Die GNU autotools

[Nadav Har'El]

On Mon, Jan 10, 2011, Shlomi Fish wrote about "Re: Die GNU autotools":
> On Monday 10 Jan 2011 12:49:25 Ilya A. Volynets-Evenbakh wrote:
> > My feelings too. A while ago I got so tired of autotools that I even
> > started working on my own build system intended as a semi-drop-in
> > replacement. It's purely make-based. If interested, take a look at
> > the sources http://sources.total-knowledge.com/gitweb/?p=adon-banai.git
> > 
> 
> Well, after a small experimentation with SCons ( http://www.scons.org/ ) which 
> I didn't really like (but is still better than GNU Autohell), I've finally 
> settled on CMake - http://www.cmake.org/ - which is awesome in almost every 

It saddens me that people bundle Autoconf and Automake under one name
"autotools", because it causes people to miss that Autoconf *is* the best
thing since sliced bread, while the rest of them are, well, not.

To appreciate just how great autoconf is, you have to remember what transpired
before it was invented in 1991.

In the 80s, if you had a C program which was to run on the many variants of
Unix that existed then, you'd normally write a complex Makefile with all
sorts of parameters, and before a user could compile your program, he would
need to edit this Makefile, and turn on or off various flags, fill in locations
of various programs, and so on. This was extremely annoying so two solutions
were invented: Larry Wall (of Perl fame) invented "Metaconfig" which would
*ask* the user questions instead of asking him to edit a Makefile - this was
somewhat easier, but equally annoying and time-consuming. The X-Windows people
invented "imake", where the user would basically answer all possible questions
once (and put them in a system-global config file), and when the user runs
"xmkmf" a Makefile is created from an "IMakefile" using these defaults.
Imake was also not a silver bullet, because it made it impossible for new
projects to ask new questions beyond the "usual" ones that were already
answered when X11 was installed.

Then (1991) came autoconf, and solved all these problems. It wouldn't ask
you silly questions that it could figure out automatically (if some library
is available, were is some binary, is some feature of the C compiler available,
etc.), and every program could define the specific questions it needed
answered, using basic building blocks that autoconf made available. Autoconf
was so good, and so much better than anything that was available before, that
pretty soon *every* free software came with a "configure" script.

Fast forward 20 years, and autoconf is just as good as it used to be, but
most people are starting to forget why it was needed, and only remember its
quirkiness, like the fact it uses the bizarre "m4" as its base.
One reason why people forget how good autoconf is, is that they hardly see
different variants of Unix, and the differences between Linux distributions
are typically smaller. Another reason for forgetting autoconf's greatness is
that "normal" people don't compile any more! Most Linux users get precompiled
binaries from their distributions, and it is the distribution's packagers
which do the compilation. Finally, these packagers (who do the compilation)
don't really care if the source code used autoconf, or a hand-tweaked Makefile,
because they anyway *patch* the source code with all sort of distribution-
specific modifications, so they could care less about *patching* the Makefile.
This state of affairs is, in my opinion, sad.

Once you forget why autoconf is important, it's easy to start believing that
all sorts of unrelated tools could somehow replace it. Things like Cmake
and Adon-Banai can hardly be considered replacements to Autoconf - perhaps
they are better "make", perhaps they are "imake done again", but not
"better than autoconf".
(note: since I never actually used Cmake or Adon-Banai, I may be missing
something, so feel free to correct me).


-- 
Nadav Har'El                        |       Monday, Jan 10 2011, 5 Shevat 5771
nyh at math.technion.ac.il             |-----------------------------------------
Phone +972-523-790466, ICQ 13349191 |A bird in the hand is safer than one
http://nadav.harel.org.il           |overhead.