Update experimental Java 8 support to use Desugar instead of Retrolambda

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.
 
 import argparse
 import os
 import shutil
 import sys
 import tempfile
 
 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', '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, android_sdk_jar,
+                bootclasspath):
+  cmd = [
+      'java',
+      '-jar',
+      _DESUGAR_JAR_PATH,
+      '--input',
+      input_jar,
+      '--bootclasspath_entry',
+      bootclasspath,
+      '--output',
+      output_jar,
+      '--desugar_try_with_resources_if_needed=false',
+  ]
+  for path in sorted(classpath) + [android_sdk_jar]:

[agrieve, 2017/07/20 00:26:51]

shouldn't sort the classpath. Order could matter.

[F, 2017/07/20 17:30:56]

Done. Thanks! I misunderstood "ordered" in the parameter description as
"alphabetically ordered". My bad

+    cmd += ['--classpath_entry', path]
+  build_utils.CheckOutput(cmd, print_stdout=False)
 
 
 def main():
   args = build_utils.ExpandFileArgs(sys.argv[1:])
   parser = argparse.ArgumentParser()
   build_utils.AddDepfileOption(parser)
   parser.add_argument('--input-jar', required=True,
                       help='Jar input path to include .class files from.')
   parser.add_argument('--output-jar', required=True,
                       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', required=True,
+                      help='Javac bootclasspath.')
   options = parser.parse_args(args)
 
   options.classpath = build_utils.ParseGnList(options.classpath)
-  input_paths = options.classpath + [options.input_jar]
+  input_paths = options.classpath + [options.input_jar,
+                                     options.android_sdk_jar,
+                                     options.bootclasspath]

[agrieve, 2017/07/20 00:26:51]

I don't think this is quite right. There's no reason to have both a
"bootclasspath" as well as "android_sdk_jar". Use just one or the other.

Note that bootclasspath implies that it's a colon:separated:list of files

It doesn't make sense to use both the android .jar as well as the android
.interface.jar. They are semantically the same in this context (just use the
interface jar)

[F, 2017/07/20 17:30:56]

Done.

   output_paths = [options.output_jar]
 
   build_utils.CallAndWriteDepfileIfStale(
       lambda: _OnStaleMd5(options.input_jar, options.output_jar,
-                          options.classpath, options.android_sdk_jar),
+                          options.classpath, options.android_sdk_jar,
+                          options.bootclasspath),
       options,
       input_paths=input_paths,
       input_strings=[],
-      output_paths=output_paths)
+      output_paths=output_paths,
+      depfile_deps=input_paths)
 
 
 if __name__ == '__main__':
   sys.exit(main())