8356941: AbstractMethodError in HotSpot Due to Incorrect Handling of Private Method

Reviewed-by: coleenp, heidinga

Author: David Holmes

src/hotspot/share/classfile/defaultMethods.cpp

@@ -658,13 +658,11 @@ static void find_empty_vtable_slots(GrowableArray<EmptyVtableSlot*>* slots,
     if (super->default_methods() != nullptr) {
       for (int i = 0; i < super->default_methods()->length(); ++i) {
         Method* m = super->default_methods()->at(i);
-        // m is a method that would have been a miranda if not for the
-        // default method processing that occurred on behalf of our superclass,
-        // so it's a method we want to re-examine in this new context.  That is,
-        // unless we have a real implementation of it in the current class.
         if (!already_in_vtable_slots(slots, m)) {
+          // m is a method that we need to re-examine, unless we have a valid concrete
+          // implementation in the current class - see FindMethodsByErasedSig::visit.
           Method* impl = klass->lookup_method(m->name(), m->signature());
-          if (impl == nullptr || impl->is_overpass() || impl->is_static()) {
+          if (impl == nullptr || impl->is_overpass() || impl->is_static() || impl->is_private()) {
             slots->append(new EmptyVtableSlot(m));
           }
         }

test/hotspot/jtreg/vmTestbase/vm/runtime/defmeth/PrivateMethodsTest.java

@@ -680,6 +680,8 @@ public void testPrivateSuperClassMethodDefaultMethod(TestBuilder b) {
      * public class C extends B { }
      *
      * TEST: { B b = new C(); b.m()I throws IllegalAccessError; }
+     * TEST: { I b = new B(); b.m()I returns 3; }
+     * TEST: { I c = new C(); c.m()I returns 3; }
      */
     public void testPrivateSuperClassMethodDefaultMethodNoOverride(TestBuilder b) {
         ConcreteClass A = b.clazz("A")
@@ -694,6 +696,10 @@ public void testPrivateSuperClassMethodDefaultMethodNoOverride(TestBuilder b) {
 
         ConcreteClass C = b.clazz("C").extend(B).build();
 
-        b.test().privateCallSite(B, C, "m", "()I").throws_(IllegalAccessError.class).done();
+        b.test().privateCallSite(B, C, "m", "()I").throws_(IllegalAccessError.class).done()
+         .test().       callSite(I, B, "m", "()I").returns(3).done()
+         .test().       callSite(I, C, "m", "()I").returns(3).done()
+        ;
+
     }
 }