Set OMPI_DECLSPEC in CMake files, so that applications that using Open MPI libraries don't need to define OMPI_IMPORTS explicitly.

This commit was SVN r20829.

contrib/platform/win32/CMakeModules/ompi_configure.cmake

@@ -133,6 +133,13 @@ SET(OMPI_F90_ABSOLUTE "\"none\"")
 
 SET(OMPI_F90_BUILD_SIZE "\"small\"")
 
+# set the im/export decleration here. 
+# Don't bother with OMPI_IMPORTS
+IF(BUILD_SHARED_LIBS)
+  SET(OMPI_DECLSPEC "__declspec(dllimport)")
+ELSE(BUILD_SHARED_LIBS)
+  SET(OMPI_DECLSPEC "")
+ENDIF(BUILD_SHARED_LIBS)
 
 ###################################################################
 #                              Options                            #
@@ -255,7 +262,7 @@ ENDIF(OMPI_PROVIDE_MPI_FILE_INTERFACE)
 
 
 OPTION(OMPI_WANT_CXX_BINDINGS
-  "Whether we want MPI cxx support or not." OFF)
+  "Whether we want MPI cxx support or not." ON)
 MARK_AS_ADVANCED(OMPI_WANT_CXX_BINDINGS)
 IF(OMPI_WANT_CXX_BINDINGS)
   SET(OMPI_WANT_CXX_BINDINGS 1)

contrib/platform/win32/ConfigFiles/mpi.h.cmake

@@ -136,6 +136,9 @@
 /* Whether OMPI should provide MPI File interface */
 #cmakedefine OMPI_PROVIDE_MPI_FILE_INTERFACE ${OMPI_PROVIDE_MPI_FILE_INTERFACE}
 
+/* Define OMPI_DECLSPEC based on build type (static/shared). */
+#define OMPI_DECLSPEC ${OMPI_DECLSPEC}
+
 #ifndef OMPI_DECLSPEC
 #  if defined(WIN32) || defined(_WIN32)
 #    if defined(OMPI_IMPORTS)