tools/git/mffr.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Usage: mffr.py [-d] [-g *.h] [-g *.cc] REGEXP REPLACEMENT
   7
   8 This tool performs a fast find-and-replace operation on files in
   9 the current git repository.
  10
  11 The -d flag selects a default set of globs (C++ and Objective-C/C++
  12 source files). The -g flag adds a single glob to the list and may
  13 be used multiple times. If neither -d nor -g is specified, the tool
  14 searches all files (*.*).
  15
  16 REGEXP uses full Python regexp syntax. REPLACEMENT can use
  17 back-references.
  18 """
  19
  20 import optparse
  21 import re
  22 import subprocess
  23 import sys
  24
  25
  26 # We need to use shell=True with subprocess on Windows so that it
  27 # finds 'git' from the path, but can lead to undesired behavior on
  28 # Linux.
  29 _USE_SHELL = (sys.platform == 'win32')
  30
  31
  32 def MultiFileFindReplace(original, replacement, file_globs):
  33   """Implements fast multi-file find and replace.
  34
  35   Given an |original| string and a |replacement| string, find matching
  36   files by running git grep on |original| in files matching any
  37   pattern in |file_globs|.
  38
  39   Once files are found, |re.sub| is run to replace |original| with
  40   |replacement|.  |replacement| may use capture group back-references.
  41
  42   Args:
  43     original: '(#(include|import)\s*["<])chrome/browser/ui/browser.h([>"])'
  44     replacement: '\1chrome/browser/ui/browser/browser.h\3'
  45     file_globs: ['*.cc', '*.h', '*.m', '*.mm']
  46
  47   Returns the list of files modified.
  48
  49   Raises an exception on error.
  50   """
  51   # Posix extended regular expressions do not reliably support the "\s"
  52   # shorthand.
  53   posix_ere_original = re.sub(r"\\s", "[[:space:]]", original)
  54   if sys.platform == 'win32':
  55     posix_ere_original = posix_ere_original.replace('"', '""')
  56   out, err = subprocess.Popen(
  57       ['git', 'grep', '-E', '--name-only', posix_ere_original,
  58        '--'] + file_globs,
  59       stdout=subprocess.PIPE,
  60       shell=_USE_SHELL).communicate()
  61   referees = out.splitlines()
  62
  63   for referee in referees:
  64     with open(referee) as f:
  65       original_contents = f.read()
  66     contents = re.sub(original, replacement, original_contents)
  67     if contents == original_contents:
  68       raise Exception('No change in file %s although matched in grep' %
  69                       referee)
  70     with open(referee, 'wb') as f:
  71       f.write(contents)
  72
  73   return referees
  74
  75
  76 def main():
  77   parser = optparse.OptionParser(usage='''
  78 (1) %prog <options> REGEXP REPLACEMENT
  79 REGEXP uses full Python regexp syntax. REPLACEMENT can use back-references.
  80
  81 (2) %prog <options> -i <file>
  82 <file> should contain a list (in Python syntax) of
  83 [REGEXP, REPLACEMENT, [GLOBS]] lists, e.g.:
  84 [
  85   [r"(foo|bar)", r"\1baz", ["*.cc", "*.h"]],
  86   ["54", "42"],
  87 ]
  88 As shown above, [GLOBS] can be omitted for a given search-replace list, in which
  89 case the corresponding search-replace will use the globs specified on the
  90 command line.''')
  91   parser.add_option('-d', action='store_true',
  92                     dest='use_default_glob',
  93                     help='Perform the change on C++ and Objective-C(++) source '
  94                     'and header files.')
  95   parser.add_option('-f', action='store_true',
  96                     dest='force_unsafe_run',
  97                     help='Perform the run even if there are uncommitted local '
  98                     'changes.')
  99   parser.add_option('-g', action='append',
 100                     type='string',
 101                     default=[],
 102                     metavar="<glob>",
 103                     dest='user_supplied_globs',
 104                     help='Perform the change on the specified glob. Can be '
 105                     'specified multiple times, in which case the globs are '
 106                     'unioned.')
 107   parser.add_option('-i', "--input_file",
 108                     type='string',
 109                     action='store',
 110                     default='',
 111                     metavar="<file>",
 112                     dest='input_filename',
 113                     help='Read arguments from <file> rather than the command '
 114                     'line. NOTE: To be sure of regular expressions being '
 115                     'interpreted correctly, use raw strings.')
 116   opts, args = parser.parse_args()
 117   if opts.use_default_glob and opts.user_supplied_globs:
 118     print '"-d" and "-g" cannot be used together'
 119     parser.print_help()
 120     return 1
 121
 122   from_file = opts.input_filename != ""
 123   if (from_file and len(args) != 0) or (not from_file and len(args) != 2):
 124     parser.print_help()
 125     return 1
 126
 127   if not opts.force_unsafe_run:
 128     out, err = subprocess.Popen(['git', 'status', '--porcelain'],
 129                                 stdout=subprocess.PIPE,
 130                                 shell=_USE_SHELL).communicate()
 131     if out:
 132       print 'ERROR: This tool does not print any confirmation prompts,'
 133       print 'so you should only run it with a clean staging area and cache'
 134       print 'so that reverting a bad find/replace is as easy as running'
 135       print '  git checkout -- .'
 136       print ''
 137       print 'To override this safeguard, pass the -f flag.'
 138       return 1
 139
 140   global_file_globs = ['*.*']
 141   if opts.use_default_glob:
 142     global_file_globs = ['*.cc', '*.h', '*.m', '*.mm']
 143   elif opts.user_supplied_globs:
 144     global_file_globs = opts.user_supplied_globs
 145
 146   # Construct list of search-replace tasks.
 147   search_replace_tasks = []
 148   if opts.input_filename == '':
 149     original = args[0]
 150     replacement = args[1]
 151     search_replace_tasks.append([original, replacement, global_file_globs])
 152   else:
 153     f = open(opts.input_filename)
 154     search_replace_tasks = eval("".join(f.readlines()))
 155     for task in search_replace_tasks:
 156       if len(task) == 2:
 157         task.append(global_file_globs)
 158     f.close()
 159
 160   for (original, replacement, file_globs) in search_replace_tasks:
 161     print 'File globs:  %s' % file_globs
 162     print 'Original:    %s' % original
 163     print 'Replacement: %s' % replacement
 164     MultiFileFindReplace(original, replacement, file_globs)
 165   return 0
 166
 167
 168 if __name__ == '__main__':
 169   sys.exit(main())