g77/gfortran incompatibilities---name mangling

[Tim Prince]

sean yang wrote:
> I saw a same question asked on the mailing list(date back to last year), 
> but it was not answered.
> 
> Can I somehow make the code compiled by gfortran compatible to the code 
> compiled by g77? Because symbol name in lots of libraries are g77 
> compitable. Here is a concrete example,
> 
> I tried to compile the following mpi programs with g77(the fotran 
> compiler under the directory  /usr/bin on my machine) and gfotran (the 
> fortran compiler I generated from gcc 4.0.2)
> #/usr/bin/g77 -c test.f
> #nm test.o
> 00000029 T MAIN__
>         U mpi_comm_rank__
>         U mpi_comm_size__
>         U mpi_finalize__
>         U mpi_init__
> 
> 
> #/home/gcc402/bin/gfortran -c test.f
> #nm test.o
> 00000000 T MAIN__
>         U mpi_comm_rank_
>         U mpi_comm_size_
>         U mpi_finalize_
>         U mpi_init_
> --------------------test.f-------------
>        program main
> 
>      include 'mpif.h'
> 
>      double precision  PI25DT
>      parameter        (PI25DT = 3.141592653589793238462643d0)
> 
>      double precision  mypi, pi, h, sum, x, f, a
>      integer n, myid, numprocs, i, rc
> c                                 function to integrate
>      f(a) = 4.d0 / (1.d0 + a*a)
> 
>      call MPI_INIT( ierr )
>      call MPI_COMM_RANK( MPI_COMM_WORLD, myid, ierr )
>      call MPI_COMM_SIZE( MPI_COMM_WORLD, numprocs, ierr )
> 
> 30   call MPI_FINALIZE(rc)
>      stop
>      end
AFAIK, every version of MPI includes a system for adapting to the 
default underscore-appending scheme of gfortran.  That scheme would be 
preferable to use of the second_underscore option.  In either case, 
you'll have to break out TFM.  If you are trying to combine g77 and 
gfortran, don't.  Several versions of MPI also have FAQs and help lists 
of their own.