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| author | Masahiro Yamada <masahiroy@kernel.org> | 2024-04-23 01:41:04 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-05-02 19:48:26 +0900 |
| commit | 6a1215888e23aa9fbc514086402f04708c84f454 (patch) | |
| tree | 354f1463af09a8daa3dd80b459265148f183a414 /Documentation | |
| parent | d9a1dab65aa2d4de7244731c97c70491997225f2 (diff) | |
kconfig: remove 'optional' property support
The 'choice' statement is primarily used to exclusively select one
option, but the 'optional' property allows all entries to be disabled.
In the following example, both A and B can be disabled simultaneously:
choice
prompt "choose A, B, or nothing"
optional
config A
bool "A"
config B
bool "B"
endchoice
You can achieve the equivalent outcome by other means.
A common solution is to add another option to guard the choice block.
In the following example, you can set ENABLE_A_B_CHOICE=n to disable
the entire choice block:
choice
prompt "choose A or B"
depends on ENABLE_A_B_CHOICE
config A
bool "A"
config B
bool "B"
endchoice
Another approach is to insert one more entry:
choice
prompt "choose A, B, or disable both"
config A
bool "A"
config B
bool "B"
config DISABLE_A_AND_B
bool "choose this to disable both A and B"
endchoice
Some real examples are DEBUG_INFO_NONE, INITRAMFS_COMPRESSION_NONE,
LTO_NONE, etc.
The 'optional' property is even more unnecessary for a tristate choice.
Without the 'optional' property, you can disable A and B; you can set
'm' in the choice prompt, and disable A and B individually:
choice
prompt "choose one built-in or make them modular"
config A
tristate "A"
config B
tristate "B"
endchoice
In conclusion, the 'optional' property was unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kbuild/kconfig-language.rst | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index 79ac2e8184f6..555c2f839969 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -410,9 +410,6 @@ to be set to 'm'. This can be used if multiple drivers for a single hardware exists and only a single driver can be compiled/loaded into the kernel, but all drivers can be compiled as modules. -A choice accepts another option "optional", which allows to set the -choice to 'n' and no entry needs to be selected. - comment:: "comment" <prompt> |