A cleanup for MDEV-13919 sql_mode=ORACLE: Derive length of VARCHAR SP param...

The intent of this patch is to avoid copying arguments from
a pair "Item **args, uint arg_count" to List<Item> in
sp_head::execute_function(). If the number of a stored function parameters
is huge, such copying can affect performance.

Change:
1. Adding a new method Row_definition_list::adjust_formal_params_to_actual_params,
   which accepts a pair of "Item **, uint".
2. Modifying the code to use the new method:
   - the calls for sp_rcontext::retrieve_field_definitions() and
     Row_definition_list::adjust_formal_params_to_actual_params() have
     been moved from sp_rcontext::create() to sp_head::rcontext_create(),
     to handle different argument notations easier (Item** vs List<Item>).
   - sp_rcontext::create() now assumes that the passed Row_definition_list
     is already adjusted to the actual SP parameters, and all "TYPE OF"
     and "ROWTYPE OF" references are resolved.
3. Removing creation of List<Item> in sp_head::execute_procedure(),
   using the code with "Item**, uint" notation instead.
4. Improvement of the code for MDEV-10577:
   As a good side effect, this patch gets rid of double security context
   switch inside sp_head::execute_trigger():
   sp_rcontext is created when the context is already switched,
   so the second context switch inside sp_head::rcontext_create() was
   redundant. This is solved by adding a "bool switch_secutiry_ctx" parameter
   to rcontext_create(), so now execute_function() and execute_procedure()
   pass "true", while execute_trigger() passes "false".

1 files changed, 17 insertions, 11 deletions

diff --git a/sql/sp_rcontext.cc b/sql/sp_rcontext.cc
index e82947835f0..43a42b579bd 100644
--- a/sql/sp_rcontext.cc
+++ b/sql/sp_rcontext.cc
@@ -63,25 +63,15 @@ sp_rcontext::~sp_rcontext()
 sp_rcontext *sp_rcontext::create(THD *thd,
                                  const sp_pcontext *root_parsing_ctx,
                                  Field *return_value_fld,
-                                 bool resolve_type_refs,
-                                 List<Item> *args)
+                                 Row_definition_list &field_def_lst)
 {
   sp_rcontext *ctx= new (thd->mem_root) sp_rcontext(root_parsing_ctx,
                                                     return_value_fld,
                                                     thd->in_sub_stmt);
-
   if (!ctx)
     return NULL;
 
-  Row_definition_list field_def_lst;
-  ctx->m_root_parsing_ctx->retrieve_field_definitions(&field_def_lst);
-
-  if (args &&
-      field_def_lst.adjust_formal_params_to_actual_params(thd, args))
-    return NULL;
-
   if (ctx->alloc_arrays(thd) ||
-      (resolve_type_refs && field_def_lst.resolve_type_refs(thd)) ||
       ctx->init_var_table(thd, field_def_lst) ||
       ctx->init_var_items(thd, field_def_lst))
   {
@@ -110,6 +100,22 @@ bool Row_definition_list::
 }
 
 
+bool Row_definition_list::
+       adjust_formal_params_to_actual_params(THD *thd,
+                                             Item **args, uint arg_count)
+{
+  List_iterator<Spvar_definition> it(*this);
+  DBUG_ASSERT(elements >= arg_count );
+  Spvar_definition *def;
+  for (uint i= 0; (def= it++) && (i < arg_count) ; i++)
+  {
+    if (def->type_handler()->adjust_spparam_type(def, args[i]))
+      return true;
+  }
+  return false;
+}
+
+
 bool sp_rcontext::alloc_arrays(THD *thd)
 {
   {