Add a revert script.

tools/revert.py

+#!/usr/bin/python
+
+# Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import optparse
+import os
+import platform
+import subprocess
+import sys
+
+"""A script used to revert one or a sequence of consecutive CLs, for svn and
+git-svn users.
+"""
+
+def parse_args():
+  parser = optparse.OptionParser()
+  parser.add_option('--revisions', '-r', dest='rev_range', action='store',
+                    default=None, help='The revision number(s) of the commits '
+                    'you wish to undo. An individual number, or a range (8-10, '
+                    '8..10, or 8:10).')
+  args, _ = parser.parse_args()
+  revision_range = args.rev_range
+  if revision_range == None:
+    maybe_fail('You must specify at least one revision number to revert.')
+  if revision_range.find('-') > -1 or revision_range.find(':') > -1 or \
+      revision_range.find('..') > -1:
+    # We have a range of commits to revert.
+    split = revision_range.split('-')
+    if len(split) == 1:
+      split = revision_range.split(':')
+    if len(split) == 1:
+      split = revision_range.split('..')
+    start = int(split[0])
+    end = int(split[1])
+    if start > end:
+      temp = start
+      start = end
+      end = temp
+    if start != end:
+      maybe_fail('Warning: are you sure you want to revert a range of '
+                 'revisions? If you just want to revert one CL, only specify '
+                 'one revision number.', user_input=True)
+  else:
+    start = end = int(revision_range)
+  return start, end
+
+def maybe_fail(msg, user_input=False):
+  """Determine if we have encountered a condition upon which our script cannot
+  continue, and abort if so.
+  Args:
+    - msg: The error or user prompt message to print.
+    - user_input: True if we require user confirmation to continue. We assume
+                  that the user must enter y to proceed.
+  """
+  if user_input:
+    force = raw_input(msg + ' (y/N) ')
+    if force != 'y':
+      sys.exit(0)
+  else:
+    print msg
+    sys.exit(1)
+
+def has_new_code(is_git):
+  """Tests if there are any newer versions of files on the server.
+  Args:
+    - is_git: True if we are working in a git repository.
+  """
+  os.chdir(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+  if not is_git:
+    results = run_cmd(['svn', 'st'])
+  else:
+    results = run_cmd(['git', 'status'])
+  for line in results.split('\n'):
+    if not is_git and (not line.strip().startswith('?') and line != ''):
+      return True
+    elif is_git and ('Changes to be committed' in line or 
+        'Changes not staged for commit:' in line):
+      return True
+  if is_git:
+    p = subprocess.Popen(['git', 'log', '-1'], stdout=subprocess.PIPE)
+    output, _ = p.communicate()
+    if find_git_info(output) == None:
+      return True
+  return False
+
+def run_cmd(cmd_list):
+  """Run the specified command and print out any output to stdout."""
+  print ' '.join(cmd_list)
+  out = subprocess.PIPE
+  p = subprocess.Popen(cmd_list, stdout=out, stderr=subprocess.PIPE,
+                       stdin=subprocess.PIPE,
+                       shell=(platform.system()=='Windows'))
+  output, stderr = p.communicate()
+  if output:
+    print output
+  if stderr:
+    print stderr
+  return output
+
+def runs_git():
+  """Returns True if we're standing in an svn-git repository."""
+  p = subprocess.Popen(['svn', 'info'], stdout=subprocess.PIPE,
+                       stderr=subprocess.PIPE)
+  output, err = p.communicate()
+  if err != None and 'is not a working copy' in err:
+    p = subprocess.Popen(['git', 'status'], stdout=subprocess.PIPE)
+    output, _ = p.communicate()
+    if 'fatal: Not a git repository' in output:
+      maybe_fail('Error: not running git or svn.')
+    else:
+      return True
+  return False
+
+def find_git_info(git_log, rev_num=None):
+  """Determine the latest svn revision number if rev_num = None, or find the 
+  git commit_id that corresponds to a particular svn revision number.
+  """
+  for line in git_log.split('\n'):
+    tokens = line.split()
+    if len(tokens) == 2 and tokens[0] == 'commit':
+      current_commit_id = tokens[1]
+    elif len(tokens) > 0 and tokens[0] == 'git-svn-id:':
+      revision_number = int(tokens[1].split('@')[1])
+      if revision_number == rev_num:
+        return current_commit_id
+      if rev_num == None:
+        return revision_number
+
+def revert(start, end, is_git):
+  """Revert the sequence of CLs.
+  Args:
+    - start: The first CL to revert.
+    - end: The last CL to revert.
+    - is_git: True if we are in a git-svn checkout.
+  """
+  if not is_git:
+    run_cmd(['svn', 'merge', '-r', '%d:%d' % (end, start-1), '.'])
+  else:
+    # If we're running git, we have to use the log feature to find the commit
+    # id(s) that correspond to the particular revision number(s).
+    output = run_cmd(['git', 'log', '-1'])
+    current_revision = find_git_info(output)
+    distance = (current_revision-start) + 1
+    reverts = [start]
+    commit_msg = '"Reverting %d"' % start
+    if end != start:
+      reverts = range(start, end + 1)
+      reverts.reverse()
+      commit_msg = '%s-%d"' % (commit_msg[:-1], end)
+    for revert in reverts:
+      git_commit_id = find_git_info(output, revert)
+      run_cmd(['git', 'revert', '-n', git_commit_id])
+    run_cmd(['git', 'commit', '-m', commit_msg])
+
+def main():
+  revisions = parse_args()
+  git_user = runs_git()
+  if has_new_code(git_user):
+    if git_user:
+      maybe_fail('Your tree has local modifications! Move to a clean tree and '
+          'try running this script again.')
+    else:
+      maybe_fail('WARNING: This checkout has local modifications!! This could '
+           'result in a CL that is not just a revert and/or you could lose your'
+           ' local changes! Are you **SURE** you want to continue? ',
+         user_input=True)
+  if git_user:
+    run_cmd(['git', 'cl', 'rebase'])
+  run_cmd(['gclient', 'sync'])
+  revert(revisions[0], revisions[1], git_user)
+  print ('Reverting success! The buildbots and your teammates thank you! Now '

[Siggi Cherem (dart-lang), 2012/05/08 17:48:23]

:) nice message.

One suggestion, maybe reword the 'reverting success', it leads me to think that
this script also submitted it (if I'm lazy and decide not to read the full
sentence, believe me, people do)

+         'create a CL, and submit!')
+
+if __name__ == '__main__':
+  main()