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