C++/Fortran mixing

NM · Jul 22 '05, 07:00 AM

Re: C++/Fortran mixing

I forgot to post lines from rates.f and dest.f
rates.f:118 dx = x_max**alpha - x_min**alpha
dest.f:126 l = iabs(nint(Amdes t(km-1)))

**E. Robert Tisdale** · Jul 22 '05, 07:00 AM

Re: C++/Fortran mixing

NM wrote:[color=blue]
>
> I am trying to link C++ and Fortran.I am not very familiar with Fortran.
> I have been successful in linking C++ and fortran using g++ and ifc for
> simple program. So adding _ to at the end of fortran subroutine names when
> calling from C++ is working. Now I want to move to bigger program. I have a
> rather big Fortran code which compiles and links fine under ifc. Now I
> changed the program main in Fortran into a subroutine main_sub so that I can
> call this subroutine main_sub from C++. I am getting error in linking. For
> your convenience I am pasting the output of both linking the main program in
> ifc and linking the program with g++. Any help will be appreciated regarding
> the undefined reference.[/color]

[snip]

Everything looks OK
except that the link editor ld can't resolve some references.
Most likely this is because you have neglected to include
a [Fortran] library which defines these references.
Your Fortran compiler ifc knows which libraries are required
but your C++ compiler mpiCC does not.

cd to a directory containing your Fortran libraries

/lusr/share/software/intel/compiler70/ia32/lib/

for example and type

nm -o *.a *.so *.so.3 | grep a_floorq

You should get a list of references to a_floorq.
The ones labeled U are undefined but those labeled T are defined.
Just include the corresponding library along with

-lIEPCF90 -lcode_unified

in your Makefile.

NM · Jul 22 '05, 07:00 AM

Re: C++/Fortran mixing

Thanks. It is working :-)

"E. Robert Tisdale" <E.Robert.Tisda le@jpl.nasa.gov > wrote in message
news:403E6A8F.9 050504@jpl.nasa .gov...[color=blue]
> NM wrote:[color=green]
> >
> > I am trying to link C++ and Fortran.I am not very familiar with Fortran.
> > I have been successful in linking C++ and fortran using g++ and ifc for
> > simple program. So adding _ to at the end of fortran subroutine names[/color][/color]
when[color=blue][color=green]
> > calling from C++ is working. Now I want to move to bigger program. I[/color][/color]
have a[color=blue][color=green]
> > rather big Fortran code which compiles and links fine under ifc. Now I
> > changed the program main in Fortran into a subroutine main_sub so that I[/color][/color]
can[color=blue][color=green]
> > call this subroutine main_sub from C++. I am getting error in linking.[/color][/color]
For[color=blue][color=green]
> > your convenience I am pasting the output of both linking the main[/color][/color]
program in[color=blue][color=green]
> > ifc and linking the program with g++. Any help will be appreciated[/color][/color]
regarding[color=blue][color=green]
> > the undefined reference.[/color]
>
> [snip]
>
> Everything looks OK
> except that the link editor ld can't resolve some references.
> Most likely this is because you have neglected to include
> a [Fortran] library which defines these references.
> Your Fortran compiler ifc knows which libraries are required
> but your C++ compiler mpiCC does not.
>
> cd to a directory containing your Fortran libraries
>
> /lusr/share/software/intel/compiler70/ia32/lib/
>
> for example and type
>
> nm -o *.a *.so *.so.3 | grep a_floorq
>
> You should get a list of references to a_floorq.
> The ones labeled U are undefined but those labeled T are defined.
> Just include the corresponding library along with
>
> -lIEPCF90 -lcode_unified
>
> in your Makefile.
>[/color]

**Jack Klein** · Jul 22 '05, 07:00 AM

Re: C++/Fortran mixing

On Thu, 26 Feb 2004 15:30:43 -0600, "NM" <nm@nm.com> wrote in
comp.lang.c++:
[color=blue]
> Hi all
> I am trying to link C++ and Fortran.I am not very familiar with Fortran.
> I have been successful in linking C++ and fortran using g++ and ifc for
> simple program. So adding _ to at the end of fortran subroutine names when
> calling from C++ is working. Now I want to move to bigger program. I have a
> rather big Fortran code which compiles and links fine under ifc. Now I
> changed the program main in Fortran into a subroutine main_sub so that I can
> call this subroutine main_sub from C++. I am getting error in linking. For
> your convenience I am pasting the output of both linking the main program in
> ifc and linking the program with g++. Any help will be appreciated regarding
> the undefined reference. Thanks
>
> NM[/color]

I can't speak for the group comp.lang.fortr an, but your question is
off-topic here in comp.lang.c++. The C++ language does not define an
interface to Fortran, or indeed any other language except C in some
circumstances, and all such mechanisms are completely
compiler-specific and beyond the pale here.

If you need advice on the C++ side of things, you need to ask in a
compiler-specific support group.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.l earn.c-c++

404 Not Found

http://www.contrib.andrew.cmu.edu/~ajo/docs/FAQ-acllc.html

**William Clodius** · Jul 22 '05, 07:02 AM

Re: C++/Fortran mixing

Jack Klein wrote:
[color=blue]
> On Thu, 26 Feb 2004 15:30:43 -0600, "NM" <nm@nm.com> wrote in
> comp.lang.c++:
>[color=green]
> > Hi all
> > I am trying to link C++ and Fortran.I am not very familiar with Fortran.
> > I have been successful in linking C++ and fortran using g++ and ifc for
> > simple program. So adding _ to at the end of fortran subroutine names when
> > calling from C++ is working. Now I want to move to bigger program. I have a
> > rather big Fortran code which compiles and links fine under ifc. Now I
> > changed the program main in Fortran into a subroutine main_sub so that I can
> > call this subroutine main_sub from C++. I am getting error in linking. For
> > your convenience I am pasting the output of both linking the main program in
> > ifc and linking the program with g++. Any help will be appreciated regarding
> > the undefined reference. Thanks
> >
> > NM[/color]
>
> I can't speak for the group comp.lang.fortr an, but your question is
> off-topic here in comp.lang.c++. The C++ language does not define an
> interface to Fortran, or indeed any other language except C in some
> circumstances, and all such mechanisms are completely
> compiler-specific and beyond the pale here.
> <snip>[/color]

FWIW - Two points

1. The only current standard conforming way to do this is via Ada. Ada 95(?)
defines conventions to "link" with Fortran 77 and C89, so you can, in principle
do this if you
a. have an Ada compiler available (GNAT is widely portable and free)
b. learn enough Ada to deal with the details of this issue.
c. Learn the C++ C linkage conventions
c. Have C++ and Fortran compilers compatible with the Ada compiler, e.g., g77 and
the g++ compiler are compatible with gnat. Be aware that many Fortran codes use
extensions of F77. g77 incorporates the omnipresent MIL-STD extensions, but few
others. G95 is a work in progress.

2. There will "soon" be a n Ada independent standard conforming means of doing
this, as Fortran 2003 defines C linkage conventions, is near the end of its
second review, and is not expectted to require a third review. Although this is
one of the largest additions by F03 to F95, it is also perhaps the most requested
feature, so the most recent version of "many" (anyway more than 3) F95 compilers
already incorporate versions of these conventions (based on earlier drafts) as an
extension.

--

-------------------------------------------------------------
William B. Clodius Space & Remote Sensing Sciences
Tech. Staff Member, ISR-2 Phone: (505) 665-9370
Mail Stop B244 FAX: (505) 665-4414
Los Alamos National Lab. Group office: (505) 667-5776
Fed Ex add: Bikini Atoll Rd. Email: remove gibberish
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-------------------------------------------------------------

C++/Fortran mixing

C++/Fortran mixing

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