    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.commons.compress.harmony.unpack200.bytecode.forms;
    020
    021import org.apache.commons.compress.harmony.pack200.Pack200Exception;
    022import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode;
    023import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager;
    024
    025/**
    026 * Some bytecodes (such as (a)ldc, fldc and ildc) have single-byte references to the class pool. This class is the abstract superclass of those classes.
    027 */
    028public abstract class SingleByteReferenceForm extends ReferenceForm {
    029
    030    protected boolean widened;
    031
    032    /**
    033     * Constructs a new instance with the specified opcode, name, operandType and rewrite.
    034     *
    035     * @param opcode  index corresponding to the opcode's value.
    036     * @param name    String printable name of the opcode.
    037     * @param rewrite Operand positions (which will later be rewritten in ByteCodes) are indicated by -1.
    038     */
    039    public SingleByteReferenceForm(final int opcode, final String name, final int[] rewrite) {
    040        super(opcode, name, rewrite);
    041    }
    042
    043    @Override
    044    protected abstract int getOffset(OperandManager operandManager);
    045
    046    @Override
    047    protected abstract int getPoolID();
    048
    049    @Override
    050    public boolean nestedMustStartClassPool() {
    051        return !widened;
    052    }
    053
    054    @Override
    055    protected void setNestedEntries(final ByteCode byteCode, final OperandManager operandManager, final int offset) throws Pack200Exception {
    056        super.setNestedEntries(byteCode, operandManager, offset);
    057        if (widened) {
    058            byteCode.setNestedPositions(new int[][] { { 0, 2 } });
    059        } else {
    060            byteCode.setNestedPositions(new int[][] { { 0, 1 } });
    061        }
    062    }
    063}