Refactor parts of Item_func_sp into Item_sp

In preparation for implementing custom aggregate functions, refactor
the common code between regular stored functions and aggregate stored
functions. This includes:

* initialising SP result field
* executing a SP
* access checks

In addition, refactor sp_head::execute_function to take two extra
parameters, a function rcontext and a Query_arena. These two paremeters
were initially initialised and destroyed within
sp_head::execute_function, but for aggregate stored functions we will
require control over their lifetime. The owner of these objects now
becomes Item_sp.

Signed-off-by: Vicențiu Ciorbaru <vicentiu@mariadb.org>

1 files changed, 2 insertions, 17 deletions

diff --git a/sql/item_func.h b/sql/item_func.h
index ed6f800fd17..07c6b5bb8d3 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -2732,26 +2732,12 @@ public:
  *
  */
 
-class sp_head;
-class sp_name;
-struct st_sp_security_context;
-
-class Item_func_sp :public Item_func
+class Item_func_sp :public Item_func,
+                    public Item_sp
 {
 private:
-  Name_resolution_context *context;
-  sp_name *m_name;
-  mutable sp_head *m_sp;
-  TABLE *dummy_table;
-  uchar result_buf[64];
-  /*
-     The result field of the concrete stored function.
-  */
-  Field *sp_result_field;
 
   bool execute();
-  bool execute_impl(THD *thd);
-  bool init_result_field(THD *thd, sp_head *sp);
 
 protected:
   bool is_expensive_processor(void *arg)
@@ -2843,7 +2829,6 @@ public:
   virtual bool change_context_processor(void *cntx)
     { context= (Name_resolution_context *)cntx; return FALSE; }
 
-  bool sp_check_access(THD * thd);
   virtual enum Functype functype() const { return FUNC_SP; }
 
   bool fix_fields(THD *thd, Item **ref);