Linking preinstalled libraries from gfortran in Mac OSx 10.6 - linker

Question

I have been trying to compile a certain code written in fortran90 and C, for a few days now. I am using gfortran and gcc. The code needs to link to lapack, blas and fftw3 libraries. I have all three installed in my macbook pro. But when I run the configure script, for some reason, it fails to locate the fftw3 libraries.
Here is my configure line:
./configure --prefix=`pwd` --with-fft=fftw3 \
--with-fft-lib='-I/opt/local/include -L/opt/local/lib -lfftw3 -lm' \
--with-blas='-I/opt/local -L/opt/local -lblas' \
--with-lapack='-I/opt/local -L/opt/local -llapack' \
FCFLAGS='-O3 -m64'
I have used exactly the same linking line for lapack, blas and as well as fftw3. Configure is able to find lapack and blas but fails to link fftw3. Does anyone have any idea what is happening here? I would appreciate any help.
Thanks,
kopinjol
Hi everyone,
First of all thanks Hristo Iliev for your answers earlier. I have been able to fix that problem with linking the libraries. You were right about using different compilers for the libraries and the main code. That was the problem. And when I compiled them with the same compiler, the linking problem went away. But now I have another issue.
In the code there is a function call like this:
call io_open(info_files(n_files)%unit,trim(dir)//"/info")
The io_open function is defined as follows:
subroutine io_open(unit, file, status, form)
integer, intent(out) :: unit
character(len=*), intent(in) :: file
character(len=*), intent(in), optional :: status, form
integer :: iostat
character(len=20) :: status_, form_
The error I get is this:
call io_open(info_files(n_files)%unit, trim(dir)
1
Error: Syntax error in argument list at (1)
Basically it seems that the code gives a syntax error in
trim(dir)//"/info"
which is the filename in the function call.
Now the code compiles without any problem on a linux box (I was using ubuntu, the most recent release). I get the error only on my macbook pro running osx 10.6 .
Also surprisingly, the code compiles when I define an extra variable fname as
fname=trim(dir)//"/info"
and then use it for the function call
call io_open(info_files(n_files)%unit,fname)
Now I can make the substitution in all the function calls in the code, which are quite a few and it will probably take me a few hours to make the change by hand. But it somehow doesn't make sense that the same code with the same compilers compile without error in linux but fails in the mac. Does anyone have any idea as to what may be going wrong? I will appreciate any input.
Thanks in advance,
kopinjol

Answer 1

Thanks for the reply Hristo Iliev. I just figured out the problem. The problem was that I was using different versions of the same compiler. Once I updated the environment variables with compilers of the same versions, it all started working.
This is what I did,
export FC="gfortran-mp-4.6 -m64"
export F77="gfortran-mp-4.6 -m64"
export F90="gfortran-mp-4.6 -m64"
export CC="gcc-mp-4.6 -m64"
export CXX="g++-mp-4.6 -m64"
export CPP="cpp-mp-4.6 -m64 -C -ansi"
export FCCPP="cpp-mp-4.6 -m64 -C -ansi"
export FCFLAGS="-O3"
export FFLAGS="-O3"
As explained in the APE mailing list.
Thanks again,
kopinjol