MDEV-21064 Add a new class sp_expr_lex and a new grammar rule expr_lex

Adding:
- new class sp_expr_lex
- new grammar rule expr_lex, which includes both reset_lex()
  and its corresponding restore_lex()

Also:
- Moving a few methods from LEX to sp_expr_lex.
- Moving the code from *.yy to new method sp_expr_lex methods
  sp_repeat_loop_finalize() and sp_if_expr().

This change makes it easier to edit the related grammar
(and makes it easier to unify sql_yacc.yy and sql_yacc_ora.yy later).

sql/sp_head.cc

@@ -3078,7 +3078,7 @@ bool sp_head::add_instr_freturn(THD *thd, sp_pcontext *spcont,
 {
   sp_instr_freturn *i= new (thd->mem_root)
                        sp_instr_freturn(instructions(), spcont, item,
-                       m_return_field_def.type_handler(), thd->lex);
+                       m_return_field_def.type_handler(), lex);
   if (i == NULL || add_instr(i))
     return true;
   m_flags|= sp_head::HAS_RETURN;

sql/sql_lex.cc

@@ -61,7 +61,7 @@ const LEX_CSTRING param_clex_str= {"?", 1};
   @return 0 on success
 */
 
-int LEX::case_stmt_action_expr(Item* expr)
+int sp_expr_lex::case_stmt_action_expr()
 {
   int case_expr_id= spcont->register_case_expr();
   sp_instr_set_case_expr *i;
@@ -70,8 +70,8 @@ int LEX::case_stmt_action_expr(Item* expr)
     return 1;
 
   i= new (thd->mem_root)
-    sp_instr_set_case_expr(sphead->instructions(), spcont, case_expr_id, expr,
-                           this);
+    sp_instr_set_case_expr(sphead->instructions(), spcont, case_expr_id,
+                           get_item(), this);
 
   sphead->add_cont_backpatch(i);
   return sphead->add_instr(i);
@@ -85,7 +85,7 @@ int LEX::case_stmt_action_expr(Item* expr)
   @param simple true for simple cases, false for searched cases
 */
 
-int LEX::case_stmt_action_when(Item *when, bool simple)
+int sp_expr_lex::case_stmt_action_when(bool simple)
 {
   uint ip= sphead->instructions();
   sp_instr_jump_if_not *i;
@@ -104,11 +104,11 @@ int LEX::case_stmt_action_when(Item *when, bool simple)
     }
 #endif
 
-    expr= new (thd->mem_root) Item_func_eq(thd, var, when);
+    expr= new (thd->mem_root) Item_func_eq(thd, var, get_item());
     i= new (thd->mem_root) sp_instr_jump_if_not(ip, spcont, expr, this);
   }
   else
-    i= new (thd->mem_root) sp_instr_jump_if_not(ip, spcont, when, this);
+    i= new (thd->mem_root) sp_instr_jump_if_not(ip, spcont, get_item(), this);
 
   /*
     BACKPATCH: Registering forward jump from
@@ -7334,7 +7334,7 @@ bool LEX::sp_exit_block(THD *thd, sp_label *lab, Item *when)
   sp_instr_jump_if_not *i= new (thd->mem_root)
                            sp_instr_jump_if_not(sphead->instructions(),
                                                 spcont,
-                                                when, thd->lex);
+                                                when, this);
   if (unlikely(i == NULL) ||
       unlikely(sphead->add_instr(i)) ||
       unlikely(sp_exit_block(thd, lab)))
@@ -7397,17 +7397,40 @@ bool LEX::sp_continue_loop(THD *thd, sp_label *lab)
 }
 
 
-bool LEX::sp_continue_loop(THD *thd, sp_label *lab, Item *when)
+bool LEX::sp_continue_statement(THD *thd)
 {
-  if (!when)
-    return sp_continue_loop(thd, lab);
+  sp_label *lab= spcont->find_label_current_loop_start();
+  if (unlikely(!lab))
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "CONTINUE", "");
+    return true;
+  }
+  DBUG_ASSERT(lab->type == sp_label::ITERATION);
+  return sp_continue_loop(thd, lab);
+}
 
+
+bool LEX::sp_continue_statement(THD *thd, const LEX_CSTRING *label_name)
+{
+  sp_label *lab= spcont->find_label(label_name);
+  if (!lab || lab->type != sp_label::ITERATION)
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "CONTINUE", label_name->str);
+    return true;
+  }
+  return sp_continue_loop(thd, lab);
+}
+
+
+bool LEX::sp_continue_loop(THD *thd, sp_label *lab, Item *when)
+{
+  DBUG_ASSERT(when);
   DBUG_ASSERT(sphead == thd->lex->sphead);
   DBUG_ASSERT(spcont == thd->lex->spcont);
   sp_instr_jump_if_not *i= new (thd->mem_root)
                            sp_instr_jump_if_not(sphead->instructions(),
                                                 spcont,
-                                                when, thd->lex);
+                                                when, this);
   if (unlikely(i == NULL) ||
       unlikely(sphead->add_instr(i)) ||
       unlikely(sp_continue_loop(thd, lab)))
@@ -7417,7 +7440,7 @@ bool LEX::sp_continue_loop(THD *thd, sp_label *lab, Item *when)
 }
 
 
-bool LEX::sp_continue_statement(THD *thd, Item *when)
+bool sp_expr_lex::sp_continue_when_statement(THD *thd)
 {
   sp_label *lab= spcont->find_label_current_loop_start();
   if (unlikely(!lab))
@@ -7426,12 +7449,12 @@ bool LEX::sp_continue_statement(THD *thd, Item *when)
     return true;
   }
   DBUG_ASSERT(lab->type == sp_label::ITERATION);
-  return sp_continue_loop(thd, lab, when);
+  return sp_continue_loop(thd, lab, get_item());
 }
 
 
-bool LEX::sp_continue_statement(THD *thd, const LEX_CSTRING *label_name,
-                                Item *when)
+bool sp_expr_lex::sp_continue_when_statement(THD *thd,
+                                             const LEX_CSTRING *label_name)
 {
   sp_label *lab= spcont->find_label(label_name);
   if (!lab || lab->type != sp_label::ITERATION)
@@ -7439,7 +7462,7 @@ bool LEX::sp_continue_statement(THD *thd, const LEX_CSTRING *label_name,
     my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "CONTINUE", label_name->str);
     return true;
   }
-  return sp_continue_loop(thd, lab, when);
+  return sp_continue_loop(thd, lab, get_item());
 }
 
 
@@ -7504,10 +7527,10 @@ void LEX::sp_pop_loop_empty_label(THD *thd)
 }
 
 
-bool LEX::sp_while_loop_expression(THD *thd, Item *expr)
+bool LEX::sp_while_loop_expression(THD *thd, Item *item)
 {
   sp_instr_jump_if_not *i= new (thd->mem_root)
-    sp_instr_jump_if_not(sphead->instructions(), spcont, expr, this);
+    sp_instr_jump_if_not(sphead->instructions(), spcont, item, this);
   return (unlikely(i == NULL) ||
           /* Jumping forward */
           unlikely(sphead->push_backpatch(thd, i, spcont->last_label())) ||
@@ -11065,3 +11088,45 @@ bool LEX::set_cast_type_udt(Lex_cast_type_st *type,
   return false;
 }
 
+
+bool sp_expr_lex::sp_repeat_loop_finalize(THD *thd)
+{
+  uint ip= sphead->instructions();
+  sp_label *lab= spcont->last_label();  /* Jumping back */
+  sp_instr_jump_if_not *i= new (thd->mem_root)
+    sp_instr_jump_if_not(ip, spcont, get_item(), lab->ip, this);
+  if (unlikely(i == NULL) ||
+      unlikely(sphead->add_instr(i)))
+    return true;
+  /* We can shortcut the cont_backpatch here */
+  i->m_cont_dest= ip+1;
+  return false;
+}
+
+
+bool sp_expr_lex::sp_if_expr(THD *thd)
+{
+  uint ip= sphead->instructions();
+  sp_instr_jump_if_not *i= new (thd->mem_root)
+                           sp_instr_jump_if_not(ip, spcont, get_item(), this);
+  return
+    (unlikely(i == NULL) ||
+    unlikely(sphead->push_backpatch(thd, i,
+                                    spcont->push_label(thd, &empty_clex_str,
+                                                       0))) ||
+    unlikely(sphead->add_cont_backpatch(i)) ||
+    unlikely(sphead->add_instr(i)));
+}
+
+
+bool LEX::sp_if_after_statements(THD *thd)
+{
+  uint ip= sphead->instructions();
+  sp_instr_jump *i= new (thd->mem_root) sp_instr_jump(ip, spcont);
+  if (unlikely(i == NULL) ||
+      unlikely(sphead->add_instr(i)))
+    return true;
+  sphead->backpatch(spcont->pop_label());
+  sphead->push_backpatch(thd, i, spcont->push_label(thd, &empty_clex_str, 0));
+  return false;
+}

sql/sql_lex.h

@@ -267,6 +267,7 @@ class sp_name;
 class sp_instr;
 class sp_pcontext;
 class sp_variable;
+class sp_expr_lex;
 class sp_assignment_lex;
 class st_alter_tablespace;
 class partition_info;
@@ -3224,7 +3225,6 @@ struct LEX: public Query_tables_list
   bool sp_exit_block(THD *thd, sp_label *lab, Item *when);
 
   bool sp_continue_loop(THD *thd, sp_label *lab);
-  bool sp_continue_loop(THD *thd, sp_label *lab, Item *when);
 
   bool sp_for_loop_condition(THD *thd, const Lex_for_loop_st &loop);
   bool sp_for_loop_increment(THD *thd, const Lex_for_loop_st &loop);
@@ -3235,6 +3235,10 @@ struct LEX: public Query_tables_list
     @retval true  ERROR (fields are not allowed). Error is raised.
   */
   bool check_expr_allows_fields_or_error(THD *thd, const char *name) const;
+
+protected:
+  bool sp_continue_loop(THD *thd, sp_label *lab, Item *when);
+
 public:
   void parse_error(uint err_number= ER_SYNTAX_ERROR);
   inline bool is_arena_for_set_stmt() {return arena_for_set_stmt != 0;}
@@ -3754,8 +3758,6 @@ struct LEX: public Query_tables_list
                                 const Lex_field_type_st &def);
   bool sf_return_fill_definition(const Lex_field_type_st &def);
 
-  int case_stmt_action_expr(Item* expr);
-  int case_stmt_action_when(Item *when, bool simple);
   int case_stmt_action_then();
   bool setup_select_in_parentheses();
   bool set_trigger_new_row(const LEX_CSTRING *name, Item *val);
@@ -4120,8 +4122,8 @@ struct LEX: public Query_tables_list
   bool sp_leave_statement(THD *thd, const LEX_CSTRING *label_name);
   bool sp_goto_statement(THD *thd, const LEX_CSTRING *label_name);
 
-  bool sp_continue_statement(THD *thd, Item *when);
-  bool sp_continue_statement(THD *thd, const LEX_CSTRING *label_name, Item *when);
+  bool sp_continue_statement(THD *thd);
+  bool sp_continue_statement(THD *thd, const LEX_CSTRING *label_name);
   bool sp_iterate_statement(THD *thd, const LEX_CSTRING *label_name);
 
   bool maybe_start_compound_statement(THD *thd);
@@ -4131,6 +4133,7 @@ struct LEX: public Query_tables_list
   void sp_pop_loop_empty_label(THD *thd);
   bool sp_while_loop_expression(THD *thd, Item *expr);
   bool sp_while_loop_finalize(THD *thd);
+  bool sp_if_after_statements(THD *thd);
   bool sp_push_goto_label(THD *thd, const LEX_CSTRING *label_name);
 
   Item_param *add_placeholder(THD *thd, const LEX_CSTRING *name,
@@ -4827,6 +4830,35 @@ class sp_lex_set_var: public sp_lex_local
 };
 
 
+class sp_expr_lex: public sp_lex_local
+{
+  Item *m_item;       // The expression
+public:
+  sp_expr_lex(THD *thd, LEX *oldlex)
+   :sp_lex_local(thd, oldlex),
+    m_item(NULL)
+  { }
+  void set_item(Item *item)
+  {
+    m_item= item;
+  }
+  Item *get_item() const
+  {
+    return m_item;
+  }
+  bool sp_continue_when_statement(THD *thd);
+  bool sp_continue_when_statement(THD *thd, const LEX_CSTRING *label_name);
+  int case_stmt_action_expr();
+  int case_stmt_action_when(bool simple);
+  bool sp_while_loop_expression(THD *thd)
+  {
+    return LEX::sp_while_loop_expression(thd, get_item());
+  }
+  bool sp_repeat_loop_finalize(THD *thd);
+  bool sp_if_expr(THD *thd);
+};
+
+
 /**
   An assignment specific LEX, which additionally has an Item (an expression)
   and an associated with the Item free_list, which is usually freed

sql/sql_yacc.yy

@@ -236,6 +236,7 @@ void turn_parser_debug_on()
   Item_basic_constant *item_basic_constant;
   Key_part_spec *key_part;
   LEX *lex;
+  sp_expr_lex *expr_lex;
   sp_assignment_lex *assignment_lex;
   class sp_lex_cursor *sp_cursor_stmt;
   LEX_CSTRING *lex_str_ptr;
@@ -1420,7 +1421,6 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         signal_allowed_expr
         simple_target_specification
         condition_number
-        reset_lex_expr
         opt_versioning_interval_start
 
 %type <item_param> param_marker
@@ -1441,6 +1441,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         sp_cursor_stmt_lex
         sp_cursor_stmt
 
+%type <expr_lex>
+        expr_lex
+
 %type <assignment_lex>
         assignment_source_lex
         assignment_source_expr
@@ -3702,15 +3705,11 @@ RETURN_ALLMODES_SYM:
         ;
 
 sp_proc_stmt_return:
-          RETURN_ALLMODES_SYM
-          { Lex->sphead->reset_lex(thd); }
-          expr
+          RETURN_ALLMODES_SYM expr_lex
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            if (unlikely(sp->m_handler->add_instr_freturn(thd, sp, lex->spcont,
-                                                          $3, lex)) ||
-                unlikely(sp->restore_lex(thd)))
+            sp_head *sp= $2->sphead;
+            if (unlikely(sp->m_handler->add_instr_freturn(thd, sp, $2->spcont,
+                                                          $2->get_item(), $2)))
               MYSQL_YYABORT;
           }
         | RETURN_ORACLE_SYM
@@ -3723,10 +3722,6 @@ sp_proc_stmt_return:
           }
         ;
 
-reset_lex_expr:
-          { Lex->sphead->reset_lex(thd); } expr { $$= $2; }
-        ;
-
 sp_proc_stmt_exit_oracle:
           EXIT_ORACLE_SYM
           {
@@ -3738,16 +3733,14 @@ sp_proc_stmt_exit_oracle:
             if (unlikely(Lex->sp_exit_statement(thd, &$2, NULL)))
               MYSQL_YYABORT;
           }
-        | EXIT_ORACLE_SYM WHEN_SYM reset_lex_expr
+        | EXIT_ORACLE_SYM WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_exit_statement(thd, $3)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($3->sp_exit_statement(thd, $3->get_item())))
               MYSQL_YYABORT;
           }
-        | EXIT_ORACLE_SYM label_ident WHEN_SYM reset_lex_expr
+        | EXIT_ORACLE_SYM label_ident WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_exit_statement(thd, &$2, $4)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($4->sp_exit_statement(thd, &$2, $4->get_item())))
               MYSQL_YYABORT;
           }
         ;
@@ -3755,24 +3748,22 @@ sp_proc_stmt_exit_oracle:
 sp_proc_stmt_continue_oracle:
           CONTINUE_ORACLE_SYM
           {
-            if (unlikely(Lex->sp_continue_statement(thd, NULL)))
+            if (unlikely(Lex->sp_continue_statement(thd)))
               MYSQL_YYABORT;
           }
         | CONTINUE_ORACLE_SYM label_ident
           {
-            if (unlikely(Lex->sp_continue_statement(thd, &$2, NULL)))
+            if (unlikely(Lex->sp_continue_statement(thd, &$2)))
               MYSQL_YYABORT;
           }
-        | CONTINUE_ORACLE_SYM WHEN_SYM reset_lex_expr
+        | CONTINUE_ORACLE_SYM WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_continue_statement(thd, $3)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($3->sp_continue_when_statement(thd)))
               MYSQL_YYABORT;
           }
-        | CONTINUE_ORACLE_SYM label_ident WHEN_SYM reset_lex_expr
+        | CONTINUE_ORACLE_SYM label_ident WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_continue_statement(thd, &$2, $4)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($4->sp_continue_when_statement(thd, &$2)))
               MYSQL_YYABORT;
           }
         ;
@@ -3802,6 +3793,26 @@ sp_proc_stmt_goto_oracle:
           }
         ;
 
+
+expr_lex:
+          {
+            DBUG_ASSERT(Lex->sphead);
+            if (unlikely(!($<expr_lex>$= new (thd->mem_root)
+                           sp_expr_lex(thd, thd->lex))))
+              MYSQL_YYABORT;
+            Lex->sphead->reset_lex(thd, $<expr_lex>$);
+          }
+          expr
+          {
+            $$= $<expr_lex>1;
+            $$->sp_lex_in_use= true;
+            $$->set_item($2);
+            if ($$->sphead->restore_lex(thd))
+              MYSQL_YYABORT;
+          }
+        ;
+
+
 assignment_source_lex:
           {
             DBUG_ASSERT(Lex->sphead);
@@ -3951,34 +3962,15 @@ sp_fetch_list:
         ;
 
 sp_if:
-          { Lex->sphead->reset_lex(thd); }
-          expr THEN_SYM
+          expr_lex THEN_SYM
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            uint ip= sp->instructions();
-            sp_instr_jump_if_not *i= new (thd->mem_root)
-              sp_instr_jump_if_not(ip, ctx, $2, lex);
-            if (unlikely(i == NULL) ||
-                unlikely(sp->push_backpatch(thd, i, ctx->push_label(thd, &empty_clex_str, 0))) ||
-                unlikely(sp->add_cont_backpatch(i)) ||
-                unlikely(sp->add_instr(i)))
-              MYSQL_YYABORT;
-            if (unlikely(sp->restore_lex(thd)))
+            if (unlikely($1->sp_if_expr(thd)))
               MYSQL_YYABORT;
           }
           sp_proc_stmts1
           {
-            sp_head *sp= Lex->sphead;
-            sp_pcontext *ctx= Lex->spcont;
-            uint ip= sp->instructions();
-            sp_instr_jump *i= new (thd->mem_root) sp_instr_jump(ip, ctx);
-            if (unlikely(i == NULL) ||
-                unlikely(sp->add_instr(i)))
+            if (unlikely($1->sp_if_after_statements(thd)))
               MYSQL_YYABORT;
-            sp->backpatch(ctx->pop_label());
-            sp->push_backpatch(thd, i, ctx->push_label(thd, &empty_clex_str, 0));
           }
           sp_elseifs
           {
@@ -4065,13 +4057,9 @@ case_stmt_specification:
         ;
 
 case_stmt_body:
-          { Lex->sphead->reset_lex(thd); /* For expr $2 */ }
-          expr
+          expr_lex
           {
-            if (unlikely(Lex->case_stmt_action_expr($2)))
-              MYSQL_YYABORT;
-
-            if (Lex->sphead->restore_lex(thd))
+            if (unlikely($1->case_stmt_action_expr()))
               MYSQL_YYABORT;
           }
           simple_when_clause_list
@@ -4091,19 +4079,10 @@ searched_when_clause_list:
         ;
 
 simple_when_clause:
-          WHEN_SYM
-          {
-            Lex->sphead->reset_lex(thd); /* For expr $3 */
-          }
-          expr
+          WHEN_SYM expr_lex
           {
             /* Simple case: <caseval> = <whenval> */
-
-            LEX *lex= Lex;
-            if (unlikely(lex->case_stmt_action_when($3, true)))
-              MYSQL_YYABORT;
-            /* For expr $3 */
-            if (unlikely(lex->sphead->restore_lex(thd)))
+            if (unlikely($2->case_stmt_action_when(true)))
               MYSQL_YYABORT;
           }
           THEN_SYM
@@ -4115,17 +4094,9 @@ simple_when_clause:
         ;
 
 searched_when_clause:
-          WHEN_SYM
+          WHEN_SYM expr_lex
           {
-            Lex->sphead->reset_lex(thd); /* For expr $3 */
-          }
-          expr
-          {
-            LEX *lex= Lex;
-            if (unlikely(lex->case_stmt_action_when($3, false)))
-              MYSQL_YYABORT;
-            /* For expr $3 */
-            if (unlikely(lex->sphead->restore_lex(thd)))
+            if (unlikely($2->case_stmt_action_when(false)))
               MYSQL_YYABORT;
           }
           THEN_SYM
@@ -4265,12 +4236,9 @@ loop_body:
         ;
 
 while_body:
-          expr DO_SYM
+          expr_lex DO_SYM
           {
-            LEX *lex= Lex;
-            if (unlikely(lex->sp_while_loop_expression(thd, $1)))
-              MYSQL_YYABORT;
-            if (lex->sphead->restore_lex(thd))
+            if (unlikely($1->sp_while_loop_expression(thd)))
               MYSQL_YYABORT;
           }
           sp_proc_stmts1 END WHILE_SYM
@@ -4281,22 +4249,10 @@ while_body:
         ;
 
 repeat_body:
-          sp_proc_stmts1 UNTIL_SYM 
-          { Lex->sphead->reset_lex(thd); }
-          expr END REPEAT_SYM
+          sp_proc_stmts1 UNTIL_SYM expr_lex END REPEAT_SYM
           {
-            LEX *lex= Lex;
-            uint ip= lex->sphead->instructions();
-            sp_label *lab= lex->spcont->last_label();  /* Jumping back */
-            sp_instr_jump_if_not *i= new (thd->mem_root)
-              sp_instr_jump_if_not(ip, lex->spcont, $4, lab->ip, lex);
-            if (unlikely(i == NULL) ||
-                unlikely(lex->sphead->add_instr(i)))
-              MYSQL_YYABORT;
-            if (lex->sphead->restore_lex(thd))
+            if ($3->sp_repeat_loop_finalize(thd))
               MYSQL_YYABORT;
-            /* We can shortcut the cont_backpatch here */
-            i->m_cont_dest= ip+1;
           }
         ;
 
@@ -4320,7 +4276,6 @@ sp_labeled_control:
           {
             if (unlikely(Lex->sp_push_loop_label(thd, &$1)))
               MYSQL_YYABORT;
-            Lex->sphead->reset_lex(thd);
           }
           while_body pop_sp_loop_label
           { }
@@ -4371,7 +4326,6 @@ sp_unlabeled_control:
           {
             if (unlikely(Lex->sp_push_loop_empty_label(thd)))
               MYSQL_YYABORT;
-            Lex->sphead->reset_lex(thd);
           }
           while_body
           {

sql/sql_yacc_ora.yy

@@ -213,6 +213,7 @@ void ORAerror(THD *thd, const char *s)
   Item_basic_constant *item_basic_constant;
   Key_part_spec *key_part;
   LEX *lex;
+  sp_expr_lex *expr_lex;
   sp_assignment_lex *assignment_lex;
   class sp_lex_cursor *sp_cursor_stmt;
   LEX_CSTRING *lex_str_ptr;
@@ -1397,7 +1398,6 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         signal_allowed_expr
         simple_target_specification
         condition_number
-        reset_lex_expr
         opt_versioning_interval_start
 
 %type <item_param> param_marker
@@ -1418,6 +1418,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         sp_cursor_stmt_lex
         sp_cursor_stmt
 
+%type <expr_lex>
+        expr_lex
+
 %type <assignment_lex>
         assignment_source_lex
         assignment_source_expr
@@ -4080,15 +4083,11 @@ RETURN_ALLMODES_SYM:
         ;
 
 sp_proc_stmt_return:
-          RETURN_ALLMODES_SYM
-          { Lex->sphead->reset_lex(thd); }
-          expr
+          RETURN_ALLMODES_SYM expr_lex
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            if (unlikely(sp->m_handler->add_instr_freturn(thd, sp, lex->spcont,
-                                                          $3, lex)) ||
-                unlikely(sp->restore_lex(thd)))
+            sp_head *sp= $2->sphead;
+            if (unlikely(sp->m_handler->add_instr_freturn(thd, sp, $2->spcont,
+                                                          $2->get_item(), $2)))
               MYSQL_YYABORT;
           }
         | RETURN_ORACLE_SYM
@@ -4101,10 +4100,6 @@ sp_proc_stmt_return:
           }
         ;
 
-reset_lex_expr:
-          { Lex->sphead->reset_lex(thd); } expr { $$= $2; }
-        ;
-
 sp_proc_stmt_exit_oracle:
           EXIT_ORACLE_SYM
           {
@@ -4116,16 +4111,14 @@ sp_proc_stmt_exit_oracle:
             if (unlikely(Lex->sp_exit_statement(thd, &$2, NULL)))
               MYSQL_YYABORT;
           }
-        | EXIT_ORACLE_SYM WHEN_SYM reset_lex_expr
+        | EXIT_ORACLE_SYM WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_exit_statement(thd, $3)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($3->sp_exit_statement(thd, $3->get_item())))
               MYSQL_YYABORT;
           }
-        | EXIT_ORACLE_SYM label_ident WHEN_SYM reset_lex_expr
+        | EXIT_ORACLE_SYM label_ident WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_exit_statement(thd, &$2, $4)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($4->sp_exit_statement(thd, &$2, $4->get_item())))
               MYSQL_YYABORT;
           }
         ;
@@ -4133,24 +4126,22 @@ sp_proc_stmt_exit_oracle:
 sp_proc_stmt_continue_oracle:
           CONTINUE_ORACLE_SYM
           {
-            if (unlikely(Lex->sp_continue_statement(thd, NULL)))
+            if (unlikely(Lex->sp_continue_statement(thd)))
               MYSQL_YYABORT;
           }
         | CONTINUE_ORACLE_SYM label_ident
           {
-            if (unlikely(Lex->sp_continue_statement(thd, &$2, NULL)))
+            if (unlikely(Lex->sp_continue_statement(thd, &$2)))
               MYSQL_YYABORT;
           }
-        | CONTINUE_ORACLE_SYM WHEN_SYM reset_lex_expr
+        | CONTINUE_ORACLE_SYM WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_continue_statement(thd, $3)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($3->sp_continue_when_statement(thd)))
               MYSQL_YYABORT;
           }
-        | CONTINUE_ORACLE_SYM label_ident WHEN_SYM reset_lex_expr
+        | CONTINUE_ORACLE_SYM label_ident WHEN_SYM expr_lex
           {
-            if (unlikely(Lex->sp_continue_statement(thd, &$2, $4)) ||
-                unlikely(Lex->sphead->restore_lex(thd)))
+            if (unlikely($4->sp_continue_when_statement(thd, &$2)))
               MYSQL_YYABORT;
           }
         ;
@@ -4187,6 +4178,26 @@ remember_lex:
           }
         ;
 
+
+expr_lex:
+          {
+            DBUG_ASSERT(Lex->sphead);
+            if (unlikely(!($<expr_lex>$= new (thd->mem_root)
+                           sp_expr_lex(thd, thd->lex))))
+              MYSQL_YYABORT;
+            Lex->sphead->reset_lex(thd, $<expr_lex>$);
+          }
+          expr
+          {
+            $$= $<expr_lex>1;
+            $$->sp_lex_in_use= true;
+            $$->set_item($2);
+            if ($$->sphead->restore_lex(thd))
+              MYSQL_YYABORT;
+          }
+        ;
+
+
 assignment_source_lex:
           {
             DBUG_ASSERT(Lex->sphead);
@@ -4336,34 +4347,15 @@ sp_fetch_list:
         ;
 
 sp_if:
-          { Lex->sphead->reset_lex(thd); }
-          expr THEN_SYM
+          expr_lex THEN_SYM
           {
-            LEX *lex= Lex;
-            sp_head *sp= lex->sphead;
-            sp_pcontext *ctx= lex->spcont;
-            uint ip= sp->instructions();
-            sp_instr_jump_if_not *i= new (thd->mem_root)
-              sp_instr_jump_if_not(ip, ctx, $2, lex);
-            if (unlikely(i == NULL) ||
-                unlikely(sp->push_backpatch(thd, i, ctx->push_label(thd, &empty_clex_str, 0))) ||
-                unlikely(sp->add_cont_backpatch(i)) ||
-                unlikely(sp->add_instr(i)))
-              MYSQL_YYABORT;
-            if (unlikely(sp->restore_lex(thd)))
+            if (unlikely($1->sp_if_expr(thd)))
               MYSQL_YYABORT;
           }
           sp_proc_stmts1_implicit_block
           {
-            sp_head *sp= Lex->sphead;
-            sp_pcontext *ctx= Lex->spcont;
-            uint ip= sp->instructions();
-            sp_instr_jump *i= new (thd->mem_root) sp_instr_jump(ip, ctx);
-            if (unlikely(i == NULL) ||
-                unlikely(sp->add_instr(i)))
+            if (unlikely($1->sp_if_after_statements(thd)))
               MYSQL_YYABORT;
-            sp->backpatch(ctx->pop_label());
-            sp->push_backpatch(thd, i, ctx->push_label(thd, &empty_clex_str, 0));
           }
           sp_elseifs
           {
@@ -4450,13 +4442,9 @@ case_stmt_specification:
         ;
 
 case_stmt_body:
-          { Lex->sphead->reset_lex(thd); /* For expr $2 */ }
-          expr
+          expr_lex
           {
-            if (unlikely(Lex->case_stmt_action_expr($2)))
-              MYSQL_YYABORT;
-
-            if (Lex->sphead->restore_lex(thd))
+            if (unlikely($1->case_stmt_action_expr()))
               MYSQL_YYABORT;
           }
           simple_when_clause_list
@@ -4476,19 +4464,10 @@ searched_when_clause_list:
         ;
 
 simple_when_clause:
-          WHEN_SYM
-          {
-            Lex->sphead->reset_lex(thd); /* For expr $3 */
-          }
-          expr
+          WHEN_SYM expr_lex
           {
             /* Simple case: <caseval> = <whenval> */
-
-            LEX *lex= Lex;
-            if (unlikely(lex->case_stmt_action_when($3, true)))
-              MYSQL_YYABORT;
-            /* For expr $3 */
-            if (unlikely(lex->sphead->restore_lex(thd)))
+            if (unlikely($2->case_stmt_action_when(true)))
               MYSQL_YYABORT;
           }
           THEN_SYM
@@ -4500,17 +4479,9 @@ simple_when_clause:
         ;
 
 searched_when_clause:
-          WHEN_SYM
+          WHEN_SYM expr_lex
           {
-            Lex->sphead->reset_lex(thd); /* For expr $3 */
-          }
-          expr
-          {
-            LEX *lex= Lex;
-            if (unlikely(lex->case_stmt_action_when($3, false)))
-              MYSQL_YYABORT;
-            /* For expr $3 */
-            if (unlikely(lex->sphead->restore_lex(thd)))
+            if (unlikely($2->case_stmt_action_when(false)))
               MYSQL_YYABORT;
           }
           THEN_SYM
@@ -4740,12 +4711,9 @@ loop_body:
         ;
 
 while_body:
-          expr LOOP_SYM
+          expr_lex LOOP_SYM
           {
-            LEX *lex= Lex;
-            if (unlikely(lex->sp_while_loop_expression(thd, $1)))
-              MYSQL_YYABORT;
-            if (lex->sphead->restore_lex(thd))
+            if (unlikely($1->sp_while_loop_expression(thd)))
               MYSQL_YYABORT;
           }
           sp_proc_stmts1 END LOOP_SYM
@@ -4756,22 +4724,10 @@ while_body:
         ;
 
 repeat_body:
-          sp_proc_stmts1 UNTIL_SYM 
-          { Lex->sphead->reset_lex(thd); }
-          expr END REPEAT_SYM
+          sp_proc_stmts1 UNTIL_SYM expr_lex END REPEAT_SYM
           {
-            LEX *lex= Lex;
-            uint ip= lex->sphead->instructions();
-            sp_label *lab= lex->spcont->last_label();  /* Jumping back */
-            sp_instr_jump_if_not *i= new (thd->mem_root)
-              sp_instr_jump_if_not(ip, lex->spcont, $4, lab->ip, lex);
-            if (unlikely(i == NULL) ||
-                unlikely(lex->sphead->add_instr(i)))
-              MYSQL_YYABORT;
-            if (lex->sphead->restore_lex(thd))
+            if ($3->sp_repeat_loop_finalize(thd))
               MYSQL_YYABORT;
-            /* We can shortcut the cont_backpatch here */
-            i->m_cont_dest= ip+1;
           }
         ;
 
@@ -4795,7 +4751,6 @@ sp_labeled_control:
           {
             if (unlikely(Lex->sp_push_loop_label(thd, &$1)))
               MYSQL_YYABORT;
-            Lex->sphead->reset_lex(thd);
           }
           while_body pop_sp_loop_label
           { }
@@ -4846,7 +4801,6 @@ sp_unlabeled_control:
           {
             if (unlikely(Lex->sp_push_loop_empty_label(thd)))
               MYSQL_YYABORT;
-            Lex->sphead->reset_lex(thd);
           }
           while_body
           {