1 /*
2 * Copyright (c) 2011, 2015, 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
28 import java.lang.annotation.Annotation;
29 import java.lang.reflect.Field;
30
31 import jdk.vm.ci.common.JVMCIError;
32 import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.Option;
33 import jdk.vm.ci.meta.JavaType;
34 import jdk.vm.ci.meta.LocationIdentity;
35 import jdk.vm.ci.meta.MetaAccessProvider;
36 import jdk.vm.ci.meta.ModifiersProvider;
37 import jdk.vm.ci.meta.ResolvedJavaField;
38 import jdk.vm.ci.meta.ResolvedJavaType;
39
40 /**
41 * Represents a field in a HotSpot type.
42 */
43 class HotSpotResolvedJavaFieldImpl implements HotSpotResolvedJavaField, HotSpotProxified {
44
45 /**
46 * Mark well-known stable fields as such.
47 */
48 private static final boolean ImplicitStableValues = HotSpotJVMCIRuntime.getBooleanProperty(Option.ImplicitStableValues, true);
49
50 private final HotSpotResolvedObjectTypeImpl holder;
51 private final String name;
52 private JavaType type;
53 private final int offset;
54
55 /**
56 * This value contains all flags as stored in the VM including internal ones.
57 */
58 private final int modifiers;
59 private final LocationIdentity locationIdentity = new FieldLocationIdentity(this);
60
61 public static class FieldLocationIdentity extends LocationIdentity {
62 HotSpotResolvedJavaField inner;
63
64 public FieldLocationIdentity(HotSpotResolvedJavaFieldImpl inner) {
65 this.inner = inner;
66 }
67
68 @Override
69 public boolean isImmutable() {
70 return false;
71 }
72
73 @Override
74 public boolean equals(Object obj) {
75 if (this == obj) {
76 return true;
77 }
78 if (obj instanceof FieldLocationIdentity) {
79 FieldLocationIdentity fieldLocationIdentity = (FieldLocationIdentity) obj;
80 return inner.equals(fieldLocationIdentity.inner);
81
82 }
83 return false;
84 }
85
86 @Override
87 public int hashCode() {
88 return inner.hashCode();
89 }
90
91 @Override
92 public String toString() {
93 return inner.getName();
94 }
95 }
96
97 HotSpotResolvedJavaFieldImpl(HotSpotResolvedObjectTypeImpl holder, String name, JavaType type, long offset, int modifiers) {
98 this.holder = holder;
99 this.name = name;
100 this.type = type;
101 assert offset != -1;
102 assert offset == (int) offset : "offset larger than int";
103 this.offset = (int) offset;
104 this.modifiers = modifiers;
105 }
106
107 @Override
108 public boolean equals(Object obj) {
109 if (this == obj) {
110 return true;
111 }
112 if (obj instanceof HotSpotResolvedJavaField) {
113 HotSpotResolvedJavaFieldImpl that = (HotSpotResolvedJavaFieldImpl) obj;
114 if (that.offset != this.offset || that.isStatic() != this.isStatic()) {
115 return false;
116 } else if (this.holder.equals(that.holder)) {
117 assert this.name.equals(that.name) && this.type.equals(that.type);
118 return true;
119 }
120 }
121 return false;
122 }
123
124 @Override
125 public int hashCode() {
126 return name.hashCode();
127 }
128
129 @Override
130 public int getModifiers() {
131 return modifiers & ModifiersProvider.jvmFieldModifiers();
132 }
133
134 @Override
135 public boolean isInternal() {
136 return (modifiers & config().jvmAccFieldInternal) != 0;
137 }
138
139 /**
140 * Determines if a given object contains this field.
141 *
142 * @return true iff this is a non-static field and its declaring class is assignable from
143 * {@code object}'s class
144 */
145 public boolean isInObject(Object object) {
146 if (isStatic()) {
147 return false;
148 }
149 return getDeclaringClass().isAssignableFrom(HotSpotResolvedObjectTypeImpl.fromObjectClass(object.getClass()));
150 }
151
152 @Override
153 public HotSpotResolvedObjectTypeImpl getDeclaringClass() {
154 return holder;
155 }
156
157 @Override
158 public String getName() {
159 return name;
160 }
161
162 @Override
163 public JavaType getType() {
164 // Pull field into local variable to prevent a race causing
165 // a ClassCastException below
166 JavaType currentType = type;
167 if (currentType instanceof HotSpotUnresolvedJavaType) {
168 // Don't allow unresolved types to hang around forever
169 HotSpotUnresolvedJavaType unresolvedType = (HotSpotUnresolvedJavaType) currentType;
170 ResolvedJavaType resolved = unresolvedType.reresolve(holder);
171 if (resolved != null) {
172 type = resolved;
173 }
174 }
175 return type;
176 }
177
178 public int offset() {
179 return offset;
180 }
181
182 @Override
183 public String toString() {
184 return format("HotSpotField<%H.%n %t:") + offset + ">";
185 }
186
187 @Override
188 public boolean isSynthetic() {
189 return (config().jvmAccSynthetic & modifiers) != 0;
190 }
191
192 /**
193 * Checks if this field has the {@link Stable} annotation.
194 *
195 * @return true if field has {@link Stable} annotation, false otherwise
196 */
197 public boolean isStable() {
198 if ((config().jvmAccFieldStable & modifiers) != 0) {
199 return true;
200 }
201 assert getAnnotation(Stable.class) == null;
202 if (ImplicitStableValues && isImplicitStableField()) {
203 return true;
204 }
205 return false;
206 }
207
208 @Override
209 public Annotation[] getAnnotations() {
210 Field javaField = toJava();
211 if (javaField != null) {
212 return javaField.getAnnotations();
213 }
214 return new Annotation[0];
215 }
216
217 @Override
218 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
219 Field javaField = toJava();
220 if (javaField != null) {
221 return javaField.getAnnotation(annotationClass);
222 }
223 return null;
224 }
225
226 private Field toJavaCache;
227
228 private Field toJava() {
229 if (toJavaCache != null) {
230 return toJavaCache;
231 }
232
233 if (isInternal()) {
234 return null;
235 }
236 try {
237 return toJavaCache = holder.mirror().getDeclaredField(name);
238 } catch (NoSuchFieldException | NoClassDefFoundError e) {
239 return null;
240 }
241 }
242
243 private boolean isArray() {
244 JavaType fieldType = getType();
245 return fieldType instanceof ResolvedJavaType && ((ResolvedJavaType) fieldType).isArray();
246 }
247
248 private boolean isImplicitStableField() {
249 if (isSyntheticEnumSwitchMap()) {
250 return true;
251 }
252 if (isWellKnownImplicitStableField()) {
253 return true;
254 }
255 return false;
256 }
257
258 public boolean isDefaultStable() {
259 assert this.isStable();
260 if (isSyntheticEnumSwitchMap()) {
261 return true;
262 }
263 return false;
264 }
265
266 private boolean isSyntheticEnumSwitchMap() {
267 if (isSynthetic() && isStatic() && isArray()) {
268 if (isFinal() && name.equals("$VALUES") || name.equals("ENUM$VALUES")) {
269 // generated int[] field for EnumClass::values()
270 return true;
271 } else if (name.startsWith("$SwitchMap$") || name.startsWith("$SWITCH_TABLE$")) {
272 // javac and ecj generate a static field in an inner class for a switch on an enum
273 // named $SwitchMap$p$k$g$EnumClass and $SWITCH_TABLE$p$k$g$EnumClass, respectively
274 return true;
275 }
276 }
277 return false;
278 }
279
280 private boolean isWellKnownImplicitStableField() {
281 return WellKnownImplicitStableField.test(this);
282 }
283
284 static class WellKnownImplicitStableField {
285 /**
286 * @return {@code true} if the field is a well-known stable field.
287 */
288 public static boolean test(HotSpotResolvedJavaField field) {
289 return field.equals(STRING_VALUE_FIELD);
290 }
291
292 private static final ResolvedJavaField STRING_VALUE_FIELD;
293
294 static {
295 try {
296 MetaAccessProvider metaAccess = runtime().getHostJVMCIBackend().getMetaAccess();
297 STRING_VALUE_FIELD = metaAccess.lookupJavaField(String.class.getDeclaredField("value"));
298 } catch (SecurityException | NoSuchFieldException e) {
299 throw new JVMCIError(e);
300 }
301 }
302 }
303
304 public LocationIdentity getLocationIdentity() {
305 return locationIdentity;
306 }
307 }