def METHOD_NAME():
    file_defs = ['*', BZ_OS]
    files = ''
    for file_def in file_defs:
        if file_def not in C['source']:
            continue
        for entry in C['source'][file_def]:
            glob_files = glob.glob(entry, recursive = True)
            if len(glob_files) > 0:
                files += ' '.join(glob_files) + ' '
    return files