llvm/utils/gn/build/write_vcsrevision.py

   1 #!/usr/bin/env python3
   2
   3 """Gets the current revision and writes it to VCSRevision.h."""
   4
   5 import argparse
   6 import os
   7 import subprocess
   8 import sys
   9
  10
  11 THIS_DIR = os.path.abspath(os.path.dirname(__file__))
  12 LLVM_DIR = os.path.dirname(os.path.dirname(os.path.dirname(THIS_DIR)))
  13
  14
  15 def which(program):
  16     # distutils.spawn.which() doesn't find .bat files,
  17     # https://bugs.python.org/issue2200
  18     for path in os.environ["PATH"].split(os.pathsep):
  19         candidate = os.path.join(path, program)
  20         if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
  21             return candidate
  22     return None
  23
  24
  25 def main():
  26     parser = argparse.ArgumentParser(description=__doc__)
  27     parser.add_argument(
  28         "-d",
  29         "--depfile",
  30         help="if set, writes a depfile that causes this script "
  31         "to re-run each time the current revision changes",
  32     )
  33     parser.add_argument(
  34         "--write-git-rev",
  35         action="store_true",
  36         help="if set, writes git revision, else writes #undef",
  37     )
  38     parser.add_argument(
  39         "--name",
  40         action="append",
  41         help="if set, writes a depfile that causes this script "
  42         "to re-run each time the current revision changes",
  43     )
  44     parser.add_argument("vcs_header", help="path to the output file to write")
  45     args = parser.parse_args()
  46
  47     vcsrevision_contents = ""
  48     if args.write_git_rev:
  49         git, use_shell = which("git"), False
  50         if not git:
  51             git = which("git.exe")
  52         if not git:
  53             git, use_shell = which("git.bat"), True
  54         git_dir = (
  55             subprocess.check_output(
  56                 [git, "rev-parse", "--git-dir"], cwd=LLVM_DIR, shell=use_shell
  57             )
  58             .decode()
  59             .strip()
  60         )
  61         if not os.path.isdir(git_dir):
  62             print('.git dir not found at "%s"' % git_dir, file=sys.stderr)
  63             return 1
  64
  65         rev = (
  66             subprocess.check_output(
  67                 [git, "rev-parse", "--short", "HEAD"], cwd=git_dir, shell=use_shell
  68             )
  69             .decode()
  70             .strip()
  71         )
  72         url = (
  73             subprocess.check_output(
  74                 [git, "remote", "get-url", "origin"], cwd=git_dir, shell=use_shell
  75             )
  76             .decode()
  77             .strip()
  78         )
  79         for name in args.name:
  80             vcsrevision_contents += '#define %s_REVISION "%s"\n' % (name, rev)
  81             vcsrevision_contents += '#define %s_REPOSITORY "%s"\n' % (name, url)
  82     else:
  83         for name in args.name:
  84             vcsrevision_contents += "#undef %s_REVISION\n" % name
  85             vcsrevision_contents += "#undef %s_REPOSITORY\n" % name
  86
  87     # If the output already exists and is identical to what we'd write,
  88     # return to not perturb the existing file's timestamp.
  89     if (
  90         os.path.exists(args.vcs_header)
  91         and open(args.vcs_header).read() == vcsrevision_contents
  92     ):
  93         return 0
  94
  95     # http://neugierig.org/software/blog/2014/11/binary-revisions.html
  96     if args.depfile:
  97         build_dir = os.getcwd()
  98         with open(args.depfile, "w") as depfile:
  99             depfile.write(
 100                 "%s: %s\n"
 101                 % (
 102                     args.vcs_header,
 103                     os.path.relpath(os.path.join(git_dir, "logs", "HEAD"), build_dir),
 104                 )
 105             )
 106     open(args.vcs_header, "w").write(vcsrevision_contents)
 107
 108
 109 if __name__ == "__main__":
 110     sys.exit(main())