env) }
430 getFixityEnv :: TcRn FixityEnv
431 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
433 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
434 extendFixityEnv new_bit
435 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
436 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
438 getDefaultTys :: TcRn (Maybe [Type])
439 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
442 %************************************************************************
446 %************************************************************************
449 getSrcSpanM :: TcRn SrcSpan
450 -- Avoid clash with Name.getSrcLoc
451 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
453 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
454 setSrcSpan loc thing_inside
455 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
456 | otherwise = thing_inside -- Don't overwrite useful info with useless
458 addLocM :: (a -> TcM b) -> Located a -> TcM b
459 addLocM fn (L loc a) = setSrcSpan loc $ fn a
461 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
462 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
464 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
465 wrapLocFstM fn (L loc a) =
470 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
471 wrapLocSndM fn (L loc a) =
479 getErrsVar :: TcRn (TcRef Messages)
480 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
482 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
483 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
485 addErr :: Message -> TcRn ()
486 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
488 addLocErr :: Located e -> (e -> Message) -> TcRn ()
489 addLocErr (L loc e) fn = addErrAt loc (fn e)
491 addErrAt :: SrcSpan -> Message -> TcRn ()
492 addErrAt loc msg = addLongErrAt loc msg empty
494 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
495 addLongErrAt loc msg extra
496 = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
497 errs_var <- getErrsVar ;
498 rdr_env <- getGlobalRdrEnv ;
499 let { err = mkLongErrMsg loc (mkPrintUnqualified rdr_env) msg extra } ;
500 (warns, errs) <- readMutVar errs_var ;
501 writeMutVar errs_var (warns, errs `snocBag` err) }
503 addErrs :: [(SrcSpan,Message)] -> TcRn ()
504 addErrs msgs = mappM_ add msgs
506 add (loc,msg) = addErrAt loc msg
508 addReport :: Message -> TcRn ()
509 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
511 addReportAt :: SrcSpan -> Message -> TcRn ()
513 = do { errs_var <- getErrsVar ;
514 rdr_env <- getGlobalRdrEnv ;
515 let { warn = mkWarnMsg loc (mkPrintUnqualified rdr_env) msg } ;
516 (warns, errs) <- readMutVar errs_var ;
517 writeMutVar errs_var (warns `snocBag` warn, errs) }
519 addWarn :: Message -> TcRn ()
520 addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
522 addWarnAt :: SrcSpan -> Message -> TcRn ()
523 addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
525 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
526 addLocWarn (L loc e) fn = addReportAt loc (fn e)
528 checkErr :: Bool -> Message -> TcRn ()
529 -- Add the error if the bool is False
530 checkErr ok msg = checkM ok (addErr msg)
532 warnIf :: Bool -> Message -> TcRn ()
533 warnIf True msg = addWarn msg
534 warnIf False msg = return ()
536 addMessages :: Messages -> TcRn ()
537 addMessages (m_warns, m_errs)
538 = do { errs_var <- getErrsVar ;
539 (warns, errs) <- readMutVar errs_var ;
540 writeMutVar errs_var (warns `unionBags` m_warns,
541 errs `unionBags` m_errs) }
543 discardWarnings :: TcRn a -> TcRn a
544 -- Ignore warnings inside the thing inside;
545 -- used to ignore-unused-variable warnings inside derived code
546 -- With -dppr-debug, the effects is switched off, so you can still see
547 -- what warnings derived code would give
548 discardWarnings thing_inside
549 | opt_PprStyle_Debug = thing_inside
551 = do { errs_var <- newMutVar emptyMessages
552 ; result <- setErrsVar errs_var thing_inside
553 ; (_warns, errs) <- readMutVar errs_var
554 ; addMessages (emptyBag, errs)
560 try_m :: TcRn r -> TcRn (Either Exception r)
561 -- Does try_m, with a debug-trace on failure
563 = do { mb_r <- tryM thing ;
565 Left exn -> do { traceTc (exn_msg exn); return mb_r }
566 Right r -> return mb_r }
568 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
570 -----------------------
571 recoverM :: TcRn r -- Recovery action; do this if the main one fails
572 -> TcRn r -- Main action: do this first
574 -- Errors in 'thing' are retained
575 recoverM recover thing
576 = do { mb_res <- try_m thing ;
579 Right res -> returnM res }
581 -----------------------
582 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
583 -- (tryTc m) executes m, and returns
584 -- Just r, if m succeeds (returning r)
585 -- Nothing, if m fails
586 -- It also returns all the errors and warnings accumulated by m
587 -- It always succeeds (never raises an exception)
589 = do { errs_var <- newMutVar emptyMessages ;
590 res <- try_m (setErrsVar errs_var m) ;
591 msgs <- readMutVar errs_var ;
592 return (msgs, case res of
594 Right val -> Just val)
595 -- The exception is always the IOEnv built-in
596 -- in exception; see IOEnv.failM
599 -----------------------
600 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
601 -- Run the thing, returning
602 -- Just r, if m succceeds with no error messages
603 -- Nothing, if m fails, or if it succeeds but has error messages
604 -- Either way, the messages are returned; even in the Just case
605 -- there might be warnings
607 = do { (msgs, res) <- tryTc thing
609 ; let errs_found = errorsFound dflags msgs
610 ; return (msgs, case res of
612 Just val | errs_found -> Nothing
613 | otherwise -> Just val)
616 -----------------------
617 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
618 -- Just like tryTcErrs, except that it ensures that the LIE
619 -- for the thing is propagated only if there are no errors
620 -- Hence it's restricted to the type-check monad
621 tryTcLIE thing_inside
622 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
624 Nothing -> return (msgs, Nothing)
625 Just val -> do { extendLIEs lie; return (msgs, Just val) }
628 -----------------------
629 tryTcLIE_ :: TcM r -> TcM r -> TcM r
630 -- (tryTcLIE_ r m) tries m;
631 -- if m succeeds with no error messages, it's the answer
632 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
633 tryTcLIE_ recover main
634 = do { (msgs, mb_res) <- tryTcLIE main
636 Just val -> do { addMessages msgs -- There might be warnings
638 Nothing -> recover -- Discard all msgs
641 -----------------------
642 checkNoErrs :: TcM r -> TcM r
643 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
644 -- If m fails then (checkNoErrsTc m) fails.
645 -- If m succeeds, it checks whether m generated any errors messages
646 -- (it might have recovered internally)
647 -- If so, it fails too.
648 -- Regardless, any errors generated by m are propagated to the enclosing context.
650 = do { (msgs, mb_res) <- tryTcLIE main
654 Just val -> return val
657 ifErrsM :: TcRn r -> TcRn r -> TcRn r
658 -- ifErrsM bale_out main
659 -- does 'bale_out' if there are errors in errors collection
660 -- otherwise does 'main'
661 ifErrsM bale_out normal
662 = do { errs_var <- getErrsVar ;
663 msgs <- readMutVar errs_var ;
665 if errorsFound dflags msgs then
670 failIfErrsM :: TcRn ()
671 -- Useful to avoid error cascades
672 failIfErrsM = ifErrsM failM (return ())
676 %************************************************************************
678 Context management and error message generation
681 %************************************************************************
684 getErrCtxt :: TcM ErrCtxt
685 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
687 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
688 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
690 addErrCtxt :: Message -> TcM a -> TcM a
691 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
693 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
694 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
696 -- Helper function for the above
697 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
698 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
699 env { tcl_ctxt = upd ctxt })
701 -- Conditionally add an error context
702 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
703 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
704 maybeAddErrCtxt Nothing thing_inside = thing_inside
706 popErrCtxt :: TcM a -> TcM a
707 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
709 getInstLoc :: InstOrigin -> TcM InstLoc
711 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
712 return (InstLoc origin loc (tcl_ctxt env)) }
714 addInstCtxt :: InstLoc -> TcM a -> TcM a
715 -- Add the SrcSpan and context from the first Inst in the list
716 -- (they all have similar locations)
717 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
718 = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
721 The addErrTc functions add an error message, but do not cause failure.
722 The 'M' variants pass a TidyEnv that has already been used to
723 tidy up the message; we then use it to tidy the context messages
726 addErrTc :: Message -> TcM ()
727 addErrTc err_msg = do { env0 <- tcInitTidyEnv
728 ; addErrTcM (env0, err_msg) }
730 addErrsTc :: [Message] -> TcM ()
731 addErrsTc err_msgs = mappM_ addErrTc err_msgs
733 addErrTcM :: (TidyEnv, Message) -> TcM ()
734 addErrTcM (tidy_env, err_msg)
735 = do { ctxt <- getErrCtxt ;
737 add_err_tcm tidy_env err_msg loc ctxt }
740 The failWith functions add an error message and cause failure
743 failWithTc :: Message -> TcM a -- Add an error message and fail
745 = addErrTc err_msg >> failM
747 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
748 failWithTcM local_and_msg
749 = addErrTcM local_and_msg >> failM
751 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
752 checkTc True err = returnM ()
753 checkTc False err = failWithTc err
756 Warnings have no 'M' variant, nor failure
759 addWarnTc :: Message -> TcM ()
761 = do { ctxt <- getErrCtxt ;
762 env0 <- tcInitTidyEnv ;
763 ctxt_msgs <- do_ctxt env0 ctxt ;
764 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
766 warnTc :: Bool -> Message -> TcM ()
767 warnTc warn_if_true warn_msg
768 | warn_if_true = addWarnTc warn_msg
769 | otherwise = return ()
772 -----------------------------------
775 We initialise the "tidy-env", used for tidying types before printing,
776 by building a reverse map from the in-scope type variables to the
777 OccName that the programmer originally used for them
780 tcInitTidyEnv :: TcM TidyEnv
782 = do { lcl_env <- getLclEnv
783 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
784 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
786 ; return (foldl add emptyTidyEnv nm_tv_prs) }
788 add (env,subst) (name, tyvar)
789 = case tidyOccName env (nameOccName name) of
790 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
792 tyvar' = setTyVarName tyvar name'
793 name' = tidyNameOcc name occ'
796 -----------------------------------
797 Other helper functions
800 add_err_tcm tidy_env err_msg loc ctxt
801 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
802 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
806 do_ctxt tidy_env (c:cs)
807 = do { (tidy_env', m) <- c tidy_env ;
808 ms <- do_ctxt tidy_env' cs ;
811 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
812 | otherwise = take 3 ctxt
815 debugTc is useful for monadic debugging code
818 debugTc :: TcM () -> TcM ()
820 debugTc thing = thing
822 debugTc thing = return ()
826 %************************************************************************
828 Type constraints (the so-called LIE)
830 %************************************************************************
833 nextDFunIndex :: TcM Int -- Get the next dfun index
834 nextDFunIndex = do { env <- getGblEnv
835 ; let dfun_n_var = tcg_dfun_n env
836 ; n <- readMutVar dfun_n_var
837 ; writeMutVar dfun_n_var (n+1)
840 getLIEVar :: TcM (TcRef LIE)
841 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
843 setLIEVar :: TcRef LIE -> TcM a -> TcM a
844 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
846 getLIE :: TcM a -> TcM (a, [Inst])
847 -- (getLIE m) runs m, and returns the type constraints it generates
849 = do { lie_var <- newMutVar emptyLIE ;
850 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
852 lie <- readMutVar lie_var ;
853 return (res, lieToList lie) }
855 extendLIE :: Inst -> TcM ()
857 = do { lie_var <- getLIEVar ;
858 lie <- readMutVar lie_var ;
859 writeMutVar lie_var (inst `consLIE` lie) }
861 extendLIEs :: [Inst] -> TcM ()
865 = do { lie_var <- getLIEVar ;
866 lie <- readMutVar lie_var ;
867 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
871 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
872 -- Set the local type envt, but do *not* disturb other fields,
873 -- notably the lie_var
874 setLclTypeEnv lcl_env thing_inside
875 = updLclEnv upd thing_inside
877 upd env = env { tcl_env = tcl_env lcl_env,
878 tcl_tyvars = tcl_tyvars lcl_env }
882 %************************************************************************
884 Template Haskell context
886 %************************************************************************
889 recordThUse :: TcM ()
890 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
892 keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
893 keepAliveTc n = do { env <- getGblEnv;
894 ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
896 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
897 keepAliveSetTc ns = do { env <- getGblEnv;
898 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
900 getStage :: TcM ThStage
901 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
903 setStage :: ThStage -> TcM a -> TcM a
904 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
908 %************************************************************************
910 Stuff for the renamer's local env
912 %************************************************************************
915 getLocalRdrEnv :: RnM LocalRdrEnv
916 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
918 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
919 setLocalRdrEnv rdr_env thing_inside
920 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
924 %************************************************************************
926 Stuff for interface decls
928 %************************************************************************
931 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
932 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
934 if_tv_env = emptyOccEnv,
935 if_id_env = emptyOccEnv }
937 initIfaceTcRn :: IfG a -> TcRn a
938 initIfaceTcRn thing_inside
939 = do { tcg_env <- getGblEnv
940 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
941 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
942 ; setEnvs (if_env, ()) thing_inside }
944 initIfaceExtCore :: IfL a -> TcRn a
945 initIfaceExtCore thing_inside
946 = do { tcg_env <- getGblEnv
947 ; let { mod = tcg_mod tcg_env
948 ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
949 ; if_env = IfGblEnv {
950 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
951 ; if_lenv = mkIfLclEnv mod doc
953 ; setEnvs (if_env, if_lenv) thing_inside }
955 initIfaceCheck :: HscEnv -> IfG a -> IO a
956 -- Used when checking the up-to-date-ness of the old Iface
957 -- Initialise the environment with no useful info at all
958 initIfaceCheck hsc_env do_this
959 = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
960 ; initTcRnIf 'i' hsc_env gbl_env () do_this
963 initIfaceTc :: ModIface
964 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
965 -- Used when type-checking checking an up-to-date interface file
966 -- No type envt from the current module, but we do know the module dependencies
967 initIfaceTc iface do_this
968 = do { tc_env_var <- newMutVar emptyTypeEnv
969 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
970 ; if_lenv = mkIfLclEnv mod doc
972 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
975 mod = mi_module iface
976 doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
978 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
979 -- Used when sucking in new Rules in SimplCore
980 -- We have available the type envt of the module being compiled, and we must use it
981 initIfaceRules hsc_env guts do_this
983 type_info = (mg_module guts, return (mg_types guts))
984 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
987 -- Run the thing; any exceptions just bubble out from here
988 ; initTcRnIf 'i' hsc_env gbl_env () do_this
991 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
992 initIfaceLcl mod loc_doc thing_inside
993 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
995 getIfModule :: IfL Module
996 getIfModule = do { env <- getLclEnv; return (if_mod env) }
999 failIfM :: Message -> IfL a
1000 -- The Iface monad doesn't have a place to accumulate errors, so we
1001 -- just fall over fast if one happens; it "shouldnt happen".
1002 -- We use IfL here so that we can get context info out of the local env
1004 = do { env <- getLclEnv
1005 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
1006 ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
1009 --------------------
1010 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1011 -- Run thing_inside in an interleaved thread.
1012 -- It shares everything with the parent thread, so this is DANGEROUS.
1014 -- It returns Nothing if the computation fails
1016 -- It's used for lazily type-checking interface
1017 -- signatures, which is pretty benign
1019 forkM_maybe doc thing_inside
1020 = do { unsafeInterleaveM $
1021 do { traceIf (text "Starting fork {" <+> doc)
1023 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1026 Right r -> do { traceIf (text "} ending fork" <+> doc)
1030 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1031 -- Otherwise we silently discard errors. Errors can legitimately
1032 -- happen when compiling interface signatures (see tcInterfaceSigs)
1033 ifOptM Opt_D_dump_if_trace
1034 (print_errs (hang (text "forkM failed:" <+> doc)
1035 4 (text (show exn))))
1037 ; traceIf (text "} ending fork (badly)" <+> doc)
1041 print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
1043 forkM :: SDoc -> IfL a -> IfL a
1044 forkM doc thing_inside
1045 = do { mb_res <- forkM_maybe doc thing_inside
1046 ; return (case mb_res of
1047 Nothing -> pgmError "Cannot continue after interface file error"
1048 -- pprPanic "forkM" doc