1 /*

     2  * Copyright (c) 2000, 2012, 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 com.sun.tools.javadoc;

    27 

    28 import static com.sun.tools.javac.code.Flags.*;

    29 

    30 /**

    31  *   A class whose instances are filters over Modifier bits.

    32  *   Filtering is done by returning boolean values.

    33  *   Classes, methods and fields can be filtered, or filtering

    34  *   can be done directly on modifier bits.

    35  *

    36  *  <p><b>This is NOT part of any supported API.

    37  *  If you write code that depends on this, you do so at your own risk.

    38  *  This code and its internal interfaces are subject to change or

    39  *  deletion without notice.</b>

    40  *

    41  *   @see com.sun.tools.javac.code.Flags

    42  *   @author Robert Field

    43  */

    44 

    45 public class ModifierFilter {

    46 

    47     /**

    48     * Package private access.

    49     * A "pseudo-" modifier bit that can be used in the

    50     * constructors of this class to specify package private

    51     * access. This is needed since there is no Modifier.PACKAGE.

    52     */

    53     public static final long PACKAGE = 0x8000000000000000L;

    54 

    55     /**

    56     * All access modifiers.

    57     * A short-hand set of modifier bits that can be used in the

    58     * constructors of this class to specify all access modifiers,

    59     * Same as PRIVATE | PROTECTED | PUBLIC | PACKAGE.

    60     */

    61     public static final long ALL_ACCESS =

    62                 PRIVATE | PROTECTED | PUBLIC | PACKAGE;

    63 

    64     private long oneOf;

    65     private long must;

    66     private long cannot;

    67 

    68     private static final int ACCESS_BITS = PRIVATE | PROTECTED | PUBLIC;

    69 

    70     /**

    71      * Constructor - Specify a filter.

    72      *

    73      * @param   oneOf   If zero, everything passes the filter.

    74      *                  If non-zero, at least one of the specified

    75      *                  bits must be on in the modifier bits to

    76      *                  pass the filter.

    77      */

    78     public ModifierFilter(long oneOf) {

    79         this(oneOf, 0, 0);

    80     }

    81 

    82     /**

    83      * Constructor - Specify a filter.

    84      * For example, the filter below  will only pass synchronized

    85      * methods that are private or package private access and are

    86      * not native or static.

    87      * <pre>

    88      * ModifierFilter(  Modifier.PRIVATE | ModifierFilter.PACKAGE,

    89      *                  Modifier.SYNCHRONIZED,

    90      *                  Modifier.NATIVE | Modifier.STATIC)

    91      * </pre><p>

    92      * Each of the three arguments must either be

    93      * zero or the or'ed combination of the bits specified in the

    94      * class Modifier or this class. During filtering, these values

    95      * are compared against the modifier bits as follows:

    96      *

    97      * @param   oneOf   If zero, ignore this argument.

    98      *                  If non-zero, at least one of the bits must be on.

    99      * @param   must    All bits specified must be on.

   100      * @param   cannot  None of the bits specified can be on.

   101      */

   102     public ModifierFilter(long oneOf, long must, long cannot) {

   103         this.oneOf = oneOf;

   104         this.must = must;

   105         this.cannot = cannot;

   106     }

   107 

   108     /**

   109      * Filter on modifier bits.

   110      *

   111      * @param   modifierBits    Bits as specified in the Modifier class

   112      *

   113      * @return                  Whether the modifierBits pass this filter.

   114      */

   115     public boolean checkModifier(int modifierBits) {

   116         // Add in the "pseudo-" modifier bit PACKAGE, if needed

   117         long fmod = ((modifierBits & ACCESS_BITS) == 0) ?

   118                         modifierBits | PACKAGE :

   119                         modifierBits;

   120         return ((oneOf == 0) || ((oneOf & fmod) != 0)) &&

   121                 ((must & fmod) == must) &&

   122                 ((cannot & fmod) == 0);

   123     }

   124 

   125 } // end ModifierFilter