1 /*
   2  * Copyright (c) 2013, 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.options;
  24 
  25 /**
  26  * Describes the attributes of a static field {@linkplain Option option} and provides access to its
  27  * {@linkplain OptionValue value}.
  28  */
  29 public final class OptionDescriptor {
  30 
  31     protected final String name;
  32     protected final Class<?> type;
  33     protected final String help;
  34     protected final OptionValue<?> option;
  35     protected final Class<?> declaringClass;
  36     protected final String fieldName;
  37 
  38     public static OptionDescriptor create(String name, Class<?> type, String help, Class<?> declaringClass, String fieldName, OptionValue<?> option) {
  39         OptionDescriptor result = option.getDescriptor();
  40         if (result == null) {
  41             result = new OptionDescriptor(name, type, help, declaringClass, fieldName, option);
  42             option.setDescriptor(result);
  43         }
  44         assert result.name.equals(name) && result.type == type && result.declaringClass == declaringClass && result.fieldName.equals(fieldName) && result.option == option;
  45         return result;
  46     }
  47 
  48     private OptionDescriptor(String name, Class<?> type, String help, Class<?> declaringClass, String fieldName, OptionValue<?> option) {
  49         this.name = name;
  50         this.type = type;
  51         this.help = help;
  52         this.option = option;
  53         this.declaringClass = declaringClass;
  54         this.fieldName = fieldName;
  55         assert !type.isPrimitive() : "must used boxed type instead of " + type;
  56     }
  57 
  58     /**
  59      * Gets the type of values stored in the option. This will be the boxed type for a primitive
  60      * option.
  61      */
  62     public Class<?> getType() {
  63         return type;
  64     }
  65 
  66     /**
  67      * Gets a descriptive help message for the option.
  68      */
  69     public String getHelp() {
  70         return help;
  71     }
  72 
  73     /**
  74      * Gets the name of the option. It's up to the client of this object how to use the name to get
  75      * a user specified value for the option from the environment.
  76      */
  77     public String getName() {
  78         return name;
  79     }
  80 
  81     /**
  82      * Gets the boxed option value.
  83      */
  84     public OptionValue<?> getOptionValue() {
  85         return option;
  86     }
  87 
  88     public Class<?> getDeclaringClass() {
  89         return declaringClass;
  90     }
  91 
  92     public String getFieldName() {
  93         return fieldName;
  94     }
  95 
  96     /**
  97      * Gets a description of the location where this option is stored.
  98      */
  99     public String getLocation() {
 100         return getDeclaringClass().getName() + "." + getFieldName();
 101     }
 102 }