[llvm-dev] Building LLVM 3.7.1 on OS X

[Antoine Pitrou via llvm-dev]

Hello,

I haven't found any relevant info in the docs about this. I'm trying to
build LLVM 3.7.1 on OS X but it fails in the configuration phase. Here
are the relevant parts of the output:

$ cmake -DCMAKE_INSTALL_PREFIX=/Volumes/HD2/jenkins/workspace/LLVMDev/label/osxbuild/miniconda/envs/_build -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD=host -DLLVM_INCLUDE_TESTS=OFF -DLLVM_INCLUDE_UTILS=OFF -DLLVM_INCLUDE_DOCS=OFF -DLLVM_INCLUDE_EXAMPLES=OFF ..
-- The C compiler identification is AppleClang 4.1.0.4211166
-- The CXX compiler identification is AppleClang 4.1.0.4211166
[...]
-- Looking for __atomic_fetch_add_4 in atomic
-- Looking for __atomic_fetch_add_4 in atomic - not found
CMake Error at cmake/modules/CheckAtomic.cmake:36 (message):
  Host compiler appears to require libatomic, but cannot find it.
Call Stack (most recent call first):
  cmake/config-ix.cmake:291 (include)
  CMakeLists.txt:360 (include)


How is libatomic supposed to be installed on OS X?
(perhaps it's somewhat of a newbie question - I'm not a OS X user...)

Thank you,

Antoine.