1 /*
2 * Copyright (c) 2011, 2019, 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.HotSpotJVMCIRuntime.runtime;
26 import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
27 import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
28 import static jdk.internal.misc.Unsafe.ADDRESS_SIZE;
29
30 import java.lang.annotation.Annotation;
31
32 import jdk.internal.vm.annotation.Stable;
33
34 import jdk.vm.ci.meta.JavaConstant;
35 import jdk.vm.ci.meta.JavaType;
36 import jdk.vm.ci.meta.ResolvedJavaType;
37 import jdk.vm.ci.meta.UnresolvedJavaType;
38
39 /**
40 * Represents a field in a HotSpot type.
41 */
42 class HotSpotResolvedJavaFieldImpl implements HotSpotResolvedJavaField {
43
44 private final HotSpotResolvedObjectTypeImpl holder;
45 private JavaType type;
46
47 /**
48 * Value of {@code fieldDescriptor::access_flags()}.
49 */
50 private final int offset;
51
52 /**
53 * Value of {@code fieldDescriptor::index()}.
54 */
55 private final short index;
56
57 /**
58 * This value contains all flags as stored in the VM including internal ones.
59 */
60 private final int modifiers;
61
62 HotSpotResolvedJavaFieldImpl(HotSpotResolvedObjectTypeImpl holder, JavaType type, long offset, int modifiers, int index) {
63 this.holder = holder;
64 this.type = type;
65 this.index = (short) index;
66 assert this.index == index;
67 assert offset != -1;
68 assert offset == (int) offset : "offset larger than int";
69 this.offset = (int) offset;
70 this.modifiers = modifiers;
71 }
72
73 @Override
74 public boolean equals(Object obj) {
75 if (this == obj) {
76 return true;
77 }
78 if (obj instanceof HotSpotResolvedJavaFieldImpl) {
79 HotSpotResolvedJavaFieldImpl that = (HotSpotResolvedJavaFieldImpl) obj;
80 if (that.offset != this.offset || that.isStatic() != this.isStatic()) {
81 return false;
82 } else if (this.holder.equals(that.holder)) {
83 return true;
84 }
85 }
86 return false;
87 }
88
89 @Override
90 public int hashCode() {
91 return holder.hashCode() ^ offset;
92 }
93
94 @Override
95 public int getModifiers() {
96 return modifiers & HotSpotModifiers.jvmFieldModifiers();
97 }
98
99 @Override
100 public boolean isInternal() {
101 return (modifiers & config().jvmAccFieldInternal) != 0;
102 }
103
104 /**
105 * Determines if a given object contains this field.
106 *
107 * @return true iff this is a non-static field and its declaring class is assignable from
108 * {@code object}'s class
109 */
110 @Override
111 public boolean isInObject(JavaConstant object) {
112 if (isStatic()) {
113 return false;
114 }
115 HotSpotObjectConstant constant = (HotSpotObjectConstant) object;
116 return getDeclaringClass().isAssignableFrom(constant.getType());
117 }
118
119 @Override
120 public HotSpotResolvedObjectTypeImpl getDeclaringClass() {
121 return holder;
122 }
123
124 @Override
125 public String getName() {
126 return holder.createFieldInfo(index).getName();
127 }
128
129 @Override
130 public JavaType getType() {
131 // Pull field into local variable to prevent a race causing
132 // a ClassCastException below
133 JavaType currentType = type;
134 if (currentType instanceof UnresolvedJavaType) {
135 // Don't allow unresolved types to hang around forever
136 UnresolvedJavaType unresolvedType = (UnresolvedJavaType) currentType;
137 JavaType resolved = HotSpotJVMCIRuntime.runtime().lookupType(unresolvedType.getName(), holder, false);
138 if (resolved instanceof ResolvedJavaType) {
139 type = resolved;
140 }
141 }
142 return type;
143
144 }
145
146 @Override
147 public int getOffset() {
148 return offset;
149 }
150
151 /**
152 * Gets the value of this field's index (i.e. {@code fieldDescriptor::index()} in the encoded
153 * fields of the declaring class.
154 */
155 int getIndex() {
156 return index;
157 }
158
159 @Override
160 public String toString() {
161 return format("HotSpotResolvedJavaFieldImpl<%H.%n %t:") + offset + ">";
162 }
163
164 @Override
165 public boolean isSynthetic() {
166 return (config().jvmAccSynthetic & modifiers) != 0;
167 }
168
169 /**
170 * Checks if this field has the {@link Stable} annotation.
171 *
172 * @return true if field has {@link Stable} annotation, false otherwise
173 */
174 @Override
175 public boolean isStable() {
176 return (config().jvmAccFieldStable & modifiers) != 0;
177 }
178
179 private boolean hasAnnotations() {
180 if (!isInternal()) {
181 HotSpotVMConfig config = config();
182 final long metaspaceAnnotations = UNSAFE.getAddress(holder.getMetaspaceKlass() + config.instanceKlassAnnotationsOffset);
183 if (metaspaceAnnotations != 0) {
184 long fieldsAnnotations = UNSAFE.getAddress(metaspaceAnnotations + config.annotationsFieldAnnotationsOffset);
185 if (fieldsAnnotations != 0) {
186 long fieldAnnotations = UNSAFE.getAddress(fieldsAnnotations + config.fieldsAnnotationsBaseOffset + (ADDRESS_SIZE * index));
187 return fieldAnnotations != 0;
188 }
189 }
190 }
191 return false;
192 }
193
194 @Override
195 public Annotation[] getAnnotations() {
196 if (!hasAnnotations()) {
197 return new Annotation[0];
198 }
199 return runtime().reflection.getFieldAnnotations(this);
200 }
201
202 @Override
203 public Annotation[] getDeclaredAnnotations() {
204 if (!hasAnnotations()) {
205 return new Annotation[0];
206 }
207 return runtime().reflection.getFieldDeclaredAnnotations(this);
208 }
209
210 @Override
211 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
212 if (!hasAnnotations()) {
213 return null;
214 }
215 return runtime().reflection.getFieldAnnotation(this, annotationClass);
216 }
217 }