Ben Murdoch | f91f061 | 2016-11-29 16:50:11 +0000 | [diff] [blame] | 1 | # Copyright 2015 the V8 project 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 V8. |
| 6 | # |
| 7 | # USAGE: |
| 8 | # |
| 9 | # 1. Install YCM [https://github.com/Valloric/YouCompleteMe] |
| 10 | # (Googlers should check out [go/ycm]) |
| 11 | # |
| 12 | # 2. Profit |
| 13 | # |
| 14 | # |
| 15 | # Usage notes: |
| 16 | # |
| 17 | # * You must use ninja & clang to build V8. |
| 18 | # |
| 19 | # * You must have run gyp_v8 and built V8 recently. |
| 20 | # |
| 21 | # |
| 22 | # Hacking notes: |
| 23 | # |
| 24 | # * The purpose of this script is to construct an accurate enough command line |
| 25 | # for YCM to pass to clang so it can build and extract the symbols. |
| 26 | # |
| 27 | # * Right now, we only pull the -I and -D flags. That seems to be sufficient |
| 28 | # for everything I've used it for. |
| 29 | # |
| 30 | # * That whole ninja & clang thing? We could support other configs if someone |
| 31 | # were willing to write the correct commands and a parser. |
| 32 | # |
| 33 | # * This has only been tested on gTrusty. |
| 34 | |
| 35 | |
| 36 | import os |
| 37 | import os.path |
| 38 | import subprocess |
| 39 | import sys |
| 40 | |
| 41 | |
| 42 | # Flags from YCM's default config. |
| 43 | flags = [ |
| 44 | '-DUSE_CLANG_COMPLETER', |
| 45 | '-std=gnu++11', |
| 46 | '-x', |
| 47 | 'c++', |
| 48 | ] |
| 49 | |
| 50 | |
| 51 | def PathExists(*args): |
| 52 | return os.path.exists(os.path.join(*args)) |
| 53 | |
| 54 | |
| 55 | def FindV8SrcFromFilename(filename): |
| 56 | """Searches for the root of the V8 checkout. |
| 57 | |
| 58 | Simply checks parent directories until it finds .gclient and v8/. |
| 59 | |
| 60 | Args: |
| 61 | filename: (String) Path to source file being edited. |
| 62 | |
| 63 | Returns: |
| 64 | (String) Path of 'v8/', or None if unable to find. |
| 65 | """ |
| 66 | curdir = os.path.normpath(os.path.dirname(filename)) |
| 67 | while not (PathExists(curdir, 'v8') and PathExists(curdir, 'v8', 'DEPS') |
| 68 | and (PathExists(curdir, '.gclient') |
| 69 | or PathExists(curdir, 'v8', '.git'))): |
| 70 | nextdir = os.path.normpath(os.path.join(curdir, '..')) |
| 71 | if nextdir == curdir: |
| 72 | return None |
| 73 | curdir = nextdir |
| 74 | return os.path.join(curdir, 'v8') |
| 75 | |
| 76 | |
| 77 | def GetClangCommandFromNinjaForFilename(v8_root, filename): |
| 78 | """Returns the command line to build |filename|. |
| 79 | |
| 80 | Asks ninja how it would build the source file. If the specified file is a |
| 81 | header, tries to find its companion source file first. |
| 82 | |
| 83 | Args: |
| 84 | v8_root: (String) Path to v8/. |
| 85 | filename: (String) Path to source file being edited. |
| 86 | |
| 87 | Returns: |
| 88 | (List of Strings) Command line arguments for clang. |
| 89 | """ |
| 90 | if not v8_root: |
| 91 | return [] |
| 92 | |
| 93 | # Generally, everyone benefits from including V8's root, because all of |
| 94 | # V8's includes are relative to that. |
| 95 | v8_flags = ['-I' + os.path.join(v8_root)] |
| 96 | |
| 97 | # Version of Clang used to compile V8 can be newer then version of |
| 98 | # libclang that YCM uses for completion. So it's possible that YCM's libclang |
| 99 | # doesn't know about some used warning options, which causes compilation |
| 100 | # warnings (and errors, because of '-Werror'); |
| 101 | v8_flags.append('-Wno-unknown-warning-option') |
| 102 | |
| 103 | # Header files can't be built. Instead, try to match a header file to its |
| 104 | # corresponding source file. |
| 105 | if filename.endswith('.h'): |
| 106 | alternates = ['.cc', '.cpp'] |
| 107 | for alt_extension in alternates: |
| 108 | alt_name = filename[:-2] + alt_extension |
| 109 | if os.path.exists(alt_name): |
| 110 | filename = alt_name |
| 111 | break |
| 112 | else: |
| 113 | if filename.endswith('-inl.h'): |
| 114 | for alt_extension in alternates: |
| 115 | alt_name = filename[:-6] + alt_extension |
| 116 | if os.path.exists(alt_name): |
| 117 | filename = alt_name |
| 118 | break; |
| 119 | else: |
| 120 | # If this is a standalone -inl.h file with no source, the best we can |
| 121 | # do is try to use the default flags. |
| 122 | return v8_flags |
| 123 | else: |
| 124 | # If this is a standalone .h file with no source, the best we can do is |
| 125 | # try to use the default flags. |
| 126 | return v8_flags |
| 127 | |
| 128 | sys.path.append(os.path.join(v8_root, 'tools', 'ninja')) |
| 129 | from ninja_output import GetNinjaOutputDirectory |
| 130 | out_dir = os.path.realpath(GetNinjaOutputDirectory(v8_root)) |
| 131 | |
| 132 | # Ninja needs the path to the source file relative to the output build |
| 133 | # directory. |
| 134 | rel_filename = os.path.relpath(os.path.realpath(filename), out_dir) |
| 135 | |
| 136 | # Ask ninja how it would build our source file. |
| 137 | p = subprocess.Popen(['ninja', '-v', '-C', out_dir, '-t', |
| 138 | 'commands', rel_filename + '^'], |
| 139 | stdout=subprocess.PIPE) |
| 140 | stdout, stderr = p.communicate() |
| 141 | if p.returncode: |
| 142 | return v8_flags |
| 143 | |
| 144 | # Ninja might execute several commands to build something. We want the last |
| 145 | # clang command. |
| 146 | clang_line = None |
| 147 | for line in reversed(stdout.split('\n')): |
| 148 | if 'clang' in line: |
| 149 | clang_line = line |
| 150 | break |
| 151 | else: |
| 152 | return v8_flags |
| 153 | |
| 154 | # Parse flags that are important for YCM's purposes. |
| 155 | for flag in clang_line.split(' '): |
| 156 | if flag.startswith('-I'): |
| 157 | # Relative paths need to be resolved, because they're relative to the |
| 158 | # output dir, not the source. |
| 159 | if flag[2] == '/': |
| 160 | v8_flags.append(flag) |
| 161 | else: |
| 162 | abs_path = os.path.normpath(os.path.join(out_dir, flag[2:])) |
| 163 | v8_flags.append('-I' + abs_path) |
| 164 | elif flag.startswith('-std'): |
| 165 | v8_flags.append(flag) |
| 166 | elif flag.startswith('-') and flag[1] in 'DWFfmO': |
| 167 | if flag == '-Wno-deprecated-register' or flag == '-Wno-header-guard': |
| 168 | # These flags causes libclang (3.3) to crash. Remove it until things |
| 169 | # are fixed. |
| 170 | continue |
| 171 | v8_flags.append(flag) |
| 172 | |
| 173 | return v8_flags |
| 174 | |
| 175 | |
| 176 | def FlagsForFile(filename): |
| 177 | """This is the main entry point for YCM. Its interface is fixed. |
| 178 | |
| 179 | Args: |
| 180 | filename: (String) Path to source file being edited. |
| 181 | |
| 182 | Returns: |
| 183 | (Dictionary) |
| 184 | 'flags': (List of Strings) Command line flags. |
| 185 | 'do_cache': (Boolean) True if the result should be cached. |
| 186 | """ |
| 187 | v8_root = FindV8SrcFromFilename(filename) |
| 188 | v8_flags = GetClangCommandFromNinjaForFilename(v8_root, filename) |
| 189 | final_flags = flags + v8_flags |
| 190 | return { |
| 191 | 'flags': final_flags, |
| 192 | 'do_cache': True |
| 193 | } |