DexBackedTryBlock.java revision 8daecd0246fb0d4eb29f53ab4ef99b506d395401
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; 33 34import org.jf.dexlib2.DexFile; 35import org.jf.dexlib2.DexFileReader; 36import org.jf.dexlib2.iface.ExceptionHandler; 37import org.jf.dexlib2.iface.TryBlock; 38import org.jf.dexlib2.dexbacked.util.VariableSizeList; 39 40import javax.annotation.Nonnull; 41import java.util.List; 42 43public class DexBackedTryBlock implements TryBlock { 44 public final DexFile dexFile; 45 46 public final int startIndex; 47 public final int instructionCount; 48 49 private final int exceptionHandlersOffset; 50 51 public DexBackedTryBlock(DexFile dexFile, 52 int offset, 53 int handlersStartOffset) { 54 this.dexFile = dexFile; 55 this.startIndex = dexFile.readSmallUint(offset); 56 this.instructionCount = dexFile.readUshort(offset+4); 57 this.exceptionHandlersOffset = handlersStartOffset + dexFile.readUshort(6); 58 } 59 60 @Override public int getStartIndex() { return startIndex; } 61 @Override public int getInstructionCount() { return instructionCount; } 62 63 @Nonnull 64 @Override 65 public List<? extends ExceptionHandler> getExceptionHandlers() { 66 DexFileReader reader = dexFile.readerAt(exceptionHandlersOffset); 67 final int encodedSize = reader.readSleb128(); 68 69 if (encodedSize > 0) { 70 //no catch-all 71 return new VariableSizeList<ExceptionHandler>(dexFile, reader.getOffset()) { 72 @Nonnull 73 @Override 74 protected ExceptionHandler readItem(DexFileReader dexFileReader, int index) { 75 return new DexBackedExceptionHandler(dexFileReader); 76 } 77 @Override public int size() { return encodedSize; } 78 }; 79 } else { 80 //with catch-all 81 final int sizeWithCatchAll = (-1 * encodedSize) + 1; 82 return new VariableSizeList<ExceptionHandler>(dexFile, reader.getOffset()) { 83 @Nonnull 84 @Override 85 protected ExceptionHandler readItem(DexFileReader dexFileReader, int index) { 86 if (index == sizeWithCatchAll-1) { 87 return new DexBackedCatchAllExceptionHandler(dexFileReader); 88 } else { 89 return new DexBackedExceptionHandler(dexFileReader); 90 } 91 } 92 @Override public int size() { return sizeWithCatchAll; } 93 }; 94 } 95 } 96} 97