Re: [RFC PATCH v6] Documentation/arch: Add Documentation/arch-features.txt

On Thu, May 14, 2015 at 12:16:15PM +0200, Ingo Molnar wrote:

* Josh Triplett [off-list ref] wrote:

quoted

On Wed, May 13, 2015 at 09:27:57AM -0700, Josh Triplett wrote:

quoted

How likely is this to get out of date?  Are people going to 
remember to patch this when they add a feature to their 
architecture?  If they found out they had work to do by reading 
this file, which is the goal, then they'll likely remember to edit 
the file; however, if they find the feature and fix it without 
knowing about the file, will someone notice?

Is there any way we can *generate* this file from Kconfig?  Can we 
extract the necessary "this is possible to enable" or "this arch 
selects this symbol" information from Kconfig, and together with 
the list of symbols for features needing architecture support, 
generate the table?

Just tried this.  Looks like it's pretty trivial for most of these 
features: just make ARCH=thearch allyesconfig, then look for the 
config symbol in the result.

No, that's not nearly enough to do a correct support matrix, for 
example due to subarchitectures that aren't included in an 
allyesconfig.

Still feasible to automate with a bit more scripting.

There are also many #define driven features.

It'd be nice to move those over to Kconfig.

- Josh Triplett