llvm/utils/gn/build/write_vcsrevision.py

   1 #!/usr/bin/env python
   2
   3 """Gets the current revision and writes it to VCSRevision.h."""
   4
   5 from __future__ import print_function
   6
   7 import argparse
   8 import os
   9 import subprocess
  10 import sys
  11
  12
  13 THIS_DIR = os.path.abspath(os.path.dirname(__file__))
  14 LLVM_DIR = os.path.dirname(os.path.dirname(os.path.dirname(THIS_DIR)))
  15
  16
  17 def which(program):
  18     # distutils.spawn.which() doesn't find .bat files,
  19     # https://bugs.python.org/issue2200
  20     for path in os.environ["PATH"].split(os.pathsep):
  21         candidate = os.path.join(path, program)
  22         if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
  23             return candidate
  24     return None
  25
  26
  27 def main():
  28     parser = argparse.ArgumentParser(description=__doc__)
  29     parser.add_argument('-d', '--depfile',
  30                         help='if set, writes a depfile that causes this script '
  31                              'to re-run each time the current revision changes')
  32     parser.add_argument('--write-git-rev', action='store_true',
  33                         help='if set, writes git revision, else writes #undef')
  34     parser.add_argument('--name', action='append',
  35                         help='if set, writes a depfile that causes this script '
  36                              'to re-run each time the current revision changes')
  37     parser.add_argument('vcs_header', help='path to the output file to write')
  38     args = parser.parse_args()
  39
  40     vcsrevision_contents = ''
  41     if args.write_git_rev:
  42         git, use_shell = which('git'), False
  43         if not git: git = which('git.exe')
  44         if not git: git, use_shell = which('git.bat'), True
  45         git_dir = subprocess.check_output(
  46                 [git, 'rev-parse', '--git-dir'],
  47                 cwd=LLVM_DIR, shell=use_shell).decode().strip()
  48         if not os.path.isdir(git_dir):
  49             print('.git dir not found at "%s"' % git_dir, file=sys.stderr)
  50             return 1
  51
  52         rev = subprocess.check_output(
  53                 [git, 'rev-parse', '--short', 'HEAD'],
  54                 cwd=git_dir, shell=use_shell).decode().strip()
  55         url = subprocess.check_output(
  56                 [git, 'remote', 'get-url', 'origin'],
  57                 cwd=git_dir, shell=use_shell).decode().strip()
  58         for name in args.name:
  59             vcsrevision_contents += '#define %s_REVISION "%s"\n' % (name, rev)
  60             vcsrevision_contents += '#define %s_REPOSITORY "%s"\n' % (name, url)
  61     else:
  62         for name in args.name:
  63             vcsrevision_contents += '#undef %s_REVISION\n' % name
  64             vcsrevision_contents += '#undef %s_REPOSITORY\n' % name
  65
  66     # If the output already exists and is identical to what we'd write,
  67     # return to not perturb the existing file's timestamp.
  68     if os.path.exists(args.vcs_header) and \
  69             open(args.vcs_header).read() == vcsrevision_contents:
  70         return 0
  71
  72     # http://neugierig.org/software/blog/2014/11/binary-revisions.html
  73     if args.depfile:
  74         build_dir = os.getcwd()
  75         with open(args.depfile, 'w') as depfile:
  76             depfile.write('%s: %s\n' % (
  77                 args.vcs_header,
  78                 os.path.relpath(os.path.join(git_dir, 'logs', 'HEAD'),
  79                                 build_dir)))
  80     open(args.vcs_header, 'w').write(vcsrevision_contents)
  81
  82
  83 if __name__ == '__main__':
  84     sys.exit(main())