Ok, so didn't win, but I was able to change the rules.
Using this as a reference, I first compiled the CUDA code with nvcc, thus creating several object ( *.o ) files. These object files were then added to the list of object files linked by gcc when creating the library, libA. In addition, the follwing linker arguments were added to the gcc command "-L/usr/local/cuda/lib64 -lcudart" (I'm using an x64 machine).
It is EXTREMELY IMPORTANT to point out that you must place any library dependency AFTER the object file that needs it. If you don't gcc will complain about undefined references. A good rule of thumb is to place all libraries at the end of your gcc line. See below for details.
In a nutshell here's what worked:
CUDA:
nvcc -arch=sm_30 -c *.cu -Xcompiler -fPIC
C:
gcc *.c -c -fPIC -L/usr/local/cuda/lib64 -lcudart -lmysqlclient [many other shared libraries]
gcc -shared -Wl,-soname,libA.so -o libA.so *.o [cuda_obj_file_dir]/*.o -L/usr/local/cuda/lib64 -lcudart -lmysqlclient [many other shared libraries]
Many thanks to Anton Kovalenko for advice. Unfortunately, I wasn't able to solve my ultimate goal, but maybe this will serve as an intermediate for someone else, as it is doing for me now.