tools/android/find_unused_resources.py

   1 #!/usr/bin/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 """Lists unused Java strings and other resources."""
   7
   8 import optparse
   9 import re
  10 import subprocess
  11 import sys
  12
  13
  14 def GetLibraryResources(r_txt_paths):
  15   """Returns the resources packaged in a list of libraries.
  16
  17   Args:
  18     r_txt_paths: paths to each library's generated R.txt file which lists the
  19         resources it contains.
  20
  21   Returns:
  22     The resources in the libraries as a list of tuples (type, name). Example:
  23     [('drawable', 'arrow'), ('layout', 'month_picker'), ...]
  24   """
  25   resources = []
  26   for r_txt_path in r_txt_paths:
  27     with open(r_txt_path, 'r') as f:
  28       for line in f:
  29         line = line.strip()
  30         if not line:
  31           continue
  32         data_type, res_type, name, _ = line.split(None, 3)
  33         assert data_type in ('int', 'int[]')
  34         # Hide attrs, which are redundant with styleables and always appear
  35         # unused, and hide ids, which are innocuous even if unused.
  36         if res_type in ('attr', 'id'):
  37           continue
  38         resources.append((res_type, name))
  39   return resources
  40
  41
  42 def GetUsedResources(source_paths, resource_types):
  43   """Returns the types and names of resources used in Java or resource files.
  44
  45   Args:
  46     source_paths: a list of files or folders collectively containing all the
  47         Java files, resource files, and the AndroidManifest.xml.
  48     resource_types: a list of resource types to look for.  Example:
  49         ['string', 'drawable']
  50
  51   Returns:
  52     The resources referenced by the Java and resource files as a list of tuples
  53     (type, name).  Example:
  54     [('drawable', 'app_icon'), ('layout', 'month_picker'), ...]
  55   """
  56   type_regex = '|'.join(map(re.escape, resource_types))
  57   patterns = [r'@(())(%s)/(\w+)' % type_regex,
  58               r'\b((\w+\.)*)R\.(%s)\.(\w+)' % type_regex]
  59   resources = []
  60   for pattern in patterns:
  61     p = subprocess.Popen(
  62         ['grep', '-REIhoe', pattern] + source_paths,
  63         stdout=subprocess.PIPE)
  64     grep_out, grep_err = p.communicate()
  65     # Check stderr instead of return code, since return code is 1 when no
  66     # matches are found.
  67     assert not grep_err, 'grep failed'
  68     matches = re.finditer(pattern, grep_out)
  69     for match in matches:
  70       package = match.group(1)
  71       if package == 'android.':
  72         continue
  73       type_ = match.group(3)
  74       name = match.group(4)
  75       resources.append((type_, name))
  76   return resources
  77
  78
  79 def FormatResources(resources):
  80   """Formats a list of resources for printing.
  81
  82   Args:
  83     resources: a list of resources, given as (type, name) tuples.
  84   """
  85   return '\n'.join(['%-12s %s' % (t, n) for t, n in sorted(resources)])
  86
  87
  88 def ParseArgs(args):
  89   parser = optparse.OptionParser()
  90   parser.add_option('-v', help='Show verbose output', action='store_true')
  91   parser.add_option('-s', '--source-path', help='Specify a source folder path '
  92                     '(e.g. ui/android/java)', action='append', default=[])
  93   parser.add_option('-r', '--r-txt-path', help='Specify a "first-party" R.txt '
  94                     'file (e.g. out/Debug/content_shell_apk/R.txt)',
  95                     action='append', default=[])
  96   parser.add_option('-t', '--third-party-r-txt-path', help='Specify an R.txt '
  97                     'file for a third party library', action='append',
  98                     default=[])
  99   options, args = parser.parse_args(args=args)
 100   if args:
 101     parser.error('positional arguments not allowed')
 102   if not options.source_path:
 103     parser.error('at least one source folder path must be specified with -s')
 104   if not options.r_txt_path:
 105     parser.error('at least one R.txt path must be specified with -r')
 106   return (options.v, options.source_path, options.r_txt_path,
 107           options.third_party_r_txt_path)
 108
 109
 110 def main(args=None):
 111   verbose, source_paths, r_txt_paths, third_party_r_txt_paths = ParseArgs(args)
 112   defined_resources = (set(GetLibraryResources(r_txt_paths)) -
 113                        set(GetLibraryResources(third_party_r_txt_paths)))
 114   resource_types = list(set([r[0] for r in defined_resources]))
 115   used_resources = set(GetUsedResources(source_paths, resource_types))
 116   unused_resources = defined_resources - used_resources
 117   undefined_resources = used_resources - defined_resources
 118
 119   # aapt dump fails silently. Notify the user if things look wrong.
 120   if not defined_resources:
 121     print >> sys.stderr, (
 122         'Warning: No resources found. Did you provide the correct R.txt paths?')
 123   if not used_resources:
 124     print >> sys.stderr, (
 125         'Warning: No resources referenced from Java or resource files. Did you '
 126         'provide the correct source paths?')
 127   if undefined_resources:
 128     print >> sys.stderr, (
 129         'Warning: found %d "undefined" resources that are referenced by Java '
 130         'files or by other resources, but are not defined anywhere. Run with '
 131         '-v to see them.' % len(undefined_resources))
 132
 133   if verbose:
 134     print '%d undefined resources:' % len(undefined_resources)
 135     print FormatResources(undefined_resources), '\n'
 136     print '%d resources defined:' % len(defined_resources)
 137     print FormatResources(defined_resources), '\n'
 138     print '%d used resources:' % len(used_resources)
 139     print FormatResources(used_resources), '\n'
 140     print '%d unused resources:' % len(unused_resources)
 141   print FormatResources(unused_resources)
 142
 143
 144 if __name__ == '__main__':
 145   main()