1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.bcel.generic;
18
19 import java.io.DataOutputStream;
20 import java.io.IOException;
21
22 import org.apache.bcel.Const;
23 import org.apache.bcel.ExceptionConst;
24 import org.apache.bcel.classfile.ConstantInvokeDynamic;
25 import org.apache.bcel.classfile.ConstantNameAndType;
26 import org.apache.bcel.classfile.ConstantPool;
27 import org.apache.bcel.util.ByteSequence;
28
29 /**
30 * Class for INVOKEDYNAMIC. Not an instance of InvokeInstruction, since that class expects to be able to get the class
31 * of the method. Ignores the bootstrap mechanism entirely.
32 *
33 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5.invokedynamic"> The
34 * invokedynamic instruction in The Java Virtual Machine Specification</a>
35 * @since 6.0
36 */
37 public class INVOKEDYNAMIC extends InvokeInstruction {
38
39 /**
40 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
41 */
42 INVOKEDYNAMIC() {
43 }
44
45 public INVOKEDYNAMIC(final int index) {
46 super(Const.INVOKEDYNAMIC, index);
47 }
48
49 /**
50 * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
51 * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
52 *
53 * @param v Visitor object
54 */
55 @Override
56 public void accept(final Visitor v) {
57 v.visitExceptionThrower(this);
58 v.visitTypedInstruction(this);
59 v.visitStackConsumer(this);
60 v.visitStackProducer(this);
61 v.visitLoadClass(this);
62 v.visitCPInstruction(this);
63 v.visitFieldOrMethod(this);
64 v.visitInvokeInstruction(this);
65 v.visitINVOKEDYNAMIC(this);
66 }
67
68 /**
69 * Dump instruction as byte code to stream out.
70 *
71 * @param out Output stream
72 */
73 @Override
74 public void dump(final DataOutputStream out) throws IOException {
75 out.writeByte(super.getOpcode());
76 out.writeShort(super.getIndex());
77 out.writeByte(0);
78 out.writeByte(0);
79 }
80
81 /**
82 * Override the parent method because our class name is held elsewhere.
83 *
84 * Note: Contrary to this method's name it does not return the class name of the invoke target; rather it returns the
85 * name of the method that will be used to invoke the Lambda method generated by this invoke dynamic instruction.
86 */
87 @Override
88 public String getClassName(final ConstantPoolGen cpg) {
89 final ConstantPool cp = cpg.getConstantPool();
90 final ConstantInvokeDynamic cid = cp.getConstant(super.getIndex(), Const.CONSTANT_InvokeDynamic, ConstantInvokeDynamic.class);
91 return cp.getConstant(cid.getNameAndTypeIndex(), ConstantNameAndType.class).getName(cp);
92 }
93
94 @Override
95 public Class<?>[] getExceptions() {
96 return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_INTERFACE_METHOD_RESOLUTION, ExceptionConst.UNSATISFIED_LINK_ERROR,
97 ExceptionConst.ABSTRACT_METHOD_ERROR, ExceptionConst.ILLEGAL_ACCESS_ERROR, ExceptionConst.INCOMPATIBLE_CLASS_CHANGE_ERROR);
98 }
99
100 /**
101 * Since InvokeDynamic doesn't refer to a reference type, just return {@link Object}, as that is the only type we can
102 * say for sure the reference will be.
103 *
104 * @param cpg the ConstantPoolGen used to create the instruction
105 * @return an ObjectType for {@link Object}
106 * @since 6.1
107 */
108 @Override
109 public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
110 return new ObjectType(Object.class.getName());
111 }
112
113 /**
114 * Read needed data (i.e., index) from file.
115 */
116 @Override
117 protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
118 super.initFromFile(bytes, wide);
119 super.setLength(5);
120 bytes.readByte(); // Skip 0 byte
121 bytes.readByte(); // Skip 0 byte
122 }
123
124 }