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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
48 public class DataflowInterpreter implements Opcodes, Interpreter {
49
50 public Value newValue(final Type type) {
51 return new DataflowValue(type == null ? 1 : type.getSize());
52 }
53
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
76 public Value copyOperation(final AbstractInsnNode insn, final Value value) {
77 return new DataflowValue(value.getSize(), insn);
78 }
79
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
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
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
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
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 |
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