Mercurial > hg > Members > kono > jpf-core
view src/main/gov/nasa/jpf/jvm/bytecode/ARRAYLENGTH.java @ 0:61d41facf527
initial v8 import (history reset)
author | Peter Mehlitz <Peter.C.Mehlitz@nasa.gov> |
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date | Fri, 23 Jan 2015 10:14:01 -0800 |
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/* * Copyright (C) 2014, United States Government, as represented by the * Administrator of the National Aeronautics and Space Administration. * All rights reserved. * * The Java Pathfinder core (jpf-core) platform is licensed under the * Apache License, Version 2.0 (the "License"); you may not use this file except * in compliance with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0. * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package gov.nasa.jpf.jvm.bytecode; import gov.nasa.jpf.vm.ElementInfo; import gov.nasa.jpf.vm.Instruction; import gov.nasa.jpf.vm.MJIEnv; import gov.nasa.jpf.vm.StackFrame; import gov.nasa.jpf.vm.ThreadInfo; /** * Get length of array * ..., arrayref => ..., length */ public class ARRAYLENGTH extends Instruction implements JVMInstruction { protected int arrayRef; /** * only makes sense from an executeInstruction() or instructionExecuted() listener, * it is undefined outside of insn exec notifications */ public int getArrayRef (ThreadInfo ti){ if (ti.isPreExec()){ return peekArrayRef(ti); } else { return arrayRef; } } public ElementInfo peekArrayElementInfo (ThreadInfo ti){ int aref = getArrayRef(ti); return ti.getElementInfo(aref); } @Override public Instruction execute (ThreadInfo ti) { StackFrame frame = ti.getModifiableTopFrame(); arrayRef = frame.pop(); if (arrayRef == MJIEnv.NULL){ return ti.createAndThrowException("java.lang.NullPointerException", "array length of null object"); } ElementInfo ei = ti.getElementInfo(arrayRef); frame.push(ei.arrayLength(), false); return getNext(ti); } @Override public int getByteCode () { return 0xBE; } @Override public void accept(JVMInstructionVisitor insVisitor) { insVisitor.visit(this); } protected int peekArrayRef (ThreadInfo ti) { return ti.getTopFrame().peek(); } }