/******************************************************************************
* Copyright (c) 2002 - 2014 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*****************************************************************************/
package com.ibm.wala.cfg.exc;
import com.ibm.wala.cfg.ControlFlowGraph;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.cfg.exc.intra.NullPointerState;
import com.ibm.wala.util.CancelException;
import com.ibm.wala.util.MonitorUtil.IProgressMonitor;
import com.ibm.wala.util.graph.GraphIntegrity.UnsoundGraphException;
/**
* This abstract class is used as interface for analysis that remove impossible
* control flow from a CFG. This is done by detecting exceptions that may always
* (or never) appear.
*
* @author Juergen Graf <graf@kit.edu>
*
*/
public interface ExceptionPruningAnalysis<I, T extends IBasicBlock<I>> {
/**
* 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.
* @param 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.
* @return Number of edges that have been removed from the cfg.
* @throws UnsoundGraphException
* Thrown if the original CFG contains inconsistencies.
* @throws CancelException
* Thrown if the user requested cancellation through the progress
* monitor.
*/
int compute(IProgressMonitor progress) throws UnsoundGraphException, CancelException;
/**
* 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.
*
* @return The improved CFG without edges that were detected as impossible
* flow.
*/
ControlFlowGraph<I, T> getCFG();
/**
* Returns true if the corresponding method contains instructions that may
* throw an exception. Run compute(IPrograssMonitor) first.
* @return true if the corresponding method contains instructions that may
* throw an exception.
*/
boolean hasExceptions();
/**
* Returns the state of a node. The node has to be part of the cfg.
* @param bb Node
* @return NullPointerState
*/
NullPointerState getState(T bb);
}