21.5 Writing macros within the GNU Autotools framework

With a good grasp of M4 concepts, we may turn our attention to applying these principles to writing `configure.in' files and new `.m4' macro files. There are some differences between writing generic M4 input files and macros within the GNU Autotools framework and these will be covered in this section, along with some useful hints on working within the framework. This section ties in closely with 23. Writing New Macros for Autoconf.

Now that you are familiar with the capabilities of M4, you can forget about the names of the built-in M4 macros--they should be avoided in the GNU Autotools framework. Where appropriate, the framework provides a collection of macros that are laid on top of the M4 built-ins. For instance, the macros in the AC_ family are just regular M4 macros that take a number of arguments and rely on an extensive library of AC_ support macros.