Recursion support made for SP (BUG#10100).

client/mysqltest.c

@@ -3313,6 +3313,8 @@ static int handle_error(const char *query, struct st_query *q,
          (q->expected_errno[i].code.errnum == err_errno)) ||
         ((q->expected_errno[i].type == ERR_SQLSTATE) &&
          (strcmp(q->expected_errno[i].code.sqlstate, err_sqlstate) == 0)))
+    {
+      if (!disable_result_log)
       {
         if (q->expected_errors == 1)
         {
@@ -3328,6 +3330,7 @@ static int handle_error(const char *query, struct st_query *q,
                  (q->expected_errno[0].type == ERR_ERRNO &&
                   q->expected_errno[0].code.errnum != 0))
           dynstr_append(ds,"Got one of the listed errors\n");
+      }
       /* OK */
       DBUG_RETURN(0);
     }
@@ -3335,11 +3338,14 @@ static int handle_error(const char *query, struct st_query *q,
 
   DBUG_PRINT("info",("i: %d  expected_errors: %d", i, q->expected_errors));
 
+  if (!disable_result_log)
+  {
     dynstr_append_mem(ds, "ERROR ",6);
     replace_dynstr_append(ds, err_sqlstate);
     dynstr_append_mem(ds, ": ", 2);
     replace_dynstr_append(ds, err_error);
     dynstr_append_mem(ds, "\n", 1);
+  }
 
   if (i)
   {

mysql-test/r/sp-dynamic.result

@@ -33,6 +33,8 @@ begin
 execute stmt;
 end|
 prepare stmt from "call p1()"|
+set @SAVE_SP_RECURSION_LEVELS=@@max_sp_recursion_depth|
+set @@max_sp_recursion_depth=100|
 execute stmt|
 ERROR HY000: The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner
 execute stmt|
@@ -40,11 +42,18 @@ ERROR HY000: The prepared statement contains a stored routine call that refers t
 execute stmt|
 ERROR HY000: The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner
 call p1()|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner
+call p1()|
+ERROR HY000: The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner
+call p1()|
+ERROR HY000: The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner
+set @@max_sp_recursion_depth=@SAVE_SP_RECURSION_LEVELS|
+call p1()|
+ERROR HY000: Recursive limit 0 (as set by the max_sp_recursion_depth variable) was exceeded for routine p1
 call p1()|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: Recursive limit 0 (as set by the max_sp_recursion_depth variable) was exceeded for routine p1
 call p1()|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: Recursive limit 0 (as set by the max_sp_recursion_depth variable) was exceeded for routine p1
 drop procedure p1|
 create procedure p1()
 begin

mysql-test/r/sp-error.result

@@ -708,7 +708,7 @@ return (i in (100, 200, bug11394(i-1), 400));
 end if;
 end|
 select bug11394(2)|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: Recursive stored functions and triggers are not allowed.
 drop function bug11394|
 create function bug11394_1(i int) returns int
 begin
@@ -719,7 +719,7 @@ return (select bug11394_1(i-1));
 end if;
 end|
 select bug11394_1(2)|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: Recursive stored functions and triggers are not allowed.
 drop function bug11394_1|
 create function bug11394_2(i int) returns int return i|
 select bug11394_2(bug11394_2(10))|
@@ -733,7 +733,10 @@ call bug11394(i - 1,(select 1));
 end if;
 end|
 call bug11394(2, 1)|
-ERROR HY000: Recursive stored routines are not allowed.
+ERROR HY000: Recursive limit 0 (as set by the max_sp_recursion_depth variable) was exceeded for routine bug11394
+set @@max_sp_recursion_depth=10|
+call bug11394(2, 1)|
+set @@max_sp_recursion_depth=default|
 drop procedure bug11394|
 CREATE PROCEDURE BUG_12490() HELP CONTENTS;
 ERROR 0A000: HELP is not allowed in stored procedures

mysql-test/r/sp.result

@@ -3617,4 +3617,189 @@ count(*)
 drop table t3, t4|
 drop procedure bug14210|
 set @@session.max_heap_table_size=default|
+drop function if exists bug10100f|
+drop procedure if exists bug10100p|
+drop procedure if exists bug10100t|
+drop procedure if exists bug10100pt|
+drop procedure if exists bug10100pv|
+drop procedure if exists bug10100pd|
+drop procedure if exists bug10100pc|
+create function bug10100f(prm int) returns int
+begin
+if prm > 1 then
+return prm * bug10100f(prm - 1);
+end if;
+return 1;
+end|
+create procedure bug10100p(prm int, inout res int)
+begin
+set res = res * prm;
+if prm > 1 then
+call bug10100p(prm - 1, res);  
+end if;
+end|
+create procedure bug10100t(prm int)
+begin
+declare res int;
+set res = 1;
+call bug10100p(prm, res);
+select res;
+end|
+create table t3 (a int)|
+insert into t3 values (0)|
+create view v1 as select a from t3;
+create procedure bug10100pt(level int, lim int)
+begin
+if level < lim then
+update t3 set a=level;
+FLUSH TABLES;
+call bug10100pt(level+1, lim);
+else
+select * from t3;
+end if;
+end|
+create procedure bug10100pv(level int, lim int)
+begin
+if level < lim then
+update v1 set a=level;
+FLUSH TABLES;
+call bug10100pv(level+1, lim);
+else
+select * from v1;
+end if;
+end|
+prepare stmt2 from "select * from t3;";
+create procedure bug10100pd(level int, lim int)
+begin
+if level < lim then
+select level;
+prepare stmt1 from "update t3 set a=a+2";
+execute stmt1;
+FLUSH TABLES;
+execute stmt1;
+FLUSH TABLES;
+execute stmt1;
+FLUSH TABLES;
+deallocate prepare stmt1;
+execute stmt2;
+select * from t3;
+call bug10100pd(level+1, lim);
+else
+execute stmt2;
+end if;
+end|
+create procedure bug10100pc(level int, lim int)
+begin
+declare lv int;
+declare c cursor for select a from t3;
+open c;
+if level < lim then
+select level;
+fetch c into lv;
+select lv;
+update t3 set a=level+lv;
+FLUSH TABLES;
+call bug10100pc(level+1, lim);
+else
+select * from t3;
+end if;
+close c;
+end|
+set @@max_sp_recursion_depth=4|
+select @@max_sp_recursion_depth|
+@@max_sp_recursion_depth
+4
+select bug10100f(3)|
+ERROR HY000: Recursive stored functions and triggers are not allowed.
+select bug10100f(6)|
+ERROR HY000: Recursive stored functions and triggers are not allowed.
+call bug10100t(5)|
+res
+120
+call bug10100pt(1,5)|
+a
+4
+call bug10100pv(1,5)|
+a
+4
+update t3 set a=1|
+call bug10100pd(1,5)|
+level
+1
+a
+7
+a
+7
+level
+2
+a
+13
+a
+13
+level
+3
+a
+19
+a
+19
+level
+4
+a
+25
+a
+25
+a
+25
+select * from t3|
+a
+25
+update t3 set a=1|
+call bug10100pc(1,5)|
+level
+1
+lv
+1
+level
+2
+lv
+2
+level
+3
+lv
+4
+level
+4
+lv
+7
+a
+11
+select * from t3|
+a
+11
+set @@max_sp_recursion_depth=0|
+select @@max_sp_recursion_depth|
+@@max_sp_recursion_depth
+0
+select bug10100f(5)|
+ERROR HY000: Recursive stored functions and triggers are not allowed.
+call bug10100t(5)|
+ERROR HY000: Recursive limit 0 (as set by the max_sp_recursion_depth variable) was exceeded for routine bug10100p
+set @@max_sp_recursion_depth=255|
+set @var=1|
+call bug10100p(255, @var)|
+call bug10100pt(1,255)|
+call bug10100pv(1,255)|
+call bug10100pd(1,255)|
+call bug10100pc(1,255)|
+set @@max_sp_recursion_depth=0|
+deallocate prepare stmt2|
+drop function bug10100f|
+drop procedure bug10100p|
+drop procedure bug10100t|
+drop procedure bug10100pt|
+drop procedure bug10100pv|
+drop procedure bug10100pd|
+drop procedure bug10100pc|
+drop view v1|
+drop table t3|
 drop table t1,t2;

mysql-test/r/trigger.result

@@ -703,8 +703,11 @@ create trigger t1_ai after insert on t1
 for each row insert into t2 values (new.f1+1);
 create trigger t2_ai after insert on t2
 for each row insert into t1 values (new.f2+1);
+set @SAVE_SP_RECURSION_LEVELS=@@max_sp_recursion_depth;
+set @@max_sp_recursion_depth=100;
 insert into t1 values (1);
 ERROR HY000: Can't update table 't1' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
+set @@max_sp_recursion_depth=@SAVE_SP_RECURSION_LEVELS;
 select * from t1;
 f1
 1

mysql-test/r/variables.result

@@ -351,6 +351,14 @@ set global rpl_recovery_rank=100;
 set global server_id=100;
 set global slow_launch_time=100;
 set sort_buffer_size=100;
+set @@max_sp_recursion_depth=10;
+select @@max_sp_recursion_depth;
+@@max_sp_recursion_depth
+10
+set @@max_sp_recursion_depth=0;
+select @@max_sp_recursion_depth;
+@@max_sp_recursion_depth
+0
 set sql_auto_is_null=1;
 select @@sql_auto_is_null;
 @@sql_auto_is_null

mysql-test/t/sp-dynamic.test

@@ -26,18 +26,29 @@ begin
   execute stmt;
 end|
 prepare stmt from "call p1()"|
+# Allow SP resursion to be show that it has not influence here
+set @SAVE_SP_RECURSION_LEVELS=@@max_sp_recursion_depth|
+set @@max_sp_recursion_depth=100|
 --error ER_PS_NO_RECURSION
 execute stmt|
 --error ER_PS_NO_RECURSION
 execute stmt|
 --error ER_PS_NO_RECURSION
 execute stmt|
---error ER_SP_NO_RECURSION 
+--error ER_PS_NO_RECURSION 
+call p1()|
+--error ER_PS_NO_RECURSION 
 call p1()|
---error ER_SP_NO_RECURSION 
+--error ER_PS_NO_RECURSION
 call p1()|
---error ER_SP_NO_RECURSION 
+set @@max_sp_recursion_depth=@SAVE_SP_RECURSION_LEVELS|
+--error ER_SP_RECURSION_LIMIT 
 call p1()|
+--error ER_SP_RECURSION_LIMIT
+call p1()|
+--error ER_SP_RECURSION_LIMIT
+call p1()|
+
 drop procedure p1|
 #
 # C. Create/drop a stored procedure in Dynamic SQL.

mysql-test/t/sp-error.test

@@ -1044,10 +1044,11 @@ begin
     call bug11394(i - 1,(select 1));
   end if;
 end|
-# Again if we allow recursion for stored procedures (without 
-# additional efforts) the following statement will crash the server.
---error 1424
+--error ER_SP_RECURSION_LIMIT
+call bug11394(2, 1)|
+set @@max_sp_recursion_depth=10|
 call bug11394(2, 1)|
+set @@max_sp_recursion_depth=default|
 drop procedure bug11394|
 delimiter ;|
 

mysql-test/t/sp.test

@@ -4541,6 +4541,160 @@ drop table t3, t4|
 drop procedure bug14210|
 set @@session.max_heap_table_size=default|
 
+#
+# BUG#10100: function (and stored procedure?) recursivity problem
+#
+--disable_warnings
+drop function if exists bug10100f|
+drop procedure if exists bug10100p|
+drop procedure if exists bug10100t|
+drop procedure if exists bug10100pt|
+drop procedure if exists bug10100pv|
+drop procedure if exists bug10100pd|
+drop procedure if exists bug10100pc|
+--enable_warnings
+# routines with simple recursion
+create function bug10100f(prm int) returns int
+begin
+  if prm > 1 then
+    return prm * bug10100f(prm - 1);
+  end if;
+  return 1;
+end|
+create procedure bug10100p(prm int, inout res int)
+begin
+  set res = res * prm;
+  if prm > 1 then
+    call bug10100p(prm - 1, res);  
+  end if;
+end|
+create procedure bug10100t(prm int)
+begin
+  declare res int;
+  set res = 1;
+  call bug10100p(prm, res);
+  select res;
+end|
+
+# a procedure which use tables and recursion
+create table t3 (a int)|
+insert into t3 values (0)|
+create view v1 as select a from t3;
+create procedure bug10100pt(level int, lim int)
+begin
+  if level < lim then
+    update t3 set a=level;
+    FLUSH TABLES;
+    call bug10100pt(level+1, lim);
+  else
+    select * from t3;
+  end if;
+end|
+# view & recursion
+create procedure bug10100pv(level int, lim int)
+begin
+  if level < lim then
+    update v1 set a=level;
+    FLUSH TABLES;
+    call bug10100pv(level+1, lim);
+  else
+    select * from v1;
+  end if;
+end|
+# dynamic sql & recursion
+prepare stmt2 from "select * from t3;";
+create procedure bug10100pd(level int, lim int)
+begin
+  if level < lim then
+    select level;
+    prepare stmt1 from "update t3 set a=a+2";
+    execute stmt1;
+    FLUSH TABLES;
+    execute stmt1;
+    FLUSH TABLES;
+    execute stmt1;
+    FLUSH TABLES;
+    deallocate prepare stmt1;
+    execute stmt2;
+    select * from t3;
+    call bug10100pd(level+1, lim);
+  else
+    execute stmt2;
+  end if;
+end|
+# cursor & recursion
+create procedure bug10100pc(level int, lim int)
+begin
+  declare lv int;
+  declare c cursor for select a from t3;
+  open c;
+  if level < lim then
+    select level;
+    fetch c into lv;
+    select lv;
+    update t3 set a=level+lv;
+    FLUSH TABLES;
+    call bug10100pc(level+1, lim);
+  else
+    select * from t3;
+  end if;
+  close c;
+end|
+
+set @@max_sp_recursion_depth=4|
+select @@max_sp_recursion_depth|
+-- error ER_SP_NO_RECURSION
+select bug10100f(3)|
+-- error ER_SP_NO_RECURSION
+select bug10100f(6)|
+call bug10100t(5)|
+call bug10100pt(1,5)|
+call bug10100pv(1,5)|
+update t3 set a=1|
+call bug10100pd(1,5)|
+select * from t3|
+update t3 set a=1|
+call bug10100pc(1,5)|
+select * from t3|
+set @@max_sp_recursion_depth=0|
+select @@max_sp_recursion_depth|
+-- error ER_SP_NO_RECURSION
+select bug10100f(5)|
+-- error ER_SP_RECURSION_LIMIT
+call bug10100t(5)|
+
+#end of the stack checking
+set @@max_sp_recursion_depth=255|
+set @var=1|
+#disable log because error about stack overrun contains numbers which
+#depend on a system
+-- disable_result_log
+-- error ER_STACK_OVERRUN_NEED_MORE
+call bug10100p(255, @var)|
+-- error ER_STACK_OVERRUN_NEED_MORE
+call bug10100pt(1,255)|
+-- error ER_STACK_OVERRUN_NEED_MORE
+call bug10100pv(1,255)|
+-- error ER_STACK_OVERRUN_NEED_MORE
+call bug10100pd(1,255)|
+-- error ER_STACK_OVERRUN_NEED_MORE
+call bug10100pc(1,255)|
+-- enable_result_log
+set @@max_sp_recursion_depth=0|
+
+deallocate prepare stmt2|
+
+drop function bug10100f|
+drop procedure bug10100p|
+drop procedure bug10100t|
+drop procedure bug10100pt|
+drop procedure bug10100pv|
+drop procedure bug10100pd|
+drop procedure bug10100pc|
+drop view v1|
+drop table t3|
+
+
 #
 # BUG#NNNN: New bug synopsis
 #

mysql-test/t/trigger.test

@@ -743,8 +743,12 @@ create trigger t1_ai after insert on t1
   for each row insert into t2 values (new.f1+1);
 create trigger t2_ai after insert on t2
   for each row insert into t1 values (new.f2+1);
+# Allow SP resursion to be show that it has not influence here
+set @SAVE_SP_RECURSION_LEVELS=@@max_sp_recursion_depth;
+set @@max_sp_recursion_depth=100;
 --error ER_CANT_UPDATE_USED_TABLE_IN_SF_OR_TRG
 insert into t1 values (1);
+set @@max_sp_recursion_depth=@SAVE_SP_RECURSION_LEVELS;
 select * from t1;
 select * from t2;
 drop trigger t1_ai;

mysql-test/t/variables.test

@@ -237,6 +237,10 @@ set global rpl_recovery_rank=100;
 set global server_id=100;
 set global slow_launch_time=100;
 set sort_buffer_size=100;
+set @@max_sp_recursion_depth=10;
+select @@max_sp_recursion_depth;
+set @@max_sp_recursion_depth=0;
+select @@max_sp_recursion_depth;
 set sql_auto_is_null=1;
 select @@sql_auto_is_null;
 set @@sql_auto_is_null=0;

sql/item_func.cc

@@ -4690,10 +4690,16 @@ Item_func_sp::sp_result_field(void) const
 {
   Field *field;
   DBUG_ENTER("Item_func_sp::sp_result_field");
+  DBUG_PRINT("info", ("sp: %s, flags: %x, level: %lu",
+                      (m_sp ? "YES" : "NO"),
+                      (m_sp ? m_sp->m_flags : (uint)0),
+                      (m_sp ? m_sp->m_recursion_level : (ulong)0)));
 
   if (!m_sp)
   {
-    if (!(m_sp= sp_find_function(current_thd, m_name, TRUE)))
+    THD *thd= current_thd;
+    if (!(m_sp= sp_find_routine(thd, TYPE_ENUM_FUNCTION, m_name,
+                                &thd->sp_func_cache, TRUE)))
     {
       my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", m_name->m_qname.str);
       DBUG_RETURN(0);
@@ -4925,7 +4931,8 @@ Item_func_sp::find_and_check_access(THD *thd, ulong want_access,
   bool res= TRUE;
 
   *save= 0;                                     // Safety if error
-  if (! m_sp && ! (m_sp= sp_find_function(thd, m_name, TRUE)))
+  if (! m_sp && ! (m_sp= sp_find_routine(thd, TYPE_ENUM_FUNCTION, m_name,
+                                         &thd->sp_func_cache, TRUE)))
   {
     my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", m_name->m_qname.str);
     goto error;

sql/mysqld.cc

@@ -4543,6 +4543,7 @@ enum options_mysqld
   OPT_OPTIMIZER_PRUNE_LEVEL,
   OPT_UPDATABLE_VIEWS_WITH_LIMIT,
   OPT_SP_AUTOMATIC_PRIVILEGES,
+  OPT_MAX_SP_RECURSION_DEPTH,
   OPT_AUTO_INCREMENT, OPT_AUTO_INCREMENT_OFFSET,
   OPT_ENABLE_LARGE_PAGES,
   OPT_TIMED_MUTEXES,
@@ -5745,6 +5746,11 @@ The minimum value for this variable is 4096.",
    (gptr*) &global_system_variables.read_buff_size,
    (gptr*) &max_system_variables.read_buff_size,0, GET_ULONG, REQUIRED_ARG,
    128*1024L, IO_SIZE*2+MALLOC_OVERHEAD, ~0L, MALLOC_OVERHEAD, IO_SIZE, 0},
+  {"max_sp_recursion_depth", OPT_MAX_SP_RECURSION_DEPTH,
+   "Maximum stored procedure recursion depth. (discussed with docs).",
+   (gptr*) &global_system_variables.max_sp_recursion_depth,
+   (gptr*) &max_system_variables.max_sp_recursion_depth, 0, GET_ULONG,
+   OPT_ARG, 0, 0, 255, 0, 1, 0 },
 #ifdef HAVE_REPLICATION
   {"relay_log_purge", OPT_RELAY_LOG_PURGE,
    "0 = do not purge relay logs. 1 = purge them as soon as they are no more needed.",

sql/set_var.cc

@@ -258,6 +258,8 @@ sys_var_long_ptr	sys_max_relay_log_size("max_relay_log_size",
                                                fix_max_relay_log_size);
 sys_var_thd_ulong	sys_max_sort_length("max_sort_length",
 					    &SV::max_sort_length);
+sys_var_thd_ulong	sys_max_sp_recursion_depth("max_sp_recursion_depth",
+                                                   &SV::max_sp_recursion_depth);
 sys_var_max_user_conn   sys_max_user_connections("max_user_connections");
 sys_var_thd_ulong	sys_max_tmp_tables("max_tmp_tables",
 					   &SV::max_tmp_tables);
@@ -628,6 +630,7 @@ sys_var *sys_variables[]=
   &sys_max_relay_log_size,
   &sys_max_seeks_for_key,
   &sys_max_sort_length,
+  &sys_max_sp_recursion_depth,
   &sys_max_tmp_tables,
   &sys_max_user_connections,
   &sys_max_write_lock_count,
@@ -892,6 +895,8 @@ struct show_var_st init_vars[]= {
   {sys_max_relay_log_size.name, (char*) &sys_max_relay_log_size,    SHOW_SYS},
   {sys_max_seeks_for_key.name,  (char*) &sys_max_seeks_for_key,	    SHOW_SYS},
   {sys_max_sort_length.name,	(char*) &sys_max_sort_length,	    SHOW_SYS},
+  {sys_max_sp_recursion_depth.name,
+    (char*) &sys_max_sp_recursion_depth, SHOW_SYS},
   {sys_max_tmp_tables.name,	(char*) &sys_max_tmp_tables,	    SHOW_SYS},
   {sys_max_user_connections.name,(char*) &sys_max_user_connections, SHOW_SYS},
   {sys_max_write_lock_count.name, (char*) &sys_max_write_lock_count,SHOW_SYS},

sql/share/errmsg.txt

@@ -5361,7 +5361,7 @@ ER_COMMIT_NOT_ALLOWED_IN_SF_OR_TRG
 ER_NO_DEFAULT_FOR_VIEW_FIELD
         eng "Field of view '%-.64s.%-.64s' underlying table doesn't have a default value"
 ER_SP_NO_RECURSION
-        eng "Recursive stored routines are not allowed."
+        eng "Recursive stored functions and triggers are not allowed."
 ER_TOO_BIG_SCALE 42000 S1009
         eng "Too big scale %d specified for column '%-.64s'. Maximum is %d."
 ER_TOO_BIG_PRECISION 42000 S1009
@@ -5421,3 +5421,5 @@ ER_NO_REFERENCED_ROW_2 23000
 	eng "Cannot add or update a child row: a foreign key constraint fails (%.192s)"
 ER_SP_BAD_VAR_SHADOW 42000
 	eng "Variable '%-.64s' must be quoted with `...`, or renamed"
+ER_SP_RECURSION_LIMIT
+        eng "Recursive limit %d (as set by the max_sp_recursion_depth variable) was exceeded for routine %.64s"

sql/sp.h

@@ -36,7 +36,8 @@ int
 sp_drop_db_routines(THD *thd, char *db);
 
 sp_head *
-sp_find_procedure(THD *thd, sp_name *name, bool cache_only = 0);
+sp_find_routine(THD *thd, int type, sp_name *name,
+                sp_cache **cp, bool cache_only);
 
 int
 sp_exists_routine(THD *thd, TABLE_LIST *procs, bool any, bool no_error);
@@ -57,9 +58,6 @@ sp_show_create_procedure(THD *thd, sp_name *name);
 int
 sp_show_status_procedure(THD *thd, const char *wild);
 
-sp_head *
-sp_find_function(THD *thd, sp_name *name, bool cache_only = 0);
-
 int
 sp_create_function(THD *thd, sp_head *sp);
 

sql/sp_head.cc

@@ -437,7 +437,8 @@ sp_head::operator delete(void *ptr, size_t size)
 
 sp_head::sp_head()
   :Query_arena(&main_mem_root, INITIALIZED_FOR_SP),
-   m_flags(0), m_returns_cs(NULL)
+   m_flags(0), m_returns_cs(NULL), m_recursion_level(0), m_next_cached_sp(0),
+   m_first_instance(this), m_first_free_instance(this), m_last_cached_sp(this)
 {
   extern byte *
     sp_table_key(const byte *ptr, uint *plen, my_bool first);
@@ -615,6 +616,7 @@ sp_head::create(THD *thd)
 sp_head::~sp_head()
 {
   destroy();
+  delete m_next_cached_sp;
   if (m_thd)
     restore_thd_mem_root(m_thd);
 }
@@ -840,6 +842,31 @@ static bool subst_spvars(THD *thd, sp_instr *instr, LEX_STRING *query_str)
 }
 
 
+/*
+  Return appropriate error about recursion limit reaching
+
+  SYNOPSIS
+    sp_head::recursion_level_error()
+
+  NOTE
+    For functions and triggers we return error about prohibited recursion.
+    For stored procedures we return about reaching recursion limit.
+*/
+
+void sp_head::recursion_level_error()
+{
+  if (m_type == TYPE_ENUM_PROCEDURE)
+  {
+    THD *thd= current_thd;
+    my_error(ER_SP_RECURSION_LIMIT, MYF(0),
+             thd->variables.max_sp_recursion_depth,
+             m_name);
+  }
+  else
+    my_error(ER_SP_NO_RECURSION, MYF(0));
+}
+
+
 /*
   Execute the routine. The main instruction jump loop is there 
   Assume the parameters already set.
@@ -869,37 +896,31 @@ int sp_head::execute(THD *thd)
   Item_change_list old_change_list;
   String old_packet;
 
-  /* init per-instruction memroot */
-  init_alloc_root(&execute_mem_root, MEM_ROOT_BLOCK_SIZE, 0);
-
-
   /* Use some extra margin for possible SP recursion and functions */
-  if (check_stack_overrun(thd, 4*STACK_MIN_SIZE, olddb))
+  if (check_stack_overrun(thd, 8 * STACK_MIN_SIZE, (char*)&old_packet))
   {
     DBUG_RETURN(-1);
   }
 
-  if (m_flags & IS_INVOKED)
-  {
+  /* init per-instruction memroot */
+  init_alloc_root(&execute_mem_root, MEM_ROOT_BLOCK_SIZE, 0);
+
+  DBUG_ASSERT(!(m_flags & IS_INVOKED));
+  m_flags|= IS_INVOKED;
+  m_first_instance->m_first_free_instance= m_next_cached_sp;
+  DBUG_PRINT("info", ("first free for 0x%lx ++: 0x%lx->0x%lx, level: %lu, flags %x",
+                      (ulong)m_first_instance, this, m_next_cached_sp,
+                      m_next_cached_sp->m_recursion_level,
+                      m_next_cached_sp->m_flags));
   /*
-      We have to disable recursion for stored routines since in
-      many cases LEX structure and many Item's can't be used in
-      reentrant way now.
-
-      TODO: We can circumvent this problem by using separate
-      sp_head instances for each recursive invocation.
-
-      NOTE: Theoretically arguments of procedure can be evaluated
-      before its invocation so there should be no problem with
-      recursion. But since we perform cleanup for CALL statement
-      as for any other statement only after its execution, its LEX
-      structure is not reusable for recursive calls. Thus we have
-      to prohibit recursion for stored procedures too.
+    Check that if there are not any instances after this one then
+    pointer to the last instance points on this instance or if there are
+    some instances after this one then recursion level of next instance
+    greater then recursion level of current instance on 1
   */
-    my_error(ER_SP_NO_RECURSION, MYF(0));
-    DBUG_RETURN(-1);
-  }
-  m_flags|= IS_INVOKED;
+  DBUG_ASSERT((m_next_cached_sp == 0 &&
+               m_first_instance->m_last_cached_sp == this) ||
+              (m_recursion_level + 1 == m_next_cached_sp->m_recursion_level));
 
   dbchanged= FALSE;
   if (m_db.length &&
@@ -1074,6 +1095,29 @@ int sp_head::execute(THD *thd)
       ret= mysql_change_db(thd, olddb, 1);
   }
   m_flags&= ~IS_INVOKED;
+  DBUG_PRINT("info", ("first free for 0x%lx --: 0x%lx->0x%lx, level: %lu, flags %x",
+                      (ulong)m_first_instance,
+                      m_first_instance->m_first_free_instance, this,
+                      m_recursion_level, m_flags));
+  /*
+    Check that we have one of following:
+
+    1) there are not free instances which means that this instance is last
+    in the list of instances (pointer to the last instance point on it and
+    ther are not other instances after this one in the list)
+
+    2) There are some free instances which mean that first free instance
+    should go just after this one and recursion level of that free instance
+    should be on 1 more then recursion leven of this instance.
+  */
+  DBUG_ASSERT((m_first_instance->m_first_free_instance == 0 &&
+               this == m_first_instance->m_last_cached_sp &&
+               m_next_cached_sp == 0) ||
+              (m_first_instance->m_first_free_instance != 0 &&
+               m_first_instance->m_first_free_instance == m_next_cached_sp &&
+               m_first_instance->m_first_free_instance->m_recursion_level ==
+               m_recursion_level + 1));
+  m_first_instance->m_first_free_instance= this;
   DBUG_RETURN(ret);
 }
 

sql/sp_head.h

@@ -140,6 +140,32 @@ public:
   LEX_STRING m_definer_host;
   longlong m_created;
   longlong m_modified;
+  /* Recursion level of the current SP instance. The levels are numbered from 0 */
+  ulong m_recursion_level;
+  /*
+    A list of diferent recursion level instances for the same procedure.
+    For every recursion level we have a sp_head instance. This instances
+    connected in the list. The list ordered by increasing recursion level
+    (m_recursion_level).
+  */
+  sp_head *m_next_cached_sp;
+  /*
+    Pointer to the first element of the above list
+  */
+  sp_head *m_first_instance;
+  /*
+    Pointer to the first free (non-INVOKED) routine in the list of
+    cached instances for this SP. This pointer is set only for the first
+    SP in the list of instences (see above m_first_cached_sp pointer).
+    The pointer equal to 0 if we have no free instances.
+    For non-first instance value of this pointer meanless (point to itself);
+  */
+  sp_head *m_first_free_instance;
+  /*
+    Pointer to the last element in the list of instances of the SP.
+    For non-first instance value of this pointer meanless (point to itself);
+  */
+  sp_head *m_last_cached_sp;
   /*
     Set containing names of stored routines used by this routine.
     Note that unlike elements of similar set for statement elements of this
@@ -262,6 +288,8 @@ public:
   void optimize();
   void opt_mark(uint ip);
 
+  void recursion_level_error();
+
   inline sp_instr *
   get_instr(uint i)
   {

sql/sql_base.cc

@@ -1087,6 +1087,11 @@ TABLE *open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
   /* find a unused table in the open table cache */
   if (refresh)
     *refresh=0;
+
+  /* an open table operation needs a lot of the stack space */
+  if (check_stack_overrun(thd, 8 * STACK_MIN_SIZE, (char *)&alias))
+    return 0;
+
   if (thd->killed)
     DBUG_RETURN(0);
   key_length= (uint) (strmov(strmov(key, table_list->db)+1,

sql/sql_class.h

@@ -534,6 +534,7 @@ struct system_variables
   ulong completion_type;
   /* Determines which non-standard SQL behaviour should be enabled */
   ulong sql_mode;
+  ulong max_sp_recursion_depth;
   /* check of key presence in updatable view */
   ulong updatable_views_with_limit;
   ulong default_week_format;

sql/sql_parse.cc

@@ -3694,7 +3694,8 @@ end_with_restore_list:
     if (check_access(thd,INSERT_ACL,"mysql",0,1,0,0))
       break;
 #ifdef HAVE_DLOPEN
-    if (sp_find_function(thd, lex->spname))
+    if (sp_find_routine(thd, TYPE_ENUM_FUNCTION, lex->spname,
+                        &thd->sp_func_cache, FALSE))
     {
       my_error(ER_UDF_EXISTS, MYF(0), lex->spname->m_name.str);
       goto error;
@@ -4228,7 +4229,8 @@ end_with_restore_list:
         By this moment all needed SPs should be in cache so no need to look 
         into DB. 
       */
-      if (!(sp= sp_find_procedure(thd, lex->spname, TRUE)))
+      if (!(sp= sp_find_routine(thd, TYPE_ENUM_PROCEDURE, lex->spname,
+                                &thd->sp_proc_cache, TRUE)))
       {
 	my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "PROCEDURE",
                  lex->spname->m_qname.str);
@@ -4364,9 +4366,11 @@ end_with_restore_list:
 
       memcpy(&chistics, &lex->sp_chistics, sizeof(chistics));
       if (lex->sql_command == SQLCOM_ALTER_PROCEDURE)
-	sp= sp_find_procedure(thd, lex->spname);
+        sp= sp_find_routine(thd, TYPE_ENUM_PROCEDURE, lex->spname,
+                            &thd->sp_proc_cache, FALSE);
       else
-	sp= sp_find_function(thd, lex->spname);
+        sp= sp_find_routine(thd, TYPE_ENUM_FUNCTION, lex->spname,
+                            &thd->sp_func_cache, FALSE);
       mysql_reset_errors(thd, 0);
       if (! sp)
       {
@@ -4435,9 +4439,11 @@ end_with_restore_list:
       char *db, *name;
 
       if (lex->sql_command == SQLCOM_DROP_PROCEDURE)
-	sp= sp_find_procedure(thd, lex->spname);
+        sp= sp_find_routine(thd, TYPE_ENUM_PROCEDURE, lex->spname,
+                            &thd->sp_proc_cache, FALSE);
       else
-	sp= sp_find_function(thd, lex->spname);
+        sp= sp_find_routine(thd, TYPE_ENUM_FUNCTION, lex->spname,
+                            &thd->sp_func_cache, FALSE);
       mysql_reset_errors(thd, 0);
       if (sp)
       {