gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c

/* Verify that we check for uninitialized values passed to functions
   that we have special-cased state-machine handling for.  */

int dup (int old_fd);
int not_dup (int old_fd);

int
test_1 ()
{
  int m;
  return dup (m); /* { dg-warning "use of uninitialized value 'm'" "uninit" } */
}

int
test_2 ()
{
  int m;
  return not_dup (m); /* { dg-warning "use of uninitialized value 'm'" } */
}