Package org.spongepowered.asm.mixin.injection.struct

Class Target.Extension

java.lang.Object
org.spongepowered.asm.mixin.injection.struct.Target.Extension
Enclosing class:
Target
public class Target.Extension extends Object
A stateful extension of stack or locals space for a target method which can be applied.

Stack and locals extensions are generally localised to a particular injection. This means they don't necessarily need to accumulate, it's generally sufficient to expand the method's original stack or locals size by the extension amount, with the largest extension determining the final stack size of the method.

Before this mechanism, injectors generally needed to keep track of their extension sizes via arbitrary integers, then apply them in one go. However some injector logic made the flow of these integers hard to track and lead to insidious bugs when values which should be combined were instead applied sequentially. The minor performance trade-off of using extensions to track these operations is covered by the increase in robustness.

  • Method Details

    • add

      public Target.Extension add()
      Add 1 to this extension
      Returns:
      fluent interface

    • add

      public Target.Extension add(int size)
      Add the specified size to this extension
      Parameters:
      size - size to add
      Returns:
      fluent interface

    • add

      public Target.Extension add(org.objectweb.asm.Type[] types)
      Add the size of the supplied type array to this extension. The size of the supplied args will first be computed, then the result will be added to the extension.
      Parameters:
      types - Types to add
      Returns:
      fluent interface

    • set

      public Target.Extension set(int size)
      Set the size of this extension
      Parameters:
      size - Size to set
      Returns:
      fluent interface

    • get

      public int get()
      Get the current size of this extension
      Returns:
      fluent interface

    • apply

      public void apply()
      Apply this extension to the target. This reduces the current size to zero so that a new operation can begin if required.