GN: Use a custom script for package_apk() build step rather than ANT

build/android/gyp/apkbuilder.py

Index: build/android/gyp/apkbuilder.py
diff --git a/build/android/gyp/apkbuilder.py b/build/android/gyp/apkbuilder.py
new file mode 100755
index 0000000000000000000000000000000000000000..4c04b9ac4620ccf2ff618144acbac0979ffb17cb
--- /dev/null
+++ b/build/android/gyp/apkbuilder.py
@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.

[Yaron, 2015/09/24 17:25:17]

Can you share a design doc for your time machine?

[agrieve, 2015/09/24 18:48:15]

Done.

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Adds the code parts to a resource APK."""
+
+import argparse
+import os
+import shutil
+import sys
+import zipfile
+
+from util import build_utils
+
+
+def _ParseArgs(args):
+  parser = argparse.ArgumentParser()
+  build_utils.AddDepfileOption(parser)
+  parser.add_argument('--resource-apk',
+                      help='An .ap_ file built using aapt',
+                      required=True)
+  parser.add_argument('--output-apk',
+                      help='Path to the output file',
+                      required=True)
+  parser.add_argument('--dex-file',

[Yaron, 2015/09/24 17:25:17]

It seems like this will be need to be a list in the case of multidex.

[agrieve, 2015/09/24 18:48:15]

multidex uses a single .zip file to pass multiple dex files. There is no
multidex logic in GN yet, so not easy to add logic for it yet. My plan for
follow-ups:

1. Add support for EMMA (crbug/535290)
2. Add support for multidex and hook it up to GYP (deleting ant.py)

+                      help='Path to the classes.dex to use')
+  # TODO(agrieve): Switch this to be a list of files rather than a directory.
+  parser.add_argument('--native-libs-dir',
+                      help='Directory containing native libraries to include',
+                      default=[])
+  parser.add_argument('--android-abi',
+                      help='Android architecture to use for native libraries')
+  options = parser.parse_args(args)
+  if options.native_libs_dir and not options.android_abi:
+    raise Exception('Must specify --android-abi with --native-libs-dir')
+  return options
+
+
+def _ListSubPaths(path):
+  """Returns a list of full paths to all files in the given path."""
+  return [os.path.join(path, name) for name in os.listdir(path)]
+
+
+def main(args):
+  args = build_utils.ExpandFileArgs(args)
+  options = _ParseArgs(args)
+
+  native_libs = []
+  if options.native_libs_dir:
+    native_libs = _ListSubPaths(options.native_libs_dir)
+
+  input_paths = [options.resource_apk] + native_libs
+  if options.dex_file:
+    input_paths.append(options.dex_file)
+
+  def on_stale_md5():
+    tmp_apk = options.output_apk + '.tmp'

[Yaron, 2015/09/24 17:25:17]

I guess this is guaranteed to be cleaned up if successful? If you fail to build
some apks, but not others, you would pollute the output location. Probably not
an issue in practice - I was just thinking about builder/tester split bots which
upload these unnecessarily. You could use a temp dir but I'll admit I don't feel
strongly about it.

[agrieve, 2015/09/24 18:48:15]

Changed it to use a proper temp file.

[Yaron, 2015/09/24 18:56:11]

There is tempfile.NamedTemporaryFile() which could've handled this with a "with"

+    # Work on a .tmp output to avoid creating an output if anything goes wrong.
+    shutil.copyfile(options.resource_apk, tmp_apk)
+
+    # TODO(agrieve): It would be more efficient to combine this step
+    # with finalize_apk(), which sometimes aligns and uncompresses the
+    # native libraries.
+    with zipfile.ZipFile(tmp_apk, 'a', zipfile.ZIP_DEFLATED) as apk:
+      for path in native_libs:
+        dest_path = 'lib/%s/%s' % (options.android_abi, os.path.basename(path))
+        apk.write(path, dest_path)
+      if options.dex_file:
+        apk.write(options.dex_file, 'classes.dex')

[Yaron, 2015/09/24 17:25:17]

How are multidex'd files named?

[agrieve, 2015/09/24 18:48:15]

classes.dex, classes2.dex, classes3.dex...

+
+    shutil.move(tmp_apk, options.output_apk)
+
+  build_utils.CallAndRecordIfStale(
+      on_stale_md5,
+      options,
+      input_paths=input_paths,
+      output_paths=[options.output_apk])
+
+
+if __name__ == '__main__':
+  main(sys.argv[1:])