2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[RnMonad]{The monad used by the renamer}
21 #include "HsVersions.h"
23 #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 405
24 import IOExts ( fixIO )
25 #elif defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 302
26 import PrelIOBase ( fixIO ) -- Should be in GlaExts
28 import IOBase ( fixIO )
30 import IOExts ( IORef, newIORef, readIORef, writeIORef, unsafePerformIO )
34 import RnHsSyn ( RenamedFixitySig )
35 import BasicTypes ( Version )
36 import SrcLoc ( noSrcLoc )
37 import ErrUtils ( addShortErrLocLine, addShortWarnLocLine,
38 pprBagOfErrors, ErrMsg, WarnMsg, Message
40 import Name ( Name, OccName, NamedThing(..),
41 isLocallyDefinedName, nameModule, nameOccName,
44 import Module ( Module, ModuleName, ModuleHiMap, SearchPath, WhereFrom,
45 mkModuleHiMaps, moduleName, mkVanillaModule, mkSearchPath
48 import RdrName ( RdrName, dummyRdrVarName, rdrNameOcc )
49 import CmdLineOpts ( opt_D_dump_rn_trace, opt_HiMap )
50 import PrelInfo ( builtinNames )
51 import TysWiredIn ( boolTyCon )
52 import SrcLoc ( SrcLoc, mkGeneratedSrcLoc )
53 import Unique ( Unique, getUnique, unboundKey )
54 import UniqFM ( UniqFM )
55 import FiniteMap ( FiniteMap, emptyFM, bagToFM, lookupFM, addToFM, addListToFM,
56 addListToFM_C, addToFM_C, eltsFM, fmToList
58 import Bag ( Bag, mapBag, emptyBag, isEmptyBag, snocBag )
59 import Maybes ( mapMaybe )
66 infixr 9 `thenRn`, `thenRn_`
70 %************************************************************************
72 \subsection{Somewhat magical interface to other monads}
74 %************************************************************************
77 ioToRnM :: IO r -> RnM d (Either IOError r)
78 ioToRnM io rn_down g_down = (io >>= \ ok -> return (Right ok))
80 (\ err -> return (Left err))
82 traceRn :: SDoc -> RnM d ()
83 traceRn msg | opt_D_dump_rn_trace = putDocRn msg
84 | otherwise = returnRn ()
86 putDocRn :: SDoc -> RnM d ()
87 putDocRn msg = ioToRnM (printErrs msg) `thenRn_`
92 %************************************************************************
94 \subsection{Data types}
96 %************************************************************************
98 %===================================================
99 \subsubsection{ MONAD TYPES}
100 %===================================================
103 type RnM d r = RnDown -> d -> IO r
104 type RnMS r = RnM SDown r -- Renaming source
105 type RnMG r = RnM () r -- Getting global names etc
108 data RnDown = RnDown {
109 rn_mod :: ModuleName,
111 rn_ns :: IORef RnNameSupply,
112 rn_errs :: IORef (Bag WarnMsg, Bag ErrMsg),
113 rn_ifaces :: IORef Ifaces,
114 rn_hi_maps :: (ModuleHiMap, -- for .hi files
115 ModuleHiMap) -- for .hi-boot files
118 -- For renaming source code
122 rn_genv :: GlobalRdrEnv,
123 -- Global envt; the fixity component gets extended
124 -- with local fixity decls
126 rn_lenv :: LocalRdrEnv, -- Local name envt
127 -- Does *not* include global name envt; may shadow it
128 -- Includes both ordinary variables and type variables;
129 -- they are kept distinct because tyvar have a different
130 -- occurrence contructor (Name.TvOcc)
131 -- We still need the unsullied global name env so that
132 -- we can look up record field names
134 rn_fixenv :: FixityEnv -- Local fixities
135 -- The global fixities are held in the
136 -- rn_ifaces field. Why? See the comments
137 -- with RnIfaces.lookupFixity
140 data RnMode = SourceMode -- Renaming source code
141 | InterfaceMode -- Renaming interface declarations.
144 %===================================================
145 \subsubsection{ ENVIRONMENTS}
146 %===================================================
149 --------------------------------
150 type RdrNameEnv a = FiniteMap RdrName a
151 type GlobalRdrEnv = RdrNameEnv [Name] -- The list is because there may be name clashes
152 -- These only get reported on lookup,
153 -- not on construction
154 type LocalRdrEnv = RdrNameEnv Name
156 emptyRdrEnv :: RdrNameEnv a
157 lookupRdrEnv :: RdrNameEnv a -> RdrName -> Maybe a
158 addListToRdrEnv :: RdrNameEnv a -> [(RdrName,a)] -> RdrNameEnv a
159 extendRdrEnv :: RdrNameEnv a -> RdrName -> a -> RdrNameEnv a
161 emptyRdrEnv = emptyFM
162 lookupRdrEnv = lookupFM
163 addListToRdrEnv = addListToFM
165 extendRdrEnv = addToFM
166 rdrEnvToList = fmToList
168 --------------------------------
169 type NameEnv a = UniqFM a -- Domain is Name
171 emptyNameEnv :: NameEnv a
172 nameEnvElts :: NameEnv a -> [a]
173 addToNameEnv_C :: (a->a->a) -> NameEnv a -> Name -> a -> NameEnv a
174 addToNameEnv :: NameEnv a -> Name -> a -> NameEnv a
175 plusNameEnv :: NameEnv a -> NameEnv a -> NameEnv a
176 extendNameEnv :: NameEnv a -> [(Name,a)] -> NameEnv a
177 lookupNameEnv :: NameEnv a -> Name -> Maybe a
178 delFromNameEnv :: NameEnv a -> Name -> NameEnv a
179 elemNameEnv :: Name -> NameEnv a -> Bool
181 emptyNameEnv = emptyUFM
182 nameEnvElts = eltsUFM
183 addToNameEnv_C = addToUFM_C
184 addToNameEnv = addToUFM
185 plusNameEnv = plusUFM
186 extendNameEnv = addListToUFM
187 lookupNameEnv = lookupUFM
188 delFromNameEnv = delFromUFM
189 elemNameEnv = elemUFM
191 --------------------------------
192 type FixityEnv = NameEnv RenamedFixitySig
193 -- We keep the whole fixity sig so that we
194 -- can report line-number info when there is a duplicate
195 -- fixity declaration
199 --------------------------------
203 , FiniteMap String Int
204 -- This is used as a name supply for dictionary functions
205 -- From the inst decl we derive a string, usually by glomming together
206 -- the class and tycon name -- but it doesn't matter exactly how;
207 -- this map then gives a unique int for each inst decl with that
208 -- string. (In Haskell 98 there can only be one,
209 -- but not so in more extended versions; also class CC type T
210 -- and class C type TT might both give the string CCT
212 -- We could just use one Int for all the instance decls, but this
213 -- way the uniques change less when you add an instance decl,
214 -- hence less recompilation
216 , FiniteMap (ModuleName, OccName) Name
217 -- Ensures that one (module,occname) pair gets one unique
218 , FiniteMap OccName Name
219 -- Ensures that one implicit parameter name gets one unique
223 --------------------------------
224 data ExportEnv = ExportEnv Avails Fixities [ModuleName]
225 -- The list of modules is the modules exported
226 -- with 'module M' in the export list
228 type Avails = [AvailInfo]
229 type Fixities = [(Name, Fixity)]
231 type ExportAvails = (FiniteMap ModuleName Avails,
232 -- Used to figure out "module M" export specifiers
233 -- Includes avails only from *unqualified* imports
234 -- (see 1.4 Report Section 5.1.1)
236 NameEnv AvailInfo) -- Used to figure out all other export specifiers.
237 -- Maps a Name to the AvailInfo that contains it
240 data GenAvailInfo name = Avail name -- An ordinary identifier
241 | AvailTC name -- The name of the type or class
242 [name] -- The available pieces of type/class.
243 -- NB: If the type or class is itself
244 -- to be in scope, it must be in this list.
245 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
247 type AvailInfo = GenAvailInfo Name
248 type RdrAvailInfo = GenAvailInfo OccName
251 %===================================================
252 \subsubsection{ INTERFACE FILE STUFF}
253 %===================================================
256 type ExportItem = (ModuleName, [RdrAvailInfo])
257 type VersionInfo name = [ImportVersion name]
259 type ImportVersion name = (ModuleName, Version, WhetherHasOrphans, WhatsImported name)
261 type WhetherHasOrphans = Bool
263 -- * an instance decl in a module other than the defn module for
264 -- one of the tycons or classes in the instance head
265 -- * a transformation rule in a module other than the one defining
266 -- the function in the head of the rule.
268 data WhatsImported name = Everything
269 | Specifically [LocalVersion name] -- List guaranteed non-empty
271 -- ("M", hif, ver, Everything) means there was a "module M" in
272 -- this module's export list, so we just have to go by M's version, "ver",
273 -- not the list of LocalVersions.
276 type LocalVersion name = (name, Version)
280 pi_mod :: Version, -- Module version number
281 pi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
282 pi_usages :: [ImportVersion OccName], -- Usages
283 pi_exports :: [ExportItem], -- Exports
284 pi_decls :: [(Version, RdrNameHsDecl)], -- Local definitions
285 pi_insts :: [RdrNameInstDecl], -- Local instance declarations
286 pi_rules :: [RdrNameRuleDecl], -- Rules
287 pi_deprecs :: [(Maybe FAST_STRING, FAST_STRING)] -- Deprecations, the type is currently only a hack
290 type InterfaceDetails = (WhetherHasOrphans,
291 VersionInfo Name, -- Version information for what this module imports
292 ExportEnv) -- What modules this one depends on
295 -- needed by Main to fish out the fixities assoc list.
296 getIfaceFixities :: InterfaceDetails -> Fixities
297 getIfaceFixities (_, _, ExportEnv _ fs _) = fs
300 type RdrNamePragma = () -- Fudge for now
303 data Ifaces = Ifaces {
304 iImpModInfo :: ImportedModuleInfo,
305 -- Modules this one depends on: that is, the union
306 -- of the modules its *direct* imports depend on.
307 -- NB: The direct imports have .hi files that enumerate *all* the
308 -- dependencies (direct or not) of the imported module.
310 iDecls :: DeclsMap, -- A single, global map of Names to decls
312 iFixes :: FixityEnv, -- A single, global map of Names to fixities
313 -- See comments with RnIfaces.lookupFixity
316 -- All the names (whether "big" or "small", whether wired-in or not,
317 -- whether locally defined or not) that have been slurped in so far.
319 iVSlurp :: [(Name,Version)],
320 -- All the (a) non-wired-in (b) "big" (c) non-locally-defined
321 -- names that have been slurped in so far, with their versions.
322 -- This is used to generate the "usage" information for this module.
323 -- Subset of the previous field.
325 iInsts :: Bag GatedDecl,
326 -- The as-yet un-slurped instance decls; this bag is depleted when we
327 -- slurp an instance decl so that we don't slurp the same one twice.
328 -- Each is 'gated' by the names that must be available before
329 -- this instance decl is needed.
331 iRules :: Bag GatedDecl
332 -- Ditto transformation rules
335 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
337 type ImportedModuleInfo
338 = FiniteMap ModuleName (Version, Bool, Maybe (Module, Bool, Avails))
339 -- Suppose the domain element is module 'A'
341 -- The first Bool is True if A contains
342 -- 'orphan' rules or instance decls
344 -- The second Bool is true if the interface file actually
345 -- read was an .hi-boot file
347 -- Nothing => A's interface not yet read, but this module has
348 -- imported a module, B, that itself depends on A
350 -- Just xx => A's interface has been read. The Module in
351 -- the Just has the correct Dll flag
353 -- This set is used to decide whether to look for
354 -- A.hi or A.hi-boot when importing A.f.
355 -- Basically, we look for A.hi if A is in the map, and A.hi-boot
358 type DeclsMap = NameEnv (Version, AvailInfo, Bool, (Module, RdrNameHsDecl))
359 -- A DeclsMap contains a binding for each Name in the declaration
360 -- including the constructors of a type decl etc.
361 -- The Bool is True just for the 'main' Name.
365 %************************************************************************
367 \subsection{Main monad code}
369 %************************************************************************
372 initRn :: ModuleName -> UniqSupply -> SearchPath -> SrcLoc
374 -> IO (r, Bag ErrMsg, Bag WarnMsg)
376 initRn mod us dirs loc do_rn = do
377 himaps <- mkModuleHiMaps dirs
378 names_var <- newIORef (us, emptyFM, builtins, emptyFM)
379 errs_var <- newIORef (emptyBag,emptyBag)
380 iface_var <- newIORef emptyIfaces
382 rn_down = RnDown { rn_loc = loc, rn_ns = names_var,
385 rn_ifaces = iface_var,
389 res <- do_rn rn_down ()
391 -- grab errors and return
392 (warns, errs) <- readIORef errs_var
394 return (res, errs, warns)
397 initRnMS :: GlobalRdrEnv -> FixityEnv -> RnMode -> RnMS r -> RnM d r
398 initRnMS rn_env fixity_env mode thing_inside rn_down g_down
400 s_down = SDown { rn_genv = rn_env, rn_lenv = emptyRdrEnv,
401 rn_fixenv = fixity_env, rn_mode = mode }
403 thing_inside rn_down s_down
405 initIfaceRnMS :: Module -> RnMS r -> RnM d r
406 initIfaceRnMS mod thing_inside
407 = initRnMS emptyRdrEnv emptyNameEnv InterfaceMode $
408 setModuleRn (moduleName mod) thing_inside
410 emptyIfaces :: Ifaces
411 emptyIfaces = Ifaces { iImpModInfo = emptyFM,
412 iDecls = emptyNameEnv,
413 iFixes = emptyNameEnv,
414 iSlurp = unitNameSet (mkUnboundName dummyRdrVarName),
415 -- Pretend that the dummy unbound name has already been
416 -- slurped. This is what's returned for an out-of-scope name,
417 -- and we don't want thereby to try to suck it in!
423 -- mkUnboundName makes a place-holder Name; it shouldn't be looked at except possibly
424 -- during compiler debugging.
425 mkUnboundName :: RdrName -> Name
426 mkUnboundName rdr_name = mkLocalName unboundKey (rdrNameOcc rdr_name) noSrcLoc
428 isUnboundName :: Name -> Bool
429 isUnboundName name = getUnique name == unboundKey
431 builtins :: FiniteMap (ModuleName,OccName) Name
434 mapBag (\ name -> ((moduleName (nameModule name), nameOccName name), name))
438 @renameSourceCode@ is used to rename stuff ``out-of-line'';
439 that is, not as part of the main renamer.
440 Sole examples: derived definitions,
441 which are only generated in the type checker.
443 The @RnNameSupply@ includes a @UniqueSupply@, so if you call it more than
444 once you must either split it, or install a fresh unique supply.
447 renameSourceCode :: ModuleName
452 renameSourceCode mod_name name_supply m
454 -- It's not really unsafe! When renaming source code we
455 -- only do any I/O if we need to read in a fixity declaration;
456 -- and that doesn't happen in pragmas etc
458 mkModuleHiMaps (mkSearchPath opt_HiMap) >>= \ himaps ->
459 newIORef name_supply >>= \ names_var ->
460 newIORef (emptyBag,emptyBag) >>= \ errs_var ->
462 rn_down = RnDown { rn_loc = mkGeneratedSrcLoc, rn_ns = names_var,
463 rn_errs = errs_var, rn_hi_maps = himaps,
465 rn_ifaces = panic "rnameSourceCode: rn_ifaces" -- Not required
467 s_down = SDown { rn_mode = InterfaceMode,
468 -- So that we can refer to PrelBase.True etc
469 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
470 rn_fixenv = emptyNameEnv }
472 m rn_down s_down >>= \ result ->
474 readIORef errs_var >>= \ (warns,errs) ->
476 (if not (isEmptyBag errs) then
477 pprTrace "Urk! renameSourceCode found errors" (display errs)
479 else if not (isEmptyBag warns) then
480 pprTrace "Note: renameSourceCode found warnings" (display warns)
488 display errs = pprBagOfErrors errs
490 {-# INLINE thenRn #-}
491 {-# INLINE thenRn_ #-}
492 {-# INLINE returnRn #-}
495 returnRn :: a -> RnM d a
496 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
497 thenRn_ :: RnM d a -> RnM d b -> RnM d b
498 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
499 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
500 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
501 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
502 flatMapRn :: (a -> RnM d [b]) -> [a] -> RnM d [b]
503 sequenceRn :: [RnM d a] -> RnM d [a]
504 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
505 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
506 fixRn :: (a -> RnM d a) -> RnM d a
508 returnRn v gdown ldown = return v
509 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
510 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
511 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
512 andRn combiner m1 m2 gdown ldown
513 = m1 gdown ldown >>= \ res1 ->
514 m2 gdown ldown >>= \ res2 ->
515 return (combiner res1 res2)
517 sequenceRn [] = returnRn []
518 sequenceRn (m:ms) = m `thenRn` \ r ->
519 sequenceRn ms `thenRn` \ rs ->
522 mapRn f [] = returnRn []
524 = f x `thenRn` \ r ->
525 mapRn f xs `thenRn` \ rs ->
528 mapRn_ f [] = returnRn ()
533 foldlRn k z [] = returnRn z
534 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
537 mapAndUnzipRn f [] = returnRn ([],[])
538 mapAndUnzipRn f (x:xs)
539 = f x `thenRn` \ (r1, r2) ->
540 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
541 returnRn (r1:rs1, r2:rs2)
543 mapAndUnzip3Rn f [] = returnRn ([],[],[])
544 mapAndUnzip3Rn f (x:xs)
545 = f x `thenRn` \ (r1, r2, r3) ->
546 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
547 returnRn (r1:rs1, r2:rs2, r3:rs3)
549 mapMaybeRn f [] = returnRn []
550 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
551 mapMaybeRn f xs `thenRn` \ rs ->
553 Nothing -> returnRn rs
554 Just r -> returnRn (r:rs)
556 flatMapRn f [] = returnRn []
557 flatMapRn f (x:xs) = f x `thenRn` \ r ->
558 flatMapRn f xs `thenRn` \ rs ->
564 %************************************************************************
566 \subsection{Boring plumbing for common part}
568 %************************************************************************
572 \subsubsection{ Errors and warnings}
573 %=====================
576 failWithRn :: a -> Message -> RnM d a
577 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
578 = readIORef errs_var >>= \ (warns,errs) ->
579 writeIORef errs_var (warns, errs `snocBag` err) >>
582 err = addShortErrLocLine loc msg
584 warnWithRn :: a -> Message -> RnM d a
585 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
586 = readIORef errs_var >>= \ (warns,errs) ->
587 writeIORef errs_var (warns `snocBag` warn, errs) >>
590 warn = addShortWarnLocLine loc msg
592 addErrRn :: Message -> RnM d ()
593 addErrRn err = failWithRn () err
595 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
596 checkRn False err = addErrRn err
597 checkRn True err = returnRn ()
599 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
600 warnCheckRn False err = addWarnRn err
601 warnCheckRn True err = returnRn ()
603 addWarnRn :: Message -> RnM d ()
604 addWarnRn warn = warnWithRn () warn
606 checkErrsRn :: RnM d Bool -- True <=> no errors so far
607 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
608 = readIORef errs_var >>= \ (warns,errs) ->
609 return (isEmptyBag errs)
614 \subsubsection{ Source location}
615 %=====================
618 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
619 pushSrcLocRn loc' m down l_down
620 = m (down {rn_loc = loc'}) l_down
622 getSrcLocRn :: RnM d SrcLoc
623 getSrcLocRn down l_down
624 = return (rn_loc down)
628 \subsubsection{ Name supply}
629 %=====================
632 getNameSupplyRn :: RnM d RnNameSupply
633 getNameSupplyRn rn_down l_down
634 = readIORef (rn_ns rn_down)
636 setNameSupplyRn :: RnNameSupply -> RnM d ()
637 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
638 = writeIORef names_var names'
640 -- See comments with RnNameSupply above.
641 newInstUniq :: String -> RnM d Int
642 newInstUniq key (RnDown {rn_ns = names_var}) l_down
643 = readIORef names_var >>= \ (us, mapInst, cache, ipcache) ->
645 uniq = case lookupFM mapInst key of
648 mapInst' = addToFM mapInst key uniq
650 writeIORef names_var (us, mapInst', cache, ipcache) >>
653 getUniqRn :: RnM d Unique
654 getUniqRn (RnDown {rn_ns = names_var}) l_down
655 = readIORef names_var >>= \ (us, mapInst, cache, ipcache) ->
657 (us1,us') = splitUniqSupply us
659 writeIORef names_var (us', mapInst, cache, ipcache) >>
660 return (uniqFromSupply us1)
664 \subsubsection{ Module}
665 %=====================
668 getModuleRn :: RnM d ModuleName
669 getModuleRn (RnDown {rn_mod = mod_name}) l_down
672 setModuleRn :: ModuleName -> RnM d a -> RnM d a
673 setModuleRn new_mod enclosed_thing rn_down l_down
674 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
678 %************************************************************************
680 \subsection{Plumbing for rename-source part}
682 %************************************************************************
685 \subsubsection{ RnEnv}
686 %=====================
689 getNameEnvs :: RnMS (GlobalRdrEnv, LocalRdrEnv)
690 getNameEnvs rn_down (SDown {rn_genv = global_env, rn_lenv = local_env})
691 = return (global_env, local_env)
693 getLocalNameEnv :: RnMS LocalRdrEnv
694 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
697 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
698 setLocalNameEnv local_env' m rn_down l_down
699 = m rn_down (l_down {rn_lenv = local_env'})
701 getFixityEnv :: RnMS FixityEnv
702 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
705 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
706 extendFixityEnv fixes enclosed_scope
707 rn_down l_down@(SDown {rn_fixenv = fixity_env})
709 new_fixity_env = extendNameEnv fixity_env fixes
711 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
715 \subsubsection{ Mode}
716 %=====================
719 getModeRn :: RnMS RnMode
720 getModeRn rn_down (SDown {rn_mode = mode})
723 setModeRn :: RnMode -> RnMS a -> RnMS a
724 setModeRn new_mode thing_inside rn_down l_down
725 = thing_inside rn_down (l_down {rn_mode = new_mode})
729 %************************************************************************
731 \subsection{Plumbing for rename-globals part}
733 %************************************************************************
736 getIfacesRn :: RnM d Ifaces
737 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
738 = readIORef iface_var
740 setIfacesRn :: Ifaces -> RnM d ()
741 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
742 = writeIORef iface_var ifaces
744 getHiMaps :: RnM d (ModuleHiMap, ModuleHiMap)
745 getHiMaps (RnDown {rn_hi_maps = himaps}) _
750 lookupModuleRn :: ModuleName -> RnM d Module
752 getHiMaps `thenRn` \ (himap, _) ->
753 case lookupFM himap x of
754 Nothing -> returnRn (mkVanillaModule x)
755 Just (_,x) -> returnRn x