Re: [gentoo-user] Re: Do we have to build gcc with fortran now?

[Michael Schreckenbauer]

Am Sonntag, 26. Juni 2011, 15:01:19 schrieb Dale:
> Michael Schreckenbauer wrote:
> > Am Sonntag, 26. Juni 2011, 10:28:47 schrieb Dale:
> >> Michael Schreckenbauer wrote:
> >>> Am Samstag, 25. Juni 2011, 14:58:56 schrieb Peter Humphrey:
> >>>> Whether "many" operations are written in Fortran is immaterial.
> >>>> What
> >>>> matters to me is whether any on my system are. If they aren't, I
> >>>> don't need a Fortran compiler and I'd rather not waste system
> >>>> resources on building one.
> >>>
> >>> Try euse -I fortran.
> >>> If anything besides gcc pops up, you should have one.
> >>>
> >>> Regards
> >>> Michael
> >>
> >> That doesn't appear to work like it should then.  I get this:
> >>
> >> root@fireball / # euse -I fortran
> >> global use flags (searching: fortran)
> >> ************************************************************
> >> [+ CD   ] fortran - Adds support for fortran (formerly f77)
> >>
> >> Installed packages matching this USE flag:
> >> sys-devel/gcc-4.4.5
> >>
> >> local use flags (searching: fortran)
> >> ************************************************************
> >> no matching entries found
> >> root@fireball / #
> >>
> >> Thing is, I know a couple packages use it on this rig because I just
> >> had
> >> to recompile them.  Cantor and R are two that I recall.
> >>
> >> Maybe it is because it is not a option in the list?  The USE flag that
> >> is.
> >
> > Iirc you had problems with -fortran, because you have packages that
> > really need fortran. My suggestion was for people like Peter, who have
> > no problems without fortran. It shows only packages which could perform
> > better, if a fortran compiler is available and otherwise fallback to a
> > C implementation. At least, I think it does :)
> >
> >> Dale
> >>
> >> :-)  :-)
> >
> > Michael
>
> Thing is, I switched it back and programs on here now need fortran to
> build.  So, euse is not reporting it but R and Cantor won't build
> without fortran.

That's because R needs a fortran compiler to compile. It does not have a C 
fallback solution for its maths. cantor depends on R per default. So it won't 
build until a working R is installed.
Peter is not having problems without fortran. Everything compiles fine. So I am 
quite shure he has neither R nor cantor installed or any other program that 
needs a fortran compiler to build at all.
This euse command shows only packages where fortran is optional. This means 
better performance, when enabled, in all (at least almost all) cases.

> Basically, euse should also report R and cantor but it
> isn't.  If mine isn't reporting that, then Peter's may not either.

That's impossible, I think. euse reports USE-flags. These programs don't have a 
fortran-USE-flag. R needs it unconditionally..

> Dale
> :-)  :-)

Michael