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