/* Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef PARSE_TREE_ITEMS_INCLUDED
#define PARSE_TREE_ITEMS_INCLUDED

#include "my_global.h"
#include "item_create.h"        // Create_func
#include "item_sum.h"           // Item_sum_count
#include "item_timefunc.h"      // Item_func_now_local
#include "parse_tree_helpers.h" // Parse_tree_item
#include "sp.h"                 // sp_check_name
#include "sp_head.h"            // sp_head
#include "sql_parse.h"          // negate_expression

class PTI_table_wild : public Parse_tree_item
{
  typedef Parse_tree_item super;

  const char *schema;
  const char *table;

public:
  explicit PTI_table_wild(const POS &pos,
                          const char *schema_arg, const char *table_arg)
  : super(pos), schema(schema_arg), table(table_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **item);
};


class PTI_negate_expression : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;

public:
  PTI_negate_expression(const POS &pos, Item *expr_arg)
  : super(pos), expr(expr_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res) || expr->itemize(pc, &expr))
      return true;

    *res= negate_expression(pc, expr);
    return *res == NULL;
  }
};

class PTI_comp_op : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *left;
  chooser_compare_func_creator boolfunc2creator;
  Item *right;

public:
  PTI_comp_op(const POS &pos, Item *left_arg,
              chooser_compare_func_creator boolfunc2creator_arg,
              Item *right_arg)
  : super(pos), left(left_arg), boolfunc2creator(boolfunc2creator_arg),
    right(right_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


class PTI_comp_op_all : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *left;
  chooser_compare_func_creator comp_op;
  bool is_all;
  PT_subselect *subselect;

public:
  PTI_comp_op_all(const POS &pos, Item *left_arg,
                  chooser_compare_func_creator comp_op_arg, bool is_all_arg,
                  PT_subselect *subselect_arg)
  : super(pos), left(left_arg), comp_op(comp_op_arg),
    is_all(is_all_arg), subselect(subselect_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


class PTI_simple_ident_ident : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING ident;
  Symbol_location raw;

public:
  PTI_simple_ident_ident(const POS &pos, const LEX_STRING &ident_arg)
  : super(pos), ident(ident_arg), raw(pos.raw)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


/**
  Parse tree Item wrapper for 3-dimentional simple_ident-s
*/
class PTI_simple_ident_q_3d : public Parse_tree_item
{
  typedef Parse_tree_item super;

protected:
  const char* db;
  const char* table;
  const char* field;

public:
  PTI_simple_ident_q_3d(const POS &pos, const char *db_arg,
                         const char *table_arg, const char *field_arg)
  : super(pos), db(db_arg), table(table_arg), field(field_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    THD *thd= pc->thd;
    const char* schema=
      thd->get_protocol()->has_client_capability(CLIENT_NO_SCHEMA) ? NULL : db;
    if (pc->select->no_table_names_allowed)
    {
      my_error(ER_TABLENAME_NOT_ALLOWED_HERE,
               MYF(0), table, thd->where);
    }
    if ((pc->select->parsing_place != CTX_HAVING) ||
        (pc->select->get_in_sum_expr() > 0))
    {
      *res= new (pc->mem_root) Item_field(POS(), schema, table, field);
    }
    else
    {
      *res= new (pc->mem_root) Item_ref(POS(), schema, table, field);
    }
    return *res == NULL || (*res)->itemize(pc, res);
  }
};


/**
  Parse tree Item wrapper for 3-dimentional simple_ident-s
*/
class PTI_simple_ident_q_2d : public PTI_simple_ident_q_3d
{
  typedef PTI_simple_ident_q_3d super;

public:
  PTI_simple_ident_q_2d(const POS &pos,
                         const char *table_arg, const char *field_arg)
  : super(pos, NULL, table_arg, field_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};



class PTI_simple_ident_nospvar_ident : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING ident;

public:
  PTI_simple_ident_nospvar_ident(const POS &pos, const LEX_STRING &ident_arg)
  : super(pos), ident(ident_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    if ((pc->select->parsing_place != CTX_HAVING) ||
        (pc->select->get_in_sum_expr() > 0))
    {
      *res= new (pc->mem_root) Item_field(POS(), NullS, NullS, ident.str);
    }
    else
    {
      *res= new (pc->mem_root) Item_ref(POS(), NullS, NullS, ident.str);
    }
    return *res == NULL || (*res)->itemize(pc, res);
  }
};


class PTI_function_call_nonkeyword_now : public Item_func_now_local
{
  typedef Item_func_now_local super;

public:
  explicit PTI_function_call_nonkeyword_now(const POS &pos, uint8 dec_arg)
  : super(pos, dec_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    pc->thd->lex->safe_to_cache_query= 0;
    return false;
  }
};


class PTI_function_call_nonkeyword_sysdate : public Parse_tree_item
{
  typedef Parse_tree_item super;

  uint8 dec;

public:
  explicit PTI_function_call_nonkeyword_sysdate(const POS &pos, uint8 dec_arg)
  : super(pos), dec(dec_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    /*
      Unlike other time-related functions, SYSDATE() is
      replication-unsafe because it is not affected by the
      TIMESTAMP variable.  It is unsafe even if
      sysdate_is_now=1, because the slave may have
      sysdate_is_now=0.
    */
    THD *thd= pc->thd;
    LEX *lex= thd->lex;
    lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_FUNCTION);
    if (global_system_variables.sysdate_is_now == 0)
      *res= new (pc->mem_root) Item_func_sysdate_local(dec);
    else
      *res= new (pc->mem_root) Item_func_now_local(dec);
    if (*res == NULL)
      return true;
    lex->safe_to_cache_query=0;

    return false;
  }
};


class PTI_udf_expr : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;
  LEX_STRING select_alias;
  Symbol_location expr_loc;

public:
  PTI_udf_expr(const POS &pos,
               Item *expr_arg, const LEX_STRING &select_alias_arg,
               const Symbol_location &expr_loc_arg)
  : super(pos), expr(expr_arg), select_alias(select_alias_arg),
    expr_loc(expr_loc_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


class PTI_function_call_generic_ident_sys : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING ident;
  PT_item_list *opt_udf_expr_list;

  udf_func *udf;

public:
  PTI_function_call_generic_ident_sys(const POS &pos,
                                      const LEX_STRING &ident_arg,
                                      PT_item_list *opt_udf_expr_list_arg)
  : super(pos), ident(ident_arg),
    opt_udf_expr_list(opt_udf_expr_list_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    THD *thd= pc->thd;
#ifdef HAVE_DLOPEN
    udf= 0;
    if (using_udf_functions &&
        (udf= find_udf(ident.str, ident.length)) &&
        udf->type == UDFTYPE_AGGREGATE)
    {
      pc->select->in_sum_expr++;
    }
#endif

    if (sp_check_name(&ident))
      return true;

    /*
      Implementation note:
      names are resolved with the following order:
      - MySQL native functions,
      - User Defined Functions,
      - Stored Functions (assuming the current <use> database)

      This will be revised with WL#2128 (SQL PATH)
    */
    Create_func *builder= find_native_function_builder(thd, ident);
    if (builder)
      *res= builder->create_func(thd, ident, opt_udf_expr_list);
    else
    {
#ifdef HAVE_DLOPEN
      if (udf)
      {
        if (udf->type == UDFTYPE_AGGREGATE)
        {
          pc->select->in_sum_expr--;
        }

        *res= Create_udf_func::s_singleton.create(thd, udf, opt_udf_expr_list);
      }
      else
#endif
      {
        builder= find_qualified_function_builder(thd);
        DBUG_ASSERT(builder);
        *res= builder->create_func(thd, ident, opt_udf_expr_list);
      }
    }
    return *res == NULL || (*res)->itemize(pc, res);
  }
};


/**
  Parse tree Item wrapper for 2-dimentional functional names (ex.: db.func_name)
*/
class PTI_function_call_generic_2d : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING db;
  LEX_STRING func;
  PT_item_list *opt_expr_list;

public:
  PTI_function_call_generic_2d(const POS &pos, const LEX_STRING &db_arg,
                               const LEX_STRING &func_arg,
                               PT_item_list *opt_expr_list_arg)
  : super(pos), db(db_arg), func(func_arg), opt_expr_list(opt_expr_list_arg)
  {}

  
  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    /*
      The following in practice calls:
      <code>Create_sp_func::create()</code>
      and builds a stored function.

      However, it's important to maintain the interface between the
      parser and the implementation in item_create.cc clean,
      since this will change with WL#2128 (SQL PATH):
      - INFORMATION_SCHEMA.version() is the SQL 99 syntax for the native
      function version(),
      - MySQL.version() is the SQL 2003 syntax for the native function
      version() (a vendor can specify any schema).
    */

    if (!db.str ||
        (check_and_convert_db_name(&db, FALSE) != IDENT_NAME_OK))
      return true;
    if (sp_check_name(&func))
      return true;

    Create_qfunc *builder= find_qualified_function_builder(pc->thd);
    DBUG_ASSERT(builder);
    *res= builder->create(pc->thd, db, func, true, opt_expr_list);
    return *res == NULL || (*res)->itemize(pc, res);
  }
};


class PTI_password : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;

public:
  PTI_password(const POS &pos, Item *expr_arg) : super(pos), expr(expr_arg) {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res) || expr->itemize(pc, &expr))
      return true;

    THD *thd= pc->thd;
    thd->lex->contains_plaintext_password= true;
    *res= new (pc->mem_root) Item_func_password(expr);
    return *res == NULL;
  }
};


class PTI_text_literal : public Item_string
{
  typedef Item_string super;

protected:
  bool is_7bit;
  LEX_STRING literal;

  PTI_text_literal(const POS &pos,
                   bool is_7bit_arg,
                   const LEX_STRING &literal_arg)
  : super(pos), is_7bit(is_7bit_arg), literal(literal_arg)
  {}
};


class PTI_text_literal_text_string : public PTI_text_literal
{
  typedef PTI_text_literal super;

public:
  PTI_text_literal_text_string(const POS &pos,
                               bool is_7bit_arg,
                               const LEX_STRING &literal)
  : super(pos, is_7bit_arg, literal)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    THD *thd= pc->thd;
    LEX_STRING tmp;
    const CHARSET_INFO *cs_con= thd->variables.collation_connection;
    const CHARSET_INFO *cs_cli= thd->variables.character_set_client;
    uint repertoire= is_7bit && my_charset_is_ascii_based(cs_cli) ?
                     MY_REPERTOIRE_ASCII : MY_REPERTOIRE_UNICODE30;
    if (thd->charset_is_collation_connection ||
        (repertoire == MY_REPERTOIRE_ASCII &&
         my_charset_is_ascii_based(cs_con)))
      tmp= literal;
    else
    {
      if (thd->convert_string(&tmp, cs_con, literal.str, literal.length,
                              cs_cli))
        return true;
    }
    init(tmp.str, tmp.length, cs_con, DERIVATION_COERCIBLE, repertoire);
    return false;
  }
};


class PTI_text_literal_nchar_string : public PTI_text_literal
{
  typedef PTI_text_literal super;

public:
  PTI_text_literal_nchar_string(const POS &pos,
                                bool is_7bit_arg,
                                const LEX_STRING &literal)
  : super(pos, is_7bit_arg, literal)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    uint repertoire= is_7bit ? MY_REPERTOIRE_ASCII : MY_REPERTOIRE_UNICODE30;
    DBUG_ASSERT(my_charset_is_ascii_based(national_charset_info));
    init(literal.str, literal.length, national_charset_info,
         DERIVATION_COERCIBLE, repertoire);
    return false;
  }
};


class PTI_text_literal_underscore_charset : public PTI_text_literal
{
  typedef PTI_text_literal super;

  const CHARSET_INFO *cs;

public:
  PTI_text_literal_underscore_charset(const POS &pos,
                                      bool is_7bit_arg,
                                      const CHARSET_INFO *cs_arg,
                                      const LEX_STRING &literal)
  : super(pos, is_7bit_arg, literal), cs(cs_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    init(literal.str, literal.length, cs,
         DERIVATION_COERCIBLE, MY_REPERTOIRE_UNICODE30);
    set_repertoire_from_value();
    set_cs_specified(TRUE);
    return false;
  }
};


class PTI_text_literal_concat : public PTI_text_literal
{
  typedef PTI_text_literal super;

  PTI_text_literal *head;

public:
  PTI_text_literal_concat(const POS &pos, bool is_7bit_arg,
                          PTI_text_literal *head_arg, const LEX_STRING &tail)
  : super(pos, is_7bit_arg, tail), head(head_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    Item *tmp_head;
    if (super::itemize(pc, res) || head->itemize(pc, &tmp_head))
      return true;

    DBUG_ASSERT(tmp_head->type() == STRING_ITEM);
    Item_string *head_str= static_cast<Item_string *>(tmp_head);

    head_str->append(literal.str, literal.length);
    if (!(head_str->collation.repertoire & MY_REPERTOIRE_EXTENDED))
    {
      /*
         If the string has been pure ASCII so far,
         check the new part.
      */
      const CHARSET_INFO *cs= pc->thd->variables.collation_connection;
      head_str->collation.repertoire|= my_string_repertoire(cs,
                                                            literal.str,
                                                            literal.length);
    }
    *res= head_str;
    return false;
  }
};


class PTI_num_literal_num : public Item_int
{
  typedef Item_int super;

public:
  PTI_num_literal_num(const POS &pos,
                       const LEX_STRING &num, int dummy_error= 0)
  : super(pos, num, my_strtoll10(num.str, NULL, &dummy_error),
          static_cast<uint>(num.length))
  {}
};


class PTI_temporal_literal : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING literal;
  enum_field_types field_type;
  const CHARSET_INFO *cs;

public:
  PTI_temporal_literal(const POS &pos, const LEX_STRING &literal_arg,
                       enum_field_types field_type_arg,
                       const CHARSET_INFO *cs_arg)
  : super(pos), literal(literal_arg), field_type(field_type_arg), cs(cs_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    *res= create_temporal_literal(pc->thd, literal.str, literal.length, cs,
                                  field_type, true);
    return *res == NULL;
  }
};


class PTI_literal_underscore_charset_hex_num : public Item_string
{
  typedef Item_string super;

public:
  PTI_literal_underscore_charset_hex_num(const POS &pos,
                                         const CHARSET_INFO *charset,
                                         const LEX_STRING &literal)
  : super(pos, null_name_string,
          Item_hex_string::make_hex_str(literal.str, literal.length), charset)
  {} 

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    set_repertoire_from_value();
    set_cs_specified(TRUE);
    return check_well_formed_result(&str_value, true, true) == NULL;
  }
};


class PTI_literal_underscore_charset_bin_num : public Item_string
{
  typedef Item_string super;

public:
  PTI_literal_underscore_charset_bin_num(const POS &pos,
                                         const CHARSET_INFO *charset,
                                         const LEX_STRING &literal)
  : super(pos, null_name_string,
          Item_bin_string::make_bin_str(literal.str, literal.length), charset)
  {} 

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    set_cs_specified(TRUE);
    return check_well_formed_result(&str_value, true, true) == NULL;
  }
};


class PTI_variable_aux_set_var : public Item_func_set_user_var
{
  typedef Item_func_set_user_var super;

public:
  PTI_variable_aux_set_var(const POS &pos, const LEX_STRING &var, Item *expr)
  : super(pos, var, expr, false)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    LEX *lex= pc->thd->lex;
    if (!lex->parsing_options.allows_variable)
    {
      my_error(ER_VIEW_SELECT_VARIABLE, MYF(0));
      return true;
    }
    lex->set_uncacheable(pc->select, UNCACHEABLE_RAND);
    lex->set_var_list.push_back(this);
    return false;
  }
};


class PTI_variable_aux_ident_or_text : public Item_func_get_user_var
{
  typedef Item_func_get_user_var super;

public:
  PTI_variable_aux_ident_or_text(const POS &pos, const LEX_STRING &var)
  : super(pos, var)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    LEX *lex= pc->thd->lex;
    if (!lex->parsing_options.allows_variable)
    {
      my_error(ER_VIEW_SELECT_VARIABLE, MYF(0));
      return true;
    }
    lex->set_uncacheable(pc->select, UNCACHEABLE_RAND);
    return false;
  }
};


/**
  Parse tree Item wrapper for 3-dimentional variable names
  
  Example: @global.default.x
*/
class PTI_variable_aux_3d : public Parse_tree_item
{
  typedef Parse_tree_item super;

  enum_var_type var_type;
  LEX_STRING var;
  POS var_pos;
  LEX_STRING component;

public:
  PTI_variable_aux_3d(const POS &pos, enum_var_type var_type_arg,
                      const LEX_STRING &var_arg,
                      const POS &var_pos_arg,
                      const LEX_STRING &component_arg)
  : super(pos),
    var_type(var_type_arg), var(var_arg), var_pos(var_pos_arg),
    component(component_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    LEX *lex= pc->thd->lex;
    if (!lex->parsing_options.allows_variable)
    {
      my_error(ER_VIEW_SELECT_VARIABLE, MYF(0));
      return true;
    }

    /* disallow "SELECT @@global.global.variable" */
    if (var.str && component.str && check_reserved_words(&var))
    {
      error(pc, var_pos);
      return true;
    }
    if (!(*res= get_system_var(pc, var_type, var, component)))
      return true;
    if (!my_strcasecmp(system_charset_info, var.str, "warning_count") ||
        !my_strcasecmp(system_charset_info, var.str, "error_count"))
    {
      /*
        "Diagnostics variable" used in a non-diagnostics statement.
        Save the information we need for the former, but clear the
        rest of the diagnostics area on account of the latter.
        See reset_condition_info().
      */
      lex->keep_diagnostics= DA_KEEP_COUNTS;
    }
    if (!((Item_func_get_system_var*) *res)->is_written_to_binlog())
      lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_SYSTEM_VARIABLE);

    return false;
  }
};


class PTI_count_sym : public Item_sum_count
{
  typedef Item_sum_count super;

public:
  PTI_count_sym(const POS &pos) : super(pos, (Item*)NULL) {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    args[0]= new (pc->mem_root) Item_int((int32) 0L, 1);
    if (args[0] == NULL)
      return true;

    return super::itemize(pc, res);
  }
};

class PTI_in_sum_expr : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;

public:
  PTI_in_sum_expr(const POS &pos, Item *expr_arg)
  : super(pos), expr(expr_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    pc->select->in_sum_expr++;

    if (super::itemize(pc, res) || expr->itemize(pc, &expr))
      return true;
    
    pc->select->in_sum_expr--;

    *res= expr;
    return false;
  }
};


class PTI_singlerow_subselect : public Parse_tree_item
{
  typedef Parse_tree_item super;

  PT_subselect *subselect;

public:
  PTI_singlerow_subselect(const POS &pos, PT_subselect *subselect_arg)
  : super(pos), subselect(subselect_arg)
  {}

  bool itemize(Parse_context *pc, Item **res);
};


class PTI_exists_subselect : public Parse_tree_item
{
  typedef Parse_tree_item super;

  PT_subselect *subselect;

public:
  PTI_exists_subselect(const POS &pos, PT_subselect *subselect_arg)
  : super(pos), subselect(subselect_arg)
  {}

  bool itemize(Parse_context *pc, Item **res);
};


class PTI_odbc_date : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING ident;
  Item *expr;

public:
  PTI_odbc_date(const POS &pos, const LEX_STRING &ident_arg, Item *expr_arg)
  : super(pos), ident(ident_arg), expr(expr_arg)
  {}

  bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res) || expr->itemize(pc, &expr))
      return true;

    Item_string *item;
    *res= NULL;
    /*
      If "expr" is reasonably short pure ASCII string literal,
      try to parse known ODBC style date, time or timestamp literals,
      e.g:
      SELECT {d'2001-01-01'};
      SELECT {t'10:20:30'};
      SELECT {ts'2001-01-01 10:20:30'};
    */
    if (expr->type() == Item::STRING_ITEM &&
       (item= (Item_string *) expr) &&
        item->collation.repertoire == MY_REPERTOIRE_ASCII &&
        item->str_value.length() < MAX_DATE_STRING_REP_LENGTH * 4)
    {
      enum_field_types type= MYSQL_TYPE_STRING;
      ErrConvString str(&item->str_value);
      LEX_STRING *ls= &ident;
      if (ls->length == 1)
      {
        if (ls->str[0] == 'd')  /* {d'2001-01-01'} */
          type= MYSQL_TYPE_DATE;
        else if (ls->str[0] == 't') /* {t'10:20:30'} */
          type= MYSQL_TYPE_TIME;
      }
      else if (ls->length == 2) /* {ts'2001-01-01 10:20:30'} */
      {
        if (ls->str[0] == 't' && ls->str[1] == 's')
          type= MYSQL_TYPE_DATETIME;
      }
      if (type != MYSQL_TYPE_STRING)
        *res= create_temporal_literal(pc->thd,
                                      str.ptr(), str.length(),
                                      system_charset_info,
                                      type, false);
    }
    if (*res == NULL)
      *res= expr;
    return false;
  }
};


class PTI_handle_sql2003_note184_exception : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *left;
  bool is_negation;
  Item *right;

public:
  PTI_handle_sql2003_note184_exception(const POS &pos, Item *left_arg,
                                       bool is_negation_arg, Item *right_arg)
  : super(pos), left(left_arg), is_negation(is_negation_arg), right(right_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


class PTI_expr_with_alias : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;
  Symbol_location expr_loc;
  LEX_STRING alias;

public:
  PTI_expr_with_alias(const POS &pos,
                      Item *expr_arg, const Symbol_location &expr_loc_arg,
                      const LEX_STRING &alias_arg)
  : super(pos), expr(expr_arg), expr_loc(expr_loc_arg), alias(alias_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res);
};


class PTI_limit_option_ident : public Parse_tree_item
{
  typedef Parse_tree_item super;

  LEX_STRING ident;
  Symbol_location ident_loc;

public:
  explicit PTI_limit_option_ident(const POS &pos, const LEX_STRING &ident_arg,
                                  const Symbol_location &ident_loc_arg)
  : super(pos), ident(ident_arg), ident_loc(ident_loc_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    LEX *lex= pc->thd->lex;
    sp_head *sp= lex->sphead;
    const char *query_start_ptr=
      sp ? sp->m_parser_data.get_current_stmt_start_ptr() : NULL;

    Item_splocal *v= create_item_for_sp_var(pc->thd, ident, NULL,
                                            query_start_ptr,
                                            ident_loc.start,
                                            ident_loc.end);
    if (!v)
      return true;

    lex->safe_to_cache_query= false;

    if (v->type() != Item::INT_ITEM)
    {
      my_error(ER_WRONG_SPVAR_TYPE_IN_LIMIT, MYF(0));
      return true;
    }

    v->limit_clause_param= true;
    *res= v;
    return false;
  }
};


class PTI_limit_option_param_marker : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item_param *param_marker;

public:
  explicit PTI_limit_option_param_marker(const POS &pos,
                                         Item_param *param_marker_arg)
  : super(pos), param_marker(param_marker_arg)
  {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    Item *tmp_param;
    if (super::itemize(pc, res) || param_marker->itemize(pc, &tmp_param))
      return true;
    /*
      The Item_param::type() function may return various values, so we can't
      simply compare tmp_param->type() with some constant, cast tmp_param
      to Item_param* and assign the result back to param_marker.
      OTOH we ensure that Item_param::itemize() always substitute the output
      parameter with "this" pointer of Item_param object, so we can skip
      the check and the assignment.
    */
    DBUG_ASSERT(tmp_param == param_marker);

    param_marker->limit_clause_param= true;
    *res= param_marker;
    return false;
  }
};


template<enum_parsing_context Context>
class PTI_context : public Parse_tree_item
{
  typedef Parse_tree_item super;

  Item *expr;

public:
  PTI_context(const POS &pos, Item *expr_arg) : super(pos), expr(expr_arg) {}

  virtual bool itemize(Parse_context *pc, Item **res)
  {
    if (super::itemize(pc, res))
      return true;

    pc->select->parsing_place= Context;

    if (expr->itemize(pc, &expr))
      return true;

    // Ensure we're resetting parsing place of the right select
    DBUG_ASSERT(pc->select->parsing_place == Context);
    pc->select->parsing_place= CTX_NONE;
    DBUG_ASSERT(expr != NULL);
    expr->top_level_item();

    *res= expr;
    return false;
  }
};

#endif /* PARSE_TREE_ITEMS_INCLUDED */