#!/usr/bin/env python# SPDX-License-Identifier: GPL-2.0## Copyright (C) Google LLC, 2018## Author: Tom Roeder <tmroeder@google.com>#"""A tool for generating compile_commands.json in the Linux kernel.""" import argparseimport jsonimport loggingimport osimport re _DEFAULT_OUTPUT = 'compile_commands.json'_DEFAULT_LOG_LEVEL = 'WARNING' _FILENAME_PATTERN = r'^\..*\.cmd$'_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'] # A kernel build generally has over 2000 entries in its compile_commands.json# database. If this code finds 300 or fewer, then warn the user that they might# not have all the .cmd files, and they might need to compile the kernel._LOW_COUNT_THRESHOLD = 300  def parse_arguments():    """Sets up and parses command-line arguments.     Returns:        log_level: A logging level to filter log output.        directory: The directory to search for .cmd files.        output: Where to write the compile-commands JSON file.    """    usage = 'Creates a compile_commands.json database from kernel .cmd files'    parser = argparse.ArgumentParser(description=usage)     directory_help = ('Path to the kernel source directory to search '                      '(defaults to the working directory)')    parser.add_argument('-d', '--directory', type=str, help=directory_help)     output_help = ('The location to write compile_commands.json (defaults to '                   'compile_commands.json in the search directory)')    parser.add_argument('-o', '--output', type=str, help=output_help)     log_level_help = ('The level of log messages to produce (one of ' +                      ', '.join(_VALID_LOG_LEVELS) + '; defaults to ' +                      _DEFAULT_LOG_LEVEL + ')')    parser.add_argument(        '--log_level', type=str, default=_DEFAULT_LOG_LEVEL,        help=log_level_help)     args = parser.parse_args()     log_level = args.log_level    if log_level not in _VALID_LOG_LEVELS:        raise ValueError('%s is not a valid log level' % log_level)     directory = args.directory or os.getcwd()    output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)    directory = os.path.abspath(directory)     return log_level, directory, output  def process_line(root_directory, file_directory, command_prefix, relative_path):    """Extracts information from a .cmd line and creates an entry from it.     Args:        root_directory: The directory that was searched for .cmd files. Usually            used directly in the "directory" entry in compile_commands.json.        file_directory: The path to the directory the .cmd file was found in.        command_prefix: The extracted command line, up to the last element.        relative_path: The .c file from the end of the extracted command.            Usually relative to root_directory, but sometimes relative to            file_directory and sometimes neither.     Returns:        An entry to append to compile_commands.     Raises:        ValueError: Could not find the extracted file based on relative_path and            root_directory or file_directory.    """    # The .cmd files are intended to be included directly by Make, so they    # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the    # kernel version). The compile_commands.json file is not interepreted    # by Make, so this code replaces the escaped version with '#'.    prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')     cur_dir = root_directory    expected_path = os.path.join(cur_dir, relative_path)    if not os.path.exists(expected_path):        # Try using file_directory instead. Some of the tools have a different        # style of .cmd file than the kernel.        cur_dir = file_directory        expected_path = os.path.join(cur_dir, relative_path)        if not os.path.exists(expected_path):            raise ValueError('File %s not in %s or %s' %                             (relative_path, root_directory, file_directory))    return {        'directory': cur_dir,        'file': relative_path,        'command': prefix + relative_path,    }  def main():    """Walks through the directory and finds and parses .cmd files."""    log_level, directory, output = parse_arguments()     level = getattr(logging, log_level)    logging.basicConfig(format='%(levelname)s: %(message)s', level=level)     filename_matcher = re.compile(_FILENAME_PATTERN)    line_matcher = re.compile(_LINE_PATTERN)     compile_commands = []    for dirpath, _, filenames in os.walk(directory):        for filename in filenames:            if not filename_matcher.match(filename):                continue            filepath = os.path.join(dirpath, filename)             with open(filepath, 'rt') as f:                for line in f:                    result = line_matcher.match(line)                    if not result:                        continue                     try:                        entry = process_line(directory, dirpath,                                             result.group(1), result.group(2))                        compile_commands.append(entry)                    except ValueError as err:                        logging.info('Could not add line from %s: %s',                                     filepath, err)     with open(output, 'wt') as f:        json.dump(compile_commands, f, indent=2, sort_keys=True)     count = len(compile_commands)    if count < _LOW_COUNT_THRESHOLD:        logging.warning(            'Found %s entries. Have you compiled the kernel?', count)  if __name__ == '__main__':    main()