/*
 * Bytecode Analysis Framework
 * Copyright (C) 2003,2004 University of Maryland
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.ba;

import org.apache.bcel.generic.InstructionHandle;

public class ReturnPathAnalysis extends ForwardDataflowAnalysis<ReturnPath> implements EdgeTypes {
    public ReturnPathAnalysis(DepthFirstSearch dfs) {
        super(dfs);
    }

    @Override
    public ReturnPath createFact() {
        return new ReturnPath(ReturnPath.TOP);
    }

    @Override
    public void copy(ReturnPath source, ReturnPath dest) {
        dest.copyFrom(source);
    }

    @Override
    public void initEntryFact(ReturnPath fact) {
        fact.setKind(ReturnPath.RETURNS);
    }

    @Override
    public void makeFactTop(ReturnPath fact) {
        fact.setKind(ReturnPath.TOP);
    }

    @Override
    public boolean isTop(ReturnPath fact) {
        return fact.getKind() == ReturnPath.TOP;
    }

    @Override
    public boolean same(ReturnPath fact1, ReturnPath fact2) {
        return fact1.sameAs(fact2);
    }

    @Override
    public void transferInstruction(InstructionHandle handle, BasicBlock basicBlock, ReturnPath fact)
            throws DataflowAnalysisException {
        // Nothing to do
    }

    @Override
    public boolean isFactValid(ReturnPath fact) {
        return true;
    }

    @Override
    public void meetInto(ReturnPath fact, Edge edge, ReturnPath result) throws DataflowAnalysisException {
        switch (edge.getType()) {
        case UNHANDLED_EXCEPTION_EDGE:
            fact = new ReturnPath(ReturnPath.UE);
            break;
        case EXIT_EDGE:
            fact = new ReturnPath(ReturnPath.EXIT);
            break;
        default:
            break;
        }

        result.mergeWith(fact);
    }

    // public static void main(String[] argv) throws Exception {
    // if (argv.length != 1) {
    // System.err.println("Usage: " + ReturnPathAnalysis.class.getName() +
    // " <classfile>");
    // System.exit(1);
    // }
    //
    // DataflowTestDriver<ReturnPath, ReturnPathAnalysis> driver = new
    // DataflowTestDriver<ReturnPath, ReturnPathAnalysis>() {
    // @Override
    // public Dataflow<ReturnPath, ReturnPathAnalysis>
    // createDataflow(ClassContext classContext, Method method)
    // throws CFGBuilderException, DataflowAnalysisException {
    // return classContext.getReturnPathDataflow(method);
    // }
    // };
    //
    // driver.execute(argv[0]);
    // }
}

