# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# Autocompletion config for YouCompleteMe in Chromium.
#
# USAGE:
#
# 1. Install YCM [https://github.com/Valloric/YouCompleteMe]
# (Googlers should check out [go/ycm])
#
# 2. Point to this config file in your .vimrc:
# let g:ycm_global_ycm_extra_conf =
# '<chrome_depot>/src/tools/vim/chromium.ycm_extra_conf.py'
#
# 3. Profit
#
#
# Usage notes:
#
# * You must use ninja & clang to build Chromium.
#
# * You must have run gyp_chromium and built Chromium recently.
#
#
# Hacking notes:
#
# * The purpose of this script is to construct an accurate enough command line
# for YCM to pass to clang so it can build and extract the symbols.
#
# * Right now, we only pull the -I and -D flags. That seems to be sufficient
# for everything I've used it for.
#
# * That whole ninja & clang thing? We could support other configs if someone
# were willing to write the correct commands and a parser.
#
# * This has only been tested on gPrecise.
import os
import subprocess
# Flags from YCM's default config.
flags = [
'-DUSE_CLANG_COMPLETER',
'-std=c++11',
'-x',
'c++',
]
def PathExists(*args):
return os.path.exists(os.path.join(*args))
def FindChromeSrcFromFilename(filename):
"""Searches for the root of the Chromium checkout.
Simply checks parent directories until it finds .gclient and src/.
Args:
filename: (String) Path to source file being edited.
Returns:
(String) Path of 'src/', or None if unable to find.
"""
curdir = os.path.normpath(os.path.dirname(filename))
while not (PathExists(curdir, 'src') and PathExists(curdir, 'src', 'DEPS')
and (PathExists(curdir, '.gclient')
or PathExists(curdir, 'src', '.git'))):
nextdir = os.path.normpath(os.path.join(curdir, '..'))
if nextdir == curdir:
return None
curdir = nextdir
return os.path.join(curdir, 'src')
# Largely copied from ninja-build.vim (guess_configuration)
def GetNinjaOutputDirectory(chrome_root):
"""Returns either <chrome_root>/out/Release or <chrome_root>/out/Debug.
The configuration chosen is the one most recently generated/built."""
root = os.path.join(chrome_root, 'out')
debug_path = os.path.join(root, 'Debug')
release_path = os.path.join(root, 'Release')
def is_release_15s_newer(test_path):
try:
debug_mtime = os.path.getmtime(os.path.join(debug_path, test_path))
except os.error:
debug_mtime = 0
try:
rel_mtime = os.path.getmtime(os.path.join(release_path, test_path))
except os.error:
rel_mtime = 0
return rel_mtime - debug_mtime >= 15
if is_release_15s_newer('build.ninja') or is_release_15s_newer('protoc'):
return release_path
return debug_path
def GetClangCommandFromNinjaForFilename(chrome_root, filename):
"""Returns the command line to build |filename|.
Asks ninja how it would build the source file. If the specified file is a
header, tries to find its companion source file first.
Args:
chrome_root: (String) Path to src/.
filename: (String) Path to source file being edited.
Returns:
(List of Strings) Command line arguments for clang.
"""
if not chrome_root:
return []
# Generally, everyone benefits from including Chromium's src/, because all of
# Chromium's includes are relative to that.
chrome_flags = ['-I' + os.path.join(chrome_root)]
# Header files can't be built. Instead, try to match a header file to its
# corresponding source file.
if filename.endswith('.h'):
alternates = ['.cc', '.cpp']
for alt_extension in alternates:
alt_name = filename[:-2] + alt_extension
if os.path.exists(alt_name):
filename = alt_name
break
else:
# If this is a standalone .h file with no source, the best we can do is
# try to use the default flags.
return chrome_flags
# Ninja needs the path to the source file from the output build directory.
# Cut off the common part and /.
subdir_filename = filename[len(chrome_root)+1:]
rel_filename = os.path.join('..', '..', subdir_filename)
out_dir = GetNinjaOutputDirectory(chrome_root)
# Ask ninja how it would build our source file.
p = subprocess.Popen(['ninja', '-v', '-C', out_dir, '-t',
'commands', rel_filename + '^'],
stdout=subprocess.PIPE)
stdout, stderr = p.communicate()
if p.returncode:
return chrome_flags
# Ninja might execute several commands to build something. We want the last
# clang command.
clang_line = None
for line in reversed(stdout.split('\n')):
if 'clang' in line:
clang_line = line
break
else:
return chrome_flags
# Parse out the -I and -D flags. These seem to be the only ones that are
# important for YCM's purposes.
for flag in clang_line.split(' '):
if flag.startswith('-I'):
# Relative paths need to be resolved, because they're relative to the
# output dir, not the source.
if flag[2] == '/':
chrome_flags.append(flag)
else:
abs_path = os.path.normpath(os.path.join(out_dir, flag[2:]))
chrome_flags.append('-I' + abs_path)
elif flag.startswith('-') and flag[1] in 'DWFfmO':
if flag == '-Wno-deprecated-register' or flag == '-Wno-header-guard':
# These flags causes libclang (3.3) to crash. Remove it until things
# are fixed.
continue
chrome_flags.append(flag)
return chrome_flags
def FlagsForFile(filename):
"""This is the main entry point for YCM. Its interface is fixed.
Args:
filename: (String) Path to source file being edited.
Returns:
(Dictionary)
'flags': (List of Strings) Command line flags.
'do_cache': (Boolean) True if the result should be cached.
"""
chrome_root = FindChromeSrcFromFilename(filename)
chrome_flags = GetClangCommandFromNinjaForFilename(chrome_root,
filename)
final_flags = flags + chrome_flags
return {
'flags': final_flags,
'do_cache': True
}