decl2.c (add_using_namespace): Iterate over namespaces used indirectly.

	* decl2.c (add_using_namespace): Iterate over namespaces used
	indirectly.
	* decl.c (lookup_name_real): Accept namespace aliases as locals.
	(cat_namespace_levels): Ignore aliases.
	(duplicate_decls): Ignore duplicate aliases.
	* decl2.c (do_namespace_alias): Process block level namespace
	aliases. Store alias with pushdecl. Remove odr errors.
	* parse.y (namespace_alias): New non-terminal.
	(extdef): Use it.

From-SVN: r21201

gcc/cp/ChangeLog

+1998-07-15  Martin v. Lwis  <loewis@informatik.hu-berlin.de>
+
+	* decl2.c (add_using_namespace): Iterate over namespaces used
+	indirectly.
+
+	* decl.c (lookup_name_real): Accept namespace aliases as locals.
+	(cat_namespace_levels): Ignore aliases.
+	(duplicate_decls): Ignore duplicate aliases.
+	* decl2.c (do_namespace_alias): Process block level namespace
+	aliases. Store alias with pushdecl. Remove odr errors.
+	* parse.y (namespace_alias): New non-terminal.
+	(extdef): Use it.
+
 1998-07-15  Jason Merrill  <jason@yorick.cygnus.com>
 
 	* decl2.c (arg_assoc_type): Handle METHOD_TYPE like FUNCTION_TYPE.

gcc/cp/decl.c

@@ -1865,7 +1865,8 @@ cat_namespace_levels()
   /* The nested namespaces appear in the names list of their ancestors. */
   for (current = last; current; current = TREE_CHAIN (current))
     {
-      if (TREE_CODE (current) != NAMESPACE_DECL)
+      if (TREE_CODE (current) != NAMESPACE_DECL
+          || DECL_NAMESPACE_ALIAS (current))
 	continue;
       if (!DECL_LANG_SPECIFIC (current))
 	{
@@ -2740,6 +2741,11 @@ duplicate_decls (newdecl, olddecl)
     /* One of the declarations is a template instantiation, and the
        other is not a template at all.  That's OK.  */
     return 0;
+  else if (TREE_CODE (newdecl) == NAMESPACE_DECL
+           && DECL_NAMESPACE_ALIAS (newdecl)
+           && DECL_NAMESPACE_ALIAS (newdecl) == DECL_NAMESPACE_ALIAS (olddecl))
+    /* Redeclaration of namespace alias, ignore it. */
+    return 1;
   else
     {
       char *errmsg = redeclaration_error_message (newdecl, olddecl);
@@ -4913,12 +4919,26 @@ lookup_name_real (name, prefer_type, nonclass, namespaces_only)
 
   locval = classval = NULL_TREE;
 
-  if (!namespaces_only && !current_binding_level->namespace_p
-      && IDENTIFIER_LOCAL_VALUE (name)
-      /* Kludge to avoid infinite recursion with identifier_type_value.  */
-      && (prefer_type <= 0
-          || TREE_CODE (IDENTIFIER_LOCAL_VALUE (name)) == TYPE_DECL))
-    locval = IDENTIFIER_LOCAL_VALUE (name);
+  if (!current_binding_level->namespace_p
+      && IDENTIFIER_LOCAL_VALUE (name))
+    switch (TREE_CODE (IDENTIFIER_LOCAL_VALUE (name)))
+      {
+      case NAMESPACE_DECL:
+        /* A namespace is rejected only if we strictly require types. */
+        if (prefer_type <= 1)
+          locval = IDENTIFIER_LOCAL_VALUE (name);
+        break;
+      case TYPE_DECL:
+        /* A type is rejected only if we strictly require namespaces. */
+        if (!namespaces_only)
+          locval = IDENTIFIER_LOCAL_VALUE (name);
+        break;
+      default:
+        /* We require neither types or namespaces. */
+        if (!namespaces_only && prefer_type <= 0)
+          locval = IDENTIFIER_LOCAL_VALUE (name);
+        break;
+      }
 
   /* In C++ class fields are between local and global scope,
      just before the global scope.  */

gcc/cp/decl2.c

@@ -3877,9 +3877,14 @@ add_using_namespace (user, used, indirect)
   /* Add user to the used's users list. */
   DECL_NAMESPACE_USERS (used)
     = perm_tree_cons (user, 0, DECL_NAMESPACE_USERS (used));
-		      
-  for (iter = DECL_NAMESPACE_USERS (user); iter; iter = TREE_CHAIN (iter))
+
+  /* Recursively add all namespaces used. */
+  for (iter = DECL_NAMESPACE_USING (used); iter; iter = TREE_CHAIN (iter))
     /* indirect usage */
+    add_using_namespace (user, TREE_PURPOSE (iter), 1);
+
+  /* Tell everyone using us about the new used namespaces. */
+  for (iter = DECL_NAMESPACE_USERS (user); iter; iter = TREE_CHAIN (iter))
     add_using_namespace (TREE_PURPOSE (iter), used, 1);
 }
 
@@ -4370,25 +4375,10 @@ do_namespace_alias (alias, namespace)
 
   namespace = ORIGINAL_NAMESPACE (namespace);
 
-  binding = binding_for_name (alias, current_namespace);
-  old = BINDING_VALUE (binding);
-  if (old)
-    {
-      if (TREE_CODE (old) == NAMESPACE_DECL
-          && DECL_NAMESPACE_ALIAS (old) == namespace)
-        /* Ok: redeclaration. */
-        return;
-      cp_error ("invalid namespace alias `%D'", alias);
-      cp_error_at ("`%D' previously declared here", old);
-    }
-  else
-    {
-      /* Build the alias. */
-      alias = build_lang_decl (NAMESPACE_DECL, alias, void_type_node);     
-      DECL_NAMESPACE_ALIAS (alias) = namespace;
-      DECL_CONTEXT (alias) = FROB_CONTEXT (current_namespace);
-      BINDING_VALUE (binding) = alias;
-    }
+  /* Build the alias. */
+  alias = build_lang_decl (NAMESPACE_DECL, alias, void_type_node);     
+  DECL_NAMESPACE_ALIAS (alias) = namespace;
+  pushdecl (alias);
 }
 
 /* Check a non-member using-declaration. Return the name and scope

gcc/cp/parse.y

@@ -403,7 +403,16 @@ extdef:
 		{ push_namespace (NULL_TREE); }
 	  extdefs_opt '}'
 		{ pop_namespace (); }
-	| NAMESPACE identifier '=' 
+	| namespace_alias
+	| using_decl ';'
+		{ do_toplevel_using_decl ($1); }
+	| using_directive
+	| extension extdef
+		{ pedantic = $<itype>1; }
+	;
+
+namespace_alias:
+          NAMESPACE identifier '=' 
                 { begin_only_namespace_names (); }
           any_id ';'
 		{
@@ -412,11 +421,6 @@ extdef:
 		    $5 = lastiddecl;
 		  do_namespace_alias ($2, $5);
 		}
-	| using_decl ';'
-		{ do_toplevel_using_decl ($1); }
-	| using_directive
-	| extension extdef
-		{ pedantic = $<itype>1; }
 	;
 
 using_decl:
@@ -3288,6 +3292,7 @@ simple_stmt:
 	| using_directive
 	| namespace_using_decl
 	        { do_local_using_decl ($1); }
+	| namespace_alias
 	;
 
 function_try_block: