1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.commons.compress.harmony.unpack200.bytecode.forms;
20
21 import java.util.Objects;
22
23 import org.apache.commons.compress.harmony.pack200.Pack200Exception;
24 import org.apache.commons.compress.harmony.unpack200.SegmentConstantPool;
25 import org.apache.commons.compress.harmony.unpack200.bytecode.ByteCode;
26 import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry;
27 import org.apache.commons.compress.harmony.unpack200.bytecode.OperandManager;
28
29 /**
30 * Abstract class of all ByteCodeForms which add a nested entry from the globalConstantPool.
31 */
32 public abstract class ReferenceForm extends ByteCodeForm {
33
34 /**
35 * Constructs a new instance with the specified opcode, name, operandType and rewrite.
36 *
37 * @param opcode index corresponding to the opcode's value.
38 * @param name String printable name of the opcode.
39 * @param rewrite Operand positions (which will later be rewritten in ByteCodes) are indicated by -1.
40 */
41 public ReferenceForm(final int opcode, final String name, final int[] rewrite) {
42 super(opcode, name, rewrite);
43 }
44
45 protected abstract int getOffset(OperandManager operandManager);
46
47 protected abstract int getPoolID();
48
49 /*
50 * (non-Javadoc)
51 *
52 * @see org.apache.commons.compress.harmony.unpack200.bytecode.forms.ByteCodeForm#setByteCodeOperands(org.apache.commons.
53 * compress.harmony.unpack200.bytecode.ByteCode, org.apache.commons.compress.harmony.unpack200.bytecode.OperandTable,
54 * org.apache.commons.compress.harmony.unpack200.Segment)
55 */
56 @Override
57 public void setByteCodeOperands(final ByteCode byteCode, final OperandManager operandManager, final int codeLength) throws Pack200Exception {
58 final int offset = getOffset(operandManager);
59 try {
60 setNestedEntries(byteCode, operandManager, offset);
61 } catch (final Pack200Exception ex) {
62 throw new Error("Got a pack200 exception. What to do?");
63 }
64 }
65
66 /**
67 * Sets the nested entries.
68 *
69 * @param byteCode byte codes.
70 * @param operandManager Operand manager.
71 * @param offset offset.
72 * @throws Pack200Exception if support for a type is not supported or the offset not in the range [0, {@link Integer#MAX_VALUE}].
73 */
74 protected void setNestedEntries(final ByteCode byteCode, final OperandManager operandManager, final int offset) throws Pack200Exception {
75 final SegmentConstantPool globalPool = operandManager.globalConstantPool();
76 final ClassFileEntry[] nested = { globalPool.getConstantPoolEntry(getPoolID(), offset) };
77 Objects.requireNonNull(nested[0], "Null nested entries are not allowed");
78 byteCode.setNested(nested);
79 byteCode.setNestedPositions(new int[][] { { 0, 2 } });
80 }
81 }