1 /*
   2  * Copyright (c) 1999, 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.javac.code;
  27 
  28 import java.util.Collections;
  29 import java.util.EnumSet;
  30 import java.util.Map;
  31 import java.util.Set;
  32 
  33 import javax.lang.model.element.Modifier;
  34 
  35 /** Access flags and other modifiers for Java classes and members.
  36  *
  37  *  <p><b>This is NOT part of any supported API.
  38  *  If you write code that depends on this, you do so at your own risk.
  39  *  This code and its internal interfaces are subject to change or
  40  *  deletion without notice.</b>
  41  */
  42 public class Flags {
  43 
  44     private Flags() {} // uninstantiable
  45 
  46     public static String toString(long flags) {
  47         StringBuilder buf = new StringBuilder();
  48         String sep = "";
  49         for (Flag s : asFlagSet(flags)) {
  50             buf.append(sep);
  51             buf.append(s);
  52             sep = " ";
  53         }
  54         return buf.toString();
  55     }
  56 
  57     public static EnumSet<Flag> asFlagSet(long mask) {
  58         EnumSet<Flag> flags = EnumSet.noneOf(Flag.class);
  59         if ((mask&PUBLIC) != 0) flags.add(Flag.PUBLIC);
  60         if ((mask&PRIVATE) != 0) flags.add(Flag.PRIVATE);
  61         if ((mask&PROTECTED) != 0) flags.add(Flag.PROTECTED);
  62         if ((mask&STATIC) != 0) flags.add(Flag.STATIC);
  63         if ((mask&FINAL) != 0) flags.add(Flag.FINAL);
  64         if ((mask&SYNCHRONIZED) != 0) flags.add(Flag.SYNCHRONIZED);
  65         if ((mask&VOLATILE) != 0) flags.add(Flag.VOLATILE);
  66         if ((mask&TRANSIENT) != 0) flags.add(Flag.TRANSIENT);
  67         if ((mask&NATIVE) != 0) flags.add(Flag.NATIVE);
  68         if ((mask&INTERFACE) != 0) flags.add(Flag.INTERFACE);
  69         if ((mask&ABSTRACT) != 0) flags.add(Flag.ABSTRACT);
  70         if ((mask&DEFAULT) != 0) flags.add(Flag.DEFAULT);
  71         if ((mask&STRICTFP) != 0) flags.add(Flag.STRICTFP);
  72         if ((mask&BRIDGE) != 0) flags.add(Flag.BRIDGE);
  73         if ((mask&SYNTHETIC) != 0) flags.add(Flag.SYNTHETIC);
  74         if ((mask&DEPRECATED) != 0) flags.add(Flag.DEPRECATED);
  75         if ((mask&HASINIT) != 0) flags.add(Flag.HASINIT);
  76         if ((mask&ENUM) != 0) flags.add(Flag.ENUM);
  77         if ((mask&IPROXY) != 0) flags.add(Flag.IPROXY);
  78         if ((mask&NOOUTERTHIS) != 0) flags.add(Flag.NOOUTERTHIS);
  79         if ((mask&EXISTS) != 0) flags.add(Flag.EXISTS);
  80         if ((mask&COMPOUND) != 0) flags.add(Flag.COMPOUND);
  81         if ((mask&CLASS_SEEN) != 0) flags.add(Flag.CLASS_SEEN);
  82         if ((mask&SOURCE_SEEN) != 0) flags.add(Flag.SOURCE_SEEN);
  83         if ((mask&LOCKED) != 0) flags.add(Flag.LOCKED);
  84         if ((mask&UNATTRIBUTED) != 0) flags.add(Flag.UNATTRIBUTED);
  85         if ((mask&ANONCONSTR) != 0) flags.add(Flag.ANONCONSTR);
  86         if ((mask&ACYCLIC) != 0) flags.add(Flag.ACYCLIC);
  87         if ((mask&PARAMETER) != 0) flags.add(Flag.PARAMETER);
  88         if ((mask&VARARGS) != 0) flags.add(Flag.VARARGS);
  89         return flags;
  90     }
  91 
  92     /* Standard Java flags.
  93      */
  94     public static final int PUBLIC       = 1<<0;
  95     public static final int PRIVATE      = 1<<1;
  96     public static final int PROTECTED    = 1<<2;
  97     public static final int STATIC       = 1<<3;
  98     public static final int FINAL        = 1<<4;
  99     public static final int SYNCHRONIZED = 1<<5;
 100     public static final int VOLATILE     = 1<<6;
 101     public static final int TRANSIENT    = 1<<7;
 102     public static final int NATIVE       = 1<<8;
 103     public static final int INTERFACE    = 1<<9;
 104     public static final int ABSTRACT     = 1<<10;
 105     public static final int STRICTFP     = 1<<11;
 106 
 107     /* Flag that marks a symbol synthetic, added in classfile v49.0. */
 108     public static final int SYNTHETIC    = 1<<12;
 109 
 110     /** Flag that marks attribute interfaces, added in classfile v49.0. */
 111     public static final int ANNOTATION   = 1<<13;
 112 
 113     /** An enumeration type or an enumeration constant, added in
 114      *  classfile v49.0. */
 115     public static final int ENUM         = 1<<14;
 116 
 117     public static final int StandardFlags = 0x0fff;
 118     public static final int ModifierFlags = StandardFlags & ~INTERFACE;
 119 
 120     // Because the following access flags are overloaded with other
 121     // bit positions, we translate them when reading and writing class
 122     // files into unique bits positions: ACC_SYNTHETIC <-> SYNTHETIC,
 123     // for example.
 124     public static final int ACC_SUPER    = 0x0020;
 125     public static final int ACC_BRIDGE   = 0x0040;
 126     public static final int ACC_VARARGS  = 0x0080;
 127 
 128     /*****************************************
 129      * Internal compiler flags (no bits in the lower 16).
 130      *****************************************/
 131 
 132     /** Flag is set if symbol is deprecated.
 133      */
 134     public static final int DEPRECATED   = 1<<17;
 135 
 136     /** Flag is set for a variable symbol if the variable's definition
 137      *  has an initializer part.
 138      */
 139     public static final int HASINIT          = 1<<18;
 140 
 141     /** Flag is set for compiler-generated anonymous method symbols
 142      *  that `own' an initializer block.
 143      */
 144     public static final int BLOCK            = 1<<20;
 145 
 146     /** Flag is set for compiler-generated abstract methods that implement
 147      *  an interface method (Miranda methods).
 148      */
 149     public static final int IPROXY           = 1<<21;
 150 
 151     /** Flag is set for nested classes that do not access instance members
 152      *  or `this' of an outer class and therefore don't need to be passed
 153      *  a this$n reference.  This flag is currently set only for anonymous
 154      *  classes in superclass constructor calls and only for pre 1.4 targets.
 155      *  todo: use this flag for optimizing away this$n parameters in
 156      *  other cases.
 157      */
 158     public static final int NOOUTERTHIS  = 1<<22;
 159 
 160     /** Flag is set for package symbols if a package has a member or
 161      *  directory and therefore exists.
 162      */
 163     public static final int EXISTS           = 1<<23;
 164 
 165     /** Flag is set for compiler-generated compound classes
 166      *  representing multiple variable bounds
 167      */
 168     public static final int COMPOUND     = 1<<24;
 169 
 170     /** Flag is set for class symbols if a class file was found for this class.
 171      */
 172     public static final int CLASS_SEEN   = 1<<25;
 173 
 174     /** Flag is set for class symbols if a source file was found for this
 175      *  class.
 176      */
 177     public static final int SOURCE_SEEN  = 1<<26;
 178 
 179     /* State flags (are reset during compilation).
 180      */
 181 
 182     /** Flag for class symbols is set and later re-set as a lock in
 183      *  Enter to detect cycles in the superclass/superinterface
 184      *  relations.  Similarly for constructor call cycle detection in
 185      *  Attr.
 186      */
 187     public static final int LOCKED           = 1<<27;
 188 
 189     /** Flag for class symbols is set and later re-set to indicate that a class
 190      *  has been entered but has not yet been attributed.
 191      */
 192     public static final int UNATTRIBUTED = 1<<28;
 193 
 194     /** Flag for synthesized default constructors of anonymous classes.
 195      */
 196     public static final int ANONCONSTR   = 1<<29;
 197 
 198     /** Flag for class symbols to indicate it has been checked and found
 199      *  acyclic.
 200      */
 201     public static final int ACYCLIC          = 1<<30;
 202 
 203     /** Flag that marks bridge methods.
 204      */
 205     public static final long BRIDGE          = 1L<<31;
 206 
 207     /** Flag that marks formal parameters.
 208      */
 209     public static final long PARAMETER   = 1L<<33;
 210 
 211     /** Flag that marks varargs methods.
 212      */
 213     public static final long VARARGS   = 1L<<34;
 214 
 215     /** Flag for annotation type symbols to indicate it has been
 216      *  checked and found acyclic.
 217      */
 218     public static final long ACYCLIC_ANN      = 1L<<35;
 219 
 220     /** Flag that marks a generated default constructor.
 221      */
 222     public static final long GENERATEDCONSTR   = 1L<<36;
 223 
 224     /** Flag that marks a hypothetical method that need not really be
 225      *  generated in the binary, but is present in the symbol table to
 226      *  simplify checking for erasure clashes - also used for 292 poly sig methods.
 227      */
 228     public static final long HYPOTHETICAL   = 1L<<37;
 229 
 230     /**
 231      * Flag that marks an internal proprietary class.
 232      */
 233     public static final long PROPRIETARY = 1L<<38;
 234 
 235     /**
 236      * Flag that marks a a multi-catch parameter
 237      */
 238     public static final long UNION = 1L<<39;
 239 
 240     /**
 241      * Flag that marks a special kind of bridge methods (the ones that
 242      * come from restricted supertype bounds)
 243      */
 244     public static final long OVERRIDE_BRIDGE = 1L<<40;
 245 
 246     /**
 247      * Flag that marks an 'effectively final' local variable
 248      */
 249     public static final long EFFECTIVELY_FINAL = 1L<<41;
 250 
 251     /**
 252      * Flag that marks non-override equivalent methods with the same signature
 253      */
 254     public static final long CLASH = 1L<<42;
 255 
 256     /**
 257      * Flag that marks either a default method or an interface containing default methods
 258      */
 259     public static final long DEFAULT = 1L<<43;
 260 
 261     /**
 262      * Flag that marks class as auxiliary, ie a non-public class following
 263      * the public class in a source file, that could block implicit compilation.
 264      */
 265     public static final long AUXILIARY = 1L<<44;
 266     
 267     /** 
 268      * Flag that marks that a symbol is not available in the current profile
 269      */
 270     public static final long NOT_IN_PROFILE = 1L<<45;
 271 
 272     /** Modifier masks.
 273      */
 274     public static final int
 275         AccessFlags           = PUBLIC | PROTECTED | PRIVATE,
 276         LocalClassFlags       = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
 277         MemberClassFlags      = LocalClassFlags | INTERFACE | AccessFlags,
 278         ClassFlags            = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
 279         InterfaceVarFlags     = FINAL | STATIC | PUBLIC,
 280         VarFlags              = AccessFlags | FINAL | STATIC |
 281                                 VOLATILE | TRANSIENT | ENUM,
 282         ConstructorFlags      = AccessFlags,
 283         InterfaceMethodFlags  = ABSTRACT | PUBLIC,
 284         MethodFlags           = AccessFlags | ABSTRACT | STATIC | NATIVE |
 285                                 SYNCHRONIZED | FINAL | STRICTFP;
 286     public static final long
 287         ExtendedStandardFlags       = (long)StandardFlags | DEFAULT,
 288         InterfaceDefaultMethodMask  = ABSTRACT | PUBLIC | STRICTFP | SYNCHRONIZED | DEFAULT,
 289         LocalVarFlags               = FINAL | PARAMETER;
 290 
 291 
 292     public static Set<Modifier> asModifierSet(long flags) {
 293         Set<Modifier> modifiers = modifierSets.get(flags);
 294         if (modifiers == null) {
 295             modifiers = java.util.EnumSet.noneOf(Modifier.class);
 296             if (0 != (flags & PUBLIC))    modifiers.add(Modifier.PUBLIC);
 297             if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
 298             if (0 != (flags & PRIVATE))   modifiers.add(Modifier.PRIVATE);
 299             if (0 != (flags & ABSTRACT))  modifiers.add(Modifier.ABSTRACT);
 300             if (0 != (flags & STATIC))    modifiers.add(Modifier.STATIC);
 301             if (0 != (flags & FINAL))     modifiers.add(Modifier.FINAL);
 302             if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
 303             if (0 != (flags & VOLATILE))  modifiers.add(Modifier.VOLATILE);
 304             if (0 != (flags & SYNCHRONIZED))
 305                                           modifiers.add(Modifier.SYNCHRONIZED);
 306             if (0 != (flags & NATIVE))    modifiers.add(Modifier.NATIVE);
 307             if (0 != (flags & STRICTFP))  modifiers.add(Modifier.STRICTFP);
 308             modifiers = Collections.unmodifiableSet(modifiers);
 309             modifierSets.put(flags, modifiers);
 310         }
 311         return modifiers;
 312     }
 313 
 314     // Cache of modifier sets.
 315     private static final Map<Long, Set<Modifier>> modifierSets =
 316         new java.util.concurrent.ConcurrentHashMap<Long, Set<Modifier>>(64);
 317 
 318     public static boolean isStatic(Symbol symbol) {
 319         return (symbol.flags() & STATIC) != 0;
 320     }
 321 
 322     public static boolean isEnum(Symbol symbol) {
 323         return (symbol.flags() & ENUM) != 0;
 324     }
 325 
 326     public static boolean isConstant(Symbol.VarSymbol symbol) {
 327         return symbol.getConstValue() != null;
 328     }
 329 
 330     public enum Flag {
 331 
 332         PUBLIC("public"),
 333         PRIVATE("private"),
 334         PROTECTED("protected"),
 335         STATIC("static"),
 336         FINAL("final"),
 337         SYNCHRONIZED("synchronized"),
 338         VOLATILE("volatile"),
 339         TRANSIENT("transient"),
 340         NATIVE("native"),
 341         INTERFACE("interface"),
 342         ABSTRACT("abstract"),
 343         DEFAULT("default"),
 344         STRICTFP("strictfp"),
 345         BRIDGE("bridge"),
 346         SYNTHETIC("synthetic"),
 347         DEPRECATED("deprecated"),
 348         HASINIT("hasinit"),
 349         ENUM("enum"),
 350         IPROXY("iproxy"),
 351         NOOUTERTHIS("noouterthis"),
 352         EXISTS("exists"),
 353         COMPOUND("compound"),
 354         CLASS_SEEN("class_seen"),
 355         SOURCE_SEEN("source_seen"),
 356         LOCKED("locked"),
 357         UNATTRIBUTED("unattributed"),
 358         ANONCONSTR("anonconstr"),
 359         ACYCLIC("acyclic"),
 360         PARAMETER("parameter"),
 361         VARARGS("varargs"),
 362         PACKAGE("package");
 363 
 364         private final String name;
 365 
 366         Flag(String name) {
 367             this.name = name;
 368         }
 369 
 370         public String toString() {
 371             return name;
 372         }
 373     }
 374 }