This script generates a database of compiler flags, namely
compile_commands.json. It is quite useful for text editors that use
clangd LSP (e.g. Vim, Neovim).
It was ported from Linux's sources:
- tag: v6.4
- revision 6995e2de6891c724bfeb2db33d7b87775f913ad1
Modifications for U-Boot compatibility will be added in a follow-up
commit.
Signed-off-by: Joao Marcos Costa <jmcosta...@gmail.com>
---
scripts/gen_compile_commands.py | 228 ++++++++++++++++++++++++++++++++
1 file changed, 228 insertions(+)
create mode 100755 scripts/gen_compile_commands.py
diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
new file mode 100755
index 0000000000..15ba56527a
--- /dev/null
+++ b/scripts/gen_compile_commands.py
@@ -0,0 +1,228 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2018
+#
+# Author: Tom Roeder <tmroe...@google.com>
+#
+"""A tool for generating compile_commands.json in the Linux kernel."""
+
+import argparse
+import json
+import logging
+import os
+import re
+import subprocess
+import sys
+
+_DEFAULT_OUTPUT = 'compile_commands.json'
+_DEFAULT_LOG_LEVEL = 'WARNING'
+
+_FILENAME_PATTERN = r'^\..*\.cmd$'
+_LINE_PATTERN = r'^savedcmd_[^ ]*\.o := (.* )([^ ]*\.c) *(;|$)'
+_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
+# The tools/ directory adopts a different build system, and produces .cmd
+# files in a different format. Do not support it.
+_EXCLUDE_DIRS = ['.git', 'Documentation', 'include', 'tools']
+
+def parse_arguments():
+ """Sets up and parses command-line arguments.
+
+ Returns:
+ log_level: A logging level to filter log output.
+ directory: The work directory where the objects were built.
+ ar: Command used for parsing .a archives.
+ output: Where to write the compile-commands JSON file.
+ paths: The list of files/directories to handle to find .cmd files.
+ """
+ usage = 'Creates a compile_commands.json database from kernel .cmd files'
+ parser = argparse.ArgumentParser(description=usage)
+
+ directory_help = ('specify the output directory used for the kernel build '
+ '(defaults to the working directory)')
+ parser.add_argument('-d', '--directory', type=str, default='.',
+ help=directory_help)
+
+ output_help = ('path to the output command database (defaults to ' +
+ _DEFAULT_OUTPUT + ')')
+ parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
+ help=output_help)
+
+ log_level_help = ('the level of log messages to produce (defaults to ' +
+ _DEFAULT_LOG_LEVEL + ')')
+ parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
+ default=_DEFAULT_LOG_LEVEL, help=log_level_help)
+
+ ar_help = 'command used for parsing .a archives'
+ parser.add_argument('-a', '--ar', type=str, default='llvm-ar',
help=ar_help)
+
+ paths_help = ('directories to search or files to parse '
+ '(files should be *.o, *.a, or modules.order). '
+ 'If nothing is specified, the current directory is searched')
+ parser.add_argument('paths', type=str, nargs='*', help=paths_help)
+
+ args = parser.parse_args()
+
+ return (args.log_level,
+ os.path.abspath(args.directory),
+ args.output,
+ args.ar,
+ args.paths if len(args.paths) > 0 else [args.directory])
+
+
+def cmdfiles_in_dir(directory):
+ """Generate the iterator of .cmd files found under the directory.
+
+ Walk under the given directory, and yield every .cmd file found.
+
+ Args:
+ directory: The directory to search for .cmd files.
+
+ Yields:
+ The path to a .cmd file.
+ """
+
+ filename_matcher = re.compile(_FILENAME_PATTERN)
+ exclude_dirs = [ os.path.join(directory, d) for d in _EXCLUDE_DIRS ]
+
+ for dirpath, dirnames, filenames in os.walk(directory, topdown=True):
+ # Prune unwanted directories.
+ if dirpath in exclude_dirs:
+ dirnames[:] = []
+ continue
+
+ for filename in filenames:
+ if filename_matcher.match(filename):
+ yield os.path.join(dirpath, filename)
+
+
+def to_cmdfile(path):
+ """Return the path of .cmd file used for the given build artifact
+
+ Args:
+ Path: file path
+
+ Returns:
+ The path to .cmd file
+ """
+ dir, base = os.path.split(path)
+ return os.path.join(dir, '.' + base + '.cmd')
+
+
+def cmdfiles_for_a(archive, ar):
+ """Generate the iterator of .cmd files associated with the archive.
+
+ Parse the given archive, and yield every .cmd file used to build it.
+
+ Args:
+ archive: The archive to parse
+
+ Yields:
+ The path to every .cmd file found
+ """
+ for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
+ yield to_cmdfile(obj)
+
+
+def cmdfiles_for_modorder(modorder):
+ """Generate the iterator of .cmd files associated with the modules.order.
+
+ Parse the given modules.order, and yield every .cmd file used to build the
+ contained modules.
+
+ Args:
+ modorder: The modules.order file to parse
+
+ Yields:
+ The path to every .cmd file found
+ """
+ with open(modorder) as f:
+ for line in f:
+ obj = line.rstrip()
+ base, ext = os.path.splitext(obj)
+ if ext != '.o':
+ sys.exit('{}: module path must end with .o'.format(obj))
+ mod = base + '.mod'
+ # Read from *.mod, to get a list of objects that compose the
module.
+ with open(mod) as m:
+ for mod_line in m:
+ yield to_cmdfile(mod_line.rstrip())
+
+
+def process_line(root_directory, command_prefix, file_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.
+ command_prefix: The extracted command line, up to the last element.
+ file_path: The .c file from the end of the extracted command.
+ Usually relative to root_directory, but sometimes absolute.
+
+ Returns:
+ An entry to append to compile_commands.
+
+ Raises:
+ ValueError: Could not find the extracted file based on file_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)', '#')
+
+ # Use os.path.abspath() to normalize the path resolving '.' and '..' .
+ abs_path = os.path.abspath(os.path.join(root_directory, file_path))
+ if not os.path.exists(abs_path):
+ raise ValueError('File %s not found' % abs_path)
+ return {
+ 'directory': root_directory,
+ 'file': abs_path,
+ 'command': prefix + file_path,
+ }
+
+
+def main():
+ """Walks through the directory and finds and parses .cmd files."""
+ log_level, directory, output, ar, paths = parse_arguments()
+
+ level = getattr(logging, log_level)
+ logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
+
+ line_matcher = re.compile(_LINE_PATTERN)
+
+ compile_commands = []
+
+ for path in paths:
+ # If 'path' is a directory, handle all .cmd files under it.
+ # Otherwise, handle .cmd files associated with the file.
+ # built-in objects are linked via vmlinux.a
+ # Modules are listed in modules.order.
+ if os.path.isdir(path):
+ cmdfiles = cmdfiles_in_dir(path)
+ elif path.endswith('.a'):
+ cmdfiles = cmdfiles_for_a(path, ar)
+ elif path.endswith('modules.order'):
+ cmdfiles = cmdfiles_for_modorder(path)
+ else:
+ sys.exit('{}: unknown file type'.format(path))
+
+ for cmdfile in cmdfiles:
+ with open(cmdfile, 'rt') as f:
+ result = line_matcher.match(f.readline())
+ if result:
+ try:
+ entry = process_line(directory, result.group(1),
+ result.group(2))
+ compile_commands.append(entry)
+ except ValueError as err:
+ logging.info('Could not add line from %s: %s',
+ cmdfile, err)
+
+ with open(output, 'wt') as f:
+ json.dump(compile_commands, f, indent=2, sort_keys=True)
+
+
+if __name__ == '__main__':
+ main()
--
2.41.0
