编译ATL工程的连接错误：msvcrt.lib(dllsupp.obj) : error LNK2005: __fltused already defined in StdAfx.obj

[ecai]

一个ATL工程， DEBUG版本已经通过，编译 ReleaseMinSize版本时出现以下错误：

Linking...
msvcrt.lib(dllsupp.obj) : error LNK2005: __fltused already defined in StdAfx.obj
msvcrt.lib(dllsupp.obj) : warning LNK4006: __fltused already defined in StdAfx.obj; second definition ignored
Creating library ReleaseMinSize/VideoMod.lib and object ReleaseMinSize/VideoMod.exp
ReleaseMinSize/VideoMod.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

说明：
1： _fltused 是在 atlimpl.cpp中定义的变量（Line 106）

#if !defined(_M_ALPHA) && !defined(_M_PPC)
//RISC always initializes floating point and always defines _fltused
extern "C" const int _fltused = 0;
#endif

2： atlimpl.cpp 在 stdafx.cpp 中被包含（AppWizard自动生成的代码）：

// stdafx.cpp
#include "stdafx.h"

#ifdef _ATL_STATIC_REGISTRY
#include <statreg.h>
#include <statreg.cpp>
#endif

#include <atlimpl.cpp>

Thank first!

[masterz]

try to remove the preprocessor _ATL_MIN_CRT

[ecai]

Problem solved! But Why?

When the ATL COM AppWizard generates the default project, it defines the macro _ATL_MIN_CRT. This macro is defined so that you don't bring the C Run-Time Library into your code if you don't need it.

和 _fltused有什么关系？if defined _ATL_MIN_CRT, we may get errors like this:

LIBCMT.LIB(crt0.obj) : error LNK2001: unresolved external symbol _main

But now there is a multiply defined symbol, it puzzels me!
I will give you score first, but please give me further explanation

[masterz]

someone declare this as a bug of VC.