MPI program fails to link on my desktop

[jfavre]

mpic++ .o main.cpp -o main
main.cpp: In function ‘void write_binary(std::string, data::Field&, data::SubDomain&, data::Discretization&)’:
main.cpp:60:95: warning: deprecated conversion from string constant to ‘char’ [-Wwrite-strings]
result = MPI_File_set_view(filehandle, disp, MPI_DOUBLE, filetype, "native", MPI_INFO_NULL);
^
data.o: In function data::SubDomain::print()': data.cpp:(.text+0x3f6): undefined reference toomp_get_wtime'
data.cpp:(.text+0x409): undefined reference to omp_get_wtime' /tmp/ccjgrECG.o: In functionmain':
main.cpp:(.text+0xad5): undefined reference to omp_get_wtime' main.cpp:(.text+0xd04): undefined reference toomp_get_wtime'
collect2: error: ld returned 1 exit status
make: *** [main] Error 1