kconfig-language: improve menuconfig usage description

Improper menuconfig usage leads to empty menu entries.
zconfdump() is able to reveal some real-life examples:
- menuconfig VFIO_NOIOMMU
- menuconfig RESET_CONTROLLER
- menuconfig SND_ARM

To avoid future occurrences of those, improve the menuconfig syntax
description.

Signed-off-by: Eugeniu Rosca <rosca.eugeniu@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Eugeniu Rosca 2016-08-03 00:40:34 +02:00 committed by Jonathan Corbet
parent 22c6bbe41e
commit cfd7c612ba
1 changed files with 38 additions and 1 deletions

View File

@ -274,7 +274,44 @@ menuconfig:
This is similar to the simple config entry above, but it also gives a
hint to front ends, that all suboptions should be displayed as a
separate list of options.
separate list of options. To make sure all the suboptions will really
show up under the menuconfig entry and not outside of it, every item
from the <config options> list must depend on the menuconfig symbol.
In practice, this is achieved by using one of the next two constructs:
(1):
menuconfig M
if M
config C1
config C2
endif
(2):
menuconfig M
config C1
depends on M
config C2
depends on M
In the following examples (3) and (4), C1 and C2 still have the M
dependency, but will not appear under menuconfig M anymore, because
of C0, which doesn't depend on M:
(3):
menuconfig M
config C0
if M
config C1
config C2
endif
(4):
menuconfig M
config C0
config C1
depends on M
config C2
depends on M
choices: