Home | History | Annotate | Download | only in vim 
      1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 
      5 # Autocompletion config for YouCompleteMe in Chromium.
      6 #
      7 # USAGE:
      8 #
      9 #   1. Install YCM [https://github.com/Valloric/YouCompleteMe]
     10 #          (Googlers should check out [go/ycm])
     11 #
     12 #   2. Point to this config file in your .vimrc:
     13 #          let g:ycm_global_ycm_extra_conf =
     14 #              '<chrome_depot>/src/tools/vim/chromium.ycm_extra_conf.py'
     15 #
     16 #   3. Profit
     17 #
     18 #
     19 # Usage notes:
     20 #
     21 #   * You must use ninja & clang to build Chromium.
     22 #
     23 #   * You must have run gyp_chromium and built Chromium recently.
     24 #
     25 #
     26 # Hacking notes:
     27 #
     28 #   * The purpose of this script is to construct an accurate enough command line
     29 #     for YCM to pass to clang so it can build and extract the symbols.
     30 #
     31 #   * Right now, we only pull the -I and -D flags. That seems to be sufficient
     32 #     for everything I've used it for.
     33 #
     34 #   * That whole ninja & clang thing? We could support other configs if someone
     35 #     were willing to write the correct commands and a parser.
     36 #
     37 #   * This has only been tested on gPrecise.
     38 
     39 
     40 import os
     41 import subprocess
     42 
     43 
     44 # Flags from YCM's default config.
     45 flags = [
     46 '-DUSE_CLANG_COMPLETER',
     47 '-std=c++11',
     48 '-x',
     49 'c++',
     50 ]
     51 
     52 
     53 def PathExists(*args):
     54   return os.path.exists(os.path.join(*args))
     55 
     56 
     57 def FindChromeSrcFromFilename(filename):
     58   """Searches for the root of the Chromium checkout.
     59 
     60   Simply checks parent directories until it finds .gclient and src/.
     61 
     62   Args:
     63     filename: (String) Path to source file being edited.
     64 
     65   Returns:
     66     (String) Path of 'src/', or None if unable to find.
     67   """
     68   curdir = os.path.normpath(os.path.dirname(filename))
     69   while not (PathExists(curdir, 'src') and PathExists(curdir, 'src', 'DEPS')
     70              and (PathExists(curdir, '.gclient')
     71                   or PathExists(curdir, 'src', '.git'))):
     72     nextdir = os.path.normpath(os.path.join(curdir, '..'))
     73     if nextdir == curdir:
     74       return None
     75     curdir = nextdir
     76   return os.path.join(curdir, 'src')
     77 
     78 
     79 # Largely copied from ninja-build.vim (guess_configuration)
     80 def GetNinjaOutputDirectory(chrome_root):
     81   """Returns <chrome_root>/<output_dir>/(Release|Debug).
     82 
     83   The configuration chosen is the one most recently generated/built. Detects
     84   a custom output_dir specified by GYP_GENERATOR_FLAGS."""
     85 
     86   output_dir = 'out'
     87   generator_flags = os.getenv('GYP_GENERATOR_FLAGS', '').split(' ')
     88   for flag in generator_flags:
     89     name_value = flag.split('=', 1)
     90     if len(name_value) == 2 and name_value[0] == 'output_dir':
     91       output_dir = name_value[1]
     92 
     93   root = os.path.join(chrome_root, output_dir)
     94   debug_path = os.path.join(root, 'Debug')
     95   release_path = os.path.join(root, 'Release')
     96 
     97   def is_release_15s_newer(test_path):
     98     try:
     99       debug_mtime = os.path.getmtime(os.path.join(debug_path, test_path))
    100     except os.error:
    101       debug_mtime = 0
    102     try:
    103       rel_mtime = os.path.getmtime(os.path.join(release_path, test_path))
    104     except os.error:
    105       rel_mtime = 0
    106     return rel_mtime - debug_mtime >= 15
    107 
    108   if is_release_15s_newer('build.ninja') or is_release_15s_newer('protoc'):
    109     return release_path
    110   return debug_path
    111 
    112 
    113 def GetClangCommandFromNinjaForFilename(chrome_root, filename):
    114   """Returns the command line to build |filename|.
    115 
    116   Asks ninja how it would build the source file. If the specified file is a
    117   header, tries to find its companion source file first.
    118 
    119   Args:
    120     chrome_root: (String) Path to src/.
    121     filename: (String) Path to source file being edited.
    122 
    123   Returns:
    124     (List of Strings) Command line arguments for clang.
    125   """
    126   if not chrome_root:
    127     return []
    128 
    129   # Generally, everyone benefits from including Chromium's src/, because all of
    130   # Chromium's includes are relative to that.
    131   chrome_flags = ['-I' + os.path.join(chrome_root)]
    132 
    133   # Header files can't be built. Instead, try to match a header file to its
    134   # corresponding source file.
    135   if filename.endswith('.h'):
    136     alternates = ['.cc', '.cpp']
    137     for alt_extension in alternates:
    138       alt_name = filename[:-2] + alt_extension
    139       if os.path.exists(alt_name):
    140         filename = alt_name
    141         break
    142     else:
    143       # If this is a standalone .h file with no source, the best we can do is
    144       # try to use the default flags.
    145       return chrome_flags
    146 
    147   # Ninja needs the path to the source file from the output build directory.
    148   # Cut off the common part and /.
    149   subdir_filename = filename[len(chrome_root)+1:]
    150   rel_filename = os.path.join('..', '..', subdir_filename)
    151 
    152   out_dir = GetNinjaOutputDirectory(chrome_root)
    153 
    154   # Ask ninja how it would build our source file.
    155   p = subprocess.Popen(['ninja', '-v', '-C', out_dir, '-t',
    156                         'commands', rel_filename + '^'],
    157                        stdout=subprocess.PIPE)
    158   stdout, stderr = p.communicate()
    159   if p.returncode:
    160     return chrome_flags
    161 
    162   # Ninja might execute several commands to build something. We want the last
    163   # clang command.
    164   clang_line = None
    165   for line in reversed(stdout.split('\n')):
    166     if 'clang' in line:
    167       clang_line = line
    168       break
    169   else:
    170     return chrome_flags
    171 
    172   # Parse flags that are important for YCM's purposes.
    173   for flag in clang_line.split(' '):
    174     if flag.startswith('-I'):
    175       # Relative paths need to be resolved, because they're relative to the
    176       # output dir, not the source.
    177       if flag[2] == '/':
    178         chrome_flags.append(flag)
    179       else:
    180         abs_path = os.path.normpath(os.path.join(out_dir, flag[2:]))
    181         chrome_flags.append('-I' + abs_path)
    182     elif flag.startswith('-std'):
    183       chrome_flags.append(flag)
    184     elif flag.startswith('-') and flag[1] in 'DWFfmO':
    185       if flag == '-Wno-deprecated-register' or flag == '-Wno-header-guard':
    186         # These flags causes libclang (3.3) to crash. Remove it until things
    187         # are fixed.
    188         continue
    189       chrome_flags.append(flag)
    190 
    191   return chrome_flags
    192 
    193 
    194 def FlagsForFile(filename):
    195   """This is the main entry point for YCM. Its interface is fixed.
    196 
    197   Args:
    198     filename: (String) Path to source file being edited.
    199 
    200   Returns:
    201     (Dictionary)
    202       'flags': (List of Strings) Command line flags.
    203       'do_cache': (Boolean) True if the result should be cached.
    204   """
    205   chrome_root = FindChromeSrcFromFilename(filename)
    206   chrome_flags = GetClangCommandFromNinjaForFilename(chrome_root,
    207                                                      filename)
    208   final_flags = flags + chrome_flags
    209 
    210   return {
    211     'flags': final_flags,
    212     'do_cache': True
    213   }
    214