1 /*
   2  * Copyright (c) 2007, 2009, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.classfile;
  27 
  28 import java.io.IOException;
  29 
  30 /**
  31  * See JVMS, section 4.8.16.
  32  *
  33  *  <p><b>This is NOT part of any supported API.
  34  *  If you write code that depends on this, you do so at your own risk.
  35  *  This code and its internal interfaces are subject to change or
  36  *  deletion without notice.</b>
  37  */
  38 public class Annotation {
  39     static class InvalidAnnotation extends AttributeException {
  40         private static final long serialVersionUID = -4620480740735772708L;
  41         InvalidAnnotation(String msg) {
  42             super(msg);
  43         }
  44     }
  45 
  46     Annotation(ClassReader cr) throws IOException, InvalidAnnotation {
  47         type_index = cr.readUnsignedShort();
  48         num_element_value_pairs = cr.readUnsignedShort();
  49         element_value_pairs = new element_value_pair[num_element_value_pairs];
  50         for (int i = 0; i < element_value_pairs.length; i++)
  51             element_value_pairs[i] = new element_value_pair(cr);
  52     }
  53 
  54     public Annotation(ConstantPool constant_pool,
  55             int type_index,
  56             element_value_pair[] element_value_pairs) {
  57         this.type_index = type_index;
  58         num_element_value_pairs = element_value_pairs.length;
  59         this.element_value_pairs = element_value_pairs;
  60     }
  61 
  62     public int length() {
  63         int n = 2 /*type_index*/ + 2 /*num_element_value_pairs*/;
  64         for (element_value_pair pair: element_value_pairs)
  65             n += pair.length();
  66         return n;
  67     }
  68 
  69     public final int type_index;
  70     public final int num_element_value_pairs;
  71     public final element_value_pair element_value_pairs[];
  72 
  73     /**
  74      * See JVMS, section 4.8.16.1.
  75      */
  76     public static abstract class element_value {
  77         public static element_value read(ClassReader cr)
  78                 throws IOException, InvalidAnnotation {
  79             int tag = cr.readUnsignedByte();
  80             switch (tag) {
  81             case 'B':
  82             case 'C':
  83             case 'D':
  84             case 'F':
  85             case 'I':
  86             case 'J':
  87             case 'S':
  88             case 'Z':
  89             case 's':
  90                 return new Primitive_element_value(cr, tag);
  91 
  92             case 'e':
  93                 return new Enum_element_value(cr, tag);
  94 
  95             case 'c':
  96                 return new Class_element_value(cr, tag);
  97 
  98             case '@':
  99                 return new Annotation_element_value(cr, tag);
 100 
 101             case '[':
 102                 return new Array_element_value(cr, tag);
 103 
 104             default:
 105                 throw new InvalidAnnotation("unrecognized tag: " + tag);
 106             }
 107         }
 108 
 109         protected element_value(int tag) {
 110             this.tag = tag;
 111         }
 112 
 113         public abstract int length();
 114 
 115         public abstract <R,P> R accept(Visitor<R,P> visitor, P p);
 116 
 117         public interface Visitor<R,P> {
 118             R visitPrimitive(Primitive_element_value ev, P p);
 119             R visitEnum(Enum_element_value ev, P p);
 120             R visitClass(Class_element_value ev, P p);
 121             R visitAnnotation(Annotation_element_value ev, P p);
 122             R visitArray(Array_element_value ev, P p);
 123         }
 124 
 125         public final int tag;
 126     }
 127 
 128     public static class Primitive_element_value extends element_value {
 129         Primitive_element_value(ClassReader cr, int tag) throws IOException {
 130             super(tag);
 131             const_value_index = cr.readUnsignedShort();
 132         }
 133 
 134         public Primitive_element_value(int const_value_index, int tag) {
 135             super(tag);
 136             this.const_value_index = const_value_index;
 137         }
 138 
 139         @Override
 140         public int length() {
 141             return 2;
 142         }
 143 
 144         public <R,P> R accept(Visitor<R,P> visitor, P p) {
 145             return visitor.visitPrimitive(this, p);
 146         }
 147 
 148         public final int const_value_index;
 149 
 150     }
 151 
 152     public static class Enum_element_value extends element_value {
 153         Enum_element_value(ClassReader cr, int tag) throws IOException {
 154             super(tag);
 155             type_name_index = cr.readUnsignedShort();
 156             const_name_index = cr.readUnsignedShort();
 157         }
 158 
 159         public Enum_element_value(int type_name_index, int const_name_index, int tag) {
 160             super(tag);
 161             this.type_name_index = type_name_index;
 162             this.const_name_index = const_name_index;
 163         }
 164 
 165         @Override
 166         public int length() {
 167             return 4;
 168         }
 169 
 170         public <R,P> R accept(Visitor<R,P> visitor, P p) {
 171             return visitor.visitEnum(this, p);
 172         }
 173 
 174         public final int type_name_index;
 175         public final int const_name_index;
 176     }
 177 
 178     public static class Class_element_value extends element_value {
 179         Class_element_value(ClassReader cr, int tag) throws IOException {
 180             super(tag);
 181             class_info_index = cr.readUnsignedShort();
 182         }
 183 
 184         public Class_element_value(int class_info_index, int tag) {
 185             super(tag);
 186             this.class_info_index = class_info_index;
 187         }
 188 
 189         @Override
 190         public int length() {
 191             return 2;
 192         }
 193 
 194         public <R,P> R accept(Visitor<R,P> visitor, P p) {
 195             return visitor.visitClass(this, p);
 196         }
 197 
 198         public final int class_info_index;
 199     }
 200 
 201     public static class Annotation_element_value extends element_value {
 202         Annotation_element_value(ClassReader cr, int tag)
 203                 throws IOException, InvalidAnnotation {
 204             super(tag);
 205             annotation_value = new Annotation(cr);
 206         }
 207 
 208         public Annotation_element_value(Annotation annotation_value, int tag) {
 209             super(tag);
 210             this.annotation_value = annotation_value;
 211         }
 212 
 213         @Override
 214         public int length() {
 215             return annotation_value.length();
 216         }
 217 
 218         public <R,P> R accept(Visitor<R,P> visitor, P p) {
 219             return visitor.visitAnnotation(this, p);
 220         }
 221 
 222         public final Annotation annotation_value;
 223     }
 224 
 225     public static class Array_element_value extends element_value {
 226         Array_element_value(ClassReader cr, int tag)
 227                 throws IOException, InvalidAnnotation {
 228             super(tag);
 229             num_values = cr.readUnsignedShort();
 230             values = new element_value[num_values];
 231             for (int i = 0; i < values.length; i++)
 232                 values[i] = element_value.read(cr);
 233         }
 234 
 235         public Array_element_value(element_value[] values, int tag) {
 236             super(tag);
 237             this.num_values = values.length;
 238             this.values = values;
 239         }
 240 
 241         @Override
 242         public int length() {
 243             int n = 2;
 244             for (int i = 0; i < values.length; i++)
 245                 n += values[i].length();
 246             return n;
 247         }
 248 
 249         public <R,P> R accept(Visitor<R,P> visitor, P p) {
 250             return visitor.visitArray(this, p);
 251         }
 252 
 253         public final int num_values;
 254         public final element_value[] values;
 255     }
 256 
 257     public static class element_value_pair {
 258         element_value_pair(ClassReader cr)
 259                 throws IOException, InvalidAnnotation {
 260             element_name_index = cr.readUnsignedShort();
 261             value = element_value.read(cr);
 262         }
 263 
 264         public element_value_pair(int element_name_index, element_value value) {
 265             this.element_name_index = element_name_index;
 266             this.value = value;
 267         }
 268 
 269         public int length() {
 270             return 2 + value.length();
 271         }
 272 
 273         public final int element_name_index;
 274         public final element_value value;
 275     }
 276 }