gcl.py

#!/usr/bin/python
# Copyright (c) 2006-2009 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.

"""Wrapper script around Rietveld's upload.py that groups files into
changelists."""

import getpass
import os
import random
import re
import shutil
import string
import subprocess
import sys
import tempfile
from third_party import upload
import urllib2

import breakpad

# gcl now depends on gclient.
from scm import SVN
import gclient_utils

__version__ = '1.1.3'


CODEREVIEW_SETTINGS = {
  # Ideally, we want to set |CODE_REVIEW_SERVER| to a generic server like
  # codereview.appspot.com and remove |CC_LIST| and |VIEW_VC|. In practice, we
  # need these settings so developers making changes in directories such as
  # Chromium's src/third_party/WebKit will send change lists to the correct
  # server.
  #
  # To make gcl send reviews to a different server, check in a file named
  # "codereview.settings" (see |CODEREVIEW_SETTINGS_FILE| below) to your
  # project's base directory and add the following line to codereview.settings:
  # CODE_REVIEW_SERVER: codereview.yourserver.org
  #
  # Default values.
  "CODE_REVIEW_SERVER": "codereview.chromium.org",
  "CC_LIST": "chromium-reviews@chromium.org",
  "VIEW_VC": "http://src.chromium.org/viewvc/chrome?view=rev&revision=",
}

# globals that store the root of the current repository and the directory where
# we store information about changelists.
REPOSITORY_ROOT = ""

# Filename where we store repository specific information for gcl.
CODEREVIEW_SETTINGS_FILE = "codereview.settings"

# Warning message when the change appears to be missing tests.
MISSING_TEST_MSG = "Change contains new or modified methods, but no new tests!"

# Global cache of files cached in GetCacheDir().
FILES_CACHE = {}

def CheckHomeForFile(filename):
  """Checks the users home dir for the existence of the given file.  Returns
  the path to the file if it's there, or None if it is not.
  """
  home_vars = ['HOME']
  if sys.platform in ('cygwin', 'win32'):
    home_vars.append('USERPROFILE')
  for home_var in home_vars:
    home = os.getenv(home_var)
    if home != None:
      full_path = os.path.join(home, filename)
      if os.path.exists(full_path):
        return full_path
  return None

def UnknownFiles(extra_args):
  """Runs svn status and returns unknown files.

  Any args in |extra_args| are passed to the tool to support giving alternate
  code locations.
  """
  return [item[1] for item in SVN.CaptureStatus(extra_args)
          if item[0][0] == '?']


def GetRepositoryRoot():
  """Returns the top level directory of the current repository.

  The directory is returned as an absolute path.
  """
  global REPOSITORY_ROOT
  if not REPOSITORY_ROOT:
    REPOSITORY_ROOT = SVN.GetCheckoutRoot(os.getcwd())
    if not REPOSITORY_ROOT:
      raise gclient_utils.Error("gcl run outside of repository")
  return REPOSITORY_ROOT


def GetInfoDir():
  """Returns the directory where gcl info files are stored."""
  return os.path.join(GetRepositoryRoot(), '.svn', 'gcl_info')


def GetChangesDir():
  """Returns the directory where gcl change files are stored."""
  return os.path.join(GetInfoDir(), 'changes')


def GetCacheDir():
  """Returns the directory where gcl change files are stored."""
  return os.path.join(GetInfoDir(), 'cache')


def GetCachedFile(filename, max_age=60*60*24*3, use_root=False):
  """Retrieves a file from the repository and caches it in GetCacheDir() for
  max_age seconds.

  use_root: If False, look up the arborescence for the first match, otherwise go
            directory to the root repository.

  Note: The cache will be inconsistent if the same file is retrieved with both
        use_root=True and use_root=False. Don't be stupid.
  """
  global FILES_CACHE
  if filename not in FILES_CACHE:
    # Don't try to look up twice.
    FILES_CACHE[filename] = None
    # First we check if we have a cached version.
    try:
      cached_file = os.path.join(GetCacheDir(), filename)
    except gclient_utils.Error:
      return None
    if (not os.path.exists(cached_file) or
        os.stat(cached_file).st_mtime > max_age):
      dir_info = SVN.CaptureInfo(".")
      repo_root = dir_info["Repository Root"]
      if use_root:
        url_path = repo_root
      else:
        url_path = dir_info["URL"]
      content = ""
      while True:
        # Look in the repository at the current level for the file.
        svn_path = url_path + "/" + filename
        content, rc = RunShellWithReturnCode(["svn", "cat", svn_path])
        if not rc:
          # Exit the loop if the file was found. Override content.
          break
        # Make sure to mark settings as empty if not found.
        content = ""
        if url_path == repo_root:
          # Reached the root. Abandoning search.
          break
        # Go up one level to try again.
        url_path = os.path.dirname(url_path)
      # Write a cached version even if there isn't a file, so we don't try to
      # fetch it each time.
      gclient_utils.FileWrite(cached_file, content)
    else:
      content = gclient_utils.FileRead(cached_file, 'r')
    # Keep the content cached in memory.
    FILES_CACHE[filename] = content
  return FILES_CACHE[filename]


def GetCodeReviewSetting(key):
  """Returns a value for the given key for this repository."""
  # Use '__just_initialized' as a flag to determine if the settings were
  # already initialized.
  global CODEREVIEW_SETTINGS
  if '__just_initialized' not in CODEREVIEW_SETTINGS:
    settings_file = GetCachedFile(CODEREVIEW_SETTINGS_FILE)
    if settings_file:
      for line in settings_file.splitlines():
        if not line or line.startswith("#"):
          continue
        k, v = line.split(": ", 1)
        CODEREVIEW_SETTINGS[k] = v
    CODEREVIEW_SETTINGS.setdefault('__just_initialized', None)
  return CODEREVIEW_SETTINGS.get(key, "")


def Warn(msg):
  ErrorExit(msg, exit=False)


def ErrorExit(msg, exit=True):
  """Print an error message to stderr and optionally exit."""
  print >>sys.stderr, msg
  if exit:
    sys.exit(1)


def RunShellWithReturnCode(command, print_output=False):
  """Executes a command and returns the output and the return code."""
  # Use a shell for subcommands on Windows to get a PATH search, and because svn
  # may be a batch file.
  use_shell = sys.platform.startswith("win")
  p = subprocess.Popen(command, stdout=subprocess.PIPE,
                       stderr=subprocess.STDOUT, shell=use_shell,
                       universal_newlines=True)
  if print_output:
    output_array = []
    while True:
      line = p.stdout.readline()
      if not line:
        break
      if print_output:
        print line.strip('\n')
      output_array.append(line)
    output = "".join(output_array)
  else:
    output = p.stdout.read()
  p.wait()
  p.stdout.close()
  return output, p.returncode


def RunShell(command, print_output=False):
  """Executes a command and returns the output."""
  return RunShellWithReturnCode(command, print_output)[0]


def FilterFlag(args, flag):
  """Returns True if the flag is present in args list.

  The flag is removed from args if present.
  """
  if flag in args:
    args.remove(flag)
    return True
  return False


class ChangeInfo(object):
  """Holds information about a changelist.

    name: change name.
    issue: the Rietveld issue number or 0 if it hasn't been uploaded yet.
    patchset: the Rietveld latest patchset number or 0.
    description: the description.
    files: a list of 2 tuple containing (status, filename) of changed files,
           with paths being relative to the top repository directory.
    local_root: Local root directory
  """

  _SEPARATOR = "\n-----\n"
  # The info files have the following format:
  # issue_id, patchset\n   (, patchset is optional)
  # _SEPARATOR\n
  # filepath1\n
  # filepath2\n
  # .
  # .
  # filepathn\n
  # _SEPARATOR\n
  # description

  def __init__(self, name, issue, patchset, description, files, local_root,
               needs_upload=False):
    self.name = name
    self.issue = int(issue)
    self.patchset = int(patchset)
    self.description = description
    if files is None:
      files = []
    self._files = files
    self.patch = None
    self._local_root = local_root
    self.needs_upload = needs_upload

  def NeedsUpload(self):
    return self.needs_upload

  def GetFileNames(self):
    """Returns the list of file names included in this change."""
    return [f[1] for f in self._files]

  def GetFiles(self):
    """Returns the list of files included in this change with their status."""
    return self._files

  def GetLocalRoot(self):
    """Returns the local repository checkout root directory."""
    return self._local_root

  def Exists(self):
    """Returns True if this change already exists (i.e., is not new)."""
    return (self.issue or self.description or self._files)

  def _NonDeletedFileList(self):
    """Returns a list of files in this change, not including deleted files."""
    return [f[1] for f in self.GetFiles()
            if not f[0].startswith("D")]

  def _AddedFileList(self):
    """Returns a list of files added in this change."""
    return [f[1] for f in self.GetFiles() if f[0].startswith("A")]

  def Save(self):
    """Writes the changelist information to disk."""
    if self.NeedsUpload():
      needs_upload = "dirty"
    else:
      needs_upload = "clean"
    data = ChangeInfo._SEPARATOR.join([
        "%d, %d, %s" % (self.issue, self.patchset, needs_upload),
        "\n".join([f[0] + f[1] for f in self.GetFiles()]),
        self.description])
    gclient_utils.FileWrite(GetChangelistInfoFile(self.name), data)

  def Delete(self):
    """Removes the changelist information from disk."""
    os.remove(GetChangelistInfoFile(self.name))

  def CloseIssue(self):
    """Closes the Rietveld issue for this changelist."""
    data = [("description", self.description),]
    ctype, body = upload.EncodeMultipartFormData(data, [])
    SendToRietveld("/%d/close" % self.issue, body, ctype)

  def UpdateRietveldDescription(self):
    """Sets the description for an issue on Rietveld."""
    data = [("description", self.description),]
    ctype, body = upload.EncodeMultipartFormData(data, [])
    SendToRietveld("/%d/description" % self.issue, body, ctype)

  def MissingTests(self):
    """Returns True if the change looks like it needs unit tests but has none.

    A change needs unit tests if it contains any new source files or methods.
    """
    SOURCE_SUFFIXES = [".cc", ".cpp", ".c", ".m", ".mm"]
    # Ignore third_party entirely.
    files = [f for f in self._NonDeletedFileList()
             if f.find("third_party") == -1]
    added_files = [f for f in self._AddedFileList()
                   if f.find("third_party") == -1]

    # If the change is entirely in third_party, we're done.
    if len(files) == 0:
      return False

    # Any new or modified test files?
    # A test file's name ends with "test.*" or "tests.*".
    test_files = [test for test in files
                  if os.path.splitext(test)[0].rstrip("s").endswith("test")]
    if len(test_files) > 0:
      return False

    # Any new source files?
    source_files = [item for item in added_files
                    if os.path.splitext(item)[1] in SOURCE_SUFFIXES]
    if len(source_files) > 0:
      return True

    # Do the long test, checking the files for new methods.
    return self._HasNewMethod()

  def _HasNewMethod(self):
    """Returns True if the changeset contains any new functions, or if a
    function signature has been changed.

    A function is identified by starting flush left, containing a "(" before
    the next flush-left line, and either ending with "{" before the next
    flush-left line or being followed by an unindented "{".

    Currently this returns True for new methods, new static functions, and
    methods or functions whose signatures have been changed.

    Inline methods added to header files won't be detected by this. That's
    acceptable for purposes of determining if a unit test is needed, since
    inline methods should be trivial.
    """
    # To check for methods added to source or header files, we need the diffs.
    # We'll generate them all, since there aren't likely to be many files
    # apart from source and headers; besides, we'll want them all if we're
    # uploading anyway.
    if self.patch is None:
      self.patch = GenerateDiff(self.GetFileNames())

    definition = ""
    for line in self.patch.splitlines():
      if not line.startswith("+"):
        continue
      line = line.strip("+").rstrip(" \t")
      # Skip empty lines, comments, and preprocessor directives.
      # TODO(pamg): Handle multiline comments if it turns out to be a problem.
      if line == "" or line.startswith("/") or line.startswith("#"):
        continue

      # A possible definition ending with "{" is complete, so check it.
      if definition.endswith("{"):
        if definition.find("(") != -1:
          return True
        definition = ""

      # A { or an indented line, when we're in a definition, continues it.
      if (definition != "" and
          (line == "{" or line.startswith(" ") or line.startswith("\t"))):
        definition += line

      # A flush-left line starts a new possible function definition.
      elif not line.startswith(" ") and not line.startswith("\t"):
        definition = line

    return False

  @staticmethod
  def Load(changename, local_root, fail_on_not_found, update_status):
    """Gets information about a changelist.

    Args:
      fail_on_not_found: if True, this function will quit the program if the
        changelist doesn't exist.
      update_status: if True, the svn status will be updated for all the files
        and unchanged files will be removed.

    Returns: a ChangeInfo object.
    """
    info_file = GetChangelistInfoFile(changename)
    if not os.path.exists(info_file):
      if fail_on_not_found:
        ErrorExit("Changelist " + changename + " not found.")
      return ChangeInfo(changename, 0, 0, '', None, local_root,
                        needs_upload=False)
    split_data = gclient_utils.FileRead(info_file, 'r').split(
        ChangeInfo._SEPARATOR, 2)
    if len(split_data) != 3:
      ErrorExit("Changelist file %s is corrupt" % info_file)
    items = split_data[0].split(', ')
    issue = 0
    patchset = 0
    needs_upload = False
    if items[0]:
      issue = int(items[0])
    if len(items) > 1:
      patchset = int(items[1])
    if len(items) > 2:
      needs_upload = (items[2] == "dirty")
    files = []
    for line in split_data[1].splitlines():
      status = line[:7]
      filename = line[7:]
      files.append((status, filename))
    description = split_data[2]
    save = False
    if update_status:
      for item in files:
        filename = os.path.join(local_root, item[1])
        status_result = SVN.CaptureStatus(filename)
        if not status_result or not status_result[0][0]:
          # File has been reverted.
          save = True
          files.remove(item)
          continue
        status = status_result[0][0]
        if status != item[0]:
          save = True
          files[files.index(item)] = (status, item[1])
    change_info = ChangeInfo(changename, issue, patchset, description, files,
                             local_root, needs_upload)
    if save:
      change_info.Save()
    return change_info


def GetChangelistInfoFile(changename):
  """Returns the file that stores information about a changelist."""
  if not changename or re.search(r'[^\w-]', changename):
    ErrorExit("Invalid changelist name: " + changename)
  return os.path.join(GetChangesDir(), changename)


def LoadChangelistInfoForMultiple(changenames, local_root, fail_on_not_found,
                                  update_status):
  """Loads many changes and merge their files list into one pseudo change.

  This is mainly usefull to concatenate many changes into one for a 'gcl try'.
  """
  changes = changenames.split(',')
  aggregate_change_info = ChangeInfo(changenames, 0, 0, '', None, local_root,
                                     needs_upload=False)
  for change in changes:
    aggregate_change_info._files += ChangeInfo.Load(change,
                                                    local_root,
                                                    fail_on_not_found,
                                                    update_status).GetFiles()
  return aggregate_change_info


def GetCLs():
  """Returns a list of all the changelists in this repository."""
  cls = os.listdir(GetChangesDir())
  if CODEREVIEW_SETTINGS_FILE in cls:
    cls.remove(CODEREVIEW_SETTINGS_FILE)
  return cls


def GenerateChangeName():
  """Generate a random changelist name."""
  random.seed()
  current_cl_names = GetCLs()
  while True:
    cl_name = (random.choice(string.ascii_lowercase) +
               random.choice(string.digits) +
               random.choice(string.ascii_lowercase) +
               random.choice(string.digits))
    if cl_name not in current_cl_names:
      return cl_name


def GetModifiedFiles():
  """Returns a set that maps from changelist name to (status,filename) tuples.

  Files not in a changelist have an empty changelist name.  Filenames are in
  relation to the top level directory of the current repository.  Note that
  only the current directory and subdirectories are scanned, in order to
  improve performance while still being flexible.
  """
  files = {}

  # Since the files are normalized to the root folder of the repositary, figure
  # out what we need to add to the paths.
  dir_prefix = os.getcwd()[len(GetRepositoryRoot()):].strip(os.sep)

  # Get a list of all files in changelists.
  files_in_cl = {}
  for cl in GetCLs():
    change_info = ChangeInfo.Load(cl, GetRepositoryRoot(),
                                  fail_on_not_found=True, update_status=False)
    for status, filename in change_info.GetFiles():
      files_in_cl[filename] = change_info.name

  # Get all the modified files.
  status_result = SVN.CaptureStatus(None)
  for line in status_result:
    status = line[0]
    filename = line[1]
    if status[0] == "?":
      continue
    if dir_prefix:
      filename = os.path.join(dir_prefix, filename)
    change_list_name = ""
    if filename in files_in_cl:
      change_list_name = files_in_cl[filename]
    files.setdefault(change_list_name, []).append((status, filename))

  return files


def GetFilesNotInCL():
  """Returns a list of tuples (status,filename) that aren't in any changelists.

  See docstring of GetModifiedFiles for information about path of files and
  which directories are scanned.
  """
  modified_files = GetModifiedFiles()
  if "" not in modified_files:
    return []
  return modified_files[""]


def SendToRietveld(request_path, payload=None,
                   content_type="application/octet-stream", timeout=None):
  """Send a POST/GET to Rietveld.  Returns the response body."""
  server = GetCodeReviewSetting("CODE_REVIEW_SERVER")
  def GetUserCredentials():
    """Prompts the user for a username and password."""
    email = upload.GetEmail("Email (login for uploading to %s)" % server)
    password = getpass.getpass("Password for %s: " % email)
    return email, password
  rpc_server = upload.HttpRpcServer(server,
                                    GetUserCredentials,
                                    host_override=server,
                                    save_cookies=True)
  try:
    return rpc_server.Send(request_path, payload, content_type, timeout)
  except urllib2.URLError:
    if timeout is None:
      ErrorExit("Error accessing url %s" % request_path)
    else:
      return None


def GetIssueDescription(issue):
  """Returns the issue description from Rietveld."""
  return SendToRietveld("/%d/description" % issue)


def Opened(show_unknown_files):
  """Prints a list of modified files in the current directory down."""
  files = GetModifiedFiles()
  cl_keys = files.keys()
  cl_keys.sort()
  for cl_name in cl_keys:
    if not cl_name:
      continue
    note = ""
    change_info = ChangeInfo.Load(cl_name, GetRepositoryRoot(),
                                  fail_on_not_found=True, update_status=False)
    if len(change_info.GetFiles()) != len(files[cl_name]):
      note = " (Note: this changelist contains files outside this directory)"
    print "\n--- Changelist " + cl_name + note + ":"
    for filename in files[cl_name]:
      print "".join(filename)
  if show_unknown_files:
    unknown_files = UnknownFiles([])
  if (files.get('') or (show_unknown_files and len(unknown_files))):
    print "\n--- Not in any changelist:"
    for item in files.get('', []):
      print "".join(item)
    if show_unknown_files:
      for filename in unknown_files:
        print "?      %s" % filename


def Help(argv=None):
  if argv:
    if argv[0] == 'try':
      TryChange(None, ['--help'], swallow_exception=False)
      return
    if argv[0] == 'upload':
      upload.RealMain(['upload.py', '--help'])
      return

  print (
"""GCL is a wrapper for Subversion that simplifies working with groups of files.
version """ + __version__ + """

Basic commands:
-----------------------------------------
   gcl change change_name
      Add/remove files to a changelist. Only scans the current directory and
      subdirectories.

   gcl upload change_name [-r reviewer1@gmail.com,reviewer2@gmail.com,...]
                          [--send_mail] [--no_try] [--no_presubmit]
                          [--no_watchlists]
      Uploads the changelist to the server for review.
      (You can create the file '.gcl_upload_no_try' in your home dir to
      skip the automatic tries.)

   gcl commit change_name [--no_presubmit]
      Commits the changelist to the repository.

   gcl lint change_name
      Check all the files in the changelist for possible style violations.

Advanced commands:
-----------------------------------------
   gcl delete change_name
      Deletes a changelist.

   gcl diff change_name
      Diffs all files in the changelist.

   gcl presubmit change_name
      Runs presubmit checks without uploading the changelist.

   gcl diff
      Diffs all files in the current directory and subdirectories that aren't in
      a changelist.

   gcl changes
      Lists all the the changelists and the files in them.

   gcl nothave [optional directory]
      Lists files unknown to Subversion.

   gcl opened
      Lists modified files in the current directory and subdirectories.

   gcl settings
      Print the code review settings for this directory.

   gcl status
      Lists modified and unknown files in the current directory and
      subdirectories.

   gcl try change_name
      Sends the change to the tryserver so a trybot can do a test run on your
      code. To send multiple changes as one path, use a comma-separated list
      of changenames.
      --> Use 'gcl help try' for more information!

   gcl deleteempties
      Deletes all changelists that have no files associated with them. Careful,
      you can lose your descriptions.

   gcl help [command]
      Print this help menu, or help for the given command if it exists.
""")

def GetEditor():
  editor = os.environ.get("SVN_EDITOR")
  if not editor:
    editor = os.environ.get("EDITOR")

  if not editor:
    if sys.platform.startswith("win"):
      editor = "notepad"
    else:
      editor = "vi"

  return editor


def GenerateDiff(files, root=None):
  return SVN.GenerateDiff(files, root=root)


def OptionallyDoPresubmitChecks(change_info, committing, args):
  if FilterFlag(args, "--no_presubmit") or FilterFlag(args, "--force"):
    return True
  return DoPresubmitChecks(change_info, committing, True)


def UploadCL(change_info, args):
  if not change_info.GetFiles():
    print "Nothing to upload, changelist is empty."
    return
  if not OptionallyDoPresubmitChecks(change_info, False, args):
    return
  # Might want to support GetInfoDir()/GetRepositoryRoot() like
  # CheckHomeForFile() so the skip of tries can be per tree basis instead
  # of user global.
  no_try = FilterFlag(args, "--no_try") or \
           FilterFlag(args, "--no-try") or \
           not (CheckHomeForFile(".gcl_upload_no_try") is None)
  no_watchlists = FilterFlag(args, "--no_watchlists") or \
                  FilterFlag(args, "--no-watchlists")

  # Map --send-mail to --send_mail
  if FilterFlag(args, "--send-mail"):
    args.append("--send_mail")

  # Supports --clobber for the try server.
  clobber = FilterFlag(args, "--clobber")

  # Disable try when the server is overridden.
  server_1 = re.compile(r"^-s\b.*")
  server_2 = re.compile(r"^--server\b.*")
  for arg in args:
    if server_1.match(arg) or server_2.match(arg):
      no_try = True
      break

  upload_arg = ["upload.py", "-y"]
  upload_arg.append("--server=" + GetCodeReviewSetting("CODE_REVIEW_SERVER"))
  upload_arg.extend(args)

  desc_file = ""
  if change_info.issue:  # Uploading a new patchset.
    found_message = False
    for arg in args:
      if arg.startswith("--message") or arg.startswith("-m"):
        found_message = True
        break

    if not found_message:
      upload_arg.append("--message=''")

    upload_arg.append("--issue=%d" % change_info.issue)
  else: # First time we upload.
    handle, desc_file = tempfile.mkstemp(text=True)
    os.write(handle, change_info.description)
    os.close(handle)

    # Watchlist processing -- CC people interested in this changeset
    # http://dev.chromium.org/developers/contributing-code/watchlists
    if not no_watchlists:
      import watchlists
      watchlist = watchlists.Watchlists(change_info.GetLocalRoot())
      watchers = watchlist.GetWatchersForPaths(change_info.GetFileNames())

    cc_list = GetCodeReviewSetting("CC_LIST")
    if not no_watchlists and watchers:
        # Filter out all empty elements and join by ','
        cc_list = ','.join(filter(None, [cc_list] + watchers))
    if cc_list:
      upload_arg.append("--cc=" + cc_list)
    upload_arg.append("--description_file=" + desc_file + "")
    if change_info.description:
      subject = change_info.description[:77]
      if subject.find("\r\n") != -1:
        subject = subject[:subject.find("\r\n")]
      if subject.find("\n") != -1:
        subject = subject[:subject.find("\n")]
      if len(change_info.description) > 77:
        subject = subject + "..."
      upload_arg.append("--message=" + subject)

    if GetCodeReviewSetting("PRIVATE") == "True":
      upload_arg.append("--private")

  # Change the current working directory before calling upload.py so that it
  # shows the correct base.
  previous_cwd = os.getcwd()
  os.chdir(change_info.GetLocalRoot())

  # If we have a lot of files with long paths, then we won't be able to fit
  # the command to "svn diff".  Instead, we generate the diff manually for
  # each file and concatenate them before passing it to upload.py.
  if change_info.patch is None:
    change_info.patch = GenerateDiff(change_info.GetFileNames())
  issue, patchset = upload.RealMain(upload_arg, change_info.patch)
  if issue and patchset:
    change_info.issue = int(issue)
    change_info.patchset = int(patchset)
    change_info.Save()

  if desc_file:
    os.remove(desc_file)

  # Do background work on Rietveld to lint the file so that the results are
  # ready when the issue is viewed.
  SendToRietveld("/lint/issue%s_%s" % (issue, patchset), timeout=0.5)

  # Move back before considering try, so GetCodeReviewSettings is
  # consistent.
  os.chdir(previous_cwd)

  # Once uploaded to Rietveld, send it to the try server.
  if not no_try:
    try_on_upload = GetCodeReviewSetting('TRY_ON_UPLOAD')
    if try_on_upload and try_on_upload.lower() == 'true':
      trychange_args = []
      if clobber:
        trychange_args.append('--clobber')
      TryChange(change_info, trychange_args, swallow_exception=True)



def PresubmitCL(change_info):
  """Reports what presubmit checks on the change would report."""
  if not change_info.GetFiles():
    print "Nothing to presubmit check, changelist is empty."
    return

  print "*** Presubmit checks for UPLOAD would report: ***"
  DoPresubmitChecks(change_info, False, False)

  print "\n*** Presubmit checks for COMMIT would report: ***"
  DoPresubmitChecks(change_info, True, False)


def TryChange(change_info, args, swallow_exception):
  """Create a diff file of change_info and send it to the try server."""
  try:
    import trychange
  except ImportError:
    if swallow_exception:
      return
    ErrorExit("You need to install trychange.py to use the try server.")

  trychange_args = []
  if change_info:
    trychange_args.extend(['--name', change_info.name])
    if change_info.issue:
      trychange_args.extend(["--issue", str(change_info.issue)])
    if change_info.patchset:
      trychange_args.extend(["--patchset", str(change_info.patchset)])
    trychange_args.extend(args)
    file_list = change_info.GetFileNames()
  else:
    trychange_args.extend(args)
    file_list = None
  trychange.TryChange(trychange_args,
                      file_list=file_list,
                      swallow_exception=swallow_exception,
                      prog='gcl try')


def Commit(change_info, args):
  if not change_info.GetFiles():
    print "Nothing to commit, changelist is empty."
    return
  if not OptionallyDoPresubmitChecks(change_info, True, args):
    return

  # We face a problem with svn here: Let's say change 'bleh' modifies
  # svn:ignore on dir1\. but another unrelated change 'pouet' modifies
  # dir1\foo.cc. When the user `gcl commit bleh`, foo.cc is *also committed*.
  # The only fix is to use --non-recursive but that has its issues too:
  # Let's say if dir1 is deleted, --non-recursive must *not* be used otherwise
  # you'll get "svn: Cannot non-recursively commit a directory deletion of a
  # directory with child nodes". Yay...
  commit_cmd = ["svn", "commit"]
  if change_info.issue:
    # Get the latest description from Rietveld.
    change_info.description = GetIssueDescription(change_info.issue)

  commit_message = change_info.description.replace('\r\n', '\n')
  if change_info.issue:
    commit_message += ('\nReview URL: http://%s/%d' %
                       (GetCodeReviewSetting("CODE_REVIEW_SERVER"),
                        change_info.issue))

  handle, commit_filename = tempfile.mkstemp(text=True)
  os.write(handle, commit_message)
  os.close(handle)

  handle, targets_filename = tempfile.mkstemp(text=True)
  os.write(handle, "\n".join(change_info.GetFileNames()))
  os.close(handle)

  commit_cmd += ['--file=' + commit_filename]
  commit_cmd += ['--targets=' + targets_filename]
  # Change the current working directory before calling commit.
  previous_cwd = os.getcwd()
  os.chdir(change_info.GetLocalRoot())
  output = RunShell(commit_cmd, True)
  os.remove(commit_filename)
  os.remove(targets_filename)
  if output.find("Committed revision") != -1:
    change_info.Delete()

    if change_info.issue:
      revision = re.compile(".*?\nCommitted revision (\d+)",
                            re.DOTALL).match(output).group(1)
      viewvc_url = GetCodeReviewSetting("VIEW_VC")
      change_info.description = change_info.description + '\n'
      if viewvc_url:
        change_info.description += "\nCommitted: " + viewvc_url + revision
      change_info.CloseIssue()
  os.chdir(previous_cwd)


def Change(change_info, args):
  """Creates/edits a changelist."""
  silent = FilterFlag(args, "--silent")

  # Verify the user is running the change command from a read-write checkout.
  svn_info = SVN.CaptureInfo('.')
  if not svn_info:
    ErrorExit("Current checkout is unversioned.  Please retry with a versioned "
              "directory.")

  if (len(args) == 1):
    filename = args[0]
    f = open(filename, 'rU')
    override_description = f.read()
    f.close()
  else:
    override_description = None

  if change_info.issue and not change_info.NeedsUpload():
    try:
      description = GetIssueDescription(change_info.issue)
    except urllib2.HTTPError, err:
      if err.code == 404:
        # The user deleted the issue in Rietveld, so forget the old issue id.
        description = change_info.description
        change_info.issue = 0
        change_info.Save()
      else:
        ErrorExit("Error getting the description from Rietveld: " + err)
  else:
    if override_description:
      description = override_description
    else:
      description = change_info.description

  other_files = GetFilesNotInCL()

  # Edited files (as opposed to files with only changed properties) will have
  # a letter for the first character in the status string.
  file_re = re.compile(r"^[a-z].+\Z", re.IGNORECASE)
  affected_files = [x for x in other_files if file_re.match(x[0])]
  unaffected_files = [x for x in other_files if not file_re.match(x[0])]

  separator1 = ("\n---All lines above this line become the description.\n"
                "---Repository Root: " + change_info.GetLocalRoot() + "\n"
                "---Paths in this changelist (" + change_info.name + "):\n")
  separator2 = "\n\n---Paths modified but not in any changelist:\n\n"
  text = (description + separator1 + '\n' +
          '\n'.join([f[0] + f[1] for f in change_info.GetFiles()]))

  if change_info.Exists():
    text += (separator2 +
            '\n'.join([f[0] + f[1] for f in affected_files]) + '\n')
  else:
    text += ('\n'.join([f[0] + f[1] for f in affected_files]) + '\n' +
            separator2)
  text += '\n'.join([f[0] + f[1] for f in unaffected_files]) + '\n'

  handle, filename = tempfile.mkstemp(text=True)
  os.write(handle, text)
  os.close(handle)

  if not silent:
    os.system(GetEditor() + " " + filename)

  result = gclient_utils.FileRead(filename, 'r')
  os.remove(filename)

  if not result:
    return

  split_result = result.split(separator1, 1)
  if len(split_result) != 2:
    ErrorExit("Don't modify the text starting with ---!\n\n" + result)

  # Update the CL description if it has changed.
  new_description = split_result[0]
  cl_files_text = split_result[1]
  if new_description != description or override_description:
    change_info.description = new_description
    change_info.needs_upload = True

  new_cl_files = []
  for line in cl_files_text.splitlines():
    if not len(line):
      continue
    if line.startswith("---"):
      break
    status = line[:7]
    filename = line[7:]
    new_cl_files.append((status, filename))

  if (not len(change_info._files)) and (not change_info.issue) and \
      (not len(new_description) and (not new_cl_files)):
    ErrorExit("Empty changelist not saved")

  change_info._files = new_cl_files
  change_info.Save()
  if svn_info.get('URL', '').startswith('http:'):
    Warn("WARNING: Creating CL in a read-only checkout.  You will not be "
         "able to commit it!")

  print change_info.name + " changelist saved."
  if change_info.MissingTests():
    Warn("WARNING: " + MISSING_TEST_MSG)

  # Update the Rietveld issue.
  if change_info.issue and change_info.NeedsUpload():
    change_info.UpdateRietveldDescription()
    change_info.needs_upload = False
    change_info.Save()


# Valid extensions for files we want to lint.
DEFAULT_LINT_REGEX = r"(.*\.cpp|.*\.cc|.*\.h)"
DEFAULT_LINT_IGNORE_REGEX = r"$^"

def Lint(change_info, args):
  """Runs cpplint.py on all the files in |change_info|"""
  try:
    import cpplint
  except ImportError:
    ErrorExit("You need to install cpplint.py to lint C++ files.")

  # Change the current working directory before calling lint so that it
  # shows the correct base.
  previous_cwd = os.getcwd()
  os.chdir(change_info.GetLocalRoot())

  # Process cpplints arguments if any.
  filenames = cpplint.ParseArguments(args + change_info.GetFileNames())

  white_list = GetCodeReviewSetting("LINT_REGEX")
  if not white_list:
    white_list = DEFAULT_LINT_REGEX
  white_regex = re.compile(white_list)
  black_list = GetCodeReviewSetting("LINT_IGNORE_REGEX")
  if not black_list:
    black_list = DEFAULT_LINT_IGNORE_REGEX
  black_regex = re.compile(black_list)
  for filename in filenames:
    if white_regex.match(filename):
      if black_regex.match(filename):
        print "Ignoring file %s" % filename
      else:
        cpplint.ProcessFile(filename, cpplint._cpplint_state.verbose_level)
    else:
      print "Skipping file %s" % filename

  print "Total errors found: %d\n" % cpplint._cpplint_state.error_count
  os.chdir(previous_cwd)


def DoPresubmitChecks(change_info, committing, may_prompt):
  """Imports presubmit, then calls presubmit.DoPresubmitChecks."""
  # Need to import here to avoid circular dependency.
  import presubmit_support
  root_presubmit = GetCachedFile('PRESUBMIT.py', use_root=True)
  change = presubmit_support.SvnChange(change_info.name,
                                       change_info.description,
                                       change_info.GetLocalRoot(),
                                       change_info.GetFiles(),
                                       change_info.issue,
                                       change_info.patchset)
  result = presubmit_support.DoPresubmitChecks(change=change,
                                               committing=committing,
                                               verbose=False,
                                               output_stream=sys.stdout,
                                               input_stream=sys.stdin,
                                               default_presubmit=root_presubmit,
                                               may_prompt=may_prompt)
  if not result and may_prompt:
    print "\nPresubmit errors, can't continue (use --no_presubmit to bypass)"
  return result


def Changes():
  """Print all the changelists and their files."""
  for cl in GetCLs():
    change_info = ChangeInfo.Load(cl, GetRepositoryRoot(), True, True)
    print "\n--- Changelist " + change_info.name + ":"
    for filename in change_info.GetFiles():
      print "".join(filename)


def DeleteEmptyChangeLists():
  """Delete all changelists that have no files."""
  print "\n--- Deleting:"
  for cl in GetCLs():
    change_info = ChangeInfo.Load(cl, GetRepositoryRoot(), True, True)
    if not len(change_info._files):
      print change_info.name
      change_info.Delete()


def main(argv=None):
  if argv is None:
    argv = sys.argv

  if len(argv) == 1:
    Help()
    return 0;

  try:
    # Create the directories where we store information about changelists if it
    # doesn't exist.
    if not os.path.exists(GetInfoDir()):
      os.mkdir(GetInfoDir())
    if not os.path.exists(GetChangesDir()):
      os.mkdir(GetChangesDir())
    if not os.path.exists(GetCacheDir()):
      os.mkdir(GetCacheDir())
  except gclient_utils.Error:
    # Will throw an exception if not run in a svn checkout.
    pass

  # Commands that don't require an argument.
  command = argv[1]
  if command == "opened" or command == "status":
    Opened(command == "status")
    return 0
  if command == "nothave":
    __pychecker__ = 'no-returnvalues'
    for filename in UnknownFiles(argv[2:]):
      print "?      " + "".join(filename)
    return 0
  if command == "changes":
    Changes()
    return 0
  if command == "help":
    Help(argv[2:])
    return 0
  if command == "diff" and len(argv) == 2:
    files = GetFilesNotInCL()
    print GenerateDiff([x[1] for x in files])
    return 0
  if command == "settings":
    # Force load settings
    GetCodeReviewSetting("UNKNOWN");
    del CODEREVIEW_SETTINGS['__just_initialized']
    print '\n'.join(("%s: %s" % (str(k), str(v))
                     for (k,v) in CODEREVIEW_SETTINGS.iteritems()))
    return 0
  if command == "deleteempties":
    DeleteEmptyChangeLists()
    return 0

  if command == "change":
    if len(argv) == 2:
      # Generate a random changelist name.
      changename = GenerateChangeName()
    elif argv[2] == '--force':
      changename = GenerateChangeName()
      # argv[3:] is passed to Change() as |args| later. Change() should receive
      # |args| which includes '--force'.
      argv.insert(2, changename)
    else:
      changename = argv[2]
  elif len(argv) == 2:
    ErrorExit("Need a changelist name.")
  else:
    changename = argv[2]

  # When the command is 'try' and --patchset is used, the patch to try
  # is on the Rietveld server. 'change' creates a change so it's fine if the
  # change didn't exist. All other commands require an existing change.
  fail_on_not_found = command != "try" and command != "change"
  if command == "try" and changename.find(',') != -1:
    change_info = LoadChangelistInfoForMultiple(changename, GetRepositoryRoot(),
                                                True, True)
  else:
    change_info = ChangeInfo.Load(changename, GetRepositoryRoot(),
                                  fail_on_not_found, True)

  if command == "change":
    Change(change_info, argv[3:])
  elif command == "lint":
    Lint(change_info, argv[3:])
  elif command == "upload":
    UploadCL(change_info, argv[3:])
  elif command == "presubmit":
    PresubmitCL(change_info)
  elif command in ("commit", "submit"):
    Commit(change_info, argv[3:])
  elif command == "delete":
    change_info.Delete()
  elif command == "try":
    # When the change contains no file, send the "changename" positional
    # argument to trychange.py.
    if change_info.GetFiles():
      args = argv[3:]
    else:
      change_info = None
      args = argv[2:]
    TryChange(change_info, args, swallow_exception=False)
  else:
    # Everything else that is passed into gcl we redirect to svn, after adding
    # the files. This allows commands such as 'gcl diff xxx' to work.
    if command == "diff" and not change_info.GetFileNames():
      return 0
    args =["svn", command]
    root = GetRepositoryRoot()
    args.extend([os.path.join(root, x) for x in change_info.GetFileNames()])
    RunShell(args, True)
  return 0


if __name__ == "__main__":
  sys.exit(main())