一段漏洞百出的代码

最新推荐文章于 2025-12-05 14:38:10 发布

原创最新推荐文章于 2025-12-05 14:38:10 发布 · 866 阅读

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本文展示了一段存在内存管理问题的C++代码，并通过详细分析指出了其中的问题所在，如构造函数中未分配足够的内存空间、析构函数中未正确释放内存、拷贝构造函数缺失等。随后给出了修改后的代码示例，展示了如何正确地实现类成员变量的内存分配与释放。

下面是一段漏洞百出的代码:

#include <string.h>

#include <stdio.h>

class Base

{

private:

char * name;

public:

Base(char * className)

{

name = new char[strlen(className)];

strcpy(name, className);

}

~Base()

{

delete name;

}

char * copyName()

{

char newname [256];

strcpy(newname, name);

return newname;

}

virtual char * getName()

{

return name;

}

static void print(Base base)

{

printf("name: %s /n" , base.name);

}

};

class Subclass : public Base

{

public:

Subclass(char * className) : Base(className)

{

}

};

int main()

{

Base * pBase = new Subclass("test");

Base::print(*pBase);

printf("name: %s /n", pBase->getName());

printf("new name: %s/n ", pBase->copyName());

return 0;

}

这是经过修改的:

#include <string.h>
#include <stdio.h>

class Base
{
private:
    char * name;
public:
    Base(char * className = NULL)
    {
        name = new char[strlen(className)+1];
        strcpy(name, className);
  name[strlen(className)] = '/0';
    }

Base(Base& base)
{
  if ( base.name )
  {
   name = new char[strlen(base.name)+1];
   strcpy(name, base.name);
   name[strlen(base.name)] = '/0';
  }
  else
   name = '/0';
}

    ~Base()
    {
  if ( name )
   delete []name;
    }

    char * copyName()
    {
        char* newname = new char[strlen(name)+1];
        strcpy(newname, name);
  newname[strlen(name)] = '/0';
        return newname;
    }

    virtual char * getName()
    {
        return name;
    }

    static void print(Base base)
    {
        printf("name: %s/n" , base.name);
    }
};

class Subclass : public Base
{
public:
    Subclass(char * className) : Base(className)
    {
    }
};

int main()
{
Base * pBase = new Subclass("test");

Base::print(*pBase);
printf("name: %s/n", pBase->getName());

char * tempName = pBase->copyName();
printf("new name: %s/n", tempName);
delete []tempName;

delete pBase;

return 0;
}