blob: 25d01c1881797fee99f83ef63eb0b5802d88d048 [file] [log] [blame]
# Copyright 2015 the V8 project 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 V8.
# 1. Install YCM []
# (Googlers should check out [go/ycm])
# 2. Profit
# Usage notes:
# * You must use ninja & clang to build V8.
# * You must have run gyp_v8 and built V8 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 gTrusty.
import os
import os.path
import subprocess
import sys
# Flags from YCM's default config.
flags = [
def PathExists(*args):
return os.path.exists(os.path.join(*args))
def FindV8SrcFromFilename(filename):
"""Searches for the root of the V8 checkout.
Simply checks parent directories until it finds .gclient and v8/.
filename: (String) Path to source file being edited.
(String) Path of 'v8/', or None if unable to find.
curdir = os.path.normpath(os.path.dirname(filename))
while not (PathExists(curdir, 'v8') and PathExists(curdir, 'v8', 'DEPS')
and (PathExists(curdir, '.gclient')
or PathExists(curdir, 'v8', '.git'))):
nextdir = os.path.normpath(os.path.join(curdir, '..'))
if nextdir == curdir:
return None
curdir = nextdir
return os.path.join(curdir, 'v8')
def GetClangCommandFromNinjaForFilename(v8_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.
v8_root: (String) Path to v8/.
filename: (String) Path to source file being edited.
(List of Strings) Command line arguments for clang.
if not v8_root:
return []
# Generally, everyone benefits from including V8's root, because all of
# V8's includes are relative to that.
v8_flags = ['-I' + os.path.join(v8_root)]
# Version of Clang used to compile V8 can be newer then version of
# libclang that YCM uses for completion. So it's possible that YCM's libclang
# doesn't know about some used warning options, which causes compilation
# warnings (and errors, because of '-Werror');
# Header files can't be built. Instead, try to match a header file to its
# corresponding source file.
if filename.endswith('.h'):
base = filename[:-6] if filename.endswith('-inl.h') else filename[:-2]
for alternate in [base + e for e in ['.cc', '.cpp']]:
if os.path.exists(alternate):
filename = alternate
# If this is a standalone .h file with no source, we ask ninja for the
# compile flags of some generic cc file ('src/utils/'). This
# should contain most/all of the interesting flags for other targets too.
filename = os.path.join(v8_root, 'src', 'utils', '')
sys.path.append(os.path.join(v8_root, 'tools', 'ninja'))
from ninja_output import GetNinjaOutputDirectory
out_dir = os.path.realpath(GetNinjaOutputDirectory(v8_root))
# Ninja needs the path to the source file relative to the output build
# directory.
rel_filename = os.path.relpath(os.path.realpath(filename), out_dir)
# Ask ninja how it would build our source file.
p = subprocess.Popen(['ninja', '-v', '-C', out_dir, '-t',
'commands', rel_filename + '^'],
stdout, stderr = p.communicate()
if p.returncode:
return v8_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
return v8_flags
# Parse flags 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] == '/':
abs_path = os.path.normpath(os.path.join(out_dir, flag[2:]))
v8_flags.append('-I' + abs_path)
elif flag.startswith('-std'):
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.
return v8_flags
def FlagsForFile(filename):
"""This is the main entry point for YCM. Its interface is fixed.
filename: (String) Path to source file being edited.
'flags': (List of Strings) Command line flags.
'do_cache': (Boolean) True if the result should be cached.
v8_root = FindV8SrcFromFilename(filename)
v8_flags = GetClangCommandFromNinjaForFilename(v8_root, filename)
final_flags = flags + v8_flags
return {
'flags': final_flags,
'do_cache': True