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.meta; 24 25 import java.lang.annotation.Annotation; 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 { 35 /** 36 * Checks whether this type has a finalizer method. 37 * 38 * @return {@code true} if this class has a finalizer 39 */ 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 */ 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 boolean isInterface(); 56 57 /** 58 * Checks whether this type is an instance class. 59 * 60 * @return {@code true} if this type is an instance class 61 */ 62 boolean isInstanceClass(); 63 64 /** 65 * Checks whether this type is an array class. 66 * 67 * @return {@code true} if this type is an array class 68 */ 69 boolean isArray(); 70 71 /** 72 * Checks whether this type is primitive. 73 * 74 * @return {@code true} if this type is primitive 75 */ 76 boolean isPrimitive(); 77 78 /** 79 * {@inheritDoc} 80 * <p> 81 * Only the flags specified in the JVM specification will be included in the returned mask. This 82 * method is identical to {@link Class#getModifiers()} in terms of the value return for this 83 * type. 84 */ 85 int getModifiers(); 86 87 /* 88 * The setting of the final bit for types is a bit confusing since arrays are marked as final. 89 * This method provides a semantically equivalent test that appropriate for types. 90 */ 91 default boolean isLeaf() { 92 return getElementalType().isFinalFlagSet(); 93 } 94 95 /** 96 * Checks whether this type is initialized. If a type is initialized it implies that it was 97 * {@link #isLinked() linked} and that the static initializer has run. 98 * 99 * @return {@code true} if this type is initialized 100 */ 101 boolean isInitialized(); 102 103 /** 104 * Initializes this type. 105 */ 106 void initialize(); 107 108 /** 109 * Checks whether this type is linked and verified. When a type is linked the static initializer 110 * has not necessarily run. An {@link #isInitialized() initialized} type is always linked. 111 * 112 * @return {@code true} if this type is linked 113 */ 114 boolean isLinked(); 115 116 /** 117 * Determines if this type is either the same as, or is a superclass or superinterface of, the 118 * type represented by the specified parameter. This method is identical to 119 * {@link Class#isAssignableFrom(Class)} in terms of the value return for this type. 120 */ 121 boolean isAssignableFrom(ResolvedJavaType other); 122 123 /** 124 * Returns true if this type is exactly the type {@link java.lang.Object}. 125 */ 126 default boolean isJavaLangObject() { 127 // Removed assertion due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=434442 128 return getSuperclass() == null && !isInterface() && getJavaKind() == JavaKind.Object; 129 } 130 131 /** 132 * Checks whether the specified object is an instance of this type. 133 * 134 * @param obj the object to test 135 * @return {@code true} if the object is an instance of this type 136 */ 137 boolean isInstance(JavaConstant obj); 138 139 /** 140 * Returns this type if it is an exact type otherwise returns null. This type is exact if it is 141 * void, primitive, final, or an array of a final or primitive type. 142 * 143 * @return this type if it is exact; {@code null} otherwise 144 */ 145 ResolvedJavaType asExactType(); 146 147 /** 148 * Gets the super class of this type. If this type represents either the {@code Object} class, 149 * an interface, a primitive type, or void, then null is returned. If this object represents an 150 * array class then the type object representing the {@code Object} class is returned. 151 */ 152 ResolvedJavaType getSuperclass(); 153 154 /** 155 * Gets the interfaces implemented or extended by this type. This method is analogous to 156 * {@link Class#getInterfaces()} and as such, only returns the interfaces directly implemented 157 * or extended by this type. 158 */ 159 ResolvedJavaType[] getInterfaces(); 160 161 /** 162 * Gets the single implementor of this type. Calling this method on a non-interface type causes 163 * an exception. 164 * <p> 165 * If the compiler uses the result of this method for its compilation, the usage must be guarded 166 * because the verifier can not guarantee that the assigned type really implements this 167 * interface. Additionally, class loading can invalidate the result of this method. 168 * 169 * @return {@code null} if there is no implementor, the implementor if there is only one, or 170 * {@code this} if there are more than one. 171 */ 172 ResolvedJavaType getSingleImplementor(); 173 174 /** 175 * Walks the class hierarchy upwards and returns the least common class that is a superclass of 176 * both the current and the given type. 177 * 178 * @return the least common type that is a super type of both the current and the given type, or 179 * {@code null} if primitive types are involved. 180 */ 181 ResolvedJavaType findLeastCommonAncestor(ResolvedJavaType otherType); 182 183 /** 184 * Attempts to get a leaf concrete subclass of this type. 185 * <p> 186 * For an {@linkplain #isArray() array} type A, the leaf concrete subclass is A if the 187 * {@linkplain #getElementalType() elemental} type of A is final (which includes primitive 188 * types). Otherwise {@code null} is returned for A. 189 * <p> 190 * For a non-array type T, the result is the leaf concrete type in the current hierarchy of T. 191 * <p> 192 * A runtime may decide not to manage or walk a large hierarchy and so the result is 193 * conservative. That is, a non-null result is guaranteed to be the leaf concrete class in T's 194 * hierarchy <b>at the current point in time</b> but a null result does not necessarily imply 195 * that there is no leaf concrete class in T's hierarchy. 196 * <p> 197 * If the compiler uses the result of this method for its compilation, it must register the 198 * {@link AssumptionResult} in its {@link Assumptions} because dynamic class loading can 199 * invalidate the result of this method. 200 * 201 * @return an {@link AssumptionResult} containing the leaf concrete subclass for this type as 202 * described above 203 */ 204 AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype(); 205 206 ResolvedJavaType getComponentType(); 207 208 default ResolvedJavaType getElementalType() { 209 ResolvedJavaType t = this; 210 while (t.isArray()) { 211 t = t.getComponentType(); 212 } 213 return t; 214 } 215 216 ResolvedJavaType getArrayClass(); 217 218 /** 219 * Resolves the method implementation for virtual dispatches on objects of this dynamic type. 220 * This resolution process only searches "up" the class hierarchy of this type. A broader search 221 * that also walks "down" the hierarchy is implemented by 222 * {@link #findUniqueConcreteMethod(ResolvedJavaMethod)}. For interface types it returns null 223 * since no concrete object can be an interface. 224 * 225 * @param method the method to select the implementation of 226 * @param callerType the caller or context type used to perform access checks 227 * @return the method that would be selected at runtime (might be abstract) or {@code null} if 228 * it can not be resolved 229 */ 230 ResolvedJavaMethod resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType); 231 232 /** 233 * A convenience wrapper for {@link #resolveMethod(ResolvedJavaMethod, ResolvedJavaType)} that 234 * only returns non-abstract methods. 235 * 236 * @param method the method to select the implementation of 237 * @param callerType the caller or context type used to perform access checks 238 * @return the concrete method that would be selected at runtime, or {@code null} if there is no 239 * concrete implementation of {@code method} in this type or any of its superclasses 240 */ 241 default ResolvedJavaMethod resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType) { 242 ResolvedJavaMethod resolvedMethod = resolveMethod(method, callerType); 243 if (resolvedMethod == null || resolvedMethod.isAbstract()) { 244 return null; 245 } 246 return resolvedMethod; 247 } 248 249 /** 250 * Given a {@link ResolvedJavaMethod} A, returns a concrete {@link ResolvedJavaMethod} B that is 251 * the only possible unique target for a virtual call on A(). Returns {@code null} if either no 252 * such concrete method or more than one such method exists. Returns the method A if A is a 253 * concrete method that is not overridden. 254 * <p> 255 * If the compiler uses the result of this method for its compilation, it must register an 256 * assumption because dynamic class loading can invalidate the result of this method. 257 * 258 * @param method the method A for which a unique concrete target is searched 259 * @return the unique concrete target or {@code null} if no such target exists or assumptions 260 * are not supported by this runtime 261 */ 262 AssumptionResult<ResolvedJavaMethod> findUniqueConcreteMethod(ResolvedJavaMethod method); 263 264 /** 265 * Returns the instance fields of this class, including 266 * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned 267 * for array and primitive types. The order of fields returned by this method is stable. That 268 * is, for a single JVM execution the same order is returned each time this method is called. It 269 * is also the "natural" order, which means that the JVM would expect the fields in this order 270 * if no specific order is given. 271 * 272 * @param includeSuperclasses if true, then instance fields for the complete hierarchy of this 273 * type are included in the result 274 * @return an array of instance fields 275 */ 276 ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses); 277 278 /** 279 * Returns the static fields of this class, including 280 * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned 281 * for array and primitive types. The order of fields returned by this method is stable. That 282 * is, for a single JVM execution the same order is returned each time this method is called. 283 */ 284 ResolvedJavaField[] getStaticFields(); 285 286 /** 287 * Returns all annotations of this class. If no annotations are present, an array of length 0 is 288 * returned. 289 */ 290 Annotation[] getAnnotations(); 291 292 /** 293 * Returns the annotation for the specified type of this class, if such an annotation is 294 * present. 295 * 296 * @param annotationClass the Class object corresponding to the annotation type 297 * @return this element's annotation for the specified annotation type if present on this class, 298 * else {@code null} 299 */ 300 <T extends Annotation> T getAnnotation(Class<T> annotationClass); 301 302 /** 303 * Returns the instance field of this class (or one of its super classes) at the given offset, 304 * or {@code null} if there is no such field. 305 * 306 * @param offset the offset of the field to look for 307 * @return the field with the given offset, or {@code null} if there is no such field. 308 */ 309 ResolvedJavaField findInstanceFieldWithOffset(long offset, JavaKind expectedKind); 310 311 /** 312 * Returns name of source file of this type. 313 */ 314 String getSourceFileName(); 315 316 /** 317 * Returns {@code true} if the type is a local type. 318 */ 319 boolean isLocal(); 320 321 /** 322 * Returns {@code true} if the type is a member type. 323 */ 324 boolean isMember(); 325 326 /** 327 * Returns the enclosing type of this type, if it exists, or {@code null}. 328 */ 329 ResolvedJavaType getEnclosingType(); 330 331 /** 332 * Returns an array reflecting all the constructors declared by this type. This method is 333 * similar to {@link Class#getDeclaredConstructors()} in terms of returned constructors. 334 */ 335 ResolvedJavaMethod[] getDeclaredConstructors(); 336 337 /** 338 * Returns an array reflecting all the methods declared by this type. This method is similar to 339 * {@link Class#getDeclaredMethods()} in terms of returned methods. 340 */ 341 ResolvedJavaMethod[] getDeclaredMethods(); 342 343 /** 344 * Returns the {@code <clinit>} method for this class if there is one. 345 */ 346 ResolvedJavaMethod getClassInitializer(); 347 348 /** 349 * Returns true if this type represents an interface and it should be trusted even in places 350 * where the JVM verifier would not give any guarantees other than {@link Object}. 351 */ 352 boolean isTrustedInterfaceType(); 353 354 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 */ 369 boolean isCloneableWithAllocation(); 370 }