sandmark.util.stacksimulator
Class StackData

java.lang.Object
  |
  +--sandmark.util.stacksimulator.StackData

Direct Known Subclasses:

PrimitiveData, ReferenceData

public abstract class StackData

extends java.lang.Object

StackData is the superclass of all first class data elements.

Author:

Kelly Heffner (kheffner@cs.arizona.edu)

Constructor Summary

protected

StackData(de.fub.bytecode.generic.InstructionHandle h)

Method Summary

boolean	equals(java.lang.Object o) Tests for equality between any two data elements.
de.fub.bytecode.generic.InstructionHandle	getInstruction() Specifies the instruction handle for the instruction that placed this object on the stack.
abstract int	getSize() Specifies the size of this object on the operand stack.
abstract de.fub.bytecode.generic.Type	getType() Specifies the type of the data.
abstract StackData	undefinedVersion() Returns the same type of stack data as this instance, without any definition.

Methods inherited from class java.lang.Object

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

Constructor Detail

StackData

protected StackData(de.fub.bytecode.generic.InstructionHandle h)

Method Detail

getSize

public abstract int getSize()

Specifies the size of this object on the operand stack.

Returns:

the size of the object in bytes, 1 or 2.

getType

public abstract de.fub.bytecode.generic.Type getType()

Specifies the type of the data.

Returns:

a type object which is the type (or a superclass of the type) for the data object

equals

public boolean equals(java.lang.Object o)

Tests for equality between any two data elements. Two StackData objects are equal iff they have the same instruction handle as their creation point. (subclasses have more restrictions for equality)

Overrides:

equals in class java.lang.Object

Parameters:

o - the object to test equality against

Throws:

java.lang.ClassCastException - if o is not an instance of StackData

getInstruction

public de.fub.bytecode.generic.InstructionHandle getInstruction()

Specifies the instruction handle for the instruction that placed this object on the stack.

undefinedVersion

public abstract StackData undefinedVersion()

Returns the same type of stack data as this instance, without any definition. For example, an IntData object would return a new IntData object that has undefined value when undefinedVersion is called.

Returns:

A similar instance to this object, with no definition data