re-enable the stack-trace functionality (it had been inadvertently disabled

in a merge a long time ago).  Set default signals to print a stack trace from
none to SIGBUS,SIGSEGV.

This commit was SVN r8603.

ompi/runtime/ompi_mpi_init.c

@@ -232,12 +232,10 @@ int ompi_mpi_init(int argc, char **argv, int requested, int *provided)
         }
     }
 
-#if 0
     if (OMPI_SUCCESS != (ret = opal_util_register_stackhandlers ())) {
         error = "util_register_stackhandlers() failed";
         goto error;
     }
-#endif
 
     /* initialize datatypes. This step should be done early as it will
      * create the local convertor and local arch used in the proc

ompi/runtime/ompi_mpi_params.c

@@ -19,6 +19,9 @@
 #include "ompi_config.h"
 
 #include <time.h>
+#ifdef HAVE_SIGNAL_H
+#include <signal.h>
+#endif
 
 #include "ompi/include/constants.h"
 #include "ompi/runtime/mpiruntime.h"
@@ -71,9 +74,33 @@ int ompi_mpi_register_params(void)
     /*
      * This string is going to be used in opal/util/stacktrace.c
      */
-    mca_base_param_reg_string_name("mpi", "signal", 
-                                   "If a signal is received, display the stack trace frame",
-                                   false, false, NULL, NULL);
+    {
+        char *string = NULL;
+        int j;
+        int signals[] = {
+#ifdef SIGBUS
+            SIGBUS,
+#endif
+#ifdef SIGSEGV
+            SIGSEGV,
+#endif
+            -1
+        };
+        for (j = 0 ; signals[j] != -1 ; ++j) {
+            if (j == 0) {
+                asprintf(&string, "%d", signals[j]);
+            } else {
+                char *tmp;
+                asprintf(&tmp, "%s,%d", string, signals[j]);
+                free(string);
+                string = tmp;
+            }
+        }
+
+        mca_base_param_reg_string_name("mpi", "signal", 
+                                       "If a signal is received, display the stack trace frame",
+                                       false, false, string, NULL);
+    }
     
     /*
      * opal_progress: decide whether to yield and the event library