Home | History | Annotate | Download | only in Code 
      1 /*
      2  * [The "BSD licence"]
      3  * Copyright (c) 2010 Ben Gruver (JesusFreke)
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 package org.jf.dexlib.Code;
     30 
     31 import org.jf.dexlib.*;
     32 import org.jf.dexlib.Util.NumberUtils;
     33 
     34 public abstract class InstructionWithReference extends Instruction {
     35     private Item referencedItem;
     36     private ReferenceType referenceType;
     37 
     38     protected InstructionWithReference(Opcode opcode, Item referencedItem) {
     39         super(opcode);
     40         this.referencedItem = referencedItem;
     41         this.referenceType = opcode.referenceType;
     42         checkReferenceType();
     43     }
     44 
     45     protected InstructionWithReference(Opcode opcode, Item referencedItem, ReferenceType referenceType) {
     46         super(opcode);
     47         this.referencedItem = referencedItem;
     48         this.referenceType = referenceType;
     49         checkReferenceType();
     50     }
     51 
     52     protected InstructionWithReference(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
     53         super(opcode);
     54 
     55         this.referenceType = readReferenceType(opcode, buffer, bufferIndex);
     56         int itemIndex = getReferencedItemIndex(buffer, bufferIndex);
     57         lookupReferencedItem(dexFile, opcode, itemIndex);
     58     }
     59 
     60     protected int getReferencedItemIndex(byte[] buffer, int bufferIndex) {
     61         return NumberUtils.decodeUnsignedShort(buffer, bufferIndex + 2);
     62     }
     63 
     64     public ReferenceType getReferenceType() {
     65         return referenceType;
     66     }
     67 
     68     public Item getReferencedItem() {
     69         return referencedItem;
     70     }
     71 
     72     protected ReferenceType readReferenceType(Opcode opcode, byte[] buffer, int bufferIndex) {
     73         return opcode.referenceType;
     74     }
     75 
     76     private void lookupReferencedItem(DexFile dexFile, Opcode opcode, int itemIndex) {
     77         switch (referenceType) {
     78             case field:
     79                 referencedItem = dexFile.FieldIdsSection.getItemByIndex(itemIndex);
     80                 return;
     81             case method:
     82                 referencedItem = dexFile.MethodIdsSection.getItemByIndex(itemIndex);
     83                 return;
     84             case type:
     85                 referencedItem = dexFile.TypeIdsSection.getItemByIndex(itemIndex);
     86                 return;
     87             case string:
     88                 referencedItem = dexFile.StringIdsSection.getItemByIndex(itemIndex);
     89         }
     90     }
     91 
     92 
     93     private void checkReferenceType() {
     94         switch (referenceType) {
     95             case field:
     96                 if (!(referencedItem instanceof FieldIdItem)) {
     97                     throw new RuntimeException(referencedItem.getClass().getSimpleName() +
     98                             " is the wrong item type for opcode " + opcode.name + ". Expecting FieldIdItem.");
     99                 }
    100                 return;
    101             case method:
    102                 if (!(referencedItem instanceof MethodIdItem)) {
    103                     throw new RuntimeException(referencedItem.getClass().getSimpleName() +
    104                             " is the wrong item type for opcode " + opcode.name + ". Expecting MethodIdItem.");
    105                 }
    106                 return;
    107             case type:
    108                 if (!(referencedItem instanceof TypeIdItem)) {
    109                     throw new RuntimeException(referencedItem.getClass().getSimpleName() +
    110                             " is the wrong item type for opcode " + opcode.name + ". Expecting TypeIdItem.");
    111                 }
    112                 return;
    113             case string:
    114                 if (!(referencedItem instanceof StringIdItem)) {
    115                     throw new RuntimeException(referencedItem.getClass().getSimpleName() +
    116                             " is the wrong item type for opcode " + opcode.name + ". Expecting StringIdItem.");
    117                 }
    118                 return;
    119             default:
    120                 if (referencedItem != null) {
    121                     throw new RuntimeException(referencedItem.getClass().getSimpleName() +
    122                             " is invalid for opcode " + opcode.name + ". This opcode does not reference an item");
    123                 }
    124         }
    125     }
    126 }
    127