Oversized module object files on Mac OSX

[Adrian Turner]

Dear gfortran mailing list,

I am using gfortran on a Mac OSX to compile a program that has many 
modules which declare fixed size arrays. The resulting object files are 
the same size as the declared array, which makes the executable 
enormous. Below is an example:

program test
   real, dimension(1000) :: a
end program test

gfortran test.f90 -o test.exe

This compiles fine with the size of the executable independent of the 
size of the declared array. There are problems with the following module:

module test_module
   real, dimension(1000) :: a
end module test_module

gfortran -c test_module.f90

The size of the test_module.o object file in this case includes the 
memory allocation for the variable. e.g. if the array size is 10000000 
then the size of test_module.o is 40000356 bytes. This doesn't happen 
with the other fortran compilers I use. Is there any way to prevent this 
from happening?

akt% uname -a
Darwin m21.cpom.ucl.ac.uk 8.10.0 Darwin Kernel Version 8.10.0: Wed May 
23 16:50:59 PDT 2007; root:xnu-792.21.3~1/RELEASE_PPC Power Macintosh 
powerpc

akt% /opt/local/bin/gfortran -v
Using built-in specs.
Target: powerpc-apple-darwin8.10.0
Configured with: ../gcc-4.2.1/configure --prefix=/opt/local 
--enable-languages=c,c++,java,objc,obj-c++,fortran 
--libdir=/opt/local/lib/gcc42 --includedir=/opt/local/include/gcc42 
--infodir=/opt/local/share/info --mandir=/opt/local/share/man 
--with-local-prefix=/opt/local --with-system-zlib --disable-nls 
--disable-multilib --program-suffix=-mp-4.2 
--with-gxx-include-dir=/opt/local/include/gcc42/c++/ 
--with-gmp=/opt/local --with-mpfr=/opt/local
Thread model: posix
gcc version 4.2.1


Regards,
Adrian Turner
Centre for Polar Observation and Modelling
University College London