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, 73 insertions, 71 deletions

diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index d804e568b79..1d0d3341b37 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -34,8 +34,9 @@
 #include "sp_cache.h"                     // sp_invalidate_cache
 #include <mysys_err.h>
 
-LEX_STRING *make_lex_string(LEX_STRING *lex_str, const char* str, uint length,
-                            MEM_ROOT *mem_root)
+LEX_CSTRING *make_lex_string(LEX_CSTRING *lex_str,
+                             const char* str, uint length,
+                             MEM_ROOT *mem_root)
 {
   if (!(lex_str->str= strmake_root(mem_root, str, length)))
     return 0;
@@ -56,9 +57,9 @@ public:
   static Trigger_creation_ctx *create(THD *thd,
                                       const char *db_name,
                                       const char *table_name,
-                                      const LEX_STRING *client_cs_name,
-                                      const LEX_STRING *connection_cl_name,
-                                      const LEX_STRING *db_cl_name);
+                                      const LEX_CSTRING *client_cs_name,
+                                      const LEX_CSTRING *connection_cl_name,
+                                      const LEX_CSTRING *db_cl_name);
 
   Trigger_creation_ctx(CHARSET_INFO *client_cs,
                        CHARSET_INFO *connection_cl,
@@ -92,9 +93,9 @@ Trigger_creation_ctx *
 Trigger_creation_ctx::create(THD *thd,
                              const char *db_name,
                              const char *table_name,
-                             const LEX_STRING *client_cs_name,
-                             const LEX_STRING *connection_cl_name,
-                             const LEX_STRING *db_cl_name)
+                             const LEX_CSTRING *client_cs_name,
+                             const LEX_CSTRING *connection_cl_name,
+                             const LEX_CSTRING *db_cl_name)
 {
   CHARSET_INFO *client_cs;
   CHARSET_INFO *connection_cl;
@@ -162,7 +163,7 @@ Trigger_creation_ctx::create(THD *thd,
 
 /*************************************************************************/
 
-static const LEX_STRING triggers_file_type=
+static const LEX_CSTRING triggers_file_type=
   { C_STRING_WITH_LEN("TRIGGERS") };
 
 const char * const TRG_EXT= ".TRG";
@@ -176,37 +177,37 @@ const char * const TRG_EXT= ".TRG";
 static File_option triggers_file_parameters[]=
 {
   {
-    { C_STRING_WITH_LEN("triggers") },
+    { STRING_WITH_LEN("triggers") },
     my_offsetof(class Table_triggers_list, definitions_list),
     FILE_OPTIONS_STRLIST
   },
   {
-    { C_STRING_WITH_LEN("sql_modes") },
+    { STRING_WITH_LEN("sql_modes") },
     my_offsetof(class Table_triggers_list, definition_modes_list),
     FILE_OPTIONS_ULLLIST
   },
   {
-    { C_STRING_WITH_LEN("definers") },
+    { STRING_WITH_LEN("definers") },
     my_offsetof(class Table_triggers_list, definers_list),
     FILE_OPTIONS_STRLIST
   },
   {
-    { C_STRING_WITH_LEN("client_cs_names") },
+    { STRING_WITH_LEN("client_cs_names") },
     my_offsetof(class Table_triggers_list, client_cs_names),
     FILE_OPTIONS_STRLIST
   },
   {
-    { C_STRING_WITH_LEN("connection_cl_names") },
+    { STRING_WITH_LEN("connection_cl_names") },
     my_offsetof(class Table_triggers_list, connection_cl_names),
     FILE_OPTIONS_STRLIST
   },
   {
-    { C_STRING_WITH_LEN("db_cl_names") },
+    { STRING_WITH_LEN("db_cl_names") },
     my_offsetof(class Table_triggers_list, db_cl_names),
     FILE_OPTIONS_STRLIST
   },
   {
-    { C_STRING_WITH_LEN("created") },
+    { STRING_WITH_LEN("created") },
     my_offsetof(class Table_triggers_list, create_times),
     FILE_OPTIONS_ULLLIST
   },
@@ -215,7 +216,7 @@ static File_option triggers_file_parameters[]=
 
 File_option sql_modes_parameters=
 {
-  { C_STRING_WITH_LEN("sql_modes") },
+  { STRING_WITH_LEN("sql_modes") },
   my_offsetof(class Table_triggers_list, definition_modes_list),
   FILE_OPTIONS_ULLLIST
 };
@@ -238,18 +239,18 @@ static const int TRG_NUM_REQUIRED_PARAMETERS= 7;
 
 struct st_trigname
 {
-  LEX_STRING trigger_table;
+  LEX_CSTRING trigger_table;
 };
 
-static const LEX_STRING trigname_file_type=
-  { C_STRING_WITH_LEN("TRIGGERNAME") };
+static const LEX_CSTRING trigname_file_type=
+  { STRING_WITH_LEN("TRIGGERNAME") };
 
 const char * const TRN_EXT= ".TRN";
 
 static File_option trigname_file_parameters[]=
 {
   {
-    { C_STRING_WITH_LEN("trigger_table")},
+    { STRING_WITH_LEN("trigger_table")},
     offsetof(struct st_trigname, trigger_table),
     FILE_OPTIONS_ESTRING
   },
@@ -260,9 +261,9 @@ static File_option trigname_file_parameters[]=
 class Handle_old_incorrect_sql_modes_hook: public Unknown_key_hook
 {
 private:
-  char *path;
+  const char *path;
 public:
-  Handle_old_incorrect_sql_modes_hook(char *file_path)
+  Handle_old_incorrect_sql_modes_hook(const char *file_path)
     :path(file_path)
   {};
   virtual bool process_unknown_string(const char *&unknown_key, uchar* base,
@@ -273,15 +274,15 @@ public:
 class Handle_old_incorrect_trigger_table_hook: public Unknown_key_hook
 {
 public:
-  Handle_old_incorrect_trigger_table_hook(char *file_path,
-                                          LEX_STRING *trigger_table_arg)
+  Handle_old_incorrect_trigger_table_hook(const char *file_path,
+                                          LEX_CSTRING *trigger_table_arg)
     :path(file_path), trigger_table_value(trigger_table_arg)
   {};
   virtual bool process_unknown_string(const char *&unknown_key, uchar* base,
                                       MEM_ROOT *mem_root, const char *end);
 private:
-  char *path;
-  LEX_STRING *trigger_table_value;
+  const char *path;
+  LEX_CSTRING *trigger_table_value;
 };
 
 
@@ -299,7 +300,7 @@ class Deprecated_trigger_syntax_handler : public Internal_error_handler
 private:
 
   char m_message[MYSQL_ERRMSG_SIZE];
-  LEX_STRING *m_trigger_name;
+  LEX_CSTRING *m_trigger_name;
 
 public:
 
@@ -329,7 +330,7 @@ public:
     return false;
   }
 
-  LEX_STRING *get_trigger_name() { return m_trigger_name; }
+  LEX_CSTRING *get_trigger_name() { return m_trigger_name; }
   char *get_error_message() { return m_message; }
 };
 
@@ -643,10 +644,10 @@ end:
 
 static void build_trig_stmt_query(THD *thd, TABLE_LIST *tables,
                                   String *stmt_query, String *trigger_def,
-                                  LEX_STRING *trg_definer,
+                                  LEX_CSTRING *trg_definer,
                                   char trg_definer_holder[])
 {
-  LEX_STRING stmt_definition;
+  LEX_CSTRING stmt_definition;
   LEX *lex= thd->lex;
   uint prefix_trimmed, suffix_trimmed;
   size_t original_length;
@@ -671,7 +672,7 @@ static void build_trig_stmt_query(THD *thd, TABLE_LIST *tables,
   }
   else
   {
-    *trg_definer= empty_lex_str;
+    *trg_definer= empty_clex_str;
   }
 
 
@@ -736,7 +737,7 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
   LEX *lex= thd->lex;
   TABLE *table= tables->table;
   char file_buff[FN_REFLEN], trigname_buff[FN_REFLEN];
-  LEX_STRING file, trigname_file;
+  LEX_CSTRING file, trigname_file;
   char trg_definer_holder[USER_HOST_BUFF_SIZE];
   Item_trigger_field *trg_field;
   struct st_trigname trigname;
@@ -839,7 +840,7 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
                           ER_TRG_ALREADY_EXISTS,
                           ER_THD(thd, ER_TRG_ALREADY_EXISTS),
                           trigname_buff);
-      LEX_STRING trg_definer_tmp;
+      LEX_CSTRING trg_definer_tmp;
       String trigger_def;
 
       /*
@@ -1050,7 +1051,7 @@ bool Table_triggers_list::save_trigger_file(THD *thd, const char *db,
                                             const char *table_name)
 {
   char file_buff[FN_REFLEN];
-  LEX_STRING file;
+  LEX_CSTRING file;
 
   if (create_lists_needed_for_files(thd->mem_root))
     return true;
@@ -1070,7 +1071,7 @@ bool Table_triggers_list::save_trigger_file(THD *thd, const char *db,
   @param remove_from_list	If set, remove trigger if found
 */
 
-Trigger *Table_triggers_list::find_trigger(const LEX_STRING *name,
+Trigger *Table_triggers_list::find_trigger(const LEX_CSTRING *name,
                                            bool remove_from_list)
 {
   for (uint i= 0; i < (uint)TRG_EVENT_MAX; i++)
@@ -1125,7 +1126,7 @@ Trigger *Table_triggers_list::find_trigger(const LEX_STRING *name,
 bool Table_triggers_list::drop_trigger(THD *thd, TABLE_LIST *tables,
                                        String *stmt_query)
 {
-  const LEX_STRING *sp_name= &thd->lex->spname->m_name; // alias
+  const LEX_CSTRING *sp_name= &thd->lex->spname->m_name; // alias
   char path[FN_REFLEN];
   Trigger *trigger;
 
@@ -1298,7 +1299,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
                                        bool names_only)
 {
   char path_buff[FN_REFLEN];
-  LEX_STRING path;
+  LEX_CSTRING path;
   File_parser *parser;
   LEX_STRING save_db;
   DBUG_ENTER("Table_triggers_list::check_n_load");
@@ -1318,7 +1319,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
     if (is_equal(&triggers_file_type, parser->type()))
     {
       Handle_old_incorrect_sql_modes_hook sql_modes_hook(path.str);
-      LEX_STRING *trg_create_str;
+      LEX_CSTRING *trg_create_str;
       ulonglong *trg_sql_mode, *trg_create_time;
       Trigger *trigger;
       Table_triggers_list *trigger_list=
@@ -1332,7 +1333,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
                         &sql_modes_hook))
         goto error;
 
-      List_iterator_fast<LEX_STRING> it(trigger_list->definitions_list);
+      List_iterator_fast<LEX_CSTRING> it(trigger_list->definitions_list);
 
       if (!trigger_list->definitions_list.is_empty() &&
           (trigger_list->client_cs_names.is_empty() ||
@@ -1351,10 +1352,10 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
       status_var_increment(thd->status_var.feature_trigger);
 
       List_iterator_fast<ulonglong> itm(trigger_list->definition_modes_list);
-      List_iterator_fast<LEX_STRING> it_definer(trigger_list->definers_list);
-      List_iterator_fast<LEX_STRING> it_client_cs_name(trigger_list->client_cs_names);
-      List_iterator_fast<LEX_STRING> it_connection_cl_name(trigger_list->connection_cl_names);
-      List_iterator_fast<LEX_STRING> it_db_cl_name(trigger_list->db_cl_names);
+      List_iterator_fast<LEX_CSTRING> it_definer(trigger_list->definers_list);
+      List_iterator_fast<LEX_CSTRING> it_client_cs_name(trigger_list->client_cs_names);
+      List_iterator_fast<LEX_CSTRING> it_connection_cl_name(trigger_list->connection_cl_names);
+      List_iterator_fast<LEX_CSTRING> it_db_cl_name(trigger_list->db_cl_names);
       List_iterator_fast<ulonglong> it_create_times(trigger_list->create_times);
       LEX *old_lex= thd->lex, lex;
       sp_rcontext *save_spcont= thd->spcont;
@@ -1369,7 +1370,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
       {
         sp_head *sp;
         sql_mode_t sql_mode;
-        LEX_STRING *trg_definer;
+        LEX_CSTRING *trg_definer;
         Trigger_creation_ctx *creation_ctx;
 
         /*
@@ -1386,7 +1387,8 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
         thd->variables.sql_mode= sql_mode;
 
         Parser_state parser_state;
-        if (parser_state.init(thd, trg_create_str->str, trg_create_str->length))
+        if (parser_state.init(thd, (char*) trg_create_str->str,
+                              trg_create_str->length))
           goto err_with_lex_cleanup;
 
         if (!trigger_list->client_cs_names.is_empty())
@@ -1441,7 +1443,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
         trigger->sql_mode= sql_mode;
         trigger->definition= *trg_create_str;
         trigger->create_time= trg_create_time ? *trg_create_time : 0;
-        trigger->name= sp ? sp->m_name : empty_lex_str;
+        trigger->name= sp ? sp->m_name : empty_clex_str;
         trigger->on_table_name.str= (char*) lex.raw_trg_on_table_name_begin;
         trigger->on_table_name.length= (lex.raw_trg_on_table_name_end -
                                         lex.raw_trg_on_table_name_begin);
@@ -1464,7 +1466,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
 
         if (parse_error)
         {
-          LEX_STRING *name;
+          LEX_CSTRING *name;
 
           /*
             In case of errors, disable all triggers for the table, but keep
@@ -1483,7 +1485,7 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
               goto err_with_lex_cleanup;
           }
           trigger->definer= ((!trg_definer || !trg_definer->length) ?
-                             empty_lex_str : *trg_definer);
+                             empty_clex_str : *trg_definer);
           continue;
         }
 
@@ -1509,8 +1511,8 @@ bool Table_triggers_list::check_n_load(THD *thd, const char *db,
             schema.
           */
 
-          sp->set_definer((char*) "", 0);
-          trigger->definer= empty_lex_str;
+          sp->set_definer("", 0);
+          trigger->definer= empty_clex_str;
 
           /*
             trigger_list without definer information are executed under the
@@ -1622,7 +1624,7 @@ error:
 void Table_triggers_list::add_trigger(trg_event_type event,
                                       trg_action_time_type action_time,
                                       trigger_order_type ordering_clause,
-                                      LEX_STRING *anchor_trigger_name,
+                                      LEX_CSTRING *anchor_trigger_name,
                                       Trigger *trigger)
 {
   Trigger **parent= &triggers[event][action_time];
@@ -1673,8 +1675,9 @@ void Table_triggers_list::add_trigger(trg_event_type event,
     True    error
 */
 
-void Trigger::get_trigger_info(LEX_STRING *trigger_stmt,
-                               LEX_STRING *trigger_body, LEX_STRING *definer)
+void Trigger::get_trigger_info(LEX_CSTRING *trigger_stmt,
+                               LEX_CSTRING *trigger_body,
+                               LEX_STRING *definer)
 {
   DBUG_ENTER("get_trigger_info");
 
@@ -1726,7 +1729,7 @@ bool add_table_for_trigger(THD *thd,
   LEX *lex= thd->lex;
   char trn_path_buff[FN_REFLEN];
   LEX_STRING trn_path= { trn_path_buff, 0 };
-  LEX_STRING tbl_name= null_lex_str;
+  LEX_CSTRING tbl_name= null_clex_str;
 
   DBUG_ENTER("add_table_for_trigger");
 
@@ -1750,7 +1753,8 @@ bool add_table_for_trigger(THD *thd,
     DBUG_RETURN(TRUE);
   }
 
-  if (load_table_name_for_trigger(thd, trg_name, &trn_path, &tbl_name))
+  if (load_table_name_for_trigger(thd, trg_name, (LEX_CSTRING*) &trn_path,
+                                  &tbl_name))
     DBUG_RETURN(TRUE);
 
   *table= sp_add_to_query_tables(thd, lex, trg_name->m_db.str,
@@ -1774,7 +1778,8 @@ bool add_table_for_trigger(THD *thd,
     True    error
 */
 
-bool Table_triggers_list::drop_all_triggers(THD *thd, char *db, char *name)
+bool Table_triggers_list::drop_all_triggers(THD *thd, const char *db,
+                                            const char *name)
 {
   TABLE table;
   char path[FN_REFLEN];
@@ -1848,7 +1853,7 @@ struct change_table_name_param
   THD *thd;
   const char *old_db_name;
   const char *new_db_name;
-  LEX_STRING *new_table_name;
+  LEX_CSTRING *new_table_name;
   Trigger *stopper;
 };
 
@@ -1857,8 +1862,8 @@ bool
 Table_triggers_list::change_table_name_in_triggers(THD *thd,
                                                    const char *old_db_name,
                                                    const char *new_db_name,
-                                                   LEX_STRING *old_table_name,
-                                                   LEX_STRING *new_table_name)
+                                                   LEX_CSTRING *old_table_name,
+                                                   LEX_CSTRING *new_table_name)
 {
   struct change_table_name_param param;
   sql_mode_t save_sql_mode= thd->variables.sql_mode;
@@ -1890,9 +1895,8 @@ bool Trigger::change_table_name(void* param_arg)
 {
   change_table_name_param *param= (change_table_name_param*) param_arg;
   THD *thd= param->thd;
-  LEX_STRING *new_table_name= param->new_table_name;
-
-  LEX_STRING *def= &definition, new_def;
+  LEX_CSTRING *new_table_name= param->new_table_name;
+  LEX_CSTRING *def= &definition, new_def;
   size_t on_q_table_name_len, before_on_len;
   String buff;
 
@@ -1947,7 +1951,7 @@ bool Trigger::change_table_name(void* param_arg)
 Trigger *
 Table_triggers_list::change_table_name_in_trignames(const char *old_db_name,
                                                     const char *new_db_name,
-                                                    LEX_STRING *new_table_name,
+                                                    LEX_CSTRING *new_table_name,
                                                     Trigger *trigger)
 {
   struct change_table_name_param param;
@@ -1966,7 +1970,7 @@ bool Trigger::change_on_table_name(void* param_arg)
 
   char trigname_buff[FN_REFLEN];
   struct st_trigname trigname;
-  LEX_STRING trigname_file;
+  LEX_CSTRING trigname_file;
 
   if (param->stopper == this)
     return 0;                                   // Stop processing
@@ -2056,8 +2060,8 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
       result= 1;
       goto end;
     }
-    LEX_STRING old_table_name= { (char *) old_alias, strlen(old_alias) };
-    LEX_STRING new_table_name= { (char *) new_table, strlen(new_table) };
+    LEX_CSTRING old_table_name= { (char *) old_alias, strlen(old_alias) };
+    LEX_CSTRING new_table_name= { (char *) new_table, strlen(new_table) };
     /*
       Since triggers should be in the same schema as their subject tables
       moving table with them between two schemas raises too many questions.
@@ -2468,16 +2472,14 @@ bool check_trn_exists(const LEX_STRING *trn_path)
 
 bool load_table_name_for_trigger(THD *thd,
                                  const sp_name *trg_name,
-                                 const LEX_STRING *trn_path,
-                                 LEX_STRING *tbl_name)
+                                 const LEX_CSTRING *trn_path,
+                                 LEX_CSTRING *tbl_name)
 {
   File_parser *parser;
   struct st_trigname trn_data;
-
   Handle_old_incorrect_trigger_table_hook trigger_table_hook(
                                           trn_path->str,
                                           &trn_data.trigger_table);
-
   DBUG_ENTER("load_table_name_for_trigger");
 
   /* Parse the TRN-file. */