Question

I’m trying to run some MPI programs in xcode 4. I installed openmpi from MacPort by typing sudo port install openmpi and the installation finished normally. Then I added opt/local/include/openmpi to my user header search paths, dragged the “libmpi.dylib” and “libmpi_cxx.dylib” into my project.

But then when I tried to run the program, I got the following error message:

Undefined symbols for architecture x86_64:
  "_MPI_Comm_accept", referenced from:
      MPI::Intracomm::Accept(char const*, MPI::Info const&, int) const in main.o
  "_MPI_Comm_connect", referenced from:
      MPI::Intracomm::Connect(char const*, MPI::Info const&, int) const in main.o
  "_MPI_Comm_disconnect", referenced from:
      MPI::Comm::Disconnect() in main.o
  "_MPI_Comm_get_errhandler", referenced from:
      MPI::Comm::Get_errhandler() const in main.o
  "_MPI_Comm_set_errhandler", referenced from:
      MPI::Comm::Set_errhandler(MPI::Errhandler const&) const in main.o
  "_MPI_Comm_spawn", referenced from:
      MPI::Intracomm::Spawn(char const*, char const**, int, MPI::Info const&, int) const in main.o
      MPI::Intracomm::Spawn(char const*, char const**, int, MPI::Info const&, int, int*) const in main.o
  "_MPI_Comm_spawn_multiple", referenced from:
      MPI::Intracomm::Spawn_multiple(int, char const**, char const***, int const*, MPI::Info const*, int) in main.o
      MPI::Intracomm::Spawn_multiple(int, char const**, char const***, int const*, MPI::Info const*, int, int*) in main.o
  "_MPI_Grequest_complete", referenced from:
      MPI::Grequest::Complete() in main.o
  "_MPI_Op_commutative", referenced from:
      MPI::Op::Is_commutative() const in main.o
  "_MPI_Reduce_local", referenced from:
      MPI::Op::Reduce_local(void const*, void*, int, MPI::Datatype const&) const in main.o
  "_MPI_Win_call_errhandler", referenced from:
      MPI::Win::Call_errhandler(int) const in main.o
  "_MPI_Win_get_errhandler", referenced from:
      MPI::Win::Get_errhandler() const in main.o
  "_MPI_Win_set_errhandler", referenced from:
      MPI::Win::Set_errhandler(MPI::Errhandler const&) const in main.o
  "_ompi_mpi_comm_null", referenced from:
      MPI::Intracomm::Intracomm(ompi_communicator_t*) in main.o
      MPI::Graphcomm::Graphcomm(ompi_communicator_t* const&) in main.o
      MPI::Cartcomm::Cartcomm(ompi_communicator_t* const&) in main.o
  "_ompi_mpi_comm_world", referenced from:
      _main in main.o
  "_ompi_mpi_double", referenced from:
      _main in main.o
  "_ompi_mpi_op_sum", referenced from:
      _main in main.o
  "_ompi_op_set_cxx_callback", referenced from:
      MPI::Op::Init(void (*)(void const*, void*, int, MPI::Datatype const&), bool) in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Am I missing anything in the above installation processes?

Answer 1

I had the same problem, when I compiled openmpi from the sources, added header and library search paths, but forgot to add libraries as the linker flags to the build settings. Adding them solved this. You can type mpicc –showme to see the libraries that are necessary for mpi to run.