Remove unnecessary finalizer

[sharwell]

Diagnostic

A common mistake when implementing IDisposable is including an unnecessary finalizer. The proposed diagnostic would identify finalizers with the following form:

~ClassName()
{
    Dispose(false);
}

It would then examine the methods called by Dispose(bool) method within that class.

1. Ignore any block of code guarded by if (disposing), where disposing is the first parameter to Dispose(bool).
2. Ignore any call to IDisposable.Dispose.

If any method calls are remaining after the above steps, do not report the diagnostic.

The message reported by the diagnostic might have the name UnnecessaryFinalizer and a message like the following:

Unnecessary user-defined finalizers should be removed.

Code Fix

The code fix for the above diagnostic is to simply remove the user-defined finalizer.