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.ElementType;
  26 import java.lang.annotation.Retention;
  27 import java.lang.annotation.RetentionPolicy;
  28 import java.lang.annotation.Target;
  29 
  30 /**
  31  * Refers to a C++ field in the VM.
  32  */
  33 @Target(ElementType.FIELD)
  34 @Retention(RetentionPolicy.RUNTIME)
  35 public @interface HotSpotVMField {
  36 
  37     /**
  38      * Types of information this annotation can return.
  39      */
  40     enum Type {
  41         /**
  42          * Returns the offset of this field within the type. Only valid for instance fields.
  43          */
  44         OFFSET,
  45 
  46         /**
  47          * Returns the absolute address of this field. Only valid for static fields.
  48          */
  49         ADDRESS,
  50 
  51         /**
  52          * Returns the value of this field. Only valid for static fields.
  53          */
  54         VALUE;
  55     }
  56 
  57     /**
  58      * Specifies what type of information to return.
  59      *
  60      * @see Type
  61      */
  62     Type get();
  63 
  64     /**
  65      * Returns the type name containing this field.
  66      *
  67      * @return name of containing type
  68      */
  69     String type();
  70 
  71     /**
  72      * Returns the name of this field.
  73      *
  74      * @return name of field
  75      */
  76     String name();
  77 
  78     /**
  79      * List of architectures where this constant is required. Names are derived from
  80      * {@link HotSpotVMConfig#getHostArchitectureName()}. An empty list implies that the constant is
  81      * required on all architectures.
  82      */
  83     @SuppressWarnings("javadoc")
  84     String[] archs() default {};
  85 }