1 #!/usr/bin/env python 2 3 # Copyright 2016 The Shaderc Authors. All rights reserved. 4 # 5 # Licensed under the Apache License, Version 2.0 (the "License"); 6 # you may not use this file except in compliance with the License. 7 # You may obtain a copy of the License at 8 # 9 # http://www.apache.org/licenses/LICENSE-2.0 10 # 11 # Unless required by applicable law or agreed to in writing, software 12 # distributed under the License is distributed on an "AS IS" BASIS, 13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 # See the License for the specific language governing permissions and 15 # limitations under the License. 16 17 # Updates build-version.inc in the current directory, unless the update is 18 # identical to the existing content. 19 # 20 # Args: <shaderc-dir> <spirv-tools-dir> <glslang-dir> 21 # 22 # For each directory, there will be a line in build-version.inc containing that 23 # directory's "git describe" output enclosed in double quotes and appropriately 24 # escaped. 25 26 from __future__ import print_function 27 28 import datetime 29 import os.path 30 import re 31 import subprocess 32 import sys 33 import time 34 35 OUTFILE = 'build-version.inc' 36 37 38 def command_output(cmd, directory): 39 """Runs a command in a directory and returns its standard output stream. 40 41 Captures the standard error stream. 42 43 Raises a RuntimeError if the command fails to launch or otherwise fails. 44 """ 45 p = subprocess.Popen(cmd, 46 cwd=directory, 47 stdout=subprocess.PIPE, 48 stderr=subprocess.PIPE) 49 (stdout, _) = p.communicate() 50 if p.returncode != 0: 51 raise RuntimeError('Failed to run {} in {}'.format(cmd, directory)) 52 return stdout 53 54 55 def deduce_software_version(directory): 56 """Returns a software version number parsed from the CHANGES file 57 in the given directory. 58 59 The CHANGES file describes most recent versions first. 60 """ 61 62 # Match the first well-formed version-and-date line. 63 # Allow trailing whitespace in the checked-out source code has 64 # unexpected carriage returns on a linefeed-only system such as 65 # Linux. 66 pattern = re.compile(r'^(v\d+\.\d+(-dev)?) \d\d\d\d-\d\d-\d\d\s*$') 67 changes_file = os.path.join(directory, 'CHANGES') 68 with open(changes_file) as f: 69 for line in f.readlines(): 70 match = pattern.match(line) 71 if match: 72 return match.group(1) 73 raise Exception('No version number found in {}'.format(changes_file)) 74 75 76 def describe(directory): 77 """Returns a string describing the current Git HEAD version as descriptively 78 as possible. 79 80 Runs 'git describe', or alternately 'git rev-parse HEAD', in directory. If 81 successful, returns the output; otherwise returns 'unknown hash, <date>'.""" 82 try: 83 # decode() is needed here for Python3 compatibility. In Python2, 84 # str and bytes are the same type, but not in Python3. 85 # Popen.communicate() returns a bytes instance, which needs to be 86 # decoded into text data first in Python3. And this decode() won't 87 # hurt Python2. 88 return command_output(['git', 'describe'], directory).rstrip().decode() 89 except: 90 try: 91 return command_output( 92 ['git', 'rev-parse', 'HEAD'], directory).rstrip().decode() 93 except: 94 # This is the fallback case where git gives us no information, 95 # e.g. because the source tree might not be in a git tree. 96 # In this case, usually use a timestamp. However, to ensure 97 # reproducible builds, allow the builder to override the wall 98 # clock time with enviornment variable SOURCE_DATE_EPOCH 99 # containing a (presumably) fixed timestamp. 100 timestamp = int(os.environ.get('SOURCE_DATE_EPOCH', time.time())) 101 formatted = datetime.date.fromtimestamp(timestamp).isoformat() 102 return 'unknown hash, {}'.format(formatted) 103 104 105 def get_version_string(project, directory): 106 """Returns a detailed version string for a given project with its directory, 107 which consists of software version string and git description string.""" 108 detailed_version_string_lst = [project] 109 if project != 'glslang': 110 detailed_version_string_lst.append(deduce_software_version(directory)) 111 detailed_version_string_lst.append(describe(directory).replace('"', '\\"')) 112 return ' '.join(detailed_version_string_lst) 113 114 115 def main(): 116 if len(sys.argv) != 4: 117 print('usage: {} <shaderc-dir> <spirv-tools-dir> <glslang-dir>'.format( 118 sys.argv[0])) 119 sys.exit(1) 120 121 projects = ['shaderc', 'spirv-tools', 'glslang'] 122 new_content = ''.join([ 123 '"{}\\n"\n'.format(get_version_string(p, d)) 124 for (p, d) in zip(projects, sys.argv[1:]) 125 ]) 126 127 if os.path.isfile(OUTFILE): 128 with open(OUTFILE, 'r') as f: 129 if new_content == f.read(): 130 return 131 with open(OUTFILE, 'w') as f: 132 f.write(new_content) 133 134 135 if __name__ == '__main__': 136 main() 137
