1/*
2 * Copyright (c) 1997, 2003, 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).
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 */
25
26package sun.tools.util;
27
28import sun.tools.java.*;
29
30
31/**
32 *   A class whose instances are filters over Modifier bits.
33 *   Filtering is done by returning boolean values.
34 *   Classes, methods and fields can be filtered, or filtering
35 *   can be done directly on modifier bits.
36 *
37 * WARNING: The contents of this source file are not part of any
38 * supported API.  Code that depends on them does so at its own risk:
39 * they are subject to change or removal without notice.
40 *
41 *   @see java.lang.reflect.Modifier
42 *   @author Robert Field
43 */
44
45public
46class ModifierFilter extends java.lang.reflect.Modifier {
47
48    /**
49    * Package private access.
50    * A "pseudo-" modifier bit that can be used in the
51    * constructors of this class to specify package private
52    * access. This is needed since there is no Modifier.PACKAGE.
53    */
54    public static final long PACKAGE = 0x8000000000000000L;
55
56    /**
57    * All access modifiers.
58    * A short-hand set of modifier bits that can be used in the
59    * constructors of this class to specify all access modifiers,
60    * Same as PRIVATE | PROTECTED | PUBLIC | PACKAGE.
61    */
62    public static final long ALL_ACCESS =
63                PRIVATE | PROTECTED | PUBLIC | PACKAGE;
64
65    private long oneOf;
66    private long must;
67    private long cannot;
68
69    private static final int ACCESS_BITS = PRIVATE | PROTECTED | PUBLIC;
70
71    /**
72     * Constructor - Specify a filter.
73     *
74     * @param   oneOf   If zero, everything passes the filter.
75     *                  If non-zero, at least one of the specified
76     *                  bits must be on in the modifier bits to
77     *                  pass the filter.
78     */
79    public
80    ModifierFilter(long oneOf) {
81        this(oneOf, 0, 0);
82    }
83
84    /**
85     * Constructor - Specify a filter.
86     * For example, the filter below  will only pass synchronized
87     * methods that are private or package private access and are
88     * not native or static.
89     * <pre>
90     * ModifierFilter(  Modifier.PRIVATE | ModifierFilter.PACKAGE,
91     *                  Modifier.SYNCHRONIZED,
92     *                  Modifier.NATIVE | Modifier.STATIC)
93     * </pre><p>
94     * Each of the three arguments must either be
95     * zero or the or'ed combination of the bits specified in the
96     * class Modifier or this class. During filtering, these values
97     * are compared against the modifier bits as follows:
98     *
99     * @param   oneOf   If zero, ignore this argument.
100     *                  If non-zero, at least one of the bits must be on.
101     * @param   must    All bits specified must be on.
102     * @param   cannot  None of the bits specified can be on.
103     */
104    public
105    ModifierFilter(long oneOf, long must, long cannot) {
106        this.oneOf = oneOf;
107        this.must = must;
108        this.cannot = cannot;
109    }
110
111    /**
112     * Filter on modifier bits.
113     *
114     * @param   modifierBits    Bits as specified in the Modifier class
115     *
116     * @return                  Whether the modifierBits pass this filter.
117     */
118    public boolean checkModifier(int modifierBits) {
119        // Add in the "pseudo-" modifier bit PACKAGE, if needed
120        long fmod = ((modifierBits & ACCESS_BITS) == 0) ?
121                        modifierBits | PACKAGE :
122                        modifierBits;
123        return ((oneOf == 0) || ((oneOf & fmod) != 0)) &&
124                ((must & fmod) == must) &&
125                ((cannot & fmod) == 0);
126    }
127
128    /**
129     * Filter a MemberDefinition.
130     *
131     * @param   field           A MemberDefinition
132     *
133     * @return                  Whether the modifier of the field
134     *                          passes this filter.
135     *
136     * @see sun.tools.MemberDefinition
137     */
138    public boolean checkMember(MemberDefinition field) {
139        return checkModifier(field.getModifiers());
140    }
141
142    /**
143     * Filter a ClassDefinition.
144     *
145     * @param   cdef            A ClassDefinition
146     *
147     * @return                  Whether the modifier of the class
148     *                          passes this filter.
149     *
150     * @see sun.tools.ClassDefinition
151     */
152    public boolean checkClass(ClassDefinition cdef) {
153        return checkModifier(cdef.getModifiers());
154    }
155
156} // end ModifierFilter
157