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 import java.net.URL;
27
28 import jdk.vm.ci.meta.Assumptions.AssumptionResult;
29
30 /**
31 * Represents a resolved Java type. Types include primitives, objects, {@code void}, and arrays
32 * thereof. Types, like fields and methods, are resolved through {@link ConstantPool constant pools}
33 * .
34 */
35 public interface ResolvedJavaType extends JavaType, ModifiersProvider {
36 /**
37 * Checks whether this type has a finalizer method.
38 *
39 * @return {@code true} if this class has a finalizer
40 */
41 boolean hasFinalizer();
42
43 /**
44 * Checks whether this type has any finalizable subclasses so far. Any decisions based on this
45 * information require the registration of a dependency, since this information may change.
46 *
47 * @return {@code true} if this class has any subclasses with finalizers
48 */
49 AssumptionResult<Boolean> hasFinalizableSubclass();
50
51 /**
52 * Checks whether this type is an interface.
53 *
54 * @return {@code true} if this type is an interface
55 */
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 */
63 boolean isInstanceClass();
64
65 /**
66 * Checks whether this type is an array class.
67 *
68 * @return {@code true} if this type is an array class
69 */
70 boolean isArray();
71
72 /**
73 * Checks whether this type is primitive.
74 *
75 * @return {@code true} if this type is primitive
76 */
77 boolean isPrimitive();
78
79 /**
80 * {@inheritDoc}
81 * <p>
82 * Only the flags specified in the JVM specification will be included in the returned mask. This
83 * method is identical to {@link Class#getModifiers()} in terms of the value return for this
84 * type.
85 */
86 int getModifiers();
87
88 /*
89 * The setting of the final bit for types is a bit confusing since arrays are marked as final.
90 * This method provides a semantically equivalent test that appropriate for types.
91 */
92 default boolean isLeaf() {
93 return getElementalType().isFinalFlagSet();
94 }
95
96 /**
97 * Checks whether this type is initialized. If a type is initialized it implies that it was
98 * {@link #isLinked() linked} and that the static initializer has run.
99 *
100 * @return {@code true} if this type is initialized
101 */
102 boolean isInitialized();
103
104 /**
105 * Initializes this type.
106 */
107 void initialize();
108
109 /**
110 * Checks whether this type is linked and verified. When a type is linked the static initializer
111 * has not necessarily run. An {@link #isInitialized() initialized} type is always linked.
112 *
113 * @return {@code true} if this type is linked
114 */
115 boolean isLinked();
116
117 /**
118 * Determines if this type is either the same as, or is a superclass or superinterface of, the
119 * type represented by the specified parameter. This method is identical to
120 * {@link Class#isAssignableFrom(Class)} in terms of the value return for this type.
121 */
122 boolean isAssignableFrom(ResolvedJavaType other);
123
124 /**
125 * Returns true if this type is exactly the type {@link java.lang.Object}.
126 */
127 default boolean isJavaLangObject() {
128 // Removed assertion due to https://bugs.eclipse.org/bugs/show_bug.cgi?id=434442
129 return getSuperclass() == null && !isInterface() && getJavaKind() == JavaKind.Object;
130 }
131
132 /**
133 * Checks whether the specified object is an instance of this type.
134 *
135 * @param obj the object to test
136 * @return {@code true} if the object is an instance of this type
137 */
138 boolean isInstance(JavaConstant obj);
139
140 /**
141 * Returns this type if it is an exact type otherwise returns null. This type is exact if it is
142 * void, primitive, final, or an array of a final or primitive type.
143 *
144 * @return this type if it is exact; {@code null} otherwise
145 */
146 ResolvedJavaType asExactType();
147
148 /**
149 * Gets the super class of this type. If this type represents either the {@code Object} class,
150 * an interface, a primitive type, or void, then null is returned. If this object represents an
151 * array class then the type object representing the {@code Object} class is returned.
152 */
153 ResolvedJavaType getSuperclass();
154
155 /**
156 * Gets the interfaces implemented or extended by this type. This method is analogous to
157 * {@link Class#getInterfaces()} and as such, only returns the interfaces directly implemented
158 * or extended by this type.
159 */
160 ResolvedJavaType[] getInterfaces();
161
162 /**
163 * Gets the single implementor of this type. Calling this method on a non-interface type causes
164 * an exception.
165 * <p>
166 * If the compiler uses the result of this method for its compilation, the usage must be guarded
167 * because the verifier can not guarantee that the assigned type really implements this
168 * interface. Additionally, class loading can invalidate the result of this method.
169 *
170 * @return {@code null} if there is no implementor, the implementor if there is only one, or
171 * {@code this} if there are more than one.
172 */
173 ResolvedJavaType getSingleImplementor();
174
175 /**
176 * Walks the class hierarchy upwards and returns the least common class that is a superclass of
177 * both the current and the given type.
178 *
179 * @return the least common type that is a super type of both the current and the given type, or
180 * {@code null} if primitive types are involved.
181 */
182 ResolvedJavaType findLeastCommonAncestor(ResolvedJavaType otherType);
183
184 /**
185 * Attempts to get a leaf concrete subclass of this type.
186 * <p>
187 * For an {@linkplain #isArray() array} type A, the leaf concrete subclass is A if the
188 * {@linkplain #getElementalType() elemental} type of A is final (which includes primitive
189 * types). Otherwise {@code null} is returned for A.
190 * <p>
191 * For a non-array type T, the result is the leaf concrete type in the current hierarchy of T.
192 * <p>
193 * A runtime may decide not to manage or walk a large hierarchy and so the result is
194 * conservative. That is, a non-null result is guaranteed to be the leaf concrete class in T's
195 * hierarchy <b>at the current point in time</b> but a null result does not necessarily imply
196 * that there is no leaf concrete class in T's hierarchy.
197 * <p>
198 * If the compiler uses the result of this method for its compilation, it must register the
199 * {@link AssumptionResult} in its {@link Assumptions} because dynamic class loading can
200 * invalidate the result of this method.
201 *
202 * @return an {@link AssumptionResult} containing the leaf concrete subclass for this type as
203 * described above
204 */
205 AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype();
206
207 ResolvedJavaType getComponentType();
208
209 default ResolvedJavaType getElementalType() {
210 ResolvedJavaType t = this;
211 while (t.isArray()) {
212 t = t.getComponentType();
213 }
214 return t;
215 }
216
217 ResolvedJavaType getArrayClass();
218
219 /**
220 * Resolves the method implementation for virtual dispatches on objects of this dynamic type.
221 * This resolution process only searches "up" the class hierarchy of this type.
222 *
223 * @param method the method to select the implementation of
224 * @param callerType the caller or context type used to perform access checks
225 * @return the link-time resolved method (might be abstract) or {@code null} if it can not be
226 * linked
227 */
228 ResolvedJavaMethod resolveMethod(ResolvedJavaMethod method, ResolvedJavaType callerType);
229
230 /**
231 * Resolves the method implementation for virtual dispatches on objects of this dynamic type.
232 * This resolution process only searches "up" the class hierarchy of this type. A broader search
233 * that also walks "down" the hierarchy is implemented by
234 * {@link #findUniqueConcreteMethod(ResolvedJavaMethod)}.
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 ResolvedJavaMethod resolveConcreteMethod(ResolvedJavaMethod method, ResolvedJavaType callerType);
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 */
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 */
270 ResolvedJavaField[] getInstanceFields(boolean includeSuperclasses);
271
272 /**
273 * Returns the static fields of this class, including
274 * {@linkplain ResolvedJavaField#isInternal() internal} fields. A zero-length array is returned
275 * for array and primitive types. The order of fields returned by this method is stable. That
276 * is, for a single JVM execution the same order is returned each time this method is called.
277 */
278 ResolvedJavaField[] getStaticFields();
279
280 /**
281 * Returns all annotations of this class. If no annotations are present, an array of length 0 is
282 * returned.
283 */
284 Annotation[] getAnnotations();
285
286 /**
287 * Returns the annotation for the specified type of this class, if such an annotation is
288 * present.
289 *
290 * @param annotationClass the Class object corresponding to the annotation type
291 * @return this element's annotation for the specified annotation type if present on this class,
292 * else {@code null}
293 */
294 <T extends Annotation> T getAnnotation(Class<T> annotationClass);
295
296 /**
297 * Returns the instance field of this class (or one of its super classes) at the given offset,
298 * or {@code null} if there is no such field.
299 *
300 * @param offset the offset of the field to look for
301 * @return the field with the given offset, or {@code null} if there is no such field.
302 */
303 ResolvedJavaField findInstanceFieldWithOffset(long offset, JavaKind expectedKind);
304
305 /**
306 * Returns name of source file of this type.
307 */
308 String getSourceFileName();
309
310 /**
311 * Returns the class file path - if available - of this type, or {@code null}.
312 */
313 URL getClassFilePath();
314
315 /**
316 * Returns {@code true} if the type is a local type.
317 */
318 boolean isLocal();
319
320 /**
321 * Returns {@code true} if the type is a member type.
322 */
323 boolean isMember();
324
325 /**
326 * Returns the enclosing type of this type, if it exists, or {@code null}.
327 */
328 ResolvedJavaType getEnclosingType();
329
330 /**
331 * Returns an array reflecting all the constructors declared by this type. This method is
332 * similar to {@link Class#getDeclaredConstructors()} in terms of returned constructors.
333 */
334 ResolvedJavaMethod[] getDeclaredConstructors();
335
336 /**
337 * Returns an array reflecting all the methods declared by this type. This method is similar to
338 * {@link Class#getDeclaredMethods()} in terms of returned methods.
339 */
340 ResolvedJavaMethod[] getDeclaredMethods();
341
342 /**
343 * Returns the {@code <clinit>} method for this class if there is one.
344 */
345 ResolvedJavaMethod getClassInitializer();
346
347 /**
348 * Returns true if this type represents an interface and it should be trusted even in places
349 * where the JVM verifier would not give any guarantees other than {@link Object}.
350 */
351 boolean isTrustedInterfaceType();
352
353 default ResolvedJavaMethod findMethod(String name, Signature signature) {
354 for (ResolvedJavaMethod method : getDeclaredMethods()) {
355 if (method.getName().equals(name) && method.getSignature().equals(signature)) {
356 return method;
357 }
358 }
359 return null;
360 }
361 }