1 /*
2 * Copyright (c) 2001, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.reflect;
27
28 import java.io.Externalizable;
29 import java.io.ObjectInputStream;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectStreamClass;
32 import java.io.OptionalDataException;
33 import java.io.Serializable;
34 import java.lang.invoke.MethodHandle;
35 import java.lang.invoke.MethodHandles;
36 import java.lang.reflect.Field;
37 import java.lang.reflect.Executable;
38 import java.lang.reflect.InvocationTargetException;
39 import java.lang.reflect.Method;
40 import java.lang.reflect.Constructor;
41 import java.lang.reflect.Modifier;
42 import java.security.Permission;
43 import java.security.PrivilegedAction;
44 import java.util.Objects;
45 import java.util.Properties;
46
47 import sun.reflect.misc.ReflectUtil;
48 import sun.security.action.GetPropertyAction;
49
50 /** <P> The master factory for all reflective objects, both those in
51 java.lang.reflect (Fields, Methods, Constructors) as well as their
52 delegates (FieldAccessors, MethodAccessors, ConstructorAccessors).
53 </P>
54
55 <P> The methods in this class are extremely unsafe and can cause
56 subversion of both the language and the verifier. For this reason,
57 they are all instance methods, and access to the constructor of
58 this factory is guarded by a security check, in similar style to
59 {@link jdk.internal.misc.Unsafe}. </P>
60 */
61
62 public class ReflectionFactory {
63
64 private static boolean initted = false;
65 private static final Permission reflectionFactoryAccessPerm
66 = new RuntimePermission("reflectionFactoryAccess");
67 private static final ReflectionFactory soleInstance = new ReflectionFactory();
68 // Provides access to package-private mechanisms in java.lang.reflect
69 private static volatile LangReflectAccess langReflectAccess;
70
71 /* Method for static class initializer <clinit>, or null */
72 private static volatile Method hasStaticInitializerMethod;
73
74 //
75 // "Inflation" mechanism. Loading bytecodes to implement
76 // Method.invoke() and Constructor.newInstance() currently costs
77 // 3-4x more than an invocation via native code for the first
78 // invocation (though subsequent invocations have been benchmarked
79 // to be over 20x faster). Unfortunately this cost increases
80 // startup time for certain applications that use reflection
81 // intensively (but only once per class) to bootstrap themselves.
82 // To avoid this penalty we reuse the existing JVM entry points
83 // for the first few invocations of Methods and Constructors and
84 // then switch to the bytecode-based implementations.
85 //
86 // Package-private to be accessible to NativeMethodAccessorImpl
87 // and NativeConstructorAccessorImpl
88 private static boolean noInflation = false;
89 private static int inflationThreshold = 15;
90
91 private ReflectionFactory() {
92 }
93
94 /**
95 * A convenience class for acquiring the capability to instantiate
96 * reflective objects. Use this instead of a raw call to {@link
97 * #getReflectionFactory} in order to avoid being limited by the
98 * permissions of your callers.
99 *
100 * <p>An instance of this class can be used as the argument of
101 * <code>AccessController.doPrivileged</code>.
102 */
103 public static final class GetReflectionFactoryAction
104 implements PrivilegedAction<ReflectionFactory> {
105 public ReflectionFactory run() {
106 return getReflectionFactory();
107 }
108 }
109
110 /**
111 * Provides the caller with the capability to instantiate reflective
112 * objects.
113 *
114 * <p> First, if there is a security manager, its
115 * <code>checkPermission</code> method is called with a {@link
116 * java.lang.RuntimePermission} with target
117 * <code>"reflectionFactoryAccess"</code>. This may result in a
118 * security exception.
119 *
120 * <p> The returned <code>ReflectionFactory</code> object should be
121 * carefully guarded by the caller, since it can be used to read and
122 * write private data and invoke private methods, as well as to load
123 * unverified bytecodes. It must never be passed to untrusted code.
124 *
125 * @exception SecurityException if a security manager exists and its
126 * <code>checkPermission</code> method doesn't allow
127 * access to the RuntimePermission "reflectionFactoryAccess". */
128 public static ReflectionFactory getReflectionFactory() {
129 SecurityManager security = System.getSecurityManager();
130 if (security != null) {
131 // TO DO: security.checkReflectionFactoryAccess();
132 security.checkPermission(reflectionFactoryAccessPerm);
133 }
134 return soleInstance;
135 }
136
137 //--------------------------------------------------------------------------
138 //
139 // Routines used by java.lang.reflect
140 //
141 //
142
143 /** Called only by java.lang.reflect.Modifier's static initializer */
144 public void setLangReflectAccess(LangReflectAccess access) {
145 langReflectAccess = access;
146 }
147
148 /**
149 * Note: this routine can cause the declaring class for the field
150 * be initialized and therefore must not be called until the
151 * first get/set of this field.
152 * @param field the field
153 * @param override true if caller has overridden accessibility
154 */
155 public FieldAccessor newFieldAccessor(Field field, boolean override) {
156 checkInitted();
157 return UnsafeFieldAccessorFactory.newFieldAccessor(field, override);
158 }
159
160 public MethodAccessor newMethodAccessor(Method method) {
161 checkInitted();
162
163 if (noInflation && !ReflectUtil.isVMAnonymousClass(method.getDeclaringClass())) {
164 return new MethodAccessorGenerator().
165 generateMethod(method.getDeclaringClass(),
166 method.getName(),
167 method.getParameterTypes(),
168 method.getReturnType(),
169 method.getExceptionTypes(),
170 method.getModifiers());
171 } else {
172 NativeMethodAccessorImpl acc =
173 new NativeMethodAccessorImpl(method);
174 DelegatingMethodAccessorImpl res =
175 new DelegatingMethodAccessorImpl(acc);
176 acc.setParent(res);
177 return res;
178 }
179 }
180
181 public ConstructorAccessor newConstructorAccessor(Constructor<?> c) {
182 checkInitted();
183
184 Class<?> declaringClass = c.getDeclaringClass();
185 if (Modifier.isAbstract(declaringClass.getModifiers())) {
186 return new InstantiationExceptionConstructorAccessorImpl(null);
187 }
188 if (declaringClass == Class.class) {
189 return new InstantiationExceptionConstructorAccessorImpl
190 ("Can not instantiate java.lang.Class");
191 }
192 // Bootstrapping issue: since we use Class.newInstance() in
193 // the ConstructorAccessor generation process, we have to
194 // break the cycle here.
195 if (Reflection.isSubclassOf(declaringClass,
196 ConstructorAccessorImpl.class)) {
197 return new BootstrapConstructorAccessorImpl(c);
198 }
199
200 if (noInflation && !ReflectUtil.isVMAnonymousClass(c.getDeclaringClass())) {
201 return new MethodAccessorGenerator().
202 generateConstructor(c.getDeclaringClass(),
203 c.getParameterTypes(),
204 c.getExceptionTypes(),
205 c.getModifiers());
206 } else {
207 NativeConstructorAccessorImpl acc =
208 new NativeConstructorAccessorImpl(c);
209 DelegatingConstructorAccessorImpl res =
210 new DelegatingConstructorAccessorImpl(acc);
211 acc.setParent(res);
212 return res;
213 }
214 }
215
216 //--------------------------------------------------------------------------
217 //
218 // Routines used by java.lang
219 //
220 //
221
222 /** Creates a new java.lang.reflect.Field. Access checks as per
223 java.lang.reflect.AccessibleObject are not overridden. */
224 public Field newField(Class<?> declaringClass,
225 String name,
226 Class<?> type,
227 int modifiers,
228 int slot,
229 String signature,
230 byte[] annotations)
231 {
232 return langReflectAccess().newField(declaringClass,
233 name,
234 type,
235 modifiers,
236 slot,
237 signature,
238 annotations);
239 }
240
241 /** Creates a new java.lang.reflect.Method. Access checks as per
242 java.lang.reflect.AccessibleObject are not overridden. */
243 public Method newMethod(Class<?> declaringClass,
244 String name,
245 Class<?>[] parameterTypes,
246 Class<?> returnType,
247 Class<?>[] checkedExceptions,
248 int modifiers,
249 int slot,
250 String signature,
251 byte[] annotations,
252 byte[] parameterAnnotations,
253 byte[] annotationDefault)
254 {
255 return langReflectAccess().newMethod(declaringClass,
256 name,
257 parameterTypes,
258 returnType,
259 checkedExceptions,
260 modifiers,
261 slot,
262 signature,
263 annotations,
264 parameterAnnotations,
265 annotationDefault);
266 }
267
268 /** Creates a new java.lang.reflect.Constructor. Access checks as
269 per java.lang.reflect.AccessibleObject are not overridden. */
270 public Constructor<?> newConstructor(Class<?> declaringClass,
271 Class<?>[] parameterTypes,
272 Class<?>[] checkedExceptions,
273 int modifiers,
274 int slot,
275 String signature,
276 byte[] annotations,
277 byte[] parameterAnnotations)
278 {
279 return langReflectAccess().newConstructor(declaringClass,
280 parameterTypes,
281 checkedExceptions,
282 modifiers,
283 slot,
284 signature,
285 annotations,
286 parameterAnnotations);
287 }
288
289 /** Gets the MethodAccessor object for a java.lang.reflect.Method */
290 public MethodAccessor getMethodAccessor(Method m) {
291 return langReflectAccess().getMethodAccessor(m);
292 }
293
294 /** Sets the MethodAccessor object for a java.lang.reflect.Method */
295 public void setMethodAccessor(Method m, MethodAccessor accessor) {
296 langReflectAccess().setMethodAccessor(m, accessor);
297 }
298
299 /** Gets the ConstructorAccessor object for a
300 java.lang.reflect.Constructor */
301 public ConstructorAccessor getConstructorAccessor(Constructor<?> c) {
302 return langReflectAccess().getConstructorAccessor(c);
303 }
304
305 /** Sets the ConstructorAccessor object for a
306 java.lang.reflect.Constructor */
307 public void setConstructorAccessor(Constructor<?> c,
308 ConstructorAccessor accessor)
309 {
310 langReflectAccess().setConstructorAccessor(c, accessor);
311 }
312
313 /** Makes a copy of the passed method. The returned method is a
314 "child" of the passed one; see the comments in Method.java for
315 details. */
316 public Method copyMethod(Method arg) {
317 return langReflectAccess().copyMethod(arg);
318 }
319
320 /** Makes a copy of the passed method. The returned method is NOT
321 * a "child" but a "sibling" of the Method in arg. Should only be
322 * used on non-root methods. */
323 public Method leafCopyMethod(Method arg) {
324 return langReflectAccess().leafCopyMethod(arg);
325 }
326
327
328 /** Makes a copy of the passed field. The returned field is a
329 "child" of the passed one; see the comments in Field.java for
330 details. */
331 public Field copyField(Field arg) {
332 return langReflectAccess().copyField(arg);
333 }
334
335 /** Makes a copy of the passed constructor. The returned
336 constructor is a "child" of the passed one; see the comments
337 in Constructor.java for details. */
338 public <T> Constructor<T> copyConstructor(Constructor<T> arg) {
339 return langReflectAccess().copyConstructor(arg);
340 }
341
342 /** Gets the byte[] that encodes TypeAnnotations on an executable.
343 */
344 public byte[] getExecutableTypeAnnotationBytes(Executable ex) {
345 return langReflectAccess().getExecutableTypeAnnotationBytes(ex);
346 }
347
348 //--------------------------------------------------------------------------
349 //
350 // Routines used by serialization
351 //
352 //
353
354 public final Constructor<?> newConstructorForExternalization(Class<?> cl) {
355 if (!Externalizable.class.isAssignableFrom(cl)) {
356 return null;
357 }
358 try {
359 Constructor<?> cons = cl.getConstructor();
360 cons.setAccessible(true);
361 return cons;
362 } catch (NoSuchMethodException ex) {
363 return null;
364 }
365 }
366
367 public final Constructor<?> newConstructorForSerialization(Class<?> cl) {
368 Class<?> initCl = cl;
369 while (Serializable.class.isAssignableFrom(initCl)) {
370 if ((initCl = initCl.getSuperclass()) == null) {
371 return null;
372 }
373 }
374 Constructor<?> constructorToCall;
375 try {
376 constructorToCall = initCl.getDeclaredConstructor();
377 int mods = constructorToCall.getModifiers();
378 if ((mods & Modifier.PRIVATE) != 0 ||
379 ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) == 0 &&
380 !packageEquals(cl, initCl))) {
381 return null;
382 }
383 } catch (NoSuchMethodException ex) {
384 return null;
385 }
386
387 ConstructorAccessor acc = new MethodAccessorGenerator().
388 generateSerializationConstructor(cl,
389 constructorToCall.getParameterTypes(),
390 constructorToCall.getExceptionTypes(),
391 constructorToCall.getModifiers(),
392 constructorToCall.getDeclaringClass());
393 Constructor<?> c = newConstructor(constructorToCall.getDeclaringClass(),
394 constructorToCall.getParameterTypes(),
395 constructorToCall.getExceptionTypes(),
396 constructorToCall.getModifiers(),
397 langReflectAccess().
398 getConstructorSlot(constructorToCall),
399 langReflectAccess().
400 getConstructorSignature(constructorToCall),
401 langReflectAccess().
402 getConstructorAnnotations(constructorToCall),
403 langReflectAccess().
404 getConstructorParameterAnnotations(constructorToCall));
405 setConstructorAccessor(c, acc);
406 c.setAccessible(true);
407 return c;
408 }
409
410 public final MethodHandle readObjectForSerialization(Class<?> cl) {
411 return findReadWriteObjectForSerialization(cl, "readObject", ObjectInputStream.class);
412 }
413
414 public final MethodHandle readObjectNoDataForSerialization(Class<?> cl) {
415 return findReadWriteObjectForSerialization(cl, "readObjectNoData", ObjectInputStream.class);
416 }
417
418 public final MethodHandle writeObjectForSerialization(Class<?> cl) {
419 return findReadWriteObjectForSerialization(cl, "writeObject", ObjectOutputStream.class);
420 }
421
422 private final MethodHandle findReadWriteObjectForSerialization(Class<?> cl,
423 String methodName,
424 Class<?> streamClass) {
425 if (!Serializable.class.isAssignableFrom(cl)) {
426 return null;
427 }
428
429 try {
430 Method meth = cl.getDeclaredMethod(methodName, streamClass);
431 int mods = meth.getModifiers();
432 if (meth.getReturnType() != Void.TYPE ||
433 Modifier.isStatic(mods) ||
434 !Modifier.isPrivate(mods)) {
435 return null;
436 }
437 meth.setAccessible(true);
438 return MethodHandles.lookup().unreflect(meth);
439 } catch (NoSuchMethodException ex) {
440 return null;
441 } catch (IllegalAccessException ex1) {
442 throw new InternalError("Error", ex1);
443 }
444 }
445
446 /**
447 * Returns a MethodHandle for {@code writeReplace} on the serializable class
448 * or null if no match found.
449 * @param cl a serializable class
450 * @returnss the {@code writeReplace} MethodHandle or {@code null} if not found
451 */
452 public final MethodHandle writeReplaceForSerialization(Class<?> cl) {
453 return getReplaceResolveForSerialization(cl, "writeReplace");
454 }
455
456 /**
457 * Returns a MethodHandle for {@code readResolve} on the serializable class
458 * or null if no match found.
459 * @param cl a serializable class
460 * @returns the {@code writeReplace} MethodHandle or {@code null} if not found
461 */
462 public final MethodHandle readResolveForSerialization(Class<?> cl) {
463 return getReplaceResolveForSerialization(cl, "readResolve");
464 }
465
466 /**
467 * Lookup readResolve or writeReplace on a class with specified
468 * signature constraints.
469 * @param cl a serializable class
470 * @param methodName the method name to find
471 * @returns a MethodHandle for the method or {@code null} if not found or
472 * has the wrong signature.
473 */
474 private MethodHandle getReplaceResolveForSerialization(Class<?> cl,
475 String methodName) {
476 if (!Serializable.class.isAssignableFrom(cl)) {
477 return null;
478 }
479
480 Class<?> defCl = cl;
481 while (defCl != null) {
482 try {
483 Method m = defCl.getDeclaredMethod(methodName);
484 if (m.getReturnType() != Object.class) {
485 return null;
486 }
487 int mods = m.getModifiers();
488 if (Modifier.isStatic(mods) | Modifier.isAbstract(mods)) {
489 return null;
490 } else if (Modifier.isPublic(mods) | Modifier.isProtected(mods)) {
491 // fall through
492 } else if (Modifier.isPrivate(mods) && (cl != defCl)) {
493 return null;
494 } else if (!packageEquals(cl, defCl)) {
495 return null;
496 }
497 try {
498 // Normal return
499 m.setAccessible(true);
500 return MethodHandles.lookup().unreflect(m);
501 } catch (IllegalAccessException ex0) {
502 // setAccessible should prevent IAE
503 throw new InternalError("Error", ex0);
504 }
505 } catch (NoSuchMethodException ex) {
506 defCl = defCl.getSuperclass();
507 }
508 }
509 return null;
510 }
511
512 /**
513 * Returns true if the given class defines a static initializer method,
514 * false otherwise.
515 */
516 public final boolean hasStaticInitializerForSerialization(Class<?> cl) {
517 Method m = hasStaticInitializerMethod;
518 if (m == null) {
519 try {
520 m = ObjectStreamClass.class.getDeclaredMethod("hasStaticInitializer",
521 new Class<?>[]{Class.class});
522 m.setAccessible(true);
523 hasStaticInitializerMethod = m;
524 } catch (NoSuchMethodException ex) {
525 throw new InternalError("No such method hasStaticInitializer on "
526 + ObjectStreamClass.class, ex);
527 }
528 }
529 try {
530 return (Boolean) m.invoke(null, cl);
531 } catch (InvocationTargetException | IllegalAccessException ex) {
532 throw new InternalError("Exception invoking hasStaticInitializer", ex);
533 }
534 }
535
536 /**
537 * Return the accessible constructor for OptionalDataException signaling eof.
538 * @returns the eof constructor for OptionalDataException
539 */
540 public final Constructor<OptionalDataException> newOptionalDataExceptionForSerialization() {
541 try {
542 Constructor<OptionalDataException> boolCtor =
543 OptionalDataException.class.getDeclaredConstructor(Boolean.TYPE);
544 boolCtor.setAccessible(true);
545 return boolCtor;
546 } catch (NoSuchMethodException ex) {
547 throw new InternalError("Constructor not found", ex);
548 }
549 }
550
551 //--------------------------------------------------------------------------
552 //
553 // Internals only below this point
554 //
555
556 static int inflationThreshold() {
557 return inflationThreshold;
558 }
559
560 /** We have to defer full initialization of this class until after
561 the static initializer is run since java.lang.reflect.Method's
562 static initializer (more properly, that for
563 java.lang.reflect.AccessibleObject) causes this class's to be
564 run, before the system properties are set up. */
565 private static void checkInitted() {
566 if (initted) return;
567
568 // Tests to ensure the system properties table is fully
569 // initialized. This is needed because reflection code is
570 // called very early in the initialization process (before
571 // command-line arguments have been parsed and therefore
572 // these user-settable properties installed.) We assume that
573 // if System.out is non-null then the System class has been
574 // fully initialized and that the bulk of the startup code
575 // has been run.
576
577 if (System.out == null) {
578 // java.lang.System not yet fully initialized
579 return;
580 }
581
582 Properties props = GetPropertyAction.privilegedGetProperties();
583 String val = props.getProperty("sun.reflect.noInflation");
584 if (val != null && val.equals("true")) {
585 noInflation = true;
586 }
587
588 val = props.getProperty("sun.reflect.inflationThreshold");
589 if (val != null) {
590 try {
591 inflationThreshold = Integer.parseInt(val);
592 } catch (NumberFormatException e) {
593 throw new RuntimeException("Unable to parse property sun.reflect.inflationThreshold", e);
594 }
595 }
596
597 initted = true;
598 }
599
600 private static LangReflectAccess langReflectAccess() {
601 if (langReflectAccess == null) {
602 // Call a static method to get class java.lang.reflect.Modifier
603 // initialized. Its static initializer will cause
604 // setLangReflectAccess() to be called from the context of the
605 // java.lang.reflect package.
606 Modifier.isPublic(Modifier.PUBLIC);
607 }
608 return langReflectAccess;
609 }
610
611 /**
612 * Returns true if classes are defined in the classloader and same package, false
613 * otherwise.
614 * @param cl1 a class
615 * @param cl2 another class
616 * @returns true if the two classes are in the same classloader and package
617 */
618 private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {
619 return cl1.getClassLoader() == cl2.getClassLoader() &&
620 Objects.equals(cl1.getPackage(), cl2.getPackage());
621 }
622
623 }