1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 package com.sun.org.apache.bcel.internal.generic;
   6 
   7 /* ====================================================================
   8  * The Apache Software License, Version 1.1
   9  *
  10  * Copyright (c) 2001 The Apache Software Foundation.  All rights
  11  * reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  *
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  *
  20  * 2. Redistributions in binary form must reproduce the above copyright
  21  *    notice, this list of conditions and the following disclaimer in
  22  *    the documentation and/or other materials provided with the
  23  *    distribution.
  24  *
  25  * 3. The end-user documentation included with the redistribution,
  26  *    if any, must include the following acknowledgment:
  27  *       "This product includes software developed by the
  28  *        Apache Software Foundation (http://www.apache.org/)."
  29  *    Alternately, this acknowledgment may appear in the software itself,
  30  *    if and wherever such third-party acknowledgments normally appear.
  31  *
  32  * 4. The names "Apache" and "Apache Software Foundation" and
  33  *    "Apache BCEL" must not be used to endorse or promote products
  34  *    derived from this software without prior written permission. For
  35  *    written permission, please contact apache@apache.org.
  36  *
  37  * 5. Products derived from this software may not be called "Apache",
  38  *    "Apache BCEL", nor may "Apache" appear in their name, without
  39  *    prior written permission of the Apache Software Foundation.
  40  *
  41  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  42  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  43  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  45  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  46  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  47  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  48  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  49  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  50  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  51  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  * ====================================================================
  54  *
  55  * This software consists of voluntary contributions made by many
  56  * individuals on behalf of the Apache Software Foundation.  For more
  57  * information on the Apache Software Foundation, please see
  58  * <http://www.apache.org/>.
  59  */
  60 
  61 import com.sun.org.apache.bcel.internal.classfile.*;
  62 
  63 /**
  64  * This class represents an exception handler, i.e., specifies the  region where
  65  * a handler is active and an instruction where the actual handling is done.
  66  * pool as parameters. Opposed to the JVM specification the end of the handled
  67  * region is set to be inclusive, i.e. all instructions between start and end
  68  * are protected including the start and end instructions (handles) themselves.
  69  * The end of the region is automatically mapped to be exclusive when calling
  70  * getCodeException(), i.e., there is no difference semantically.
  71  *
  72  * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
  73  * @see     MethodGen
  74  * @see     CodeException
  75  * @see     InstructionHandle
  76  */
  77 public final class CodeExceptionGen
  78   implements InstructionTargeter, Cloneable, java.io.Serializable {
  79   private InstructionHandle start_pc;
  80   private InstructionHandle end_pc;
  81   private InstructionHandle handler_pc;
  82   private ObjectType        catch_type;
  83 
  84   /**
  85    * Add an exception handler, i.e., specify region where a handler is active and an
  86    * instruction where the actual handling is done.
  87    *
  88    * @param start_pc Start of handled region (inclusive)
  89    * @param end_pc End of handled region (inclusive)
  90    * @param handler_pc Where handling is done
  91    * @param catch_type which exception is handled, null for ANY
  92    */
  93   public CodeExceptionGen(InstructionHandle start_pc, InstructionHandle end_pc,
  94                           InstructionHandle handler_pc, ObjectType catch_type) {
  95     setStartPC(start_pc);
  96     setEndPC(end_pc);
  97     setHandlerPC(handler_pc);
  98     this.catch_type = catch_type;
  99   }
 100 
 101   /**
 102    * Get CodeException object.<BR>
 103    *
 104    * This relies on that the instruction list has already been dumped
 105    * to byte code or or that the `setPositions' methods has been
 106    * called for the instruction list.
 107    *
 108    * @param cp constant pool
 109    */
 110   public CodeException getCodeException(ConstantPoolGen cp) {
 111     return new CodeException(start_pc.getPosition(),
 112                              end_pc.getPosition() + end_pc.getInstruction().getLength(),
 113                              handler_pc.getPosition(),
 114                              (catch_type == null)? 0 : cp.addClass(catch_type));
 115   }
 116 
 117   /* Set start of handler
 118    * @param start_pc Start of handled region (inclusive)
 119    */
 120   public final void setStartPC(InstructionHandle start_pc) {
 121     BranchInstruction.notifyTargetChanging(this.start_pc, this);
 122     this.start_pc = start_pc;
 123     BranchInstruction.notifyTargetChanged(this.start_pc, this);
 124   }
 125 
 126   /* Set end of handler
 127    * @param end_pc End of handled region (inclusive)
 128    */
 129   public final void setEndPC(InstructionHandle end_pc) {
 130     BranchInstruction.notifyTargetChanging(this.end_pc, this);
 131     this.end_pc = end_pc;
 132     BranchInstruction.notifyTargetChanged(this.end_pc, this);
 133   }
 134 
 135   /* Set handler code
 136    * @param handler_pc Start of handler
 137    */
 138   public final void setHandlerPC(InstructionHandle handler_pc) {
 139     BranchInstruction.notifyTargetChanging(this.handler_pc, this);
 140     this.handler_pc = handler_pc;
 141     BranchInstruction.notifyTargetChanged(this.handler_pc, this);
 142   }
 143 
 144   /**
 145    * @param old_ih old target, either start or end
 146    * @param new_ih new target
 147    */
 148   @Override
 149   public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
 150     boolean targeted = false;
 151 
 152     if(start_pc == old_ih) {
 153       targeted = true;
 154       setStartPC(new_ih);
 155     }
 156 
 157     if(end_pc == old_ih) {
 158       targeted = true;
 159       setEndPC(new_ih);
 160     }
 161 
 162     if(handler_pc == old_ih) {
 163       targeted = true;
 164       setHandlerPC(new_ih);
 165     }
 166 
 167     if(!targeted)
 168       throw new ClassGenException("Not targeting " + old_ih + ", but {" + start_pc + ", " +
 169                                   end_pc + ", " + handler_pc + "}");
 170   }
 171 
 172   /**
 173    * @return true, if ih is target of this handler
 174    */
 175   @Override
 176   public boolean containsTarget(InstructionHandle ih) {
 177     return (start_pc == ih) || (end_pc == ih) || (handler_pc == ih);
 178   }
 179 
 180   /** Sets the type of the Exception to catch. Set 'null' for ANY. */
 181   public void              setCatchType(ObjectType catch_type)        { this.catch_type = catch_type; }
 182   /** Gets the type of the Exception to catch, 'null' for ANY. */
 183   public ObjectType        getCatchType()                             { return catch_type; }
 184 
 185   /** @return start of handled region (inclusive)
 186    */
 187   public InstructionHandle getStartPC()                               { return start_pc; }
 188 
 189   /** @return end of handled region (inclusive)
 190    */
 191   public InstructionHandle getEndPC()                                 { return end_pc; }
 192 
 193   /** @return start of handler
 194    */
 195   public InstructionHandle getHandlerPC()                             { return handler_pc; }
 196 
 197   @Override
 198   public String toString() {
 199     return "CodeExceptionGen(" + start_pc + ", " + end_pc + ", " + handler_pc + ")";
 200   }
 201 
 202   @Override
 203   public Object clone() {
 204     try {
 205       return super.clone();
 206     } catch(CloneNotSupportedException e) {
 207       System.err.println(e);
 208       return null;
 209     }
 210   }
 211 }