Problem :
What is the easiest way to setup full Clang, libc++ and LLVM as default global toolchain? All of my attempts to build it, in most of the configurations I could think of, resulted in working Clang, but it didn’t use libc++ headers, but default GCC’s libstd++’s ones, resulting in numerous faults in incompatible pieces of library code.
I would like it working out of the box, without having to do magic in .bashrc or passing all those -stdlib=libc++ and -lc++ to compiler and linker.
Solution :
Judging on how LLVM and Clang have been integrated into FreeBSD’s base, i think you will need to hack Clang’s internals to set library and headers paths (lib/Frontend/InitHeaderSearch.cpp) for your system.
Using libc++ as default definitely needs changing the code (grep lib/Frontend/CompilerInvocation.cpp for “UseLibcxx”). You will probably need to hack system linker too to change -lstdc++ to -lc++.
Personally, i’d recommend you just setting CC, CXX, CFLAGS, CXXFLAGS and other vars to achieve same result without much hassle. It works for me flawlessly on FreeBSD.