Re: GNAT and GNU build system

[Ludovic Brenta <ludovic.brenta@insalien.org>]

I also tend to think that autoconf and automake are poor hacks meant
to circumvent the deficiencies of C; just like make in fact.  However,
I see one situation where it makes sense to use them in Ada, and that
is when you want to build a binding to a C library that has
platform-dependent parts.  This is best illustrated by Florist, which
has a rather convoluted build process:

1) It uses configure to generate a Makefile and a config.h
2) The Makefile compiles a number of C source files, and links them into
   an executable, named c-posix
3) The Makefile executes c-posix, which writes a gnatprep configuration
   file and a C file, c-posix-signals.c
4) The Makefile runs gnatprep, with the configuration file, to generate
   several Ada files
5) The Makefile compiles and links c-posix-signals.c
6) Executes c-posix-signals, which creates posix_signals.ads
7) Compiles all the Ada files
8) Links the compiled files into a library

See http://buildd.debian.org/fetch.php?&pkg=libflorist-3.15p-1&ver=3.15p-3&arch=sparc&stamp=1069154570&file=log&as=raw

But the conclusion I draw from all this is: do your very best to avoid
such a complicated build process if possible!  Unless you are
interfacing to the operating system, there is very little reason to
use the autotools.  GNAT and Florist together should provide you all
the portability you need (and yes, GNAT does use autoconf/automake,
because GCC does).

-- 
Ludovic Brenta.