summaryrefslogtreecommitdiff
path: root/scripts/gen_compile_commands.py
diff options
context:
space:
mode:
Diffstat (limited to 'scripts/gen_compile_commands.py')
-rwxr-xr-xscripts/gen_compile_commands.py151
1 files changed, 151 insertions, 0 deletions
diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
new file mode 100755
index 000000000000..7915823b92a5
--- /dev/null
+++ b/scripts/gen_compile_commands.py
@@ -0,0 +1,151 @@
+#!/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 argparse
+import json
+import logging
+import os
+import 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 500 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 = 500
+
+
+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()