1/* 2 * [The "BSD licence"] 3 * Copyright (c) 2011 Ben Gruver 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 29package org.jf.dexlib.Code.Analysis; 30 31import org.jf.dexlib.*; 32import org.jf.dexlib.Code.Format.Instruction22c; 33import org.jf.dexlib.Code.Instruction; 34import org.jf.dexlib.Code.InstructionWithReference; 35import org.jf.dexlib.Util.AccessFlags; 36 37import java.util.HashMap; 38 39public class SyntheticAccessorResolver { 40 public static final int METHOD = 0; 41 public static final int GETTER = 1; 42 public static final int SETTER = 2; 43 44 private final DexFileClassMap classMap; 45 private final HashMap<MethodIdItem, AccessedMember> resolvedAccessors = new HashMap<MethodIdItem, AccessedMember>(); 46 47 public SyntheticAccessorResolver(DexFile dexFile) { 48 classMap = new DexFileClassMap(dexFile); 49 } 50 51 public static boolean looksLikeSyntheticAccessor(MethodIdItem methodIdItem) { 52 return methodIdItem.getMethodName().getStringValue().startsWith("access$"); 53 } 54 55 public AccessedMember getAccessedMember(MethodIdItem methodIdItem) { 56 AccessedMember accessedMember = resolvedAccessors.get(methodIdItem); 57 if (accessedMember != null) { 58 return accessedMember; 59 } 60 61 ClassDefItem classDefItem = classMap.getClassDefByType(methodIdItem.getContainingClass()); 62 if (classDefItem == null) { 63 return null; 64 } 65 66 ClassDataItem classDataItem = classDefItem.getClassData(); 67 if (classDataItem == null) { 68 return null; 69 } 70 71 ClassDataItem.EncodedMethod encodedMethod = classDataItem.findDirectMethodByMethodId(methodIdItem); 72 if (encodedMethod == null) { 73 return null; 74 } 75 76 //A synthetic accessor will be marked synthetic 77 if ((encodedMethod.accessFlags & AccessFlags.SYNTHETIC.getValue()) == 0) { 78 return null; 79 } 80 81 Instruction[] instructions = encodedMethod.codeItem.getInstructions(); 82 83 //TODO: add support for odexed formats 84 switch (instructions[0].opcode.format) { 85 case Format35c: 86 case Format3rc: { 87 //a synthetic method access should be either 2 or 3 instructions, depending on if the method returns 88 //anything or not 89 if (instructions.length < 2 || instructions.length > 3) { 90 return null; 91 } 92 InstructionWithReference instruction = (InstructionWithReference)instructions[0]; 93 Item referencedItem = instruction.getReferencedItem(); 94 if (!(referencedItem instanceof MethodIdItem)) { 95 return null; 96 } 97 MethodIdItem referencedMethodIdItem = (MethodIdItem)referencedItem; 98 99 accessedMember = new AccessedMember(METHOD, referencedMethodIdItem); 100 resolvedAccessors.put(methodIdItem, accessedMember); 101 return accessedMember; 102 } 103 case Format22c: { 104 //a synthetic field access should be exactly 2 instructions. The set/put, and then the return 105 if (instructions.length != 2) { 106 return null; 107 } 108 Instruction22c instruction = (Instruction22c)instructions[0]; 109 Item referencedItem = instruction.getReferencedItem(); 110 if (!(referencedItem instanceof FieldIdItem)) { 111 return null; 112 } 113 FieldIdItem referencedFieldIdItem = (FieldIdItem)referencedItem; 114 115 if (instruction.opcode.setsRegister() || instruction.opcode.setsWideRegister()) { 116 //If the instruction sets a register, that means it is a getter - it gets the field value and 117 //stores it in the register 118 accessedMember = new AccessedMember(GETTER, referencedFieldIdItem); 119 } else { 120 accessedMember = new AccessedMember(SETTER, referencedFieldIdItem); 121 } 122 123 resolvedAccessors.put(methodIdItem, accessedMember); 124 return accessedMember; 125 } 126 default: 127 return null; 128 } 129 } 130 131 public static class AccessedMember { 132 public final int accessedMemberType; 133 public final Item accessedMember; 134 135 public AccessedMember(int accessedMemberType, Item accessedMember) { 136 this.accessedMemberType = accessedMemberType; 137 this.accessedMember = accessedMember; 138 } 139 } 140} 141