Determining which static libraries are linked unnecessarily

I want to cut down library dependencies on some C++ executables I'm compiling for Linux with GCC. There is a list of probably 40 static libraries that being linked. I want to determine which ones are unnecessary, and I would rather not try removing them one at a time to find out.

Is there an option in GCC to make it warn about libraries that are linked but don't resolve any symbols?

Are there any Linux tools available that will help me out?

To be clearn, I'm not concerned with unused code being linked into the executable. Rather, I'm concerned with the unnecessary build dependencies. I'd like to cut down my build times.