/*

 * Copyright (c) 2008, 2013, 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.tools.javac.util.Assert;

/**

 * Describes the type of program element an extended annotation (or extended

 * compound attribute) targets.

 *

 * By comparison, a Tree.Kind has enum values for all elements in the AST, and

 * it does not provide enough resolution for type arguments (i.e., whether an

 * annotation targets a type argument in a local variable, method return type,

 * or a typecast).

 *

 *  <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>

 */

// Code duplicated in com.sun.tools.classfile.TypeAnnotation.TargetType

public enum TargetType {

    /** For annotations on a class type parameter declaration. */

    CLASS_TYPE_PARAMETER(0x00),

    /** For annotations on a method type parameter declaration. */

    METHOD_TYPE_PARAMETER(0x01),

    /** For annotations on the type of an "extends" or "implements" clause. */

    CLASS_EXTENDS(0x10),

    /** For annotations on a bound of a type parameter of a class. */

    CLASS_TYPE_PARAMETER_BOUND(0x11),

    /** For annotations on a bound of a type parameter of a method. */

    METHOD_TYPE_PARAMETER_BOUND(0x12),

    /** For annotations on a field. */

    FIELD(0x13),

    /** For annotations on a method return type. */

    METHOD_RETURN(0x14),

    /** For annotations on the method receiver. */

    METHOD_RECEIVER(0x15),

    /** For annotations on a method parameter. */

    METHOD_FORMAL_PARAMETER(0x16),

    /** For annotations on a throws clause in a method declaration. */

    THROWS(0x17),

    /** For annotations on a local variable. */

    LOCAL_VARIABLE(0x40, true),

    /** For annotations on a resource variable. */

    RESOURCE_VARIABLE(0x41, true),

    /** For annotations on an exception parameter. */

    EXCEPTION_PARAMETER(0x42, true),

    /** For annotations on a type test. */

    INSTANCEOF(0x43, true),

    /** For annotations on an object creation expression. */

    NEW(0x44, true),

    /** For annotations on a constructor reference receiver. */

    CONSTRUCTOR_REFERENCE(0x45, true),

    /** For annotations on a method reference receiver. */

    METHOD_REFERENCE(0x46, true),

    /** For annotations on a typecast. */

    CAST(0x47, true),

    /** For annotations on a type argument of an object creation expression. */

    CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT(0x48, true),

    /** For annotations on a type argument of a method call. */

    METHOD_INVOCATION_TYPE_ARGUMENT(0x49, true),

    /** For annotations on a type argument of a constructor reference. */

    CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT(0x4A, true),

    /** For annotations on a type argument of a method reference. */

    METHOD_REFERENCE_TYPE_ARGUMENT(0x4B, true),

    /** For annotations with an unknown target. */

    UNKNOWN(0xFF);

    private static final int MAXIMUM_TARGET_TYPE_VALUE = 0x4B;

    private final int targetTypeValue;

    private final boolean isLocal;

    private TargetType(int targetTypeValue) {

        this(targetTypeValue, false);

    }

    private TargetType(int targetTypeValue, boolean isLocal) {

        if (targetTypeValue < 0

                || targetTypeValue > 255)

                Assert.error("Attribute type value needs to be an unsigned byte: " + String.format("0x%02X", targetTypeValue));

        this.targetTypeValue = targetTypeValue;

        this.isLocal = isLocal;

    }

    /**

     * Returns whether or not this TargetType represents an annotation whose

     * target is exclusively a tree in a method body

     *

     * Note: wildcard bound targets could target a local tree and a class

     * member declaration signature tree

     */

    public boolean isLocal() {

        return isLocal;

    }

    public int targetTypeValue() {

        return this.targetTypeValue;

    }

    private static final TargetType[] targets;

    static {

        targets = new TargetType[MAXIMUM_TARGET_TYPE_VALUE + 1];

        TargetType[] alltargets = values();

        for (TargetType target : alltargets) {

            if (target.targetTypeValue != UNKNOWN.targetTypeValue)

                targets[target.targetTypeValue] = target;

        }

        for (int i = 0; i <= MAXIMUM_TARGET_TYPE_VALUE; ++i) {

            if (targets[i] == null)

                targets[i] = UNKNOWN;

        }

    }

    public static boolean isValidTargetTypeValue(int tag) {

        if (tag == UNKNOWN.targetTypeValue)

            return true;

        return (tag >= 0 && tag < targets.length);

    }

    public static TargetType fromTargetTypeValue(int tag) {

        if (tag == UNKNOWN.targetTypeValue)

            return UNKNOWN;

        if (tag < 0 || tag >= targets.length)

            Assert.error("Unknown TargetType: " + tag);

        return targets[tag];

    }

}