Error during cmake build : CXX compiler must support Cilk

Question

I am trying to install cilk++ according to this website and am at the steps in section "Cilk Plus Runtime". When I go to build, I get the following output:

$ cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_INSTALL_PREFIX=./install ..
CMake Error at CMakeLists.txt:132 (message):
  CXX compiler must support Cilk.


-- Configuring incomplete, errors occurred!
See also "/Users/anthonymcknight/Documents/cubing/bfs/lab4/cilk/cilkrts-0.1.2/build/CMakeFiles/CMakeOutput.log".
See also "/Users/anthonymcknight/Documents/cubing/bfs/lab4/cilk/cilkrts-0.1.2/build/CMakeFiles/CMakeError.log".

I thought clang and clang++ (which I checked with --version are indeed installed) would be sufficient. Do I need to update clang and clang++? There are no troubleshooting steps on the instructions website, so I'm not sure what I need to do to finally get cilk++ up and running on my laptop.

Thanks in advance,

Anthony

Answer 1

Expanding on my comment:

When you configure this Cilk Plus Runtime with CMake, CMake first verifies the compiler by attempting to compile a simple test program (see here). If the compilation fails, CMake prints the error you see:

CMake Error at CMakeLists.txt:132 (message):
  CXX compiler must support Cilk.

On the Intel Cilk Plus runtime Github page (cilkrts), it has some compiler requirements listed for those trying to build this library:

You need the CMake tool and a C/C++ compiler that supports the Cilk language extensions. The requirements for each operating systems are:

• Common: CMake 3.4.3 or later Make tools such as make
• Linux: Tapir/LLVM compiler, or GCC* 4.9.2 or later (depracated), or Cilk-enabled branch of Clang*/LLVM* (http://cilkplus.github.io), or Intel(R) C++ Compiler v12.1 or later (depracated)
• OS X: Tapir/LLVM compiler, or Cilk-enabled branch of Clang*/LLVM* (http://cilkplus.github.io), or Intel C++ Compiler v12.1 or later (depracated)

Since you are using Clang as your compiler, be sure it is a Cilk-enabled branch of Clang, as specified in the requirements. Or, you can try to use the Tapir/LLVM compiler.