PostSharp: How to mix semantic and non-semantic advising?

Question

For example I have OnMethodBoundaryAspect logger which I apply to iterator method:

public override void OnEntry(MethodExecutionArgs args) {
    BeginMethodScope( args );
    Logger.LogRequestEntry();
}

public override void OnSuccess(MethodExecutionArgs args) {
    Logger.LogRequestSuccess();
}

public override void OnException(MethodExecutionArgs args) {
    Logger.LogRequestError( args.Exception );
}

public override void OnExit(MethodExecutionArgs args) {
    EndMethodScope( args );
}

If I use semantic advising:

• OnEntry is invoked when IEnumerable is started.
• OnExit is invoked when IEnumerable is finished.

If I use non-semantic advising:

• OnEntry/OnExit is invoked before/after creation of IEnumerable.

But what if I want to use both ways at once? Because I want to log the method call itself (not iteration starting).

Maybe I can achieve this with low-level advices?

Answer 1

Yes, you can achieve this by creating two groups of advices within the same aspect, as shown in the example below.

[PSerializable]
public class MyAspect : MethodLevelAspect
{
    [OnMethodEntryAdvice(SemanticallyAdvisedMethodKinds = SemanticallyAdvisedMethodKinds.None)]
    [AdviceDependency(AspectDependencyAction.Order, AspectDependencyPosition.Before, nameof(OnEntrySemantic))]
    [SelfPointcut]
    public void OnEntry( MethodExecutionArgs args )
    {
        Console.WriteLine("OnEntry");
    }

    [OnMethodExitAdvice( Master = nameof( OnEntry ) )]
    public void OnExit( MethodExecutionArgs args )
    {
        Console.WriteLine( "OnExit" );
    }

    [OnMethodEntryAdvice]
    [SelfPointcut]
    public void OnEntrySemantic( MethodExecutionArgs args )
    {
        Console.WriteLine( "OnEntrySemantic" );
    }

    [OnMethodExitAdvice( Master = nameof( OnEntrySemantic ) )]
    public void OnExitSemantic( MethodExecutionArgs args )
    {
        Console.WriteLine( "OnExitSemantic" );
    }
}

P.S. The current version of PostSharp will emit a build-time warning for the example above. This is due to a bug that should be fixed in one of the upcoming releases. The run-time behavior of the aspect is not affected.