Re: configure sets CFLAGS or how to disable default CFLAGS='-g -O2' for gcc?

[Ralf Corsepius]

On Tue, 2006-04-04 at 22:09 -0700, Jacob Meuser wrote:
> On Tue, Apr 04, 2006 at 06:31:16PM -0600, Ed Hartnett wrote:
> > Ralf Corsepius <address@hidden> writes:
> 
> > > If you really want to do something like you do, you'd have to check the
> > > compilerm, if it accepts "-q64" and if "-q64" actually does what you
> > > expect it to do.
> > >
> > > In short: You have opened a can of worms, you'd better avoid.
> > 
> > I would like to do it the autoconf way, but we use cfortran.h, which
> > requires a different value in CPPFLAGS for each fortran compiler.
> > 
> > If I don't have my configure script provide that parameter, the build
> > breaks and the user emails me.
> 
> maybe I misunderstand something here, but it sounds like you both
> agree:  add only flags that you know will work on the platform in
> use.
To some degree you are right. 

The problem is: all Ed does is in his snippet (From his earlier mail) is:

> AC_MSG_CHECKING([whether configure should try to set CFLAGS])
> if test "x${CFLAGS+set}" = xset; then
>    enable_cflags_setting=no
> else
>    enable_cflags_setting=yes
> fi
> AC_MSG_RESULT($enable_cflags_setting)
> 
> then later...
> 
>         test "x$enable_cflags_setting" = xyes && CFLAGS="$CFLAGS -q64"

I.e. he adds -q64 to CFLAGS if the user doesn't specify CFLAGS.

This is problematic, because he doesn't
1. Check if the compiler supports -q64
2. Doesn't check if -q64 actually does what he wants it to do.

-q64 might do what he wants on those platforms he uses as development
environment, but that's it:
* Compilers might not support -q64.
* -q64 might have different meanings for different compilers.
* -q64 could have different meanings for different architectures.

This will cause errors when building his package.

Ralf