1 /*

     2  * Copyright (c) 2007, 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.  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 

    27 package com.sun.tools.classfile;

    28 

    29 import java.io.IOException;

    30 

    31 /**

    32  * See JVMS, section 4.4.

    33  *

    34  *  <p><b>This is NOT part of any supported API.

    35  *  If you write code that depends on this, you do so at your own risk.

    36  *  This code and its internal interfaces are subject to change or

    37  *  deletion without notice.</b>

    38  */

    39 public class Descriptor {

    40     public static class InvalidDescriptor extends DescriptorException {

    41         private static final long serialVersionUID = 1L;

    42         InvalidDescriptor(String desc) {

    43             this.desc = desc;

    44             this.index = -1;

    45         }

    46 

    47         InvalidDescriptor(String desc, int index) {

    48             this.desc = desc;

    49             this.index = index;

    50         }

    51 

    52         @Override

    53         public String getMessage() {

    54             // i18n

    55             if (index == -1)

    56                 return "invalid descriptor \"" + desc + "\"";

    57             else

    58                 return "descriptor is invalid at offset " + index + " in \"" + desc + "\"";

    59         }

    60 

    61         public final String desc;

    62         public final int index;

    63 

    64     }

    65 

    66     public Descriptor(ClassReader cr) throws IOException {

    67         this(cr.readUnsignedShort());

    68     }

    69 

    70     public Descriptor(int index) {

    71         this.index = index;

    72 

    73     }

    74 

    75     public String getValue(ConstantPool constant_pool) throws ConstantPoolException {

    76         return constant_pool.getUTF8Value(index);

    77     }

    78 

    79     public int getParameterCount(ConstantPool constant_pool)

    80             throws ConstantPoolException, InvalidDescriptor {

    81         String desc = getValue(constant_pool);

    82         int end = desc.indexOf(")");

    83         if (end == -1)

    84             throw new InvalidDescriptor(desc);

    85         parse(desc, 0, end + 1);

    86         return count;

    87 

    88     }

    89 

    90     public String getParameterTypes(ConstantPool constant_pool)

    91             throws ConstantPoolException, InvalidDescriptor {

    92         String desc = getValue(constant_pool);

    93         int end = desc.indexOf(")");

    94         if (end == -1)

    95             throw new InvalidDescriptor(desc);

    96         return parse(desc, 0, end + 1);

    97     }

    98 

    99     public String getReturnType(ConstantPool constant_pool)

   100             throws ConstantPoolException, InvalidDescriptor {

   101         String desc = getValue(constant_pool);

   102         int end = desc.indexOf(")");

   103         if (end == -1)

   104             throw new InvalidDescriptor(desc);

   105         return parse(desc, end + 1, desc.length());

   106     }

   107 

   108     public String getFieldType(ConstantPool constant_pool)

   109             throws ConstantPoolException, InvalidDescriptor {

   110         String desc = getValue(constant_pool);

   111         return parse(desc, 0, desc.length());

   112     }

   113 

   114     private String parse(String desc, int start, int end)

   115             throws InvalidDescriptor {

   116         int p = start;

   117         StringBuilder sb = new StringBuilder();

   118         int dims = 0;

   119         count = 0;

   120 

   121         while (p < end) {

   122             String type;

   123             char ch;

   124             switch (ch = desc.charAt(p++)) {

   125                 case '(':

   126                     sb.append('(');

   127                     continue;

   128 

   129                 case ')':

   130                     sb.append(')');

   131                     continue;

   132 

   133                 case '[':

   134                     dims++;

   135                     continue;

   136 

   137                 case 'B':

   138                     type = "byte";

   139                     break;

   140 

   141                 case 'C':

   142                     type = "char";

   143                     break;

   144 

   145                 case 'D':

   146                     type = "double";

   147                     break;

   148 

   149                 case 'F':

   150                     type = "float";

   151                     break;

   152 

   153                 case 'I':

   154                     type = "int";

   155                     break;

   156 

   157                 case 'J':

   158                     type = "long";

   159                     break;

   160 

   161                 case 'L':

   162                     int sep = desc.indexOf(';', p);

   163                     if (sep == -1)

   164                         throw new InvalidDescriptor(desc, p - 1);

   165                     type = desc.substring(p, sep).replace('/', '.');

   166                     p = sep + 1;

   167                     break;

   168 

   169                 case 'S':

   170                     type = "short";

   171                     break;

   172 

   173                 case 'Z':

   174                     type = "boolean";

   175                     break;

   176 

   177                 case 'V':

   178                     type = "void";

   179                     break;

   180 

   181                 default:

   182                     throw new InvalidDescriptor(desc, p - 1);

   183             }

   184 

   185             if (sb.length() > 1 && sb.charAt(0) == '(')

   186                 sb.append(", ");

   187             sb.append(type);

   188             for ( ; dims > 0; dims-- )

   189                 sb.append("[]");

   190 

   191             count++;

   192         }

   193 

   194         return sb.toString();

   195     }

   196 

   197     public final int index;

   198     private int count;

   199 }