gh-93939: Add script to check extension modules

[tiran]

Add script Tools/scripts/check_modules.py to check and validate builtin
and shared extension modules. The script also handles Modules/Setup and
will eventually replace setup.py.

• Issue: Build shared extensions without distutils #93939

[vstinner]

"check modules" is very generic. Would you mind to elaborate the purpose of the script? I understand that the purpose is to check which modules are built successfully and which ones are disabled. Maybe say "check modules build"?

It seems like the script also renames extensions which cannot be imported.

Please elaborate the docstring of the script also.

[tiran]

Do you have an idea for a better name? check_extension_modules maybe?

[vstinner]

Do you have an idea for a better name?

check_extensions_build or check_built_extensions.

[tiran]

The script does the same as setup.py methods check_extension_import and summary + LIST_MODULE_NAMES hack in a more generalized way. The main difference is that the new script handles Makefile variables and all makesetup files instead of relying on distutils.

[vstinner]

Thanks for the updated docstring.

[erlend-aasland]

I took only a quick glance for now. If this can replace setup.py, this is a very nice improvement to the build system!

Should we add a check that adds a user-friendly warning if you try to run this script in the source directory? Someone will create an issue about that in the future.