Comment by expede
10 hours ago
(Author here). Early in development I did exactly this with a macro. It was confusing when you wanted to refactor the code to change lock orders, harder to make clear error messages, and so on. Forcing the user to assign in a level means that it's clear(er?) to users what's happening, we don't need fancy (and difficult to debug) macro magic, and users can still do the linearisation themselves. That's the HOPE at least.
IMO compile time locking levels should be preferred whenever possible... but the biggest problem with compile time levels is that they, well, check at compile time. If you need to make mutexes at runtime (eg mange exclusive access to documents uploaded to a server by users) then you need to be able to safely acquire those too (provided in surelock with LockSet).
I can definitely believe explicit levels has more actionable errors. Type-shenaniganry without identifiable names can be pretty awful to unravel.
On that note though, I haven't found a whole lot of documentation or blog posts around trying to make better errors in macros or other compile-time checks. Have you looked at that/do you know of any decent detailed sources? I haven't looked too hard yet, but also I just don't have any good place to start, and Google's kind of garbage at the moment.