Changing field::field_name and Item::name to LEX_CSTRING

Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
  accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
  access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)

Changes:
- This caused some ABI changes
  - lex_string_set now uses LEX_CSTRING
  - Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
  errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
  parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
  code
- Added item_empty_name and item_used_name to be able to distingush between
  items that was given an empty name and items that was not given a name
  This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
  my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
  set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
  give the error.

TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
  (as part of lower_case_table_names)

1 files changed, 16 insertions, 12 deletions

diff --git a/sql/event_queue.cc b/sql/event_queue.cc
index ae8ba258717..9ffb9935634 100644
--- a/sql/event_queue.cc
+++ b/sql/event_queue.cc
@@ -238,11 +238,13 @@ Event_queue::create_event(THD *thd, Event_queue_element *new_element,
 */
 
 void
-Event_queue::update_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
+Event_queue::update_event(THD *thd, const LEX_CSTRING *dbname,
+                          const LEX_CSTRING *name,
                           Event_queue_element *new_element)
 {
   DBUG_ENTER("Event_queue::update_event");
-  DBUG_PRINT("enter", ("thd: 0x%lx  et=[%s.%s]", (long) thd, dbname.str, name.str));
+  DBUG_PRINT("enter", ("thd: %p  et: [%s.%s]", thd, dbname->str,
+                       name->str));
 
   if ((new_element->status == Event_parse_data::DISABLED) ||
       (new_element->status == Event_parse_data::SLAVESIDE_DISABLED))
@@ -287,11 +289,12 @@ Event_queue::update_event(THD *thd, LEX_STRING dbname, LEX_STRING name,
 */
 
 void
-Event_queue::drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name)
+Event_queue::drop_event(THD *thd, const LEX_CSTRING *dbname,
+                        const LEX_CSTRING *name)
 {
   DBUG_ENTER("Event_queue::drop_event");
-  DBUG_PRINT("enter", ("thd: 0x%lx  db :%s  name: %s", (long) thd,
-                       dbname.str, name.str));
+  DBUG_PRINT("enter", ("thd: %p  db: %s  name: %s", thd,
+                       dbname->str, name->str));
 
   LOCK_QUEUE_DATA();
   find_n_remove_event(dbname, name);
@@ -325,12 +328,12 @@ Event_queue::drop_event(THD *thd, LEX_STRING dbname, LEX_STRING name)
 */
 
 void
-Event_queue::drop_matching_events(THD *thd, LEX_STRING pattern,
-                           bool (*comparator)(LEX_STRING, Event_basic *))
+Event_queue::drop_matching_events(THD *thd, const LEX_CSTRING *pattern,
+                           bool (*comparator)(const LEX_CSTRING *, Event_basic *))
 {
   uint i;
   DBUG_ENTER("Event_queue::drop_matching_events");
-  DBUG_PRINT("enter", ("pattern=%s", pattern.str));
+  DBUG_PRINT("enter", ("pattern: %s", pattern->str));
 
   for (i= queue_first_element(&queue) ;
        i <= queue_last_element(&queue) ;
@@ -380,7 +383,7 @@ Event_queue::drop_matching_events(THD *thd, LEX_STRING pattern,
 */
 
 void
-Event_queue::drop_schema_events(THD *thd, LEX_STRING schema)
+Event_queue::drop_schema_events(THD *thd, const LEX_CSTRING *schema)
 {
   DBUG_ENTER("Event_queue::drop_schema_events");
   LOCK_QUEUE_DATA();
@@ -404,7 +407,8 @@ Event_queue::drop_schema_events(THD *thd, LEX_STRING schema)
 */
 
 void
-Event_queue::find_n_remove_event(LEX_STRING db, LEX_STRING name)
+Event_queue::find_n_remove_event(const LEX_CSTRING *db,
+                                 const LEX_CSTRING *name)
 {
   uint i;
   DBUG_ENTER("Event_queue::find_n_remove_event");
@@ -414,7 +418,7 @@ Event_queue::find_n_remove_event(LEX_STRING db, LEX_STRING name)
        i++)
   {
     Event_queue_element *et= (Event_queue_element *) queue_element(&queue, i);
-    DBUG_PRINT("info", ("[%s.%s]==[%s.%s]?", db.str, name.str,
+    DBUG_PRINT("info", ("[%s.%s]==[%s.%s]?", db->str, name->str,
                         et->dbname.str, et->name.str));
     if (event_basic_identifier_equal(db, name, et))
     {
@@ -683,7 +687,7 @@ end:
 
     Event_db_repository *db_repository= Events::get_db_repository();
     (void) db_repository->update_timing_fields_for_event(thd,
-                            (*event_name)->dbname, (*event_name)->name,
+                            &(*event_name)->dbname, &(*event_name)->name,
                             last_executed, (ulonglong) status);
   }