Remember that the compiler wrapper is a thin layer around the compiler used to build the MPI library. Under the hood, it will call the same compiler and augment it with additional arguments, such as include paths and libraries, needed to successfully build a parallel program.
Which flags does the wrapper actually apply when compiling and linking a source file? We can probe this using the --showme option to the compiler wrapper. To find out the compiler flags we can use:
$ mpicxx --showme:compile-pthread
Whereas to find out the linker flags we use the following:
$ mpicxx --showme:link-pthread -Wl,-rpath -Wl,/usr/lib/openmpi -Wl,--enable-new-dtags -L/usr/lib/openmpi -lmpi_cxx -lmpi
Similarly to the previous OpenMP recipe, we have ...