2 // System.Diagnostics.Contracts.Internal.ContractHelper.cs
5 // Chris Bacon (chrisbacon76@gmail.com)
7 // Copyright 2010 Novell (http://www.novell.com)
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 #if NET_4_0 || MOONLIGHT
33 using System.Runtime.ConstrainedExecution;
35 namespace System.Diagnostics.Contracts.Internal
37 public static class ContractHelper
39 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
41 public static string RaiseContractFailedEvent (ContractFailureKind failureKind, string userMessage, string conditionText, Exception innerException)
44 StringBuilder msg = new StringBuilder (60);
45 switch (failureKind) {
46 case ContractFailureKind.Assert:
47 msg.Append ("Assertion failed");
49 case ContractFailureKind.Assume:
50 msg.Append ("Assumption failed");
52 case ContractFailureKind.Invariant:
53 msg.Append ("Invariant failed");
55 case ContractFailureKind.Postcondition:
56 msg.Append ("Postcondition failed");
58 case ContractFailureKind.PostconditionOnException:
59 msg.Append ("Postcondition failed after throwing an exception");
61 case ContractFailureKind.Precondition:
62 msg.Append ("Precondition failed");
65 throw new NotSupportedException ("Not supported: " + failureKind);
67 if (conditionText != null) {
69 msg.Append (conditionText);
73 if (userMessage != null) {
75 msg.Append (userMessage);
77 string msgString = msg.ToString ();
79 Exception handlerException = null;
80 bool unwind = false, handled = false;
82 var contractFailed = Contract.InternalContractFailedEvent;
83 if (contractFailed != null) {
84 // Execute all event handlers
85 var handlers = contractFailed.GetInvocationList ();
86 var e = new ContractFailedEventArgs (failureKind, msgString, conditionText, innerException);
87 foreach (var handler in handlers) {
89 handler.DynamicInvoke (null, e);
90 } catch (Exception ex) {
92 // If multiple handlers throw an exception then the specification states that it
93 // is undetermined which one becomes the InnerException.
94 handlerException = ex.InnerException;
102 Exception ex = innerException ?? handlerException;
103 throw new ContractException (msgString, failureKind, conditionText, userMessage, ex);
106 return handled ? null : msgString;
109 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
110 [DebuggerNonUserCode]
111 public static void TriggerFailure (ContractFailureKind kind, string displayMessage, string userMessage, string conditionText, Exception innerException)
113 StringBuilder msg = new StringBuilder (50);
115 if (conditionText != null) {
116 msg.Append ("Expression: ");
117 msg.AppendLine (conditionText);
119 msg.Append ("Description: ");
120 if (displayMessage != null) {
121 msg.Append (displayMessage);
124 if (Environment.UserInteractive) {
125 // FIXME: This should trigger an assertion.
126 // But code will never get here at the moment, as Environment.UserInteractive currently
127 // always returns false.
128 throw new ContractShouldAssertException (msg.ToString ());
130 // Note that FailFast() currently throws a NotImplementedException()
131 Environment.FailFast(msg.ToString()/*, new ExecutionEngineException()*/);