/*

 * Copyright (c) 1999, 2014, 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).

 *

 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javac.code;

import com.sun.source.tree.Tree.Kind;

import javax.lang.model.type.TypeKind;

import static com.sun.tools.javac.code.TypeTag.NumericClasses.*;

/** An interface for type tag values, which distinguish between different

 *  sorts of types.

 *

 *  <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 enum TypeTag {

    /** The tag of the basic type `byte'.

     */

    BYTE(BYTE_CLASS, BYTE_SUPERCLASSES, true),

    /** The tag of the basic type `char'.

     */

    CHAR(CHAR_CLASS, CHAR_SUPERCLASSES, true),

    /** The tag of the basic type `short'.

     */

    SHORT(SHORT_CLASS, SHORT_SUPERCLASSES, true),

    /** The tag of the basic type `long'.

     */

    LONG(LONG_CLASS, LONG_SUPERCLASSES, true),

    /** The tag of the basic type `float'.

     */

    FLOAT(FLOAT_CLASS, FLOAT_SUPERCLASSES, true),

    /** The tag of the basic type `int'.

     */

    INT(INT_CLASS, INT_SUPERCLASSES, true),

    /** The tag of the basic type `double'.

     */

    DOUBLE(DOUBLE_CLASS, DOUBLE_CLASS, true),

    /** The tag of the basic type `boolean'.

     */

    BOOLEAN(0, 0, true),

    /** The tag of the type `void'.

     */

    VOID,

    /** The tag of all class and interface types.

     */

    CLASS,

    /** The tag of all array types.

     */

    ARRAY,

    /** The tag of all (monomorphic) method types.

     */

    METHOD,

    /** The tag of all package "types".

     */

    PACKAGE,

    /** The tag of all module "types".

     */

    MODULE,

    /** The tag of all (source-level) type variables.

     */

    TYPEVAR,

    /** The tag of all type arguments.

     */

    WILDCARD,

    /** The tag of all polymorphic (method-) types.

     */

    FORALL,

    /** The tag of deferred expression types in method context

     */

    DEFERRED,

    /** The tag of the bottom type {@code <null>}.

     */

    BOT,

    /** The tag of a missing type.

     */

    NONE,

    /** The tag of the error type.

     */

    ERROR,

    /** The tag of an unknown type

     */

    UNKNOWN,

    /** The tag of all instantiatable type variables.

     */

    UNDETVAR,

    /** Pseudo-types, these are special tags

     */

    UNINITIALIZED_THIS,

    UNINITIALIZED_OBJECT;

    final int superClasses;

    final int numericClass;

    final boolean isPrimitive;

    private TypeTag() {

        this(0, 0, false);

    }

    private TypeTag(int numericClass, int superClasses, boolean isPrimitive) {

        this.superClasses = superClasses;

        this.numericClass = numericClass;

        this.isPrimitive = isPrimitive;

    }

    public static class NumericClasses {

        public static final int BYTE_CLASS = 1;

        public static final int CHAR_CLASS = 2;

        public static final int SHORT_CLASS = 4;

        public static final int INT_CLASS = 8;

        public static final int LONG_CLASS = 16;

        public static final int FLOAT_CLASS = 32;

        public static final int DOUBLE_CLASS = 64;

        static final int BYTE_SUPERCLASSES = BYTE_CLASS | SHORT_CLASS | INT_CLASS |

                LONG_CLASS | FLOAT_CLASS | DOUBLE_CLASS;

        static final int CHAR_SUPERCLASSES = CHAR_CLASS | INT_CLASS |

                LONG_CLASS | FLOAT_CLASS | DOUBLE_CLASS;

        static final int SHORT_SUPERCLASSES = SHORT_CLASS | INT_CLASS |

                LONG_CLASS | FLOAT_CLASS | DOUBLE_CLASS;

        static final int INT_SUPERCLASSES = INT_CLASS | LONG_CLASS | FLOAT_CLASS | DOUBLE_CLASS;

        static final int LONG_SUPERCLASSES = LONG_CLASS | FLOAT_CLASS | DOUBLE_CLASS;

        static final int FLOAT_SUPERCLASSES = FLOAT_CLASS | DOUBLE_CLASS;

    }

    public boolean isStrictSubRangeOf(TypeTag tag) {

        /*  Please don't change the implementation of this method to call method

         *  isSubRangeOf. Both methods are called from hotspot code, the current

         *  implementation is better performance-wise than the commented modification.

         */

        return (this.superClasses & tag.numericClass) != 0 && this != tag;

    }

    public boolean isSubRangeOf(TypeTag tag) {

        return (this.superClasses & tag.numericClass) != 0;

    }

    /** Returns the number of type tags.

     */

    public static int getTypeTagCount() {

        // last two tags are not included in the total as long as they are pseudo-types

        return (UNDETVAR.ordinal() + 1);

    }

    public Kind getKindLiteral() {

        switch (this) {

        case INT:

            return Kind.INT_LITERAL;

        case LONG:

            return Kind.LONG_LITERAL;

        case FLOAT:

            return Kind.FLOAT_LITERAL;

        case DOUBLE:

            return Kind.DOUBLE_LITERAL;

        case BOOLEAN:

            return Kind.BOOLEAN_LITERAL;

        case CHAR:

            return Kind.CHAR_LITERAL;

        case CLASS:

            return Kind.STRING_LITERAL;

        case BOT:

            return Kind.NULL_LITERAL;

        default:

            throw new AssertionError("unknown literal kind " + this);

        }

    }

    public TypeKind getPrimitiveTypeKind() {

        switch (this) {

        case BOOLEAN:

            return TypeKind.BOOLEAN;

        case BYTE:

            return TypeKind.BYTE;

        case SHORT:

            return TypeKind.SHORT;

        case INT:

            return TypeKind.INT;

        case LONG:

            return TypeKind.LONG;

        case CHAR:

            return TypeKind.CHAR;

        case FLOAT:

            return TypeKind.FLOAT;

        case DOUBLE:

            return TypeKind.DOUBLE;

        case VOID:

            return TypeKind.VOID;

        default:

            throw new AssertionError("unknown primitive type " + this);

        }

    }

}