Subject: Re: bug#43255: 28.0.50; feature/native-comp void-function subr-native-lambda-list

From: Andrea Corallo <[email-masked]>
Date: Tue, 08 Sep 2020 16:02:01 +0000

Eli Zaretskii <[email-masked]> writes:

>> From: Andrea Corallo <[email-masked]>
>> Cc: Stefan Kangas <[email-masked]>, [email-masked],
>>         [email-masked]
>> Date: Tue, 08 Sep 2020 14:54:31 +0000
>> 
>> >> AFAICT, when using the native-comp branch, Lisp files are automatically
>> >> compiled without me having to do anything.
>> >
>> > That'd be a misfeature, I think: it means that users who build their
>> > own Emacs will have their build take hours.  I'd prefer to have an
>> > option to delay native compilation to some later time, ideally have it
>> > JIT-compiled, like Guile does.
>> >
>> > Is this possible?
>> 
>> The only files that is mandatory to have compiled Ahead of Time are the
>> one dumped
>
> Why do these have to be compiled ahead of time?

Nothing technically prevents to have the native compiler at disposal on
a system that is entirely and exclusively byte compiled, is just a
configuration that ATM we do not expose (I think we'll do it).

It can be useful (actually *it is* every time the native compiler fails
to boo-strap) but is not something an average user would want to use.

>> That said I think what Stefan meant is precisely that compilation is
>> happening automatically Jit like with no user intervention.
>
> And that can be turned on and off as the user sees fit?  If so, that's
> why I said that the native-compilation part is not important to have
> in the version description, only in the set of supported features.

The user can turn deferred compilation off (by default is on).
According to this metric any feature that can be partially or completely
disabled is not worth to be mentioned there, even if is a rework of the
execution engine.  That's maybe correct, if you like to suggest a more
appropriate place to put this information that is evident to the user I
would be appreciated that.  I've opened #43269 to discuss this.

Thanks!

  Andrea