Re: [RFC 0/6] Regressions for "imply" behavior change

From: Geert Uytterhoeven
Date: Fri Apr 10 2020 - 03:26:54 EST


Hi Saeed,

On Fri, Apr 10, 2020 at 4:41 AM Saeed Mahameed <saeedm@xxxxxxxxxxxx> wrote:
> On Thu, 2020-04-09 at 11:41 +0300, Jani Nikula wrote:
> > For example, you have two graphics drivers, one builtin and another
> > module. Then you have backlight as a module. Using IS_REACHABLE(),
> > backlight would work in one driver, but not the other. I'm sure there
> > is
> > the oddball person who finds this desirable, but the overwhelming
> > majority would just make the deps such that either you make all of
> > them
> > modules, or also require backlight to be builtin.
>
> the previous imply semantics handled this by forcing backlight to be
> built-in, which worked nicely.

Which may have worked fine for backlight, but not for other symbols
with dependencies that are not always met.

=> Use "select" to enable something unconditionally, but this can only
be used if the target's dependencies are met.
=> Use "imply" to enable an optional feature conditionally.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds