Clean up mtime_iso8601.rl

src/mtime_iso8601.rl

-# Copyright (c) 2013-2024 MPI-M, Luis Kornblueh, Rahul Sinha and DWD, Florian Prill. All rights reserved.
-#
-# SPDX-License-Identifier: BSD-3-Clause
-#
+// Copyright (c) 2013-2024 MPI-M, Luis Kornblueh, Rahul Sinha and DWD, Florian Prill. All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+//
+
 /*! \cond PRIVATE */
 /**
  * @brief ISO 8601_2004 complaint Time.
@@ -36,14 +37,19 @@
 #define YEAR_UPPER_BOUND 2147483647L
 #define YEAR_LOWER_BOUND -2147483648L
 
-// #define SECOND_UPPER_BOUND 86399
-
 // Allowed year range = 2147483647 TO -2147483648
 bool RAISE_YEAR_OUT_OF_BOUND_EXCEPTION = false;
 
 // Allowed second max = 86399
 bool RAISE_SECOND_UPPER_LIMIT_EXCEPTION = false;
 
+// Ignore unused static variables generated by Ragel
+#if defined(__NVCOMPILER)
+#  pragma diag_suppress declared_but_not_referenced
+#elif defined(__GNUC__)
+#  pragma GCC diagnostic ignored "-Wunused-const-variable"
+#endif
+
 %%{
   machine date_machine;
   write data;