Qt, windows and _POSIX_

Question

I'm working on building Qt 4.8.1 in VisualStudio 2005 and I was getting an issue that the compiler could not find _fileno.

After some research, I found that in stdio.h it has

#ifdef  _POSIX_
_CRTIMP __checkReturn int __cdecl fileno(__in FILE * _File);
#else
_CRTIMP __checkReturn int __cdecl _fileno(__in FILE * _File);
#endif

I then looked through the qt code and found that qfsfilengine_win.cpp and qfilesystemengine_win.cpp both have

#define _POSIX_

It seems to me that this would be a mistake, and if I remove these lines, it seems to build successfully.

Does anyone know why these files would be defining _POSIX_?

Thanks.

Answer 1

It seems that this is indeed a bug in Qt. If you are building Qt for windows without precompiled headers and you run into this problem, just delete the #define _POSIX_ calls in qfsfilengine_win.cpp and qfilesystemengine_win.cpp and it will build successfully.