def preProcess(self):
        self.CILPolicyRE = re.compile(r'.*mono/.*/policy.*/policy.*\.config$')
        self.legalCharsRE = re.compile('[.0-9A-Za-z_+-/]')
        self.pythonInterpRE = re.compile(r'\.[a-z]+-\d\dm?')

        # interpolate macros, using canonical path form with no trailing /
        self.sonameSubtrees = set(os.path.normpath(x % self.macros)
                                  for x in self.sonameSubtrees)
        self.pythonFlagCache = {}
        self.pythonTroveFlagCache = {}
        self.pythonVersionCache = {}