Add a generic error code MPI_T_ERR_INVALID of MPI-3.1

The error code will be introduced in MPI-3.1. The code is used in
MPI_T_pvar_read, which has motivated for adding the error code.

See also https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/400

Signed-off-by: Antonio J. Pena <apenya@mcs.anl.gov>

src/include/mpi.h.in

@@ -866,12 +866,13 @@ typedef int (MPIX_Grequest_wait_function)(int, void **, double, MPI_Status *);
 #define MPI_T_ERR_PVAR_NO_WRITE     71  /* Pvar can't be written or reset */
 #define MPI_T_ERR_PVAR_NO_ATOMIC    72  /* Pvar can't be R/W atomically */
 #define MPI_T_ERR_INVALID_NAME      73  /* Name doesn't match */
+#define MPI_T_ERR_INVALID           74  /* Generic error code for MPI_T added in MPI-3.1 */
 
 
 #define MPI_ERR_LASTCODE    0x3fffffff  /* Last valid error code for a 
 					   predefined error class */
 /* WARNING: this is also defined in mpishared.h.  Update both locations */
-#define MPICH_ERR_LAST_CLASS 73     /* It is also helpful to know the
+#define MPICH_ERR_LAST_CLASS 74     /* It is also helpful to know the
 				       last valid class */
 
 #define MPICH_ERR_FIRST_MPIX 100 /* Define a gap here because sock is

src/include/mpishared.h

@@ -62,7 +62,7 @@
 #include "mpierrs.h"
 
 /* FIXME: This is extracted from mpi.h.in, where it may not be appropriate */
-#define MPICH_ERR_LAST_CLASS 73     /* It is also helpful to know the
+#define MPICH_ERR_LAST_CLASS 74     /* It is also helpful to know the
 				       last valid class */
 
 #include "mpifunc.h"

src/mpi_t/pvar_read.c

@@ -35,11 +35,11 @@ int MPIR_T_pvar_read_impl(MPI_T_pvar_session session, MPI_T_pvar_handle handle,
     int i, mpi_errno = MPI_SUCCESS;
 
     /* Reading a never started pvar, or a stopped and then reset wartermark,
-     * will run into this nasty situation. Wait for an error code to be defined
-     * by the Standard. Currently, use MPI_ERR_OTHER.
+     * will run into this nasty situation. Return a generic MPI_T error code,
+     * which is defined in MPI-3.1.
      */
     if (!MPIR_T_pvar_is_oncestarted(handle)) {
-        mpi_errno = MPI_ERR_OTHER;
+        mpi_errno = MPI_T_ERR_INVALID;
         goto fn_fail;
     }