1/* 2 * Copyright 2012, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32package org.jf.dexlib2.dexbacked.instruction; 33 34import org.jf.dexlib2.Opcode; 35import org.jf.dexlib2.dexbacked.DexBackedDexFile; 36import org.jf.dexlib2.dexbacked.util.FixedSizeList; 37import org.jf.dexlib2.iface.instruction.formats.ArrayPayload; 38import org.jf.util.ExceptionWithContext; 39 40import javax.annotation.Nonnull; 41import java.util.List; 42 43public class DexBackedArrayPayload extends DexBackedInstruction implements ArrayPayload { 44 public static final Opcode OPCODE = Opcode.ARRAY_PAYLOAD; 45 46 public final int elementWidth; 47 public final int elementCount; 48 49 private static final int ELEMENT_WIDTH_OFFSET = 2; 50 private static final int ELEMENT_COUNT_OFFSET = 4; 51 private static final int ELEMENTS_OFFSET = 8; 52 53 public DexBackedArrayPayload(@Nonnull DexBackedDexFile dexFile, 54 int instructionStart) { 55 super(dexFile, OPCODE, instructionStart); 56 57 elementWidth = dexFile.readUshort(instructionStart + ELEMENT_WIDTH_OFFSET); 58 elementCount = dexFile.readSmallUint(instructionStart + ELEMENT_COUNT_OFFSET); 59 if (((long)elementWidth) * elementCount > Integer.MAX_VALUE) { 60 throw new ExceptionWithContext("Invalid array-payload instruction: element width*count overflows"); 61 } 62 } 63 64 @Override public int getElementWidth() { return elementWidth; } 65 66 @Nonnull 67 @Override 68 public List<Number> getArrayElements() { 69 final int elementsStart = instructionStart + ELEMENTS_OFFSET; 70 71 abstract class ReturnedList extends FixedSizeList<Number> { 72 @Override public int size() { return elementCount; } 73 } 74 75 switch (elementWidth) { 76 case 1: 77 return new ReturnedList() { 78 @Nonnull 79 @Override 80 public Number readItem(int index) { 81 return dexFile.readByte(elementsStart + index); 82 } 83 }; 84 case 2: 85 return new ReturnedList() { 86 @Nonnull 87 @Override 88 public Number readItem(int index) { 89 return dexFile.readShort(elementsStart + index*2); 90 } 91 }; 92 case 4: 93 return new ReturnedList() { 94 @Nonnull 95 @Override 96 public Number readItem(int index) { 97 return dexFile.readInt(elementsStart + index*4); 98 } 99 }; 100 case 8: 101 return new ReturnedList() { 102 @Nonnull 103 @Override 104 public Number readItem(int index) { 105 return dexFile.readLong(elementsStart + index*8); 106 } 107 }; 108 default: 109 throw new ExceptionWithContext("Invalid element width: %d", elementWidth); 110 } 111 } 112 113 @Override 114 public int getCodeUnits() { 115 return 4 + (elementWidth*elementCount + 1) / 2; 116 } 117} 118