1b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato/* 2b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * ProGuard -- shrinking, optimization, obfuscation, and preverification 3b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * of Java bytecode. 4b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 5b9cc48a43ed984587c939d02fba5316bf5c0df6eYing Wang * Copyright (c) 2002-2013 Eric Lafortune (eric@graphics.cornell.edu) 6b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 7b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * This program is free software; you can redistribute it and/or modify it 8b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * under the terms of the GNU General Public License as published by the Free 9b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Software Foundation; either version 2 of the License, or (at your option) 10b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * any later version. 11b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 12b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * This program is distributed in the hope that it will be useful, but WITHOUT 13b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * more details. 16b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 17b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * You should have received a copy of the GNU General Public License along 18b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * with this program; if not, write to the Free Software Foundation, Inc., 19b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 21b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onoratopackage proguard.classfile.instruction; 22b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 23b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onoratoimport proguard.classfile.*; 24b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onoratoimport proguard.classfile.attribute.CodeAttribute; 25b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onoratoimport proguard.classfile.instruction.visitor.InstructionVisitor; 26b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 27b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato/** 28b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * This Instruction represents a simple instruction without variable arguments 29b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * or constant pool references. 30b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * 31b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * @author Eric Lafortune 32b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 33b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onoratopublic class LookUpSwitchInstruction extends SwitchInstruction 34b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato{ 35b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public int[] cases; 36b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 37b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 38b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 39b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Creates an uninitialized LookUpSwitchInstruction. 40b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 41b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public LookUpSwitchInstruction() {} 42b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 43b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 44b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 45b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Creates a new LookUpSwitchInstruction with the given arguments. 46b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 47b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public LookUpSwitchInstruction(byte opcode, 48b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int defaultOffset, 49b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int[] cases, 50b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int[] jumpOffsets) 51b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 52b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.opcode = opcode; 53b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.defaultOffset = defaultOffset; 54b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.cases = cases; 55b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.jumpOffsets = jumpOffsets; 56b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 57b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 58b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 59b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 60b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Copies the given instruction into this instruction. 61b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * @param lookUpSwitchInstruction the instruction to be copied. 62b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * @return this instruction. 63b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 64b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public LookUpSwitchInstruction copy(LookUpSwitchInstruction lookUpSwitchInstruction) 65b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 66b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.opcode = lookUpSwitchInstruction.opcode; 67b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.defaultOffset = lookUpSwitchInstruction.defaultOffset; 68b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.cases = lookUpSwitchInstruction.cases; 69b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.jumpOffsets = lookUpSwitchInstruction.jumpOffsets; 70b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 71b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return this; 72b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 73b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 74b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 75b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Implementations for Instruction. 76b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 77b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public Instruction shrink() 78b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 79b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // There aren't any ways to shrink this instruction. 80b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return this; 81b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 82b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 83b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato protected void readInfo(byte[] code, int offset) 84b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 85b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Skip up to three padding bytes. 86b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato offset += -offset & 3; 87b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 88b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Read the two 32-bit arguments. 89b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato defaultOffset = readInt(code, offset); offset += 4; 90b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int jumpOffsetCount = readInt(code, offset); offset += 4; 91b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 92b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Read the matches-offset pairs. 93b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato cases = new int[jumpOffsetCount]; 94b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato jumpOffsets = new int[jumpOffsetCount]; 95b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 96b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato for (int index = 0; index < jumpOffsetCount; index++) 97b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 98b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato cases[index] = readInt(code, offset); offset += 4; 99b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato jumpOffsets[index] = readInt(code, offset); offset += 4; 100b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 101b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 102b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 103b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 104b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato protected void writeInfo(byte[] code, int offset) 105b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 106b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write up to three padding bytes. 107b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato while ((offset & 3) != 0) 108b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 109b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeByte(code, offset++, 0); 110b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 111b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 112b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write the two 32-bit arguments. 113b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, defaultOffset); offset += 4; 114b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, cases.length); offset += 4; 115b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 116b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write the matches-offset pairs. 117b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato for (int index = 0; index < cases.length; index++) 118b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 119b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, cases[index]); offset += 4; 120b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, jumpOffsets[index]); offset += 4; 121b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 122b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 123b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 124b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 125b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public int length(int offset) 126b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 127b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return 1 + (-(offset+1) & 3) + 8 + cases.length * 8; 128b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 129b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 130b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 131b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, InstructionVisitor instructionVisitor) 132b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 133b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato instructionVisitor.visitLookUpSwitchInstruction(clazz, method, codeAttribute, offset, this); 134b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 135b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato} 136