Pin Chrome's shortcut to the Win10 Start menu on install and OS upgrade.
[chromium-blink-merge.git] / build / util / lastchange.py
blob3f3ee4af47117c5d00143713217a27964eb226c6
1 #!/usr/bin/env python
2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
3 # Use of this source code is governed by a BSD-style license that can be
4 # found in the LICENSE file.
6 """
7 lastchange.py -- Chromium revision fetching utility.
8 """
10 import re
11 import optparse
12 import os
13 import subprocess
14 import sys
16 _GIT_SVN_ID_REGEX = re.compile(r'.*git-svn-id:\s*([^@]*)@([0-9]+)', re.DOTALL)
18 class VersionInfo(object):
19 def __init__(self, url, revision):
20 self.url = url
21 self.revision = revision
24 def FetchSVNRevision(directory, svn_url_regex):
25 """
26 Fetch the Subversion branch and revision for a given directory.
28 Errors are swallowed.
30 Returns:
31 A VersionInfo object or None on error.
32 """
33 try:
34 proc = subprocess.Popen(['svn', 'info'],
35 stdout=subprocess.PIPE,
36 stderr=subprocess.PIPE,
37 cwd=directory,
38 shell=(sys.platform=='win32'))
39 except OSError:
40 # command is apparently either not installed or not executable.
41 return None
42 if not proc:
43 return None
45 attrs = {}
46 for line in proc.stdout:
47 line = line.strip()
48 if not line:
49 continue
50 key, val = line.split(': ', 1)
51 attrs[key] = val
53 try:
54 match = svn_url_regex.search(attrs['URL'])
55 if match:
56 url = match.group(2)
57 else:
58 url = ''
59 revision = attrs['Revision']
60 except KeyError:
61 return None
63 return VersionInfo(url, revision)
66 def RunGitCommand(directory, command):
67 """
68 Launches git subcommand.
70 Errors are swallowed.
72 Returns:
73 A process object or None.
74 """
75 command = ['git'] + command
76 # Force shell usage under cygwin. This is a workaround for
77 # mysterious loss of cwd while invoking cygwin's git.
78 # We can't just pass shell=True to Popen, as under win32 this will
79 # cause CMD to be used, while we explicitly want a cygwin shell.
80 if sys.platform == 'cygwin':
81 command = ['sh', '-c', ' '.join(command)]
82 try:
83 proc = subprocess.Popen(command,
84 stdout=subprocess.PIPE,
85 stderr=subprocess.PIPE,
86 cwd=directory,
87 shell=(sys.platform=='win32'))
88 return proc
89 except OSError:
90 return None
93 def FetchGitRevision(directory):
94 """
95 Fetch the Git hash for a given directory.
97 Errors are swallowed.
99 Returns:
100 A VersionInfo object or None on error.
102 hsh = ''
103 proc = RunGitCommand(directory, ['rev-parse', 'HEAD'])
104 if proc:
105 output = proc.communicate()[0].strip()
106 if proc.returncode == 0 and output:
107 hsh = output
108 if not hsh:
109 return None
110 pos = ''
111 proc = RunGitCommand(directory, ['cat-file', 'commit', 'HEAD'])
112 if proc:
113 output = proc.communicate()[0]
114 if proc.returncode == 0 and output:
115 for line in reversed(output.splitlines()):
116 if line.startswith('Cr-Commit-Position:'):
117 pos = line.rsplit()[-1].strip()
118 break
119 if not pos:
120 return VersionInfo('git', hsh)
121 return VersionInfo('git', '%s-%s' % (hsh, pos))
124 def FetchGitSVNURLAndRevision(directory, svn_url_regex, go_deeper):
126 Fetch the Subversion URL and revision through Git.
128 Errors are swallowed.
130 Returns:
131 A tuple containing the Subversion URL and revision.
133 git_args = ['log', '-1', '--format=%b']
134 if go_deeper:
135 git_args.append('--grep=git-svn-id')
136 proc = RunGitCommand(directory, git_args)
137 if proc:
138 output = proc.communicate()[0].strip()
139 if proc.returncode == 0 and output:
140 # Extract the latest SVN revision and the SVN URL.
141 # The target line is the last "git-svn-id: ..." line like this:
142 # git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85528 0039d316....
143 match = _GIT_SVN_ID_REGEX.search(output)
144 if match:
145 revision = match.group(2)
146 url_match = svn_url_regex.search(match.group(1))
147 if url_match:
148 url = url_match.group(2)
149 else:
150 url = ''
151 return url, revision
152 return None, None
155 def FetchGitSVNRevision(directory, svn_url_regex, go_deeper):
157 Fetch the Git-SVN identifier for the local tree.
159 Errors are swallowed.
161 url, revision = FetchGitSVNURLAndRevision(directory, svn_url_regex, go_deeper)
162 if url and revision:
163 return VersionInfo(url, revision)
164 return None
167 def FetchVersionInfo(default_lastchange, directory=None,
168 directory_regex_prior_to_src_url='chrome|blink|svn',
169 go_deeper=False):
171 Returns the last change (in the form of a branch, revision tuple),
172 from some appropriate revision control system.
174 svn_url_regex = re.compile(
175 r'.*/(' + directory_regex_prior_to_src_url + r')(/.*)')
177 version_info = (FetchSVNRevision(directory, svn_url_regex) or
178 FetchGitSVNRevision(directory, svn_url_regex, go_deeper) or
179 FetchGitRevision(directory))
180 if not version_info:
181 if default_lastchange and os.path.exists(default_lastchange):
182 revision = open(default_lastchange, 'r').read().strip()
183 version_info = VersionInfo(None, revision)
184 else:
185 version_info = VersionInfo(None, None)
186 return version_info
188 def GetHeaderGuard(path):
190 Returns the header #define guard for the given file path.
191 This treats everything after the last instance of "src/" as being a
192 relevant part of the guard. If there is no "src/", then the entire path
193 is used.
195 src_index = path.rfind('src/')
196 if src_index != -1:
197 guard = path[src_index + 4:]
198 else:
199 guard = path
200 guard = guard.upper()
201 return guard.replace('/', '_').replace('.', '_').replace('\\', '_') + '_'
203 def GetHeaderContents(path, define, version):
205 Returns what the contents of the header file should be that indicate the given
206 revision. Note that the #define is specified as a string, even though it's
207 currently always a SVN revision number, in case we need to move to git hashes.
209 header_guard = GetHeaderGuard(path)
211 header_contents = """/* Generated by lastchange.py, do not edit.*/
213 #ifndef %(header_guard)s
214 #define %(header_guard)s
216 #define %(define)s "%(version)s"
218 #endif // %(header_guard)s
220 header_contents = header_contents % { 'header_guard': header_guard,
221 'define': define,
222 'version': version }
223 return header_contents
225 def WriteIfChanged(file_name, contents):
227 Writes the specified contents to the specified file_name
228 iff the contents are different than the current contents.
230 try:
231 old_contents = open(file_name, 'r').read()
232 except EnvironmentError:
233 pass
234 else:
235 if contents == old_contents:
236 return
237 os.unlink(file_name)
238 open(file_name, 'w').write(contents)
241 def main(argv=None):
242 if argv is None:
243 argv = sys.argv
245 parser = optparse.OptionParser(usage="lastchange.py [options]")
246 parser.add_option("-d", "--default-lastchange", metavar="FILE",
247 help="Default last change input FILE.")
248 parser.add_option("-m", "--version-macro",
249 help="Name of C #define when using --header. Defaults to " +
250 "LAST_CHANGE.",
251 default="LAST_CHANGE")
252 parser.add_option("-o", "--output", metavar="FILE",
253 help="Write last change to FILE. " +
254 "Can be combined with --header to write both files.")
255 parser.add_option("", "--header", metavar="FILE",
256 help="Write last change to FILE as a C/C++ header. " +
257 "Can be combined with --output to write both files.")
258 parser.add_option("--revision-only", action='store_true',
259 help="Just print the SVN revision number. Overrides any " +
260 "file-output-related options.")
261 parser.add_option("-s", "--source-dir", metavar="DIR",
262 help="Use repository in the given directory.")
263 parser.add_option("--git-svn-go-deeper", action='store_true',
264 help="In a Git-SVN repo, dig down to the last committed " +
265 "SVN change (historic behaviour).")
266 opts, args = parser.parse_args(argv[1:])
268 out_file = opts.output
269 header = opts.header
271 while len(args) and out_file is None:
272 if out_file is None:
273 out_file = args.pop(0)
274 if args:
275 sys.stderr.write('Unexpected arguments: %r\n\n' % args)
276 parser.print_help()
277 sys.exit(2)
279 if opts.source_dir:
280 src_dir = opts.source_dir
281 else:
282 src_dir = os.path.dirname(os.path.abspath(__file__))
284 version_info = FetchVersionInfo(opts.default_lastchange,
285 directory=src_dir,
286 go_deeper=opts.git_svn_go_deeper)
288 if version_info.revision == None:
289 version_info.revision = '0'
291 if opts.revision_only:
292 print version_info.revision
293 else:
294 contents = "LASTCHANGE=%s\n" % version_info.revision
295 if not out_file and not opts.header:
296 sys.stdout.write(contents)
297 else:
298 if out_file:
299 WriteIfChanged(out_file, contents)
300 if header:
301 WriteIfChanged(header,
302 GetHeaderContents(header, opts.version_macro,
303 version_info.revision))
305 return 0
308 if __name__ == '__main__':
309 sys.exit(main())