cleanup: class my_var

* split my_var class in three - base my_var and two descencants, move
  properties into descendants, remove if(), create a virtual method instead
* factor out the common code in the select_var_ident parser rule

sql/sql_class.cc

@@ -3731,6 +3731,18 @@ Statement_map::~Statement_map()
   my_hash_free(&st_hash);
 }
 
+bool my_var_user::set(THD *thd, Item *item)
+{
+  Item_func_set_user_var *suv= new Item_func_set_user_var(name, item);
+  suv->save_item_result(item);
+  return suv->fix_fields(thd, 0) || suv->update();
+}
+
+bool my_var_sp::set(THD *thd, Item *item)
+{
+  return thd->spcont->set_variable(thd, offset, &item);
+}
+
 int select_dumpvar::send_data(List<Item> &items)
 {
   List_iterator_fast<my_var> var_li(var_list);
@@ -3751,20 +3763,8 @@ int select_dumpvar::send_data(List<Item> &items)
   }
   while ((mv= var_li++) && (item= it++))
   {
-    if (mv->local)
-    {
-      if (thd->spcont->set_variable(thd, mv->offset, &item))
-	    DBUG_RETURN(1);
-    }
-    else
-    {
-      Item_func_set_user_var *suv= new Item_func_set_user_var(mv->s, item);
-      suv->save_item_result(item);
-      if (suv->fix_fields(thd, 0))
-        DBUG_RETURN (1);
-      if (suv->update())
-        DBUG_RETURN (1);
-    }
+    if (mv->set(thd, item))
+      DBUG_RETURN(1);
   }
   DBUG_RETURN(thd->is_error());
 }

sql/sql_class.h

@@ -4773,21 +4773,35 @@ class multi_update :public select_result_interceptor
 
 class my_var : public Sql_alloc  {
 public:
-  LEX_STRING s;
-#ifndef DBUG_OFF
+  const LEX_STRING name;
+  enum type { SESSION_VAR, LOCAL_VAR, PARAM_VAR };
+  type scope;
+  my_var(const LEX_STRING& j, enum type s) : name(j), scope(s) { }
+  virtual ~my_var() {}
+  virtual bool set(THD *thd, Item *val) = 0;
+};
+
+class my_var_sp: public my_var {
+public:
+  uint offset;
+  enum_field_types type;
   /*
     Routine to which this Item_splocal belongs. Used for checking if correct
     runtime context is used for variable handling.
   */
   sp_head *sp;
-#endif
-  bool local;
-  uint offset;
-  enum_field_types type;
-  my_var (LEX_STRING& j, bool i, uint o, enum_field_types t)
-    :s(j), local(i), offset(o), type(t)
-  {}
-  ~my_var() {}
+  my_var_sp(const LEX_STRING& j, uint o, enum_field_types t, sp_head *s)
+    : my_var(j, LOCAL_VAR), offset(o), type(t), sp(s) { }
+  ~my_var_sp() { }
+  bool set(THD *thd, Item *val);
+};
+
+class my_var_user: public my_var {
+public:
+  my_var_user(const LEX_STRING& j)
+    : my_var(j, SESSION_VAR) { }
+  ~my_var_user() { }
+  bool set(THD *thd, Item *val);
 };
 
 class select_dumpvar :public select_result_interceptor {

sql/sql_yacc.yy

@@ -933,6 +933,7 @@ static bool sp_create_assignment_instr(THD *thd, bool no_lookahead)
   struct { int vars, conds, hndlrs, curs; } spblock;
   sp_name *spname;
   LEX *lex;
+  class my_var *myvar;
   sp_head *sphead;
   struct p_elem_val *p_elem_value;
   enum index_hint_type index_hint;
@@ -1804,6 +1805,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 
 %type <dyncol_def_list> dyncall_create_list
 
+%type <myvar> select_outvar
+
 %type <NONE>
         analyze_stmt_command
         query verb_clause create change select do drop insert replace insert2
@@ -11557,16 +11560,13 @@ select_var_list:
         | select_var_ident {}
         ;
 
-select_var_ident:  
-          '@' ident_or_text
+select_var_ident: select_outvar
           {
-            LEX *lex=Lex;
-            if (lex->result) 
+            if (Lex->result)
             {
-              my_var *var= new my_var($2,0,0,(enum_field_types)0);
-              if (var == NULL)
+              if ($1 == NULL)
                 MYSQL_YYABORT;
-              ((select_dumpvar *)lex->result)->var_list.push_back(var);
+              ((select_dumpvar *)Lex->result)->var_list.push_back($1);
             }
             else
             {
@@ -11574,37 +11574,27 @@ select_var_ident:
                 The parser won't create select_result instance only
                 if it's an EXPLAIN.
               */
-              DBUG_ASSERT(lex->describe);
+              DBUG_ASSERT(Lex->describe);
             }
           }
+        ;
+
+select_outvar:
+          '@' ident_or_text
+          {
+            $$ = Lex->result ? new my_var_user($2) : NULL;
+          }
         | ident_or_text
           {
-            LEX *lex=Lex;
             sp_variable *t;
 
-            if (!lex->spcont || !(t=lex->spcont->find_variable($1, false)))
+            if (!Lex->spcont || !(t= Lex->spcont->find_variable($1, false)))
             {
               my_error(ER_SP_UNDECLARED_VAR, MYF(0), $1.str);
               MYSQL_YYABORT;
             }
-            if (lex->result)
-            {
-              my_var *var= new my_var($1,1,t->offset,t->type);
-              if (var == NULL)
-                MYSQL_YYABORT;
-              ((select_dumpvar *)lex->result)->var_list.push_back(var);
-#ifndef DBUG_OFF
-              var->sp= lex->sphead;
-#endif
-            }
-            else
-            {
-              /*
-                The parser won't create select_result instance only
-                if it's an EXPLAIN.
-              */
-              DBUG_ASSERT(lex->describe);
-            }
+            $$ = Lex->result ? new my_var_sp($1, t->offset, t->type, Lex->sphead)
+                             : NULL;
           }
         ;