| #!/usr/bin/env python | 
 | # Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file | 
 | # for details. All rights reserved. Use of this source code is governed by a | 
 | # BSD-style license that can be found in the LICENSE file. | 
 |  | 
 | import utils | 
 | import subprocess | 
 |  | 
 | def GitClone(url, checkout_dir): | 
 |   cmd = ['git', 'clone', url, checkout_dir] | 
 |   utils.PrintCmd(cmd) | 
 |   return subprocess.check_call(cmd) | 
 |  | 
 | def GetHeadRevision(checkout_dir, use_master=False): | 
 |   revision_from = 'origin/master' if use_master else 'HEAD' | 
 |   cmd = ['git', 'rev-parse', revision_from] | 
 |   utils.PrintCmd(cmd) | 
 |   with utils.ChangedWorkingDirectory(checkout_dir): | 
 |     return subprocess.check_output(cmd).strip() |