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__ >= 302
24 import PrelIOBase ( fixIO ) -- Should be in GlaExts
26 import IOBase ( fixIO )
28 import IOExts ( IORef, newIORef, readIORef, writeIORef, unsafePerformIO )
32 import RnHsSyn ( RenamedFixitySig )
33 import BasicTypes ( Version )
34 import SrcLoc ( noSrcLoc )
35 import ErrUtils ( addShortErrLocLine, addShortWarnLocLine,
36 pprBagOfErrors, ErrMsg, WarnMsg, Message
38 import Name ( Name, OccName, NamedThing(..),
39 isLocallyDefinedName, nameModule, nameOccName,
42 import Module ( Module, ModuleName, ModuleHiMap, SearchPath, WhereFrom,
43 mkModuleHiMaps, moduleName
46 import RdrName ( RdrName, dummyRdrVarName, rdrNameOcc )
47 import CmdLineOpts ( opt_D_dump_rn_trace, opt_IgnoreIfacePragmas )
48 import PrelInfo ( builtinNames )
49 import TysWiredIn ( boolTyCon )
50 import SrcLoc ( SrcLoc, mkGeneratedSrcLoc )
51 import Unique ( Unique, getUnique, unboundKey )
52 import UniqFM ( UniqFM )
53 import FiniteMap ( FiniteMap, emptyFM, bagToFM, lookupFM, addToFM, addListToFM,
54 addListToFM_C, addToFM_C, eltsFM, fmToList
56 import Bag ( Bag, mapBag, emptyBag, isEmptyBag, snocBag )
57 import Maybes ( mapMaybe )
64 infixr 9 `thenRn`, `thenRn_`
68 %************************************************************************
70 \subsection{Somewhat magical interface to other monads}
72 %************************************************************************
75 ioToRnM :: IO r -> RnM d (Either IOError r)
76 ioToRnM io rn_down g_down = (io >>= \ ok -> return (Right ok))
78 (\ err -> return (Left err))
80 traceRn :: SDoc -> RnM d ()
81 traceRn msg | opt_D_dump_rn_trace = putDocRn msg
82 | otherwise = returnRn ()
84 putDocRn :: SDoc -> RnM d ()
85 putDocRn msg = ioToRnM (printErrs msg) `thenRn_`
90 %************************************************************************
92 \subsection{Data types}
94 %************************************************************************
96 %===================================================
97 \subsubsection{ MONAD TYPES}
98 %===================================================
101 type RnM d r = RnDown -> d -> IO r
102 type RnMS r = RnM SDown r -- Renaming source
103 type RnMG r = RnM () r -- Getting global names etc
106 data RnDown = RnDown {
107 rn_mod :: ModuleName,
109 rn_ns :: IORef RnNameSupply,
110 rn_errs :: IORef (Bag WarnMsg, Bag ErrMsg),
111 rn_ifaces :: IORef Ifaces,
112 rn_hi_maps :: (ModuleHiMap, -- for .hi files
113 ModuleHiMap) -- for .hi-boot files
116 -- For renaming source code
120 rn_genv :: GlobalRdrEnv,
121 -- Global envt; the fixity component gets extended
122 -- with local fixity decls
124 rn_lenv :: LocalRdrEnv, -- Local name envt
125 -- Does *not* include global name envt; may shadow it
126 -- Includes both ordinary variables and type variables;
127 -- they are kept distinct because tyvar have a different
128 -- occurrence contructor (Name.TvOcc)
129 -- We still need the unsullied global name env so that
130 -- we can look up record field names
132 rn_fixenv :: FixityEnv -- Local fixities
133 -- The global ones are held in the
137 data RnMode = SourceMode -- Renaming source code
138 | InterfaceMode -- Renaming interface declarations.
141 %===================================================
142 \subsubsection{ ENVIRONMENTS}
143 %===================================================
146 --------------------------------
147 type RdrNameEnv a = FiniteMap RdrName a
148 type GlobalRdrEnv = RdrNameEnv [Name] -- The list is because there may be name clashes
149 -- These only get reported on lookup,
150 -- not on construction
151 type LocalRdrEnv = RdrNameEnv Name
153 emptyRdrEnv :: RdrNameEnv a
154 lookupRdrEnv :: RdrNameEnv a -> RdrName -> Maybe a
155 addListToRdrEnv :: RdrNameEnv a -> [(RdrName,a)] -> RdrNameEnv a
156 extendRdrEnv :: RdrNameEnv a -> RdrName -> a -> RdrNameEnv a
158 emptyRdrEnv = emptyFM
159 lookupRdrEnv = lookupFM
160 addListToRdrEnv = addListToFM
162 extendRdrEnv = addToFM
163 rdrEnvToList = fmToList
165 --------------------------------
166 type NameEnv a = UniqFM a -- Domain is Name
168 emptyNameEnv :: NameEnv a
169 nameEnvElts :: NameEnv a -> [a]
170 addToNameEnv_C :: (a->a->a) -> NameEnv a -> Name -> a -> NameEnv a
171 addToNameEnv :: NameEnv a -> Name -> a -> NameEnv a
172 plusNameEnv :: NameEnv a -> NameEnv a -> NameEnv a
173 extendNameEnv :: NameEnv a -> [(Name,a)] -> NameEnv a
174 lookupNameEnv :: NameEnv a -> Name -> Maybe a
175 delFromNameEnv :: NameEnv a -> Name -> NameEnv a
176 elemNameEnv :: Name -> NameEnv a -> Bool
178 emptyNameEnv = emptyUFM
179 nameEnvElts = eltsUFM
180 addToNameEnv_C = addToUFM_C
181 addToNameEnv = addToUFM
182 plusNameEnv = plusUFM
183 extendNameEnv = addListToUFM
184 lookupNameEnv = lookupUFM
185 delFromNameEnv = delFromUFM
186 elemNameEnv = elemUFM
188 --------------------------------
189 type FixityEnv = NameEnv RenamedFixitySig
190 -- We keep the whole fixity sig so that we
191 -- can report line-number info when there is a duplicate
192 -- fixity declaration
196 --------------------------------
200 , FiniteMap String Int
201 -- This is used as a name supply for dictionary functions
202 -- From the inst decl we derive a string, usually by glomming together
203 -- the class and tycon name -- but it doesn't matter exactly how;
204 -- this map then gives a unique int for each inst decl with that
205 -- string. (In Haskell 98 there can only be one,
206 -- but not so in more extended versions; also class CC type T
207 -- and class C type TT might both give the string CCT
209 -- We could just use one Int for all the instance decls, but this
210 -- way the uniques change less when you add an instance decl,
211 -- hence less recompilation
213 , FiniteMap (ModuleName, OccName) Name
214 -- Ensures that one (module,occname) pair gets one unique
218 --------------------------------
219 data ExportEnv = ExportEnv Avails Fixities
220 type Avails = [AvailInfo]
221 type Fixities = [(Name, Fixity)]
223 type ExportAvails = (FiniteMap ModuleName Avails,
224 -- Used to figure out "module M" export specifiers
225 -- Includes avails only from *unqualified* imports
226 -- (see 1.4 Report Section 5.1.1)
228 NameEnv AvailInfo) -- Used to figure out all other export specifiers.
229 -- Maps a Name to the AvailInfo that contains it
232 data GenAvailInfo name = Avail name -- An ordinary identifier
233 | AvailTC name -- The name of the type or class
234 [name] -- The available pieces of type/class.
235 -- NB: If the type or class is itself
236 -- to be in scope, it must be in this list.
237 -- Thus, typically: AvailTC Eq [Eq, ==, /=]
239 type AvailInfo = GenAvailInfo Name
240 type RdrAvailInfo = GenAvailInfo OccName
243 %===================================================
244 \subsubsection{ INTERFACE FILE STUFF}
245 %===================================================
248 type ExportItem = (ModuleName, [RdrAvailInfo])
249 type VersionInfo name = [ImportVersion name]
251 type ImportVersion name = (ModuleName, Version, WhetherHasOrphans, WhatsImported name)
253 type WhetherHasOrphans = Bool
255 -- * an instance decl in a module other than the defn module for
256 -- one of the tycons or classes in the instance head
257 -- * a transformation rule in a module other than the one defining
258 -- the function in the head of the rule.
260 data WhatsImported name = Everything
261 | Specifically [LocalVersion name] -- List guaranteed non-empty
263 -- ("M", hif, ver, Everything) means there was a "module M" in
264 -- this module's export list, so we just have to go by M's version, "ver",
265 -- not the list of LocalVersions.
268 type LocalVersion name = (name, Version)
272 pi_mod :: Version, -- Module version number
273 pi_orphan :: WhetherHasOrphans, -- Whether this module has orphans
274 pi_usages :: [ImportVersion OccName], -- Usages
275 pi_exports :: [ExportItem], -- Exports
276 pi_decls :: [(Version, RdrNameHsDecl)], -- Local definitions
277 pi_insts :: [RdrNameInstDecl], -- Local instance declarations
278 pi_rules :: [RdrNameRuleDecl] -- Rules
281 type InterfaceDetails = (WhetherHasOrphans,
282 VersionInfo Name, -- Version information for what this module imports
283 ExportEnv) -- What modules this one depends on
286 -- needed by Main to fish out the fixities assoc list.
287 getIfaceFixities :: InterfaceDetails -> Fixities
288 getIfaceFixities (_, _, ExportEnv _ fs) = fs
291 type RdrNamePragma = () -- Fudge for now
294 data Ifaces = Ifaces {
295 iImpModInfo :: ImportedModuleInfo,
296 -- Modules this one depends on: that is, the union
297 -- of the modules its direct imports depend on.
299 iDecls :: DeclsMap, -- A single, global map of Names to decls
301 iFixes :: FixityEnv, -- A single, global map of Names to fixities
304 -- All the names (whether "big" or "small", whether wired-in or not,
305 -- whether locally defined or not) that have been slurped in so far.
307 iVSlurp :: [(Name,Version)],
308 -- All the (a) non-wired-in (b) "big" (c) non-locally-defined
309 -- names that have been slurped in so far, with their versions.
310 -- This is used to generate the "usage" information for this module.
311 -- Subset of the previous field.
313 iInsts :: Bag GatedDecl,
314 -- The as-yet un-slurped instance decls; this bag is depleted when we
315 -- slurp an instance decl so that we don't slurp the same one twice.
316 -- Each is 'gated' by the names that must be available before
317 -- this instance decl is needed.
319 iRules :: Bag GatedDecl
320 -- Ditto transformation rules
323 type GatedDecl = (NameSet, (Module, RdrNameHsDecl))
325 type ImportedModuleInfo
326 = FiniteMap ModuleName (Version, Bool, Maybe (Module, Bool, Avails))
327 -- Suppose the domain element is module 'A'
329 -- The first Bool is True if A contains
330 -- 'orphan' rules or instance decls
332 -- The second Bool is true if the interface file actually
333 -- read was an .hi-boot file
335 -- Nothing => A's interface not yet read, but this module has
336 -- imported a module, B, that itself depends on A
338 -- Just xx => A's interface has been read. The Module in
339 -- the Just has the correct Dll flag
341 -- This set is used to decide whether to look for
342 -- A.hi or A.hi-boot when importing A.f.
343 -- Basically, we look for A.hi if A is in the map, and A.hi-boot
346 type DeclsMap = NameEnv (Version, AvailInfo, Bool, (Module, RdrNameHsDecl))
347 -- A DeclsMap contains a binding for each Name in the declaration
348 -- including the constructors of a type decl etc.
349 -- The Bool is True just for the 'main' Name.
353 %************************************************************************
355 \subsection{Main monad code}
357 %************************************************************************
360 initRn :: ModuleName -> UniqSupply -> SearchPath -> SrcLoc
362 -> IO (r, Bag ErrMsg, Bag WarnMsg)
364 initRn mod us dirs loc do_rn = do
365 himaps <- mkModuleHiMaps dirs
366 names_var <- newIORef (us, emptyFM, builtins)
367 errs_var <- newIORef (emptyBag,emptyBag)
368 iface_var <- newIORef emptyIfaces
370 rn_down = RnDown { rn_loc = loc, rn_ns = names_var,
373 rn_ifaces = iface_var,
377 res <- do_rn rn_down ()
379 -- grab errors and return
380 (warns, errs) <- readIORef errs_var
382 return (res, errs, warns)
385 initRnMS :: GlobalRdrEnv -> FixityEnv -> RnMode -> RnMS r -> RnM d r
386 initRnMS rn_env fixity_env mode thing_inside rn_down g_down
388 s_down = SDown { rn_genv = rn_env, rn_lenv = emptyRdrEnv,
389 rn_fixenv = fixity_env, rn_mode = mode }
391 thing_inside rn_down s_down
393 initIfaceRnMS :: Module -> RnMS r -> RnM d r
394 initIfaceRnMS mod thing_inside
395 = initRnMS emptyRdrEnv emptyNameEnv InterfaceMode $
396 setModuleRn (moduleName mod) thing_inside
398 emptyIfaces :: Ifaces
399 emptyIfaces = Ifaces { iImpModInfo = emptyFM,
400 iDecls = emptyNameEnv,
401 iFixes = emptyNameEnv,
402 iSlurp = unitNameSet (mkUnboundName dummyRdrVarName),
403 -- Pretend that the dummy unbound name has already been
404 -- slurped. This is what's returned for an out-of-scope name,
405 -- and we don't want thereby to try to suck it in!
411 -- mkUnboundName makes a place-holder Name; it shouldn't be looked at except possibly
412 -- during compiler debugging.
413 mkUnboundName :: RdrName -> Name
414 mkUnboundName rdr_name = mkLocalName unboundKey (rdrNameOcc rdr_name) noSrcLoc
416 isUnboundName :: Name -> Bool
417 isUnboundName name = getUnique name == unboundKey
419 builtins :: FiniteMap (ModuleName,OccName) Name
422 mapBag (\ name -> ((moduleName (nameModule name), nameOccName name), name))
426 @renameSourceCode@ is used to rename stuff ``out-of-line'';
427 that is, not as part of the main renamer.
428 Sole examples: derived definitions,
429 which are only generated in the type checker.
431 The @RnNameSupply@ includes a @UniqueSupply@, so if you call it more than
432 once you must either split it, or install a fresh unique supply.
435 renameSourceCode :: ModuleName
440 renameSourceCode mod_name name_supply m
442 -- It's not really unsafe! When renaming source code we
443 -- only do any I/O if we need to read in a fixity declaration;
444 -- and that doesn't happen in pragmas etc
446 newIORef name_supply >>= \ names_var ->
447 newIORef (emptyBag,emptyBag) >>= \ errs_var ->
449 rn_down = RnDown { rn_loc = mkGeneratedSrcLoc, rn_ns = names_var,
452 s_down = SDown { rn_mode = InterfaceMode,
453 -- So that we can refer to PrelBase.True etc
454 rn_genv = emptyRdrEnv, rn_lenv = emptyRdrEnv,
455 rn_fixenv = emptyNameEnv }
457 m rn_down s_down >>= \ result ->
459 readIORef errs_var >>= \ (warns,errs) ->
461 (if not (isEmptyBag errs) then
462 pprTrace "Urk! renameSourceCode found errors" (display errs)
464 else if not (isEmptyBag warns) then
465 pprTrace "Note: renameSourceCode found warnings" (display warns)
473 display errs = pprBagOfErrors errs
475 {-# INLINE thenRn #-}
476 {-# INLINE thenRn_ #-}
477 {-# INLINE returnRn #-}
480 returnRn :: a -> RnM d a
481 thenRn :: RnM d a -> (a -> RnM d b) -> RnM d b
482 thenRn_ :: RnM d a -> RnM d b -> RnM d b
483 andRn :: (a -> a -> a) -> RnM d a -> RnM d a -> RnM d a
484 mapRn :: (a -> RnM d b) -> [a] -> RnM d [b]
485 mapRn_ :: (a -> RnM d b) -> [a] -> RnM d ()
486 mapMaybeRn :: (a -> RnM d (Maybe b)) -> [a] -> RnM d [b]
487 sequenceRn :: [RnM d a] -> RnM d [a]
488 foldlRn :: (b -> a -> RnM d b) -> b -> [a] -> RnM d b
489 mapAndUnzipRn :: (a -> RnM d (b,c)) -> [a] -> RnM d ([b],[c])
490 fixRn :: (a -> RnM d a) -> RnM d a
492 returnRn v gdown ldown = return v
493 thenRn m k gdown ldown = m gdown ldown >>= \ r -> k r gdown ldown
494 thenRn_ m k gdown ldown = m gdown ldown >> k gdown ldown
495 fixRn m gdown ldown = fixIO (\r -> m r gdown ldown)
496 andRn combiner m1 m2 gdown ldown
497 = m1 gdown ldown >>= \ res1 ->
498 m2 gdown ldown >>= \ res2 ->
499 return (combiner res1 res2)
501 sequenceRn [] = returnRn []
502 sequenceRn (m:ms) = m `thenRn` \ r ->
503 sequenceRn ms `thenRn` \ rs ->
506 mapRn f [] = returnRn []
508 = f x `thenRn` \ r ->
509 mapRn f xs `thenRn` \ rs ->
512 mapRn_ f [] = returnRn ()
517 foldlRn k z [] = returnRn z
518 foldlRn k z (x:xs) = k z x `thenRn` \ z' ->
521 mapAndUnzipRn f [] = returnRn ([],[])
522 mapAndUnzipRn f (x:xs)
523 = f x `thenRn` \ (r1, r2) ->
524 mapAndUnzipRn f xs `thenRn` \ (rs1, rs2) ->
525 returnRn (r1:rs1, r2:rs2)
527 mapAndUnzip3Rn f [] = returnRn ([],[],[])
528 mapAndUnzip3Rn f (x:xs)
529 = f x `thenRn` \ (r1, r2, r3) ->
530 mapAndUnzip3Rn f xs `thenRn` \ (rs1, rs2, rs3) ->
531 returnRn (r1:rs1, r2:rs2, r3:rs3)
533 mapMaybeRn f [] = returnRn []
534 mapMaybeRn f (x:xs) = f x `thenRn` \ maybe_r ->
535 mapMaybeRn f xs `thenRn` \ rs ->
537 Nothing -> returnRn rs
538 Just r -> returnRn (r:rs)
543 %************************************************************************
545 \subsection{Boring plumbing for common part}
547 %************************************************************************
551 \subsubsection{ Errors and warnings}
552 %=====================
555 failWithRn :: a -> Message -> RnM d a
556 failWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
557 = readIORef errs_var >>= \ (warns,errs) ->
558 writeIORef errs_var (warns, errs `snocBag` err) >>
561 err = addShortErrLocLine loc msg
563 warnWithRn :: a -> Message -> RnM d a
564 warnWithRn res msg (RnDown {rn_errs = errs_var, rn_loc = loc}) l_down
565 = readIORef errs_var >>= \ (warns,errs) ->
566 writeIORef errs_var (warns `snocBag` warn, errs) >>
569 warn = addShortWarnLocLine loc msg
571 addErrRn :: Message -> RnM d ()
572 addErrRn err = failWithRn () err
574 checkRn :: Bool -> Message -> RnM d () -- Check that a condition is true
575 checkRn False err = addErrRn err
576 checkRn True err = returnRn ()
578 warnCheckRn :: Bool -> Message -> RnM d () -- Check that a condition is true
579 warnCheckRn False err = addWarnRn err
580 warnCheckRn True err = returnRn ()
582 addWarnRn :: Message -> RnM d ()
583 addWarnRn warn = warnWithRn () warn
585 checkErrsRn :: RnM d Bool -- True <=> no errors so far
586 checkErrsRn (RnDown {rn_errs = errs_var}) l_down
587 = readIORef errs_var >>= \ (warns,errs) ->
588 return (isEmptyBag errs)
593 \subsubsection{ Source location}
594 %=====================
597 pushSrcLocRn :: SrcLoc -> RnM d a -> RnM d a
598 pushSrcLocRn loc' m down l_down
599 = m (down {rn_loc = loc'}) l_down
601 getSrcLocRn :: RnM d SrcLoc
602 getSrcLocRn down l_down
603 = return (rn_loc down)
607 \subsubsection{ Name supply}
608 %=====================
611 getNameSupplyRn :: RnM d RnNameSupply
612 getNameSupplyRn rn_down l_down
613 = readIORef (rn_ns rn_down)
615 setNameSupplyRn :: RnNameSupply -> RnM d ()
616 setNameSupplyRn names' (RnDown {rn_ns = names_var}) l_down
617 = writeIORef names_var names'
619 -- See comments with RnNameSupply above.
620 newInstUniq :: String -> RnM d Int
621 newInstUniq key (RnDown {rn_ns = names_var}) l_down
622 = readIORef names_var >>= \ (us, mapInst, cache) ->
624 uniq = case lookupFM mapInst key of
627 mapInst' = addToFM mapInst key uniq
629 writeIORef names_var (us, mapInst', cache) >>
632 getUniqRn :: RnM d Unique
633 getUniqRn (RnDown {rn_ns = names_var}) l_down
634 = readIORef names_var >>= \ (us, mapInst, cache) ->
636 (us1,us') = splitUniqSupply us
638 writeIORef names_var (us', mapInst, cache) >>
639 return (uniqFromSupply us1)
643 \subsubsection{ Module}
644 %=====================
647 getModuleRn :: RnM d ModuleName
648 getModuleRn (RnDown {rn_mod = mod_name}) l_down
651 setModuleRn :: ModuleName -> RnM d a -> RnM d a
652 setModuleRn new_mod enclosed_thing rn_down l_down
653 = enclosed_thing (rn_down {rn_mod = new_mod}) l_down
657 %************************************************************************
659 \subsection{Plumbing for rename-source part}
661 %************************************************************************
664 \subsubsection{ RnEnv}
665 %=====================
668 getNameEnvs :: RnMS (GlobalRdrEnv, LocalRdrEnv)
669 getNameEnvs rn_down (SDown {rn_genv = global_env, rn_lenv = local_env})
670 = return (global_env, local_env)
672 getLocalNameEnv :: RnMS LocalRdrEnv
673 getLocalNameEnv rn_down (SDown {rn_lenv = local_env})
676 setLocalNameEnv :: LocalRdrEnv -> RnMS a -> RnMS a
677 setLocalNameEnv local_env' m rn_down l_down
678 = m rn_down (l_down {rn_lenv = local_env'})
680 getFixityEnv :: RnMS FixityEnv
681 getFixityEnv rn_down (SDown {rn_fixenv = fixity_env})
684 extendFixityEnv :: [(Name, RenamedFixitySig)] -> RnMS a -> RnMS a
685 extendFixityEnv fixes enclosed_scope
686 rn_down l_down@(SDown {rn_fixenv = fixity_env})
688 new_fixity_env = extendNameEnv fixity_env fixes
690 enclosed_scope rn_down (l_down {rn_fixenv = new_fixity_env})
694 \subsubsection{ Mode}
695 %=====================
698 getModeRn :: RnMS RnMode
699 getModeRn rn_down (SDown {rn_mode = mode})
702 setModeRn :: RnMode -> RnMS a -> RnMS a
703 setModeRn new_mode thing_inside rn_down l_down
704 = thing_inside rn_down (l_down {rn_mode = new_mode})
708 %************************************************************************
710 \subsection{Plumbing for rename-globals part}
712 %************************************************************************
715 getIfacesRn :: RnM d Ifaces
716 getIfacesRn (RnDown {rn_ifaces = iface_var}) _
717 = readIORef iface_var
719 setIfacesRn :: Ifaces -> RnM d ()
720 setIfacesRn ifaces (RnDown {rn_ifaces = iface_var}) _
721 = writeIORef iface_var ifaces
723 getHiMaps :: RnM d (ModuleHiMap, ModuleHiMap)
724 getHiMaps (RnDown {rn_hi_maps = himaps}) _