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 * Determines if this type is either the same as, or is a superclass or superinterface of, the 110 * type represented by the specified parameter. This method is identical to 111 * {@link Class#isAssignableFrom(Class)} in terms of the value return for this type. 112 */ isAssignableFrom(ResolvedJavaType other)113 boolean isAssignableFrom(ResolvedJavaType other); 114 115 /** 116 * Returns the {@link ResolvedJavaType} object representing the host class of this VM anonymous 117 * class (as opposed to the unrelated concept specified by {@link Class#isAnonymousClass()}) or 118 * {@code null} if this object does not represent a VM anonymous class. 119 */ getHostClass()120 ResolvedJavaType getHostClass(); 121 122 /** 123 * Returns true if this type is exactly the type {@link java.lang.Object}. 124 */ isJavaLangObject()125 default boolean isJavaLangObject() { 126 // Removed assertion due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=434442 127 return getSuperclass() == null && !isInterface() && getJavaKind() == JavaKind.Object; 128 } 129 130 /** 131 * Checks whether the specified object is an instance of this type. 132 * 133 * @param obj the object to test 134 * @return {@code true} if the object is an instance of this type 135 */ isInstance(JavaConstant obj)136 boolean isInstance(JavaConstant obj); 137 138 /** 139 * Gets the super class of this type. If this type represents either the {@code Object} class, 140 * an interface, a primitive type, or void, then null is returned. If this object represents an 141 * array class then the type object representing the {@code Object} class is returned. 142 */ getSuperclass()143 ResolvedJavaType getSuperclass(); 144 145 /** 146 * Gets the interfaces implemented or extended by this type. This method is analogous to 147 * {@link Class#getInterfaces()} and as such, only returns the interfaces directly implemented 148 * or extended by this type. 149 */ getInterfaces()150 ResolvedJavaType[] getInterfaces(); 151 152 /** 153 * Gets the single implementor of this type. Calling this method on a non-interface type causes 154 * an exception. 155 * <p> 156 * If the compiler uses the result of this method for its compilation, the usage must be guarded 157 * because the verifier can not guarantee that the assigned type really implements this 158 * interface. Additionally, class loading can invalidate the result of this method. 159 * 160 * @return {@code null} if there is no implementor, the implementor if there is only one, or 161 * {@code this} if there are more than one. 162 */ getSingleImplementor()163 ResolvedJavaType getSingleImplementor(); 164 165 /** 166 * Walks the class hierarchy upwards and returns the least common class that is a superclass of 167 * both the current and the given type. 168 * 169 * @return the least common type that is a super type of both the current and the given type, or 170 * {@code null} if primitive types are involved. 171 */ findLeastCommonAncestor(ResolvedJavaType otherType)172 ResolvedJavaType findLeastCommonAncestor(ResolvedJavaType otherType); 173 174 /** 175 * Attempts to get a leaf concrete subclass of this type. 176 * <p> 177 * For an {@linkplain #isArray() array} type A, the leaf concrete subclass is A if the 178 * {@linkplain #getElementalType() elemental} type of A is final (which includes primitive 179 * types). Otherwise {@code null} is returned for A. 180 * <p> 181 * For a non-array type T, the result is the leaf concrete type in the current hierarchy of T. 182 * <p> 183 * A runtime may decide not to manage or walk a large hierarchy and so the result is 184 * conservative. That is, a non-null result is guaranteed to be the leaf concrete class in T's 185 * hierarchy <b>at the current point in time</b> but a null result does not necessarily imply 186 * that there is no leaf concrete class in T's hierarchy. 187 * <p> 188 * If the compiler uses the result of this method for its compilation, it must register the 189 * {@link AssumptionResult} in its {@link Assumptions} because dynamic class loading can 190 * invalidate the result of this method. 191 * 192 * @return an {@link AssumptionResult} containing the leaf concrete subclass for this type as 193 * described above 194 */ findLeafConcreteSubtype()195 AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype(); 196 197 @Override getComponentType()198 ResolvedJavaType getComponentType(); 199 200 @Override getElementalType()201 default ResolvedJavaType getElementalType() { 202 ResolvedJavaType t = this; 203 while (t.isArray()) { 204 t = t.getComponentType(); 205 } 206 return t; 207 } 208 209 @Override getArrayClass()210 ResolvedJavaType getArrayClass(); 211 212 /** 213 * Resolves the method implementation for virtual dispatches on objects of this dynamic type. 214 * This resolution process only searches "up" the class hierarchy of this type. A broader search 215 * that also walks "down" the hierarchy is implemented by 216 * {@link #findUniqueConcreteMethod(ResolvedJavaMethod)}. For interface types it returns null 217 * since no concrete object can be an interface. 218 * 219 * @param method the method to select the implementation of 220 * @param callerType the caller or context type used to perform access checks 221 * @return the link-time resolved method (might be abstract) or {@code null} if it is either a 222 * signature polymorphic method or can not be linked. 223 */ resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType)224 ResolvedJavaMethod resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType); 225 226 /** 227 * A convenience wrapper for {@link #resolveMethod(ResolvedJavaMethod, ResolvedJavaType)} that 228 * only returns non-abstract methods. 229 * 230 * @param method the method to select the implementation of 231 * @param callerType the caller or context type used to perform access checks 232 * @return the concrete method that would be selected at runtime, or {@code null} if there is no 233 * concrete implementation of {@code method} in this type or any of its superclasses 234 */ resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType)235 default ResolvedJavaMethod resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType) { 236 ResolvedJavaMethod resolvedMethod = resolveMethod(method, callerType); 237 if (resolvedMethod == null || resolvedMethod.isAbstract()) { 238 return null; 239 } 240 return resolvedMethod; 241 } 242 243 /** 244 * Given a {@link ResolvedJavaMethod} A, returns a concrete {@link ResolvedJavaMethod} B that is 245 * the only possible unique target for a virtual call on A(). Returns {@code null} if either no 246 * such concrete method or more than one such method exists. Returns the method A if A is a 247 * concrete method that is not overridden. 248 * <p> 249 * If the compiler uses the result of this method for its compilation, it must register an 250 * assumption because dynamic class loading can invalidate the result of this method. 251 * 252 * @param method the method A for which a unique concrete target is searched 253 * @return the unique concrete target or {@code null} if no such target exists or assumptions 254 * are not supported by this runtime 255 */ findUniqueConcreteMethod(ResolvedJavaMethod method)256 AssumptionResult<ResolvedJavaMethod> findUniqueConcreteMethod(ResolvedJavaMethod method); 257 258 /** 259 * Returns the instance fields of this class, including 260 * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned 261 * for array and primitive types. The order of fields returned by this method is stable. That 262 * is, for a single JVM execution the same order is returned each time this method is called. It 263 * is also the "natural" order, which means that the JVM would expect the fields in this order 264 * if no specific order is given. 265 * 266 * @param includeSuperclasses if true, then instance fields for the complete hierarchy of this 267 * type are included in the result 268 * @return an array of instance fields 269 */ getInstanceFields(boolean includeSuperclasses)270 ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses); 271 272 /** 273 * Returns the static fields of this class, including {@linkplain ResolvedJavaField#isInternal() 274 * internal} fields. A zero-length array is returned for array and primitive types. The order of 275 * fields returned by this method is stable. That is, for a single JVM execution the same order 276 * is returned each time this method is called. 277 */ getStaticFields()278 ResolvedJavaField[] getStaticFields(); 279 280 /** 281 * Returns the instance field of this class (or one of its super classes) at the given offset, 282 * or {@code null} if there is no such field. 283 * 284 * @param offset the offset of the field to look for 285 * @return the field with the given offset, or {@code null} if there is no such field. 286 */ findInstanceFieldWithOffset(long offset, JavaKind expectedKind)287 ResolvedJavaField findInstanceFieldWithOffset(long offset, JavaKind expectedKind); 288 289 /** 290 * Returns name of source file of this type. 291 */ getSourceFileName()292 String getSourceFileName(); 293 294 /** 295 * Returns {@code true} if the type is a local type. 296 */ isLocal()297 boolean isLocal(); 298 299 /** 300 * Returns {@code true} if the type is a member type. 301 */ isMember()302 boolean isMember(); 303 304 /** 305 * Returns the enclosing type of this type, if it exists, or {@code null}. 306 */ getEnclosingType()307 ResolvedJavaType getEnclosingType(); 308 309 /** 310 * Returns an array reflecting all the constructors declared by this type. This method is 311 * similar to {@link Class#getDeclaredConstructors()} in terms of returned constructors. 312 */ getDeclaredConstructors()313 ResolvedJavaMethod[] getDeclaredConstructors(); 314 315 /** 316 * Returns an array reflecting all the methods declared by this type. This method is similar to 317 * {@link Class#getDeclaredMethods()} in terms of returned methods. 318 */ getDeclaredMethods()319 ResolvedJavaMethod[] getDeclaredMethods(); 320 321 /** 322 * Returns the {@code <clinit>} method for this class if there is one. 323 */ getClassInitializer()324 ResolvedJavaMethod getClassInitializer(); 325 findMethod(String name, Signature signature)326 default ResolvedJavaMethod findMethod(String name, Signature signature) { 327 for (ResolvedJavaMethod method : getDeclaredMethods()) { 328 if (method.getName().equals(name) && method.getSignature().equals(signature)) { 329 return method; 330 } 331 } 332 return null; 333 } 334 335 /** 336 * Returns true if this type is {@link Cloneable} and can be safely cloned by creating a normal 337 * Java allocation and populating it from the fields returned by 338 * {@link #getInstanceFields(boolean)}. Some types may require special handling by the platform 339 * so they would to go through the normal {@link Object#clone} path. 340 */ isCloneableWithAllocation()341 boolean isCloneableWithAllocation(); 342 343 /** 344 * Lookup an unresolved type relative to an existing resolved type. 345 */ 346 @SuppressWarnings("unused") lookupType(UnresolvedJavaType unresolvedJavaType, boolean resolve)347 default ResolvedJavaType lookupType(UnresolvedJavaType unresolvedJavaType, boolean resolve) { 348 return null; 349 } 350 351 @SuppressWarnings("unused") resolveField(UnresolvedJavaField unresolvedJavaField, ResolvedJavaType accessingClass)352 default ResolvedJavaField resolveField(UnresolvedJavaField unresolvedJavaField, ResolvedJavaType accessingClass) { 353 return null; 354 } 355 } 356