clang/tools/clang-format/clang-format-diff.py

   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 """
  12 This script reads input from a unified diff and reformats all the changed
  13 lines. This is useful to reformat all the lines touched by a specific patch.
  14 Example 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
  19 It should be noted that the filename contained in the diff is used unmodified
  20 to determine the source file to update. Users calling this script directly
  21 should be careful to ensure that the path in the diff is correct relative to the
  22 current working directory.
  23 """
  24 from __future__ import absolute_import, division, print_function
  25
  26 import argparse
  27 import difflib
  28 import re
  29 import subprocess
  30 import sys
  31
  32 if sys.version_info.major >= 3:
  33     from io import StringIO
  34 else:
  35     from io import BytesIO as StringIO
  36
  37
  38 def 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
 143 if __name__ == '__main__':
 144   main()