Open MPI installation test file with generic Makefile

main.cpp

#include <iostream>

#include <mpi.h>

struct Info {
  int world_size;
  int world_rank;
  struct Processor {
    char name[MPI_MAX_PROCESSOR_NAME];
    int name_len;
  } processor;
};

int main() {
  auto info = Info();

  MPI_Init(nullptr, nullptr);

  MPI_Comm_size(MPI_COMM_WORLD, &info.world_size);
  MPI_Comm_rank(MPI_COMM_WORLD, &info.world_rank);
  MPI_Get_processor_name(info.processor.name, &info.processor.name_len);

  std::cout << "Hello, world! From processor " << info.processor.name << ", rank " << info.world_rank + 1 << "/"
            << info.world_size << std::endl;

  MPI_Finalize();

  return 0;
}

Makefile

BIN?=main
OMPI_CC=clang++ mpic++
MPICXX?=mpic++
MPIRUN?=mpirun
EXT?=cpp
LINKS?=

SRCS=$(shell find . -name "*."$(EXT))
DIRS=$(shell find ./* -type d)
OBJS=$(patsubst %.$(EXT),%.o,$(SRCS))
INCS=$(addprefix -I, $(DIRS))

CPPFLAGS+=-std=c++17 -Wall $(INCS)
LDFLAGS+=$(addprefix -l, $(LINKS))

.PHONY: all run clean

all: $(BIN)

$(EXT).o: $(SRCS)
	$(CXX) $(CPPFLAGS) -c $<

$(BIN): $(OBJS)
	$(MPICXX) $(CPPFLAGS) -o $(BIN) $(notdir $(OBJS)) $(LDFLAGS)

run: all
	-$(MPIRUN) ./$(BIN)

clean:
	-rm -f $(notdir $(OBJS)) $(BIN)