Question

C宏里面代码什么意思（附代码）//安全遍历#define list_for_each_safe(cur,tmp,list

Answer 1

#define list_for_each_safe(cur, tmp, list)

for (cur = (list)->head.next,

tmp = (cur)->next;

cur != &(list)->head;

cur = tmp, tmp = (tmp)->next)

上面这些是宏代码,

下面这些是调用这个宏.

list_for_each_safe(cur, tmp, dlist) {

dlist->del(cur);

}

再说说宏代码吧：

是个连接符,由于宏定义基本是在同一行的,但是有些代码比较长,在同一行定义看起来很别扭,所以加了个 就可以换行了,所以 相当于换行符.

这个 list_for_each_safe(cur, tmp, list) 看起来像个函数吧,你也可以看成函数,差不多意思.

for (cur = (list)->head.next,

tmp = (cur)->next;

cur != &(list)->head;

cur = tmp, tmp = (tmp)->next)

上面这一堆就是个for循环的条件表达式,类似于 for(i=0;i