doc: avoid non-standard value for Kconfig predefines

[pabigot]

When building with Kconfig a symbol CONFIG_FOO is either undefined, or
defined to the integer literal 1. There are styles and use cases
where this is important, e.g. using "#if (CONFIG_FOO - 0)" which would
not work with a macro expanding to the identifier y. Use the standard
default definition instead of a special non-default one.

Also consistently use space rather than tab indentation within the
multi-line setting, and alphabetize the CONFIG_ predefines.

(This is cleanup preparatory to adding another predefine in a PR where documentation should always be generated for API that's available conditional on CONFIG_POLL. A more complex alternative is to drop all these Kconfig symbols and add a predefine DOXYGEN as suggested by https://gist.github.com/mbolivar/cd82dd45dd0d2ea153425c9506d61929 following the standard practice demonstrated at

zephyr/ext/hal/cmsis/Core_R/Include/core_cr.h

Line 277 in 78c6241

#if __CORTEX_R == 4 || __CORTEX_R == 5 || defined(DOXYGEN)

)

[mbolivar]

Looks fine to me. Conflicts with #21727, fix is trivial for whoever gets merged first.

[andrewboie]

this isn't right, if you want to mimic exactly what ends up in autoconf.h you need to define these all to '1'

please look for "autoconf.h" in a build directory to see what I mean

[pabigot]

this isn't right, if you want to mimic exactly what ends up in autoconf.h you need to define these all to '1'

No we don't. As the comment before PREDEFINED states:

If the definition and the "=" are omitted, "=1" is assumed.

dismissed

[andrewboie]

A bit subtle for my taste, why not just explicitly set to "1" and avoid confusing people?
I'll remove my -1 though.

[pabigot]

A bit subtle for my taste, why not just explicitly set to "1" and avoid confusing people?

Mostly because Doxygen is doing exactly what make(1) does when given -DFOO. Some people (including me) will be more confused by seeing an unnecessary explicit assignment.

I'll remove my -1 though.

Thanks.

[dbkinder]

OK, I think.