1 (c) The University of Glasgow 2002
5 newGlobalBinder, newIPName, newImplicitBinder,
6 lookupIfaceTop, lookupIfaceExt,
7 lookupOrig, lookupIfaceTc,
8 newIfaceName, newIfaceNames,
9 extendIfaceIdEnv, extendIfaceTyVarEnv,
10 tcIfaceLclId, tcIfaceTyVar,
12 lookupAvail, ifaceExportNames,
15 allocateGlobalBinder, initNameCache,
18 #include "HsVersions.h"
21 import IfaceType ( IfaceExtName(..), IfaceTyCon(..), ifaceTyConName )
22 import TysWiredIn ( tupleTyCon, tupleCon )
23 import HscTypes ( NameCache(..), HscEnv(..), GenAvailInfo(..),
24 IfaceExport, OrigNameCache )
25 import TyCon ( TyCon, tyConName )
26 import DataCon ( dataConWorkId, dataConName )
27 import Var ( TyVar, Id, varName )
28 import Name ( Name, nameUnique, nameModule,
29 nameOccName, nameSrcLoc,
30 getOccName, nameParent_maybe,
31 isWiredInName, mkIPName,
32 mkExternalName, mkInternalName )
33 import NameSet ( NameSet, emptyNameSet, addListToNameSet )
34 import OccName ( OccName, isTupleOcc_maybe, tcName, dataName, occNameFS,
35 lookupOccEnv, unitOccEnv, extendOccEnv )
36 import PrelNames ( gHC_PRIM, dATA_TUP )
37 import Module ( Module, emptyModuleEnv, ModuleName, modulePackageId,
38 lookupModuleEnv, extendModuleEnv_C, mkModule )
39 import UniqFM ( lookupUFM, addListToUFM )
40 import FastString ( FastString )
41 import UniqSupply ( UniqSupply, splitUniqSupply, uniqFromSupply, uniqsFromSupply )
42 import FiniteMap ( emptyFM, lookupFM, addToFM )
43 import BasicTypes ( IPName(..), mapIPName )
44 import SrcLoc ( SrcLoc, noSrcLoc )
50 %*********************************************************
52 Allocating new Names in the Name Cache
54 %*********************************************************
57 newGlobalBinder :: Module -> OccName -> Maybe Name -> SrcLoc -> TcRnIf a b Name
58 -- Used for source code and interface files, to make the
59 -- Name for a thing, given its Module and OccName
61 -- The cache may already already have a binding for this thing,
62 -- because we may have seen an occurrence before, but now is the
63 -- moment when we know its Module and SrcLoc in their full glory
65 newGlobalBinder mod occ mb_parent loc
66 = do { mod `seq` occ `seq` return () -- See notes with lookupOrig_help
67 -- ; traceIf (text "newGlobalBinder" <+> ppr mod <+> ppr occ <+> ppr loc)
68 ; name_supply <- getNameCache
69 ; let (name_supply', name) = allocateGlobalBinder
72 ; setNameCache name_supply'
77 -> Module -> OccName -> Maybe Name -> SrcLoc
79 allocateGlobalBinder name_supply mod occ mb_parent loc
80 = case lookupOrigNameCache (nsNames name_supply) mod occ of
81 -- A hit in the cache! We are at the binding site of the name.
82 -- This is the moment when we know the defining parent and SrcLoc
83 -- of the Name, so we set these fields in the Name we return.
85 -- Then (bogus) multiple bindings of the same Name
86 -- get different SrcLocs can can be reported as such.
88 -- Possible other reason: it might be in the cache because we
89 -- encountered an occurrence before the binding site for an
90 -- implicitly-imported Name. Perhaps the current SrcLoc is
91 -- better... but not really: it'll still just say 'imported'
93 -- IMPORTANT: Don't mess with wired-in names.
94 -- Their wired-in-ness is in their NameSort
95 -- and their Module is correct.
97 Just name | isWiredInName name -> (name_supply, name)
98 | otherwise -> (new_name_supply, name')
100 uniq = nameUnique name
101 name' = mkExternalName uniq mod occ mb_parent loc
102 new_cache = extend_name_cache (nsNames name_supply) mod occ name'
103 new_name_supply = name_supply {nsNames = new_cache}
105 -- Miss in the cache!
106 -- Build a completely new Name, and put it in the cache
107 Nothing -> (new_name_supply, name)
109 (us', us1) = splitUniqSupply (nsUniqs name_supply)
110 uniq = uniqFromSupply us1
111 name = mkExternalName uniq mod occ mb_parent loc
112 new_cache = extend_name_cache (nsNames name_supply) mod occ name
113 new_name_supply = name_supply {nsUniqs = us', nsNames = new_cache}
116 newImplicitBinder :: Name -- Base name
117 -> (OccName -> OccName) -- Occurrence name modifier
118 -> TcRnIf m n Name -- Implicit name
119 -- Called in BuildTyCl to allocate the implicit binders of type/class decls
120 -- For source type/class decls, this is the first occurrence
121 -- For iface ones, the LoadIface has alrady allocated a suitable name in the cache
123 -- An *implicit* name has the base-name as parent
124 newImplicitBinder base_name mk_sys_occ
125 = newGlobalBinder (nameModule base_name)
126 (mk_sys_occ (nameOccName base_name))
128 (nameSrcLoc base_name)
130 parent_name = case nameParent_maybe base_name of
131 Just parent_name -> parent_name
134 ifaceExportNames :: [IfaceExport] -> TcRnIf gbl lcl NameSet
135 ifaceExportNames exports
136 = foldlM do_one emptyNameSet exports
138 do_one acc (mod, exports) = foldlM (do_avail mod) acc exports
139 do_avail mod acc avail = do { ns <- lookupAvail mod avail
140 ; return (addListToNameSet acc ns) }
142 lookupAvail :: Module -> GenAvailInfo OccName -> TcRnIf a b [Name]
143 -- Find all the names arising from an import
144 -- Make sure the parent info is correct, even though we may not
145 -- yet have read the interface for this module
146 lookupAvail mod (Avail n) = do { n' <- lookupOrig mod n;
148 lookupAvail mod (AvailTC p_occ occs)
149 = do { p_name <- lookupOrig mod p_occ
150 ; let lookup_sub occ | occ == p_occ = return p_name
151 | otherwise = lookup_orig mod occ (Just p_name)
152 ; mappM lookup_sub occs }
153 -- Remember that 'occs' is all the exported things, including
154 -- the parent. It's possible to export just class ops without
155 -- the class, via C( op ). If the class was exported too we'd
158 -- The use of lookupOrigSub here (rather than lookupOrig)
159 -- ensures that the subordinate names record their parent;
160 -- and that in turn ensures that the GlobalRdrEnv
161 -- has the correct parent for all the names in its range.
162 -- For imported things, we may only suck in the interface later, if ever.
163 -- Reason for all this:
164 -- Suppose module M exports type A.T, and constructor A.MkT
165 -- Then, we know that A.MkT is a subordinate name of A.T,
166 -- even though we aren't at the binding site of A.T
167 -- And it's important, because we may simply re-export A.T
168 -- without ever sucking in the declaration itself.
171 lookupOrig :: Module -> OccName -> TcRnIf a b Name
172 -- Even if we get a miss in the original-name cache, we
173 -- make a new External Name.
175 -- SrcLoc to noSrcLoc
177 -- They'll be overwritten, in due course, by LoadIface.loadDecl.
178 lookupOrig mod occ = lookup_orig mod occ Nothing
180 lookup_orig :: Module -> OccName -> Maybe Name -> TcRnIf a b Name
181 -- Used when we know the parent of the thing we are looking up
182 lookup_orig mod occ mb_parent
183 = do { -- First ensure that mod and occ are evaluated
184 -- If not, chaos can ensue:
185 -- we read the name-cache
186 -- then pull on mod (say)
187 -- which does some stuff that modifies the name cache
188 -- This did happen, with tycon_mod in TcIface.tcIfaceAlt (DataAlt..)
189 mod `seq` occ `seq` return ()
191 ; name_supply <- getNameCache
192 ; case lookupOrigNameCache (nsNames name_supply) mod occ of {
193 Just name -> returnM name ;
196 { let { (us', us1) = splitUniqSupply (nsUniqs name_supply)
197 ; uniq = uniqFromSupply us1
198 ; name = mkExternalName uniq mod occ mb_parent noSrcLoc
199 ; new_cache = extend_name_cache (nsNames name_supply) mod occ name
200 ; new_name_supply = name_supply {nsUniqs = us', nsNames = new_cache}
202 ; setNameCache new_name_supply
206 newIPName :: IPName OccName -> TcRnIf m n (IPName Name)
207 newIPName occ_name_ip
208 = getNameCache `thenM` \ name_supply ->
210 ipcache = nsIPs name_supply
212 case lookupFM ipcache key of
213 Just name_ip -> returnM name_ip
214 Nothing -> setNameCache new_ns `thenM_`
217 (us', us1) = splitUniqSupply (nsUniqs name_supply)
218 uniq = uniqFromSupply us1
219 name_ip = mapIPName (mkIPName uniq) occ_name_ip
220 new_ipcache = addToFM ipcache key name_ip
221 new_ns = name_supply {nsUniqs = us', nsIPs = new_ipcache}
223 key = occ_name_ip -- Ensures that ?x and %x get distinct Names
226 Local helper functions (not exported)
229 lookupOrigNameCache :: OrigNameCache -> Module -> OccName -> Maybe Name
230 lookupOrigNameCache nc mod occ
231 | mod == dATA_TUP || mod == gHC_PRIM, -- Boxed tuples from one,
232 Just tup_info <- isTupleOcc_maybe occ -- unboxed from the other
233 = -- Special case for tuples; there are too many
234 -- of them to pre-populate the original-name cache
235 Just (mk_tup_name tup_info)
237 mk_tup_name (ns, boxity, arity)
238 | ns == tcName = tyConName (tupleTyCon boxity arity)
239 | ns == dataName = dataConName (tupleCon boxity arity)
240 | otherwise = varName (dataConWorkId (tupleCon boxity arity))
242 lookupOrigNameCache nc mod occ -- The normal case
243 = case lookupModuleEnv nc mod of
245 Just occ_env -> lookupOccEnv occ_env occ
247 extendOrigNameCache :: OrigNameCache -> Name -> OrigNameCache
248 extendOrigNameCache nc name
249 = extend_name_cache nc (nameModule name) (nameOccName name) name
251 extend_name_cache :: OrigNameCache -> Module -> OccName -> Name -> OrigNameCache
252 extend_name_cache nc mod occ name
253 = extendModuleEnv_C combine nc mod (unitOccEnv occ name)
255 combine occ_env _ = extendOccEnv occ_env occ name
257 getNameCache :: TcRnIf a b NameCache
258 getNameCache = do { HscEnv { hsc_NC = nc_var } <- getTopEnv;
261 setNameCache :: NameCache -> TcRnIf a b ()
262 setNameCache nc = do { HscEnv { hsc_NC = nc_var } <- getTopEnv;
263 writeMutVar nc_var nc }
268 initNameCache :: UniqSupply -> [Name] -> NameCache
269 initNameCache us names
270 = NameCache { nsUniqs = us,
271 nsNames = initOrigNames names,
274 initOrigNames :: [Name] -> OrigNameCache
275 initOrigNames names = foldl extendOrigNameCache emptyModuleEnv names
280 %************************************************************************
282 Type variables and local Ids
284 %************************************************************************
287 tcIfaceLclId :: FastString -> IfL Id
289 = do { lcl <- getLclEnv
290 ; case (lookupUFM (if_id_env lcl) occ) of
291 Just ty_var -> return ty_var
292 Nothing -> failIfM (text "Iface id out of scope: " <+> ppr occ)
295 extendIfaceIdEnv :: [Id] -> IfL a -> IfL a
296 extendIfaceIdEnv ids thing_inside
297 = do { env <- getLclEnv
298 ; let { id_env' = addListToUFM (if_id_env env) pairs
299 ; pairs = [(occNameFS (getOccName id), id) | id <- ids] }
300 ; setLclEnv (env { if_id_env = id_env' }) thing_inside }
303 tcIfaceTyVar :: FastString -> IfL TyVar
305 = do { lcl <- getLclEnv
306 ; case (lookupUFM (if_tv_env lcl) occ) of
307 Just ty_var -> return ty_var
308 Nothing -> failIfM (text "Iface type variable out of scope: " <+> ppr occ)
311 extendIfaceTyVarEnv :: [TyVar] -> IfL a -> IfL a
312 extendIfaceTyVarEnv tyvars thing_inside
313 = do { env <- getLclEnv
314 ; let { tv_env' = addListToUFM (if_tv_env env) pairs
315 ; pairs = [(occNameFS (getOccName tv), tv) | tv <- tyvars] }
316 ; setLclEnv (env { if_tv_env = tv_env' }) thing_inside }
320 %************************************************************************
322 Getting from RdrNames to Names
324 %************************************************************************
327 lookupIfaceTc :: IfaceTyCon -> IfL Name
328 lookupIfaceTc (IfaceTc ext) = lookupIfaceExt ext
329 lookupIfaceTc other_tc = return (ifaceTyConName other_tc)
331 lookupIfaceExt :: IfaceExtName -> IfL Name
332 lookupIfaceExt (ExtPkg mod occ) = lookupOrig mod occ
333 lookupIfaceExt (HomePkg mod occ _) = lookupHomePackage mod occ
334 lookupIfaceExt (LocalTop occ) = lookupIfaceTop occ
335 lookupIfaceExt (LocalTopSub occ _) = lookupIfaceTop occ
337 lookupIfaceTop :: OccName -> IfL Name
338 -- Look up a top-level name from the current Iface module
340 = do { env <- getLclEnv; lookupOrig (if_mod env) occ }
342 lookupHomePackage :: ModuleName -> OccName -> IfL Name
343 lookupHomePackage mod_name occ
344 = do { env <- getLclEnv;
345 ; let this_pkg = modulePackageId (if_mod env)
346 ; lookupOrig (mkModule this_pkg mod_name) occ }
348 newIfaceName :: OccName -> IfL Name
350 = do { uniq <- newUnique
351 ; return $! mkInternalName uniq occ noSrcLoc }
353 newIfaceNames :: [OccName] -> IfL [Name]
355 = do { uniqs <- newUniqueSupply
356 ; return [ mkInternalName uniq occ noSrcLoc
357 | (occ,uniq) <- occs `zip` uniqsFromSupply uniqs] }