fix some compiler warnings

Signed-off-by: Howard Pritchard <[email protected]>

Author: hppritcha

ompi/tools/mpirun/main.c

@@ -32,7 +32,6 @@
 #include "prte.h"
 #endif
 
-
 static void append_prefixes(char ***out, const char *in)
 {
     if (NULL == in) {
@@ -79,6 +78,7 @@ static void setup_mca_prefixes(void)
     opal_argv_free(tmp);
 }
 
+__opal_attribute_unused__
 static char *find_prterun(void)
 {
     char *filename = NULL;
@@ -112,10 +112,9 @@ static char *find_prterun(void)
 int main(int argc, char *argv[])
 {
     char *opal_prefix = getenv("OPAL_PREFIX");
-    char *full_prterun_path = NULL;
-    char **prterun_args = NULL;
+    char __opal_attribute_unused__ *full_prterun_path = NULL;
+    char __opal_attribute_unused__ **prterun_args = NULL;
     int ret;
-    size_t i;
 
     ret = opal_init_util(&argc, &argv);
     if (OMPI_SUCCESS != ret) {
@@ -185,7 +184,7 @@ int main(int argc, char *argv[])
 
     /* Copy all the mpirun arguments to prterun.
      * TODO: Need to handle --prefix rationally here. */
-    for (i = 1; NULL != argv[i]; i++) {
+    for (size_t i = 1; NULL != argv[i]; i++) {
         opal_argv_append_nosize(&prterun_args, argv[i]);
     }
     ret = execv(full_prterun_path, prterun_args);