summaryrefslogtreecommitdiffstats
path: root/Documentation/kbuild
diff options
context:
space:
mode:
authorMasahiro Yamada <masahiroy@kernel.org>2020-03-02 15:23:40 +0900
committerMasahiro Yamada <masahiroy@kernel.org>2020-03-13 10:05:34 +0900
commit3a9dd3ecb207b2cb8a4aabd12d20e43fa360b66d (patch)
tree7586526ac545db8fae708e3ad928b7a0789ea312 /Documentation/kbuild
parentdef2fbffe62c00c330c7f41584a356001179c59c (diff)
downloadlinux-3a9dd3ecb207b2cb8a4aabd12d20e43fa360b66d.tar.bz2
kconfig: make 'imply' obey the direct dependency
The 'imply' statement may create unmet direct dependency when the implied symbol depends on m. [Test Code] config FOO tristate "foo" imply BAZ config BAZ tristate "baz" depends on BAR config BAR def_tristate m config MODULES def_bool y option modules If you set FOO=y, BAZ is also promoted to y, which results in the following .config file: CONFIG_FOO=y CONFIG_BAZ=y CONFIG_BAR=m CONFIG_MODULES=y This does not meet the dependency 'BAZ depends on BAR'. Unlike 'select', what is worse, Kconfig never shows the 'WARNING: unmet direct dependencies detected for ...' for this case. Because 'imply' is considered to be weaker than 'depends on', Kconfig should take the direct dependency into account. For clarification, describe this case in kconfig-language.rst too. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'Documentation/kbuild')
-rw-r--r--Documentation/kbuild/kconfig-language.rst15
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst
index d4d988aea679..a1601ec3317b 100644
--- a/Documentation/kbuild/kconfig-language.rst
+++ b/Documentation/kbuild/kconfig-language.rst
@@ -159,11 +159,11 @@ applicable everywhere (see syntax).
Given the following example::
config FOO
- tristate
+ tristate "foo"
imply BAZ
config BAZ
- tristate
+ tristate "baz"
depends on BAR
The following values are possible:
@@ -174,6 +174,9 @@ applicable everywhere (see syntax).
n y n N/m/y
m y m M/y/n
y y y Y/m/n
+ n m n N/m
+ m m m M/n
+ y m n M/n
y n * N
=== === ============= ==============
@@ -191,6 +194,14 @@ applicable everywhere (see syntax).
...
}
+ Note: If the feature provided by BAZ is highly desirable for FOO,
+ FOO should imply not only BAZ, but also its dependency BAR::
+
+ config FOO
+ tristate "foo"
+ imply BAR
+ imply BAZ
+
- limiting menu display: "visible if" <expr>
This attribute is only applicable to menu blocks, if the condition is