2 # SPDX-License-Identifier: GPL-2.0
4 # Copyright (C) Google LLC, 2018
6 # Author: Tom Roeder <tmroeder@google.com>
8 """A tool for generating compile_commands.json in the Linux kernel."""
16 _DEFAULT_OUTPUT = 'compile_commands.json'
17 _DEFAULT_LOG_LEVEL = 'WARNING'
19 _FILENAME_PATTERN = r'^\..*\.cmd$'
20 _LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
21 _VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
23 # A kernel build generally has over 2000 entries in its compile_commands.json
24 # database. If this code finds 300 or fewer, then warn the user that they might
25 # not have all the .cmd files, and they might need to compile the kernel.
26 _LOW_COUNT_THRESHOLD = 300
29 def parse_arguments():
30 """Sets up and parses command-line arguments.
33 log_level: A logging level to filter log output.
34 directory: The work directory where the objects were built.
35 output: Where to write the compile-commands JSON file.
36 paths: The list of directories to handle to find .cmd files.
38 usage = 'Creates a compile_commands.json database from kernel .cmd files'
39 parser = argparse.ArgumentParser(description=usage)
41 directory_help = ('specify the output directory used for the kernel build '
42 '(defaults to the working directory)')
43 parser.add_argument('-d', '--directory', type=str, default='.',
46 output_help = ('path to the output command database (defaults to ' +
47 _DEFAULT_OUTPUT + ')')
48 parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
51 log_level_help = ('the level of log messages to produce (defaults to ' +
52 _DEFAULT_LOG_LEVEL + ')')
53 parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
54 default=_DEFAULT_LOG_LEVEL, help=log_level_help)
56 args = parser.parse_args()
58 return (args.log_level,
59 os.path.abspath(args.directory),
64 def cmdfiles_in_dir(directory):
65 """Generate the iterator of .cmd files found under the directory.
67 Walk under the given directory, and yield every .cmd file found.
70 directory: The directory to search for .cmd files.
73 The path to a .cmd file.
76 filename_matcher = re.compile(_FILENAME_PATTERN)
78 for dirpath, _, filenames in os.walk(directory):
79 for filename in filenames:
80 if filename_matcher.match(filename):
81 yield os.path.join(dirpath, filename)
84 def process_line(root_directory, command_prefix, file_path):
85 """Extracts information from a .cmd line and creates an entry from it.
88 root_directory: The directory that was searched for .cmd files. Usually
89 used directly in the "directory" entry in compile_commands.json.
90 command_prefix: The extracted command line, up to the last element.
91 file_path: The .c file from the end of the extracted command.
92 Usually relative to root_directory, but sometimes absolute.
95 An entry to append to compile_commands.
98 ValueError: Could not find the extracted file based on file_path and
99 root_directory or file_directory.
101 # The .cmd files are intended to be included directly by Make, so they
102 # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
103 # kernel version). The compile_commands.json file is not interepreted
104 # by Make, so this code replaces the escaped version with '#'.
105 prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
107 # Use os.path.abspath() to normalize the path resolving '.' and '..' .
108 abs_path = os.path.abspath(os.path.join(root_directory, file_path))
109 if not os.path.exists(abs_path):
110 raise ValueError('File %s not found' % abs_path)
112 'directory': root_directory,
114 'command': prefix + file_path,
119 """Walks through the directory and finds and parses .cmd files."""
120 log_level, directory, output, paths = parse_arguments()
122 level = getattr(logging, log_level)
123 logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
125 line_matcher = re.compile(_LINE_PATTERN)
127 compile_commands = []
130 cmdfiles = cmdfiles_in_dir(path)
132 for cmdfile in cmdfiles:
133 with open(cmdfile, 'rt') as f:
134 result = line_matcher.match(f.readline())
137 entry = process_line(directory, result.group(1),
139 compile_commands.append(entry)
140 except ValueError as err:
141 logging.info('Could not add line from %s: %s',
144 with open(output, 'wt') as f:
145 json.dump(compile_commands, f, indent=2, sort_keys=True)
147 count = len(compile_commands)
148 if count < _LOW_COUNT_THRESHOLD:
150 'Found %s entries. Have you compiled the kernel?', count)
153 if __name__ == '__main__':