[C++ Patch] PR 63786

[Paolo Carlini]

Hi,

we are crashing on this kind of invalid code because we don't early 
check the case with check_for_bare_parameter_packs. Tested x86_64-linux.

Thanks,
Paolo.

//////////////////////
/cp
2014-11-25  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/63786
        * parser.c (cp_parser_label_for_labeled_statement): Check the case
        with check_for_bare_parameter_packs.

/testsuite
2014-11-25  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/63786
        * g++.dg/cpp0x/variadic163.C: New.
Index: cp/parser.c
===================================================================
--- cp/parser.c (revision 218039)
+++ cp/parser.c (working copy)
@@ -9820,6 +9820,8 @@ cp_parser_label_for_labeled_statement (cp_parser*
        cp_lexer_consume_token (parser->lexer);
        /* Parse the constant-expression.  */
        expr = cp_parser_constant_expression (parser);
+       if (check_for_bare_parameter_packs (expr))
+         expr = error_mark_node;
 
        ellipsis = cp_lexer_peek_token (parser->lexer);
        if (ellipsis->type == CPP_ELLIPSIS)
@@ -9826,8 +9828,9 @@ cp_parser_label_for_labeled_statement (cp_parser*
          {
            /* Consume the `...' token.  */
            cp_lexer_consume_token (parser->lexer);
-           expr_hi =
-             cp_parser_constant_expression (parser);
+           expr_hi = cp_parser_constant_expression (parser);
+           if (check_for_bare_parameter_packs (expr_hi))
+             expr_hi = error_mark_node;
 
            /* We don't need to emit warnings here, as the common code
               will do this for us.  */
Index: testsuite/g++.dg/cpp0x/variadic163.C
===================================================================
--- testsuite/g++.dg/cpp0x/variadic163.C        (revision 0)
+++ testsuite/g++.dg/cpp0x/variadic163.C        (working copy)
@@ -0,0 +1,21 @@
+// PR c++/63786
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+template <int... Is>
+int f(int i) {
+    switch (i) {
+        case Is:       // { dg-error "not expanded" }
+            return 0;
+    }
+
+    switch (i) {
+        case 0 ...Is:  // { dg-error "not expanded" }
+            return 0;
+    }
+    return 0;
+}
+
+int main() {
+    f<1,2,3>(1);
+}