HELP: configure: error:

I am trying to compiler the clang followed the ,and facing this problem when on the
6th steps,I was wondering if everybody could help me ?I don't know what to
do with it .
configure: error: Selected compiler could not find or parse C++ standard
library headers. Rerun with CC=c-compiler CXX=c++-compiler ./configure ...

What compiler is currently set to CC/CXX? Do you have a build of clang on your path? If so, which version of clang?