1 /*** 2 * ASM: a very small and fast Java bytecode manipulation framework 3 * Copyright (c) 2000-2005 INRIA, France Telecom 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. Neither the name of the copyright holders nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 28 * THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 package org.objectweb.asm.tree.analysis; 31 32 import java.util.HashSet; 33 import java.util.List; 34 import java.util.Set; 35 36 import org.objectweb.asm.Opcodes; 37 import org.objectweb.asm.Type; 38 import org.objectweb.asm.tree.AbstractInsnNode; 39 import org.objectweb.asm.tree.FieldInsnNode; 40 import org.objectweb.asm.tree.LdcInsnNode; 41 import org.objectweb.asm.tree.MethodInsnNode; 42 43 /** 44 * An {@link Interpreter} for {@link DataflowValue} values. 45 * 46 * @author Eric Bruneton 47 */ 48 public class DataflowInterpreter implements Opcodes, Interpreter { 49 newValue(final Type type)50 public Value newValue(final Type type) { 51 return new DataflowValue(type == null ? 1 : type.getSize()); 52 } 53 newOperation(final AbstractInsnNode insn)54 public Value newOperation(final AbstractInsnNode insn) { 55 int size; 56 switch (insn.getOpcode()) { 57 case LCONST_0: 58 case LCONST_1: 59 case DCONST_0: 60 case DCONST_1: 61 size = 2; 62 break; 63 case LDC: 64 Object cst = ((LdcInsnNode) insn).cst; 65 size = cst instanceof Long || cst instanceof Double ? 2 : 1; 66 break; 67 case GETSTATIC: 68 size = Type.getType(((FieldInsnNode) insn).desc).getSize(); 69 break; 70 default: 71 size = 1; 72 } 73 return new DataflowValue(size, insn); 74 } 75 copyOperation(final AbstractInsnNode insn, final Value value)76 public Value copyOperation(final AbstractInsnNode insn, final Value value) { 77 return new DataflowValue(value.getSize(), insn); 78 } 79 unaryOperation(final AbstractInsnNode insn, final Value value)80 public Value unaryOperation(final AbstractInsnNode insn, final Value value) 81 { 82 int size; 83 switch (insn.getOpcode()) { 84 case LNEG: 85 case DNEG: 86 case I2L: 87 case I2D: 88 case L2D: 89 case F2L: 90 case F2D: 91 case D2L: 92 size = 2; 93 break; 94 case GETFIELD: 95 size = Type.getType(((FieldInsnNode) insn).desc).getSize(); 96 break; 97 default: 98 size = 1; 99 } 100 return new DataflowValue(size, insn); 101 } 102 binaryOperation( final AbstractInsnNode insn, final Value value1, final Value value2)103 public Value binaryOperation( 104 final AbstractInsnNode insn, 105 final Value value1, 106 final Value value2) 107 { 108 int size; 109 switch (insn.getOpcode()) { 110 case LALOAD: 111 case DALOAD: 112 case LADD: 113 case DADD: 114 case LSUB: 115 case DSUB: 116 case LMUL: 117 case DMUL: 118 case LDIV: 119 case DDIV: 120 case LREM: 121 case DREM: 122 case LSHL: 123 case LSHR: 124 case LUSHR: 125 case LAND: 126 case LOR: 127 case LXOR: 128 size = 2; 129 break; 130 default: 131 size = 1; 132 } 133 return new DataflowValue(size, insn); 134 } 135 ternaryOperation( final AbstractInsnNode insn, final Value value1, final Value value2, final Value value3)136 public Value ternaryOperation( 137 final AbstractInsnNode insn, 138 final Value value1, 139 final Value value2, 140 final Value value3) 141 { 142 return new DataflowValue(1, insn); 143 } 144 naryOperation(final AbstractInsnNode insn, final List values)145 public Value naryOperation(final AbstractInsnNode insn, final List values) { 146 int size; 147 if (insn.getOpcode() == MULTIANEWARRAY) { 148 size = 1; 149 } else { 150 size = Type.getReturnType(((MethodInsnNode) insn).desc).getSize(); 151 } 152 return new DataflowValue(size, insn); 153 } 154 merge(final Value v, final Value w)155 public Value merge(final Value v, final Value w) { 156 DataflowValue dv = (DataflowValue) v; 157 DataflowValue dw = (DataflowValue) w; 158 if (dv.insns instanceof SmallSet && dw.insns instanceof SmallSet) { 159 Set s = ((SmallSet) dv.insns).union((SmallSet) dw.insns); 160 if (s == dv.insns && dv.size == dw.size) { 161 return v; 162 } else { 163 return new DataflowValue(Math.min(dv.size, dw.size), s); 164 } 165 } 166 if (dv.size != dw.size || !dv.insns.containsAll(dw.insns)) { 167 Set s = new HashSet(); 168 s.addAll(dv.insns); 169 s.addAll(dw.insns); 170 return new DataflowValue(Math.min(dv.size, dw.size), s); 171 } 172 return v; 173 } 174 } 175