23.3 Guidelines for writing macros
There are some guidelines which should be followed when writing a macro.
The criteria for a well-written macro are that it should be easy to use,
well documented and, most importantly, portable. Portability is a
difficult problem that requires much anticipation on the part of the
macro writer. This section will discuss the design considerations for
using a static Autoconf test at compile time versus a test at runtime.
It will also cover some of the characteristics of a good macro including
non-interactive behavior, properly formatted output and a clean
interface for the user of the macro.