def check_extensions_list(self, extensions):
        if not isinstance(extensions, list):
            raise DistutilsSetupError, \
                  "'ext_modules' option must be a list of Extension instances"

        for i, ext in enumerate(extensions):
            if isinstance(ext, Extension):
                continue                # OK! (assume type-checking done
                                        # by Extension constructor)

            if not isinstance(ext, tuple) or len(ext) != 2:
                raise DistutilsSetupError, \
                      ("each element of 'ext_modules' option must be an "
                       "Extension instance or 2-tuple")

            ext_name, build_info = ext

            log.warn(("old-style (ext_name, build_info) tuple found in "
                      "ext_modules for extension '%s'"
                      "-- please convert to Extension instance" % ext_name))

            if not (isinstance(ext_name, str) and
                    extension_name_re.match(ext_name)):
                raise DistutilsSetupError, \
                      ("first element of each tuple in 'ext_modules' "
                       "must be the extension name (a string)")

            if not isinstance(build_info, dict):
                raise DistutilsSetupError, \
                      ("second element of each tuple in 'ext_modules' "
                       "must be a dictionary (build info)")

            # OK, the (ext_name, build_info) dict is type-safe: convert it
            # to an Extension instance.
            ext = Extension(ext_name, build_info['sources'])

            # Easy stuff: one-to-one mapping from dict elements to
            # instance attributes.
            for key in ('include_dirs', 'library_dirs', 'libraries',
                        'extra_objects', 'extra_compile_args',
                        'extra_link_args'):
                val = build_info.get(key)
                if val is not None:
                    setattr(ext, key, val)

            # Medium-easy stuff: same syntax/semantics, different names.
            ext.runtime_library_dirs = build_info.get('rpath')
            if 'def_file' in build_info:
                log.warn("'def_file' element of build info dict "
                         "no longer supported")

            # Non-trivial stuff: 'macros' split into 'define_macros'
            # and 'undef_macros'.
            macros = build_info.get('macros')
            if macros:
                ext.define_macros = []
                ext.undef_macros = []
                for macro in macros:
                    if not (isinstance(macro, tuple) and len(macro) in (1, 2)):
                        raise DistutilsSetupError, \
                              ("'macros' element of build info dict "
                               "must be 1- or 2-tuple")
                    if len(macro) == 1:
                        ext.undef_macros.append(macro[0])
                    elif len(macro) == 2:
                        ext.define_macros.append(macro)

            extensions[i] = ext
Return the index's keys.
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/distutils/command/build_ext.py/build_ext.check_extensions_list--crossover with--dataset/ETHPy150Open espeed/bulbs/bulbs/rexster/index.py/AutomaticIndex.keys