/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

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

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

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.classfile.ConstantUtf8;

/**

 * Super class for InvokeInstruction and FieldInstruction, since they have

 * some methods in common!

 *

 */

public abstract class FieldOrMethod extends CPInstruction implements LoadClass {

    /**

     * Empty constructor needed for Instruction.readInstruction.

     * Not to be used otherwise.

     */

    FieldOrMethod() {

        // no init

    }

    /**

     * @param index to constant pool

     */

    protected FieldOrMethod(final short opcode, final int index) {

        super(opcode, index);

    }

    /** @return signature of referenced method/field.

     */

    public String getSignature(final ConstantPoolGen cpg) {

        final ConstantPool cp = cpg.getConstantPool();

        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());

        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());

        return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();

    }

    /** @return name of referenced method/field.

     */

    public String getName(final ConstantPoolGen cpg) {

        final ConstantPool cp = cpg.getConstantPool();

        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());

        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());

        return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();

    }

    /**

     * @return name of the referenced class/interface

     * @deprecated If the instruction references an array class,

     *    this method will return "java.lang.Object".

     *    For code generated by Java 1.5, this answer is

     *    sometimes wrong (e.g., if the "clone()" method is

     *    called on an array).  A better idea is to use

     *    the {@link #getReferenceType(ConstantPoolGen)} method, which correctly distinguishes

     *    between class types and array types.

     *

     */

    @Deprecated

    public String getClassName(final ConstantPoolGen cpg) {

        final ConstantPool cp = cpg.getConstantPool();

        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());

        final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);

        if (className.startsWith("[")) {

            // Turn array classes into java.lang.Object.

            return "java.lang.Object";

        }

        return className.replace('/', '.');

    }

    /** @return type of the referenced class/interface

     * @deprecated If the instruction references an array class,

     *    the ObjectType returned will be invalid.  Use

     *    getReferenceType() instead.

     */

    @Deprecated

    public ObjectType getClassType(final ConstantPoolGen cpg) {

        return ObjectType.getInstance(getClassName(cpg));

    }

    /**

     * Gets the reference type representing the class, interface,

     * or array class referenced by the instruction.

     * @param cpg the ConstantPoolGen used to create the instruction

     * @return an ObjectType (if the referenced class type is a class

     *   or interface), or an ArrayType (if the referenced class

     *   type is an array class)

     */

    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {

        final ConstantPool cp = cpg.getConstantPool();

        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());

        String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);

        if (className.startsWith("[")) {

            return (ArrayType) Type.getType(className);

        }

        className = className.replace('/', '.');

        return ObjectType.getInstance(className);

    }

    /**

     * Gets the ObjectType of the method return or field.

     *

     * @return type of the referenced class/interface

     * @throws ClassGenException when the field is (or method returns) an array,

     */

    @Override

    public ObjectType getLoadClassType(final ConstantPoolGen cpg) {

        final ReferenceType rt = getReferenceType(cpg);

        if (rt instanceof ObjectType) {

            return (ObjectType) rt;

        }

        throw new ClassGenException(rt.getClass().getCanonicalName() + " " +

                rt.getSignature() + " does not represent an ObjectType");

    }

}