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}