Follow on to r12146. For platforms that dont' have a ptrdiff_t definition,

provide one for the internals of Open MPI.  For mpi.h, typedef MPI_Aint
either to ptrdiff_t or whatever we used as ptrdiff_t if that type doesn't
actually exist.

This commit was SVN r12212.

The following SVN revision numbers were found above:
  r12146 --> open-mpi/ompi@8852c00c36

configure.ac

@@ -199,7 +199,8 @@ AC_CHECK_TYPES(uint64_t)
 AC_CHECK_TYPES(intptr_t)
 AC_CHECK_TYPES(uintptr_t)
 AC_CHECK_TYPES(mode_t)
-
+AC_CHECK_TYPES(ssize_t)
+AC_CHECK_TYPES(ptrdiff_t)
 
 #
 # Check for type sizes
@@ -219,6 +220,12 @@ AC_CHECK_SIZEOF(float)
 AC_CHECK_SIZEOF(double)
 AC_CHECK_SIZEOF(void *)
 AC_CHECK_SIZEOF(size_t)
+if test $ac_cv_type_ssize_t = yes ; then
+    AC_CHECK_SIZEOF(ssize_t)
+fi
+if test $ac_cv_type_ptrdiff_t = yes; then
+    AC_CHECK_SIZEOF(ptrdiff_t)
+fi
 
 #
 # Check for type alignments
@@ -770,6 +777,22 @@ if test "$MPI_OFFSET_TYPE" = "not found"; then
 fi
 AC_DEFINE_UNQUOTED(OMPI_MPI_OFFSET_TYPE, $MPI_OFFSET_TYPE, [Type of MPI_Offset -- has to be defined here and typedef'ed later because mpi.h does not get AC SUBST's])
 
+#
+# Check for MPI_Aint type.  Yes, there are platforms where
+# sizeof(void*) != sizeof(long) (64 bit Windows, apparently).
+#
+if test $ac_cv_type_ptrdiff_t = yes ; then
+    ompi_ptrdiff_t="ptrdiff_t"
+elif test $ac_cv_sizeof_void_p -eq $ac_cv_sizeof_long ; then
+    ompi_ptrdiff_t="long"
+elif test $ac_cv_type_long_long = yes -a $ac_cv_sizeof_void_p -eq $ac_cv_sizeof_long_long ; then
+    ompi_ptrdiff_t="long long"
+else
+    AC_MSG_ERROR([Could not find datatype to emulate ptrdiff_t.  Cannot continue])
+fi
+AC_DEFINE_UNQUOTED([OMPI_PTRDIFF_TYPE], [$ompi_ptrdiff_t],
+    [type to use for ptrdiff_t])
+
 #
 # If we haven't already, figure out an MPI datatype that corresponds
 # to the back-end C type of MPI_Offset.

ompi/include/mpi.h.in

@@ -71,6 +71,9 @@
 /* Type of MPI_Offset -- has to be defined here and typedef'ed later because mpi.h does not get AC SUBST's */
 #undef OMPI_MPI_OFFSET_TYPE
 
+/* type to use for ptrdiff_t, if it does not exist, set to ptrdiff_t if it does exist */
+#undef OMPI_PTRDIFF_TYPE
+
 /* Whether we want MPI cxx support or not */
 #undef OMPI_WANT_CXX_BINDINGS
 
@@ -92,6 +95,9 @@
 /* MPI datatype corresponding to MPI_Offset */
 #undef OMPI_OFFSET_DATATYPE
 
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
 /* A  type that allows us to have sentinel type values that are still
    valid */
 #undef ompi_fortran_bogus_type_t
@@ -112,10 +118,15 @@
 #define MPI_Fint ompi_fortran_integer_t
 #endif
 
-#endif
+#endif /* #ifndef OMPI_CONFIG_H */
 
 /* @OMPI_END_CONFIGURE_SECTION@ */
 
+/* include for ptrdiff_t */
+#ifdef STDC_HEADERS
+#include <stddef.h>
+#endif
+
 #ifndef OMPI_BUILDING
 #define OMPI_BUILDING 0
 #endif
@@ -148,8 +159,8 @@ extern "C" {
 /*
  * Typedefs
  */
-#include <stddef.h>
-typedef ptrdiff_t MPI_Aint;
+
+typedef OMPI_PTRDIFF_TYPE MPI_Aint;
 typedef OMPI_MPI_OFFSET_TYPE MPI_Offset;
 typedef struct ompi_communicator_t *MPI_Comm;
 typedef struct ompi_datatype_t *MPI_Datatype;

opal/include/opal_config_bottom.h

@@ -123,6 +123,10 @@
  **********************************************************************/
 #if OMPI_BUILDING
 
+#ifndef HAVE_PTRDIFF_T
+typedef OMPI_PTRDIFF_TYPE ptrdiff_t;
+#endif
+
 /*
  * If we're in C, we may need to bring in the bool type and true/false
  * constants.  OMPI_NEED_C_BOOL will be true if the compiler either