1#!/usr/bin/python2
2#
3#  Copyright 2015 Google Inc. All Rights Reserved
4"""The script to generate a cleanup script after setup.sh.
5
6This script takes a set of flags, telling it what setup.sh changed
7during the set up process. Based on the values of the input flags, it
8generates a cleanup script, named ${BOARD}_cleanup.sh, which will
9undo the changes made by setup.sh, returning everything to its
10original state.
11"""
12
13from __future__ import print_function
14
15import argparse
16import sys
17
18
19def Usage(parser, msg):
20  print('ERROR: ' + msg)
21  parser.print_help()
22  sys.exit(1)
23
24
25def Main(argv):
26  """Generate a script to undo changes done by setup.sh
27
28    The script setup.sh makes a change that needs to be
29    undone, namely it creates a soft link making /build/${board} point
30    to /build/${board}.work.  To do this, it had to see if
31    /build/${board} already existed, and if so, whether it was a real
32    tree or a soft link.  If it was soft link, it saved the old value
33    of the link, then deleted it and created the new link.  If it was
34    a real tree, it renamed the tree to /build/${board}.save, and then
35    created the new soft link.  If the /build/${board} did not
36    previously exist, then it just created the new soft link.
37
38    This function takes arguments that tell it exactly what setup.sh
39    actually did, then generates a script to undo those exact changes.
40  """
41
42  parser = argparse.ArgumentParser()
43  parser.add_argument(
44      '--board',
45      dest='board',
46      required=True,
47      help='Chromeos board for packages/image.')
48
49  parser.add_argument(
50      '--old_tree_missing',
51      dest='tree_existed',
52      action='store_false',
53      help='Did /build/${BOARD} exist.',
54      default=True)
55
56  parser.add_argument(
57      '--renamed_tree',
58      dest='renamed_tree',
59      action='store_true',
60      help='Was /build/${BOARD} saved & renamed.',
61      default=False)
62
63  parser.add_argument(
64      '--old_link',
65      dest='old_link',
66      help=('The original build tree soft link.'))
67
68  options = parser.parse_args(argv[1:])
69
70  if options.old_link or options.renamed_tree:
71    if not options.tree_existed:
72      Usage(parser, 'If --tree_existed is False, cannot have '
73            '--renamed_tree or --old_link')
74
75  if options.old_link and options.renamed_tree:
76    Usage(parser, '--old_link and --renamed_tree are incompatible options.')
77
78  if options.tree_existed:
79    if not options.old_link and not options.renamed_tree:
80      Usage(parser, 'If --tree_existed is True, then must have either '
81            '--old_link or --renamed_tree')
82
83  out_filename = 'cros_pkg/' + options.board + '_cleanup.sh'
84
85  with open(out_filename, 'w') as out_file:
86    out_file.write('#!/bin/bash\n\n')
87    # First, remove the 'new' soft link.
88    out_file.write('sudo rm /build/%s\n' % options.board)
89    if options.tree_existed:
90      if options.renamed_tree:
91        # Old build tree existed and was a real tree, so it got
92        # renamed.  Move the renamed tree back to the original tree.
93        out_file.write('sudo mv /build/%s.save /build/%s\n' %
94                       (options.board, options.board))
95      else:
96        # Old tree existed and was already a soft link.  Re-create the
97        # original soft link.
98        original_link = options.old_link
99        if original_link[0] == "'":
100          original_link = original_link[1:]
101        if original_link[-1] == "'":
102          original_link = original_link[:-1]
103        out_file.write('sudo ln -s %s /build/%s\n' % (original_link,
104                                                      options.board))
105    out_file.write('\n')
106    # Remove common.sh file
107    out_file.write('rm common/common.sh\n')
108
109  return 0
110
111
112if __name__ == '__main__':
113  retval = Main(sys.argv)
114  sys.exit(retval)
115