InterfaceProcessor should keep some bridge methods
This CL updates InterfaceProcessor such that some default interface methods will be kept as virtual methods even if they are marked as bridge methods. This is needed if there is a default interface method that is marked as a bridge method, but does not override a method declared in a supertype of the current interface (such a situation can happen as a result of vertical class merging).
Change-Id: I60905948401f647a0ed27582e128ef562a4c8a84
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
index f4a76e6..c538e86 100644
--- a/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
+++ b/src/main/java/com/android/tools/r8/ir/desugar/InterfaceProcessor.java
@@ -9,6 +9,7 @@
import com.android.tools.r8.graph.ClassAccessFlags;
import com.android.tools.r8.graph.Code;
import com.android.tools.r8.graph.DexAnnotationSet;
+import com.android.tools.r8.graph.DexClass;
import com.android.tools.r8.graph.DexCode;
import com.android.tools.r8.graph.DexEncodedField;
import com.android.tools.r8.graph.DexEncodedMethod;
@@ -18,11 +19,15 @@
import com.android.tools.r8.graph.DexTypeList;
import com.android.tools.r8.graph.MethodAccessFlags;
import com.android.tools.r8.origin.SynthesizedOrigin;
+import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
+import java.util.Deque;
+import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Map;
+import java.util.Set;
// Default and static method interface desugaring processor for interfaces.
//
@@ -78,7 +83,7 @@
}
// Remove bridge methods.
- if (!virtual.accessFlags.isBridge()) {
+ if (interfaceMethodRemovalChangesApi(virtual, iface)) {
remainingMethods.add(virtual);
}
}
@@ -180,6 +185,38 @@
companionClasses.put(iface, companionClass);
}
+ // Returns true if the given interface method must be kept on [iface] after moving its
+ // implementation to the companion class of [iface]. This is always the case for non-bridge
+ // methods. Bridge methods that does not override an implementation in a super-interface must
+ // also be kept (such a situation can happen if the vertical class merger merges two interfaces).
+ private boolean interfaceMethodRemovalChangesApi(DexEncodedMethod method, DexClass iface) {
+ if (method.accessFlags.isBridge()) {
+ Deque<DexType> worklist = new ArrayDeque<>();
+ Set<DexType> seenBefore = new HashSet<>();
+ if (iface.superType != null) {
+ worklist.add(iface.superType);
+ }
+ Collections.addAll(worklist, iface.interfaces.values);
+ while (!worklist.isEmpty()) {
+ DexType superType = worklist.pop();
+ if (!seenBefore.add(superType)) {
+ continue;
+ }
+ DexClass clazz = rewriter.findDefinitionFor(superType);
+ if (clazz != null) {
+ if (clazz.lookupVirtualMethod(method.method) != null) {
+ return false;
+ }
+ if (clazz.superType != null) {
+ worklist.add(clazz.superType);
+ }
+ Collections.addAll(worklist, clazz.interfaces.values);
+ }
+ }
+ }
+ return true;
+ }
+
private boolean isStaticMethod(DexEncodedMethod method) {
if (method.accessFlags.isNative()) {
throw new Unimplemented("Native interface methods are not yet supported.");
