Re: changing the default compilers for autoconf

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

According to Sanjay Gianchandani on 9/17/2007 1:16 AM:

Hi Sanjay,

>> 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.
>>

> sorry for mailing you directly, but I wasnt getting much response on the
> mailing list, and I am still wondering as to which direction to proceed...
> these changes that u suggested, if i inject them in acspecific.m4, wont that
> serve my purpose?

It might serve your purpose, but you would then be forking your own
version of autoconf, because Ralf was pretty clear that the autoconf
preference of GCC is a policy decision that we are not going to change
lightly, and I agree with Ralf's analysis.

> I am not exactly sure though, as I am not completely aware of the flow of
> autoconf...
> any help would be greatly appreciated...

Ralf's advice about reading the autoconf manual and implementing a
config.site file is most appropriate to your situation.  In other words,
you DON'T want to alter autoconf itself, rather, you want to add a file
separate from autoconf, but which autoconf reads at startup, that controls
how autoconf will behave on your machine.

> moreover, I read somewhere that autoconf also uses some flags at compile
> time, which means that I would need to ensure that these flags work in the
> same way for the "changed" compiler too, right? any ideas abt which flags
> autoconf uses?

If autoconf detects that you are using gcc, but did not specify CFLAGS,
then it defaults CFLAGS to '-g -O2'.  But for other compilers, autoconf
doesn't generally know enough about your compiler to assume any set of
default flags.  So I don't know what you are worried about.  Beyond that,
autoconf is open source, so feel free to take a look at the output it
generates to make sure of how autoconf was behaving.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFG7m/884KuGfSFAYARAociAJ9dCTiSPERJvY0uKFibxZuz4xOJkgCdFq10
PyZAu4wMzAkWYiAGN7uHJ5o=
=THVd
-----END PGP SIGNATURE-----