2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
5 \section[RdrName]{@RdrName@}
9 RdrName(..), -- Constructors exported only to BinIface
12 mkRdrUnqual, mkRdrQual,
13 mkUnqual, mkVarUnqual, mkQual, mkOrig,
14 nameRdrName, getRdrName,
18 rdrNameModule, rdrNameOcc, setRdrNameSpace,
19 isRdrDataCon, isRdrTyVar, isRdrTc, isQual, isUnqual,
20 isOrig, isOrig_maybe, isExact, isExact_maybe, isSrcRdrName,
22 -- Printing; instance Outputable RdrName
25 LocalRdrEnv, emptyLocalRdrEnv, extendLocalRdrEnv,
26 lookupLocalRdrEnv, elemLocalRdrEnv,
29 GlobalRdrEnv, emptyGlobalRdrEnv, mkGlobalRdrEnv, plusGlobalRdrEnv,
30 lookupGlobalRdrEnv, pprGlobalRdrEnv, globalRdrEnvElts,
31 lookupGRE_RdrName, lookupGRE_Name,
33 -- GlobalRdrElt, Provenance, ImportSpec
34 GlobalRdrElt(..), Provenance(..), ImportSpec(..),
39 #include "HsVersions.h"
41 import OccName ( NameSpace, tcName, varName,
42 OccName, UserFS, EncodedFS,
43 mkSysOccFS, setOccNameSpace,
44 mkOccFS, mkVarOcc, occNameFlavour,
45 isDataOcc, isTvOcc, isTcOcc,
46 OccEnv, emptyOccEnv, extendOccEnvList, lookupOccEnv,
47 elemOccEnv, plusOccEnv_C, extendOccEnv_C, foldOccEnv,
50 import Module ( ModuleName, mkSysModuleNameFS, mkModuleNameFS )
51 import Name ( Name, NamedThing(getName), nameModuleName, nameParent_maybe,
52 nameOccName, isExternalName, nameSrcLoc )
53 import Maybes ( seqMaybe )
54 import SrcLoc ( SrcLoc, isGoodSrcLoc, SrcSpan )
55 import BasicTypes( DeprecTxt )
57 import Util ( thenCmp )
61 %************************************************************************
63 \subsection{The main data type}
65 %************************************************************************
70 -- Used for ordinary, unqualified occurrences
72 | Qual ModuleName OccName
73 -- A qualified name written by the user in
74 -- *source* code. The module isn't necessarily
75 -- the module where the thing is defined;
76 -- just the one from which it is imported
78 | Orig ModuleName OccName
79 -- An original name; the module is the *defining* module.
80 -- This is used when GHC generates code that will be fed
81 -- into the renamer (e.g. from deriving clauses), but where
82 -- we want to say "Use Prelude.map dammit".
85 -- We know exactly the Name. This is used
86 -- (a) when the parser parses built-in syntax like "[]"
87 -- and "(,)", but wants a RdrName from it
88 -- (b) when converting names to the RdrNames in IfaceTypes
89 -- Here an Exact RdrName always contains an External Name
90 -- (Internal Names are converted to simple Unquals)
91 -- (c) possibly, by the meta-programming stuff
95 %************************************************************************
97 \subsection{Simple functions}
99 %************************************************************************
102 rdrNameModule :: RdrName -> ModuleName
103 rdrNameModule (Qual m _) = m
104 rdrNameModule (Orig m _) = m
105 rdrNameModule (Exact n) = nameModuleName n
106 rdrNameModule (Unqual n) = pprPanic "rdrNameModule" (ppr n)
108 rdrNameOcc :: RdrName -> OccName
109 rdrNameOcc (Qual _ occ) = occ
110 rdrNameOcc (Unqual occ) = occ
111 rdrNameOcc (Orig _ occ) = occ
112 rdrNameOcc (Exact name) = nameOccName name
114 setRdrNameSpace :: RdrName -> NameSpace -> RdrName
115 -- This rather gruesome function is used mainly by the parser
116 -- When parsing data T a = T | T1 Int
117 -- we parse the data constructors as *types* because of parser ambiguities,
118 -- so then we need to change the *type constr* to a *data constr*
120 -- The original-name case *can* occur when parsing
121 -- data [] a = [] | a : [a]
122 -- For the orig-name case we return an unqualified name.
123 setRdrNameSpace (Unqual occ) ns = Unqual (setOccNameSpace ns occ)
124 setRdrNameSpace (Qual m occ) ns = Qual m (setOccNameSpace ns occ)
125 setRdrNameSpace (Orig m occ) ns = Orig m (setOccNameSpace ns occ)
126 setRdrNameSpace (Exact n) ns = Orig (nameModuleName n)
127 (setOccNameSpace ns (nameOccName n))
131 -- These two are the basic constructors
132 mkRdrUnqual :: OccName -> RdrName
133 mkRdrUnqual occ = Unqual occ
135 mkRdrQual :: ModuleName -> OccName -> RdrName
136 mkRdrQual mod occ = Qual mod occ
138 mkOrig :: ModuleName -> OccName -> RdrName
139 mkOrig mod occ = Orig mod occ
142 mkDerivedRdrName :: Name -> (OccName -> OccName) -> (RdrName)
143 mkDerivedRdrName parent mk_occ
144 = mkOrig (nameModuleName parent) (mk_occ (nameOccName parent))
147 -- These two are used when parsing source files
148 -- They do encode the module and occurrence names
149 mkUnqual :: NameSpace -> UserFS -> RdrName
150 mkUnqual sp n = Unqual (mkOccFS sp n)
152 mkVarUnqual :: UserFS -> RdrName
153 mkVarUnqual n = Unqual (mkOccFS varName n)
155 mkQual :: NameSpace -> (UserFS, UserFS) -> RdrName
156 mkQual sp (m, n) = Qual (mkModuleNameFS m) (mkOccFS sp n)
158 getRdrName :: NamedThing thing => thing -> RdrName
159 getRdrName name = nameRdrName (getName name)
161 nameRdrName :: Name -> RdrName
162 nameRdrName name = Exact name
163 -- Keep the Name even for Internal names, so that the
164 -- unique is still there for debug printing, particularly
165 -- of Types (which are converted to IfaceTypes before printing)
167 nukeExact :: Name -> RdrName
169 | isExternalName n = Orig (nameModuleName n) (nameOccName n)
170 | otherwise = Unqual (nameOccName n)
174 isRdrDataCon rn = isDataOcc (rdrNameOcc rn)
175 isRdrTyVar rn = isTvOcc (rdrNameOcc rn)
176 isRdrTc rn = isTcOcc (rdrNameOcc rn)
178 isSrcRdrName (Unqual _) = True
179 isSrcRdrName (Qual _ _) = True
180 isSrcRdrName _ = False
182 isUnqual (Unqual _) = True
183 isUnqual other = False
185 isQual (Qual _ _) = True
188 isOrig (Orig _ _) = True
191 isOrig_maybe (Orig m n) = Just (m,n)
192 isOrig_maybe _ = Nothing
194 isExact (Exact _) = True
195 isExact other = False
197 isExact_maybe (Exact n) = Just n
198 isExact_maybe other = Nothing
202 %************************************************************************
204 \subsection{Instances}
206 %************************************************************************
209 instance Outputable RdrName where
210 ppr (Exact name) = ppr name
211 ppr (Unqual occ) = ppr occ <+> ppr_name_space occ
212 ppr (Qual mod occ) = ppr mod <> dot <> ppr occ <+> ppr_name_space occ
213 ppr (Orig mod occ) = ppr mod <> dot <> ppr occ <+> ppr_name_space occ
215 ppr_name_space occ = ifPprDebug (parens (text (occNameFlavour occ)))
217 instance OutputableBndr RdrName where
219 | isTvOcc (rdrNameOcc n) = char '@' <+> ppr n
222 instance Eq RdrName where
223 (Exact n1) == (Exact n2) = n1==n2
224 -- Convert exact to orig
225 (Exact n1) == r2@(Orig _ _) = nukeExact n1 == r2
226 r1@(Orig _ _) == (Exact n2) = r1 == nukeExact n2
228 (Orig m1 o1) == (Orig m2 o2) = m1==m2 && o1==o2
229 (Qual m1 o1) == (Qual m2 o2) = m1==m2 && o1==o2
230 (Unqual o1) == (Unqual o2) = o1==o2
233 instance Ord RdrName where
234 a <= b = case (a `compare` b) of { LT -> True; EQ -> True; GT -> False }
235 a < b = case (a `compare` b) of { LT -> True; EQ -> False; GT -> False }
236 a >= b = case (a `compare` b) of { LT -> False; EQ -> True; GT -> True }
237 a > b = case (a `compare` b) of { LT -> False; EQ -> False; GT -> True }
239 -- Unqual < Qual < Orig
240 -- We always convert Exact to Orig before comparing
241 compare (Exact n1) (Exact n2) | n1==n2 = EQ -- Short cut
242 | otherwise = nukeExact n1 `compare` nukeExact n2
243 compare (Exact n1) n2 = nukeExact n1 `compare` n2
244 compare n1 (Exact n2) = n1 `compare` nukeExact n2
247 compare (Qual m1 o1) (Qual m2 o2) = (o1 `compare` o2) `thenCmp` (m1 `compare` m2)
248 compare (Orig m1 o1) (Orig m2 o2) = (o1 `compare` o2) `thenCmp` (m1 `compare` m2)
249 compare (Unqual o1) (Unqual o2) = o1 `compare` o2
251 compare (Unqual _) _ = LT
252 compare (Qual _ _) (Orig _ _) = LT
258 %************************************************************************
262 %************************************************************************
264 A LocalRdrEnv is used for local bindings (let, where, lambda, case)
265 It is keyed by OccName, because we never use it for qualified names.
268 type LocalRdrEnv = OccEnv Name
270 emptyLocalRdrEnv = emptyOccEnv
272 extendLocalRdrEnv :: LocalRdrEnv -> [Name] -> LocalRdrEnv
273 extendLocalRdrEnv env names
274 = extendOccEnvList env [(nameOccName n, n) | n <- names]
276 lookupLocalRdrEnv :: LocalRdrEnv -> RdrName -> Maybe Name
277 lookupLocalRdrEnv env (Exact name) = Just name
278 lookupLocalRdrEnv env (Unqual occ) = lookupOccEnv env occ
279 lookupLocalRdrEnv env other = Nothing
281 elemLocalRdrEnv :: RdrName -> LocalRdrEnv -> Bool
282 elemLocalRdrEnv rdr_name env
283 | isUnqual rdr_name = rdrNameOcc rdr_name `elemOccEnv` env
288 %************************************************************************
292 %************************************************************************
295 type GlobalRdrEnv = OccEnv [GlobalRdrElt]
296 -- Keyed by OccName; when looking up a qualified name
297 -- we look up the OccName part, and then check the Provenance
298 -- to see if the appropriate qualification is valid. This
299 -- saves routinely doubling the size of the env by adding both
300 -- qualified and unqualified names to the domain.
302 -- The list in the range is reqd because there may be name clashes
303 -- These only get reported on lookup, not on construction
305 -- INVARIANT: All the members of the list have distinct
306 -- gre_name fields; that is, no duplicate Names
308 emptyGlobalRdrEnv = emptyOccEnv
310 globalRdrEnvElts :: GlobalRdrEnv -> [GlobalRdrElt]
311 globalRdrEnvElts env = foldOccEnv (++) [] env
314 = GRE { gre_name :: Name,
315 gre_prov :: Provenance, -- Why it's in scope
316 gre_deprec :: Maybe DeprecTxt -- Whether this name is deprecated
319 instance Outputable GlobalRdrElt where
320 ppr gre = ppr name <+> pp_parent (nameParent_maybe name)
321 <+> parens (pprNameProvenance gre)
324 pp_parent (Just p) = brackets (text "parent:" <+> ppr p)
325 pp_parent Nothing = empty
327 pprGlobalRdrEnv :: GlobalRdrEnv -> SDoc
329 = vcat (map pp (occEnvElts env))
331 pp gres = ppr (nameOccName (gre_name (head gres))) <> colon <+>
332 vcat [ ppr (gre_name gre) <+> pprNameProvenance gre
337 lookupGlobalRdrEnv :: GlobalRdrEnv -> OccName -> [GlobalRdrElt]
338 lookupGlobalRdrEnv env rdr_name = case lookupOccEnv env rdr_name of
342 lookupGRE_RdrName :: RdrName -> GlobalRdrEnv -> [GlobalRdrElt]
343 lookupGRE_RdrName rdr_name env
344 = case lookupOccEnv env occ of
346 Just gres | isUnqual rdr_name -> filter unQualOK gres
347 | otherwise -> filter (hasQual mod) gres
349 mod = rdrNameModule rdr_name
350 occ = rdrNameOcc rdr_name
352 lookupGRE_Name :: GlobalRdrEnv -> Name -> [GlobalRdrElt]
353 lookupGRE_Name env name
354 = [ gre | gre <- lookupGlobalRdrEnv env (nameOccName name),
355 gre_name gre == name ]
358 isLocalGRE :: GlobalRdrElt -> Bool
359 isLocalGRE (GRE {gre_prov = LocalDef _}) = True
360 isLocalGRE other = False
362 unQualOK :: GlobalRdrElt -> Bool
363 -- An unqualifed version of this thing is in scope
364 unQualOK (GRE {gre_prov = LocalDef _}) = True
365 unQualOK (GRE {gre_prov = Imported is _}) = not (all is_qual is)
367 hasQual :: ModuleName -> GlobalRdrElt -> Bool
368 -- A qualified version of this thing is in scope
369 hasQual mod (GRE {gre_prov = LocalDef m}) = m == mod
370 hasQual mod (GRE {gre_prov = Imported is _}) = any ((== mod) . is_as) is
372 plusGlobalRdrEnv :: GlobalRdrEnv -> GlobalRdrEnv -> GlobalRdrEnv
373 plusGlobalRdrEnv env1 env2 = plusOccEnv_C (foldr insertGRE) env1 env2
375 mkGlobalRdrEnv :: [GlobalRdrElt] -> GlobalRdrEnv
377 = foldr add emptyGlobalRdrEnv gres
379 add gre env = extendOccEnv_C (foldr insertGRE) env
380 (nameOccName (gre_name gre))
383 insertGRE :: GlobalRdrElt -> [GlobalRdrElt] -> [GlobalRdrElt]
384 insertGRE new_g [] = [new_g]
385 insertGRE new_g (old_g : old_gs)
386 | gre_name new_g == gre_name old_g
387 = new_g `plusGRE` old_g : old_gs
389 = old_g : insertGRE new_g old_gs
391 plusGRE :: GlobalRdrElt -> GlobalRdrElt -> GlobalRdrElt
392 -- Used when the gre_name fields match
394 = GRE { gre_name = gre_name g1,
395 gre_prov = gre_prov g1 `plusProv` gre_prov g2,
396 gre_deprec = gre_deprec g1 `seqMaybe` gre_deprec g2 }
397 -- Could the deprecs be different? If we re-export
398 -- something deprecated, is it propagated? I forget.
402 %************************************************************************
406 %************************************************************************
408 The "provenance" of something says how it came to be in scope.
412 = LocalDef -- Defined locally
415 | Imported -- Imported
416 [ImportSpec] -- INVARIANT: non-empty
417 Bool -- True iff the thing was named *explicitly*
418 -- in *any* of the import specs rather than being
419 -- imported as part of a group;
423 -- Here, everything imported by B, and the constructors of T
424 -- are not named explicitly; only T is named explicitly.
425 -- This info is used when warning of unused names.
427 data ImportSpec -- Describes a particular import declaration
428 -- Shared among all the Provenaces for a particular
429 -- import declaration
431 is_mod :: ModuleName, -- 'import Muggle'
432 -- Note the Muggle may well not be
433 -- the defining module for this thing!
434 is_as :: ModuleName, -- 'as M' (or 'Muggle' if there is no 'as' clause)
435 is_qual :: Bool, -- True <=> qualified (only)
436 is_loc :: SrcSpan } -- Location of import statment
438 -- Comparison of provenance is just used for grouping
439 -- error messages (in RnEnv.warnUnusedBinds)
440 instance Eq Provenance where
441 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
443 instance Eq ImportSpec where
444 p1 == p2 = case p1 `compare` p2 of EQ -> True; _ -> False
446 instance Ord Provenance where
447 compare (LocalDef _) (LocalDef _) = EQ
448 compare (LocalDef _) (Imported _ _) = LT
449 compare (Imported _ _) (LocalDef _) = GT
450 compare (Imported is1 _) (Imported is2 _) = compare (head is1) (head is2)
452 instance Ord ImportSpec where
453 compare is1 is2 = (is_mod is1 `compare` is_mod is2) `thenCmp`
454 (is_loc is1 `compare` is_loc is2)
458 plusProv :: Provenance -> Provenance -> Provenance
459 -- Choose LocalDef over Imported
460 -- There is an obscure bug lurking here; in the presence
461 -- of recursive modules, something can be imported *and* locally
462 -- defined, and one might refer to it with a qualified name from
463 -- the import -- but I'm going to ignore that because it makes
464 -- the isLocalGRE predicate so much nicer this way
465 plusProv (LocalDef m1) (LocalDef m2)
466 = pprPanic "plusProv" (ppr m1 <+> ppr m2)
467 plusProv p1@(LocalDef _) p2 = p1
468 plusProv p1 p2@(LocalDef _) = p2
469 plusProv (Imported is1 ex1) (Imported is2 ex2)
470 = Imported (is1++is2) (ex1 || ex2)
472 pprNameProvenance :: GlobalRdrElt -> SDoc
473 pprNameProvenance (GRE {gre_name = name, gre_prov = LocalDef _})
474 = ptext SLIT("defined at") <+> ppr (nameSrcLoc name)
475 pprNameProvenance (GRE {gre_name = name, gre_prov = Imported (why:whys) _})
476 = sep [ppr_reason why, nest 2 (ppr_defn (nameSrcLoc name))]
479 = ptext SLIT("imported from") <+> ppr (is_mod imp_spec)
480 <+> ptext SLIT("at") <+> ppr (is_loc imp_spec)
482 ppr_defn loc | isGoodSrcLoc loc = parens (ptext SLIT("defined at") <+> ppr loc)