[project @ 2002-10-09 16:28:56 by simonpj]

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

diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs
index 3e440e9..5877872 100644 (file)
--- a/ghc/compiler/rename/RnNames.lhs
+++ b/ghc/compiler/rename/RnNames.lhs
@@ -29,7 +29,7 @@ import Module         ( Module, ModuleName, moduleName,
                          moduleNameUserString, 
                          unitModuleEnvByName, lookupModuleEnvByName,
                          moduleEnvElts )
-import Name            ( Name, nameSrcLoc, nameOccName, nameModule )
+import Name            ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName )
 import NameSet
 import NameEnv
 import OccName         ( OccName, dataName, isTcOcc )
@@ -180,7 +180,7 @@ importsFromImportDecl this_mod_name
 
        mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) 
        gbl_env      = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails deprecs
-       imports      = mkImportAvails qual_mod unqual_imp gbl_env filtered_avails
+       imports      = mkImportAvails qual_mod unqual_imp filtered_avails
     in
     returnM (gbl_env, imports { imp_mods = dir_imp})
     }
@@ -241,9 +241,9 @@ importsFromLocalDecls group
            -- Optimisation: filter out names for built-in syntax
            -- They just clutter up the environment (esp tuples), and the parser
            -- will generate Exact RdrNames for them, so the cluttered
-           -- envt is no use.  To avoid doing this filter all the type,
+           -- envt is no use.  To avoid doing this filter all the time,
            -- we use -fno-implicit-prelude as a clue that the filter is
-           -- worth while.  Really, it's only useful for Base and Tuple.
+           -- worth while.  Really, it's only useful for GHC.Base and GHC.Tuple.
            --
            -- It's worth doing because it makes the environment smaller for
            -- every module that imports the Prelude
@@ -255,7 +255,7 @@ importsFromLocalDecls group
            -- but that stops them being Exact, so they get looked up.  Sigh.
            -- It doesn't matter because it only affects the Data.Tuple really.
            -- The important thing is to trim down the exports.
-       imports = mkImportAvails mod_name unqual_imp gbl_env avails'
+       imports = mkImportAvails mod_name unqual_imp avails'
        avails' | implicit_prelude = filter not_built_in_syntax avails
                | otherwise        = avails
        not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a))
@@ -513,12 +513,14 @@ exports_from_avail export_items warn_dup_exports
        = case lookupModuleEnvByName mod_avail_env mod of
            Nothing             -> addErr (modExportErr mod)    `thenM_`
                                   returnM acc
-           Just mod_avails 
-               -> foldlM (check_occs warn_dup_exports ie) 
-                         occs mod_avails                  `thenM` \ occs' ->
-                  let
+           Just avail_env
+               -> let
+                       mod_avails = availEnvElts avail_env
                        avails' = foldl addAvail avails mod_avails
                   in
+                  foldlM (check_occs warn_dup_exports ie) 
+                         occs mod_avails       `thenM` \ occs' ->
+
                   returnM (mod:mods, occs', avails')
 
     exports_from_item acc@(mods, occs, avails) ie
@@ -615,9 +617,15 @@ reportUnusedNames gbl_env used_names
     (defined_and_used, defined_but_not_used) = partition used defined_names
     used gre = gre_name gre `elemNameSet` really_used_names
     
-    -- Filter out the ones only defined implicitly
+    -- Filter out the ones that are 
+    --  (a) defined in this module, and
+    -- (b) not defined by a 'deriving' clause 
+    -- The latter have an Internal Name, so we can filter them out easily
     bad_locals :: [GlobalRdrElt]
-    bad_locals = filter isLocalGRE defined_but_not_used
+    bad_locals = filter is_bad defined_but_not_used
+
+    is_bad :: GlobalRdrElt -> Bool
+    is_bad gre = isLocalGRE gre && isExternalName (gre_name gre)
     
     bad_imports :: [GlobalRdrElt]
     bad_imports = filter bad_imp defined_but_not_used