1 /*
   2  * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.hotspotvmconfig;
  24 
  25 import java.lang.annotation.*;
  26 
  27 /**
  28  * Refers to a C++ field in the VM.
  29  */
  30 @Target(ElementType.FIELD)
  31 @Retention(RetentionPolicy.RUNTIME)
  32 public @interface HotSpotVMField {
  33 
  34     /**
  35      * Types of information this annotation can return.
  36      */
  37     enum Type {
  38         /**
  39          * Returns the offset of this field within the type. Only valid for instance fields.
  40          */
  41         OFFSET,
  42 
  43         /**
  44          * Returns the absolute address of this field. Only valid for static fields.
  45          */
  46         ADDRESS,
  47 
  48         /**
  49          * Returns the value of this field. Only valid for static fields.
  50          */
  51         VALUE;
  52     }
  53 
  54     /**
  55      * Specifies what type of information to return.
  56      *
  57      * @see Type
  58      */
  59     Type get();
  60 
  61     /**
  62      * Returns the type name containing this field.
  63      *
  64      * @return name of containing type
  65      */
  66     String type();
  67 
  68     /**
  69      * Returns the name of this field.
  70      *
  71      * @return name of field
  72      */
  73     String name();
  74 
  75     /**
  76      * List of architectures where this constant is required. Names are derived from
  77      * {@link HotSpotVMConfig#getHostArchitectureName()}. An empty list implies that the constant is
  78      * required on all architectures.
  79      */
  80     @SuppressWarnings("javadoc")
  81     String[] archs() default {};
  82 }