Adding YouCompleteMe config for WebRTC.
Mostly just copied from Chromium, replacing instances of "chromium" with
"webrtc".
BUG=None
NOTRY=True
Review-Url: https://codereview.webrtc.org/2725233002
Cr-Commit-Position: refs/heads/master@{#16988}
diff --git a/tools-webrtc/vim/webrtc.ycm_extra_conf.py b/tools-webrtc/vim/webrtc.ycm_extra_conf.py
new file mode 100644
index 0000000..b716e45
--- /dev/null
+++ b/tools-webrtc/vim/webrtc.ycm_extra_conf.py
@@ -0,0 +1,357 @@
+# Copyright (c) 2017 The WebRTC 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 in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS. All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+# Autocompletion config for YouCompleteMe in WebRTC. This is just copied from
+# tools/vim in chromium with very minor modifications.
+#
+# USAGE:
+#
+# 1. Install YCM [https://github.com/Valloric/YouCompleteMe]
+# (Googlers should check out [go/ycm])
+#
+# 2. Create a symbolic link to this file called .ycm_extra_conf.py in the
+# directory above your WebRTC checkout (i.e. next to your .gclient file).
+#
+# cd src
+# ln -rs tools-webrtc/vim/webrtc.ycm_extra_conf.py \
+# ../.ycm_extra_conf.py
+#
+# 3. (optional) Whitelist the .ycm_extra_conf.py from step #2 by adding the
+# following to your .vimrc:
+#
+# let g:ycm_extra_conf_globlist=['<path to .ycm_extra_conf.py>']
+#
+# You can also add other .ycm_extra_conf.py files you want to use to this
+# list to prevent excessive prompting each time you visit a directory
+# covered by a config file.
+#
+# 4. Profit
+#
+#
+# Usage notes:
+#
+# * You must use ninja & clang to build WebRTC.
+#
+# * You must have run "gn gen" and built WebRTC 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 os.path
+import shlex
+import subprocess
+import sys
+
+# Flags from YCM's default config.
+_default_flags = [
+ '-DUSE_CLANG_COMPLETER',
+ '-std=c++11',
+ '-x',
+ 'c++',
+]
+
+_header_alternates = ('.cc', '.cpp', '.c', '.mm', '.m')
+
+_extension_flags = {
+ '.m': ['-x', 'objective-c'],
+ '.mm': ['-x', 'objective-c++'],
+}
+
+def PathExists(*args):
+ return os.path.exists(os.path.join(*args))
+
+
+def FindWebrtcSrcFromFilename(filename):
+ """Searches for the root of the WebRTC 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 (os.path.basename(curdir) == 'src'
+ and PathExists(curdir, 'DEPS')
+ and (PathExists(curdir, '..', '.gclient')
+ or PathExists(curdir, '.git'))):
+ nextdir = os.path.normpath(os.path.join(curdir, '..'))
+ if nextdir == curdir:
+ return None
+ curdir = nextdir
+ return curdir
+
+
+def GetDefaultSourceFile(webrtc_root, filename):
+ """Returns the default source file to use as an alternative to |filename|.
+
+ Compile flags used to build the default source file is assumed to be a
+ close-enough approximation for building |filename|.
+
+ Args:
+ webrtc_root: (String) Absolute path to the root of WebRTC checkout.
+ filename: (String) Absolute path to the source file.
+
+ Returns:
+ (String) Absolute path to substitute source file.
+ """
+ if 'test.' in filename:
+ return os.path.join(webrtc_root, 'base', 'logging_unittest.cc')
+ return os.path.join(webrtc_root, 'base', 'logging.cc')
+
+
+def GetNinjaBuildOutputsForSourceFile(out_dir, filename):
+ """Returns a list of build outputs for filename.
+
+ The list is generated by invoking 'ninja -t query' tool to retrieve a list of
+ inputs and outputs of |filename|. This list is then filtered to only include
+ .o and .obj outputs.
+
+ Args:
+ out_dir: (String) Absolute path to ninja build output directory.
+ filename: (String) Absolute path to source file.
+
+ Returns:
+ (List of Strings) List of target names. Will return [] if |filename| doesn't
+ yield any .o or .obj outputs.
+ """
+ # Ninja needs the path to the source file relative to the output build
+ # directory.
+ rel_filename = os.path.relpath(filename, out_dir)
+
+ p = subprocess.Popen(['ninja', '-C', out_dir, '-t', 'query', rel_filename],
+ stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
+ universal_newlines=True)
+ stdout, _ = p.communicate()
+ if p.returncode != 0:
+ return []
+
+ # The output looks like:
+ # ../../relative/path/to/source.cc:
+ # outputs:
+ # obj/reative/path/to/target.source.o
+ # obj/some/other/target2.source.o
+ # another/target.txt
+ #
+ outputs_text = stdout.partition('\n outputs:\n')[2]
+ output_lines = [line.strip() for line in outputs_text.split('\n')]
+ return [target for target in output_lines
+ if target and (target.endswith('.o') or target.endswith('.obj'))]
+
+
+def GetClangCommandLineForNinjaOutput(out_dir, build_target):
+ """Returns the Clang command line for building |build_target|
+
+ Asks ninja for the list of commands used to build |filename| and returns the
+ final Clang invocation.
+
+ Args:
+ out_dir: (String) Absolute path to ninja build output directory.
+ build_target: (String) A build target understood by ninja
+
+ Returns:
+ (String or None) Clang command line or None if a Clang command line couldn't
+ be determined.
+ """
+ p = subprocess.Popen(['ninja', '-v', '-C', out_dir,
+ '-t', 'commands', build_target],
+ stdout=subprocess.PIPE, universal_newlines=True)
+ stdout, _ = p.communicate()
+ if p.returncode != 0:
+ return None
+
+ # Ninja will return multiple build steps for all dependencies up to
+ # |build_target|. The build step we want is the last Clang invocation, which
+ # is expected to be the one that outputs |build_target|.
+ for line in reversed(stdout.split('\n')):
+ if 'clang' in line:
+ return line
+ return None
+
+
+def GetClangCommandLineFromNinjaForSource(out_dir, filename):
+ """Returns a Clang command line used to build |filename|.
+
+ The same source file could be built multiple times using different tool
+ chains. In such cases, this command returns the first Clang invocation. We
+ currently don't prefer one toolchain over another. Hopefully the tool chain
+ corresponding to the Clang command line is compatible with the Clang build
+ used by YCM.
+
+ Args:
+ out_dir: (String) Absolute path to WebRTC checkout.
+ filename: (String) Absolute path to source file.
+
+ Returns:
+ (String or None): Command line for Clang invocation using |filename| as a
+ source. Returns None if no such command line could be found.
+ """
+ build_targets = GetNinjaBuildOutputsForSourceFile(out_dir, filename)
+ for build_target in build_targets:
+ command_line = GetClangCommandLineForNinjaOutput(out_dir, build_target)
+ if command_line:
+ return command_line
+ return None
+
+
+def GetClangOptionsFromCommandLine(clang_commandline, out_dir,
+ additional_flags):
+ """Extracts relevant command line options from |clang_commandline|
+
+ Args:
+ clang_commandline: (String) Full Clang invocation.
+ out_dir: (String) Absolute path to ninja build directory. Relative paths in
+ the command line are relative to |out_dir|.
+ additional_flags: (List of String) Additional flags to return.
+
+ Returns:
+ (List of Strings) The list of command line flags for this source file. Can
+ be empty.
+ """
+ clang_flags = [] + additional_flags
+
+ # Parse flags that are important for YCM's purposes.
+ clang_tokens = shlex.split(clang_commandline)
+ for flag_index, flag in enumerate(clang_tokens):
+ if flag.startswith('-I'):
+ # Relative paths need to be resolved, because they're relative to the
+ # output dir, not the source.
+ if flag[2] == '/':
+ clang_flags.append(flag)
+ else:
+ abs_path = os.path.normpath(os.path.join(out_dir, flag[2:]))
+ clang_flags.append('-I' + abs_path)
+ elif flag.startswith('-std'):
+ clang_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
+ clang_flags.append(flag)
+ elif flag == '-isysroot':
+ # On Mac -isysroot <path> is used to find the system headers.
+ # Copy over both flags.
+ if flag_index + 1 < len(clang_tokens):
+ clang_flags.append(flag)
+ clang_flags.append(clang_tokens[flag_index + 1])
+ elif flag.startswith('--sysroot='):
+ # On Linux we use a sysroot image.
+ sysroot_path = flag.lstrip('--sysroot=')
+ if sysroot_path.startswith('/'):
+ clang_flags.append(flag)
+ else:
+ abs_path = os.path.normpath(os.path.join(out_dir, sysroot_path))
+ clang_flags.append('--sysroot=' + abs_path)
+ return clang_flags
+
+
+def GetClangOptionsFromNinjaForFilename(webrtc_root, filename):
+ """Returns the Clang command line options needed for building |filename|.
+
+ Command line options are based on the command used by ninja for building
+ |filename|. If |filename| is a .h file, uses its companion .cc or .cpp file.
+ If a suitable companion file can't be located or if ninja doesn't know about
+ |filename|, then uses default source files in WebRTC for determining the
+ commandline.
+
+ Args:
+ webrtc_root: (String) Path to src/.
+ filename: (String) Absolute path to source file being edited.
+
+ Returns:
+ (List of Strings) The list of command line flags for this source file. Can
+ be empty.
+ """
+ if not webrtc_root:
+ return []
+
+ # Generally, everyone benefits from including WebRTC's src/, because all of
+ # WebRTC's includes are relative to that.
+ additional_flags = ['-I' + os.path.join(webrtc_root)]
+
+ # Version of Clang used to compile WebRTC 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');
+ additional_flags.append('-Wno-unknown-warning-option')
+
+ sys.path.append(os.path.join(webrtc_root, 'tools', 'vim'))
+ from ninja_output import GetNinjaOutputDirectory
+ out_dir = GetNinjaOutputDirectory(webrtc_root)
+
+ basename, extension = os.path.splitext(filename)
+ if extension == '.h':
+ candidates = [basename + ext for ext in _header_alternates]
+ else:
+ candidates = [filename]
+
+ clang_line = None
+ buildable_extension = extension
+ for candidate in candidates:
+ clang_line = GetClangCommandLineFromNinjaForSource(out_dir, candidate)
+ if clang_line:
+ buildable_extension = os.path.splitext(candidate)[1]
+ break
+
+ additional_flags += _extension_flags.get(buildable_extension, [])
+
+ if not clang_line:
+ # If ninja didn't know about filename or it's companion files, then try a
+ # default build target. It is possible that the file is new, or build.ninja
+ # is stale.
+ clang_line = GetClangCommandLineFromNinjaForSource(
+ out_dir, GetDefaultSourceFile(webrtc_root, filename))
+
+ if not clang_line:
+ return additional_flags
+
+ return GetClangOptionsFromCommandLine(clang_line, out_dir, additional_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.
+ """
+ abs_filename = os.path.abspath(filename)
+ webrtc_root = FindWebrtcSrcFromFilename(abs_filename)
+ clang_flags = GetClangOptionsFromNinjaForFilename(webrtc_root, abs_filename)
+
+ # If clang_flags could not be determined, then assume that was due to a
+ # transient failure. Preventing YCM from caching the flags allows us to try to
+ # determine the flags again.
+ should_cache_flags_for_file = bool(clang_flags)
+
+ final_flags = _default_flags + clang_flags
+
+ return {
+ 'flags': final_flags,
+ 'do_cache': should_cache_flags_for_file
+ }