Question

我不确定我接近这个的方式是否比它必须更复杂。如果您有任何想法，请推荐更好的选择。我正在尝试创建一系列节点（窗口），每个节点都包含一串备用节点（框架结构中的可视信息）。

以下是我的调试器突出显示的行：

temp->obj_tail->next = n;

// temp is a node, and temp->obj_tail dereferences a node of the same struct

我得到了回复：“程序收到信号SIGSEGV，分段错误。”

我使用此构造函数将head，tail和temp初始化为NULL

cmenu::cmenu():
    head(NULL),
    tail(NULL),
    temp(NULL)
{
}

调用类函数的主函数

cmenu Menu;

Menu.addWindow("side_bar");
Menu.addWindow("home");
Menu.addWindow("help");

//Box structs defined here, code omitted.

Menu.addBox("side_bar", "box_1", box1);
Menu.addBox("home", "box_2", box2);
Menu.addBox("help", "box_3", box3);

.h

中的相应结构

struct box
{
    int x; int y; int z;
    int w; int h;
    int fill_color; int fill_char;
    int text_color; std::string text;
    bool enabled;

box():
    x(0),y(0),z(0),
    w(0), h(0),
    fill_color(8), fill_char(32), enabled(true),
    text_color(15), text(""){}
};


class cmenu
{
    private:

        typedef struct node
        {
            node* next;       // Next node
            node* prev;       // Prev node
            node* obj_head;   // Head of other node stack
            node* obj_tail;   // Tail of other node stack
            bool enabled;     // Allows toggle of element
            std::string id;   // Used to ID nodes
            box box;          // Visual element

        } *nodePtr;

        nodePtr head;
        nodePtr tail;
        nodePtr temp;


// class functions here, code omitted.

};

发生错误的类.cpp中的函数

void cmenu::addBox(std::string win_id, std::string box_id, box b)
{
    temp = head;
    while (temp->id != win_id) {
        if (temp != tail) {
            temp = temp->next;
        }
    }

    // At this point the program has found the node with the id of
    // win_id. And now my goal is to connect a new and separate 
    // string of nodes to the obj_head and obj_tail.
    // This can only happen if there has already been a node connected
    // which is what the else statement does when temp->obj_tail is NULL
    // so this shouldn't be happening

    if (temp->id == win_id) {

        nodePtr n = new node;

        n->id = box_id; // The id is assigned
        n->box = b;     // The box struct is set/copied to the passed parameter

        // obj_tail is NULL when no nodes are connected to the obj_head/obj_tail
        if (temp->obj_tail != NULL) {
            temp->obj_tail->next = n;
            n->prev = temp->obj_tail;
            n->next = NULL;
            temp->obj_tail = n;
        }
        else {
            n->next = NULL;
            n->prev = NULL;
            // This is where obj_head and obj_tail are assigned and cannot be NULL.
            temp->obj_head = n; 
            temp->obj_tail = n;
        }
    }
}

解除引用节点时的分段错误SIGSEGV

0 个答案: