Compiling glibc with llvm


I read on the gentoo website that glibc cannot be compiled using llvm because of some GNU extensions which LLVM does not support.

Has there been any success in compiling glibc using LLVM so as to get the bytecode?
We are looking to do whole program analysis to look at control flows including those in libc… we were hoping that we could get the control flows using LLVM API’s for glibc.

Has anyone tried this before?