1 /*
2 * Copyright (c) 2009, 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.HotSpotResolvedObjectTypeImpl.fromObjectClass;
26
27 import java.lang.invoke.CallSite;
28 import java.lang.invoke.ConstantCallSite;
29 import java.lang.invoke.MethodHandle;
30
31 import jdk.vm.ci.meta.Assumptions;
32 import jdk.vm.ci.meta.Constant;
33 import jdk.vm.ci.meta.JavaConstant;
34 import jdk.vm.ci.meta.JavaKind;
35 import jdk.vm.ci.meta.ResolvedJavaType;
36
37 /**
38 * Represents a constant non-{@code null} object reference, within the compiler and across the
39 * compiler/runtime interface.
40 */
41 final class HotSpotObjectConstantImpl implements HotSpotObjectConstant {
42
43 static JavaConstant forObject(Object object) {
44 return forObject(object, false);
45 }
46
47 static JavaConstant forObject(Object object, boolean compressed) {
48 if (object == null) {
49 return compressed ? HotSpotCompressedNullConstant.COMPRESSED_NULL : JavaConstant.NULL_POINTER;
50 } else {
51 return new HotSpotObjectConstantImpl(object, compressed);
52 }
53 }
54
55 public static JavaConstant forBoxedValue(JavaKind kind, Object value) {
56 if (kind == JavaKind.Object) {
57 return HotSpotObjectConstantImpl.forObject(value);
58 } else {
59 return JavaConstant.forBoxedPrimitive(value);
60 }
61 }
62
63 static Object asBoxedValue(Constant constant) {
64 if (JavaConstant.isNull(constant)) {
65 return null;
66 } else if (constant instanceof HotSpotObjectConstantImpl) {
67 return ((HotSpotObjectConstantImpl) constant).object;
68 } else {
69 return ((JavaConstant) constant).asBoxedPrimitive();
70 }
71 }
72
73 private final Object object;
74 private final boolean compressed;
75
76 private HotSpotObjectConstantImpl(Object object, boolean compressed) {
77 this.object = object;
78 this.compressed = compressed;
79 assert object != null;
80 }
81
82 @Override
83 public JavaKind getJavaKind() {
84 return JavaKind.Object;
85 }
86
87 /**
88 * Package-private accessor for the object represented by this constant.
89 */
90 Object object() {
91 return object;
92 }
93
94 public boolean isCompressed() {
95 return compressed;
96 }
97
98 public JavaConstant compress() {
99 assert !compressed;
100 return new HotSpotObjectConstantImpl(object, true);
101 }
102
103 public JavaConstant uncompress() {
104 assert compressed;
105 return new HotSpotObjectConstantImpl(object, false);
106 }
107
108 public HotSpotResolvedObjectType getType() {
109 return fromObjectClass(object.getClass());
110 }
111
112 public JavaConstant getClassLoader() {
113 if (object instanceof Class) {
114 /*
115 * This is an intrinsic for getClassLoader0, which occurs after any security checks. We
116 * can't call that directly so just call getClassLoader.
117 */
118 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getClassLoader());
119 }
120 return null;
121 }
122
123 public int getIdentityHashCode() {
124 return System.identityHashCode(object);
125 }
126
127 public JavaConstant getComponentType() {
128 if (object instanceof Class) {
129 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getComponentType());
130 }
131 return null;
132 }
133
134 public JavaConstant getSuperclass() {
135 if (object instanceof Class) {
136 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getSuperclass());
137 }
138 return null;
139 }
140
141 public JavaConstant getCallSiteTarget(Assumptions assumptions) {
142 if (object instanceof CallSite) {
143 CallSite callSite = (CallSite) object;
144 MethodHandle target = callSite.getTarget();
145 if (!(callSite instanceof ConstantCallSite)) {
146 if (assumptions == null) {
147 return null;
148 }
149 assumptions.record(new Assumptions.CallSiteTargetValue(callSite, target));
150 }
151 return HotSpotObjectConstantImpl.forObject(target);
152 }
153 return null;
154 }
155
156 @SuppressFBWarnings(value = "ES_COMPARING_STRINGS_WITH_EQ", justification = "reference equality is what we want")
157 public boolean isInternedString() {
158 if (object instanceof String) {
159 String s = (String) object;
160 return s.intern() == s;
161 }
162 return false;
163 }
164
165 public <T> T asObject(Class<T> type) {
166 if (type.isInstance(object)) {
167 return type.cast(object);
168 }
169 return null;
170 }
171
172 public Object asObject(ResolvedJavaType type) {
173 if (type.isInstance(this)) {
174 return object;
175 }
176 return null;
177 }
178
179 @Override
180 public boolean isNull() {
181 return false;
182 }
183
184 @Override
185 public boolean isDefaultForKind() {
186 return false;
187 }
188
189 @Override
190 public Object asBoxedPrimitive() {
191 throw new IllegalArgumentException();
192 }
193
194 @Override
195 public int asInt() {
196 throw new IllegalArgumentException();
197 }
198
199 @Override
200 public boolean asBoolean() {
201 throw new IllegalArgumentException();
202 }
203
204 @Override
205 public long asLong() {
206 throw new IllegalArgumentException();
207 }
208
209 @Override
210 public float asFloat() {
211 throw new IllegalArgumentException();
212 }
213
214 @Override
215 public double asDouble() {
216 throw new IllegalArgumentException();
217 }
218
219 @Override
220 public int hashCode() {
221 return System.identityHashCode(object);
222 }
223
224 @Override
225 public boolean equals(Object o) {
226 if (o == this) {
227 return true;
228 } else if (o instanceof HotSpotObjectConstantImpl) {
229 HotSpotObjectConstantImpl other = (HotSpotObjectConstantImpl) o;
230 return object == other.object && compressed == other.compressed;
231 }
232 return false;
233 }
234
235 @Override
236 public String toValueString() {
237 if (object instanceof String) {
238 return "\"" + (String) object + "\"";
239 } else {
240 return JavaKind.Object.format(object);
241 }
242 }
243
244 @Override
245 public String toString() {
246 return (compressed ? "NarrowOop" : getJavaKind().getJavaName()) + "[" + JavaKind.Object.format(object) + "]";
247 }
248 }