C++：編譯單元獨立性和舊winsock2.h類型重定義錯誤

Question

據我所知，編譯階段相互之間沒有任何關係。你能解釋爲什麼我有那麼奇怪的行爲：在一個A.cpp（實際上不使用socket api並且不包括winsock2.h）中包含windows.h之後，在編譯ANOTHER B.cpp時出錯winsock2.h winsock.h衝突。這個B.cpp根本沒有改變。提前致謝。

編輯：它實際上是一個編譯而不是鏈接錯誤。我已經把MSVC編譯器在詳細模式在這裏頭包括樹：

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' 

我之前遇到過這個問題，知道 的#define WIN32_LEAN_AND_MEAN 包括之前Windows頭修復它。但爲什麼在這種情況下發生？

Answer 1

Windows.h包含winsock。所以，即使你不直接包含，也不會使用它，它將被包含在內。 #define WIN32_LEAN_AND_MEAN解決了這個問題，因爲這會強制只包含必要的頭文件。

可能性：

• 你莫名其妙地結束，包括的Winsock/WINSOCK2兩次嘗試刪除Winsock直接包括和只包括WINDOWS.H

• 您已經添加了窗口/ winsock的一個共同的頭文件：檢查包含層次結構。要進行測試，請移除常見標題，並嘗試將它們直接包含在源文件中

• 您是否打開了預編譯頭文件？請關閉該

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