Compilation problems with GDC/GCC

[DRex via Digitalmars-d-learn]

I have project which involves both C and D code.  For reasons 
that are much too long to explain, I have to use GCC to compile 
the C code into object files (GDC to compile the D code into 
object files) and then ld to link all the object files together.  
Now (unless I am missing something) ld cant link D object files 
(a whole bunch of errors about undefined references to a million 
different things) which I can only assume is attributed to ld not 
knowing about the D libraries and runtime.  GDC can link D object 
files just fine, but again for reasons too long to explain, I 
cannot use GDC to link the object files together.

I need to take a handful of specific C files and a handful of 
Specific D files and link them together (and redirect it into 
another .o object file using the -r switch of ld) but again, ld 
can't deal with D object files.  I have tried using the -Xlinker 
as well as -Wl switches from GDC to pass the -r switch to the 
linker, but GDC just spews out "/usr/bin/ld: cannot find -lgcc_s" 
and fails.

Sorry if I am making no sense, if I am not being clear, let me 
know and I will try to re-explain, hoping someone can help me.

Cheers.