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

Class ArgOffsets

  • All Implemented Interfaces:
    IChainedDecoration<ArgOffsets>
    public class ArgOffsets
extends java.lang.Object
implements IChainedDecoration<ArgOffsets>
    Decoration which stores a linear offset of arguments when a node replacement results in a call to a method with the same arguments as the original (replaced) call but offset by some fixed amount. Since ModifyArg and ModifyArgs always assume the method args are on the top of the stack (which they must be), this results in locating the original method args as as a contiguous "window" of arguments somewhere in the middle of the args as they exist at application time.

    Injectors which mutate the arguments of an invocation should apply this decoration to indicate the starting offset and size of the window which contains the original args.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static ArgOffsets DEFAULT
      Null offsets
      static java.lang.String KEY
      Decoration key for this decoration type

    • Constructor Summary

      Constructors 
      Constructor Description
      ArgOffsets​(int offset, int length)
      Create contiguous offsets starting from start and continuing for length

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      org.objectweb.asm.Type[] apply​(org.objectweb.asm.Type[] args)
      Apply this offset collection to the supplied argument array
      int getArgIndex​(int index)
      Compute the argument index for the specified new index
      int getArgIndex​(int index, boolean mustBeInWindow)
      Compute the argument index for the specified new index
      int getEndIndex()
      Compute the argument index for the end of the window (offset length)
      int getLength()
      Get the size of the offset window
      int getStartIndex()
      Compute the argument index for the start of the window (offet 0)
      boolean isEmpty()
      Get whether this argument offset window is empty
      void replace​(ArgOffsets old)
      Called when this decoration replaces a previous decoration with the same key
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • DEFAULT

        public static ArgOffsets DEFAULT
        Null offsets

      • KEY

        public static final java.lang.String KEY
        Decoration key for this decoration type
        See Also:
        Constant Field Values

    • Constructor Detail

      • ArgOffsets

        public ArgOffsets​(int offset,
                  int length)
        Create contiguous offsets starting from start and continuing for length
        Parameters:
        offset - start index
        length - length

    • Method Detail

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • getLength

        public int getLength()
        Get the size of the offset window

      • isEmpty

        public boolean isEmpty()
        Get whether this argument offset window is empty

      • getStartIndex

        public int getStartIndex()
        Compute the argument index for the start of the window (offet 0)
        Returns:
        the offset index for the start of the window (inclusive)

      • getEndIndex

        public int getEndIndex()
        Compute the argument index for the end of the window (offset length)
        Returns:
        the offset index for the end of the window (inclusive)

      • getArgIndex

        public int getArgIndex​(int index)
        Compute the argument index for the specified new index
        Parameters:
        index - The new index to compute
        Returns:
        The original index based on this mapping

      • getArgIndex

        public int getArgIndex​(int index,
                       boolean mustBeInWindow)
        Compute the argument index for the specified new index
        Parameters:
        index - The new index to compute
        mustBeInWindow - Throw an exception if the requested index exceeds the length of the defined window
        Returns:
        The original index based on this mapping

      • apply

        public org.objectweb.asm.Type[] apply​(org.objectweb.asm.Type[] args)
        Apply this offset collection to the supplied argument array
        Parameters:
        args - New arguments
        Returns:
        Unmapped arguments