xref: /llvm-project/clang/tools/clang-format/clang-format-diff.py (revision c49406d18c84b5b0c4f90703e162d9496cf28db6) 
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                      help='custom pattern selecting file paths to reformat '
48                      '(case sensitive, override -iregex)')
49  parser.add_argument('-iregex', metavar='PATTERN', default=
50                      r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hpp|m|mm|inc|js)',
51                      help='custom pattern selecting file paths to reformat '
52                      '(case insensitive, override -regex)')
53  parser.add_argument(
54      '-style',
55      help=
56      'formatting style to apply (LLVM, Google, Chromium, Mozilla, WebKit)')
57  args = parser.parse_args()
58
59  # Extract changed lines for each file.
60  filename = None
61  lines_by_file = {}
62  for line in sys.stdin:
63    match = re.search('^\+\+\+\ (.*?/){%s}(\S*)' % args.p, line)
64    if match:
65      filename = match.group(2)
66    if filename == None:
67      continue
68
69    if args.regex != '':
70      if not re.match(args.regex, filename):
71        continue
72    else:
73      if not re.match(args.iregex, filename, re.IGNORECASE):
74        continue
75
76    match = re.search('^@@.*\+(\d+)(,(\d+))?', line)
77    if match:
78      start_line = int(match.group(1))
79      line_count = 1
80      if match.group(3):
81        line_count = int(match.group(3))
82      if line_count == 0:
83        continue
84      end_line = start_line + line_count - 1;
85      lines_by_file.setdefault(filename, []).extend(
86          ['-lines', str(start_line) + ':' + str(end_line)])
87
88  # Reformat files containing changes in place.
89  for filename, lines in lines_by_file.iteritems():
90    command = [binary, filename]
91    if args.i:
92      command.append('-i')
93    command.extend(lines)
94    if args.style:
95      command.extend(['-style', args.style])
96    p = subprocess.Popen(command, stdout=subprocess.PIPE,
97                         stderr=None, stdin=subprocess.PIPE)
98    stdout, stderr = p.communicate()
99    if p.returncode != 0:
100      sys.exit(p.returncode);
101
102    if not args.i:
103      with open(filename) as f:
104        code = f.readlines()
105      formatted_code = StringIO.StringIO(stdout).readlines()
106      diff = difflib.unified_diff(code, formatted_code,
107                                  filename, filename,
108                                  '(before formatting)', '(after formatting)')
109      diff_string = string.join(diff, '')
110      if len(diff_string) > 0:
111        sys.stdout.write(diff_string)
112
113if __name__ == '__main__':
114  main()
115