Split item->flags into base_flags and with_flags

This was done to simplify copying of with_* flags

Other things:
- Changed Flags to C++ enums, which enables gdb to print
  out bit values for the flags. This also enables compiler
  errors if one tries to manipulate a non existing bit in
  a variable.
- Added set_maybe_null() as a shortcut as setting the
  MAYBE_NULL flags was used in a LOT of places.
- Renamed PARAM flag to SP_VAR to ensure it's not confused with persistent
  statement parameters.

1 files changed, 23 insertions, 29 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index 67251b73faf..21aaebdd52e 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -133,12 +133,7 @@ void Item_func::sync_with_sum_func_and_with_field(List<Item> &list)
   List_iterator_fast<Item> li(list);
   Item *item;
   while ((item= li++))
-  {
-    flags|= (item->flags & (ITEM_FLAG_WITH_SUM_FUNC |
-                            ITEM_FLAG_WITH_WINDOW_FUNC |
-                            ITEM_FLAG_WITH_FIELD |
-                            ITEM_FLAG_WITH_PARAM));
-  }
+    with_flags|= item->with_flags;
 }
 
 
@@ -353,8 +348,8 @@ Item_func::fix_fields(THD *thd, Item **ref)
 	return TRUE;				/* purecov: inspected */
       item= *arg;
 
-      flags|= item->flags & ~(ITEM_FLAG_IS_AUTOGENERATED_NAME |
-                              ITEM_FLAG_IS_IN_WITH_CYCLE);
+      base_flags|= item->base_flags & item_base_t::MAYBE_NULL;
+      with_flags|= item->with_flags;
       used_tables_and_const_cache_join(item);
       not_null_tables_cache|= item->not_null_tables();
     }
@@ -363,7 +358,7 @@ Item_func::fix_fields(THD *thd, Item **ref)
     return true;
   if (fix_length_and_dec())
     return TRUE;
-  flags|= ITEM_FLAG_FIXED;
+  base_flags|= item_base_t::FIXED;
   return FALSE;
 }
 
@@ -379,7 +374,7 @@ Item_func::quick_fix_field()
         (*arg)->quick_fix_field();
     }
   }
-  flags|= ITEM_FLAG_FIXED;
+  base_flags|= item_base_t::FIXED;
 }
 
 
@@ -593,9 +588,12 @@ void Item_func::split_sum_func(THD *thd,  Ref_ptr_array ref_pointer_array,
                                List<Item> &fields, uint flags)
 {
   Item **arg, **arg_end;
+  DBUG_ENTER("Item_func::split_sum_func");
+
   for (arg= args, arg_end= args+arg_count; arg != arg_end ; arg++)
     (*arg)->split_sum_func2(thd, ref_pointer_array, fields, arg,
                             flags | SPLIT_SUM_SKIP_REGISTERED);
+  DBUG_VOID_RETURN;
 }
 
 
@@ -1586,7 +1584,7 @@ bool Item_func_div::fix_length_and_dec()
   DBUG_ENTER("Item_func_div::fix_length_and_dec");
   DBUG_PRINT("info", ("name %s", func_name()));
   prec_increment= current_thd->variables.div_precincrement;
-  flags|= ITEM_FLAG_MAYBE_NULL; // division by zero
+  set_maybe_null(); // division by zero
 
   const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_div;
   DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_non_commutative_test;);
@@ -1664,7 +1662,7 @@ bool Item_func_int_div::fix_length_and_dec()
   uint32 prec= args[0]->decimal_int_part();
   set_if_smaller(prec, MY_INT64_NUM_DECIMAL_DIGITS);
   fix_char_length(prec);
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
   unsigned_flag=args[0]->unsigned_flag | args[1]->unsigned_flag;
   return false;
 }
@@ -1744,7 +1742,7 @@ bool Item_func_mod::fix_length_and_dec()
 {
   DBUG_ENTER("Item_func_mod::fix_length_and_dec");
   DBUG_PRINT("info", ("name %s", func_name()));
-  flags|= ITEM_FLAG_MAYBE_NULL; // division by zero
+  set_maybe_null(); // division by zero
   const Type_aggregator *aggregator= &type_handler_data->m_type_aggregator_for_mod;
   DBUG_EXECUTE_IF("num_op", aggregator= &type_handler_data->m_type_aggregator_non_commutative_test;);
   DBUG_ASSERT(!aggregator->is_commutative());
@@ -2553,7 +2551,7 @@ void Item_func_round::fix_arg_datetime()
     return NULL.
   */
   if (!truncate)
-    flags|= ITEM_FLAG_MAYBE_NULL;
+    set_maybe_null();
   fix_arg_temporal(&type_handler_datetime2, MAX_DATETIME_WIDTH);
 }
 
@@ -3235,7 +3233,7 @@ longlong Item_func_field::val_int()
 
 bool Item_func_field::fix_length_and_dec()
 {
-  flags&= (item_flags_t) ~ITEM_FLAG_MAYBE_NULL;
+  base_flags&= ~item_base_t::MAYBE_NULL;
   max_length=3;
   cmp_type= args[0]->result_type();
   for (uint i=1; i < arg_count ; i++)
@@ -3479,7 +3477,7 @@ udf_handler::fix_fields(THD *thd, Item_func_or_sum *func,
   args=arguments;
 
   /* Fix all arguments */
-  func->flags&= (Item::item_flags_t) ~ITEM_FLAG_MAYBE_NULL;
+  func->base_flags&= ~item_base_t::MAYBE_NULL;
   func->used_tables_and_const_cache_init();
 
   if ((f_args.arg_count=arg_count))
@@ -3514,12 +3512,8 @@ udf_handler::fix_fields(THD *thd, Item_func_or_sum *func,
       */
       if (item->collation.collation->state & MY_CS_BINSORT)
 	func->collation.set(&my_charset_bin);
-      func->flags|= (item->flags & (ITEM_FLAG_MAYBE_NULL |
-                                    ITEM_FLAG_WITH_SUM_FUNC |
-                                    ITEM_FLAG_WITH_WINDOW_FUNC |
-                                    ITEM_FLAG_WITH_FIELD |
-                                    ITEM_FLAG_WITH_PARAM |
-                                    ITEM_FLAG_WITH_SUBQUERY));
+      func->base_flags|= item->base_flags & item_base_t::MAYBE_NULL;
+      func->with_flags|= item->with_flags;
       func->used_tables_and_const_cache_join(item);
       f_args.arg_type[i]=item->result_type();
     }
@@ -4789,7 +4783,7 @@ bool Item_func_set_user_var::fix_fields(THD *thd, Item **ref)
 bool
 Item_func_set_user_var::fix_length_and_dec()
 {
-  flags|= (args[0]->flags & ITEM_FLAG_MAYBE_NULL);
+  base_flags|= (args[0]->base_flags & item_base_t::MAYBE_NULL);
   decimals=args[0]->decimals;
   if (args[0]->collation.derivation == DERIVATION_NUMERIC)
   {
@@ -5646,7 +5640,7 @@ bool Item_func_get_user_var::fix_length_and_dec()
 {
   THD *thd=current_thd;
   int error;
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
   decimals=NOT_FIXED_DEC;
   max_length=MAX_BLOB_WIDTH;
 
@@ -5856,7 +5850,7 @@ void Item_func_get_system_var::update_null_value()
 bool Item_func_get_system_var::fix_length_and_dec()
 {
   char *cptr;
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
   max_length= 0;
 
   if (var->check_type(var_type))
@@ -6219,7 +6213,7 @@ bool Item_func_match::fix_fields(THD *thd, Item **ref)
 
   status_var_increment(thd->status_var.feature_fulltext);
 
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
   join_key=0;
 
   /*
@@ -6555,7 +6549,7 @@ Item_func_sp::Item_func_sp(THD *thd, Name_resolution_context *context_arg,
                            sp_name *name, const Sp_handler *sph):
   Item_func(thd), Item_sp(thd, context_arg, name), m_handler(sph)
 {
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
 }
 
 
@@ -6564,7 +6558,7 @@ Item_func_sp::Item_func_sp(THD *thd, Name_resolution_context *context_arg,
                            List<Item> &list):
   Item_func(thd, list), Item_sp(thd, context_arg, name_arg), m_handler(sph)
 {
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
 }
 
 
@@ -6620,7 +6614,7 @@ bool Item_func_sp::fix_length_and_dec()
   Type_std_attributes::set(sp_result_field->type_std_attributes());
   // There is a bug in the line below. See MDEV-11292 for details.
   collation.derivation= DERIVATION_COERCIBLE;
-  flags|= ITEM_FLAG_MAYBE_NULL;
+  set_maybe_null();
 
   DBUG_RETURN(FALSE);
 }