1 /*
2  * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
3  */
4 /*
5  * Licensed to the Apache Software Foundation (ASF) under one or more
6  * contributor license agreements.  See the NOTICE file distributed with
7  * this work for additional information regarding copyright ownership.
8  * The ASF licenses this file to You under the Apache License, Version 2.0
9  * (the "License"); you may not use this file except in compliance with
10  * the License.  You may obtain a copy of the License at
11  *
12  *      http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20 
21 package com.sun.org.apache.bcel.internal.generic;
22 
23 /**
24  * DCONST - Push 0.0 or 1.0, other values cause an exception
25  *
26  * <PRE>Stack: ... -&gt; ..., </PRE>
27  *
28  * @LastModified: Jan 2020
29  */
30 public class DCONST extends Instruction implements ConstantPushInstruction {
31 
32     private double value;
33 
34 
35     /**
36      * Empty constructor needed for Instruction.readInstruction.
37      * Not to be used otherwise.
38      */
DCONST()39     DCONST() {
40     }
41 
42 
DCONST(final double f)43     public DCONST(final double f) {
44         super(com.sun.org.apache.bcel.internal.Const.DCONST_0, (short) 1);
45         if (f == 0.0) {
46             super.setOpcode(com.sun.org.apache.bcel.internal.Const.DCONST_0);
47         } else if (f == 1.0) {
48             super.setOpcode(com.sun.org.apache.bcel.internal.Const.DCONST_1);
49         } else {
50             throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
51         }
52         value = f;
53     }
54 
55 
56     @Override
getValue()57     public Number getValue() {
58         return value;
59     }
60 
61 
62     /** @return Type.DOUBLE
63      */
64     @Override
getType( final ConstantPoolGen cp )65     public Type getType( final ConstantPoolGen cp ) {
66         return Type.DOUBLE;
67     }
68 
69 
70     /**
71      * Call corresponding visitor method(s). The order is:
72      * Call visitor methods of implemented interfaces first, then
73      * call methods according to the class hierarchy in descending order,
74      * i.e., the most specific visitXXX() call comes last.
75      *
76      * @param v Visitor object
77      */
78     @Override
accept( final Visitor v )79     public void accept( final Visitor v ) {
80         v.visitPushInstruction(this);
81         v.visitStackProducer(this);
82         v.visitTypedInstruction(this);
83         v.visitConstantPushInstruction(this);
84         v.visitDCONST(this);
85     }
86 }
87