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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 *
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package com.sun.tools.javac.code;

import java.util.Collections;
import java.util.EnumSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import javax.lang.model.element.Modifier;

import com.sun.tools.javac.util.Assert;
import com.sun.tools.javac.util.StringUtils;

Access flags and other modifiers for Java classes and members.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/** Access flags and other modifiers for Java classes and members.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class Flags {

    private Flags() {} // uninstantiable

    public static String toString(long flags) {
        StringBuilder buf = new StringBuilder();
        String sep = "";
        for (Flag flag : asFlagSet(flags)) {
            buf.append(sep);
            buf.append(flag);
            sep = " ";
        }
        return buf.toString();
    }

    public static EnumSet<Flag> asFlagSet(long flags) {
        EnumSet<Flag> flagSet = EnumSet.noneOf(Flag.class);
        for (Flag flag : Flag.values()) {
            if ((flags & flag.value) != 0) {
                flagSet.add(flag);
                flags &= ~flag.value;
            }
        }
        Assert.check(flags == 0);
        return flagSet;
    }

    /* Standard Java flags.
     */
    public static final int PUBLIC       = 1;
    public static final int PRIVATE      = 1<<1;
    public static final int PROTECTED    = 1<<2;
    public static final int STATIC       = 1<<3;
    public static final int FINAL        = 1<<4;
    public static final int SYNCHRONIZED = 1<<5;
    public static final int VOLATILE     = 1<<6;
    public static final int TRANSIENT    = 1<<7;
    public static final int NATIVE       = 1<<8;
    public static final int INTERFACE    = 1<<9;
    public static final int ABSTRACT     = 1<<10;
    public static final int STRICTFP     = 1<<11;

    /* Flag that marks a symbol synthetic, added in classfile v49.0. */
    public static final int SYNTHETIC    = 1<<12;

    
Flag that marks attribute interfaces, added in classfile v49.0. /** Flag that marks attribute interfaces, added in classfile v49.0. */
    public static final int ANNOTATION   = 1<<13;

    
An enumeration type or an enumeration constant, added in
 classfile v49.0. /** An enumeration type or an enumeration constant, added in
     *  classfile v49.0. */
    public static final int ENUM         = 1<<14;

    
Added in SE8, represents constructs implicitly declared in source. /** Added in SE8, represents constructs implicitly declared in source. */
    public static final int MANDATED     = 1<<15;

    public static final int StandardFlags = 0x0fff;

    // Because the following access flags are overloaded with other
    // bit positions, we translate them when reading and writing class
    // files into unique bits positions: ACC_SYNTHETIC <-> SYNTHETIC,
    // for example.
    public static final int ACC_SUPER    = 0x0020;
    public static final int ACC_BRIDGE   = 0x0040;
    public static final int ACC_VARARGS  = 0x0080;
    public static final int ACC_MODULE   = 0x8000;

    /*****************************************
     * Internal compiler flags (no bits in the lower 16).
     *****************************************/

    
Flag is set if symbol is deprecated.  See also DEPRECATED_REMOVAL.
/** Flag is set if symbol is deprecated.  See also DEPRECATED_REMOVAL.
     */
    public static final int DEPRECATED   = 1<<17;

    
Flag is set for a variable symbol if the variable's definition
 has an initializer part.
/** Flag is set for a variable symbol if the variable's definition
     *  has an initializer part.
     */
    public static final int HASINIT          = 1<<18;

    
Flag is set for compiler-generated anonymous method symbols
 that `own' an initializer block.
/** Flag is set for compiler-generated anonymous method symbols
     *  that `own' an initializer block.
     */
    public static final int BLOCK            = 1<<20;

    /** Flag bit 21 is available. (used earlier to tag compiler-generated abstract methods that implement
     *  an interface method (Miranda methods)).
     */

    
Flag is set for nested classes that do not access instance members
 or `this' of an outer class and therefore don't need to be passed
 a this$n reference.  This value is currently set only for anonymous
 classes in superclass constructor calls.
 todo: use this value for optimizing away this$n parameters in
 other cases.
/** Flag is set for nested classes that do not access instance members
     *  or `this' of an outer class and therefore don't need to be passed
     *  a this$n reference.  This value is currently set only for anonymous
     *  classes in superclass constructor calls.
     *  todo: use this value for optimizing away this$n parameters in
     *  other cases.
     */
    public static final int NOOUTERTHIS  = 1<<22;

    
Flag is set for package symbols if a package has a member or
 directory and therefore exists.
/** Flag is set for package symbols if a package has a member or
     *  directory and therefore exists.
     */
    public static final int EXISTS           = 1<<23;

    
Flag is set for compiler-generated compound classes
 representing multiple variable bounds
/** Flag is set for compiler-generated compound classes
     *  representing multiple variable bounds
     */
    public static final int COMPOUND     = 1<<24;

    
Flag is set for class symbols if a class file was found for this class.
/** Flag is set for class symbols if a class file was found for this class.
     */
    public static final int CLASS_SEEN   = 1<<25;

    
Flag is set for class symbols if a source file was found for this
 class.
/** Flag is set for class symbols if a source file was found for this
     *  class.
     */
    public static final int SOURCE_SEEN  = 1<<26;

    /* State flags (are reset during compilation).
     */

    
Flag for class symbols is set and later re-set as a lock in
 Enter to detect cycles in the superclass/superinterface
 relations.  Similarly for constructor call cycle detection in
 Attr.
/** Flag for class symbols is set and later re-set as a lock in
     *  Enter to detect cycles in the superclass/superinterface
     *  relations.  Similarly for constructor call cycle detection in
     *  Attr.
     */
    public static final int LOCKED           = 1<<27;

    
Flag for class symbols is set and later re-set to indicate that a class
 has been entered but has not yet been attributed.
/** Flag for class symbols is set and later re-set to indicate that a class
     *  has been entered but has not yet been attributed.
     */
    public static final int UNATTRIBUTED = 1<<28;

    
Flag for synthesized default constructors of anonymous classes.
/** Flag for synthesized default constructors of anonymous classes.
     */
    public static final int ANONCONSTR   = 1<<29;

    
Flag for class symbols to indicate it has been checked and found
 acyclic.
/** Flag for class symbols to indicate it has been checked and found
     *  acyclic.
     */
    public static final int ACYCLIC          = 1<<30;

    
Flag that marks bridge methods.
/** Flag that marks bridge methods.
     */
    public static final long BRIDGE          = 1L<<31;

    
Flag that marks formal parameters.
/** Flag that marks formal parameters.
     */
    public static final long PARAMETER   = 1L<<33;

    
Flag that marks varargs methods.
/** Flag that marks varargs methods.
     */
    public static final long VARARGS   = 1L<<34;

    
Flag for annotation type symbols to indicate it has been
 checked and found acyclic.
/** Flag for annotation type symbols to indicate it has been
     *  checked and found acyclic.
     */
    public static final long ACYCLIC_ANN      = 1L<<35;

    
Flag that marks a generated default constructor.
/** Flag that marks a generated default constructor.
     */
    public static final long GENERATEDCONSTR   = 1L<<36;

    
Flag that marks a hypothetical method that need not really be
 generated in the binary, but is present in the symbol table to
 simplify checking for erasure clashes - also used for 292 poly sig methods.
/** Flag that marks a hypothetical method that need not really be
     *  generated in the binary, but is present in the symbol table to
     *  simplify checking for erasure clashes - also used for 292 poly sig methods.
     */
    public static final long HYPOTHETICAL   = 1L<<37;

    
Flag that marks an internal proprietary class.
/**
     * Flag that marks an internal proprietary class.
     */
    public static final long PROPRIETARY = 1L<<38;

    
Flag that marks a multi-catch parameter.
/**
     * Flag that marks a multi-catch parameter.
     */
    public static final long UNION = 1L<<39;

    // Flag bit (1L << 40) is available.

    
Flag that marks an 'effectively final' local variable.
/**
     * Flag that marks an 'effectively final' local variable.
     */
    public static final long EFFECTIVELY_FINAL = 1L<<41;

    
Flag that marks non-override equivalent methods with the same signature.
/**
     * Flag that marks non-override equivalent methods with the same signature.
     */
    public static final long CLASH = 1L<<42;

    
Flag that marks either a default method or an interface containing default methods.
/**
     * Flag that marks either a default method or an interface containing default methods.
     */
    public static final long DEFAULT = 1L<<43;

    
Flag that marks class as auxiliary, ie a non-public class following
the public class in a source file, that could block implicit compilation.
/**
     * Flag that marks class as auxiliary, ie a non-public class following
     * the public class in a source file, that could block implicit compilation.
     */
    public static final long AUXILIARY = 1L<<44;

    
Flag that marks that a symbol is not available in the current profile
/**
     * Flag that marks that a symbol is not available in the current profile
     */
    public static final long NOT_IN_PROFILE = 1L<<45;

    
Flag that indicates that an override error has been detected by Check.
/**
     * Flag that indicates that an override error has been detected by Check.
     */
    public static final long BAD_OVERRIDE = 1L<<45;

    
Flag that indicates a signature polymorphic method (292).
/**
     * Flag that indicates a signature polymorphic method (292).
     */
    public static final long SIGNATURE_POLYMORPHIC = 1L<<46;

    
Flag that indicates that an inference variable is used in a 'throws' clause.
/**
     * Flag that indicates that an inference variable is used in a 'throws' clause.
     */
    public static final long THROWS = 1L<<47;

    
Flag that marks potentially ambiguous overloads
/**
     * Flag that marks potentially ambiguous overloads
     */
    public static final long POTENTIALLY_AMBIGUOUS = 1L<<48;

    
Flag that marks a synthetic method body for a lambda expression
/**
     * Flag that marks a synthetic method body for a lambda expression
     */
    public static final long LAMBDA_METHOD = 1L<<49;

    
Flag to control recursion in TransTypes
/**
     * Flag to control recursion in TransTypes
     */
    public static final long TYPE_TRANSLATED = 1L<<50;

    
Flag to indicate class symbol is for module-info
/**
     * Flag to indicate class symbol is for module-info
     */
    public static final long MODULE = 1L<<51;

    
Flag to indicate the given ModuleSymbol is an automatic module.
/**
     * Flag to indicate the given ModuleSymbol is an automatic module.
     */
    public static final long AUTOMATIC_MODULE = 1L<<52;

    
Flag to indicate the given ModuleSymbol is a system module.
/**
     * Flag to indicate the given ModuleSymbol is a system module.
     */
    public static final long SYSTEM_MODULE = 1L<<53;

    
Flag to indicate the given symbol has a @Deprecated annotation.
/**
     * Flag to indicate the given symbol has a @Deprecated annotation.
     */
    public static final long DEPRECATED_ANNOTATION = 1L<<54;

    
Flag to indicate the given symbol has been deprecated and marked for removal.
/**
     * Flag to indicate the given symbol has been deprecated and marked for removal.
     */
    public static final long DEPRECATED_REMOVAL = 1L<<55;

    
Flag to indicate the given PackageSymbol contains any non-.java and non-.class resources.
/**
     * Flag to indicate the given PackageSymbol contains any non-.java and non-.class resources.
     */
    public static final long HAS_RESOURCE = 1L<<56;

    
Modifier masks.
/** Modifier masks.
     */
    public static final int
        AccessFlags           = PUBLIC | PROTECTED | PRIVATE,
        LocalClassFlags       = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
        MemberClassFlags      = LocalClassFlags | INTERFACE | AccessFlags,
        ClassFlags            = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
        InterfaceVarFlags     = FINAL | STATIC | PUBLIC,
        VarFlags              = AccessFlags | FINAL | STATIC |
                                VOLATILE | TRANSIENT | ENUM,
        ConstructorFlags      = AccessFlags,
        InterfaceMethodFlags  = ABSTRACT | PUBLIC,
        MethodFlags           = AccessFlags | ABSTRACT | STATIC | NATIVE |
                                SYNCHRONIZED | FINAL | STRICTFP;
    public static final long
        ExtendedStandardFlags       = (long)StandardFlags | DEFAULT,
        ModifierFlags               = ((long)StandardFlags & ~INTERFACE) | DEFAULT,
        InterfaceMethodMask         = ABSTRACT | PRIVATE | STATIC | PUBLIC | STRICTFP | DEFAULT,
        AnnotationTypeElementMask   = ABSTRACT | PUBLIC,
        LocalVarFlags               = FINAL | PARAMETER,
        ReceiverParamFlags          = PARAMETER;


    public static Set<Modifier> asModifierSet(long flags) {
        Set<Modifier> modifiers = modifierSets.get(flags);
        if (modifiers == null) {
            modifiers = java.util.EnumSet.noneOf(Modifier.class);
            if (0 != (flags & PUBLIC))    modifiers.add(Modifier.PUBLIC);
            if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
            if (0 != (flags & PRIVATE))   modifiers.add(Modifier.PRIVATE);
            if (0 != (flags & ABSTRACT))  modifiers.add(Modifier.ABSTRACT);
            if (0 != (flags & STATIC))    modifiers.add(Modifier.STATIC);
            if (0 != (flags & FINAL))     modifiers.add(Modifier.FINAL);
            if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
            if (0 != (flags & VOLATILE))  modifiers.add(Modifier.VOLATILE);
            if (0 != (flags & SYNCHRONIZED))
                                          modifiers.add(Modifier.SYNCHRONIZED);
            if (0 != (flags & NATIVE))    modifiers.add(Modifier.NATIVE);
            if (0 != (flags & STRICTFP))  modifiers.add(Modifier.STRICTFP);
            if (0 != (flags & DEFAULT))   modifiers.add(Modifier.DEFAULT);
            modifiers = Collections.unmodifiableSet(modifiers);
            modifierSets.put(flags, modifiers);
        }
        return modifiers;
    }

    // Cache of modifier sets.
    private static final Map<Long, Set<Modifier>> modifierSets = new ConcurrentHashMap<>(64);

    public static boolean isStatic(Symbol symbol) {
        return (symbol.flags() & STATIC) != 0;
    }

    public static boolean isEnum(Symbol symbol) {
        return (symbol.flags() & ENUM) != 0;
    }

    public static boolean isConstant(Symbol.VarSymbol symbol) {
        return symbol.getConstValue() != null;
    }


    public enum Flag {
        PUBLIC(Flags.PUBLIC),
        PRIVATE(Flags.PRIVATE),
        PROTECTED(Flags.PROTECTED),
        STATIC(Flags.STATIC),
        FINAL(Flags.FINAL),
        SYNCHRONIZED(Flags.SYNCHRONIZED),
        VOLATILE(Flags.VOLATILE),
        TRANSIENT(Flags.TRANSIENT),
        NATIVE(Flags.NATIVE),
        INTERFACE(Flags.INTERFACE),
        ABSTRACT(Flags.ABSTRACT),
        DEFAULT(Flags.DEFAULT),
        STRICTFP(Flags.STRICTFP),
        BRIDGE(Flags.BRIDGE),
        SYNTHETIC(Flags.SYNTHETIC),
        ANNOTATION(Flags.ANNOTATION),
        DEPRECATED(Flags.DEPRECATED),
        HASINIT(Flags.HASINIT),
        BLOCK(Flags.BLOCK),
        ENUM(Flags.ENUM),
        MANDATED(Flags.MANDATED),
        NOOUTERTHIS(Flags.NOOUTERTHIS),
        EXISTS(Flags.EXISTS),
        COMPOUND(Flags.COMPOUND),
        CLASS_SEEN(Flags.CLASS_SEEN),
        SOURCE_SEEN(Flags.SOURCE_SEEN),
        LOCKED(Flags.LOCKED),
        UNATTRIBUTED(Flags.UNATTRIBUTED),
        ANONCONSTR(Flags.ANONCONSTR),
        ACYCLIC(Flags.ACYCLIC),
        PARAMETER(Flags.PARAMETER),
        VARARGS(Flags.VARARGS),
        ACYCLIC_ANN(Flags.ACYCLIC_ANN),
        GENERATEDCONSTR(Flags.GENERATEDCONSTR),
        HYPOTHETICAL(Flags.HYPOTHETICAL),
        PROPRIETARY(Flags.PROPRIETARY),
        UNION(Flags.UNION),
        EFFECTIVELY_FINAL(Flags.EFFECTIVELY_FINAL),
        CLASH(Flags.CLASH),
        AUXILIARY(Flags.AUXILIARY),
        NOT_IN_PROFILE(Flags.NOT_IN_PROFILE),
        BAD_OVERRIDE(Flags.BAD_OVERRIDE),
        SIGNATURE_POLYMORPHIC(Flags.SIGNATURE_POLYMORPHIC),
        THROWS(Flags.THROWS),
        LAMBDA_METHOD(Flags.LAMBDA_METHOD),
        TYPE_TRANSLATED(Flags.TYPE_TRANSLATED),
        MODULE(Flags.MODULE),
        AUTOMATIC_MODULE(Flags.AUTOMATIC_MODULE),
        SYSTEM_MODULE(Flags.SYSTEM_MODULE),
        DEPRECATED_ANNOTATION(Flags.DEPRECATED_ANNOTATION),
        DEPRECATED_REMOVAL(Flags.DEPRECATED_REMOVAL),
        HAS_RESOURCE(Flags.HAS_RESOURCE);

        Flag(long flag) {
            this.value = flag;
            this.lowercaseName = StringUtils.toLowerCase(name());
        }

        @Override
        public String toString() {
            return lowercaseName;
        }

        final long value;
        final String lowercaseName;
    }

}