CMake and no-warn MSVC support

[SamuelMarks]

WiP but it currently builds fine on Windows (no warning).

PS: In terms of strncat_s I suppose I can guard that rather than include an implementation (if you prefer).

[silentbicycle]

This should target the develop branch, as noted at the beginning of CONTRIBUTING.md. master will be renamed to release eventually, changes are only merged there as part of versioned releases.

Should this be a draft PR? ("WiP but it currently builds fine on Windows (no warning).")

I currently don't use Windows at all, so I won't be able to test this.

[silentbicycle]

Rather than adding a substitute implementation of gettimeofday here, it could just call GetSystemTime and SystemTimeToFileTime then use the milliseconds field. Actually replicating the overall behavior of gettimeofday isn't important -- it's just grabbing a timestamp to use as a seed for example code.

[silentbicycle]

Is this really necessary? strnlen and strncat are in the C standard library.

Note the bit in the README about the LOC limit -- this would exceed that, considerably.

Also, it adds a substantial block of code with a different license. I'd really prefer to avoid doing that.

[SamuelMarks]

Yes but strnlen_s and strncat_s are missing.

Again happy to remove the code and just use a different macro-branch for MSVC, the goal is to get it to compile in MSVC without throwing any warnings related to https://learn.microsoft.com/en-us/cpp/c-runtime-library/security-features-in-the-crt

[silentbicycle]

This should go in contrib/, as should the cmake directory, to make it clear that this is a contributed extension rather than something necessary for using it. I haven't used cmake much, so I won't actively maintain it myself.

[SamuelMarks]

Happy to move the cmake directory to contrib but without a CMakeLists.txt in project root others cloning this repo won't realise that it has CMake integrated. E.g., whence cloning in an IDE like CLion.

[foxx]

As a temporary workaround, this will at least make things compile:

#pragma warning( push )
#pragma warning( disable: 4996)
GREATEST_MAIN_DEFS();
#pragma warning( pop )

However, it would be nice if Greatest used the security enhanced CRT functions when compiling for windows.

I'd be happy to help with any testing etc if that would help push a fix through for next release.