blob: 2a1ca60051023c081c1fef86ba0f012db53d69e4 [file] [log] [blame]
#!/usr/bin/env python
# Copyright (c) 2016 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Updates an output file with version info unless the new content is the same
# as the existing content.
#
# Args: <changes-file> <output-file>
#
# The output file will contain a line of text consisting of two C source syntax
# string literals separated by a comma:
# - The software version deduced from the given CHANGES file.
# - A longer string with the project name, the software version number, and
# git commit information for the CHANGES file's directory. The commit
# information is the output of "git describe" if that succeeds, or "git
# rev-parse HEAD" if that succeeds, or otherwise a message containing the
# phrase "unknown hash".
# The string contents are escaped as necessary.
import datetime
import errno
import os
import os.path
import re
import subprocess
import sys
import time
def mkdir_p(directory):
"""Make the directory, and all its ancestors as required. Any of the
directories are allowed to already exist."""
if directory == "":
# We're being asked to make the current directory.
return
try:
os.makedirs(directory)
except OSError as e:
if e.errno == errno.EEXIST and os.path.isdir(directory):
pass
else:
raise
def command_output(cmd, directory):
"""Runs a command in a directory and returns its standard output stream.
Captures the standard error stream.
Raises a RuntimeError if the command fails to launch or otherwise fails.
"""
p = subprocess.Popen(cmd,
cwd=directory,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
(stdout, _) = p.communicate()
if p.returncode != 0:
raise RuntimeError('Failed to run %s in %s' % (cmd, directory))
return stdout
def deduce_software_version(changes_file):
"""Returns a software version number parsed from the given CHANGES file.
The CHANGES file describes most recent versions first.
"""
# Match the first well-formed version-and-date line.
# Allow trailing whitespace in the checked-out source code has
# unexpected carriage returns on a linefeed-only system such as
# Linux.
pattern = re.compile(r'^(v\d+\.\d+(-dev)?) \d\d\d\d-\d\d-\d\d\s*$')
with open(changes_file, mode='r') as f:
for line in f.readlines():
match = pattern.match(line)
if match:
return match.group(1)
raise Exception('No version number found in {}'.format(changes_file))
def describe(directory):
"""Returns a string describing the current Git HEAD version as descriptively
as possible.
Runs 'git describe', or alternately 'git rev-parse HEAD', in directory. If
successful, returns the output; otherwise returns 'unknown hash, <date>'."""
try:
# decode() is needed here for Python3 compatibility. In Python2,
# str and bytes are the same type, but not in Python3.
# Popen.communicate() returns a bytes instance, which needs to be
# decoded into text data first in Python3. And this decode() won't
# hurt Python2.
return command_output(['git', 'describe'], directory).rstrip().decode()
except:
try:
return command_output(
['git', 'rev-parse', 'HEAD'], directory).rstrip().decode()
except:
# This is the fallback case where git gives us no information,
# e.g. because the source tree might not be in a git tree.
# In this case, usually use a timestamp. However, to ensure
# reproducible builds, allow the builder to override the wall
# clock time with environment variable SOURCE_DATE_EPOCH
# containing a (presumably) fixed timestamp.
timestamp = int(os.environ.get('SOURCE_DATE_EPOCH', time.time()))
formatted = datetime.datetime.utcfromtimestamp(timestamp).isoformat()
return 'unknown hash, {}'.format(formatted)
def main():
if len(sys.argv) != 3:
print('usage: {} <changes-files> <output-file>'.format(sys.argv[0]))
sys.exit(1)
output_file = sys.argv[2]
mkdir_p(os.path.dirname(output_file))
software_version = deduce_software_version(sys.argv[1])
directory = os.path.dirname(sys.argv[1])
new_content = '"{}", "SPIRV-Tools {} {}"\n'.format(
software_version, software_version,
describe(directory).replace('"', '\\"'))
if os.path.isfile(output_file):
with open(output_file, 'r') as f:
if new_content == f.read():
return
with open(output_file, 'w') as f:
f.write(new_content)
if __name__ == '__main__':
main()