2 % (c) The University of Glasgow 2006
12 import TcRnTypes -- Re-export all
13 import IOEnv -- Re-export all
15 import HsSyn hiding (LIE)
52 %************************************************************************
56 %************************************************************************
62 -> Bool -- True <=> retain renamed syntax trees
65 -> IO (Messages, Maybe r)
66 -- Nothing => error thrown by the thing inside
67 -- (error messages should have been printed already)
69 initTc hsc_env hsc_src keep_rn_syntax mod do_this
70 = do { errs_var <- newIORef (emptyBag, emptyBag) ;
71 tvs_var <- newIORef emptyVarSet ;
72 dfuns_var <- newIORef emptyNameSet ;
73 keep_var <- newIORef emptyNameSet ;
74 th_var <- newIORef False ;
75 dfun_n_var <- newIORef 1 ;
76 type_env_var <- case hsc_type_env_var hsc_env of {
77 Just (_mod, te_var) -> return te_var ;
78 Nothing -> newIORef emptyNameEnv } ;
80 maybe_rn_syntax empty_val
81 | keep_rn_syntax = Just empty_val
82 | otherwise = Nothing ;
87 tcg_rdr_env = hsc_global_rdr_env hsc_env,
88 tcg_fix_env = emptyNameEnv,
89 tcg_field_env = emptyNameEnv,
90 tcg_default = Nothing,
91 tcg_type_env = hsc_global_type_env hsc_env,
92 tcg_type_env_var = type_env_var,
93 tcg_inst_env = emptyInstEnv,
94 tcg_fam_inst_env = emptyFamInstEnv,
95 tcg_inst_uses = dfuns_var,
98 tcg_imports = emptyImportAvails,
101 tcg_rn_imports = maybe_rn_syntax [],
102 tcg_rn_exports = maybe_rn_syntax [],
103 tcg_rn_decls = maybe_rn_syntax emptyRnGroup,
105 tcg_binds = emptyLHsBinds,
106 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 extendRecFieldEnv :: RecFieldEnv -> RnM a -> RnM a
415 extendRecFieldEnv new_bit
416 = updGblEnv (\env@(TcGblEnv { tcg_field_env = old_env }) ->
417 env {tcg_field_env = old_env `plusNameEnv` new_bit})
419 getDeclaredDefaultTys :: TcRn (Maybe [Type])
420 getDeclaredDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
423 %************************************************************************
427 %************************************************************************
430 getSrcSpanM :: TcRn SrcSpan
431 -- Avoid clash with Name.getSrcLoc
432 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
434 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
435 setSrcSpan loc thing_inside
436 | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
437 | otherwise = thing_inside -- Don't overwrite useful info with useless
439 addLocM :: (a -> TcM b) -> Located a -> TcM b
440 addLocM fn (L loc a) = setSrcSpan loc $ fn a
442 wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
443 wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
445 wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
446 wrapLocFstM fn (L loc a) =
451 wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
452 wrapLocSndM fn (L loc a) =
460 getErrsVar :: TcRn (TcRef Messages)
461 getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
463 setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
464 setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
466 addErr :: Message -> TcRn () -- Ignores the context stack
467 addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
469 failWith :: Message -> TcRn a
470 failWith msg = addErr msg >> failM
472 addLocErr :: Located e -> (e -> Message) -> TcRn ()
473 addLocErr (L loc e) fn = addErrAt loc (fn e)
475 addErrAt :: SrcSpan -> Message -> TcRn ()
476 addErrAt loc msg = addLongErrAt loc msg empty
478 addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
479 addLongErrAt loc msg extra
480 = do { traceTc (ptext (sLit "Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
481 errs_var <- getErrsVar ;
482 rdr_env <- getGlobalRdrEnv ;
484 let { err = mkLongErrMsg loc (mkPrintUnqualified dflags rdr_env) msg extra } ;
485 (warns, errs) <- readMutVar errs_var ;
486 writeMutVar errs_var (warns, errs `snocBag` err) }
488 addErrs :: [(SrcSpan,Message)] -> TcRn ()
489 addErrs msgs = mapM_ add msgs
491 add (loc,msg) = addErrAt loc msg
493 addReport :: Message -> TcRn ()
494 addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
496 addReportAt :: SrcSpan -> Message -> TcRn ()
498 = do { errs_var <- getErrsVar ;
499 rdr_env <- getGlobalRdrEnv ;
501 let { warn = mkWarnMsg loc (mkPrintUnqualified dflags rdr_env) msg } ;
502 (warns, errs) <- readMutVar errs_var ;
503 writeMutVar errs_var (warns `snocBag` warn, errs) }
505 addWarn :: Message -> TcRn ()
506 addWarn msg = addReport (ptext (sLit "Warning:") <+> msg)
508 addWarnAt :: SrcSpan -> Message -> TcRn ()
509 addWarnAt loc msg = addReportAt loc (ptext (sLit "Warning:") <+> msg)
511 addLocWarn :: Located e -> (e -> Message) -> TcRn ()
512 addLocWarn (L loc e) fn = addReportAt loc (fn e)
514 checkErr :: Bool -> Message -> TcRn ()
515 -- Add the error if the bool is False
516 checkErr ok msg = unless ok (addErr msg)
518 warnIf :: Bool -> Message -> TcRn ()
519 warnIf True msg = addWarn msg
520 warnIf False _ = return ()
522 addMessages :: Messages -> TcRn ()
523 addMessages (m_warns, m_errs)
524 = do { errs_var <- getErrsVar ;
525 (warns, errs) <- readMutVar errs_var ;
526 writeMutVar errs_var (warns `unionBags` m_warns,
527 errs `unionBags` m_errs) }
529 discardWarnings :: TcRn a -> TcRn a
530 -- Ignore warnings inside the thing inside;
531 -- used to ignore-unused-variable warnings inside derived code
532 -- With -dppr-debug, the effects is switched off, so you can still see
533 -- what warnings derived code would give
534 discardWarnings thing_inside
535 | opt_PprStyle_Debug = thing_inside
537 = do { errs_var <- newMutVar emptyMessages
538 ; result <- setErrsVar errs_var thing_inside
539 ; (_warns, errs) <- readMutVar errs_var
540 ; addMessages (emptyBag, errs)
546 #if __GLASGOW_HASKELL__ < 609
547 try_m :: TcRn r -> TcRn (Either Exception r)
549 try_m :: TcRn r -> TcRn (Either ErrorCall 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 _ -> 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 -> return res }
572 -----------------------
573 mapAndRecoverM :: (a -> TcRn b) -> [a] -> TcRn [b]
574 -- Drop elements of the input that fail, so the result
575 -- list can be shorter than the argument list
576 mapAndRecoverM _ [] = return []
577 mapAndRecoverM f (x:xs) = do { mb_r <- try_m (f x)
578 ; rs <- mapAndRecoverM f xs
579 ; return (case mb_r of
584 -----------------------
585 tryTc :: TcRn a -> TcRn (Messages, Maybe a)
586 -- (tryTc m) executes m, and returns
587 -- Just r, if m succeeds (returning r)
588 -- Nothing, if m fails
589 -- It also returns all the errors and warnings accumulated by m
590 -- It always succeeds (never raises an exception)
592 = do { errs_var <- newMutVar emptyMessages ;
593 res <- try_m (setErrsVar errs_var m) ;
594 msgs <- readMutVar errs_var ;
595 return (msgs, case res of
597 Right val -> Just val)
598 -- The exception is always the IOEnv built-in
599 -- in exception; see IOEnv.failM
602 -----------------------
603 tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
604 -- Run the thing, returning
605 -- Just r, if m succceeds with no error messages
606 -- Nothing, if m fails, or if it succeeds but has error messages
607 -- Either way, the messages are returned; even in the Just case
608 -- there might be warnings
610 = do { (msgs, res) <- tryTc thing
612 ; let errs_found = errorsFound dflags msgs
613 ; return (msgs, case res of
615 Just val | errs_found -> Nothing
616 | otherwise -> Just val)
619 -----------------------
620 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
621 -- Just like tryTcErrs, except that it ensures that the LIE
622 -- for the thing is propagated only if there are no errors
623 -- Hence it's restricted to the type-check monad
624 tryTcLIE thing_inside
625 = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
627 Nothing -> return (msgs, Nothing)
628 Just val -> do { extendLIEs lie; return (msgs, Just val) }
631 -----------------------
632 tryTcLIE_ :: TcM r -> TcM r -> TcM r
633 -- (tryTcLIE_ r m) tries m;
634 -- if m succeeds with no error messages, it's the answer
635 -- otherwise tryTcLIE_ drops everything from m and tries r instead.
636 tryTcLIE_ recover main
637 = do { (msgs, mb_res) <- tryTcLIE main
639 Just val -> do { addMessages msgs -- There might be warnings
641 Nothing -> recover -- Discard all msgs
644 -----------------------
645 checkNoErrs :: TcM r -> TcM r
646 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
647 -- If m fails then (checkNoErrsTc m) fails.
648 -- If m succeeds, it checks whether m generated any errors messages
649 -- (it might have recovered internally)
650 -- If so, it fails too.
651 -- Regardless, any errors generated by m are propagated to the enclosing context.
653 = do { (msgs, mb_res) <- tryTcLIE main
657 Just val -> return val
660 ifErrsM :: TcRn r -> TcRn r -> TcRn r
661 -- ifErrsM bale_out main
662 -- does 'bale_out' if there are errors in errors collection
663 -- otherwise does 'main'
664 ifErrsM bale_out normal
665 = do { errs_var <- getErrsVar ;
666 msgs <- readMutVar errs_var ;
668 if errorsFound dflags msgs then
673 failIfErrsM :: TcRn ()
674 -- Useful to avoid error cascades
675 failIfErrsM = ifErrsM failM (return ())
679 %************************************************************************
681 Context management and error message generation
684 %************************************************************************
687 getErrCtxt :: TcM ErrCtxt
688 getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
690 setErrCtxt :: ErrCtxt -> TcM a -> TcM a
691 setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
693 addErrCtxt :: Message -> TcM a -> TcM a
694 addErrCtxt msg = addErrCtxtM (\env -> return (env, msg))
696 addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
697 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
699 -- Helper function for the above
700 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
701 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
702 env { tcl_ctxt = upd ctxt })
704 -- Conditionally add an error context
705 maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
706 maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
707 maybeAddErrCtxt Nothing thing_inside = thing_inside
709 popErrCtxt :: TcM a -> TcM a
710 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (_ : ms) -> ms })
712 getInstLoc :: InstOrigin -> TcM InstLoc
714 = do { loc <- getSrcSpanM ; env <- getLclEnv ;
715 return (InstLoc origin loc (tcl_ctxt env)) }
717 addInstCtxt :: InstLoc -> TcM a -> TcM a
718 -- Add the SrcSpan and context from the first Inst in the list
719 -- (they all have similar locations)
720 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
721 = setSrcSpan src_loc (updCtxt (\_ -> ctxt) thing_inside)
724 The addErrTc functions add an error message, but do not cause failure.
725 The 'M' variants pass a TidyEnv that has already been used to
726 tidy up the message; we then use it to tidy the context messages
729 addErrTc :: Message -> TcM ()
730 addErrTc err_msg = do { env0 <- tcInitTidyEnv
731 ; addErrTcM (env0, err_msg) }
733 addErrsTc :: [Message] -> TcM ()
734 addErrsTc err_msgs = mapM_ addErrTc err_msgs
736 addErrTcM :: (TidyEnv, Message) -> TcM ()
737 addErrTcM (tidy_env, err_msg)
738 = do { ctxt <- getErrCtxt ;
740 add_err_tcm tidy_env err_msg loc ctxt }
743 The failWith functions add an error message and cause failure
746 failWithTc :: Message -> TcM a -- Add an error message and fail
748 = addErrTc err_msg >> failM
750 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
751 failWithTcM local_and_msg
752 = addErrTcM local_and_msg >> failM
754 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
755 checkTc True _ = return ()
756 checkTc False err = failWithTc err
759 Warnings have no 'M' variant, nor failure
762 addWarnTc :: Message -> TcM ()
763 addWarnTc msg = do { env0 <- tcInitTidyEnv
764 ; addWarnTcM (env0, msg) }
766 addWarnTcM :: (TidyEnv, Message) -> TcM ()
767 addWarnTcM (env0, msg)
768 = do { ctxt <- getErrCtxt ;
769 ctxt_msgs <- do_ctxt env0 ctxt ;
770 addReport (vcat (ptext (sLit "Warning:") <+> msg : ctxt_to_use ctxt_msgs)) }
772 warnTc :: Bool -> Message -> TcM ()
773 warnTc warn_if_true warn_msg
774 | warn_if_true = addWarnTc warn_msg
775 | otherwise = return ()
778 -----------------------------------
781 We initialise the "tidy-env", used for tidying types before printing,
782 by building a reverse map from the in-scope type variables to the
783 OccName that the programmer originally used for them
786 tcInitTidyEnv :: TcM TidyEnv
788 = do { lcl_env <- getLclEnv
789 ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
790 | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
792 ; return (foldl add emptyTidyEnv nm_tv_prs) }
794 add (env,subst) (name, tyvar)
795 = case tidyOccName env (nameOccName name) of
796 (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
798 tyvar' = setTyVarName tyvar name'
799 name' = tidyNameOcc name occ'
802 -----------------------------------
803 Other helper functions
806 add_err_tcm :: TidyEnv -> Message -> SrcSpan
807 -> [TidyEnv -> TcM (TidyEnv, SDoc)]
809 add_err_tcm tidy_env err_msg loc ctxt
810 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
811 addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
813 do_ctxt :: TidyEnv -> [TidyEnv -> TcM (TidyEnv, SDoc)] -> TcM [SDoc]
816 do_ctxt tidy_env (c:cs)
817 = do { (tidy_env', m) <- c tidy_env ;
818 ms <- do_ctxt tidy_env' cs ;
821 ctxt_to_use :: [SDoc] -> [SDoc]
822 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
823 | otherwise = take 3 ctxt
826 debugTc is useful for monadic debugging code
829 debugTc :: TcM () -> TcM ()
832 | otherwise = return ()
835 %************************************************************************
837 Type constraints (the so-called LIE)
839 %************************************************************************
842 nextDFunIndex :: TcM Int -- Get the next dfun index
843 nextDFunIndex = do { env <- getGblEnv
844 ; let dfun_n_var = tcg_dfun_n env
845 ; n <- readMutVar dfun_n_var
846 ; writeMutVar dfun_n_var (n+1)
849 getLIEVar :: TcM (TcRef LIE)
850 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
852 setLIEVar :: TcRef LIE -> TcM a -> TcM a
853 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
855 getLIE :: TcM a -> TcM (a, [Inst])
856 -- (getLIE m) runs m, and returns the type constraints it generates
858 = do { lie_var <- newMutVar emptyLIE ;
859 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
861 lie <- readMutVar lie_var ;
862 return (res, lieToList lie) }
864 extendLIE :: Inst -> TcM ()
866 = do { lie_var <- getLIEVar ;
867 lie <- readMutVar lie_var ;
868 writeMutVar lie_var (inst `consLIE` lie) }
870 extendLIEs :: [Inst] -> TcM ()
874 = do { lie_var <- getLIEVar ;
875 lie <- readMutVar lie_var ;
876 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
880 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
881 -- Set the local type envt, but do *not* disturb other fields,
882 -- notably the lie_var
883 setLclTypeEnv lcl_env thing_inside
884 = updLclEnv upd thing_inside
886 upd env = env { tcl_env = tcl_env lcl_env,
887 tcl_tyvars = tcl_tyvars lcl_env }
891 %************************************************************************
893 Template Haskell context
895 %************************************************************************
898 recordThUse :: TcM ()
899 recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
901 keepAliveTc :: Id -> TcM () -- Record the name in the keep-alive set
903 | isLocalId id = do { env <- getGblEnv;
904 ; updMutVar (tcg_keep env) (`addOneToNameSet` idName id) }
905 | otherwise = return ()
907 keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
908 keepAliveSetTc ns = do { env <- getGblEnv;
909 ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
911 getStage :: TcM ThStage
912 getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
914 setStage :: ThStage -> TcM a -> TcM a
915 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
919 %************************************************************************
921 Stuff for the renamer's local env
923 %************************************************************************
926 getLocalRdrEnv :: RnM LocalRdrEnv
927 getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
929 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
930 setLocalRdrEnv rdr_env thing_inside
931 = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
935 %************************************************************************
937 Stuff for interface decls
939 %************************************************************************
942 mkIfLclEnv :: Module -> SDoc -> IfLclEnv
943 mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
945 if_tv_env = emptyUFM,
946 if_id_env = emptyUFM }
948 initIfaceTcRn :: IfG a -> TcRn a
949 initIfaceTcRn thing_inside
950 = do { tcg_env <- getGblEnv
951 ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
952 ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
953 ; setEnvs (if_env, ()) thing_inside }
955 initIfaceExtCore :: IfL a -> TcRn a
956 initIfaceExtCore thing_inside
957 = do { tcg_env <- getGblEnv
958 ; let { mod = tcg_mod tcg_env
959 ; doc = ptext (sLit "External Core file for") <+> quotes (ppr mod)
960 ; if_env = IfGblEnv {
961 if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
962 ; if_lenv = mkIfLclEnv mod doc
964 ; setEnvs (if_env, if_lenv) thing_inside }
966 initIfaceCheck :: HscEnv -> IfG a -> IO a
967 -- Used when checking the up-to-date-ness of the old Iface
968 -- Initialise the environment with no useful info at all
969 initIfaceCheck hsc_env do_this
970 = do let rec_types = case hsc_type_env_var hsc_env of
971 Just (mod,var) -> Just (mod, readMutVar var)
973 gbl_env = IfGblEnv { if_rec_types = rec_types }
974 initTcRnIf 'i' hsc_env gbl_env () do_this
976 initIfaceTc :: ModIface
977 -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
978 -- Used when type-checking checking an up-to-date interface file
979 -- No type envt from the current module, but we do know the module dependencies
980 initIfaceTc iface do_this
981 = do { tc_env_var <- newMutVar emptyTypeEnv
982 ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
983 ; if_lenv = mkIfLclEnv mod doc
985 ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
988 mod = mi_module iface
989 doc = ptext (sLit "The interface for") <+> quotes (ppr mod)
991 initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
992 -- Used when sucking in new Rules in SimplCore
993 -- We have available the type envt of the module being compiled, and we must use it
994 initIfaceRules hsc_env guts do_this
996 type_info = (mg_module guts, return (mg_types guts))
997 ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
1000 -- Run the thing; any exceptions just bubble out from here
1001 ; initTcRnIf 'i' hsc_env gbl_env () do_this
1004 initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
1005 initIfaceLcl mod loc_doc thing_inside
1006 = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
1008 getIfModule :: IfL Module
1009 getIfModule = do { env <- getLclEnv; return (if_mod env) }
1011 --------------------
1012 failIfM :: Message -> IfL a
1013 -- The Iface monad doesn't have a place to accumulate errors, so we
1014 -- just fall over fast if one happens; it "shouldnt happen".
1015 -- We use IfL here so that we can get context info out of the local env
1017 = do { env <- getLclEnv
1018 ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
1019 ; liftIO (printErrs (full_msg defaultErrStyle))
1022 --------------------
1023 forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1024 -- Run thing_inside in an interleaved thread.
1025 -- It shares everything with the parent thread, so this is DANGEROUS.
1027 -- It returns Nothing if the computation fails
1029 -- It's used for lazily type-checking interface
1030 -- signatures, which is pretty benign
1032 forkM_maybe doc thing_inside
1033 = do { unsafeInterleaveM $
1034 do { traceIf (text "Starting fork {" <+> doc)
1036 updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1039 Right r -> do { traceIf (text "} ending fork" <+> doc)
1043 -- Bleat about errors in the forked thread, if -ddump-if-trace is on
1044 -- Otherwise we silently discard errors. Errors can legitimately
1045 -- happen when compiling interface signatures (see tcInterfaceSigs)
1046 ifOptM Opt_D_dump_if_trace
1047 (print_errs (hang (text "forkM failed:" <+> doc)
1048 4 (text (show exn))))
1050 ; traceIf (text "} ending fork (badly)" <+> doc)
1054 print_errs sdoc = liftIO (printErrs (sdoc defaultErrStyle))
1056 forkM :: SDoc -> IfL a -> IfL a
1057 forkM doc thing_inside
1058 = do { mb_res <- forkM_maybe doc thing_inside
1059 ; return (case mb_res of
1060 Nothing -> pgmError "Cannot continue after interface file error"
1061 -- pprPanic "forkM" doc