org.spongepowered.asm.mixin.injection.invoke

Class RedirectInjector

java.lang.Object

org.spongepowered.asm.mixin.injection.code.Injector

org.spongepowered.asm.mixin.injection.invoke.InvokeInjector

org.spongepowered.asm.mixin.injection.invoke.RedirectInjector

Direct Known Subclasses:

ModifyConstantInjector

public class RedirectInjector
extends InvokeInjector

A bytecode injector which allows a method call, field access or new object creation to be redirected to the annotated handler method. For method redirects, the handler method signature must match the hooked method precisely but prepended with an arg of the owning object's type to accept the object instance the method was going to be invoked upon. For example when hooking the following call:

   int abc = 0;
   int def = 1;
   Foo someObject = new Foo();
   
   // Hooking this method
   boolean xyz = someObject.bar(abc, def);

The signature of the redirected method should be:

public boolean barProxy(Foo someObject, int abc, int def)

For obvious reasons this does not apply for static methods, for static methods it is sufficient that the signature simply match the hooked method.

For field redirections, see the details in Redirect for the required signature of the handler method.

For constructor redirections, the signature of the handler method should match the constructor itself, return type should be of the type of object being created.

Nested Class Summary

Nested classes/interfaces inherited from class org.spongepowered.asm.mixin.injection.code.Injector

Injector.TargetNode

Field Summary

Fields

Modifier and Type	Field and Description
protected org.spongepowered.asm.mixin.injection.invoke.RedirectInjector.Meta	meta

Fields inherited from class org.spongepowered.asm.mixin.injection.invoke.InvokeInjector

annotationType

Fields inherited from class org.spongepowered.asm.mixin.injection.code.Injector

classNode, info, isStatic, logger, methodArgs, methodNode, returnType

Constructor Summary

Constructors

Modifier	Constructor and Description
	RedirectInjector(InjectionInfo info)
protected	RedirectInjector(InjectionInfo info, java.lang.String annotationType)

Method Summary

Modifier and Type	Method and Description
protected void	addTargetNode(Target target, java.util.List<InjectionNodes.InjectionNode> myNodes, org.spongepowered.asm.lib.tree.AbstractInsnNode insn, java.util.Set<InjectionPoint> nominators)
protected boolean	checkDescriptor(java.lang.String desc, Target target, java.lang.String type) Check that the handler descriptor matches the calculated descriptor for the access being redirected.
protected void	checkTarget(Target target) Sanity checks on target
protected void	inject(Target target, InjectionNodes.InjectionNode node)
void	injectArrayRedirect(Target target, org.spongepowered.asm.lib.tree.FieldInsnNode fieldNode, org.spongepowered.asm.lib.tree.AbstractInsnNode varNode, boolean withArgs, java.lang.String type) The code for actually redirecting the array element is the same regardless of whether it's a read or write because it just depends on the actual handler signature, the correct arguments are already on the stack thanks to the nature of xALOAD and xASTORE.
protected void	injectAtConstructor(Target target, InjectionNodes.InjectionNode node)
protected void	injectAtInvoke(Target target, InjectionNodes.InjectionNode node) Redirect a method invocation
void	injectAtScalarField(Target target, org.spongepowered.asm.lib.tree.FieldInsnNode fieldNode, int opCode, org.spongepowered.asm.lib.Type ownerType, org.spongepowered.asm.lib.Type fieldType) Redirect a field get or set
protected void	postInject(Target target, InjectionNodes.InjectionNode node)
protected boolean	preInject(InjectionNodes.InjectionNode node)
protected void	validateParams(org.spongepowered.asm.mixin.injection.invoke.RedirectInjector.RedirectedInvoke invoke) Perform validation of an invoke handler parameters, each parameter in the handler must match the expected type or be annotated with Coerce and be a supported supertype of the incoming type.

Methods inherited from class org.spongepowered.asm.mixin.injection.invoke.InvokeInjector

checkTargetForNode, checkTargetModifiers, invokeHandlerWithArgs, invokeHandlerWithArgs, pushArgs, sanityCheck, storeArgs, storeArgs

Methods inherited from class org.spongepowered.asm.mixin.injection.code.Injector

canCoerce, canCoerce, canCoerce, find, findTargetNodes, inject, invokeHandler, invokeHandler, throwException, toString

Methods inherited from class java.lang.Object

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

Field Detail

meta

protected org.spongepowered.asm.mixin.injection.invoke.RedirectInjector.Meta meta

Constructor Detail

RedirectInjector

public RedirectInjector(InjectionInfo info)

Parameters:

info - Injection info

RedirectInjector

protected RedirectInjector(InjectionInfo info,
                           java.lang.String annotationType)

Method Detail

checkTarget

protected void checkTarget(Target target)

Description copied from class: InvokeInjector

Sanity checks on target

Overrides:

checkTarget in class InvokeInjector

Parameters:

target - target

addTargetNode

protected void addTargetNode(Target target,
                             java.util.List<InjectionNodes.InjectionNode> myNodes,
                             org.spongepowered.asm.lib.tree.AbstractInsnNode insn,
                             java.util.Set<InjectionPoint> nominators)

Overrides:

addTargetNode in class Injector

inject

protected void inject(Target target,
                      InjectionNodes.InjectionNode node)

Overrides:

inject in class InvokeInjector

preInject

protected boolean preInject(InjectionNodes.InjectionNode node)

postInject

protected void postInject(Target target,
                          InjectionNodes.InjectionNode node)

Overrides:

postInject in class Injector

injectAtInvoke

protected void injectAtInvoke(Target target,
                              InjectionNodes.InjectionNode node)

Redirect a method invocation

Specified by:

injectAtInvoke in class InvokeInjector

Parameters:

target - Target to inject into

node - Discovered instruction node

validateParams

protected void validateParams(org.spongepowered.asm.mixin.injection.invoke.RedirectInjector.RedirectedInvoke invoke)

Perform validation of an invoke handler parameters, each parameter in the handler must match the expected type or be annotated with Coerce and be a supported supertype of the incoming type.

Parameters:

invoke - invocation being redirected

injectArrayRedirect

public void injectArrayRedirect(Target target,
                                org.spongepowered.asm.lib.tree.FieldInsnNode fieldNode,
                                org.spongepowered.asm.lib.tree.AbstractInsnNode varNode,
                                boolean withArgs,
                                java.lang.String type)

The code for actually redirecting the array element is the same regardless of whether it's a read or write because it just depends on the actual handler signature, the correct arguments are already on the stack thanks to the nature of xALOAD and xASTORE.

Parameters:

target - target method

fieldNode - field node

varNode - array access node

withArgs - true if the descriptor includes captured arguments from the target method signature

type - description of access type for use in error messages

injectAtScalarField

public void injectAtScalarField(Target target,
                                org.spongepowered.asm.lib.tree.FieldInsnNode fieldNode,
                                int opCode,
                                org.spongepowered.asm.lib.Type ownerType,
                                org.spongepowered.asm.lib.Type fieldType)

Redirect a field get or set

Parameters:

target - target method

fieldNode - field access node

opCode - field access type

ownerType - type of the field owner

fieldType - field type

checkDescriptor

protected boolean checkDescriptor(java.lang.String desc,
                                  Target target,
                                  java.lang.String type)

Check that the handler descriptor matches the calculated descriptor for the access being redirected.

Parameters:

desc - computed descriptor

target - target method

type - redirector type in human-readable text, for error messages

Returns:

true if the descriptor was found and includes target method args, false if the descriptor was found and does not capture target args

injectAtConstructor

protected void injectAtConstructor(Target target,
                                   InjectionNodes.InjectionNode node)