01: //
02: // Copyright (C) 2005 United States Government as represented by the
03: // Administrator of the National Aeronautics and Space Administration
04: // (NASA). All Rights Reserved.
05: //
06: // This software is distributed under the NASA Open Source Agreement
07: // (NOSA), version 1.3. The NOSA has been approved by the Open Source
08: // Initiative. See the file NOSA-1.3-JPF at the top of the distribution
09: // 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.ElementInfo;
23: import gov.nasa.jpf.jvm.KernelState;
24: import gov.nasa.jpf.jvm.SystemState;
25: import gov.nasa.jpf.jvm.ThreadInfo;
26:
27: import gov.nasa.jpf.jvm.FieldInfo;
28: import gov.nasa.jpf.jvm.DynamicArea;
29:
30: /**
31: * Fetch field from object
32: * ..., objectref => ..., value
33: */
34: public class GETFIELD extends InstanceFieldInstruction {
35: public Instruction execute(SystemState ss, KernelState ks,
36: ThreadInfo ti) {
37: int objRef = lastThis = ti.pop();
38: if (objRef == -1) {
39: return ti.createAndThrowException(
40: "java.lang.NullPointerException",
41: "referencing field '" + fname + "' on null object");
42: }
43:
44: FieldInfo fi = getFieldInfo();
45: ElementInfo ei = DynamicArea.getHeap().get(objRef);
46:
47: // We could encapsulate the push in ElementInfo, but not the GET, so
48: // we keep it at a similiar level
49: switch (fi.getStorageSize()) {
50: case 1:
51: ti.push(ei.getIntField(fi), fi.isReference());
52: break;
53: case 2:
54: ti.longPush(ei.getLongField(fi));
55: break;
56: default:
57: throw new JPFException("invalid field type");
58: }
59:
60: return getNext(ti);
61: }
62:
63: public int getByteCode() {
64: return 0xB4;
65: }
66:
67: public boolean isSchedulingRelevant(SystemState ss, KernelState ks,
68: ThreadInfo ti) {
69: // note that reachable doesn't really mean it's accessible, but
70: // we get the reachability for free during GC
71:
72: if (ti.usePorFieldBoundaries()) {
73: int objRef = ti.peek();
74: return isSchedulingRelevant(ks, ti, objRef);
75: }
76:
77: return false;
78: }
79:
80: }
|