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


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.JPFException;
22 import gov.nasa.jpf.jvm.KernelState;
23 import gov.nasa.jpf.jvm.SystemState;
24 import gov.nasa.jpf.jvm.ThreadInfo;
25 import gov.nasa.jpf.jvm.ClassInfo;
26 import gov.nasa.jpf.jvm.Types;
27
28 import org.apache.bcel.classfile.ConstantFloat;
29 import org.apache.bcel.classfile.ConstantInteger;
30 import org.apache.bcel.classfile.ConstantPool;
31 import org.apache.bcel.classfile.ConstantString;
32 import org.apache.bcel.generic.ConstantPoolGen;
33 import org.apache.bcel.generic.Type;
34
35
36 /**
37  * Push item from runtime constant pool
38  * ... => ..., value
39  */
40 public class LDC extends Instruction {
41   private String JavaDoc string;
42   private int value;
43   private boolean isString;
44
45   public void setPeer (org.apache.bcel.generic.Instruction i, ConstantPool cp) {
46     ConstantPoolGen cpg = ClassInfo.getConstantPoolGen(cp);
47     Type type = ((org.apache.bcel.generic.LDC) i).getType(cpg);
48
49     if (type == Type.STRING) {
50       isString = true;
51       string = cp.constantToString(cp.getConstant(
52                                          ((ConstantString) cp.getConstant(
53                                                 ((org.apache.bcel.generic.LDC) i).getIndex())).getStringIndex()));
54     } else if (type == Type.INT) {
55       isString = false;
56       string = null;
57       value = ((ConstantInteger) cp.getConstant(
58                      ((org.apache.bcel.generic.LDC) i).getIndex())).getBytes();
59     } else if (type == Type.FLOAT) {
60       isString = false;
61       string = null;
62       value = Types.floatToInt(
63                     ((ConstantFloat) cp.getConstant(
64                            ((org.apache.bcel.generic.LDC) i).getIndex())).getBytes());
65     } else {
66       throw new JPFException("invalid type of constant");
67     }
68   }
69
70   public Instruction execute (SystemState ss, KernelState ks, ThreadInfo th) {
71     if (isString) {
72       th.push(ks.da.newConstantString(string), true);
73     } else {
74       th.push(value, false);
75     }
76
77     return getNext(th);
78   }
79
80   public int getByteCode () {
81     return 0x12;
82   }
83 }
84
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