Re: maturity levels: a first pass

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

Robert P. J. Day wrote:
> +	  This feature gives you the ability to de-select entire sets of
> +	  kernel features based on how they've been tagged with the
> +	  "maturity" directive.

Why expose the end-user to implementation details like "been tagged with
the 'maturity' directive"?

...
> +config MATURITY_DEPRECATED
> +	bool "Display DEPRECATED features."
...

Maybe you rather want

	bool "Allow to select DEPRECATED features."

because MATURITY_DEPRECATED=N probably means "Do not allow to select
DEPRECATED features" which implies that deprecated features will be
deselected.  In your wording, MATURITY_DEPRECATED=N would be just "Do
not display DEPRECATED features" which is probably less than what you
want it to be.

That said, I don't know if the approach is going into the right
direction.  For example, the way you are starting it requires updates to
all Kconfig UIs/scripts, to work correctly.  Otherwise, users could
select ACTIVATE_MATURITY but the tags would still be ignored.

Another approach could be to
  - continue to use "config EXPERIMENTAL" and "depends on EXPERIMENTAL"
    and extend it for OBSOLETE, and if you cannot resist, for
    DEPRECATED,
  - extend interactive UIs like xconfig and menuconfig and oldconfig to
    display an EXPERIMENTAL sign alongside the title of an option
    which depends on EXPERIMENTAL,
  - delete occurrences of the string EXPERIMENTAL from titles of options
    and help texts,
  - vice versa for OBSOLETE, and if you cannot resist, for
    DEPRECATED.
This does what you want while it keeps contents separate from
presentation and avoids to extend the Kconfig language.  A simple
Kconfig language without presentational ballast allows for creation of a
multitude of fine-tuned configurator UIs/scripts, which can be extended
by all sorts of features, e.g. better support in dealing with obsolete
configuration options.
-- 
Stefan Richter
-=====-=-=== -=-- ===-=
http://arcgraph.de/sr/