/* ReflectUtil.java - JSR 166 reflection hooks
   Copyright (C) 2006 Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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independent module, the terms and conditions of the license of that
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this exception to your version of the library, but you are not
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exception statement from your version. */

package sun.reflect.misc;

import java.lang.reflect.Modifier;

public class ReflectUtil
{
  // We use this inaccessible inner class as an argument type
  // in verifyMemberAccess.  All current users of this method
  // in the JSR 166 RI pass 'null' for this argument, and
  // consequently we don't know what it means.  Using a funny
  // type like this for the argument means that if the RI changes,
  // we will see a compilation error.
  private static class MustBeNull
  {
  }

  public static void checkPackageAccess(Class declaringClass)
  {
    // FIXME: not sure what to check here.
  }

  /**
   * Perform access checks on a member of a class.  This API is
   * derived from the public domain code in the JSR 166 reference
   * implementation.
   * @param caller the class requesting access to the member
   * @param declarer the declaring class of the member
   * @param ignored unknown parameter; always null
   * @param modifiers the modifiers on the member
   */
  public static void ensureMemberAccess(Class caller,
                                        Class declarer,
                                        MustBeNull ignored,
                                        int modifiers)
  {
    // Same class, always ok.
    if (caller == declarer)
      return;
    // Public access is ok.
    if ((modifiers & Modifier.PUBLIC) != 0)
      return;
    // Protected access and request comes from
    // a subclass of the declarer -- ok.
    if ((modifiers & Modifier.PROTECTED) != 0
        && declarer.isAssignableFrom(caller))
      return;
    // Package-private access, or protected access,
    // and the packages are the same --ok.
    if ((modifiers & Modifier.PRIVATE) == 0
        && caller.getPackage() == declarer.getPackage())
      return;
    // Otherwise, no.
    throw new IllegalAccessError();
  }
}