001 /*
002 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.tools.javac.code;
027
028 import java.util.EnumSet;
029 import java.util.Collections;
030 import java.util.Map;
031 import java.util.Set;
032 import javax.lang.model.element.Modifier;
033
034 /** Access flags and other modifiers for Java classes and members.
035 *
036 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
037 * you write code that depends on this, you do so at your own risk.
038 * This code and its internal interfaces are subject to change or
039 * deletion without notice.</b>
040 */
041 public class Flags {
042
043 private Flags() {} // uninstantiable
044
045 public static String toString(long flags) {
046 StringBuffer buf = new StringBuffer();
047 String sep = "";
048 for (Flag s : asFlagSet(flags)) {
049 buf.append(sep);
050 buf.append(s);
051 sep = " ";
052 }
053 return buf.toString();
054 }
055
056 public static EnumSet<Flag> asFlagSet(long mask) {
057 EnumSet<Flag> flags = EnumSet.noneOf(Flag.class);
058 if ((mask&PUBLIC) != 0) flags.add(Flag.PUBLIC);
059 if ((mask&PRIVATE) != 0) flags.add(Flag.PRIVATE);
060 if ((mask&PROTECTED) != 0) flags.add(Flag.PROTECTED);
061 if ((mask&STATIC) != 0) flags.add(Flag.STATIC);
062 if ((mask&FINAL) != 0) flags.add(Flag.FINAL);
063 if ((mask&SYNCHRONIZED) != 0) flags.add(Flag.SYNCHRONIZED);
064 if ((mask&VOLATILE) != 0) flags.add(Flag.VOLATILE);
065 if ((mask&TRANSIENT) != 0) flags.add(Flag.TRANSIENT);
066 if ((mask&NATIVE) != 0) flags.add(Flag.NATIVE);
067 if ((mask&INTERFACE) != 0) flags.add(Flag.INTERFACE);
068 if ((mask&ABSTRACT) != 0) flags.add(Flag.ABSTRACT);
069 if ((mask&STRICTFP) != 0) flags.add(Flag.STRICTFP);
070 if ((mask&BRIDGE) != 0) flags.add(Flag.BRIDGE);
071 if ((mask&SYNTHETIC) != 0) flags.add(Flag.SYNTHETIC);
072 if ((mask&DEPRECATED) != 0) flags.add(Flag.DEPRECATED);
073 if ((mask&HASINIT) != 0) flags.add(Flag.HASINIT);
074 if ((mask&ENUM) != 0) flags.add(Flag.ENUM);
075 if ((mask&IPROXY) != 0) flags.add(Flag.IPROXY);
076 if ((mask&NOOUTERTHIS) != 0) flags.add(Flag.NOOUTERTHIS);
077 if ((mask&EXISTS) != 0) flags.add(Flag.EXISTS);
078 if ((mask&COMPOUND) != 0) flags.add(Flag.COMPOUND);
079 if ((mask&CLASS_SEEN) != 0) flags.add(Flag.CLASS_SEEN);
080 if ((mask&SOURCE_SEEN) != 0) flags.add(Flag.SOURCE_SEEN);
081 if ((mask&LOCKED) != 0) flags.add(Flag.LOCKED);
082 if ((mask&UNATTRIBUTED) != 0) flags.add(Flag.UNATTRIBUTED);
083 if ((mask&ANONCONSTR) != 0) flags.add(Flag.ANONCONSTR);
084 if ((mask&ACYCLIC) != 0) flags.add(Flag.ACYCLIC);
085 if ((mask&PARAMETER) != 0) flags.add(Flag.PARAMETER);
086 if ((mask&VARARGS) != 0) flags.add(Flag.VARARGS);
087 if ((mask&SEPARABLE) != 0) flags.add(Flag.SEPARABLE);
088 return flags;
089 }
090
091 /* Standard Java flags.
092 */
093 public static final int PUBLIC = 1<<0;
094 public static final int PRIVATE = 1<<1;
095 public static final int PROTECTED = 1<<2;
096 public static final int STATIC = 1<<3;
097 public static final int FINAL = 1<<4;
098 public static final int SYNCHRONIZED = 1<<5;
099 public static final int VOLATILE = 1<<6;
100 public static final int TRANSIENT = 1<<7;
101 public static final int NATIVE = 1<<8;
102 public static final int INTERFACE = 1<<9;
103 public static final int ABSTRACT = 1<<10;
104 public static final int STRICTFP = 1<<11;
105
106 /* Flag that marks a symbol synthetic, added in classfile v49.0. */
107 public static final int SYNTHETIC = 1<<12;
108
109 /** Flag that marks attribute interfaces, added in classfile v49.0. */
110 public static final int ANNOTATION = 1<<13;
111
112 /** An enumeration type or an enumeration constant, added in
113 * classfile v49.0. */
114 public static final int ENUM = 1<<14;
115
116 public static final int SEPARABLE = 1<<15;
117
118 public static final int StandardFlags = 0x0fff | SEPARABLE;
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.
227 */
228 public static final long HYPOTHETICAL = 1L<<37;
229
230 /**
231 * Flag that marks a Sun proprietary class.
232 */
233 public static final long PROPRIETARY = 1L<<38;
234
235 /** Modifier masks.
236 */
237 public static final int
238 AccessFlags = PUBLIC | PROTECTED | PRIVATE,
239 LocalClassFlags = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
240 MemberClassFlags = LocalClassFlags | INTERFACE | AccessFlags,
241 ClassFlags = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
242 InterfaceVarFlags = FINAL | STATIC | PUBLIC,
243 VarFlags = AccessFlags | FINAL | STATIC |
244 VOLATILE | TRANSIENT | ENUM,
245 ConstructorFlags = AccessFlags | SEPARABLE,
246 AllowedInterfaceMethodFlags = ABSTRACT | PUBLIC | SEPARABLE,
247 ImplicitInterfaceMethodFlags = ABSTRACT | PUBLIC,
248 MethodFlags = AccessFlags | ABSTRACT | STATIC | NATIVE |
249 SYNCHRONIZED | FINAL | STRICTFP | SEPARABLE;
250 public static final long
251 LocalVarFlags = FINAL | PARAMETER;
252
253 public static Set<Modifier> asModifierSet(long flags) {
254 Set<Modifier> modifiers = modifierSets.get(flags);
255 if (modifiers == null) {
256 modifiers = java.util.EnumSet.noneOf(Modifier.class);
257 if (0 != (flags & PUBLIC)) modifiers.add(Modifier.PUBLIC);
258 if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
259 if (0 != (flags & PRIVATE)) modifiers.add(Modifier.PRIVATE);
260 if (0 != (flags & ABSTRACT)) modifiers.add(Modifier.ABSTRACT);
261 if (0 != (flags & STATIC)) modifiers.add(Modifier.STATIC);
262 if (0 != (flags & FINAL)) modifiers.add(Modifier.FINAL);
263 if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
264 if (0 != (flags & VOLATILE)) modifiers.add(Modifier.VOLATILE);
265 if (0 != (flags & SYNCHRONIZED))
266 modifiers.add(Modifier.SYNCHRONIZED);
267 if (0 != (flags & NATIVE)) modifiers.add(Modifier.NATIVE);
268 if (0 != (flags & STRICTFP)) modifiers.add(Modifier.STRICTFP);
269 if (0 != (flags & SEPARABLE)) modifiers.add(Modifier.SEPARABLE);
270 modifiers = Collections.unmodifiableSet(modifiers);
271 modifierSets.put(flags, modifiers);
272 }
273 return modifiers;
274 }
275
276 // Cache of modifier sets.
277 private static Map<Long, Set<Modifier>> modifierSets =
278 new java.util.concurrent.ConcurrentHashMap<Long, Set<Modifier>>(64);
279
280 public static boolean isStatic(Symbol symbol) {
281 return (symbol.flags() & STATIC) != 0;
282 }
283
284 public static boolean isEnum(Symbol symbol) {
285 return (symbol.flags() & ENUM) != 0;
286 }
287
288 public static boolean isConstant(Symbol.VarSymbol symbol) {
289 return symbol.getConstValue() != null;
290 }
291
292 public enum Flag {
293
294 PUBLIC("public"),
295 PRIVATE("private"),
296 PROTECTED("protected"),
297 STATIC("static"),
298 FINAL("final"),
299 SYNCHRONIZED("synchronized"),
300 VOLATILE("volatile"),
301 TRANSIENT("transient"),
302 NATIVE("native"),
303 INTERFACE("interface"),
304 ABSTRACT("abstract"),
305 STRICTFP("strictfp"),
306 BRIDGE("bridge"),
307 SYNTHETIC("synthetic"),
308 DEPRECATED("deprecated"),
309 HASINIT("hasinit"),
310 ENUM("enum"),
311 IPROXY("iproxy"),
312 NOOUTERTHIS("noouterthis"),
313 EXISTS("exists"),
314 COMPOUND("compound"),
315 CLASS_SEEN("class_seen"),
316 SOURCE_SEEN("source_seen"),
317 LOCKED("locked"),
318 UNATTRIBUTED("unattributed"),
319 ANONCONSTR("anonconstr"),
320 ACYCLIC("acyclic"),
321 PARAMETER("parameter"),
322 VARARGS("varargs"),
323 PACKAGE("package"),
324 SEPARABLE("separable");
325
326 String name;
327
328 Flag(String name) {
329 this.name = name;
330 }
331
332 public String toString() {
333 return name;
334 }
335 }
336 }