Pull code from vyasr/cython-cmake/

[vyasr]

@jcfr I've got the full package largely working in https://github.com/vyasr/cython-cmake/. I think we should either delete this repository and migrate that one into the scikit-build org, or force push all the changes from that repo to overwrite the code in this one. It looks like the only code in this repo at the moment is from some cookiecutter-like template, so either approach should be safe.

[vyasr]

There are still some significant changes that need to be made before my cython-cmake is ready for a release, but they're mostly around things like CI or Windows support and would be better handled in a shared repository rather than one that I own.

[jcfr]

Thanks for consolidating your work into the cython-cmake repository 🙏
This will be helpful 🚀

[jcfr]

History associated with the files FindCython.cmake and UseCython.cmake from the repositories thewtex/cython-cmake-example¹ and scikit-build/scikit-build² has been extracted and integrated into this project.

Then, relevant updates from vyasr/cython-cmake have been adapted.

The modernized function is called Cython_compile_pyx and it internally passes the -M³ flag to cython as well as the corresponding custom command parameter called DEPFILE⁴.

The CMake modules are distributed in the cython-cmake wheel. See https://pypi.org/project/cython-cmake/

#   Cython_compile_pyx(<pyx_file1> [<pyx_file2> ...]
#                     [TARGET_LANGUAGE C | CXX]
#                     [LANGUAGE_LEVEL 2 | 3 | 3str]
#                     [OUTPUT_VAR <OutputVar>])

Footnotes

1. https://github.com/thewtex/cython-cmake-example/tree/master/cmake ↩

2. https://github.com/scikit-build/scikit-build/tree/main/skbuild/resources/cmake ↩

3. https://cython.readthedocs.io/en/latest/src/changes.html#build-integration ↩

4. https://cmake.org/cmake/help/latest/command/add_custom_command.html ↩

[jcfr]

The core-cython-hello sample project has also been updated to use the Cython_compile_pyx function. See scikit-build/scikit-build-sample-projects#43