Ben Clayton | fbe9a23 | 2020-06-17 11:17:19 +0100 | [diff] [blame^] | 1 | #!/usr/bin/env python |
| 2 | |
| 3 | # Copyright (c) 2020 Google Inc. |
| 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 | import datetime |
| 18 | import errno |
| 19 | import os |
| 20 | import os.path |
| 21 | import re |
| 22 | import subprocess |
| 23 | import sys |
| 24 | import time |
| 25 | |
| 26 | usage = """{} emits a string to stdout or file with project version information. |
| 27 | |
| 28 | args: <project-dir> [<input-string>] [-i <input-file>] [-o <output-file>] |
| 29 | |
| 30 | Either <input-string> or -i <input-file> needs to be provided. |
| 31 | |
| 32 | The tool will output the provided string or file content with the following |
| 33 | tokens substituted: |
| 34 | |
| 35 | <major> - The major version point parsed from the CHANGES.md file. |
| 36 | <minor> - The minor version point parsed from the CHANGES.md file. |
| 37 | <patch> - The point version point parsed from the CHANGES.md file. |
| 38 | <flavor> - The optional dash suffix parsed from the CHANGES.md file (excluding |
| 39 | dash prefix). |
| 40 | <-flavor> - The optional dash suffix parsed from the CHANGES.md file (including |
| 41 | dash prefix). |
| 42 | <date> - The optional date of the release in the form YYYY-MM-DD |
| 43 | <commit> - The git commit information for the directory taken from |
| 44 | "git describe" if that succeeds, or "git rev-parse HEAD" |
| 45 | if that succeeds, or otherwise a message containing the phrase |
| 46 | "unknown hash". |
| 47 | |
| 48 | -o is an optional flag for writing the output string to the given file. If |
| 49 | ommitted then the string is printed to stdout. |
| 50 | """ |
| 51 | |
| 52 | def mkdir_p(directory): |
| 53 | """Make the directory, and all its ancestors as required. Any of the |
| 54 | directories are allowed to already exist.""" |
| 55 | |
| 56 | if directory == "": |
| 57 | # We're being asked to make the current directory. |
| 58 | return |
| 59 | |
| 60 | try: |
| 61 | os.makedirs(directory) |
| 62 | except OSError as e: |
| 63 | if e.errno == errno.EEXIST and os.path.isdir(directory): |
| 64 | pass |
| 65 | else: |
| 66 | raise |
| 67 | |
| 68 | |
| 69 | def command_output(cmd, directory): |
| 70 | """Runs a command in a directory and returns its standard output stream. |
| 71 | |
| 72 | Captures the standard error stream. |
| 73 | |
| 74 | Raises a RuntimeError if the command fails to launch or otherwise fails. |
| 75 | """ |
| 76 | p = subprocess.Popen(cmd, |
| 77 | cwd=directory, |
| 78 | stdout=subprocess.PIPE, |
| 79 | stderr=subprocess.PIPE) |
| 80 | (stdout, _) = p.communicate() |
| 81 | if p.returncode != 0: |
| 82 | raise RuntimeError('Failed to run %s in %s' % (cmd, directory)) |
| 83 | return stdout |
| 84 | |
| 85 | |
| 86 | def deduce_software_version(directory): |
| 87 | """Returns a software version number parsed from the CHANGES.md file |
| 88 | in the given directory. |
| 89 | |
| 90 | The CHANGES.md file describes most recent versions first. |
| 91 | """ |
| 92 | |
| 93 | # Match the first well-formed version-and-date line. |
| 94 | # Allow trailing whitespace in the checked-out source code has |
| 95 | # unexpected carriage returns on a linefeed-only system such as |
| 96 | # Linux. |
| 97 | pattern = re.compile(r'^#* +(\d+)\.(\d+)\.(\d+)(-\w+)? (\d\d\d\d-\d\d-\d\d)? *$') |
| 98 | changes_file = os.path.join(directory, 'CHANGES.md') |
| 99 | with open(changes_file, mode='r') as f: |
| 100 | for line in f.readlines(): |
| 101 | match = pattern.match(line) |
| 102 | if match: |
| 103 | return { |
| 104 | "major": match.group(1), |
| 105 | "minor": match.group(2), |
| 106 | "patch": match.group(3), |
| 107 | "flavor": match.group(4).lstrip("-"), |
| 108 | "-flavor": match.group(4), |
| 109 | "date": match.group(5), |
| 110 | } |
| 111 | raise Exception('No version number found in {}'.format(changes_file)) |
| 112 | |
| 113 | |
| 114 | def describe(directory): |
| 115 | """Returns a string describing the current Git HEAD version as descriptively |
| 116 | as possible. |
| 117 | |
| 118 | Runs 'git describe', or alternately 'git rev-parse HEAD', in directory. If |
| 119 | successful, returns the output; otherwise returns 'unknown hash, <date>'.""" |
| 120 | try: |
| 121 | # decode() is needed here for Python3 compatibility. In Python2, |
| 122 | # str and bytes are the same type, but not in Python3. |
| 123 | # Popen.communicate() returns a bytes instance, which needs to be |
| 124 | # decoded into text data first in Python3. And this decode() won't |
| 125 | # hurt Python2. |
| 126 | return command_output(['git', 'describe'], directory).rstrip().decode() |
| 127 | except: |
| 128 | try: |
| 129 | return command_output( |
| 130 | ['git', 'rev-parse', 'HEAD'], directory).rstrip().decode() |
| 131 | except: |
| 132 | # This is the fallback case where git gives us no information, |
| 133 | # e.g. because the source tree might not be in a git tree. |
| 134 | # In this case, usually use a timestamp. However, to ensure |
| 135 | # reproducible builds, allow the builder to override the wall |
| 136 | # clock time with environment variable SOURCE_DATE_EPOCH |
| 137 | # containing a (presumably) fixed timestamp. |
| 138 | timestamp = int(os.environ.get('SOURCE_DATE_EPOCH', time.time())) |
| 139 | formatted = datetime.datetime.utcfromtimestamp(timestamp).isoformat() |
| 140 | return 'unknown hash, {}'.format(formatted) |
| 141 | |
| 142 | def parse_args(): |
| 143 | directory = None |
| 144 | input_string = None |
| 145 | input_file = None |
| 146 | output_file = None |
| 147 | |
| 148 | if len(sys.argv) < 2: |
| 149 | raise Exception("Invalid number of arguments") |
| 150 | |
| 151 | directory = sys.argv[1] |
| 152 | i = 2 |
| 153 | |
| 154 | if not sys.argv[i].startswith("-"): |
| 155 | input_string = sys.argv[i] |
| 156 | i = i + 1 |
| 157 | |
| 158 | while i < len(sys.argv): |
| 159 | opt = sys.argv[i] |
| 160 | i = i + 1 |
| 161 | |
| 162 | if opt == "-i" or opt == "-o": |
| 163 | if i == len(sys.argv): |
| 164 | raise Exception("Expected path after {}".format(opt)) |
| 165 | val = sys.argv[i] |
| 166 | i = i + 1 |
| 167 | if (opt == "-i"): |
| 168 | input_file = val |
| 169 | elif (opt == "-o"): |
| 170 | output_file = val |
| 171 | else: |
| 172 | raise Exception("Unknown flag {}".format(opt)) |
| 173 | |
| 174 | return { |
| 175 | "directory": directory, |
| 176 | "input_string": input_string, |
| 177 | "input_file": input_file, |
| 178 | "output_file": output_file, |
| 179 | } |
| 180 | |
| 181 | def main(): |
| 182 | args = None |
| 183 | try: |
| 184 | args = parse_args() |
| 185 | except Exception as e: |
| 186 | print(e) |
| 187 | print("\nUsage:\n") |
| 188 | print(usage.format(sys.argv[0])) |
| 189 | sys.exit(1) |
| 190 | |
| 191 | directory = args["directory"] |
| 192 | template = args["input_string"] |
| 193 | if template == None: |
| 194 | with open(args["input_file"], 'r') as f: |
| 195 | template = f.read() |
| 196 | output_file = args["output_file"] |
| 197 | |
| 198 | software_version = deduce_software_version(directory) |
| 199 | commit = describe(directory) |
| 200 | output = template \ |
| 201 | .replace("<major>", software_version["major"]) \ |
| 202 | .replace("<minor>", software_version["minor"]) \ |
| 203 | .replace("<patch>", software_version["patch"]) \ |
| 204 | .replace("<flavor>", software_version["flavor"]) \ |
| 205 | .replace("<-flavor>", software_version["-flavor"]) \ |
| 206 | .replace("<date>", software_version["date"]) \ |
| 207 | .replace("<commit>", commit) |
| 208 | |
| 209 | if output_file is None: |
| 210 | print(output) |
| 211 | else: |
| 212 | mkdir_p(os.path.dirname(output_file)) |
| 213 | |
| 214 | if os.path.isfile(output_file): |
| 215 | with open(output_file, 'r') as f: |
| 216 | if output == f.read(): |
| 217 | return |
| 218 | |
| 219 | with open(output_file, 'w') as f: |
| 220 | f.write(output) |
| 221 | |
| 222 | if __name__ == '__main__': |
| 223 | main() |