C2021: Generate NULL-check for class pointer

[INFORMATION]

Description

Operations with pointers to related classes always need separate NULL-checks before adding offsets from base classes to inherited classes.

Example
  class A {

  
  };

  
  class B : public A{

  
  };

  
  void main() {

  
    A *ap;

  
    B *bp;

  
    ap=bp;  // warning

  
  }

  
Tips

Try to avoid operations with pointers to different, but related classes.