Make R8 dump keep rule file and use it on L8

Bug: 1056751
Change-Id: Ifbf0eaed0c6a99725893e798df56298768085474
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2194071
Commit-Queue: Henry Jian <hzjian@google.com>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#771585}

build/android/gyp/dex_jdk_libs.py

@@ -29,30 +29,44 @@ def _ParseArgs(args):
   return options
 
 
-def main(args):
-  options = _ParseArgs(args)
-
+def DexJdkLibJar(r8_path, min_api, desugar_jdk_libs_json, desugar_jdk_libs_jar,
+                 keep_rule_file, output):
   # TODO(agrieve): Spews a lot of stderr about missing classes.
   with build_utils.TempDir() as tmp_dir:
     cmd = [
         build_utils.JAVA_PATH,
         '-jar',
-        options.r8_path,
+        r8_path,
         'l8',
         '--min-api',
-        options.min_api,
-        #'--lib', build_utils.JAVA_HOME,
+        min_api,
+        '--lib',
+        build_utils.JAVA_HOME,
         '--desugared-lib',
-        options.desugar_jdk_libs_json,
-        '--output',
-        tmp_dir,
-        options.desugar_jdk_libs_jar
+        desugar_jdk_libs_json,
     ]
-    subprocess.check_output(cmd, stderr=subprocess.STDOUT)
 
+    if keep_rule_file:
+      cmd += ['--pg-conf', keep_rule_file]
+
+    cmd += ['--output', tmp_dir, desugar_jdk_libs_jar]
+
+    subprocess.check_output(cmd, stderr=subprocess.STDOUT)
     if os.path.exists(os.path.join(tmp_dir, 'classes2.dex')):
       raise Exception('Achievement unlocked: desugar_jdk_libs is multidex!')
-    shutil.move(os.path.join(tmp_dir, 'classes.dex'), options.output)
+
+    # classes.dex might not exists if the "desugar_jdk_libs_jar" is not used
+    # at all.
+    if os.path.exists(os.path.join(tmp_dir, 'classes.dex')):
+      shutil.move(os.path.join(tmp_dir, 'classes.dex'), output)
+      return True
+    return False
+
+
+def main(args):
+  options = _ParseArgs(args)
+  DexJdkLibJar(options.r8_path, options.min_api, options.desugar_jdk_libs_json,
+               options.desugar_jdk_libs_jar, None, options.output)
 
 
 if __name__ == '__main__':

build/android/gyp/proguard.py

@@ -12,6 +12,7 @@ import sys
 import tempfile
 import zipfile
 
+import dex_jdk_libs
 from util import build_utils
 from util import diff_utils
 
@@ -116,6 +117,8 @@ def _ParseOptions():
                       action='append',
                       required=True,
                       help='GN-list of .jar files to optimize.')
+  parser.add_argument('--desugar-jdk-libs-jar',
+                      help='Path to desugar_jdk_libs.jar.')
   parser.add_argument('--output-path', help='Path to the generated .jar file.')
   parser.add_argument(
       '--proguard-configs',
@@ -196,6 +199,8 @@ def _ParseOptions():
   parser.add_argument(
       '--stamp',
       help='File to touch upon success. Mutually exclusive with --output-path')
+  parser.add_argument('--desugared-library-keep-rule-output',
+                      help='Path to desugared library keep rule output file.')
 
   options = parser.parse_args(args)
 
@@ -265,12 +270,18 @@ class _DexPathContext(object):
     self.staging_dir = os.path.join(work_dir, name)
     os.mkdir(self.staging_dir)
 
-  def CreateOutput(self):
+  def CreateOutput(self, has_imported_lib=False, keep_rule_output=None):
     found_files = build_utils.FindInDirectory(self.staging_dir)
     if not found_files:
       raise Exception('Missing dex outputs in {}'.format(self.staging_dir))
 
     if self._final_output_path.endswith('.dex'):
+      if has_imported_lib:
+        raise Exception(
+            'Trying to create a single .dex file, but a dependency requires '
+            'JDK Library Desugaring (which necessitates a second file).'
+            'Refer to %s to see what desugaring was required' %
+            keep_rule_output)
       if len(found_files) != 1:
         raise Exception('Expected exactly 1 dex file output, found: {}'.format(
             '\t'.join(found_files)))
@@ -330,7 +341,12 @@ def _OptimizeWithR8(options,
     ]
 
     if options.desugar_jdk_libs_json:
-      cmd += ['--desugared-lib', options.desugar_jdk_libs_json]
+      cmd += [
+          '--desugared-lib',
+          options.desugar_jdk_libs_json,
+          '--desugared-library-keep-rule-output',
+          options.desugared_library_keep_rule_output,
+      ]
 
     if options.min_api:
       cmd += ['--min-api', options.min_api]
@@ -379,7 +395,18 @@ def _OptimizeWithR8(options,
           'android/docs/java_optimization.md#Debugging-common-failures\n'))
       raise ProguardProcessError(err, debugging_link)
 
-    base_dex_context.CreateOutput()
+    base_has_imported_lib = False
+    if options.desugar_jdk_libs_json:
+      existing_files = build_utils.FindInDirectory(base_dex_context.staging_dir)
+      base_has_imported_lib = dex_jdk_libs.DexJdkLibJar(
+          options.r8_path, options.min_api, options.desugar_jdk_libs_json,
+          options.desugar_jdk_libs_jar,
+          options.desugared_library_keep_rule_output,
+          os.path.join(base_dex_context.staging_dir,
+                       'classes%d.dex' % (len(existing_files) + 1)))
+
+    base_dex_context.CreateOutput(base_has_imported_lib,
+                                  options.desugared_library_keep_rule_output)
     for feature in feature_contexts:
       feature.CreateOutput()
 

build/android/gyp/proguard.pydeps

 # Generated by running:
 #   build/print_python_deps.py --root build/android/gyp --output build/android/gyp/proguard.pydeps build/android/gyp/proguard.py
 ../../gn_helpers.py
+dex_jdk_libs.py
 proguard.py
 util/__init__.py
 util/build_utils.py

build/config/android/config.gni

@@ -236,7 +236,7 @@ if (is_android || is_chromeos) {
     enable_bazel_desugar = true
 
     # Enables Java library desugaring.
-    # This will cause an extra 1MB classes.dex file to appear in every apk.
+    # This will cause an extra classes.dex file to appear in every apk.
     enable_jdk_library_desugaring = false
   }
 

build/config/android/internal_rules.gni

@@ -1085,6 +1085,19 @@ if (enable_java_templates) {
         rebase_path(_desugar_jdk_libs_json, root_build_dir),
       ]
       _inputs += [ _desugar_jdk_libs_json ]
+
+      _args += [
+        "--desugar-jdk-libs-jar",
+        rebase_path(_desugar_jdk_libs_jar, root_build_dir),
+      ]
+      _inputs += [ _desugar_jdk_libs_jar ]
+
+      _desugared_library_keep_rule_output_path =
+          "$target_gen_dir/$target_name.desugared_library_keep_rules.flags"
+      _args += [
+        "--desugared-library-keep-rule-output",
+        rebase_path(_desugared_library_keep_rule_output_path, root_build_dir),
+      ]
     }
 
     _enable_assert = is_java_debug || dcheck_always_on
@@ -3826,10 +3839,15 @@ if (enable_java_templates) {
 #   verify_native_libs_and_assets_target_name: (optional): If set, will verify
 #     the list of included native libraries and assets is consistent with an
 #     expectation file.
+#   proguard_enabled: Optional. True if proguarding is enabled for this
+#     bundle. Default is to enable this only for release builds. Note that
+#     this will always perform synchronized proguarding.
 template("create_android_app_bundle_module") {
   _rebased_build_config = rebase_path(invoker.build_config, root_build_dir)
   _rebased_native_libraries_config =
       rebase_path(invoker.native_libraries_config, root_build_dir)
+  _proguard_enabled =
+      defined(invoker.proguard_enabled) && invoker.proguard_enabled
 
   forward_variables_from(invoker,
                          [
@@ -3900,8 +3918,9 @@ template("create_android_app_bundle_module") {
     _args += [ "--dex-file=@FileArg($_rebased_build_config:final_dex:path)" ]
   }
 
-  # TODO(https://crbug.com/1056751): Add support for proguarding jdk libs.
-  if (enable_jdk_library_desugaring && invoker.module_name == "base") {
+  # The library is imported via proguard when proguard is enabled.
+  if (!_proguard_enabled && enable_jdk_library_desugaring &&
+      invoker.module_name == "base") {
     _all_jdk_libs = "//build/android:all_jdk_libs"
     _deps += [ _all_jdk_libs ]
     _jdk_libs_dex =

build/config/android/rules.gni

@@ -3163,8 +3163,7 @@ if (enable_java_templates) {
 
         deps = _deps + [ ":$_build_config_target" ]
 
-        # TODO(https://crbug.com/1056751): Add support for proguarding jdk libs.
-        if (enable_jdk_library_desugaring) {
+        if (!_proguard_enabled && enable_jdk_library_desugaring) {
           _all_jdk_libs = "//build/android:all_jdk_libs"
           deps += [ _all_jdk_libs ]
           jdk_libs_dex = get_label_info(_all_jdk_libs, "target_out_dir") +
@@ -4706,6 +4705,7 @@ if (enable_java_templates) {
                                  "is_multi_abi",
                                  "min_sdk_version",
                                  "uncompress_dex",
+                                 "proguard_enabled",
                                ])
         module_name = _module.name
         build_config = _module_build_config