Allow there to be no default hostfile without generating an error

This commit was SVN r25930.

orte/runtime/orte_globals.c

@@ -150,6 +150,7 @@ bool orte_report_launch_progress = false;
 
 /* allocation specification */
 char *orte_default_hostfile = NULL;
+bool orte_default_hostfile_given = false;
 char *orte_rankfile = NULL;
 #ifdef __WINDOWS__
 char *orte_ccp_headnode;

orte/runtime/orte_globals.h

@@ -615,6 +615,7 @@ ORTE_DECLSPEC extern bool orte_report_launch_progress;
 
 /* allocation specification */
 ORTE_DECLSPEC extern char *orte_default_hostfile;
+ORTE_DECLSPEC extern bool orte_default_hostfile_given;
 ORTE_DECLSPEC extern char *orte_rankfile;
 #ifdef __WINDOWS__
 ORTE_DECLSPEC extern char *orte_ccp_headnode;

orte/runtime/orte_mca_params.c

@@ -251,16 +251,24 @@ int orte_register_params(void)
                                 false, false, 1000, &orte_timeout_usec_per_proc);
     
     /* default hostfile */
-    asprintf(&orte_default_hostfile, "%s/etc/openmpi-default-hostfile", opal_install_dirs.prefix);
     mca_base_param_reg_string_name("orte", "default_hostfile",
                                    "Name of the default hostfile (relative or absolute path, \"none\" to ignore environmental or default MCA param setting)",
-                                   false, false, orte_default_hostfile, &orte_default_hostfile);
-    if (0 == strcmp(orte_default_hostfile, "none")) {
-        free(orte_default_hostfile);
+                                   false, false, NULL, &strval);
+    if (NULL == strval) {
+        /* nothing was given, so define the default */
+        asprintf(&orte_default_hostfile, "%s/etc/openmpi-default-hostfile", opal_install_dirs.prefix);
+        /* flag that nothing was given */
+        orte_default_hostfile_given = false;
+    } else if (0 == strcmp(orte_default_hostfile, "none")) {
         orte_default_hostfile = NULL;
+        /* flag that it was given */
+        orte_default_hostfile_given = true;
+    } else {
+        orte_default_hostfile = strval;
+        /* flag that it was given */
+        orte_default_hostfile_given = true;
     }
     
-    
 #ifdef __WINDOWS__
     mca_base_param_reg_string_name("orte", "ccp_headnode",
                                    "Name of the cluster head node. (For Windows CCP only.)",

orte/util/hostfile/hostfile.c

@@ -419,8 +419,25 @@ static int hostfile_parse(const char *hostfile, opal_list_t* updates, opal_list_
     orte_util_hostfile_done = false;
     orte_util_hostfile_in = fopen(hostfile, "r");
     if (NULL == orte_util_hostfile_in) {
-        orte_show_help("help-hostfile.txt", "no-hostfile", true, hostfile);
-        rc = ORTE_ERR_NOT_FOUND;
+        if (NULL == orte_default_hostfile ||
+            0 != strcmp(orte_default_hostfile, hostfile)) {
+            /* not the default hostfile, so not finding it
+             * is an error
+             */
+            orte_show_help("help-hostfile.txt", "no-hostfile", true, hostfile);
+            rc = ORTE_ERR_SILENT;
+            goto unlock;
+        }
+        /* if this is the default hostfile and it was given,
+         * then it's an error
+         */
+        if (orte_default_hostfile_given) {
+            orte_show_help("help-hostfile.txt", "no-hostfile", true, hostfile);
+            rc = ORTE_ERR_NOT_FOUND;
+            goto unlock;
+        }
+        /* otherwise, not finding it is okay */
+        rc = ORTE_SUCCESS;
         goto unlock;
     }