[C++11] There can be only one ref qualifier at most.

[Ed Smith-Rowland]

This is a minor nit on the C++ reference qualifiers.
Obviously, ref quals are not a sequence.
Adding multiple ref quals did error out but this patch cleans up the 
error from a few unexpected tokens to one root cause.
Also _seq is removed from te cp_parser function name.
builds and passes all tests on x86_64-linux.

Ed

Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c     (revision 197464)
+++ gcc/cp/parser.c     (working copy)
@@ -2020,7 +2020,7 @@
   (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 @@
                  /* 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 @@
    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;
-  cp_token *token = cp_lexer_peek_token (parser->lexer);
-  switch (token->type)
+
+  while (true)
     {
-    case CPP_AND:
-      ref_qual = REF_QUAL_LVALUE;
-      break;
-    case CPP_AND_AND:
-      ref_qual = REF_QUAL_RVALUE;
-      break;
+      cp_ref_qualifier curr_ref_qual = REF_QUAL_NONE;
+      cp_token *token = cp_lexer_peek_token (parser->lexer);
+
+      switch (token->type)
+       {
+       case CPP_AND:
+         curr_ref_qual = REF_QUAL_LVALUE;
+         break;
+
+       case CPP_AND_AND:
+         curr_ref_qual = REF_QUAL_RVALUE;
+         break;
+
+       default:
+         curr_ref_qual = REF_QUAL_NONE;
+         break;
+       }
+
+      if (!curr_ref_qual)
+       break;
+      else if (ref_qual)
+       {
+         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);
-      cp_lexer_consume_token (parser->lexer);
-    }
+    maybe_warn_cpp0x (CPP0X_REF_QUALIFIER);
 
   return ref_qual;
 }
Index: gcc/testsuite/g++.dg/cpp0x/ref-qual-multi-neg.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/ref-qual-multi-neg.C     (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/ref-qual-multi-neg.C     (revision 0)
@@ -0,0 +1,7 @@
+// { dg-require-effective-target c++11 }
+
+class Foo
+{
+public:
+  void bar() const && & { }  // { dg-error "multiple ref-qualifiers" }
+};
gcc/cp:

2013-04-05  Ed Smith-Rowland  <3dw...@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.

gcc/testsuite:

2013-04-05  Ed Smith-Rowland  <3dw...@verizon.net>

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