net.bytebuddy.implementation.bind.annotation.SuperCallHandle Maven / Gradle / Ivy
/*
* Copyright 2014 - Present 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.bind.annotation;
import net.bytebuddy.description.annotation.AnnotationDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.method.MethodList;
import net.bytebuddy.description.method.ParameterDescription;
import net.bytebuddy.description.type.TypeDefinition;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.description.type.TypeList;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.bind.MethodDelegationBinder;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.assign.Assigner;
import net.bytebuddy.implementation.bytecode.collection.ArrayFactory;
import net.bytebuddy.implementation.bytecode.constant.IntegerConstant;
import net.bytebuddy.implementation.bytecode.constant.NullConstant;
import net.bytebuddy.implementation.bytecode.member.MethodInvocation;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import net.bytebuddy.utility.JavaType;
import org.objectweb.asm.Opcodes;
import java.lang.annotation.*;
import java.util.ArrayList;
import java.util.List;
import static net.bytebuddy.matcher.ElementMatchers.named;
/**
* Parameters that are annotated with this annotation will be assigned a {@code java.lang.invoke.MethodHandle} invoking
* the {@code super} implementation.
*
* @see net.bytebuddy.implementation.MethodDelegation
* @see TargetMethodAnnotationDrivenBinder
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface SuperCallHandle {
/**
* Determines if the method handle should invoke the default method to the intercepted method if a common
* super method invocation is not applicable. For this to be possible, the default method must not be ambiguous.
*
* @return {@code true} if the invocation should fall back to invoking the default method.
*/
boolean fallbackToDefault() default true;
/**
* Assigns {@code null} to the parameter if it is impossible to invoke the super method or a possible dominant default method, if permitted.
*
* @return {@code true} if a {@code null} constant should be assigned to this parameter in case that a legal binding is impossible.
*/
boolean nullIfImpossible() default false;
/**
* A binder for handling the {@link SuperCallHandle} annotation.
*
* @see TargetMethodAnnotationDrivenBinder
*/
enum Binder implements TargetMethodAnnotationDrivenBinder.ParameterBinder {
/**
* The singleton instance.
*/
INSTANCE;
/**
* A description of the {@link SuperCallHandle#fallbackToDefault()} method.
*/
private static final MethodDescription.InDefinedShape FALLBACK_TO_DEFAULT;
/**
* A description of the {@link SuperCallHandle#nullIfImpossible()} method.
*/
private static final MethodDescription.InDefinedShape NULL_IF_IMPOSSIBLE;
/*
* Resolves annotation properties.
*/
static {
MethodList methods = TypeDescription.ForLoadedType.of(SuperCallHandle.class).getDeclaredMethods();
FALLBACK_TO_DEFAULT = methods.filter(named("fallbackToDefault")).getOnly();
NULL_IF_IMPOSSIBLE = methods.filter(named("nullIfImpossible")).getOnly();
}
/**
* {@inheritDoc}
*/
public Class getHandledType() {
return SuperCallHandle.class;
}
/**
* {@inheritDoc}
*/
public MethodDelegationBinder.ParameterBinding bind(AnnotationDescription.Loadable annotation,
MethodDescription source,
ParameterDescription target,
Implementation.Target implementationTarget,
Assigner assigner,
Assigner.Typing typing) {
if (!target.getType().asErasure().isAssignableFrom(JavaType.METHOD_HANDLE.getTypeStub())) {
throw new IllegalStateException("A method handle for a super method invocation cannot be assigned to " + target);
} else if (source.isConstructor()) {
return annotation.getValue(NULL_IF_IMPOSSIBLE).resolve(Boolean.class)
? new MethodDelegationBinder.ParameterBinding.Anonymous(NullConstant.INSTANCE)
: MethodDelegationBinder.ParameterBinding.Illegal.INSTANCE;
}
Implementation.SpecialMethodInvocation specialMethodInvocation = (annotation.getValue(FALLBACK_TO_DEFAULT).resolve(Boolean.class)
? implementationTarget.invokeDominant(source.asSignatureToken())
: implementationTarget.invokeSuper(source.asSignatureToken())).withCheckedCompatibilityTo(source.asTypeToken());
StackManipulation stackManipulation;
if (specialMethodInvocation.isValid()) {
List stackManipulations = new ArrayList(1
+ (source.isStatic() ? 0 : 2)
+ source.getParameters().size() * 3);
stackManipulations.add(specialMethodInvocation.toMethodHandle().toStackManipulation());
if (!source.isStatic()) {
stackManipulations.add(MethodVariableAccess.loadThis());
stackManipulations.add(MethodInvocation.invoke(new MethodDescription.Latent(JavaType.METHOD_HANDLE.getTypeStub(), new MethodDescription.Token("bindTo",
Opcodes.ACC_PUBLIC,
JavaType.METHOD_HANDLE.getTypeStub().asGenericType(),
new TypeList.Generic.Explicit(TypeDefinition.Sort.describe(Object.class))))));
}
if (!source.getParameters().isEmpty()) {
List values = new ArrayList(source.getParameters().size());
for (ParameterDescription parameterDescription : source.getParameters()) {
values.add(parameterDescription.getType().isPrimitive() ? new StackManipulation.Compound(MethodVariableAccess.load(parameterDescription), assigner.assign(parameterDescription.getType(),
parameterDescription.getType().asErasure().asBoxed().asGenericType(),
typing)) : MethodVariableAccess.load(parameterDescription));
}
stackManipulations.add(IntegerConstant.forValue(0));
stackManipulations.add(ArrayFactory.forType(TypeDescription.ForLoadedType.of(Object.class).asGenericType()).withValues(values));
stackManipulations.add(MethodInvocation.invoke(new MethodDescription.Latent(JavaType.METHOD_HANDLES.getTypeStub(), new MethodDescription.Token("insertArguments",
Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC,
JavaType.METHOD_HANDLE.getTypeStub().asGenericType(),
new TypeList.Generic.Explicit(JavaType.METHOD_HANDLE.getTypeStub(), TypeDefinition.Sort.describe(int.class), TypeDefinition.Sort.describe(Object[].class))))));
}
stackManipulation = new StackManipulation.Compound(stackManipulations);
} else if (annotation.getValue(NULL_IF_IMPOSSIBLE).resolve(Boolean.class)) {
stackManipulation = NullConstant.INSTANCE;
} else {
return MethodDelegationBinder.ParameterBinding.Illegal.INSTANCE;
}
return new MethodDelegationBinder.ParameterBinding.Anonymous(stackManipulation);
}
}
}