gcc should warn when the stack frame for a called varargs function
is in excess of a -Wframe-larger-than=NNN bytes. Such a check could
be done at each call site, to see whether the outgoing arguments
alone already exhaust NNN.
Please be aware that the linux kernel uses this flag in its builds
as a tool to help limit runtime stack consumption, as a safety/security
matter. So it goes beyond a "nice to have".
Still present as of gcc 4.5.