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.
33 using System.Reflection;
34 using System.Runtime.ConstrainedExecution;
35 using System.Diagnostics.Contracts;
36 using System.Diagnostics;
38 namespace System.Runtime.CompilerServices
40 public static class ContractHelper
42 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.MayFail)]
44 public static string RaiseContractFailedEvent (ContractFailureKind failureKind, string userMessage, string conditionText, Exception innerException)
47 StringBuilder msg = new StringBuilder (60);
48 switch (failureKind) {
49 case ContractFailureKind.Assert:
50 msg.Append ("Assertion failed");
52 case ContractFailureKind.Assume:
53 msg.Append ("Assumption failed");
55 case ContractFailureKind.Invariant:
56 msg.Append ("Invariant failed");
58 case ContractFailureKind.Postcondition:
59 msg.Append ("Postcondition failed");
61 case ContractFailureKind.PostconditionOnException:
62 msg.Append ("Postcondition failed after throwing an exception");
64 case ContractFailureKind.Precondition:
65 msg.Append ("Precondition failed");
68 throw new NotSupportedException ("Not supported: " + failureKind);
70 if (conditionText != null) {
72 msg.Append (conditionText);
76 if (userMessage != null) {
78 msg.Append (userMessage);
80 string msgString = msg.ToString ();
82 Exception handlerException = null;
83 bool unwind = false, handled = false;
85 var contractFailed = Contract.InternalContractFailedEvent;
86 if (contractFailed != null) {
87 // Execute all event handlers
88 var handlers = contractFailed.GetInvocationList ();
89 var e = new ContractFailedEventArgs (failureKind, msgString, conditionText, innerException);
90 foreach (var handler in handlers) {
92 handler.DynamicInvoke (null, e);
93 } catch (Exception ex) {
95 // If multiple handlers throw an exception then the specification states that it
96 // is undetermined which one becomes the InnerException.
97 handlerException = ex.InnerException;
105 Exception ex = innerException ?? handlerException;
106 throw new ContractException (msgString, failureKind, conditionText, userMessage, ex);
109 return handled ? null : msgString;
112 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
113 [DebuggerNonUserCode]
114 public static void TriggerFailure (ContractFailureKind kind, string displayMessage, string userMessage, string conditionText, Exception innerException)
116 StringBuilder msg = new StringBuilder (50);
118 if (conditionText != null) {
119 msg.Append ("Expression: ");
120 msg.AppendLine (conditionText);
122 msg.Append ("Description: ");
123 if (displayMessage != null) {
124 msg.Append (displayMessage);
126 if (Environment.UserInteractive) {
127 // FIXME: This should trigger an assertion.
128 // But code will never get here at the moment, as Environment.UserInteractive currently
129 // always returns false.
130 throw new ContractShouldAssertException (msg.ToString ());
132 // Note that FailFast() currently throws a NotImplementedException()
133 Environment.FailFast(msg.ToString()/*, new ExecutionEngineException()*/);