Linking Fortran to C++

[Ingo Krabbe]

Am Montag, 17. Juli 2006 18:06 schrieb Americo Barbosa da Cunha Junior:
> I've trying to link a Fortran code to a C++ code.
>
> First I create the object files for both languages:
>
> g77  -c  ckinterp.f   math.f   xerror.f  cklib.f  vode.f  conp.f
> g++  -c  linear_alg.cpp  teste.cpp
>
> Than I use the g++ to link:
>
> g++  -o  jac *.o -lg2c -lm
>
> The GCC returns a message like:
>
> cklib.o: In function `ckcomp_':cklib.f:(.text+0x2b43): multiple
> definition of `ckcomp_'
> ckinterp.o:ckinterp.f:(.text+0xa9b3): first defined here

If you read the error messages your problem comes out quite clearly.  There 
are definitions of symbols (functions or global variables) that exist in two 
files.  Here for example there is a cklib.o and a ckinterp.o that both seem 
to contain ckcomp_

So you should first check if these functions might have been introduced in 
both fortran files.  Note that the fortran name of ckcomp_ might be ckcomp or 
CKCOMP (I don't know the right name translation).

> conp.o: In function `MAIN__':conp.f:(.text+0x0): multiple definition of
> `MAIN__'
> ckinterp.o:ckinterp.f:(.text+0x0): first defined here
> /usr/bin/ld: Warning: size of symbol `MAIN__' changed from 11317 in
> ckinterp.o to 3528 in conp.o

you also seem to have multiple main entry points.

> xerror.o: In function `xerrwv_':xerror.f:(.text+0xfc0): multiple
> definition of `xerrwv_'
> vode.o:vode.f:(.text+0x7484): first defined here

some of your multiple definitions might also come from include files.  But I'm 
not that sure about include files in fortran.

> /usr/bin/ld: Warning: size of symbol `xerrwv_' changed from 457 in
> vode.o to 593 in xerror.o

if you aren't a programmer and more special the programmer of that code, you 
should ask the programmer to provide a valid make file.

When I'm right your ckinterp is a part of the CHEMKIN Software which isn't 
open source and seemed to be under some restricted license.  But if you have 
access to this software there should be an API Documentation.