我有下面的堆栈实现使用双向链表，我想在reverse函数中使用第二个堆栈，但是我得到了错误。如何做到这一点，假设我想返回s2。

#include <stdio.h>
#include <stdlib.h>

typedef struct Node {
    int data;
    struct Node* prev;
    struct Node* next;
} Node;

//---------------------Stack---------------------

typedef struct Stack {
    int size;
    Node* head;
    Node* tail;
    int top;
} Stack;

const Stack stack_init = { .size = 0, .head = NULL, .tail = NULL, .top = -1 };

Node* create_node(int elm) {
    Node* node = malloc(sizeof * node);
    if (!node) return node;
    node->data = elm;
    node->prev = NULL;
    node->next = NULL;
    return node;
}

int is_empty_s(Stack *s) {
    return s->tail == NULL;
}

void push(Stack *s, int elm) {
    Node* updated_head = create_node(elm);
    if (!s->head) {
        s->head = updated_head;
        s->tail = s->head;
    } else {
        updated_head->next = s->head;
        s->head->prev = updated_head;
        s->head = updated_head;
    }
    s->size++;
    s->top = s->head->data;
}

int pop(Stack *s) {
    if (!is_empty_s(s)) {
        Node* node = s->head;
        int elm = node->data;
        s->head = s->head->next;
        if (s->head) {
            s->head->prev = NULL;
            s->top = s->head->data;
        }
        else {
            s->tail = NULL;
            s->top = -1;
        }
        s->size--;
        free(node);
        return elm;
    }
}

Stack* reverse_s(Stack *s) { // iterative: using another stack, queue
    Stack *s2 = stack_init;
    while (s->tail) {
        push(s2, pop(s));
    }
    return s2;
}

int main() {

    Stack s1 = stack_init;
    // Queue queue1 = queue_init; { .size = 0, .head = NULL, .tail = NULL, .front = -1 };
    push(&s1, 5);
    push(&s1, 4);
    return 0;
}

正如你所看到的，reverse函数还没有完成，我是C新手，不知道如何处理这个语法。