Thu, 10 Oct 2013 08:51:55 +0200
8021237: clean up JavacAnnotatedConstruct
Summary: Refactored the static helper methods in JavacAnnoConstructs into ordinary methods and put them in a common superclass (AnnoConstruct) of Symbol and Type.
Reviewed-by: jjg, vromero, jfranck
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
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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
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24 */
25 package com.sun.tools.javac.code;
27 import java.lang.annotation.Annotation;
28 import java.lang.reflect.InvocationTargetException;
29 import java.lang.reflect.Method;
31 import javax.lang.model.AnnotatedConstruct;
33 import com.sun.tools.javac.model.AnnotationProxyMaker;
34 import com.sun.tools.javac.util.List;
35 import com.sun.tools.javac.util.ListBuffer;
37 /**
38 * Common super type for annotated constructs such as Types and Symbols.
39 *
40 * This class should *not* contain any fields since it would have a significant
41 * impact on the javac memory footprint.
42 *
43 * <p><b>This is NOT part of any supported API.
44 * If you write code that depends on this, you do so at your own
45 * risk. This code and its internal interfaces are subject to change
46 * or deletion without notice.</b></p>
47 */
48 public abstract class AnnoConstruct implements AnnotatedConstruct {
51 // Override to enforce a narrower return type.
52 @Override
53 public abstract List<? extends Attribute.Compound> getAnnotationMirrors();
56 // This method is part of the javax.lang.model API, do not use this in javac code.
57 protected <A extends Annotation> Attribute.Compound getAttribute(Class<A> annoType) {
58 String name = annoType.getName();
60 for (Attribute.Compound anno : getAnnotationMirrors()) {
61 if (name.equals(anno.type.tsym.flatName().toString()))
62 return anno;
63 }
65 return null;
66 }
69 @SuppressWarnings("unchecked")
70 protected <A extends Annotation> A[] getInheritedAnnotations(Class<A> annoType) {
71 return (A[]) java.lang.reflect.Array.newInstance(annoType, 0); // annoType is the Class for A
72 }
75 // This method is part of the javax.lang.model API, do not use this in javac code.
76 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annoType) {
78 if (!annoType.isAnnotation())
79 throw new IllegalArgumentException("Not an annotation type: "
80 + annoType);
81 // If annoType does not declare a container this is equivalent to wrapping
82 // getAnnotation(...) in an array.
83 Class <? extends Annotation> containerType = getContainer(annoType);
84 if (containerType == null) {
85 A res = getAnnotation(annoType);
86 int size = res == null ? 0 : 1;
88 @SuppressWarnings("unchecked") // annoType is the Class for A
89 A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);
90 if (res != null)
91 arr[0] = res;
92 return arr;
93 }
95 // So we have a containing type
96 String annoTypeName = annoType.getName();
97 String containerTypeName = containerType.getName();
98 int directIndex = -1, containerIndex = -1;
99 Attribute.Compound direct = null, container = null;
100 // Find directly (explicit or implicit) present annotations
101 int index = -1;
102 for (Attribute.Compound attribute : getAnnotationMirrors()) {
103 index++;
104 if (attribute.type.tsym.flatName().contentEquals(annoTypeName)) {
105 directIndex = index;
106 direct = attribute;
107 } else if(containerTypeName != null &&
108 attribute.type.tsym.flatName().contentEquals(containerTypeName)) {
109 containerIndex = index;
110 container = attribute;
111 }
112 }
114 // Deal with inherited annotations
115 if (direct == null && container == null)
116 return getInheritedAnnotations(annoType);
118 // Pack them in an array
119 Attribute[] contained0 = null;
120 if (container != null)
121 contained0 = unpackAttributes(container);
122 ListBuffer<Attribute.Compound> compounds = new ListBuffer<>();
123 if (contained0 != null) {
124 for (Attribute a : contained0)
125 if (a instanceof Attribute.Compound)
126 compounds = compounds.append((Attribute.Compound)a);
127 }
128 Attribute.Compound[] contained = compounds.toArray(new Attribute.Compound[compounds.size()]);
130 int size = (direct == null ? 0 : 1) + contained.length;
131 @SuppressWarnings("unchecked") // annoType is the Class for A
132 A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);
134 // if direct && container, which is first?
135 int insert = -1;
136 int length = arr.length;
137 if (directIndex >= 0 && containerIndex >= 0) {
138 if (directIndex < containerIndex) {
139 arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
140 insert = 1;
141 } else {
142 arr[arr.length - 1] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
143 insert = 0;
144 length--;
145 }
146 } else if (directIndex >= 0) {
147 arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);
148 return arr;
149 } else {
150 // Only container
151 insert = 0;
152 }
154 for (int i = 0; i + insert < length; i++)
155 arr[insert + i] = AnnotationProxyMaker.generateAnnotation(contained[i], annoType);
157 return arr;
158 }
161 // This method is part of the javax.lang.model API, do not use this in javac code.
162 public <A extends Annotation> A getAnnotation(Class<A> annoType) {
164 if (!annoType.isAnnotation())
165 throw new IllegalArgumentException("Not an annotation type: " + annoType);
167 Attribute.Compound c = getAttribute(annoType);
168 return c == null ? null : AnnotationProxyMaker.generateAnnotation(c, annoType);
169 }
171 // Needed to unpack the runtime view of containing annotations
172 private static final Class<? extends Annotation> REPEATABLE_CLASS = initRepeatable();
173 private static final Method VALUE_ELEMENT_METHOD = initValueElementMethod();
175 private static Class<? extends Annotation> initRepeatable() {
176 try {
177 // Repeatable will not be available when bootstrapping on
178 // JDK 7 so use a reflective lookup instead of a class
179 // literal for Repeatable.class.
180 return Class.forName("java.lang.annotation.Repeatable").asSubclass(Annotation.class);
181 } catch (ClassNotFoundException | SecurityException e) {
182 return null;
183 }
184 }
186 private static Method initValueElementMethod() {
187 if (REPEATABLE_CLASS == null)
188 return null;
190 Method m = null;
191 try {
192 m = REPEATABLE_CLASS.getMethod("value");
193 if (m != null)
194 m.setAccessible(true);
195 return m;
196 } catch (NoSuchMethodException e) {
197 return null;
198 }
199 }
202 // Helper to getAnnotationsByType
203 private static Class<? extends Annotation> getContainer(Class<? extends Annotation> annoType) {
204 // Since we can not refer to java.lang.annotation.Repeatable until we are
205 // bootstrapping with java 8 we need to get the Repeatable annotation using
206 // reflective invocations instead of just using its type and element method.
207 if (REPEATABLE_CLASS != null &&
208 VALUE_ELEMENT_METHOD != null) {
209 // Get the Repeatable instance on the annotations declaration
210 Annotation repeatable = (Annotation)annoType.getAnnotation(REPEATABLE_CLASS);
211 if (repeatable != null) {
212 try {
213 // Get the value element, it should be a class
214 // indicating the containing annotation type
215 @SuppressWarnings("unchecked")
216 Class<? extends Annotation> containerType = (Class)VALUE_ELEMENT_METHOD.invoke(repeatable);
217 if (containerType == null)
218 return null;
220 return containerType;
221 } catch (ClassCastException | IllegalAccessException | InvocationTargetException e) {
222 return null;
223 }
224 }
225 }
226 return null;
227 }
230 // Helper to getAnnotationsByType
231 private static Attribute[] unpackAttributes(Attribute.Compound container) {
232 // We now have an instance of the container,
233 // unpack it returning an instance of the
234 // contained type or null
235 return ((Attribute.Array)container.member(container.type.tsym.name.table.names.value)).values;
236 }
238 }