2 * Copyright (C) 2014, United States Government, as represented by the
3 * Administrator of the National Aeronautics and Space Administration.
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
10 * http://www.apache.org/licenses/LICENSE-2.0.
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.
18 package gov.nasa.jpf.jvm.bytecode;
20 import gov.nasa.jpf.vm.ElementInfo;
21 import gov.nasa.jpf.vm.Instruction;
22 import gov.nasa.jpf.vm.MJIEnv;
23 import gov.nasa.jpf.vm.StackFrame;
24 import gov.nasa.jpf.vm.ThreadInfo;
29 * ..., arrayref => ..., length
31 public class ARRAYLENGTH extends Instruction implements JVMInstruction {
33 protected int arrayRef;
36 * only makes sense from an executeInstruction() or instructionExecuted() listener,
37 * it is undefined outside of insn exec notifications
39 public int getArrayRef (ThreadInfo ti){
41 return peekArrayRef(ti);
47 public ElementInfo peekArrayElementInfo (ThreadInfo ti){
48 int aref = getArrayRef(ti);
49 return ti.getElementInfo(aref);
53 public Instruction execute (ThreadInfo ti) {
54 StackFrame frame = ti.getModifiableTopFrame();
56 arrayRef = frame.pop();
58 if (arrayRef == MJIEnv.NULL){
59 return ti.createAndThrowException("java.lang.NullPointerException",
60 "array length of null object");
63 ElementInfo ei = ti.getElementInfo(arrayRef);
64 frame.push(ei.arrayLength(), false);
70 public int getByteCode () {
75 public void accept(JVMInstructionVisitor insVisitor) {
76 insVisitor.visit(this);
79 protected int peekArrayRef (ThreadInfo ti) {
80 return ti.getTopFrame().peek();