1/*
2 * Copyright (c) 2007, 2015, 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
26package com.sun.tools.classfile;
27
28import java.io.IOException;
29import java.util.LinkedHashSet;
30import java.util.Set;
31
32/**
33 * See JVMS, sections 4.2, 4.6, 4.7.
34 *
35 *  <p><b>This is NOT part of any supported API.
36 *  If you write code that depends on this, you do so at your own risk.
37 *  This code and its internal interfaces are subject to change or
38 *  deletion without notice.</b>
39 */
40public class AccessFlags {
41    public static final int ACC_PUBLIC        = 0x0001; // class, inner, field, method
42    public static final int ACC_PRIVATE       = 0x0002; //        inner, field, method
43    public static final int ACC_PROTECTED     = 0x0004; //        inner, field, method
44    public static final int ACC_STATIC        = 0x0008; //        inner, field, method
45    public static final int ACC_FINAL         = 0x0010; // class, inner, field, method
46    public static final int ACC_SUPER         = 0x0020; // class
47    public static final int ACC_SYNCHRONIZED  = 0x0020; //                      method
48    public static final int ACC_VOLATILE      = 0x0040; //               field
49    public static final int ACC_BRIDGE        = 0x0040; //                      method
50    public static final int ACC_TRANSIENT     = 0x0080; //               field
51    public static final int ACC_VARARGS       = 0x0080; //                      method
52    public static final int ACC_NATIVE        = 0x0100; //                      method
53    public static final int ACC_INTERFACE     = 0x0200; // class, inner
54    public static final int ACC_ABSTRACT      = 0x0400; // class, inner,        method
55    public static final int ACC_STRICT        = 0x0800; //                      method
56    public static final int ACC_SYNTHETIC     = 0x1000; // class, inner, field, method
57    public static final int ACC_ANNOTATION    = 0x2000; // class, inner
58    public static final int ACC_ENUM          = 0x4000; // class, inner, field
59    public static final int ACC_MANDATED      = 0x8000; //                          method parameter
60    public static final int ACC_MODULE        = 0x8000; // class
61
62    public static enum Kind { Class, InnerClass, Field, Method}
63
64    AccessFlags(ClassReader cr) throws IOException {
65        this(cr.readUnsignedShort());
66    }
67
68    public AccessFlags(int flags) {
69        this.flags = flags;
70    }
71
72    public AccessFlags ignore(int mask) {
73        return new AccessFlags(flags & ~mask);
74    }
75
76    public boolean is(int mask) {
77        return (flags & mask) != 0;
78    }
79
80    public int byteLength() {
81        return 2;
82    }
83
84    private static final int[] classModifiers = {
85        ACC_PUBLIC, ACC_FINAL, ACC_ABSTRACT
86    };
87
88    private static final int[] classFlags = {
89        ACC_PUBLIC, ACC_FINAL, ACC_SUPER, ACC_INTERFACE, ACC_ABSTRACT,
90        ACC_SYNTHETIC, ACC_ANNOTATION, ACC_ENUM, ACC_MODULE
91    };
92
93    public Set<String> getClassModifiers() {
94        int f = ((flags & ACC_INTERFACE) != 0 ? flags & ~ACC_ABSTRACT : flags);
95        return getModifiers(f, classModifiers, Kind.Class);
96    }
97
98    public Set<String> getClassFlags() {
99        return getFlags(classFlags, Kind.Class);
100    }
101
102    private static final int[] innerClassModifiers = {
103        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
104        ACC_ABSTRACT
105    };
106
107    private static final int[] innerClassFlags = {
108        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL, ACC_SUPER,
109        ACC_INTERFACE, ACC_ABSTRACT, ACC_SYNTHETIC, ACC_ANNOTATION, ACC_ENUM
110    };
111
112    public Set<String> getInnerClassModifiers() {
113        int f = ((flags & ACC_INTERFACE) != 0 ? flags & ~ACC_ABSTRACT : flags);
114        return getModifiers(f, innerClassModifiers, Kind.InnerClass);
115    }
116
117    public Set<String> getInnerClassFlags() {
118        return getFlags(innerClassFlags, Kind.InnerClass);
119    }
120
121    private static final int[] fieldModifiers = {
122        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
123        ACC_VOLATILE, ACC_TRANSIENT
124    };
125
126    private static final int[] fieldFlags = {
127        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
128        ACC_VOLATILE, ACC_TRANSIENT, ACC_SYNTHETIC, ACC_ENUM
129    };
130
131    public Set<String> getFieldModifiers() {
132        return getModifiers(fieldModifiers, Kind.Field);
133    }
134
135    public Set<String> getFieldFlags() {
136        return getFlags(fieldFlags, Kind.Field);
137    }
138
139    private static final int[] methodModifiers = {
140        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
141        ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT, ACC_STRICT
142    };
143
144    private static final int[] methodFlags = {
145        ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
146        ACC_SYNCHRONIZED, ACC_BRIDGE, ACC_VARARGS, ACC_NATIVE, ACC_ABSTRACT,
147        ACC_STRICT, ACC_SYNTHETIC
148    };
149
150    public Set<String> getMethodModifiers() {
151        return getModifiers(methodModifiers, Kind.Method);
152    }
153
154    public Set<String> getMethodFlags() {
155        return getFlags(methodFlags, Kind.Method);
156    }
157
158    private Set<String> getModifiers(int[] modifierFlags, Kind t) {
159        return getModifiers(flags, modifierFlags, t);
160    }
161
162    private static Set<String> getModifiers(int flags, int[] modifierFlags, Kind t) {
163        Set<String> s = new LinkedHashSet<>();
164        for (int m: modifierFlags) {
165            if ((flags & m) != 0)
166                s.add(flagToModifier(m, t));
167        }
168        return s;
169    }
170
171    private Set<String> getFlags(int[] expectedFlags, Kind t) {
172        Set<String> s = new LinkedHashSet<>();
173        int f = flags;
174        for (int e: expectedFlags) {
175            if ((f & e) != 0) {
176                s.add(flagToName(e, t));
177                f = f & ~e;
178            }
179        }
180        while (f != 0) {
181            int bit = Integer.highestOneBit(f);
182            s.add("0x" + Integer.toHexString(bit));
183            f = f & ~bit;
184        }
185        return s;
186    }
187
188    private static String flagToModifier(int flag, Kind t) {
189        switch (flag) {
190            case ACC_PUBLIC:
191                return "public";
192            case ACC_PRIVATE:
193                return "private";
194            case ACC_PROTECTED:
195                return "protected";
196            case ACC_STATIC:
197                return "static";
198            case ACC_FINAL:
199                return "final";
200            case ACC_SYNCHRONIZED:
201                return "synchronized";
202            case 0x80:
203                return (t == Kind.Field ? "transient" : null);
204            case ACC_VOLATILE:
205                return "volatile";
206            case ACC_NATIVE:
207                return "native";
208            case ACC_ABSTRACT:
209                return "abstract";
210            case ACC_STRICT:
211                return "strictfp";
212            case ACC_MANDATED:
213                return "mandated";
214            default:
215                return null;
216        }
217    }
218
219    private static String flagToName(int flag, Kind t) {
220        switch (flag) {
221        case ACC_PUBLIC:
222            return "ACC_PUBLIC";
223        case ACC_PRIVATE:
224            return "ACC_PRIVATE";
225        case ACC_PROTECTED:
226            return "ACC_PROTECTED";
227        case ACC_STATIC:
228            return "ACC_STATIC";
229        case ACC_FINAL:
230            return "ACC_FINAL";
231        case 0x20:
232            return (t == Kind.Class ? "ACC_SUPER" : "ACC_SYNCHRONIZED");
233        case 0x40:
234            return (t == Kind.Field ? "ACC_VOLATILE" : "ACC_BRIDGE");
235        case 0x80:
236            return (t == Kind.Field ? "ACC_TRANSIENT" : "ACC_VARARGS");
237        case ACC_NATIVE:
238            return "ACC_NATIVE";
239        case ACC_INTERFACE:
240            return "ACC_INTERFACE";
241        case ACC_ABSTRACT:
242            return "ACC_ABSTRACT";
243        case ACC_STRICT:
244            return "ACC_STRICT";
245        case ACC_SYNTHETIC:
246            return "ACC_SYNTHETIC";
247        case ACC_ANNOTATION:
248            return "ACC_ANNOTATION";
249        case ACC_ENUM:
250            return "ACC_ENUM";
251        case 0x8000:
252            return (t == Kind.Class ? "ACC_MODULE" : "ACC_MANDATED");
253        default:
254            return null;
255        }
256    }
257
258    public final int flags;
259}
260