gcc USE=fortran ... how many ebuilds needs fortran nowadays?

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eccerr0r · Post by **eccerr0r** » Tue Dec 11, 2012 1:40 am

I was looking at my Geode GX1 machine and while it was taking days on end to rebuild gcc, I noticed it was building gfortran...

Fortran on an embedded box?

I ended up having to set USE=-fortran and hope that it will save come compile time.

But here I wonder, how often is gfortran used? Is there a way to tell all the packages that require gcc with USE=fortran enabled? Is it enough to have the default USE=fortran?

Post by **John R. Graham** » Tue Dec 11, 2012 2:22 am

Depends on your profession. It's used (to me) a surprising amount for scientific computing still. I doubt there's a single ebuild that depends on the fortran USE flag other than gcc itself. But embedded? Nothing for sure.

- John

Hypnos · Post by **Hypnos** » Tue Dec 11, 2012 2:55 am

Mostly scientific apps, compilers and supporting tools.

Code: Select all

# grep -r fortran /usr/portage/ | grep IUSE | cut -d ':' -f 1 | grep 'ebuild$' | cut -d\/ -f 4,5 | uniq | sort

dev-lang/path64
dev-perl/PDL
sci-astronomy/wcslib
sci-libs/acml
sci-libs/amd
sci-libs/arprec
sci-libs/cfitsio
sci-libs/fftw
sci-libs/getdata
sci-libs/gpp4
sci-libs/grib_api
sci-libs/hdf
sci-libs/hdf5
sci-libs/hypre
sci-libs/lis
sci-libs/mkl
sci-libs/netcdf
sci-libs/plplot
sci-libs/qd
sci-visualization/grace
sys-cluster/mpe2
sys-cluster/mpich2
sys-cluster/mvapich2
sys-cluster/openmpi
sys-devel/gcc
sys-devel/gcc-apple
virtual/mpi

There may be deps in some eclasses, too.

eccerr0r · Post by **eccerr0r** » Tue Dec 11, 2012 7:01 am

I only wonder because somehow USE=fortran is default somehow, and most systems really don't ever use gfortran... so why is it a default USE? I suppose it's good to have if you do need it but most people don't?

Hypnos · Post by **Hypnos** » Tue Dec 11, 2012 7:16 am

I think it's a remnant of the drobbins days, when everything was turned on by default.

Until recently, 'gnustep' was enabled by default.

gringo · Post by **gringo** » Tue Dec 11, 2012 10:56 am

i have been disabling gccs fortran use for many years now but, as others mentioned already, its really up to your usage.
I for example have no sci-* packages installed apart from those depending on libreoffice, and those do not requiere fortran.

cheers

Post by **aCOSwt** » Tue Dec 11, 2012 11:12 am

Pardon me eccerr0r... I just cannot resist trolling :

"Real Programmers do List Processing in Fortran.
Real Programmers do String Manipulation in Fortran.
Real Programmers do Accounting (if they do it at all) in Fortran.
Real Programmers do Artificial Intelligence programs in Fortran.

If you can't do it in Fortran, do it in assembly language. If you can't do it in assembly language, it isn't worth doing."

1983 !... A great moment in the history of programming indeed.
Well... that was when JRG was young of course...

Post by **John R. Graham** » Tue Dec 11, 2012 11:53 am

LOL. True (the crack about my age, I mean.)

My father-in-law is a scientist: a mathematician and theoretical ecologist. I help him from time to time with his Fortran code but I haven't written it for my own benefit in over 30 years.

- John

LiamOS · Post by **LiamOS** » Tue Dec 11, 2012 2:34 pm

I'm studying physics at the moment and Fortran is occasionally used, particularly in weather simulations for some reason. It doesn't concern me too much, and I set USE="-fortran" when feasible.

The first time I ever saw Fortran code I actually thought it was some kind of joke.

Post by **aCOSwt** » Tue Dec 11, 2012 2:40 pm

LiamOS wrote:The first time I ever saw Fortran code I actually thought it was some kind of joke.
----------
CFLAGS=" -O999999"

F(C)FLAGS=${CFLAGS}
This is... *not* a joke !

eccerr0r · Post by **eccerr0r** » Tue Dec 11, 2012 3:26 pm

Well I hope the default is changed. While I'm not saying that Fortran's value as a language is diminished by this, it's installing something that most people would not use.

I have the same comment about the LUA interpreter that sometimes gets installed as well as TCL but there are some programs that use them once in a while then go away...

Hmm...

Post by **John R. Graham** » Tue Dec 11, 2012 3:35 pm

Well, I agree with you. I had fortran off for ages until I had to work with my father-in-law. You probably know this but all you have to do is

Code: Select all

USE="-fortran" emerge -uDNvp --with-bdeps=y world

to see if you would be affected. If only the compilers are shown to rebuild, then you're safe.

- John

Etal · Post by **Etal** » Tue Dec 11, 2012 4:50 pm

Last time I tried it, turning off fortran did not decrease the compile time in any noticeable way, so I just leave it on.

eccerr0r · Post by **eccerr0r** » Tue Dec 11, 2012 9:46 pm

Yeah I don't think the total build time would be that much lower, but it would be slightly lower and use slightly less disk space...

Not that much space but if you have a < 2GB disk, every MB counts...

-rw-r--r-- 1 root root 1481482 Dec 7 14:31 libgfortran.a
-rwxr-xr-x 1 root root 781368 Dec 7 14:30 libgfortran.so.3.0.0*