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 
 26 package com.sun.tools.classfile;
 27 
 28 import java.io.IOException;
 29 import java.util.LinkedHashSet;
 30 import 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  */
 40 public 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 }