[project @ 2001-12-07 08:12:53 by sof]

[ghc-hetmet.git] / ghc / compiler / rename / RnNames.lhs

diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs
index 7c65a96..078863f 100644 (file)
--- a/ghc/compiler/rename/RnNames.lhs
+++ b/ghc/compiler/rename/RnNames.lhs
@@ -32,7 +32,7 @@ import NameSet
 import NameEnv
 import HscTypes                ( Provenance(..), ImportReason(..), GlobalRdrEnv,
                          GenAvailInfo(..), AvailInfo, Avails, AvailEnv, 
-                         Deprecations(..), ModIface(..)
+                         Deprecations(..), ModIface(..), emptyAvailEnv
                        )
 import RdrName         ( rdrNameOcc, setRdrNameOcc )
 import OccName         ( setOccNameSpace, dataName )
@@ -178,7 +178,7 @@ importsFromImportDecl this_mod_name (ImportDecl imp_mod_name from qual_only as_m
 
        mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) 
        gbl_env      = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails hides deprecs
-       exports      = mkExportAvails qual_mod unqual_imp gbl_env filtered_avails
+       exports      = mkExportAvails qual_mod unqual_imp gbl_env hides filtered_avails
     in
     returnRn (gbl_env, exports)
 \end{code}
@@ -220,7 +220,7 @@ importsFromLocalDecls this_mod decls
            -- the defn of a non-deprecated thing, when changing a module's 
            -- interface
 
-       exports    = mkExportAvails mod_name unqual_imp gbl_env            avails
+       exports    = mkExportAvails mod_name unqual_imp gbl_env hides avails
     in
     returnRn (gbl_env, exports)
 
@@ -272,8 +272,9 @@ filterImports :: ModuleName                 -- The module being imported
              -> WhereFrom                      -- Tells whether it's a {-# SOURCE #-} import
              -> Maybe (Bool, [RdrNameIE])      -- Import spec; True => hiding
              -> [AvailInfo]                    -- What's available
-             -> RnMG ([AvailInfo],             -- What's actually imported
-                      [AvailInfo],             -- What's to be hidden
+             -> RnMG ([AvailInfo],             -- "chosens"
+                      [AvailInfo],             -- "hides"
+                       -- The true imports are "chosens" - "hides"
                        -- (It's convenient to return both the above sets, because
                        --  the substraction can be done more efficiently when
                        --  building the environment.)
@@ -366,8 +367,8 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails
 mkEmptyExportAvails :: ModuleName -> ExportAvails
 mkEmptyExportAvails mod_name = (unitFM mod_name [], emptyNameEnv)
 
-mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> ExportAvails
-mkExportAvails mod_name unqual_imp gbl_env avails
+mkExportAvails :: ModuleName -> Bool -> GlobalRdrEnv -> [AvailInfo] -> [AvailInfo] -> ExportAvails
+mkExportAvails mod_name unqual_imp gbl_env hides avails 
   = (mod_avail_env, entity_avail_env)
   where
     mod_avail_env = unitFM mod_name unqual_avails 
@@ -382,7 +383,7 @@ mkExportAvails mod_name unqual_imp gbl_env avails
                  | otherwise      = mapMaybe prune avails
 
     prune (Avail n) | unqual_in_scope n = Just (Avail n)
-    prune (Avail n) | otherwise                = Nothing
+                    | otherwise                = Nothing
     prune (AvailTC n ns) | null uqs     = Nothing
                         | otherwise    = Just (AvailTC n uqs)
                         where
@@ -390,8 +391,30 @@ mkExportAvails mod_name unqual_imp gbl_env avails
 
     unqual_in_scope n = unQualInScope gbl_env n
 
-    entity_avail_env = mkNameEnv [ (name,avail) | avail <- avails, 
-                                                 name  <- availNames avail]
+
+    entity_avail_env  = mkNameEnv ([ (availName avail,avail) | avail <- effective_avails ]  ++
+                                       -- sigh - need to have the method/field names in
+                                       -- the environment also, so that export lists
+                                       -- can be computed precisely (cf. exportsFromAvail)
+                                  [ (name,avail) | avail <- effective_avails,
+                                                   name  <- avNames avail ] )
+
+    avNames (Avail n) = [n]
+    avNames (AvailTC n ns) = filter (/=n) ns
+
+       -- remove 'hides' names from the avail list.
+    effective_avails = foldl wipeOut avails hides
+      where
+        wipeOut as (Avail n)       = mapMaybe (delName n) as
+       wipeOut as (AvailTC n ns)  = foldl wipeOut as (map Avail ns)
+
+       delName x a@(Avail n) 
+         | n == x    = Nothing
+          | otherwise = Just a
+       delName x (AvailTC n ns) 
+         = case (filter (/=x) ns) of
+             [] -> Nothing
+             xs -> Just (AvailTC n xs)
 
 plusExportAvails ::  ExportAvails ->  ExportAvails ->  ExportAvails
 plusExportAvails (m1, e1) (m2, e2)