'Converts or warns on conditional keys.  Xcode supports conditional keys,
such as CODE_SIGN_IDENTITY[sdk=iphoneos*].  This is a partial implementation
with some keys converted while the rest force a warning.'

def _ConvertConditionalKeys(self, configname):

    settings = self.xcode_settings[configname]
    conditional_keys = [key for key in settings if key.endswith(']')]
    for key in conditional_keys:
        if key.endswith('[sdk=iphoneos*]'):
            if configname.endswith('iphoneos'):
                new_key = key.split('[')[0]
                settings[new_key] = settings[key]
        else:
            print 'Warning:    Conditional    keys    not    implemented,    ignoring:', '    '.join(conditional_keys)
        del settings[key]
