Implemented syntax recognition for DROP ROLE

sql/mysqld.cc

@@ -3448,6 +3448,7 @@ SHOW_VAR com_status_vars[]= {
   {"drop_function",        (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_FUNCTION]), SHOW_LONG_STATUS},
   {"drop_index",           (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_INDEX]), SHOW_LONG_STATUS},
   {"drop_procedure",       (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_PROCEDURE]), SHOW_LONG_STATUS},
+  {"drop_role",            (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_ROLE]), SHOW_LONG_STATUS},
   {"drop_server",          (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_SERVER]), SHOW_LONG_STATUS},
   {"drop_table",           (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_TABLE]), SHOW_LONG_STATUS},
   {"drop_trigger",         (char*) offsetof(STATUS_VAR, com_stat[(uint) SQLCOM_DROP_TRIGGER]), SHOW_LONG_STATUS},

sql/sql_lex.h

@@ -169,7 +169,7 @@ enum enum_sql_command {
   SQLCOM_SHOW_WARNS, SQLCOM_EMPTY_QUERY, SQLCOM_SHOW_ERRORS,
   SQLCOM_SHOW_STORAGE_ENGINES, SQLCOM_SHOW_PRIVILEGES,
   SQLCOM_HELP, SQLCOM_CREATE_USER, SQLCOM_DROP_USER, SQLCOM_RENAME_USER,
-  SQLCOM_CREATE_ROLE,
+  SQLCOM_CREATE_ROLE, SQLCOM_DROP_ROLE,
   SQLCOM_REVOKE_ALL, SQLCOM_CHECKSUM,
   SQLCOM_CREATE_PROCEDURE, SQLCOM_CREATE_SPFUNCTION, SQLCOM_CALL,
   SQLCOM_DROP_PROCEDURE, SQLCOM_ALTER_PROCEDURE,SQLCOM_ALTER_FUNCTION,

sql/sql_parse.cc

@@ -3761,6 +3761,12 @@ end_with_restore_list:
     my_ok(thd);
     break;
   }
+  case SQLCOM_DROP_ROLE:
+  {
+    /* TODO */
+    my_ok(thd);
+    break;
+  }
   case SQLCOM_REVOKE_ALL:
   {
     if (check_access(thd, UPDATE_ACL, "mysql", NULL, NULL, 1, 1) &&

sql/sql_yacc.yy

@@ -11001,6 +11001,10 @@ drop:
           {
             Lex->sql_command = SQLCOM_DROP_USER;
           }
+        | DROP ROLE_SYM clear_privileges opt_if_exists role_list
+          {
+            Lex->sql_command = SQLCOM_DROP_ROLE;
+          }
         | DROP VIEW_SYM opt_if_exists
           {
             LEX *lex= Lex;