mcs/class/referencesource/mscorlib/system/reflection/mdconstant.cs

   1 // ==++==
   2 //
   3 //   Copyright(c) Microsoft Corporation.  All rights reserved.
   4 //
   5 // ==--==
   6 // <OWNER>Microsoft</OWNER>
   7 //
   8
   9 namespace System.Reflection
  10 {
  11     using System;
  12
  13     internal static class MdConstant
  14     {
  15         [System.Security.SecurityCritical]  // auto-generated
  16         public static unsafe Object GetValue(MetadataImport scope, int token, RuntimeTypeHandle fieldTypeHandle, bool raw)
  17         {
  18             CorElementType corElementType = 0;
  19             long buffer = 0;
  20             int length;
  21             String stringVal;
  22
  23             stringVal = scope.GetDefaultValue(token, out buffer, out length, out corElementType);
  24
  25             RuntimeType fieldType = fieldTypeHandle.GetRuntimeType();
  26
  27             if (fieldType.IsEnum && raw == false)
  28             {
  29                 long defaultValue = 0;
  30
  31                 switch (corElementType)
  32                 {
  33                     #region Switch
  34
  35                     case CorElementType.Void:
  36                         return DBNull.Value;
  37
  38                     case CorElementType.Char:
  39                         defaultValue = *(char*)&buffer;
  40                         break;
  41
  42                     case CorElementType.I1:
  43                         defaultValue = *(sbyte*)&buffer;
  44                         break;
  45
  46                     case CorElementType.U1:
  47                         defaultValue = *(byte*)&buffer;
  48                         break;
  49
  50                     case CorElementType.I2:
  51                         defaultValue = *(short*)&buffer;
  52                         break;
  53
  54                     case CorElementType.U2:
  55                         defaultValue = *(ushort*)&buffer;
  56                         break;
  57
  58                     case CorElementType.I4:
  59                         defaultValue = *(int*)&buffer;
  60                         break;
  61
  62                     case CorElementType.U4:
  63                         defaultValue = *(uint*)&buffer;
  64                         break;
  65
  66                     case CorElementType.I8:
  67                         defaultValue = buffer;
  68                         break;
  69
  70                     case CorElementType.U8:
  71                         defaultValue = buffer;
  72                         break;
  73
  74                     default:
  75                         throw new FormatException(Environment.GetResourceString("Arg_BadLiteralFormat"));
  76                     #endregion
  77                 }
  78
  79                 return RuntimeType.CreateEnum(fieldType, defaultValue);
  80             }
  81             else if (fieldType == typeof(DateTime))
  82             {
  83                 long defaultValue = 0;
  84
  85                 switch (corElementType)
  86                 {
  87                     #region Switch
  88
  89                     case CorElementType.Void:
  90                         return DBNull.Value;
  91
  92                     case CorElementType.I8:
  93                         defaultValue = buffer;
  94                         break;
  95
  96                     case CorElementType.U8:
  97                         defaultValue = buffer;
  98                         break;
  99
 100                     default:
 101                         throw new FormatException(Environment.GetResourceString("Arg_BadLiteralFormat"));
 102                     #endregion
 103                 }
 104
 105                 return new DateTime(defaultValue);
 106             }
 107             else
 108             {
 109                 switch (corElementType)
 110                 {
 111                     #region Switch
 112
 113                     case CorElementType.Void:
 114                         return DBNull.Value;
 115
 116                     case CorElementType.Char:
 117                         return *(char*)&buffer;
 118
 119                     case CorElementType.I1:
 120                         return *(sbyte*)&buffer;
 121
 122                     case CorElementType.U1:
 123                         return *(byte*)&buffer;
 124
 125                     case CorElementType.I2:
 126                         return *(short*)&buffer;
 127
 128                     case CorElementType.U2:
 129                         return *(ushort*)&buffer;
 130
 131                     case CorElementType.I4:
 132                         return *(int*)&buffer;
 133
 134                     case CorElementType.U4:
 135                         return *(uint*)&buffer;
 136
 137                     case CorElementType.I8:
 138                         return buffer;
 139
 140                     case CorElementType.U8:
 141                         return (ulong)buffer;
 142
 143                     case CorElementType.Boolean :
 144                         // The boolean value returned from the metadata engine is stored as a
 145                         // BOOL, which actually maps to an int. We need to read it out as an int
 146                         // to avoid problems on big-endian machines.
 147                         return (*(int*)&buffer != 0);
 148
 149                     case CorElementType.R4 :
 150                         return *(float*)&buffer;
 151
 152                     case CorElementType.R8:
 153                         return *(double*)&buffer;
 154
 155                     case CorElementType.String:
 156                         // A string constant can be empty but never null.
 157                         // A nullref constant can only be type CorElementType.Class.
 158                         return stringVal == null ? String.Empty : stringVal;
 159
 160                     case CorElementType.Class:
 161                         return null;
 162
 163                     default:
 164                         throw new FormatException(Environment.GetResourceString("Arg_BadLiteralFormat"));
 165                     #endregion
 166                 }
 167             }
 168         }
 169     }
 170
 171 }