C++逆向学习(四) 类

测试代码

基类 base ，派生类 derived ，分别有成员变量、成员函数、虚函数

#include<stdio.h>
#include<stdlib.h>

class base {
public:
    int a;
    double b;
    base() {
        this->a = 1;
        this->b = 2.3;
        printf("base constructor\n");
    }
    void func() {
        printf("%d  %lf\n", a, b);
    }
    virtual void v_func() {
        printf("base v_func()\n");
    }
    ~base() {
        printf("base destructor\n");
    }
};

class derived :public base {
public:
    derived() {
        printf("derived constructor\n");
    }
    virtual void v_func() {
        printf("derived v_func()");
    }
    ~derived() {
        printf("derived destructor\n");
    }
};


int main(int argc, char** argv) {
    base a;
    a.func();
    a.v_func();

    base* b = (base*)new derived();
    b->func();
    b->v_func();
    return 0;
}

编译： g++ test.cpp -o test

IDA视角

IDA打开，如下：

this指针

可以看到， base:: 的每个函数都传入了一个参数 (base*)&v5 ，正是类实例的 this指针

以下是普通成员函数 func() 的调用过程

<