gcc/testsuite/gcc.dg/torture/pr109331.c

/* { dg-do compile } */

char *ustol_dpp;
void ustol(int flags)
{
  char *s;
  if (s)
    flags |= 3;
  switch (flags & 3)
  case 3:
    while (*s)
    case '+':
      ++s;
  if (flags)
    ustol_dpp = s;
}