Package com.ibm.wala.cfg.exc.intra

Class ExplodedCFGNullPointerAnalysis

java.lang.Object

com.ibm.wala.cfg.exc.intra.ExplodedCFGNullPointerAnalysis

All Implemented Interfaces:

ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

public class ExplodedCFGNullPointerAnalysis
extends Object
implements ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

Intraprocedural null pointer analysis for the exploded control flow graph.

Author:

Juergen Graf <graf@kit.edu>

Constructor Summary

Constructors

Constructor	Description
ExplodedCFGNullPointerAnalysis(TypeReference[] ignoredExceptions, IR ir, ParameterState paramState, MethodState mState, boolean optHasExceptions)

Method Summary

Modifier and Type	Method	Description
int	compute(MonitorUtil.IProgressMonitor progress)	Computes impossible control flow that is due to exceptions that definitely will not appear or that will always be thrown.
ControlFlowGraph<SSAInstruction,IExplodedBasicBlock>	getCFG()	Returns the result of the analysis: A control flow graph where impossible control flow has been removed.
NullPointerState	getState(IExplodedBasicBlock bb)	Returns the state of a node.
boolean	hasExceptions()	Returns true if the corresponding method contains instructions that may throw an exception which is not caught in the same method.

Methods inherited from class java.lang.Object

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

Constructor Details

ExplodedCFGNullPointerAnalysis

public ExplodedCFGNullPointerAnalysis(TypeReference[] ignoredExceptions,
 IR ir,
 ParameterState paramState,
 MethodState mState,
 boolean optHasExceptions)

Method Details

compute

public int compute(MonitorUtil.IProgressMonitor progress)
            throws GraphIntegrity.UnsoundGraphException,
CancelException

Description copied from interface: ExceptionPruningAnalysis

Computes impossible control flow that is due to exceptions that definitely will not appear or that will always be thrown. You have to run this method before using getPruned() to extract the result of the analysis.

Specified by:

compute in interface ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

Parameters:

progress - A progress monitor that is used to display the progress of the analysis. It can also be used to detect a cancel request from the user. The common behavior is to cancel the method if progress.isCanceled() is true by throwing a CancelException.

Returns:

Number of edges that have been removed from the cfg.

Throws:

GraphIntegrity.UnsoundGraphException - Thrown if the original CFG contains inconsistencies.

CancelException - Thrown if the user requested cancellation through the progress monitor.

getCFG

public ControlFlowGraph<SSAInstruction,IExplodedBasicBlock> getCFG()

Description copied from interface: ExceptionPruningAnalysis

Returns the result of the analysis: A control flow graph where impossible control flow has been removed. The way how and which impossible flow is detected may vary between different implementations of this class. Run compute(IProgressMonitor) first.

Specified by:

getCFG in interface ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

Returns:

The improved CFG without edges that were detected as impossible flow.

hasExceptions

public boolean hasExceptions()

Description copied from interface: ExceptionPruningAnalysis

Returns true if the corresponding method contains instructions that may throw an exception which is not caught in the same method. Run compute(IPrograssMonitor) first.

Specified by:

hasExceptions in interface ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

Returns:

true if the corresponding method contains instructions that may throw an exception which is not caught in the same method

getState

public NullPointerState getState(IExplodedBasicBlock bb)

Description copied from interface: ExceptionPruningAnalysis

Returns the state of a node. The node has to be part of the cfg.

Specified by:

getState in interface ExceptionPruningAnalysis<SSAInstruction,IExplodedBasicBlock>

Parameters:

bb - Node

Returns:

NullPointerState