    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.SegmentConstantPool;
    023import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode;
    024import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry;
    025import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager;
    026
    027/**
    028 * This class implements the byte code form for those bytecodes which have class references (and only class references).
    029 */
    030public class ClassRefForm extends ReferenceForm {
    031
    032    protected boolean widened;
    033
    034    /**
    035     * Constructs a new instance with the specified opcode, name, operandType and rewrite.
    036     *
    037     * @param opcode  index corresponding to the opcode's value.
    038     * @param name    String printable name of the opcode.
    039     * @param rewrite Operand positions (which will later be rewritten in ByteCodes) are indicated by -1.
    040     */
    041    public ClassRefForm(final int opcode, final String name, final int[] rewrite) {
    042        super(opcode, name, rewrite);
    043    }
    044
    045    /**
    046     * Constructs a new instance with the specified opcode, name, operandType and rewrite.
    047     *
    048     * @param opcode  index corresponding to the opcode's value.
    049     * @param name    String printable name of the opcode.
    050     * @param rewrite Operand positions (which will later be rewritten in ByteCodes) are indicated by -1.
    051     * @param widened TODO.
    052     */
    053    public ClassRefForm(final int opcode, final String name, final int[] rewrite, final boolean widened) {
    054        this(opcode, name, rewrite);
    055        this.widened = widened;
    056    }
    057
    058    @Override
    059    protected int getOffset(final OperandManager operandManager) {
    060        return operandManager.nextClassRef();
    061    }
    062
    063    @Override
    064    protected int getPoolID() {
    065        return SegmentConstantPool.CP_CLASS;
    066    }
    067
    068    @Override
    069    protected void setNestedEntries(final ByteCode byteCode, final OperandManager operandManager, final int offset) throws Pack200Exception {
    070        // If the offset is not zero, proceed normally.
    071        if (offset != 0) {
    072            super.setNestedEntries(byteCode, operandManager, offset - 1);
    073            return;
    074        }
    075        // If the offset is 0, ClassRefForms refer to
    076        // the current class. Add that as the nested class.
    077        // (This is true for all bc_classref forms in
    078        // the spec except for multianewarray, which has
    079        // its own form.)
    080        final SegmentConstantPool globalPool = operandManager.globalConstantPool();
    081        // How do I get this class?
    082        final ClassFileEntry[] nested = { globalPool.getClassPoolEntry(operandManager.getCurrentClass()) };
    083        byteCode.setNested(nested);
    084        byteCode.setNestedPositions(new int[][] { { 0, 2 } });
    085    }
    086}