Package org.spongepowered.asm.mixin.injection.points

Class ConstructorHead

java.lang.Object

org.spongepowered.asm.mixin.injection.InjectionPoint

org.spongepowered.asm.mixin.injection.points.MethodHead

org.spongepowered.asm.mixin.injection.points.ConstructorHead

public class ConstructorHead
extends MethodHead

Like HEAD, this injection point can be used to specify the first instruction in a method, but provides special handling for constructors. For regular method, the behaviour is identical to HEAD .

By default, this injection point attempts to select the first instruction after any initialisers (including initialisers merged by mixins) but will fall back to selecting the first instruction after the delegate call (eg. a call to super() or this()) in the case where heuristic detection of the initialisers fails. This behaviour can be overridden by providing the enforce parameter to enforce selection of a specific location.

enforce=POST_DELEGATE

Select the instruction immediately after the delegate constructor

enforce=POST_MIXIN

Select the instruction immediately after all mixin-initialised field initialisers, this is similar to POST_DELEGATE if no applied mixins have initialisers for target class fields, except that the injection point will be after any mixin-supplied initialisers.

enforce=PRE_BODY

Selects the first instruction in the target method body, as determined by the line numbers. If the target method does not have line numbers available, the result is equivalent to POST_DELEGATE.

Example default behaviour:

   @At(value = "CTOR_HEAD", unsafe = true)

Example behaviour enforcing post-delegate injection point:

   @At(value = "CTOR_HEAD", unsafe = true, args="enforce=POST_DELEGATE")
   

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 final ILogger	logger	Logger

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

DEFAULT_ALLOWED_SHIFT_BY, MAX_ALLOWED_SHIFT_BY

Constructor Summary

Constructors

Constructor	Description
ConstructorHead(InjectionPointData data)

Method Summary

Modifier and Type	Method	Description
boolean	find(String desc, org.objectweb.asm.tree.InsnList insns, Collection<org.objectweb.asm.tree.AbstractInsnNode> nodes)	Find injection points in the supplied insn list

Methods inherited from class org.spongepowered.asm.mixin.injection.points.MethodHead

checkPriority

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

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

Methods inherited from class java.lang.Object

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

Field Details

logger

protected final ILogger logger

Logger

Constructor Details

ConstructorHead

public ConstructorHead(InjectionPointData data)

Method Details

find

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

Description copied from class: InjectionPoint

Find injection points in the supplied insn list

Overrides:

find in class MethodHead

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