MDEV-15714 Remove the use of STRING_ITEM from the parser

sql/item.cc

@@ -4043,6 +4043,23 @@ Item *Item_null::clone_item(THD *thd)
   return new (thd->mem_root) Item_null(thd, name.str);
 }
 
+
+Item_basic_constant *
+Item_null::make_string_literal_concat(THD *thd, const LEX_CSTRING *str)
+{
+  DBUG_ASSERT(thd->variables.sql_mode & MODE_EMPTY_STRING_IS_NULL);
+  if (str->length)
+  {
+    CHARSET_INFO *cs= thd->variables.collation_connection;
+    uint repertoire= my_string_repertoire(cs, str->str, str->length);
+    return new (thd->mem_root) Item_string(thd,
+                                           str->str, (uint) str->length, cs,
+                                           DERIVATION_COERCIBLE, repertoire);
+  }
+  return this;
+}
+
+
 /*********************** Item_param related ******************************/
 
 Item_param::Item_param(THD *thd, const LEX_CSTRING *name_arg,
@@ -6998,6 +7015,41 @@ Item *Item_string::clone_item(THD *thd)
 }
 
 
+Item_basic_constant *
+Item_string::make_string_literal_concat(THD *thd, const LEX_CSTRING *str)
+{
+  append(str->str, (uint32) str->length);
+  if (!(collation.repertoire & MY_REPERTOIRE_EXTENDED))
+  {
+    // If the string has been pure ASCII so far, check the new part.
+    CHARSET_INFO *cs= thd->variables.collation_connection;
+    collation.repertoire|= my_string_repertoire(cs, str->str, str->length);
+  }
+  return this;
+}
+
+
+/*
+  If "this" is a 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'};
+*/
+Item *Item_string::make_odbc_literal(THD *thd, const LEX_CSTRING *typestr)
+{
+  enum_field_types type= odbc_temporal_literal_type(typestr);
+  Item *res= type == MYSQL_TYPE_STRING ? this :
+             create_temporal_literal(thd, val_str(NULL), type, false);
+  /*
+    create_temporal_literal() returns NULL if failed to parse the string,
+    or the string format did not match the type, e.g.:  {d'2001-01-01 10:10:10'}
+  */
+  return res ? res : this;
+}
+
+
 static int save_int_value_in_field (Field *field, longlong nr, 
                                     bool null_value, bool unsigned_flag)
 {

sql/item.h

@@ -1554,6 +1554,10 @@ class Item: public Value_source,
   virtual Item *copy_andor_structure(THD *thd) { return this; }
   virtual Item *real_item() { return this; }
   virtual Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); }
+  virtual Item *make_odbc_literal(THD *thd, const LEX_CSTRING *typestr)
+  {
+    return this;
+  }
 
   static CHARSET_INFO *default_charset();
 
@@ -2329,6 +2333,12 @@ class Item_basic_constant :public Item_basic_value
   void set_used_tables(table_map map) { used_table_map= map; }
   table_map used_tables() const { return used_table_map; }
   bool check_vcol_func_processor(void *arg) { return FALSE;}
+  virtual Item_basic_constant *make_string_literal_concat(THD *thd,
+                                                          const LEX_CSTRING *)
+  {
+    DBUG_ASSERT(0);
+    return this;
+  }
   /* to prevent drop fixed flag (no need parent cleanup call) */
   void cleanup()
   {
@@ -3169,6 +3179,8 @@ class Item_null :public Item_basic_constant
 
   Item *safe_charset_converter(THD *thd, CHARSET_INFO *tocs);
   bool check_partition_func_processor(void *int_arg) {return FALSE;}
+  Item_basic_constant *make_string_literal_concat(THD *thd,
+                                                  const LEX_CSTRING *);
   Item *get_copy(THD *thd)
   { return get_item_copy<Item_null>(thd, this); }
 };
@@ -3956,7 +3968,10 @@ class Item_string :public Item_basic_constant
     }
     return MYSQL_TYPE_STRING; // Not a temporal literal
   }
-  
+  Item_basic_constant *make_string_literal_concat(THD *thd,
+                                                  const LEX_CSTRING *);
+  Item *make_odbc_literal(THD *thd, const LEX_CSTRING *typestr);
+
   Item *get_copy(THD *thd)
   { return get_item_copy<Item_string>(thd, this); }
 

sql/sql_class.cc

@@ -2495,8 +2495,8 @@ bool THD::convert_string(String *s, CHARSET_INFO *from_cs, CHARSET_INFO *to_cs)
 }
 
 
-Item *THD::make_string_literal(const char *str, size_t length,
-                               uint repertoire)
+Item_basic_constant *
+THD::make_string_literal(const char *str, size_t length, uint repertoire)
 {
   if (!length && (variables.sql_mode & MODE_EMPTY_STRING_IS_NULL))
     return new (mem_root) Item_null(this, 0, variables.collation_connection);
@@ -2517,7 +2517,8 @@ Item *THD::make_string_literal(const char *str, size_t length,
 }
 
 
-Item *THD::make_string_literal_nchar(const Lex_string_with_metadata_st &str)
+Item_basic_constant *
+THD::make_string_literal_nchar(const Lex_string_with_metadata_st &str)
 {
   DBUG_ASSERT(my_charset_is_ascii_based(national_charset_info));
   if (!str.length && (variables.sql_mode & MODE_EMPTY_STRING_IS_NULL))
@@ -2530,8 +2531,9 @@ Item *THD::make_string_literal_nchar(const Lex_string_with_metadata_st &str)
 }
 
 
-Item *THD::make_string_literal_charset(const Lex_string_with_metadata_st &str,
-                                       CHARSET_INFO *cs)
+Item_basic_constant *
+THD::make_string_literal_charset(const Lex_string_with_metadata_st &str,
+                                 CHARSET_INFO *cs)
 {
   if (!str.length && (variables.sql_mode & MODE_EMPTY_STRING_IS_NULL))
     return new (mem_root) Item_null(this, 0, cs);
@@ -2540,34 +2542,6 @@ Item *THD::make_string_literal_charset(const Lex_string_with_metadata_st &str,
 }
 
 
-Item *THD::make_string_literal_concat(Item *item, const LEX_CSTRING &str)
-{
-  if (item->type() == Item::NULL_ITEM)
-  {
-    DBUG_ASSERT(variables.sql_mode & MODE_EMPTY_STRING_IS_NULL);
-    if (str.length)
-    {
-      CHARSET_INFO *cs= variables.collation_connection;
-      uint repertoire= my_string_repertoire(cs, str.str, str.length);
-      return new (mem_root) Item_string(this, str.str, (uint)str.length, cs,
-                                        DERIVATION_COERCIBLE, repertoire);
-    }
-    return item;
-  }
-
-  DBUG_ASSERT(item->type() == Item::STRING_ITEM);
-  DBUG_ASSERT(item->basic_const_item());
-  static_cast<Item_string*>(item)->append(str.str, (uint)str.length);
-  if (!(item->collation.repertoire & MY_REPERTOIRE_EXTENDED))
-  {
-    // If the string has been pure ASCII so far, check the new part.
-    CHARSET_INFO *cs= variables.collation_connection;
-    item->collation.repertoire|= my_string_repertoire(cs, str.str, str.length);
-  }
-  return item;
-}
-
-
 /*
   Update some cache variables when character set changes
 */

sql/sql_class.h

@@ -3721,17 +3721,16 @@ class THD :public Statement,
     @param length     - length of the string
     @param repertoire - the repertoire of the string
   */
-  Item *make_string_literal(const char *str, size_t length,
-                            uint repertoire);
-  Item *make_string_literal(const Lex_string_with_metadata_st &str)
+  Item_basic_constant *make_string_literal(const char *str, size_t length,
+                                           uint repertoire);
+  Item_basic_constant *make_string_literal(const Lex_string_with_metadata_st &str)
   {
     uint repertoire= str.repertoire(variables.character_set_client);
     return make_string_literal(str.str, str.length, repertoire);
   }
-  Item *make_string_literal_nchar(const Lex_string_with_metadata_st &str);
-  Item *make_string_literal_charset(const Lex_string_with_metadata_st &str,
-                                    CHARSET_INFO *cs);
-  Item *make_string_literal_concat(Item *item1, const LEX_CSTRING &str);
+  Item_basic_constant *make_string_literal_nchar(const Lex_string_with_metadata_st &str);
+  Item_basic_constant *make_string_literal_charset(const Lex_string_with_metadata_st &str,
+                                                   CHARSET_INFO *cs);
   void add_changed_table(TABLE *table);
   void add_changed_table(const char *key, size_t key_length);
   CHANGED_TABLE_LIST * changed_table_dup(const char *key, size_t key_length);

sql/sql_yacc.yy

@@ -807,6 +807,7 @@ Virtual_column_info *add_virtual_expression(THD *thd, Item *expr)
   Item *item;
   Item_num *item_num;
   Item_param *item_param;
+  Item_basic_constant *item_basic_constant;
   Key_part_spec *key_part;
   LEX *lex;
   sp_assignment_lex *assignment_lex;
@@ -1760,7 +1761,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         replace_lock_option opt_low_priority insert_lock_option load_data_lock
 
 %type <item>
-        literal text_literal insert_ident order_ident temporal_literal
+        literal insert_ident order_ident temporal_literal
         simple_ident expr sum_expr in_sum_expr
         variable variable_aux bool_pri
         predicate bit_expr parenthesized_expr
@@ -1792,6 +1793,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %type <item_num>
         NUM_literal
 
+%type <item_basic_constant> text_literal
+
 %type <item_list>
         expr_list opt_udf_expr_list udf_expr_list when_list when_list_opt_else
         ident_list ident_list_arg opt_expr_list
@@ -9948,27 +9951,8 @@ column_default_non_parenthesized_expr:
           }
         | '{' ident expr '}'
           {
-            $$= NULL;
-            /*
-              If "expr" is reasonably short pure ASCII string literal,
-              try to parse known ODBC style date, time or timestamp literals,
-              e.g:
-              SELECT {d'2001-01-01'};
-              SELECT {t'10:20:30'};
-              SELECT {ts'2001-01-01 10:20:30'};
-            */
-            if ($3->type() == Item::STRING_ITEM)
-            {
-              Item_string *item= (Item_string *) $3;
-              enum_field_types type= item->odbc_temporal_literal_type(&$2);
-              if (type != MYSQL_TYPE_STRING)
-              {
-                $$= create_temporal_literal(thd, item->val_str(NULL),
-                                            type, false);
-              }
-            }
-            if ($$ == NULL)
-              $$= $3;
+            if (!($$= $3->make_odbc_literal(thd, &$2)))
+              MYSQL_YYABORT;
           }
         | MATCH ident_list_arg AGAINST '(' bit_expr fulltext_options ')'
           {
@@ -14682,7 +14666,7 @@ text_literal:
           }
         | text_literal TEXT_STRING_literal
           {
-            if (!($$= thd->make_string_literal_concat($1, $2)))
+            if (!($$= $1->make_string_literal_concat(thd, &$2)))
               MYSQL_YYABORT;
           }
         ;

sql/sql_yacc_ora.yy

@@ -198,6 +198,7 @@ void ORAerror(THD *thd, const char *s)
   Item *item;
   Item_num *item_num;
   Item_param *item_param;
+  Item_basic_constant *item_basic_constant;
   Key_part_spec *key_part;
   LEX *lex;
   sp_assignment_lex *assignment_lex;
@@ -1156,7 +1157,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         replace_lock_option opt_low_priority insert_lock_option load_data_lock
 
 %type <item>
-        literal text_literal insert_ident order_ident temporal_literal
+        literal insert_ident order_ident temporal_literal
         simple_ident expr sum_expr in_sum_expr
         variable variable_aux bool_pri
         predicate bit_expr parenthesized_expr
@@ -1189,6 +1190,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
 %type <item_num>
         NUM_literal
 
+%type <item_basic_constant> text_literal
+
 %type <item_list>
         expr_list opt_udf_expr_list udf_expr_list when_list when_list_opt_else
         ident_list ident_list_arg opt_expr_list
@@ -9727,27 +9730,8 @@ column_default_non_parenthesized_expr:
           }
         | '{' ident expr '}'
           {
-            $$= NULL;
-            /*
-              If "expr" is reasonably short pure ASCII string literal,
-              try to parse known ODBC style date, time or timestamp literals,
-              e.g:
-              SELECT {d'2001-01-01'};
-              SELECT {t'10:20:30'};
-              SELECT {ts'2001-01-01 10:20:30'};
-            */
-            if ($3->type() == Item::STRING_ITEM)
-            {
-              Item_string *item= (Item_string *) $3;
-              enum_field_types type= item->odbc_temporal_literal_type(&$2);
-              if (type != MYSQL_TYPE_STRING)
-              {
-                $$= create_temporal_literal(thd, item->val_str(NULL),
-                                            type, false);
-              }
-            }
-            if ($$ == NULL)
-              $$= $3;
+            if (!($$= $3->make_odbc_literal(thd, &$2)))
+              MYSQL_YYABORT;
           }
         | MATCH ident_list_arg AGAINST '(' bit_expr fulltext_options ')'
           {
@@ -14404,7 +14388,7 @@ text_literal:
           }
         | text_literal TEXT_STRING_literal
           {
-            if (!($$= thd->make_string_literal_concat($1, $2)))
+            if (!($$= $1->make_string_literal_concat(thd, &$2)))
               MYSQL_YYABORT;
           }
         ;