Jo Shields a575963da9 Imported Upstream version 3.6.0
Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14
2014-08-13 10:39:27 +01:00

142 lines
4.6 KiB
C#

//
// ContractHelper.cs
//
// Authors:
// Chris Bacon (chrisbacon76@gmail.com)
//
// Copyright 2010 Novell (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
#if NET_4_5
using System;
using System.Text;
using System.Reflection;
using System.Runtime.ConstrainedExecution;
using System.Diagnostics.Contracts;
using System.Diagnostics;
namespace System.Runtime.CompilerServices
{
public static class ContractHelper
{
[ReliabilityContract (Consistency.WillNotCorruptState, Cer.MayFail)]
[DebuggerNonUserCode]
public static string RaiseContractFailedEvent (ContractFailureKind failureKind, string userMessage, string conditionText, Exception innerException)
{
StringBuilder msg = new StringBuilder (60);
switch (failureKind) {
case ContractFailureKind.Assert:
msg.Append ("Assertion failed");
break;
case ContractFailureKind.Assume:
msg.Append ("Assumption failed");
break;
case ContractFailureKind.Invariant:
msg.Append ("Invariant failed");
break;
case ContractFailureKind.Postcondition:
msg.Append ("Postcondition failed");
break;
case ContractFailureKind.PostconditionOnException:
msg.Append ("Postcondition failed after throwing an exception");
break;
case ContractFailureKind.Precondition:
msg.Append ("Precondition failed");
break;
default:
throw new NotSupportedException ("Not supported: " + failureKind);
}
if (conditionText != null) {
msg.Append (": ");
msg.Append (conditionText);
} else {
msg.Append ('.');
}
if (userMessage != null) {
msg.Append (" ");
msg.Append (userMessage);
}
string msgString = msg.ToString ();
Exception handlerException = null;
bool unwind = false, handled = false;
var contractFailed = Contract.InternalContractFailedEvent;
if (contractFailed != null) {
// Execute all event handlers
var handlers = contractFailed.GetInvocationList ();
var e = new ContractFailedEventArgs (failureKind, msgString, conditionText, innerException);
foreach (var handler in handlers) {
try {
handler.DynamicInvoke (null, e);
} catch (Exception ex) {
e.SetUnwind ();
// If multiple handlers throw an exception then the specification states that it
// is undetermined which one becomes the InnerException.
handlerException = ex.InnerException;
}
}
unwind = e.Unwind;
handled = e.Handled;
}
if (unwind) {
Exception ex = innerException ?? handlerException;
throw new ContractException (msgString, failureKind, conditionText, userMessage, ex);
}
return handled ? null : msgString;
}
[ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
[DebuggerNonUserCode]
public static void TriggerFailure (ContractFailureKind kind, string displayMessage, string userMessage, string conditionText, Exception innerException)
{
StringBuilder msg = new StringBuilder (50);
if (conditionText != null) {
msg.Append ("Expression: ");
msg.AppendLine (conditionText);
}
msg.Append ("Description: ");
if (displayMessage != null) {
msg.Append (displayMessage);
}
if (Environment.UserInteractive) {
// FIXME: This should trigger an assertion.
// But code will never get here at the moment, as Environment.UserInteractive currently
// always returns false.
throw new ContractShouldAssertException (msg.ToString ());
} else {
// Note that FailFast() currently throws a NotImplementedException()
Environment.FailFast(msg.ToString()/*, new ExecutionEngineException()*/);
}
}
}
}
#endif