Exactly, I think only option 2 and 3 makes sense, but since you already
confirmed that option 2 is not worth...
It may be possible to combine variants 2 and 4. Have time_t always be
64bit, add the helpers you suggested (time_add, time_diff etc.)
Then, if chosen by a Kconfig option, the helpers could switch to
alternate versions which would type-cast the operands to smaller size
(say 32bit). The compiler takes care of the rest. The option obviously
needs sufficiently visible warning about implications of selecting it
(which implies it needs to be off by default so the user actually reads
the warning.)
Advantages:
- time_t is 64bit
- if some operation involving time is missed and not converted to use
the helpers, things will still work correctly
Disadvantages:
- casting the type of the operands may suppress warnings and hide bugs
- fairly intrusive change
Unless I am missing something, this could work - not sure if something
like this can be merged without support from 32bit world though.
