Since NetBSD 6, the base system has included clang.  
It works on ARM, PowerPC, x86, and possibly SPARC64, but is not built by default.  
To use it, set in mk.conf:

    MKGCC=no
    MKLLVM=yes
    HAVE_LLVM=yes
    PKGSRC_COMPILER=clang
    CLANGBASE=/usr

And run "build.sh release". This will apply for both pkgsrc and base.



tunable                | explanation
-----------------------|----------------------------------------------------
MKGCC=no               | needed as building GCC alongside is not maintained
MKLLVM=yes             | builds LLVM libraries
HAVE_LLVM=yes          | controls clang being built
PKGSRC_COMPILER=clang  | instructs pkgsrc it's clang
CLANGBASE=/usr         | instructs pkgsrc where to look for the compiler

# status

[[NetBSD-current clang build status|https://releng.netbsd.org/builds/HEAD-llvm/]]