1 /*

     2  * Copyright (c) 2003, 2015, 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.reflect;

    27 

    28 import java.lang.reflect.*;

    29 

    30 /** Provides reflective access to the constant pools of classes.

    31     Currently this is needed to provide reflective access to annotations

    32     but may be used by other internal subsystems in the future. */

    33 

    34 public class ConstantPool {

    35   // Number of entries in this constant pool (= maximum valid constant pool index)

    36   public int      getSize()                      { return getSize0            (constantPoolOop);        }

    37   public Class<?> getClassAt         (int index) { return getClassAt0         (constantPoolOop, index); }

    38   public Class<?> getClassAtIfLoaded (int index) { return getClassAtIfLoaded0 (constantPoolOop, index); }

    39   // Returns a class reference index for a method or a field.

    40   public int getClassRefIndexAt(int index) {

    41       return getClassRefIndexAt0(constantPoolOop, index);

    42   }

    43   // Returns either a Method or Constructor.

    44   // Static initializers are returned as Method objects.

    45   public Member   getMethodAt        (int index) { return getMethodAt0        (constantPoolOop, index); }

    46   public Member   getMethodAtIfLoaded(int index) { return getMethodAtIfLoaded0(constantPoolOop, index); }

    47   public Field    getFieldAt         (int index) { return getFieldAt0         (constantPoolOop, index); }

    48   public Field    getFieldAtIfLoaded (int index) { return getFieldAtIfLoaded0 (constantPoolOop, index); }

    49   // Fetches the class name, member (field, method or interface

    50   // method) name, and type descriptor as an array of three Strings

    51   public String[] getMemberRefInfoAt (int index) { return getMemberRefInfoAt0 (constantPoolOop, index); }

    52   // Returns a name and type reference index for a method, a field or an invokedynamic.

    53   public int getNameAndTypeRefIndexAt(int index) {

    54       return getNameAndTypeRefIndexAt0(constantPoolOop, index);

    55   }

    56   // Fetches the name and type from name_and_type index as an array of two Strings

    57   public String[] getNameAndTypeRefInfoAt(int index) {

    58       return getNameAndTypeRefInfoAt0(constantPoolOop, index);

    59   }

    60   public int      getIntAt           (int index) { return getIntAt0           (constantPoolOop, index); }

    61   public long     getLongAt          (int index) { return getLongAt0          (constantPoolOop, index); }

    62   public float    getFloatAt         (int index) { return getFloatAt0         (constantPoolOop, index); }

    63   public double   getDoubleAt        (int index) { return getDoubleAt0        (constantPoolOop, index); }

    64   public String   getStringAt        (int index) { return getStringAt0        (constantPoolOop, index); }

    65   public String   getUTF8At          (int index) { return getUTF8At0          (constantPoolOop, index); }

    66   public Tag getTagAt(int index) {

    67       return Tag.valueOf(getTagAt0(constantPoolOop, index));

    68   }

    69 

    70   public static enum Tag {

    71       UTF8(1),

    72       INTEGER(3),

    73       FLOAT(4),

    74       LONG(5),

    75       DOUBLE(6),

    76       CLASS(7),

    77       STRING(8),

    78       FIELDREF(9),

    79       METHODREF(10),

    80       INTERFACEMETHODREF(11),

    81       NAMEANDTYPE(12),

    82       METHODHANDLE(15),

    83       METHODTYPE(16),

    84       INVOKEDYNAMIC(18),

    85       INVALID(0);

    86 

    87       private final int tagCode;

    88 

    89       private Tag(int tagCode) {

    90           this.tagCode = tagCode;

    91       }

    92 

    93       private static Tag valueOf(byte v) {

    94           for (Tag tag : Tag.values()) {

    95               if (tag.tagCode == v) {

    96                   return tag;

    97               }

    98           }

    99           throw new IllegalArgumentException("Unknown constant pool tag code " + v);

   100       }

   101    }

   102   //---------------------------------------------------------------------------

   103   // Internals only below this point

   104   //

   105 

   106   static {

   107       Reflection.registerFieldsToFilter(ConstantPool.class, new String[] { "constantPoolOop" });

   108   }

   109 

   110   // HotSpot-internal constant pool object (set by the VM, name known to the VM)

   111   private Object constantPoolOop;

   112 

   113   private native int      getSize0            (Object constantPoolOop);

   114   private native Class<?> getClassAt0         (Object constantPoolOop, int index);

   115   private native Class<?> getClassAtIfLoaded0 (Object constantPoolOop, int index);

   116   private native int      getClassRefIndexAt0 (Object constantPoolOop, int index);

   117   private native Member   getMethodAt0        (Object constantPoolOop, int index);

   118   private native Member   getMethodAtIfLoaded0(Object constantPoolOop, int index);

   119   private native Field    getFieldAt0         (Object constantPoolOop, int index);

   120   private native Field    getFieldAtIfLoaded0 (Object constantPoolOop, int index);

   121   private native String[] getMemberRefInfoAt0 (Object constantPoolOop, int index);

   122   private native int      getNameAndTypeRefIndexAt0(Object constantPoolOop, int index);

   123   private native String[] getNameAndTypeRefInfoAt0(Object constantPoolOop, int index);

   124   private native int      getIntAt0           (Object constantPoolOop, int index);

   125   private native long     getLongAt0          (Object constantPoolOop, int index);

   126   private native float    getFloatAt0         (Object constantPoolOop, int index);

   127   private native double   getDoubleAt0        (Object constantPoolOop, int index);

   128   private native String   getStringAt0        (Object constantPoolOop, int index);

   129   private native String   getUTF8At0          (Object constantPoolOop, int index);

   130   private native byte     getTagAt0           (Object constantPoolOop, int index);

   131 }