scripts: kconfig: Improve the 'user value != actual value' warning

Symbols that are assigned values in .config files must have satisfied
dependencies, and must have a prompt. Otherwise, the assigned value is
ignored. A warning is printed if the symbol ends up with a different
value than the assigned value as a result.

It might be difficult to know how to fix the problem just from seeing
the current warning. Add some hints to it to help out:

  - The symbol information dialog in menuconfig is good for figuring out
    dependencies that need to be enabled. Mention menuconfig in the
    warning.

  - The page for the symbol in the autogenerated Kconfig docs can be
    helpful too, so link it. There's a slight chance that it'll be
    outdated, but it's usually correct when working on the master
    branch.

Automatically enabling dependencies is much trickier than it might seem
at first, due to the generality of Kconfig. See
https://github.com/zephyrproject-rtos/zephyr/issues/8181 for some
discussion.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
1 file changed