/*

 * 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

 * 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 jdk.internal.org.objectweb.asm;

/**

 * An edge in the control flow graph of a method. Each node of this graph is a basic block,

 * represented with the Label corresponding to its first instruction. Each edge goes from one node

 * to another, i.e. from one basic block to another (called the predecessor and successor blocks,

 * respectively). An edge corresponds either to a jump or ret instruction or to an exception

 * handler.

 *

 * @see Label

 * @author Eric Bruneton

 */

final class Edge {

    /**

      * A control flow graph edge corresponding to a jump or ret instruction. Only used with {@link

      * ClassWriter#COMPUTE_FRAMES}.

      */

    static final int JUMP = 0;

    /**

      * A control flow graph edge corresponding to an exception handler. Only used with {@link

      * ClassWriter#COMPUTE_MAXS}.

      */

    static final int EXCEPTION = 0x7FFFFFFF;

    /**

      * Information about this control flow graph edge.

      *

      * <ul>

      *   <li>If {@link ClassWriter#COMPUTE_MAXS} is used, this field contains either a stack size

      *       delta (for an edge corresponding to a jump instruction), or the value EXCEPTION (for an

      *       edge corresponding to an exception handler). The stack size delta is the stack size just

      *       after the jump instruction, minus the stack size at the beginning of the predecessor

      *       basic block, i.e. the one containing the jump instruction.

      *   <li>If {@link ClassWriter#COMPUTE_FRAMES} is used, this field contains either the value JUMP

      *       (for an edge corresponding to a jump instruction), or the index, in the {@link

      *       ClassWriter} type table, of the exception type that is handled (for an edge corresponding

      *       to an exception handler).

      * </ul>

      */

    final int info;

    /** The successor block of this control flow graph edge. */

    final Label successor;

    /**

      * The next edge in the list of outgoing edges of a basic block. See {@link Label#outgoingEdges}.

      */

    Edge nextEdge;

    /**

      * Constructs a new Edge.

      *

      * @param info see {@link #info}.

      * @param successor see {@link #successor}.

      * @param nextEdge see {@link #nextEdge}.

      */

    Edge(final int info, final Label successor, final Edge nextEdge) {

        this.info = info;

        this.successor = successor;

        this.nextEdge = nextEdge;

    }

}