Re: [PATCH] kconfig: Warn on dead select or imply for choice values

[Julian Braha]

Hi Nicolas,

On 8/4/26 13:45, Nicolas Schier wrote:
> Update the internal kconfig check to print a warning on 'select' and
> 'imply' statements that target on choice values.
> 
> Julian Braha reported that kconfig's 'select' and 'imply' do not work
> for choice values but have no effect all.  Show a warning instead of
> error-out to allow kconfig to check the whole kconfig rule set.
> 
> Reported-by: Julian Braha <julianbraha@xxxxxxxxx>
> Closes: https://lore.kernel.org/linux-kbuild/20260715220149.48700-1-julianbraha@xxxxxxxxx/ # [1]
> Suggested-by: Kees Cook <kees@xxxxxxxxxx>
> Suggested-by: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Signed-off-by: Nicolas Schier <nsc@xxxxxxxxxx>

Reviewed-by: Julian Braha <julianbraha@xxxxxxxxx>
Tested-by: Julian Braha <julianbraha@xxxxxxxxx>

> ---
> Depends on related fixes in Kconfig files:
> https://lore.kernel.org/r/20260729203845.387239-1-julianbraha@xxxxxxxxx # change-requested
> https://lore.kernel.org/r/20260801160140.2391000-1-julianbraha@xxxxxxxxx # under-review
> https://lore.kernel.org/r/20260714112047.2304856-1-julianbraha@xxxxxxxxx # under-review
> https://lore.kernel.org/r/20260723104933.117413-1-julianbraha@xxxxxxxxx # applied to mips-next
> https://lore.kernel.org/r/20260723122818.437802-1-julianbraha@xxxxxxxxx # applied

Note that there was actually a 6th of these broken select-choices that I
had forgotten to list. Though my patch for that has also already been
applied:
https://lore.kernel.org/all/20260722220618.198164-1-julianbraha@xxxxxxxxx/

> ---
>  scripts/kconfig/menu.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
> index b2d8d4e11e07..fc8d8cfe034d 100644
> --- a/scripts/kconfig/menu.c
> +++ b/scripts/kconfig/menu.c
> @@ -287,6 +287,10 @@ static void sym_check_prop(struct symbol *sym)
>  				    "'%s' has wrong type. '%s' only "
>  				    "accept arguments of bool and "
>  				    "tristate type", sym2->name, use);
> +			if (sym_is_choice_value(sym2))
> +				prop_warn(prop,
> +					  "config symbol '%s' uses %s for '%s', but '%s' is a choice value",
> +					  sym->name, use, sym2->name, sym2->name);
>  			break;
>  		case P_RANGE:
>  			if (sym->type != S_INT && sym->type != S_HEX)
> 
> ---
> base-commit: 6946cd5d0aa4dd10a414ddcb7a10844fdb0ad345
> change-id: 20260802-kconfig-warn-on-dead-select-for-choice-value-bd71a1de1a96
> prerequisite-message-id: <20260729203845.387239-1-julianbraha@xxxxxxxxx>
> prerequisite-patch-id: 3bb796da65f588d1df5003dac5af7a9d7420f266
> prerequisite-message-id: <20260801160140.2391000-1-julianbraha@xxxxxxxxx>
> prerequisite-patch-id: 5277c28b2d25752fb7e5827ed744b0cf0c619574
> prerequisite-message-id: <20260714112047.2304856-1-julianbraha@xxxxxxxxx>
> prerequisite-patch-id: bef2d24caba30e7dc2ac5189c10b6473485a1e3c
> prerequisite-message-id: <20260723104933.117413-1-julianbraha@xxxxxxxxx>
> prerequisite-patch-id: da49e2868fbb19afc3195cbd2868739a94aa02c3
> prerequisite-message-id: <20260723122818.437802-1-julianbraha@xxxxxxxxx>
> prerequisite-patch-id: 3c894964a57e4e30515fcb14226dae725555c25e
> 
> Best regards,
> --  
> Nicolas
> 

- Julian Braha