/*
 * Copyright 2014 - 2020 Rafael Winterhalter
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.bytebuddy.implementation;

import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.dynamic.scaffold.InstrumentedType;
import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
import net.bytebuddy.implementation.bytecode.Removal;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.member.MethodReturn;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import org.objectweb.asm.MethodVisitor;

This implementation will create a new method which simply calls its super method. If no such method is defined, an exception will be thrown. Constructors are considered to have a super method if the direct super class defines a constructor with an identical signature. Default methods are invoked as such if they are non-ambiguous. Static methods can have a (pseudo) super method if a type that defines such a method is rebased. Rebased types can also shadow constructors or methods of an actual super class. Besides implementing constructors, this implementation is useful when a method of a super type is not supposed to be altered but should be equipped with additional annotations. Furthermore, this implementation allows to hard code a super method call to be performed after performing another Implementation.
/** * This implementation will create a new method which simply calls its super method. If no such method is defined, * an exception will be thrown. Constructors are considered to have a super method if the direct super class defines * a constructor with an identical signature. Default methods are invoked as such if they are non-ambiguous. Static * methods can have a (pseudo) super method if a type that defines such a method is rebased. Rebased types can also * shadow constructors or methods of an actual super class. Besides implementing constructors, this implementation * is useful when a method of a super type is not supposed to be altered but should be equipped with additional * annotations. Furthermore, this implementation allows to hard code a super method call to be performed after * performing another {@link Implementation}. */
public enum SuperMethodCall implements Implementation.Composable {
The singleton instance.
/** * The singleton instance. */
INSTANCE;
{@inheritDoc}
/** * {@inheritDoc} */
public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; }
{@inheritDoc}
/** * {@inheritDoc} */
public ByteCodeAppender appender(Target implementationTarget) { return new Appender(implementationTarget, Appender.TerminationHandler.RETURNING); }
{@inheritDoc}
/** * {@inheritDoc} */
public Implementation andThen(Implementation implementation) { return new Compound(WithoutReturn.INSTANCE, implementation); }
{@inheritDoc}
/** * {@inheritDoc} */
public Composable andThen(Composable implementation) { return new Compound.Composable(WithoutReturn.INSTANCE, implementation); }
A super method invocation where the return value is dropped instead of returning from the method.
/** * A super method invocation where the return value is dropped instead of returning from the method. */
protected enum WithoutReturn implements Implementation {
The singleton instance.
/** * The singleton instance. */
INSTANCE;
{@inheritDoc}
/** * {@inheritDoc} */
public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; }
{@inheritDoc}
/** * {@inheritDoc} */
public ByteCodeAppender appender(Target implementationTarget) { return new Appender(implementationTarget, Appender.TerminationHandler.DROPPING); } }
An appender for implementing a SuperMethodCall.
/** * An appender for implementing a {@link net.bytebuddy.implementation.SuperMethodCall}. */
@HashCodeAndEqualsPlugin.Enhance protected static class Appender implements ByteCodeAppender {
The target of the current implementation.
/** * The target of the current implementation. */
private final Target implementationTarget;
The termination handler to apply after invoking the super method.
/** * The termination handler to apply after invoking the super method. */
private final TerminationHandler terminationHandler;
Creates a new appender.
Params:
  • implementationTarget – The implementation target of the current type creation.
  • terminationHandler – The termination handler to apply after invoking the super method.
/** * Creates a new appender. * * @param implementationTarget The implementation target of the current type creation. * @param terminationHandler The termination handler to apply after invoking the super method. */
protected Appender(Target implementationTarget, TerminationHandler terminationHandler) { this.implementationTarget = implementationTarget; this.terminationHandler = terminationHandler; }
{@inheritDoc}
/** * {@inheritDoc} */
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext, MethodDescription instrumentedMethod) { StackManipulation superMethodCall = implementationTarget .invokeDominant(instrumentedMethod.asSignatureToken()) .withCheckedCompatibilityTo(instrumentedMethod.asTypeToken()); if (!superMethodCall.isValid()) { throw new IllegalStateException("Cannot call super (or default) method for " + instrumentedMethod); } StackManipulation.Size size = new StackManipulation.Compound( MethodVariableAccess.allArgumentsOf(instrumentedMethod).prependThisReference(), superMethodCall, terminationHandler.of(instrumentedMethod) ).apply(methodVisitor, implementationContext); return new Size(size.getMaximalSize(), instrumentedMethod.getStackSize()); }
A handler that determines how to handle the method return value.
/** * A handler that determines how to handle the method return value. */
protected enum TerminationHandler {
A termination handler that returns the value of the super method invocation.
/** * A termination handler that returns the value of the super method invocation. */
RETURNING { @Override protected StackManipulation of(MethodDescription methodDescription) { return MethodReturn.of(methodDescription.getReturnType()); } },
A termination handler that simply pops the value of the super method invocation off the stack.
/** * A termination handler that simply pops the value of the super method invocation off the stack. */
DROPPING { @Override protected StackManipulation of(MethodDescription methodDescription) { return Removal.of(methodDescription.getReturnType()); } };
Creates a stack manipulation that represents this handler's behavior.
Params:
  • methodDescription – The method for which this handler is supposed to create a stack manipulation for.
Returns:The stack manipulation that implements this handler.
/** * Creates a stack manipulation that represents this handler's behavior. * * @param methodDescription The method for which this handler is supposed to create a stack * manipulation for. * @return The stack manipulation that implements this handler. */
protected abstract StackManipulation of(MethodDescription methodDescription); } } }