After some painful experiences, I understand the problem of dangling pointers and double free. I am seeking proper solutions. aStruct has a number of fields including other arrays.

aStruct *A=NULL, *B = NULL;
A = (aStruct*) calloc(1, sizeof(sStruct));
B = A;
free_aStruct(A);
...
//bunch of other code in various places.
...
free_aStruct(B);

Is there any way to write free_aStruct(X) so that free_aStruct(B) exists gracefully??

void free_aStruct(aStruct *X){
  if (X ! = NULL){
      if (X->a != NULL){free(X->a); x->a = NULL;}
      free(X); X = NULL;
}
}

Doing above only sets A = NULL when free_aStruct(A); is called. B is now dangling. How can this situation be avoided / remedied? Is reference counting the only viable solution? or, are there other "defensive" free approaches, to prevent free_aStruct(B); from exploding?

Thanks,

Russ