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Fixed BUG#14498: Stored procedures: hang if undefined variable and exception 

  The problem was to continue at the right place in the code after the
  test expression in a flow control statement fails with an exception
  (internally, the test in sp_instr_jump_if_not), and the exception is
  caught by a continue handler. Execution must then be resumed after the
  the entire flow control statement (END IF, END WHILE, etc).


mysql-test/r/sp.result:
  New test case for BUG#14498.
mysql-test/t/sp.test:
  New test case for BUG#14498.
  (Note that one call is disabled at the moment. Depends on BUG#14643.)
sql/sp_head.cc:
  Added a continuation destination for sp_instr_jump_if_not, for the case when
  an error in the test expression causes a continue handler to catch.
  This includes new members in sp_instr_jump_if_not, adjustment of the optmizer
  (mark and move methods), and separate backpatching code (since we can't use
  the normal one for this).
  
  Also removed the class sp_instr_jump, since it's never used.
  
  ...and added some comments to the optimizer.
sql/sp_head.h:
  Added a continuation destination for sp_instr_jump_if_not, for the case when
  an error in the test expression causes a continue handler to catch.
  This includes new members in sp_instr_jump_if_not, adjustment of the optmizer
  (mark and move methods), and separate backpatching code (since we can't use
  the normal one for this).
  
  Also removed the class sp_instr_jump, since it's never used.
sql/sql_yacc.yy:
  Added backpatching of the continue destination for all conditional statements
  (using sp_instr_jump_if_not).
parent d6b2fc2f
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Showing with 308 additions and 110 deletions
mysql-test/r/sp.result
View file @ 84ac5c13
......@@ -3575,4 +3575,88 @@ DROP VIEW bug13095_v1
DROP PROCEDURE IF EXISTS bug13095;
DROP VIEW IF EXISTS bug13095_v1;
DROP TABLE IF EXISTS bug13095_t1;
drop procedure if exists bug14498_1|
drop procedure if exists bug14498_2|
drop procedure if exists bug14498_3|
drop procedure if exists bug14498_4|
drop procedure if exists bug14498_5|
create procedure bug14498_1()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
if v then
select 'yes' as 'v';
else
select 'no' as 'v';
end if;
select 'done' as 'End';
end|
create procedure bug14498_2()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
while v do
select 'yes' as 'v';
end while;
select 'done' as 'End';
end|
create procedure bug14498_3()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
repeat
select 'maybe' as 'v';
until v end repeat;
select 'done' as 'End';
end|
create procedure bug14498_4()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
case v
when 1 then
select '1' as 'v';
when 2 then
select '2' as 'v';
else
select '?' as 'v';
end case;
select 'done' as 'End';
end|
create procedure bug14498_5()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
case
when v = 1 then
select '1' as 'v';
when v = 2 then
select '2' as 'v';
else
select '?' as 'v';
end case;
select 'done' as 'End';
end|
call bug14498_1()|
Handler
error
End
done
call bug14498_2()|
Handler
error
End
done
call bug14498_3()|
v
maybe
Handler
error
End
done
call bug14498_5()|
Handler
error
End
done
drop procedure bug14498_1|
drop procedure bug14498_2|
drop procedure bug14498_3|
drop procedure bug14498_4|
drop procedure bug14498_5|
drop table t1,t2;
mysql-test/t/sp.test
View file @ 84ac5c13
......@@ -4489,6 +4489,92 @@ DROP TABLE IF EXISTS bug13095_t1;
delimiter |;
#
# BUG#14498: Stored procedures: hang if undefined variable and exception
#
--disable_warnings
drop procedure if exists bug14498_1|
drop procedure if exists bug14498_2|
drop procedure if exists bug14498_3|
drop procedure if exists bug14498_4|
drop procedure if exists bug14498_5|
--enable_warnings
create procedure bug14498_1()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
if v then
select 'yes' as 'v';
else
select 'no' as 'v';
end if;
select 'done' as 'End';
end|
create procedure bug14498_2()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
while v do
select 'yes' as 'v';
end while;
select 'done' as 'End';
end|
create procedure bug14498_3()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
repeat
select 'maybe' as 'v';
until v end repeat;
select 'done' as 'End';
end|
create procedure bug14498_4()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
case v
when 1 then
select '1' as 'v';
when 2 then
select '2' as 'v';
else
select '?' as 'v';
end case;
select 'done' as 'End';
end|
create procedure bug14498_5()
begin
declare continue handler for sqlexception select 'error' as 'Handler';
case
when v = 1 then
select '1' as 'v';
when v = 2 then
select '2' as 'v';
else
select '?' as 'v';
end case;
select 'done' as 'End';
end|
call bug14498_1()|
call bug14498_2()|
call bug14498_3()|
# QQ We can't call this at the moment, due to a known bug (BUG#14643)
#call bug14498_4()|
call bug14498_5()|
drop procedure bug14498_1|
drop procedure bug14498_2|
drop procedure bug14498_3|
drop procedure bug14498_4|
drop procedure bug14498_5|
#
# BUG#NNNN: New bug synopsis
#
......
sql/sp_head.cc
View file @ 84ac5c13
......@@ -437,13 +437,14 @@ 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_cont_level(0)
{
extern byte *
sp_table_key(const byte *ptr, uint *plen, my_bool first);
DBUG_ENTER("sp_head::sp_head");
m_backpatch.empty();
m_cont_backpatch.empty();
m_lex.empty();
hash_init(&m_sptabs, system_charset_info, 0, 0, 0, sp_table_key, 0, 0);
hash_init(&m_sroutines, system_charset_info, 0, 0, 0, sp_sroutine_key, 0, 0);
......@@ -1568,6 +1569,39 @@ sp_head::check_backpatch(THD *thd)
return 0;
}
void
sp_head::new_cont_backpatch(sp_instr_jump_if_not *i)
{
m_cont_level+= 1;
if (i)
{
/* Use the cont. destination slot to store the level */
i->m_cont_dest= m_cont_level;
(void)m_cont_backpatch.push_front(i);
}
}
void
sp_head::add_cont_backpatch(sp_instr_jump_if_not *i)
{
i->m_cont_dest= m_cont_level;
(void)m_cont_backpatch.push_front(i);
}
void
sp_head::do_cont_backpatch()
{
uint dest= instructions();
uint lev= m_cont_level--;
sp_instr_jump_if_not *i;
while ((i= m_cont_backpatch.head()) && i->m_cont_dest == lev)
{
i->m_cont_dest= dest;
(void)m_cont_backpatch.pop();
}
}
void
sp_head::set_info(char *definer, uint definerlen,
longlong created, longlong modified,
......@@ -1782,7 +1816,10 @@ sp_head::show_create_function(THD *thd)
/*
TODO: what does this do??
Do some minimal optimization of the code:
1) Mark used instructions
1.1) While doing this, shortcut jumps to jump instructions
2) Compact the code, removing unused instructions
*/
void sp_head::optimize()
......@@ -1805,7 +1842,7 @@ void sp_head::optimize()
else
{
if (src != dst)
{
{ // Move the instruction and update prev. jumps
sp_instr *ibp;
List_iterator_fast<sp_instr> li(bp);
......@@ -1813,8 +1850,7 @@ void sp_head::optimize()
while ((ibp= li++))
{
sp_instr_jump *ji= static_cast<sp_instr_jump *>(ibp);
if (ji->m_dest == src)
ji->m_dest= dst;
ji->set_destination(src, dst);
}
}
i->opt_move(dst, &bp);
......@@ -2144,65 +2180,6 @@ sp_instr_jump::opt_move(uint dst, List<sp_instr> *bp)
}
/*
sp_instr_jump_if class functions
*/
int
sp_instr_jump_if::execute(THD *thd, uint *nextp)
{
DBUG_ENTER("sp_instr_jump_if::execute");
DBUG_PRINT("info", ("destination: %u", m_dest));
DBUG_RETURN(m_lex_keeper.reset_lex_and_exec_core(thd, nextp, TRUE, this));
}
int
sp_instr_jump_if::exec_core(THD *thd, uint *nextp)
{
Item *it;
int res;
it= sp_prepare_func_item(thd, &m_expr);
if (!it)
res= -1;
else
{
res= 0;
if (it->val_bool())
*nextp = m_dest;
else
*nextp = m_ip+1;
}
return res;
}
void
sp_instr_jump_if::print(String *str)
{
str->reserve(12);
str->append("jump_if ");
str->qs_append(m_dest);
str->append(' ');
m_expr->print(str);
}
uint
sp_instr_jump_if::opt_mark(sp_head *sp)
{
sp_instr *i;
marked= 1;
if ((i= sp->get_instr(m_dest)))
{
m_dest= i->opt_shortcut_jump(sp, this);
m_optdest= sp->get_instr(m_dest);
}
sp->opt_mark(m_dest);
return m_ip+1;
}
/*
sp_instr_jump_if_not class functions
*/
......@@ -2224,7 +2201,10 @@ sp_instr_jump_if_not::exec_core(THD *thd, uint *nextp)
it= sp_prepare_func_item(thd, &m_expr);
if (! it)
{
res= -1;
*nextp = m_cont_dest;
}
else
{
res= 0;
......@@ -2241,10 +2221,12 @@ sp_instr_jump_if_not::exec_core(THD *thd, uint *nextp)
void
sp_instr_jump_if_not::print(String *str)
{
str->reserve(16);
str->reserve(24);
str->append("jump_if_not ");
str->qs_append(m_dest);
str->append(' ');
str->append('(');
str->qs_append(m_cont_dest);
str->append(") ");
m_expr->print(str);
}
......@@ -2261,9 +2243,35 @@ sp_instr_jump_if_not::opt_mark(sp_head *sp)
m_optdest= sp->get_instr(m_dest);
}
sp->opt_mark(m_dest);
if ((i= sp->get_instr(m_cont_dest)))
{
m_cont_dest= i->opt_shortcut_jump(sp, this);
m_cont_optdest= sp->get_instr(m_cont_dest);
}
sp->opt_mark(m_cont_dest);
return m_ip+1;
}
void
sp_instr_jump_if_not::opt_move(uint dst, List<sp_instr> *bp)
{
/*
cont. destinations may point backwards after shortcutting jumps
during the mark phase. If it's still pointing forwards, only
push this for backpatching if sp_instr_jump::opt_move() will not
do it (i.e. if the m_dest points backwards).
*/
if (m_cont_dest > m_ip)
{ // Forward
if (m_dest < m_ip)
bp->push_back(this);
}
else if (m_cont_optdest)
m_cont_dest= m_cont_optdest->m_ip; // Backward
/* This will take care of m_dest and m_ip */
sp_instr_jump::opt_move(dst, bp);
}
/*
sp_instr_freturn class functions
......
sql/sp_head.h
View file @ 84ac5c13
......@@ -38,6 +38,7 @@ sp_get_flags_for_command(LEX *lex);
struct sp_label;
class sp_instr;
class sp_instr_jump_if_not;
struct sp_cond_type;
struct sp_pvar;
......@@ -240,6 +241,18 @@ class sp_head :private Query_arena
int
check_backpatch(THD *thd);
// Start a new cont. backpatch level. If 'i' is NULL, the level is just incr.
void
new_cont_backpatch(sp_instr_jump_if_not *i);
// Add an instruction to the current level
void
add_cont_backpatch(sp_instr_jump_if_not *i);
// Backpatch (and pop) the current level to the current position.
void
do_cont_backpatch();
char *name(uint *lenp = 0) const
{
if (lenp)
......@@ -309,6 +322,18 @@ class sp_head :private Query_arena
sp_instr *instr;
} bp_t;
List<bp_t> m_backpatch; // Instructions needing backpatching
/*
We need a special list for backpatching of conditional jump's continue
destination (in the case of a continue handler catching an error in
the test), since it would otherwise interfere with the normal backpatch
mechanism - jump_if_not instructions have two different destination
which are to be patched differently.
Since these occur in a more restricted way (always the same "level" in
the code), we don't need the label.
*/
List<sp_instr_jump_if_not> m_cont_backpatch;
uint m_cont_level; // The current cont. backpatch level
/*
Multi-set representing optimized list of tables to be locked by this
routine. Does not include tables which are used by invoked routines.
......@@ -622,50 +647,17 @@ class sp_instr_jump : public sp_instr
m_dest= dest;
}
protected:
sp_instr *m_optdest; // Used during optimization
}; // class sp_instr_jump : public sp_instr
class sp_instr_jump_if : public sp_instr_jump
{
sp_instr_jump_if(const sp_instr_jump_if &); /* Prevent use of these */
void operator=(sp_instr_jump_if &);
public:
sp_instr_jump_if(uint ip, sp_pcontext *ctx, Item *i, LEX *lex)
: sp_instr_jump(ip, ctx), m_expr(i), m_lex_keeper(lex, TRUE)
{}
sp_instr_jump_if(uint ip, sp_pcontext *ctx, Item *i, uint dest, LEX *lex)
: sp_instr_jump(ip, ctx, dest), m_expr(i), m_lex_keeper(lex, TRUE)
{}
virtual ~sp_instr_jump_if()
{}
virtual int execute(THD *thd, uint *nextp);
virtual int exec_core(THD *thd, uint *nextp);
virtual void print(String *str);
virtual uint opt_mark(sp_head *sp);
virtual uint opt_shortcut_jump(sp_head *sp, sp_instr *start)
virtual void set_destination(uint old_dest, uint new_dest)
{
return m_ip;
if (m_dest == old_dest)
m_dest= new_dest;
}
private:
protected:
Item *m_expr; // The condition
sp_lex_keeper m_lex_keeper;
sp_instr *m_optdest; // Used during optimization
}; // class sp_instr_jump_if : public sp_instr_jump
}; // class sp_instr_jump : public sp_instr
class sp_instr_jump_if_not : public sp_instr_jump
......@@ -675,12 +667,16 @@ class sp_instr_jump_if_not : public sp_instr_jump
public:
uint m_cont_dest; // Where continue handlers will go
sp_instr_jump_if_not(uint ip, sp_pcontext *ctx, Item *i, LEX *lex)
: sp_instr_jump(ip, ctx), m_expr(i), m_lex_keeper(lex, TRUE)
: sp_instr_jump(ip, ctx), m_cont_dest(0), m_expr(i),
m_lex_keeper(lex, TRUE), m_cont_optdest(0)
{}
sp_instr_jump_if_not(uint ip, sp_pcontext *ctx, Item *i, uint dest, LEX *lex)
: sp_instr_jump(ip, ctx, dest), m_expr(i), m_lex_keeper(lex, TRUE)
: sp_instr_jump(ip, ctx, dest), m_cont_dest(0), m_expr(i),
m_lex_keeper(lex, TRUE), m_cont_optdest(0)
{}
virtual ~sp_instr_jump_if_not()
......@@ -699,10 +695,20 @@ class sp_instr_jump_if_not : public sp_instr_jump
return m_ip;
}
virtual void opt_move(uint dst, List<sp_instr> *ibp);
virtual void set_destination(uint old_dest, uint new_dest)
{
sp_instr_jump::set_destination(old_dest, new_dest);
if (m_cont_dest == old_dest)
m_cont_dest= new_dest;
}
private:
Item *m_expr; // The condition
sp_lex_keeper m_lex_keeper;
sp_instr *m_cont_optdest; // Used during optimization
}; // class sp_instr_jump_if_not : public sp_instr_jump
......
sql/sql_yacc.yy
View file @ 84ac5c13
......@@ -2009,14 +2009,21 @@ sp_proc_stmt:
}
sp->restore_lex(YYTHD);
}
| IF sp_if END IF {}
| IF
{ Lex->sphead->new_cont_backpatch(NULL); }
sp_if END IF
{ Lex->sphead->do_cont_backpatch(); }
| CASE_SYM WHEN_SYM
{
Lex->sphead->m_flags&= ~sp_head::IN_SIMPLE_CASE;
Lex->sphead->new_cont_backpatch(NULL);
}
sp_case END CASE_SYM {}
sp_case END CASE_SYM { Lex->sphead->do_cont_backpatch(); }
| CASE_SYM
{ Lex->sphead->reset_lex(YYTHD); }
{
Lex->sphead->reset_lex(YYTHD);
Lex->sphead->new_cont_backpatch(NULL);
}
expr WHEN_SYM
{
/* We "fake" this by using an anonymous variable which we
......@@ -2038,6 +2045,7 @@ sp_proc_stmt:
sp_case END CASE_SYM
{
Lex->spcont->pop_pvar();
Lex->sphead->do_cont_backpatch();
}
| sp_labeled_control
{}
......@@ -2306,6 +2314,7 @@ sp_if:
$2, lex);
sp->push_backpatch(i, ctx->push_label((char *)"", 0));
sp->add_cont_backpatch(i);
sp->add_instr(i);
sp->restore_lex(YYTHD);
}
......@@ -2360,6 +2369,7 @@ sp_case:
lex->variables_used= 1;
}
sp->push_backpatch(i, ctx->push_label((char *)"", 0));
sp->add_cont_backpatch(i);
sp->add_instr(i);
sp->restore_lex(YYTHD);
}
......@@ -2489,6 +2499,7 @@ sp_unlabeled_control:
/* Jumping forward */
sp->push_backpatch(i, lex->spcont->last_label());
sp->new_cont_backpatch(i);
sp->add_instr(i);
sp->restore_lex(YYTHD);
}
......@@ -2500,6 +2511,7 @@ sp_unlabeled_control:
sp_instr_jump *i = new sp_instr_jump(ip, lex->spcont, lab->ip);
lex->sphead->add_instr(i);
lex->sphead->do_cont_backpatch();
}
| REPEAT_SYM sp_proc_stmts1 UNTIL_SYM
{ Lex->sphead->reset_lex(YYTHD); }
......@@ -2513,6 +2525,8 @@ sp_unlabeled_control:
lex);
lex->sphead->add_instr(i);
lex->sphead->restore_lex(YYTHD);
/* We can shortcut the cont_backpatch here */
i->m_cont_dest= ip+1;
}
;
......
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