/*

 * Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.bcel.internal.generic;

import java.io.DataOutputStream;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

import com.sun.org.apache.bcel.internal.ExceptionConst;

import com.sun.org.apache.bcel.internal.classfile.ConstantInvokeDynamic;

import com.sun.org.apache.bcel.internal.classfile.ConstantNameAndType;

import com.sun.org.apache.bcel.internal.classfile.ConstantPool;

import com.sun.org.apache.bcel.internal.util.ByteSequence;

/**

 * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class

 * expects to be able to get the class of the method. Ignores the bootstrap

 * mechanism entirely.

 *

 * @see

 * <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic">

 * The invokedynamic instruction in The Java Virtual Machine Specification</a>

 * @since 6.0

 * @LastModified: May 2021

 */

public class INVOKEDYNAMIC extends InvokeInstruction {

    /**

     * Empty constructor needed for Instruction.readInstruction.

     * Not to be used otherwise.

     */

    INVOKEDYNAMIC() {

    }

    public INVOKEDYNAMIC(final int index) {

        super(Const.INVOKEDYNAMIC, index);

    }

    /**

     * Dump instruction as byte code to stream out.

     * @param out Output stream

     */

    @Override

    public void dump( final DataOutputStream out ) throws IOException {

        out.writeByte(super.getOpcode());

        out.writeShort(super.getIndex());

        out.writeByte(0);

        out.writeByte(0);

       }

    /**

     * Read needed data (i.e., index) from file.

     */

    @Override

    protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {

        super.initFromFile(bytes, wide);

        super.setLength(5);

        bytes.readByte(); // Skip 0 byte

        bytes.readByte(); // Skip 0 byte

    }

    /**

     * @return mnemonic for instruction with symbolic references resolved

     */

    @Override

    public String toString( final ConstantPool cp ) {

        return super.toString(cp);

    }

    @Override

    public Class<?>[] getExceptions() {

        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION,

            ExceptionConst.UNSATISFIED_LINK_ERROR,

            ExceptionConst.ABSTRACT_METHOD_ERROR,

            ExceptionConst.ILLEGAL_ACCESS_ERROR,

            ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);

    }

    /**

     * Call corresponding visitor method(s). The order is:

     * Call visitor methods of implemented interfaces first, then

     * call methods according to the class hierarchy in descending order,

     * i.e., the most specific visitXXX() call comes last.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitExceptionThrower(this);

        v.visitTypedInstruction(this);

        v.visitStackConsumer(this);

        v.visitStackProducer(this);

        v.visitLoadClass(this);

        v.visitCPInstruction(this);

        v.visitFieldOrMethod(this);

        v.visitInvokeInstruction(this);

        v.visitINVOKEDYNAMIC(this);

    }

    /**

     * Override the parent method because our classname is held elsewhere.

     *

     * @param cpg the ConstantPool generator

     * @deprecated in FieldOrMethod

     *

     * @return name of the referenced class/interface

     */

    @Override

    @Deprecated

    public String getClassName( final ConstantPoolGen cpg ) {

        final ConstantPool cp = cpg.getConstantPool();

        final ConstantInvokeDynamic cid = (ConstantInvokeDynamic) cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic);

        return ((ConstantNameAndType) cp.getConstant(cid.getNameAndTypeIndex())).getName(cp);

    }

    /**

     * Since InvokeDynamic doesn't refer to a reference type, just return java.lang.Object,

     * as that is the only type we can say for sure the reference will be.

     *

     * @param cpg

     *            the ConstantPoolGen used to create the instruction

     * @return an ObjectType for java.lang.Object

     * @since 6.1

     */

    @Override

    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {

        return new ObjectType(Object.class.getName());

    }

}