Convert "opal_show_help" to be a global variable pointer.

It is statically initialized to the real back-end OPAL show_help
function.  During orte_show_help_init(), the variable is re-assigned
with the value of the back-end ORTE show_help function (the one that
does error message aggregation).  

Therefore, anything that calls opal_show_help() after a certain point
in orte_init() will have their show_help messages be aggregated.
w00t!  Even code down in OPAL -- that has no knowledge of ORTE -- will
have their messages aggregated.  '''Double w00t!'''

During orte_show_help_finalize(), we restore the original pointer
value so that it something calls opal_show_help() after
orte_finalize(), it'll still work properly (but it won't be
aggregated).  

This commit was SVN r24185.

Author: jsquyres

opal/util/show_help.c

@@ -42,6 +42,18 @@ static const char *dash_line = "------------------------------------------------
 static int output_stream = -1;
 static char **search_dirs = NULL;
 
+/*
+ * Local functions
+ */
+static int opal_show_vhelp_internal(const char *filename, const char *topic, 
+                                    bool want_error_header, va_list arglist);
+static int opal_show_help_internal(const char *filename, const char *topic, 
+                                   bool want_error_header, ...);
+
+opal_show_help_fn_t opal_show_help = opal_show_help_internal;
+opal_show_vhelp_fn_t opal_show_vhelp = opal_show_vhelp_internal;
+
+
 int opal_show_help_init(void)
 {
     opal_output_stream_t lds;
@@ -311,8 +323,8 @@ char *opal_show_help_string(const char *filename, const char *topic,
     return output;
 }
 
-int opal_show_vhelp(const char *filename, const char *topic, 
-                    bool want_error_header, va_list arglist)
+static int opal_show_vhelp_internal(const char *filename, const char *topic, 
+                                    bool want_error_header, va_list arglist)
 {
     char *output;
 
@@ -329,8 +341,8 @@ int opal_show_vhelp(const char *filename, const char *topic,
     return (NULL == output) ? OPAL_ERROR : OPAL_SUCCESS;
 }
 
-int opal_show_help(const char *filename, const char *topic, 
-                   bool want_error_header, ...)
+static int opal_show_help_internal(const char *filename, const char *topic, 
+                                   bool want_error_header, ...)
 {
     va_list arglist;
     int rc;

opal/util/show_help.h

@@ -128,15 +128,17 @@ OPAL_DECLSPEC int opal_show_help_finalize(void);
  * based on the topic, and displays it.  If want_error_header is
  * true, a header and footer of asterisks are also displayed.
  */
-OPAL_DECLSPEC int opal_show_help(const char *filename, const char *topic, 
-                                 bool want_error_header, ...);
+typedef int (*opal_show_help_fn_t)(const char *filename, const char *topic, 
+                                   bool want_error_header, ...);
+OPAL_DECLSPEC extern opal_show_help_fn_t opal_show_help;
 
 /**
  * This function does the same thing as opal_show_help(), but accepts
  * a va_list form of varargs.
  */
-OPAL_DECLSPEC int opal_show_vhelp(const char *filename, const char *topic, 
-                                  bool want_error_header, va_list ap);
+typedef int (*opal_show_vhelp_fn_t)(const char *filename, const char *topic, 
+                                    bool want_error_header, va_list ap);
+OPAL_DECLSPEC extern opal_show_vhelp_fn_t opal_show_vhelp;
 
 /**
  * This function does the same thing as opal_show_help(), but returns

orte/util/show_help.c

@@ -130,6 +130,8 @@ static bool show_help_timer_set = false;
 static opal_event_t show_help_timer_event;
 static bool ready;
 
+static opal_show_help_fn_t save_help = NULL;
+
 static void tuple_list_item_constructor(tuple_list_item_t *obj)
 {
     obj->tli_filename = NULL;
@@ -576,14 +578,17 @@ int orte_show_help_init(void)
 {
     OPAL_OUTPUT_VERBOSE((5, orte_debug_output, "orte_show_help init"));
 
+    /* Show help duplicate detection */
     if (ready) {
         return ORTE_SUCCESS;
     }
     ready = true;
 
-    /* Show help duplicate detection */
     OBJ_CONSTRUCT(&abd_tuples, opal_list_t);
 
+    save_help = opal_show_help;
+    opal_show_help = orte_show_help;
+
     return ORTE_SUCCESS;
 }
 
@@ -593,7 +598,10 @@ void orte_show_help_finalize(void)
         return;
     }
     ready = false;
-    
+
+    opal_show_help = save_help;
+    save_help = NULL;
+
     /* Shutdown show_help, showing final messages */
     if (ORTE_PROC_IS_HNP) {
         show_accumulated_duplicates(0, 0, NULL);
@@ -606,7 +614,6 @@ void orte_show_help_finalize(void)
         orte_rml.recv_cancel(ORTE_NAME_WILDCARD, ORTE_RML_TAG_SHOW_HELP);
         return;
     }
-
 }
 
 int orte_show_help(const char *filename, const char *topic,