Update experimental Java 8 support to use Desugar instead of Retrolambda

Our experiments show that Desugar, a Google-developed open-source tool,
outperforms Retrolambda in both APK sizes and Java method counts. This
CL replaces Retrolambda with Desugar in our experimental Java 8 support.

BUG=730711

Review-Url: https://codereview.chromium.org/2985523002
Cr-Commit-Position: refs/heads/master@{#491183}

DEPS

@@ -1056,16 +1056,6 @@ hooks_os = {
                  '-l', 'third_party/ow2_asm'
       ],
     },
-    {
-      'name': 'retrolambda',
-      'pattern': '.',
-      'action': ['python',
-                 'src/build/android/update_deps/update_third_party_deps.py',
-                 'download',
-                 '-b', 'chromium-android-tools/retrolambda',
-                 '-l', 'third_party/retrolambda'
-      ],
-    },
     {
       'name': 'desugar',
       'pattern': '.',

build/android/gyp/retrolambda.py → build/android/gyp/desugar.py

 #!/usr/bin/env python
 #
-# Copyright 2016 The Chromium Authors. All rights reserved.
+# Copyright 2017 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.
 
@@ -15,26 +15,29 @@ from util import build_utils
 
 _SRC_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__),
                                          '..', '..', '..'))
-_RETROLAMBDA_JAR_PATH = os.path.normpath(os.path.join(
-    _SRC_ROOT, 'third_party', 'retrolambda', 'retrolambda-2.5.1.jar'))
+_DESUGAR_JAR_PATH = os.path.normpath(os.path.join(
+    _SRC_ROOT, 'third_party', 'bazel', 'desugar', 'Desugar.jar'))
 
 
-def _OnStaleMd5(input_jar, output_jar, classpath, android_sdk_jar):
-  with build_utils.TempDir() as temp_dir:
-    build_utils.ExtractAll(input_jar, path=temp_dir)
-    cmd = [
-        'java',
-        '-Dretrolambda.inputDir=' + temp_dir,
-        '-Dretrolambda.classpath=' +
-            ':'.join([temp_dir] + classpath + [android_sdk_jar]),
-        '-javaagent:' + _RETROLAMBDA_JAR_PATH,
-        '-jar',
-        _RETROLAMBDA_JAR_PATH,
-    ]
-
-    build_utils.CheckOutput(cmd, print_stdout=False)
-    build_utils.ZipDir(output_jar + '.tmp', temp_dir)
-    shutil.move(output_jar + '.tmp', output_jar)
+def _OnStaleMd5(input_jar, output_jar, classpath, bootclasspath_entry):
+  cmd = [
+      'java',
+      '-jar',
+      _DESUGAR_JAR_PATH,
+      '--input',
+      input_jar,
+      '--bootclasspath_entry',
+      bootclasspath_entry,
+      '--output',
+      output_jar,
+      # Disable try-with-resources due to proguard duplicate zip entry error
+      # TODO(zpeng): Enable try-with-resources with
+      #    desugar_try_with_resources_omit_runtime_classes
+      '--desugar_try_with_resources_if_needed=false',
+  ]
+  for path in classpath:
+    cmd += ['--classpath_entry', path]
+  build_utils.CheckOutput(cmd, print_stdout=False)
 
 
 def main():
@@ -47,21 +50,26 @@ def main():
                       help='Jar output path.')
   parser.add_argument('--classpath', required=True,
                       help='Classpath.')
-  parser.add_argument('--android-sdk-jar', required=True,
-                      help='Android sdk jar path.')
+  parser.add_argument('--bootclasspath-entry', required=True,
+                      help='Path to javac bootclasspath interface jar.')
   options = parser.parse_args(args)
 
   options.classpath = build_utils.ParseGnList(options.classpath)
-  input_paths = options.classpath + [options.input_jar]
+  input_paths = options.classpath + [
+      options.bootclasspath_entry,
+      options.input_jar,
+  ]
   output_paths = [options.output_jar]
+  depfile_deps = options.classpath + [_DESUGAR_JAR_PATH]
 
   build_utils.CallAndWriteDepfileIfStale(
       lambda: _OnStaleMd5(options.input_jar, options.output_jar,
-                          options.classpath, options.android_sdk_jar),
+                          options.classpath, options.bootclasspath_entry),
       options,
       input_paths=input_paths,
       input_strings=[],
-      output_paths=output_paths)
+      output_paths=output_paths,
+      depfile_deps=depfile_deps)
 
 
 if __name__ == '__main__':

build/config/android/config.gni

@@ -169,8 +169,8 @@ if (is_android) {
     # abi in 64-bit Monochrome and WebView.
     build_apk_secondary_abi = true
 
-    # Enables java8 language features (via retrolambda).
-    # work-in-progress (http://crbug.com/642600)
+    # Enables java8 language features (via Desugar).
+    # work-in-progress (http://crbug.com/730711)
     use_java8 = false
 
     # Build incremental targets whenever possible.

build/config/android/internal_rules.gni

@@ -1190,10 +1190,10 @@ if (enable_java_templates) {
         defined(invoker.supports_android) && invoker.supports_android &&
         (is_java_debug || dcheck_always_on)
 
-    _retrolambda =
+    _desugar =
         defined(invoker.supports_android) && invoker.supports_android &&
         ((defined(invoker.process_java8) && invoker.process_java8) || use_java8)
-
+  
     _deps = []
     _previous_output_jar = _input_jar_path
 
@@ -1269,14 +1269,17 @@ if (enable_java_templates) {
       _previous_output_jar = _assert_output_jar
     }
 
-    if (_retrolambda) {
-      _retrolambda_target = "${target_name}__retrolambda"
-      _retrolambda_input_jar = _previous_output_jar
-      _retrolambda_output_jar = "$target_out_dir/$target_name-retrolambda.jar"
+    assert(!defined(invoker.alternative_android_sdk_ijar) ||
+        invoker.alternative_android_sdk_ijar != "")
+    assert(!defined(invoker.alternative_android_sdk_ijar_dep) ||
+        invoker.alternative_android_sdk_ijar_dep != "")
+    if (_desugar) {
+      _desugar_target = "${target_name}__desugar"
+      _desugar_input_jar = _previous_output_jar
+      _desugar_output_jar = "$target_out_dir/$target_name-desugar.jar"
 
-      android_sdk_jar = "$android_sdk/android.jar"
-      action(_retrolambda_target) {
-        script = "//build/android/gyp/retrolambda.py"
+      action(_desugar_target) {
+        script = "//build/android/gyp/desugar.py"
         deps = _deps
         if (defined(invoker.deps)) {
           deps += invoker.deps
@@ -1286,27 +1289,35 @@ if (enable_java_templates) {
         }
         inputs = [
           _build_config,
-          _retrolambda_input_jar,
+          _desugar_input_jar,
         ]
         outputs = [
-          _retrolambda_output_jar,
+          _desugar_output_jar,
         ]
+        if (defined(invoker.alternative_android_sdk_ijar)) {
+          deps += [ invoker.alternative_android_sdk_ijar_dep ]
+          _android_sdk_ijar = invoker.alternative_android_sdk_ijar
+        } else {
+          deps += [ "//build/android:android_ijar" ]
+          _android_sdk_ijar = "$root_out_dir/lib.java/android.interface.jar"
+        }
+        inputs += [ _android_sdk_ijar ]
         args = [
           "--input-jar",
-          rebase_path(_retrolambda_input_jar, root_build_dir),
+          rebase_path(_desugar_input_jar, root_build_dir),
           "--output-jar",
-          rebase_path(_retrolambda_output_jar, root_build_dir),
+          rebase_path(_desugar_output_jar, root_build_dir),
           "--classpath=@FileArg($_rebased_build_config:javac:classpath)",
-          "--android-sdk-jar",
-          rebase_path(android_sdk_jar, root_build_dir),
+          "--bootclasspath-entry",
+          rebase_path(_android_sdk_ijar, root_build_dir),
         ]
       }
 
       _deps = []
-      _deps = [ ":$_retrolambda_target" ]
-      _previous_output_jar = _retrolambda_output_jar
+      _deps = [ ":$_desugar_target" ]
+      _previous_output_jar = _desugar_output_jar
     }
-
+    
     _output_jar_target = "${target_name}__copy"
     copy(_output_jar_target) {
       deps = _deps
@@ -2053,8 +2064,8 @@ if (enable_java_templates) {
       forward_variables_from(invoker,
                              [
                                "jar_excluded_patterns",
-                               "strip_resource_classes",
                                "process_java8",
+                               "strip_resource_classes",
                              ])
 
       visibility = [
@@ -2346,7 +2357,12 @@ if (enable_java_templates) {
     }
 
     process_java_prebuilt(_process_prebuilt_target_name) {
-      forward_variables_from(invoker, [ "jar_excluded_patterns" ])
+      forward_variables_from(invoker,
+                             [
+                               "alternative_android_sdk_ijar",
+                               "alternative_android_sdk_ijar_dep",
+                               "jar_excluded_patterns",
+                             ])
       supports_android = _supports_android
       build_config = _build_config
       input_jar_path = _javac_jar_path

third_party/.gitignore

@@ -158,7 +158,6 @@
 /pywebsocket/src
 /re2/src
 /requests/src
-/retrolambda/*.jar
 /robolectric/lib/android-all-4.3_r2-robolectric-0.jar
 /robolectric/lib/android-all-5.0.0_r2-robolectric-1.jar
 /robolectric/lib/android-all-7.1.0_r7-robolectric-0.jar

third_party/retrolambda/OWNERS

-agrieve@chromium.org
-zpeng@chromium.org
-
-# COMPONENT: Build

third_party/retrolambda/README.chromium

-Name: Retrolambda, backport of Java 8's lambda expressions to Java 7, 6, 5
-Short Name: retrolambda
-URL: https://github.com/orfjackal/retrolambda/
-Version: 2.5.1
-License: Apache 2.0
-License File: NOT_SHIPPED
-Security Critical: no
-
-Description:
-Retrolambda is a Java library used by the build process to transform Java 8's
-bytecode to Java 7's bytecode. It is used to enable Java 8 features such as
-lambda expressions for Chrome on Android without switching from javac to Jack.
-
-Local Modifications:
-None
-
-Update instructions (requires @google.com account):
-- Download jar from Maven Central
-http://central.maven.org/maven2/net/orfjackal/retrolambda/retrolambda
-- Modify build/android/gyp/retrolambda.py and verify the new jar works
-- Remove existing SHA1 file
-- If gcloud auth tokens are not set up, run
-$ download_from_google_storage --config
-- Upload new jar to gcloud. In third_party/retrolambda, run
-$ upload_to_google_storage.py -b chromium-android-tools/retrolambda {new_jar}
-

third_party/retrolambda/retrolambda-2.5.1.jar.sha1

-03db6629d3ba0168c580af3be44fe54014dfb105
\ No newline at end of file