net.bytebuddy.asm

Class MemberSubstitution

java.lang.Object

net.bytebuddy.asm.MemberSubstitution

All Implemented Interfaces:

AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper

@HashCodeAndEqualsPlugin.Enhance
public class MemberSubstitution
extends Object
implements AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper

Substitutes field access, method invocations or constructor calls within a method's body.

Note: This substitution must not be used to match constructor calls to an instrumented class's super constructor invocation from within a constructor. Matching such constructors will result in an invalid stack and a verification error.

Note: This visitor will compute the required stack size on a best effort basis. For allocating an optimal stack size, ASM needs to be configured to compute the stack size.

Important: This component relies on using a TypePool for locating types within method bodies. Within a redefinition or a rebasement, this type pool normally resolved correctly by Byte Buddy. When subclassing a type, the type pool must be set explicitly, using DynamicType.Builder.make(TypePool) or any similar method. It is however not normally necessary to use this component when subclassing a type where methods are only defined explicitly.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	MemberSubstitution.AllArguments Assigns an array containing all arguments of the targeted element to the annotated parameter.
static interface	MemberSubstitution.Argument Indicates that the annotated parameter should be mapped to the parameter with index MemberSubstitution.Argument.value().
static interface	MemberSubstitution.Current Indicates that the annotated parameter should be assigned the value of the result that was yielded by the previous chain expression.
static interface	MemberSubstitution.FieldGetterHandle Indicates that the annotated parameter should be mapped to a java.lang.invoke.MethodHandle representing a field getter.
static interface	MemberSubstitution.FieldSetterHandle Indicates that the annotated parameter should be mapped to a java.lang.invoke.MethodHandle representing a field setter.
static interface	MemberSubstitution.FieldValue Indicates that the annotated parameter should be mapped to a field in the scope of the instrumented type.
static interface	MemberSubstitution.Origin Indicates that the annotated parameter should be mapped to a representation of the substituted element or instrumented method.
protected static interface	MemberSubstitution.Replacement A replacement combines a MemberSubstitution.Substitution and a way of choosing if this substitution should be applied for a discovered member.
static interface	MemberSubstitution.SelfCallHandle Indicates that the annotated parameter should load a java.lang.invoke.MethodHandle that represents an invocation of the substituted expression or instrumented method.
static class	MemberSubstitution.Source Identifies the source of an instruction that might describe a value of the substituted element or the instrumented method.
static interface	MemberSubstitution.StubValue Indicates that the annotated parameter should always return a boxed version of the instrumented method's return value (i.e.
protected static class	MemberSubstitution.SubstitutingMethodVisitor A method visitor that applies a substitution for matched methods.
static interface	MemberSubstitution.Substitution A substitution replaces or enhances an interaction with a field or method within an instrumented method.
static interface	MemberSubstitution.This Indicates that the annotated parameter should be mapped to the this reference of the substituted field, method, constructor or of the instrumented method.
static interface	MemberSubstitution.TypePoolResolver A type pool resolver is responsible for resolving a TypePool for locating substituted members.
static interface	MemberSubstitution.Unused Indicates that the annotated parameter should always return a default value (i.e.
static class	MemberSubstitution.WithoutSpecification A member substitution that lacks a specification for how to substitute the matched members references within a method body.

Field Summary

Fields

Modifier and Type	Field and Description
protected static int	THIS_REFERENCE The index of the this reference within a non-static method.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MemberSubstitution(boolean strict) Creates a default member substitution.
protected	MemberSubstitution(MethodGraph.Compiler methodGraphCompiler, MemberSubstitution.TypePoolResolver typePoolResolver, boolean strict, boolean failIfNoMatch, MemberSubstitution.Replacement.Factory replacementFactory) Creates a new member substitution.

Method Summary

Modifier and Type	Method and Description
MemberSubstitution.WithoutSpecification	constructor(ElementMatcher<? super MethodDescription> matcher) Substitutes any constructor invocation that matches the given matcher.
MemberSubstitution.WithoutSpecification	element(ElementMatcher<? super ByteCodeElement.Member> matcher) Substitutes any interaction with a field or method that matches the given matcher.
MemberSubstitution	failIfNoMatch(boolean failIfNoMatch) Specifies if this substitution should fail if applied on a method without a match.
MemberSubstitution.WithoutSpecification.ForMatchedField	field(ElementMatcher<? super FieldDescription> matcher) Substitutes any field access that matches the given matcher.
MemberSubstitution.WithoutSpecification	invokable(ElementMatcher<? super MethodDescription> matcher) Substitutes any method or constructor invocation that matches the given matcher.
MemberSubstitution.WithoutSpecification.ForMatchedMethod	method(ElementMatcher<? super MethodDescription> matcher) Substitutes any method invocation that matches the given matcher.
AsmVisitorWrapper.ForDeclaredMethods	on(ElementMatcher<? super MethodDescription> matcher) Applies this member substitution to any method that matches the supplied matcher.
static MemberSubstitution	relaxed() Creates a member substitution that skips any unresolvable fields or methods that are referenced within a method body.
static MemberSubstitution	strict() Creates a member substitution that requires the resolution of all fields and methods that are referenced within a method body.
MemberSubstitution	with(MemberSubstitution.TypePoolResolver typePoolResolver) Specifies a type pool resolver to be used for locating members.
MemberSubstitution	with(MethodGraph.Compiler methodGraphCompiler) Specifies the use of a specific method graph compiler for the resolution of virtual methods.
MethodVisitor	wrap(TypeDescription instrumentedType, MethodDescription instrumentedMethod, MethodVisitor methodVisitor, Implementation.Context implementationContext, TypePool typePool, int writerFlags, int readerFlags) Wraps a method visitor.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

THIS_REFERENCE

protected static final int THIS_REFERENCE

The index of the this reference within a non-static method.

See Also:

Constant Field Values

Constructor Detail

MemberSubstitution

protected MemberSubstitution(boolean strict)

Creates a default member substitution.

Parameters:

strict - true if the method processing should be strict where an exception is raised if a member cannot be found.

MemberSubstitution

protected MemberSubstitution(MethodGraph.Compiler methodGraphCompiler,
                             MemberSubstitution.TypePoolResolver typePoolResolver,
                             boolean strict,
                             boolean failIfNoMatch,
                             MemberSubstitution.Replacement.Factory replacementFactory)

Creates a new member substitution.

Parameters:

methodGraphCompiler - The method graph compiler to use.

typePoolResolver - The type pool resolver to use.

strict - true if the method processing should be strict where an exception is raised if a member cannot be found.

failIfNoMatch - true if the instrumentation should fail if applied to a method without match.

replacementFactory - The replacement factory to use.

Method Detail

strict

public static MemberSubstitution strict()

Creates a member substitution that requires the resolution of all fields and methods that are referenced within a method body. Doing so, this component raises an exception if any member cannot be resolved what makes this component unusable when facing optional types.

Returns:

A strict member substitution.

relaxed

public static MemberSubstitution relaxed()

Creates a member substitution that skips any unresolvable fields or methods that are referenced within a method body. Using a relaxed member substitution, methods containing optional types are supported. In the process, it is however possible that misconfigurations of this component remain undiscovered.

Returns:

A relaxed member substitution.

element

public MemberSubstitution.WithoutSpecification element(ElementMatcher<? super ByteCodeElement.Member> matcher)

Substitutes any interaction with a field or method that matches the given matcher.

Parameters:

matcher - The matcher to determine what access to byte code elements to substitute.

Returns:

A specification that allows to determine how to substitute any interaction with byte code elements that match the supplied matcher.

field

public MemberSubstitution.WithoutSpecification.ForMatchedField field(ElementMatcher<? super FieldDescription> matcher)

Substitutes any field access that matches the given matcher.

Parameters:

matcher - The matcher to determine what fields to substitute.

Returns:

A specification that allows to determine how to substitute any field access that match the supplied matcher.

method

public MemberSubstitution.WithoutSpecification.ForMatchedMethod method(ElementMatcher<? super MethodDescription> matcher)

Substitutes any method invocation that matches the given matcher.

Parameters:

matcher - The matcher to determine what methods to substitute.

Returns:

A specification that allows to determine how to substitute any method invocations that match the supplied matcher.

constructor

public MemberSubstitution.WithoutSpecification constructor(ElementMatcher<? super MethodDescription> matcher)

Substitutes any constructor invocation that matches the given matcher.

Parameters:

matcher - The matcher to determine what constructors to substitute.

Returns:

A specification that allows to determine how to substitute any constructor invocations that match the supplied matcher.

invokable

public MemberSubstitution.WithoutSpecification invokable(ElementMatcher<? super MethodDescription> matcher)

Substitutes any method or constructor invocation that matches the given matcher.

Parameters:

matcher - The matcher to determine what method or constructors to substitute.

Returns:

A specification that allows to determine how to substitute any constructor invocations that match the supplied matcher.

with

public MemberSubstitution with(MethodGraph.Compiler methodGraphCompiler)

Specifies the use of a specific method graph compiler for the resolution of virtual methods.

Parameters:

methodGraphCompiler - The method graph compiler to use.

Returns:

A new member substitution that is equal to this but uses the specified method graph compiler.

with

public MemberSubstitution with(MemberSubstitution.TypePoolResolver typePoolResolver)

Specifies a type pool resolver to be used for locating members.

Parameters:

typePoolResolver - The type pool resolver to use.

Returns:

A new instance of this member substitution that uses the supplied type pool resolver.

failIfNoMatch

public MemberSubstitution failIfNoMatch(boolean failIfNoMatch)

Specifies if this substitution should fail if applied on a method without a match.

Parameters:

failIfNoMatch - true if the instrumentation should fail if applied to a method without match.

Returns:

A new instance of this member substitution that fails if applied on a method without a match.

on

public AsmVisitorWrapper.ForDeclaredMethods on(ElementMatcher<? super MethodDescription> matcher)

Applies this member substitution to any method that matches the supplied matcher.

Parameters:

matcher - The matcher to determine this substitutions application.

Returns:

An ASM visitor wrapper that applies all specified substitutions for any matched method.

wrap

public MethodVisitor wrap(TypeDescription instrumentedType,
                          MethodDescription instrumentedMethod,
                          MethodVisitor methodVisitor,
                          Implementation.Context implementationContext,
                          TypePool typePool,
                          int writerFlags,
                          int readerFlags)

Wraps a method visitor.

Specified by:

wrap in interface AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper

Parameters:

instrumentedType - The instrumented type.

instrumentedMethod - The method that is currently being defined.

methodVisitor - The original field visitor that defines the given method.

implementationContext - The implementation context to use.

typePool - The type pool to use.

writerFlags - The ASM ClassWriter reader flags to consider.

readerFlags - The ASM ClassReader reader flags to consider.

Returns:

The wrapped method visitor.