1 /*
2 * Copyright (c) 1997, 2018, 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 java.lang.reflect;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.invoke.MethodHandle;
30 import java.lang.ref.WeakReference;
31 import java.security.AccessController;
32
33 import jdk.internal.misc.VM;
34 import jdk.internal.module.IllegalAccessLogger;
35 import jdk.internal.reflect.CallerSensitive;
36 import jdk.internal.reflect.Reflection;
37 import jdk.internal.reflect.ReflectionFactory;
38 import sun.security.action.GetPropertyAction;
39 import sun.security.util.SecurityConstants;
40
41 /**
42 * The {@code AccessibleObject} class is the base class for {@code Field},
43 * {@code Method}, and {@code Constructor} objects (known as <em>reflected
44 * objects</em>). It provides the ability to flag a reflected object as
45 * suppressing checks for Java language access control when it is used. This
46 * permits sophisticated applications with sufficient privilege, such as Java
47 * Object Serialization or other persistence mechanisms, to manipulate objects
48 * in a manner that would normally be prohibited.
49 *
50 * <p> Java language access control prevents use of private members outside
51 * their top-level class; package access members outside their package; protected members
52 * outside their package or subclasses; and public members outside their
53 * module unless they are declared in an {@link Module#isExported(String,Module)
54 * exported} package and the user {@link Module#canRead reads} their module. By
55 * default, Java language access control is enforced (with one variation) when
56 * {@code Field}s, {@code Method}s, or {@code Constructor}s are used to get or
57 * set fields, to invoke methods, or to create and initialize new instances of
58 * classes, respectively. Every reflected object checks that the code using it
59 * is in an appropriate class, package, or module. </p>
60 *
61 * <p> The one variation from Java language access control is that the checks
62 * by reflected objects assume readability. That is, the module containing
63 * the use of a reflected object is assumed to read the module in which
64 * the underlying field, method, or constructor is declared. </p>
65 *
66 * <p> Whether the checks for Java language access control can be suppressed
67 * (and thus, whether access can be enabled) depends on whether the reflected
68 * object corresponds to a member in an exported or open package
69 * (see {@link #setAccessible(boolean)}). </p>
70 *
71 * @jls 6.6 Access Control
72 * @since 1.2
73 * @revised 9
74 * @spec JPMS
75 */
76 public class AccessibleObject implements AnnotatedElement {
77
78 static void checkPermission() {
79 SecurityManager sm = System.getSecurityManager();
80 if (sm != null) {
81 // SecurityConstants.ACCESS_PERMISSION is used to check
82 // whether a client has sufficient privilege to defeat Java
83 // language access control checks.
84 sm.checkPermission(SecurityConstants.ACCESS_PERMISSION);
85 }
86 }
87
88 /**
89 * Convenience method to set the {@code accessible} flag for an
90 * array of reflected objects with a single security check (for efficiency).
91 *
92 * <p> This method may be used to enable access to all reflected objects in
93 * the array when access to each reflected object can be enabled as
94 * specified by {@link #setAccessible(boolean) setAccessible(boolean)}. </p>
95 *
96 * <p>If there is a security manager, its
97 * {@code checkPermission} method is first called with a
98 * {@code ReflectPermission("suppressAccessChecks")} permission.
99 *
100 * <p>A {@code SecurityException} is also thrown if any of the elements of
101 * the input {@code array} is a {@link java.lang.reflect.Constructor}
102 * object for the class {@code java.lang.Class} and {@code flag} is true.
103 *
104 * @param array the array of AccessibleObjects
105 * @param flag the new value for the {@code accessible} flag
106 * in each object
107 * @throws InaccessibleObjectException if access cannot be enabled for all
108 * objects in the array
109 * @throws SecurityException if the request is denied by the security manager
110 * or an element in the array is a constructor for {@code
111 * java.lang.Class}
112 * @see SecurityManager#checkPermission
113 * @see ReflectPermission
114 * @revised 9
115 * @spec JPMS
116 */
117 @CallerSensitive
118 public static void setAccessible(AccessibleObject[] array, boolean flag) {
119 checkPermission();
120 if (flag) {
121 Class<?> caller = Reflection.getCallerClass();
122 array = array.clone();
123 for (AccessibleObject ao : array) {
124 ao.checkCanSetAccessible(caller);
125 }
126 }
127 for (AccessibleObject ao : array) {
128 ao.setAccessible0(flag);
129 }
130 }
131
132 /**
133 * Set the {@code accessible} flag for this reflected object to
134 * the indicated boolean value. A value of {@code true} indicates that
135 * the reflected object should suppress checks for Java language access
136 * control when it is used. A value of {@code false} indicates that
137 * the reflected object should enforce checks for Java language access
138 * control when it is used, with the variation noted in the class description.
139 *
140 * <p> This method may be used by a caller in class {@code C} to enable
141 * access to a {@link Member member} of {@link Member#getDeclaringClass()
142 * declaring class} {@code D} if any of the following hold: </p>
143 *
144 * <ul>
145 * <li> {@code C} and {@code D} are in the same module. </li>
146 *
147 * <li> The member is {@code public} and {@code D} is {@code public} in
148 * a package that the module containing {@code D} {@link
149 * Module#isExported(String,Module) exports} to at least the module
150 * containing {@code C}. </li>
151 *
152 * <li> The member is {@code protected} {@code static}, {@code D} is
153 * {@code public} in a package that the module containing {@code D}
154 * exports to at least the module containing {@code C}, and {@code C}
155 * is a subclass of {@code D}. </li>
156 *
157 * <li> {@code D} is in a package that the module containing {@code D}
158 * {@link Module#isOpen(String,Module) opens} to at least the module
159 * containing {@code C}.
160 * All packages in unnamed and open modules are open to all modules and
161 * so this method always succeeds when {@code D} is in an unnamed or
162 * open module. </li>
163 * </ul>
164 *
165 * <p> This method cannot be used to enable access to private members,
166 * members with default (package) access, protected instance members, or
167 * protected constructors when the declaring class is in a different module
168 * to the caller and the package containing the declaring class is not open
169 * to the caller's module. </p>
170 *
171 * <p> If there is a security manager, its
172 * {@code checkPermission} method is first called with a
173 * {@code ReflectPermission("suppressAccessChecks")} permission.
174 *
175 * @param flag the new value for the {@code accessible} flag
176 * @throws InaccessibleObjectException if access cannot be enabled
177 * @throws SecurityException if the request is denied by the security manager
178 * @see #trySetAccessible
179 * @see java.lang.invoke.MethodHandles#privateLookupIn
180 * @revised 9
181 * @spec JPMS
182 */
183 @CallerSensitive // overrides in Method/Field/Constructor are @CS
184 public void setAccessible(boolean flag) {
185 AccessibleObject.checkPermission();
186 setAccessible0(flag);
187 }
188
189 /**
190 * Sets the accessible flag and returns the new value
191 */
192 boolean setAccessible0(boolean flag) {
193 this.override = flag;
194 return flag;
195 }
196
197 /**
198 * Set the {@code accessible} flag for this reflected object to {@code true}
199 * if possible. This method sets the {@code accessible} flag, as if by
200 * invoking {@link #setAccessible(boolean) setAccessible(true)}, and returns
201 * the possibly-updated value for the {@code accessible} flag. If access
202 * cannot be enabled, i.e. the checks or Java language access control cannot
203 * be suppressed, this method returns {@code false} (as opposed to {@code
204 * setAccessible(true)} throwing {@code InaccessibleObjectException} when
205 * it fails).
206 *
207 * <p> This method is a no-op if the {@code accessible} flag for
208 * this reflected object is {@code true}.
209 *
210 * <p> For example, a caller can invoke {@code trySetAccessible}
211 * on a {@code Method} object for a private instance method
212 * {@code p.T::privateMethod} to suppress the checks for Java language access
213 * control when the {@code Method} is invoked.
214 * If {@code p.T} class is in a different module to the caller and
215 * package {@code p} is open to at least the caller's module,
216 * the code below successfully sets the {@code accessible} flag
217 * to {@code true}.
218 *
219 * <pre>
220 * {@code
221 * p.T obj = ....; // instance of p.T
222 * :
223 * Method m = p.T.class.getDeclaredMethod("privateMethod");
224 * if (m.trySetAccessible()) {
225 * m.invoke(obj);
226 * } else {
227 * // package p is not opened to the caller to access private member of T
228 * ...
229 * }
230 * }</pre>
231 *
232 * <p> If there is a security manager, its {@code checkPermission} method
233 * is first called with a {@code ReflectPermission("suppressAccessChecks")}
234 * permission. </p>
235 *
236 * @return {@code true} if the {@code accessible} flag is set to {@code true};
237 * {@code false} if access cannot be enabled.
238 * @throws SecurityException if the request is denied by the security manager
239 *
240 * @since 9
241 * @spec JPMS
242 * @see java.lang.invoke.MethodHandles#privateLookupIn
243 */
244 @CallerSensitive
245 public final boolean trySetAccessible() {
246 AccessibleObject.checkPermission();
247
248 if (override == true) return true;
249
250 // if it's not a Constructor, Method, Field then no access check
251 if (!Member.class.isInstance(this)) {
252 return setAccessible0(true);
253 }
254
255 // does not allow to suppress access check for Class's constructor
256 Class<?> declaringClass = ((Member) this).getDeclaringClass();
257 if (declaringClass == Class.class && this instanceof Constructor) {
258 return false;
259 }
260
261 if (checkCanSetAccessible(Reflection.getCallerClass(),
262 declaringClass,
263 false)) {
264 return setAccessible0(true);
265 } else {
266 return false;
267 }
268 }
269
270
271 /**
272 * If the given AccessibleObject is a {@code Constructor}, {@code Method}
273 * or {@code Field} then checks that its declaring class is in a package
274 * that can be accessed by the given caller of setAccessible.
275 */
276 void checkCanSetAccessible(Class<?> caller) {
277 // do nothing, needs to be overridden by Constructor, Method, Field
278 }
279
280 final void checkCanSetAccessible(Class<?> caller, Class<?> declaringClass) {
281 checkCanSetAccessible(caller, declaringClass, true);
282 }
283
284 private boolean checkCanSetAccessible(Class<?> caller,
285 Class<?> declaringClass,
286 boolean throwExceptionIfDenied) {
287 if (caller == MethodHandle.class) {
288 throw new IllegalCallerException(); // should not happen
289 }
290
291 Module callerModule = caller.getModule();
292 Module declaringModule = declaringClass.getModule();
293
294 if (callerModule == declaringModule) return true;
295 if (callerModule == Object.class.getModule()) return true;
296 if (!declaringModule.isNamed()) return true;
297
298 String pn = declaringClass.getPackageName();
299 int modifiers;
300 if (this instanceof Executable) {
301 modifiers = ((Executable) this).getModifiers();
302 } else {
303 modifiers = ((Field) this).getModifiers();
304 }
305
306 // class is public and package is exported to caller
307 boolean isClassPublic = Modifier.isPublic(declaringClass.getModifiers());
308 if (isClassPublic && declaringModule.isExported(pn, callerModule)) {
309 // member is public
310 if (Modifier.isPublic(modifiers)) {
311 logIfExportedForIllegalAccess(caller, declaringClass);
312 return true;
313 }
314
315 // member is protected-static
316 if (Modifier.isProtected(modifiers)
317 && Modifier.isStatic(modifiers)
318 && isSubclassOf(caller, declaringClass)) {
319 logIfExportedForIllegalAccess(caller, declaringClass);
320 return true;
321 }
322 }
323
324 // package is open to caller
325 if (declaringModule.isOpen(pn, callerModule)) {
326 logIfOpenedForIllegalAccess(caller, declaringClass);
327 return true;
328 }
329
330 if (throwExceptionIfDenied) {
331 // not accessible
332 String msg = "Unable to make ";
333 if (this instanceof Field)
334 msg += "field ";
335 msg += this + " accessible: " + declaringModule + " does not \"";
336 if (isClassPublic && Modifier.isPublic(modifiers))
337 msg += "exports";
338 else
339 msg += "opens";
340 msg += " " + pn + "\" to " + callerModule;
341 InaccessibleObjectException e = new InaccessibleObjectException(msg);
342 if (printStackTraceWhenAccessFails()) {
343 e.printStackTrace(System.err);
344 }
345 throw e;
346 }
347 return false;
348 }
349
350 private boolean isSubclassOf(Class<?> queryClass, Class<?> ofClass) {
351 while (queryClass != null) {
352 if (queryClass == ofClass) {
353 return true;
354 }
355 queryClass = queryClass.getSuperclass();
356 }
357 return false;
358 }
359
360 private void logIfOpenedForIllegalAccess(Class<?> caller, Class<?> declaringClass) {
361 Module callerModule = caller.getModule();
362 Module targetModule = declaringClass.getModule();
363 // callerModule is null during early startup
364 if (callerModule != null && !callerModule.isNamed() && targetModule.isNamed()) {
365 IllegalAccessLogger logger = IllegalAccessLogger.illegalAccessLogger();
366 if (logger != null) {
367 logger.logIfOpenedForIllegalAccess(caller, declaringClass, this::toShortString);
368 }
369 }
370 }
371
372 private void logIfExportedForIllegalAccess(Class<?> caller, Class<?> declaringClass) {
373 Module callerModule = caller.getModule();
374 Module targetModule = declaringClass.getModule();
375 // callerModule is null during early startup
376 if (callerModule != null && !callerModule.isNamed() && targetModule.isNamed()) {
377 IllegalAccessLogger logger = IllegalAccessLogger.illegalAccessLogger();
378 if (logger != null) {
379 logger.logIfExportedForIllegalAccess(caller, declaringClass, this::toShortString);
380 }
381 }
382 }
383
384 /**
385 * Returns a short descriptive string to describe this object in log messages.
386 */
387 String toShortString() {
388 return toString();
389 }
390
391 /**
392 * Get the value of the {@code accessible} flag for this reflected object.
393 *
394 * @return the value of the object's {@code accessible} flag
395 *
396 * @deprecated
397 * This method is deprecated because its name hints that it checks
398 * if the reflected object is accessible when it actually indicates
399 * if the checks for Java language access control are suppressed.
400 * This method may return {@code false} on a reflected object that is
401 * accessible to the caller. To test if this reflected object is accessible,
402 * it should use {@link #canAccess(Object)}.
403 *
404 * @revised 9
405 * @spec JPMS
406 */
407 @Deprecated(since="9")
408 public boolean isAccessible() {
409 return override;
410 }
411
412 /**
413 * Test if the caller can access this reflected object. If this reflected
414 * object corresponds to an instance method or field then this method tests
415 * if the caller can access the given {@code obj} with the reflected object.
416 * For instance methods or fields then the {@code obj} argument must be an
417 * instance of the {@link Member#getDeclaringClass() declaring class}. For
418 * static members and constructors then {@code obj} must be {@code null}.
419 *
420 * <p> This method returns {@code true} if the {@code accessible} flag
421 * is set to {@code true}, i.e. the checks for Java language access control
422 * are suppressed, or if the caller can access the member as
423 * specified in <cite>The Java™ Language Specification</cite>,
424 * with the variation noted in the class description. </p>
425 *
426 * @param obj an instance object of the declaring class of this reflected
427 * object if it is an instance method or field
428 *
429 * @return {@code true} if the caller can access this reflected object.
430 *
431 * @throws IllegalArgumentException
432 * <ul>
433 * <li> if this reflected object is a static member or constructor and
434 * the given {@code obj} is non-{@code null}, or </li>
435 * <li> if this reflected object is an instance method or field
436 * and the given {@code obj} is {@code null} or of type
437 * that is not a subclass of the {@link Member#getDeclaringClass()
438 * declaring class} of the member.</li>
439 * </ul>
440 *
441 * @since 9
442 * @spec JPMS
443 * @jls 6.6 Access Control
444 * @see #trySetAccessible
445 * @see #setAccessible(boolean)
446 */
447 @CallerSensitive
448 public final boolean canAccess(Object obj) {
449 if (!Member.class.isInstance(this)) {
450 return override;
451 }
452
453 Class<?> declaringClass = ((Member) this).getDeclaringClass();
454 int modifiers = ((Member) this).getModifiers();
455 if (!Modifier.isStatic(modifiers) &&
456 (this instanceof Method || this instanceof Field)) {
457 if (obj == null) {
458 throw new IllegalArgumentException("null object for " + this);
459 }
460 // if this object is an instance member, the given object
461 // must be a subclass of the declaring class of this reflected object
462 if (!declaringClass.isAssignableFrom(obj.getClass())) {
463 throw new IllegalArgumentException("object is not an instance of "
464 + declaringClass.getName());
465 }
466 } else if (obj != null) {
467 throw new IllegalArgumentException("non-null object for " + this);
468 }
469
470 // access check is suppressed
471 if (override) return true;
472
473 Class<?> caller = Reflection.getCallerClass();
474 Class<?> targetClass;
475 if (this instanceof Constructor) {
476 targetClass = declaringClass;
477 } else {
478 targetClass = Modifier.isStatic(modifiers) ? null : obj.getClass();
479 }
480 return verifyAccess(caller, declaringClass, targetClass, modifiers);
481 }
482
483 /**
484 * Constructor: only used by the Java Virtual Machine.
485 */
486 protected AccessibleObject() {}
487
488 // Indicates whether language-level access checks are overridden
489 // by this object. Initializes to "false". This field is used by
490 // Field, Method, and Constructor.
491 //
492 // NOTE: for security purposes, this field must not be visible
493 // outside this package.
494 boolean override;
495
496 // Reflection factory used by subclasses for creating field,
497 // method, and constructor accessors. Note that this is called
498 // very early in the bootstrapping process.
499 static final ReflectionFactory reflectionFactory =
500 AccessController.doPrivileged(
501 new ReflectionFactory.GetReflectionFactoryAction());
502
503 /**
504 * @throws NullPointerException {@inheritDoc}
505 * @since 1.5
506 */
507 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
508 throw new AssertionError("All subclasses should override this method");
509 }
510
511 /**
512 * {@inheritDoc}
513 * @throws NullPointerException {@inheritDoc}
514 * @since 1.5
515 */
516 @Override
517 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
518 return AnnotatedElement.super.isAnnotationPresent(annotationClass);
519 }
520
521 /**
522 * @throws NullPointerException {@inheritDoc}
523 * @since 1.8
524 */
525 @Override
526 public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) {
527 throw new AssertionError("All subclasses should override this method");
528 }
529
530 /**
531 * @since 1.5
532 */
533 public Annotation[] getAnnotations() {
534 return getDeclaredAnnotations();
535 }
536
537 /**
538 * @throws NullPointerException {@inheritDoc}
539 * @since 1.8
540 */
541 @Override
542 public <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) {
543 // Only annotations on classes are inherited, for all other
544 // objects getDeclaredAnnotation is the same as
545 // getAnnotation.
546 return getAnnotation(annotationClass);
547 }
548
549 /**
550 * @throws NullPointerException {@inheritDoc}
551 * @since 1.8
552 */
553 @Override
554 public <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) {
555 // Only annotations on classes are inherited, for all other
556 // objects getDeclaredAnnotationsByType is the same as
557 // getAnnotationsByType.
558 return getAnnotationsByType(annotationClass);
559 }
560
561 /**
562 * @since 1.5
563 */
564 public Annotation[] getDeclaredAnnotations() {
565 throw new AssertionError("All subclasses should override this method");
566 }
567
568 // Shared access checking logic.
569
570 // For non-public members or members in package-private classes,
571 // it is necessary to perform somewhat expensive access checks.
572 // If the access check succeeds for a given class, it will
573 // always succeed (it is not affected by the granting or revoking
574 // of permissions); we speed up the check in the common case by
575 // remembering the last Class for which the check succeeded.
576 //
577 // The simple access check for Constructor is to see if
578 // the caller has already been seen, verified, and cached.
579 //
580 // A more complicated access check cache is needed for Method and Field
581 // The cache can be either null (empty cache), {caller,targetClass} pair,
582 // or a caller (with targetClass implicitly equal to memberClass).
583 // In the {caller,targetClass} case, the targetClass is always different
584 // from the memberClass.
585 volatile Object accessCheckCache;
586
587 private static class Cache {
588 final WeakReference<Class<?>> callerRef;
589 final WeakReference<Class<?>> targetRef;
590
591 Cache(Class<?> caller, Class<?> target) {
592 this.callerRef = new WeakReference<>(caller);
593 this.targetRef = new WeakReference<>(target);
594 }
595
596 boolean isCacheFor(Class<?> caller, Class<?> refc) {
597 return callerRef.get() == caller && targetRef.get() == refc;
598 }
599
600 static Object protectedMemberCallerCache(Class<?> caller, Class<?> refc) {
601 return new Cache(caller, refc);
602 }
603 }
604
605 /*
606 * Returns true if the previous access check was verified for the
607 * given caller accessing a protected member with an instance of
608 * the given targetClass where the target class is different than
609 * the declaring member class.
610 */
611 private boolean isAccessChecked(Class<?> caller, Class<?> targetClass) {
612 Object cache = accessCheckCache; // read volatile
613 if (cache instanceof Cache) {
614 return ((Cache) cache).isCacheFor(caller, targetClass);
615 }
616 return false;
617 }
618
619 /*
620 * Returns true if the previous access check was verified for the
621 * given caller accessing a static member or an instance member of
622 * the target class that is the same as the declaring member class.
623 */
624 private boolean isAccessChecked(Class<?> caller) {
625 Object cache = accessCheckCache; // read volatile
626 if (cache instanceof WeakReference) {
627 @SuppressWarnings("unchecked")
628 WeakReference<Class<?>> ref = (WeakReference<Class<?>>) cache;
629 return ref.get() == caller;
630 }
631 return false;
632 }
633
634 final void checkAccess(Class<?> caller, Class<?> memberClass,
635 Class<?> targetClass, int modifiers)
636 throws IllegalAccessException
637 {
638 if (!verifyAccess(caller, memberClass, targetClass, modifiers)) {
639 IllegalAccessException e = Reflection.newIllegalAccessException(
640 caller, memberClass, targetClass, modifiers);
641 if (printStackTraceWhenAccessFails()) {
642 e.printStackTrace(System.err);
643 }
644 throw e;
645 }
646 }
647
648 final boolean verifyAccess(Class<?> caller, Class<?> memberClass,
649 Class<?> targetClass, int modifiers)
650 {
651 if (caller == memberClass) { // quick check
652 return true; // ACCESS IS OK
653 }
654 if (targetClass != null // instance member or constructor
655 && Modifier.isProtected(modifiers)
656 && targetClass != memberClass) {
657 if (isAccessChecked(caller, targetClass)) {
658 return true; // ACCESS IS OK
659 }
660 } else if (isAccessChecked(caller)) {
661 // Non-protected case (or targetClass == memberClass or static member).
662 return true; // ACCESS IS OK
663 }
664
665 // If no return, fall through to the slow path.
666 return slowVerifyAccess(caller, memberClass, targetClass, modifiers);
667 }
668
669 // Keep all this slow stuff out of line:
670 private boolean slowVerifyAccess(Class<?> caller, Class<?> memberClass,
671 Class<?> targetClass, int modifiers)
672 {
673 if (!Reflection.verifyMemberAccess(caller, memberClass, targetClass, modifiers)) {
674 // access denied
675 return false;
676 }
677
678 // access okay
679 logIfExportedForIllegalAccess(caller, memberClass);
680
681 // Success: Update the cache.
682 Object cache = (targetClass != null
683 && Modifier.isProtected(modifiers)
684 && targetClass != memberClass)
685 ? Cache.protectedMemberCallerCache(caller, targetClass)
686 : new WeakReference<>(caller);
687 accessCheckCache = cache; // write volatile
688 return true;
689 }
690
691 // true to print a stack trace when access fails
692 private static volatile boolean printStackWhenAccessFails;
693
694 // true if printStack* values are initialized
695 private static volatile boolean printStackPropertiesSet;
696
697 /**
698 * Returns true if a stack trace should be printed when access fails.
699 */
700 private static boolean printStackTraceWhenAccessFails() {
701 if (!printStackPropertiesSet && VM.initLevel() >= 1) {
702 String s = GetPropertyAction.privilegedGetProperty(
703 "sun.reflect.debugModuleAccessChecks");
704 if (s != null) {
705 printStackWhenAccessFails = !s.equalsIgnoreCase("false");
706 }
707 printStackPropertiesSet = true;
708 }
709 return printStackWhenAccessFails;
710 }
711
712 /**
713 * Returns the root AccessibleObject; or null if this object is the root.
714 *
715 * All subclasses override this method.
716 */
717 AccessibleObject getRoot() {
718 throw new InternalError();
719 }
720 }