为甚么VS2005重复定义没有报错?

C/C++ code

extern HANDLE                                                g_carportHandle ;        //诊断串口句柄    extern DEFAULT_MSGATTR                                        g_defaultMsgAttr;         //MSG项的缺省参数    static U8                                                    m_CAN_ANS_T;    static U8                                                    m_CAN_ANS_R;[color=#FF0000]    static THREAD_DATA                                            m_threaddata;    static THREAD_DATA                                            m_threaddata;