Android: Roll R8

Keeping R8 revision the same, but updated local modifications:
* Expose dexsplitter-related R8 flags
   * Taken from reverted change:
     https://chromium-review.googlesource.com/c/chromium/src/+/2014309
* Disable stateless lambda "optimization"
* Makes horizontal & vertical class merging separate flags.
* Make --file-per-class use DexFilePerClassFile rather than
  DexFilePerClass (fixes incremental dexing /w desugar_with_d8).

Also updates update instructions.

Bug: 1032609
Change-Id: I1553785fa103ed3164206e0397fe320cce980f61
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2127512
Reviewed-by: Sam Maier <smaier@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755098}

DEPS

@@ -1331,7 +1331,7 @@ deps = {
       'packages': [
           {
               'package': 'chromium/third_party/r8',
-              'version': 'C28ypVbWD-R2M9x9fH7QniIsYjJrKoUhxqEV_cZR4qgC',
+              'version': 'QBuWB80TzI5JFXtwaZQbr91Ry3Lb0AmRl8kBchm5FY0C',
           },
       ],
       'condition': 'checkout_android',

build/config/android/internal_rules.gni

@@ -1375,14 +1375,11 @@ if (enable_java_templates) {
         } else if (enable_incremental_d8 &&
                    !(defined(invoker.disable_incremental) &&
                      invoker.disable_incremental)) {
-          # TODO(crbug.com/1015559): Fix incremental builds when d8 is desugaring.
-          if (!desugar_with_d8) {
-            # Don't use incremental dexing for ProGuarded inputs as a precaution.
-            args += [
-              "--incremental-dir",
-              rebase_path("$target_out_dir/$target_name", root_build_dir),
-            ]
-          }
+          # Don't use incremental dexing for ProGuarded inputs as a precaution.
+          args += [
+            "--incremental-dir",
+            rebase_path("$target_out_dir/$target_name", root_build_dir),
+          ]
         }
 
         if (_enable_multidex) {

third_party/r8/README.chromium

@@ -18,6 +18,29 @@ Turning off outlining because it caused issues when synchronized proguarding
 Trichrome due to illegal dex references (crbug.com/956839). Will only be used
 for android_apk() targets that set `disable_r8_outlining = true`):
 
-Increase callGraphCycleEliminatorMaxDepthThreshold (b/143685705).
+Added --feature-jar flag for doing dex splitting.
 
-Patch is located at //third_party/r8/local_modifications.diff.
+local_modifications.diff created via:
+git diff >local_modifications.diff
+
+Update Instructions:
+# Download R8:
+git clone https://r8.googlesource.com/r8
+cd r8
+# Apply the patch:
+git apply $CHROMIUM_SRC/third_party/r8/local_modifications.diff
+# Build:
+tools/gradle.py r8
+# Shrink (improves r8/d8 launch time):
+java -jar build/libs/r8.jar --debug --classfile --output r8.jar \
+    --lib $CHROMIUM_SRC/third_party/jdk/current --pg-conf src/main/keep.txt \
+    --no-minification --no-desugaring build/libs/r8.jar
+rm $CHROMIUM_SRC/third_party/r8/libs/r8.jar
+cp r8.jar $CHROMIUM_SRC/third_party/r8/libs/r8.jar
+
+# Upload to CIPD:
+cipd create --pkg-def cipd.yaml # Make note of the instance ID
+
+# Manually update:
+* README.chromium (version number via "java -jar lib/r8.jar --version")
+* //DEPS (instance ID output by cipd create)

third_party/r8/cipd.yaml

@@ -2,21 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# Example for updating r8 in the current dir:
-#   Run:
-#     cd <r8 code directory>
-#     tools/gradle.py r8 # Building R8
-#     cd -
-#
-#     cipd auth-login
-#     rm lib/r8.jar
-#     cp <r8 code directory>/build/libs/r8.jar lib/r8.jar
-#     java -jar lib/r8.jar --version
-#     cipd create --pkg-def cipd.yaml # Make note of the instance ID
-#   Manually update:
-#     README.chromium (version number)
-#     //DEPS (instance ID output by cipd create)
-
+# To create CIPD package run the following command.
+# cipd create --pkg-def cipd.yaml
 package: chromium/third_party/r8
 description: >
   R8 is a proguard-like optimizer that also has the option to dex.

third_party/r8/local_modifications.diff

@@ -1,5 +1,84 @@
+diff --git a/src/main/java/com/android/tools/r8/D8CommandParser.java b/src/main/java/com/android/tools/r8/D8CommandParser.java
+index f66fff8f3..c63f4f566 100644
+--- a/src/main/java/com/android/tools/r8/D8CommandParser.java
++++ b/src/main/java/com/android/tools/r8/D8CommandParser.java
+@@ -205,7 +205,7 @@ public class D8CommandParser extends BaseCompilerCommandParser<D8Command, D8Comm
+         }
+         compilationMode = CompilationMode.RELEASE;
+       } else if (arg.equals("--file-per-class")) {
+-        outputMode = OutputMode.DexFilePerClass;
++        outputMode = OutputMode.DexFilePerClassFile;
+       } else if (arg.equals("--output")) {
+         if (outputPath != null) {
+           builder.error(
+diff --git a/src/main/java/com/android/tools/r8/R8Command.java b/src/main/java/com/android/tools/r8/R8Command.java
+index 4051f9cef..6d034d5b8 100644
+--- a/src/main/java/com/android/tools/r8/R8Command.java
++++ b/src/main/java/com/android/tools/r8/R8Command.java
+@@ -42,6 +42,8 @@ import java.util.function.BiPredicate;
+ import java.util.function.Consumer;
+ import java.util.function.Function;
+
++import com.android.tools.r8.DexIndexedConsumer.DirectoryConsumer;
++
+ /**
+  * Immutable command structure for an invocation of the {@link R8} compiler.
+  *
+@@ -234,6 +236,15 @@ public final class R8Command extends BaseCompilerCommand {
+       return self();
+     }
+
++    public Builder addFeatureJar(Path inputJarPath, Path outputPath) {
++      addFeatureSplit(splitBuilder ->
++          splitBuilder
++            .addProgramResourceProvider(ArchiveProgramResourceProvider.fromArchive(inputJarPath))
++            .setProgramConsumer(new DirectoryConsumer(outputPath))
++            .build());
++      return self();
++    }
++
+     /**
+      * Set a consumer for receiving the proguard-map content.
+      *
+diff --git a/src/main/java/com/android/tools/r8/R8CommandParser.java b/src/main/java/com/android/tools/r8/R8CommandParser.java
+index 22ebb5e42..b53e4c59e 100644
+--- a/src/main/java/com/android/tools/r8/R8CommandParser.java
++++ b/src/main/java/com/android/tools/r8/R8CommandParser.java
+@@ -24,6 +24,7 @@ public class R8CommandParser extends BaseCompilerCommandParser<R8Command, R8Comm
+           "--min-api",
+           "--main-dex-rules",
+           "--main-dex-list",
++          "--feature-jar",
+           "--main-dex-list-output",
+           "--pg-conf",
+           "--pg-map-output",
+@@ -205,6 +206,11 @@ public class R8CommandParser extends BaseCompilerCommandParser<R8Command, R8Comm
+         builder.setDisableDesugaring(true);
+       } else if (arg.equals("--main-dex-rules")) {
+         builder.addMainDexRulesFiles(Paths.get(nextArg));
++      } else if (arg.equals("--feature-jar")) {
++        String[] argParts = nextArg.split(":");
++        String featureJarInputPath = argParts[0];
++        String featureJarOutputPath = argParts[1];
++        builder.addFeatureJar(Paths.get(featureJarInputPath), Paths.get(featureJarOutputPath));
+       } else if (arg.equals("--main-dex-list")) {
+         builder.addMainDexListFiles(Paths.get(nextArg));
+       } else if (arg.equals("--main-dex-list-output")) {
+diff --git a/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java b/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
+index 0831e6d93..49c1a202b 100644
+--- a/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
++++ b/src/main/java/com/android/tools/r8/ir/desugar/LambdaClass.java
+@@ -206,7 +206,7 @@ public final class LambdaClass {
+   }
+
+   public final boolean isStateless() {
+-    return descriptor.isStateless();
++    return false;  // descriptor.isStateless();
+   }
+
+   void addSynthesizedFrom(DexProgramClass clazz) {
 diff --git a/src/main/java/com/android/tools/r8/utils/InternalOptions.java b/src/main/java/com/android/tools/r8/utils/InternalOptions.java
-index 232b54a54..5c3a227b3 100644
+index 232b54a54..fd45dfe36 100644
 --- a/src/main/java/com/android/tools/r8/utils/InternalOptions.java
 +++ b/src/main/java/com/android/tools/r8/utils/InternalOptions.java
 @@ -198,8 +198,8 @@ public class InternalOptions {
@@ -8,8 +87,8 @@ index 232b54a54..5c3a227b3 100644
        System.getProperty("com.android.tools.r8.fieldBitAccessAnalysis") != null;
 -  public boolean enableHorizontalClassMerging = true;
 -  public boolean enableVerticalClassMerging = true;
-+  public boolean enableHorizontalClassMerging = System.getProperty("com.android.tools.r8.enableClassMerging") != null;
-+  public boolean enableVerticalClassMerging = System.getProperty("com.android.tools.r8.enableClassMerging") != null;
++  public boolean enableHorizontalClassMerging = System.getProperty("com.android.tools.r8.enableHorizontalClassMerging") != null;
++  public boolean enableVerticalClassMerging = System.getProperty("com.android.tools.r8.enableVerticalClassMerging") != null;
    public boolean enableArgumentRemoval = true;
    public boolean enableUnusedArgumentRemoval = true;
    public boolean enableUnusedInterfaceRemoval = true;
@@ -22,3 +101,20 @@ index 232b54a54..5c3a227b3 100644
      public int minSize = 3;
      public int maxSize = 99;
      public int threshold = 20;
+diff --git a/src/main/keep.txt b/src/main/keep.txt
+index b0c58c916..5e4405175 100644
+--- a/src/main/keep.txt
++++ b/src/main/keep.txt
+@@ -27,4 +27,10 @@
+ -keep public class com.android.tools.r8.compatproguard.CompatProguard { public static void main(java.lang.String[]); }
+
+ # Compatibility command line program used by in google3.
+--keep public class com.android.tools.r8.compatdx.CompatDx { public static void main(java.lang.String[]); }
+\ No newline at end of file
++-keep public class com.android.tools.r8.compatdx.CompatDx { public static void main(java.lang.String[]); }
++
++-keep public class com.android.tools.r8.SwissArmyKnife { *; }
++
++# Chrome: We want to maintain stack traces from the R8 tool, so disable
++# optimizations.
++-dontoptimize