xref: /llvm-project/clang/tools/clang-format/clang-format-diff.py (revision 8c7cbdf53ad0d0dc596dea63be31520a2d7e1819) 
1#!/usr/bin/python
2#
3#===- clang-format-diff.py - ClangFormat Diff Reformatter ----*- python -*--===#
4#
5#                     The LLVM Compiler Infrastructure
6#
7# This file is distributed under the University of Illinois Open Source
8# License. See LICENSE.TXT for details.
9#
10#===------------------------------------------------------------------------===#
11
12r"""
13ClangFormat Diff Reformatter
14============================
15
16This script reads input from a unified diff and reformats all the changed
17lines. This is useful to reformat all the lines touched by a specific patch.
18Example usage for git users:
19
20  git diff -U0 HEAD^ | clang-format-diff.py -p1 -i
21
22"""
23
24import argparse
25import difflib
26import re
27import string
28import subprocess
29import StringIO
30import sys
31
32
33# Change this to the full path if clang-format is not on the path.
34binary = 'clang-format'
35
36
37def main():
38  parser = argparse.ArgumentParser(description=
39                                   'Reformat changed lines in diff. Without -i '
40                                   'option just output the diff that would be '
41                                   'introduced.')
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=
47                      r'.*\.(cpp|cc|CPP|C|c\+\+|cxx|c|h|hpp|m|mm|inc|js)',
48                      help='custom pattern selecting file paths to reformat')
49  parser.add_argument(
50      '-style',
51      help=
52      'formatting style to apply (LLVM, Google, Chromium, Mozilla, WebKit)')
53  args = parser.parse_args()
54
55  # Extract changed lines for each file.
56  filename = None
57  lines_by_file = {}
58  for line in sys.stdin:
59    match = re.search('^\+\+\+\ (.*?/){%s}(\S*)' % args.p, line)
60    if match:
61      filename = match.group(2)
62    if filename == None:
63      continue
64
65    if not re.match(args.regex, filename):
66      continue
67
68    match = re.search('^@@.*\+(\d+)(,(\d+))?', line)
69    if match:
70      start_line = int(match.group(1))
71      line_count = 1
72      if match.group(3):
73        line_count = int(match.group(3))
74      if line_count == 0:
75        continue
76      end_line = start_line + line_count - 1;
77      lines_by_file.setdefault(filename, []).extend(
78          ['-lines', str(start_line) + ':' + str(end_line)])
79
80  # Reformat files containing changes in place.
81  for filename, lines in lines_by_file.iteritems():
82    command = [binary, filename]
83    if args.i:
84      command.append('-i')
85    command.extend(lines)
86    if args.style:
87      command.extend(['-style', args.style])
88    p = subprocess.Popen(command, stdout=subprocess.PIPE,
89                         stderr=None, stdin=subprocess.PIPE)
90    stdout, stderr = p.communicate()
91    if p.returncode != 0:
92      sys.exit(p.returncode);
93
94    if not args.i:
95      with open(filename) as f:
96        code = f.readlines()
97      formatted_code = StringIO.StringIO(stdout).readlines()
98      diff = difflib.unified_diff(code, formatted_code,
99                                  filename, filename,
100                                  '(before formatting)', '(after formatting)')
101      diff_string = string.join(diff, '')
102      if len(diff_string) > 0:
103        sys.stdout.write(diff_string)
104
105if __name__ == '__main__':
106  main()
107