lg_cffi_setup.py

# adapted from https://caremad.io/2015/06/distributing-a-cffi-project-redux/ on 18 May 2016

from distutils.command.build import build
from setuptools.command.install import install

SETUP_REQUIRES_ERROR = (
    "Requested setup command that needs 'setup_requires' while command line "
    "arguments implied a side effect free command or option."
)

NO_SETUP_REQUIRES_ARGUMENTS = [
    "-h", "--help",
    "-n", "--dry-run",
    "-q", "--quiet",
    "-v", "--verbose",
    "-v", "--version",
    "--author",
    "--author-email",
    "--classifiers",
    "--contact",
    "--contact-email",
    "--description",
    "--egg-base",
    "--fullname",
    "--help-commands",
    "--keywords",
    "--licence",
    "--license",
    "--long-description",
    "--maintainer",
    "--maintainer-email",
    "--name",
    "--no-user-cfg",
    "--obsoletes",
    "--platforms",
    "--provides",
    "--requires",
    "--url",
    "clean",
    "egg_info",
    "register",
    "sdist",
    "upload",
]


class DummyCFFIBuild(build):
    def run(self):
        raise RuntimeError(SETUP_REQUIRES_ERROR)


class DummyCFFIInstall(install):
    def run(self):
        raise RuntimeError(SETUP_REQUIRES_ERROR)


def keywords_with_side_effects(argv, **kwargs):
    def is_short_option(argument):
        """Check whether a command line argument is a short option."""
        return len(argument) >= 2 and argument[0] == '-' and argument[1] != '-'

    def expand_short_options(argument):
        """Expand combined short options into canonical short options."""
        return ('-' + char for char in argument[1:])

    def argument_without_setup_requirements(argv, i):
        """Check whether a command line argument needs setup requirements."""
        if argv[i] in NO_SETUP_REQUIRES_ARGUMENTS:
            # Simple case: An argument which is either an option or a command
            # which doesn't need setup requirements.
            return True
        elif (is_short_option(argv[i]) and
              all(option in NO_SETUP_REQUIRES_ARGUMENTS
                  for option in expand_short_options(argv[i]))):
            # Not so simple case: Combined short options none of which need
            # setup requirements.
            return True
        elif argv[i - 1:i] == ['--egg-base']:
            # Tricky case: --egg-info takes an argument which should not make
            # us use setup_requires (defeating the purpose of this code).
            return True
        else:
            return False

    if all(argument_without_setup_requirements(argv, i)
           for i in range(1, len(argv))):
        try:
            cmdclass = kwargs["cmdclass"]
        except KeyError:
            cmdclass = kwargs["cmdclass"] = {}
        cmdclass["build"] = DummyCFFIBuild
        cmdclass["install"] = DummyCFFIInstall

    return kwargs