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 TableSwitchInstruction extends SwitchInstruction 34b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato{ 35b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public int lowCase; 36b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public int highCase; 37b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 38b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 39b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 40b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Creates an uninitialized TableSwitchInstruction. 41b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 42b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public TableSwitchInstruction() {} 43b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 44b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 45b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 46b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Creates a new TableSwitchInstruction with the given arguments. 47b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 48b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public TableSwitchInstruction(byte opcode, 49b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int defaultOffset, 50b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int lowCase, 51b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int highCase, 52b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int[] jumpOffsets) 53b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 54b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.opcode = opcode; 55b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.defaultOffset = defaultOffset; 56b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.lowCase = lowCase; 57b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.highCase = highCase; 58b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.jumpOffsets = jumpOffsets; 59b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 60b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 61b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 62b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato /** 63b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * Copies the given instruction into this instruction. 64b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * @param tableSwitchInstruction the instruction to be copied. 65b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato * @return this instruction. 66b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato */ 67b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public TableSwitchInstruction copy(TableSwitchInstruction tableSwitchInstruction) 68b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 69b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.opcode = tableSwitchInstruction.opcode; 70b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.defaultOffset = tableSwitchInstruction.defaultOffset; 71b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.lowCase = tableSwitchInstruction.lowCase; 72b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.highCase = tableSwitchInstruction.highCase; 73b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato this.jumpOffsets = tableSwitchInstruction.jumpOffsets; 74b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 75b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return this; 76b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 77b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 78b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 79b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Implementations for Instruction. 80b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 81b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public Instruction shrink() 82b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 83b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // There aren't any ways to shrink this instruction. 84b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return this; 85b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 86b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 87b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato protected void readInfo(byte[] code, int offset) 88b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 89b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Skip up to three padding bytes. 90b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato offset += -offset & 3; 91b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 92b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Read the three 32-bit arguments. 93b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato defaultOffset = readInt(code, offset); offset += 4; 94b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato lowCase = readInt(code, offset); offset += 4; 95b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato highCase = readInt(code, offset); offset += 4; 96b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 97b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Read the jump offsets. 98b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato jumpOffsets = new int[highCase - lowCase + 1]; 99b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 100b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato for (int index = 0; index < jumpOffsets.length; index++) 101b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 102b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato jumpOffsets[index] = readInt(code, offset); offset += 4; 103b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 104b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 105b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 106b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 107b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato protected void writeInfo(byte[] code, int offset) 108b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 109b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write up to three padding bytes. 110b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato while ((offset & 3) != 0) 111b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 112b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeByte(code, offset++, 0); 113b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 114b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 115b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write the three 32-bit arguments. 116b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, defaultOffset); offset += 4; 117b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, lowCase); offset += 4; 118b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, highCase); offset += 4; 119b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 120b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato // Write the jump offsets. 121b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato int length = highCase - lowCase + 1; 122b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato for (int index = 0; index < length; index++) 123b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 124b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato writeInt(code, offset, jumpOffsets[index]); offset += 4; 125b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 126b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 127b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 128b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 129b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public int length(int offset) 130b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 131b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato return 1 + (-(offset+1) & 3) + 12 + (highCase - lowCase + 1) * 4; 132b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 133b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 134b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato 135b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, InstructionVisitor instructionVisitor) 136b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato { 137b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato instructionVisitor.visitTableSwitchInstruction(clazz, method, codeAttribute, offset, this); 138b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato } 139b72c5c2e5482cf10117b2b25f642f7616b2326c3Joe Onorato} 140