    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 *
    017 */
    018package org.apache.bcel.generic;
    019
    020import java.util.StringTokenizer;
    021
    022import org.apache.bcel.Const;
    023import org.apache.bcel.classfile.Constant;
    024import org.apache.bcel.classfile.ConstantCP;
    025import org.apache.bcel.classfile.ConstantPool;
    026
    027/**
    028 * Super class for the INVOKExxx family of instructions.
    029 *
    030 */
    031public abstract class InvokeInstruction extends FieldOrMethod implements ExceptionThrower,
    032        StackConsumer, StackProducer {
    033
    034    /**
    035     * Empty constructor needed for Instruction.readInstruction.
    036     * Not to be used otherwise.
    037     */
    038    InvokeInstruction() {
    039    }
    040
    041
    042    /**
    043     * @param index to constant pool
    044     */
    045    protected InvokeInstruction(final short opcode, final int index) {
    046        super(opcode, index);
    047    }
    048
    049
    050    /**
    051     * @return mnemonic for instruction with symbolic references resolved
    052     */
    053    @Override
    054    public String toString( final ConstantPool cp ) {
    055        final Constant c = cp.getConstant(super.getIndex());
    056        final StringTokenizer tok = new StringTokenizer(cp.constantToString(c));
    057
    058        final String opcodeName = Const.getOpcodeName(super.getOpcode());
    059
    060        final StringBuilder sb = new StringBuilder(opcodeName);
    061        if (tok.hasMoreTokens()) {
    062            sb.append(" ");
    063            sb.append(tok.nextToken().replace('.', '/'));
    064            if (tok.hasMoreTokens()) {
    065                sb.append(tok.nextToken());
    066            }
    067        }
    068
    069        return sb.toString();
    070    }
    071
    072
    073    /**
    074     * Also works for instructions whose stack effect depends on the
    075     * constant pool entry they reference.
    076     * @return Number of words consumed from stack by this instruction
    077     */
    078    @Override
    079    public int consumeStack( final ConstantPoolGen cpg ) {
    080        int sum;
    081        if ((super.getOpcode() == Const.INVOKESTATIC) || (super.getOpcode() == Const.INVOKEDYNAMIC)) {
    082            sum = 0;
    083        } else {
    084            sum = 1; // this reference
    085        }
    086
    087        final String signature = getSignature(cpg);
    088        sum += Type.getArgumentTypesSize(signature);
    089        return sum;
    090    }
    091
    092
    093    /**
    094     * Also works for instructions whose stack effect depends on the
    095     * constant pool entry they reference.
    096     * @return Number of words produced onto stack by this instruction
    097     */
    098    @Override
    099    public int produceStack( final ConstantPoolGen cpg ) {
    100        final String signature = getSignature(cpg);
    101        return Type.getReturnTypeSize(signature);
    102    }
    103
    104    /**
    105     * This overrides the deprecated version as we know here that the referenced class
    106     * may legally be an array.
    107     *
    108     * @return name of the referenced class/interface
    109     * @throws IllegalArgumentException if the referenced class is an array (this should not happen)
    110     */
    111    @Override
    112    public String getClassName( final ConstantPoolGen cpg ) {
    113        final ConstantPool cp = cpg.getConstantPool();
    114        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    115        final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    116        return className.replace('/', '.');
    117    }
    118
    119    /** @return return type of referenced method.
    120     */
    121    @Override
    122    public Type getType( final ConstantPoolGen cpg ) {
    123        return getReturnType(cpg);
    124    }
    125
    126
    127    /** @return name of referenced method.
    128     */
    129    public String getMethodName( final ConstantPoolGen cpg ) {
    130        return getName(cpg);
    131    }
    132
    133
    134    /** @return return type of referenced method.
    135     */
    136    public Type getReturnType( final ConstantPoolGen cpg ) {
    137        return Type.getReturnType(getSignature(cpg));
    138    }
    139
    140
    141    /** @return argument types of referenced method.
    142     */
    143    public Type[] getArgumentTypes( final ConstantPoolGen cpg ) {
    144        return Type.getArgumentTypes(getSignature(cpg));
    145    }
    146
    147}