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// 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 org.ssssssss.script.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.
*
*
* - 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.
*
- 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).
*
*/
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;
}
}