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 expects to be able to get the class
032 * of the method. Ignores the bootstrap mechanism entirely.
033 *
034 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic"> The
035 *      invokedynamic instruction in The Java Virtual Machine Specification</a>
036 * @since 6.0
037 */
038public class INVOKEDYNAMIC extends InvokeInstruction {
039
040    /**
041     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
042     */
043    INVOKEDYNAMIC() {
044    }
045
046    public INVOKEDYNAMIC(final int index) {
047        super(Const.INVOKEDYNAMIC, index);
048    }
049
050    /**
051     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
052     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
053     *
054     * @param v Visitor object
055     */
056    @Override
057    public void accept(final Visitor v) {
058        v.visitExceptionThrower(this);
059        v.visitTypedInstruction(this);
060        v.visitStackConsumer(this);
061        v.visitStackProducer(this);
062        v.visitLoadClass(this);
063        v.visitCPInstruction(this);
064        v.visitFieldOrMethod(this);
065        v.visitInvokeInstruction(this);
066        v.visitINVOKEDYNAMIC(this);
067    }
068
069    /**
070     * Dump instruction as byte code to stream out.
071     *
072     * @param out Output stream
073     */
074    @Override
075    public void dump(final DataOutputStream out) throws IOException {
076        out.writeByte(super.getOpcode());
077        out.writeShort(super.getIndex());
078        out.writeByte(0);
079        out.writeByte(0);
080    }
081
082    /**
083     * Override the parent method because our classname is held elsewhere.
084     *
085     * Note: Contrary to this method's name it does not return the classname of the invoke target; rather it returns the
086     * name of the method that will be used to invoke the Lambda method generated by this invoke dynamic instruction.
087     */
088    @Override
089    public String getClassName(final ConstantPoolGen cpg) {
090        final ConstantPool cp = cpg.getConstantPool();
091        final ConstantInvokeDynamic cid = cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic, ConstantInvokeDynamic.class);
092        return cp.getConstant(cid.getNameAndTypeIndex(), ConstantNameAndType.class).getName(cp);
093    }
094
095    @Override
096    public Class<?>[] getExceptions() {
097        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION, ExceptionConst.UNSATISFIED_LINK_ERROR,
098            ExceptionConst.ABSTRACT_METHOD_ERROR, ExceptionConst.ILLEGAL_ACCESS_ERROR, ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
099    }
100
101    /**
102     * Since InvokeDynamic doesn't refer to a reference type, just return java.lang.Object, as that is the only type we can
103     * say for sure the reference will be.
104     *
105     * @param cpg the ConstantPoolGen used to create the instruction
106     * @return an ObjectType for java.lang.Object
107     * @since 6.1
108     */
109    @Override
110    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
111        return new ObjectType(Object.class.getName());
112    }
113
114    /**
115     * Read needed data (i.e., index) from file.
116     */
117    @Override
118    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
119        super.initFromFile(bytes, wide);
120        super.setLength(5);
121        bytes.readByte(); // Skip 0 byte
122        bytes.readByte(); // Skip 0 byte
123    }
124
125}