org.apache.flex.abc.semantics

Class Label

java.lang.Object

org.apache.flex.abc.semantics.Label

All Implemented Interfaces:

Cloneable, Comparable<Label>

public final class Label
extends Object
implements Comparable<Label>, Cloneable

A Label represents the target of a branch instruction; it is not the ABC OP_Label instruction. Note: this class has a natural ordering that is inconsistent with equals.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Label.LabelKind

Field Summary

Fields

Modifier and Type	Field and Description
static int	NO_POSITION The inital offset of a label.

Constructor Summary

Constructors

Constructor and Description
Label()
Label(String label_text)
Label(String label_text, Label.LabelKind mustTargetExectuable)

Method Summary

Methods

Modifier and Type	Method and Description
void	adjustOffset(int base_offset) This Label has been inherited by a new InstructionList, so its offset must be adjusted to point to its new position within the inheriting InstructionList.
Object	clone() Clone this label.
int	compareTo(Label o) The natural sort order for a Label is its instruction's offset.
int	getPosition()
void	setPosition(int pos) Set this Label's offset in its initial InstructionList.
boolean	targetMustBeExecutable() Does this label have to fall on an executable instruction, or can it fall on any old instruction (such as a OP_debugline).
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

NO_POSITION

public static final int NO_POSITION

The inital offset of a label. This offset must be set to a known value before the Label can be active.

See Also:

Constant Field Values

Constructor Detail

Label

public Label(String label_text)

Label

public Label(String label_text,
     Label.LabelKind mustTargetExectuable)

Label

public Label()

Method Detail

compareTo

public int compareTo(Label o)

The natural sort order for a Label is its instruction's offset.

Specified by:

compareTo in interface Comparable<Label>

toString

public String toString()

Overrides:

toString in class Object

setPosition

public void setPosition(int pos)

Set this Label's offset in its initial InstructionList.

Parameters:

pos - - the Label's offset in the InstructionList.

See Also:

, which the InstructionList keeps this position updated.

getPosition

public int getPosition()

Returns:

this Label's offset in its owning InstructionList.

adjustOffset

public void adjustOffset(int base_offset)

This Label has been inherited by a new InstructionList, so its offset must be adjusted to point to its new position within the inheriting InstructionList. (Or, the owning InstructionList's order was perturbed by a prepend() or similar ad-hoc adjustment.)

Parameters:

base_offset - - the amount to adjust the position. Think of the position as a displacement, and the inherting list's size as a base.

clone

public Object clone()

Clone this label.

Overrides:

clone in class Object

Returns:

a shallow copy of the label (it doesn't have any deep state).

targetMustBeExecutable

public boolean targetMustBeExecutable()

Does this label have to fall on an executable instruction, or can it fall on any old instruction (such as a OP_debugline).