    View Javadoc
    1   package org.apache.bcel.generic;
    2
    3   /* ====================================================================
    4    * The Apache Software License, Version 1.1
    5    *
    6    * Copyright (c) 2001 The Apache Software Foundation.  All rights
    7    * reserved.
    8    *
    9    * Redistribution and use in source and binary forms, with or without
    10   * modification, are permitted provided that the following conditions
    11   * are met:
    12   *
    13   * 1. Redistributions of source code must retain the above copyright
    14   *    notice, this list of conditions and the following disclaimer.
    15   *
    16   * 2. Redistributions in binary form must reproduce the above copyright
    17   *    notice, this list of conditions and the following disclaimer in
    18   *    the documentation and/or other materials provided with the
    19   *    distribution.
    20   *
    21   * 3. The end-user documentation included with the redistribution,
    22   *    if any, must include the following acknowledgment:
    23   *       "This product includes software developed by the
    24   *        Apache Software Foundation (http://www.apache.org/)."
    25   *    Alternately, this acknowledgment may appear in the software itself,
    26   *    if and wherever such third-party acknowledgments normally appear.
    27   *
    28   * 4. The names "Apache" and "Apache Software Foundation" and
    29   *    "Apache BCEL" must not be used to endorse or promote products
    30   *    derived from this software without prior written permission. For
    31   *    written permission, please contact apache@apache.org.
    32   *
    33   * 5. Products derived from this software may not be called "Apache",
    34   *    "Apache BCEL", nor may "Apache" appear in their name, without
    35   *    prior written permission of the Apache Software Foundation.
    36   *
    37   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
    38   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    39   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    40   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
    41   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    42   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    43   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    44   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    45   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    46   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    47   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    48   * SUCH DAMAGE.
    49   * ====================================================================
    50   *
    51   * This software consists of voluntary contributions made by many
    52   * individuals on behalf of the Apache Software Foundation.  For more
    53   * information on the Apache Software Foundation, please see
    54   * <http://www.apache.org/>;.
    55   */
    56
    57  /***
    58   * Equality of instructions isn't clearly to be defined. You might
    59   * wish, for example, to compare whether instructions have the same
    60   * meaning. E.g., whether two INVOKEVIRTUALs describe the same
    61   * call.<br>The DEFAULT comparator however, considers two instructions
    62   * to be equal if they have same opcode and point to the same indexes
    63   * (if any) in the constant pool or the same local variable index. Branch
    64   * instructions must have the same target.
    65   *
    66   * @see Instruction
    67   * @version $Id: InstructionComparator.java,v 1.3 2002/10/11 20:33:07 mdahm Exp $
    68   * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
    69   */
    70  public interface InstructionComparator {
    71    public static final InstructionComparator DEFAULT =
    72      new InstructionComparator() {
    73  	public boolean equals(Instruction i1, Instruction i2) {
    74  	  if(i1.opcode == i2.opcode) {
    75  	    if(i1 instanceof Select) {
    76  	      InstructionHandle[] t1 = ((Select)i1).getTargets();
    77  	      InstructionHandle[] t2 = ((Select)i2).getTargets();
    78
    79  	      if(t1.length == t2.length) {
    80  		for(int i = 0; i < t1.length; i++) {
    81  		  if(t1[i] != t2[i]) {
    82  		    return false;
    83  		  }
    84  		}
    85
    86  		return true;
    87  	      }
    88  	    } else if(i1 instanceof BranchInstruction) {
    89  	      return ((BranchInstruction)i1).target ==
    90  		((BranchInstruction)i2).target;
    91  	    } else if(i1 instanceof ConstantPushInstruction) {
    92  	      return ((ConstantPushInstruction)i1).getValue().
    93  		equals(((ConstantPushInstruction)i2).getValue());
    94  	    } else if(i1 instanceof IndexedInstruction) {
    95  	      return ((IndexedInstruction)i1).getIndex() ==
    96  		((IndexedInstruction)i2).getIndex();
    97  	    } else if(i1 instanceof NEWARRAY) {
    98  	      return ((NEWARRAY)i1).getTypecode() == ((NEWARRAY)i2).getTypecode();
    99  	    } else {
    100 	      return true;
    101 	    }
    102 	  }
    103
    104 	  return false;
    105 	}
    106       };
    107
    108   public boolean equals(Instruction i1, Instruction i2);
    109 }

This page was automatically generated by Maven