Below are two structures viz Stu and Class. I have declared array of pointers of type Class in main and passing that to Delete function so that I can deallocate the memory(using free).

When I compile this code it shows same warning on many lines like in the Delete function below.

typedef struct Stu {
  struct Stu *prev, *next;
  unsigned int Roll_No, Marks, Id;
  char Name[20], Address[20];
} Stu;

typedef struct Class {
  Stu *next;
  char Class_Name[10];
  unsigned int Total_Stds;
} Class;

void Delete(Class *cls[], unsigned int cha) {
  unsigned int i;
  Class *temp;

  for (i = 0; i < cha; i++) {
    printf("%s removed\n", cls[i]->Class_Name);
    temp = cls[i];
    cls[i] = cls[i]->next; // Warning comes here
    free(temp);
  }
}


int main() {
 Class *cls[5];
 ...
 Delete(cls,c);
 ...
 return 0;
}