7 #include "HsVersions.h"
9 import HsSyn ( MonoBinds(..) )
10 import HscTypes ( HscEnv(..), PersistentCompilerState(..),
11 emptyFixityEnv, emptyGlobalRdrEnv, TyThing,
12 ExternalPackageState(..), HomePackageTable,
13 ModDetails(..), HomeModInfo(..), Deprecations(..),
14 GlobalRdrEnv, LocalRdrEnv, NameCache, FixityEnv,
15 GhciMode, lookupType, unQualInScope )
17 import Module ( Module, moduleName, unitModuleEnv, foldModuleEnv )
18 import Name ( Name, isInternalName )
20 import NameEnv ( extendNameEnvList )
21 import InstEnv ( InstEnv, extendInstEnv )
22 import TysWiredIn ( integerTy, doubleTy )
24 import VarSet ( emptyVarSet )
25 import VarEnv ( TidyEnv, emptyTidyEnv )
26 import RdrName ( emptyRdrEnv )
27 import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
28 addShortErrLocLine, addShortWarnLocLine, printErrorsAndWarnings )
29 import SrcLoc ( SrcLoc, noSrcLoc )
30 import NameEnv ( emptyNameEnv )
31 import Bag ( emptyBag )
33 import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
34 import Unique ( Unique )
35 import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug )
36 import BasicTypes ( FixitySig )
37 import Bag ( snocBag, unionBags )
39 import Maybe ( isJust )
41 import DATA_IOREF ( newIORef, readIORef )
44 %************************************************************************
46 Standard combinators, but specialised for this monad
49 6%************************************************************************
52 mappM :: (a -> TcRn m b) -> [a] -> TcRn m [b]
53 mappM_ :: (a -> TcRn m b) -> [a] -> TcRn m ()
54 -- Funny names to avoid clash with Prelude
55 sequenceM :: [TcRn m a] -> TcRn m [a]
56 foldlM :: (a -> b -> TcRn m a) -> a -> [b] -> TcRn m a
57 mapAndUnzipM :: (a -> TcRn m (b,c)) -> [a] -> TcRn m ([b],[c])
58 mapAndUnzip3M :: (a -> TcRn m (b,c,d)) -> [a] -> TcRn m ([b],[c],[d])
59 checkM :: Bool -> TcRn m () -> TcRn m () -- Perform arg if bool is False
60 ifM :: Bool -> TcRn m () -> TcRn m () -- Perform arg if bool is True
62 mappM f [] = return []
63 mappM f (x:xs) = do { r <- f x; rs <- mappM f xs; return (r:rs) }
65 mappM_ f [] = return ()
66 mappM_ f (x:xs) = f x >> mappM_ f xs
68 sequenceM [] = return []
69 sequenceM (x:xs) = do { r <- x; rs <- sequenceM xs; return (r:rs) }
71 foldlM k z [] = return z
72 foldlM k z (x:xs) = do { r <- k z x; foldlM k r xs }
74 mapAndUnzipM f [] = return ([],[])
75 mapAndUnzipM f (x:xs) = do { (r,s) <- f x;
76 (rs,ss) <- mapAndUnzipM f xs;
79 mapAndUnzip3M f [] = return ([],[], [])
80 mapAndUnzip3M f (x:xs) = do { (r,s,t) <- f x;
81 (rs,ss,ts) <- mapAndUnzip3M f xs;
82 return (r:rs, s:ss, t:ts) }
84 checkM True err = return ()
85 checkM False err = err
87 ifM True do_it = do_it
88 ifM False do_it = return ()
92 %************************************************************************
96 %************************************************************************
99 initTc :: HscEnv -> PersistentCompilerState
102 -> IO (PersistentCompilerState, Maybe r)
103 -- Nothing => error thrown by the thing inside
104 -- (error messages should have been printed already)
106 initTc (HscEnv { hsc_mode = ghci_mode,
108 hsc_dflags = dflags })
110 = do { us <- mkSplitUniqSupply 'a' ;
111 us_var <- newIORef us ;
112 errs_var <- newIORef (emptyBag, emptyBag) ;
113 tvs_var <- newIORef emptyVarSet ;
114 usg_var <- newIORef emptyUsages ;
115 nc_var <- newIORef (pcs_nc pcs) ;
116 eps_var <- newIORef eps ;
119 env = Env { env_top = top_env,
122 env_loc = noSrcLoc } ;
125 top_mode = ghci_mode,
131 top_errs = errs_var } ;
135 tcg_usages = usg_var,
136 tcg_rdr_env = emptyGlobalRdrEnv,
137 tcg_fix_env = emptyFixityEnv,
138 tcg_default = defaultDefaultTys,
139 tcg_type_env = emptyNameEnv,
140 tcg_ist = mkImpTypeEnv eps hpt,
141 tcg_inst_env = mkImpInstEnv dflags eps hpt,
143 tcg_imports = init_imports,
144 tcg_binds = EmptyMonoBinds,
145 tcg_deprecs = NoDeprecs,
152 tcl_level = topStage,
153 tcl_env = emptyNameEnv,
154 tcl_tyvars = tvs_var,
155 tcl_lie = panic "initTc:LIE" } ;
156 -- LIE only valid inside a getLIE
159 -- OK, here's the business end!
160 maybe_res <- catch (do { res <- runTcRn env do_this ;
162 (\_ -> return Nothing) ;
164 -- Print any error messages
165 msgs <- readIORef errs_var ;
166 printErrorsAndWarnings msgs ;
168 -- Get final PCS and return
169 eps' <- readIORef eps_var ;
170 nc' <- readIORef nc_var ;
171 let { pcs' = PCS { pcs_EPS = eps', pcs_nc = nc' } ;
172 final_res | errorsFound dflags msgs = Nothing
173 | otherwise = maybe_res } ;
175 return (pcs', final_res)
180 init_imports = emptyImportAvails { imp_qual = unitModuleEnv mod emptyAvailEnv }
181 -- Initialise tcg_imports with an empty set of bindings for
182 -- this module, so that if we see 'module M' in the export
183 -- list, and there are no bindings in M, we don't bleat
184 -- "unknown module M".
186 defaultDefaultTys :: [Type]
187 defaultDefaultTys = [integerTy, doubleTy]
189 mkImpInstEnv :: DynFlags -> ExternalPackageState -> HomePackageTable -> InstEnv
190 mkImpInstEnv dflags eps hpt
191 = foldModuleEnv (add . md_insts . hm_details)
195 -- We shouldn't get instance conflict errors from
196 -- the package and home type envs
197 add dfuns inst_env = WARN( not (null errs), vcat (map snd errs) ) inst_env'
199 (inst_env', errs) = extendInstEnv dflags inst_env dfuns
201 -- mkImpTypeEnv makes the imported symbol table
202 mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
203 -> Name -> Maybe TyThing
204 mkImpTypeEnv pcs hpt = lookup
207 lookup name | isInternalName name = Nothing
208 | otherwise = lookupType hpt pte name
212 %************************************************************************
216 %************************************************************************
219 getTopEnv :: TcRn m TopEnv
220 getTopEnv = do { env <- getEnv; return (env_top env) }
222 getGblEnv :: TcRn m TcGblEnv
223 getGblEnv = do { env <- getEnv; return (env_gbl env) }
225 updGblEnv :: (TcGblEnv -> TcGblEnv) -> TcRn m a -> TcRn m a
226 updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
227 env { env_gbl = upd gbl })
229 setGblEnv :: TcGblEnv -> TcRn m a -> TcRn m a
230 setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
232 getLclEnv :: TcRn m m
233 getLclEnv = do { env <- getEnv; return (env_lcl env) }
235 updLclEnv :: (m -> m) -> TcRn m a -> TcRn m a
236 updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
237 env { env_lcl = upd lcl })
239 setLclEnv :: m -> TcRn m a -> TcRn n a
240 setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
246 getDOpts :: TcRn m DynFlags
247 getDOpts = do { env <- getTopEnv; return (top_dflags env) }
249 doptM :: DynFlag -> TcRn m Bool
250 doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
252 ifOptM :: DynFlag -> TcRn m () -> TcRn m () -- Do it flag is true
253 ifOptM flag thing_inside = do { b <- doptM flag;
254 if b then thing_inside else return () }
256 getGhciMode :: TcRn m GhciMode
257 getGhciMode = do { env <- getTopEnv; return (top_mode env) }
261 getSrcLocM :: TcRn m SrcLoc
262 -- Avoid clash with Name.getSrcLoc
263 getSrcLocM = do { env <- getEnv; return (env_loc env) }
265 addSrcLoc :: SrcLoc -> TcRn m a -> TcRn m a
266 addSrcLoc loc = updEnv (\env -> env { env_loc = loc })
270 getEps :: TcRn m ExternalPackageState
271 getEps = do { env <- getTopEnv; readMutVar (top_eps env) }
273 setEps :: ExternalPackageState -> TcRn m ()
274 setEps eps = do { env <- getTopEnv; writeMutVar (top_eps env) eps }
276 getHpt :: TcRn m HomePackageTable
277 getHpt = do { env <- getTopEnv; return (top_hpt env) }
279 getModule :: TcRn m Module
280 getModule = do { env <- getGblEnv; return (tcg_mod env) }
282 getGlobalRdrEnv :: TcRn m GlobalRdrEnv
283 getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
285 getImports :: TcRn m ImportAvails
286 getImports = do { env <- getGblEnv; return (tcg_imports env) }
288 getFixityEnv :: TcRn m FixityEnv
289 getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
291 extendFixityEnv :: [(Name,FixitySig Name)] -> RnM a -> RnM a
292 extendFixityEnv new_bit
293 = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
294 env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
296 getDefaultTys :: TcRn m [Type]
297 getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
301 getUsageVar :: TcRn m (TcRef EntityUsage)
302 getUsageVar = do { env <- getGblEnv; return (tcg_usages env) }
304 getUsages :: TcRn m EntityUsage
305 getUsages = do { usg_var <- getUsageVar; readMutVar usg_var }
307 updUsages :: (EntityUsage -> EntityUsage) -> TcRn m ()
308 updUsages upd = do { usg_var <- getUsageVar ;
309 usg <- readMutVar usg_var ;
310 writeMutVar usg_var (upd usg) }
314 %************************************************************************
318 %************************************************************************
321 getErrsVar :: TcRn m (TcRef Messages)
322 getErrsVar = do { env <- getTopEnv; return (top_errs env) }
324 setErrsVar :: TcRef Messages -> TcRn m a -> TcRn m a
325 setErrsVar v = updEnv (\ env@(Env { env_top = top_env }) ->
326 env { env_top = top_env { top_errs = v }})
328 addErr :: Message -> TcRn m ()
329 addErr msg = do { loc <- getSrcLocM ; addErrAt loc msg }
331 addErrAt :: SrcLoc -> Message -> TcRn m ()
333 = do { errs_var <- getErrsVar ;
334 rdr_env <- getGlobalRdrEnv ;
335 let { err = addShortErrLocLine loc (unQualInScope rdr_env) msg } ;
336 (warns, errs) <- readMutVar errs_var ;
337 writeMutVar errs_var (warns, errs `snocBag` err) }
339 addErrs :: [(SrcLoc,Message)] -> TcRn m ()
340 addErrs msgs = mappM_ add msgs
342 add (loc,msg) = addErrAt loc msg
344 addWarn :: Message -> TcRn m ()
346 = do { errs_var <- getErrsVar ;
348 rdr_env <- getGlobalRdrEnv ;
349 let { warn = addShortWarnLocLine loc (unQualInScope rdr_env) msg } ;
350 (warns, errs) <- readMutVar errs_var ;
351 writeMutVar errs_var (warns `snocBag` warn, errs) }
353 checkErr :: Bool -> Message -> TcRn m ()
354 -- Add the error if the bool is False
355 checkErr ok msg = checkM ok (addErr msg)
357 warnIf :: Bool -> Message -> TcRn m ()
358 warnIf True msg = addWarn msg
359 warnIf False msg = return ()
361 addMessages :: Messages -> TcRn m ()
362 addMessages (m_warns, m_errs)
363 = do { errs_var <- getErrsVar ;
364 (warns, errs) <- readMutVar errs_var ;
365 writeMutVar errs_var (warns `unionBags` m_warns,
366 errs `unionBags` m_errs) }
371 recoverM :: TcRn m r -- Recovery action; do this if the main one fails
372 -> TcRn m r -- Main action: do this first
374 recoverM recover thing
375 = do { mb_res <- tryM thing ;
378 Right res -> returnM res }
380 tryTc :: TcRn m a -> TcRn m (Messages, Maybe a)
381 -- (tryTc m) executes m, and returns
382 -- Just r, if m succeeds (returning r) and caused no errors
383 -- Nothing, if m fails, or caused errors
384 -- It also returns all the errors accumulated by m
385 -- (even in the Just case, there might be warnings)
387 -- It always succeeds (never raises an exception)
389 = do { errs_var <- newMutVar emptyMessages ;
391 mb_r <- tryM (setErrsVar errs_var m) ;
393 new_errs <- readMutVar errs_var ;
400 Right r | errorsFound dflags new_errs -> Nothing
401 | otherwise -> Just r)
404 tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
405 -- Just like tryTc, except that it ensures that the LIE
406 -- for the thing is propagated only if there are no errors
407 -- Hence it's restricted to the type-check monad
408 tryTcLIE thing_inside
409 = do { ((errs, mb_r), lie) <- getLIE (tryTc thing_inside) ;
410 ifM (isJust mb_r) (extendLIEs lie) ;
411 return (errs, mb_r) }
413 tryTcLIE_ :: TcM r -> TcM r -> TcM r
414 -- (tryM_ r m) tries m; if it succeeds it returns it,
415 -- otherwise it returns r. Any error messages added by m are discarded,
416 -- whether or not m succeeds.
417 tryTcLIE_ recover main
418 = do { (_msgs, mb_res) <- tryTcLIE main ;
420 Just res -> return res
423 checkNoErrs :: TcM r -> TcM r
424 -- (checkNoErrs m) succeeds iff m succeeds and generates no errors
425 -- If m fails then (checkNoErrsTc m) fails.
426 -- If m succeeds, it checks whether m generated any errors messages
427 -- (it might have recovered internally)
428 -- If so, it fails too.
429 -- Regardless, any errors generated by m are propagated to the enclosing context.
431 = do { (msgs, mb_res) <- tryTcLIE main ;
438 ifErrsM :: TcRn m r -> TcRn m r -> TcRn m r
439 -- ifErrsM bale_out main
440 -- does 'bale_out' if there are errors in errors collection
441 -- otherwise does 'main'
442 ifErrsM bale_out normal
443 = do { errs_var <- getErrsVar ;
444 msgs <- readMutVar errs_var ;
446 if errorsFound dflags msgs then
451 failIfErrsM :: TcRn m ()
452 -- Useful to avoid error cascades
453 failIfErrsM = ifErrsM failM (return ())
457 forkM :: SDoc -> TcM a -> TcM (Maybe a)
458 -- Run thing_inside in an interleaved thread. It gets a separate
461 -- but everything else is shared, so this is DANGEROUS.
463 -- It returns Nothing if the computation fails
465 -- It's used for lazily type-checking interface
466 -- signatures, which is pretty benign
468 forkM doc thing_inside
469 = do { us <- newUniqueSupply ;
471 do { us_var <- newMutVar us ;
472 (msgs, mb_res) <- tryTcLIE (setUsVar us_var thing_inside) ;
474 Just r -> return (Just r)
476 -- Bleat about errors in the forked thread
477 ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
478 printErrorsAndWarnings msgs }) ;
482 hdr_doc = text "forkM failed:" <+> doc
486 %************************************************************************
490 %************************************************************************
493 getUsVar :: TcRn m (TcRef UniqSupply)
494 getUsVar = do { env <- getTopEnv; return (top_us env) }
496 setUsVar :: TcRef UniqSupply -> TcRn m a -> TcRn m a
497 setUsVar v = updEnv (\ env@(Env { env_top = top_env }) ->
498 env { env_top = top_env { top_us = v }})
500 newUnique :: TcRn m Unique
501 newUnique = do { us <- newUniqueSupply ;
502 return (uniqFromSupply us) }
504 newUniqueSupply :: TcRn m UniqSupply
506 = do { u_var <- getUsVar ;
507 us <- readMutVar u_var ;
508 let { (us1, us2) = splitUniqSupply us } ;
509 writeMutVar u_var us1 ;
515 getNameCache :: TcRn m NameCache
516 getNameCache = do { TopEnv { top_nc = nc_var } <- getTopEnv;
519 setNameCache :: NameCache -> TcRn m ()
520 setNameCache nc = do { TopEnv { top_nc = nc_var } <- getTopEnv;
521 writeMutVar nc_var nc }
525 %************************************************************************
529 %************************************************************************
532 traceTc, traceRn :: SDoc -> TcRn a ()
533 traceRn = dumpOptTcRn Opt_D_dump_rn_trace
534 traceTc = dumpOptTcRn Opt_D_dump_tc_trace
535 traceSplice = dumpOptTcRn Opt_D_dump_splices
536 traceHiDiffs = dumpOptTcRn Opt_D_dump_hi_diffs
538 dumpOptTcRn :: DynFlag -> SDoc -> TcRn a ()
539 dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
541 dumpTcRn :: SDoc -> TcRn a ()
542 dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
543 ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
547 %************************************************************************
549 Context management and error message generation
552 %************************************************************************
555 setErrCtxtM, addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
556 setErrCtxtM msg = updCtxt (\ msgs -> [msg])
557 addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
559 setErrCtxt, addErrCtxt :: Message -> TcM a -> TcM a
560 setErrCtxt msg = setErrCtxtM (\env -> returnM (env, msg))
561 addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
563 popErrCtxt :: TcM a -> TcM a
564 popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
566 getErrCtxt :: TcM ErrCtxt
567 getErrCtxt = do { env <- getLclEnv ; return (tcl_ctxt env) }
569 -- Helper function for the above
570 updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
571 updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
572 env { tcl_ctxt = upd ctxt })
574 getInstLoc :: InstOrigin -> TcM InstLoc
576 = do { loc <- getSrcLocM ; env <- getLclEnv ;
577 return (InstLoc origin loc (tcl_ctxt env)) }
579 addInstCtxt :: InstLoc -> TcM a -> TcM a
580 -- Add the SrcLoc and context from the first Inst in the list
581 -- (they all have similar locations)
582 addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
583 = addSrcLoc src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
586 The addErrTc functions add an error message, but do not cause failure.
587 The 'M' variants pass a TidyEnv that has already been used to
588 tidy up the message; we then use it to tidy the context messages
591 addErrTc :: Message -> TcM ()
592 addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
594 addErrsTc :: [Message] -> TcM ()
595 addErrsTc err_msgs = mappM_ addErrTc err_msgs
597 addErrTcM :: (TidyEnv, Message) -> TcM ()
598 addErrTcM (tidy_env, err_msg)
599 = do { ctxt <- getErrCtxt ;
601 add_err_tcm tidy_env err_msg loc ctxt }
604 The failWith functions add an error message and cause failure
607 failWithTc :: Message -> TcM a -- Add an error message and fail
609 = addErrTc err_msg >> failM
611 failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
612 failWithTcM local_and_msg
613 = addErrTcM local_and_msg >> failM
615 checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
616 checkTc True err = returnM ()
617 checkTc False err = failWithTc err
620 Warnings have no 'M' variant, nor failure
623 addWarnTc :: Message -> TcM ()
625 = do { ctxt <- getErrCtxt ;
626 ctxt_msgs <- do_ctxt emptyTidyEnv ctxt ;
627 addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
629 warnTc :: Bool -> Message -> TcM ()
630 warnTc warn_if_true warn_msg
631 | warn_if_true = addWarnTc warn_msg
632 | otherwise = return ()
638 add_err_tcm tidy_env err_msg loc ctxt
639 = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
640 addErrAt loc (vcat (err_msg : ctxt_to_use ctxt_msgs)) }
644 do_ctxt tidy_env (c:cs)
645 = do { (tidy_env', m) <- c tidy_env ;
646 ms <- do_ctxt tidy_env' cs ;
649 ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
650 | otherwise = take 3 ctxt
653 %************************************************************************
655 Other stuff specific to type checker
657 %************************************************************************
660 getLIEVar :: TcM (TcRef LIE)
661 getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
663 setLIEVar :: TcRef LIE -> TcM a -> TcM a
664 setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
666 getLIE :: TcM a -> TcM (a, [Inst])
667 -- (getLIE m) runs m, and returns the type constraints it generates
669 = do { lie_var <- newMutVar emptyLIE ;
670 res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
672 lie <- readMutVar lie_var ;
673 return (res, lieToList lie) }
675 extendLIE :: Inst -> TcM ()
677 = do { lie_var <- getLIEVar ;
678 lie <- readMutVar lie_var ;
679 writeMutVar lie_var (inst `consLIE` lie) }
681 extendLIEs :: [Inst] -> TcM ()
685 = do { lie_var <- getLIEVar ;
686 lie <- readMutVar lie_var ;
687 writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
692 getStage :: TcM Stage
693 getStage = do { env <- getLclEnv; return (tcl_level env) }
695 setStage :: Stage -> TcM a -> TcM a
696 setStage s = updLclEnv (\ env -> env { tcl_level = s })
698 setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
699 -- Set the local type envt, but do *not* disturb other fields,
700 -- notably the lie_var
701 setLclTypeEnv lcl_env thing_inside
702 = updLclEnv upd thing_inside
704 upd env = env { tcl_env = tcl_env lcl_env,
705 tcl_tyvars = tcl_tyvars lcl_env }
709 %************************************************************************
711 Stuff for the renamer's local env
713 %************************************************************************
716 initRn :: RnMode -> RnM a -> TcRn m a
717 initRn mode thing_inside
718 = do { env <- getGblEnv ;
719 let { lcl_env = RnLclEnv {
721 rn_lenv = emptyRdrEnv }} ;
722 setLclEnv lcl_env thing_inside }
726 getLocalRdrEnv :: RnM LocalRdrEnv
727 getLocalRdrEnv = do { env <- getLclEnv; return (rn_lenv env) }
729 setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
730 setLocalRdrEnv rdr_env thing_inside
731 = updLclEnv (\env -> env {rn_lenv = rdr_env}) thing_inside
733 getModeRn :: RnM RnMode
734 getModeRn = do { env <- getLclEnv; return (rn_mode env) }