1 /* 2 * Copyright (c) 2009, 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.meta; 24 25 import java.lang.reflect.AnnotatedElement; 26 27 import jdk.vm.ci.meta.Assumptions.AssumptionResult; 28 29 /** 30 * Represents a resolved Java type. Types include primitives, objects, {@code void}, and arrays 31 * thereof. Types, like fields and methods, are resolved through {@link ConstantPool constant pools} 32 * . 33 */ 34 public interface ResolvedJavaType extends JavaType, ModifiersProvider, AnnotatedElement { 35 /** 36 * Checks whether this type has a finalizer method. 37 * 38 * @return {@code true} if this class has a finalizer 39 */ hasFinalizer()40 boolean hasFinalizer(); 41 42 /** 43 * Checks whether this type has any finalizable subclasses so far. Any decisions based on this 44 * information require the registration of a dependency, since this information may change. 45 * 46 * @return {@code true} if this class has any subclasses with finalizers 47 */ hasFinalizableSubclass()48 AssumptionResult<Boolean> hasFinalizableSubclass(); 49 50 /** 51 * Checks whether this type is an interface. 52 * 53 * @return {@code true} if this type is an interface 54 */ 55 @Override isInterface()56 boolean isInterface(); 57 58 /** 59 * Checks whether this type is an instance class. 60 * 61 * @return {@code true} if this type is an instance class 62 */ isInstanceClass()63 boolean isInstanceClass(); 64 65 /** 66 * Checks whether this type is primitive. 67 * 68 * @return {@code true} if this type is primitive 69 */ isPrimitive()70 boolean isPrimitive(); 71 72 /* 73 * The setting of the final bit for types is a bit confusing since arrays are marked as final. 74 * This method provides a semantically equivalent test that appropriate for types. 75 */ isLeaf()76 default boolean isLeaf() { 77 return getElementalType().isFinalFlagSet(); 78 } 79 80 /** 81 * Checks whether this type is an enum. 82 * 83 * @return {@code true} if this type is an enum 84 */ isEnum()85 boolean isEnum(); 86 87 /** 88 * Checks whether this type is initialized. If a type is initialized it implies that it was 89 * {@link #isLinked() linked} and that the static initializer has run. 90 * 91 * @return {@code true} if this type is initialized 92 */ isInitialized()93 boolean isInitialized(); 94 95 /** 96 * Initializes this type. 97 */ initialize()98 void initialize(); 99 100 /** 101 * Checks whether this type is linked and verified. When a type is linked the static initializer 102 * has not necessarily run. An {@link #isInitialized() initialized} type is always linked. 103 * 104 * @return {@code true} if this type is linked 105 */ isLinked()106 boolean isLinked(); 107 108 /** 109 * Links this type. If this method returns normally, then future calls of {@link #isLinked} will 110 * return true and future calls of {@link #link} are no-ops. If the method throws an exception, 111 * then future calls of {@link #isLinked} will return false and future calls of {@link #link} 112 * will reattempt the linking step which might succeed or throw an exception. 113 */ link()114 default void link() { 115 throw new UnsupportedOperationException("link is unsupported"); 116 } 117 118 /** 119 * Checks whether this type or any of its supertypes or superinterfaces has default methods. 120 */ hasDefaultMethods()121 default boolean hasDefaultMethods() { 122 throw new UnsupportedOperationException("hasDefaultMethods is unsupported"); 123 } 124 125 /** 126 * Checks whether this type declares defaults methods. 127 */ declaresDefaultMethods()128 default boolean declaresDefaultMethods() { 129 throw new UnsupportedOperationException("declaresDefaultMethods is unsupported"); 130 } 131 132 /** 133 * Determines if this type is either the same as, or is a superclass or superinterface of, the 134 * type represented by the specified parameter. This method is identical to 135 * {@link Class#isAssignableFrom(Class)} in terms of the value return for this type. 136 */ isAssignableFrom(ResolvedJavaType other)137 boolean isAssignableFrom(ResolvedJavaType other); 138 139 /** 140 * Returns {@code null} since support for VM anonymous class was removed by JDK-8243287. 141 * This method is preserved for JVMCI backwards compatibility. 142 */ 143 @Deprecated getHostClass()144 default ResolvedJavaType getHostClass() { 145 return null; 146 } 147 148 /** 149 * Returns true if this type is exactly the type {@link java.lang.Object}. 150 */ isJavaLangObject()151 default boolean isJavaLangObject() { 152 // Removed assertion due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=434442 153 return getSuperclass() == null && !isInterface() && getJavaKind() == JavaKind.Object; 154 } 155 156 /** 157 * Checks whether the specified object is an instance of this type. 158 * 159 * @param obj the object to test 160 * @return {@code true} if the object is an instance of this type 161 */ isInstance(JavaConstant obj)162 boolean isInstance(JavaConstant obj); 163 164 /** 165 * Gets the super class of this type. If this type represents either the {@code Object} class, 166 * an interface, a primitive type, or void, then null is returned. If this object represents an 167 * array class then the type object representing the {@code Object} class is returned. 168 */ getSuperclass()169 ResolvedJavaType getSuperclass(); 170 171 /** 172 * Gets the interfaces implemented or extended by this type. This method is analogous to 173 * {@link Class#getInterfaces()} and as such, only returns the interfaces directly implemented 174 * or extended by this type. 175 */ getInterfaces()176 ResolvedJavaType[] getInterfaces(); 177 178 /** 179 * Gets the single implementor of this type. Calling this method on a non-interface type causes 180 * an exception. 181 * <p> 182 * If the compiler uses the result of this method for its compilation, the usage must be guarded 183 * because the verifier can not guarantee that the assigned type really implements this 184 * interface. Additionally, class loading can invalidate the result of this method. 185 * 186 * @return {@code null} if there is no implementor, the implementor if there is only one, or 187 * {@code this} if there are more than one. 188 */ getSingleImplementor()189 ResolvedJavaType getSingleImplementor(); 190 191 /** 192 * Walks the class hierarchy upwards and returns the least common class that is a superclass of 193 * both the current and the given type. 194 * 195 * @return the least common type that is a super type of both the current and the given type, or 196 * {@code null} if primitive types are involved. 197 */ findLeastCommonAncestor(ResolvedJavaType otherType)198 ResolvedJavaType findLeastCommonAncestor(ResolvedJavaType otherType); 199 200 /** 201 * Attempts to get a leaf concrete subclass of this type. 202 * <p> 203 * For an {@linkplain #isArray() array} type A, the leaf concrete subclass is A if the 204 * {@linkplain #getElementalType() elemental} type of A is final (which includes primitive 205 * types). Otherwise {@code null} is returned for A. 206 * <p> 207 * For a non-array type T, the result is the leaf concrete type in the current hierarchy of T. 208 * <p> 209 * A runtime may decide not to manage or walk a large hierarchy and so the result is 210 * conservative. That is, a non-null result is guaranteed to be the leaf concrete class in T's 211 * hierarchy <b>at the current point in time</b> but a null result does not necessarily imply 212 * that there is no leaf concrete class in T's hierarchy. 213 * <p> 214 * If the compiler uses the result of this method for its compilation, it must register the 215 * {@link AssumptionResult} in its {@link Assumptions} because dynamic class loading can 216 * invalidate the result of this method. 217 * 218 * @return an {@link AssumptionResult} containing the leaf concrete subclass for this type as 219 * described above 220 */ findLeafConcreteSubtype()221 AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype(); 222 223 @Override getComponentType()224 ResolvedJavaType getComponentType(); 225 226 @Override getElementalType()227 default ResolvedJavaType getElementalType() { 228 ResolvedJavaType t = this; 229 while (t.isArray()) { 230 t = t.getComponentType(); 231 } 232 return t; 233 } 234 235 @Override getArrayClass()236 ResolvedJavaType getArrayClass(); 237 238 /** 239 * Resolves the method implementation for virtual dispatches on objects of this dynamic type. 240 * This resolution process only searches "up" the class hierarchy of this type. A broader search 241 * that also walks "down" the hierarchy is implemented by 242 * {@link #findUniqueConcreteMethod(ResolvedJavaMethod)}. For interface types it returns null 243 * since no concrete object can be an interface. 244 * 245 * @param method the method to select the implementation of 246 * @param callerType the caller or context type used to perform access checks 247 * @return the link-time resolved method (might be abstract) or {@code null} if it is either a 248 * signature polymorphic method or can not be linked. 249 */ resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType)250 ResolvedJavaMethod resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType); 251 252 /** 253 * A convenience wrapper for {@link #resolveMethod(ResolvedJavaMethod, ResolvedJavaType)} that 254 * only returns non-abstract methods. 255 * 256 * @param method the method to select the implementation of 257 * @param callerType the caller or context type used to perform access checks 258 * @return the concrete method that would be selected at runtime, or {@code null} if there is no 259 * concrete implementation of {@code method} in this type or any of its superclasses 260 */ resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType)261 default ResolvedJavaMethod resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType) { 262 ResolvedJavaMethod resolvedMethod = resolveMethod(method, callerType); 263 if (resolvedMethod == null || resolvedMethod.isAbstract()) { 264 return null; 265 } 266 return resolvedMethod; 267 } 268 269 /** 270 * Given a {@link ResolvedJavaMethod} A, returns a concrete {@link ResolvedJavaMethod} B that is 271 * the only possible unique target for a virtual call on A(). Returns {@code null} if either no 272 * such concrete method or more than one such method exists. Returns the method A if A is a 273 * concrete method that is not overridden. 274 * <p> 275 * If the compiler uses the result of this method for its compilation, it must register an 276 * assumption because dynamic class loading can invalidate the result of this method. 277 * 278 * @param method the method A for which a unique concrete target is searched 279 * @return the unique concrete target or {@code null} if no such target exists or assumptions 280 * are not supported by this runtime 281 */ findUniqueConcreteMethod(ResolvedJavaMethod method)282 AssumptionResult<ResolvedJavaMethod> findUniqueConcreteMethod(ResolvedJavaMethod method); 283 284 /** 285 * Returns the instance fields of this class, including 286 * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned 287 * for array and primitive types. The order of fields returned by this method is stable. That 288 * is, for a single JVM execution the same order is returned each time this method is called. It 289 * is also the "natural" order, which means that the JVM would expect the fields in this order 290 * if no specific order is given. 291 * 292 * @param includeSuperclasses if true, then instance fields for the complete hierarchy of this 293 * type are included in the result 294 * @return an array of instance fields 295 */ getInstanceFields(boolean includeSuperclasses)296 ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses); 297 298 /** 299 * Returns the static fields of this class, including {@linkplain ResolvedJavaField#isInternal() 300 * internal} fields. A zero-length array is returned for array and primitive types. The order of 301 * fields returned by this method is stable. That is, for a single JVM execution the same order 302 * is returned each time this method is called. 303 */ getStaticFields()304 ResolvedJavaField[] getStaticFields(); 305 306 /** 307 * Returns the instance field of this class (or one of its super classes) at the given offset, 308 * or {@code null} if there is no such field. 309 * 310 * @param offset the offset of the field to look for 311 * @return the field with the given offset, or {@code null} if there is no such field. 312 */ findInstanceFieldWithOffset(long offset, JavaKind expectedKind)313 ResolvedJavaField findInstanceFieldWithOffset(long offset, JavaKind expectedKind); 314 315 /** 316 * Returns name of source file of this type. 317 */ getSourceFileName()318 String getSourceFileName(); 319 320 /** 321 * Returns {@code true} if the type is a local type. 322 */ isLocal()323 boolean isLocal(); 324 325 /** 326 * Returns {@code true} if the type is a member type. 327 */ isMember()328 boolean isMember(); 329 330 /** 331 * Returns the enclosing type of this type, if it exists, or {@code null}. 332 */ getEnclosingType()333 ResolvedJavaType getEnclosingType(); 334 335 /** 336 * Returns an array reflecting all the constructors declared by this type. This method is 337 * similar to {@link Class#getDeclaredConstructors()} in terms of returned constructors. Calling 338 * this method forces this type to be {@link #link linked}. 339 */ getDeclaredConstructors()340 ResolvedJavaMethod[] getDeclaredConstructors(); 341 342 /** 343 * Returns an array reflecting all the methods declared by this type. This method is similar to 344 * {@link Class#getDeclaredMethods()} in terms of returned methods. Calling this method forces 345 * this type to be {@link #link linked}. 346 */ getDeclaredMethods()347 ResolvedJavaMethod[] getDeclaredMethods(); 348 349 /** 350 * Returns the {@code <clinit>} method for this class if there is one. 351 */ getClassInitializer()352 ResolvedJavaMethod getClassInitializer(); 353 findMethod(String name, Signature signature)354 default ResolvedJavaMethod findMethod(String name, Signature signature) { 355 for (ResolvedJavaMethod method : getDeclaredMethods()) { 356 if (method.getName().equals(name) && method.getSignature().equals(signature)) { 357 return method; 358 } 359 } 360 return null; 361 } 362 363 /** 364 * Returns true if this type is {@link Cloneable} and can be safely cloned by creating a normal 365 * Java allocation and populating it from the fields returned by 366 * {@link #getInstanceFields(boolean)}. Some types may require special handling by the platform 367 * so they would to go through the normal {@link Object#clone} path. 368 */ isCloneableWithAllocation()369 boolean isCloneableWithAllocation(); 370 371 /** 372 * Lookup an unresolved type relative to an existing resolved type. 373 */ 374 @SuppressWarnings("unused") lookupType(UnresolvedJavaType unresolvedJavaType, boolean resolve)375 default ResolvedJavaType lookupType(UnresolvedJavaType unresolvedJavaType, boolean resolve) { 376 return null; 377 } 378 379 @SuppressWarnings("unused") resolveField(UnresolvedJavaField unresolvedJavaField, ResolvedJavaType accessingClass)380 default ResolvedJavaField resolveField(UnresolvedJavaField unresolvedJavaField, ResolvedJavaType accessingClass) { 381 return null; 382 } 383 } 384