
#include <stdio.h>
// source base:
// https://stackoverflow.com/questions/4007268/what-exactly-is-meant-by-de-referencing-a-null-pointer
int main() {
  int a, b, c, x; // some integers
  int *pi;        // a pointer to an integer
  int *ok;
  a = 5;
  ok = &a;
  pi = &a; // pi points to a
  b = *pi;
  pi = NULL;
  x = *ok; //NOWARN
  c = *pi; //WARN

  return 1;
}
