| /* | |
| * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. Oracle designates this | |
| * particular file as subject to the "Classpath" exception as provided | |
| * by Oracle in the LICENSE file that accompanied this code. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| package java.lang.reflect; | |
| import java.lang.annotation.Annotation; | |
| import java.lang.invoke.MethodHandle; | |
| import java.lang.ref.WeakReference; | |
| import jdk.internal.access.SharedSecrets; | |
| import jdk.internal.misc.VM; | |
| import jdk.internal.reflect.CallerSensitive; | |
| import jdk.internal.reflect.Reflection; | |
| import jdk.internal.reflect.ReflectionFactory; | |
| /** | |
| * The {@code AccessibleObject} class is the base class for {@code Field}, | |
| * {@code Method}, and {@code Constructor} objects (known as <em>reflected | |
| * objects</em>). It provides the ability to flag a reflected object as | |
| * suppressing checks for Java language access control when it is used. This | |
| * permits sophisticated applications with sufficient privilege, such as Java | |
| * Object Serialization or other persistence mechanisms, to manipulate objects | |
| * in a manner that would normally be prohibited. | |
| * | |
| * <p> Java language access control prevents use of private members outside | |
| * their top-level class; package access members outside their package; protected members | |
| * outside their package or subclasses; and public members outside their | |
| * module unless they are declared in an {@link Module#isExported(String,Module) | |
| * exported} package and the user {@link Module#canRead reads} their module. By | |
| * default, Java language access control is enforced (with one variation) when | |
| * {@code Field}s, {@code Method}s, or {@code Constructor}s are used to get or | |
| * set fields, to invoke methods, or to create and initialize new instances of | |
| * classes, respectively. Every reflected object checks that the code using it | |
| * is in an appropriate class, package, or module. The check when invoked by | |
| * <a href="{@docRoot}/../specs/jni/index.html">JNI code</a> with no Java | |
| * class on the stack only succeeds if the member and the declaring class are | |
| * public, and the class is in a package that is exported to all modules. </p> | |
| * | |
| * <p> The one variation from Java language access control is that the checks | |
| * by reflected objects assume readability. That is, the module containing | |
| * the use of a reflected object is assumed to read the module in which | |
| * the underlying field, method, or constructor is declared. </p> | |
| * | |
| * <p> Whether the checks for Java language access control can be suppressed | |
| * (and thus, whether access can be enabled) depends on whether the reflected | |
| * object corresponds to a member in an exported or open package | |
| * (see {@link #setAccessible(boolean)}). </p> | |
| * | |
| * @spec jni/index.html Java Native Interface Specification | |
| * @jls 6.6 Access Control | |
| * @since 1.2 | |
| */ | |
| public class AccessibleObject implements AnnotatedElement { | |
| static { | |
| // AccessibleObject is initialized early in initPhase1 | |
| SharedSecrets.setJavaLangReflectAccess(new ReflectAccess()); | |
| } | |
| /** | |
| * Convenience method to set the {@code accessible} flag for an | |
| * array of reflected objects. | |
| * | |
| * <p> This method may be used to enable access to all reflected objects in | |
| * the array when access to each reflected object can be enabled as | |
| * specified by {@link #setAccessible(boolean) setAccessible(boolean)}. </p> | |
| * | |
| * <p>A {@code SecurityException} is thrown if any of the elements of | |
| * the input {@code array} is a {@link java.lang.reflect.Constructor} | |
| * object for the class {@code java.lang.Class} and {@code flag} is true. | |
| * | |
| * @param array the array of AccessibleObjects | |
| * @param flag the new value for the {@code accessible} flag | |
| * in each object | |
| * @throws InaccessibleObjectException if access cannot be enabled for all | |
| * objects in the array | |
| * @throws SecurityException if an element in the array is a constructor for {@code | |
| * java.lang.Class} | |
| */ | |
| @CallerSensitive | |
| public static void setAccessible(AccessibleObject[] array, boolean flag) { | |
| if (flag) { | |
| Class<?> caller = Reflection.getCallerClass(); | |
| array = array.clone(); | |
| for (AccessibleObject ao : array) { | |
| ao.checkCanSetAccessible(caller); | |
| } | |
| } | |
| for (AccessibleObject ao : array) { | |
| ao.setAccessible0(flag); | |
| } | |
| } | |
| /** | |
| * Set the {@code accessible} flag for this reflected object to | |
| * the indicated boolean value. A value of {@code true} indicates that | |
| * the reflected object should suppress checks for Java language access | |
| * control when it is used. A value of {@code false} indicates that | |
| * the reflected object should enforce checks for Java language access | |
| * control when it is used, with the variation noted in the class description. | |
| * | |
| * <p> This method may be used by a caller in class {@code C} to enable | |
| * access to a {@link Member member} of {@link Member#getDeclaringClass() | |
| * declaring class} {@code D} if any of the following hold: </p> | |
| * | |
| * <ul> | |
| * <li> {@code C} and {@code D} are in the same module. </li> | |
| * | |
| * <li> The member is {@code public} and {@code D} is {@code public} in | |
| * a package that the module containing {@code D} {@link | |
| * Module#isExported(String,Module) exports} to at least the module | |
| * containing {@code C}. </li> | |
| * | |
| * <li> The member is {@code protected} {@code static}, {@code D} is | |
| * {@code public} in a package that the module containing {@code D} | |
| * exports to at least the module containing {@code C}, and {@code C} | |
| * is a subclass of {@code D}. </li> | |
| * | |
| * <li> {@code D} is in a package that the module containing {@code D} | |
| * {@link Module#isOpen(String,Module) opens} to at least the module | |
| * containing {@code C}. | |
| * All packages in unnamed and open modules are open to all modules and | |
| * so this method always succeeds when {@code D} is in an unnamed or | |
| * open module. </li> | |
| * </ul> | |
| * | |
| * <p> This method may be used by <a href="{@docRoot}/../specs/jni/index.html">JNI code</a> | |
| * with no caller class on the stack to enable access to a {@link Member member} | |
| * of {@link Member#getDeclaringClass() declaring class} {@code D} if and only if: | |
| * <ul> | |
| * <li> The member is {@code public} and {@code D} is {@code public} in | |
| * a package that the module containing {@code D} {@link | |
| * Module#isExported(String,Module) exports} unconditionally. </li> | |
| * </ul> | |
| * | |
| * <p> This method cannot be used to enable access to private members, | |
| * members with default (package) access, protected instance members, or | |
| * protected constructors when the declaring class is in a different module | |
| * to the caller and the package containing the declaring class is not open | |
| * to the caller's module. </p> | |
| * | |
| * <p> This method cannot be used to enable {@linkplain Field#set <em>write</em>} | |
| * access to a <em>non-modifiable</em> final field. The following fields | |
| * are non-modifiable: | |
| * <ul> | |
| * <li>static final fields declared in any class or interface</li> | |
| * <li>final fields declared in a {@linkplain Class#isHidden() hidden class}</li> | |
| * <li>final fields declared in a {@linkplain Class#isRecord() record}</li> | |
| * </ul> | |
| * <p> The {@code accessible} flag when {@code true} suppresses Java language access | |
| * control checks to only enable {@linkplain Field#get <em>read</em>} access to | |
| * these non-modifiable final fields. | |
| * | |
| * @param flag the new value for the {@code accessible} flag | |
| * @throws InaccessibleObjectException if access cannot be enabled | |
| * | |
| * @spec jni/index.html Java Native Interface Specification | |
| * @see #trySetAccessible | |
| * @see java.lang.invoke.MethodHandles#privateLookupIn | |
| */ | |
| @CallerSensitive // overrides in Method/Field/Constructor are @CS | |
| public void setAccessible(boolean flag) { | |
| setAccessible0(flag); | |
| } | |
| /** | |
| * Sets the accessible flag and returns the new value | |
| */ | |
| boolean setAccessible0(boolean flag) { | |
| this.override = flag; | |
| return flag; | |
| } | |
| /** | |
| * Set the {@code accessible} flag for this reflected object to {@code true} | |
| * if possible. This method sets the {@code accessible} flag, as if by | |
| * invoking {@link #setAccessible(boolean) setAccessible(true)}, and returns | |
| * the possibly-updated value for the {@code accessible} flag. If access | |
| * cannot be enabled, i.e. the checks or Java language access control cannot | |
| * be suppressed, this method returns {@code false} (as opposed to {@code | |
| * setAccessible(true)} throwing {@code InaccessibleObjectException} when | |
| * it fails). | |
| * | |
| * <p> This method is a no-op if the {@code accessible} flag for | |
| * this reflected object is {@code true}. | |
| * | |
| * <p> For example, a caller can invoke {@code trySetAccessible} | |
| * on a {@code Method} object for a private instance method | |
| * {@code p.T::privateMethod} to suppress the checks for Java language access | |
| * control when the {@code Method} is invoked. | |
| * If {@code p.T} class is in a different module to the caller and | |
| * package {@code p} is open to at least the caller's module, | |
| * the code below successfully sets the {@code accessible} flag | |
| * to {@code true}. | |
| * | |
| * <pre> | |
| * {@code | |
| * p.T obj = ....; // instance of p.T | |
| * : | |
| * Method m = p.T.class.getDeclaredMethod("privateMethod"); | |
| * if (m.trySetAccessible()) { | |
| * m.invoke(obj); | |
| * } else { | |
| * // package p is not opened to the caller to access private member of T | |
| * ... | |
| * } | |
| * }</pre> | |
| * | |
| * <p> If this method is invoked by <a href="{@docRoot}/../specs/jni/index.html">JNI code</a> | |
| * with no caller class on the stack, the {@code accessible} flag can | |
| * only be set if the member and the declaring class are public, and | |
| * the class is in a package that is exported unconditionally. </p> | |
| * | |
| * @return {@code true} if the {@code accessible} flag is set to {@code true}; | |
| * {@code false} if access cannot be enabled. | |
| * | |
| * @spec jni/index.html Java Native Interface Specification | |
| * @since 9 | |
| * @see java.lang.invoke.MethodHandles#privateLookupIn | |
| */ | |
| @CallerSensitive | |
| public final boolean trySetAccessible() { | |
| if (override == true) return true; | |
| // if it's not a Constructor, Method, Field then no access check | |
| if (!Member.class.isInstance(this)) { | |
| return setAccessible0(true); | |
| } | |
| // does not allow to suppress access check for Class's constructor | |
| Class<?> declaringClass = ((Member) this).getDeclaringClass(); | |
| if (declaringClass == Class.class && this instanceof Constructor) { | |
| return false; | |
| } | |
| if (checkCanSetAccessible(Reflection.getCallerClass(), | |
| declaringClass, | |
| false)) { | |
| return setAccessible0(true); | |
| } else { | |
| return false; | |
| } | |
| } | |
| /** | |
| * If the given AccessibleObject is a {@code Constructor}, {@code Method} | |
| * or {@code Field} then checks that its declaring class is in a package | |
| * that can be accessed by the given caller of setAccessible. | |
| */ | |
| void checkCanSetAccessible(Class<?> caller) { | |
| // do nothing, needs to be overridden by Constructor, Method, Field | |
| } | |
| final void checkCanSetAccessible(Class<?> caller, Class<?> declaringClass) { | |
| checkCanSetAccessible(caller, declaringClass, true); | |
| } | |
| private boolean checkCanSetAccessible(Class<?> caller, | |
| Class<?> declaringClass, | |
| boolean throwExceptionIfDenied) { | |
| if (caller == MethodHandle.class) { | |
| throw new IllegalCallerException(); // should not happen | |
| } | |
| if (caller == null) { | |
| // No caller frame when a native thread attaches to the VM | |
| // only allow access to a public accessible member | |
| boolean canAccess = Reflection.verifyPublicMemberAccess(declaringClass, declaringClass.getModifiers()); | |
| if (!canAccess && throwExceptionIfDenied) { | |
| throwInaccessibleObjectException(caller, declaringClass); | |
| } | |
| return canAccess; | |
| } | |
| Module callerModule = caller.getModule(); | |
| Module declaringModule = declaringClass.getModule(); | |
| if (callerModule == declaringModule) return true; | |
| if (callerModule == Object.class.getModule()) return true; | |
| if (!declaringModule.isNamed()) return true; | |
| String pn = declaringClass.getPackageName(); | |
| int modifiers = ((Member)this).getModifiers(); | |
| // class is public and package is exported to caller | |
| boolean isClassPublic = Modifier.isPublic(declaringClass.getModifiers()); | |
| if (isClassPublic && declaringModule.isExported(pn, callerModule)) { | |
| // member is public | |
| if (Modifier.isPublic(modifiers)) { | |
| return true; | |
| } | |
| // member is protected-static | |
| if (Modifier.isProtected(modifiers) | |
| && Modifier.isStatic(modifiers) | |
| && isSubclassOf(caller, declaringClass)) { | |
| return true; | |
| } | |
| } | |
| // package is open to caller | |
| if (declaringModule.isOpen(pn, callerModule)) { | |
| return true; | |
| } | |
| if (throwExceptionIfDenied) { | |
| throwInaccessibleObjectException(caller, declaringClass); | |
| } | |
| return false; | |
| } | |
| private void throwInaccessibleObjectException(Class<?> caller, Class<?> declaringClass) { | |
| boolean isClassPublic = Modifier.isPublic(declaringClass.getModifiers()); | |
| String pn = declaringClass.getPackageName(); | |
| int modifiers = ((Member)this).getModifiers(); | |
| // not accessible | |
| String msg = "Unable to make "; | |
| if (this instanceof Field) | |
| msg += "field "; | |
| msg += this + " accessible"; | |
| msg += caller == null ? " by JNI attached native thread with no caller frame: " : ": "; | |
| msg += declaringClass.getModule() + " does not \""; | |
| if (isClassPublic && Modifier.isPublic(modifiers)) | |
| msg += "exports"; | |
| else | |
| msg += "opens"; | |
| msg += " " + pn + "\"" ; | |
| if (caller != null) | |
| msg += " to " + caller.getModule(); | |
| InaccessibleObjectException e = new InaccessibleObjectException(msg); | |
| if (printStackTraceWhenAccessFails()) { | |
| e.printStackTrace(System.err); | |
| } | |
| throw e; | |
| } | |
| private boolean isSubclassOf(Class<?> queryClass, Class<?> ofClass) { | |
| while (queryClass != null) { | |
| if (queryClass == ofClass) { | |
| return true; | |
| } | |
| queryClass = queryClass.getSuperclass(); | |
| } | |
| return false; | |
| } | |
| /** | |
| * Returns a short descriptive string to describe this object in log messages. | |
| */ | |
| String toShortString() { | |
| return toString(); | |
| } | |
| /** | |
| * Get the value of the {@code accessible} flag for this reflected object. | |
| * | |
| * @return the value of the object's {@code accessible} flag | |
| * | |
| * @deprecated | |
| * This method is deprecated because its name hints that it checks | |
| * if the reflected object is accessible when it actually indicates | |
| * if the checks for Java language access control are suppressed. | |
| * This method may return {@code false} on a reflected object that is | |
| * accessible to the caller. To test if this reflected object is accessible, | |
| * it should use {@link #canAccess(Object)}. | |
| */ | |
| @Deprecated(since="9") | |
| public boolean isAccessible() { | |
| return override; | |
| } | |
| /** | |
| * Test if the caller can access this reflected object. If this reflected | |
| * object corresponds to an instance method or field then this method tests | |
| * if the caller can access the given {@code obj} with the reflected object. | |
| * For instance methods or fields then the {@code obj} argument must be an | |
| * instance of the {@link Member#getDeclaringClass() declaring class}. For | |
| * static members and constructors then {@code obj} must be {@code null}. | |
| * | |
| * <p> This method returns {@code true} if the {@code accessible} flag | |
| * is set to {@code true}, i.e. the checks for Java language access control | |
| * are suppressed, or if the caller can access the member as | |
| * specified in <cite>The Java Language Specification</cite>, | |
| * with the variation noted in the class description. | |
| * If this method is invoked by <a href="{@docRoot}/../specs/jni/index.html">JNI code</a> | |
| * with no caller class on the stack, this method returns {@code true} | |
| * if the member and the declaring class are public, and the class is in | |
| * a package that is exported unconditionally. </p> | |
| * | |
| * @param obj an instance object of the declaring class of this reflected | |
| * object if it is an instance method or field | |
| * | |
| * @return {@code true} if the caller can access this reflected object. | |
| * | |
| * @throws IllegalArgumentException | |
| * <ul> | |
| * <li> if this reflected object is a static member or constructor and | |
| * the given {@code obj} is non-{@code null}, or </li> | |
| * <li> if this reflected object is an instance method or field | |
| * and the given {@code obj} is {@code null} or of type | |
| * that is not a subclass of the {@link Member#getDeclaringClass() | |
| * declaring class} of the member.</li> | |
| * </ul> | |
| * | |
| * @spec jni/index.html Java Native Interface Specification | |
| * @since 9 | |
| * @jls 6.6 Access Control | |
| * @see #trySetAccessible | |
| * @see #setAccessible(boolean) | |
| */ | |
| @CallerSensitive | |
| public final boolean canAccess(Object obj) { | |
| if (!Member.class.isInstance(this)) { | |
| return override; | |
| } | |
| Class<?> declaringClass = ((Member) this).getDeclaringClass(); | |
| int modifiers = ((Member) this).getModifiers(); | |
| if (!Modifier.isStatic(modifiers) && | |
| (this instanceof Method || this instanceof Field)) { | |
| if (obj == null) { | |
| throw new IllegalArgumentException("null object for " + this); | |
| } | |
| // if this object is an instance member, the given object | |
| // must be a subclass of the declaring class of this reflected object | |
| if (!declaringClass.isInstance(obj)) { | |
| throw new IllegalArgumentException("object is not an instance of " | |
| + declaringClass.getName()); | |
| } | |
| } else if (obj != null) { | |
| throw new IllegalArgumentException("non-null object for " + this); | |
| } | |
| // access check is suppressed | |
| if (override) return true; | |
| Class<?> caller = Reflection.getCallerClass(); | |
| Class<?> targetClass; | |
| if (this instanceof Constructor) { | |
| targetClass = declaringClass; | |
| } else { | |
| targetClass = Modifier.isStatic(modifiers) ? null : obj.getClass(); | |
| } | |
| return verifyAccess(caller, declaringClass, targetClass, modifiers); | |
| } | |
| /** | |
| * Constructor: only used by the Java Virtual Machine. | |
| */ | |
| @Deprecated(since="17") | |
| protected AccessibleObject() {} | |
| // Indicates whether language-level access checks are overridden | |
| // by this object. Initializes to "false". This field is used by | |
| // Field, Method, and Constructor. | |
| // | |
| // NOTE: for security purposes, this field must not be visible | |
| // outside this package. | |
| boolean override; | |
| // Reflection factory used by subclasses for creating field, | |
| // method, and constructor accessors. Note that this is called | |
| // very early in the bootstrapping process. | |
| static final ReflectionFactory reflectionFactory = ReflectionFactory.getReflectionFactory(); | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotation returned by this method is a | |
| * declaration annotation. | |
| * | |
| * @implSpec | |
| * The default implementation throws {@link | |
| * UnsupportedOperationException}; subclasses should override this method. | |
| * | |
| * @throws NullPointerException {@inheritDoc} | |
| * @since 1.5 | |
| */ | |
| @Override | |
| public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { | |
| throw new UnsupportedOperationException("All subclasses should override this method"); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * @throws NullPointerException {@inheritDoc} | |
| * @since 1.5 | |
| */ | |
| @Override | |
| public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) { | |
| return AnnotatedElement.super.isAnnotationPresent(annotationClass); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotations returned by this method are | |
| * declaration annotations. | |
| * | |
| * @implSpec | |
| * The default implementation throws {@link | |
| * UnsupportedOperationException}; subclasses should override this method. | |
| * | |
| * @throws NullPointerException {@inheritDoc} | |
| * @since 1.8 | |
| */ | |
| @Override | |
| public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) { | |
| throw new UnsupportedOperationException("All subclasses should override this method"); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotations returned by this method are | |
| * declaration annotations. | |
| * | |
| * @since 1.5 | |
| */ | |
| @Override | |
| public Annotation[] getAnnotations() { | |
| return getDeclaredAnnotations(); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotation returned by this method is a | |
| * declaration annotation. | |
| * | |
| * @throws NullPointerException {@inheritDoc} | |
| * @since 1.8 | |
| */ | |
| @Override | |
| public <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) { | |
| // Only annotations on classes are inherited, for all other | |
| // objects getDeclaredAnnotation is the same as | |
| // getAnnotation. | |
| return getAnnotation(annotationClass); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotations returned by this method are | |
| * declaration annotations. | |
| * | |
| * @throws NullPointerException {@inheritDoc} | |
| * @since 1.8 | |
| */ | |
| @Override | |
| public <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) { | |
| // Only annotations on classes are inherited, for all other | |
| // objects getDeclaredAnnotationsByType is the same as | |
| // getAnnotationsByType. | |
| return getAnnotationsByType(annotationClass); | |
| } | |
| /** | |
| * {@inheritDoc} | |
| * | |
| * <p> Note that any annotations returned by this method are | |
| * declaration annotations. | |
| * | |
| * @implSpec | |
| * The default implementation throws {@link | |
| * UnsupportedOperationException}; subclasses should override this method. | |
| * | |
| * @since 1.5 | |
| */ | |
| @Override | |
| public Annotation[] getDeclaredAnnotations() { | |
| throw new UnsupportedOperationException("All subclasses should override this method"); | |
| } | |
| // Shared access checking logic. | |
| // For non-public members or members in package-private classes, | |
| // it is necessary to perform somewhat expensive access checks. | |
| // If the access check succeeds for a given class, it will | |
| // always succeed; we speed up the check in the common case by | |
| // remembering the last Class for which the check succeeded. | |
| // | |
| // The simple access check for Constructor is to see if | |
| // the caller has already been seen, verified, and cached. | |
| // | |
| // A more complicated access check cache is needed for Method and Field | |
| // The cache can be either null (empty cache), {caller,targetClass} pair, | |
| // or a caller (with targetClass implicitly equal to memberClass). | |
| // In the {caller,targetClass} case, the targetClass is always different | |
| // from the memberClass. | |
| volatile Object accessCheckCache; | |
| private static class Cache { | |
| final WeakReference<Class<?>> callerRef; | |
| final WeakReference<Class<?>> targetRef; | |
| Cache(Class<?> caller, Class<?> target) { | |
| this.callerRef = new WeakReference<>(caller); | |
| this.targetRef = new WeakReference<>(target); | |
| } | |
| boolean isCacheFor(Class<?> caller, Class<?> refc) { | |
| return callerRef.refersTo(caller) && targetRef.refersTo(refc); | |
| } | |
| static Object protectedMemberCallerCache(Class<?> caller, Class<?> refc) { | |
| return new Cache(caller, refc); | |
| } | |
| } | |
| /* | |
| * Returns true if the previous access check was verified for the | |
| * given caller accessing a protected member with an instance of | |
| * the given targetClass where the target class is different than | |
| * the declaring member class. | |
| */ | |
| private boolean isAccessChecked(Class<?> caller, Class<?> targetClass) { | |
| Object cache = accessCheckCache; // read volatile | |
| if (cache instanceof Cache c) { | |
| return c.isCacheFor(caller, targetClass); | |
| } | |
| return false; | |
| } | |
| /* | |
| * Returns true if the previous access check was verified for the | |
| * given caller accessing a static member or an instance member of | |
| * the target class that is the same as the declaring member class. | |
| */ | |
| private boolean isAccessChecked(Class<?> caller) { | |
| Object cache = accessCheckCache; // read volatile | |
| if (cache instanceof WeakReference) { | |
| @SuppressWarnings("unchecked") | |
| WeakReference<Class<?>> ref = (WeakReference<Class<?>>) cache; | |
| return ref.refersTo(caller); | |
| } | |
| return false; | |
| } | |
| final void checkAccess(Class<?> caller, Class<?> memberClass, | |
| Class<?> targetClass, int modifiers) | |
| throws IllegalAccessException | |
| { | |
| if (!verifyAccess(caller, memberClass, targetClass, modifiers)) { | |
| IllegalAccessException e = Reflection.newIllegalAccessException( | |
| caller, memberClass, targetClass, modifiers); | |
| if (printStackTraceWhenAccessFails()) { | |
| e.printStackTrace(System.err); | |
| } | |
| throw e; | |
| } | |
| } | |
| final boolean verifyAccess(Class<?> caller, Class<?> memberClass, | |
| Class<?> targetClass, int modifiers) | |
| { | |
| if (caller == memberClass) { // quick check | |
| return true; // ACCESS IS OK | |
| } | |
| if (targetClass != null // instance member or constructor | |
| && Modifier.isProtected(modifiers) | |
| && targetClass != memberClass) { | |
| if (isAccessChecked(caller, targetClass)) { | |
| return true; // ACCESS IS OK | |
| } | |
| } else if (isAccessChecked(caller)) { | |
| // Non-protected case (or targetClass == memberClass or static member). | |
| return true; // ACCESS IS OK | |
| } | |
| // If no return, fall through to the slow path. | |
| return slowVerifyAccess(caller, memberClass, targetClass, modifiers); | |
| } | |
| // Keep all this slow stuff out of line: | |
| private boolean slowVerifyAccess(Class<?> caller, Class<?> memberClass, | |
| Class<?> targetClass, int modifiers) | |
| { | |
| if (caller == null) { | |
| // No caller frame when a native thread attaches to the VM | |
| // only allow access to a public accessible member | |
| return Reflection.verifyPublicMemberAccess(memberClass, modifiers); | |
| } | |
| if (!Reflection.verifyMemberAccess(caller, memberClass, targetClass, modifiers)) { | |
| // access denied | |
| return false; | |
| } | |
| // Success: Update the cache. | |
| Object cache = (targetClass != null | |
| && Modifier.isProtected(modifiers) | |
| && targetClass != memberClass) | |
| ? Cache.protectedMemberCallerCache(caller, targetClass) | |
| : new WeakReference<>(caller); | |
| accessCheckCache = cache; // write volatile | |
| return true; | |
| } | |
| // true to print a stack trace when access fails | |
| private static volatile boolean printStackWhenAccessFails; | |
| // true if printStack* values are initialized | |
| private static volatile boolean printStackPropertiesSet; | |
| /** | |
| * Returns true if a stack trace should be printed when access fails. | |
| */ | |
| private static boolean printStackTraceWhenAccessFails() { | |
| if (!printStackPropertiesSet && VM.initLevel() >= 1) { | |
| String s = System.getProperty("sun.reflect.debugModuleAccessChecks"); | |
| if (s != null) { | |
| printStackWhenAccessFails = !s.equalsIgnoreCase("false"); | |
| } | |
| printStackPropertiesSet = true; | |
| } | |
| return printStackWhenAccessFails; | |
| } | |
| /** | |
| * Returns the root AccessibleObject; or null if this object is the root. | |
| * | |
| * All subclasses override this method. | |
| */ | |
| AccessibleObject getRoot() { | |
| throw new InternalError(); | |
| } | |
| } |