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(autoconf.info)Automake

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Automake
========

   The ubiquity of `make' means that a `Makefile' is almost the only
viable way to distribute automatic build rules for software, but one
quickly runs into `make''s numerous limitations.  Its lack of support
for automatic dependency tracking, recursive builds in subdirectories,
reliable timestamps (e.g. for network filesystems), and so on, mean
that developers must painfully (and often incorrectly) reinvent the
wheel for each project.  Portability is non-trivial, thanks to the
quirks of `make' on many systems.  On top of all this is the manual
labor required to implement the many standard targets that users have
come to expect (`make install', `make distclean', `make uninstall',
etc.).  Since you are, of course, using Autoconf, you also have to
insert repetitive code in your `Makefile.in' to recognize `@CC@',
`@CFLAGS@', and other substitutions provided by `configure'.  Into this
mess steps "Automake".

   Automake allows you to specify your build needs in a `Makefile.am'
file with a vastly simpler and more powerful syntax than that of a plain
`Makefile', and then generates a portable `Makefile.in' for use with
Autoconf.  For example, the `Makefile.am' to build and install a simple
"Hello world" program might look like:

     bin_PROGRAMS = hello
     hello_SOURCES = hello.c

The resulting `Makefile.in' (~400 lines) automatically supports all the
standard targets, the substitutions provided by Autoconf, automatic
dependency tracking, `VPATH' building, and so on.  `make' will build
the `hello' program, and `make install' will install it in
`/usr/local/bin' (or whatever prefix was given to `configure', if not
`/usr/local').

   Automake may require that additional tools be present on the
_developer's_ machine.  For example, the `Makefile.in' that the
developer works with may not be portable (e.g. it might use special
features of your compiler to automatically generate dependency
information).  Running `make dist', however, produces a
`hello-1.0.tar.gz' package (or whatever the program/version is) with a
`Makefile.in' that will work on any system.

   The benefits of Automake increase for larger packages (especially
ones with subdirectories), but even for small programs the added
convenience and portability can be substantial.  And that's not all...