mcs/class/corlib/System/IntPtr.cs

   1 //
   2 // System.IntPtr.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // Maintainer:
   8 //       Michael Lambert, michaellambert@email.com
   9 //
  10 // (C) Ximian, Inc.  http://www.ximian.com
  11 //
  12 // Remarks:
  13 //   Requires '/unsafe' compiler option.  This class uses void*,
  14 //   in overloaded constructors, conversion, and cast members in
  15 //   the public interface.  Using pointers is not valid CLS and
  16 //   the methods in question have been marked with  the
  17 //   CLSCompliant attribute that avoid compiler warnings.
  18 //
  19 // FIXME: How do you specify a native int in C#?  I am going to have to do some figuring out
  20 //
  21
  22 //
  23 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  24 //
  25 // Permission is hereby granted, free of charge, to any person obtaining
  26 // a copy of this software and associated documentation files (the
  27 // "Software"), to deal in the Software without restriction, including
  28 // without limitation the rights to use, copy, modify, merge, publish,
  29 // distribute, sublicense, and/or sell copies of the Software, and to
  30 // permit persons to whom the Software is furnished to do so, subject to
  31 // the following conditions:
  32 //
  33 // The above copyright notice and this permission notice shall be
  34 // included in all copies or substantial portions of the Software.
  35 //
  36 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  37 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  38 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  39 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  40 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  41 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  42 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  43 //
  44
  45 using System.Globalization;
  46 using System.Runtime.Serialization;
  47
  48 #if NET_2_0
  49 using System.Runtime.ConstrainedExecution;
  50 #endif
  51
  52 namespace System
  53 {
  54         [Serializable]
  55 #if NET_2_0
  56         [System.Runtime.InteropServices.ComVisible (true)]
  57 #endif
  58         public unsafe struct IntPtr : ISerializable
  59         {
  60                 private void *m_value;
  61
  62                 public static readonly IntPtr Zero;
  63
  64 #if NET_2_0
  65                 [ReliabilityContract (Consistency.MayCorruptInstance, Cer.MayFail)]
  66 #endif
  67                 public IntPtr (int value)
  68                 {
  69                         m_value = (void *) value;
  70                 }
  71
  72 #if NET_2_0
  73                 [ReliabilityContract (Consistency.MayCorruptInstance, Cer.MayFail)]
  74 #endif
  75                 public IntPtr (long value)
  76                 {
  77                         /* FIXME: Needs to figure the exact check which works on all architectures */
  78                         /*
  79                         if (((value >> 32 > 0) || (value < 0)) && (IntPtr.Size < 8)) {
  80                                 throw new OverflowException (
  81                                         Locale.GetText ("This isn't a 64bits machine."));
  82                         }
  83                         */
  84
  85                         m_value = (void *) value;
  86                 }
  87
  88                 [CLSCompliant (false)]
  89 #if NET_2_0
  90                 [ReliabilityContract (Consistency.MayCorruptInstance, Cer.MayFail)]
  91 #endif
  92                 unsafe public IntPtr (void *value)
  93                 {
  94                         m_value = value;
  95                 }
  96
  97                 private IntPtr (SerializationInfo info, StreamingContext context)
  98                 {
  99                         long savedValue = info.GetInt64 ("value");
 100                         m_value = (void *) savedValue;
 101                 }
 102
 103                 public static int Size {
 104 #if NET_2_0
 105                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 106 #endif
 107                         get {
 108                                 return sizeof (void *);
 109                         }
 110                 }
 111
 112                 void ISerializable.GetObjectData (SerializationInfo info, StreamingContext context)
 113                 {
 114                         if (info == null)
 115                                 throw new ArgumentNullException ("info");
 116
 117                         info.AddValue ("value", ToInt64 ());
 118                 }
 119
 120                 public override bool Equals (object obj)
 121                 {
 122                         if (!(obj is System.IntPtr))
 123                                 return false;
 124
 125                         return ((IntPtr) obj).m_value == m_value;
 126                 }
 127
 128                 public override int GetHashCode ()
 129                 {
 130                         return (int) m_value;
 131                 }
 132
 133 #if NET_2_0
 134                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 135 #endif
 136                 public int ToInt32 ()
 137                 {
 138                         return (int) m_value;
 139                 }
 140
 141 #if NET_2_0
 142                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 143 #endif
 144                 public long ToInt64 ()
 145                 {
 146                         // pointer to long conversion is done using conv.u8 by the compiler
 147                         if (Size == 4)
 148                                 return (long)(int)m_value;
 149                         else
 150                                 return (long)m_value;
 151                 }
 152
 153                 [CLSCompliant (false)]
 154 #if NET_2_0
 155                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 156 #endif
 157                 unsafe public void *ToPointer ()
 158                 {
 159                         return m_value;
 160                 }
 161
 162                 override public string ToString ()
 163                 {
 164                         return ToString (null);
 165                 }
 166
 167 #if NET_2_0
 168                 public
 169 #endif
 170                 string ToString (string format)
 171                 {
 172                         if (Size == 4)
 173                                 return ((int) m_value).ToString (format);
 174                         else
 175                                 return ((long) m_value).ToString (format);
 176                 }
 177
 178 #if NET_2_0
 179                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 180 #endif
 181                 public static bool operator == (IntPtr value1, IntPtr value2)
 182                 {
 183                         return (value1.m_value == value2.m_value);
 184                 }
 185
 186 #if NET_2_0
 187                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 188 #endif
 189                 public static bool operator != (IntPtr value1, IntPtr value2)
 190                 {
 191                         return (value1.m_value != value2.m_value);
 192                 }
 193
 194 #if NET_2_0
 195                 [ReliabilityContractAttribute (Consistency.MayCorruptInstance, Cer.MayFail)]
 196 #endif
 197                 public static explicit operator IntPtr (int value)
 198                 {
 199                         return new IntPtr (value);
 200                 }
 201
 202 #if NET_2_0
 203                 [ReliabilityContractAttribute (Consistency.MayCorruptInstance, Cer.MayFail)]
 204 #endif
 205                 public static explicit operator IntPtr (long value)
 206                 {
 207                         return new IntPtr (value);
 208                 }
 209
 210 #if NET_2_0
 211                 [ReliabilityContractAttribute (Consistency.MayCorruptInstance, Cer.MayFail)]
 212 #endif
 213                 [CLSCompliant (false)]
 214                 unsafe public static explicit operator IntPtr (void *value)
 215                 {
 216                         return new IntPtr (value);
 217                 }
 218
 219                 public static explicit operator int (IntPtr value)
 220                 {
 221                         return (int) value.m_value;
 222                 }
 223
 224                 public static explicit operator long (IntPtr value)
 225                 {
 226                         return value.ToInt64 ();
 227                 }
 228
 229                 [CLSCompliant (false)]
 230                 unsafe public static explicit operator void * (IntPtr value)
 231                 {
 232                         return value.m_value;
 233                 }
 234         }
 235 }