Re: changing the default compilers for autoconf

[Ralf Wildenhues]

Hello Sanjay,

* Sanjay Gianchandani wrote on Fri, Sep 07, 2007 at 02:55:16PM CEST:
> I have been working on Solaris, and have been trying to increase the
> efficiency of autoconf built softwares on the system.
> The main issue here is that autoconf by default, and as a rule, uses the GNU
> based compilers to make the software, while
> on Solaris, Sun Studio compilers prove to be much more efficient.

For yourself, just get in the habit of using
  .../configure -C CC=cc CXX=CC F77=f77 FC=f95

or write a config.site file that sets these as defaults once and for
all, for your system; see
<http://www.gnu.org/software/autoconf/manual/html_node/Site-Defaults.html>
for more information.

If you want to change the defaults for your specific package, but every
user of it, then you can put something like
  : ${CC=cc}
  : ${CXX=CC}
  # ...

in your configure.ac, right before AC_PROG_CC; but be warned that users
may not like your decision all that much and at least require that you
do this only on Solaris.  For that, invoke AC_CANONICAL_HOST and then
match $host against *-*-solaris*:
  AC_CANONICAL_HOST
  case $host in
  *-*-solaris*)  : ${CC=cc}  ... ;;
  esac
  AC_PROG_CC

As to changing Autoconf's defaults globally, i.e., for everyone and
every package without package-specific modifications: preference of GCC,
the GNU Compiler Collection, is a policy decision.  From an effort point
of view, you'd have more luck in improving GCC so that it ends up being
the better compiler, than getting GNU to promote a proprietary compiler
over its own free one.  ;-)

Cheers,
Ralf