bin/git_sha1_gen.py

   1 """
   2 Generate the contents of the git_sha1.h file.
   3 """
   4
   5 import argparse
   6 import os
   7 import os.path
   8 import subprocess
   9 import sys
  10
  11
  12 def get_git_sha1():
  13     """Try to get the git SHA1 with git rev-parse."""
  14     git_dir = os.path.join(os.path.dirname(sys.argv[0]), '..', '.git')
  15     try:
  16         git_sha1 = subprocess.check_output([
  17             'git',
  18             '--git-dir=' + git_dir,
  19             'rev-parse',
  20             'HEAD',
  21         ], stderr=open(os.devnull, 'w')).decode("ascii")
  22     except Exception:
  23         # don't print anything if it fails
  24         git_sha1 = ''
  25     return git_sha1
  26
  27
  28 def write_if_different(contents):
  29     """
  30     Avoid touching the output file if it doesn't need modifications
  31     Useful to avoid triggering rebuilds when nothing has changed.
  32     """
  33     if os.path.isfile(args.output):
  34         with open(args.output, 'r') as file:
  35             if file.read() == contents:
  36                 return
  37     with open(args.output, 'w') as file:
  38         file.write(contents)
  39
  40
  41 parser = argparse.ArgumentParser()
  42 parser.add_argument('--output', help='File to write the #define in',
  43                     required=True)
  44 args = parser.parse_args()
  45
  46 git_sha1 = os.environ.get('MESA_GIT_SHA1_OVERRIDE', get_git_sha1())[:10]
  47 if git_sha1:
  48     write_if_different('#define MESA_GIT_SHA1 " (git-' + git_sha1 + ')"')
  49 else:
  50     write_if_different('#define MESA_GIT_SHA1 ""')