src/hotspot/share/classfile/defaultMethods.cpp

*** 1,7 ****
  /*
!  * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 765,783 ****
      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.
  //
! // First if finds any name/signature slots that need any implementation (either
  // because they are miranda or a superclass's implementation is an overpass
  // itself).  For each slot, iterate over the hierarchy, to see if they contain a
  // signature that matches the slot we are looking at.
  //
! // For each slot filled, we generate an overpass method that either calls the
! // unique default method candidate using invokespecial, or throws an exception
! // (in the case of no default method candidates, or more than one valid
! // candidate).  These methods are then added to the class's method list.
  // The JVM does not create bridges nor handle generic signatures here.
  void DefaultMethods::generate_default_methods(
      InstanceKlass* klass, const GrowableArray<Method*>* mirandas, TRAPS) {
    assert(klass != NULL, "invariant");
  
--- 765,782 ----
      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.
  //
! // First it finds any name/signature slots that need any implementation (either
  // because they are miranda or a superclass's implementation is an overpass
  // itself).  For each slot, iterate over the hierarchy, to see if they contain a
  // signature that matches the slot we are looking at.
  //
! // For each slot filled, we either record the default method candidate in the
! // klass default_methods list or, only to handle exception cases, we create an
! // overpass method that throws an exception and add it to the klass methods list.
  // The JVM does not create bridges nor handle generic signatures here.
  void DefaultMethods::generate_default_methods(
      InstanceKlass* klass, const GrowableArray<Method*>* mirandas, TRAPS) {
    assert(klass != NULL, "invariant");
  
*** 899,908 ****
--- 898,912 ----
  // 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.
+ //
+ // Note that if overpass method are ever created that are not exception
+ // throwing methods then the loader constraint checking logic for vtable and
+ // itable creation needs to be changed to check loader constraints for the
+ // overpass methods that do not throw exceptions.
  static void create_defaults_and_exceptions(
      GrowableArray<EmptyVtableSlot*>* slots,
      InstanceKlass* klass, TRAPS) {
  
    GrowableArray<Method*> overpasses;