Re: check for C99-compliant snprintf

[Paul Eggert]

It's a bit of a pain that this will reject all cross-compiled snprintfs.
Is there some way you can test for this at compile-time?

Does the nonstandard snprintf have exactly the same signature as the
C99 snprintf?  If not, we should be able to catch this at
compile-time.

Does the nonstandard implementation have a vsnprintf?  If not, we
could test for that at link-time and cross-compiles wouldn't have to
substitute snprintf except on clearly pre-C99 systems.

Basically, I'm looking for any way we can distinguish the nonstandard
implementation without running it.