Replace strings in generator expressions by lists

The function target_compile_options in combination with
generator expressions does not handle strings with space
separated compiler flags and inserts quotes.

Also MPI_<lang>_COMPILE_FLAGS is deprecated since cmake 3.10
and should be replaced by MPI_<lang>_COMPILE_OPRIONS and
MPI_<lang>_COMPILE_DEFINITIONS.
Those variables are already lists of compiler flags and thus well
suited to solve the bug.

This fixes the build error described in issue #676 when using MPICH,
which is the same error as described in issue #704.

Signed-off-by: Elias Lettl <elias.lettl@physik.uni-augsburg.de>

Author: lettleli

src/mpi/CMakeLists.txt

@@ -22,7 +22,9 @@ set_target_properties(opencoarrays_mod
   Fortran_MODULE_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}/${mod_dir_tail}"
   POSITION_INDEPENDENT_CODE TRUE)
 target_compile_options(opencoarrays_mod
-  PRIVATE $<$<COMPILE_LANGUAGE:Fortran>:${MPI_Fortran_COMPILE_FLAGS}>)
+  PRIVATE $<$<COMPILE_LANGUAGE:Fortran>:${MPI_Fortran_COMPILE_OPTIONS}>)
+target_compile_definitions(opencoarrays_mod
+  PRIVATE $<$<COMPILE_LANGUAGE:Fortran>:${MPI_Fortran_COMPILE_DEFINITIONS}>)
 target_link_libraries(opencoarrays_mod
   PUBLIC ${MPI_Fortran_LINK_FLAGS}
   PUBLIC ${MPI_Fortran_LIBRARIES})
@@ -53,9 +55,13 @@ target_include_directories(caf_mpi_static PUBLIC
   $<BUILD_INTERFACE:${CMAKE_SOURCE_DIR}/src>
   $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
 target_compile_options(caf_mpi
-  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_FLAGS}>)
+  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_OPTIONS}>)
+target_compile_definitions(caf_mpi
+  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_DEFINITIONS}>)
 target_compile_options(caf_mpi_static
-  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_FLAGS}>)
+  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_OPTIONS}>)
+target_compile_definitions(caf_mpi_static
+  PUBLIC $<$<COMPILE_LANGUAGE:C>:${MPI_C_COMPILE_DEFINITIONS}>)
 
 set(CAF_SO_VERSION 0)
 if(gfortran_compiler)