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|cppm|ccm|cxxm|c\+\+m|c|cl|h|hh|hpp|hxx'
51                      r'|m|mm|inc|js|ts|proto|protodevel|java|cs|json)',
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('-fallback-style',
62                      help='The name of the predefined style used as a'
63                      'fallback in case clang-format is invoked with'
64                      '-style=file, but can not find the .clang-format'
65                      'file to use.')
66  parser.add_argument('-binary', default='clang-format',
67                      help='location of binary to use for clang-format')
68  args = parser.parse_args()
69
70  # Extract changed lines for each file.
71  filename = None
72  lines_by_file = {}
73  for line in sys.stdin:
74    match = re.search(r'^\+\+\+\ (.*?/){%s}(\S*)' % args.p, line)
75    if match:
76      filename = match.group(2)
77    if filename is None:
78      continue
79
80    if args.regex is not None:
81      if not re.match('^%s$' % args.regex, filename):
82        continue
83    else:
84      if not re.match('^%s$' % args.iregex, filename, re.IGNORECASE):
85        continue
86
87    match = re.search(r'^@@.*\+(\d+)(,(\d+))?', line)
88    if match:
89      start_line = int(match.group(1))
90      line_count = 1
91      if match.group(3):
92        line_count = int(match.group(3))
93      # Also format lines range if line_count is 0 in case of deleting
94      # surrounding statements.
95      end_line = start_line
96      if line_count != 0:
97        end_line += line_count - 1
98      lines_by_file.setdefault(filename, []).extend(
99          ['-lines', str(start_line) + ':' + str(end_line)])
100
101  # Reformat files containing changes in place.
102  for filename, lines in lines_by_file.items():
103    if args.i and args.verbose:
104      print('Formatting {}'.format(filename))
105    command = [args.binary, filename]
106    if args.i:
107      command.append('-i')
108    if args.sort_includes:
109      command.append('-sort-includes')
110    command.extend(lines)
111    if args.style:
112      command.extend(['-style', args.style])
113    if args.fallback_style:
114      command.extend(['-fallback-style', args.fallback_style])
115
116    try:
117      p = subprocess.Popen(command,
118                           stdout=subprocess.PIPE,
119                           stderr=None,
120                           stdin=subprocess.PIPE,
121                           universal_newlines=True)
122    except OSError as e:
123      # Give the user more context when clang-format isn't
124      # found/isn't executable, etc.
125      raise RuntimeError(
126        'Failed to run "%s" - %s"' % (" ".join(command), e.strerror))
127
128    stdout, stderr = p.communicate()
129    if p.returncode != 0:
130      sys.exit(p.returncode)
131
132    if not args.i:
133      with open(filename) as f:
134        code = f.readlines()
135      formatted_code = StringIO(stdout).readlines()
136      diff = difflib.unified_diff(code, formatted_code,
137                                  filename, filename,
138                                  '(before formatting)', '(after formatting)')
139      diff_string = ''.join(diff)
140      if len(diff_string) > 0:
141        sys.stdout.write(diff_string)
142
143if __name__ == '__main__':
144  main()
145