org.sosy_lab.cpachecker.cpa.arg.ARGTransferRelation.java Source code

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Here is the source code for org.sosy_lab.cpachecker.cpa.arg.ARGTransferRelation.java

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/*
 *  CPAchecker is a tool for configurable software verification.
 *  This file is part of CPAchecker.
 *
 *  Copyright (C) 2007-2014  Dirk Beyer
 *  All rights reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *
 *  CPAchecker web page:
 *    http://cpachecker.sosy-lab.org
 */
package org.sosy_lab.cpachecker.cpa.arg;

import static org.sosy_lab.cpachecker.util.CFAUtils.leavingEdges;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import org.sosy_lab.cpachecker.cfa.model.CFAEdge;
import org.sosy_lab.cpachecker.cfa.model.CFANode;
import org.sosy_lab.cpachecker.core.interfaces.AbstractState;
import org.sosy_lab.cpachecker.core.interfaces.Precision;
import org.sosy_lab.cpachecker.core.interfaces.TransferRelation;
import org.sosy_lab.cpachecker.core.interfaces.pcc.ProofChecker;
import org.sosy_lab.cpachecker.exceptions.CPATransferException;
import org.sosy_lab.cpachecker.util.AbstractStates;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;

public class ARGTransferRelation implements TransferRelation {

    private final TransferRelation transferRelation;

    public ARGTransferRelation(TransferRelation tr) {
        transferRelation = tr;
    }

    @Override
    public Collection<ARGState> getAbstractSuccessors(AbstractState pElement, Precision pPrecision)
            throws CPATransferException, InterruptedException {
        ARGState element = (ARGState) pElement;

        // covered elements may be in the reached set, but should always be ignored
        if (element.isCovered()) {
            return Collections.emptySet();
        }

        element.markExpanded();

        AbstractState wrappedState = element.getWrappedState();
        Collection<? extends AbstractState> successors = transferRelation.getAbstractSuccessors(wrappedState,
                pPrecision);
        if (successors.isEmpty()) {
            return Collections.emptySet();
        }

        Collection<ARGState> wrappedSuccessors = new ArrayList<>();
        for (AbstractState absElement : successors) {
            ARGState successorElem = new ARGState(absElement, element);
            wrappedSuccessors.add(successorElem);
        }

        return wrappedSuccessors;
    }

    @Override
    public Collection<? extends AbstractState> getAbstractSuccessorsForEdge(AbstractState pState,
            Precision pPrecision, CFAEdge pCfaEdge) {

        throw new UnsupportedOperationException("ARGCPA needs to be used as the outer-most CPA,"
                + " thus it does not support returning successors for a single edge.");
    }

    @Override
    public Collection<? extends AbstractState> strengthen(AbstractState element, List<AbstractState> otherElements,
            CFAEdge cfaEdge, Precision precision) {
        return null;
    }

    boolean areAbstractSuccessors(AbstractState pElement, CFAEdge pCfaEdge,
            Collection<? extends AbstractState> pSuccessors, ProofChecker wrappedProofChecker)
            throws CPATransferException, InterruptedException {
        ARGState element = (ARGState) pElement;

        assert Iterables.elementsEqual(element.getChildren(), pSuccessors);

        AbstractState wrappedState = element.getWrappedState();
        Multimap<CFAEdge, AbstractState> wrappedSuccessors = HashMultimap.create();
        for (AbstractState absElement : pSuccessors) {
            ARGState successorElem = (ARGState) absElement;
            wrappedSuccessors.put(element.getEdgeToChild(successorElem), successorElem.getWrappedState());
        }

        if (pCfaEdge != null) {
            return wrappedProofChecker.areAbstractSuccessors(wrappedState, pCfaEdge,
                    wrappedSuccessors.get(pCfaEdge));
        }

        CFANode loc = AbstractStates.extractLocation(element);
        for (CFAEdge edge : leavingEdges(loc)) {
            if (!wrappedProofChecker.areAbstractSuccessors(wrappedState, edge, wrappedSuccessors.get(edge))) {
                return false;
            }
        }
        return true;
    }
}