1 /*
2 * Copyright (c) 2011, 2016, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package jdk.vm.ci.hotspot;
24
25 import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
26
27 import java.lang.annotation.Annotation;
28 import java.lang.reflect.Field;
29
30 import jdk.internal.vm.annotation.Stable;
31 import jdk.vm.ci.meta.JavaType;
32 import jdk.vm.ci.meta.ModifiersProvider;
33 import jdk.vm.ci.meta.ResolvedJavaType;
34
35 /**
36 * Represents a field in a HotSpot type.
37 */
38 class HotSpotResolvedJavaFieldImpl implements HotSpotResolvedJavaField {
39
40 private final HotSpotResolvedObjectTypeImpl holder;
41 private final String name;
42 private JavaType type;
43 private final int offset;
44
45 /**
46 * This value contains all flags as stored in the VM including internal ones.
47 */
48 private final int modifiers;
49
50 HotSpotResolvedJavaFieldImpl(HotSpotResolvedObjectTypeImpl holder, String name, JavaType type, long offset, int modifiers) {
51 this.holder = holder;
52 this.name = name;
53 this.type = type;
54 assert offset != -1;
55 assert offset == (int) offset : "offset larger than int";
56 this.offset = (int) offset;
57 this.modifiers = modifiers;
58 }
59
60 @Override
61 public boolean equals(Object obj) {
62 if (this == obj) {
63 return true;
64 }
65 if (obj instanceof HotSpotResolvedJavaField) {
66 HotSpotResolvedJavaFieldImpl that = (HotSpotResolvedJavaFieldImpl) obj;
67 if (that.offset != this.offset || that.isStatic() != this.isStatic()) {
68 return false;
69 } else if (this.holder.equals(that.holder)) {
70 assert this.name.equals(that.name) && this.type.equals(that.type);
71 return true;
72 }
73 }
74 return false;
75 }
76
77 @Override
78 public int hashCode() {
79 return name.hashCode();
80 }
81
82 @Override
83 public int getModifiers() {
84 return modifiers & ModifiersProvider.jvmFieldModifiers();
85 }
86
87 @Override
88 public boolean isInternal() {
89 return (modifiers & config().jvmAccFieldInternal) != 0;
90 }
91
92 /**
93 * Determines if a given object contains this field.
94 *
95 * @return true iff this is a non-static field and its declaring class is assignable from
96 * {@code object}'s class
97 */
98 public boolean isInObject(Object object) {
99 if (isStatic()) {
100 return false;
101 }
102 return getDeclaringClass().isAssignableFrom(HotSpotResolvedObjectTypeImpl.fromObjectClass(object.getClass()));
103 }
104
105 @Override
106 public HotSpotResolvedObjectTypeImpl getDeclaringClass() {
107 return holder;
108 }
109
110 @Override
111 public String getName() {
112 return name;
113 }
114
115 @Override
116 public JavaType getType() {
117 // Pull field into local variable to prevent a race causing
118 // a ClassCastException below
119 JavaType currentType = type;
120 if (currentType instanceof HotSpotUnresolvedJavaType) {
121 // Don't allow unresolved types to hang around forever
122 HotSpotUnresolvedJavaType unresolvedType = (HotSpotUnresolvedJavaType) currentType;
123 ResolvedJavaType resolved = unresolvedType.reresolve(holder);
124 if (resolved != null) {
125 type = resolved;
126 }
127 }
128 return type;
129 }
130
131 public int offset() {
132 return offset;
133 }
134
135 @Override
136 public String toString() {
137 return format("HotSpotField<%H.%n %t:") + offset + ">";
138 }
139
140 @Override
141 public boolean isSynthetic() {
142 return (config().jvmAccSynthetic & modifiers) != 0;
143 }
144
145 /**
146 * Checks if this field has the {@link Stable} annotation.
147 *
148 * @return true if field has {@link Stable} annotation, false otherwise
149 */
150 public boolean isStable() {
151 return (config().jvmAccFieldStable & modifiers) != 0;
152 }
153
154 @Override
155 public Annotation[] getAnnotations() {
156 Field javaField = toJava();
157 if (javaField != null) {
158 return javaField.getAnnotations();
159 }
160 return new Annotation[0];
161 }
162
163 @Override
164 public Annotation[] getDeclaredAnnotations() {
165 Field javaField = toJava();
166 if (javaField != null) {
167 return javaField.getDeclaredAnnotations();
168 }
169 return new Annotation[0];
170 }
171
172 @Override
173 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
174 Field javaField = toJava();
175 if (javaField != null) {
176 return javaField.getAnnotation(annotationClass);
177 }
178 return null;
179 }
180
181 private Field toJavaCache;
182
183 private Field toJava() {
184 if (toJavaCache != null) {
185 return toJavaCache;
186 }
187
188 if (isInternal()) {
189 return null;
190 }
191 try {
192 return toJavaCache = holder.mirror().getDeclaredField(name);
193 } catch (NoSuchFieldException | NoClassDefFoundError e) {
194 return null;
195 }
196 }
197 }