[ycm] The YouCompleteMe configuration is not VIM specific.

tools/vim/v8.ycm_extra_conf.py

-# 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.
-#
-# 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 =
-#              '<v8_root>/tools/vim/v8.ycm_extra_conf.py'
-#
-#   3. 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 = [
-'-DUSE_CLANG_COMPLETER',
-'-std=gnu++0x',
-'-x',
-'c++',
-]
-
-
-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/.
-
-  Args:
-    filename: (String) Path to source file being edited.
-
-  Returns:
-    (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.
-
-  Args:
-    v8_root: (String) Path to v8/.
-    filename: (String) Path to source file being edited.
-
-  Returns:
-    (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');
-  v8_flags.append('-Wno-unknown-warning-option')
-
-  # 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 filename.endswith('-inl.h'):
-        for alt_extension in alternates:
-          alt_name = filename[:-6] + alt_extension
-          if os.path.exists(alt_name):
-            filename = alt_name
-            break;
-        else:
-          # If this is a standalone -inl.h file with no source, the best we can
-          # do is try to use the default flags.
-          return v8_flags
-      else:
-        # If this is a standalone .h file with no source, the best we can do is
-        # try to use the default flags.
-        return v8_flags
-
-  sys.path.append(os.path.join(v8_root, 'tools', 'vim'))
-  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=subprocess.PIPE)
-  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
-      break
-  else:
-    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] == '/':
-        v8_flags.append(flag)
-      else:
-        abs_path = os.path.normpath(os.path.join(out_dir, flag[2:]))
-        v8_flags.append('-I' + abs_path)
-    elif flag.startswith('-std'):
-      v8_flags.append(flag)
-    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
-      v8_flags.append(flag)
-
-  return v8_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.
-  """
-  v8_root = FindV8SrcFromFilename(filename)
-  v8_flags = GetClangCommandFromNinjaForFilename(v8_root, filename)
-  final_flags = flags + v8_flags
-  return {
-    'flags': final_flags,
-    'do_cache': True
-  }