Update find_unused_resources.py to ignore third party resources.

find_unused_resources.py thinks that resources defined in third party
libraries are all unused. This updates the script to ignore those
resources.

BUG=149661
R=bulach@chromium.org, cjhopman@chromium.org

Review URL: https://codereview.chromium.org/23591017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221769 0039d316-1c4b-4281-b951-d872f2087c98

tools/android/find_unused_resources.py

@@ -11,25 +11,32 @@ import subprocess
 import sys
 
 
-def GetApkResources(apk_path):
-  """Returns the types and names of resources packaged in an APK.
+def GetLibraryResources(r_txt_paths):
+  """Returns the resources packaged in a list of libraries.
 
   Args:
-    apk_path: path to the APK.
+    r_txt_paths: paths to each library's generated R.txt file which lists the
+        resources it contains.
 
   Returns:
-    The resources in the APK as a list of tuples (type, name). Example:
+    The resources in the libraries as a list of tuples (type, name). Example:
     [('drawable', 'arrow'), ('layout', 'month_picker'), ...]
   """
-  p = subprocess.Popen(
-      ['aapt', 'dump', 'resources', apk_path],
-      stdout=subprocess.PIPE)
-  dump_out, _ = p.communicate()
-  assert p.returncode == 0, 'aapt dump failed'
-  matches = re.finditer(
-      r'^\s+spec resource 0x[0-9a-fA-F]+ [\w.]+:(?P<type>\w+)/(?P<name>\w+)',
-      dump_out, re.MULTILINE)
-  return [m.group('type', 'name') for m in matches]
+  resources = []
+  for r_txt_path in r_txt_paths:
+    with open(r_txt_path, 'r') as f:
+      for line in f:
+        line = line.strip()
+        if not line:
+          continue
+        data_type, res_type, name, _ = line.split(None, 3)
+        assert data_type in ('int', 'int[]')
+        # Hide attrs, which are redundant with styleables and always appear
+        # unused, and hide ids, which are innocuous even if unused.
+        if res_type in ('attr', 'id'):
+          continue
+        resources.append((res_type, name))
+  return resources
 
 
 def GetUsedResources(source_paths, resource_types):
@@ -79,43 +86,55 @@ def FormatResources(resources):
 
 
 def ParseArgs(args):
-  usage = 'usage: %prog [-v] APK_PATH SOURCE_PATH...'
-  parser = optparse.OptionParser(usage=usage)
+  parser = optparse.OptionParser()
   parser.add_option('-v', help='Show verbose output', action='store_true')
+  parser.add_option('-s', '--source-path', help='Specify a source folder path '
+                    '(e.g. ui/android/java)', action='append', default=[])
+  parser.add_option('-r', '--r-txt-path', help='Specify a "first-party" R.txt '
+                    'file (e.g. out/Debug/content_shell_apk/R.txt)',
+                    action='append', default=[])
+  parser.add_option('-t', '--third-party-r-txt-path', help='Specify an R.txt '
+                    'file for a third party library', action='append',
+                    default=[])
   options, args = parser.parse_args(args=args)
-  if len(args) < 2:
-    parser.error('must provide APK_PATH and SOURCE_PATH arguments')
-  return options.v, args[0], args[1:]
+  if args:
+    parser.error('positional arguments not allowed')
+  if not options.source_path:
+    parser.error('at least one source folder path must be specified with -s')
+  if not options.r_txt_path:
+    parser.error('at least one R.txt path must be specified with -r')
+  return (options.v, options.source_path, options.r_txt_path,
+          options.third_party_r_txt_path)
 
 
 def main(args=None):
-  verbose, apk_path, source_paths = ParseArgs(args)
-  apk_resources = GetApkResources(apk_path)
-  resource_types = list(set([r[0] for r in apk_resources]))
-  used_resources = GetUsedResources(source_paths, resource_types)
-  unused_resources = set(apk_resources) - set(used_resources)
-  undefined_resources = set(used_resources) - set(apk_resources)
+  verbose, source_paths, r_txt_paths, third_party_r_txt_paths = ParseArgs(args)
+  defined_resources = (set(GetLibraryResources(r_txt_paths)) -
+                       set(GetLibraryResources(third_party_r_txt_paths)))
+  resource_types = list(set([r[0] for r in defined_resources]))
+  used_resources = set(GetUsedResources(source_paths, resource_types))
+  unused_resources = defined_resources - used_resources
+  undefined_resources = used_resources - defined_resources
 
   # aapt dump fails silently. Notify the user if things look wrong.
-  if not apk_resources:
+  if not defined_resources:
     print >> sys.stderr, (
-        'Warning: No resources found in the APK. Did you provide the correct '
-        'APK path?')
+        'Warning: No resources found. Did you provide the correct R.txt paths?')
   if not used_resources:
     print >> sys.stderr, (
-        'Warning: No resources references from Java or resource files. Did you '
+        'Warning: No resources referenced from Java or resource files. Did you '
         'provide the correct source paths?')
   if undefined_resources:
     print >> sys.stderr, (
         'Warning: found %d "undefined" resources that are referenced by Java '
-        'files or by other resources, but are not in the APK. Run with -v to '
-        'see them.' % len(undefined_resources))
+        'files or by other resources, but are not defined anywhere. Run with '
+        '-v to see them.' % len(undefined_resources))
 
   if verbose:
     print '%d undefined resources:' % len(undefined_resources)
     print FormatResources(undefined_resources), '\n'
-    print '%d resources packaged into the APK:' % len(apk_resources)
-    print FormatResources(apk_resources), '\n'
+    print '%d resources defined:' % len(defined_resources)
+    print FormatResources(defined_resources), '\n'
     print '%d used resources:' % len(used_resources)
     print FormatResources(used_resources), '\n'
     print '%d unused resources:' % len(unused_resources)