llvm dev - Mar 2011 - [LLVMdev] How to force to link a bitcode archive?

Hi, 

In the presence of both a normal archive (e.g., libclangLex.a) and a
bitcode archive (e.g., libclangLex.bca), how to force the llvm linker
(llvm-ld) to link to the bitcode archive instead of the normal
archive? Currently, I achieved the goal by removing the normal
archive, but I am wondering if there is a better to do so?

Best, 
Xiaolong