mcs/class/corlib/System.Diagnostics.Contracts/Contract.cs

   1 //
   2 // System.Diagnostics.Contracts.Contract.cs
   3 //
   4 // Authors:
   5 //    Miguel de Icaza (miguel@gnome.org)
   6 //    Chris Bacon (chrisbacon76@gmail.com)
   7 //    Marek Safar (marek.safar@gmail.com)
   8 //
   9 // Copyright 2009, 2010 Novell (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 #if NET_4_0 || MOONLIGHT
  32
  33 using System;
  34 using System.Collections.Generic;
  35 using System.Diagnostics.Contracts.Internal;
  36 using System.Runtime.ConstrainedExecution;
  37
  38 namespace System.Diagnostics.Contracts
  39 {
  40         public static class Contract
  41         {
  42                 public static event EventHandler<ContractFailedEventArgs> ContractFailed;
  43
  44                 // Used in test
  45                 internal static EventHandler<ContractFailedEventArgs> InternalContractFailedEvent {
  46                         get { return ContractFailed; }
  47                 }
  48
  49                 // Used in test
  50                 internal static Type GetContractExceptionType ()
  51                 {
  52                         return typeof (ContractException);
  53                 }
  54
  55                 // Used in test
  56                 internal static Type GetContractShouldAssertExceptionType ()
  57                 {
  58                         return typeof (ContractShouldAssertException);
  59                 }
  60
  61                 static void ReportFailure (ContractFailureKind kind, string userMessage, string conditionText, Exception innerException)
  62                 {
  63                         string msg = ContractHelper.RaiseContractFailedEvent (kind, userMessage, conditionText, innerException);
  64                         // if msg is null, then it has been handled already, so don't do anything here
  65                         if (msg != null)
  66                                 ContractHelper.TriggerFailure (kind, msg, userMessage, conditionText, innerException);
  67                 }
  68
  69                 static void AssertMustUseRewriter (ContractFailureKind kind, string message)
  70                 {
  71                         ContractHelper.TriggerFailure (kind, "Assembly must be re-written by the code contract rewritter", null, message, null);
  72                 }
  73
  74                 [ConditionalAttribute("CONTRACTS_FULL")]
  75                 [ConditionalAttribute("DEBUG")]
  76                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
  77                 public static void Assert (bool condition)
  78                 {
  79                         if (condition)
  80                                 return;
  81
  82                         ReportFailure (ContractFailureKind.Assert, null, null, null);
  83                 }
  84
  85                 [ConditionalAttribute("DEBUG")]
  86                 [ConditionalAttribute("CONTRACTS_FULL")]
  87                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
  88                 public static void Assert (bool condition, string userMessage)
  89                 {
  90                         if (condition)
  91                                 return;
  92
  93                         ReportFailure (ContractFailureKind.Assert, userMessage, null, null);
  94                 }
  95
  96                 [ConditionalAttribute("DEBUG")]
  97                 [ConditionalAttribute("CONTRACTS_FULL")]
  98                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
  99                 public static void Assume(bool condition)
 100                 {
 101                         // At runtime, this behaves like assert
 102                         if (condition)
 103                                 return;
 104
 105                         ReportFailure (ContractFailureKind.Assume, null, null, null);
 106                 }
 107
 108                 [ConditionalAttribute("CONTRACTS_FULL")]
 109                 [ConditionalAttribute("DEBUG")]
 110                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 111                 public static void Assume (bool condition, string userMessage)
 112                 {
 113                         // At runtime, this behaves like assert
 114                         if (condition)
 115                                 return;
 116
 117                         ReportFailure (ContractFailureKind.Assume, userMessage, null, null);
 118                 }
 119
 120                 [ConditionalAttribute("CONTRACTS_FULL")]
 121                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 122                 public static void EndContractBlock ()
 123                 {
 124                         // Marker method, no code required.
 125                 }
 126
 127                 [ConditionalAttribute("CONTRACTS_FULL")]
 128                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 129                 public static void Ensures (bool condition)
 130                 {
 131                         AssertMustUseRewriter (ContractFailureKind.Postcondition, "Contract.Ensures");
 132                 }
 133
 134                 [ConditionalAttribute("CONTRACTS_FULL")]
 135                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 136                 public static void Ensures (bool condition, string userMessage)
 137                 {
 138                         AssertMustUseRewriter (ContractFailureKind.Postcondition, "Contract.Ensures");
 139                 }
 140
 141                 [ConditionalAttribute("CONTRACTS_FULL")]
 142                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 143                 public static void EnsuresOnThrow<TException> (bool condition) where TException : Exception
 144                 {
 145                         AssertMustUseRewriter (ContractFailureKind.Postcondition, "Contract.EnsuresOnThrow");
 146                 }
 147
 148                 [ConditionalAttribute("CONTRACTS_FULL")]
 149                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 150                 public static void EnsuresOnThrow<TException> (bool condition, string userMessage) where TException : Exception
 151                 {
 152                         AssertMustUseRewriter (ContractFailureKind.Postcondition, "Contract.EnsuresOnThrow");
 153                 }
 154
 155                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 156                 public static bool Exists<T> (IEnumerable<T> collection, Predicate<T> predicate)
 157                 {
 158                         if (predicate == null)
 159                                 throw new ArgumentNullException ("predicate");
 160                         if (collection == null)
 161                                 throw new ArgumentNullException ("collection");
 162
 163                         foreach (var t in collection)
 164                                 if (predicate (t))
 165                                         return true;
 166                         return false;
 167                 }
 168
 169                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 170                 public static bool Exists (int fromInclusive, int toExclusive, Predicate<int> predicate)
 171                 {
 172                         if (predicate == null)
 173                                 throw new ArgumentNullException ("predicate");
 174                         if (toExclusive < fromInclusive)
 175                                 throw new ArgumentException ("toExclusitve < fromInclusive");
 176
 177                         for (int i = fromInclusive; i < toExclusive; i++)
 178                                 if (predicate (i))
 179                                         return true;
 180
 181                         return false;
 182                 }
 183
 184                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 185                 public static bool ForAll<T> (IEnumerable<T> collection, Predicate<T> predicate)
 186                 {
 187                         if (predicate == null)
 188                                 throw new ArgumentNullException ("predicate");
 189                         if (collection == null)
 190                                 throw new ArgumentNullException ("collection");
 191
 192                         foreach (var t in collection)
 193                                 if (!predicate (t))
 194                                         return false;
 195
 196                         return true;
 197                 }
 198
 199                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 200                 public static bool ForAll (int fromInclusive, int toExclusive, Predicate<int> predicate)
 201                 {
 202                         if (predicate == null)
 203                                 throw new ArgumentNullException ("predicate");
 204                         if (toExclusive < fromInclusive)
 205                                 throw new ArgumentException ("toExclusitve < fromInclusive");
 206
 207                         for (int i = fromInclusive; i < toExclusive; i++)
 208                                 if (!predicate (i))
 209                                         return false;
 210
 211                         return true;
 212                 }
 213
 214                 [ConditionalAttribute("CONTRACTS_FULL")]
 215                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 216                 public static void Invariant (bool condition)
 217                 {
 218                         AssertMustUseRewriter (ContractFailureKind.Invariant, "Contract.Invariant");
 219                 }
 220
 221                 [ConditionalAttribute("CONTRACTS_FULL")]
 222                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 223                 public static void Invariant (bool condition, string userMessage)
 224                 {
 225                         AssertMustUseRewriter (ContractFailureKind.Invariant, "Contract.Invariant");
 226                 }
 227
 228                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 229                 public static T OldValue<T> (T value)
 230                 {
 231                         // Marker method, no code required.
 232                         return default (T);
 233                 }
 234
 235                 [ConditionalAttribute("CONTRACTS_FULL")]
 236                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 237                 public static void Requires (bool condition)
 238                 {
 239                         AssertMustUseRewriter (ContractFailureKind.Precondition, "Contract.Requires");
 240                 }
 241
 242                 [ConditionalAttribute("CONTRACTS_FULL")]
 243                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 244                 public static void Requires (bool condition, string userMessage)
 245                 {
 246                         AssertMustUseRewriter (ContractFailureKind.Precondition, "Contract.Requires");
 247                 }
 248
 249                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 250                 public static void Requires<TException> (bool condition) where TException : Exception
 251                 {
 252                         AssertMustUseRewriter (ContractFailureKind.Precondition, "Contract.Requires<TException>");
 253                 }
 254
 255                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 256                 public static void Requires<TException> (bool condition, string userMessage) where TException : Exception
 257                 {
 258                         AssertMustUseRewriter (ContractFailureKind.Precondition, "Contract.Requires<TException>");
 259                 }
 260
 261                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 262                 public static T Result<T> ()
 263                 {
 264                         // Marker method, no code required.
 265                         return default (T);
 266                 }
 267
 268                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 269                 public static T ValueAtReturn<T> (out T value)
 270                 {
 271                         // Marker method, no code required.
 272                         return value = default (T);
 273                 }
 274         }
 275 }
 276
 277 #endif