1#!/usr/bin/env python
2# Copyright (c) 2012 The Chromium Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6"""
7  Invokes git diff [args...] and inserts file:line in front of each line of diff
8  output where possible.
9
10  This is useful from an IDE that allows you to double-click lines that begin
11  with file:line to open and jump to that point in the file.
12
13Synopsis:
14  %prog [git diff args...]
15
16Examples:
17  %prog
18  %prog HEAD
19"""
20
21import subprocess
22import sys
23
24
25def GitShell(args, ignore_return=False):
26  """A shell invocation suitable for communicating with git. Returns
27  output as list of lines, raises exception on error.
28  """
29  job = subprocess.Popen(args,
30                         shell=True,
31                         stdout=subprocess.PIPE,
32                         stderr=subprocess.STDOUT)
33  (out, err) = job.communicate()
34  if job.returncode != 0 and not ignore_return:
35    print out
36    raise Exception("Error %d running command %s" % (
37        job.returncode, args))
38  return out.split('\n')
39
40
41def PrintGitDiff(extra_args):
42  """Outputs git diff extra_args with file:line inserted into relevant lines."""
43  current_file = '';
44  line_num = 0;
45  lines = GitShell('git diff %s' % ' '.join(extra_args))
46  for line in lines:
47    # Pass-through lines:
48    #  diff --git a/file.c b/file.c
49    #  index 0e38c2d..8cd69ae 100644
50    #  --- a/file.c
51    if (line.startswith('diff ') or
52        line.startswith('index ') or
53        line.startswith('--- ')):
54      print line
55      continue
56
57    # Get the filename from the +++ line:
58    #  +++ b/file.c
59    if line.startswith('+++ '):
60      # Filename might be /dev/null or a/file or b/file.
61      # Skip the first two characters unless it starts with /.
62      current_file = line[4:] if line[4] == '/' else line[6:]
63      print line
64      continue
65
66    # Update line number from the @@ lines:
67    #  @@ -41,9 +41,9 @@ def MyFunc():
68    #            ^^
69    if line.startswith('@@ '):
70      _, old_nr, new_nr, _ = line.split(' ', 3)
71      line_num = int(new_nr.split(',')[0])
72      print line
73      continue
74    print current_file + ':' + repr(line_num) + ':' + line
75
76    # Increment line number for lines that start with ' ' or '+':
77    #  @@ -41,4 +41,4 @@ def MyFunc():
78    #  file.c:41: // existing code
79    #  file.c:42: // existing code
80    #  file.c:43:-// deleted code
81    #  file.c:43:-// deleted code
82    #  file.c:43:+// inserted code
83    #  file.c:44:+// inserted code
84    if line.startswith(' ') or line.startswith('+'):
85      line_num += 1
86
87
88def main():
89  PrintGitDiff(sys.argv[1:])
90
91
92if __name__ == '__main__':
93  main()
94