jdk/src/java.base/share/classes/sun/invoke/anon/ConstantPoolVisitor.java
changeset 35307 50b5ac3cfb59
parent 35239 2c2395ac7604
parent 35306 74feccca64cc
child 35308 7dbbcead95f6
child 35692 ee66ced7896c
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35239:2c2395ac7604 35307:50b5ac3cfb59
     1 /*
       
     2  * Copyright (c) 2008, 2011, 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 sun.invoke.anon;
       
    27 
       
    28 /**
       
    29  * A visitor called by {@link ConstantPoolParser#parse(ConstantPoolVisitor)}
       
    30  * when a constant pool entry is parsed.
       
    31  * <p>
       
    32  * A visit* method is called when a constant pool entry is parsed.
       
    33  * The first argument is always the constant pool index.
       
    34  * The second argument is always the constant pool tag,
       
    35  * even for methods like {@link #visitUTF8(int, byte, String)} which only apply to one tag.
       
    36  * String arguments refer to Utf8 or NameAndType entries declared elsewhere,
       
    37  * and are always accompanied by the indexes of those entries.
       
    38  * <p>
       
    39  * The order of the calls to the visit* methods is not necessarily related
       
    40  * to the order of the entries in the constant pool.
       
    41  * If one entry has a reference to another entry, the latter (lower-level)
       
    42  * entry will be visited first.
       
    43  * <p>
       
    44  * The following table shows the relation between constant pool entry
       
    45  * types and the corresponding visit* methods:
       
    46  *
       
    47  * <table border=1 cellpadding=5 summary="constant pool visitor methods">
       
    48  * <tr><th>Tag(s)</th><th>Method</th></tr>
       
    49  * <tr>
       
    50  *   <td>{@link #CONSTANT_Utf8}</td>
       
    51  *   <td>{@link #visitUTF8(int, byte, String)}</td>
       
    52  * </tr><tr>
       
    53  *   <td>{@link #CONSTANT_Integer}, {@link #CONSTANT_Float},
       
    54  *       {@link #CONSTANT_Long}, {@link #CONSTANT_Double}</td>
       
    55  *   <td>{@link #visitConstantValue(int, byte, Object)}</td>
       
    56  * </tr><tr>
       
    57  *   <td>{@link #CONSTANT_String}, {@link #CONSTANT_Class}</td>
       
    58  *   <td>{@link #visitConstantString(int, byte, String, int)}</td>
       
    59  * </tr><tr>
       
    60  *   <td>{@link #CONSTANT_NameAndType}</td>
       
    61  *   <td>{@link #visitDescriptor(int, byte, String, String, int, int)}</td>
       
    62  * </tr><tr>
       
    63  *   <td>{@link #CONSTANT_Fieldref},
       
    64  *       {@link #CONSTANT_Methodref},
       
    65  *       {@link #CONSTANT_InterfaceMethodref}</td>
       
    66  *   <td>{@link #visitMemberRef(int, byte, String, String, String, int, int)}</td>
       
    67  * </tr>
       
    68  * </table>
       
    69  *
       
    70  * @see ConstantPoolPatch
       
    71  * @author Remi Forax
       
    72  * @author jrose
       
    73  */
       
    74 public class ConstantPoolVisitor {
       
    75   /** Called each time an UTF8 constant pool entry is found.
       
    76    * @param index the constant pool index
       
    77    * @param tag always {@link #CONSTANT_Utf8}
       
    78    * @param utf8 string encoded in modified UTF-8 format passed as a {@code String}
       
    79    *
       
    80    * @see ConstantPoolPatch#putUTF8(int, String)
       
    81    */
       
    82   public void visitUTF8(int index, byte tag, String utf8) {
       
    83     // do nothing
       
    84   }
       
    85 
       
    86   /** Called for each constant pool entry that encodes an integer,
       
    87    *  a float, a long, or a double.
       
    88    *  Constant strings and classes are not managed by this method but
       
    89    *  by {@link #visitConstantString(int, byte, String, int)}.
       
    90    *
       
    91    * @param index the constant pool index
       
    92    * @param tag one of {@link #CONSTANT_Integer},
       
    93    *            {@link #CONSTANT_Float},
       
    94    *            {@link #CONSTANT_Long},
       
    95    *            or {@link #CONSTANT_Double}
       
    96    * @param value encoded value
       
    97    *
       
    98    * @see ConstantPoolPatch#putConstantValue(int, Object)
       
    99    */
       
   100   public void visitConstantValue(int index, byte tag, Object value) {
       
   101     // do nothing
       
   102   }
       
   103 
       
   104   /** Called for each constant pool entry that encodes a string or a class.
       
   105    * @param index the constant pool index
       
   106    * @param tag one of {@link #CONSTANT_String},
       
   107    *            {@link #CONSTANT_Class},
       
   108    * @param name string body or class name (using dot separator)
       
   109    * @param nameIndex the index of the Utf8 string for the name
       
   110    *
       
   111    * @see ConstantPoolPatch#putConstantValue(int, byte, Object)
       
   112    */
       
   113   public void visitConstantString(int index, byte tag,
       
   114                                   String name, int nameIndex) {
       
   115     // do nothing
       
   116   }
       
   117 
       
   118   /** Called for each constant pool entry that encodes a name and type.
       
   119    * @param index the constant pool index
       
   120    * @param tag always {@link #CONSTANT_NameAndType}
       
   121    * @param memberName a field or method name
       
   122    * @param signature the member signature
       
   123    * @param memberNameIndex index of the Utf8 string for the member name
       
   124    * @param signatureIndex index of the Utf8 string for the signature
       
   125    *
       
   126    * @see ConstantPoolPatch#putDescriptor(int, String, String)
       
   127    */
       
   128   public void visitDescriptor(int index, byte tag,
       
   129                               String memberName, String signature,
       
   130                               int memberNameIndex, int signatureIndex) {
       
   131     // do nothing
       
   132   }
       
   133 
       
   134   /** Called for each constant pool entry that encodes a field or method.
       
   135    * @param index the constant pool index
       
   136    * @param tag one of {@link #CONSTANT_Fieldref},
       
   137    *            or {@link #CONSTANT_Methodref},
       
   138    *            or {@link #CONSTANT_InterfaceMethodref}
       
   139    * @param className the class name (using dot separator)
       
   140    * @param memberName name of the field or method
       
   141    * @param signature the field or method signature
       
   142    * @param classNameIndex index of the Utf8 string for the class name
       
   143    * @param descriptorIndex index of the NameAndType descriptor constant
       
   144    *
       
   145    * @see ConstantPoolPatch#putMemberRef(int, byte, String, String, String)
       
   146    */
       
   147   public void visitMemberRef(int index, byte tag,
       
   148                              String className, String memberName, String signature,
       
   149                              int classNameIndex, int descriptorIndex) {
       
   150     // do nothing
       
   151   }
       
   152 
       
   153     public static final byte
       
   154       CONSTANT_None = 0,
       
   155       CONSTANT_Utf8 = 1,
       
   156       //CONSTANT_Unicode = 2,               /* unused */
       
   157       CONSTANT_Integer = 3,
       
   158       CONSTANT_Float = 4,
       
   159       CONSTANT_Long = 5,
       
   160       CONSTANT_Double = 6,
       
   161       CONSTANT_Class = 7,
       
   162       CONSTANT_String = 8,
       
   163       CONSTANT_Fieldref = 9,
       
   164       CONSTANT_Methodref = 10,
       
   165       CONSTANT_InterfaceMethodref = 11,
       
   166       CONSTANT_NameAndType = 12;
       
   167 
       
   168     private static String[] TAG_NAMES = {
       
   169         "Empty",
       
   170         "Utf8",
       
   171         null, //"Unicode",
       
   172         "Integer",
       
   173         "Float",
       
   174         "Long",
       
   175         "Double",
       
   176         "Class",
       
   177         "String",
       
   178         "Fieldref",
       
   179         "Methodref",
       
   180         "InterfaceMethodref",
       
   181         "NameAndType"
       
   182     };
       
   183 
       
   184     public static String tagName(byte tag) {
       
   185         String name = null;
       
   186         if ((tag & 0xFF) < TAG_NAMES.length)
       
   187             name = TAG_NAMES[tag];
       
   188         if (name == null)
       
   189             name = "Unknown#"+(tag&0xFF);
       
   190         return name;
       
   191     }
       
   192 }