#!/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.
"""
import re
import optparse
import os
import subprocess
import sys
_GIT_SVN_ID_REGEX = re.compile(r'.*git-svn-id:\s*([^@]*)@([0-9]+)', re.DOTALL)
class VersionInfo(object):
def __init__(self, url, revision):
self.url = url
self.revision = revision
def FetchSVNRevision(directory, svn_url_regex):
"""
Fetch the Subversion branch and revision for a given directory.
Errors are swallowed.
Returns:
A VersionInfo object or None on error.
"""
try:
proc = subprocess.Popen(['svn', 'info'],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
cwd=directory,
shell=(sys.platform=='win32'))
except OSError:
# command is apparently either not installed or not executable.
return None
if not proc:
return None
attrs = {}
for line in proc.stdout:
line = line.strip()
if not line:
continue
key, val = line.split(': ', 1)
attrs[key] = val
try:
match = svn_url_regex.search(attrs['URL'])
if match:
url = match.group(2)
else:
url = ''
revision = attrs['Revision']
except KeyError:
return None
return VersionInfo(url, revision)
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:
return None
def FetchGitRevision(directory):
"""
Fetch the Git hash for a given directory.
Errors are swallowed.
Returns:
A VersionInfo object or None on error.
"""
proc = RunGitCommand(directory, ['rev-parse', 'HEAD'])
if proc:
output = proc.communicate()[0].strip()
if proc.returncode == 0 and output:
return VersionInfo('git', output[:7])
return None
def FetchGitSVNURLAndRevision(directory, svn_url_regex):
"""
Fetch the Subversion URL and revision through Git.
Errors are swallowed.
Returns:
A tuple containing the Subversion URL and revision.
"""
proc = RunGitCommand(directory, ['log', '-1',
'--grep=git-svn-id', '--format=%b'])
if proc:
output = proc.communicate()[0].strip()
if proc.returncode == 0 and output:
# Extract the latest SVN revision and the SVN URL.
# The target line is the last "git-svn-id: ..." line like this:
# git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85528 0039d316....
match = _GIT_SVN_ID_REGEX.search(output)
if match:
revision = match.group(2)
url_match = svn_url_regex.search(match.group(1))
if url_match:
url = url_match.group(2)
else:
url = ''
return url, revision
return None, None
def FetchGitSVNRevision(directory, svn_url_regex):
"""
Fetch the Git-SVN identifier for the local tree.
Errors are swallowed.
"""
url, revision = FetchGitSVNURLAndRevision(directory, svn_url_regex)
if url and revision:
return VersionInfo(url, revision)
return None
def FetchVersionInfo(default_lastchange, directory=None,
directory_regex_prior_to_src_url='chrome|blink|svn'):
"""
Returns the last change (in the form of a branch, revision tuple),
from some appropriate revision control system.
"""
svn_url_regex = re.compile(
r'.*/(' + directory_regex_prior_to_src_url + r')(/.*)')
version_info = (FetchSVNRevision(directory, svn_url_regex) or
FetchGitSVNRevision(directory, svn_url_regex) or
FetchGitRevision(directory))
if not version_info:
if default_lastchange and os.path.exists(default_lastchange):
revision = open(default_lastchange, 'r').read().strip()
version_info = VersionInfo(None, revision)
else:
version_info = VersionInfo(None, None)
return version_info
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. Note that the #define is specified as a string, even though it's
currently always a SVN revision number, in case we need to move to git hashes.
"""
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 WriteIfChanged(file_name, contents):
"""
Writes the specified contents to the specified file_name
iff the contents are different than the current contents.
"""
try:
old_contents = open(file_name, 'r').read()
except EnvironmentError:
pass
else:
if contents == old_contents:
return
os.unlink(file_name)
open(file_name, 'w').write(contents)
def main(argv=None):
if argv is None:
argv = sys.argv
parser = optparse.OptionParser(usage="lastchange.py [options]")
parser.add_option("-d", "--default-lastchange", metavar="FILE",
help="Default last change input FILE.")
parser.add_option("-m", "--version-macro",
help="Name of C #define when using --header. Defaults to " +
"LAST_CHANGE.",
default="LAST_CHANGE")
parser.add_option("-o", "--output", metavar="FILE",
help="Write last change to FILE. " +
"Can be combined with --header to write both files.")
parser.add_option("", "--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_option("--revision-only", action='store_true',
help="Just print the SVN revision number. Overrides any " +
"file-output-related options.")
parser.add_option("-s", "--source-dir", metavar="DIR",
help="Use repository in the given directory.")
opts, args = parser.parse_args(argv[1:])
out_file = opts.output
header = opts.header
while len(args) and out_file is None:
if out_file is None:
out_file = args.pop(0)
if args:
sys.stderr.write('Unexpected arguments: %r\n\n' % args)
parser.print_help()
sys.exit(2)
if opts.source_dir:
src_dir = opts.source_dir
else:
src_dir = os.path.dirname(os.path.abspath(__file__))
version_info = FetchVersionInfo(opts.default_lastchange, src_dir)
if version_info.revision == None:
version_info.revision = '0'
if opts.revision_only:
print version_info.revision
else:
contents = "LASTCHANGE=%s\n" % version_info.revision
if not out_file and not opts.header:
sys.stdout.write(contents)
else:
if out_file:
WriteIfChanged(out_file, contents)
if header:
WriteIfChanged(header,
GetHeaderContents(header, opts.version_macro,
version_info.revision))
return 0
if __name__ == '__main__':
sys.exit(main())