Conflicting types while building FreeImage with MinGW

[velika12]

Hello! I have a problem trying to compile OpenCascade according to your instructions here. The only difference is that I use MinGW installed with Qt. The compilation stops with this error

[  5%] Building C object oce-win-bundle/FreeImage.cmake/CMakeFiles/FreeImage.dir
/__/libs/FreeImage/Source/LibJXR/image/sys/strcodec.c.obj
d:/oce/oce-win-bundle/libs/FreeImage/Source/LibJXR/image/sys/strcodec.c:674:5: error: conflicting types for '_byteswap_ulong' U32 _byteswap_ulong(U32 bits)
In file included from d:/oce/oce-win-bundle/libs/FreeImage/Source/LibJXR/image/sys/windowsmediaphoto.h:35:0,
                 from d:/oce/oce-win-bundle/libs/FreeImage/Source/LibJXR/image/sys/strcodec.h:35,
                 from d:/oce/oce-win-bundle/libs/FreeImage/Source/LibJXR/image/sys/strcodec.c:28:
d:/Programs/Qt/Qt5.5.0/Tools/mingw492_32/i686-w64-mingw32/include/stdlib.h:356:25: note: previous declaration of '_byteswap_ulong' was here
   unsigned long __cdecl _byteswap_ulong (unsigned long _Long);
                         ^
oce-win-bundle/FreeImage.cmake/CMakeFiles/FreeImage.dir/build.make:9238: recipe
for target `oce-win-bundle/FreeImage.cmake/CMakeFiles/FreeImage.dir/__/libs/Free
Image/Source/LibJXR/image/sys/strcodec.c.obj' failed
make[2]: *** [oce-win-bundle/FreeImage.cmake/CMakeFiles/FreeImage.dir/__/libs/Fr
eeImage/Source/LibJXR/image/sys/strcodec.c.obj] Error 1
CMakeFiles/Makefile2:1149: recipe for target 'oce-win-bundle/FreeImage.cmake/CMa
keFiles/FreeImage.dir/all' failed
make[1]: *** [oce-win-bundle/FreeImage.cmake/CMakeFiles/FreeImage.dir/all] Error
 2
Makefile:160: recipe for target `all' failed
make: *** [all] Error 2

Everything completes successfully if I don't specify FreeImage dependency with cmake, but I need this library. Could you help me to solve this problem?

[velika12]

I have found the conflicting _byteswap_ulong in D:\oce\oce-win-bundle\libs\FreeImage\Source\LibJXR\image\sys\strcodec.c and just commented its definition. This action helped me to compile the code with FreeImage.

Maybe there is some bug in preprocessor checks? Here is the code

//================================================================
// Memory access functions
//================================================================
#if (defined(WIN32) && !defined(UNDER_CE) && (!defined(__MINGW32__) || defined(__MINGW64_TOOLCHAIN__) || defined(__MINGW64__))) || (defined(UNDER_CE) && defined(_ARM_))
// WinCE ARM and Desktop x86
#else
// other platform
#ifdef _BIG__ENDIAN_
#define _byteswap_ulong(x)  (x)
#else // _BIG__ENDIAN_
U32 _byteswap_ulong(U32 bits)
{
    U32 r = (bits & 0xffu) << 24;
    r |= (bits << 8) & 0xff0000u;
    r |= ((bits >> 8) & 0xff00u);
    r |= ((bits >> 24) & 0xffu);

    return r;
}
#endif // _BIG__ENDIAN_
#endif

I use Windows 7 64-bit.