[cfe-dev] Clang inconsistency with gcc on Windows

[Edward Diener]

On 5/31/2015 2:05 PM, Yaron Keren wrote:
> Boost tries to supplies its own version of the Windows API to avoid
> including WIndows.h
> Boost version of the API is not strictly identical to Windows.h, so if
> Windows.h do get included somehow such errors happen. I always
> -DBOOST_USE_WINDOWS_H to force Boost to use Windows.h instead of its own.

Thanks, that does work.

I still would like to know why clang is giving errors in the situation I 
describe in my OP and gcc is not. I am not saying that clang is wrong to 
do so but clearly it is not being compatible with gcc in this area.

>
>
>
> 2015-05-31 20:48 GMT+03:00 Edward Diener
> <eldlistmailingz at tropicsoft.com
> <mailto:eldlistmailingz at tropicsoft.com>>:
>
>     Compiling some Boost library code the latest clang has produced an
>     inconsistency with gcc on Windows that is making it impossible to
>     build Boost libraries successfully.
>
>     The code in question, where clang is given an error:
>
>         clang-linux.compile.c++.without-pth
>         ..\..\..\bin.v2\libs\context\build\clang-linux-3.7.0\debug\threading-multi\windows\stack_traits.obj
>         In file included from
>         ..\..\..\libs\context\src\windows\stack_traits.cpp:24:
>         In file included from ..\..\..\boost/thread.hpp:13:
>         In file included from ..\..\..\boost/thread/thread.hpp:12:
>         In file included from ..\..\..\boost/thread/thread_only.hpp:15:
>         In file included from
>         ..\..\..\boost/thread/win32/thread_data.hpp:10:
>         In file included from ..\..\..\boost/thread/thread_time.hpp:10:
>         In file included from
>         ..\..\..\boost/date_time/microsec_time_clock.hpp:23:
>         ..\..\..\boost/date_time/filetime_functions.hpp:57:46: error:
>         conflicting types for 'GetSystemTimeAsFileTime'
>                  __declspec(dllimport) void __stdcall
>         GetSystemTimeAsFileTime(FILETIME* lpFileTime);
>                                                       ^
>         /mingw/include\winbase.h:1397:24: note: previous declaration is here
>         WINBASEAPI void WINAPI GetSystemTimeAsFileTime(LPFILETIME);
>
>                               ^
>
>     and more of the same in many places building Boost libraries with clang.
>
>     This is with the latest clang, which I build with mingw/gcc-4.8.1 on
>     Windows.
>
>     With gcc-4.8.1:
>
>         gcc.compile.c++
>         ..\..\..\bin.v2\libs\context\build\gcc-mingw-4.8.1\debug\threading-multi\windows\stack_traits.o
>
>
>     With gcc-4.9.2
>
>         gcc.compile.c++
>         ..\..\..\bin.v2\libs\context\build\gcc-mingw-4.9.2\debug\threading-multi\windows\stack_traits.o
>
>
>     This is happening extensively in Boost code which uses the Windows
>     API when compiling under Windows.
>
>     I do not know what WINBASEAPI is supposed to resove to under mingw,
>     but clearly it should not be different for gcc and clang under
>     Windows and gcc has no problems with this.