summaryrefslogtreecommitdiffstats
path: root/third_party/libwebrtc/build/util/lastchange.py
blob: 02a36642b1f052466bc798b476b81f16eddc97b9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
#!/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.

"""
lastchange.py -- Chromium revision fetching utility.
"""
from __future__ import print_function

import argparse
import collections
import datetime
import logging
import os
import subprocess
import sys

VersionInfo = collections.namedtuple("VersionInfo",
                                     ("revision_id", "revision", "timestamp"))

class GitError(Exception):
  pass

# This function exists for compatibility with logic outside this
# repository that uses this file as a library.
# TODO(eliribble) remove this function after it has been ported into
# the repositories that depend on it
def RunGitCommand(directory, command):
  """
  Launches git subcommand.

  Errors are swallowed.

  Returns:
    A process object or None.
  """
  command = ['git'] + command
  # Force shell usage under cygwin. This is a workaround for
  # mysterious loss of cwd while invoking cygwin's git.
  # We can't just pass shell=True to Popen, as under win32 this will
  # cause CMD to be used, while we explicitly want a cygwin shell.
  if sys.platform == 'cygwin':
    command = ['sh', '-c', ' '.join(command)]
  try:
    proc = subprocess.Popen(command,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE,
                            cwd=directory,
                            shell=(sys.platform=='win32'))
    return proc
  except OSError as e:
    logging.error('Command %r failed: %s' % (' '.join(command), e))
    return None


def _RunGitCommand(directory, command):
  """Launches git subcommand.

  Returns:
    The stripped stdout of the git command.
  Raises:
    GitError on failure, including a nonzero return code.
  """
  command = ['git'] + command
  # Force shell usage under cygwin. This is a workaround for
  # mysterious loss of cwd while invoking cygwin's git.
  # We can't just pass shell=True to Popen, as under win32 this will
  # cause CMD to be used, while we explicitly want a cygwin shell.
  if sys.platform == 'cygwin':
    command = ['sh', '-c', ' '.join(command)]
  try:
    logging.info("Executing '%s' in %s", ' '.join(command), directory)
    proc = subprocess.Popen(command,
                            stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE,
                            cwd=directory,
                            shell=(sys.platform=='win32'))
    stdout, stderr = tuple(x.decode(encoding='utf_8')
                           for x in proc.communicate())
    stdout = stdout.strip()
    logging.debug("returncode: %d", proc.returncode)
    logging.debug("stdout: %s", stdout)
    logging.debug("stderr: %s", stderr)
    if proc.returncode != 0 or not stdout:
      raise GitError((
          "Git command '{}' in {} failed: "
          "rc={}, stdout='{}' stderr='{}'").format(
          " ".join(command), directory, proc.returncode, stdout, stderr))
    return stdout
  except OSError as e:
    raise GitError("Git command 'git {}' in {} failed: {}".format(
        " ".join(command), directory, e))


def GetMergeBase(directory, ref):
  """
  Return the merge-base of HEAD and ref.

  Args:
    directory: The directory containing the .git directory.
    ref: The ref to use to find the merge base.
  Returns:
    The git commit SHA of the merge-base as a string.
  """
  logging.debug("Calculating merge base between HEAD and %s in %s",
                ref, directory)
  command = ['merge-base', 'HEAD', ref]
  return _RunGitCommand(directory, command)


def FetchGitRevision(directory, commit_filter, start_commit="HEAD"):
  """
  Fetch the Git hash (and Cr-Commit-Position if any) for a given directory.

  Args:
    directory: The directory containing the .git directory.
    commit_filter: A filter to supply to grep to filter commits
    start_commit: A commit identifier. The result of this function
      will be limited to only consider commits before the provided
      commit.
  Returns:
    A VersionInfo object. On error all values will be 0.
  """
  hash_ = ''

  git_args = ['log', '-1', '--format=%H %ct']
  if commit_filter is not None:
    git_args.append('--grep=' + commit_filter)

  git_args.append(start_commit)

  output = _RunGitCommand(directory, git_args)
  hash_, commit_timestamp = output.split()
  if not hash_:
    return VersionInfo('0', '0', 0)

  revision = hash_
  output = _RunGitCommand(directory, ['cat-file', 'commit', hash_])
  for line in reversed(output.splitlines()):
    if line.startswith('Cr-Commit-Position:'):
      pos = line.rsplit()[-1].strip()
      logging.debug("Found Cr-Commit-Position '%s'", pos)
      revision = "{}-{}".format(hash_, pos)
      break
  return VersionInfo(hash_, revision, int(commit_timestamp))


def GetHeaderGuard(path):
  """
  Returns the header #define guard for the given file path.
  This treats everything after the last instance of "src/" as being a
  relevant part of the guard. If there is no "src/", then the entire path
  is used.
  """
  src_index = path.rfind('src/')
  if src_index != -1:
    guard = path[src_index + 4:]
  else:
    guard = path
  guard = guard.upper()
  return guard.replace('/', '_').replace('.', '_').replace('\\', '_') + '_'


def GetHeaderContents(path, define, version):
  """
  Returns what the contents of the header file should be that indicate the given
  revision.
  """
  header_guard = GetHeaderGuard(path)

  header_contents = """/* Generated by lastchange.py, do not edit.*/

#ifndef %(header_guard)s
#define %(header_guard)s

#define %(define)s "%(version)s"

#endif  // %(header_guard)s
"""
  header_contents = header_contents % { 'header_guard': header_guard,
                                        'define': define,
                                        'version': version }
  return header_contents


def GetGitTopDirectory(source_dir):
  """Get the top git directory - the directory that contains the .git directory.

  Args:
    source_dir: The directory to search.
  Returns:
    The output of "git rev-parse --show-toplevel" as a string
  """
  return _RunGitCommand(source_dir, ['rev-parse', '--show-toplevel'])


def WriteIfChanged(file_name, contents):
  """
  Writes the specified contents to the specified file_name
  iff the contents are different than the current contents.
  Returns if new data was written.
  """
  try:
    old_contents = open(file_name, 'r').read()
  except EnvironmentError:
    pass
  else:
    if contents == old_contents:
      return False
    os.unlink(file_name)
  open(file_name, 'w').write(contents)
  return True


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

  parser = argparse.ArgumentParser(usage="lastchange.py [options]")
  parser.add_argument("-m", "--version-macro",
                    help=("Name of C #define when using --header. Defaults to "
                          "LAST_CHANGE."))
  parser.add_argument("-o", "--output", metavar="FILE",
                    help=("Write last change to FILE. "
                          "Can be combined with --header to write both files."))
  parser.add_argument("--header", metavar="FILE",
                    help=("Write last change to FILE as a C/C++ header. "
                          "Can be combined with --output to write both files."))
  parser.add_argument("--merge-base-ref",
                    default=None,
                    help=("Only consider changes since the merge "
                          "base between HEAD and the provided ref"))
  parser.add_argument("--revision-id-only", action='store_true',
                    help=("Output the revision as a VCS revision ID only (in "
                          "Git, a 40-character commit hash, excluding the "
                          "Cr-Commit-Position)."))
  parser.add_argument("--revision-id-prefix",
                      metavar="PREFIX",
                      help=("Adds a string prefix to the VCS revision ID."))
  parser.add_argument("--print-only", action="store_true",
                    help=("Just print the revision string. Overrides any "
                          "file-output-related options."))
  parser.add_argument("-s", "--source-dir", metavar="DIR",
                    help="Use repository in the given directory.")
  parser.add_argument("--filter", metavar="REGEX",
                    help=("Only use log entries where the commit message "
                          "matches the supplied filter regex. Defaults to "
                          "'^Change-Id:' to suppress local commits."),
                    default='^Change-Id:')

  args, extras = parser.parse_known_args(argv[1:])

  logging.basicConfig(level=logging.WARNING)

  out_file = args.output
  header = args.header
  commit_filter=args.filter

  while len(extras) and out_file is None:
    if out_file is None:
      out_file = extras.pop(0)
  if extras:
    sys.stderr.write('Unexpected arguments: %r\n\n' % extras)
    parser.print_help()
    sys.exit(2)

  source_dir = args.source_dir or os.path.dirname(os.path.abspath(__file__))
  try:
    git_top_dir = GetGitTopDirectory(source_dir)
  except GitError as e:
    logging.error("Failed to get git top directory from '%s': %s",
                  source_dir, e)
    return 2

  if args.merge_base_ref:
    try:
      merge_base_sha = GetMergeBase(git_top_dir, args.merge_base_ref)
    except GitError as e:
      logging.error("You requested a --merge-base-ref value of '%s' but no "
                    "merge base could be found between it and HEAD. Git "
                    "reports: %s", args.merge_base_ref, e)
      return 3
  else:
    merge_base_sha = 'HEAD'

  try:
    version_info = FetchGitRevision(git_top_dir, commit_filter, merge_base_sha)
  except GitError as e:
    logging.error("Failed to get version info: %s", e)
    logging.info(("Falling back to a version of 0.0.0 to allow script to "
        "finish. This is normal if you are bootstrapping a new environment "
        "or do not have a git repository for any other reason. If not, this "
        "could represent a serious error."))
    version_info = VersionInfo('0', '0', 0)

  revision_string = version_info.revision
  if args.revision_id_only:
    revision_string = version_info.revision_id

  if args.revision_id_prefix:
    revision_string = args.revision_id_prefix + revision_string

  if args.print_only:
    print(revision_string)
  else:
    lastchange_year = datetime.datetime.utcfromtimestamp(
        version_info.timestamp).year
    contents_lines = [
        "LASTCHANGE=%s" % revision_string,
        "LASTCHANGE_YEAR=%s" % lastchange_year,
    ]
    contents = '\n'.join(contents_lines) + '\n'
    if not out_file and not args.header:
      sys.stdout.write(contents)
    else:
      if out_file:
        committime_file = out_file + '.committime'
        out_changed = WriteIfChanged(out_file, contents)
        if out_changed or not os.path.exists(committime_file):
          with open(committime_file, 'w') as timefile:
            timefile.write(str(version_info.timestamp))
      if header:
        WriteIfChanged(header,
                       GetHeaderContents(header, args.version_macro,
                                         revision_string))

  return 0


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