001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.generic;
020
021import java.io.DataOutputStream;
022import java.io.IOException;
023
024import org.apache.bcel.Const;
025import org.apache.bcel.ExceptionConst;
026import org.apache.bcel.classfile.ConstantInvokeDynamic;
027import org.apache.bcel.classfile.ConstantNameAndType;
028import org.apache.bcel.classfile.ConstantPool;
029import org.apache.bcel.util.ByteSequence;
030
031/**
032 * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class expects to be able to get the class
033 * of the method. Ignores the bootstrap mechanism entirely.
034 *
035 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic"> The
036 *      invokedynamic instruction in The Java Virtual Machine Specification</a>
037 * @since 6.0
038 */
039public class INVOKEDYNAMIC extends InvokeInstruction {
040
041    /**
042     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
043     */
044    INVOKEDYNAMIC() {
045    }
046
047    public INVOKEDYNAMIC(final int index) {
048        super(Const.INVOKEDYNAMIC, index);
049    }
050
051    /**
052     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
053     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
054     *
055     * @param v Visitor object
056     */
057    @Override
058    public void accept(final Visitor v) {
059        v.visitExceptionThrower(this);
060        v.visitTypedInstruction(this);
061        v.visitStackConsumer(this);
062        v.visitStackProducer(this);
063        v.visitLoadClass(this);
064        v.visitCPInstruction(this);
065        v.visitFieldOrMethod(this);
066        v.visitInvokeInstruction(this);
067        v.visitINVOKEDYNAMIC(this);
068    }
069
070    /**
071     * Dump instruction as byte code to stream out.
072     *
073     * @param out Output stream
074     */
075    @Override
076    public void dump(final DataOutputStream out) throws IOException {
077        out.writeByte(super.getOpcode());
078        out.writeShort(super.getIndex());
079        out.writeByte(0);
080        out.writeByte(0);
081    }
082
083    /**
084     * Override the parent method because our class name is held elsewhere.
085     *
086     * Note: Contrary to this method's name it does not return the class name of the invoke target; rather it returns the
087     * name of the method that will be used to invoke the Lambda method generated by this invoke dynamic instruction.
088     */
089    @Override
090    public String getClassName(final ConstantPoolGen cpg) {
091        final ConstantPool cp = cpg.getConstantPool();
092        final ConstantInvokeDynamic cid = cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic, ConstantInvokeDynamic.class);
093        return cp.getConstant(cid.getNameAndTypeIndex(), ConstantNameAndType.class).getName(cp);
094    }
095
096    @Override
097    public Class<?>[] getExceptions() {
098        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION, ExceptionConst.UNSATISFIED_LINK_ERROR,
099            ExceptionConst.ABSTRACT_METHOD_ERROR, ExceptionConst.ILLEGAL_ACCESS_ERROR, ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
100    }
101
102    /**
103     * Since InvokeDynamic doesn't refer to a reference type, just return {@link Object}, as that is the only type we can
104     * say for sure the reference will be.
105     *
106     * @param cpg the ConstantPoolGen used to create the instruction
107     * @return an ObjectType for {@link Object}
108     * @since 6.1
109     */
110    @Override
111    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
112        return new ObjectType(Object.class.getName());
113    }
114
115    /**
116     * Reads needed data (i.e., index) from file.
117     */
118    @Override
119    protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
120        super.initFromFile(bytes, wide);
121        super.setLength(5);
122        bytes.readByte(); // Skip 0 byte
123        bytes.readByte(); // Skip 0 byte
124    }
125
126}