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 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package com.sun.tools.javac.code;

import java.util.EnumSet;
import java.util.Set;
import java.util.Locale;

import com.sun.source.tree.MemberReferenceTree;
import com.sun.tools.javac.api.Formattable;
import com.sun.tools.javac.api.Messages;

import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.TypeTag.CLASS;
import static com.sun.tools.javac.code.TypeTag.PACKAGE;
import static com.sun.tools.javac.code.TypeTag.TYPEVAR;

Internal symbol kinds, which distinguish between elements of
 different subclasses of Symbol. Symbol kinds are organized so they can be
 or'ed to sets.
 
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.
/** Internal symbol kinds, which distinguish between elements of
 *  different subclasses of Symbol. Symbol kinds are organized so they can be
 *  or'ed to sets.
 *
 *  <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 Kinds {

    private Kinds() {} // uninstantiable

    
Kind of symbols.
IMPORTANT: This is an ordered type.  The ordering of
declarations in this enum matters.  Be careful when changing
it.
/**
     * Kind of symbols.
     *
     * IMPORTANT: This is an ordered type.  The ordering of
     * declarations in this enum matters.  Be careful when changing
     * it.
     */
    public enum Kind {
        NIL(Category.BASIC, KindSelector.NIL),
        PCK(Category.BASIC, KindName.PACKAGE, KindSelector.PCK),
        TYP(Category.BASIC, KindName.CLASS, KindSelector.TYP),
        VAR(Category.BASIC, KindName.VAR, KindSelector.VAR),
        MTH(Category.BASIC, KindName.METHOD, KindSelector.MTH),
        POLY(Category.BASIC, KindSelector.POLY),
        MDL(Category.BASIC, KindSelector.MDL),
        ERR(Category.ERROR, KindSelector.ERR),
        AMBIGUOUS(Category.RESOLUTION_TARGET),                         // overloaded       target
        HIDDEN(Category.RESOLUTION_TARGET),                            // not overloaded   non-target
        STATICERR(Category.RESOLUTION_TARGET),                         // overloaded?      target
        MISSING_ENCL(Category.RESOLUTION),                             // not overloaded   non-target
        BAD_RESTRICTED_TYPE(Category.RESOLUTION),                      // not overloaded   non-target
        ABSENT_VAR(Category.RESOLUTION_TARGET, KindName.VAR),          // not overloaded   non-target
        WRONG_MTHS(Category.RESOLUTION_TARGET, KindName.METHOD),       // overloaded       target
        WRONG_MTH(Category.RESOLUTION_TARGET, KindName.METHOD),        // not overloaded   target
        ABSENT_MTH(Category.RESOLUTION_TARGET, KindName.METHOD),       // not overloaded   non-target
        ABSENT_TYP(Category.RESOLUTION_TARGET, KindName.CLASS);        // not overloaded   non-target

        // There are essentially two "levels" to the Kind datatype.
        // The first is a totally-ordered set of categories of
        // solutions.  Within each category, we have more
        // possibilities.
        private enum Category {
            BASIC, ERROR, RESOLUTION, RESOLUTION_TARGET;
        }

        private final KindName kindName;
        private final KindName absentKind;
        private final KindSelector selector;
        private final Category category;

        private Kind(Category category) {
            this(category, null, null, null);
        }

        private Kind(Category category,
                     KindSelector selector) {
            this(category, null, null, selector);
        }

        private Kind(Category category,
                     KindName absentKind) {
            this(category, null, absentKind, null);
        }

        private Kind(Category category,
                     KindName kindName,
                     KindSelector selector) {
            this(category, kindName, null, selector);
        }

        private Kind(Category category,
                     KindName kindName,
                     KindName absentKind,
                     KindSelector selector) {
            this.category = category;
            this.kindName = kindName;
            this.absentKind = absentKind;
            this.selector = selector;
        }

        public KindSelector toSelector() {
            return selector;
        }

        public boolean matches(KindSelector kindSelectors) {
            return selector.contains(kindSelectors);
        }

        public boolean isResolutionError() {
            return category == Category.RESOLUTION || category == Category.RESOLUTION_TARGET;
        }

        public boolean isResolutionTargetError() {
            return category == Category.RESOLUTION_TARGET;
        }

        public boolean isValid() {
            return category == Category.BASIC;
        }

        public boolean betterThan(Kind other) {
            return ordinal() < other.ordinal();
        }

        public KindName kindName() {
            if (kindName == null) {
                throw new AssertionError("Unexpected kind: " + this);
            } else {
                return kindName;
            }
        }

        public KindName absentKind() {
            if (absentKind == null) {
                throw new AssertionError("Unexpected kind: " + this);
            } else {
                return absentKind;
            }
        }
    }

    public static class KindSelector {

        //basic selectors
        public static final KindSelector NIL = new KindSelector(0);
        public static final KindSelector PCK = new KindSelector(0x01);
        public static final KindSelector TYP = new KindSelector(0x02);
        public static final KindSelector VAR = new KindSelector(0x04);
        public static final KindSelector VAL = new KindSelector(0x0c);
        public static final KindSelector MTH = new KindSelector(0x10);
        public static final KindSelector POLY = new KindSelector(0x20);
        public static final KindSelector MDL = new KindSelector(0x40);
        public static final KindSelector ERR = new KindSelector(0x7f);
        public static final KindSelector ASG = new KindSelector(0x84);

        //common derived selectors
        public static final KindSelector TYP_PCK = of(TYP, PCK);
        public static final KindSelector VAL_MTH = of(VAL, MTH);
        public static final KindSelector VAL_POLY = of(VAL, POLY);
        public static final KindSelector VAL_TYP = of(VAL, TYP);
        public static final KindSelector VAL_TYP_PCK = of(VAL, TYP, PCK);

        private final byte data;

        private KindSelector(int data) {
            this.data = (byte) data;
        }

        public static KindSelector of(KindSelector... kindSelectors) {
            byte newData = 0;
            for (KindSelector kindSel : kindSelectors) {
                newData |= kindSel.data;
            }
            return new KindSelector(newData);
        }

        public boolean subset(KindSelector other) {
            return (data & ~other.data) == 0;
        }

        public boolean contains(KindSelector other) {
            return (data & other.data) != 0;
        }

        
A set of KindName(s) representing a set of symbol's kinds. /** A set of KindName(s) representing a set of symbol's kinds. */
        public Set<KindName> kindNames() {
            EnumSet<KindName> kinds = EnumSet.noneOf(KindName.class);
            if ((data & VAL.data) != 0) {
                if ((data & VAL.data) == VAR.data) kinds.add(KindName.VAR);
                else kinds.add(KindName.VAL);
            }
            if ((data & MTH.data) != 0) kinds.add(KindName.METHOD);
            if ((data & TYP.data) != 0) kinds.add(KindName.CLASS);
            if ((data & PCK.data) != 0) kinds.add(KindName.PACKAGE);
            if ((data & MDL.data) != 0) kinds.add(KindName.MODULE);
            return kinds;
        }
    }

    public enum KindName implements Formattable {
        ANNOTATION("kindname.annotation"),
        CONSTRUCTOR("kindname.constructor"),
        INTERFACE("kindname.interface"),
        ENUM("kindname.enum"),
        STATIC("kindname.static"),
        TYPEVAR("kindname.type.variable"),
        BOUND("kindname.type.variable.bound"),
        VAR("kindname.variable"),
        VAL("kindname.value"),
        METHOD("kindname.method"),
        CLASS("kindname.class"),
        STATIC_INIT("kindname.static.init"),
        INSTANCE_INIT("kindname.instance.init"),
        PACKAGE("kindname.package"),
        MODULE("kindname.module"),
        RECORD_COMPONENT("kindname.record.component"),
        RECORD("kindname.record");

        private final String name;

        KindName(String name) {
            this.name = name;
        }

        public String toString() {
            return name;
        }

        public String getKind() {
            return "Kindname";
        }

        public String toString(Locale locale, Messages messages) {
            String s = toString();
            return messages.getLocalizedString(locale, "compiler.misc." + s);
        }
    }

    public static KindName kindName(MemberReferenceTree.ReferenceMode mode) {
        switch (mode) {
            case INVOKE: return KindName.METHOD;
            case NEW: return KindName.CONSTRUCTOR;
            default : throw new AssertionError("Unexpected mode: "+ mode);
        }
    }

    
A KindName representing a given symbol
/** A KindName representing a given symbol
     */
    public static KindName kindName(Symbol sym) {
        switch (sym.getKind()) {
        case PACKAGE:
            return KindName.PACKAGE;

        case ENUM:
            return KindName.ENUM;

        case ANNOTATION_TYPE:
        case CLASS:
            return KindName.CLASS;

        case RECORD:
            return KindName.RECORD;

        case INTERFACE:
            return KindName.INTERFACE;

        case TYPE_PARAMETER:
            return KindName.TYPEVAR;

        case BINDING_VARIABLE:
        case ENUM_CONSTANT:
        case PARAMETER:
        case LOCAL_VARIABLE:
        case EXCEPTION_PARAMETER:
        case RESOURCE_VARIABLE:
            return KindName.VAR;

        case FIELD:
            return ((sym.flags_field & RECORD) != 0) ? KindName.RECORD_COMPONENT : KindName.VAR;

        case CONSTRUCTOR:
            return KindName.CONSTRUCTOR;

        case METHOD:
            return KindName.METHOD;
        case STATIC_INIT:
            return KindName.STATIC_INIT;
        case INSTANCE_INIT:
            return KindName.INSTANCE_INIT;

        default:
                throw new AssertionError("Unexpected kind: "+sym.getKind());
        }
    }

    
A KindName representing the kind of a given class/interface type.
/** A KindName representing the kind of a given class/interface type.
     */
    public static KindName typeKindName(Type t) {
        if (t.hasTag(TYPEVAR) ||
            t.hasTag(CLASS) && (t.tsym.flags() & COMPOUND) != 0)
            return KindName.BOUND;
        else if (t.hasTag(PACKAGE))
            return KindName.PACKAGE;
        else if ((t.tsym.flags_field & ANNOTATION) != 0)
            return KindName.ANNOTATION;
        else if ((t.tsym.flags_field & INTERFACE) != 0)
            return KindName.INTERFACE;
        else
            return KindName.CLASS;
    }

}