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.inittimer.SuppressFBWarnings; 32 import jdk.vm.ci.meta.Assumptions; 33 import jdk.vm.ci.meta.Constant; 34 import jdk.vm.ci.meta.JavaConstant; 35 import jdk.vm.ci.meta.JavaKind; 36 import jdk.vm.ci.meta.ResolvedJavaType; 37 38 /** 39 * Represents a constant non-{@code null} object reference, within the compiler and across the 40 * compiler/runtime interface. 41 */ 42 final class HotSpotObjectConstantImpl implements HotSpotObjectConstant, HotSpotProxified { 43 44 static JavaConstant forObject(Object object) { 45 return forObject(object, false); 46 } 47 48 static JavaConstant forObject(Object object, boolean compressed) { 49 if (object == null) { 50 return compressed ? HotSpotCompressedNullConstant.COMPRESSED_NULL : JavaConstant.NULL_POINTER; 51 } else { 52 return new HotSpotObjectConstantImpl(object, compressed); 53 } 54 } 55 56 static JavaConstant forStableArray(Object object, int stableDimension, boolean isDefaultStable) { 57 if (object == null) { 58 return JavaConstant.NULL_POINTER; 59 } else { 60 assert object.getClass().isArray(); 61 return new HotSpotObjectConstantImpl(object, false, stableDimension, isDefaultStable); 62 } 63 } 64 65 public static JavaConstant forBoxedValue(JavaKind kind, Object value) { 66 if (kind == JavaKind.Object) { 67 return HotSpotObjectConstantImpl.forObject(value); 68 } else { 69 return JavaConstant.forBoxedPrimitive(value); 70 } 71 } 72 73 static Object asBoxedValue(Constant constant) { 74 if (JavaConstant.isNull(constant)) { 75 return null; 76 } else if (constant instanceof HotSpotObjectConstantImpl) { 77 return ((HotSpotObjectConstantImpl) constant).object; 78 } else { 79 return ((JavaConstant) constant).asBoxedPrimitive(); 80 } 81 } 82 83 private final Object object; 84 private final boolean compressed; 85 private final byte stableDimension; 86 private final boolean isDefaultStable; 87 88 private HotSpotObjectConstantImpl(Object object, boolean compressed, int stableDimension, boolean isDefaultStable) { 89 this.object = object; 90 this.compressed = compressed; 91 this.stableDimension = (byte) stableDimension; 92 this.isDefaultStable = isDefaultStable; 93 assert object != null; 94 assert stableDimension == 0 || (object != null && object.getClass().isArray()); 95 assert stableDimension >= 0 && stableDimension <= 255; 96 assert !isDefaultStable || stableDimension > 0; 97 } 98 99 private HotSpotObjectConstantImpl(Object object, boolean compressed) { 100 this(object, compressed, 0, false); 101 } 102 103 @Override 104 public JavaKind getJavaKind() { 105 return JavaKind.Object; 106 } 107 108 /** 109 * Package-private accessor for the object represented by this constant. 110 */ 111 Object object() { 112 return object; 113 } 114 115 public boolean isCompressed() { 116 return compressed; 117 } 118 119 public JavaConstant compress() { 120 assert !compressed; 121 return new HotSpotObjectConstantImpl(object, true, stableDimension, isDefaultStable); 122 } 123 124 public JavaConstant uncompress() { 125 assert compressed; 126 return new HotSpotObjectConstantImpl(object, false, stableDimension, isDefaultStable); 127 } 128 129 public HotSpotResolvedObjectType getType() { 130 return fromObjectClass(object.getClass()); 131 } 132 133 public JavaConstant getClassLoader() { 134 if (object instanceof Class) { 135 /* 136 * This is an intrinsic for getClassLoader0, which occurs after any security checks. We 137 * can't call that directly so just call getClassLoader. 138 */ 139 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getClassLoader()); 140 } 141 return null; 142 } 143 144 public int getIdentityHashCode() { 145 return System.identityHashCode(object); 146 } 147 148 public JavaConstant getComponentType() { 149 if (object instanceof Class) { 150 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getComponentType()); 151 } 152 return null; 153 } 154 155 public JavaConstant getSuperclass() { 156 if (object instanceof Class) { 157 return HotSpotObjectConstantImpl.forObject(((Class<?>) object).getSuperclass()); 158 } 159 return null; 160 } 161 162 public JavaConstant getCallSiteTarget(Assumptions assumptions) { 163 if (object instanceof CallSite) { 164 CallSite callSite = (CallSite) object; 165 MethodHandle target = callSite.getTarget(); 166 if (!(callSite instanceof ConstantCallSite)) { 167 if (assumptions == null) { 168 return null; 169 } 170 assumptions.record(new Assumptions.CallSiteTargetValue(callSite, target)); 171 } 172 return HotSpotObjectConstantImpl.forObject(target); 173 } 174 return null; 175 } 176 177 @SuppressFBWarnings(value = "ES_COMPARING_STRINGS_WITH_EQ", justification = "reference equality is what we want") 178 public boolean isInternedString() { 179 if (object instanceof String) { 180 String s = (String) object; 181 return s.intern() == s; 182 } 183 return false; 184 } 185 186 public <T> T asObject(Class<T> type) { 187 if (type.isInstance(object)) { 188 return type.cast(object); 189 } 190 return null; 191 } 192 193 public Object asObject(ResolvedJavaType type) { 194 if (type.isInstance(this)) { 195 return object; 196 } 197 return null; 198 } 199 200 @Override 201 public boolean isNull() { 202 return false; 203 } 204 205 @Override 206 public boolean isDefaultForKind() { 207 return false; 208 } 209 210 @Override 211 public Object asBoxedPrimitive() { 212 throw new IllegalArgumentException(); 213 } 214 215 @Override 216 public int asInt() { 217 throw new IllegalArgumentException(); 218 } 219 220 @Override 221 public boolean asBoolean() { 222 throw new IllegalArgumentException(); 223 } 224 225 @Override 226 public long asLong() { 227 throw new IllegalArgumentException(); 228 } 229 230 @Override 231 public float asFloat() { 232 throw new IllegalArgumentException(); 233 } 234 235 @Override 236 public double asDouble() { 237 throw new IllegalArgumentException(); 238 } 239 240 @Override 241 public int hashCode() { 242 return System.identityHashCode(object); 243 } 244 245 @Override 246 public boolean equals(Object o) { 247 if (o == this) { 248 return true; 249 } else if (o instanceof HotSpotObjectConstantImpl) { 250 HotSpotObjectConstantImpl other = (HotSpotObjectConstantImpl) o; 251 return object == other.object && compressed == other.compressed && stableDimension == other.stableDimension && isDefaultStable == other.isDefaultStable; 252 } 253 return false; 254 } 255 256 @Override 257 public String toValueString() { 258 if (object instanceof String) { 259 return "\"" + (String) object + "\""; 260 } else { 261 return JavaKind.Object.format(object); 262 } 263 } 264 265 @Override 266 public String toString() { 267 return (compressed ? "NarrowOop" : getJavaKind().getJavaName()) + "[" + JavaKind.Object.format(object) + "]"; 268 } 269 270 /** 271 * Number of stable dimensions if this constant is a stable array. 272 */ 273 public int getStableDimension() { 274 return stableDimension & 0xff; 275 } 276 277 /** 278 * Returns {@code true} if this is a stable array constant and its elements should be considered 279 * as stable regardless of whether they are default values. 280 */ 281 public boolean isDefaultStable() { 282 return isDefaultStable; 283 } 284 }