实现内存检测工具

思路就是覆盖原有的malloc和free函数，并记录内存申请和释放情况

struct MEM_INFO 
{
        int m_addr;
        int m_size;
        char m_strFile[1024];
        int m_nLine;
};

hash_map<int, MEM_INFO> hstbl;

void* xmalloc(unsigned int size, const char* strFile, int nLine)
{
        void* pRet = malloc(size);

        MEM_INFO info;
        info.m_addr = (int)pRet;
        info.m_size = size;
        strcpy(info.m_strFile, strFile);
        info.m_nLine = nLine;

        hstbl[info.m_addr] = info;

        return pRet;
}

void xfree(void* p)
{
        hash_map<int, MEM_INFO>::iterator it = hstbl.find((int)p);

        if(it == hstbl.end()) return;

        free(p);
        hstbl.erase(it);
}

#define malloc(x) xmalloc(x, __FILE__, __LINE__)//调用malloc的文件以及对应的行
#define free(x) xfree(x)

void PrintLeak()
{
        hash_map<int, MEM_INFO>::iterator it = hstbl.begin();
        for (; it != hstbl.end(); it++)
        {
                cout<<"Memory leak at File: "<<it->second.m_strFile<<
                " line: "<<it->second.m_nLine<<" address: "<<it->second.m_nLine
                <<" size: "<<it->second.m_size<<endl;
                cout<<"******************************************************************"<<endl;
        }
}

void test()
{
        void* p = malloc(sizeof(int));
        void* q = malloc(sizeof(int));
        free(p);
        PrintLeak();
}