merge_from_chromium.py revision 5568eda06be15d573395eaba779d62c09f6f96f1 
1#!/usr/bin/env 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"""
18Merge Chromium into the Android tree. See the output of --help for details.
19
20"""
21import optparse
22import os
23import re
24import sys
25
26import merge_common
27
28
29# We need to import this *after* merging from upstream to get the latest
30# version. Set it to none here to catch uses before it's imported.
31webview_licenses = None
32
33
34AUTOGEN_MESSAGE = 'This commit was generated by merge_from_chromium.py.'
35
36
37def _ReadGitFile(git_url, git_branch, sha1, path):
38  """Reads a file from a remote git project at a specific revision.
39  Args:
40    git_url: The URL of the git server.
41    git_branch: The branch to read.
42    sha1: The SHA1 at which to read.
43    path: The relative path of the file to read.
44  Returns:
45    The contents of the specified file.
46  """
47
48  # We fetch the branch to a temporary head so that we don't download the same
49  # commits multiple times.
50  merge_common.GetCommandStdout(['git', 'fetch', '-f', git_url,
51                                 git_branch + ':cached_upstream'])
52
53  args = ['git', 'show', '%s:%s' % (sha1, path)]
54  return merge_common.GetCommandStdout(args)
55
56
57def _ParseDEPS(git_url, git_branch, sha1):
58  """Parses the .DEPS.git file from Chromium and returns its contents.
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 for each project and the SHA1 at which it should be
99  merged.
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  """
106
107  deps_fallback_order = [
108      deps_vars['deps'],
109      deps_vars['deps_os']['unix'],
110      deps_vars['deps_os']['android'],
111  ]
112  result = {}
113  for path in third_party_projects:
114    for deps in deps_fallback_order:
115      url_plus_sha1 = deps.get(os.path.join('src', path))
116      if url_plus_sha1:
117        break
118    else:
119      raise RuntimeError(
120          ('Could not find .DEPS.git entry for project %s. This probably '
121           'means that the project list in merge_from_chromium.py needs to be '
122           'updated.') %
123          path)
124    match = re.match('(.*?)@(.*)', url_plus_sha1)
125    url = match.group(1)
126    sha1 = match.group(2)
127    print '  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):
133  """Merges into this repository all projects required by the specified branch
134  of Chromium, at the SVN revision. Uses a git subtree merge for each project.
135  Directories in the main Chromium repository which are not needed by Clank are
136  not merged.
137  Args:
138    git_url: The URL of the git server for the Chromium branch to merge to
139    git_branch: The branch name to merge to
140    svn_revision: The SVN revision for the main Chromium repository
141    root_sha1: The git SHA1 for the main Chromium repository
142  """
143
144  # The logic for this step lives here, in the Android tree, as it makes no
145  # sense for a Chromium tree to know about this merge.
146
147  print 'Parsing DEPS ...'
148  deps_vars = _ParseDEPS(git_url, git_branch, root_sha1)
149
150  merge_info = _GetThirdPartyProjectMergeInfo(merge_common.THIRD_PARTY_PROJECTS,
151                                              deps_vars)
152
153  for path in merge_info:
154    url = merge_info[path]['url']
155    sha1 = merge_info[path]['sha1']
156    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
157    merge_common.GetCommandStdout(['git', 'checkout',
158                                   '-b', 'merge-from-chromium',
159                                   '-t', 'goog/master-chromium'], cwd=dest_dir)
160    print 'Fetching project %s at %s ...' % (path, sha1)
161    merge_common.GetCommandStdout(['git', 'fetch', url], cwd=dest_dir)
162    if merge_common.GetCommandStdout(['git', 'rev-list', '-1', 'HEAD..' + sha1],
163                                     cwd=dest_dir):
164      print 'Merging project %s at %s ...' % (path, sha1)
165      # Merge conflicts make git merge return 1, so ignore errors
166      merge_common.GetCommandStdout(['git', 'merge', '--no-commit', sha1],
167                                    cwd=dest_dir, ignore_errors=True)
168      merge_common.CheckNoConflictsAndCommitMerge(
169          'Merge %s from %s at %s\n\n%s' % (path, url, sha1, AUTOGEN_MESSAGE),
170          cwd=dest_dir)
171    else:
172      print 'No new commits to merge in project %s' % path
173
174  # Handle root repository separately.
175  merge_common.GetCommandStdout(['git', 'checkout', '-b', 'merge-from-chromium',
176                                 '-t', 'goog/master-chromium'])
177  print 'Fetching Chromium at %s ...' % root_sha1
178  merge_common.GetCommandStdout(['git', 'fetch', git_url, git_branch])
179  print 'Merging Chromium at %s ...' % root_sha1
180  # Merge conflicts make git merge return 1, so ignore errors
181  merge_common.GetCommandStdout(['git', 'merge', '--no-commit', root_sha1],
182                                ignore_errors=True)
183  merge_common.CheckNoConflictsAndCommitMerge(
184      'Merge Chromium from %s branch %s at r%s (%s)\n\n%s'
185      % (git_url, git_branch, svn_revision, root_sha1, AUTOGEN_MESSAGE))
186
187  print 'Getting directories to exclude ...'
188
189  # We import this now that we have merged the latest version.
190  # It imports to a global in order that it can be used to generate NOTICE
191  # later. We also disable writing bytecode to keep the source tree clean.
192  sys.path.append(os.path.join(merge_common.REPOSITORY_ROOT, 'android_webview',
193                               'tools'))
194  sys.dont_write_bytecode = True
195  global webview_licenses
196  import webview_licenses
197  import known_issues
198
199  for path, exclude_list in known_issues.KNOWN_INCOMPATIBLE.iteritems():
200    print '  %s' % '\n  '.join(os.path.join(path, x) for x in exclude_list)
201    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
202    merge_common.GetCommandStdout(['git', 'rm', '-rf', '--ignore-unmatch'] +
203                                  exclude_list, cwd=dest_dir)
204    if _ModifiedFilesInIndex(dest_dir):
205      merge_common.GetCommandStdout(['git', 'commit', '-m',
206                                     'Exclude incompatible directories'],
207                                    cwd=dest_dir)
208
209  directories_left_over = webview_licenses.GetIncompatibleDirectories()
210  if directories_left_over:
211    raise RuntimeError('Incompatibly licensed directories remain: ' +
212                       '\n'.join(directories_left_over))
213  return True
214
215
216def _GenerateMakefiles(svn_revision):
217  """Run gyp to generate the makefiles required to build Chromium in the
218  Android build system.
219  """
220
221  print 'Regenerating makefiles ...'
222  # TODO(torne): The .tmp files are generated by
223  # third_party/WebKit/Source/WebCore/WebCore.gyp/WebCore.gyp into the source
224  # tree. We should avoid this, or at least use a more specific name to avoid
225  # accidentally removing or adding other files.
226  for path in merge_common.ALL_PROJECTS:
227    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
228    merge_common.GetCommandStdout(['git', 'rm', '--ignore-unmatch',
229                                   'GypAndroid.*.mk', '*.target.*.mk',
230                                   '*.host.*.mk', '*.tmp'], cwd=dest_dir)
231
232  merge_common.GetCommandStdout(['android_webview/tools/gyp_webview'])
233
234  for path in merge_common.ALL_PROJECTS:
235    dest_dir = os.path.join(merge_common.REPOSITORY_ROOT, path)
236    # git add doesn't have an --ignore-unmatch so we have to do this instead:
237    merge_common.GetCommandStdout(['git', 'add', '-f', 'GypAndroid.*.mk'],
238                                  ignore_errors=True, cwd=dest_dir)
239    merge_common.GetCommandStdout(['git', 'add', '-f', '*.target.*.mk'],
240                                  ignore_errors=True, cwd=dest_dir)
241    merge_common.GetCommandStdout(['git', 'add', '-f', '*.host.*.mk'],
242                                  ignore_errors=True, cwd=dest_dir)
243    merge_common.GetCommandStdout(['git', 'add', '-f', '*.tmp'],
244                                  ignore_errors=True, cwd=dest_dir)
245    # Only try to commit the makefiles if something has actually changed.
246    if _ModifiedFilesInIndex(dest_dir):
247      merge_common.GetCommandStdout(['git', 'commit', '-m',
248          'Update makefiles after merge of Chromium at r%s\n\n%s' %
249          (svn_revision, AUTOGEN_MESSAGE)], cwd=dest_dir)
250
251
252def _ModifiedFilesInIndex(cwd=merge_common.REPOSITORY_ROOT):
253  """Returns whether git's index includes modified files, ie 'added' changes.
254  """
255  status = merge_common.GetCommandStdout(['git', 'status', '--porcelain'],
256                                         cwd=cwd)
257  return re.search(r'^[MADRC]', status, flags=re.MULTILINE) != None
258
259
260def _GenerateNoticeFile(svn_revision):
261  """Generates a NOTICE file for all third-party code (from Android's
262  perspective) that lives in the Chromium tree and commits it to the root of
263  the repository.
264  Args:
265    svn_revision: The SVN revision for the main Chromium repository
266  """
267
268  print 'Regenerating NOTICE file ...'
269
270  contents = webview_licenses.GenerateNoticeFile()
271
272  with open(os.path.join(merge_common.REPOSITORY_ROOT, 'NOTICE'), 'w') as f:
273    f.write(contents)
274  merge_common.GetCommandStdout(['git', 'add', 'NOTICE'])
275  # Only try to commit the NOTICE update if the file has actually changed.
276  if _ModifiedFilesInIndex():
277    merge_common.GetCommandStdout([
278        'git', 'commit', '-m',
279        'Update NOTICE file after merge of Chromium at r%s\n\n%s'
280        % (svn_revision, AUTOGEN_MESSAGE)])
281
282
283def _GenerateLastChange(svn_revision):
284  """Write a build/util/LASTCHANGE file containing the current revision. This is
285  used in the Chromium build to include the version number.
286  Args:
287    svn_revision: The SVN revision for the main Chromium repository
288  """
289
290  print 'Updating LASTCHANGE ...'
291  with open(os.path.join(merge_common.REPOSITORY_ROOT, 'build/util/LASTCHANGE'),
292            'w') as f:
293    f.write("LASTCHANGE=%s\n" % svn_revision)
294  merge_common.GetCommandStdout(['git', 'add', '-f', 'build/util/LASTCHANGE'])
295  if _ModifiedFilesInIndex():
296    merge_common.GetCommandStdout([
297        'git', 'commit', '-m',
298        'Update LASTCHANGE file after merge of Chromium at r%s\n\n%s'
299        % (svn_revision, AUTOGEN_MESSAGE)])
300
301
302def _GetSVNRevisionAndSHA1(git_url, git_branch, svn_revision):
303  print 'Getting SVN revision and SHA1 ...'
304  merge_common.GetCommandStdout(['git', 'fetch', '-f', git_url,
305                                 git_branch + ':cached_upstream'])
306  if svn_revision:
307    # Sometimes, we see multiple commits with the same git SVN ID. No idea why.
308    # We take the most recent.
309    sha1 = merge_common.GetCommandStdout([
310        'git', 'log', '--grep=git-svn-id: .*@%s' % svn_revision,
311        '--format=%H', 'cached_upstream']).split()[0]
312  else:
313    # Just use the latest commit.
314    # TODO: We may be able to use a LKGR?
315    commit = merge_common.GetCommandStdout([
316        'git', 'log', '-n1', '--grep=git-svn-id:', '--format=%H%n%b',
317        'cached_upstream'])
318    sha1 = commit.split()[0]
319    svn_revision = re.search(r'^git-svn-id: .*@([0-9]+)', commit,
320                             flags=re.MULTILINE).group(1)
321  return (svn_revision, sha1)
322
323
324def _Snapshot(git_url, git_branch, svn_revision, autopush):
325  """Takes a snapshot of the specified Chromium tree at the specified SVN
326  revision and merges it into this repository. Also generates Android makefiles
327  and generates a top-level NOTICE file suitable for use in the Android build.
328  Args:
329    git_url: The URL of the git server for the Chromium branch to merge to
330    svn_revision: The SVN revision for the main Chromium repository
331  """
332
333  (svn_revision, root_sha1) = _GetSVNRevisionAndSHA1(git_url, git_branch,
334                                                     svn_revision)
335  if not merge_common.GetCommandStdout(['git', 'rev-list', '-1',
336                                        'HEAD..' + root_sha1]):
337    print ('No new commits to merge from %s branch %s at r%s (%s)' %
338        (git_url, git_branch, svn_revision, root_sha1))
339    return
340
341  print ('Snapshotting Chromium from %s branch %s at r%s (%s)' %
342         (git_url, git_branch, svn_revision, root_sha1))
343
344  # 1. Merge, accounting for excluded directories
345  _MergeProjects(git_url, git_branch, svn_revision, root_sha1)
346
347  # 2. Generate Android NOTICE file
348  _GenerateNoticeFile(svn_revision)
349
350  # 3. Generate LASTCHANGE file
351  _GenerateLastChange(svn_revision)
352
353  # 4. Generate Android makefiles
354  _GenerateMakefiles(svn_revision)
355
356  # 5. Push result to server
357  merge_common.PushToServer(autopush, 'merge-from-chromium', 'master-chromium')
358
359  return True
360
361
362def main():
363  parser = optparse.OptionParser(usage='%prog [options]')
364  parser.epilog = ('Takes a snapshot of the Chromium tree at the specified '
365                   'Chromium SVN revision and merges it into this repository. '
366                   'Paths marked as excluded for license reasons are removed '
367                   'as part of the merge. Also generates Android makefiles and '
368                   'generates a top-level NOTICE file suitable for use in the '
369                   'Android build.')
370  parser.add_option(
371      '', '--git_url',
372      default='http://git.chromium.org/chromium/src.git',
373      help=('The URL of the git server for the Chromium branch to merge. '
374            'Defaults to upstream.'))
375  parser.add_option(
376      '', '--git_branch',
377      default='git-svn',
378      help=('The name of the upstream branch to merge. Defaults to git-svn.'))
379  parser.add_option(
380      '', '--svn_revision',
381      default=None,
382      help=('Merge to the specified chromium SVN revision, rather than using '
383            'the current latest revision.'))
384  parser.add_option(
385      '', '--autopush',
386      default=False, action='store_true',
387      help=('Automatically push the result to the server without prompting if'
388            'the merge was successful.'))
389  (options, args) = parser.parse_args()
390  if args:
391    parser.print_help()
392    return 1
393
394  if 'ANDROID_BUILD_TOP' not in os.environ:
395    print >>sys.stderr, 'You need to run the Android envsetup.sh and lunch.'
396    return 1
397
398  if not _Snapshot(options.git_url, options.git_branch, options.svn_revision,
399                   options.autopush):
400    return 1
401
402  return 0
403
404if __name__ == '__main__':
405  sys.exit(main())
406