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.