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Byte Buddy is a Java library for creating Java classes at run time.
This artifact is a build of Byte Buddy with a remaining dependency onto ASM.
You should never depend on this module without repackaging Byte Buddy and ASM into your own namespace.
package net.bytebuddy.asm;
import lombok.EqualsAndHashCode;
import net.bytebuddy.description.ByteCodeElement;
import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.field.FieldList;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.method.MethodList;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.description.type.TypeList;
import net.bytebuddy.dynamic.scaffold.MethodGraph;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.bytecode.Duplication;
import net.bytebuddy.implementation.bytecode.Removal;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.StackSize;
import net.bytebuddy.implementation.bytecode.constant.DefaultValue;
import net.bytebuddy.implementation.bytecode.member.FieldAccess;
import net.bytebuddy.implementation.bytecode.member.MethodInvocation;
import net.bytebuddy.matcher.ElementMatcher;
import net.bytebuddy.pool.TypePool;
import net.bytebuddy.utility.CompoundList;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import static net.bytebuddy.matcher.ElementMatchers.*;
/**
*
* Substitutes field access or method invocations within a method's body.
*
*
* Important: This component relies on using a {@link 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 {@link net.bytebuddy.dynamic.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.
*
*/
@EqualsAndHashCode(callSuper = false)
public class MemberSubstitution implements AsmVisitorWrapper.ForDeclaredMethods.MethodVisitorWrapper {
/**
* The method graph compiler to use.
*/
private final MethodGraph.Compiler methodGraphCompiler;
/**
* {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
*/
private final boolean strict;
/**
* The substitution to apply.
*/
private final Substitution substitution;
/**
* Creates a new member substitutor.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
*/
protected MemberSubstitution(MethodGraph.Compiler methodGraphCompiler, boolean strict, Substitution substitution) {
this.methodGraphCompiler = methodGraphCompiler;
this.strict = strict;
this.substitution = substitution;
}
/**
* Creates a member substitutor 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.
*
* @return A strict member substitutor.
*/
public static MemberSubstitution strict() {
return new MemberSubstitution(MethodGraph.Compiler.DEFAULT, true, Substitution.NoOp.INSTANCE);
}
/**
* Creates a member substitutor that skips any unresolvable fields or methods that are referenced within a method body. Using a relaxed
* member substitutor, methods containing optional types are supported. In the process, it is however possible that misconfigurations
* of this component remain undiscovered.
*
* @return A relaxed member substitutor.
*/
public static MemberSubstitution relaxed() {
return new MemberSubstitution(MethodGraph.Compiler.DEFAULT, false, Substitution.NoOp.INSTANCE);
}
/**
* Substitutes any interaction with a field or method that matches the given matcher.
*
* @param matcher The matcher to determine what access to byte code elements to substitute.
* @return A specification that allows to determine how to substitute any interaction with byte code elements that match the supplied matcher.
*/
public WithoutSpecification element(ElementMatcher matcher) {
return new WithoutSpecification.ForMatchedByteCodeElement(methodGraphCompiler, strict, substitution, matcher);
}
/**
* Substitutes any field access that matches the given matcher.
*
* @param matcher The matcher to determine what fields to substitute.
* @return A specification that allows to determine how to substitute any field access that match the supplied matcher.
*/
public WithoutSpecification.ForMatchedField field(ElementMatcher matcher) {
return new WithoutSpecification.ForMatchedField(methodGraphCompiler, strict, substitution, matcher);
}
/**
* Substitutes any method invocation that matches the given matcher.
*
* @param matcher The matcher to determine what methods to substitute.
* @return A specification that allows to determine how to substitute any method invocations that match the supplied matcher.
*/
public WithoutSpecification.ForMatchedMethod method(ElementMatcher matcher) {
return new WithoutSpecification.ForMatchedMethod(methodGraphCompiler, strict, substitution, matcher);
}
/**
* Substitutes any constructor invocation that matches the given matcher.
*
* @param matcher The matcher to determine what constructors to substitute.
* @return A specification that allows to determine how to substitute any constructor invocations that match the supplied matcher.
*/
public WithoutSpecification constructor(ElementMatcher matcher) {
return invokable(isConstructor().and(matcher));
}
/**
* Substitutes any method or constructor invocation that matches the given matcher.
*
* @param matcher The matcher to determine what method or constructors to substitute.
* @return A specification that allows to determine how to substitute any constructor invocations that match the supplied matcher.
*/
public WithoutSpecification invokable(ElementMatcher matcher) {
return new WithoutSpecification.ForMatchedMethod(methodGraphCompiler, strict, substitution, matcher);
}
/**
* Specifies the use of a specific method graph compiler for the resolution of virtual methods.
*
* @param methodGraphCompiler The method graph compiler to use.
* @return A new member substitution that is equal to this but uses the specified method graph compiler.
*/
public MemberSubstitution with(MethodGraph.Compiler methodGraphCompiler) {
return new MemberSubstitution(methodGraphCompiler, strict, substitution);
}
/**
* Applies this member substitutor to any method that matches the supplied matcher.
*
* @param matcher The matcher to determine this substitutors application.
* @return An ASM visitor wrapper that applies all specified substitutions for any matched method.
*/
public AsmVisitorWrapper.ForDeclaredMethods on(ElementMatcher matcher) {
return new AsmVisitorWrapper.ForDeclaredMethods().method(matcher, this);
}
@Override
public MethodVisitor wrap(TypeDescription instrumentedType,
MethodDescription instrumentedMethod,
MethodVisitor methodVisitor,
Implementation.Context implementationContext,
TypePool typePool,
int writerFlags,
int readerFlags) {
return new SubstitutingMethodVisitor(methodVisitor,
methodGraphCompiler,
strict,
substitution,
instrumentedType,
implementationContext,
typePool);
}
/**
* A member substitution that lacks a specification for how to substitute the matched members references within a method body.
*/
@EqualsAndHashCode
public abstract static class WithoutSpecification {
/**
* The method graph compiler to use.
*/
protected final MethodGraph.Compiler methodGraphCompiler;
/**
* {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
*/
protected final boolean strict;
/**
* The substitution to apply.
*/
protected final Substitution substitution;
/**
* Creates a new member substitution that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
*/
protected WithoutSpecification(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution) {
this.methodGraphCompiler = methodGraphCompiler;
this.strict = strict;
this.substitution = substitution;
}
/**
* Subs any interaction with a matched byte code element. Any value read from the element will be replaced with the stubbed
* value's default, i.e. {@code null} for reference types and the specific {@code 0} value for primitive types. Any writen
* value will simply be discarded.
*
* @return A member substitution that stubs any interaction with a matched byte code element.
*/
public MemberSubstitution stub() {
return new MemberSubstitution(methodGraphCompiler,
strict,
new Substitution.Compound(doStub(), substitution));
}
/**
* Applies the stubbing for this instance.
*
* @return A suitable substitution.
*/
protected abstract Substitution doStub();
/**
*
* Replaces any interaction with a matched byte code element by an interaction with the specified field. If a field
* is replacing a method or constructor invocation, it is treated as if it was a field getter or setter respectively.
*
*
* A replacement can only be applied if the field is compatible to the original byte code element, i.e. consumes an
* instance of the declaring type if it is not {@code static} as an argument and consumes or produces an instance of
* the field's type.
*
*
* @param field The field to access instead of interacting with any of the matched byte code elements.
* @return A member substitution that replaces any matched byte code element with an access of the specified field.
*/
public MemberSubstitution replaceWith(Field field) {
return replaceWith(new FieldDescription.ForLoadedField(field));
}
/**
*
* Replaces any interaction with a matched byte code element by an interaction with the specified field. If a field
* is replacing a method or constructor invocation, it is treated as if it was a field getter or setter respectively.
*
*
* A replacement can only be applied if the field is compatible to the original byte code element, i.e. consumes an
* instance of the declaring type if it is not {@code static} as an argument and consumes or produces an instance of
* the field's type.
*
*
* @param fieldDescription The field to access instead of interacting with any of the matched byte code elements.
* @return A member substitution that replaces any matched byte code element with an access of the specified field.
*/
public MemberSubstitution replaceWith(FieldDescription fieldDescription) {
return new MemberSubstitution(methodGraphCompiler,
strict,
new Substitution.Compound(doReplaceWith(fieldDescription), substitution));
}
/**
* Creates a substitution for replacing the byte code elements matched by this instance with an access of the specified field.
*
* @param fieldDescription The field to access.
* @return A suitable substitution.
*/
protected abstract Substitution doReplaceWith(FieldDescription fieldDescription);
/**
*
* Replaces any interaction with a matched byte code element by an invocation of the specified method. If a method
* is replacing a field access, it is treated as if it was replacing an invocation of the field's getter or setter respectively.
*
*
* A replacement can only be applied if the method is compatible to the original byte code element, i.e. consumes compatible
* arguments and returns a compatible value. If the method is not {@code static}, it is treated as if {@code this} was an implcit
* first argument.
*
*
* @param method The method to invoke instead of interacting with any of the matched byte code elements.
* @return A member substitution that replaces any matched byte code element with an invocation of the specified method.
*/
public MemberSubstitution replaceWith(Method method) {
return replaceWith(new MethodDescription.ForLoadedMethod(method));
}
/**
*
* Replaces any interaction with a matched byte code element by an invocation of the specified method. If a method
* is replacing a field access, it is treated as if it was replacing an invocation of the field's getter or setter respectively.
*
*
* A replacement can only be applied if the method is compatible to the original byte code element, i.e. consumes compatible
* arguments and returns a compatible value. If the method is not {@code static}, it is treated as if {@code this} was an implcit
* first argument.
*
*
* Important: It is not allowed to specifiy a constructor or the static type initializer as a replacement.
*
*
* @param methodDescription The method to invoke instead of interacting with any of the matched byte code elements.
* @return A member substitution that replaces any matched byte code element with an invocation of the specified method.
*/
public MemberSubstitution replaceWith(MethodDescription methodDescription) {
if (!methodDescription.isMethod()) {
throw new IllegalArgumentException("Cannot use " + methodDescription + " as a replacement");
}
return new MemberSubstitution(methodGraphCompiler,
strict,
new Substitution.Compound(doReplaceWith(methodDescription), substitution));
}
/**
* Creates a substitution for replacing the byte code elements matched by this instance with an invocation of the specified method.
*
* @param methodDescription The method to invoke.
* @return A suitable substitution.
*/
protected abstract Substitution doReplaceWith(MethodDescription methodDescription);
/**
* Describes a member substitution that requires a specification for how to replace a byte code element.
*/
@EqualsAndHashCode(callSuper = true)
protected static class ForMatchedByteCodeElement extends WithoutSpecification {
/**
* A matcher for any byte code elements that should be substituted.
*/
private final ElementMatcher matcher;
/**
* Creates a new member substitution for a matched byte code element that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param matcher A matcher for any byte code elements that should be substituted.
*/
protected ForMatchedByteCodeElement(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
ElementMatcher matcher) {
super(methodGraphCompiler, strict, substitution);
this.matcher = matcher;
}
@Override
protected Substitution doStub() {
return Substitution.ForElementMatchers.of(matcher, Substitution.Resolver.Stubbing.INSTANCE);
}
@Override
protected Substitution doReplaceWith(FieldDescription fieldDescription) {
return Substitution.ForElementMatchers.of(matcher, new Substitution.Resolver.FieldAccessing(fieldDescription));
}
@Override
protected Substitution doReplaceWith(MethodDescription methodDescription) {
return Substitution.ForElementMatchers.of(matcher, new Substitution.Resolver.MethodInvoking(methodDescription));
}
}
/**
* Describes a member substitution that requires a specification for how to replace a field.
*/
@EqualsAndHashCode(callSuper = true)
public static class ForMatchedField extends WithoutSpecification {
/**
* A matcher for any field that should be substituted.
*/
private final ElementMatcher matcher;
/**
* {@code true} if read access to a field should be substituted.
*/
private final boolean matchRead;
/**
* {@code true} if write access to a field should be substituted.
*/
private final boolean matchWrite;
/**
* Creates a new member substitution for a matched field that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param matcher A matcher for any field that should be substituted.
*/
protected ForMatchedField(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
ElementMatcher matcher) {
this(methodGraphCompiler, strict, substitution, matcher, true, true);
}
/**
* Creates a new member substitution for a matched field that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param matcher A matcher for any field that should be substituted.
* @param matchRead {@code true} if read access to a field should be substituted.
* @param matchWrite {@code true} if write access to a field should be substituted.
*/
protected ForMatchedField(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
ElementMatcher matcher,
boolean matchRead,
boolean matchWrite) {
super(methodGraphCompiler, strict, substitution);
this.matcher = matcher;
this.matchRead = matchRead;
this.matchWrite = matchWrite;
}
/**
* When invoked, only read access of the previously matched field is substituted.
*
* @return This instance with the limitation that only read access to the matched field is substituted.
*/
public WithoutSpecification onRead() {
return new ForMatchedField(methodGraphCompiler, strict, substitution, matcher, true, false);
}
/**
* When invoked, only write access of the previously matched field is substituted.
*
* @return This instance with the limitation that only write access to the matched field is substituted.
*/
public WithoutSpecification onWrite() {
return new ForMatchedField(methodGraphCompiler, strict, substitution, matcher, false, true);
}
@Override
protected Substitution doStub() {
return Substitution.ForElementMatchers.ofField(matcher, matchRead, matchWrite, Substitution.Resolver.Stubbing.INSTANCE);
}
@Override
protected Substitution doReplaceWith(FieldDescription fieldDescription) {
return Substitution.ForElementMatchers.ofField(matcher, matchRead, matchWrite, new Substitution.Resolver.FieldAccessing(fieldDescription));
}
@Override
protected Substitution doReplaceWith(MethodDescription methodDescription) {
return Substitution.ForElementMatchers.ofField(matcher, matchRead, matchWrite, new Substitution.Resolver.MethodInvoking(methodDescription));
}
}
/**
* Describes a member substitution that requires a specification for how to replace a method or constructor.
*/
@EqualsAndHashCode(callSuper = true)
public static class ForMatchedMethod extends WithoutSpecification {
/**
* A matcher for any method or constructor that should be substituted.
*/
private final ElementMatcher matcher;
/**
* {@code true} if this specification includes virtual invocations.
*/
private final boolean includeVirtualCalls;
/**
* {@code true} if this specification includes {@code super} invocations.
*/
private final boolean includeSuperCalls;
/**
* Creates a new member substitution for a matched method that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param matcher A matcher for any method or constructor that should be substituted.
*/
protected ForMatchedMethod(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
ElementMatcher matcher) {
this(methodGraphCompiler, strict, substitution, matcher, true, true);
}
/**
* Creates a new member substitution for a matched method that requires a specification for how to perform a substitution.
*
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param matcher A matcher for any method or constructor that should be substituted.
* @param includeVirtualCalls {@code true} if this specification includes virtual invocations.
* @param includeSuperCalls {@code true} if this specification includes {@code super} invocations.
*/
protected ForMatchedMethod(MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
ElementMatcher matcher,
boolean includeVirtualCalls,
boolean includeSuperCalls) {
super(methodGraphCompiler, strict, substitution);
this.matcher = matcher;
this.includeVirtualCalls = includeVirtualCalls;
this.includeSuperCalls = includeSuperCalls;
}
/**
* Limits the substituted method calls to method calls that invoke a method virtually (as opposed to a {@code super} invocation).
*
* @return This specification where only virtual methods are matched if they are not invoked as a virtual call.
*/
public WithoutSpecification onVirtualCall() {
return new ForMatchedMethod(methodGraphCompiler, strict, substitution, isVirtual().and(matcher), true, false);
}
/**
* Limits the substituted method calls to method calls that invoke a method as a {@code super} call.
*
* @return This specification where only virtual methods are matched if they are not invoked as a super call.
*/
public WithoutSpecification onSuperCall() {
return new ForMatchedMethod(methodGraphCompiler, strict, substitution, isVirtual().and(matcher), false, true);
}
@Override
protected Substitution doStub() {
return Substitution.ForElementMatchers.ofMethod(matcher, includeVirtualCalls, includeSuperCalls, Substitution.Resolver.Stubbing.INSTANCE);
}
@Override
protected Substitution doReplaceWith(FieldDescription fieldDescription) {
return Substitution.ForElementMatchers.ofMethod(matcher,
includeVirtualCalls,
includeSuperCalls,
new Substitution.Resolver.FieldAccessing(fieldDescription));
}
@Override
protected Substitution doReplaceWith(MethodDescription methodDescription) {
return Substitution.ForElementMatchers.ofMethod(matcher,
includeVirtualCalls,
includeSuperCalls,
new Substitution.Resolver.MethodInvoking(methodDescription));
}
}
}
/**
* Resolves an actual substitution.
*/
protected interface Substitution {
/**
* Resolves a field access within a method body.
*
* @param fieldDescription The field being accessed.
* @param writeAccess {@code true} if the access is for writing to the field, {@code false} if the field is read.
* @return A resolver for the supplied field access.
*/
Resolver resolve(FieldDescription.InDefinedShape fieldDescription, boolean writeAccess);
/**
* Resolves a method invocation within a method body.
*
* @param methodDescription The method being invoked.
* @param invocationType The method's invocation type.
* @return A resolver for the supplied method invocation.
*/
Resolver resolve(MethodDescription methodDescription, InvocationType invocationType);
/**
* A resolver supplies an implementation for a substitution.
*/
interface Resolver {
/**
* Checks if this resolver was actually resolved, i.e. if a member should be substituted at all.
*
* @return {@code true} if a found member should be substituted.
*/
boolean isResolved();
/**
* Applies this resolver. This is only legal for resolved resolvers.
*
* @param instrumentedType The instrumented type.
* @param target The substituted byte code element.
* @param arguments The factual arguments to the byte code element.
* @param result The expected result type or {@code void} if no result is expected.
* @return A stack manipulation that applies the resolved byte code representing the substitution.
*/
StackManipulation apply(TypeDescription instrumentedType,
ByteCodeElement target,
TypeList.Generic arguments,
TypeDescription.Generic result);
/**
* An unresolved resolver that does not apply a substitution.
*/
enum Unresolved implements Resolver {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public boolean isResolved() {
return false;
}
@Override
public StackManipulation apply(TypeDescription instrumentedType,
ByteCodeElement target,
TypeList.Generic arguments,
TypeDescription.Generic result) {
throw new IllegalStateException("Cannot apply unresolved resolver");
}
}
/**
* A resolver that stubs any interaction with a byte code element.
*/
enum Stubbing implements Resolver {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public boolean isResolved() {
return true;
}
@Override
public StackManipulation apply(TypeDescription instrumentedType,
ByteCodeElement target,
TypeList.Generic arguments,
TypeDescription.Generic result) {
List stackManipulations = new ArrayList(arguments.size());
for (int index = arguments.size() - 1; index >= 0; index--) {
stackManipulations.add(Removal.of(arguments.get(index)));
}
return new StackManipulation.Compound(CompoundList.of(stackManipulations, DefaultValue.of(result.asErasure())));
}
}
/**
* A resolver that replaces an interaction with a byte code element with a field access.
*/
@EqualsAndHashCode
class FieldAccessing implements Resolver {
/**
* The field that is used for substitution.
*/
private final FieldDescription fieldDescription;
/**
* Creates a resolver for a field access.
*
* @param fieldDescription The field that is used for substitution.
*/
protected FieldAccessing(FieldDescription fieldDescription) {
this.fieldDescription = fieldDescription;
}
@Override
public boolean isResolved() {
return true;
}
@Override
public StackManipulation apply(TypeDescription instrumentedType,
ByteCodeElement target,
TypeList.Generic arguments,
TypeDescription.Generic result) {
if (!fieldDescription.isAccessibleTo(instrumentedType)) {
throw new IllegalStateException(instrumentedType + " cannot access " + fieldDescription);
} else if (result.represents(void.class)) {
if (arguments.size() != (fieldDescription.isStatic() ? 1 : 2)) {
throw new IllegalStateException("Cannot set " + fieldDescription + " with " + arguments);
} else if (!fieldDescription.isStatic() && !arguments.get(0).asErasure().isAssignableTo(fieldDescription.getDeclaringType().asErasure())) {
throw new IllegalStateException("Cannot set " + fieldDescription + " on " + arguments.get(0));
} else if (!arguments.get(fieldDescription.isStatic() ? 0 : 1).asErasure().isAssignableTo(fieldDescription.getType().asErasure())) {
throw new IllegalStateException("Cannot set " + fieldDescription + " to " + arguments.get(fieldDescription.isStatic() ? 0 : 1));
}
return FieldAccess.forField(fieldDescription).write();
} else {
if (arguments.size() != (fieldDescription.isStatic() ? 0 : 1)) {
throw new IllegalStateException("Cannot set " + fieldDescription + " with " + arguments);
} else if (!fieldDescription.isStatic() && !arguments.get(0).asErasure().isAssignableTo(fieldDescription.getDeclaringType().asErasure())) {
throw new IllegalStateException("Cannot get " + fieldDescription + " on " + arguments.get(0));
} else if (!fieldDescription.getType().asErasure().isAssignableTo(result.asErasure())) {
throw new IllegalStateException("Cannot get " + fieldDescription + " as " + result);
}
return FieldAccess.forField(fieldDescription).read();
}
}
}
/**
* A resolver that invokes a method.
*/
@EqualsAndHashCode
class MethodInvoking implements Resolver {
/**
* The method that is used for substitution.
*/
private final MethodDescription methodDescription;
/**
* Creates a resolver for a method invocation.
*
* @param methodDescription The method that is used for substitution.
*/
protected MethodInvoking(MethodDescription methodDescription) {
this.methodDescription = methodDescription;
}
@Override
public boolean isResolved() {
return true;
}
@Override
public StackManipulation apply(TypeDescription instrumentedType,
ByteCodeElement target,
TypeList.Generic arguments,
TypeDescription.Generic result) {
if (!methodDescription.isAccessibleTo(instrumentedType)) {
throw new IllegalStateException(instrumentedType + " cannot access " + methodDescription);
}
TypeList.Generic mapped = methodDescription.isStatic()
? methodDescription.getParameters().asTypeList()
: new TypeList.Generic.Explicit(CompoundList.of(methodDescription.getDeclaringType(), methodDescription.getParameters().asTypeList()));
if (!methodDescription.getReturnType().asErasure().isAssignableTo(result.asErasure())) {
throw new IllegalStateException("Cannot assign return value of " + methodDescription + " to " + result);
} else if (mapped.size() != arguments.size()) {
throw new IllegalStateException("Cannot invoke " + methodDescription + " on " + arguments);
}
for (int index = 0; index < mapped.size(); index++) {
if (!mapped.get(index).asErasure().isAssignableTo(arguments.get(index).asErasure())) {
throw new IllegalStateException("Cannot invoke " + methodDescription + " on " + arguments);
}
}
return methodDescription.isVirtual()
? MethodInvocation.invoke(methodDescription).virtual(target.getDeclaringType().asErasure())
: MethodInvocation.invoke(methodDescription);
}
}
}
/**
* Determines a method's invocation type.
*/
enum InvocationType {
/**
* Indicates that a method is called virtually.
*/
VIRTUAL,
/**
* Indicates that a method is called via a super method call.
*/
SUPER,
/**
* Indicates that an invoked method is not a virtual method.
*/
OTHER;
/**
* Creates an invocation type.
*
* @param opcode The method call's opcode.
* @param methodDescription The method being invoked.
* @return The method's invocation type.
*/
protected static InvocationType of(int opcode, MethodDescription methodDescription) {
switch (opcode) {
case Opcodes.INVOKEVIRTUAL:
case Opcodes.INVOKEINTERFACE:
return InvocationType.VIRTUAL;
case Opcodes.INVOKESPECIAL:
return methodDescription.isVirtual()
? SUPER
: OTHER;
default:
return OTHER;
}
}
/**
* Determines if a method is matched by this invocation type.
*
* @param includeVirtualCalls {@code true} if virtual calls are included.
* @param includeSuperCalls {@code true} if super method calls are included.
* @return {@code true} if this instance matches the given setup.
*/
protected boolean matches(boolean includeVirtualCalls, boolean includeSuperCalls) {
switch (this) {
case VIRTUAL:
return includeVirtualCalls;
case SUPER:
return includeSuperCalls;
default:
return true;
}
}
}
/**
* A substution that does not substitute any byte code elements.
*/
enum NoOp implements Substitution {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public Resolver resolve(FieldDescription.InDefinedShape fieldDescription, boolean writeAccess) {
return Resolver.Unresolved.INSTANCE;
}
@Override
public Resolver resolve(MethodDescription methodDescription, InvocationType invocationType) {
return Resolver.Unresolved.INSTANCE;
}
}
/**
* A substitution that uses element matchers for determining if a byte code element should be substituted.
*/
@EqualsAndHashCode
class ForElementMatchers implements Substitution {
/**
* A matcher to determine field substitution.
*/
private final ElementMatcher fieldMatcher;
/**
* A matcher to determine method substituion.
*/
private final ElementMatcher methodMatcher;
/**
* {@code true} if field read access should be substituted.
*/
private final boolean matchFieldRead;
/**
* {@code true} if field write access should be substituted.
*/
private final boolean matchFieldWrite;
/**
* {@code true} if virtual method calls should be substituted.
*/
private final boolean includeVirtualCalls;
/**
* {@code true} if super method calls should be substituted.
*/
private final boolean includeSuperCalls;
/**
* The resolver to apply on elements to substitute.
*/
private final Resolver resolver;
/**
* Creates a substitution for any byte code element that matches the supplied matcher.
*
* @param matcher The matcher to determine the substituted byte code elements.
* @param resolver The resolver to apply on elements to substitute.
* @return A substitution for all matched byte code elements.
*/
protected static Substitution of(ElementMatcher matcher, Resolver resolver) {
return new ForElementMatchers(matcher, matcher, true, true, true, true, resolver);
}
/**
* Creates a substitution for any method that matches the supplied matcher.
*
* @param matcher The matcher to determine the substituted fields.
* @param matchFieldRead {@code true} if field read access should be substituted.
* @param matchFieldWrite {@code true} if field write access should be substituted.
* @param resolver The resolver to apply on fields to substitute.
* @return A substitution for all matched fields.
*/
protected static Substitution ofField(ElementMatcher matcher,
boolean matchFieldRead,
boolean matchFieldWrite,
Resolver resolver) {
return new ForElementMatchers(matcher, none(), matchFieldRead, matchFieldWrite, false, false, resolver);
}
/**
* Creates a substitution for any method that matches the supplied matcher.
*
* @param matcher The matcher to determine the substituted fields.
* @param includeVirtualCalls {@code true} if virtual method calls should be substituted.
* @param includeSuperCalls {@code true} if super method calls should be substituted.
* @param resolver The resolver to apply on fields to substitute.
* @return A substitution for all matched fields.
*/
protected static Substitution ofMethod(ElementMatcher matcher,
boolean includeVirtualCalls,
boolean includeSuperCalls,
Resolver resolver) {
return new ForElementMatchers(none(), matcher, false, false, includeVirtualCalls, includeSuperCalls, resolver);
}
/**
* Creates a new subsitution that applies element matchers to determine what byte code elements to substitute.
*
* @param fieldMatcher The field matcher to determine fields to substitute.
* @param methodMatcher The method matcher to determine methods to substitute.
* @param matchFieldRead {@code true} if field read access should be substituted.
* @param matchFieldWrite {@code true} if field write access should be substituted.
* @param includeVirtualCalls {@code true} if virtual method calls should be substituted.
* @param includeSuperCalls {@code true} if super method calls should be substituted.
* @param resolver The resolver to apply on elements to substitute.
*/
protected ForElementMatchers(ElementMatcher fieldMatcher,
ElementMatcher methodMatcher,
boolean matchFieldRead,
boolean matchFieldWrite,
boolean includeVirtualCalls,
boolean includeSuperCalls,
Resolver resolver) {
this.fieldMatcher = fieldMatcher;
this.methodMatcher = methodMatcher;
this.matchFieldRead = matchFieldRead;
this.matchFieldWrite = matchFieldWrite;
this.includeVirtualCalls = includeVirtualCalls;
this.includeSuperCalls = includeSuperCalls;
this.resolver = resolver;
}
@Override
public Resolver resolve(FieldDescription.InDefinedShape fieldDescription, boolean writeAccess) {
return (writeAccess ? matchFieldWrite : matchFieldRead) && fieldMatcher.matches(fieldDescription)
? resolver
: Resolver.Unresolved.INSTANCE;
}
@Override
public Resolver resolve(MethodDescription methodDescription, InvocationType invocationType) {
return invocationType.matches(includeVirtualCalls, includeSuperCalls) && methodMatcher.matches(methodDescription)
? resolver
: Resolver.Unresolved.INSTANCE;
}
}
/**
* A compound substitution.
*/
@EqualsAndHashCode
class Compound implements Substitution {
/**
* The substitutions to apply in their application order.
*/
private final List substitutions;
/**
* Creates a new compound substitution.
*
* @param substitution The substitutions to apply in their application order.
*/
protected Compound(Substitution... substitution) {
this(Arrays.asList(substitution));
}
/**
* Creates a new compound substitution.
*
* @param substitutions The substitutions to apply in their application order.
*/
protected Compound(List substitutions) {
this.substitutions = new ArrayList(substitutions.size());
for (Substitution substitution : substitutions) {
if (substitution instanceof Compound) {
this.substitutions.addAll(((Compound) substitution).substitutions);
} else if (!(substitution instanceof NoOp)) {
this.substitutions.add(substitution);
}
}
}
@Override
public Resolver resolve(FieldDescription.InDefinedShape fieldDescription, boolean writeAccess) {
for (Substitution substitution : substitutions) {
Resolver resolver = substitution.resolve(fieldDescription, writeAccess);
if (resolver.isResolved()) {
return resolver;
}
}
return Resolver.Unresolved.INSTANCE;
}
@Override
public Resolver resolve(MethodDescription methodDescription, InvocationType invocationType) {
for (Substitution substitution : substitutions) {
Resolver resolver = substitution.resolve(methodDescription, invocationType);
if (resolver.isResolved()) {
return resolver;
}
}
return Resolver.Unresolved.INSTANCE;
}
}
}
/**
* A method visitor that applies a substitution for matched methods.
*/
protected static class SubstitutingMethodVisitor extends MethodVisitor {
/**
* The method graph compiler to use.
*/
private final MethodGraph.Compiler methodGraphCompiler;
/**
* {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
*/
private final boolean strict;
/**
* The substitution to apply.
*/
private final Substitution substitution;
/**
* The instrumented type.
*/
private final TypeDescription instrumentedType;
/**
* The implementation context to use.
*/
private final Implementation.Context implementationContext;
/**
* The type pool to use.
*/
private final TypePool typePool;
/**
* An additional buffer for the operand stack that is required.
*/
private int stackSizeBuffer;
/**
* Creates a new substituting method visitor.
*
* @param methodVisitor The method visitor to delegate to.
* @param methodGraphCompiler The method graph compiler to use.
* @param strict {@code true} if the method processing should be strict where an exception is raised if a member cannot be found.
* @param substitution The substitution to apply.
* @param instrumentedType The instrumented type.
* @param implementationContext The implementation context to use.
* @param typePool The type pool to use.
*/
protected SubstitutingMethodVisitor(MethodVisitor methodVisitor,
MethodGraph.Compiler methodGraphCompiler,
boolean strict,
Substitution substitution,
TypeDescription instrumentedType,
Implementation.Context implementationContext,
TypePool typePool) {
super(Opcodes.ASM6, methodVisitor);
this.methodGraphCompiler = methodGraphCompiler;
this.strict = strict;
this.substitution = substitution;
this.instrumentedType = instrumentedType;
this.implementationContext = implementationContext;
this.typePool = typePool;
stackSizeBuffer = 0;
}
@Override
public void visitFieldInsn(int opcode, String owner, String internalName, String descriptor) {
TypePool.Resolution resolution = typePool.describe(owner.replace('/', '.'));
if (resolution.isResolved()) {
FieldList candidates = resolution.resolve()
.getDeclaredFields()
.filter(named(internalName).and(hasDescriptor(descriptor)));
if (!candidates.isEmpty()) {
Substitution.Resolver resolver = substitution.resolve(candidates.getOnly(), opcode == Opcodes.PUTFIELD || opcode == Opcodes.PUTSTATIC);
if (resolver.isResolved()) {
TypeList.Generic arguments;
TypeDescription.Generic result;
switch (opcode) {
case Opcodes.PUTFIELD:
arguments = new TypeList.Generic.Explicit(candidates.getOnly().getDeclaringType(), candidates.getOnly().getType());
result = TypeDescription.Generic.VOID;
break;
case Opcodes.PUTSTATIC:
arguments = new TypeList.Generic.Explicit(candidates.getOnly().getType());
result = TypeDescription.Generic.VOID;
break;
case Opcodes.GETFIELD:
arguments = new TypeList.Generic.Explicit(candidates.getOnly().getDeclaringType());
result = candidates.getOnly().getType();
break;
case Opcodes.GETSTATIC:
arguments = new TypeList.Generic.Empty();
result = candidates.getOnly().getType();
break;
default:
throw new AssertionError();
}
resolver.apply(instrumentedType, candidates.getOnly(), arguments, result).apply(mv, implementationContext);
return;
}
} else if (strict) {
throw new IllegalStateException("Could not resolve " + owner.replace('/', '.')
+ "." + internalName + descriptor + " using " + typePool);
}
} else if (strict) {
throw new IllegalStateException("Could not resolve " + owner.replace('/', '.') + " using " + typePool);
}
super.visitFieldInsn(opcode, owner, internalName, descriptor);
}
@Override
public void visitMethodInsn(int opcode, String owner, String internalName, String descriptor, boolean isInterface) {
TypePool.Resolution resolution = typePool.describe(owner.replace('/', '.'));
if (resolution.isResolved()) {
MethodList candidates;
if (opcode == Opcodes.INVOKESPECIAL && internalName.equals(MethodDescription.CONSTRUCTOR_INTERNAL_NAME)) {
candidates = resolution.resolve()
.getDeclaredMethods()
.filter(isConstructor().and(hasDescriptor(descriptor)));
} else if (opcode == Opcodes.INVOKESTATIC || opcode == Opcodes.INVOKESPECIAL) {
candidates = resolution.resolve()
.getDeclaredMethods()
.filter(named(internalName).and(hasDescriptor(descriptor)));
} else {
candidates = methodGraphCompiler.compile(resolution.resolve())
.listNodes()
.asMethodList()
.filter(named(internalName).and(hasDescriptor(descriptor)));
}
if (!candidates.isEmpty()) {
Substitution.Resolver resolver = substitution.resolve(candidates.getOnly(), Substitution.InvocationType.of(opcode, candidates.getOnly()));
if (resolver.isResolved()) {
resolver.apply(instrumentedType,
candidates.getOnly(),
candidates.getOnly().isStatic() || candidates.getOnly().isConstructor()
? candidates.getOnly().getParameters().asTypeList()
: new TypeList.Generic.Explicit(CompoundList.of(candidates.getOnly().getDeclaringType(), candidates.getOnly().getParameters().asTypeList())),
candidates.getOnly().isConstructor()
? candidates.getOnly().getDeclaringType().asGenericType()
: candidates.getOnly().getReturnType()).apply(mv, implementationContext);
if (candidates.getOnly().isConstructor()) {
stackSizeBuffer = new StackManipulation.Compound(
Duplication.SINGLE.flipOver(TypeDescription.OBJECT),
Removal.SINGLE,
Removal.SINGLE,
Duplication.SINGLE.flipOver(TypeDescription.OBJECT),
Removal.SINGLE,
Removal.SINGLE
).apply(mv, implementationContext).getMaximalSize() + StackSize.SINGLE.getSize();
}
return;
}
} else if (strict) {
throw new IllegalStateException("Could not resolve " + owner.replace('/', '.')
+ "." + internalName + descriptor + " using " + typePool);
}
} else if (strict) {
throw new IllegalStateException("Could not resolve " + owner.replace('/', '.') + " using " + typePool);
}
super.visitMethodInsn(opcode, owner, internalName, descriptor, isInterface);
}
@Override
public void visitMaxs(int maxStack, int maxLocals) {
super.visitMaxs(maxStack + stackSizeBuffer, maxLocals);
}
}
}