1.1.7.5. unix.Vfork (C)
Check for proper usage of vfork.

Examples:

int test(int x) {
  pid_t pid = vfork(); // warn
  if (pid != 0)
    return 0;

  switch (x) {
  case 0:
    pid = 1;
    execl("", "", 0);
    _exit(1);
    break;
  case 1:
    x = 0; // warn: this assignment is prohibited
    break;
  case 2:
    foo(); // warn: this function call is prohibited
    break;
  default:
    return 0; // warn: return is prohibited
  }

  while(1);
}