1 /*
2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3  *
4  * This code is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 only, as
6  * published by the Free Software Foundation.  Oracle designates this
7  * particular file as subject to the "Classpath" exception as provided
8  * by Oracle in the LICENSE file that accompanied this code.
9  *
10  * This code is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License version
17  * 2 along with this work; if not, write to the Free Software Foundation,
18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21  * or visit www.oracle.com if you need additional information or have any
22  * questions.
23  */
24 
25 /*
26  * This file is available under and governed by the GNU General Public
27  * License version 2 only, as published by the Free Software Foundation.
28  * However, the following notice accompanied the original version of this
29  * file:
30  *
31  * ASM: a very small and fast Java bytecode manipulation framework
32  * Copyright (c) 2000-2011 INRIA, France Telecom
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms, with or without
36  * modification, are permitted provided that the following conditions
37  * are met:
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. Neither the name of the copyright holders nor the names of its
44  *    contributors may be used to endorse or promote products derived from
45  *    this software without specific prior written permission.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
48  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
51  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
52  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
53  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
54  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
55  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
56  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
57  * THE POSSIBILITY OF SUCH DAMAGE.
58  */
59 package jdk.internal.org.objectweb.asm;
60 
61 /**
62  * A visitor to visit a Java field. The methods of this class must be called in
63  * the following order: ( <tt>visitAnnotation</tt> |
64  * <tt>visitTypeAnnotation</tt> | <tt>visitAttribute</tt> )* <tt>visitEnd</tt>.
65  *
66  * @author Eric Bruneton
67  */
68 public abstract class FieldVisitor {
69 
70     /**
71      * The ASM API version implemented by this visitor. The value of this field
72      * must be one of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
73      */
74     protected final int api;
75 
76     /**
77      * The field visitor to which this visitor must delegate method calls. May
78      * be null.
79      */
80     protected FieldVisitor fv;
81 
82     /**
83      * Constructs a new {@link FieldVisitor}.
84      *
85      * @param api
86      *            the ASM API version implemented by this visitor. Must be one
87      *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
88      */
FieldVisitor(final int api)89     public FieldVisitor(final int api) {
90         this(api, null);
91     }
92 
93     /**
94      * Constructs a new {@link FieldVisitor}.
95      *
96      * @param api
97      *            the ASM API version implemented by this visitor. Must be one
98      *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
99      * @param fv
100      *            the field visitor to which this visitor must delegate method
101      *            calls. May be null.
102      */
FieldVisitor(final int api, final FieldVisitor fv)103     public FieldVisitor(final int api, final FieldVisitor fv) {
104         if (api != Opcodes.ASM4 && api != Opcodes.ASM5) {
105             throw new IllegalArgumentException();
106         }
107         this.api = api;
108         this.fv = fv;
109     }
110 
111     /**
112      * Visits an annotation of the field.
113      *
114      * @param desc
115      *            the class descriptor of the annotation class.
116      * @param visible
117      *            <tt>true</tt> if the annotation is visible at runtime.
118      * @return a visitor to visit the annotation values, or <tt>null</tt> if
119      *         this visitor is not interested in visiting this annotation.
120      */
visitAnnotation(String desc, boolean visible)121     public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
122         if (fv != null) {
123             return fv.visitAnnotation(desc, visible);
124         }
125         return null;
126     }
127 
128     /**
129      * Visits an annotation on the type of the field.
130      *
131      * @param typeRef
132      *            a reference to the annotated type. The sort of this type
133      *            reference must be {@link TypeReference#FIELD FIELD}. See
134      *            {@link TypeReference}.
135      * @param typePath
136      *            the path to the annotated type argument, wildcard bound, array
137      *            element type, or static inner type within 'typeRef'. May be
138      *            <tt>null</tt> if the annotation targets 'typeRef' as a whole.
139      * @param desc
140      *            the class descriptor of the annotation class.
141      * @param visible
142      *            <tt>true</tt> if the annotation is visible at runtime.
143      * @return a visitor to visit the annotation values, or <tt>null</tt> if
144      *         this visitor is not interested in visiting this annotation.
145      */
visitTypeAnnotation(int typeRef, TypePath typePath, String desc, boolean visible)146     public AnnotationVisitor visitTypeAnnotation(int typeRef,
147             TypePath typePath, String desc, boolean visible) {
148         if (api < Opcodes.ASM5) {
149             throw new RuntimeException();
150         }
151         if (fv != null) {
152             return fv.visitTypeAnnotation(typeRef, typePath, desc, visible);
153         }
154         return null;
155     }
156 
157     /**
158      * Visits a non standard attribute of the field.
159      *
160      * @param attr
161      *            an attribute.
162      */
visitAttribute(Attribute attr)163     public void visitAttribute(Attribute attr) {
164         if (fv != null) {
165             fv.visitAttribute(attr);
166         }
167     }
168 
169     /**
170      * Visits the end of the field. This method, which is the last one to be
171      * called, is used to inform the visitor that all the annotations and
172      * attributes of the field have been visited.
173      */
visitEnd()174     public void visitEnd() {
175         if (fv != null) {
176             fv.visitEnd();
177         }
178     }
179 }
180