nshlib/nsh_parse.c:  Replacement implementation for  This addes conditional compilation on the definition of g_nullstring[] to avoid the warning.  Suggested by SUZUKI Y
@@ -222,7 +222,9 @@ static const char g_exitstatus[] = "?";
static const char g_success[] = "0";
static const char g_failure[] = "1";
#endif
+#if defined(NSH_HAVE_VARS) || defined(CONFIG_NSH_CMDPARMS)
static const char g_nullstring[] = "";
+#endif
/****************************************************************************
* Public Data
