Add support for uncompress library in APK to the build system

build/android/gyp/finalize_apk.py

Index: build/android/gyp/finalize_apk.py
diff --git a/build/android/gyp/finalize_apk.py b/build/android/gyp/finalize_apk.py
index d64e10d0f57cba2a7b9185c2d58e53cd46751014..5c51467e7680420efd3fa5e7cecc44286b86d701 100755
--- a/build/android/gyp/finalize_apk.py
+++ b/build/android/gyp/finalize_apk.py
@@ -14,6 +14,16 @@ import tempfile
 
 from util import build_utils
 
+def RenameLibInApk(rezip_path, in_zip_file, out_zip_file):
+  rename_cmd = [
+      rezip_path,
+      'rename',
+      in_zip_file,
+      out_zip_file,
+    ]
+  build_utils.CheckOutput(rename_cmd)
+
+
 def SignApk(key_path, key_name, key_passwd, unsigned_path, signed_path):
   shutil.copy(unsigned_path, signed_path)
   sign_cmd = [
@@ -38,10 +48,31 @@ def AlignApk(zipalign_path, unaligned_path, final_path):
   build_utils.CheckOutput(align_cmd)
 
 
+def UncompressLibAndPageAlignInApk(rezip_path, in_zip_file, out_zip_file):
+  rename_cmd = [
+      rezip_path,
+      'inflatealign',
+      in_zip_file,
+      out_zip_file,
+    ]
+  build_utils.CheckOutput(rename_cmd)
+
+
+def DropDataDescriptorsInApk(rezip_path, in_zip_file, out_zip_file):
+  rename_cmd = [
+      rezip_path,
+      'dropdescriptors',
+      in_zip_file,
+      out_zip_file,
+    ]
+  build_utils.CheckOutput(rename_cmd)
+
+
 def main():
   parser = optparse.OptionParser()
 
   parser.add_option('--zipalign-path', help='Path to the zipalign tool.')
+  parser.add_option('--rezip-path', help='Path to the rezip executable.')
   parser.add_option('--unsigned-apk-path', help='Path to input unsigned APK.')
   parser.add_option('--final-apk-path',
       help='Path to output signed and aligned APK.')
@@ -49,14 +80,50 @@ def main():
   parser.add_option('--key-passwd', help='Keystore password')
   parser.add_option('--key-name', help='Keystore name')
   parser.add_option('--stamp', help='Path to touch on success.')
+  parser.add_option('--load-library-from-zip-file', type='int',
+      help='If non-zero, build the APK such that the library can be loaded ' +
+           'directly from the zip file using the crazy linker. The library ' +
+           'will be renamed, uncompressed and page aligned.')
 
   options, _ = parser.parse_args()
 
-  with tempfile.NamedTemporaryFile() as intermediate_file:
-    signed_apk_path = intermediate_file.name
+  with tempfile.NamedTemporaryFile() as signed_apk_path_tmp, \
+      tempfile.NamedTemporaryFile() as apk_to_sign_tmp, \
+      tempfile.NamedTemporaryFile() as apk_without_descriptors_tmp, \
+      tempfile.NamedTemporaryFile() as aligned_apk_tmp:
+
+    if options.load_library_from_zip_file:
+      # We alter the name of the library so that the Android Package Manager
+      # does not extract it into a separate file. This must be done before
+      # signing, as the filename is part of the signed manifest.
+      apk_to_sign = apk_to_sign_tmp.name
+      RenameLibInApk(options.rezip_path, options.unsigned_apk_path, apk_to_sign)
+    else:
+      apk_to_sign = options.unsigned_apk_path
+
+    signed_apk_path = signed_apk_path_tmp.name
     SignApk(options.key_path, options.key_name, options.key_passwd,
-            options.unsigned_apk_path, signed_apk_path)
-    AlignApk(options.zipalign_path, signed_apk_path, options.final_apk_path)
+            apk_to_sign, signed_apk_path)
+
+    if options.load_library_from_zip_file:
+      # Signing adds data descriptors to the APK. These are redundant
+      # information. We remove them as otherwise they can cause a
+      # miscalculation in the page alignment.
+      apk_to_align = apk_without_descriptors_tmp.name
+      DropDataDescriptorsInApk(
+          options.rezip_path, signed_apk_path, apk_to_align)
+      aligned_apk = aligned_apk_tmp.name
+    else:
+      apk_to_align = signed_apk_path
+      aligned_apk = options.final_apk_path
+
+    # Align uncompress items to 4 bytes
+    AlignApk(options.zipalign_path, apk_to_align, aligned_apk)
+
+    if options.load_library_from_zip_file:
+      # Uncompress the library and make sure that it is page aligned.
+      UncompressLibAndPageAlignInApk(
+          options.rezip_path, aligned_apk, options.final_apk_path)
 
   if options.stamp:
     build_utils.Touch(options.stamp)
@@ -64,5 +131,3 @@ def main():
 
 if __name__ == '__main__':
   sys.exit(main())
-
-