1 /*
   2  * Copyright (c) 2007, 2008, 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_MODULE        = 0x8000; // class, inner, field, method
  60 
  61     public static enum Kind { Class, InnerClass, Field, Method};
  62 
  63     AccessFlags(ClassReader cr) throws IOException {
  64         this(cr.readUnsignedShort());
  65     }
  66 
  67     public AccessFlags(int flags) {
  68         this.flags = flags;
  69     }
  70 
  71     public AccessFlags ignore(int mask) {
  72         return new AccessFlags(flags & ~mask);
  73     }
  74 
  75     public boolean is(int mask) {
  76         return (flags & mask) != 0;
  77     }
  78 
  79     public int byteLength() {
  80         return 2;
  81     }
  82 
  83     private static final int[] classModifiers = {
  84         ACC_PUBLIC, ACC_FINAL, ACC_ABSTRACT, ACC_MODULE
  85     };
  86 
  87     private static final int[] classFlags = {
  88         ACC_PUBLIC, ACC_FINAL, ACC_SUPER, ACC_INTERFACE, ACC_ABSTRACT,
  89         ACC_SYNTHETIC, ACC_ANNOTATION, ACC_ENUM, ACC_MODULE
  90     };
  91 
  92     public Set<String> getClassModifiers() {
  93         int f = ((flags & ACC_INTERFACE) != 0 ? flags & ~ACC_ABSTRACT : flags);
  94         return getModifiers(f, classModifiers, Kind.Class);
  95     }
  96 
  97     public Set<String> getClassFlags() {
  98         return getFlags(classFlags, Kind.Class);
  99     }
 100 
 101     private static final int[] innerClassModifiers = {
 102         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
 103         ACC_ABSTRACT, ACC_MODULE
 104     };
 105 
 106     private static final int[] innerClassFlags = {
 107         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL, ACC_SUPER,
 108         ACC_INTERFACE, ACC_ABSTRACT, ACC_SYNTHETIC, ACC_ANNOTATION, ACC_ENUM, ACC_MODULE
 109     };
 110 
 111     public Set<String> getInnerClassModifiers() {
 112         int f = ((flags & ACC_INTERFACE) != 0 ? flags & ~ACC_ABSTRACT : flags);
 113         return getModifiers(f, innerClassModifiers, Kind.InnerClass);
 114     }
 115 
 116     public Set<String> getInnerClassFlags() {
 117         return getFlags(innerClassFlags, Kind.InnerClass);
 118     }
 119 
 120     private static final int[] fieldModifiers = {
 121         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
 122         ACC_VOLATILE, ACC_TRANSIENT, ACC_MODULE
 123     };
 124 
 125     private static final int[] fieldFlags = {
 126         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
 127         ACC_VOLATILE, ACC_TRANSIENT, ACC_SYNTHETIC, ACC_ENUM, ACC_MODULE
 128     };
 129 
 130     public Set<String> getFieldModifiers() {
 131         return getModifiers(fieldModifiers, Kind.Field);
 132     }
 133 
 134     public Set<String> getFieldFlags() {
 135         return getFlags(fieldFlags, Kind.Field);
 136     }
 137 
 138     private static final int[] methodModifiers = {
 139         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
 140         ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT, ACC_STRICT, ACC_MODULE
 141     };
 142 
 143     private static final int[] methodFlags = {
 144         ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
 145         ACC_SYNCHRONIZED, ACC_BRIDGE, ACC_VARARGS, ACC_NATIVE, ACC_ABSTRACT,
 146         ACC_STRICT, ACC_SYNTHETIC, ACC_MODULE
 147     };
 148 
 149     public Set<String> getMethodModifiers() {
 150         return getModifiers(methodModifiers, Kind.Method);
 151     }
 152 
 153     public Set<String> getMethodFlags() {
 154         return getFlags(methodFlags, Kind.Method);
 155     }
 156 
 157     private Set<String> getModifiers(int[] modifierFlags, Kind t) {
 158         return getModifiers(flags, modifierFlags, t);
 159     }
 160 
 161     private static Set<String> getModifiers(int flags, int[] modifierFlags, Kind t) {
 162         Set<String> s = new LinkedHashSet<String>();
 163         for (int m: modifierFlags) {
 164             if ((flags & m) != 0)
 165                 s.add(flagToModifier(m, t));
 166         }
 167         return s;
 168     }
 169 
 170     private Set<String> getFlags(int[] expectedFlags, Kind t) {
 171         Set<String> s = new LinkedHashSet<String>();
 172         int f = flags;
 173         for (int e: expectedFlags) {
 174             if ((f & e) != 0) {
 175                 s.add(flagToName(e, t));
 176                 f = f & ~e;
 177             }
 178         }
 179         while (f != 0) {
 180             int bit = Integer.highestOneBit(f);
 181             s.add("0x" + Integer.toHexString(bit));
 182             f = f & ~bit;
 183         }
 184         return s;
 185     }
 186 
 187     private static String flagToModifier(int flag, Kind t) {
 188         switch (flag) {
 189             case ACC_PUBLIC:
 190                 return "public";
 191             case ACC_PRIVATE:
 192                 return "private";
 193             case ACC_PROTECTED:
 194                 return "protected";
 195             case ACC_STATIC:
 196                 return "static";
 197             case ACC_FINAL:
 198                 return "final";
 199             case ACC_SYNCHRONIZED:
 200                 return "synchronized";
 201             case 0x80:
 202                 return (t == Kind.Field ? "transient" : null);
 203             case ACC_VOLATILE:
 204                 return "volatile";
 205             case ACC_NATIVE:
 206                 return "native";
 207             case ACC_ABSTRACT:
 208                 return "abstract";
 209             case ACC_STRICT:
 210                 return "strictfp";
 211             case ACC_MODULE:
 212                 return "module";
 213             default:
 214                 return null;
 215         }
 216     }
 217 
 218     private static String flagToName(int flag, Kind t) {
 219         switch (flag) {
 220         case ACC_PUBLIC:
 221             return "ACC_PUBLIC";
 222         case ACC_PRIVATE:
 223             return "ACC_PRIVATE";
 224         case ACC_PROTECTED:
 225             return "ACC_PROTECTED";
 226         case ACC_STATIC:
 227             return "ACC_STATIC";
 228         case ACC_FINAL:
 229             return "ACC_FINAL";
 230         case 0x20:
 231             return (t == Kind.Class ? "ACC_SUPER" : "ACC_SYNCHRONIZED");
 232         case 0x40:
 233             return (t == Kind.Field ? "ACC_VOLATILE" : "ACC_BRIDGE");
 234         case 0x80:
 235             return (t == Kind.Field ? "ACC_TRANSIENT" : "ACC_VARARGS");
 236         case ACC_NATIVE:
 237             return "ACC_NATIVE";
 238         case ACC_INTERFACE:
 239             return "ACC_INTERFACE";
 240         case ACC_ABSTRACT:
 241             return "ACC_ABSTRACT";
 242         case ACC_STRICT:
 243             return "ACC_STRICT";
 244         case ACC_SYNTHETIC:
 245             return "ACC_SYNTHETIC";
 246         case ACC_ANNOTATION:
 247             return "ACC_ANNOTATION";
 248         case ACC_ENUM:
 249             return "ACC_ENUM";
 250         case ACC_MODULE:
 251             return "ACC_MODULE";
 252         default:
 253             return null;
 254         }
 255     }
 256 
 257     public final int flags;
 258 }