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.bcel.generic;
20
21 import java.io.DataOutputStream;
22 import java.io.IOException;
23
24 import org.apache.bcel.Const;
25 import org.apache.bcel.ExceptionConst;
26 import org.apache.bcel.classfile.ConstantInvokeDynamic;
27 import org.apache.bcel.classfile.ConstantNameAndType;
28 import org.apache.bcel.classfile.ConstantPool;
29 import org.apache.bcel.util.ByteSequence;
30
31 /**
32 * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class expects to be able to get the class
33 * of the method. Ignores the bootstrap mechanism entirely.
34 *
35 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic"> The
36 * invokedynamic instruction in The Java Virtual Machine Specification</a>
37 * @since 6.0
38 */
39 public class INVOKEDYNAMIC extends InvokeInstruction {
40
41 /**
42 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
43 */
44 INVOKEDYNAMIC() {
45 }
46
47 /**
48 * Constructs an INVOKEDYNAMIC instruction.
49 *
50 * @param index index into constant pool.
51 */
52 public INVOKEDYNAMIC(final int index) {
53 super(Const.INVOKEDYNAMIC, index);
54 super.setLength(5);
55 }
56
57 /**
58 * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
59 * methods according to the class hierarchy in descending order, that is, the most specific visitXXX() call comes last.
60 *
61 * @param v Visitor object.
62 */
63 @Override
64 public void accept(final Visitor v) {
65 v.visitExceptionThrower(this);
66 v.visitTypedInstruction(this);
67 v.visitStackConsumer(this);
68 v.visitStackProducer(this);
69 v.visitLoadClass(this);
70 v.visitCPInstruction(this);
71 v.visitFieldOrMethod(this);
72 v.visitInvokeInstruction(this);
73 v.visitINVOKEDYNAMIC(this);
74 }
75
76 /**
77 * Dumps instruction as byte code to stream out.
78 *
79 * @param out Output stream.
80 */
81 @Override
82 public void dump(final DataOutputStream out) throws IOException {
83 out.writeByte(super.getOpcode());
84 out.writeShort(super.getIndex());
85 out.writeByte(0);
86 out.writeByte(0);
87 }
88
89 /**
90 * Override the parent method because our class name is held elsewhere.
91 *
92 * Note: Contrary to this method's name it does not return the class name of the invoke target; rather it returns the
93 * name of the method that will be used to invoke the Lambda method generated by this invoke dynamic instruction.
94 */
95 @Override
96 public String getClassName(final ConstantPoolGen cpg) {
97 final ConstantPool cp = cpg.getConstantPool();
98 final ConstantInvokeDynamic cid = cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic, ConstantInvokeDynamic.class);
99 return cp.getConstant(cid.getNameAndTypeIndex(), ConstantNameAndType.class).getName(cp);
100 }
101
102 @Override
103 public Class<?>[] getExceptions() {
104 return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION, ExceptionConst.UNSATISFIED_LINK_ERROR,
105 ExceptionConst.ABSTRACT_METHOD_ERROR, ExceptionConst.ILLEGAL_ACCESS_ERROR, ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
106 }
107
108 /**
109 * Since InvokeDynamic doesn't refer to a reference type, just return {@link Object}, as that is the only type we can
110 * say for sure the reference will be.
111 *
112 * @param cpg The ConstantPoolGen used to create the instruction.
113 * @return An ObjectType for {@link Object}.
114 * @since 6.1
115 */
116 @Override
117 public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
118 return new ObjectType(Object.class.getName());
119 }
120
121 /**
122 * Reads needed data (that is, index) from file.
123 */
124 @Override
125 protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
126 super.initFromFile(bytes, wide);
127 super.setLength(5);
128 bytes.readByte(); // Skip 0 byte
129 bytes.readByte(); // Skip 0 byte
130 }
131
132 }