Widen vertical class merge policy slightly
Allow merging classes and interfaces with single a implementer if the
super type has no direct instantiations and no static fields or methods.
Change-Id: Ife712132da6bbd604b43fe6a292a714d4f9b3b7a
diff --git a/src/main/java/com/android/tools/r8/verticalclassmerging/policies/NoClassInitializationChangesPolicy.java b/src/main/java/com/android/tools/r8/verticalclassmerging/policies/NoClassInitializationChangesPolicy.java
index 8d137ee..870469d 100644
--- a/src/main/java/com/android/tools/r8/verticalclassmerging/policies/NoClassInitializationChangesPolicy.java
+++ b/src/main/java/com/android/tools/r8/verticalclassmerging/policies/NoClassInitializationChangesPolicy.java
@@ -6,7 +6,9 @@
import static com.android.tools.r8.utils.MapUtils.ignoreKey;
import com.android.tools.r8.graph.AppView;
+import com.android.tools.r8.graph.DexEncodedMethod;
import com.android.tools.r8.graph.DexProgramClass;
+import com.android.tools.r8.graph.ObjectAllocationInfoCollection;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
import com.android.tools.r8.verticalclassmerging.VerticalMergeGroup;
import com.google.common.collect.Sets;
@@ -43,6 +45,23 @@
return false;
}
}
+
+ ObjectAllocationInfoCollection objectAllocationInfoCollection =
+ appView.appInfo().getObjectAllocationInfoCollection();
+ // When the source class does not declare a class initializer, then we can merge
+ // regardless of the class initialization side effects in the target class if
+ // there is no way to trigger the class initialization side effects of the source
+ // class directly.
+ //
+ // We therefore check if the source class is not instantiated by a new-instance
+ // instruction, and that there cannot be any invoke-static of static-get
+ // instructions that target the source class.
+ if ((sourceClass.isInterface()
+ || !objectAllocationInfoCollection.isInstantiatedDirectly(sourceClass))
+ && !sourceClass.hasStaticFields()
+ && !sourceClass.getMethodCollection().hasDirectMethods(DexEncodedMethod::isStatic)) {
+ return true;
+ }
assert !sourceClass.hasClassInitializer() || !targetClass.hasClassInitializer();
return !targetClass.classInitializationMayHaveSideEffects(
appView, type -> type.isIdenticalTo(sourceClass.getType()))
