1#!/usr/bin/env python3 2# SPDX-License-Identifier: GPL-2.0 3# 4# Copyright (C) Google LLC, 2018 5# 6# Author: Tom Roeder <tmroeder@google.com> 7# 8"""A tool for generating compile_commands.json in the Linux kernel.""" 9 10import argparse 11import json 12import logging 13import os 14import re 15import subprocess 16import sys 17 18_DEFAULT_OUTPUT = 'compile_commands.json' 19_DEFAULT_LOG_LEVEL = 'WARNING' 20 21_FILENAME_PATTERN = r'^\..*\.cmd$' 22_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c) *(;|$)' 23_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'] 24# The tools/ directory adopts a different build system, and produces .cmd 25# files in a different format. Do not support it. 26_EXCLUDE_DIRS = ['.git', 'Documentation', 'include', 'tools'] 27 28def parse_arguments(): 29 """Sets up and parses command-line arguments. 30 31 Returns: 32 log_level: A logging level to filter log output. 33 directory: The work directory where the objects were built. 34 ar: Command used for parsing .a archives. 35 output: Where to write the compile-commands JSON file. 36 paths: The list of files/directories to handle to find .cmd files. 37 """ 38 usage = 'Creates a compile_commands.json database from kernel .cmd files' 39 parser = argparse.ArgumentParser(description=usage) 40 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='.', 44 help=directory_help) 45 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, 49 help=output_help) 50 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) 55 56 ar_help = 'command used for parsing .a archives' 57 parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help) 58 59 paths_help = ('directories to search or files to parse ' 60 '(files should be *.o, *.a, or modules.order). ' 61 'If nothing is specified, the current directory is searched') 62 parser.add_argument('paths', type=str, nargs='*', help=paths_help) 63 64 args = parser.parse_args() 65 66 return (args.log_level, 67 os.path.abspath(args.directory), 68 args.output, 69 args.ar, 70 args.paths if len(args.paths) > 0 else [args.directory]) 71 72 73def cmdfiles_in_dir(directory): 74 """Generate the iterator of .cmd files found under the directory. 75 76 Walk under the given directory, and yield every .cmd file found. 77 78 Args: 79 directory: The directory to search for .cmd files. 80 81 Yields: 82 The path to a .cmd file. 83 """ 84 85 filename_matcher = re.compile(_FILENAME_PATTERN) 86 exclude_dirs = [ os.path.join(directory, d) for d in _EXCLUDE_DIRS ] 87 88 for dirpath, dirnames, filenames in os.walk(directory, topdown=True): 89 # Prune unwanted directories. 90 if dirpath in exclude_dirs: 91 dirnames[:] = [] 92 continue 93 94 for filename in filenames: 95 if filename_matcher.match(filename): 96 yield os.path.join(dirpath, filename) 97 98 99def to_cmdfile(path): 100 """Return the path of .cmd file used for the given build artifact 101 102 Args: 103 Path: file path 104 105 Returns: 106 The path to .cmd file 107 """ 108 dir, base = os.path.split(path) 109 return os.path.join(dir, '.' + base + '.cmd') 110 111 112def cmdfiles_for_o(obj): 113 """Generate the iterator of .cmd files associated with the object 114 115 Yield the .cmd file used to build the given object 116 117 Args: 118 obj: The object path 119 120 Yields: 121 The path to .cmd file 122 """ 123 yield to_cmdfile(obj) 124 125 126def cmdfiles_for_a(archive, ar): 127 """Generate the iterator of .cmd files associated with the archive. 128 129 Parse the given archive, and yield every .cmd file used to build it. 130 131 Args: 132 archive: The archive to parse 133 134 Yields: 135 The path to every .cmd file found 136 """ 137 for obj in subprocess.check_output([ar, '-t', archive]).decode().split(): 138 yield to_cmdfile(obj) 139 140 141def cmdfiles_for_modorder(modorder): 142 """Generate the iterator of .cmd files associated with the modules.order. 143 144 Parse the given modules.order, and yield every .cmd file used to build the 145 contained modules. 146 147 Args: 148 modorder: The modules.order file to parse 149 150 Yields: 151 The path to every .cmd file found 152 """ 153 with open(modorder) as f: 154 for line in f: 155 ko = line.rstrip() 156 base, ext = os.path.splitext(ko) 157 if ext != '.ko': 158 sys.exit('{}: module path must end with .ko'.format(ko)) 159 mod = base + '.mod' 160 # Read from *.mod, to get a list of objects that compose the module. 161 with open(mod) as m: 162 for mod_line in m: 163 yield to_cmdfile(mod_line.rstrip()) 164 165 166def process_line(root_directory, command_prefix, file_path): 167 """Extracts information from a .cmd line and creates an entry from it. 168 169 Args: 170 root_directory: The directory that was searched for .cmd files. Usually 171 used directly in the "directory" entry in compile_commands.json. 172 command_prefix: The extracted command line, up to the last element. 173 file_path: The .c file from the end of the extracted command. 174 Usually relative to root_directory, but sometimes absolute. 175 176 Returns: 177 An entry to append to compile_commands. 178 179 Raises: 180 ValueError: Could not find the extracted file based on file_path and 181 root_directory or file_directory. 182 """ 183 # The .cmd files are intended to be included directly by Make, so they 184 # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the 185 # kernel version). The compile_commands.json file is not interepreted 186 # by Make, so this code replaces the escaped version with '#'. 187 prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#') 188 189 # Use os.path.abspath() to normalize the path resolving '.' and '..' . 190 abs_path = os.path.abspath(os.path.join(root_directory, file_path)) 191 if not os.path.exists(abs_path): 192 raise ValueError('File %s not found' % abs_path) 193 return { 194 'directory': root_directory, 195 'file': abs_path, 196 'command': prefix + file_path, 197 } 198 199 200def main(): 201 """Walks through the directory and finds and parses .cmd files.""" 202 log_level, directory, output, ar, paths = parse_arguments() 203 204 level = getattr(logging, log_level) 205 logging.basicConfig(format='%(levelname)s: %(message)s', level=level) 206 207 line_matcher = re.compile(_LINE_PATTERN) 208 209 compile_commands = [] 210 211 for path in paths: 212 # If 'path' is a directory, handle all .cmd files under it. 213 # Otherwise, handle .cmd files associated with the file. 214 # Most of built-in objects are linked via archives (built-in.a or lib.a) 215 # but some objects are linked to vmlinux directly. 216 # Modules are listed in modules.order. 217 if os.path.isdir(path): 218 cmdfiles = cmdfiles_in_dir(path) 219 elif path.endswith('.o'): 220 cmdfiles = cmdfiles_for_o(path) 221 elif path.endswith('.a'): 222 cmdfiles = cmdfiles_for_a(path, ar) 223 elif path.endswith('modules.order'): 224 cmdfiles = cmdfiles_for_modorder(path) 225 else: 226 sys.exit('{}: unknown file type'.format(path)) 227 228 for cmdfile in cmdfiles: 229 with open(cmdfile, 'rt') as f: 230 result = line_matcher.match(f.readline()) 231 if result: 232 try: 233 entry = process_line(directory, result.group(1), 234 result.group(2)) 235 compile_commands.append(entry) 236 except ValueError as err: 237 logging.info('Could not add line from %s: %s', 238 cmdfile, err) 239 240 with open(output, 'wt') as f: 241 json.dump(compile_commands, f, indent=2, sort_keys=True) 242 243 244if __name__ == '__main__': 245 main() 246