Mail Archives: djgpp/1998/05/27/07:15:18
Federico Spinazzi wrote:
> Hy all,
>
Hi Federico and other readers,
Our news server was slightly autistic last week: I could read news but
the messages I sent were not distributed outside our own system. This
may mean that this post does not come to the newsgroup. This in turn
means that this message will probably appear here after long, long time.
So my apologies if this message crops out sometimes in autumn and looks
completely outdated and irrelevant.
> I would like to ask you which is the best method to use fortran with
> djgpp:
> - f2c + gcc ?
> or
> - g77 + gcc ?
> or
> - it is possible to link fortran code to c/c++ code (this question
> probably reveals the fact that I don't know the way g77 works) ?
>
I have used both. Recently, I prefer f2c->gcc. The main reason to this
is that the djgpp version of g77 seems to be slightly broken: the
programs run normally, but crash *after* executing the stop statement.
These crashes feel uncomfortable, although it may be that everything
before STOP was done OK. (Personal note to F.Spinazzi: one of these
crashing programs was CANOCO).
Some things you must beware:
For g77, you have to change your gcc. I don't know how this goes with
the new gcc 2.8.x. That is one reason why I haven't yet upgraded my gcc.
f2c and g77 have *unidentical* libraries with the same name (libf2c.a).
The reason for this is that g77 started with f2c libraries. Since then
the g77 library started her independent life, but kept her old name.
This may be a nuisance if you have both in your pc. The problems I had
with g77 after-stop-crashes were probably problems in g77-libf2c.a,
since they did not appear with f2c-libf2c.a. However, I was then
informed by real gurus that it is not safe to mix these two
f2c-libraries.
Linking ForTran and C/C++ is *easiest* with f2c. You can maintain and
edit Fortran files, and you need only one extra -- and short, timewise
-- step during compilation. It is easiest for two reasons: Original
Fortran is easier to read than f2c-ed C/C++, and you can see with your
own eyes how you have to call your subroutines in C/C++. Real gurus know
that off-hand and they may link object files directly. We mortals may be
happy with the helping hand of f2c.
I guess that you're going to do matrix algebra. There you should
remember that Fortran sees your dynamic C-matrices as transposed. This
can be a real pain if you try to plug in Fortran subroutines, but often
it is enough that you remember this feature.
--
Jari Oksanen -- Lahtis, Finland / Luokta, Suopma / Lahti, Häme.
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