1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 package org.apache.bcel.generic; 19 20 import org.apache.bcel.Const; 21 import org.apache.bcel.ExceptionConst; 22 23 /** 24 * GETFIELD - Fetch field from object 25 * <PRE>Stack: ..., objectref -> ..., value</PRE> 26 * OR 27 * <PRE>Stack: ..., objectref -> ..., value.word1, value.word2</PRE> 28 * 29 * @version $Id$ 30 */ 31 public class GETFIELD extends FieldInstruction implements ExceptionThrower, StackConsumer, 32 StackProducer { 33 34 /** 35 * Empty constructor needed for Instruction.readInstruction. 36 * Not to be used otherwise. 37 */ GETFIELD()38 GETFIELD() { 39 } 40 41 GETFIELD(final int index)42 public GETFIELD(final int index) { 43 super(Const.GETFIELD, index); 44 } 45 46 47 @Override produceStack( final ConstantPoolGen cpg )48 public int produceStack( final ConstantPoolGen cpg ) { 49 return getFieldSize(cpg); 50 } 51 52 53 @Override getExceptions()54 public Class<?>[] getExceptions() { 55 return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_FIELD_AND_METHOD_RESOLUTION, 56 ExceptionConst.NULL_POINTER_EXCEPTION, 57 ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR); 58 } 59 60 61 /** 62 * Call corresponding visitor method(s). The order is: 63 * Call visitor methods of implemented interfaces first, then 64 * call methods according to the class hierarchy in descending order, 65 * i.e., the most specific visitXXX() call comes last. 66 * 67 * @param v Visitor object 68 */ 69 @Override accept( final Visitor v )70 public void accept( final Visitor v ) { 71 v.visitExceptionThrower(this); 72 v.visitStackConsumer(this); 73 v.visitStackProducer(this); 74 v.visitTypedInstruction(this); 75 v.visitLoadClass(this); 76 v.visitCPInstruction(this); 77 v.visitFieldOrMethod(this); 78 v.visitFieldInstruction(this); 79 v.visitGETFIELD(this); 80 } 81 } 82