parser.c (cp_parser_nested_name_specifier_opt): Diagnose invalid template-ids.

	* parser.c (cp_parser_nested_name_specifier_opt): Diagnose invalid
	template-ids.

From-SVN: r219269

gcc/cp/ChangeLog

 2015-01-06  Jason Merrill  <jason@redhat.com>
 
+	* parser.c (cp_parser_nested_name_specifier_opt): Diagnose invalid
+	template-ids.
+
 	PR c++/64455
 	* pt.c (type_dependent_expression_p): Handle variable templates.
 	* constexpr.c (potential_constant_expression_1): Use it.

gcc/cp/parser.c

@@ -5435,6 +5435,46 @@ cp_parser_nested_name_specifier_opt (cp_parser *parser,
 	      cp_lexer_consume_token (parser->lexer);
 	    }
 
+	  if (cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)
+	      && cp_lexer_nth_token_is (parser->lexer, 2, CPP_SCOPE))
+	    {
+	      /* If we have a non-type template-id followed by ::, it can't
+		 possibly be valid.  */
+	      token = cp_lexer_peek_token (parser->lexer);
+	      tree tid = token->u.tree_check_value->value;
+	      if (TREE_CODE (tid) == TEMPLATE_ID_EXPR
+		  && TREE_CODE (TREE_OPERAND (tid, 0)) != IDENTIFIER_NODE)
+		{
+		  tree tmpl = NULL_TREE;
+		  if (is_overloaded_fn (tid))
+		    {
+		      tree fns = get_fns (tid);
+		      if (!OVL_CHAIN (fns))
+			tmpl = OVL_CURRENT (fns);
+		      error_at (token->location, "function template-id %qD "
+				"in nested-name-specifier", tid);
+		    }
+		  else
+		    {
+		      /* Variable template.  */
+		      tmpl = TREE_OPERAND (tid, 0);
+		      gcc_assert (variable_template_p (tmpl));
+		      error_at (token->location, "variable template-id %qD "
+				"in nested-name-specifier", tid);
+		    }
+		  if (tmpl)
+		    inform (DECL_SOURCE_LOCATION (tmpl),
+			    "%qD declared here", tmpl);
+
+		  parser->scope = error_mark_node;
+		  error_p = true;
+		  /* As below.  */
+		  success = true;
+		  cp_lexer_consume_token (parser->lexer);
+		  cp_lexer_consume_token (parser->lexer);
+		}
+	    }
+
 	  if (cp_parser_uncommitted_to_tentative_parse_p (parser))
 	    break;
 	  /* If the next token is an identifier, and the one after

gcc/testsuite/g++.dg/cpp1y/var-templ20.C

+// { dg-do compile { target c++14 } }
+
+template <bool> struct Sink {};
+template <class T> void fn();
+template <class T> T var = T();
+
+template <class T> void f()
+{
+  Sink<fn<T>::value>();		// { dg-error "function" }
+  Sink<var<T>::value>();	// { dg-error "variable" }
+}
+// { dg-prune-output "template argument" }