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1
23
24
25 package com.sun.jdo.api.persistence.enhancer.classfile;
26
27
28 import java.io.PrintStream  ;
29
30
34
35 public class InsnConstOp extends Insn {
36
37 private ConstBasic constValue;
38
39
40
41 public int nStackArgs() {
42 int n = VMOp.ops[opcode()].nStackArgs();
43 if (n >= 0)
44 return n;
45 switch (opcode()) {
46 case opc_putstatic:
47 case opc_putfield:
48 {
49 ConstFieldRef fld = (ConstFieldRef) constValue;
50 String sig = fld.nameAndType().signature().asString();
51 if (sig.equals("J") || sig.equals("D")) return (opcode() == opc_putfield) ? 3 : 2;
53 return (opcode() == opc_putfield) ? 2 : 1;
54 }
55 case opc_invokevirtual:
56 case opc_invokespecial:
57 case opc_invokestatic:
58
59 case opc_invokeinterface:
60 {
61 ConstBasicMemberRef meth = (ConstBasicMemberRef) constValue;
62 String sig = meth.nameAndType().signature().asString();
63 int nMethodArgWords = Descriptor.countMethodArgWords(sig);
64 return nMethodArgWords +
65 ((opcode() == opc_invokestatic) ? 0 : 1);
66 }
67 default:
68 throw new InsnError("unexpected variable opcode"); }
70 }
71
72 public int nStackResults() {
73 int n = VMOp.ops[opcode()].nStackResults();
74 if (n >= 0)
75 return n;
76 switch (opcode()) {
77 case opc_getstatic:
78 case opc_getfield:
79 {
80 ConstFieldRef fld = (ConstFieldRef) constValue;
81 String sig = fld.nameAndType().signature().asString();
82 if (sig.equals("J") || sig.equals("D")) return 2;
84 return 1;
85 }
86 case opc_invokevirtual:
87 case opc_invokespecial:
88 case opc_invokestatic:
89
90 case opc_invokeinterface:
91 {
92 ConstBasicMemberRef meth = (ConstBasicMemberRef) constValue;
93 return Descriptor.countMethodReturnWords(
94 meth.nameAndType().signature().asString());
95 }
96 default:
97 throw new InsnError("unexpected variable opcode"); }
99 }
100
101 public String argTypes() {
102 switch (opcode()) {
103 case opc_putstatic:
104 case opc_putfield:
105 {
106 ConstFieldRef fld = (ConstFieldRef) constValue;
107 String sig = fld.nameAndType().signature().asString();
108 if (opcode() == opc_putstatic)
109 return sig;
110 else
111 return descriptorTypeOfObject(fld) + sig;
112 }
113 case opc_invokevirtual:
114 case opc_invokespecial:
115 case opc_invokestatic:
116
117 case opc_invokeinterface:
118 {
119 ConstBasicMemberRef meth = (ConstBasicMemberRef) constValue;
120 String argSig =
121 Descriptor.extractArgSig(meth.nameAndType().signature().asString());
122 if (opcode() == opc_invokestatic)
123 return argSig;
124 else
125 return descriptorTypeOfObject(meth) + argSig;
126 }
127 default:
128 return VMOp.ops[opcode()].argTypes();
129 }
130 }
131
132 public String resultTypes() {
133 switch (opcode()) {
134 case opc_invokevirtual:
135 case opc_invokespecial:
136 case opc_invokestatic:
137
138 case opc_invokeinterface:
139 {
140 ConstBasicMemberRef meth = (ConstBasicMemberRef) constValue;
141 String resultSig = Descriptor.extractResultSig(
142 meth.nameAndType().signature().asString());
143 if (resultSig.equals("V")) return ""; return resultSig;
146 }
147 case opc_getstatic:
148 case opc_getfield:
149 {
150 ConstFieldRef fld = (ConstFieldRef) constValue;
151 return fld.nameAndType().signature().asString();
152 }
153 case opc_ldc:
154 case opc_ldc_w:
155 case opc_ldc2_w:
156 {
157 ConstValue constVal = (ConstValue) constValue;
158 return constVal.descriptor();
159 }
160 default:
161 return VMOp.ops[opcode()].resultTypes();
162 }
163 }
164
165 public boolean branches() {
166
167 return false;
168 }
169
170
173 public ConstBasic value() {
174 return constValue;
175 }
176
177
180 public void setValue(ConstBasic newValue) {
181 checkConstant(newValue);
182 constValue = newValue;
183 }
184
185
186
187 void print (PrintStream out, int indent) {
188 ClassPrint.spaces(out, indent);
189 out.println(offset() + " " + opName(opcode()) + " pool(" + constValue.getIndex() + ")"); }
192
193 int store(byte[] buf, int index) {
194 if (opcode() == opc_ldc && !isNarrowldc())
195 buf[index++] = (byte) opc_ldc_w;
196 else
197 buf[index++] = (byte) opcode();
198 int constIndex = constValue.getIndex();
199 if (size() == 3)
200 buf[index++] = (byte) (constIndex >> 8);
201 buf[index++] = (byte)(constIndex & 0xff);
202 return index;
203 }
204
205 int size() {
206 return isNarrowldc() ? 2 : 3;
207 }
208
209 private boolean isNarrowldc() {
210 return (opcode() == opc_ldc && constValue.getIndex() < 256);
211 }
212
213
214 InsnConstOp (int theOpcode, ConstBasic theOperand) {
215 this(theOpcode, theOperand, NO_OFFSET);
216 }
217
218 InsnConstOp (int theOpcode, ConstBasic theOperand, int pc) {
219 super(theOpcode, pc);
220 constValue = theOperand;
221 checkConstant(theOperand);
222 if (theOpcode == opc_invokeinterface)
223 throw new InsnError("attempt to create an " + opName(theOpcode) + " as an InsnConstOp instead of InsnInterfaceInvoke"); }
226
227
229 InsnConstOp (int theOpcode, ConstInterfaceMethodRef theOperand, int pc) {
230 super(theOpcode, pc);
231 constValue = theOperand;
232 checkConstant(theOperand);
233 }
234
235 private void checkConstant (ConstBasic operand) {
236 switch(opcode()) {
237 case opc_ldc:
238 case opc_ldc_w:
239 case opc_ldc2_w:
240
241 if (operand == null ||
242 (! (operand instanceof ConstValue)))
243 throw new InsnError ("attempt to create an " + opName(opcode()) + " without a ConstValue operand"); break;
246
247 case opc_getstatic:
248 case opc_putstatic:
249 case opc_getfield:
250 case opc_putfield:
251
252 if (operand == null ||
253 (! (operand instanceof ConstFieldRef)))
254 throw new InsnError ("attempt to create an " + opName(opcode()) + " without a ConstFieldRef operand"); break;
257
258 case opc_invokevirtual:
259 case opc_invokespecial:
260 case opc_invokestatic:
261
262 if (operand == null ||
263 (! (operand instanceof ConstMethodRef)))
264 throw new InsnError ("attempt to create an " + opName(opcode()) + " without a ConstMethodRef operand"); break;
267
268 case opc_invokeinterface:
269
270 if (operand == null ||
271 (! (operand instanceof ConstInterfaceMethodRef)))
272 throw new InsnError("Attempt to create an " + opName(opcode()) + " without a ConstInterfaceMethodRef operand"); break;
275
276 case opc_new:
277 case opc_anewarray:
278 case opc_checkcast:
279 case opc_instanceof:
280
281 if (operand == null ||
282 (! (operand instanceof ConstClass)))
283 throw new InsnError ("attempt to create an " + opName(opcode()) + " without a ConstClass operand"); break;
286
287 default:
288 throw new InsnError ("attempt to create an " + opName(opcode()) + " with a constant operand"); }
291 }
292
293 private final String descriptorTypeOfObject(ConstBasicMemberRef memRef) {
294 String cname = memRef.className().className().asString();
295 return "L" + cname + ";"; }
297
298 }
299 |
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