Add two predefined MPI object padding tests:

1. Canary compile-time test: this is compiled whenever you compile
    the entire OMPI tree.  It's a noinst standalone library comprised
    of a single .c file, so no one will notice its addition, and it
    doesn't get linked/installed to any real build products.  If we
    are out of padding space on any predefined MPI object type, it
    will fail to compile.  This will alert/annoy a human, who will be
    able to fix the real problem.
 1. Added a "make check" test that will print out the amount of
    predefined padding left on all the MPI object types.

This commit was SVN r30268.

ompi/debuggers/Makefile.am

@@ -17,10 +17,13 @@
 # $HEADER$
 #
 
-noinst_LTLIBRARIES = libdebuggers.la libompi_debugger_canary.la
+noinst_LTLIBRARIES = \
+        libdebuggers.la \
+        libompi_debugger_canary.la \
+        libompi_predefined_pad_canary.la
 ompilib_LTLIBRARIES = libompi_dbg_msgq.la
 
-check_PROGRAMS = predefined_gap_test
+check_PROGRAMS = predefined_gap_test predefined_pad_test
 if OPAL_HAVE_DLOPEN
 check_PROGRAMS += dlopen_test
 endif
@@ -72,6 +75,19 @@ libompi_dbg_msgq_la_SOURCES = ompi_msgq_dll.c ompi_msgq_dll_defs.h $(common)
 libompi_dbg_msgq_la_CFLAGS = -g
 libompi_dbg_msgq_la_LDFLAGS = -module -avoid-version
 
+# These are checks for the padding on predefined MPI object types.
+# They are here in the debuggers/ directory (vs., for example,
+# runtime/) because a) we already had some canary tests here in this
+# directory, and b) the runtime/ directory is built by subdir objects,
+# and "make check" will *build* a test in runtime/, but it won't *run*
+# it.  :-(
+predefined_pad_test_LDFLAGS = $(WRAPPER_EXTRA_LDFLAGS)
+predefined_pad_test_LDADD = $(top_builddir)/ompi/libmpi.la
+predefined_pad_test_DEPENDENCIES = $(ompi_predefined_LDADD)
+
+libompi_predefined_pad_canary_la_SOURCES = \
+        ompi_predefined_pad_canary.c
+
 # Conditionally install the header files
 
 if WANT_INSTALL_HEADERS

ompi/debuggers/ompi_predefined_pad_canary.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc.  All rights reserved
+ * $COPYRIGHT$
+ * 
+ * Additional copyrights may follow
+ * 
+ * $HEADER$
+ */
+
+#include "ompi_config.h"
+
+/*
+ * This is a simple canary compile-time test.  If we have no padding
+ * left on predefined MPI object types, it'll fail to compile, thereby
+ * alerting/annoying a human, who can go fix the real problem.
+ */
+
+#include "ompi/communicator/communicator.h"
+#include "ompi/group/group.h"
+#include "ompi/request/request.h"
+#include "ompi/op/op.h"
+#include "ompi/datatype/ompi_datatype.h"
+#include "ompi/win/win.h"
+#include "ompi/info/info.h"
+#include "ompi/file/file.h"
+#include "ompi/message/message.h"
+
+#define S(TYPE) (sizeof(ompi_predefined_##TYPE##_t) - sizeof(ompi_##TYPE##_t))
+
+/**************************************************************************
+ * IF THIS FILE FAILS TO COMPILE, IT IS A SYMPTOM OF A LARGER PROBLEM!
+ **************************************************************************
+ *
+ * Do not attempt to fix the compile failure in this file; go fix the
+ * fact that there's no more padding left for predefined MPI objects.
+ *
+ **************************************************************************/
+
+char comm_pad[S(communicator)];
+char group_pad[S(group)];
+char request_pad[S(request)];
+char op_pad[S(op)];
+char datatype_pad[S(datatype)];
+char win_pad[S(win)];
+char info_pad[S(info)];
+char file_pad[S(file)];
+char message_pad[S(message)];

ompi/debuggers/predefined_pad_test.c

@@ -0,0 +1,76 @@
+/*   
+ * Copyright (c) 2014 Cisco Systems, Inc.  All rights reserved.
+ * $COPYRIGHT$
+ * 
+ * Additional copyrights may follow
+ * 
+ * $HEADER$
+ */
+
+/*
+ * Simple test to print out how much space is left in the padding for
+ * each of the predefined MPI object types.
+ *
+ * Warn if there is less than THRESHHOLD bytes of padding left; error
+ * if there is no space left.
+ */
+
+#include "ompi_config.h"
+
+#include <stdlib.h>
+
+#include "opal_stdint.h"
+
+#include "ompi/communicator/communicator.h"
+#include "ompi/group/group.h"
+#include "ompi/request/request.h"
+#include "ompi/op/op.h"
+#include "ompi/datatype/ompi_datatype.h"
+#include "ompi/win/win.h"
+#include "ompi/info/info.h"
+#include "ompi/file/file.h"
+#include "ompi/message/message.h"
+
+static int warnings = 0;
+static int errors = 0;
+
+#define THRESHHOLD 32
+
+
+#define PAD_CHECK(TYPE)                                                 \
+    do {                                                                \
+        size_t psize = sizeof(ompi_predefined_##TYPE##_t);              \
+        size_t size = sizeof(ompi_##TYPE##_t);                          \
+        size_t diff = psize - size;                                     \
+        if (diff <= 0) {                                                \
+            fprintf(stderr, "ERROR: Predefined " #TYPE " size: %" PRIsize_t ", " #TYPE " size: %" PRIsize_t " (%" PRIsize_t " bytes over)\n", psize, size, size - psize); \
+        } else if (diff <= THRESHHOLD) {                                \
+            fprintf(stderr, "WARNING: Predefined " #TYPE " has very little space left -- size : %" PRIsize_t ", " #TYPE " size: %" PRIsize_t " (%" PRIsize_t " bytes left)\n", psize, size, psize - size); \
+        } else {                                                        \
+            printf("Predefined " #TYPE " size : %" PRIsize_t ", " #TYPE " size: %" PRIsize_t " (%" PRIsize_t " bytes left)\n", psize, size, psize - size); \
+        }                                                               \
+    } while(0)
+
+int main(int argc, char **argv) 
+{
+    PAD_CHECK(communicator);
+    PAD_CHECK(errhandler);
+    PAD_CHECK(file);
+    PAD_CHECK(win);
+    PAD_CHECK(request);
+    PAD_CHECK(info);
+    PAD_CHECK(datatype);
+    PAD_CHECK(group);
+    PAD_CHECK(message);
+    PAD_CHECK(op);
+
+    if (warnings > 0) {
+        fprintf(stderr, "NUMBER OF WARNINGS: %d\n", warnings);
+    }
+    if (errors > 0) {
+        fprintf(stderr, "NUMBER OF ERRORS: %d\n", errors);
+        exit(1);
+    }
+    
+    return 0;
+}