Mercurial > hg > Members > kono > jpf-core

comparison src/main/gov/nasa/jpf/jvm/bytecode/LDC.java @ 0:61d41facf527

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
initial v8 import (history reset)
author Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
date Fri, 23 Jan 2015 10:14:01 -0800
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:61d41facf527
1 /*
2 * Copyright (C) 2014, United States Government, as represented by the
3 * Administrator of the National Aeronautics and Space Administration.
4 * All rights reserved.
5 *
6 * The Java Pathfinder core (jpf-core) platform is licensed under the
7 * Apache License, Version 2.0 (the "License"); you may not use this file except
8 * in compliance with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0.
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package gov.nasa.jpf.jvm.bytecode;
19
20 import gov.nasa.jpf.vm.Instruction;
21 import gov.nasa.jpf.vm.ClassInfo;
22 import gov.nasa.jpf.vm.ElementInfo;
23 import gov.nasa.jpf.vm.LoadOnJPFRequired;
24 import gov.nasa.jpf.vm.StackFrame;
25 import gov.nasa.jpf.vm.ThreadInfo;
26 import gov.nasa.jpf.vm.Types;
27
28
29 /**
30 * Push item from runtime constant pool
31 * ... => ..., value
32 */
33 public class LDC extends Instruction implements JVMInstruction {
34
35 public enum Type {STRING, CLASS, INT, FLOAT};
36
37 Type type;
38
39 protected String string; // the string value if Type.STRING, classname if Type.CLASS
40 protected int value;
41
42 public LDC() {}
43
44 public LDC (String s, boolean isClass){
45 if (isClass){
46 string = Types.getClassNameFromTypeName(s);
47 type = Type.CLASS;
48 } else {
49 string = s;
50 type = Type.STRING;
51 }
52 }
53
54 public LDC (int v){
55 value = v;
56 type = Type.INT;
57 }
58
59 public LDC (float f){
60 value = Float.floatToIntBits(f);
61 type = Type.FLOAT;
62 }
63
64
65 @Override
66 public Instruction execute (ThreadInfo ti) {
67 StackFrame frame = ti.getModifiableTopFrame();
68
69 switch (type){
70 case STRING:
71 // too bad we can't cache it, since location might change between different paths
72 ElementInfo eiValue = ti.getHeap().newInternString(string, ti);
73 value = eiValue.getObjectRef();
74 frame.pushRef(value);
75 break;
76
77 case INT:
78 case FLOAT:
79 frame.push(value);
80 break;
81
82 case CLASS:
83 ClassInfo ci;
84 // resolve the referenced class
85 try {
86 ci = ti.resolveReferencedClass(string);
87 } catch(LoadOnJPFRequired lre) {
88 return frame.getPC();
89 }
90
91 // LDC doesn't cause a <clinit> - we only register all required classes
92 // to make sure we have class objects. <clinit>s are called prior to
93 // GET/PUT or INVOKE
94 if (!ci.isRegistered()) {
95 ci.registerClass(ti);
96 }
97
98 frame.pushRef( ci.getClassObjectRef());
99
100 break;
101 }
102
103 return getNext(ti);
104 }
105
106 @Override
107 public int getLength() {
108 return 2; // opcode, index
109 }
110
111 @Override
112 public int getByteCode () {
113 return 0x12;
114 }
115
116 public int getValue() {
117 return value;
118 }
119
120 public Type getType() {
121 return type;
122 }
123
124 public boolean isString() {
125 return (type == Type.STRING);
126 }
127
128 public float getFloatValue(){
129 if(type!=Type.FLOAT){
130 throw new IllegalStateException();
131 }
132
133 return Float.intBitsToFloat(value);
134 }
135
136 public String getStringValue() { // if it is a String (not acquired from the class const pool)
137 if (type == Type.STRING) {
138 return string;
139 } else {
140 return null;
141 }
142 }
143
144 public String getClassValue() { // if it is the name of a Class (acquired from the class const pool)
145 if (type == Type.CLASS) {
146 return string;
147 } else {
148 return null;
149 }
150 }
151
152
153 @Override
154 public void accept(JVMInstructionVisitor insVisitor) {
155 insVisitor.visit(this);
156 }
157 }