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Java > Open Source Codes > gov > nasa > jpf > jvm > bytecode > INSTANCEOF


1 //
2 // Copyright (C) 2005 United States Government as represented by the
3 // Administrator of the National Aeronautics and Space Administration
4 // (NASA). All Rights Reserved.
5 //
6 // This software is distributed under the NASA Open Source Agreement
7 // (NOSA), version 1.3. The NOSA has been approved by the Open Source
8 // Initiative. See the file NOSA-1.3-JPF at the top of the distribution
9 // directory tree for the complete NOSA document.
10 //
11 // THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY
12 // KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT
13 // LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO
14 // SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
15 // A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT
16 // THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT
17 // DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE.
18 //
19 package gov.nasa.jpf.jvm.bytecode;
20
21 import gov.nasa.jpf.jvm.KernelState;
22 import gov.nasa.jpf.jvm.SystemState;
23 import gov.nasa.jpf.jvm.ThreadInfo;
24
25 import org.apache.bcel.classfile.ConstantPool;
26
27
28 /**
29  * Determine if object is of given type
30  * ..., objectref => ..., result
31  */
32 public class INSTANCEOF extends Instruction {
33   private String JavaDoc type;
34
35   public void setPeer (org.apache.bcel.generic.Instruction i, ConstantPool cp) {
36     type = cp.constantToString(cp.getConstant(
37                                      ((org.apache.bcel.generic.INSTANCEOF) i).getIndex()))
38              .replace('.', '/');
39
40     if (!type.startsWith("[")) {
41       type = "L" + type + ";";
42     }
43   }
44
45   public Instruction execute (SystemState ss, KernelState ks, ThreadInfo th) {
46     int objref = th.pop();
47
48     if (objref == -1) {
49       th.push(0, false);
50     } else if (ks.da.get(objref).instanceOf(type)) {
51       th.push(1, false);
52     } else {
53       th.push(0, false);
54     }
55
56     return getNext(th);
57   }
58
59   public int getByteCode () {
60     return 0xC1;
61   }
62 }
63
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