1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
#!/usr/bin/env python3
# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import argparse
import sys
import gclient_utils
import git_common
# Squash a branch, taking care to rebase the branch on top of the new commit
# position of its upstream branch.
def rebase_branch(branch, initial_hashes):
print('Re-parenting branch %s.' % branch)
assert initial_hashes[branch] == git_common.hash_one(branch)
upstream_branch = git_common.upstream(branch)
old_upstream_branch = initial_hashes[upstream_branch]
# Because the branch's upstream has potentially changed from squashing it,
# the current branch is rebased on top of the new upstream.
git_common.run('rebase', '--onto', upstream_branch, old_upstream_branch,
branch, '--update-refs')
# Squashes all branches that are part of the subtree starting at `branch`.
def rebase_subtree(branch, initial_hashes, downstream_branches):
# Rebase us onto our parent
rebase_branch(branch, initial_hashes)
# Recurse on downstream branches, if any.
for downstream_branch in downstream_branches[branch]:
rebase_subtree(downstream_branch, initial_hashes, downstream_branches)
def children_have_diverged(branch, downstream_branches, diverged_branches):
# If we have no diverged branches, then no children have diverged.
if not diverged_branches:
return False
# If we have diverged, then our children have diverged.
if branch in diverged_branches:
return True
# If any of our children have diverged, then we need to return true.
for downstream_branch in downstream_branches[branch]:
if children_have_diverged(downstream_branch, downstream_branches,
diverged_branches):
return True
return False
def main(args):
if gclient_utils.IsEnvCog():
print('squash-branch command is not supported in non-git environment.',
file=sys.stderr)
return 1
parser = argparse.ArgumentParser()
parser.add_argument(
'-m',
'--message',
metavar='<msg>',
default=None,
help='Use the given <msg> as the first line of the commit message.')
opts = parser.parse_args(args)
if git_common.is_dirty_git_tree('squash-branch'):
return 1
# Save off the current branch so we can return to it at the end.
return_branch = git_common.current_branch()
# Save the hashes before we mutate the tree so that we have all of the
# necessary rebasing information.
_, tree = git_common.get_branch_tree()
initial_hashes = git_common.get_hashes(tree)
downstream_branches = git_common.get_downstream_branches(tree)
diverged_branches = git_common.get_diverged_branches(tree)
# We won't be rebasing our squashed branch, so only check any potential
# children
for branch in downstream_branches[return_branch]:
if children_have_diverged(branch, downstream_branches,
diverged_branches):
print('Cannot use `git squash-branch` since some children have '
'diverged from their upstream and could cause conflicts.')
return 1
git_common.squash_current_branch(opts.message)
# Fixup our children with our new state.
for branch in downstream_branches[return_branch]:
rebase_subtree(branch, initial_hashes, downstream_branches)
git_common.run('checkout', return_branch)
return 0
if __name__ == '__main__':
try:
sys.exit(main(sys.argv[1:]))
except KeyboardInterrupt:
sys.stderr.write('interrupted\n')
sys.exit(1)
|
