+ Note: If the combination of FOO=y and BAR=m causes a link error,
+ you can guard the function call with IS_REACHABLE()::
+
+ foo_init()
+ {
+ if (IS_REACHABLE(CONFIG_BAZ))
+ baz_register(&foo);
+ ...
+ }
+
+ 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
+