|  | #!/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() |