1 /*
   2  * Copyright (c) 1999, 2013, 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&MANDATED) != 0) flags.add(Flag.MANDATED);
  78         if ((mask&IPROXY) != 0) flags.add(Flag.IPROXY);
  79         if ((mask&NOOUTERTHIS) != 0) flags.add(Flag.NOOUTERTHIS);
  80         if ((mask&EXISTS) != 0) flags.add(Flag.EXISTS);
  81         if ((mask&COMPOUND) != 0) flags.add(Flag.COMPOUND);
  82         if ((mask&CLASS_SEEN) != 0) flags.add(Flag.CLASS_SEEN);
  83         if ((mask&SOURCE_SEEN) != 0) flags.add(Flag.SOURCE_SEEN);
  84         if ((mask&LOCKED) != 0) flags.add(Flag.LOCKED);
  85         if ((mask&UNATTRIBUTED) != 0) flags.add(Flag.UNATTRIBUTED);
  86         if ((mask&ANONCONSTR) != 0) flags.add(Flag.ANONCONSTR);
  87         if ((mask&ACYCLIC) != 0) flags.add(Flag.ACYCLIC);
  88         if ((mask&PARAMETER) != 0) flags.add(Flag.PARAMETER);
  89         if ((mask&VARARGS) != 0) flags.add(Flag.VARARGS);
  90         return flags;
  91     }
  92 
  93     /* Standard Java flags.
  94      */
  95     public static final int PUBLIC       = 1<<0;
  96     public static final int PRIVATE      = 1<<1;
  97     public static final int PROTECTED    = 1<<2;
  98     public static final int STATIC       = 1<<3;
  99     public static final int FINAL        = 1<<4;
 100     public static final int SYNCHRONIZED = 1<<5;
 101     public static final int VOLATILE     = 1<<6;
 102     public static final int TRANSIENT    = 1<<7;
 103     public static final int NATIVE       = 1<<8;
 104     public static final int INTERFACE    = 1<<9;
 105     public static final int ABSTRACT     = 1<<10;
 106     public static final int STRICTFP     = 1<<11;
 107 
 108     /* Flag that marks a symbol synthetic, added in classfile v49.0. */
 109     public static final int SYNTHETIC    = 1<<12;
 110 
 111     /** Flag that marks attribute interfaces, added in classfile v49.0. */
 112     public static final int ANNOTATION   = 1<<13;
 113 
 114     /** An enumeration type or an enumeration constant, added in
 115      *  classfile v49.0. */
 116     public static final int ENUM         = 1<<14;
 117 
 118     /** Added in SE8, represents constructs implicitly declared in source. */
 119     public static final int MANDATED     = 1<<15;
 120 
 121     public static final int StandardFlags = 0x0fff;
 122     public static final int ModifierFlags = StandardFlags & ~INTERFACE;
 123 
 124     // Because the following access flags are overloaded with other
 125     // bit positions, we translate them when reading and writing class
 126     // files into unique bits positions: ACC_SYNTHETIC <-> SYNTHETIC,
 127     // for example.
 128     public static final int ACC_SUPER    = 0x0020;
 129     public static final int ACC_BRIDGE   = 0x0040;
 130     public static final int ACC_VARARGS  = 0x0080;
 131 
 132     /*****************************************
 133      * Internal compiler flags (no bits in the lower 16).
 134      *****************************************/
 135 
 136     /** Flag is set if symbol is deprecated.
 137      */
 138     public static final int DEPRECATED   = 1<<17;
 139 
 140     /** Flag is set for a variable symbol if the variable's definition
 141      *  has an initializer part.
 142      */
 143     public static final int HASINIT          = 1<<18;
 144 
 145     /** Flag is set for compiler-generated anonymous method symbols
 146      *  that `own' an initializer block.
 147      */
 148     public static final int BLOCK            = 1<<20;
 149 
 150     /** Flag is set for compiler-generated abstract methods that implement
 151      *  an interface method (Miranda methods).
 152      */
 153     public static final int IPROXY           = 1<<21;
 154 
 155     /** Flag is set for nested classes that do not access instance members
 156      *  or `this' of an outer class and therefore don't need to be passed
 157      *  a this$n reference.  This flag is currently set only for anonymous
 158      *  classes in superclass constructor calls and only for pre 1.4 targets.
 159      *  todo: use this flag for optimizing away this$n parameters in
 160      *  other cases.
 161      */
 162     public static final int NOOUTERTHIS  = 1<<22;
 163 
 164     /** Flag is set for package symbols if a package has a member or
 165      *  directory and therefore exists.
 166      */
 167     public static final int EXISTS           = 1<<23;
 168 
 169     /** Flag is set for compiler-generated compound classes
 170      *  representing multiple variable bounds
 171      */
 172     public static final int COMPOUND     = 1<<24;
 173 
 174     /** Flag is set for class symbols if a class file was found for this class.
 175      */
 176     public static final int CLASS_SEEN   = 1<<25;
 177 
 178     /** Flag is set for class symbols if a source file was found for this
 179      *  class.
 180      */
 181     public static final int SOURCE_SEEN  = 1<<26;
 182 
 183     /* State flags (are reset during compilation).
 184      */
 185 
 186     /** Flag for class symbols is set and later re-set as a lock in
 187      *  Enter to detect cycles in the superclass/superinterface
 188      *  relations.  Similarly for constructor call cycle detection in
 189      *  Attr.
 190      */
 191     public static final int LOCKED           = 1<<27;
 192 
 193     /** Flag for class symbols is set and later re-set to indicate that a class
 194      *  has been entered but has not yet been attributed.
 195      */
 196     public static final int UNATTRIBUTED = 1<<28;
 197 
 198     /** Flag for synthesized default constructors of anonymous classes.
 199      */
 200     public static final int ANONCONSTR   = 1<<29;
 201 
 202     /** Flag for class symbols to indicate it has been checked and found
 203      *  acyclic.
 204      */
 205     public static final int ACYCLIC          = 1<<30;
 206 
 207     /** Flag that marks bridge methods.
 208      */
 209     public static final long BRIDGE          = 1L<<31;
 210 
 211     /** Flag that marks formal parameters.
 212      */
 213     public static final long PARAMETER   = 1L<<33;
 214 
 215     /** Flag that marks varargs methods.
 216      */
 217     public static final long VARARGS   = 1L<<34;
 218 
 219     /** Flag for annotation type symbols to indicate it has been
 220      *  checked and found acyclic.
 221      */
 222     public static final long ACYCLIC_ANN      = 1L<<35;
 223 
 224     /** Flag that marks a generated default constructor.
 225      */
 226     public static final long GENERATEDCONSTR   = 1L<<36;
 227 
 228     /** Flag that marks a hypothetical method that need not really be
 229      *  generated in the binary, but is present in the symbol table to
 230      *  simplify checking for erasure clashes - also used for 292 poly sig methods.
 231      */
 232     public static final long HYPOTHETICAL   = 1L<<37;
 233 
 234     /**
 235      * Flag that marks an internal proprietary class.
 236      */
 237     public static final long PROPRIETARY = 1L<<38;
 238 
 239     /**
 240      * Flag that marks a multi-catch parameter.
 241      */
 242     public static final long UNION = 1L<<39;
 243 
 244     /**
 245      * Flag that marks a special kind of bridge method (the ones that
 246      * come from restricted supertype bounds).
 247      */
 248     public static final long OVERRIDE_BRIDGE = 1L<<40;
 249 
 250     /**
 251      * Flag that marks an 'effectively final' local variable.
 252      */
 253     public static final long EFFECTIVELY_FINAL = 1L<<41;
 254 
 255     /**
 256      * Flag that marks non-override equivalent methods with the same signature.
 257      */
 258     public static final long CLASH = 1L<<42;
 259 
 260     /**
 261      * Flag that marks either a default method or an interface containing default methods.
 262      */
 263     public static final long DEFAULT = 1L<<43;
 264 
 265     /**
 266      * Flag that marks class as auxiliary, ie a non-public class following
 267      * the public class in a source file, that could block implicit compilation.
 268      */
 269     public static final long AUXILIARY = 1L<<44;
 270 
 271     /**
 272      * Flag that marks that a symbol is not available in the current profile
 273      */
 274     public static final long NOT_IN_PROFILE = 1L<<45;
 275 
 276     /**
 277      * Flag that indicates that an override error has been detected by Check.
 278      */
 279     public static final long BAD_OVERRIDE = 1L<<45;
 280 
 281     /** Modifier masks.
 282      */
 283     public static final int
 284         AccessFlags           = PUBLIC | PROTECTED | PRIVATE,
 285         LocalClassFlags       = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
 286         MemberClassFlags      = LocalClassFlags | INTERFACE | AccessFlags,
 287         ClassFlags            = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
 288         InterfaceVarFlags     = FINAL | STATIC | PUBLIC,
 289         VarFlags              = AccessFlags | FINAL | STATIC |
 290                                 VOLATILE | TRANSIENT | ENUM,
 291         ConstructorFlags      = AccessFlags,
 292         InterfaceMethodFlags  = ABSTRACT | PUBLIC,
 293         MethodFlags           = AccessFlags | ABSTRACT | STATIC | NATIVE |
 294                                 SYNCHRONIZED | FINAL | STRICTFP;
 295     public static final long
 296         ExtendedStandardFlags       = (long)StandardFlags | DEFAULT,
 297         InterfaceMethodMask         = ABSTRACT | STATIC | PUBLIC | STRICTFP | DEFAULT,
 298         LocalVarFlags               = FINAL | PARAMETER;
 299 
 300 
 301     public static Set<Modifier> asModifierSet(long flags) {
 302         Set<Modifier> modifiers = modifierSets.get(flags);
 303         if (modifiers == null) {
 304             modifiers = java.util.EnumSet.noneOf(Modifier.class);
 305             if (0 != (flags & PUBLIC))    modifiers.add(Modifier.PUBLIC);
 306             if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
 307             if (0 != (flags & PRIVATE))   modifiers.add(Modifier.PRIVATE);
 308             if (0 != (flags & ABSTRACT))  modifiers.add(Modifier.ABSTRACT);
 309             if (0 != (flags & STATIC))    modifiers.add(Modifier.STATIC);
 310             if (0 != (flags & FINAL))     modifiers.add(Modifier.FINAL);
 311             if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
 312             if (0 != (flags & VOLATILE))  modifiers.add(Modifier.VOLATILE);
 313             if (0 != (flags & SYNCHRONIZED))
 314                                           modifiers.add(Modifier.SYNCHRONIZED);
 315             if (0 != (flags & NATIVE))    modifiers.add(Modifier.NATIVE);
 316             if (0 != (flags & STRICTFP))  modifiers.add(Modifier.STRICTFP);
 317             if (0 != (flags & DEFAULT))   modifiers.add(Modifier.DEFAULT);
 318             modifiers = Collections.unmodifiableSet(modifiers);
 319             modifierSets.put(flags, modifiers);
 320         }
 321         return modifiers;
 322     }
 323 
 324     // Cache of modifier sets.
 325     private static final Map<Long, Set<Modifier>> modifierSets =
 326         new java.util.concurrent.ConcurrentHashMap<Long, Set<Modifier>>(64);
 327 
 328     public static boolean isStatic(Symbol symbol) {
 329         return (symbol.flags() & STATIC) != 0;
 330     }
 331 
 332     public static boolean isEnum(Symbol symbol) {
 333         return (symbol.flags() & ENUM) != 0;
 334     }
 335 
 336     public static boolean isConstant(Symbol.VarSymbol symbol) {
 337         return symbol.getConstValue() != null;
 338     }
 339 
 340     public enum Flag {
 341 
 342         PUBLIC("public"),
 343         PRIVATE("private"),
 344         PROTECTED("protected"),
 345         STATIC("static"),
 346         FINAL("final"),
 347         SYNCHRONIZED("synchronized"),
 348         VOLATILE("volatile"),
 349         TRANSIENT("transient"),
 350         NATIVE("native"),
 351         INTERFACE("interface"),
 352         ABSTRACT("abstract"),
 353         DEFAULT("default"),
 354         STRICTFP("strictfp"),
 355         BRIDGE("bridge"),
 356         SYNTHETIC("synthetic"),
 357         DEPRECATED("deprecated"),
 358         HASINIT("hasinit"),
 359         ENUM("enum"),
 360         MANDATED("mandated"),
 361         IPROXY("iproxy"),
 362         NOOUTERTHIS("noouterthis"),
 363         EXISTS("exists"),
 364         COMPOUND("compound"),
 365         CLASS_SEEN("class_seen"),
 366         SOURCE_SEEN("source_seen"),
 367         LOCKED("locked"),
 368         UNATTRIBUTED("unattributed"),
 369         ANONCONSTR("anonconstr"),
 370         ACYCLIC("acyclic"),
 371         PARAMETER("parameter"),
 372         VARARGS("varargs"),
 373         PACKAGE("package");
 374 
 375         private final String name;
 376 
 377         Flag(String name) {
 378             this.name = name;
 379         }
 380 
 381         public String toString() {
 382             return name;
 383         }
 384     }
 385 }