1#!/usr/bin/env python3
2#
3#===- clang-format-diff.py - ClangFormat Diff Reformatter ----*- python -*--===#
4#
5# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
6# See https://llvm.org/LICENSE.txt for license information.
7# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
8#
9#===------------------------------------------------------------------------===#
10
11"""
12This script reads input from a unified diff and reformats all the changed
13lines. This is useful to reformat all the lines touched by a specific patch.
14Example usage for git/svn users:
15
16  git diff -U0 --no-color --relative HEAD^ | clang-format-diff.py -p1 -i
17  svn diff --diff-cmd=diff -x-U0 | clang-format-diff.py -i
18
19It should be noted that the filename contained in the diff is used unmodified
20to determine the source file to update. Users calling this script directly
21should be careful to ensure that the path in the diff is correct relative to the
22current working directory.
23"""
24from __future__ import absolute_import, division, print_function
25
26import argparse
27import difflib
28import re
29import subprocess
30import sys
31
32if sys.version_info.major >= 3:
33    from io import StringIO
34else:
35    from io import BytesIO as StringIO
36
37
38def main():
39  parser = argparse.ArgumentParser(description=__doc__,
40                                   formatter_class=
41                                           argparse.RawDescriptionHelpFormatter)
42  parser.add_argument('-i', action='store_true', default=False,
43                      help='apply edits to files instead of displaying a diff')
44  parser.add_argument('-p', metavar='NUM', default=0,
45                      help='strip the smallest prefix containing P slashes')
46  parser.add_argument('-regex', metavar='PATTERN', default=None,
47                      help='custom pattern selecting file paths to reformat '
48                      '(case sensitive, overrides -iregex)')
49  parser.add_argument('-iregex', metavar='PATTERN', default=
50                      r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hh|hpp|hxx|m|mm|inc|js|ts'
51                      r'|proto|protodevel|java|cs)',
52                      help='custom pattern selecting file paths to reformat '
53                      '(case insensitive, overridden by -regex)')
54  parser.add_argument('-sort-includes', action='store_true', default=False,
55                      help='let clang-format sort include blocks')
56  parser.add_argument('-v', '--verbose', action='store_true',
57                      help='be more verbose, ineffective without -i')
58  parser.add_argument('-style',
59                      help='formatting style to apply (LLVM, GNU, Google, Chromium, '
60                      'Microsoft, Mozilla, WebKit)')
61  parser.add_argument('-binary', default='clang-format',
62                      help='location of binary to use for clang-format')
63  args = parser.parse_args()
64
65  # Extract changed lines for each file.
66  filename = None
67  lines_by_file = {}
68  for line in sys.stdin:
69    match = re.search(r'^\+\+\+\ (.*?/){%s}(\S*)' % args.p, line)
70    if match:
71      filename = match.group(2)
72    if filename is None:
73      continue
74
75    if args.regex is not None:
76      if not re.match('^%s$' % args.regex, filename):
77        continue
78    else:
79      if not re.match('^%s$' % args.iregex, filename, re.IGNORECASE):
80        continue
81
82    match = re.search(r'^@@.*\+(\d+)(,(\d+))?', line)
83    if match:
84      start_line = int(match.group(1))
85      line_count = 1
86      if match.group(3):
87        line_count = int(match.group(3))
88      if line_count == 0:
89        continue
90      end_line = start_line + line_count - 1
91      lines_by_file.setdefault(filename, []).extend(
92          ['-lines', str(start_line) + ':' + str(end_line)])
93
94  # Reformat files containing changes in place.
95  for filename, lines in lines_by_file.items():
96    if args.i and args.verbose:
97      print('Formatting {}'.format(filename))
98    command = [args.binary, filename]
99    if args.i:
100      command.append('-i')
101    if args.sort_includes:
102      command.append('-sort-includes')
103    command.extend(lines)
104    if args.style:
105      command.extend(['-style', args.style])
106
107    try:
108      p = subprocess.Popen(command,
109                           stdout=subprocess.PIPE,
110                           stderr=None,
111                           stdin=subprocess.PIPE,
112                           universal_newlines=True)
113    except OSError as e:
114      # Give the user more context when clang-format isn't
115      # found/isn't executable, etc.
116      raise RuntimeError(
117        'Failed to run "%s" - %s"' % (" ".join(command), e.strerror))
118
119    stdout, stderr = p.communicate()
120    if p.returncode != 0:
121      sys.exit(p.returncode)
122
123    if not args.i:
124      with open(filename) as f:
125        code = f.readlines()
126      formatted_code = StringIO(stdout).readlines()
127      diff = difflib.unified_diff(code, formatted_code,
128                                  filename, filename,
129                                  '(before formatting)', '(after formatting)')
130      diff_string = ''.join(diff)
131      if len(diff_string) > 0:
132        sys.stdout.write(diff_string)
133
134if __name__ == '__main__':
135  main()
136