kconfig: choice default is not set if hidden under invisible menu

[sjanc]

Describe the bug
If choice with default value is under menu that is conditionally visible, default value is set only if menu is visible. This doesn't seem to affect config under same menu.

To Reproduce
menu SOME_MENU
visible if FOO

config BAR
bool "bar"
default y

choice BAZ_CHOICE
"choose baz"
default BAZ1

config BAZ1
bool "baz1"

config BAZ2
bool "baz2"

endchoice
endmenu

If FOO is not set, BAR=y , BAZ1 is unset
If FOO is set, BAR=y and BAZ1=y

Expected behavior
In example above BAZ1 should be set regardless of FOO value.

Impact
Blocks PR #39736

[tejlmand]

If choice with default value is under menu that is conditionally visible, default value is set only if menu is visible. This doesn't seem to affect config under same menu.

This is not an error and is expected behavior.
config items are still present when invisible and in those cases they will use their default value or can be enable through a select <SYMBOL> as described:
https://docs.zephyrproject.org/latest/guides/build/kconfig/setting.html#visible-and-invisible-kconfig-symbols

Invisible config only means they cannot be controlled by the user directly.

A choice is not a config item and thus it does not share the same properties.
In a choice only visible items are selectable but the default of the invisble choice is still active.

If you extend your example with:

menu SOME_MENU
    visible if FOO

choice BAZ_CHOICE
        prompt "choose baz"
        default BAZ1

config BAZ2
        bool "baz2"

endchoice
endmenu

# Here we have a visible choice:
choice BAZ_CHOICE
        prompt "visible choice baz"

config BAZ3
        bool "baz3"

config BAZ1
        bool "baz1"

endchoice

then you'll see that BAZ1 is actually the default selected value in the choice even though the line with default BAZ1 is hidden.

If you remove the default BAZ1 line you'll notice that BAZ3 becomes the default value.

So everything regarding default works as expected, but only visible config items inside the choice is selectable, and thus that impacts whether of not the default setting can be selected at all.

Closing as this is not a bug.

[sjanc]

if I add default to config under choice I get this:
warning: default on the choice symbol BT_LL_SW_SPLIT_LLCP_LEGACY (defined at subsys/bluetooth/controller/Kconfig.ll_sw_split:126) will have no effect, as defaults do not affect choice symbols

[tejlmand]

if I add default to config under choice I get this:

you should not add default on the config under the choice.
From where do you get that impression ?

This is how you do default on choice's:

choice BAZ_CHOICE
        prompt "choose baz"
        default BAZ1

as I showed here: #39756 (comment)

[sjanc]

Hi,

Yes, this is exactly why I created this issue.
If choice is under

menu SOME_MENU
visible if FOO
...
endmenu

and FOO is not set then the default wont be set.., it will be set only if FOO is set

[sjanc]

nevermind, I've misunderstood you comment, all is clear now! Thanks for help