merge_from_chromium.py revision bda7cff5dd92725ba000fe95d9434f81a7af486e 
1#!/usr/bin/python
2#
3# Copyright (C) 2012 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#      http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""Merge Chromium into the Android tree."""
18
19import contextlib
20import logging
21import optparse
22import os
23import re
24import sys
25import urllib2
26
27import merge_common
28
29
30# We need to import this *after* merging from upstream to get the latest
31# version. Set it to none here to catch uses before it's imported.
32webview_licenses = None
33
34
35AUTOGEN_MESSAGE = 'This commit was generated by merge_from_chromium.py.'
36
37
38def _ReadGitFile(git_url, git_branch, sha1, path):
39  """Reads a file from a remote git project at a specific revision.
40
41  Args:
42    git_url: The URL of the git server.
43    git_branch: The branch to fetch.
44    sha1: The SHA1 at which to read.
45    path: The relative path of the file to read.
46  Returns:
47    The contents of the specified file.
48  """
49  # We fetch the branch to a temporary head so that we don't download the same
50  # commits multiple times.
51  merge_common.GetCommandStdout(['git', 'fetch', '-f', git_url,
52                                 git_branch + ':cached_upstream'])
53  return merge_common.GetCommandStdout(['git', 'show', '%s:%s' % (sha1, path)])
54
55
56def _ParseDEPS(git_url, git_branch, sha1):
57  """Parses the .DEPS.git file from Chromium and returns its contents.
58
59  Args:
60    git_url: The URL of the git server.
61    git_branch: The branch to read.
62    sha1: The SHA1 at which to read.
63  Returns:
64    A dictionary of the contents of .DEPS.git at the specified revision
65  """
66
67  class FromImpl(object):
68    """Used to implement the From syntax."""
69
70    def __init__(self, module_name):
71      self.module_name = module_name
72
73    def __str__(self):
74      return 'From("%s")' % self.module_name
75
76  class _VarImpl(object):
77    def __init__(self, custom_vars, local_scope):
78      self._custom_vars = custom_vars
79      self._local_scope = local_scope
80
81    def Lookup(self, var_name):
82      """Implements the Var syntax."""
83      if var_name in self._custom_vars:
84        return self._custom_vars[var_name]
85      elif var_name in self._local_scope.get('vars', {}):
86        return self._local_scope['vars'][var_name]
87      raise Exception('Var is not defined: %s' % var_name)
88
89  tmp_locals = {}
90  var = _VarImpl({}, tmp_locals)
91  tmp_globals = {'From': FromImpl, 'Var': var.Lookup, 'deps_os': {}}
92  deps_content = _ReadGitFile(git_url, git_branch, sha1, '.DEPS.git')
93  exec(deps_content) in tmp_globals, tmp_locals
94  return tmp_locals
95
96
97def _GetThirdPartyProjectMergeInfo(third_party_projects, deps_vars):
98  """Gets the git URL and SHA1 for each project based on .DEPS.git.
99
100  Args:
101    third_party_projects: The list of projects to consider.
102    deps_vars: The dictionary of dependencies from .DEPS.git.
103  Returns:
104    A dictionary from project to git URL and SHA1 - 'path: (url, sha1)'
105  Raises:
106    MergeError: if a project to be merged is not found in .DEPS.git.
107  """
108  deps_fallback_order = [
109      deps_vars['deps'],
110      deps_vars['deps_os']['unix'],
111      deps_vars['deps_os']['android'],
112  ]
113  result = {}
114  for path in third_party_projects:
115    for deps in deps_fallback_order:
116      url_plus_sha1 = deps.get(os.path.join('src', path))
117      if url_plus_sha1:
118        break
119    else:
120      raise merge_common.MergeError(
121          'Could not find .DEPS.git entry for project %s. This probably '
122          'means that the project list in merge_from_chromium.py needs to be '
123          'updated.' % path)
124    match = re.match('(.*?)@(.*)', url_plus_sha1)
125    url = match.group(1)
126    sha1 = match.group(2)
127    logging.debug('  Got URL %s and SHA1 %s for project %s', url, sha1, path)
128    result[path] = {'url': url, 'sha1': sha1}
129  return result
130
131
132def _MergeProjects(git_url, git_branch, svn_revision, root_sha1, unattended):
133  """Merges each required Chromium project into the Android repository.
134
135  .DEPS.git is consulted to determine which revision each project must be merged
136  at. Only a whitelist of required projects are merged.
137
138  Args:
139    git_url: The URL of the Chromium repository to merge from.
140    git_branch: The branch in the Chromium repository to merge from.
141    svn_revision: The SVN revision in the Chromium repository to merge from.
142    root_sha1: The git hash corresponding to svn_revision.
143    unattended: Run in unattended mode.
144  Raises:
145    MergeError: If incompatibly licensed code is left after pruning.
146  """
147  # The logic for this step lives here, in the Android tree, as it makes no
148  # sense for a Chromium tree to know about this merge.
149
150  if unattended:
151    branch_create_flag = '-B'
152  else:
153    branch_create_flag = '-b'
154
155  logging.debug('Parsing DEPS ...')
156  deps_vars = _ParseDEPS(git_url, git_branch, root_sha1)
157
158  merge_info = _GetThirdPartyProjectMergeInfo(merge_common.THIRD_PARTY_PROJECTS,
159                                              deps_vars)
160
161  for path in merge_info:
162    url = merge_info[path]['url']
163    sha1 = merge_info[path]['sha1']
164    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
165    merge_common.GetCommandStdout(['git', 'checkout',
166                                   branch_create_flag, 'merge-from-chromium',
167                                   '-t', 'goog/master-chromium'], cwd=dest_dir)
168    logging.debug('Fetching project %s at %s ...', path, sha1)
169    merge_common.GetCommandStdout(['git', 'fetch', url], cwd=dest_dir)
170    if merge_common.GetCommandStdout(['git', 'rev-list', '-1', 'HEAD..' + sha1],
171                                     cwd=dest_dir):
172      logging.debug('Merging project %s at %s ...', path, sha1)
173      # Merge conflicts make git merge return 1, so ignore errors
174      merge_common.GetCommandStdout(['git', 'merge', '--no-commit', sha1],
175                                    cwd=dest_dir, ignore_errors=True)
176      merge_common.CheckNoConflictsAndCommitMerge(
177          'Merge %s from %s at %s\n\n%s' % (path, url, sha1, AUTOGEN_MESSAGE),
178          cwd=dest_dir, unattended=unattended)
179    else:
180      logging.debug('No new commits to merge in project %s', path)
181
182  # Handle root repository separately.
183  merge_common.GetCommandStdout(['git', 'checkout',
184                                 branch_create_flag, 'merge-from-chromium',
185                                 '-t', 'goog/master-chromium'])
186  logging.debug('Fetching Chromium at %s ...', root_sha1)
187  merge_common.GetCommandStdout(['git', 'fetch', git_url, git_branch])
188  logging.debug('Merging Chromium at %s ...', root_sha1)
189  # Merge conflicts make git merge return 1, so ignore errors
190  merge_common.GetCommandStdout(['git', 'merge', '--no-commit', root_sha1],
191                                ignore_errors=True)
192  merge_common.CheckNoConflictsAndCommitMerge(
193      'Merge Chromium from %s branch %s at r%s (%s)\n\n%s'
194      % (git_url, git_branch, svn_revision, root_sha1, AUTOGEN_MESSAGE),
195      unattended=unattended)
196
197  logging.debug('Getting directories to exclude ...')
198
199  # We import this now that we have merged the latest version.
200  # It imports to a global in order that it can be used to generate NOTICE
201  # later. We also disable writing bytecode to keep the source tree clean.
202  sys.path.append(os.path.join(merge_common.REPOSITORY_ROOT, 'android_webview',
203                               'tools'))
204  sys.dont_write_bytecode = True
205  global webview_licenses
206  import webview_licenses
207  import known_issues
208
209  for path, exclude_list in known_issues.KNOWN_INCOMPATIBLE.iteritems():
210    logging.debug('  %s', '\n  '.join(os.path.join(path, x) for x in
211                                      exclude_list))
212    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
213    merge_common.GetCommandStdout(['git', 'rm', '-rf', '--ignore-unmatch'] +
214                                  exclude_list, cwd=dest_dir)
215    if _ModifiedFilesInIndex(dest_dir):
216      merge_common.GetCommandStdout(['git', 'commit', '-m',
217                                     'Exclude incompatible directories'],
218                                    cwd=dest_dir)
219
220  directories_left_over = webview_licenses.GetIncompatibleDirectories()
221  if directories_left_over:
222    raise merge_common.MergeError('Incompatibly licensed directories remain: ' +
223                                  '\n'.join(directories_left_over))
224
225
226def _GenerateMakefiles(svn_revision):
227  """Run gyp to generate the Android build system makefiles.
228
229  Args:
230    svn_revision: The SVN revision to mention in generated commit messages.
231  """
232  # TODO(torne): The .tmp files are generated by
233  # third_party/WebKit/Source/WebCore/WebCore.gyp/WebCore.gyp into the source
234  # tree. We should avoid this, or at least use a more specific name to avoid
235  # accidentally removing or adding other files.
236  for path in merge_common.ALL_PROJECTS:
237    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
238    merge_common.GetCommandStdout(['git', 'rm', '--ignore-unmatch',
239                                   'GypAndroid.*.mk', '*.target.*.mk',
240                                   '*.host.*.mk', '*.tmp'], cwd=dest_dir)
241
242  merge_common.GetCommandStdout(['android_webview/tools/gyp_webview'])
243
244  for path in merge_common.ALL_PROJECTS:
245    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
246    # git add doesn't have an --ignore-unmatch so we have to do this instead:
247    merge_common.GetCommandStdout(['git', 'add', '-f', 'GypAndroid.*.mk'],
248                                  ignore_errors=True, cwd=dest_dir)
249    merge_common.GetCommandStdout(['git', 'add', '-f', '*.target.*.mk'],
250                                  ignore_errors=True, cwd=dest_dir)
251    merge_common.GetCommandStdout(['git', 'add', '-f', '*.host.*.mk'],
252                                  ignore_errors=True, cwd=dest_dir)
253    merge_common.GetCommandStdout(['git', 'add', '-f', '*.tmp'],
254                                  ignore_errors=True, cwd=dest_dir)
255    # Only try to commit the makefiles if something has actually changed.
256    if _ModifiedFilesInIndex(dest_dir):
257      merge_common.GetCommandStdout(
258          ['git', 'commit', '-m',
259           'Update makefiles after merge of Chromium at r%s\n\n%s' %
260           (svn_revision, AUTOGEN_MESSAGE)], cwd=dest_dir)
261
262
263def _ModifiedFilesInIndex(cwd=merge_common.REPOSITORY_ROOT):
264  """Returns true if git's index contains any changes."""
265  status = merge_common.GetCommandStdout(['git', 'status', '--porcelain'],
266                                         cwd=cwd)
267  return re.search(r'^[MADRC]', status, flags=re.MULTILINE) is not None
268
269
270def _GenerateNoticeFile(svn_revision):
271  """Generates and commits a NOTICE file containing code licenses.
272
273  This covers all third-party code (from Android's perspective) that lives in
274  the Chromium tree.
275
276  Args:
277    svn_revision: The SVN revision for the main Chromium repository.
278  """
279  logging.debug('Regenerating NOTICE file ...')
280
281  contents = webview_licenses.GenerateNoticeFile()
282
283  with open(os.path.join(merge_common.REPOSITORY_ROOT, 'NOTICE'), 'w') as f:
284    f.write(contents)
285  merge_common.GetCommandStdout(['git', 'add', 'NOTICE'])
286  # Only try to commit the NOTICE update if the file has actually changed.
287  if _ModifiedFilesInIndex():
288    merge_common.GetCommandStdout([
289        'git', 'commit', '-m',
290        'Update NOTICE file after merge of Chromium at r%s\n\n%s'
291        % (svn_revision, AUTOGEN_MESSAGE)])
292
293
294def _GenerateLastChange(svn_revision):
295  """Write a build/util/LASTCHANGE file containing the current revision.
296
297  The revision number is compiled into the binary at build time from this file.
298
299  Args:
300    svn_revision: The SVN revision for the main Chromium repository.
301  Raises:
302    MergeError: if the svn revision could not be found in the repository.
303  """
304  logging.debug('Updating LASTCHANGE ...')
305  with open(os.path.join(merge_common.REPOSITORY_ROOT, 'build/util/LASTCHANGE'),
306            'w') as f:
307    f.write('LASTCHANGE=%s\n' % svn_revision)
308  merge_common.GetCommandStdout(['git', 'add', '-f', 'build/util/LASTCHANGE'])
309  if _ModifiedFilesInIndex():
310    merge_common.GetCommandStdout([
311        'git', 'commit', '-m',
312        'Update LASTCHANGE file after merge of Chromium at r%s\n\n%s'
313        % (svn_revision, AUTOGEN_MESSAGE)])
314
315
316def _GetSVNRevisionAndSHA1(git_url, git_branch, svn_revision):
317  logging.debug('Getting SVN revision and SHA1 ...')
318  merge_common.GetCommandStdout(['git', 'fetch', '-f', git_url,
319                                 git_branch + ':cached_upstream'])
320  if svn_revision is None:
321    # Fetch LKGR from upstream.
322    with contextlib.closing(
323        urllib2.urlopen('https://chromium-status.appspot.com/lkgr')) as lkgr:
324      svn_revision = lkgr.read()
325  output = merge_common.GetCommandStdout([
326      'git', 'log', '--grep=git-svn-id: .*@%s' % svn_revision,
327      '--format=%H', 'cached_upstream'])
328  if not output:
329    raise merge_common.MergeError('Revision %s not found in git repo.' %
330                                  svn_revision)
331  # The log grep will sometimes match reverts/reapplies of commits. We take the
332  # oldest (last) match because the first time it appears in history is
333  # overwhelmingly likely to be the correct commit.
334  sha1 = output.split()[-1]
335  return (svn_revision, sha1)
336
337
338def Snapshot(svn_revision, unattended):
339  """Takes a snapshot of the Chromium tree and merges it into Android.
340
341  Android makefiles and a top-level NOTICE file are generated and committed
342  after the merge.
343
344  Args:
345    svn_revision: The SVN revision in the Chromium repository to merge from.
346    unattended: Run in unattended mode.
347
348  Returns:
349    True if new commits were merged; False if no new commits were present.
350  """
351  git_url = 'http://chromium.googlesource.com/chromium/src.git'
352  git_branch = 'git-svn'
353  (svn_revision, root_sha1) = _GetSVNRevisionAndSHA1(git_url, git_branch,
354                                                     svn_revision)
355  if not merge_common.GetCommandStdout(['git', 'rev-list', '-1',
356                                        'HEAD..' + root_sha1]):
357    logging.info('No new commits to merge from %s branch %s at r%s (%s)',
358                 git_url, git_branch, svn_revision, root_sha1)
359    return False
360
361  logging.info('Snapshotting Chromium from %s branch %s at r%s (%s)',
362               git_url, git_branch, svn_revision, root_sha1)
363
364  # 1. Merge, accounting for excluded directories
365  _MergeProjects(git_url, git_branch, svn_revision, root_sha1, unattended)
366
367  # 2. Generate Android NOTICE file
368  _GenerateNoticeFile(svn_revision)
369
370  # 3. Generate LASTCHANGE file
371  _GenerateLastChange(svn_revision)
372
373  # 4. Generate Android makefiles
374  _GenerateMakefiles(svn_revision)
375
376  return True
377
378
379def Push():
380  """Push the finished snapshot to the Android repository."""
381  merge_common.PushToServer('merge-from-chromium', 'master-chromium',
382                            'master-chromium-merge')
383
384
385def main():
386  parser = optparse.OptionParser(usage='%prog [options]')
387  parser.epilog = ('Takes a snapshot of the Chromium tree at the specified '
388                   'Chromium SVN revision and merges it into this repository. '
389                   'Paths marked as excluded for license reasons are removed '
390                   'as part of the merge. Also generates Android makefiles and '
391                   'generates a top-level NOTICE file suitable for use in the '
392                   'Android build.')
393  parser.add_option(
394      '', '--svn_revision',
395      default=None,
396      help=('Merge to the specified chromium SVN revision, rather than using '
397            'the current LKGR.'))
398  parser.add_option(
399      '', '--push',
400      default=False, action='store_true',
401      help=('Push the result of a previous merge to the server.'))
402  parser.add_option(
403      '', '--unattended',
404      default=False, action='store_true',
405      help=('Run in unattended mode.'))
406  (options, args) = parser.parse_args()
407  if args:
408    parser.print_help()
409    return 1
410
411  if 'ANDROID_BUILD_TOP' not in os.environ:
412    print >>sys.stderr, 'You need to run the Android envsetup.sh and lunch.'
413    return 1
414
415  logging.basicConfig(format='%(message)s', level=logging.DEBUG,
416                      stream=sys.stdout)
417
418  if options.push:
419    Push()
420  else:
421    Snapshot(options.svn_revision, options.unattended)
422
423  return 0
424
425if __name__ == '__main__':
426  sys.exit(main())
427