On 10/27/2013 12:36 PM, Hossein Talebi wrote:
Thank you for your answer.
It is not true that F2003 support is that limited: Gfortran, Intel
Fortran, Cray Fortran, IBM Fortran and PGI Fortran all support nearly
full F2003. Some other ones support the C portability of F2003
although not supporting the rest.
You're 100% right but many systems often have older versions of these
compilers that don't support the Fortran C interoperability. There is
absolutely no excuse to not upgrade but then its not always possible.
Unless there is a significant gain in functionality (or ease of support)
by moving to a Fortran 2003 compiler it would be better to be
conservative. One advantage of being able to build PETSc on a old enough
system (e.g., Debian Etch with GCC 4.1; glibc 2.4) is that you can very
easily build a static binary of your code and it will run pretty much on
every Linux machine out there.
T
* I can contribute on creating this interface. I have experience with
F2003 to C++ and it works fine while C is a lot easier. My idea is to
create the F03 interface to petsc as a separate tool. So, anyone
trying to use petsc with a F03 compiler can compile this interface
again to avoid the compiler inconsistency of Modules.
We can work on a python (or similar) script to generate the
interfaces. For example, a project called gtk-fortran uses this
method. Can any of you guys help a little for planning the interface
design?
Cheers
Hossein
On Sun, Oct 27, 2013 at 4:42 PM, Satish Balay <ba...@mcs.anl.gov
<mailto:ba...@mcs.anl.gov>> wrote:
On Sun, 27 Oct 2013, Matthew Knepley wrote:
> On Sun, Oct 27, 2013 at 6:16 AM, Hossein Talebi
<talebi.hoss...@gmail.com <mailto:talebi.hoss...@gmail.com>>wrote:
>
> > Hello All,
> >
> > I am trying to use petsc with Fortran. The initial mechanism
to use petsc
> > with FORTRAN77 that works fine. However, I found the Fortran
90 interfaces
> > difficult to work with. The very first issue is one has to
recompile petsc
> > with the Fortran compiler in case different to the one which
was used to
> > create the Fortran Mod files.
Yes - one cannot mix fortran code compiled with 2 different compilers
- or 2 different version of the same compiler wrt modules.
But we generally recommend not mixing compilers for C aswell as
this
can cause problems.
Also you don't need to use modules to get f90 interfaces. You can
include
the f90 interface include files directly in your code.
#incude "finclude/petsc.h90"
> > Also, we would still need to use C type
> > #include statements along with Fortran 'use' statement which
is not so
> > optimal.
Even if you were to use f90 modules #include is unavoidable as we
still
have other stuff in include files.
check include/finclude/petscsysdef.h include/finclude/petscsys.h
> > Since Fortran 2003 offers great interface to C, did anyone try
to write a
> > F03 interface to petsc? Using F03 features, we can have very
low data
> > access to petsc database as well.
> >
>
> F2003 support is fairly thin in the compiler world, and we have
not had
> much call for it. We do gratefully accept contributions.
Currently we have the f90 interfaces [in include/finclude/ftn-auto/]
automatically generated by bfort tool from the C interface. So to
support F03 it would be ideal if there is such a tool. [or update
bfort to do it]
Satish
--
No one trusts a model except the one who wrote it; Everyone trusts an
observation except the one who made it- Harlow Shapley
