de.rwth.dfa.jvm.samples
Class CPAbstraction

java.lang.Object
  |
  +--de.rwth.dfa.jvm.samples.AbstractSSDependingAbstraction
        |
        +--de.rwth.dfa.jvm.samples.CPAbstraction

All Implemented Interfaces:

Abstraction

Direct Known Subclasses:

CFPAbstraction

public class CPAbstraction

extends AbstractSSDependingAbstraction

implements Abstraction

Implementation of a constant propagation abstraction. It can be used to determine constant values in both stack an local variables. The domain used is CFPLattice.

Version:

$Id: CPAbstraction.java,v 1.4 2002/09/17 06:53:53 mohnen Exp $

Author:

Markus Mohnen

Inner Class Summary

protected class	CPAbstraction.AllocationFunction Pushes a CFPComponentLattice.NONNULLCOMPONENT onto the stack.
class	CPAbstraction.CPFunction The abstract base class of all function of this abstraction.
protected class	CPAbstraction.DupFunction Duplicates n elements on the stack under x other elements.
protected class	CPAbstraction.ExceptionHeaderFunction Creates a new stack with only a CFPComponentLattice.NONNULLCOMPONENT.
protected class	CPAbstraction.GenericFunction A generic function.
protected class	CPAbstraction.IncLocalFunction Increments the content of a local variable slot.
protected class	CPAbstraction.PopFunction Removes entries from the stack.
protected class	CPAbstraction.PushConstantFunction A function for pushing a constant onto the stack.
protected class	CPAbstraction.PushLocalFunction Pushes the content of a local variable slot onto the stack.
protected class	CPAbstraction.StoreLocalFunction Stores the top element in a local variable slot.
protected class	CPAbstraction.SwapFunction Swaps the top element and the element below that on the stack.

Inner classes inherited from class de.rwth.dfa.jvm.Abstraction

Abstraction.Default

Field Summary

protected CFPLattice	l The domain used in this abstraction.
protected int	maxLocals The maximal number of local variable slots in the method for this abstraction.
protected int	maxStack The maximal stack size in the method for this abstraction.

Fields inherited from class de.rwth.dfa.jvm.samples.AbstractSSDependingAbstraction

cpg, stacksizes

Fields inherited from interface de.rwth.dfa.jvm.Abstraction

DIRECTION_BACKWARD, DIRECTION_FORWARD, QUANTIFIER_ALL, QUANTIFIER_EXISTS

Constructor Summary

CPAbstraction(int maxStack, int maxLocals, de.fub.bytecode.generic.ConstantPoolGen constantPoolGen, de.fub.bytecode.generic.InstructionList methodInstrs, de.fub.bytecode.classfile.CodeException[] methodExceptions)
Creates a new CFPAbstraction instance.

CPAbstraction(int maxStack, int maxLocals, de.fub.bytecode.classfile.ConstantPool constantPool, de.fub.bytecode.generic.InstructionList methodInstrs, de.fub.bytecode.classfile.CodeException[] methodExceptions)
Creates a new CFPAbstraction instance.

Method Summary

Function	getAbstract(de.fub.bytecode.generic.InstructionHandle ih) Creates an instance of CPFunction for an instruction.
Function	getAbstract(InstructionHandleVector ihv) Returns the value of the default implementation in Abstraction.Default.
int	getDirection() Returns DIRECTION_FORWARD.
java.lang.Object	getInitialValue(de.fub.bytecode.generic.InstructionHandle ih, boolean isRoot) Returns the initial value for an instruction.
java.lang.Object	getInitialValue(InstructionHandleVector ihv, boolean isRoot) Returns the value of the default implementation in Abstraction.Default.
Lattice	getLattice() Returns the CFPLattice for this abstraction.
int	getQuantifier() Returns QUANTIFIER_ALL.

Methods inherited from class de.rwth.dfa.jvm.samples.AbstractSSDependingAbstraction

getConstantPoolGen, getStacksize

Methods inherited from class java.lang.Object

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

Field Detail

l

protected CFPLattice l

The domain used in this abstraction.

maxLocals

protected int maxLocals

The maximal number of local variable slots in the method for this abstraction.

maxStack

protected int maxStack

The maximal stack size in the method for this abstraction.

Constructor Detail

CPAbstraction

public CPAbstraction(int maxStack,
                     int maxLocals,
                     de.fub.bytecode.generic.ConstantPoolGen constantPoolGen,
                     de.fub.bytecode.generic.InstructionList methodInstrs,
                     de.fub.bytecode.classfile.CodeException[] methodExceptions)

Creates a new CFPAbstraction instance.

Parameters:

maxStack - an int value

maxLocals - an int value

constantPool - a ConstantPool value

methodInstrs - an InstructionList value

methodExceptions - a CodeException[] value

CPAbstraction

public CPAbstraction(int maxStack,
                     int maxLocals,
                     de.fub.bytecode.classfile.ConstantPool constantPool,
                     de.fub.bytecode.generic.InstructionList methodInstrs,
                     de.fub.bytecode.classfile.CodeException[] methodExceptions)

Creates a new CFPAbstraction instance.

Parameters:

maxStack - an int value

maxLocals - an int value

constantPool - a ConstantPool value

methodInstrs - an InstructionList value

methodExceptions - a CodeException[] value

Method Detail

getLattice

public Lattice getLattice()

Returns the CFPLattice for this abstraction.

Specified by:

getLattice in interface Abstraction

Returns:

a Lattice value

getInitialValue

public java.lang.Object getInitialValue(de.fub.bytecode.generic.InstructionHandle ih,
                                        boolean isRoot)

Returns the initial value for an instruction.

1. The component for the local variable slots consists of the entries

   CFPComponentLattice.NONCONSTANTCOMPONENT

   if the instruction is the entry point of the method or the entry point of an exception handler.

   CFPComponentLattice.UNKNOWNCOMPONENT

   for all other instructions.

2. The stack component has the appropriate size.
3. Each entry of the stack component is

   CFPComponentLattice.NONCONSTANTCOMPONENT

   if the instruction is the entry point of the method or the entry point of an exception handler.

   CFPComponentLattice.UNKNOWNCOMPONENT

   for all other instructions.

Specified by:

getInitialValue in interface Abstraction

Parameters:

ih - an InstructionHandle value

isRoot - a boolean value

Returns:

an Object value

getDirection

public int getDirection()

Returns DIRECTION_FORWARD.

Specified by:

getDirection in interface Abstraction

Returns:

an int value

getQuantifier

public int getQuantifier()

Returns QUANTIFIER_ALL.

Specified by:

getQuantifier in interface Abstraction

Returns:

an int value

getAbstract

public Function getAbstract(de.fub.bytecode.generic.InstructionHandle ih)

Creates an instance of CPFunction for an instruction.

Specified by:

getAbstract in interface Abstraction

Parameters:

ih - an InstructionHandle value

Returns:

a Function value

getInitialValue

public java.lang.Object getInitialValue(InstructionHandleVector ihv,
                                        boolean isRoot)

Returns the value of the default implementation in Abstraction.Default.

Specified by:

getInitialValue in interface Abstraction

Parameters:

ihv - an InstructionHandleVector value

isRoot - a boolean value

Returns:

an Object value

getAbstract

public Function getAbstract(InstructionHandleVector ihv)

Returns the value of the default implementation in Abstraction.Default.

Specified by:

getAbstract in interface Abstraction

Parameters:

ihv - an InstructionHandleVector value

Returns:

a Function value