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 java.util.Objects; 022 023import org.apache.commons.compress.harmony.pack200.Pack200Exception; 024import org.apache.commons.compress.harmony.unpack200.SegmentConstantPool; 025import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode; 026import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry; 027import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager; 028 029/** 030 * Abstract class of all ByteCodeForms which add a nested entry from the globalConstantPool. 031 */ 032public abstract class ReferenceForm extends ByteCodeForm { 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 ReferenceForm(final int opcode, final String name, final int[] rewrite) { 042 super(opcode, name, rewrite); 043 } 044 045 protected abstract int getOffset(OperandManager operandManager); 046 047 protected abstract int getPoolID(); 048 049 /* 050 * (non-Javadoc) 051 * 052 * @see org.apache.commons.compress.harmony.unpack200.bytecode.forms.ByteCodeForm#setByteCodeOperands(org.apache.commons. 053 * compress.harmony.unpack200.bytecode.ByteCode, org.apache.commons.compress.harmony.unpack200.bytecode.OperandTable, 054 * org.apache.commons.compress.harmony.unpack200.Segment) 055 */ 056 @Override 057 public void setByteCodeOperands(final ByteCode byteCode, final OperandManager operandManager, final int codeLength) throws Pack200Exception { 058 final int offset = getOffset(operandManager); 059 try { 060 setNestedEntries(byteCode, operandManager, offset); 061 } catch (final Pack200Exception ex) { 062 throw new Error("Got a pack200 exception. What to do?"); 063 } 064 } 065 066 /** 067 * Sets the nested entries. 068 * 069 * @param byteCode byte codes. 070 * @param operandManager Operand manager. 071 * @param offset offset. 072 * @throws Pack200Exception if support for a type is not supported or the offset not in the range [0, {@link Integer#MAX_VALUE}]. 073 */ 074 protected void setNestedEntries(final ByteCode byteCode, final OperandManager operandManager, final int offset) throws Pack200Exception { 075 final SegmentConstantPool globalPool = operandManager.globalConstantPool(); 076 final ClassFileEntry[] nested = { globalPool.getConstantPoolEntry(getPoolID(), offset) }; 077 Objects.requireNonNull(nested[0], "Null nested entries are not allowed"); 078 byteCode.setNested(nested); 079 byteCode.setNestedPositions(new int[][] { { 0, 2 } }); 080 } 081}