gcc/testsuite/gcc.dg/pr99224.c - gcc - Git at Google

 /* { dg-do compile } */

 void f (char *c, ...)
 {
   __builtin_next_arg (*c); /* { dg-warning "not last named argument" } */
 }
	/* { dg-do compile } */

	void f (char *c, ...)
	{
	__builtin_next_arg (c); / { dg-warning "not last named argument" } */
	}