Re: [PATCH 2/3] Kconfig: improve handling for all{rand,yes,no,}.config fragments

[Arnd Bergmann]

On Tue, Feb 20, 2018 at 6:04 PM, Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
> 2018-02-20 18:59 GMT+09:00 Arnd Bergmann <arnd@xxxxxxxx>:
>> On Tue, Feb 20, 2018 at 10:26 AM, Masahiro Yamada
>> <yamada.masahiro@xxxxxxxxxxxxx> wrote:
>>> 2018-02-17 6:41 GMT+09:00 Arnd Bergmann <arnd@xxxxxxxx>:
>>
>>>> @@ -621,14 +622,24 @@ int main(int ac, char **av)
>>>>                 case randconfig:        name = "allrandom.config"; break;
>>>>                 default: break;
>>>>                 }
>>>> -               if (conf_read_simple(name, S_DEF_USER) &&
>>>> -                   conf_read_simple("all.config", S_DEF_USER)) {
>>>> -                       fprintf(stderr,
>>>> -                               _("*** KCONFIG_ALLCONFIG set, but no \"%s\" or \"all.config\" file found\n"),
>>>> -                               name);
>>>> -                       exit(1);
>>>> +               /* try ./name, arch/$(ARCH)/configs/name and kernel/config/name */
>>>> +               if (!conf_read_simple(name, S_DEF_USER))
>>>> +                       break;
>>>> +               arch = getenv("ARCH");
>>>> +               if (arch) {
>>>> +                       snprintf(fullname, sizeof(fullname), "arch/%s/configs/%s",
>>>> +                                arch, name);
>>>> +                       if (!conf_read_simple(fullname, S_DEF_USER))
>>>> +                               break;
>>>>                 }
>>>
>>>
>>> I am not a big fan of hard-coding the kernel directory structure.
>>>
>>> We already do this [1], but I am thinking of kicking this out.
>>> [1] https://github.com/torvalds/linux/blob/v4.16-rc1/scripts/kconfig/confdata.c#L33
>>
>> Ok, I see. How about adding a way to detect that we are build-testing
>> with randconfig instead?
>
>
> How about implementing something in scripts/kconfig/Makefile?
>
> merge_config collects config fragments into 'configfiles'
>
> I was thinking of a similar thing.
>
>
> If KCONFIG_ALLCONFIG is 1,
> scripts/kconfig/Makefile searches
> './', '$srctree/', 'arch/$(SRCARCH)/configs/', 'kernel/configs/'
> and sets the found file in it,
>
> If KCONFIG_ALLCONFIG already contains a file name, it is used as-is.
>
> scripts/kconfig/conf.c will be simplified.

Yes, good idea. I'm struggling a bit with the implementation (fitting
it into the
simple-tagets rule), can you come up with a prototype?

We also need to decide what happens when e.g. both a ./all.config and
arch/${SRCARCH}/configs/allrand.config file exist, should the first path
take precedence or the more specific file?

     Arnd