单链表的栈操作C实现

今后实现了一个栈的操作，本来打算用kernel的list，后来发现双指针有点奢侈，所以就自己单链表来实现，代码如下：

----------------------------------------------------------------------------------------

/*
 * file: main.c
 * author: [e-mail]
 * history:
 * initial @ 2012-02-05
 */

#include <stdio.h>
#include "stack.h"

#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))

void main()
{
    int i;
    stack_t sk;
    int array[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

    stack_init(&sk);
    for (i=0; i < ARRAY_SIZE(array); i++)
        stack_push(&sk, &(array[i]), sizeof(array[i]));

    for (i=0; i < ARRAY_SIZE(array); i++)
        printf("%d ", *(int*)stack_pop(&sk));

    printf("\n");

    stack_exit(&sk);
}

----------------------------------------------------------------------------------------

/*
 * file: stack.h
 * author: [e-mail]
 * history:
 * initial @ 2012-02-05
 */


#ifndef __STACK_H__
#define __STACK_H__

#include <stdlib.h>

#ifndef __assert
#define __assert(x)
#endif

#ifndef NULL
#define NULL 0
#endif

extern struct node;
extern struct stack;

typedef struct stack{
    struct node *head;
}stack_t;

int stack_init(struct stack *sk);
int stack_exit(struct stack *sk);

void *stack_pop(struct stack *sk);
void stack_push(struct stack *sk, void *data, size_t size);

#endif

----------------------------------------------------------------------------------------

/*
 * file: stack.c
 * author: [e-mail]
 * history:
 * initial @ 2012-02-05
 */

#define DEBUG

#include "stack.h"
#include "stdlib.h"

#define __malloc(sz) malloc(sz)
#define __free(p) free(p)


#define __node_init(pn,pd,sz) {\
    (pn)->data=(pd); \
    (pn)->size=(sz); \
    (pn)->next=NULL; \
}

typedef struct node {
    void *data;
    size_t size;
    struct node *next;
} node_t;


void *stack_pop(struct stack *sk)
{
    void *ret=NULL;
    struct node *mark=NULL;
    __assert(sk);
    if (sk->head) {
        mark = sk->head;
        ret = mark->data;
        sk->head = sk->head->next;
        __free(mark);
    }
    return ret;
}

void stack_push(struct stack *sk, void *data, size_t size)
{
    struct node *pnew;
    __assert(sk && data);
    pnew = __malloc(sizeof(struct node));
    __assert(pnew);
    __node_init(pnew, data, size);
    /* insert the node to the head of the list */
    if (sk->head){
        pnew->next = sk->head;
        sk->head = pnew;
    }
    else {
        sk->head = pnew;
    }
}

int stack_init(struct stack *sk)
{
    __assert(sk);
    sk->head = NULL;
    return 0;
}

int stack_exit(struct stack *sk)
{
    __assert(sk);
    while(stack_pop(sk));
    return 0;
}

----------------------------------------------------------------------------------------

代码附件：

 stack.rar