re PR c++/27078 (Duplicate error message for ambiguous enum)

	PR c++/27078
	* parser.c (cp_parser_primary_expression): Don't give a duplicate
	ambiguity error.

From-SVN: r154139

gcc/cp/ChangeLog

 2009-11-12  Jason Merrill  <jason@redhat.com>
 
+	PR c++/27078
+	* parser.c (cp_parser_primary_expression): Don't give a duplicate
+	ambiguity error.
+
 	PR c++/39560
 	* decl2.c (build_anon_union_vars): Set DECL_ARTIFICIAL.
 
@@ -10,16 +14,12 @@
 	* call.c (build_conditional_expr): Check specifically for folding
 	to CALL_EXPR rather than TREE_SIDE_EFFECTS.
 
-2009-11-12  Jason Merrill  <jason@redhat.com>
-
 	* typeck.c (cv_qualified_p): New fn.
 	(decay_conversion): Use it.
 	* cp-tree.h: Declare it.
 	* tree.c (rvalue): Use it and cv_unqualified.
 	* init.c (build_aggr_init): Likewise.
 
-2009-11-12  Jason Merrill  <jason@redhat.com>
-
 	PR c++/42013
 	* call.c (build_conditional_expr): Don't fold a TREE_SIDE_EFFECTS
 	COND_EXPR in unevaluated context.
@@ -33,8 +33,6 @@
 	PR c++/39131
 	* rtti.c (emit_support_tinfos): Add DFP types.
 
-2009-11-11  Jason Merrill  <jason@redhat.com>
-
 	* call.c (build_op_delete_call): Downgrade error about
 	placement/non-placement confusion to permerror.
 

gcc/cp/parser.c

@@ -3509,6 +3509,16 @@ cp_parser_primary_expression (cp_parser *parser,
 	  {
 	    tree ambiguous_decls;
 
+	    /* If we already know that this lookup is ambiguous, then
+	       we've already issued an error message; there's no reason
+	       to check again.  */
+	    if (id_expr_token->type == CPP_NAME
+		&& id_expr_token->ambiguous_p)
+	      {
+		cp_parser_simulate_error (parser);
+		return error_mark_node;
+	      }
+
 	    decl = cp_parser_lookup_name (parser, id_expression,
 					  none_type,
 					  template_p,