libcd.lib(crt0dat.obj) : error LNK2005: _exit already defined in msvcrtd.lib(MSVCRTD.dll)-优快云博客

本文介绍在VC6环境下编译OCX时遇到的链接错误LNK2005和LNK1169等问题，分析了错误产生的原因，并提供了三种不同的解决方案。

今天在VC6下编译OCX时，由于新增加了几个静态库，在编译时报如下错误：

Linking...
LIBCMT.lib(crt0dat.obj) : error LNK2005: _exit already defined in msvcrtd.lib(MSVCRTD.dll)
LIBCMT.lib(crt0init.obj) : error LNK2005: ___xc_z already defined in msvcrtd.lib(cinitexe.obj)
LIBCMT.lib(crt0init.obj) : error LNK2005: ___xc_a already defined in msvcrtd.lib(cinitexe.obj)
LIBCMT.lib(crt0init.obj) : error LNK2005: ___xi_z already defined in msvcrtd.lib(cinitexe.obj)
LIBCMT.lib(crt0init.obj) : error LNK2005: ___xi_a already defined in msvcrtd.lib(cinitexe.obj)
LIBCMT.lib(crt0dat.obj) : warning LNK4006: _exit already defined in msvcrtd.lib(MSVCRTD.dll); second definition ignored
LIBCMT.lib(crt0init.obj) : warning LNK4006: ___xc_z already defined in msvcrtd.lib(cinitexe.obj); second definition ignored
LIBCMT.lib(crt0init.obj) : warning LNK4006: ___xc_a already defined in msvcrtd.lib(cinitexe.obj); second definition ignored
LIBCMT.lib(crt0init.obj) : warning LNK4006: ___xi_z already defined in msvcrtd.lib(cinitexe.obj); second definition ignored
LIBCMT.lib(crt0init.obj) : warning LNK4006: ___xi_a already defined in msvcrtd.lib(cinitexe.obj); second definition ignored
Creating library Debug/GXRS.lib and object Debug/GXRS.exp
LINK : warning LNK4098: defaultlib "msvcrtd.lib" conflicts with use of other libs; use /NODEFAULTLIB:library
LINK : warning LNK4098: defaultlib "LIBCMT" conflicts with use of other libs; use /NODEFAULTLIB:library
Debug/GXRS.ocx : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

GXRS.ocx - 6 error(s), 7 warning(s)

原因：原来我的程序是USE mfc in a share dll,　而libcmt.lib是静态C runtime库，这样就导致主程序和lib所使用的运行库不一致，所以应该屏蔽掉libcmt.lib，以免造成冲突。

解决方法：Project Properties, Linker, Input, 右边有个Ignore Specific Library,输入"libcmt.lib",确定即可。

其它解决方法：

解决方案1：

主程序和lib所使用的运行库不一致，project->setting-> Generation->Use MFC Static Library

解决方案2：
Project Properties, Linker, Input, 右边有个Ignore Specific Library,输入"MSVCRTD.lib",确定即可。

解决办法3：
在程序头部加上：#pragma comment(Linker,"/NODEFAULTLIB:libcd.lib")//忽略默认库

参考：

http://wenokai.blog.163.com/blog/static/6149070920106221055197/

http://hi.baidu.com/skyin0912/blog/item/0afd3ed1d651c087a1ec9c52.html

http://blog.youkuaiyun.com/jia_xiaoxin/archive/2008/08/03/2762373.aspx