bug#66706: [PATCH] Automatic elisp dialect insertion

[Jim Porter]

On 10/25/2023 12:09 PM, Mattias Engdegård wrote:
> Only now do we have a compiler warning telling them, which is only effective if 
> (a) people recompile their code when they upgrade Emacs (which they don't need 
> to do because we are almost too good at .elc backward compatibility, and some 
> run their code interpreted all the time) and (b) they look at at the warning 
> and decide to take action.

Assuming we don't want to flip the default for 'lexical-binding' just 
yet, would it be possible to warn the user any time they load 
interpreted code that uses dynamic binding?

We could potentially do the same for .elc files that were implicitly 
compiled with dynamic binding (i.e. without a "lexical-binding: nil" 
cookie), but in my opinion it would suffice to warn users when they 
recompile that file. There's nothing I'm aware of that makes the 
dynamically-bound .elc *wrong*; it's just not preferred, and one day, 
you might get a lexically-bound .elc instead.

Or we could just flip the default now.

- Jim