/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

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/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2011 INRIA, France Telecom

 * 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. Neither the name of the copyright holders nor the names of its

 *    contributors may 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

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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

package jdk.internal.org.objectweb.asm.tree.analysis;

import java.util.ArrayList;

import java.util.List;

import jdk.internal.org.objectweb.asm.tree.JumpInsnNode;

import jdk.internal.org.objectweb.asm.tree.LabelNode;

/**

 * A method subroutine (corresponds to a JSR instruction).

 *

 * @author Eric Bruneton

 */

class Subroutine {

    LabelNode start;

    boolean[] access;

    List<JumpInsnNode> callers;

    private Subroutine() {

    }

    Subroutine(final LabelNode start, final int maxLocals,

            final JumpInsnNode caller) {

        this.start = start;

        this.access = new boolean[maxLocals];

        this.callers = new ArrayList<JumpInsnNode>();

        callers.add(caller);

    }

    public Subroutine copy() {

        Subroutine result = new Subroutine();

        result.start = start;

        result.access = new boolean[access.length];

        System.arraycopy(access, 0, result.access, 0, access.length);

        result.callers = new ArrayList<JumpInsnNode>(callers);

        return result;

    }

    public boolean merge(final Subroutine subroutine) throws AnalyzerException {

        boolean changes = false;

        for (int i = 0; i < access.length; ++i) {

            if (subroutine.access[i] && !access[i]) {

                access[i] = true;

                changes = true;

            }

        }

        if (subroutine.start == start) {

            for (int i = 0; i < subroutine.callers.size(); ++i) {

                JumpInsnNode caller = subroutine.callers.get(i);

                if (!callers.contains(caller)) {

                    callers.add(caller);

                    changes = true;

                }

            }

        }

        return changes;

    }

}