我在具有不同版本的GNU的不同机器上测试了此代码段，只有一台Clang 1001.0.46.3奇怪的Mac报告分段错误。在这段代码中是否存在地址问题或指针问题？

#include <iostream>
#include <vector>

using namespace std;

class Node
{
public:
    Node* next;
    int val;

};

class List
{
private:
    Node* head;
    Node* tail;
public:
    List()
    {
        head = tail = nullptr;
    }
    bool isEmpty()
    {
        if(!head && !tail) return true;
        return false;
    }
    void pushBack(int num)
    {
        Node* newNode = new Node;
        newNode->val = num;
        if(isEmpty()) head = tail = newNode;
        else
        {
            tail->next = newNode;
            tail = tail->next; 
        }
    }

    void pushFront(int num)
    {
        Node* newNode = new Node;
        newNode->val = num;
        if(isEmpty()) head = tail = newNode;
        else
        {
            Node* tmp = head;
            newNode->next = tmp;
            head = newNode;
        }
    }

    void popBack()
    {
        if(head == tail) {delete head; head = nullptr; return;}
        Node* tmp = head;
        while(tmp->next != tail) tmp = tmp->next;
        tail = tmp;
        delete tmp->next;
        tmp->next = nullptr;
    }

    void popFront()
    {
        if(head == tail) {delete head; head = nullptr; return;}
        Node* tmp = head;
        tmp = tmp->next;
        delete head;
        head = nullptr;
        head = tmp;
    }

    int findLen()
    {
        if(isEmpty()) return 0;
        int len = 0 ;   
        Node* tmp = head;
        while(tmp)
        {
            len++;
            //if(tmp == tail) break;
            tmp = tmp->next;
        }
        return len;
    }

    void inserter(int position,int num)
    {
        if(position > findLen() || isEmpty()) return;
        int index = 0;
        Node* tmp = head;
        Node* newNode = new Node;
        newNode->val = num;
        if(position == 0) {pushFront(num); return;}
        else if(position == findLen()) {pushBack(num); return;}
        while(tmp->next)
        {
            index++;
            if(index == position)
            {
                Node* tmp2 = tmp->next;
                tmp->next = newNode;
                newNode->next = tmp2;
                return;
            }   
            tmp = tmp->next;
        }
    }

    void print()
    {
        if(isEmpty()) return;
        cout << "list = ";
        Node* tmp = head;

        while(tmp)
        {
            cout << tmp->val << " ";
            if(tmp == tail) break;
            tmp = tmp->next;
        }
        cout << endl;
    }
};



int main()
{   
    cout << "delete added" << endl;
    List testList;
    testList.pushBack(5);
    testList.pushBack(10);
    testList.pushBack(15);
    testList.pushBack(20);                          // after this line,we got segmentation fault
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    testList.pushFront(5);
    testList.pushFront(10);
    testList.pushFront(15);
    testList.pushFront(20);
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    testList.inserter(0,8);
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    testList.inserter(9,555);
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    testList.inserter(5,333);
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    cout << "popBack" << endl;
    testList.popBack();
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    cout << "popFront" << endl;
    testList.popFront();
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    cout << "popBack" << endl;
    testList.popBack();
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    cout << "popFront" << endl;
    testList.popFront();
    cout << "len = " << testList.findLen() << endl;
    testList.print();

    return 0;
}

跟进：嘿，伙计们，我自己有一些线索。我认为问题应该出在操作系统方面。在检查了相关的汇编代码之后，我注意到，即使局部变量的默认初始化值为0，它们也不总是零。我认为问题应该出在操作系统的分页方案上。我将尽力弄清楚MacOS（内核10.15.1）和linux如何选择页面以及如何为局部变量生成随机值。如果有人知道这一领域或有任何线索可以解决，请随时告诉我。干杯。