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/*
* 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.TypeDescription;
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.NullConstant;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import net.bytebuddy.utility.CompoundList;
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 an array of all arguments of the instrumented
* method.
*
*
* By default, this annotation applies a
* {@link net.bytebuddy.implementation.bind.annotation.AllArguments.Assignment#STRICT}
* assignment of the source method's parameters to the array. This implies that parameters that are not assignable to
* the annotated array's component type make the method with this parameter unbindable. To avoid this, you can
* use a {@link net.bytebuddy.implementation.bind.annotation.AllArguments.Assignment#SLACK} assignment
* which simply skips non-assignable values instead.
*
*
* Important: Don't confuse this annotation with {@link net.bytebuddy.asm.Advice.AllArguments} or
* {@link net.bytebuddy.asm.MemberSubstitution.AllArguments}. This annotation should be used with
* {@link net.bytebuddy.implementation.MethodDelegation} only.
*
*
* @see net.bytebuddy.implementation.MethodDelegation
* @see net.bytebuddy.implementation.bind.annotation.TargetMethodAnnotationDrivenBinder
* @see net.bytebuddy.implementation.bind.annotation.RuntimeType
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface AllArguments {
/**
* Defines the type of {@link net.bytebuddy.implementation.bind.annotation.AllArguments.Assignment}
* type that is applied for filling the annotated array with values.
*
* @return The assignment handling to be applied for the annotated parameter.
*/
Assignment value() default Assignment.STRICT;
/**
* Determines if the array should contain the instance that defines the intercepted value when intercepting
* a non-static method.
*
* @return {@code true} if the instance on which the intercepted method should be invoked should be
* included in the array containing the arguments.
*/
boolean includeSelf() default false;
/**
* Determines if a {@code null} value should be assigned if the instrumented method does not declare any parameters.
*
* @return {@code true} if a {@code null} value should be assigned if the instrumented method does not declare any parameters.
*/
boolean nullIfEmpty() default false;
/**
* A directive for how an {@link net.bytebuddy.implementation.bind.annotation.AllArguments}
* annotation on an array is to be interpreted.
*/
enum Assignment {
/**
* A strict assignment attempts to include all parameter values of the source method. If only one of these
* parameters is not assignable to the component type of the annotated array, the method is considered as
* non-bindable.
*/
STRICT(true),
/**
* Other than a {@link net.bytebuddy.implementation.bind.annotation.AllArguments.Assignment#STRICT}
* assignment, a slack assignment simply ignores non-bindable parameters and does not include them in the target
* array. In the most extreme case where no source method parameter is assignable to the component type
* of the annotated array, the array that is assigned to the target parameter is empty.
*/
SLACK(false);
/**
* Determines if this assignment is strict.
*/
private final boolean strict;
/**
* Creates a new assignment type.
*
* @param strict {@code true} if this assignment is strict.
*/
Assignment(boolean strict) {
this.strict = strict;
}
/**
* Returns {@code true} if this assignment is strict.
*
* @return {@code true} if this assignment is strict.
*/
protected boolean isStrict() {
return strict;
}
}
/**
* A binder for handling the
* {@link net.bytebuddy.implementation.bind.annotation.AllArguments}
* annotation.
*
* @see TargetMethodAnnotationDrivenBinder
*/
enum Binder implements TargetMethodAnnotationDrivenBinder.ParameterBinder {
/**
* The singleton instance.
*/
INSTANCE;
/**
* A description of the {@link AllArguments#value()} method.
*/
private static final MethodDescription.InDefinedShape VALUE;
/**
* A description of the {@link AllArguments#includeSelf()} method.
*/
private static final MethodDescription.InDefinedShape INCLUDE_SELF;
/**
* A description of the {@link AllArguments#nullIfEmpty()} method.
*/
private static final MethodDescription.InDefinedShape NULL_IF_EMPTY;
/*
* Resolves annotation properties.
*/
static {
MethodList methods = TypeDescription.ForLoadedType.of(AllArguments.class).getDeclaredMethods();
VALUE = methods.filter(named("value")).getOnly();
INCLUDE_SELF = methods.filter(named("includeSelf")).getOnly();
NULL_IF_EMPTY = methods.filter(named("nullIfEmpty")).getOnly();
}
/**
* {@inheritDoc}
*/
public Class getHandledType() {
return AllArguments.class;
}
/**
* {@inheritDoc}
*/
public MethodDelegationBinder.ParameterBinding bind(AnnotationDescription.Loadable annotation,
MethodDescription source,
ParameterDescription target,
Implementation.Target implementationTarget,
Assigner assigner,
Assigner.Typing typing) {
TypeDescription.Generic componentType;
if (target.getType().represents(Object.class)) {
componentType = TypeDescription.Generic.OfNonGenericType.ForLoadedType.of(Object.class);
} else if (target.getType().isArray()) {
componentType = target.getType().getComponentType();
} else {
throw new IllegalStateException("Expected an array type for all argument annotation on " + source);
}
boolean includeThis = !source.isStatic() && annotation.getValue(INCLUDE_SELF).resolve(Boolean.class);
if (!includeThis && source.getParameters().isEmpty() && annotation.getValue(NULL_IF_EMPTY).resolve(Boolean.class)) {
return new MethodDelegationBinder.ParameterBinding.Anonymous(NullConstant.INSTANCE);
}
List stackManipulations = new ArrayList(source.getParameters().size() + (includeThis ? 1 : 0));
int offset = source.isStatic() || includeThis ? 0 : 1;
for (TypeDescription.Generic sourceParameter : includeThis
? CompoundList.of(implementationTarget.getInstrumentedType().asGenericType(), source.getParameters().asTypeList())
: source.getParameters().asTypeList()) {
StackManipulation stackManipulation = new StackManipulation.Compound(
MethodVariableAccess.of(sourceParameter).loadFrom(offset),
assigner.assign(sourceParameter, componentType, typing)
);
if (stackManipulation.isValid()) {
stackManipulations.add(stackManipulation);
} else if (annotation.getValue(VALUE).load(AllArguments.class.getClassLoader()).resolve(Assignment.class).isStrict()) {
return MethodDelegationBinder.ParameterBinding.Illegal.INSTANCE;
}
offset += sourceParameter.getStackSize().getSize();
}
return new MethodDelegationBinder.ParameterBinding.Anonymous(ArrayFactory.forType(componentType).withValues(stackManipulations));
}
}
}