It would be nice to fix this so that the tests pass with -Werror. Here is a quick patch: * Fix the deprecated non-escapes * Make all the regular expressions raw strings * Fix bugs with parsing escaped quotes in C strings and char literals * Adapt from old regex module and Python 2 print statements * Add a new test file with a single test case (could easily be expanded) Documentation for the old “regex” module: https://docs.python.org/release/1.6/lib/module-regex.html