blob: 4a99886287d8d37a71cd7345b7c3e5eb5b7ebe97 [file] [log] [blame]
#!/usr/bin/python
# Copyright (c) 2011 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.
"""Update third_party/WebKit using git.
Under the assumption third_party/WebKit is a clone of git.webkit.org,
we can use git commands to make it match the version requested by DEPS.
See http://code.google.com/p/chromium/wiki/UsingWebKitGit for details on
how to use this.
"""
import logging
import optparse
import os
import re
import subprocess
import sys
def RunGit(command):
"""Run a git subcommand, returning its output."""
# On Windows, use shell=True to get PATH interpretation.
command = ['git'] + command
logging.info(' '.join(command))
shell = (os.name == 'nt')
proc = subprocess.Popen(command, shell=shell, stdout=subprocess.PIPE)
out = proc.communicate()[0].strip()
logging.info('Returned "%s"' % out)
return out
def GetOverrideShortBranchName():
"""Returns the user-configured override branch name, if any."""
override_config_name = 'chromium.sync-branch'
return RunGit(['config', '--get', override_config_name])
def GetGClientBranchName():
"""Returns the name of the magic branch that lets us know that DEPS is
managing the update cycle."""
# Is there an override branch specified?
override_branch_name = GetOverrideShortBranchName()
if not override_branch_name:
return 'refs/heads/gclient' # No override, so return the default branch.
# Verify that the branch from config exists.
ref_branch = 'refs/heads/' + override_branch_name
current_head = RunGit(['show-ref', '--hash', ref_branch])
if current_head:
return ref_branch
# Inform the user about the problem and how to fix it.
print ("The specified override branch ('%s') doesn't appear to exist." %
override_branch_name)
print "Please fix your git config value '%s'." % overide_config_name
sys.exit(1)
def GetWebKitRev():
"""Extract the 'webkit_revision' variable out of DEPS."""
locals = {'Var': lambda _: locals["vars"][_],
'From': lambda *args: None}
execfile('DEPS', {}, locals)
return locals['vars']['webkit_revision']
def FindSVNRev(target_rev):
"""Map an SVN revision to a git hash.
Like 'git svn find-rev' but without the git-svn bits."""
# We iterate through the commit log looking for "git-svn-id" lines,
# which contain the SVN revision of that commit. We can stop once
# we've found our target (or hit a revision number lower than what
# we're looking for, indicating not found).
target_rev = int(target_rev)
# regexp matching the "commit" line from the log.
commit_re = re.compile(r'^commit ([a-f\d]{40})$')
# regexp matching the git-svn line from the log.
git_svn_re = re.compile(r'^\s+git-svn-id: [^@]+@(\d+) ')
cmd = ['git', 'log', '--no-color', '--first-parent', '--pretty=medium',
'origin/master']
logging.info(' '.join(cmd))
log = subprocess.Popen(cmd, shell=(os.name == 'nt'), stdout=subprocess.PIPE)
# Track whether we saw a revision *later* than the one we're seeking.
saw_later = False
for line in log.stdout:
match = commit_re.match(line)
if match:
commit = match.group(1)
continue
match = git_svn_re.match(line)
if match:
rev = int(match.group(1))
if rev <= target_rev:
log.stdout.close() # Break pipe.
if rev < target_rev:
if not saw_later:
return None # Can't be sure whether this rev is ok.
print ("WARNING: r%d not found, so using next nearest earlier r%d" %
(target_rev, rev))
return commit
else:
saw_later = True
print "Error: reached end of log without finding commit info."
print "Something has likely gone horribly wrong."
return None
def GetRemote():
branch = GetOverrideShortBranchName()
if not branch:
branch = 'gclient'
remote = RunGit(['config', '--get', 'branch.' + branch + '.remote'])
if remote:
return remote
return 'origin'
def UpdateGClientBranch(webkit_rev, magic_gclient_branch):
"""Update the magic gclient branch to point at |webkit_rev|.
Returns: true if the branch didn't need changes."""
target = FindSVNRev(webkit_rev)
if not target:
print "r%s not available; fetching." % webkit_rev
subprocess.check_call(['git', 'fetch', GetRemote()],
shell=(os.name == 'nt'))
target = FindSVNRev(webkit_rev)
if not target:
print "ERROR: Couldn't map r%s to a git revision." % webkit_rev
sys.exit(1)
current = RunGit(['show-ref', '--hash', magic_gclient_branch])
if current == target:
return False # No change necessary.
subprocess.check_call(['git', 'update-ref', '-m', 'gclient sync',
magic_gclient_branch, target],
shell=(os.name == 'nt'))
return True
def UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch):
"""Reset the current gclient branch if that's what we have checked out."""
branch = RunGit(['symbolic-ref', '-q', 'HEAD'])
if branch != magic_gclient_branch:
print "We have now updated the 'gclient' branch, but third_party/WebKit"
print "has some other branch ('%s') checked out." % branch
print "Run 'git checkout gclient' under third_party/WebKit if you want"
print "to switch it to the version requested by DEPS."
return 1
if subprocess.call(['git', 'diff-index', '--exit-code', '--shortstat',
'HEAD'], shell=(os.name == 'nt')):
print "Resetting tree state to new revision."
subprocess.check_call(['git', 'reset', '--hard'], shell=(os.name == 'nt'))
def main():
parser = optparse.OptionParser()
parser.add_option('-v', '--verbose', action='store_true')
options, args = parser.parse_args()
if options.verbose:
logging.basicConfig(level=logging.INFO)
if not os.path.exists('third_party/WebKit/.git'):
if os.path.exists('third_party/WebKit'):
print "ERROR: third_party/WebKit appears to not be under git control."
else:
print "ERROR: third_party/WebKit could not be found."
print "Did you run this script from the right directory?"
print "See http://code.google.com/p/chromium/wiki/UsingWebKitGit for"
print "setup instructions."
return 1
webkit_rev = GetWebKitRev()
print 'Desired revision: r%s.' % webkit_rev
os.chdir('third_party/WebKit')
magic_gclient_branch = GetGClientBranchName()
changed = UpdateGClientBranch(webkit_rev, magic_gclient_branch)
if changed:
return UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch)
else:
print "Already on correct revision."
return 0
if __name__ == '__main__':
sys.exit(main())