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 * @see
036 * <a href="http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic">
037 * The invokedynamic instruction in The Java Virtual Machine Specification</a>
038 * @since 6.0
039 */
040public class INVOKEDYNAMIC extends InvokeInstruction {
041
042    /**
043     * Empty constructor needed for Instruction.readInstruction.
044     * Not to be used otherwise.
045     */
046    INVOKEDYNAMIC() {
047    }
048
049
050    public INVOKEDYNAMIC(final int index) {
051        super(Const.INVOKEDYNAMIC, index);
052    }
053
054
055    /**
056     * Dump instruction as byte code to stream out.
057     * @param out Output stream
058     */
059    @Override
060    public void dump( final DataOutputStream out ) throws IOException {
061        out.writeByte(super.getOpcode());
062        out.writeShort(super.getIndex());
063        out.writeByte(0);
064        out.writeByte(0);
065       }
066
067
068    /**
069     * Read needed data (i.e., index) from file.
070     */
071    @Override
072    protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
073        super.initFromFile(bytes, wide);
074        super.setLength(5);
075        bytes.readByte(); // Skip 0 byte
076        bytes.readByte(); // Skip 0 byte
077    }
078
079
080    /**
081     * @return mnemonic for instruction with symbolic references resolved
082     */
083    @Override
084    public String toString( final ConstantPool cp ) {
085        return super.toString(cp);
086    }
087
088
089    @Override
090    public Class<?>[] getExceptions() {
091        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION,
092            ExceptionConst.UNSATISFIED_LINK_ERROR,
093            ExceptionConst.ABSTRACT_METHOD_ERROR,
094            ExceptionConst.ILLEGAL_ACCESS_ERROR,
095            ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
096    }
097
098
099    /**
100     * Call corresponding visitor method(s). The order is:
101     * Call visitor methods of implemented interfaces first, then
102     * call methods according to the class hierarchy in descending order,
103     * i.e., the most specific visitXXX() call comes last.
104     *
105     * @param v Visitor object
106     */
107    @Override
108    public void accept( final Visitor v ) {
109        v.visitExceptionThrower(this);
110        v.visitTypedInstruction(this);
111        v.visitStackConsumer(this);
112        v.visitStackProducer(this);
113        v.visitLoadClass(this);
114        v.visitCPInstruction(this);
115        v.visitFieldOrMethod(this);
116        v.visitInvokeInstruction(this);
117        v.visitINVOKEDYNAMIC(this);
118    }
119
120    /**
121     * Override the parent method because our classname is held elsewhere.
122     */
123    @Override
124    public String getClassName( final ConstantPoolGen cpg ) {
125        final ConstantPool cp = cpg.getConstantPool();
126        final ConstantInvokeDynamic cid = (ConstantInvokeDynamic) cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic);
127        return ((ConstantNameAndType) cp.getConstant(cid.getNameAndTypeIndex())).getName(cp);
128    }
129
130
131    /**
132     * Since InvokeDynamic doesn't refer to a reference type, just return java.lang.Object,
133     * as that is the only type we can say for sure the reference will be.
134     *
135     * @param cpg
136     *            the ConstantPoolGen used to create the instruction
137     * @return an ObjectType for java.lang.Object
138     * @since 6.1
139     */
140    @Override
141    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
142        return new ObjectType(Object.class.getName());
143    }
144}