C ++：编译翻译单元独立和旧winsock2.h类型重新定义错误[重复]答案

【问题标题】：C++: Compilation of translation units independence and old winsock2.h types redefinition error [duplicate]C ++：编译翻译单元独立和旧winsock2.h类型重新定义错误[重复]
【发布时间】：2012-09-14 13:30:49
【问题描述】：

据我所知，翻译单元在编译阶段彼此之间没有任何关系。你能解释一下为什么我会有这种奇怪的行为：在一个 A.cpp 中包含 windows.h 之后（实际上不使用套接字 api 并且不包含 winsock2.h）我在编译另一个 B.cpp 时出错winsock2.h winsock.h 冲突。这个 B.cpp 根本没有改变。提前致谢。

编辑：这实际上是编译而不是链接错误。我已将 msvc 编译器置于详细模式，此处标头包含树：

2>perfomancemeter.cpp
2>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\numeric
2>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\iterator
2>Note: including file:   C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xutility
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\climits
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\yvals.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\sal.h
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtassem.h
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\vadefs.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\use_ansi.h
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\limits.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\utility
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\iosfwd
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\cstdio
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\stdio.h
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\swprintf.inl
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\cstring
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\string.h
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\cwchar
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\wchar.h
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\wtime.inl
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xstddef
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\cstddef
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\stddef.h
2>Note: including file:         C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdbg.h
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\algorithm
2>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\memory
2>Note: including file:   C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xmemory
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\cstdlib
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\stdlib.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\exception
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\eh.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\malloc.h
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\new
2>Note: including file: d:\repos\cbs\billing\common\perfomancemeter.h
2>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\vector
2>Note: including file:   C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\stdexcept
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xstring
2>Note: including file: d:\repos\cbs\billing\common\util.h
2>Note: including file:  d:\repos\cbs\billing\common\framework\include\types/types.h
2>Note: including file:  C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\string
2>Note: including file:   C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\istream
2>Note: including file:    C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\ostream
2>Note: including file:     C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\ios
2>Note: including file:      C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xlocnum
2>Note: including file:       C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\streambuf
2>Note: including file:        C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xiosbase
2>Note: including file:         C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xlocale
2>Note: including file:          C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\typeinfo
2>Note: including file:          C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xdebug
2>Note: including file:          C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xlocinfo
2>Note: including file:           C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\xlocinfo.h
2>Note: including file:            C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\ctype.h
2>Note: including file:             C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
2>Note: including file:            C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\locale.h
2>Note: including file:             C:\Program Files (x86)\Microsoft Visual Studio 8\VC\include\crtdefs.h
1>c:\program files (x86)\microsoft visual studio 8\vc\platformsdk\include\winsock2.h(112) : error C2011: 'fd_set' : 'struct' type redefinition
1>        c:\program files (x86)\microsoft visual studio 8\vc\platformsdk\include\winsock.h(54) : see declaration of 'fd_set'

我以前遇到过这个问题并且知道 #define WIN32_LEAN_AND_MEAN 在包含 windows 标头之前修复它。但是为什么会在这种情况下发生呢？

【问题讨论】：

.cpp 文件中的任何一个都包含另一个，您对情况的描述不准确（例如，您实际上在链接期间得到了错误，而不是在编译），或者发生了一些非常奇怪的事情.更多细节会有很大帮助，例如，确切的错误消息。
错误是什么？如果您确实分别编译 A 和 B，是的，它们没有理由相互冲突。我相信你实际上在做的是编译它们然后链接它们，你最终会遇到链接器错误，但是因为你没有提到实际的错误，所以这只是一个无法测试的理论。
不，伙计们，这是一个编译错误，我在原始问题中添加了详细信息

标签： c++ windows winsock

【解决方案1】：

Windows.h 包括 winsock。因此，即使您不直接包含也不使用它，它也会被包含在内。 #define WIN32_LEAN_AND_MEAN 解决了这个问题，因为这会强制只包含必要的标头。

可能性：

您不知何故最终包含了 winsock/winsock2 两次：尝试删除 winsock 直接包含并仅包含 windows.h
您已将 windows/winsock 添加到公共头文件：检查包含层次结构。为了测试，删除常见的头文件并尝试将它们直接包含在源文件中
您是否打开了预编译头文件？尝试关闭它

参考：http://social.msdn.microsoft.com/Forums/en/vcgeneral/thread/6177f9bc-db75-4317-9904-02ef55b527d0

【讨论】：

另一个选项 - 确保 winsock2.h 包含在 windows.h 之前，因为 winsock2.h 禁用 winsock.h 被编译，但反之则不正确。