menuconfig: Prompt for save if a different .config would be saved

Previously, menuconfig.py only prompted for saving the configuration if
.config didn't exist or the user changed symbol values within the
interface.

Also make it prompt for save if Kconfig symbols have been added,
removed, or have had their defaults changed, provided it would make the
saved .config differ from the loaded one.

This usually won't matter for correctness, because loading an outdated
configuration performs an implicit olddefconfig, but it's less
confusing.

Also add a Kconfig.missing_syms attribute that records all assignments
to undefined symbols in the most recently loaded .config file. This is
needed to implement the check for whether the saved .config would be
different.

As an unrelated change, always prompt for saving if a .config has been
loaded from within the menuconfig interface. The intention is probably
often to save the configuration somewhere else, even if it isn't
modified.

0 files changed, 0 insertions, 0 deletions