xtc.type
Class NullReference

java.lang.Object
  xtc.type.Reference
      xtc.type.NullReference

public class NullReference
extends Reference

Representation of a null reference. A null reference represents the null location in memory. Its type is void; it neither has a base nor an offset.

Version:

$Revision: 1.4 $

Author:

Robert Grimm

Field Summary

static NullReference

NULL The canonical null reference.

Fields inherited from class xtc.type.Reference

type

Method Summary

java.math.BigInteger	getLocation(C ops) Get this reference's absolute memory location.
boolean	hasLocation() Determine whether this reference has an absolute memory location.
boolean	isConstant() Determine whether this reference represents a compile-time constant memory location.
boolean	isNull() Determine whether this reference is a null reference.
void	write(java.lang.Appendable out) Write a human readable representation to the specified appendable.

Methods inherited from class xtc.type.Reference

add, add, difference, getBase, getField, getIndex, getType, hasBase, hasField, hasIndex, indirect, isCast, isDynamic, isIndirect, isPrefix, isStatic, isString, isVariable, subtract, subtract, toString

Methods inherited from class java.lang.Object

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

Field Detail

NULL

public static final NullReference NULL

The canonical null reference.

Method Detail

isNull

public boolean isNull()

Description copied from class: Reference

Determine whether this reference is a null reference. Note that a reference other than NULL may still return true; notably, an index reference with a null base and a zero offset still is null.

Overrides:

isNull in class Reference

Returns:

true if this reference is a null reference.

See Also:

NullReference

hasLocation

public boolean hasLocation()

Description copied from class: Reference

Determine whether this reference has an absolute memory location.

Overrides:

hasLocation in class Reference

Returns:

true if this reference has an absolute memory location.

getLocation

public java.math.BigInteger getLocation(C ops)

Description copied from class: Reference

Get this reference's absolute memory location.

Overrides:

getLocation in class Reference

Parameters:

ops - The C operations.

Returns:

The memory location.

isConstant

public boolean isConstant()

Description copied from class: Reference

Determine whether this reference represents a compile-time constant memory location.

Overrides:

isConstant in class Reference

Returns:

true if this reference represents a compile-time memory location.

write

public void write(java.lang.Appendable out)
           throws java.io.IOException

Description copied from class: Reference

Write a human readable representation to the specified appendable.

Specified by:

write in class Reference

Parameters:

out - The appendable.

Throws:

java.io.IOException - Signals an I/O error.