1 /*
2 * Copyright 2014 - 2020 Rafael Winterhalter
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package net.bytebuddy.implementation.attribute;
17
18 import net.bytebuddy.build.HashCodeAndEqualsPlugin;
19 import net.bytebuddy.description.annotation.AnnotationDescription;
20 import net.bytebuddy.description.field.FieldDescription;
21 import net.bytebuddy.description.type.TypeDescription;
22 import net.bytebuddy.jar.asm.FieldVisitor;
23
24 import java.util.ArrayList;
25 import java.util.Arrays;
26 import java.util.List;
27
28 /**
29 * An appender that writes attributes or annotations to a given ASM {@link net.bytebuddy.jar.asm.FieldVisitor}.
30 */
31 public interface FieldAttributeAppender {
32
33 /**
34 * Applies this attribute appender to a given field visitor.
35 *
36 * @param fieldVisitor The field visitor to which the attributes that are represented by this attribute appender are written to.
37 * @param fieldDescription The description of the field to which the field visitor belongs to.
38 * @param annotationValueFilter The annotation value filter to apply when writing annotations.
39 */
40 void apply(FieldVisitor fieldVisitor, FieldDescription fieldDescription, AnnotationValueFilter annotationValueFilter);
41
42 /**
43 * A field attribute appender that does not append any attributes.
44 */
45 enum NoOp implements FieldAttributeAppender, Factory {
46
47 /**
48 * The singleton instance.
49 */
50 INSTANCE;
51
52 /**
53 * {@inheritDoc}
54 */
55 public FieldAttributeAppender make(TypeDescription typeDescription) {
56 return this;
57 }
58
59 /**
60 * {@inheritDoc}
61 */
62 public void apply(FieldVisitor fieldVisitor, FieldDescription fieldDescription, AnnotationValueFilter annotationValueFilter) {
63 /* do nothing */
64 }
65 }
66
67 /**
68 * A factory that creates field attribute appenders for a given type.
69 */
70 interface Factory {
71
72 /**
73 * Returns a field attribute appender that is applicable for a given type description.
74 *
75 * @param typeDescription The type for which a field attribute appender is to be applied for.
76 * @return The field attribute appender which should be applied for the given type.
77 */
78 FieldAttributeAppender make(TypeDescription typeDescription);
79
80 /**
81 * A field attribute appender factory that combines several field attribute appender factories to be
82 * represented as a single factory.
83 */
84 @HashCodeAndEqualsPlugin.Enhance
85 class Compound implements Factory {
86
87 /**
88 * The factories that this compound factory represents in their application order.
89 */
90 private final List<Factory> factories;
91
92 /**
93 * Creates a new compound field attribute appender factory.
94 *
95 * @param factory The factories to represent in the order of their application.
96 */
97 public Compound(Factory... factory) {
98 this(Arrays.asList(factory));
99 }
100
101 /**
102 * Creates a new compound field attribute appender factory.
103 *
104 * @param factories The factories to represent in the order of their application.
105 */
106 public Compound(List<? extends Factory> factories) {
107 this.factories = new ArrayList<Factory>();
108 for (Factory factory : factories) {
109 if (factory instanceof Compound) {
110 this.factories.addAll(((Compound) factory).factories);
111 } else if (!(factory instanceof NoOp)) {
112 this.factories.add(factory);
113 }
114 }
115 }
116
117 /**
118 * {@inheritDoc}
119 */
120 public FieldAttributeAppender make(TypeDescription typeDescription) {
121 List<FieldAttributeAppender> fieldAttributeAppenders = new ArrayList<FieldAttributeAppender>(factories.size());
122 for (Factory factory : factories) {
123 fieldAttributeAppenders.add(factory.make(typeDescription));
124 }
125 return new FieldAttributeAppender.Compound(fieldAttributeAppenders);
126 }
127 }
128 }
129
130 /**
131 * An attribute appender that writes all annotations that are declared on a field.
132 */
133 enum ForInstrumentedField implements FieldAttributeAppender, Factory {
134
135 /**
136 * The singleton instance.
137 */
138 INSTANCE;
139
140 /**
141 * {@inheritDoc}
142 */
143 public void apply(FieldVisitor fieldVisitor, FieldDescription fieldDescription, AnnotationValueFilter annotationValueFilter) {
144 AnnotationAppender annotationAppender = new AnnotationAppender.Default(new AnnotationAppender.Target.OnField(fieldVisitor));
145 annotationAppender = fieldDescription.getType().accept(AnnotationAppender.ForTypeAnnotations.ofFieldType(annotationAppender, annotationValueFilter));
146 for (AnnotationDescription annotation : fieldDescription.getDeclaredAnnotations()) {
147 annotationAppender = annotationAppender.append(annotation, annotationValueFilter);
148 }
149 }
150
151 /**
152 * {@inheritDoc}
153 */
154 public FieldAttributeAppender make(TypeDescription typeDescription) {
155 return this;
156 }
157 }
158
159 /**
160 * Appends an annotation to a field. The visibility of the annotation is determined by the annotation type's
161 * {@link java.lang.annotation.RetentionPolicy} annotation.
162 */
163 @HashCodeAndEqualsPlugin.Enhance
164 class Explicit implements FieldAttributeAppender, Factory {
165
166 /**
167 * The annotations that this appender appends.
168 */
169 private final List<? extends AnnotationDescription> annotations;
170
171 /**
172 * Creates a new annotation attribute appender for explicit annotation values. All values, including default values, are copied.
173 *
174 * @param annotations The annotations to be appended to the field.
175 */
176 public Explicit(List<? extends AnnotationDescription> annotations) {
177 this.annotations = annotations;
178 }
179
180 /**
181 * {@inheritDoc}
182 */
183 public void apply(FieldVisitor fieldVisitor, FieldDescription fieldDescription, AnnotationValueFilter annotationValueFilter) {
184 AnnotationAppender appender = new AnnotationAppender.Default(new AnnotationAppender.Target.OnField(fieldVisitor));
185 for (AnnotationDescription annotation : annotations) {
186 appender = appender.append(annotation, annotationValueFilter);
187 }
188 }
189
190 /**
191 * {@inheritDoc}
192 */
193 public FieldAttributeAppender make(TypeDescription typeDescription) {
194 return this;
195 }
196 }
197
198 /**
199 * A field attribute appender that combines several method attribute appenders to be represented as a single
200 * field attribute appender.
201 */
202 @HashCodeAndEqualsPlugin.Enhance
203 class Compound implements FieldAttributeAppender {
204
205 /**
206 * The field attribute appenders this appender represents in their application order.
207 */
208 private final List<FieldAttributeAppender> fieldAttributeAppenders;
209
210 /**
211 * Creates a new compound field attribute appender.
212 *
213 * @param fieldAttributeAppender The field attribute appenders that are to be combined by this compound appender
214 * in the order of their application.
215 */
216 public Compound(FieldAttributeAppender... fieldAttributeAppender) {
217 this(Arrays.asList(fieldAttributeAppender));
218 }
219
220 /**
221 * Creates a new compound field attribute appender.
222 *
223 * @param fieldAttributeAppenders The field attribute appenders that are to be combined by this compound appender
224 * in the order of their application.
225 */
226 public Compound(List<? extends FieldAttributeAppender> fieldAttributeAppenders) {
227 this.fieldAttributeAppenders = new ArrayList<FieldAttributeAppender>();
228 for (FieldAttributeAppender fieldAttributeAppender : fieldAttributeAppenders) {
229 if (fieldAttributeAppender instanceof Compound) {
230 this.fieldAttributeAppenders.addAll(((Compound) fieldAttributeAppender).fieldAttributeAppenders);
231 } else if (!(fieldAttributeAppender instanceof NoOp)) {
232 this.fieldAttributeAppenders.add(fieldAttributeAppender);
233 }
234 }
235 }
236
237 /**
238 * {@inheritDoc}
239 */
240 public void apply(FieldVisitor fieldVisitor, FieldDescription fieldDescription, AnnotationValueFilter annotationValueFilter) {
241 for (FieldAttributeAppender fieldAttributeAppender : fieldAttributeAppenders) {
242 fieldAttributeAppender.apply(fieldVisitor, fieldDescription, annotationValueFilter);
243 }
244 }
245 }
246 }
247