/**
 *
 * Copyright (c) 2009-2012,
 *
 *  Galois, Inc. (Aaron Tomb <atomb@galois.com>, 
 *                Rogan Creswick <creswick@galois.com>, 
 *                Adam Foltzer <acfoltzer@galois.com>)
 *  Steve Suh    <suhsteve@gmail.com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The names of the contributors may not be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 *
 */

package org.scandroid.flow.functions;

import org.scandroid.domain.DomainElement;
import org.scandroid.domain.IFDSTaintDomain;
import org.scandroid.domain.LocalElement;
import org.scandroid.domain.ReturnElement;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.ibm.wala.dataflow.IFDS.IUnaryFlowFunction;
import com.ibm.wala.ssa.ISSABasicBlock;
import com.ibm.wala.util.intset.IntSet;
import com.ibm.wala.util.intset.MutableSparseIntSet;


public class CallToReturnFunction <E extends ISSABasicBlock> 
    implements IUnaryFlowFunction {
	private static final Logger logger = LoggerFactory.getLogger(CallToReturnFunction.class);

	private IFDSTaintDomain<E> domain;

	public CallToReturnFunction(IFDSTaintDomain<E> domain) {
		this.domain = domain;
	}

	@Override
	public IntSet getTargets(int d) {
		MutableSparseIntSet set = MutableSparseIntSet.makeEmpty();
        
		// Local elements (and the 0 element) flow through CallToReturn edges, 
		// but nothing else does (everything else is subject to whatever 
		// happened in the invoked function)
        if (0 == d) {
        	set.add(d);
        } else {
        	DomainElement de = domain.getMappedObject(d);
        	if (de.codeElement instanceof LocalElement || de.codeElement instanceof ReturnElement) {
        		set.add(d);
        	} else {
        		logger.trace("throwing away {}", de);
        	}
        }
		return set;
	}

}
