001/*
002 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package jdk.internal.jvmci.hotspotvmconfig;
024
025import java.lang.annotation.*;
026
027/**
028 * Refers to a C++ field in the VM.
029 */
030@Target(ElementType.FIELD)
031@Retention(RetentionPolicy.RUNTIME)
032public @interface HotSpotVMField {
033
034    /**
035     * Types of information this annotation can return.
036     */
037    enum Type {
038        /**
039         * Returns the offset of this field within the type. Only valid for instance fields.
040         */
041        OFFSET,
042
043        /**
044         * Returns the absolute address of this field. Only valid for static fields.
045         */
046        ADDRESS,
047
048        /**
049         * Returns the value of this field. Only valid for static fields.
050         */
051        VALUE;
052    }
053
054    /**
055     * Specifies what type of information to return.
056     *
057     * @see Type
058     */
059    Type get();
060
061    /**
062     * Returns the type name containing this field.
063     *
064     * @return name of containing type
065     */
066    String type();
067
068    /**
069     * Returns the name of this field.
070     *
071     * @return name of field
072     */
073    String name();
074
075    /**
076     * List of architectures where this constant is required. Names are derived from
077     * {@link HotSpotVMConfig#getHostArchitectureName()}. An empty list implies that the constant is
078     * required on all architectures.
079     */
080    @SuppressWarnings("javadoc")
081    String[] archs() default {};
082}