c - 段错误: 11 for my dynamic linked list

Question

data.h

struct Sub {
    int n;
    struct Sub *next;
}

struct Super {
    struct Sub *Sub
    void (*addSub)(struct Super *self, struct Sub *subRef);
}

数据.c

static void addSub(struct Super *self, struct Sub *subRef) {
    struct Sub *head = self->Sub;

    while(head != NULL) { // throwing segmentation fault somewhere here
        head = head->next;
    }

    // assign subRef once we reach to the end.
}

struct Super *newSuper() {
    struct Super *super = malloc(sizeof(struct Super));
    super->addSub = addSub;
    return super;
}

data_test.c

int main() {
    struct Super *super = newSuper();
    super->addSub(super, malloc(sizeof(struct Sub)));
    return 0;
}

我对 C 比较陌生，很久以前就实现了链表，但似乎无法解决空问题，过去就是这样。如何检测列表的末尾并将新值添加到末尾？

Answer 1

你必须初始化你的新对象

struct Super *newSuper() {
    struct Super *super = malloc(sizeof(struct Super));
    super->addSub = addSub;
    super->Sub = NULL;
    return super;
}

malloc 的内存未清除为任何值；它包含垃圾。

您还应该有一个 newSub 函数来创建 Sub 对象的实例，而不是使用原始 malloc 的调用者