blob: 960183675d17daec7e96eab41b365fd90ab51c53 [file] [log] [blame]
James Zern9097dcf2022-05-15 15:39:54 -07001#!/usr/bin/env python3
John Koleszara3ff6252012-08-08 09:28:01 -07002##
Yaowu Xu9c01aa12016-09-01 14:32:49 -07003## Copyright (c) 2016, Alliance for Open Media. All rights reserved
4##
5## This source code is subject to the terms of the BSD 2 Clause License and
6## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
7## was not distributed with this source code in the LICENSE file, you can
8## obtain it at www.aomedia.org/license/software. If the Alliance for Open
9## Media Patent License 1.0 was not distributed with this source code in the
10## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
John Koleszara3ff6252012-08-08 09:28:01 -070011##
12"""Calculates the "intersection" of two unified diffs.
13
14Given two diffs, A and B, it finds all hunks in B that had non-context lines
15in A and prints them to stdout. This is useful to determine the hunks in B that
16are relevant to A. The resulting file can be applied with patch(1) on top of A.
17"""
18
19__author__ = "jkoleszar@google.com"
20
John Koleszara3ff6252012-08-08 09:28:01 -070021import sys
22
John Koleszara7be7c82012-07-13 13:01:40 -070023import diff
John Koleszara3ff6252012-08-08 09:28:01 -070024
25
26def FormatDiffHunks(hunks):
27 """Re-serialize a list of DiffHunks."""
28 r = []
29 last_header = None
30 for hunk in hunks:
31 this_header = hunk.header[0:2]
32 if last_header != this_header:
33 r.extend(hunk.header)
34 last_header = this_header
35 else:
36 r.extend(hunk.header[2])
37 r.extend(hunk.lines)
38 r.append("\n")
39 return "".join(r)
40
41
42def ZipHunks(rhs_hunks, lhs_hunks):
43 """Join two hunk lists on filename."""
44 for rhs_hunk in rhs_hunks:
45 rhs_file = rhs_hunk.right.filename.split("/")[1:]
46
47 for lhs_hunk in lhs_hunks:
48 lhs_file = lhs_hunk.left.filename.split("/")[1:]
49 if lhs_file != rhs_file:
50 continue
51 yield (rhs_hunk, lhs_hunk)
52
53
54def main():
John Koleszara7be7c82012-07-13 13:01:40 -070055 old_hunks = [x for x in diff.ParseDiffHunks(open(sys.argv[1], "r"))]
56 new_hunks = [x for x in diff.ParseDiffHunks(open(sys.argv[2], "r"))]
John Koleszara3ff6252012-08-08 09:28:01 -070057 out_hunks = []
58
59 # Join the right hand side of the older diff with the left hand side of the
60 # newer diff.
61 for old_hunk, new_hunk in ZipHunks(old_hunks, new_hunks):
62 if new_hunk in out_hunks:
63 continue
64 old_lines = old_hunk.right
65 new_lines = new_hunk.left
66
67 # Determine if this hunk overlaps any non-context line from the other
68 for i in old_lines.delta_line_nums:
69 if i in new_lines:
70 out_hunks.append(new_hunk)
71 break
72
73 if out_hunks:
James Zern9097dcf2022-05-15 15:39:54 -070074 print(FormatDiffHunks(out_hunks))
John Koleszara3ff6252012-08-08 09:28:01 -070075 sys.exit(1)
76
77if __name__ == "__main__":
78 main()