How do i change pointer in function?

Question

I have a recursive function in C and i want the returned struct pointer to become the new struct in the function. Im having a problem with the returned struct because it doesnt

Answer 1

mystruct is a stack variable. In other words, you are passing the pointer by value, instead of passing it by reference.

What have you done at the moment is essentially the same as:

int f(int i) {
   ...
   i = <any value>;
   ...
}

In this case you are modifying only a copy of the value.

In your program, you are also modifying a copy of the pointer. Outside of the function the pointer stays not modified.

If you want to modify it, you need to pass a pointer to it:

location_t * recursive_foo(location_t** loc, maze_t * m){
    int x = (*loc)->x;
    int y = (*loc)->y;
    int dir = (*loc)->dir;
    ...
    *loc = recursive_foo(&temp);
    ...
    return *loc;
}