tools/roll_webgl_conformance.py - codesearch/chromium/src - Git at Google

 #!/usr/bin/env python
 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

 import argparse
 import collections
 import logging
 import os
 import re
 import subprocess
 import sys
 import time

 extra_trybots = [
   {
     "mastername": "master.tryserver.chromium.win",
     "buildernames": ["win_optional_gpu_tests_rel"]
   },
   {
     "mastername": "master.tryserver.chromium.mac",
     "buildernames": ["mac_optional_gpu_tests_rel"]
   },
   {
     "mastername": "master.tryserver.chromium.linux",
     "buildernames": ["linux_optional_gpu_tests_rel"]
   },
   {
     "mastername": "master.tryserver.chromium.android",
     "buildernames": ["android_optional_gpu_tests_rel"]
   },
 ]

 SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
 SRC_DIR = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
 sys.path.insert(0, os.path.join(SRC_DIR, 'build'))
 import find_depot_tools
 find_depot_tools.add_depot_tools_to_path()
 import roll_dep_svn
 from third_party import upload

 # Avoid depot_tools/third_party/upload.py print verbose messages.
 upload.verbosity = 0  # Errors only.

 CHROMIUM_GIT_URL = 'https://chromium.googlesource.com/chromium/src.git'
 CL_ISSUE_RE = re.compile('^Issue number: ([0-9]+) \((.*)\)$')
 REVIEW_URL_RE = re.compile('^https?://(.*)/(.*)')
 ROLL_BRANCH_NAME = 'special_webgl_roll_branch'
 TRYJOB_STATUS_SLEEP_SECONDS = 30

 # Use a shell for subcommands on Windows to get a PATH search.
 IS_WIN = sys.platform.startswith('win')
 WEBGL_PATH = os.path.join('third_party', 'webgl', 'src')
 WEBGL_REVISION_TEXT_FILE = os.path.join(
   'content', 'test', 'gpu', 'gpu_tests', 'webgl_conformance_revision.txt')

 CommitInfo = collections.namedtuple('CommitInfo', ['git_commit',
                                                    'git_repo_url'])
 CLInfo = collections.namedtuple('CLInfo', ['issue', 'url', 'review_server'])


 def _VarLookup(local_scope):
   return lambda var_name: local_scope['vars'][var_name]


 def _PosixPath(path):
   """Convert a possibly-Windows path to a posix-style path."""
   (_, path) = os.path.splitdrive(path)
   return path.replace(os.sep, '/')

 def _ParseGitCommitHash(description):
   for line in description.splitlines():
     if line.startswith('commit '):
       return line.split()[1]
   logging.error('Failed to parse git commit id from:\n%s\n', description)
   sys.exit(-1)
   return None


 def _ParseDepsFile(filename):
   with open(filename, 'rb') as f:
     deps_content = f.read()
   return _ParseDepsDict(deps_content)


 def _ParseDepsDict(deps_content):
   local_scope = {}
   global_scope = {
     'Var': _VarLookup(local_scope),
     'deps_os': {},
   }
   exec(deps_content, global_scope, local_scope)
   return local_scope


 def _GenerateCLDescriptionCommand(webgl_current, webgl_new, bugs):
   def GetChangeString(current_hash, new_hash):
     return '%s..%s' % (current_hash[0:7], new_hash[0:7]);

   def GetChangeLogURL(git_repo_url, change_string):
     return '%s/+log/%s' % (git_repo_url, change_string)

   def GetBugString(bugs):
     bug_str = 'BUG='
     for bug in bugs:
       bug_str += str(bug) + ','
     return bug_str.rstrip(',')

   change_str = GetChangeString(webgl_current.git_commit,
                                webgl_new.git_commit)
   changelog_url = GetChangeLogURL(webgl_current.git_repo_url,
                                   change_str)
   if webgl_current.git_commit == webgl_new.git_commit:
     print 'WARNING: WebGL repository is unchanged; proceeding with no-op roll'

   def GetExtraTrybotString():
     s = ''
     for t in extra_trybots:
       if s:
         s += ';'
       s += t['mastername'] + ':' + ','.join(t['buildernames'])
     return s

   extra_trybot_args = []
   if extra_trybots:
     extra_trybot_string = GetExtraTrybotString()
     extra_trybot_args = ['-m', 'CQ_INCLUDE_TRYBOTS=' + extra_trybot_string]

   return [
     '-m', 'Roll WebGL ' + change_str,
     '-m', '%s' % changelog_url,
     '-m', GetBugString(bugs),
     '-m', 'TEST=bots',
   ] + extra_trybot_args


 class AutoRoller(object):
   def __init__(self, chromium_src):
     self._chromium_src = chromium_src

   def _RunCommand(self, command, working_dir=None, ignore_exit_code=False,
                   extra_env=None):
     """Runs a command and returns the stdout from that command.

     If the command fails (exit code != 0), the function will exit the process.
     """
     working_dir = working_dir or self._chromium_src
     logging.debug('cmd: %s cwd: %s', ' '.join(command), working_dir)
     env = os.environ.copy()
     if extra_env:
       logging.debug('extra env: %s', extra_env)
       env.update(extra_env)
     p = subprocess.Popen(command, stdout=subprocess.PIPE,
                          stderr=subprocess.PIPE, shell=IS_WIN, env=env,
                          cwd=working_dir, universal_newlines=True)
     output = p.stdout.read()
     p.wait()
     p.stdout.close()
     p.stderr.close()

     if not ignore_exit_code and p.returncode != 0:
       logging.error('Command failed: %s\n%s', str(command), output)
       sys.exit(p.returncode)
     return output

   def _GetCommitInfo(self, path_below_src, git_hash=None, git_repo_url=None):
     working_dir = os.path.join(self._chromium_src, path_below_src)
     self._RunCommand(['git', 'fetch', 'origin'], working_dir=working_dir)
     revision_range = git_hash or 'origin'
     ret = self._RunCommand(
         ['git', '--no-pager', 'log', revision_range,
          '--no-abbrev-commit', '--pretty=full', '-1'],
         working_dir=working_dir)
     return CommitInfo(_ParseGitCommitHash(ret), git_repo_url)

   def _GetDepsCommitInfo(self, deps_dict, path_below_src):
     entry = deps_dict['deps'][_PosixPath('src/%s' % path_below_src)]
     at_index = entry.find('@')
     git_repo_url = entry[:at_index]
     git_hash = entry[at_index + 1:]
     return self._GetCommitInfo(path_below_src, git_hash, git_repo_url)

   def _GetCLInfo(self):
     cl_output = self._RunCommand(['git', 'cl', 'issue'])
     m = CL_ISSUE_RE.match(cl_output.strip())
     if not m:
       logging.error('Cannot find any CL info. Output was:\n%s', cl_output)
       sys.exit(-1)
     issue_number = int(m.group(1))
     url = m.group(2)

     # Parse the codereview host from the URL.
     m = REVIEW_URL_RE.match(url)
     if not m:
       logging.error('Cannot parse codereview host from URL: %s', url)
       sys.exit(-1)
     review_server = m.group(1)
     return CLInfo(issue_number, url, review_server)

   def _GetCurrentBranchName(self):
     return self._RunCommand(
         ['git', 'rev-parse', '--abbrev-ref', 'HEAD']).splitlines()[0]

   def _IsTreeClean(self):
     lines = self._RunCommand(
       ['git', 'status', '--porcelain', '-uno']).splitlines()
     if len(lines) == 0:
       return True

     logging.debug('Dirty/unversioned files:\n%s', '\n'.join(lines))
     return False

   def _GetBugList(self, path_below_src, webgl_current, webgl_new):
     # TODO(kbr): this isn't useful, at least not yet, when run against
     # the WebGL Github repository.
     working_dir = os.path.join(self._chromium_src, path_below_src)
     lines = self._RunCommand(
         ['git','log',
             '%s..%s' % (webgl_current.git_commit, webgl_new.git_commit)],
         working_dir=working_dir).split('\n')
     bugs = set()
     for line in lines:
       line = line.strip()
       bug_prefix = 'BUG='
       if line.startswith(bug_prefix):
         bugs_strings = line[len(bug_prefix):].split(',')
         for bug_string in bugs_strings:
           try:
             bugs.add(int(bug_string))
           except:
             # skip this, it may be a project specific bug such as
             # "angleproject:X" or an ill-formed BUG= message
             pass
     return bugs

   def _UpdateReadmeFile(self, readme_path, new_revision):
     readme = open(os.path.join(self._chromium_src, readme_path), 'r+')
     txt = readme.read()
     m = re.sub(re.compile('.*^Revision\: ([0-9]*).*', re.MULTILINE),
         ('Revision: %s' % new_revision), txt)
     readme.seek(0)
     readme.write(m)
     readme.truncate()

   def PrepareRoll(self, ignore_checks, run_tryjobs):
     # TODO(kjellander): use os.path.normcase, os.path.join etc for all paths for
     # cross platform compatibility.

     if not ignore_checks:
       if self._GetCurrentBranchName() != 'master':
         logging.error('Please checkout the master branch.')
         return -1
       if not self._IsTreeClean():
         logging.error('Please make sure you don\'t have any modified files.')
         return -1

     # Always clean up any previous roll.
     self.Abort()

     logging.debug('Pulling latest changes')
     if not ignore_checks:
       self._RunCommand(['git', 'pull'])

     self._RunCommand(['git', 'checkout', '-b', ROLL_BRANCH_NAME])

     # Modify Chromium's DEPS file.

     # Parse current hashes.
     deps_filename = os.path.join(self._chromium_src, 'DEPS')
     deps = _ParseDepsFile(deps_filename)
     webgl_current = self._GetDepsCommitInfo(deps, WEBGL_PATH)

     # Find ToT revisions.
     webgl_latest = self._GetCommitInfo(WEBGL_PATH)

     if IS_WIN:
       # Make sure the roll script doesn't use windows line endings
       self._RunCommand(['git', 'config', 'core.autocrlf', 'true'])

     self._UpdateDep(deps_filename, WEBGL_PATH, webgl_latest)
     self._UpdateWebGLRevTextFile(WEBGL_REVISION_TEXT_FILE, webgl_latest)

     if self._IsTreeClean():
       logging.debug('Tree is clean - no changes detected.')
       self._DeleteRollBranch()
     else:
       bugs = self._GetBugList(WEBGL_PATH, webgl_current, webgl_latest)
       description = _GenerateCLDescriptionCommand(
           webgl_current, webgl_latest, bugs)
       logging.debug('Committing changes locally.')
       self._RunCommand(['git', 'add', '--update', '.'])
       self._RunCommand(['git', 'commit'] + description)
       logging.debug('Uploading changes...')
       self._RunCommand(['git', 'cl', 'upload'],
                        extra_env={'EDITOR': 'true'})

       if run_tryjobs:
         # Kick off tryjobs.
         base_try_cmd = ['git', 'cl', 'try']
         self._RunCommand(base_try_cmd)

       cl_info = self._GetCLInfo()
       print 'Issue: %d URL: %s' % (cl_info.issue, cl_info.url)

     # Checkout master again.
     self._RunCommand(['git', 'checkout', 'master'])
     print 'Roll branch left as ' + ROLL_BRANCH_NAME
     return 0

   def _UpdateDep(self, deps_filename, dep_relative_to_src, commit_info):
     dep_name = _PosixPath(os.path.join('src', dep_relative_to_src))

     # roll_dep_svn.py relies on cwd being the Chromium checkout, so let's
     # temporarily change the working directory and then change back.
     cwd = os.getcwd()
     os.chdir(os.path.dirname(deps_filename))
     roll_dep_svn.update_deps(deps_filename, dep_relative_to_src, dep_name,
                              commit_info.git_commit, '')
     os.chdir(cwd)

   def _UpdateWebGLRevTextFile(self, txt_filename, commit_info):
     # Rolling the WebGL conformance tests must cause at least all of
     # the WebGL tests to run. There are already exclusions in
     # trybot_analyze_config.json which force all tests to run if
     # changes under src/content/test/gpu are made. (This rule
     # typically only takes effect on the GPU bots.) To make sure this
     # happens all the time, update an autogenerated text file in this
     # directory.
     with open(txt_filename, 'w') as fh:
       print >> fh, '# AUTOGENERATED FILE - DO NOT EDIT'
       print >> fh, '# SEE roll_webgl_conformance.py'
       print >> fh, 'Current webgl revision %s' % commit_info.git_commit

   def _DeleteRollBranch(self):
     self._RunCommand(['git', 'checkout', 'master'])
     self._RunCommand(['git', 'branch', '-D', ROLL_BRANCH_NAME])
     logging.debug('Deleted the local roll branch (%s)', ROLL_BRANCH_NAME)


   def _GetBranches(self):
     """Returns a tuple of active,branches.

     The 'active' is the name of the currently active branch and 'branches' is a
     list of all branches.
     """
     lines = self._RunCommand(['git', 'branch']).split('\n')
     branches = []
     active = ''
     for l in lines:
       if '*' in l:
         # The assumption is that the first char will always be the '*'.
         active = l[1:].strip()
         branches.append(active)
       else:
         b = l.strip()
         if b:
           branches.append(b)
     return (active, branches)

   def Abort(self):
     active_branch, branches = self._GetBranches()
     if active_branch == ROLL_BRANCH_NAME:
       active_branch = 'master'
     if ROLL_BRANCH_NAME in branches:
       print 'Aborting pending roll.'
       self._RunCommand(['git', 'checkout', ROLL_BRANCH_NAME])
       # Ignore an error here in case an issue wasn't created for some reason.
       self._RunCommand(['git', 'cl', 'set_close'], ignore_exit_code=True)
       self._RunCommand(['git', 'checkout', active_branch])
       self._RunCommand(['git', 'branch', '-D', ROLL_BRANCH_NAME])
     return 0


 def main():
   parser = argparse.ArgumentParser(
       description='Auto-generates a CL containing a WebGL conformance roll.')
   parser.add_argument('--abort',
     help=('Aborts a previously prepared roll. '
           'Closes any associated issues and deletes the roll branches'),
     action='store_true')
   parser.add_argument('--ignore-checks', action='store_true', default=False,
       help=('Skips checks for being on the master branch, dirty workspaces and '
             'the updating of the checkout. Will still delete and create local '
             'Git branches.'))
   parser.add_argument('--run-tryjobs', action='store_true', default=False,
       help=('Start the dry-run tryjobs for the newly generated CL. Use this '
             'when you have no need to make changes to the WebGL conformance '
             'test expectations in the same CL and want to avoid.'))
   parser.add_argument('-v', '--verbose', action='store_true', default=False,
       help='Be extra verbose in printing of log messages.')
   args = parser.parse_args()

   if args.verbose:
     logging.basicConfig(level=logging.DEBUG)
   else:
     logging.basicConfig(level=logging.ERROR)

   autoroller = AutoRoller(SRC_DIR)
   if args.abort:
     return autoroller.Abort()
   else:
     return autoroller.PrepareRoll(args.ignore_checks, args.run_tryjobs)

 if __name__ == '__main__':
   sys.exit(main())
	#!/usr/bin/env python
	# Copyright 2015 The Chromium Authors. All rights reserved.
	# Use of this source code is governed by a BSD-style license that can be
	# found in the LICENSE file.

	import argparse
	import collections
	import logging
	import os
	import re
	import subprocess
	import sys
	import time

	extra_trybots = [
	{
	"mastername": "master.tryserver.chromium.win",
	"buildernames": ["win_optional_gpu_tests_rel"]
	},
	{
	"mastername": "master.tryserver.chromium.mac",
	"buildernames": ["mac_optional_gpu_tests_rel"]
	},
	{
	"mastername": "master.tryserver.chromium.linux",
	"buildernames": ["linux_optional_gpu_tests_rel"]
	},
	{
	"mastername": "master.tryserver.chromium.android",
	"buildernames": ["android_optional_gpu_tests_rel"]
	},
	]

	SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
	SRC_DIR = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
	sys.path.insert(0, os.path.join(SRC_DIR, 'build'))
	import find_depot_tools
	find_depot_tools.add_depot_tools_to_path()
	import roll_dep_svn
	from third_party import upload

	# Avoid depot_tools/third_party/upload.py print verbose messages.
	upload.verbosity = 0 # Errors only.

	CHROMIUM_GIT_URL = 'https://chromium.googlesource.com/chromium/src.git'
	CL_ISSUE_RE = re.compile('^Issue number: ([0-9]+) \((.*)\)$')
	REVIEW_URL_RE = re.compile('^https?://(.)/(.)')
	ROLL_BRANCH_NAME = 'special_webgl_roll_branch'
	TRYJOB_STATUS_SLEEP_SECONDS = 30

	# Use a shell for subcommands on Windows to get a PATH search.
	IS_WIN = sys.platform.startswith('win')
	WEBGL_PATH = os.path.join('third_party', 'webgl', 'src')
	WEBGL_REVISION_TEXT_FILE = os.path.join(
	'content', 'test', 'gpu', 'gpu_tests', 'webgl_conformance_revision.txt')

	CommitInfo = collections.namedtuple('CommitInfo', ['git_commit',
	'git_repo_url'])
	CLInfo = collections.namedtuple('CLInfo', ['issue', 'url', 'review_server'])


	def _VarLookup(local_scope):
	return lambda var_name: local_scope['vars'][var_name]


	def _PosixPath(path):
	"""Convert a possibly-Windows path to a posix-style path."""
	(_, path) = os.path.splitdrive(path)
	return path.replace(os.sep, '/')

	def _ParseGitCommitHash(description):
	for line in description.splitlines():
	if line.startswith('commit '):
	return line.split()[1]
	logging.error('Failed to parse git commit id from:\n%s\n', description)
	sys.exit(-1)
	return None


	def _ParseDepsFile(filename):
	with open(filename, 'rb') as f:
	deps_content = f.read()
	return _ParseDepsDict(deps_content)


	def _ParseDepsDict(deps_content):
	local_scope = {}
	global_scope = {
	'Var': _VarLookup(local_scope),
	'deps_os': {},
	}
	exec(deps_content, global_scope, local_scope)
	return local_scope


	def _GenerateCLDescriptionCommand(webgl_current, webgl_new, bugs):
	def GetChangeString(current_hash, new_hash):
	return '%s..%s' % (current_hash[0:7], new_hash[0:7]);

	def GetChangeLogURL(git_repo_url, change_string):
	return '%s/+log/%s' % (git_repo_url, change_string)

	def GetBugString(bugs):
	bug_str = 'BUG='
	for bug in bugs:
	bug_str += str(bug) + ','
	return bug_str.rstrip(',')

	change_str = GetChangeString(webgl_current.git_commit,
	webgl_new.git_commit)
	changelog_url = GetChangeLogURL(webgl_current.git_repo_url,
	change_str)
	if webgl_current.git_commit == webgl_new.git_commit:
	print 'WARNING: WebGL repository is unchanged; proceeding with no-op roll'

	def GetExtraTrybotString():
	s = ''
	for t in extra_trybots:
	if s:
	s += ';'
	s += t['mastername'] + ':' + ','.join(t['buildernames'])
	return s

	extra_trybot_args = []
	if extra_trybots:
	extra_trybot_string = GetExtraTrybotString()
	extra_trybot_args = ['-m', 'CQ_INCLUDE_TRYBOTS=' + extra_trybot_string]

	return [
	'-m', 'Roll WebGL ' + change_str,
	'-m', '%s' % changelog_url,
	'-m', GetBugString(bugs),
	'-m', 'TEST=bots',
	] + extra_trybot_args


	class AutoRoller(object):
	def __init__(self, chromium_src):
	self._chromium_src = chromium_src

	def _RunCommand(self, command, working_dir=None, ignore_exit_code=False,
	extra_env=None):
	"""Runs a command and returns the stdout from that command.

	If the command fails (exit code != 0), the function will exit the process.
	"""
	working_dir = working_dir or self._chromium_src
	logging.debug('cmd: %s cwd: %s', ' '.join(command), working_dir)
	env = os.environ.copy()
	if extra_env:
	logging.debug('extra env: %s', extra_env)
	env.update(extra_env)
	p = subprocess.Popen(command, stdout=subprocess.PIPE,
	stderr=subprocess.PIPE, shell=IS_WIN, env=env,
	cwd=working_dir, universal_newlines=True)
	output = p.stdout.read()
	p.wait()
	p.stdout.close()
	p.stderr.close()

	if not ignore_exit_code and p.returncode != 0:
	logging.error('Command failed: %s\n%s', str(command), output)
	sys.exit(p.returncode)
	return output

	def _GetCommitInfo(self, path_below_src, git_hash=None, git_repo_url=None):
	working_dir = os.path.join(self._chromium_src, path_below_src)
	self._RunCommand(['git', 'fetch', 'origin'], working_dir=working_dir)
	revision_range = git_hash or 'origin'
	ret = self._RunCommand(
	['git', '--no-pager', 'log', revision_range,
	'--no-abbrev-commit', '--pretty=full', '-1'],
	working_dir=working_dir)
	return CommitInfo(_ParseGitCommitHash(ret), git_repo_url)

	def _GetDepsCommitInfo(self, deps_dict, path_below_src):
	entry = deps_dict['deps'][_PosixPath('src/%s' % path_below_src)]
	at_index = entry.find('@')
	git_repo_url = entry[:at_index]
	git_hash = entry[at_index + 1:]
	return self._GetCommitInfo(path_below_src, git_hash, git_repo_url)

	def _GetCLInfo(self):
	cl_output = self._RunCommand(['git', 'cl', 'issue'])
	m = CL_ISSUE_RE.match(cl_output.strip())
	if not m:
	logging.error('Cannot find any CL info. Output was:\n%s', cl_output)
	sys.exit(-1)
	issue_number = int(m.group(1))
	url = m.group(2)

	# Parse the codereview host from the URL.
	m = REVIEW_URL_RE.match(url)
	if not m:
	logging.error('Cannot parse codereview host from URL: %s', url)
	sys.exit(-1)
	review_server = m.group(1)
	return CLInfo(issue_number, url, review_server)

	def _GetCurrentBranchName(self):
	return self._RunCommand(
	['git', 'rev-parse', '--abbrev-ref', 'HEAD']).splitlines()[0]

	def _IsTreeClean(self):
	lines = self._RunCommand(
	['git', 'status', '--porcelain', '-uno']).splitlines()
	if len(lines) == 0:
	return True

	logging.debug('Dirty/unversioned files:\n%s', '\n'.join(lines))
	return False

	def _GetBugList(self, path_below_src, webgl_current, webgl_new):
	# TODO(kbr): this isn't useful, at least not yet, when run against
	# the WebGL Github repository.
	working_dir = os.path.join(self._chromium_src, path_below_src)
	lines = self._RunCommand(
	['git','log',
	'%s..%s' % (webgl_current.git_commit, webgl_new.git_commit)],
	working_dir=working_dir).split('\n')
	bugs = set()
	for line in lines:
	line = line.strip()
	bug_prefix = 'BUG='
	if line.startswith(bug_prefix):
	bugs_strings = line[len(bug_prefix):].split(',')
	for bug_string in bugs_strings:
	try:
	bugs.add(int(bug_string))
	except:
	# skip this, it may be a project specific bug such as
	# "angleproject:X" or an ill-formed BUG= message
	pass
	return bugs

	def _UpdateReadmeFile(self, readme_path, new_revision):
	readme = open(os.path.join(self._chromium_src, readme_path), 'r+')
	txt = readme.read()
	m = re.sub(re.compile('.^Revision\: ([0-9]).*', re.MULTILINE),
	('Revision: %s' % new_revision), txt)
	readme.seek(0)
	readme.write(m)
	readme.truncate()

	def PrepareRoll(self, ignore_checks, run_tryjobs):
	# TODO(kjellander): use os.path.normcase, os.path.join etc for all paths for
	# cross platform compatibility.

	if not ignore_checks:
	if self._GetCurrentBranchName() != 'master':
	logging.error('Please checkout the master branch.')
	return -1
	if not self._IsTreeClean():
	logging.error('Please make sure you don\'t have any modified files.')
	return -1

	# Always clean up any previous roll.
	self.Abort()

	logging.debug('Pulling latest changes')
	if not ignore_checks:
	self._RunCommand(['git', 'pull'])

	self._RunCommand(['git', 'checkout', '-b', ROLL_BRANCH_NAME])

	# Modify Chromium's DEPS file.

	# Parse current hashes.
	deps_filename = os.path.join(self._chromium_src, 'DEPS')
	deps = _ParseDepsFile(deps_filename)
	webgl_current = self._GetDepsCommitInfo(deps, WEBGL_PATH)

	# Find ToT revisions.
	webgl_latest = self._GetCommitInfo(WEBGL_PATH)

	if IS_WIN:
	# Make sure the roll script doesn't use windows line endings
	self._RunCommand(['git', 'config', 'core.autocrlf', 'true'])

	self._UpdateDep(deps_filename, WEBGL_PATH, webgl_latest)
	self._UpdateWebGLRevTextFile(WEBGL_REVISION_TEXT_FILE, webgl_latest)

	if self._IsTreeClean():
	logging.debug('Tree is clean - no changes detected.')
	self._DeleteRollBranch()
	else:
	bugs = self._GetBugList(WEBGL_PATH, webgl_current, webgl_latest)
	description = _GenerateCLDescriptionCommand(
	webgl_current, webgl_latest, bugs)
	logging.debug('Committing changes locally.')
	self._RunCommand(['git', 'add', '--update', '.'])
	self._RunCommand(['git', 'commit'] + description)
	logging.debug('Uploading changes...')
	self._RunCommand(['git', 'cl', 'upload'],
	extra_env={'EDITOR': 'true'})

	if run_tryjobs:
	# Kick off tryjobs.
	base_try_cmd = ['git', 'cl', 'try']
	self._RunCommand(base_try_cmd)

	cl_info = self._GetCLInfo()
	print 'Issue: %d URL: %s' % (cl_info.issue, cl_info.url)

	# Checkout master again.
	self._RunCommand(['git', 'checkout', 'master'])
	print 'Roll branch left as ' + ROLL_BRANCH_NAME
	return 0

	def _UpdateDep(self, deps_filename, dep_relative_to_src, commit_info):
	dep_name = _PosixPath(os.path.join('src', dep_relative_to_src))

	# roll_dep_svn.py relies on cwd being the Chromium checkout, so let's
	# temporarily change the working directory and then change back.
	cwd = os.getcwd()
	os.chdir(os.path.dirname(deps_filename))
	roll_dep_svn.update_deps(deps_filename, dep_relative_to_src, dep_name,
	commit_info.git_commit, '')
	os.chdir(cwd)

	def _UpdateWebGLRevTextFile(self, txt_filename, commit_info):
	# Rolling the WebGL conformance tests must cause at least all of
	# the WebGL tests to run. There are already exclusions in
	# trybot_analyze_config.json which force all tests to run if
	# changes under src/content/test/gpu are made. (This rule
	# typically only takes effect on the GPU bots.) To make sure this
	# happens all the time, update an autogenerated text file in this
	# directory.
	with open(txt_filename, 'w') as fh:
	print >> fh, '# AUTOGENERATED FILE - DO NOT EDIT'
	print >> fh, '# SEE roll_webgl_conformance.py'
	print >> fh, 'Current webgl revision %s' % commit_info.git_commit

	def _DeleteRollBranch(self):
	self._RunCommand(['git', 'checkout', 'master'])
	self._RunCommand(['git', 'branch', '-D', ROLL_BRANCH_NAME])
	logging.debug('Deleted the local roll branch (%s)', ROLL_BRANCH_NAME)


	def _GetBranches(self):
	"""Returns a tuple of active,branches.

	The 'active' is the name of the currently active branch and 'branches' is a
	list of all branches.
	"""
	lines = self._RunCommand(['git', 'branch']).split('\n')
	branches = []
	active = ''
	for l in lines:
	if '*' in l:
	# The assumption is that the first char will always be the '*'.
	active = l[1:].strip()
	branches.append(active)
	else:
	b = l.strip()
	if b:
	branches.append(b)
	return (active, branches)

	def Abort(self):
	active_branch, branches = self._GetBranches()
	if active_branch == ROLL_BRANCH_NAME:
	active_branch = 'master'
	if ROLL_BRANCH_NAME in branches:
	print 'Aborting pending roll.'
	self._RunCommand(['git', 'checkout', ROLL_BRANCH_NAME])
	# Ignore an error here in case an issue wasn't created for some reason.
	self._RunCommand(['git', 'cl', 'set_close'], ignore_exit_code=True)
	self._RunCommand(['git', 'checkout', active_branch])
	self._RunCommand(['git', 'branch', '-D', ROLL_BRANCH_NAME])
	return 0


	def main():
	parser = argparse.ArgumentParser(
	description='Auto-generates a CL containing a WebGL conformance roll.')
	parser.add_argument('--abort',
	help=('Aborts a previously prepared roll. '
	'Closes any associated issues and deletes the roll branches'),
	action='store_true')
	parser.add_argument('--ignore-checks', action='store_true', default=False,
	help=('Skips checks for being on the master branch, dirty workspaces and '
	'the updating of the checkout. Will still delete and create local '
	'Git branches.'))
	parser.add_argument('--run-tryjobs', action='store_true', default=False,
	help=('Start the dry-run tryjobs for the newly generated CL. Use this '
	'when you have no need to make changes to the WebGL conformance '
	'test expectations in the same CL and want to avoid.'))
	parser.add_argument('-v', '--verbose', action='store_true', default=False,
	help='Be extra verbose in printing of log messages.')
	args = parser.parse_args()

	if args.verbose:
	logging.basicConfig(level=logging.DEBUG)
	else:
	logging.basicConfig(level=logging.ERROR)

	autoroller = AutoRoller(SRC_DIR)
	if args.abort:
	return autoroller.Abort()
	else:
	return autoroller.PrepareRoll(args.ignore_checks, args.run_tryjobs)

	if __name__ == '__main__':
	sys.exit(main())