Fix compiler warnings

metadata_lock_info_duration[]: Remove the unused variable.

Add some comments /* fall through */ to silence -Wimplicit-fallthrough

pcre/pcre_compile.c

@@ -1249,6 +1249,7 @@ else
 
     if ((c = *ptr) >= CHAR_8) break;
 
+    /* fall through */
     /* Fall through with a digit less than 8 */
 
     /* \0 always starts an octal number, but we may drop through to here with a
@@ -5097,6 +5098,8 @@ for (;; ptr++)
             either not match or match, depending on whether the class is or is
             not negated. */
 
+            /* fall through */
+
             default:
             if (local_negate &&
                 (xclass || tempptr[2] != CHAR_RIGHT_SQUARE_BRACKET))
@@ -7165,7 +7168,7 @@ for (;; ptr++)
           goto FAILED;
           }
         /* Fall through to handle (?P< as (?< is handled */
-
+        /* fall through */
 
         /* ------------------------------------------------------------ */
         DEFINE_NAME:    /* Come here from (?< handling */

pcre/pcre_exec.c

@@ -1053,6 +1053,8 @@ for (;;)
     group. At this point, the return is converted into MATCH_NOMATCH so that
     previous backup points can be taken. */
 
+    /* fall through */
+
     case OP_ONCE:
     case OP_BRA:
     case OP_SBRA:

plugin/metadata_lock_info/metadata_lock_info.cc

@@ -44,12 +44,6 @@ static const LEX_STRING metadata_lock_info_lock_mode[] = {
   { C_STRING_WITH_LEN("MDL_EXCLUSIVE") },
 };
 
-static const LEX_STRING metadata_lock_info_duration[] = {
-  { C_STRING_WITH_LEN("MDL_STATEMENT") },
-  { C_STRING_WITH_LEN("MDL_TRANSACTION") },
-  { C_STRING_WITH_LEN("MDL_EXPLICIT") },
-};
-
 static ST_FIELD_INFO i_s_metadata_lock_info_fields_info[] =
 {
   {"THREAD_ID", 20, MYSQL_TYPE_LONGLONG, 0,

sql/ha_partition.cc

@@ -7899,7 +7899,7 @@ uint32 ha_partition::calculate_key_hash_value(Field **field_array)
       case MYSQL_TYPE_BLOB:
       case MYSQL_TYPE_VAR_STRING:
       case MYSQL_TYPE_GEOMETRY:
-        /* fall through. */
+        /* fall through */
       default:
         DBUG_ASSERT(0);                    // New type?
         /* Fall through for default hashing (5.5). */

storage/innobase/row/row0sel.cc

@@ -1537,6 +1537,7 @@ row_sel(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -1595,6 +1596,7 @@ row_sel(
 		switch (err) {
 		case DB_SUCCESS_LOCKED_REC:
 			err = DB_SUCCESS;
+			/* fall through */
 		case DB_SUCCESS:
 			break;
 		default:
@@ -4203,6 +4205,7 @@ row_search_for_mysql(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -4273,6 +4276,7 @@ row_search_for_mysql(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -4550,6 +4554,7 @@ row_search_for_mysql(
 				prebuilt->new_rec_locks = 1;
 			}
 			err = DB_SUCCESS;
+			/* fall through */
 		case DB_SUCCESS:
 			break;
 		case DB_LOCK_WAIT:

storage/ndb/include/util/ndb_opts.h

@@ -165,6 +165,7 @@ ndb_std_get_one_option(int optid,
   /* fall through to add the connectstring to the end
    * and set opt_ndbcluster_connectstring
    */
+  /* fall through */
   case OPT_NDB_CONNECTSTRING:
     if (opt_ndb_connectstring && opt_ndb_connectstring[0])
       my_snprintf(opt_ndb_constrbuf+opt_ndb_constrbuf_len,

storage/xtradb/row/row0sel.cc

@@ -1543,6 +1543,7 @@ row_sel(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -1601,6 +1602,7 @@ row_sel(
 		switch (err) {
 		case DB_SUCCESS_LOCKED_REC:
 			err = DB_SUCCESS;
+			/* fall through */
 		case DB_SUCCESS:
 			break;
 		default:
@@ -4172,6 +4174,7 @@ row_search_for_mysql(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -4248,6 +4251,7 @@ row_search_for_mysql(
 			switch (err) {
 			case DB_SUCCESS_LOCKED_REC:
 				err = DB_SUCCESS;
+				/* fall through */
 			case DB_SUCCESS:
 				break;
 			default:
@@ -4534,6 +4538,7 @@ row_search_for_mysql(
 				prebuilt->new_rec_locks = 1;
 			}
 			err = DB_SUCCESS;
+			/* fall through */
 		case DB_SUCCESS:
 			break;
 		case DB_LOCK_WAIT: