1#!/usr/bin/env python
2#
3#===- clang-tidy-diff.py - ClangTidy Diff Checker ------------*- 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"""
13ClangTidy Diff Checker
14======================
15
16This script reads input from a unified diff, runs clang-tidy on all changed
17files and outputs clang-tidy warnings in changed lines only. This is useful to
18detect clang-tidy regressions in the lines touched by a specific patch.
19Example usage for git/svn users:
20
21  git diff -U0 HEAD^ | clang-tidy-diff.py -p1
22  svn diff --diff-cmd=diff -x-U0 | \
23      clang-tidy-diff.py -fix -checks=-*,modernize-use-override
24
25"""
26
27import argparse
28import json
29import re
30import subprocess
31import sys
32
33
34def main():
35  parser = argparse.ArgumentParser(description=
36                                   'Run clang-tidy against changed files, and '
37                                   'output diagnostics only for modified '
38                                   'lines.')
39  parser.add_argument('-clang-tidy-binary', metavar='PATH',
40                      default='clang-tidy',
41                      help='path to clang-tidy binary')
42  parser.add_argument('-p', metavar='NUM', default=0,
43                      help='strip the smallest prefix containing P slashes')
44  parser.add_argument('-regex', metavar='PATTERN', default=None,
45                      help='custom pattern selecting file paths to check '
46                      '(case sensitive, overrides -iregex)')
47  parser.add_argument('-iregex', metavar='PATTERN', default=
48                      r'.*\.(cpp|cc|c\+\+|cxx|c|cl|h|hpp|m|mm|inc)',
49                      help='custom pattern selecting file paths to check '
50                      '(case insensitive, overridden by -regex)')
51
52  parser.add_argument('-fix', action='store_true', default=False,
53                      help='apply suggested fixes')
54  parser.add_argument('-checks',
55                      help='checks filter, when not specified, use clang-tidy '
56                      'default',
57                      default='')
58  parser.add_argument('-path', dest='build_path',
59                      help='Path used to read a compile command database.')
60  parser.add_argument('-extra-arg', dest='extra_arg',
61                      action='append', default=[],
62                      help='Additional argument to append to the compiler '
63                      'command line.')
64  parser.add_argument('-extra-arg-before', dest='extra_arg_before',
65                      action='append', default=[],
66                      help='Additional argument to prepend to the compiler '
67                      'command line.')
68  parser.add_argument('-quiet', action='store_true', default=False,
69                      help='Run clang-tidy in quiet mode')
70  clang_tidy_args = []
71  argv = sys.argv[1:]
72  if '--' in argv:
73    clang_tidy_args.extend(argv[argv.index('--'):])
74    argv = argv[:argv.index('--')]
75
76  args = parser.parse_args(argv)
77
78  # Extract changed lines for each file.
79  filename = None
80  lines_by_file = {}
81  for line in sys.stdin:
82    match = re.search('^\+\+\+\ \"?(.*?/){%s}([^ \t\n\"]*)' % args.p, line)
83    if match:
84      filename = match.group(2)
85    if filename == None:
86      continue
87
88    if args.regex is not None:
89      if not re.match('^%s$' % args.regex, filename):
90        continue
91    else:
92      if not re.match('^%s$' % args.iregex, filename, re.IGNORECASE):
93        continue
94
95    match = re.search('^@@.*\+(\d+)(,(\d+))?', line)
96    if match:
97      start_line = int(match.group(1))
98      line_count = 1
99      if match.group(3):
100        line_count = int(match.group(3))
101      if line_count == 0:
102        continue
103      end_line = start_line + line_count - 1;
104      lines_by_file.setdefault(filename, []).append([start_line, end_line])
105
106  if len(lines_by_file) == 0:
107    print("No relevant changes found.")
108    sys.exit(0)
109
110  line_filter_json = json.dumps(
111    [{"name" : name, "lines" : lines_by_file[name]} for name in lines_by_file],
112    separators = (',', ':'))
113
114  quote = "";
115  if sys.platform == 'win32':
116    line_filter_json=re.sub(r'"', r'"""', line_filter_json)
117  else:
118    quote = "'";
119
120  # Run clang-tidy on files containing changes.
121  command = [args.clang_tidy_binary]
122  command.append('-line-filter=' + quote + line_filter_json + quote)
123  if args.fix:
124    command.append('-fix')
125  if args.checks != '':
126    command.append('-checks=' + quote + args.checks + quote)
127  if args.quiet:
128    command.append('-quiet')
129  if args.build_path is not None:
130    command.append('-p=%s' % args.build_path)
131  command.extend(lines_by_file.keys())
132  for arg in args.extra_arg:
133      command.append('-extra-arg=%s' % arg)
134  for arg in args.extra_arg_before:
135      command.append('-extra-arg-before=%s' % arg)
136  command.extend(clang_tidy_args)
137
138  sys.exit(subprocess.call(' '.join(command), shell=True))
139
140if __name__ == '__main__':
141  main()
142