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/*
* Copyright (c) 2010, 2013, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package jdk.nashorn.internal.runtime.linker;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import jdk.internal.dynalink.CallSiteDescriptor;
import jdk.internal.dynalink.beans.BeansLinker;
import jdk.internal.dynalink.linker.GuardedInvocation;
import jdk.internal.dynalink.linker.LinkRequest;
import jdk.internal.dynalink.linker.LinkerServices;
import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
import jdk.internal.dynalink.support.Guards;
/**
* Links {@code BoundDynamicMethod} objects. Passes through to Dynalink's BeansLinker for linking a dynamic method
* (they only respond to "dyn:call"), and modifies the returned invocation to deal with the receiver binding.
*/
final class BoundDynamicMethodLinker implements TypeBasedGuardingDynamicLinker {
@Override
public boolean canLinkType(Class<?> type) {
return type == BoundDynamicMethod.class;
}
@Override
public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) throws Exception {
final Object objBoundDynamicMethod = linkRequest.getReceiver();
if(!(objBoundDynamicMethod instanceof BoundDynamicMethod)) {
return null;
}
final BoundDynamicMethod boundDynamicMethod = (BoundDynamicMethod)objBoundDynamicMethod;
final Object dynamicMethod = boundDynamicMethod.getDynamicMethod();
final Object boundThis = boundDynamicMethod.getBoundThis();
// Replace arguments (boundDynamicMethod, this, ...) => (dynamicMethod, boundThis, ...) when delegating to
// BeansLinker
final Object[] args = linkRequest.getArguments();
args[0] = dynamicMethod;
args[1] = boundThis;
// Use R(T0, T1, ...) => R(dynamicMethod.class, boundThis.class, ...) call site type when delegating to
// BeansLinker.
final CallSiteDescriptor descriptor = linkRequest.getCallSiteDescriptor();
final MethodType type = descriptor.getMethodType();
final Class<?> dynamicMethodClass = dynamicMethod.getClass();
final CallSiteDescriptor newDescriptor = descriptor.changeMethodType(
type.changeParameterType(0, dynamicMethodClass).changeParameterType(1, boundThis.getClass()));
// Delegate to BeansLinker
final GuardedInvocation inv = BeansLinker.getLinkerForClass(dynamicMethodClass).getGuardedInvocation(
linkRequest.replaceArguments(newDescriptor, args), linkerServices);
if(inv == null) {
return null;
}
// Bind (dynamicMethod, boundThis) to the handle
final MethodHandle boundHandle = MethodHandles.insertArguments(inv.getInvocation(), 0, dynamicMethod, boundThis);
final Class<?> p0Type = type.parameterType(0);
// Ignore incoming (boundDynamicMethod, this)
final MethodHandle droppingHandle = MethodHandles.dropArguments(boundHandle, 0, p0Type, type.parameterType(1));
// Identity guard on boundDynamicMethod object
final MethodHandle newGuard = Guards.getIdentityGuard(boundDynamicMethod);
return inv.replaceMethods(droppingHandle, newGuard.asType(newGuard.type().changeParameterType(0, p0Type)));
}
}
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