llvm-gcc-4.2/gcc/testsuite/treelang/compile/var_defs-2.tree

// { dg-do compile }
external_definition int first_nonzero (int arg5, int arg6);

first_nonzero
{
  automatic int y;
  automatic int y;  // { dg-error "Duplicate" }
  if (arg5)
    {
      return arg5;
    }
  else
    {
      automatic int j;
      j = arg6;
      return j;
    }
  return arg6;
}