2 % (c) The University of Glasgow 2006
12 import TcRnTypes -- Re-export all
13 import IOEnv -- Re-export all
15 import HsSyn hiding (LIE)
51 %************************************************************************
55 %************************************************************************
61 -> Bool -- True <=> retain renamed syntax trees
64 -> IO (Messages, Maybe r)
65 -- Nothing => error thrown by the thing inside
66 -- (error messages should have been printed already)
68 initTc hsc_env hsc_src keep_rn_syntax mod do_this
69 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
70 tvs_var <- newIORef emptyVarSet ;
71 dfuns_var <- newIORef emptyNameSet ;
72 keep_var <- newIORef emptyNameSet ;
73 th_var <- newIORef False ;
74 dfun_n_var <- newIORef 1 ;
75 type_env_var <- case hsc_type_env_var hsc_env of {
76 Just (_mod, te_var) -> return te_var ;
77 Nothing -> newIORef emptyNameEnv } ;
79 maybe_rn_syntax empty_val
80 | keep_rn_syntax = Just empty_val
81 | otherwise = Nothing ;
86 tcg_rdr_env = hsc_global_rdr_env hsc_env,
87 tcg_fix_env = emptyNameEnv,
88 tcg_field_env = RecFields emptyNameEnv emptyNameSet,
89 tcg_default = Nothing,
90 tcg_type_env = hsc_global_type_env hsc_env,
91 tcg_type_env_var = type_env_var,
92 tcg_inst_env = emptyInstEnv,
93 tcg_fam_inst_env = emptyFamInstEnv,
94 tcg_inst_uses = dfuns_var,
97 tcg_imports = emptyImportAvails,
100 tcg_rn_imports = maybe_rn_syntax [],
101 tcg_rn_exports = maybe_rn_syntax [],
102 tcg_rn_decls = maybe_rn_syntax emptyRnGroup,
104 tcg_binds = emptyLHsBinds,
105 tcg_warns = NoWarnings,
111 tcg_dfun_n = dfun_n_var,
114 tcg_hmi = HaddockModInfo Nothing Nothing Nothing Nothing,
119 tcl_loc = mkGeneralSrcSpan (fsLit "Top level"),
121 tcl_rdr = emptyLocalRdrEnv,
122 tcl_th_ctxt = topStage,
123 tcl_arrow_ctxt = NoArrowCtxt,
124 tcl_env = emptyNameEnv,
125 tcl_tyvars = tvs_var,
126 tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
130 -- OK, here's the business end!
131 maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
132 do { r <- tryM do_this
134 Right res -> return (Just res)
135 Left _ -> return Nothing } ;
137 -- Collect any error messages
138 msgs <- readIORef errs_var ;
140 let { dflags = hsc_dflags hsc_env
141 ; final_res | errorsFound dflags msgs = Nothing
142 | otherwise = maybe_res } ;
144 return (msgs, final_res)
147 initTcPrintErrors -- Used from the interactive loop only
151 -> IO (Messages, Maybe r)
152 initTcPrintErrors env mod todo = do
153 (msgs, res) <- initTc env HsSrcFile False mod todo
157 %************************************************************************
161 %************************************************************************
165 initTcRnIf :: Char -- Tag for unique supply
170 initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
171 = do { us <- mkSplitUniqSupply uniq_tag ;
172 ; us_var <- newIORef us ;
174 ; let { env = Env { env_top = hsc_env,
179 ; runIOEnv env thing_inside
183 %************************************************************************
187 %************************************************************************
190 getTopEnv :: TcRnIf gbl lcl HscEnv
191 getTopEnv = do { env <- getEnv; return (env_top env) }
193 getGblEnv :: TcRnIf gbl lcl gbl
194 getGblEnv = do { env <- getEnv; return (env_gbl env) }
196 updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
197 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
198 env { env_gbl = upd gbl })
200 setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
201 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
203 getLclEnv :: TcRnIf gbl lcl lcl
204 getLclEnv = do { env <- getEnv; return (env_lcl env) }
206 updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
207 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
208 env { env_lcl = upd lcl })
210 setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
211 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
213 getEnvs :: TcRnIf gbl lcl (gbl, lcl)
214 getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
216 setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
217 setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
224 getDOpts :: TcRnIf gbl lcl DynFlags
225 getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
227 doptM :: DynFlag -> TcRnIf gbl lcl Bool
228 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
230 setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
231 setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
232 env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
234 unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
235 unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
236 env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
238 -- | Do it flag is true
239 ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
240 ifOptM flag thing_inside = do { b <- doptM flag;
241 if b then thing_inside else return () }
243 getGhcMode :: TcRnIf gbl lcl GhcMode
244 getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
248 getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
249 getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
251 getEps :: TcRnIf gbl lcl ExternalPackageState
252 getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
254 -- Updating the EPS. This should be an atomic operation.
255 -- Note the delicate 'seq' which forces the EPS before putting it in the
256 -- variable. Otherwise what happens is that we get
257 -- write eps_var (....(unsafeRead eps_var)....)
258 -- and if the .... is strict, that's obviously bottom. By forcing it beforehand
259 -- we make the unsafeRead happen before we update the variable.
261 updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
263 updateEps upd_fn = do { traceIf (text "updating EPS")
264 ; eps_var <- getEpsVar
265 ; eps <- readMutVar eps_var
266 ; let { (eps', val) = upd_fn eps }
267 ; seq eps' (writeMutVar eps_var eps')
270 updateEps_ :: (ExternalPackageState -> ExternalPackageState)
272 updateEps_ upd_fn = do { traceIf (text "updating EPS_")
273 ; eps_var <- getEpsVar
274 ; eps <- readMutVar eps_var
275 ; let { eps' = upd_fn eps }
276 ; seq eps' (writeMutVar eps_var eps') }
278 getHpt :: TcRnIf gbl lcl HomePackageTable
279 getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
281 getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
282 getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
283 ; return (eps, hsc_HPT env) }
286 %************************************************************************
290 %************************************************************************
293 newUnique :: TcRnIf gbl lcl Unique
295 = do { env <- getEnv ;
296 let { u_var = env_us env } ;
297 us <- readMutVar u_var ;
298 case splitUniqSupply us of { (us1,_) -> do {
299 writeMutVar u_var us1 ;
300 return $! uniqFromSupply us }}}
301 -- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
302 -- a chain of unevaluated supplies behind.
303 -- NOTE 2: we use the uniq in the supply from the MutVar directly, and
304 -- throw away one half of the new split supply. This is safe because this
305 -- is the only place we use that unique. Using the other half of the split
306 -- supply is safer, but slower.
308 newUniqueSupply :: TcRnIf gbl lcl UniqSupply
310 = do { env <- getEnv ;
311 let { u_var = env_us env } ;
312 us <- readMutVar u_var ;
313 case splitUniqSupply us of { (us1,us2) -> do {
314 writeMutVar u_var us1 ;
317 newLocalName :: Name -> TcRnIf gbl lcl Name
318 newLocalName name -- Make a clone
319 = do { uniq <- newUnique
320 ; return (mkInternalName uniq (nameOccName name) (getSrcSpan name)) }
322 newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
323 newSysLocalIds fs tys
324 = do { us <- newUniqueSupply
325 ; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
327 instance MonadUnique (IOEnv (Env gbl lcl)) where
328 getUniqueM = newUnique
329 getUniqueSupplyM = newUniqueSupply
333 %************************************************************************
337 %************************************************************************
340 traceTc, traceRn, traceSplice :: SDoc -> TcRn ()
341 traceRn = traceOptTcRn Opt_D_dump_rn_trace
342 traceTc = traceOptTcRn Opt_D_dump_tc_trace
343 traceSplice = traceOptTcRn Opt_D_dump_splices
346 traceIf, traceHiDiffs :: SDoc -> TcRnIf m n ()
347 traceIf = traceOptIf Opt_D_dump_if_trace
348 traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
351 traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
352 traceOptIf flag doc = ifOptM flag $
353 liftIO (printForUser stderr alwaysQualify doc)
355 traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
356 traceOptTcRn flag doc = ifOptM flag $ do
359 ; env0 <- tcInitTidyEnv
360 ; ctxt_msgs <- do_ctxt env0 ctxt
361 ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
362 ; dumpTcRn real_doc }
364 dumpTcRn :: SDoc -> TcRn ()
365 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
367 liftIO (printForUser stderr (mkPrintUnqualified dflags rdr_env) doc) }
369 debugDumpTcRn :: SDoc -> TcRn ()
370 debugDumpTcRn doc | opt_NoDebugOutput = return ()
371 | otherwise = dumpTcRn doc
373 dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
374 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
378 %************************************************************************
380 Typechecker global environment
382 %************************************************************************
385 getModule :: TcRn Module
386 getModule = do { env <- getGblEnv; return (tcg_mod env) }
388 setModule :: Module -> TcRn a -> TcRn a
389 setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
391 tcIsHsBoot :: TcRn Bool
392 tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
394 getGlobalRdrEnv :: TcRn GlobalRdrEnv
395 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
397 getRdrEnvs :: TcRn (GlobalRdrEnv, LocalRdrEnv)
398 getRdrEnvs = do { (gbl,lcl) <- getEnvs; return (tcg_rdr_env gbl, tcl_rdr lcl) }
400 getImports :: TcRn ImportAvails
401 getImports = do { env <- getGblEnv; return (tcg_imports env) }
403 getFixityEnv :: TcRn FixityEnv
404 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
406 extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
407 extendFixityEnv new_bit
408 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
409 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
411 getRecFieldEnv :: TcRn RecFieldEnv
412 getRecFieldEnv = do { env <- getGblEnv; return (tcg_field_env env) }
414 getDeclaredDefaultTys :: TcRn (Maybe [Type])
415 getDeclaredDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
418 %************************************************************************
422 %************************************************************************
425 getSrcSpanM :: TcRn SrcSpan
426 -- Avoid clash with Name.getSrcLoc
427 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
429 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
430 setSrcSpan loc thing_inside
431 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
432 | otherwise = thing_inside -- Don't overwrite useful info with useless
434 addLocM :: (a -> TcM b) -> Located a -> TcM b
435 addLocM fn (L loc a) = setSrcSpan loc $ fn a
437 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
438 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
440 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
441 wrapLocFstM fn (L loc a) =
446 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
447 wrapLocSndM fn (L loc a) =
455 getErrsVar :: TcRn (TcRef Messages)
456 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
458 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
459 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
461 addErr :: Message -> TcRn () -- Ignores the context stack
462 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
464 failWith :: Message -> TcRn a
465 failWith msg = addErr msg >> failM
467 addLocErr :: Located e -> (e -> Message) -> TcRn ()
468 addLocErr (L loc e) fn = addErrAt loc (fn e)
470 addErrAt :: SrcSpan -> Message -> TcRn ()
471 addErrAt loc msg = addLongErrAt loc msg empty
473 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
474 addLongErrAt loc msg extra
475 = do { traceTc (ptext (sLit "Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
476 errs_var <- getErrsVar ;
477 rdr_env <- getGlobalRdrEnv ;
479 let { err = mkLongErrMsg loc (mkPrintUnqualified dflags rdr_env) msg extra } ;
480 (warns, errs) <- readMutVar errs_var ;
481 writeMutVar errs_var (warns, errs `snocBag` err) }
483 addErrs :: [(SrcSpan,Message)] -> TcRn ()
484 addErrs msgs = mapM_ add msgs
486 add (loc,msg) = addErrAt loc msg
488 addReport :: Message -> TcRn ()
489 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
491 addReportAt :: SrcSpan -> Message -> TcRn ()
493 = do { errs_var <- getErrsVar ;
494 rdr_env <- getGlobalRdrEnv ;
496 let { warn = mkWarnMsg loc (mkPrintUnqualified dflags rdr_env) msg } ;
497 (warns, errs) <- readMutVar errs_var ;
498 writeMutVar errs_var (warns `snocBag` warn, errs) }
500 addWarn :: Message -> TcRn ()
501 addWarn msg = addReport (ptext (sLit "Warning:") <+> msg)
503 addWarnAt :: SrcSpan -> Message -> TcRn ()
504 addWarnAt loc msg = addReportAt loc (ptext (sLit "Warning:") <+> msg)
506 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
507 addLocWarn (L loc e) fn = addReportAt loc (fn e)
509 checkErr :: Bool -> Message -> TcRn ()
510 -- Add the error if the bool is False
511 checkErr ok msg = unless ok (addErr msg)
513 warnIf :: Bool -> Message -> TcRn ()
514 warnIf True msg = addWarn msg
515 warnIf False _ = return ()
517 addMessages :: Messages -> TcRn ()
518 addMessages (m_warns, m_errs)
519 = do { errs_var <- getErrsVar ;
520 (warns, errs) <- readMutVar errs_var ;
521 writeMutVar errs_var (warns `unionBags` m_warns,
522 errs `unionBags` m_errs) }
524 discardWarnings :: TcRn a -> TcRn a
525 -- Ignore warnings inside the thing inside;
526 -- used to ignore-unused-variable warnings inside derived code
527 -- With -dppr-debug, the effects is switched off, so you can still see
528 -- what warnings derived code would give
529 discardWarnings thing_inside
530 | opt_PprStyle_Debug = thing_inside
532 = do { errs_var <- newMutVar emptyMessages
533 ; result <- setErrsVar errs_var thing_inside
534 ; (_warns, errs) <- readMutVar errs_var
535 ; addMessages (emptyBag, errs)
541 try_m :: TcRn r -> TcRn (Either IOEnvFailure r)
542 -- Does try_m, with a debug-trace on failure
544 = do { mb_r <- tryM thing ;
546 Left exn -> do { traceTc (exn_msg exn); return mb_r }
547 Right _ -> return mb_r }
549 exn_msg exn = text "tryTc/recoverM recovering from" <+> text (showException exn)
551 -----------------------
552 recoverM :: TcRn r -- Recovery action; do this if the main one fails
553 -> TcRn r -- Main action: do this first
555 -- Errors in 'thing' are retained
556 recoverM recover thing
557 = do { mb_res <- try_m thing ;
560 Right res -> return res }
563 -----------------------
564 mapAndRecoverM :: (a -> TcRn b) -> [a] -> TcRn [b]
565 -- Drop elements of the input that fail, so the result
566 -- list can be shorter than the argument list
567 mapAndRecoverM _ [] = return []
568 mapAndRecoverM f (x:xs) = do { mb_r <- try_m (f x)
569 ; rs <- mapAndRecoverM f xs
570 ; return (case mb_r of
575 -----------------------
576 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
577 -- (tryTc m) executes m, and returns
578 -- Just r, if m succeeds (returning r)
579 -- Nothing, if m fails
580 -- It also returns all the errors and warnings accumulated by m
581 -- It always succeeds (never raises an exception)
583 = do { errs_var <- newMutVar emptyMessages ;
584 res <- try_m (setErrsVar errs_var m) ;
585 msgs <- readMutVar errs_var ;
586 return (msgs, case res of
588 Right val -> Just val)
589 -- The exception is always the IOEnv built-in
590 -- in exception; see IOEnv.failM
593 -----------------------
594 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
595 -- Run the thing, returning
596 -- Just r, if m succceeds with no error messages
597 -- Nothing, if m fails, or if it succeeds but has error messages
598 -- Either way, the messages are returned; even in the Just case
599 -- there might be warnings
601 = do { (msgs, res) <- tryTc thing
603 ; let errs_found = errorsFound dflags msgs
604 ; return (msgs, case res of
606 Just val | errs_found -> Nothing
607 | otherwise -> Just val)
610 -----------------------
611 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
612 -- Just like tryTcErrs, except that it ensures that the LIE
613 -- for the thing is propagated only if there are no errors
614 -- Hence it's restricted to the type-check monad
615 tryTcLIE thing_inside
616 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
618 Nothing -> return (msgs, Nothing)
619 Just val -> do { extendLIEs lie; return (msgs, Just val) }
622 -----------------------
623 tryTcLIE_ :: TcM r -> TcM r -> TcM r
624 -- (tryTcLIE_ r m) tries m;
625 -- if m succeeds with no error messages, it's the answer
626 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
627 tryTcLIE_ recover main
628 = do { (msgs, mb_res) <- tryTcLIE main
630 Just val -> do { addMessages msgs -- There might be warnings
632 Nothing -> recover -- Discard all msgs
635 -----------------------
636 checkNoErrs :: TcM r -> TcM r
637 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
638 -- If m fails then (checkNoErrsTc m) fails.
639 -- If m succeeds, it checks whether m generated any errors messages
640 -- (it might have recovered internally)
641 -- If so, it fails too.
642 -- Regardless, any errors generated by m are propagated to the enclosing context.
644 = do { (msgs, mb_res) <- tryTcLIE main
648 Just val -> return val
651 ifErrsM :: TcRn r -> TcRn r -> TcRn r
652 -- ifErrsM bale_out main
653 -- does 'bale_out' if there are errors in errors collection
654 -- otherwise does 'main'
655 ifErrsM bale_out normal
656 = do { errs_var <- getErrsVar ;
657 msgs <- readMutVar errs_var ;
659 if errorsFound dflags msgs then
664 failIfErrsM :: TcRn ()
665 -- Useful to avoid error cascades
666 failIfErrsM = ifErrsM failM (return ())
670 %************************************************************************
672 Context management and error message generation
675 %************************************************************************
678 getErrCtxt :: TcM ErrCtxt
679 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
681 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
682 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
684 addErrCtxt :: Message -> TcM a -> TcM a
685 addErrCtxt msg = addErrCtxtM (\env -> return (env, msg))
687 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
688 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
690 -- Helper function for the above
691 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
692 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
693 env { tcl_ctxt = upd ctxt })
695 -- Conditionally add an error context
696 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
697 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
698 maybeAddErrCtxt Nothing thing_inside = thing_inside
700 popErrCtxt :: TcM a -> TcM a
701 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (_ : ms) -> ms })
703 getInstLoc :: InstOrigin -> TcM InstLoc
705 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
706 return (InstLoc origin loc (tcl_ctxt env)) }
708 addInstCtxt :: InstLoc -> TcM a -> TcM a
709 -- Add the SrcSpan and context from the first Inst in the list
710 -- (they all have similar locations)
711 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
712 = setSrcSpan src_loc (updCtxt (\_ -> ctxt) thing_inside)
715 The addErrTc functions add an error message, but do not cause failure.
716 The 'M' variants pass a TidyEnv that has already been used to
717 tidy up the message; we then use it to tidy the context messages
720 addErrTc :: Message -> TcM ()
721 addErrTc err_msg = do { env0 <- tcInitTidyEnv
722 ; addErrTcM (env0, err_msg) }
724 addErrsTc :: [Message] -> TcM ()
725 addErrsTc err_msgs = mapM_ addErrTc err_msgs
727 addErrTcM :: (TidyEnv, Message) -> TcM ()
728 addErrTcM (tidy_env, err_msg)
729 = do { ctxt <- getErrCtxt ;
731 add_err_tcm tidy_env err_msg loc ctxt }
734 The failWith functions add an error message and cause failure
737 failWithTc :: Message -> TcM a -- Add an error message and fail
739 = addErrTc err_msg >> failM
741 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
742 failWithTcM local_and_msg
743 = addErrTcM local_and_msg >> failM
745 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
746 checkTc True _ = return ()
747 checkTc False err = failWithTc err
750 Warnings have no 'M' variant, nor failure
753 addWarnTc :: Message -> TcM ()
754 addWarnTc msg = do { env0 <- tcInitTidyEnv
755 ; addWarnTcM (env0, msg) }
757 addWarnTcM :: (TidyEnv, Message) -> TcM ()
758 addWarnTcM (env0, msg)
759 = do { ctxt <- getErrCtxt ;
760 ctxt_msgs <- do_ctxt env0 ctxt ;
761 addReport (vcat (ptext (sLit "Warning:") <+> msg : ctxt_to_use ctxt_msgs)) }
763 warnTc :: Bool -> Message -> TcM ()
764 warnTc warn_if_true warn_msg
765 | warn_if_true = addWarnTc warn_msg
766 | otherwise = return ()
769 -----------------------------------
772 We initialise the "tidy-env", used for tidying types before printing,
773 by building a reverse map from the in-scope type variables to the
774 OccName that the programmer originally used for them
777 tcInitTidyEnv :: TcM TidyEnv
779 = do { lcl_env <- getLclEnv
780 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
781 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
783 ; return (foldl add emptyTidyEnv nm_tv_prs) }
785 add (env,subst) (name, tyvar)
786 = case tidyOccName env (nameOccName name) of
787 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
789 tyvar' = setTyVarName tyvar name'
790 name' = tidyNameOcc name occ'
793 -----------------------------------
794 Other helper functions
797 add_err_tcm :: TidyEnv -> Message -> SrcSpan
798 -> [TidyEnv -> TcM (TidyEnv, SDoc)]
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)) }
804 do_ctxt :: TidyEnv -> [TidyEnv -> TcM (TidyEnv, SDoc)] -> TcM [SDoc]
807 do_ctxt tidy_env (c:cs)
808 = do { (tidy_env', m) <- c tidy_env ;
809 ms <- do_ctxt tidy_env' cs ;
812 ctxt_to_use :: [SDoc] -> [SDoc]
813 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
814 | otherwise = take 3 ctxt
817 debugTc is useful for monadic debugging code
820 debugTc :: TcM () -> TcM ()
823 | otherwise = 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 :: Id -> TcM () -- Record the name in the keep-alive set
894 | isLocalId id = do { env <- getGblEnv;
895 ; updMutVar (tcg_keep env) (`addOneToNameSet` idName id) }
896 | otherwise = return ()
898 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
899 keepAliveSetTc ns = do { env <- getGblEnv;
900 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
902 getStage :: TcM ThStage
903 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
905 setStage :: ThStage -> TcM a -> TcM a
906 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
910 %************************************************************************
912 Stuff for the renamer's local env
914 %************************************************************************
917 getLocalRdrEnv :: RnM LocalRdrEnv
918 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
920 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
921 setLocalRdrEnv rdr_env thing_inside
922 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
926 %************************************************************************
928 Stuff for interface decls
930 %************************************************************************
933 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
934 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
936 if_tv_env = emptyUFM,
937 if_id_env = emptyUFM }
939 initIfaceTcRn :: IfG a -> TcRn a
940 initIfaceTcRn thing_inside
941 = do { tcg_env <- getGblEnv
942 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
943 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
944 ; setEnvs (if_env, ()) thing_inside }
946 initIfaceExtCore :: IfL a -> TcRn a
947 initIfaceExtCore thing_inside
948 = do { tcg_env <- getGblEnv
949 ; let { mod = tcg_mod tcg_env
950 ; doc = ptext (sLit "External Core file for") <+> quotes (ppr mod)
951 ; if_env = IfGblEnv {
952 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
953 ; if_lenv = mkIfLclEnv mod doc
955 ; setEnvs (if_env, if_lenv) thing_inside }
957 initIfaceCheck :: HscEnv -> IfG a -> IO a
958 -- Used when checking the up-to-date-ness of the old Iface
959 -- Initialise the environment with no useful info at all
960 initIfaceCheck hsc_env do_this
961 = do let rec_types = case hsc_type_env_var hsc_env of
962 Just (mod,var) -> Just (mod, readMutVar var)
964 gbl_env = IfGblEnv { if_rec_types = rec_types }
965 initTcRnIf 'i' hsc_env gbl_env () do_this
967 initIfaceTc :: ModIface
968 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
969 -- Used when type-checking checking an up-to-date interface file
970 -- No type envt from the current module, but we do know the module dependencies
971 initIfaceTc iface do_this
972 = do { tc_env_var <- newMutVar emptyTypeEnv
973 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
974 ; if_lenv = mkIfLclEnv mod doc
976 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
979 mod = mi_module iface
980 doc = ptext (sLit "The interface for") <+> quotes (ppr mod)
982 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
983 -- Used when sucking in new Rules in SimplCore
984 -- We have available the type envt of the module being compiled, and we must use it
985 initIfaceRules hsc_env guts do_this
987 type_info = (mg_module guts, return (mg_types guts))
988 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
991 -- Run the thing; any exceptions just bubble out from here
992 ; initTcRnIf 'i' hsc_env gbl_env () do_this
995 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
996 initIfaceLcl mod loc_doc thing_inside
997 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
999 getIfModule :: IfL Module
1000 getIfModule = do { env <- getLclEnv; return (if_mod env) }
1002 --------------------
1003 failIfM :: Message -> IfL a
1004 -- The Iface monad doesn't have a place to accumulate errors, so we
1005 -- just fall over fast if one happens; it "shouldnt happen".
1006 -- We use IfL here so that we can get context info out of the local env
1008 = do { env <- getLclEnv
1009 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
1010 ; liftIO (printErrs (full_msg defaultErrStyle))
1013 --------------------
1014 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1015 -- Run thing_inside in an interleaved thread.
1016 -- It shares everything with the parent thread, so this is DANGEROUS.
1018 -- It returns Nothing if the computation fails
1020 -- It's used for lazily type-checking interface
1021 -- signatures, which is pretty benign
1023 forkM_maybe doc thing_inside
1024 = do { unsafeInterleaveM $
1025 do { traceIf (text "Starting fork {" <+> doc)
1027 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1030 Right r -> do { traceIf (text "} ending fork" <+> doc)
1034 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1035 -- Otherwise we silently discard errors. Errors can legitimately
1036 -- happen when compiling interface signatures (see tcInterfaceSigs)
1037 ifOptM Opt_D_dump_if_trace
1038 (print_errs (hang (text "forkM failed:" <+> doc)
1039 4 (text (show exn))))
1041 ; traceIf (text "} ending fork (badly)" <+> doc)
1045 print_errs sdoc = liftIO (printErrs (sdoc defaultErrStyle))
1047 forkM :: SDoc -> IfL a -> IfL a
1048 forkM doc thing_inside
1049 = do { mb_res <- forkM_maybe doc thing_inside
1050 ; return (case mb_res of
1051 Nothing -> pgmError "Cannot continue after interface file error"
1052 -- pprPanic "forkM" doc