CMakeLists: add ppc case to known archs

[barracuda156]

This is a trivial PR: it simply adds ppc to a list of known archs, retaining a warning re no CI for this platform.

I have confirmed the build on Darwin ppc for liboqs 0.10.1 with no other alterations to the code.

[SWilson4]

Thanks for the PR, @barracuda156. This mirrors the current configuration for ppc64, so it seems reasonable to me.

[barracuda156]

@SWilson4 I just thought we may need to verify one thing. What is the value of CMAKE_SYSTEM_PROCESSOR when the build is done on 10.5 for ppc64?
If it uses uname -p under the hood, this returns powerpc, but the build arch should be ppc64.

I cannot test that immediately, since I have no build environment on 10.5, but let me check with CMake documentation.

A fallback would be to use CMAKE_OSX_ARCHITECTURES when on Apple, that returns a value matching the arch of the build. (Since gcc does not support fat builds, it will be a single arch always, on PowerPC.)

[barracuda156]

@SWilson4 @baentsch Sorry for a delay, will finalize this over a coming weekend.

[baentsch]

@SWilson4 @baentsch Sorry for a delay, will finalize this over a coming weekend.

@barracuda156 Please let us know when you're ready. Should this be moved to Draft to avoid an unintended merge?

Stale

[baentsch]

@barracuda156 This PR is now a bit old and I removed my approval for the time being: Can you please comment (by) when you may have time to move this to completion as discussed above?

[barracuda156]

@barracuda156 This PR is now a bit old and I removed my approval for the time being: Can you please comment (by) when you may have time to move this to completion as discussed above?

@baentsch Yeah, sorry, will finalize this by this weekend.

[barracuda156]

Ok, so yeah, CMake will have the same value for ppc and ppc64 builds on Darwin, since it uses uname -m: https://cmake.org/cmake/help/latest/variable/CMAKE_HOST_SYSTEM_PROCESSOR.html

I will rewrite a patch in a way it gonna work correctly now.

[barracuda156]

@baentsch @dstebila Could you please review?

[baentsch]

Please see the question, @barracuda156 . I also triggered CI...

[baentsch]

Thanks again for the contribution @barracuda156 !

[barracuda156]

Thanks for merging!