def _add_include_paths_to_flags(args):
    """ Add all the include paths to all three compile flags """
    for path in args.include:
        if path is not None:
            if path not in args.CPPFLAGS:
                args.CPPFLAGS += ' -I ' + path
            if path not in args.CFLAGS:
                args.CFLAGS += ' -I ' + path
            if path not in args.CXXFLAGS:
                args.CXXFLAGS += ' -I ' + path
    if args.verbose >= 4 and len(args.include) > 0:
        print('Extra include paths have been appended to the *FLAG variables:')
        print('\tCPPFLAGS=' + args.CPPFLAGS)
        print('\tCFLAGS=' + args.CFLAGS)
        print('\tCXXFLAGS=' + args.CXXFLAGS)
