Autoconf has always been a bit of a mystery to me. While working through the MailCore 2/libetpan stuff, I once again got reacquainted with Autotools and had to dive a bit deeper. John Calcote’s Autotools is an awesome reference that I found on O'Reilly Safari today.

This is mostly a set of rapid fire notes that I will probably refer back to in the future for my own reference.

Tools

• Automake - takes Makefile.am files and turns them into Makefile.in files.

• Autoconf - takes configure.ac, aclocal.m4, acsite.m4 and uses them to generate the configure script. Configure script takes .in files and outputs them with the .in stripped (e.g. Makefile.in -> Makefile)

So that’s the general flow of things here. Automake goes from .am to .in, Autoconf takes .ac and .m4 to generate the configure script (and config.h.in). Finally, ./configure takes the .in files and generates the output with the .in removed (Makefile.in -> Makefile, config.h.in -> config.h).