--- a/src/share/vm/classfile/defaultMethods.cpp	Tue Nov 19 17:44:26 2013 +0100
+++ b/src/share/vm/classfile/defaultMethods.cpp	Wed Nov 20 00:10:38 2013 +0100
@@ -171,8 +171,12 @@
   }
   bool is_cancelled() const { return _cancelled; }
 
+  // This code used to skip interface classes because their only
+  // superclass was j.l.Object which would be also covered by class
+  // superclass hierarchy walks. Now that the starting point can be
+  // an interface, we must ensure we catch j.l.Object as the super.
   static bool has_super(InstanceKlass* cls) {
-    return cls->super() != NULL && !cls->is_interface();
+    return cls->super() != NULL;
   }
 
   Node* node_at_depth(int i) const {
@@ -345,7 +349,6 @@
   }
 
   Symbol* generate_no_defaults_message(TRAPS) const;
-  Symbol* generate_abstract_method_message(Method* method, TRAPS) const;
   Symbol* generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const;
 
  public:
@@ -392,32 +395,40 @@
       return;
     }
 
+    // Qualified methods are maximally-specific methods
+    // These include public, instance concrete (=default) and abstract methods
     GrowableArray<Method*> qualified_methods;
+    int num_defaults = 0;
+    int default_index = -1;
+    int qualified_index = -1;
     for (int i = 0; i < _members.length(); ++i) {
       Pair<Method*,QualifiedState> entry = _members.at(i);
       if (entry.second == QUALIFIED) {
         qualified_methods.append(entry.first);
+        qualified_index++;
+        if (entry.first->is_default_method()) {
+          num_defaults++;
+          default_index = qualified_index;
+
+        }
       }
     }
 
     if (qualified_methods.length() == 0) {
       _exception_message = generate_no_defaults_message(CHECK);
       _exception_name = vmSymbols::java_lang_AbstractMethodError();
-    } else if (qualified_methods.length() == 1) {
-      Method* method = qualified_methods.at(0);
-      if (method->is_abstract()) {
-        _exception_message = generate_abstract_method_message(method, CHECK);
-        _exception_name = vmSymbols::java_lang_AbstractMethodError();
-      } else {
-        _selected_target = qualified_methods.at(0);
-      }
-    } else {
+    // If only one qualified method is default, select that
+    } else if (num_defaults == 1) {
+        _selected_target = qualified_methods.at(default_index);
+    } else if (num_defaults > 1) {
       _exception_message = generate_conflicts_message(&qualified_methods,CHECK);
       _exception_name = vmSymbols::java_lang_IncompatibleClassChangeError();
+      if (TraceDefaultMethods) {
+        _exception_message->print_value_on(tty);
+        tty->print_cr("");
+      }
     }
-
-    assert((has_target() ^ throws_exception()) == 1,
-           "One and only one must be true");
+    // leave abstract methods alone, they will be found via normal search path
   }
 
   bool contains_signature(Symbol* query) {
@@ -475,20 +486,6 @@
   return SymbolTable::new_symbol("No qualifying defaults found", CHECK_NULL);
 }
 
-Symbol* MethodFamily::generate_abstract_method_message(Method* method, TRAPS) const {
-  Symbol* klass = method->klass_name();
-  Symbol* name = method->name();
-  Symbol* sig = method->signature();
-  stringStream ss;
-  ss.print("Method ");
-  ss.write((const char*)klass->bytes(), klass->utf8_length());
-  ss.print(".");
-  ss.write((const char*)name->bytes(), name->utf8_length());
-  ss.write((const char*)sig->bytes(), sig->utf8_length());
-  ss.print(" is abstract");
-  return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
-}
-
 Symbol* MethodFamily::generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const {
   stringStream ss;
   ss.print("Conflicting default methods:");
@@ -595,6 +592,18 @@
 #endif // ndef PRODUCT
 };
 
+static bool already_in_vtable_slots(GrowableArray<EmptyVtableSlot*>* slots, Method* m) {
+  bool found = false;
+  for (int j = 0; j < slots->length(); ++j) {
+    if (slots->at(j)->name() == m->name() &&
+        slots->at(j)->signature() == m->signature() ) {
+      found = true;
+      break;
+    }
+  }
+  return found;
+}
+
 static GrowableArray<EmptyVtableSlot*>* find_empty_vtable_slots(
     InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
 
@@ -604,8 +613,10 @@
 
   // All miranda methods are obvious candidates
   for (int i = 0; i < mirandas->length(); ++i) {
-    EmptyVtableSlot* slot = new EmptyVtableSlot(mirandas->at(i));
-    slots->append(slot);
+    Method* m = mirandas->at(i);
+    if (!already_in_vtable_slots(slots, m)) {
+      slots->append(new EmptyVtableSlot(m));
+    }
   }
 
   // Also any overpasses in our superclasses, that we haven't implemented.
@@ -621,7 +632,26 @@
         // unless we have a real implementation of it in the current class.
         Method* impl = klass->lookup_method(m->name(), m->signature());
         if (impl == NULL || impl->is_overpass()) {
-          slots->append(new EmptyVtableSlot(m));
+          if (!already_in_vtable_slots(slots, m)) {
+            slots->append(new EmptyVtableSlot(m));
+          }
+        }
+      }
+    }
+
+    // also any default methods in our superclasses
+    if (super->default_methods() != NULL) {
+      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.
+        Method* impl = klass->lookup_method(m->name(), m->signature());
+        if (impl == NULL || impl->is_overpass()) {
+          if (!already_in_vtable_slots(slots, m)) {
+            slots->append(new EmptyVtableSlot(m));
+          }
         }
       }
     }
@@ -678,8 +708,10 @@
     Method* m = iklass->find_method(_method_name, _method_signature);
     // private interface methods are not candidates for default methods
     // invokespecial to private interface methods doesn't use default method logic
+    // The overpasses are your supertypes' errors, we do not include them
     // future: take access controls into account for superclass methods
-    if (m != NULL && (!iklass->is_interface() || m->is_public())) {
+    if (m != NULL && !m->is_static() && !m->is_overpass() &&
+         (!iklass->is_interface() || m->is_public())) {
       if (_family == NULL) {
         _family = new StatefulMethodFamily();
       }
@@ -700,7 +732,7 @@
 
 
 
-static void create_overpasses(
+static void create_defaults_and_exceptions(
     GrowableArray<EmptyVtableSlot*>* slots, InstanceKlass* klass, TRAPS);
 
 static void generate_erased_defaults(
@@ -721,6 +753,8 @@
 
 static void merge_in_new_methods(InstanceKlass* klass,
     GrowableArray<Method*>* new_methods, TRAPS);
+static void create_default_methods( InstanceKlass* klass,
+    GrowableArray<Method*>* new_methods, TRAPS);
 
 // This is the guts of the default methods implementation.  This is called just
 // after the classfile has been parsed if some ancestor has default methods.
@@ -753,7 +787,8 @@
 #ifndef PRODUCT
   if (TraceDefaultMethods) {
     ResourceMark rm;  // be careful with these!
-    tty->print_cr("Class %s requires default method processing",
+    tty->print_cr("%s %s requires default method processing",
+        klass->is_interface() ? "Interface" : "Class",
         klass->name()->as_klass_external_name());
     PrintHierarchy printer;
     printer.run(klass);
@@ -778,11 +813,11 @@
  }
 #ifndef PRODUCT
   if (TraceDefaultMethods) {
-    tty->print_cr("Creating overpasses...");
+    tty->print_cr("Creating defaults and overpasses...");
   }
 #endif // ndef PRODUCT
 
-  create_overpasses(empty_slots, klass, CHECK);
+  create_defaults_and_exceptions(empty_slots, klass, CHECK);
 
 #ifndef PRODUCT
   if (TraceDefaultMethods) {
@@ -791,66 +826,6 @@
 #endif // ndef PRODUCT
 }
 
-
-
-#ifdef ASSERT
-// Return true is broad type is a covariant return of narrow type
-static bool covariant_return_type(BasicType narrow, BasicType broad) {
-  if (narrow == broad) {
-    return true;
-  }
-  if (broad == T_OBJECT) {
-    return true;
-  }
-  return false;
-}
-#endif
-
-static int assemble_redirect(
-    BytecodeConstantPool* cp, BytecodeBuffer* buffer,
-    Symbol* incoming, Method* target, TRAPS) {
-
-  BytecodeAssembler assem(buffer, cp);
-
-  SignatureStream in(incoming, true);
-  SignatureStream out(target->signature(), true);
-  u2 parameter_count = 0;
-
-  assem.aload(parameter_count++); // load 'this'
-
-  while (!in.at_return_type()) {
-    assert(!out.at_return_type(), "Parameter counts do not match");
-    BasicType bt = in.type();
-    assert(out.type() == bt, "Parameter types are not compatible");
-    assem.load(bt, parameter_count);
-    if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
-      assem.checkcast(out.as_symbol(THREAD));
-    } else if (bt == T_LONG || bt == T_DOUBLE) {
-      ++parameter_count; // longs and doubles use two slots
-    }
-    ++parameter_count;
-    in.next();
-    out.next();
-  }
-  assert(out.at_return_type(), "Parameter counts do not match");
-  assert(covariant_return_type(out.type(), in.type()), "Return types are not compatible");
-
-  if (parameter_count == 1 && (in.type() == T_LONG || in.type() == T_DOUBLE)) {
-    ++parameter_count; // need room for return value
-  }
-  if (target->method_holder()->is_interface()) {
-    assem.invokespecial(target);
-  } else {
-    assem.invokevirtual(target);
-  }
-
-  if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
-    assem.checkcast(in.as_symbol(THREAD));
-  }
-  assem._return(in.type());
-  return parameter_count;
-}
-
 static int assemble_method_error(
     BytecodeConstantPool* cp, BytecodeBuffer* buffer, Symbol* errorName, Symbol* message, TRAPS) {
 
@@ -898,7 +873,6 @@
   m->set_max_locals(params);
   m->constMethod()->set_stackmap_data(NULL);
   m->set_code(code_start);
-  m->set_force_inline(true);
 
   return m;
 }
@@ -924,18 +898,18 @@
   }
 }
 
-// A "bridge" is a method created by javac to bridge the gap between
-// an implementation and a generically-compatible, but different, signature.
-// Bridges have actual bytecode implementation in classfiles.
-// An "overpass", on the other hand, performs the same function as a bridge
-// but does not occur in a classfile; the VM creates overpass itself,
-// when it needs a path to get from a call site to an default method, and
-// a bridge doesn't exist.
-static void create_overpasses(
+// Create default_methods list for the current class.
+// With the VM only processing erased signatures, the VM only
+// creates an overpass in a conflict case or a case with no candidates.
+// This allows virtual methods to override the overpass, but ensures
+// that a local method search will find the exception rather than an abstract
+// or default method that is not a valid candidate.
+static void create_defaults_and_exceptions(
     GrowableArray<EmptyVtableSlot*>* slots,
     InstanceKlass* klass, TRAPS) {
 
   GrowableArray<Method*> overpasses;
+  GrowableArray<Method*> defaults;
   BytecodeConstantPool bpool(klass->constants());
 
   for (int i = 0; i < slots->length(); ++i) {
@@ -943,7 +917,6 @@
 
     if (slot->is_bound()) {
       MethodFamily* method = slot->get_binding();
-      int max_stack = 0;
       BytecodeBuffer buffer;
 
 #ifndef PRODUCT
@@ -953,26 +926,27 @@
         tty->print_cr("");
         if (method->has_target()) {
           method->print_selected(tty, 1);
-        } else {
+        } else if (method->throws_exception()) {
           method->print_exception(tty, 1);
         }
       }
 #endif // ndef PRODUCT
+
       if (method->has_target()) {
         Method* selected = method->get_selected_target();
         if (selected->method_holder()->is_interface()) {
-          max_stack = assemble_redirect(
-            &bpool, &buffer, slot->signature(), selected, CHECK);
+          defaults.push(selected);
         }
       } else if (method->throws_exception()) {
-        max_stack = assemble_method_error(&bpool, &buffer, method->get_exception_name(), method->get_exception_message(), CHECK);
-      }
-      if (max_stack != 0) {
+        int max_stack = assemble_method_error(&bpool, &buffer,
+           method->get_exception_name(), method->get_exception_message(), CHECK);
         AccessFlags flags = accessFlags_from(
           JVM_ACC_PUBLIC | JVM_ACC_SYNTHETIC | JVM_ACC_BRIDGE);
-        Method* m = new_method(&bpool, &buffer, slot->name(), slot->signature(),
+         Method* m = new_method(&bpool, &buffer, slot->name(), slot->signature(),
           flags, max_stack, slot->size_of_parameters(),
           ConstMethod::OVERPASS, CHECK);
+        // We push to the methods list:
+        // overpass methods which are exception throwing methods
         if (m != NULL) {
           overpasses.push(m);
         }
@@ -983,11 +957,31 @@
 #ifndef PRODUCT
   if (TraceDefaultMethods) {
     tty->print_cr("Created %d overpass methods", overpasses.length());
+    tty->print_cr("Created %d default  methods", defaults.length());
   }
 #endif // ndef PRODUCT
 
-  switchover_constant_pool(&bpool, klass, &overpasses, CHECK);
-  merge_in_new_methods(klass, &overpasses, CHECK);
+  if (overpasses.length() > 0) {
+    switchover_constant_pool(&bpool, klass, &overpasses, CHECK);
+    merge_in_new_methods(klass, &overpasses, CHECK);
+  }
+  if (defaults.length() > 0) {
+    create_default_methods(klass, &defaults, CHECK);
+  }
+}
+
+static void create_default_methods( InstanceKlass* klass,
+    GrowableArray<Method*>* new_methods, TRAPS) {
+
+  int new_size = new_methods->length();
+  Array<Method*>* total_default_methods = MetadataFactory::new_array<Method*>(
+      klass->class_loader_data(), new_size, NULL, CHECK);
+  for (int index = 0; index < new_size; index++ ) {
+    total_default_methods->at_put(index, new_methods->at(index));
+  }
+  Method::sort_methods(total_default_methods, false, false);
+
+  klass->set_default_methods(total_default_methods);
 }
 
 static void sort_methods(GrowableArray<Method*>* methods) {
@@ -1089,7 +1083,9 @@
   klass->set_initial_method_idnum(new_size);
 
   ClassLoaderData* cld = klass->class_loader_data();
-  MetadataFactory::free_array(cld, original_methods);
+  if (original_methods ->length() > 0) {
+    MetadataFactory::free_array(cld, original_methods);
+  }
   if (original_ordering->length() > 0) {
     klass->set_method_ordering(merged_ordering);
     MetadataFactory::free_array(cld, original_ordering);