2 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
3 # Use of this source code is governed by a BSD-style license that can be
4 # found in the LICENSE file.
6 """Update third_party/WebKit using git.
8 Under the assumption third_party/WebKit is a clone of git.webkit.org,
9 we can use git commands to make it match the version requested by DEPS.
11 See http://code.google.com/p/chromium/wiki/UsingWebKitGit for details on
25 """Run a git subcommand, returning its output."""
26 # On Windows, use shell=True to get PATH interpretation.
27 command = ['git'] + command
28 logging.info(' '.join(command))
29 shell = (os.name == 'nt')
30 proc = subprocess.Popen(command, shell=shell, stdout=subprocess.PIPE)
31 out = proc.communicate()[0].strip()
32 logging.info('Returned "%s"' % out)
36 def GetOverrideShortBranchName():
37 """Returns the user-configured override branch name, if any."""
38 override_config_name = 'chromium.sync-branch'
39 return RunGit(['config', '--get', override_config_name])
42 def GetGClientBranchName():
43 """Returns the name of the magic branch that lets us know that DEPS is
44 managing the update cycle."""
45 # Is there an override branch specified?
46 override_branch_name = GetOverrideShortBranchName()
47 if not override_branch_name:
48 return 'refs/heads/gclient' # No override, so return the default branch.
50 # Verify that the branch from config exists.
51 ref_branch = 'refs/heads/' + override_branch_name
52 current_head = RunGit(['show-ref', '--hash', ref_branch])
56 # Inform the user about the problem and how to fix it.
57 print ("The specified override branch ('%s') doesn't appear to exist." %
59 print "Please fix your git config value '%s'." % overide_config_name
64 """Extract the 'webkit_revision' variable out of DEPS."""
65 locals = {'Var': lambda _: locals["vars"][_],
66 'From': lambda *args: None}
67 execfile('DEPS', {}, locals)
68 return locals['vars']['webkit_revision']
71 def GetWebKitRevFromTarball(version):
72 """Extract the 'webkit_revision' variable out of tarball DEPS."""
73 deps_url = "http://src.chromium.org/svn/releases/" + version + "/DEPS"
74 f = urllib.urlopen(deps_url)
76 m = re.search('(?<=/Source@)\w+', s)
80 def FindSVNRev(branch_name, target_rev):
81 """Map an SVN revision to a git hash.
82 Like 'git svn find-rev' but without the git-svn bits."""
84 # We iterate through the commit log looking for "git-svn-id" lines,
85 # which contain the SVN revision of that commit. We can stop once
86 # we've found our target (or hit a revision number lower than what
87 # we're looking for, indicating not found).
89 target_rev = int(target_rev)
91 # regexp matching the "commit" line from the log.
92 commit_re = re.compile(r'^commit ([a-f\d]{40})$')
93 # regexp matching the git-svn line from the log.
94 git_svn_re = re.compile(r'^\s+git-svn-id: [^@]+@(\d+) ')
96 branch_name = 'origin/master'
97 cmd = ['git', 'log', '--no-color', '--first-parent', '--pretty=medium',
99 logging.info(' '.join(cmd))
100 log = subprocess.Popen(cmd, shell=(os.name == 'nt'), stdout=subprocess.PIPE)
101 # Track whether we saw a revision *later* than the one we're seeking.
103 for line in log.stdout:
104 match = commit_re.match(line)
106 commit = match.group(1)
108 match = git_svn_re.match(line)
110 rev = int(match.group(1))
111 if rev <= target_rev:
112 log.stdout.close() # Break pipe.
115 return None # Can't be sure whether this rev is ok.
116 print ("WARNING: r%d not found, so using next nearest earlier r%d" %
122 print "Error: reached end of log without finding commit info."
123 print "Something has likely gone horribly wrong."
128 branch = GetOverrideShortBranchName()
132 remote = RunGit(['config', '--get', 'branch.' + branch + '.remote'])
138 def UpdateGClientBranch(branch_name, webkit_rev, magic_gclient_branch):
139 """Update the magic gclient branch to point at |webkit_rev|.
141 Returns: true if the branch didn't need changes."""
142 target = FindSVNRev(branch_name, webkit_rev)
144 print "r%s not available; fetching." % webkit_rev
145 subprocess.check_call(['git', 'fetch', GetRemote()],
146 shell=(os.name == 'nt'))
147 target = FindSVNRev(branch_name, webkit_rev)
149 print "ERROR: Couldn't map r%s to a git revision." % webkit_rev
152 current = RunGit(['show-ref', '--hash', magic_gclient_branch])
153 if current == target:
154 return False # No change necessary.
156 subprocess.check_call(['git', 'update-ref', '-m', 'gclient sync',
157 magic_gclient_branch, target],
158 shell=(os.name == 'nt'))
162 def UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch):
163 """Reset the current gclient branch if that's what we have checked out."""
164 branch = RunGit(['symbolic-ref', '-q', 'HEAD'])
165 if branch != magic_gclient_branch:
166 print "We have now updated the 'gclient' branch, but third_party/WebKit"
167 print "has some other branch ('%s') checked out." % branch
168 print "Run 'git checkout gclient' under third_party/WebKit if you want"
169 print "to switch it to the version requested by DEPS."
172 if subprocess.call(['git', 'diff-index', '--exit-code', '--shortstat',
173 'HEAD'], shell=(os.name == 'nt')):
174 print "Resetting tree state to new revision."
175 subprocess.check_call(['git', 'reset', '--hard'], shell=(os.name == 'nt'))
179 parser = optparse.OptionParser()
180 parser.add_option('-v', '--verbose', action='store_true')
181 parser.add_option('-r', '--revision', help="switch to desired revision")
182 parser.add_option('-t', '--tarball', help="switch to desired tarball release")
183 parser.add_option('-b', '--branch', help="branch name that gclient generate")
184 options, args = parser.parse_args()
186 logging.basicConfig(level=logging.INFO)
187 if not os.path.exists('third_party/WebKit/.git'):
188 if os.path.exists('third_party/WebKit'):
189 print "ERROR: third_party/WebKit appears to not be under git control."
191 print "ERROR: third_party/WebKit could not be found."
192 print "Did you run this script from the right directory?"
194 print "See http://code.google.com/p/chromium/wiki/UsingWebKitGit for"
195 print "setup instructions."
199 webkit_rev = options.revision
201 print "WARNING: --revision is given, so ignore --tarball"
204 webkit_rev = GetWebKitRevFromTarball(options.tarball)
206 webkit_rev = GetWebKitRev()
208 print 'Desired revision: r%s.' % webkit_rev
209 os.chdir('third_party/WebKit')
210 magic_gclient_branch = GetGClientBranchName()
211 changed = UpdateGClientBranch(options.branch, webkit_rev,
212 magic_gclient_branch)
214 return UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch)
216 print "Already on correct revision."
220 if __name__ == '__main__':