de.rwth.dfa.jvm.samples
Class CFPStackLattice

java.lang.Object
  |
  +--de.rwth.domains.templates.LiftedPOSet
        |
        +--de.rwth.domains.templates.LiftedCompleteLattice
              |
              +--de.rwth.dfa.jvm.samples.CFPStackLattice

All Implemented Interfaces:

CompleteLattice, CompletePOSet, Lattice, LowerSemiLattice, POSet, PreLattice, PreLowerSemiLattice, PreUpperSemiLattice, Set, UpperSemiLattice

public class CFPStackLattice

extends LiftedCompleteLattice

The lattice used by the constant folding propagation lattice to describe the state of the operand stack. The Hasse diagram looks like this:

    unknown stack
   /            \
   ... stacks ...
   \            /
    invalid stack
 

Each proper stack element is a stack with the maximal height of the operand stack of the method. Each entry is an element of CFPComponentLattice.

Version:

$Id: CFPStackLattice.java,v 1.2 2002/09/17 06:53:53 mohnen Exp $

Author:

Markus Mohnen

Inner classes inherited from class de.rwth.domains.Set

Set.Default

Field Summary

protected static java.lang.Object	INVALIDSTACK The top element for invalid stacks of all these lattices.
protected static java.lang.Object	UNKNOWNSTACK The top element for unknown stacks of all these lattices.

Fields inherited from class de.rwth.domains.templates.LiftedCompleteLattice

top

Fields inherited from class de.rwth.domains.templates.LiftedPOSet

bottom, poset

Constructor Summary

CFPStackLattice(int maxStack)
Creates a new CFPStackLattice instance.

Method Summary

java.lang.Object	getStack(java.lang.Object o) Returns the contained stack for all elements except top and bottom.
static void	main(java.lang.String[] args) Mini test environment.
java.lang.Object	makeElement(java.lang.Object stack) Checks if the argument is an element and returns it.

Methods inherited from class de.rwth.domains.templates.LiftedCompleteLattice

bottom, equals, isElement, iterator, iteratorSkel, join, le, lt, meet, size, sizeSkel, top

Methods inherited from class java.lang.Object

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

Field Detail

UNKNOWNSTACK

protected static final java.lang.Object UNKNOWNSTACK

The top element for unknown stacks of all these lattices.

INVALIDSTACK

protected static final java.lang.Object INVALIDSTACK

The top element for invalid stacks of all these lattices.

Constructor Detail

CFPStackLattice

public CFPStackLattice(int maxStack)

Creates a new CFPStackLattice instance.

Parameters:

maxStack - an int value

Method Detail

getStack

public java.lang.Object getStack(java.lang.Object o)

Returns the contained stack for all elements except top and bottom. Otherwise, returns its argument.

Parameters:

o - an Object value

Returns:

an Object value

makeElement

public java.lang.Object makeElement(java.lang.Object stack)

Checks if the argument is an element and returns it.

Parameters:

stack - an Object value

Returns:

an Object value

main

public static void main(java.lang.String[] args)

Mini test environment.

Parameters:

args - a String[] value