[llvm-dev] CMake warning when compiling Clang/LLVM

[Jonas Hahnfeld via llvm-dev]

Am 2018-01-26 21:55, schrieb Simone Atzeni:
> Thanks, that's the reason.
> 
> So to clarify, I should use -DLLVM_ENABLE_LIBCXX=ON only if I am
> building clang with clang?
> I got confused, I thought it was for building libc++, but having that
> under projects seems to be enough.

If libc++ is under projects/ it will get built. What LLVM_ENABLE_LIBCXX 
does is to enable _linking_ all LLVM libraries and binaries to libc++ as 
the C++ STL and that's only supported with Clang. You can specify the 
option when building with GCC, it just won't work and issue the warning 
you are seeing.

Regards,
Jonas