001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.generic;
019
020import java.io.DataOutputStream;
021import java.io.IOException;
022
023import org.apache.bcel.Const;
024import org.apache.bcel.ExceptionConst;
025import org.apache.bcel.classfile.ConstantInvokeDynamic;
026import org.apache.bcel.classfile.ConstantNameAndType;
027import org.apache.bcel.classfile.ConstantPool;
028import org.apache.bcel.util.ByteSequence;
029
030/**
031 * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class
032 * expects to be able to get the class of the method. Ignores the bootstrap
033 * mechanism entirely.
034 *
035 * @version $Id: InvokeInstruction.java 1152072 2011-07-29 01:54:05Z dbrosius $
036 * @see
037 * <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic">
038 * The invokedynamic instruction in The Java Virtual Machine Specification</a>
039 * @since 6.0
040 */
041public class INVOKEDYNAMIC extends InvokeInstruction {
042
043    /**
044     * Empty constructor needed for Instruction.readInstruction.
045     * Not to be used otherwise.
046     */
047    INVOKEDYNAMIC() {
048    }
049
050
051    public INVOKEDYNAMIC(final int index) {
052        super(Const.INVOKEDYNAMIC, index);
053    }
054
055
056    /**
057     * Dump instruction as byte code to stream out.
058     * @param out Output stream
059     */
060    @Override
061    public void dump( final DataOutputStream out ) throws IOException {
062        out.writeByte(super.getOpcode());
063        out.writeShort(super.getIndex());
064        out.writeByte(0);
065        out.writeByte(0);
066       }
067
068
069    /**
070     * Read needed data (i.e., index) from file.
071     */
072    @Override
073    protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
074        super.initFromFile(bytes, wide);
075        super.setLength(5);
076        bytes.readByte(); // Skip 0 byte
077        bytes.readByte(); // Skip 0 byte
078    }
079
080
081    /**
082     * @return mnemonic for instruction with symbolic references resolved
083     */
084    @Override
085    public String toString( final ConstantPool cp ) {
086        return super.toString(cp);
087    }
088
089
090    @Override
091    public Class<?>[] getExceptions() {
092        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION,
093            ExceptionConst.UNSATISFIED_LINK_ERROR,
094            ExceptionConst.ABSTRACT_METHOD_ERROR,
095            ExceptionConst.ILLEGAL_ACCESS_ERROR,
096            ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
097    }
098
099
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
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
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
142    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
143        return new ObjectType(Object.class.getName());
144    }
145}