[depot_tools] New "git cl upload" flag to traverse dependent branches and re-upload them

git_cl.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld."""
 
 from distutils.version import LooseVersion
 from multiprocessing.pool import ThreadPool
 import base64
+import collections
 import glob
 import httplib
 import json
 import logging
 import optparse
 import os
 import Queue
 import re
 import stat
 import sys
@@ skipping 1486 matching lines @@
               else len(branches_to_fetch))
       for x in pool.imap_unordered(fetch, branches_to_fetch):
         yield x
   else:
     # Do not use GetApprovingReviewers(), since it requires an HTTP request.
     for b in branches:
       cl = Changelist(branchref=b, auth_config=auth_config)
       url = cl.GetIssueURL()
       yield (b, url, 'waiting' if url else 'error')
 
+
+def upload_branch_deps(cl, args):
+  """Uploads CLs of local branches that are dependents of the current branch.
+
+  If the local branch dependency tree looks like:
+  test1 -> test2.1 -> test3.1
+                   -> test3.2
+        -> test2.2 -> test3.3
+
+  and you run "git cl upload --dependencies" from test1 then "git cl upload" is
+  run on the dependent branches in this order:
+  test2.1, test3.1, test3.2, test2.2, test3.3
+
+  Note: This function does not rebase your local dependent branches. Use it when
+        you make a change to the parent branch that will not conflict with its
+        dependent branches, and you would like their dependencies updated in
+        Rietveld.
+  """
+  if git_common.is_dirty_git_tree('upload-branch-deps'):
+    return 1
+
+  root_branch = cl.GetBranch()
+  if root_branch is None:
+    DieWithError('Can\'t find dependent branches from detached HEAD state. '
+                 'Get on a branch!')
+  if not cl.GetIssue() or not cl.GetPatchset():
+    DieWithError('Current branch does not have an uploaded CL. We cannot set '
+                 'patchset dependencies without an uploaded CL.')
+
+  branches = RunGit(['for-each-ref',
+                     '--format=%(refname:short) %(upstream:short)',
+                     'refs/heads'])
+  if not branches:
+    print('No local branches found.')
+    return 0
+
+  # Create a dictionary of all local branches to the branches that are dependent
+  # on it.
+  tracked_to_dependents = collections.defaultdict(list)
+  for b in branches.splitlines():
+    tokens = b.split()
+    if len(tokens) == 2:
+      branch_name, tracked = tokens
+      tracked_to_dependents[tracked].append(branch_name)
+
+  print
+  print 'The dependent local branches of %s are:' % root_branch
+  dependents = []
+  def traverse_dependents_preorder(branch, padding=''):
+    dependents_to_process = tracked_to_dependents.get(branch, [])
+    padding += '  '
+    for dependent in dependents_to_process:
+      print '%s%s' % (padding, dependent)
+      dependents.append(dependent)
+      traverse_dependents_preorder(dependent, padding)
+  traverse_dependents_preorder(root_branch)
+  print
+
+  if not dependents:
+    print 'There are no dependent local branches for %s' % root_branch
+    return 0
+
+  print ('This command will checkout all dependent branches and run '
+         '"git cl upload".')
+  ask_for_data('[Press enter to continue or ctrl-C to quit]')
+
+  # Add a default patchset title to all upload calls.
+  args.extend(['-t', 'Updated patchset dependency'])
+  # Record all dependents that failed to upload.
+  failures = {}
+  # Go through all dependents, checkout the branch and upload.
+  try:
+    for dependent_branch in dependents:
+      print
+      print '--------------------------------------'
+      print 'Running "git cl upload" from %s:' % dependent_branch
+      RunGit(['checkout', '-q', dependent_branch])
+      print
+      try:
+        if CMDupload(OptionParser(), args) != 0:
+          print 'Upload failed for %s!' % dependent_branch
+          failures[dependent_branch] = 1
+      except:  # pylint: disable=W0702
+        failures[dependent_branch] = 1
+      print
+  finally:
+    # Swap back to the original root branch.
+    RunGit(['checkout', '-q', root_branch])
+
+  print
+  print 'Upload complete for dependent branches!'
+  for dependent_branch in dependents:
+    upload_status = 'failed' if failures.get(dependent_branch) else 'succeeded'
+    print '  %s : %s' % (dependent_branch, upload_status)
+  print
+
+  return 0
+
+
 def CMDstatus(parser, args):
   """Show status of changelists.
 
   Colors are used to tell the state of the CL unless --fast is used:
     - Red      not sent for review or broken
     - Blue     waiting for review
     - Yellow   waiting for you to reply to review
     - Green    LGTM'ed
     - Magenta  in the commit queue
     - Cyan     was committed, branch can be deleted
@@ skipping 661 matching lines @@
                          'Default: remote branch head, or master')
   parser.add_option('--squash', action='store_true',
                     help='Squash multiple commits into one (Gerrit only)')
   parser.add_option('--email', default=None,
                     help='email address to use to connect to Rietveld')
   parser.add_option('--tbr-owners', dest='tbr_owners', action='store_true',
                     help='add a set of OWNERS to TBR')
   parser.add_option('--cq-dry-run', dest='cq_dry_run', action='store_true',
                     help='Send the patchset to do a CQ dry run right after '
                          'upload.')
+  parser.add_option('--dependencies', action='store_true',
+                    help='Uploads CLs of all the local branches that depend on '
+                         'the current branch')
 
+  orig_args = args
   add_git_similarity(parser)
   auth.add_auth_options(parser)
   (options, args) = parser.parse_args(args)
   auth_config = auth.extract_auth_config_from_options(options)
 
   if git_common.is_dirty_git_tree('upload'):
     return 1
 
   options.reviewers = cleanup_list(options.reviewers)
   options.cc = cleanup_list(options.cc)
@@ skipping 64 matching lines @@
                          RunGit(['rev-parse', 'HEAD']).strip())
     # Run post upload hooks, if specified.
     if settings.GetRunPostUploadHook():
       presubmit_support.DoPostUploadExecuter(
           change,
           cl,
           settings.GetRoot(),
           options.verbose,
           sys.stdout)
 
+    # Upload all dependencies if specified.
+    if options.dependencies:
+      print
+      print '--dependencies has been specified.'
+      print 'All dependent local branches will be re-uploaded.'
+      print
+      # Remove the dependencies flag from args so that we do not end up in a
+      # loop.
+      orig_args.remove('--dependencies')
+      upload_branch_deps(cl, orig_args)
   return ret
 
 
 def IsSubmoduleMergeCommit(ref):
   # When submodules are added to the repo, we expect there to be a single
   # non-git-svn merge commit at remote HEAD with a signature comment.
   pattern = '^SVN changes up to revision [0-9]*$'
   cmd = ['rev-list', '--merges', '--grep=%s' % pattern, '%s^!' % ref]
   return RunGit(cmd) != ''
 
@@ skipping 1121 matching lines @@
 if __name__ == '__main__':
   # These affect sys.stdout so do it outside of main() to simplify mocks in
   # unit testing.
   fix_encoding.fix_encoding()
   colorama.init()
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)