Package org.spongepowered.asm.mixin.injection.modify

Class BeforeLoadLocal

java.lang.Object

org.spongepowered.asm.mixin.injection.InjectionPoint

org.spongepowered.asm.mixin.injection.modify.BeforeLoadLocal

Direct Known Subclasses:

AfterStoreLocal

public class BeforeLoadLocal
extends InjectionPoint

This injection point is a companion for the ModifyVariable injector which searches for LOAD operations which match the local variables described by the injector's defined discriminators.

This allows you consumers to specify an injection immediately before a local variable is accessed in a method. Specify an ordinal of n to match the n + 1^th access of the variable in question.

ordinal

The ordinal position of the LOAD opcode for the matching local variable to search for, if not specified then the injection point returns all opcodes for which the parent annotation's discriminators match. The default value is -1 which supresses ordinal checking.

Example:

   @ModifyVariable(
       method = "md",
       ordinal = 1,
       at = @At(
           value = "LOAD",
           ordinal = 0
       )
   )

Note that if value is the only parameter specified, it can be omitted:

   @At("LOAD")

Nested Class Summary

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

InjectionPoint.AtCode, InjectionPoint.Flags, InjectionPoint.RestrictTargetLevel, InjectionPoint.Specifier

Field Summary

Fields

Modifier and Type	Field	Description
protected LocalVariableDiscriminator	discriminator	Discriminator, parsed from parent annotation
protected IMixinContext	mixin
protected int	opcode	Target opcode, inflected from return type
protected int	ordinal	Target ordinal
protected org.objectweb.asm.Type	returnType	Return type of the handler, also the type of the local variable we're interested in

Fields inherited from class org.spongepowered.asm.mixin.injection.InjectionPoint

DEFAULT_ALLOWED_SHIFT_BY, MAX_ALLOWED_SHIFT_BY

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BeforeLoadLocal(InjectionPointData data)
protected	BeforeLoadLocal(InjectionPointData data, int opcode, boolean opcodeAfter)

Method Summary

Modifier and Type	Method	Description
protected void	addMessage(java.lang.String format, java.lang.Object... args)	Notify method for subclasses to log when notable but non-fatal failures occur, for example allows subclasses to add notes when they return no results.
boolean	find(java.lang.String desc, org.objectweb.asm.tree.InsnList insns, java.util.Collection<org.objectweb.asm.tree.AbstractInsnNode> nodes)	Find injection points in the supplied insn list
java.lang.String	toString()
java.lang.String	toString(LocalVariableDiscriminator.Context context)

Methods inherited from class org.spongepowered.asm.mixin.injection.InjectionPoint

after, and, before, checkPriority, getAtCode, getId, getSlice, getSpecifier, getTargetRestriction, nextNode, or, parse, parse, parse, parse, parse, parse, parse, parse, register, register, setTargetRestriction, shift

Methods inherited from class java.lang.Object

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

Field Detail

returnType

protected final org.objectweb.asm.Type returnType

Return type of the handler, also the type of the local variable we're interested in

discriminator

protected final LocalVariableDiscriminator discriminator

Discriminator, parsed from parent annotation

opcode

protected final int opcode

Target opcode, inflected from return type

ordinal

protected final int ordinal

Target ordinal

mixin

protected final IMixinContext mixin

Constructor Detail

BeforeLoadLocal

protected BeforeLoadLocal(InjectionPointData data)

BeforeLoadLocal

protected BeforeLoadLocal(InjectionPointData data,
                          int opcode,
                          boolean opcodeAfter)

Method Detail

addMessage

protected void addMessage(java.lang.String format,
                          java.lang.Object... args)

Description copied from class: InjectionPoint

Notify method for subclasses to log when notable but non-fatal failures occur, for example allows subclasses to add notes when they return no results.

Overrides:

addMessage in class InjectionPoint

Parameters:

format - Message format

args - Format args

toString

public java.lang.String toString()

Overrides:

toString in class InjectionPoint

toString

public java.lang.String toString(LocalVariableDiscriminator.Context context)

find

public boolean find(java.lang.String desc,
                    org.objectweb.asm.tree.InsnList insns,
                    java.util.Collection<org.objectweb.asm.tree.AbstractInsnNode> nodes)

Description copied from class: InjectionPoint

Find injection points in the supplied insn list

Specified by:

find in class InjectionPoint

Parameters:

desc - Method descriptor, supplied to allow return types and arguments etc. to be determined

insns - Insn list to search in, the strategy MUST ONLY add nodes from this list to the nodes collection

nodes - Collection of nodes to populate. Injectors should NOT make any assumptions about the state of this collection and should only call the add() method

Returns:

true if one or more injection points were found