Use R.txt from AAR to generate R.java for it when building APK.

build/android/gyp/process_resources.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Process Android resources to generate R.java, and prepare for packaging.
 
 This will crunch images and generate v14 compatible resources
 (see generate_v14_compatible_resources.py).
@@ skipping 56 matching lines @@
                     help='Resources from dependents.')
 
   parser.add_option('--resource-zip-out',
                     help='Path for output zipped resources.')
 
   parser.add_option('--R-dir',
                     help='directory to hold generated R.java.')
   parser.add_option('--srcjar-out',
                     help='Path to srcjar to contain generated R.java.')
   parser.add_option('--r-text-out',
-                    help='Path to store the R.txt file generated by appt.')
+                    help='Path to store the generated R.txt file.')
+  parser.add_option('--r-text-in',
+                    help='Path to pre-existing R.txt for these resources. '
+                    'Resource names from it will be used to generate R.java '
+                    'instead of aapt-generated R.txt.')
 
   parser.add_option('--proguard-file',
                     help='Path to proguard.txt generated file')
 
   parser.add_option(
       '--v14-skip',
       action="store_true",
       help='Do not generate nor verify v14 resources')
 
   parser.add_option(
@@ skipping 74 matching lines @@
   for package, r_txt_file in zip(packages, r_txt_files):
     if package in resources_by_package:
       raise Exception(('Package name "%s" appeared twice. All '
                        'android_resources() targets must use unique package '
                        'names, or no package name at all.') % package)
     resources_by_type = resources_by_package[package]
     # The sub-R.txt files have the wrong values at this point. Read them to
     # figure out which entries belong to them, but use the values from the
     # main R.txt file.
     for entry in _ParseTextSymbolsFile(r_txt_file):
-      entry = all_resources[(entry.resource_type, entry.name)]
-      resources_by_type[entry.resource_type].append(entry)
+      entry = all_resources.get((entry.resource_type, entry.name))
+      # For most cases missing entry here is an error. It means that some
+      # library claims to have or depend on a resource that isn't included into
+      # the APK. There is one notable exception: Google Play Services (GMS).
+      # GMS is shipped as a bunch of AARs. One of them - basement - contains
+      # R.txt with ids of all resources, but most of the resources are in the
+      # other AARs. However, all other AARs reference their resources via
+      # basement's R.java so the latter must contain all ids that are in its
+      # R.txt. Most targets depend on only a subset of GMS AARs so some
+      # resources are missing, which is okay because the code that references
+      # them is missing too. We can't get an id for a resource that isn't here
+      # so the only solution is to skip the resource entry entirely.
+      #
+      # We can verify that all entries referenced in the code were generated
+      # correctly by running Proguard on the APK: it will report missing
+      # fields.
+      if entry:
+        resources_by_type[entry.resource_type].append(entry)
 
   for package, resources_by_type in resources_by_package.iteritems():
     package_r_java_dir = os.path.join(srcjar_dir, *package.split('.'))
     build_utils.MakeDirectory(package_r_java_dir)
     package_r_java_path = os.path.join(package_r_java_dir, 'R.java')
     java_file_contents = _CreateRJavaFile(
         package, resources_by_type, shared_resources)
     with open(package_r_java_path, 'w') as f:
       f.write(java_file_contents)
 
@@ skipping 241 matching lines @@
 
     if options.proguard_file:
       package_command += ['-G', options.proguard_file]
     build_utils.CheckOutput(package_command, print_stderr=False)
 
     # When an empty res/ directory is passed, aapt does not write an R.txt.
     if not os.path.exists(r_txt_path):
       build_utils.Touch(r_txt_path)
 
     if not options.include_all_resources:
+      # --include-all-resources can only be specified for generating final R
+      # classes for APK. It makes no sense for APK to have pre-generated R.txt
+      # though, because aapt-generated already lists all available resources.
+      if options.r_text_in:
+        r_txt_path = options.r_text_in
+
       packages = list(options.extra_res_packages)
       r_txt_files = list(options.extra_r_text_files)
 
       cur_package = options.custom_package
       if not options.custom_package:
         cur_package = _ExtractPackageFromManifest(options.android_manifest)
 
       # Don't create a .java file for the current resource target when:
       # - no package name was provided (either by manifest or build rules),
       # - there was already a dependent android_resources() with the same
@@ skipping 87 matching lines @@
       options,
       input_paths=input_paths,
       input_strings=input_strings,
       output_paths=output_paths,
       # TODO(agrieve): Remove R_dir when it's no longer used (used only by GYP).
       force=options.R_dir)
 
 
 if __name__ == '__main__':
   main(sys.argv[1:])