Fix: Assert that MPI_BYTE is 1 byte large

Signed-off-by: Florent Germain <florent.germain@atos.net>

Author: FlorentGermain-Bull

ompi/datatype/ompi_datatype_internal.h

@@ -133,27 +133,14 @@
  * of being redefined as independent types, they will be made synonyms to
  * the most basic type.
  */
-#if SIZEOF_CHAR == 1
+#if SIZEOF_CHAR != 1
+#error Open MPI asserts that sizeof(char) is 1. This seems not to be the case here. Please report on Open MPI github (see issue #11815)
+#endif
+
 #define OMPI_DATATYPE_MPI_CHAR                    OMPI_DATATYPE_MPI_INT8_T
 #define OMPI_DATATYPE_MPI_SIGNED_CHAR             OMPI_DATATYPE_MPI_INT8_T
 #define OMPI_DATATYPE_MPI_UNSIGNED_CHAR           OMPI_DATATYPE_MPI_UINT8_T
 #define OMPI_DATATYPE_MPI_BYTE                    OMPI_DATATYPE_MPI_UINT8_T
-#elif SIZEOF_CHAR == 2
-#define OMPI_DATATYPE_MPI_CHAR                    OMPI_DATATYPE_MPI_INT16_T
-#define OMPI_DATATYPE_MPI_SIGNED_CHAR             OMPI_DATATYPE_MPI_INT16_T
-#define OMPI_DATATYPE_MPI_UNSIGNED_CHAR           OMPI_DATATYPE_MPI_UINT16_T
-#define OMPI_DATATYPE_MPI_BYTE                    OMPI_DATATYPE_MPI_UINT16_T
-#elif SIZEOF_CHAR == 4
-#define OMPI_DATATYPE_MPI_CHAR                    OMPI_DATATYPE_MPI_INT32_T
-#define OMPI_DATATYPE_MPI_SIGNED_CHAR             OMPI_DATATYPE_MPI_INT32_T
-#define OMPI_DATATYPE_MPI_UNSIGNED_CHAR           OMPI_DATATYPE_MPI_UINT32_T
-#define OMPI_DATATYPE_MPI_BYTE                    OMPI_DATATYPE_MPI_UINT32_T
-#elif SIZEOF_CHAR == 8
-#define OMPI_DATATYPE_MPI_CHAR                    OMPI_DATATYPE_MPI_INT64_T
-#define OMPI_DATATYPE_MPI_SIGNED_CHAR             OMPI_DATATYPE_MPI_INT64_T
-#define OMPI_DATATYPE_MPI_UNSIGNED_CHAR           OMPI_DATATYPE_MPI_UINT64_T
-#define OMPI_DATATYPE_MPI_BYTE                    OMPI_DATATYPE_MPI_UINT64_T
-#endif
 
 #if SIZEOF_SHORT == 1
 #define OMPI_DATATYPE_MPI_SHORT                   OMPI_DATATYPE_MPI_INT8_T
@@ -519,27 +506,10 @@ extern const ompi_datatype_t* ompi_datatype_basicDatatypes[OMPI_DATATYPE_MPI_MAX
 #define OMPI_DATATYPE_INITIALIZER_INT64_T             OPAL_DATATYPE_INITIALIZER_INT8
 #define OMPI_DATATYPE_INITIALIZER_UINT64_T            OPAL_DATATYPE_INITIALIZER_UINT8
 
-#if SIZEOF_CHAR == 1
 #define OMPI_DATATYPE_INITIALIZER_CHAR                OPAL_DATATYPE_INITIALIZER_INT1
 #define OMPI_DATATYPE_INITIALIZER_UNSIGNED_CHAR       OPAL_DATATYPE_INITIALIZER_UINT1
 #define OMPI_DATATYPE_INITIALIZER_SIGNED_CHAR         OPAL_DATATYPE_INITIALIZER_INT1
 #define OMPI_DATATYPE_INITIALIZER_BYTE                OPAL_DATATYPE_INITIALIZER_UINT1
-#elif SIZEOF_CHAR == 2
-#define OMPI_DATATYPE_INITIALIZER_CHAR                OPAL_DATATYPE_INITIALIZER_INT2
-#define OMPI_DATATYPE_INITIALIZER_UNSIGNED_CHAR       OPAL_DATATYPE_INITIALIZER_UINT2
-#define OMPI_DATATYPE_INITIALIZER_SIGNED_CHAR         OPAL_DATATYPE_INITIALIZER_INT2
-#define OMPI_DATATYPE_INITIALIZER_BYTE                OPAL_DATATYPE_INITIALIZER_UINT2
-#elif SIZEOF_CHAR == 4
-#define OMPI_DATATYPE_INITIALIZER_CHAR                OPAL_DATATYPE_INITIALIZER_INT4
-#define OMPI_DATATYPE_INITIALIZER_UNSIGNED_CHAR       OPAL_DATATYPE_INITIALIZER_UINT4
-#define OMPI_DATATYPE_INITIALIZER_SIGNED_CHAR         OPAL_DATATYPE_INITIALIZER_INT4
-#define OMPI_DATATYPE_INITIALIZER_BYTE                OPAL_DATATYPE_INITIALIZER_UINT4
-#elif SIZEOF_CHAR == 8
-#define OMPI_DATATYPE_INITIALIZER_CHAR                OPAL_DATATYPE_INITIALIZER_INT8
-#define OMPI_DATATYPE_INITIALIZER_UNSIGNED_CHAR       OPAL_DATATYPE_INITIALIZER_UINT8
-#define OMPI_DATATYPE_INITIALIZER_SIGNED_CHAR         OPAL_DATATYPE_INITIALIZER_INT8
-#define OMPI_DATATYPE_INITIALIZER_BYTE                OPAL_DATATYPE_INITIALIZER_UINT8
-#endif
 
 #if SIZEOF_SHORT == 2
 #define OMPI_DATATYPE_INITIALIZER_SHORT               OPAL_DATATYPE_INITIALIZER_INT2