    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 org.apache.bcel.Const;
    022import org.apache.bcel.classfile.ConstantCP;
    023import org.apache.bcel.classfile.ConstantNameAndType;
    024import org.apache.bcel.classfile.ConstantPool;
    025import org.apache.bcel.classfile.ConstantUtf8;
    026import org.apache.bcel.classfile.Utility;
    027
    028/**
    029 * Super class for InvokeInstruction and FieldInstruction, since they have some methods in common!
    030 */
    031public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
    032
    033    /**
    034     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    035     */
    036    FieldOrMethod() {
    037        // no init
    038    }
    039
    040    /**
    041     * @param index to constant pool
    042     */
    043    protected FieldOrMethod(final short opcode, final int index) {
    044        super(opcode, index);
    045    }
    046
    047    /**
    048     * @return name of the referenced class/interface
    049     * @deprecated If the instruction references an array class, this method will return "java.lang.Object". For code
    050     *             generated by Java 1.5, this answer is sometimes wrong (for example, if the "clone()" method is called on an
    051     *             array). A better idea is to use the {@link #getReferenceType(ConstantPoolGen)} method, which correctly
    052     *             distinguishes between class types and array types.
    053     */
    054    @Deprecated
    055    public String getClassName(final ConstantPoolGen cpg) {
    056        final ConstantPool cp = cpg.getConstantPool();
    057        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    058        final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    059        if (className.startsWith("[")) {
    060            // Turn array classes into java.lang.Object.
    061            return "java.lang.Object";
    062        }
    063        return Utility.pathToPackage(className);
    064    }
    065
    066    /**
    067     * @return type of the referenced class/interface
    068     * @deprecated If the instruction references an array class, the ObjectType returned will be invalid. Use
    069     *             getReferenceType() instead.
    070     */
    071    @Deprecated
    072    public ObjectType getClassType(final ConstantPoolGen cpg) {
    073        return ObjectType.getInstance(getClassName(cpg));
    074    }
    075
    076    /**
    077     * Gets the ObjectType of the method return or field.
    078     *
    079     * @return type of the referenced class/interface
    080     * @throws ClassGenException when the field is (or method returns) an array,
    081     */
    082    @Override
    083    public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
    084        final ReferenceType rt = getReferenceType(cpg);
    085        if (rt instanceof ObjectType) {
    086            return (ObjectType) rt;
    087        }
    088        if (rt instanceof ArrayType) {
    089            return Type.OBJECT;
    090        }
    091        throw new ClassGenException(rt.getClass().getCanonicalName() + " " + rt.getSignature() + " does not represent an ObjectType");
    092    }
    093
    094    /**
    095     * @return name of referenced method/field.
    096     */
    097    public String getName(final ConstantPoolGen cpg) {
    098        final ConstantPool cp = cpg.getConstantPool();
    099        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    100        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
    101        return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
    102    }
    103
    104    /**
    105     * Gets the reference type representing the class, interface, or array class referenced by the instruction.
    106     *
    107     * @param cpg the ConstantPoolGen used to create the instruction
    108     * @return an ObjectType (if the referenced class type is a class or interface), or an ArrayType (if the referenced
    109     *         class type is an array class)
    110     */
    111    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
    112        final ConstantPool cp = cpg.getConstantPool();
    113        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    114        String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    115        if (className.startsWith("[")) {
    116            return (ArrayType) Type.getType(className);
    117        }
    118        className = Utility.pathToPackage(className);
    119        return ObjectType.getInstance(className);
    120    }
    121
    122    /**
    123     * @return signature of referenced method/field.
    124     */
    125    public String getSignature(final ConstantPoolGen cpg) {
    126        final ConstantPool cp = cpg.getConstantPool();
    127        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    128        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
    129        return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
    130    }
    131}