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 java.io.DataOutputStream;
21 import java.io.IOException;
22 
23 import org.apache.bcel.Const;
24 import org.apache.bcel.ExceptionConst;
25 import org.apache.bcel.classfile.ConstantInvokeDynamic;
26 import org.apache.bcel.classfile.ConstantNameAndType;
27 import org.apache.bcel.classfile.ConstantPool;
28 import org.apache.bcel.util.ByteSequence;
29 
30 /**
31  * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class
32  * expects to be able to get the class of the method. Ignores the bootstrap
33  * mechanism entirely.
34  *
35  * @version $Id: InvokeInstruction.java 1152072 2011-07-29 01:54:05Z dbrosius $
36  * @see
37  * <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic">
38  * The invokedynamic instruction in The Java Virtual Machine Specification</a>
39  * @since 6.0
40  */
41 public class INVOKEDYNAMIC extends InvokeInstruction {
42 
43     /**
44      * Empty constructor needed for Instruction.readInstruction.
45      * Not to be used otherwise.
46      */
INVOKEDYNAMIC()47     INVOKEDYNAMIC() {
48     }
49 
50 
INVOKEDYNAMIC(final int index)51     public INVOKEDYNAMIC(final int index) {
52         super(Const.INVOKEDYNAMIC, index);
53     }
54 
55 
56     /**
57      * Dump instruction as byte code to stream out.
58      * @param out Output stream
59      */
60     @Override
dump( final DataOutputStream out )61     public void dump( final DataOutputStream out ) throws IOException {
62         out.writeByte(super.getOpcode());
63         out.writeShort(super.getIndex());
64         out.writeByte(0);
65         out.writeByte(0);
66        }
67 
68 
69     /**
70      * Read needed data (i.e., index) from file.
71      */
72     @Override
initFromFile( final ByteSequence bytes, final boolean wide )73     protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
74         super.initFromFile(bytes, wide);
75         super.setLength(5);
76         bytes.readByte(); // Skip 0 byte
77         bytes.readByte(); // Skip 0 byte
78     }
79 
80 
81     /**
82      * @return mnemonic for instruction with symbolic references resolved
83      */
84     @Override
toString( final ConstantPool cp )85     public String toString( final ConstantPool cp ) {
86         return super.toString(cp);
87     }
88 
89 
90     @Override
getExceptions()91     public Class<?>[] getExceptions() {
92         return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION,
93             ExceptionConst.UNSATISFIED_LINK_ERROR,
94             ExceptionConst.ABSTRACT_METHOD_ERROR,
95             ExceptionConst.ILLEGAL_ACCESS_ERROR,
96             ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
97     }
98 
99 
100     /**
101      * Call corresponding visitor method(s). The order is:
102      * Call visitor methods of implemented interfaces first, then
103      * call methods according to the class hierarchy in descending order,
104      * i.e., the most specific visitXXX() call comes last.
105      *
106      * @param v Visitor object
107      */
108     @Override
accept( final Visitor v )109     public void accept( final Visitor v ) {
110         v.visitExceptionThrower(this);
111         v.visitTypedInstruction(this);
112         v.visitStackConsumer(this);
113         v.visitStackProducer(this);
114         v.visitLoadClass(this);
115         v.visitCPInstruction(this);
116         v.visitFieldOrMethod(this);
117         v.visitInvokeInstruction(this);
118         v.visitINVOKEDYNAMIC(this);
119     }
120 
121     /**
122      * Override the parent method because our classname is held elsewhere.
123      */
124     @Override
getClassName( final ConstantPoolGen cpg )125     public String getClassName( final ConstantPoolGen cpg ) {
126         final ConstantPool cp = cpg.getConstantPool();
127         final ConstantInvokeDynamic cid = (ConstantInvokeDynamic) cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic);
128         return ((ConstantNameAndType) cp.getConstant(cid.getNameAndTypeIndex())).getName(cp);
129     }
130 
131 
132     /**
133      * Since InvokeDynamic doesn't refer to a reference type, just return java.lang.Object,
134      * as that is the only type we can say for sure the reference will be.
135      *
136      * @param cpg
137      *            the ConstantPoolGen used to create the instruction
138      * @return an ObjectType for java.lang.Object
139      * @since 6.1
140      */
141     @Override
getReferenceType(final ConstantPoolGen cpg)142     public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
143         return new ObjectType(Object.class.getName());
144     }
145 }
146