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 32 package org.jf.dexlib2.util; 33 34 import org.jf.dexlib2.iface.instruction.Instruction; 35 import org.jf.util.ExceptionWithContext; 36 37 import javax.annotation.Nonnull; 38 import java.util.Arrays; 39 import java.util.List; 40 41 public class InstructionOffsetMap { 42 @Nonnull private final int[] instructionCodeOffsets; 43 InstructionOffsetMap(@onnull List<? extends Instruction> instructions)44 public InstructionOffsetMap(@Nonnull List<? extends Instruction> instructions) { 45 this.instructionCodeOffsets = new int[instructions.size()]; 46 47 int codeOffset = 0; 48 for (int i=0; i<instructions.size(); i++) { 49 instructionCodeOffsets[i] = codeOffset; 50 codeOffset += instructions.get(i).getCodeUnits(); 51 } 52 } 53 getInstructionIndexAtCodeOffset(int codeOffset)54 public int getInstructionIndexAtCodeOffset(int codeOffset) { 55 return getInstructionIndexAtCodeOffset(codeOffset, true); 56 } 57 getInstructionIndexAtCodeOffset(int codeOffset, boolean exact)58 public int getInstructionIndexAtCodeOffset(int codeOffset, boolean exact) { 59 int index = Arrays.binarySearch(instructionCodeOffsets, codeOffset); 60 if (index < 0) { 61 if (exact) { 62 throw new InvalidInstructionOffset(codeOffset); 63 } else { 64 // This calculation would be incorrect if index was -1 (i.e. insertion point of 0). Luckily, we can 65 // ignore this case, because codeOffset will always be non-negative, and the code offset of the first 66 // instruction will always be 0. 67 return (~index) - 1; 68 } 69 } 70 return index; 71 } 72 getInstructionCodeOffset(int index)73 public int getInstructionCodeOffset(int index) { 74 if (index < 0 || index >= instructionCodeOffsets.length) { 75 throw new InvalidInstructionIndex(index); 76 } 77 return instructionCodeOffsets[index]; 78 } 79 80 public static class InvalidInstructionOffset extends ExceptionWithContext { 81 private final int instructionOffset; 82 InvalidInstructionOffset(int instructionOffset)83 public InvalidInstructionOffset(int instructionOffset) { 84 super("No instruction at offset %d", instructionOffset); 85 this.instructionOffset = instructionOffset; 86 } 87 getInstructionOffset()88 public int getInstructionOffset() { 89 return instructionOffset; 90 } 91 } 92 93 public static class InvalidInstructionIndex extends ExceptionWithContext { 94 private final int instructionIndex; 95 InvalidInstructionIndex(int instructionIndex)96 public InvalidInstructionIndex(int instructionIndex) { 97 super("Instruction index out of bounds: %d", instructionIndex); 98 this.instructionIndex = instructionIndex; 99 } 100 getInstructionIndex()101 public int getInstructionIndex() { 102 return instructionIndex; 103 } 104 } 105 } 106