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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;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.scaffold.FieldLocator;
import net.bytebuddy.dynamic.scaffold.InstrumentedType;
import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.assign.Assigner;
import net.bytebuddy.implementation.bytecode.constant.ClassConstant;
import net.bytebuddy.implementation.bytecode.constant.DefaultValue;
import net.bytebuddy.implementation.bytecode.member.FieldAccess;
import net.bytebuddy.implementation.bytecode.member.MethodReturn;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import net.bytebuddy.utility.ConstantValue;
import net.bytebuddy.utility.JavaConstant;
import net.bytebuddy.utility.RandomString;
import net.bytebuddy.utility.nullability.AlwaysNull;
import net.bytebuddy.utility.nullability.MaybeNull;
import net.bytebuddy.jar.asm.MethodVisitor;
import net.bytebuddy.jar.asm.Opcodes;

import java.lang.reflect.Field;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import static net.bytebuddy.matcher.ElementMatchers.named;

/**
 * 

* Defines a method to access a given field by following the Java bean conventions for getters and setters: *

*
    *
  • Getter: A method named {@code getFoo()} will be instrumented to read and return the value of a field {@code foo} * or another field if one was specified explicitly. If a property is of type {@link java.lang.Boolean} or * {@code boolean}, the name {@code isFoo()} is also permitted.
  • *
  • Setter: A method named {@code setFoo(value)} will be instrumented to write the given argument {@code value} * to a field {@code foo} or to another field if one was specified explicitly.
  • *
*

* Field accessors always implement a getter if a non-{@code void} value is returned from a method and attempt to define a setter * otherwise. If a field accessor is not explicitly defined as a setter via {@link PropertyConfigurable}, an instrumented * method must define exactly one parameter. Using the latter API, an explicit parameter index can be defined and a return * value can be specified explicitly when {@code void} is not returned. *

*/ @HashCodeAndEqualsPlugin.Enhance public abstract class FieldAccessor implements Implementation { /** * The field's location. */ protected final FieldLocation fieldLocation; /** * The assigner to use. */ protected final Assigner assigner; /** * Indicates if dynamic type castings should be attempted for incompatible assignments. */ protected final Assigner.Typing typing; /** * Creates a new field accessor. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. */ protected FieldAccessor(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing) { this.fieldLocation = fieldLocation; this.assigner = assigner; this.typing = typing; } /** * Defines a field accessor where any access is targeted to a field named {@code name}. * * @param name The name of the field to be accessed. * @return A field accessor for a field of a given name. */ public static OwnerTypeLocatable ofField(String name) { return of(new FieldNameExtractor.ForFixedValue(name)); } /** * Defines a field accessor where any access is targeted to a field that matches the methods * name with the Java specification for bean properties, i.e. a method {@code getFoo} or {@code setFoo(value)} * will either read or write a field named {@code foo}. * * @return A field accessor that follows the Java naming conventions for bean properties. */ public static OwnerTypeLocatable ofBeanProperty() { return of(FieldNameExtractor.ForBeanProperty.INSTANCE, FieldNameExtractor.ForBeanProperty.CAPITALIZED); } /** * Defines a custom strategy for determining the field that is accessed by this field accessor. * * @param fieldNameExtractor The field name extractor to use. * @return A field accessor using the given field name extractor. */ public static OwnerTypeLocatable of(FieldNameExtractor fieldNameExtractor) { return of(Collections.singletonList(fieldNameExtractor)); } /** * Defines a custom strategy for determining the field that is accessed by this field accessor. * * @param fieldNameExtractor The field name extractors to use in their application order. * @return A field accessor using the given field name extractor. */ public static OwnerTypeLocatable of(FieldNameExtractor... fieldNameExtractor) { return of(Arrays.asList(fieldNameExtractor)); } /** * Defines a custom strategy for determining the field that is accessed by this field accessor. * * @param fieldNameExtractors The field name extractors to use in their application order. * @return A field accessor using the given field name extractor. */ public static OwnerTypeLocatable of(List fieldNameExtractors) { return new ForImplicitProperty(new FieldLocation.Relative(fieldNameExtractors)); } /** * Defines a field accessor where the specified field is accessed. The field must be within the hierarchy of the instrumented type. * * @param field The field being accessed. * @return A field accessor for the given field. */ public static AssignerConfigurable of(Field field) { return of(new FieldDescription.ForLoadedField(field)); } /** * Defines a field accessor where the specified field is accessed. The field must be within the hierarchy of the instrumented type. * * @param fieldDescription The field being accessed. * @return A field accessor for the given field. */ public static AssignerConfigurable of(FieldDescription fieldDescription) { return new ForImplicitProperty(new FieldLocation.Absolute(fieldDescription)); } /** * A field location represents an identified field description which depends on the instrumented type and method. */ protected interface FieldLocation { /** * Specifies a field locator factory to use. * * @param fieldLocatorFactory The field locator factory to use. * @return An appropriate field location. */ FieldLocation with(FieldLocator.Factory fieldLocatorFactory); /** * A prepared field location. * * @param instrumentedType The instrumented type. * @return A prepared field location. */ Prepared prepare(TypeDescription instrumentedType); /** * A prepared field location. */ interface Prepared { /** * Resolves the field description to use. * * @param instrumentedMethod The instrumented method. * @return The resolved field description. */ FieldDescription resolve(MethodDescription instrumentedMethod); } /** * An absolute field description representing a previously resolved field. */ @HashCodeAndEqualsPlugin.Enhance class Absolute implements FieldLocation, Prepared { /** * The field description. */ private final FieldDescription fieldDescription; /** * Creates an absolute field location. * * @param fieldDescription The field description. */ protected Absolute(FieldDescription fieldDescription) { this.fieldDescription = fieldDescription; } /** * {@inheritDoc} */ public FieldLocation with(FieldLocator.Factory fieldLocatorFactory) { throw new IllegalStateException("Cannot specify a field locator factory for an absolute field location"); } /** * {@inheritDoc} */ @SuppressFBWarnings(value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE", justification = "Assuming declaring type for type member.") public Prepared prepare(TypeDescription instrumentedType) { if (!fieldDescription.isStatic() && !instrumentedType.isAssignableTo(fieldDescription.getDeclaringType().asErasure())) { throw new IllegalStateException(fieldDescription + " is not declared by " + instrumentedType); } else if (!fieldDescription.isAccessibleTo(instrumentedType)) { throw new IllegalStateException("Cannot access " + fieldDescription + " from " + instrumentedType); } return this; } /** * {@inheritDoc} */ public FieldDescription resolve(MethodDescription instrumentedMethod) { return fieldDescription; } } /** * A relative field location where a field is located dynamically. */ @HashCodeAndEqualsPlugin.Enhance class Relative implements FieldLocation { /** * The field name extractors to use in their application order. */ private final List fieldNameExtractors; /** * The field locator factory to use. */ private final FieldLocator.Factory fieldLocatorFactory; /** * Creates a new relative field location. * * @param fieldNameExtractors The field name extractors to use in their application order. */ protected Relative(List fieldNameExtractors) { this(fieldNameExtractors, FieldLocator.ForClassHierarchy.Factory.INSTANCE); } /** * Creates a new relative field location. * * @param fieldNameExtractors The field name extractors to use in their application order. * @param fieldLocatorFactory The field locator factory to use. */ private Relative(List fieldNameExtractors, FieldLocator.Factory fieldLocatorFactory) { this.fieldNameExtractors = fieldNameExtractors; this.fieldLocatorFactory = fieldLocatorFactory; } /** * {@inheritDoc} */ public FieldLocation with(FieldLocator.Factory fieldLocatorFactory) { return new Relative(fieldNameExtractors, fieldLocatorFactory); } /** * {@inheritDoc} */ public FieldLocation.Prepared prepare(TypeDescription instrumentedType) { return new Prepared(fieldNameExtractors, fieldLocatorFactory.make(instrumentedType)); } /** * A prepared version of a field location. */ @HashCodeAndEqualsPlugin.Enhance protected static class Prepared implements FieldLocation.Prepared { /** * The field name extractor to use in their application order. */ private final List fieldNameExtractors; /** * The field locator factory to use. */ private final FieldLocator fieldLocator; /** * Creates a new relative field location. * * @param fieldNameExtractors The field name extractors to use in their application order. * @param fieldLocator The field locator to use. */ protected Prepared(List fieldNameExtractors, FieldLocator fieldLocator) { this.fieldNameExtractors = fieldNameExtractors; this.fieldLocator = fieldLocator; } /** * {@inheritDoc} */ public FieldDescription resolve(MethodDescription instrumentedMethod) { FieldLocator.Resolution resolution = FieldLocator.Resolution.Illegal.INSTANCE; Iterator iterator = fieldNameExtractors.iterator(); while (iterator.hasNext() && !resolution.isResolved()) { resolution = fieldLocator.locate(iterator.next().resolve(instrumentedMethod)); } if (!resolution.isResolved()) { throw new IllegalStateException("Cannot resolve field for " + instrumentedMethod + " using " + fieldLocator); } return resolution.getField(); } } } } /** * A field name extractor is responsible for determining a field name to a method that is implemented * to access this method. */ public interface FieldNameExtractor { /** * Extracts a field name to be accessed by a getter or setter method. * * @param methodDescription The method for which a field name is to be determined. * @return The name of the field to be accessed by this method. */ String resolve(MethodDescription methodDescription); /** * A {@link net.bytebuddy.implementation.FieldAccessor.FieldNameExtractor} that determines a field name * according to the rules of Java bean naming conventions. */ enum ForBeanProperty implements FieldNameExtractor { /** * A resolver that resolves a standard bean property name. */ INSTANCE { @Override protected char resolve(char character) { return Character.toLowerCase(character); } }, /** * A resolver that resolves a field name with a capital letter. */ CAPITALIZED { @Override protected char resolve(char character) { return Character.toUpperCase(character); } }; /** * {@inheritDoc} */ public String resolve(MethodDescription methodDescription) { String name = methodDescription.getInternalName(); int crop; if (name.startsWith("get") || name.startsWith("set")) { crop = 3; } else if (name.startsWith("is")) { crop = 2; } else { throw new IllegalArgumentException(methodDescription + " does not follow Java bean naming conventions"); } name = name.substring(crop); if (name.length() == 0) { throw new IllegalArgumentException(methodDescription + " does not specify a bean name"); } return resolve(name.charAt(0)) + name.substring(1); } /** * Resolves the first character of the bean property. * * @param character The first character. * @return The resolved first character. */ protected abstract char resolve(char character); } /** * A field name extractor that returns a fixed value. */ @HashCodeAndEqualsPlugin.Enhance class ForFixedValue implements FieldNameExtractor { /** * The name to return. */ private final String name; /** * Creates a new field name extractor for a fixed value. * * @param name The name to return. */ protected ForFixedValue(String name) { this.name = name; } /** * {@inheritDoc} */ public String resolve(MethodDescription methodDescription) { return name; } } } /** * A field accessor that allows to define the access to be a field write of a given argument. */ public interface PropertyConfigurable extends Implementation { /** *

* Defines a setter of the specified parameter for the field being described. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param index The index of the parameter for which to set the field's value. * @return An instrumentation that sets the parameter's value to the described field. */ Composable setsArgumentAt(int index); /** *

* Defines a setter of the described field's default value, i.e. {@code null} or a primitive type's * representation of {@code 0}. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @return An instrumentation that sets the field's default value. */ Composable setsDefaultValue(); /** *

* Defines a setter of a given value for the described field. If the value is a constant value, it will be * defined as a constant assignment, otherwise it is defined as a reference value that is stored in a static * field of the instrumented type. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param value The value to set. * @return An instrumentation that sets the field's value as specified. */ Composable setsValue(Object value); /** *

* Defines a setter of a given class constant value for the described field. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param typeDescription The type to set to the described field. * @return An instrumentation that sets the field's value to the given class constant. */ Composable setsValue(TypeDescription typeDescription); /** *

* Defines a setter of a given constant value for the described field. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param constant The constant to set as a value. * @return An instrumentation that sets the field's value to the given constant. */ Composable setsValue(ConstantValue constant); /** *

* Defines a setter of a given constant value for the described field. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param constant The constant to set as a value. * @return An instrumentation that sets the field's value to the given constant. */ Composable setsValue(JavaConstant constant); /** *

* Defines a setter of a value that is represented by a stack manipulation. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param stackManipulation A stack manipulation to load the field's value. * @param type The field value's type. * @return An instrumentation that sets the field's value to the given value. */ Composable setsValue(StackManipulation stackManipulation, Type type); /** *

* Defines a setter of a value that is represented by a stack manipulation. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param stackManipulation A stack manipulation to load the field's value. * @param typeDescription The field value's type. * @return An instrumentation that sets the field's value to the given value. */ Composable setsValue(StackManipulation stackManipulation, TypeDescription.Generic typeDescription); /** *

* Defines a setter of a given value for the described field. The value is kept as a referenced that is stored * in a static field of the instrumented type. The field name is chosen based on the value's hash code. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param value The value to set. * @return An instrumentation that sets the field's value as specified. */ Composable setsReference(Object value); /** *

* Defines a setter of a given value for the described field. The value is kept as a referenced that is stored * in a static field of the instrumented type. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param value The value to set. * @param name The name of the field. * @return An instrumentation that sets the field's value as specified. */ Composable setsReference(Object value, String name); /** *

* Defines a setter of a value that sets another field's value. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param field The field that holds the value to be set. * @return An instrumentation that sets the field's value to the specified field's value. */ Composable setsFieldValueOf(Field field); /** *

* Defines a setter of a value that sets another field's value. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param fieldDescription The field that holds the value to be set. * @return An instrumentation that sets the field's value to the specified field's value. */ Composable setsFieldValueOf(FieldDescription fieldDescription); /** *

* Defines a setter of a value that sets another field's value. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param fieldName The name of the field that is specified by the instrumented type. * @return An instrumentation that sets the field's value to the specified field's value. */ Composable setsFieldValueOf(String fieldName); /** *

* Defines a setter of a value that sets another field's value. *

*

* Note: If the instrumented method does not return {@code void}, a chained instrumentation must be supplied. *

* * @param fieldNameExtractor A field name extractor for the field that is specified by the instrumented type. * @return An instrumentation that sets the field's value to the specified field's value. */ Composable setsFieldValueOf(FieldNameExtractor fieldNameExtractor); } /** * A field accessor that can be configured to use a given assigner and runtime type use configuration. */ public interface AssignerConfigurable extends PropertyConfigurable { /** * Returns a field accessor that is identical to this field accessor but uses the given assigner * and runtime type use configuration. * * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @return This field accessor with the given assigner and runtime type use configuration. */ PropertyConfigurable withAssigner(Assigner assigner, Assigner.Typing typing); } /** * A field accessor that can be configured to locate a field in a specific manner. */ public interface OwnerTypeLocatable extends AssignerConfigurable { /** * Determines that a field should only be considered when it was defined in a given type. * * @param type The type to be considered. * @return This field accessor which will only considered fields that are defined in the given type. */ AssignerConfigurable in(Class type); /** * Determines that a field should only be considered when it was defined in a given type. * * @param typeDescription A description of the type to be considered. * @return This field accessor which will only considered fields that are defined in the given type. */ AssignerConfigurable in(TypeDescription typeDescription); /** * Determines that a field should only be considered when it was identified by a field locator that is * produced by the given factory. * * @param fieldLocatorFactory A factory that will produce a field locator that will be used to find locate * a field to be accessed. * @return This field accessor which will only considered fields that are defined in the given type. */ AssignerConfigurable in(FieldLocator.Factory fieldLocatorFactory); } /** * A field accessor for an implicit property where a getter or setter property is inferred from the signature. */ protected static class ForImplicitProperty extends FieldAccessor implements OwnerTypeLocatable { /** * Creates a field accessor for an implicit property. * * @param fieldLocation The field's location. */ protected ForImplicitProperty(FieldLocation fieldLocation) { this(fieldLocation, Assigner.DEFAULT, Assigner.Typing.STATIC); } /** * Creates a field accessor for an implicit property. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing The typing to use. */ private ForImplicitProperty(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing) { super(fieldLocation, assigner, typing); } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; } /** * {@inheritDoc} */ public ByteCodeAppender appender(Target implementationTarget) { return new Appender(fieldLocation.prepare(implementationTarget.getInstrumentedType())); } /** * {@inheritDoc} */ public Composable setsArgumentAt(int index) { if (index < 0) { throw new IllegalArgumentException("A parameter index cannot be negative: " + index); } return new ForSetter.OfParameterValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING, index); } /** * {@inheritDoc} */ public Composable setsDefaultValue() { return new ForSetter.OfDefaultValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING); } /** * {@inheritDoc} */ public Composable setsValue(@MaybeNull Object value) { if (value == null) { return setsDefaultValue(); } ConstantValue constant = ConstantValue.Simple.wrapOrNull(value); return constant == null ? setsReference(value) : setsValue(constant.toStackManipulation(), constant.getTypeDescription().asGenericType()); } /** * {@inheritDoc} */ public Composable setsValue(TypeDescription typeDescription) { return setsValue(ClassConstant.of(typeDescription), Class.class); } /** * {@inheritDoc} */ public Composable setsValue(ConstantValue constant) { return setsValue(constant.toStackManipulation(), constant.getTypeDescription().asGenericType()); } /** * {@inheritDoc} */ public Composable setsValue(JavaConstant constant) { return setsValue((ConstantValue) constant); } /** * {@inheritDoc} */ public Composable setsValue(StackManipulation stackManipulation, Type type) { return setsValue(stackManipulation, TypeDescription.Generic.Sort.describe(type)); } /** * {@inheritDoc} */ public Composable setsValue(StackManipulation stackManipulation, TypeDescription.Generic typeDescription) { return new ForSetter.OfConstantValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING, typeDescription, stackManipulation); } /** * {@inheritDoc} */ public Composable setsReference(Object value) { return setsReference(value, ForSetter.OfReferenceValue.PREFIX + "$" + RandomString.hashOf(value)); } /** * {@inheritDoc} */ public Composable setsReference(Object value, String name) { return new ForSetter.OfReferenceValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING, value, name); } /** * {@inheritDoc} */ public Composable setsFieldValueOf(Field field) { return setsFieldValueOf(new FieldDescription.ForLoadedField(field)); } /** * {@inheritDoc} */ public Composable setsFieldValueOf(FieldDescription fieldDescription) { return new ForSetter.OfFieldValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING, new FieldLocation.Absolute(fieldDescription)); } /** * {@inheritDoc} */ public Composable setsFieldValueOf(String fieldName) { return setsFieldValueOf(new FieldNameExtractor.ForFixedValue(fieldName)); } /** * {@inheritDoc} */ public Composable setsFieldValueOf(FieldNameExtractor fieldNameExtractor) { return new ForSetter.OfFieldValue(fieldLocation, assigner, typing, ForSetter.TerminationHandler.RETURNING, new FieldLocation.Relative(Collections.singletonList(fieldNameExtractor))); } /** * {@inheritDoc} */ public PropertyConfigurable withAssigner(Assigner assigner, Assigner.Typing typing) { return new ForImplicitProperty(fieldLocation, assigner, typing); } /** * {@inheritDoc} */ public AssignerConfigurable in(Class type) { return in(TypeDescription.ForLoadedType.of(type)); } /** * {@inheritDoc} */ public AssignerConfigurable in(TypeDescription typeDescription) { return in(new FieldLocator.ForExactType.Factory(typeDescription)); } /** * {@inheritDoc} */ public AssignerConfigurable in(FieldLocator.Factory fieldLocatorFactory) { return new ForImplicitProperty(fieldLocation.with(fieldLocatorFactory), assigner, typing); } /** * An byte code appender for an field accessor implementation. */ @HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true) protected class Appender implements ByteCodeAppender { /** * The field's location. */ private final FieldLocation.Prepared fieldLocation; /** * Creates a new byte code appender for a field accessor implementation. * * @param fieldLocation The field's location. */ protected Appender(FieldLocation.Prepared fieldLocation) { this.fieldLocation = fieldLocation; } /** * {@inheritDoc} */ public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext, MethodDescription instrumentedMethod) { if (!instrumentedMethod.isMethod()) { throw new IllegalArgumentException(instrumentedMethod + " does not describe a field getter or setter"); } FieldDescription fieldDescription = fieldLocation.resolve(instrumentedMethod); if (!fieldDescription.isStatic() && instrumentedMethod.isStatic()) { throw new IllegalStateException("Cannot set instance field " + fieldDescription + " from " + instrumentedMethod); } StackManipulation implementation, initialization = fieldDescription.isStatic() ? StackManipulation.Trivial.INSTANCE : MethodVariableAccess.loadThis(); if (!instrumentedMethod.getReturnType().represents(void.class)) { implementation = new StackManipulation.Compound( initialization, FieldAccess.forField(fieldDescription).read(), assigner.assign(fieldDescription.getType(), instrumentedMethod.getReturnType(), typing), MethodReturn.of(instrumentedMethod.getReturnType()) ); } else if (instrumentedMethod.getReturnType().represents(void.class) && instrumentedMethod.getParameters().size() == 1) { if (fieldDescription.isFinal() && instrumentedMethod.isMethod()) { throw new IllegalStateException("Cannot set final field " + fieldDescription + " from " + instrumentedMethod); } implementation = new StackManipulation.Compound( initialization, MethodVariableAccess.load(instrumentedMethod.getParameters().get(0)), assigner.assign(instrumentedMethod.getParameters().get(0).getType(), fieldDescription.getType(), typing), FieldAccess.forField(fieldDescription).write(), MethodReturn.VOID ); } else { throw new IllegalArgumentException("Method " + instrumentedMethod + " is no bean accessor"); } if (!implementation.isValid()) { throw new IllegalStateException("Cannot set or get value of " + instrumentedMethod + " using " + fieldDescription); } return new Size(implementation.apply(methodVisitor, implementationContext).getMaximalSize(), instrumentedMethod.getStackSize()); } } } /** * A field accessor for a field setter. * * @param The type of the value that is initialized per instrumented type. */ @HashCodeAndEqualsPlugin.Enhance protected abstract static class ForSetter extends FieldAccessor implements Implementation.Composable { /** * The termination handler to apply. */ private final TerminationHandler terminationHandler; /** * Creates a new field accessor for a setter instrumentation. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. */ protected ForSetter(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler) { super(fieldLocation, assigner, typing); this.terminationHandler = terminationHandler; } /** * {@inheritDoc} */ public ByteCodeAppender appender(Target implementationTarget) { return new Appender(implementationTarget.getInstrumentedType(), initialize(implementationTarget.getInstrumentedType()), fieldLocation.prepare(implementationTarget.getInstrumentedType())); } /** * Initializes a value to be used during method instrumentation. * * @param instrumentedType The instrumented type. * @return The initialized value. */ @MaybeNull protected abstract T initialize(TypeDescription instrumentedType); /** * Resolves the stack manipulation to load the value being set. * * @param initialized The method that was initialized for the instrumented type. * @param fieldDescription The field to set the value for. * @param instrumentedType The instrumented type. * @param instrumentedMethod The instrumented method. * @return The stack manipulation to apply. */ protected abstract StackManipulation resolve(@MaybeNull T initialized, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod); /** * A termination handler is responsible for handling a field accessor's return. */ protected enum TerminationHandler { /** * Returns {@code void} or throws an exception if this is not the return type of the instrumented method. */ RETURNING { @Override protected StackManipulation resolve(MethodDescription instrumentedMethod) { if (!instrumentedMethod.getReturnType().represents(void.class)) { throw new IllegalStateException("Cannot implement setter with return value for " + instrumentedMethod); } return MethodReturn.VOID; } }, /** * Does not return from the method at all. */ NON_OPERATIONAL { @Override protected StackManipulation resolve(MethodDescription instrumentedMethod) { return StackManipulation.Trivial.INSTANCE; } }; /** * Resolves the return instruction. * * @param instrumentedMethod The instrumented method. * @return An appropriate stack manipulation. */ protected abstract StackManipulation resolve(MethodDescription instrumentedMethod); } /** * A setter instrumentation for a parameter value. */ @HashCodeAndEqualsPlugin.Enhance protected static class OfParameterValue extends ForSetter { /** * The parameter's index. */ private final int index; /** * Creates a new setter instrumentation for a parameter value. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. * @param index The parameter's index. */ protected OfParameterValue(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler, int index) { super(fieldLocation, assigner, typing, terminationHandler); this.index = index; } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; } /** * {@inheritDoc} */ @AlwaysNull protected Void initialize(TypeDescription instrumentedType) { return null; } /** * {@inheritDoc} */ protected StackManipulation resolve(@MaybeNull Void unused, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod) { if (instrumentedMethod.getParameters().size() <= index) { throw new IllegalStateException(instrumentedMethod + " does not define a parameter with index " + index); } else { return new StackManipulation.Compound( MethodVariableAccess.load(instrumentedMethod.getParameters().get(index)), assigner.assign(instrumentedMethod.getParameters().get(index).getType(), fieldDescription.getType(), typing) ); } } /** * {@inheritDoc} */ public Implementation andThen(Implementation implementation) { return new Compound(new OfParameterValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, index), implementation); } /** * {@inheritDoc} */ public Composable andThen(Composable implementation) { return new Compound.Composable(new OfParameterValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, index), implementation); } } /** * A setter instrumentation that sets a {@code null} or a primitive type's default value. */ protected static class OfDefaultValue extends ForSetter { /** * Creates an intrumentation that sets a field's default value. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. */ protected OfDefaultValue(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler) { super(fieldLocation, assigner, typing, terminationHandler); } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; } /** * {@inheritDoc} */ @AlwaysNull protected Void initialize(TypeDescription instrumentedType) { return null; } /** * {@inheritDoc} */ protected StackManipulation resolve(@MaybeNull Void initialized, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod) { return DefaultValue.of(fieldDescription.getType()); } /** * {@inheritDoc} */ public Implementation andThen(Implementation implementation) { return new Compound(new OfDefaultValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL), implementation); } /** * {@inheritDoc} */ public Composable andThen(Composable implementation) { return new Compound.Composable(new OfDefaultValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL), implementation); } } /** * An instrumentation that sets a constant value to a field. */ @HashCodeAndEqualsPlugin.Enhance protected static class OfConstantValue extends ForSetter { /** * The value's type. */ private final TypeDescription.Generic typeDescription; /** * A stack manipulation to load the constant value. */ private final StackManipulation stackManipulation; /** * Creates a setter instrumentation for setting a constant value. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. * @param typeDescription The value's type. * @param stackManipulation A stack manipulation to load the constant value. */ protected OfConstantValue(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler, TypeDescription.Generic typeDescription, StackManipulation stackManipulation) { super(fieldLocation, assigner, typing, terminationHandler); this.typeDescription = typeDescription; this.stackManipulation = stackManipulation; } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; } /** * {@inheritDoc} */ @AlwaysNull protected Void initialize(TypeDescription instrumentedType) { return null; } /** * {@inheritDoc} */ protected StackManipulation resolve(@MaybeNull Void unused, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod) { return new StackManipulation.Compound(stackManipulation, assigner.assign(typeDescription, fieldDescription.getType(), typing)); } /** * {@inheritDoc} */ public Implementation andThen(Implementation implementation) { return new Compound(new OfConstantValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, typeDescription, stackManipulation), implementation); } /** * {@inheritDoc} */ public Composable andThen(Composable implementation) { return new Compound.Composable(new OfConstantValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, typeDescription, stackManipulation), implementation); } } /** * An instrumentation that sets a field to a reference value that is stored in a static field of the instrumented type. */ @HashCodeAndEqualsPlugin.Enhance protected static class OfReferenceValue extends ForSetter { /** * The prefix used for implicitly named cached fields. */ protected static final String PREFIX = "fixedFieldValue"; /** * The value to store. */ private final Object value; /** * The name of the field to store the reference in. */ private final String name; /** * Creates a setter instrumentation for setting a value stored in a static field of the instrumented type. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. * @param value The value to store. * @param name The name of the field to store the reference in. */ protected OfReferenceValue(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler, Object value, String name) { super(fieldLocation, assigner, typing, terminationHandler); this.value = value; this.name = name; } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType.withAuxiliaryField(new FieldDescription.Token(name, Opcodes.ACC_SYNTHETIC | Opcodes.ACC_STATIC | Opcodes.ACC_PUBLIC, TypeDescription.ForLoadedType.of(value.getClass()).asGenericType()), value); } /** * {@inheritDoc} */ protected FieldDescription.InDefinedShape initialize(TypeDescription instrumentedType) { return instrumentedType.getDeclaredFields().filter(named(name)).getOnly(); } /** * {@inheritDoc} */ @SuppressFBWarnings(value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE", justification = "Expects its own initialized value as argument") protected StackManipulation resolve(@MaybeNull FieldDescription.InDefinedShape target, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod) { if (fieldDescription.isFinal() && instrumentedMethod.isMethod()) { throw new IllegalArgumentException("Cannot set final field " + fieldDescription + " from " + instrumentedMethod); } return new StackManipulation.Compound( FieldAccess.forField(target).read(), assigner.assign(TypeDescription.ForLoadedType.of(value.getClass()).asGenericType(), fieldDescription.getType(), typing) ); } /** * {@inheritDoc} */ public Implementation andThen(Implementation implementation) { return new Compound(new OfReferenceValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, value, name), implementation); } /** * {@inheritDoc} */ public Composable andThen(Composable implementation) { return new Compound.Composable(new OfReferenceValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, value, name), implementation); } } /** * A setter that reads a value of another field and sets this value. */ @HashCodeAndEqualsPlugin.Enhance protected static class OfFieldValue extends ForSetter { /** * The target field locator. */ private final FieldLocation target; /** * Creates a setter that sets another field value. * * @param fieldLocation The field's location. * @param assigner The assigner to use. * @param typing Indicates if dynamic type castings should be attempted for incompatible assignments. * @param terminationHandler The termination handler to apply. * @param target The target field locator. */ protected OfFieldValue(FieldLocation fieldLocation, Assigner assigner, Assigner.Typing typing, TerminationHandler terminationHandler, FieldLocation target) { super(fieldLocation, assigner, typing, terminationHandler); this.target = target; } /** * {@inheritDoc} */ public InstrumentedType prepare(InstrumentedType instrumentedType) { return instrumentedType; } /** * {@inheritDoc} */ protected FieldLocation.Prepared initialize(TypeDescription instrumentedType) { return target.prepare(instrumentedType); } /** * {@inheritDoc} */ @SuppressFBWarnings(value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE", justification = "Expects its own initialized value as argument") protected StackManipulation resolve(@MaybeNull FieldLocation.Prepared target, FieldDescription fieldDescription, TypeDescription instrumentedType, MethodDescription instrumentedMethod) { FieldDescription resolved = target.resolve(instrumentedMethod); if (!resolved.isStatic() && instrumentedMethod.isStatic()) { throw new IllegalStateException("Cannot set instance field " + fieldDescription + " from " + instrumentedMethod); } return new StackManipulation.Compound( resolved.isStatic() ? StackManipulation.Trivial.INSTANCE : MethodVariableAccess.loadThis(), FieldAccess.forField(resolved).read(), assigner.assign(resolved.getType(), fieldDescription.getType(), typing) ); } /** * {@inheritDoc} */ public Implementation andThen(Implementation implementation) { return new Compound(new OfFieldValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, target), implementation); } /** * {@inheritDoc} */ public Composable andThen(Composable implementation) { return new Compound.Composable(new OfFieldValue(fieldLocation, assigner, typing, TerminationHandler.NON_OPERATIONAL, target), implementation); } } /** * An appender to implement a field setter. */ @HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true) protected class Appender implements ByteCodeAppender { /** * The instrumented type. */ private final TypeDescription instrumentedType; /** * The initialized value which might be {@code null}. */ @MaybeNull @HashCodeAndEqualsPlugin.ValueHandling(HashCodeAndEqualsPlugin.ValueHandling.Sort.REVERSE_NULLABILITY) private final T initialized; /** * The set field's prepared location. */ private final FieldLocation.Prepared fieldLocation; /** * Creates a new appender for a field setter. * * @param instrumentedType The instrumented type. * @param initialized The initialized value which might be {@code null}. * @param fieldLocation The set field's prepared location. */ protected Appender(TypeDescription instrumentedType, @MaybeNull T initialized, FieldLocation.Prepared fieldLocation) { this.instrumentedType = instrumentedType; this.initialized = initialized; this.fieldLocation = fieldLocation; } /** * {@inheritDoc} */ public Size apply(MethodVisitor methodVisitor, Context implementationContext, MethodDescription instrumentedMethod) { FieldDescription fieldDescription = fieldLocation.resolve(instrumentedMethod); if (!fieldDescription.isStatic() && instrumentedMethod.isStatic()) { throw new IllegalStateException("Cannot set instance field " + fieldDescription + " from " + instrumentedMethod); } else if (fieldDescription.isFinal() && instrumentedMethod.isMethod()) { throw new IllegalStateException("Cannot set final field " + fieldDescription + " from " + instrumentedMethod); } StackManipulation stackManipulation = resolve(initialized, fieldDescription, instrumentedType, instrumentedMethod); if (!stackManipulation.isValid()) { throw new IllegalStateException("Set value cannot be assigned to " + fieldDescription); } return new Size(new StackManipulation.Compound( instrumentedMethod.isStatic() ? StackManipulation.Trivial.INSTANCE : MethodVariableAccess.loadThis(), stackManipulation, FieldAccess.forField(fieldDescription).write(), terminationHandler.resolve(instrumentedMethod) ).apply(methodVisitor, implementationContext).getMaximalSize(), instrumentedMethod.getStackSize()); } } } }




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