    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 */
    017package org.apache.bcel.generic;
    018
    019import java.util.StringTokenizer;
    020
    021import org.apache.bcel.Const;
    022import org.apache.bcel.classfile.Constant;
    023import org.apache.bcel.classfile.ConstantCP;
    024import org.apache.bcel.classfile.ConstantPool;
    025import org.apache.bcel.classfile.Utility;
    026
    027/**
    028 * Super class for the INVOKExxx family of instructions.
    029 */
    030public abstract class InvokeInstruction extends FieldOrMethod implements ExceptionThrower, StackConsumer, StackProducer {
    031
    032    /**
    033     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    034     */
    035    InvokeInstruction() {
    036    }
    037
    038    /**
    039     * @param index to constant pool
    040     */
    041    protected InvokeInstruction(final short opcode, final int index) {
    042        super(opcode, index);
    043    }
    044
    045    /**
    046     * Also works for instructions whose stack effect depends on the constant pool entry they reference.
    047     *
    048     * @return Number of words consumed from stack by this instruction
    049     */
    050    @Override
    051    public int consumeStack(final ConstantPoolGen cpg) {
    052        int sum;
    053        if (super.getOpcode() == Const.INVOKESTATIC || super.getOpcode() == Const.INVOKEDYNAMIC) {
    054            sum = 0;
    055        } else {
    056            sum = 1; // this reference
    057        }
    058
    059        final String signature = getSignature(cpg);
    060        sum += Type.getArgumentTypesSize(signature);
    061        return sum;
    062    }
    063
    064    /**
    065     * @return argument types of referenced method.
    066     */
    067    public Type[] getArgumentTypes(final ConstantPoolGen cpg) {
    068        return Type.getArgumentTypes(getSignature(cpg));
    069    }
    070
    071    /**
    072     * This overrides the deprecated version as we know here that the referenced class may legally be an array.
    073     *
    074     * @return name of the referenced class/interface
    075     * @throws IllegalArgumentException if the referenced class is an array (this should not happen)
    076     */
    077    @Override
    078    public String getClassName(final ConstantPoolGen cpg) {
    079        final ConstantPool cp = cpg.getConstantPool();
    080        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    081        final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    082        return Utility.pathToPackage(className);
    083    }
    084
    085    /**
    086     * @return name of referenced method.
    087     */
    088    public String getMethodName(final ConstantPoolGen cpg) {
    089        return getName(cpg);
    090    }
    091
    092    /**
    093     * @return return type of referenced method.
    094     */
    095    public Type getReturnType(final ConstantPoolGen cpg) {
    096        return Type.getReturnType(getSignature(cpg));
    097    }
    098
    099    /**
    100     * @return return type of referenced method.
    101     */
    102    @Override
    103    public Type getType(final ConstantPoolGen cpg) {
    104        return getReturnType(cpg);
    105    }
    106
    107    /**
    108     * Also works for instructions whose stack effect depends on the constant pool entry they reference.
    109     *
    110     * @return Number of words produced onto stack by this instruction
    111     */
    112    @Override
    113    public int produceStack(final ConstantPoolGen cpg) {
    114        final String signature = getSignature(cpg);
    115        return Type.getReturnTypeSize(signature);
    116    }
    117
    118    /**
    119     * @return mnemonic for instruction with symbolic references resolved
    120     */
    121    @Override
    122    public String toString(final ConstantPool cp) {
    123        final Constant c = cp.getConstant(super.getIndex());
    124        final StringTokenizer tok = new StringTokenizer(cp.constantToString(c));
    125
    126        final String opcodeName = Const.getOpcodeName(super.getOpcode());
    127
    128        final StringBuilder sb = new StringBuilder(opcodeName);
    129        if (tok.hasMoreTokens()) {
    130            sb.append(" ");
    131            sb.append(Utility.packageToPath(tok.nextToken()));
    132            if (tok.hasMoreTokens()) {
    133                sb.append(tok.nextToken());
    134            }
    135        }
    136
    137        return sb.toString();
    138    }
    139
    140}