document modules; fixes #7

modules/mpi.cmake

@@ -1,10 +1,32 @@
+#.rst:
+#
+# Enables MPI support.
+#
+# Variables used::
+#
+#   ENABLE_MPI
+#   MPI_FOUND
+#
+# Variables modified (provided the corresponding language is enabled)::
+#
+#   CMAKE_Fortran_FLAGS
+#
+# Example autocmake.cfg entry::
+#
+#   [mpi]
+#   source: https://github.com/scisoft/autocmake/raw/master/modules/mpi.cmake
+#   docopt: --mpi Enable MPI parallelization [default: False].
+#   define: '-DENABLE_MPI=%s' % arguments['--mpi']
+
 option(ENABLE_MPI "Enable MPI parallelization" OFF)
 
 # on Cray configure with -D MPI_FOUND=1
 if(ENABLE_MPI AND NOT MPI_FOUND)
     find_package(MPI)
     if(MPI_FOUND)
-        set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${MPI_COMPILE_FLAGS}")
+        if(DEFINED CMAKE_Fortran_COMPILER_ID)
+            set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${MPI_COMPILE_FLAGS}")
+        endif()
         include_directories(${MPI_INCLUDE_PATH})
     else()
         message(FATAL_ERROR "-- You asked for MPI, but CMake could not find any MPI installation, check $PATH")