1 /*
2 * Copyright (c) 1997, 2019, 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.access.SharedSecrets;
34 import jdk.internal.misc.VM;
35 import jdk.internal.module.IllegalAccessLogger;
36 import jdk.internal.reflect.CallerSensitive;
37 import jdk.internal.reflect.Reflection;
38 import jdk.internal.reflect.ReflectionFactory;
39 import sun.security.action.GetPropertyAction;
40 import sun.security.util.SecurityConstants;
41
42 /**
43 * The {@code AccessibleObject} class is the base class for {@code Field},
44 * {@code Method}, and {@code Constructor} objects (known as <em>reflected
45 * objects</em>). It provides the ability to flag a reflected object as
46 * suppressing checks for Java language access control when it is used. This
47 * permits sophisticated applications with sufficient privilege, such as Java
48 * Object Serialization or other persistence mechanisms, to manipulate objects
49 * in a manner that would normally be prohibited.
50 *
51 * <p> Java language access control prevents use of private members outside
52 * their top-level class; package access members outside their package; protected members
53 * outside their package or subclasses; and public members outside their
54 * module unless they are declared in an {@link Module#isExported(String,Module)
55 * exported} package and the user {@link Module#canRead reads} their module. By
56 * default, Java language access control is enforced (with one variation) when
57 * {@code Field}s, {@code Method}s, or {@code Constructor}s are used to get or
58 * set fields, to invoke methods, or to create and initialize new instances of
59 * classes, respectively. Every reflected object checks that the code using it
60 * is in an appropriate class, package, or module. The check when invoked by
61 * <a href="{@docRoot}/../specs/jni/index.html">JNI code</a> with no Java
62 * class on the stack only succeeds if the member and the declaring class are
63 * public, and the class is in a package that is exported to all modules. </p>
64 *
65 * <p> The one variation from Java language access control is that the checks
66 * by reflected objects assume readability. That is, the module containing
67 * the use of a reflected object is assumed to read the module in which
68 * the underlying field, method, or constructor is declared. </p>
69 *
70 * <p> Whether the checks for Java language access control can be suppressed
71 * (and thus, whether access can be enabled) depends on whether the reflected
72 * object corresponds to a member in an exported or open package
73 * (see {@link #setAccessible(boolean)}). </p>
74 *
75 * @jls 6.6 Access Control
76 * @since 1.2
77 * @revised 9
78 * @spec JPMS
79 */
80 public class AccessibleObject implements AnnotatedElement {
81 static {
82 // AccessibleObject is initialized early in initPhase1
83 SharedSecrets.setJavaLangReflectAccess(new ReflectAccess());
84 }
85
86 static void checkPermission() {
87 SecurityManager sm = System.getSecurityManager();
88 if (sm != null) {
89 // SecurityConstants.ACCESS_PERMISSION is used to check
90 // whether a client has sufficient privilege to defeat Java
91 // language access control checks.
92 sm.checkPermission(SecurityConstants.ACCESS_PERMISSION);
93 }
94 }
95
96 /**
97 * Convenience method to set the {@code accessible} flag for an
98 * array of reflected objects with a single security check (for efficiency).
99 *
100 * <p> This method may be used to enable access to all reflected objects in
101 * the array when access to each reflected object can be enabled as
102 * specified by {@link #setAccessible(boolean) setAccessible(boolean)}. </p>
103 *
104 * <p>If there is a security manager, its
105 * {@code checkPermission} method is first called with a
106 * {@code ReflectPermission("suppressAccessChecks")} permission.
107 *
108 * <p>A {@code SecurityException} is also thrown if any of the elements of
109 * the input {@code array} is a {@link java.lang.reflect.Constructor}
110 * object for the class {@code java.lang.Class} and {@code flag} is true.
111 *
112 * @param array the array of AccessibleObjects
113 * @param flag the new value for the {@code accessible} flag
114 * in each object
115 * @throws InaccessibleObjectException if access cannot be enabled for all
116 * objects in the array
117 * @throws SecurityException if the request is denied by the security manager
118 * or an element in the array is a constructor for {@code
119 * java.lang.Class}
120 * @see SecurityManager#checkPermission
121 * @see ReflectPermission
122 * @revised 9
123 * @spec JPMS
124 */
125 @CallerSensitive
126 public static void setAccessible(AccessibleObject[] array, boolean flag) {
127 checkPermission();
128 if (flag) {
129 Class<?> caller = Reflection.getCallerClass();
130 array = array.clone();
131 for (AccessibleObject ao : array) {
132 ao.checkCanSetAccessible(caller);
133 }
134 }
135 for (AccessibleObject ao : array) {
136 ao.setAccessible0(flag);
137 }
138 }
139
140 /**
141 * Set the {@code accessible} flag for this reflected object to
142 * the indicated boolean value. A value of {@code true} indicates that
143 * the reflected object should suppress checks for Java language access
144 * control when it is used. A value of {@code false} indicates that
145 * the reflected object should enforce checks for Java language access
146 * control when it is used, with the variation noted in the class description.
147 *
148 * <p> This method may be used by a caller in class {@code C} to enable
149 * access to a {@link Member member} of {@link Member#getDeclaringClass()
150 * declaring class} {@code D} if any of the following hold: </p>
151 *
152 * <ul>
153 * <li> {@code C} and {@code D} are in the same module. </li>
154 *
155 * <li> The member is {@code public} and {@code D} is {@code public} in
156 * a package that the module containing {@code D} {@link
157 * Module#isExported(String,Module) exports} to at least the module
158 * containing {@code C}. </li>
159 *
160 * <li> The member is {@code protected} {@code static}, {@code D} is
161 * {@code public} in a package that the module containing {@code D}
162 * exports to at least the module containing {@code C}, and {@code C}
163 * is a subclass of {@code D}. </li>
164 *
165 * <li> {@code D} is in a package that the module containing {@code D}
166 * {@link Module#isOpen(String,Module) opens} to at least the module
167 * containing {@code C}.
168 * All packages in unnamed and open modules are open to all modules and
169 * so this method always succeeds when {@code D} is in an unnamed or
170 * open module. </li>
171 * </ul>
172 *
173 * <p> This method cannot be used to enable access to private members,
174 * members with default (package) access, protected instance members, or
175 * protected constructors when the declaring class is in a different module
176 * to the caller and the package containing the declaring class is not open
177 * to the caller's module. </p>
178 *
179 * <p> This method cannot be used to enable {@linkplain Field#set <em>write</em>}
180 * access to a final field declared in a {@linkplain Class#isHidden() hidden class},
181 * since such fields are not modifiable. The {@code accessible} flag when
182 * {@code true} suppresses Java language access control checks to only
183 * enable {@linkplain Field#get <em>read</em>} access to such fields.
184 *
185 * <p> If there is a security manager, its
186 * {@code checkPermission} method is first called with a
187 * {@code ReflectPermission("suppressAccessChecks")} permission.
188 *
189 * @param flag the new value for the {@code accessible} flag
190 * @throws InaccessibleObjectException if access cannot be enabled
191 * @throws SecurityException if the request is denied by the security manager
192 * @see #trySetAccessible
193 * @see java.lang.invoke.MethodHandles#privateLookupIn
194 * @revised 9
195 * @spec JPMS
196 */
197 @CallerSensitive // overrides in Method/Field/Constructor are @CS
198 public void setAccessible(boolean flag) {
199 AccessibleObject.checkPermission();
200 setAccessible0(flag);
201 }
202
203 /**
204 * Sets the accessible flag and returns the new value
205 */
206 boolean setAccessible0(boolean flag) {
207 this.override = flag;
208 return flag;
209 }
210
211 /**
212 * Set the {@code accessible} flag for this reflected object to {@code true}
213 * if possible. This method sets the {@code accessible} flag, as if by
214 * invoking {@link #setAccessible(boolean) setAccessible(true)}, and returns
215 * the possibly-updated value for the {@code accessible} flag. If access
216 * cannot be enabled, i.e. the checks or Java language access control cannot
217 * be suppressed, this method returns {@code false} (as opposed to {@code
218 * setAccessible(true)} throwing {@code InaccessibleObjectException} when
219 * it fails).
220 *
221 * <p> This method is a no-op if the {@code accessible} flag for
222 * this reflected object is {@code true}.
223 *
224 * <p> For example, a caller can invoke {@code trySetAccessible}
225 * on a {@code Method} object for a private instance method
226 * {@code p.T::privateMethod} to suppress the checks for Java language access
227 * control when the {@code Method} is invoked.
228 * If {@code p.T} class is in a different module to the caller and
229 * package {@code p} is open to at least the caller's module,
230 * the code below successfully sets the {@code accessible} flag
231 * to {@code true}.
232 *
233 * <pre>
234 * {@code
235 * p.T obj = ....; // instance of p.T
236 * :
237 * Method m = p.T.class.getDeclaredMethod("privateMethod");
238 * if (m.trySetAccessible()) {
239 * m.invoke(obj);
240 * } else {
241 * // package p is not opened to the caller to access private member of T
242 * ...
243 * }
244 * }</pre>
245 *
246 * <p> If there is a security manager, its {@code checkPermission} method
247 * is first called with a {@code ReflectPermission("suppressAccessChecks")}
248 * permission. </p>
249 *
250 * @return {@code true} if the {@code accessible} flag is set to {@code true};
251 * {@code false} if access cannot be enabled.
252 * @throws SecurityException if the request is denied by the security manager
253 *
254 * @since 9
255 * @spec JPMS
256 * @see java.lang.invoke.MethodHandles#privateLookupIn
257 */
258 @CallerSensitive
259 public final boolean trySetAccessible() {
260 AccessibleObject.checkPermission();
261
262 if (override == true) return true;
263
264 // if it's not a Constructor, Method, Field then no access check
265 if (!Member.class.isInstance(this)) {
266 return setAccessible0(true);
267 }
268
269 // does not allow to suppress access check for Class's constructor
270 Class<?> declaringClass = ((Member) this).getDeclaringClass();
271 if (declaringClass == Class.class && this instanceof Constructor) {
272 return false;
273 }
274
275 if (checkCanSetAccessible(Reflection.getCallerClass(),
276 declaringClass,
277 false)) {
278 return setAccessible0(true);
279 } else {
280 return false;
281 }
282 }
283
284
285 /**
286 * If the given AccessibleObject is a {@code Constructor}, {@code Method}
287 * or {@code Field} then checks that its declaring class is in a package
288 * that can be accessed by the given caller of setAccessible.
289 */
290 void checkCanSetAccessible(Class<?> caller) {
291 // do nothing, needs to be overridden by Constructor, Method, Field
292 }
293
294 final void checkCanSetAccessible(Class<?> caller, Class<?> declaringClass) {
295 checkCanSetAccessible(caller, declaringClass, true);
296 }
297
298 private boolean checkCanSetAccessible(Class<?> caller,
299 Class<?> declaringClass,
300 boolean throwExceptionIfDenied) {
301 if (caller == MethodHandle.class) {
302 throw new IllegalCallerException(); // should not happen
303 }
304
305 Module callerModule = caller.getModule();
306 Module declaringModule = declaringClass.getModule();
307
308 if (callerModule == declaringModule) return true;
309 if (callerModule == Object.class.getModule()) return true;
310 if (!declaringModule.isNamed()) return true;
311
312 String pn = declaringClass.getPackageName();
313 int modifiers;
314 if (this instanceof Executable) {
315 modifiers = ((Executable) this).getModifiers();
316 } else {
317 modifiers = ((Field) this).getModifiers();
318 }
319
320 // class is public and package is exported to caller
321 boolean isClassPublic = Modifier.isPublic(declaringClass.getModifiers());
322 if (isClassPublic && declaringModule.isExported(pn, callerModule)) {
323 // member is public
324 if (Modifier.isPublic(modifiers)) {
325 logIfExportedForIllegalAccess(caller, declaringClass);
326 return true;
327 }
328
329 // member is protected-static
330 if (Modifier.isProtected(modifiers)
331 && Modifier.isStatic(modifiers)
332 && isSubclassOf(caller, declaringClass)) {
333 logIfExportedForIllegalAccess(caller, declaringClass);
334 return true;
335 }
336 }
337
338 // package is open to caller
339 if (declaringModule.isOpen(pn, callerModule)) {
340 logIfOpenedForIllegalAccess(caller, declaringClass);
341 return true;
342 }
343
344 if (throwExceptionIfDenied) {
345 // not accessible
346 String msg = "Unable to make ";
347 if (this instanceof Field)
348 msg += "field ";
349 msg += this + " accessible: " + declaringModule + " does not \"";
350 if (isClassPublic && Modifier.isPublic(modifiers))
351 msg += "exports";
352 else
353 msg += "opens";
354 msg += " " + pn + "\" to " + callerModule;
355 InaccessibleObjectException e = new InaccessibleObjectException(msg);
356 if (printStackTraceWhenAccessFails()) {
357 e.printStackTrace(System.err);
358 }
359 throw e;
360 }
361 return false;
362 }
363
364 private boolean isSubclassOf(Class<?> queryClass, Class<?> ofClass) {
365 while (queryClass != null) {
366 if (queryClass == ofClass) {
367 return true;
368 }
369 queryClass = queryClass.getSuperclass();
370 }
371 return false;
372 }
373
374 private void logIfOpenedForIllegalAccess(Class<?> caller, Class<?> declaringClass) {
375 Module callerModule = caller.getModule();
376 Module targetModule = declaringClass.getModule();
377 // callerModule is null during early startup
378 if (callerModule != null && !callerModule.isNamed() && targetModule.isNamed()) {
379 IllegalAccessLogger logger = IllegalAccessLogger.illegalAccessLogger();
380 if (logger != null) {
381 logger.logIfOpenedForIllegalAccess(caller, declaringClass, this::toShortString);
382 }
383 }
384 }
385
386 private void logIfExportedForIllegalAccess(Class<?> caller, Class<?> declaringClass) {
387 Module callerModule = caller.getModule();
388 Module targetModule = declaringClass.getModule();
389 // callerModule is null during early startup
390 if (callerModule != null && !callerModule.isNamed() && targetModule.isNamed()) {
391 IllegalAccessLogger logger = IllegalAccessLogger.illegalAccessLogger();
392 if (logger != null) {
393 logger.logIfExportedForIllegalAccess(caller, declaringClass, this::toShortString);
394 }
395 }
396 }
397
398 /**
399 * Returns a short descriptive string to describe this object in log messages.
400 */
401 String toShortString() {
402 return toString();
403 }
404
405 /**
406 * Get the value of the {@code accessible} flag for this reflected object.
407 *
408 * @return the value of the object's {@code accessible} flag
409 *
410 * @deprecated
411 * This method is deprecated because its name hints that it checks
412 * if the reflected object is accessible when it actually indicates
413 * if the checks for Java language access control are suppressed.
414 * This method may return {@code false} on a reflected object that is
415 * accessible to the caller. To test if this reflected object is accessible,
416 * it should use {@link #canAccess(Object)}.
417 *
418 * @revised 9
419 * @spec JPMS
420 */
421 @Deprecated(since="9")
422 public boolean isAccessible() {
423 return override;
424 }
425
426 /**
427 * Test if the caller can access this reflected object. If this reflected
428 * object corresponds to an instance method or field then this method tests
429 * if the caller can access the given {@code obj} with the reflected object.
430 * For instance methods or fields then the {@code obj} argument must be an
431 * instance of the {@link Member#getDeclaringClass() declaring class}. For
432 * static members and constructors then {@code obj} must be {@code null}.
433 *
434 * <p> This method returns {@code true} if the {@code accessible} flag
435 * is set to {@code true}, i.e. the checks for Java language access control
436 * are suppressed, or if the caller can access the member as
437 * specified in <cite>The Java™ Language Specification</cite>,
438 * with the variation noted in the class description. </p>
439 *
440 * @param obj an instance object of the declaring class of this reflected
441 * object if it is an instance method or field
442 *
443 * @return {@code true} if the caller can access this reflected object.
444 *
445 * @throws IllegalArgumentException
446 * <ul>
447 * <li> if this reflected object is a static member or constructor and
448 * the given {@code obj} is non-{@code null}, or </li>
449 * <li> if this reflected object is an instance method or field
450 * and the given {@code obj} is {@code null} or of type
451 * that is not a subclass of the {@link Member#getDeclaringClass()
452 * declaring class} of the member.</li>
453 * </ul>
454 *
455 * @since 9
456 * @spec JPMS
457 * @jls 6.6 Access Control
458 * @see #trySetAccessible
459 * @see #setAccessible(boolean)
460 */
461 @CallerSensitive
462 public final boolean canAccess(Object obj) {
463 if (!Member.class.isInstance(this)) {
464 return override;
465 }
466
467 Class<?> declaringClass = ((Member) this).getDeclaringClass();
468 int modifiers = ((Member) this).getModifiers();
469 if (!Modifier.isStatic(modifiers) &&
470 (this instanceof Method || this instanceof Field)) {
471 if (obj == null) {
472 throw new IllegalArgumentException("null object for " + this);
473 }
474 // if this object is an instance member, the given object
475 // must be a subclass of the declaring class of this reflected object
476 if (!declaringClass.isAssignableFrom(obj.getClass())) {
477 throw new IllegalArgumentException("object is not an instance of "
478 + declaringClass.getName());
479 }
480 } else if (obj != null) {
481 throw new IllegalArgumentException("non-null object for " + this);
482 }
483
484 // access check is suppressed
485 if (override) return true;
486
487 Class<?> caller = Reflection.getCallerClass();
488 Class<?> targetClass;
489 if (this instanceof Constructor) {
490 targetClass = declaringClass;
491 } else {
492 targetClass = Modifier.isStatic(modifiers) ? null : obj.getClass();
493 }
494 return verifyAccess(caller, declaringClass, targetClass, modifiers);
495 }
496
497 /**
498 * Constructor: only used by the Java Virtual Machine.
499 */
500 protected AccessibleObject() {}
501
502 // Indicates whether language-level access checks are overridden
503 // by this object. Initializes to "false". This field is used by
504 // Field, Method, and Constructor.
505 //
506 // NOTE: for security purposes, this field must not be visible
507 // outside this package.
508 boolean override;
509
510 // Reflection factory used by subclasses for creating field,
511 // method, and constructor accessors. Note that this is called
512 // very early in the bootstrapping process.
513 static final ReflectionFactory reflectionFactory =
514 AccessController.doPrivileged(
515 new ReflectionFactory.GetReflectionFactoryAction());
516
517 /**
518 * @throws NullPointerException {@inheritDoc}
519 * @since 1.5
520 */
521 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
522 throw new AssertionError("All subclasses should override this method");
523 }
524
525 /**
526 * {@inheritDoc}
527 * @throws NullPointerException {@inheritDoc}
528 * @since 1.5
529 */
530 @Override
531 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
532 return AnnotatedElement.super.isAnnotationPresent(annotationClass);
533 }
534
535 /**
536 * @throws NullPointerException {@inheritDoc}
537 * @since 1.8
538 */
539 @Override
540 public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) {
541 throw new AssertionError("All subclasses should override this method");
542 }
543
544 /**
545 * @since 1.5
546 */
547 public Annotation[] getAnnotations() {
548 return getDeclaredAnnotations();
549 }
550
551 /**
552 * @throws NullPointerException {@inheritDoc}
553 * @since 1.8
554 */
555 @Override
556 public <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) {
557 // Only annotations on classes are inherited, for all other
558 // objects getDeclaredAnnotation is the same as
559 // getAnnotation.
560 return getAnnotation(annotationClass);
561 }
562
563 /**
564 * @throws NullPointerException {@inheritDoc}
565 * @since 1.8
566 */
567 @Override
568 public <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) {
569 // Only annotations on classes are inherited, for all other
570 // objects getDeclaredAnnotationsByType is the same as
571 // getAnnotationsByType.
572 return getAnnotationsByType(annotationClass);
573 }
574
575 /**
576 * @since 1.5
577 */
578 public Annotation[] getDeclaredAnnotations() {
579 throw new AssertionError("All subclasses should override this method");
580 }
581
582 // Shared access checking logic.
583
584 // For non-public members or members in package-private classes,
585 // it is necessary to perform somewhat expensive access checks.
586 // If the access check succeeds for a given class, it will
587 // always succeed (it is not affected by the granting or revoking
588 // of permissions); we speed up the check in the common case by
589 // remembering the last Class for which the check succeeded.
590 //
591 // The simple access check for Constructor is to see if
592 // the caller has already been seen, verified, and cached.
593 //
594 // A more complicated access check cache is needed for Method and Field
595 // The cache can be either null (empty cache), {caller,targetClass} pair,
596 // or a caller (with targetClass implicitly equal to memberClass).
597 // In the {caller,targetClass} case, the targetClass is always different
598 // from the memberClass.
599 volatile Object accessCheckCache;
600
601 private static class Cache {
602 final WeakReference<Class<?>> callerRef;
603 final WeakReference<Class<?>> targetRef;
604
605 Cache(Class<?> caller, Class<?> target) {
606 this.callerRef = new WeakReference<>(caller);
607 this.targetRef = new WeakReference<>(target);
608 }
609
610 boolean isCacheFor(Class<?> caller, Class<?> refc) {
611 return callerRef.get() == caller && targetRef.get() == refc;
612 }
613
614 static Object protectedMemberCallerCache(Class<?> caller, Class<?> refc) {
615 return new Cache(caller, refc);
616 }
617 }
618
619 /*
620 * Returns true if the previous access check was verified for the
621 * given caller accessing a protected member with an instance of
622 * the given targetClass where the target class is different than
623 * the declaring member class.
624 */
625 private boolean isAccessChecked(Class<?> caller, Class<?> targetClass) {
626 Object cache = accessCheckCache; // read volatile
627 if (cache instanceof Cache) {
628 return ((Cache) cache).isCacheFor(caller, targetClass);
629 }
630 return false;
631 }
632
633 /*
634 * Returns true if the previous access check was verified for the
635 * given caller accessing a static member or an instance member of
636 * the target class that is the same as the declaring member class.
637 */
638 private boolean isAccessChecked(Class<?> caller) {
639 Object cache = accessCheckCache; // read volatile
640 if (cache instanceof WeakReference) {
641 @SuppressWarnings("unchecked")
642 WeakReference<Class<?>> ref = (WeakReference<Class<?>>) cache;
643 return ref.get() == caller;
644 }
645 return false;
646 }
647
648 final void checkAccess(Class<?> caller, Class<?> memberClass,
649 Class<?> targetClass, int modifiers)
650 throws IllegalAccessException
651 {
652 if (!verifyAccess(caller, memberClass, targetClass, modifiers)) {
653 IllegalAccessException e = Reflection.newIllegalAccessException(
654 caller, memberClass, targetClass, modifiers);
655 if (printStackTraceWhenAccessFails()) {
656 e.printStackTrace(System.err);
657 }
658 throw e;
659 }
660 }
661
662 final boolean verifyAccess(Class<?> caller, Class<?> memberClass,
663 Class<?> targetClass, int modifiers)
664 {
665 if (caller == memberClass) { // quick check
666 return true; // ACCESS IS OK
667 }
668 if (targetClass != null // instance member or constructor
669 && Modifier.isProtected(modifiers)
670 && targetClass != memberClass) {
671 if (isAccessChecked(caller, targetClass)) {
672 return true; // ACCESS IS OK
673 }
674 } else if (isAccessChecked(caller)) {
675 // Non-protected case (or targetClass == memberClass or static member).
676 return true; // ACCESS IS OK
677 }
678
679 // If no return, fall through to the slow path.
680 return slowVerifyAccess(caller, memberClass, targetClass, modifiers);
681 }
682
683 // Keep all this slow stuff out of line:
684 private boolean slowVerifyAccess(Class<?> caller, Class<?> memberClass,
685 Class<?> targetClass, int modifiers)
686 {
687
688 if (caller == null) {
689 // No caller frame when a native thread attaches to the VM
690 // only allow access to a public accessible member
691 return Reflection.verifyPublicMemberAccess(memberClass, modifiers);
692 }
693
694 if (!Reflection.verifyMemberAccess(caller, memberClass, targetClass, modifiers)) {
695 // access denied
696 return false;
697 }
698
699 // access okay
700 logIfExportedForIllegalAccess(caller, memberClass);
701
702 // Success: Update the cache.
703 Object cache = (targetClass != null
704 && Modifier.isProtected(modifiers)
705 && targetClass != memberClass)
706 ? Cache.protectedMemberCallerCache(caller, targetClass)
707 : new WeakReference<>(caller);
708 accessCheckCache = cache; // write volatile
709 return true;
710 }
711
712 // true to print a stack trace when access fails
713 private static volatile boolean printStackWhenAccessFails;
714
715 // true if printStack* values are initialized
716 private static volatile boolean printStackPropertiesSet;
717
718 /**
719 * Returns true if a stack trace should be printed when access fails.
720 */
721 private static boolean printStackTraceWhenAccessFails() {
722 if (!printStackPropertiesSet && VM.initLevel() >= 1) {
723 String s = GetPropertyAction.privilegedGetProperty(
724 "sun.reflect.debugModuleAccessChecks");
725 if (s != null) {
726 printStackWhenAccessFails = !s.equalsIgnoreCase("false");
727 }
728 printStackPropertiesSet = true;
729 }
730 return printStackWhenAccessFails;
731 }
732
733 /**
734 * Returns the root AccessibleObject; or null if this object is the root.
735 *
736 * All subclasses override this method.
737 */
738 AccessibleObject getRoot() {
739 throw new InternalError();
740 }
741 }