Vitaly Novichkov
Once I ran build of my codecs collection on AppVeyor where my CMake script downloads latest SDL2 from HG repo, failed to link because of math functions conflict:
https://ci.appveyor.com/project/Wohlstand/audiocodecs/build/1.0.44
The revision is b94292eebb5c
There are both vanilla MinGW and MinGW-w64 are failed to build.
```
[100%] Linking C shared library libSDL2.dll
c:/mingw/bin/../lib/gcc/mingw32/5.3.0/../../../libmingwex.a(scalbn.o):(.text+0x0): multiple definition of `scalbln'
CMakeFiles\SDL2.dir/objects.a(s_scalbn.c.obj):C:/projects/audiocodecs/build-MinGW-Release-Win32/external/SDL2/src/SDL2HG/src/libm/s_scalbn.c:30: first defined here
Having the SDL functions inline is causing build issues, and in the case of malloc(), etc. causing malloc/free mismatches, if the application build environment differs from the SDL build environment.
In the interest of safety and consistency, the functions will always be in the SDL library and will only be redirected to the C library there, if they are available.
See the following threads on the SDL mailing list for the gruesome details:
* SDL_stdinc.h inlines problematic when application not compiled in exact same feature environment
* Error compiling program against SDL2 with -std=c++11 g++ flag
