1 /*
2 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package com.sun.tools.javac.code;
26
27 import java.lang.annotation.Annotation;
28 import java.lang.annotation.Inherited;
29 import java.lang.reflect.InvocationTargetException;
30 import java.lang.reflect.Method;
31
32 import javax.lang.model.AnnotatedConstruct;
33
34 import com.sun.tools.javac.model.AnnotationProxyMaker;
35 import com.sun.tools.javac.util.DefinedBy;
36 import com.sun.tools.javac.util.DefinedBy.Api;
37 import com.sun.tools.javac.util.List;
38 import com.sun.tools.javac.util.ListBuffer;
39
40 /**
41 * Common super type for annotated constructs such as Types and Symbols.
42 *
43 * This class should *not* contain any fields since it would have a significant
44 * impact on the javac memory footprint.
45 *
46 * <p><b>This is NOT part of any supported API.
47 * If you write code that depends on this, you do so at your own
48 * risk. This code and its internal interfaces are subject to change
49 * or deletion without notice.</b></p>
50 */
51 public abstract class AnnoConstruct implements AnnotatedConstruct {
52
53
54 // Override to enforce a narrower return type.
55 @Override @DefinedBy(Api.LANGUAGE_MODEL)
56 public abstract List<? extends Attribute.Compound> getAnnotationMirrors();
57
58
59 // This method is part of the javax.lang.model API, do not use this in javac code.
60 protected <A extends Annotation> Attribute.Compound getAttribute(Class<A> annoType) {
61 String name = annoType.getName();
62
63 for (Attribute.Compound anno : getAnnotationMirrors()) {
64 if (name.equals(anno.type.tsym.flatName().toString()))
65 return anno;
66 }
67
68 return null;
69 }
70
71
72 @SuppressWarnings("unchecked")
73 protected <A extends Annotation> A[] getInheritedAnnotations(Class<A> annoType) {
74 return (A[]) java.lang.reflect.Array.newInstance(annoType, 0); // annoType is the Class for A
75 }
76
77
78 // This method is part of the javax.lang.model API, do not use this in javac code.
79 @DefinedBy(Api.LANGUAGE_MODEL)
80 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annoType) {
81
82 if (!annoType.isAnnotation())
83 throw new IllegalArgumentException("Not an annotation type: "
84 + annoType);
85 // If annoType does not declare a container this is equivalent to wrapping
86 // getAnnotation(...) in an array.
87 Class <? extends Annotation> containerType = getContainer(annoType);
88 if (containerType == null) {
89 A res = getAnnotation(annoType);
90 int size = res == null ? 0 : 1;
91
92 @SuppressWarnings("unchecked") // annoType is the Class for A
93 A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);
94 if (res != null)
95 arr[0] = res;
96 return arr;
97 }
98
99 // So we have a containing type
100 String annoTypeName = annoType.getName();
101 String containerTypeName = containerType.getName();
102 int directIndex = -1, containerIndex = -1;
103 Attribute.Compound direct = null, container = null;
104 // Find directly (explicit or implicit) present annotations
105 int index = -1;
106 for (Attribute.Compound attribute : getAnnotationMirrors()) {
107 index++;
108 if (attribute.type.tsym.flatName().contentEquals(annoTypeName)) {
109 directIndex = index;
110 direct = attribute;
111 } else if(containerTypeName != null &&
112 attribute.type.tsym.flatName().contentEquals(containerTypeName)) {
113 containerIndex = index;
114 container = attribute;
115 }
116 }
117
118 // Deal with inherited annotations
119 if (direct == null && container == null &&
120 annoType.isAnnotationPresent(Inherited.class))
121 return getInheritedAnnotations(annoType);
122
123 Attribute.Compound[] contained = unpackContained(container);
124
125 // In case of an empty legacy container we might need to look for
126 // inherited annos as well
127 if (direct == null && contained.length == 0 &&
128 annoType.isAnnotationPresent(Inherited.class))
129 return getInheritedAnnotations(annoType);
130
131 int size = (direct == null ? 0 : 1) + contained.length;
132 @SuppressWarnings("unchecked") // annoType is the Class for A
133 A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);
134
135 // if direct && container, which is first?
136 int insert = -1;
137 int length = arr.length;
138 if (directIndex >= 0 && containerIndex >= 0) {
139 if (directIndex < containerIndex) {
140 arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
141 insert = 1;
142 } else {
143 arr[arr.length - 1] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
144 insert = 0;
145 length--;
146 }
147 } else if (directIndex >= 0) {
148 arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
149 return arr;
150 } else {
151 // Only container
152 insert = 0;
153 }
154
155 for (int i = 0; i + insert < length; i++)
156 arr[insert + i] = AnnotationProxyMaker.generateAnnotation(contained[i], annoType);
157
158 return arr;
159 }
160
161 private Attribute.Compound[] unpackContained(Attribute.Compound container) {
162 // Pack them in an array
163 Attribute[] contained0 = null;
164 if (container != null)
165 contained0 = unpackAttributes(container);
166 ListBuffer<Attribute.Compound> compounds = new ListBuffer<>();
167 if (contained0 != null) {
168 for (Attribute a : contained0)
169 if (a instanceof Attribute.Compound)
170 compounds = compounds.append((Attribute.Compound)a);
171 }
172 return compounds.toArray(new Attribute.Compound[compounds.size()]);
173 }
174
175 // This method is part of the javax.lang.model API, do not use this in javac code.
176 @DefinedBy(Api.LANGUAGE_MODEL)
177 public <A extends Annotation> A getAnnotation(Class<A> annoType) {
178
179 if (!annoType.isAnnotation())
180 throw new IllegalArgumentException("Not an annotation type: " + annoType);
181
182 Attribute.Compound c = getAttribute(annoType);
183 return c == null ? null : AnnotationProxyMaker.generateAnnotation(c, annoType);
184 }
185
186 // Needed to unpack the runtime view of containing annotations
187 private static final Class<? extends Annotation> REPEATABLE_CLASS = initRepeatable();
188 private static final Method VALUE_ELEMENT_METHOD = initValueElementMethod();
189
190 private static Class<? extends Annotation> initRepeatable() {
191 try {
192 // Repeatable will not be available when bootstrapping on
193 // JDK 7 so use a reflective lookup instead of a class
194 // literal for Repeatable.class.
195 return Class.forName("java.lang.annotation.Repeatable").asSubclass(Annotation.class);
196 } catch (ClassNotFoundException | SecurityException e) {
197 return null;
198 }
199 }
200
201 private static Method initValueElementMethod() {
202 if (REPEATABLE_CLASS == null)
203 return null;
204
205 Method m = null;
206 try {
207 m = REPEATABLE_CLASS.getMethod("value");
208 if (m != null)
209 m.setAccessible(true);
210 return m;
211 } catch (NoSuchMethodException e) {
212 return null;
213 }
214 }
215
216
217 // Helper to getAnnotationsByType
218 private static Class<? extends Annotation> getContainer(Class<? extends Annotation> annoType) {
219 // Since we can not refer to java.lang.annotation.Repeatable until we are
220 // bootstrapping with java 8 we need to get the Repeatable annotation using
221 // reflective invocations instead of just using its type and element method.
222 if (REPEATABLE_CLASS != null &&
223 VALUE_ELEMENT_METHOD != null) {
224 // Get the Repeatable instance on the annotations declaration
225 Annotation repeatable = (Annotation)annoType.getAnnotation(REPEATABLE_CLASS);
226 if (repeatable != null) {
227 try {
228 // Get the value element, it should be a class
229 // indicating the containing annotation type
230 @SuppressWarnings("unchecked")
231 Class<? extends Annotation> containerType = (Class)VALUE_ELEMENT_METHOD.invoke(repeatable);
232 if (containerType == null)
233 return null;
234
235 return containerType;
236 } catch (ClassCastException | IllegalAccessException | InvocationTargetException e) {
237 return null;
238 }
239 }
240 }
241 return null;
242 }
243
244
245 // Helper to getAnnotationsByType
246 private static Attribute[] unpackAttributes(Attribute.Compound container) {
247 // We now have an instance of the container,
248 // unpack it returning an instance of the
249 // contained type or null
250 return ((Attribute.Array)container.member(container.type.tsym.name.table.names.value)).values;
251 }
252
253 }