org.spongepowered.asm.mixin.injection.struct

Class ArgOffsets

java.lang.Object

org.spongepowered.asm.mixin.injection.struct.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 and Description
static ArgOffsets	DEFAULT Null offsets
static java.lang.String	KEY Decoration key for this decoration type

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and 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

replace

public void replace(ArgOffsets old)

Description copied from interface: IChainedDecoration

Called when this decoration replaces a previous decoration with the same key

Specified by:

replace in interface IChainedDecoration<ArgOffsets>

Parameters:

old - The previous decoration

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