de.rwth.dfa.jvm
Class ExecutionSolver

java.lang.Object
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  +--de.rwth.dfa.jvm.Solver
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        +--de.rwth.dfa.jvm.ExecutionSolver

public class ExecutionSolver

extends Solver

JVM abstraction solver based on direct execution. It only supports forward analyses.

Version:

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

Author:

Markus Mohnen

Fields inherited from class de.rwth.dfa.jvm.Solver

abstraction, iterations, memory, methodExceptions, methodInstrs, methodName, stopwatch

Constructor Summary

ExecutionSolver(Abstraction abstraction, java.lang.String methodName, de.fub.bytecode.generic.InstructionList methodInstrs, de.fub.bytecode.classfile.CodeException[] methodExceptions)
Creates a new ExecutionSolver instance with out stop watch.

ExecutionSolver(Abstraction abstraction, java.lang.String methodName, de.fub.bytecode.generic.InstructionList methodInstrs, de.fub.bytecode.classfile.CodeException[] methodExceptions, Stopwatch stopwatch)
Creates a new ExecutionSolver instance with stop watch.

Method Summary

protected void	compute(java.lang.Object[] solution, boolean isForward, boolean isAll) Implementations must provide this method.
protected boolean	maybeTransfer(java.lang.Object[] solution, Lattice l, boolean isAll, java.lang.Object e, java.lang.Integer targetIndex, java.util.Hashtable exFunctions)

Methods inherited from class de.rwth.dfa.jvm.Solver

getIterations, getMemory, getSolution

Methods inherited from class java.lang.Object

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

Constructor Detail

ExecutionSolver

public ExecutionSolver(Abstraction abstraction,
                       java.lang.String methodName,
                       de.fub.bytecode.generic.InstructionList methodInstrs,
                       de.fub.bytecode.classfile.CodeException[] methodExceptions,
                       Stopwatch stopwatch)

Creates a new ExecutionSolver instance with stop watch.

Parameters:

abstraction - an Abstraction value

methodName - a String value

methodInstrs - an InstructionList value

methodExceptions - a CodeException[] value

stopwatch - a Stopwatch value

ExecutionSolver

public ExecutionSolver(Abstraction abstraction,
                       java.lang.String methodName,
                       de.fub.bytecode.generic.InstructionList methodInstrs,
                       de.fub.bytecode.classfile.CodeException[] methodExceptions)

Creates a new ExecutionSolver instance with out stop watch.

Parameters:

abstraction - an Abstraction value

methodName - a String value

methodInstrs - an InstructionList value

methodExceptions - a CodeException[] value

stopwatch - a Stopwatch value

Method Detail

maybeTransfer

protected boolean maybeTransfer(java.lang.Object[] solution,
                                Lattice l,
                                boolean isAll,
                                java.lang.Object e,
                                java.lang.Integer targetIndex,
                                java.util.Hashtable exFunctions)
                         throws FunctionException

compute

protected void compute(java.lang.Object[] solution,
                       boolean isForward,
                       boolean isAll)

Description copied from class: Solver

Implementations must provide this method. Given the JVM abstraction and the method in this classes data structures, the method must compute a correct solution, i.e. an approximation of the meet over paths solution (for isAll==true). This method is called from getSolution().

1. Implementations must set the variable iterations to a sensible value.
2. If there is a stop watch, it is already running. Implementations of this method may use the split() method as often as they wish. They may not call start() or stop().
3. An approximation of the memory usage is done by getSolution(). Hence, setting memory in this method has no effect.

Overrides:

compute in class Solver

Following copied from class: de.rwth.dfa.jvm.Solver

Parameters:

solution - an Object[] value: A newly created array for the solution. It has one entry for each instruction.

isForward - a boolean value: Analysis control flow

isAll - a boolean value: Use meet or join