Don't bother trying to work out which commands require cffi and which do not...

Don't bother trying to work out which commands require cffi and which do not as 'use_system' is called for all of them

setup.py

@@ -97,138 +97,6 @@ class CFFIInstall(install):
         self.distribution.ext_modules = get_ext_modules()
         install.finalize_options(self)
 
-def keywords_with_side_effects(argv):
-    """
-    Get a dictionary with setup keywords that (can) have side effects.
-
-    :param argv: A list of strings with command line arguments.
-    :returns: A dictionary with keyword arguments for the ``setup()`` function.
-
-    This setup.py script uses the setuptools 'setup_requires' feature because
-    this is required by the cffi package to compile extension modules. The
-    purpose of ``keywords_with_side_effects()`` is to avoid triggering the cffi
-    build process as a result of setup.py invocations that don't need the cffi
-    module to be built (setup.py serves the dual purpose of exposing package
-    metadata).
-
-    All of the options listed by ``python setup.py --help`` that print
-    information should be recognized here. The commands ``clean``,
-    ``egg_info``, ``register``, ``sdist`` and ``upload`` are also recognized.
-    Any combination of these options and commands is also supported.
-
-    This function was originally based on the `setup.py script`_ of SciPy (see
-    also the discussion in `pip issue #25`_).
-
-    .. _pip issue #25: https://github.com/pypa/pip/issues/25
-    .. _setup.py script: https://github.com/scipy/scipy/blob/master/setup.py
-    """
-    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',
-    )
-
-    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))):
-        return {
-            "cmdclass": {
-                "build": DummyCFFIBuild,
-                "install": DummyCFFIInstall,
-                "build_clib": build_clib,
-                "build_ext": build_ext,
-            }
-        }
-    else:
-        return {
-            "setup_requires": [CFFI_DEPENDENCY],
-            "cmdclass": {
-                "build": CFFIBuild,
-                "install": CFFIInstall,
-                "build_clib": build_clib,
-                "build_ext": build_ext,
-            }
-        }
-
-setup_requires_error = ("Requested setup command that needs 'setup_requires' "
-                        "while command line arguments implied a side effect "
-                        "free command or option.")
-
-class DummyCFFIBuild(build):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py build`` as
-    one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
-
-class DummyCFFIInstall(install):
-    """
-    This class makes it very obvious when ``keywords_with_side_effects()`` has
-    incorrectly interpreted the command line arguments to ``setup.py install``
-    as one of the 'side effect free' commands or options.
-    """
-
-    def run(self):
-        raise RuntimeError(setup_requires_error)
-
 
 def use_system():
     install_type = os.environ.get("SODIUM_INSTALL")
@@ -368,7 +236,7 @@ setup(
 
     author=nacl.__author__,
     author_email=nacl.__email__,
-
+    setup_requires=[CFFI_DEPENDENCY],
     install_requires=[
         CFFI_DEPENDENCY,
         "six",
@@ -390,6 +258,12 @@ setup(
 
     distclass=Distribution,
     zip_safe=False,
+    cmdclass= {
+        "build": CFFIBuild,
+        "install": CFFIInstall,
+        "build_clib": build_clib,
+        "build_ext": build_ext,
+    },
 
     classifiers=[
         "Programming Language :: Python :: Implementation :: CPython",
@@ -402,5 +276,4 @@ setup(
         "Programming Language :: Python :: 3.3",
         "Programming Language :: Python :: 3.4",
     ],
-    **keywords_with_side_effects(sys.argv)
 )