When I build llvm using llvm/clang as opposed to gcc I get the following:
configure:2921: $? = 0
configure:2928: /home/rkotler/myclang/bin/clang++ -V >&5
clang: error: argument to '-V' is missing (expected 1 value)
clang: error: no input files
configure:2931: $? = 1
configure:2934: checking whether we are using the GNU C++ compiler
I suppose it was meant to behave as the corresponding GCC option:
The argument version specifies which version of GCC to run. This
is useful when multiple versions are installed. For example, ver-
sion might be 4.0, meaning to run GCC version 4.0.
Although the .td file from the clang driver seems to suggest that it's not supported (although recognized).