/*

 * Copyright 1999-2006 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.javac.code;

import java.util.Collections;

import java.util.Map;

import java.util.Set;

import javax.lang.model.element.Modifier;

/** Access flags and other modifiers for Java classes and members.

 *

 *  <p><b>This is NOT part of any API supported by Sun Microsystems.  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) {

        StringBuffer buf = new StringBuffer();

        if ((flags&PUBLIC) != 0) buf.append("public ");

        if ((flags&PRIVATE) != 0) buf.append("private ");

        if ((flags&PROTECTED) != 0) buf.append("protected ");

        if ((flags&STATIC) != 0) buf.append("static ");

        if ((flags&FINAL) != 0) buf.append("final ");

        if ((flags&SYNCHRONIZED) != 0) buf.append("synchronized ");

        if ((flags&VOLATILE) != 0) buf.append("volatile ");

        if ((flags&TRANSIENT) != 0) buf.append("transient ");

        if ((flags&NATIVE) != 0) buf.append("native ");

        if ((flags&INTERFACE) != 0) buf.append("interface ");

        if ((flags&ABSTRACT) != 0) buf.append("abstract ");

        if ((flags&STRICTFP) != 0) buf.append("strictfp ");

        if ((flags&BRIDGE) != 0) buf.append("bridge ");

        if ((flags&SYNTHETIC) != 0) buf.append("synthetic ");

        if ((flags&DEPRECATED) != 0) buf.append("deprecated ");

        if ((flags&HASINIT) != 0) buf.append("hasinit ");

        if ((flags&ENUM) != 0) buf.append("enum ");

        if ((flags&IPROXY) != 0) buf.append("iproxy ");

        if ((flags&NOOUTERTHIS) != 0) buf.append("noouterthis ");

        if ((flags&EXISTS) != 0) buf.append("exists ");

        if ((flags&COMPOUND) != 0) buf.append("compound ");

        if ((flags&CLASS_SEEN) != 0) buf.append("class_seen ");

        if ((flags&SOURCE_SEEN) != 0) buf.append("source_seen ");

        if ((flags&LOCKED) != 0) buf.append("locked ");

        if ((flags&UNATTRIBUTED) != 0) buf.append("unattributed ");

        if ((flags&ANONCONSTR) != 0) buf.append("anonconstr ");

        if ((flags&ACYCLIC) != 0) buf.append("acyclic ");

        if ((flags&PARAMETER) != 0) buf.append("parameter ");

        if ((flags&VARARGS) != 0) buf.append("varargs ");

        return buf.toString();

    }

    /* Standard Java flags.

     */

    public static final int PUBLIC       = 1<<0;

    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. */

    public static final int ANNOTATION   = 1<<13;

    /** An enumeration type or an enumeration constant, added in

     *  classfile v49.0. */

    public static final int ENUM         = 1<<14;

    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;

    /*****************************************

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

     *****************************************/

    /** Flag is set if symbol is deprecated.

     */

    public static final int DEPRECATED   = 1<<17;

    /** 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.

     */

    public static final int BLOCK            = 1<<20;

    /** Flag is set for compiler-generated abstract methods that implement

     *  an interface method (Miranda methods).

     */

    public static final int IPROXY           = 1<<21;

    /** 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 flag is currently set only for anonymous

     *  classes in superclass constructor calls and only for pre 1.4 targets.

     *  todo: use this flag 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.

     */

    public static final int EXISTS           = 1<<23;

    /** 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.

     */

    public static final int CLASS_SEEN   = 1<<25;

    /** 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.

     */

    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.

     */

    public static final int UNATTRIBUTED = 1<<28;

    /** 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.

     */

    public static final int ACYCLIC          = 1<<30;

    /** Flag that marks bridge methods.

     */

    public static final long BRIDGE          = 1L<<31;

    /** Flag that marks formal parameters.

     */

    public static final long PARAMETER   = 1L<<33;

    /** 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.

     */

    public static final long ACYCLIC_ANN      = 1L<<35;

    /** 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.

     */

    public static final long HYPOTHETICAL   = 1L<<37;

    /**

     * Flag that marks a Sun proprietary class.

     */

    public static final long PROPRIETARY = 1L<<38;

    /** 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

        LocalVarFlags         = FINAL | 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);

            modifiers = Collections.unmodifiableSet(modifiers);

            modifierSets.put(flags, modifiers);

        }

        return modifiers;

    }

    // Cache of modifier sets.

    private static Map<Long, Set<Modifier>> modifierSets =

        new java.util.concurrent.ConcurrentHashMap<Long, Set<Modifier>>(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;

    }

}