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/*
 * 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.bcp;

import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.InstructionHandle;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.Edge;
import edu.umd.cs.findbugs.ba.vna.ValueNumberFrame;

/**
 * A "meta" PatternElement that matches any of a list of other child
 * PatternElements. An example of how this is useful is that you might want to
 * match invocations of any of a number of different methods. To do this, you
 * can create a MatchAny with some number of Invoke elements as children.
 * 
 * 
 * Note that the minOccur() and maxOccur() counts of the child PatternElements
 * are ignored. A MatchAny element always matches exactly one instruction.
 *
 * @author David Hovemeyer
 * @see PatternElement
 */
public class MatchAny extends PatternElement {
    private final PatternElement[] childList;

    /**
     * Constructor.
     *
     * @param childList
     *            list of child PatternElements
     */
    @SuppressFBWarnings("EI2")
    public MatchAny(PatternElement[] childList) {
        this.childList = childList;
    }

    @Override
    public PatternElement label(String label) {
        for (PatternElement aChildList : childList) {
            aChildList.label(label);
        }
        return this;
    }

    @Override
    public PatternElement setAllowTrailingEdges(boolean allowTrailingEdges) {
        // Just forward this on to all children,
        // since it is the children that the PatternMatcher will ask
        // about edges.
        for (PatternElement aChildList : childList) {
            aChildList.setAllowTrailingEdges(allowTrailingEdges);
        }

        return this;
    }

    @Override
    public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg, ValueNumberFrame before, ValueNumberFrame after,
            BindingSet bindingSet) throws DataflowAnalysisException {

        for (PatternElement child : childList) {
            MatchResult matchResult = child.match(handle, cpg, before, after, bindingSet);
            if (matchResult != null) {
                return matchResult;
            }
        }

        return null;

    }

    @Override
    public boolean acceptBranch(Edge edge, InstructionHandle source) {
        // Note: when selecting branch instructions, only the actual
        // (child) PatternElement should be used.
        throw new IllegalStateException("shouldn't happen");
    }

    @Override
    public int minOccur() {
        return 1;
    }

    @Override
    public int maxOccur() {
        return 1;
    }
}