build: Limit scope of MPI definition and include directory

build-support/macros-and-definitions.cmake

@@ -840,8 +840,7 @@ macro(process_options)
       message(FATAL_ERROR "MPI was not found.")
     else()
       message(STATUS "MPI was found.")
-      add_definitions(-DNS3_MPI)
-      include_directories(${MPI_CXX_INCLUDE_DIRS})
+      target_compile_definitions(MPI::MPI_CXX INTERFACE NS3_MPI)
       set(ENABLE_MPI TRUE)
     endif()
   endif()

doc/manual/source/working-with-cmake.rst

@@ -2855,7 +2855,7 @@ followed by a header configuration:
     else()
       # If it is false, we add necessary C++ definitions (e.g. NS3_MPI)
       message(STATUS "MPI was found.")
-      add_definitions(-DNS3_MPI)
+      target_compile_definitions(MPI::MPI_CXX INTERFACE NS3_MPI)
 
       # Then set ENABLE_MPI to TRUE, which can be used to check
       # if NS3_MPI is enabled AND MPI was found

src/brite/examples/CMakeLists.txt

@@ -20,6 +20,6 @@ if(${ENABLE_MPI})
       ${libnix-vector-routing}
       ${libapplications}
       ${libmpi}
-      ${MPI_CXX_LIBRARIES}
+      MPI::MPI_CXX
   )
 endif()

src/mpi/CMakeLists.txt

@@ -22,6 +22,6 @@ build_lib(
     model/mpi-receiver.h
     model/parallel-communication-interface.h
   LIBRARIES_TO_LINK ${libnetwork}
-                    ${MPI_CXX_LIBRARIES}
+                    MPI::MPI_CXX
   TEST_SOURCES ${example_as_test_suite}
 )

src/mpi/examples/CMakeLists.txt

@@ -1,5 +1,3 @@
-link_libraries(${MPI_CXX_LIBRARIES})
-
 set(base_examples
     simple-distributed
     simple-distributed-mpi-comm

src/point-to-point/CMakeLists.txt

@@ -11,7 +11,7 @@ if(${ENABLE_MPI})
   )
   set(mpi_libraries
       ${libmpi}
-      ${MPI_CXX_LIBRARIES}
+      MPI::MPI_CXX
   )
 endif()