There can be only one ref qualifier at most.

gcc/cp:
2013-04-05  Ed Smith-Rowland  <3dw4rd@verizon.net>

	* g++.dg/cpp0x/ref-qual-multi-neg.C: New test.

gcc/testsuite:
2013-04-05  Ed Smith-Rowland  <3dw4rd@verizon.net>

	* parser.c (cp_parser_ref_qualifier_seq_opt): Move to
	cp_parser_ref_qualifier_opt.  Error if more than one ref-qual found.

From-SVN: r197514

gcc/cp/ChangeLog

+2013-04-05  Ed Smith-Rowland  <3dw4rd@verizon.net>
+
+	* parser.c (cp_parser_ref_qualifier_seq_opt): Move to
+	cp_parser_ref_qualifier_opt.  Error if more than one ref-qual found.
+
 2013-04-03  Jason Merrill  <jason@redhat.com>
 
 	* cp-tree.h (FUNCTION_OR_METHOD_TYPE_CHECK): Remove.

gcc/cp/parser.c

@@ -2020,7 +2020,7 @@ static cp_cv_quals cp_parser_cv_qualifier_seq_opt
   (cp_parser *);
 static cp_virt_specifiers cp_parser_virt_specifier_seq_opt
   (cp_parser *);
-static cp_ref_qualifier cp_parser_ref_qualifier_seq_opt
+static cp_ref_qualifier cp_parser_ref_qualifier_opt
   (cp_parser *);
 static tree cp_parser_late_return_type_opt
   (cp_parser *, cp_cv_quals);
@@ -16463,7 +16463,7 @@ cp_parser_direct_declarator (cp_parser* parser,
 		  /* Parse the cv-qualifier-seq.  */
 		  cv_quals = cp_parser_cv_qualifier_seq_opt (parser);
 		  /* Parse the ref-qualifier. */
-		  ref_qual = cp_parser_ref_qualifier_seq_opt (parser);
+		  ref_qual = cp_parser_ref_qualifier_opt (parser);
 		  /* And the exception-specification.  */
 		  exception_specification
 		    = cp_parser_exception_specification_opt (parser);
@@ -17031,25 +17031,46 @@ cp_parser_cv_qualifier_seq_opt (cp_parser* parser)
    Returns cp_ref_qualifier representing ref-qualifier. */
 
 static cp_ref_qualifier
-cp_parser_ref_qualifier_seq_opt (cp_parser* parser)
+cp_parser_ref_qualifier_opt (cp_parser* parser)
 {
   cp_ref_qualifier ref_qual = REF_QUAL_NONE;
+
+  while (true)
+    {
+      cp_ref_qualifier curr_ref_qual = REF_QUAL_NONE;
       cp_token *token = cp_lexer_peek_token (parser->lexer);
+
       switch (token->type)
 	{
 	case CPP_AND:
-      ref_qual = REF_QUAL_LVALUE;
+	  curr_ref_qual = REF_QUAL_LVALUE;
 	  break;
+
 	case CPP_AND_AND:
-      ref_qual = REF_QUAL_RVALUE;
+	  curr_ref_qual = REF_QUAL_RVALUE;
+	  break;
+
+	default:
+	  curr_ref_qual = REF_QUAL_NONE;
 	  break;
 	}
 
-  if (ref_qual)
+      if (!curr_ref_qual)
+	break;
+      else if (ref_qual)
 	{
-      maybe_warn_cpp0x (CPP0X_REF_QUALIFIER);
+	  error_at (token->location, "multiple ref-qualifiers");
+	  cp_lexer_purge_token (parser->lexer);
+	}
+      else
+	{
+	  ref_qual = curr_ref_qual;
 	  cp_lexer_consume_token (parser->lexer);
 	}
+    }
+
+  if (ref_qual)
+    maybe_warn_cpp0x (CPP0X_REF_QUALIFIER);
 
   return ref_qual;
 }

gcc/testsuite/ChangeLog

+2013-04-05  Ed Smith-Rowland  <3dw4rd@verizon.net>
+
+	* g++.dg/cpp0x/ref-qual-multi-neg.C: New test.
+
 2013-04-04  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/40881

gcc/testsuite/g++.dg/cpp0x/ref-qual-multi-neg.C

+// { dg-require-effective-target c++11 }
+
+class Foo
+{
+public:
+  void bar() const && & { }  // { dg-error "multiple ref-qualifiers" }
+};