Macros: Meaningful or Myth?

[Dave Decot]

Where in the dpANS is the term "macro" defined?

I find references to "the setjmp macro", and then find that "whether setjmp
is a macro or a function is unspecified", and then find out that "errno"
is to be a "macro" defined in <errno.h>.

I hope this doesn't mean the implementation has to use "#define" to
do something with errno.

Is it OK for an implementation to provide setjmp only as a real function?

Dave Decot