Mary,
There should be a compiler option that controls whether and how many
underscores get added to external names by the compiler. It sounds like the
default for that option has changed on you. I am not at work, so I cannot
check what my gcc says about it. But, you should be able to easily find the
option. Try gcc --help -v and gfortran --help -v.
Larry Baker
US Geological Survey
650-329-5608
baker@xxxxxxxx
On Dec 6, 2011, at 10:42 AM, Mary Haley wrote:
>
> I'm running into an oddity when building NetCDF 4.1.3 on the same Linux
> system, but with different versions of gcc and gfortran (4.1.2 versus 4.4.4).
>
> When I use 4.1.2, I don't get a second underscore after Fortran routine
> names, when the Fortran routine name already has an underscore. When I use
> 4.4.4, I get this second underscore, which causes an undefined reference when
> linking NetCDF with another package.
>
> I need to know how I can make sure that second underscore doesn't get
> appended?
>
> --------------------------------------------------------------------------------------------------
>
> For gcc/gfortran 4.1.2, I'm using the following settings:
>
> setenv CPPFLAGS
> '-I/glade/proj2/ncldev/install/mirage/netcdf-4.1.3-esmf/include
> -I/glade/proj2/ncldev/install/mirage/external/include'
> setenv LDFLAGS '-L/glade/proj2/ncldev/install/mirage/netcdf-4.1.3-esmf/lib
> -L/glade/proj2/ncldev/install/mirage/external/lib'
>
> setenv FC gfortran
> setenv F77 gfortran
> setenv F90 gfortran
> setenv CC gcc
> setenv CXX g++
>
> setenv CFLAGS -fPIC
> setenv FFLAGS '-fPIC -fno-second-underscore'
> setenv F90FLAGS '-fPIC -fno-second-underscore'
> setenv FCFLAGS '-fPIC -fno-second-underscore'
> setenv CXXFLAGS -fPIC
>
> make clean
> make distclean
>
> ./configure --disable-netcdf-4 --disable-dap --enable-f90 --disable-shared
> --prefix=/glade/proj2/ncldev/install/mirage/netcdf-4.1.3-esmf
>
> make all install
> make install
>
> and I get what I'd expect:
>
> % nm /glade/proj2/ncldev/install/mirage/netcdf-4.1.3-esmf/lib/libnetcdff.a |
> grep nf_inq_libvers
> 0000000000000333 T nf_inq_libvers_
> U nf_inq_libvers_
>
> Note there's only one underscore after "nf_inq_libvers" in both cases.
>
> --------------------------------------------------------------------------------------------------
> For gcc/gfortran 4.4.4, I only change the following settings:
>
> setenv FC gfortran44
> setenv F77 gfortran44
> setenv F90 gfortran44
> setenv CC gcc44
> setenv CXX g++44
>
> I then get:
>
> % nm /glade/proj2/ncldev/install/mirage/netcdf-4.1.3-esmf/lib/libnetcdff.a |
> grep nf_inq_libvers
> 0000000000000301 T nf_inq_libvers__
> U nf_inq_libvers_
>
> Note the second underscore in one case, but not the other.
>
> --------------------------------------------------------------------------------------------------
>
> Is there some code I can modify to make sure that second underscore doesn't
> get added?
>
> Thanks,
>
> --Mary
>
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