content: /*
   * Copyright (C) 2014 The Android Open Source Project
   * Copyright (c) 1997, 2014, 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;
  
  /**
   * The AccessibleObject class is the base class for Field, Method and
   * Constructor objects.  It provides the ability to flag a reflected
   * object as suppressing default Java language access control checks
   * when it is used.  The access checks--for public, default (package)
   * access, protected, and private members--are performed when Fields,
   * Methods or Constructors are used to set or get fields, to invoke
   * methods, or to create and initialize new instances of classes,
   * respectively.
   *
   * <p>Setting the {@code accessible} flag in a reflected object
   * 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>By default, a reflected object is <em>not</em> accessible.
   *
   * @see Field
   * @see Method
   * @see Constructor
   * @see ReflectPermission
   *
   * @since 1.2
   */
  public class AccessibleObject implements AnnotatedElement {
  
      // Android-removed: Code associated with SecurityManager calls.
      /*
      /**
       * The Permission object that is used to check whether a client
       * has sufficient privilege to defeat Java language access
       * control checks.
       *
      static final private java.security.Permission ACCESS_PERMISSION =
          new ReflectPermission("suppressAccessChecks");
      */
  
      /**
       * Convenience method to set the {@code accessible} flag for an
       * array of objects with a single security check (for efficiency).
       *
       * <p>First, if there is a security manager, its
       * {@code checkPermission} method is called with a
       * {@code ReflectPermission("suppressAccessChecks")} permission.
       *
       * <p>A {@code SecurityException} is raised if {@code flag} is
       * {@code true} but accessibility of any of the elements of the input
       * {@code array} may not be changed (for example, if the element
       * object is a {@link Constructor} object for the class {@link
       * Class}).  In the event of such a SecurityException, the
       * accessibility of objects is set to {@code flag} for array elements
       * upto (and excluding) the element for which the exception occurred; the
       * accessibility of elements beyond (and including) the element for which
       * the exception occurred is unchanged.
       *
       * @param array the array of AccessibleObjects
       * @param flag  the new value for the {@code accessible} flag
       *              in each object
       * @throws SecurityException if the request is denied.
       * @see SecurityManager#checkPermission
       * @see RuntimePermission
       */
      public static void setAccessible(AccessibleObject[] array, boolean flag)
          throws SecurityException {
          // Android-removed: SecurityManager calls.
          // SecurityManager sm = System.getSecurityManager();
          // if (sm != null) sm.checkPermission(ACCESS_PERMISSION);
          for (int i = 0; i < array.length; i++) {
              setAccessible0(array[i], flag);
          }
      }
  
      /**
       * Set the {@code accessible} flag for this object to
       * the indicated boolean value.  A value of {@code true} indicates that
       * the reflected object should suppress Java language access
       * checking when it is used.  A value of {@code false} indicates
       * that the reflected object should enforce Java language access checks.
       *
       * <p>First, if there is a security manager, its
       * {@code checkPermission} method is called with a
       * {@code ReflectPermission("suppressAccessChecks")} permission.
       *
       * <p>A {@code SecurityException} is raised if {@code flag} is
       * {@code true} but accessibility of this object may not be changed
       * (for example, if this element object is a {@link Constructor} object for
       * the class {@link Class}).
       *
       * <p>A {@code SecurityException} is raised if this object is a {@link
       * Constructor} object for the class
       * {@code java.lang.Class}, and {@code flag} is true.
       *
       * @param flag the new value for the {@code accessible} flag
       * @throws SecurityException if the request is denied.
       * @see SecurityManager#checkPermission
       * @see RuntimePermission
       */
      public void setAccessible(boolean flag) throws SecurityException {
          // Android-removed: SecurityManager calls.
          // SecurityManager sm = System.getSecurityManager();
          // if (sm != null) sm.checkPermission(ACCESS_PERMISSION);
          setAccessible0(this, flag);
      }
  
      /* Check that you aren't exposing java.lang.Class.<init> or sensitive
         fields in java.lang.Class. */
      private static void setAccessible0(AccessibleObject obj, boolean flag)
          throws SecurityException
      {
          if (obj instanceof Constructor && flag == true) {
              Constructor<?> c = (Constructor<?>)obj;
              // BEGIN Android-changed: Disallow making Method & Field constructors accessible.
              // if (c.getDeclaringClass() == Class.class) {
              //     throw new SecurityException("Cannot make a java.lang.Class" +
              //                                 " constructor accessible");
              // }
  
              Class<?> clazz = c.getDeclaringClass();
              if (c.getDeclaringClass() == Class.class) {
                  throw new SecurityException("Can not make a java.lang.Class" +
                                              " constructor accessible");
              } else if (clazz == Method.class) {
                  throw new SecurityException("Can not make a java.lang.reflect.Method" +
                                              " constructor accessible");
              } else if (clazz == Field.class) {
                  throw new SecurityException("Can not make a java.lang.reflect.Field" +
                                              " constructor accessible");
              }
              // END Android-changed: Disallow making Method & Field constructors accessible.
          }
          obj.override = flag;
      }
  
      /**
       * Get the value of the {@code accessible} flag for this object.
       *
       * @return the value of the object's {@code accessible} flag
       */
      public boolean isAccessible() {
          return override;
      }
  
      /**
       * Constructor: only used by the Java Virtual Machine.
       */
      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;
  
      // Android-removed: reflectionFactory: it is not used on Android.
      /*
      // 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 =
          AccessController.doPrivileged(
              new sun.reflect.ReflectionFactory.GetReflectionFactoryAction());
      */
  
      /**
       * @throws NullPointerException {@inheritDoc}
       * @since 1.5
       */
      public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
          throw new AssertionError("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);
      }
  
     /**
       * @throws NullPointerException {@inheritDoc}
       * @since 1.8
       */
      @Override
      public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) {
          throw new AssertionError("All subclasses should override this method");
      }
  
      /**
       * @since 1.5
       */
      public Annotation[] getAnnotations() {
          return getDeclaredAnnotations();
      }
  
      /**
       * @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);
      }
  
      /**
       * @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);
      }
  
      /**
       * @since 1.5
       */
      public Annotation[] getDeclaredAnnotations()  {
          throw new AssertionError("All subclasses should override this method");
      }
  
      // BEGIN Android-removed: Shared access checking logic: Not used on Android.
      /*
      // For non-public members or members in package-private classes,
      // it is necessary to perform somewhat expensive security checks.
      // If the security check succeeds for a given class, it will
      // always succeed (it is not affected by the granting or revoking
      // of permissions); we speed up the check in the common case by
      // remembering the last Class for which the check succeeded.
      //
      // The simple security check for Constructor is to see if
      // the caller has already been seen, verified, and cached.
      // (See also Class.newInstance(), which uses a similar method.)
      //
      // A more complicated security check cache is needed for Method and Field
      // The cache can be either null (empty cache), a 2-array of {caller,target},
      // or a caller (with target implicitly equal to this.clazz).
      // In the 2-array case, the target is always different from the clazz.
      volatile Object securityCheckCache;
  
      void checkAccess(Class<?> caller, Class<?> clazz, Object obj, int modifiers)
          throws IllegalAccessException
      {
          if (caller == clazz) {  // quick check
              return;             // ACCESS IS OK
          }
          Object cache = securityCheckCache;  // read volatile
          Class<?> targetClass = clazz;
          if (obj != null
              && Modifier.isProtected(modifiers)
              && ((targetClass = obj.getClass()) != clazz)) {
              // Must match a 2-list of { caller, targetClass }.
              if (cache instanceof Class[]) {
                  Class<?>[] cache2 = (Class<?>[]) cache;
                  if (cache2[1] == targetClass &&
                      cache2[0] == caller) {
                      return;     // ACCESS IS OK
                  }
                  // (Test cache[1] first since range check for [1]
                  // subsumes range check for [0].)
              }
          } else if (cache == caller) {
              // Non-protected case (or obj.class == this.clazz).
              return;             // ACCESS IS OK
          }
  
          // If no return, fall through to the slow path.
          slowCheckMemberAccess(caller, clazz, obj, modifiers, targetClass);
      }
  
      // Keep all this slow stuff out of line:
      void slowCheckMemberAccess(Class<?> caller, Class<?> clazz, Object obj, int modifiers,
                                 Class<?> targetClass)
          throws IllegalAccessException
      {
          Reflection.ensureMemberAccess(caller, clazz, obj, modifiers);
  
          // Success: Update the cache.
          Object cache = ((targetClass == clazz)
                          ? caller
                          : new Class<?>[] { caller, targetClass });
  
          // Note:  The two cache elements are not volatile,
          // but they are effectively final.  The Java memory model
          // guarantees that the initializing stores for the cache
          // elements will occur before the volatile write.
          securityCheckCache = cache;         // write volatile
      }
      */
      // END Android-removed: Shared access checking logic: Not used on Android.
  }
  