Commit c01c4cc3 authored by unknown's avatar unknown
Browse files

Bug#19194 (Right recursion in parser for CASE causes excessive stack usage, 

  limitation)
Bug#24854 (Mixing Searched Case with Simple Case inside Stored Procedure
  crashes Mysqld)

Implemented code review (19194) comments


mysql-test/r/sp_stress_case.result:
  Implemented code review comments : use SQL instead of a shell script to
  generate the code
mysql-test/t/sp_stress_case.test:
  Adjusted
sql/sql_yacc.yy:
  Added more explicit comments
BitKeeper/deleted/.del-sp_stress_case.sh:
  Delete: mysql-test/t/sp_stress_case.sh
parent 476eaae8

mysql-test/r/sp_stress_case.result

+96 −18
Original line number Diff line number Diff line 
DROP PROCEDURE IF EXISTS bug_19194_a;

DROP PROCEDURE IF EXISTS bug_19194_b;

'Silently creating PROCEDURE bug_19194_a'

'Silently creating PROCEDURE bug_19194_b'

CALL bug_19194_a(1);

DROP PROCEDURE IF EXISTS proc_19194_codegen;

DROP PROCEDURE IF EXISTS bug_19194_simple;

DROP PROCEDURE IF EXISTS bug_19194_searched;

CREATE PROCEDURE proc_19194_codegen(

IN proc_name VARCHAR(50),

IN count INTEGER,

IN simple INTEGER,

OUT body MEDIUMTEXT)

BEGIN

DECLARE code MEDIUMTEXT;

DECLARE i INT DEFAULT 1;

SET code = concat("CREATE PROCEDURE ", proc_name, "(i INT)\n");

SET code = concat(code, "BEGIN\n");

SET code = concat(code, "  DECLARE str CHAR(10);\n");

IF (simple)

THEN

SET code = concat(code, "  CASE i\n");

ELSE

SET code = concat(code, "  CASE\n");

END IF;

WHILE (i <= count)

DO

IF (simple)

THEN

SET code = concat(code, "    WHEN ", i, " THEN SET str=\"", i, "\";\n");

ELSE

SET code = concat(code, "    WHEN i=", i, " THEN SET str=\"", i, "\";\n");

END IF;

SET i = i + 1;

END WHILE;

SET code = concat(code, "    ELSE SET str=\"unknown\";\n");

SET code = concat(code, "  END CASE;\n");

SET code = concat(code, "  SELECT str;\n");

SET code = concat(code, "END\n");

SET body = code;

END|

set @body="";

call proc_19194_codegen("test_simple", 10, 1, @body);

select @body;

@body

CREATE PROCEDURE test_simple(i INT)

BEGIN

  DECLARE str CHAR(10);

  CASE i

    WHEN 1 THEN SET str="1";

    WHEN 2 THEN SET str="2";

    WHEN 3 THEN SET str="3";

    WHEN 4 THEN SET str="4";

    WHEN 5 THEN SET str="5";

    WHEN 6 THEN SET str="6";

    WHEN 7 THEN SET str="7";

    WHEN 8 THEN SET str="8";

    WHEN 9 THEN SET str="9";

    WHEN 10 THEN SET str="10";

    ELSE SET str="unknown";

  END CASE;

  SELECT str;

END



call proc_19194_codegen("test_searched", 10, 0, @body);

select @body;

@body

CREATE PROCEDURE test_searched(i INT)

BEGIN

  DECLARE str CHAR(10);

  CASE

    WHEN i=1 THEN SET str="1";

    WHEN i=2 THEN SET str="2";

    WHEN i=3 THEN SET str="3";

    WHEN i=4 THEN SET str="4";

    WHEN i=5 THEN SET str="5";

    WHEN i=6 THEN SET str="6";

    WHEN i=7 THEN SET str="7";

    WHEN i=8 THEN SET str="8";

    WHEN i=9 THEN SET str="9";

    WHEN i=10 THEN SET str="10";

    ELSE SET str="unknown";

  END CASE;

  SELECT str;

END



CALL bug_19194_simple(1);

str

1

CALL bug_19194_a(2);

CALL bug_19194_simple(2);

str

2

CALL bug_19194_a(1000);

CALL bug_19194_simple(1000);

str

1000

CALL bug_19194_a(4998);

CALL bug_19194_simple(4998);

str

4998

CALL bug_19194_a(4999);

CALL bug_19194_simple(4999);

str

4999

CALL bug_19194_a(9999);

CALL bug_19194_simple(9999);

str

unknown

CALL bug_19194_b(1);

CALL bug_19194_searched(1);

str

1

CALL bug_19194_b(2);

CALL bug_19194_searched(2);

str

2

CALL bug_19194_b(1000);

CALL bug_19194_searched(1000);

str

1000

CALL bug_19194_b(4998);

CALL bug_19194_searched(4998);

str

4998

CALL bug_19194_b(4999);

CALL bug_19194_searched(4999);

str

4999

CALL bug_19194_b(9999);

CALL bug_19194_searched(9999);

str

unknown

DROP PROCEDURE bug_19194_a;

DROP PROCEDURE bug_19194_b;
 
DROP PROCEDURE proc_19194_codegen;

DROP PROCEDURE bug_19194_simple;

DROP PROCEDURE bug_19194_searched;

mysql-test/t/sp_stress_case.sh

deleted100755 → 0
+0 −68
Original line number Diff line number Diff line 
#!/bin/sh



#

# Bug#19194 (Right recursion in parser for CASE causes excessive stack

#   usage, limitation)

#

# Because the code for the CASE statement is so massive,

# checking in an already generated .test is not practical,

# due to it's size (10 000 lines or 356 000 bytes).

#

# Patches are sent by email, which introduce size limitations.

#

# As a result, code is generated dynamically here.

# This script takes no argument, and generates code in stdout.

#



cat <<EOF

echo 'Silently creating PROCEDURE bug_19194_a';

--disable_query_log

delimiter |;

CREATE PROCEDURE bug_19194_a(i int)

BEGIN

DECLARE str CHAR(10);

  CASE i

EOF



count=1;

while true; do

  echo "    WHEN $count THEN SET str=\"$count\";"

  count=`expr $count + 1`

  test $count -gt 5000 && break

done



cat <<EOF

    ELSE SET str="unknown";

  END CASE;

  SELECT str;

END|

delimiter ;|

--enable_query_log

EOF



cat <<EOF

echo 'Silently creating PROCEDURE bug_19194_b';

--disable_query_log

delimiter |;

CREATE PROCEDURE bug_19194_b(i int)

BEGIN

DECLARE str CHAR(10);

  CASE

EOF



count=1;

while true; do

  echo "    WHEN i=$count THEN SET str=\"$count\";"

  count=`expr $count + 1`

  test $count -gt 5000 && break

done



cat <<EOF

    ELSE SET str="unknown";

  END CASE;

  SELECT str;

END|

delimiter ;|

--enable_query_log

EOF

mysql-test/t/sp_stress_case.test

+82 −23
Original line number Diff line number Diff line 


# The production code tested is not platform specific,

# but /bin/sh is needed to run the test case.



--source include/not_windows.inc



#

# Bug#19194 (Right recursion in parser for CASE causes excessive stack

#   usage, limitation)

#



# This test takes some time (8 min) in debug builds

# It's provided as a separate file so that the next line can be uncommented

# later if needed:

# -- source include/big_test.inc



--disable_warnings

DROP PROCEDURE IF EXISTS bug_19194_a;

DROP PROCEDURE IF EXISTS bug_19194_b;

DROP PROCEDURE IF EXISTS proc_19194_codegen;

DROP PROCEDURE IF EXISTS bug_19194_simple;

DROP PROCEDURE IF EXISTS bug_19194_searched;

--enable_warnings



--exec $MYSQL_TEST_DIR/t/sp_stress_case.sh | $MYSQL_TEST 2>&1

delimiter |;



CREATE PROCEDURE proc_19194_codegen(

  IN proc_name VARCHAR(50),

  IN count INTEGER,

  IN simple INTEGER,

  OUT body MEDIUMTEXT)

BEGIN

  DECLARE code MEDIUMTEXT;

  DECLARE i INT DEFAULT 1;



  SET code = concat("CREATE PROCEDURE ", proc_name, "(i INT)\n");

  SET code = concat(code, "BEGIN\n");

  SET code = concat(code, "  DECLARE str CHAR(10);\n");



  IF (simple)

  THEN

    SET code = concat(code, "  CASE i\n");

  ELSE

    SET code = concat(code, "  CASE\n");

  END IF;



  WHILE (i <= count)

  DO

    IF (simple)

    THEN

      SET code = concat(code, "    WHEN ", i, " THEN SET str=\"", i, "\";\n");

    ELSE

      SET code = concat(code, "    WHEN i=", i, " THEN SET str=\"", i, "\";\n");

    END IF;



    SET i = i + 1;

  END WHILE;



  SET code = concat(code, "    ELSE SET str=\"unknown\";\n");

  SET code = concat(code, "  END CASE;\n");

  SET code = concat(code, "  SELECT str;\n");



  SET code = concat(code, "END\n");



  SET body = code;

END|



delimiter ;|



set @body="";

call proc_19194_codegen("test_simple", 10, 1, @body);

select @body;

call proc_19194_codegen("test_searched", 10, 0, @body);

select @body;



--disable_query_log

call proc_19194_codegen("bug_19194_simple", 5000, 1, @body);

let $proc_body = `select @body`;

eval $proc_body;

call proc_19194_codegen("bug_19194_searched", 5000, 1, @body);

let $proc_body = `select @body`;

eval $proc_body;

--enable_query_log



CALL bug_19194_a(1);

CALL bug_19194_a(2);

CALL bug_19194_a(1000);

CALL bug_19194_a(4998);

CALL bug_19194_a(4999);

CALL bug_19194_a(9999);

CALL bug_19194_simple(1);

CALL bug_19194_simple(2);

CALL bug_19194_simple(1000);

CALL bug_19194_simple(4998);

CALL bug_19194_simple(4999);

CALL bug_19194_simple(9999);



CALL bug_19194_b(1);

CALL bug_19194_b(2);

CALL bug_19194_b(1000);

CALL bug_19194_b(4998);

CALL bug_19194_b(4999);

CALL bug_19194_b(9999);

CALL bug_19194_searched(1);

CALL bug_19194_searched(2);

CALL bug_19194_searched(1000);

CALL bug_19194_searched(4998);

CALL bug_19194_searched(4999);

CALL bug_19194_searched(9999);



DROP PROCEDURE bug_19194_a;

DROP PROCEDURE bug_19194_b;

DROP PROCEDURE proc_19194_codegen;

DROP PROCEDURE bug_19194_simple;

DROP PROCEDURE bug_19194_searched;

sql/sql_yacc.yy

+42 −1
Original line number Diff line number Diff line
@@ -100,6 +100,42 @@ void turn_parser_debug_on() 
/**

  Helper action for a case statement (entering the CASE).

  This helper is used for both 'simple' and 'searched' cases.

  This helper, with the other case_stmt_action_..., is executed when

  the following SQL code is parsed:

<pre>

CREATE PROCEDURE proc_19194_simple(i int)

BEGIN

  DECLARE str CHAR(10);



  CASE i

    WHEN 1 THEN SET str="1";

    WHEN 2 THEN SET str="2";

    WHEN 3 THEN SET str="3";

    ELSE SET str="unknown";

  END CASE;



  SELECT str;

END

</pre>

  The actions are used to generate the following code:

<pre>

SHOW PROCEDURE CODE proc_19194_simple;

Pos     Instruction

0       set str@1 NULL

1       set_case_expr (12) 0 i@0

2       jump_if_not 5(12) (case_expr@0 = 1)

3       set str@1 _latin1'1'

4       jump 12

5       jump_if_not 8(12) (case_expr@0 = 2)

6       set str@1 _latin1'2'

7       jump 12

8       jump_if_not 11(12) (case_expr@0 = 3)

9       set str@1 _latin1'3'

10      jump 12

11      set str@1 _latin1'unknown'

12      stmt 0 "SELECT str"

</pre>



  @param lex the parser lex context

*/
@@ -110,6 +146,7 @@ void case_stmt_action_case(LEX *lex) 
  /*

    BACKPATCH: Creating target label for the jump to

    "case_stmt_action_end_case"

    (Instruction 12 in the example)

  */



  lex->spcont->push_label((char *)"", lex->sphead->instructions());
@@ -179,6 +216,7 @@ void case_stmt_action_when(LEX *lex, Item *when, bool simple) 
  /*

    BACKPATCH: Registering forward jump from

    "case_stmt_action_when" to "case_stmt_action_then"

    (jump_if_not from instruction 2 to 5, 5 to 8 ... in the example)

  */



  sp->push_backpatch(i, ctx->push_label((char *)"", 0));
@@ -203,13 +241,15 @@ void case_stmt_action_then(LEX *lex) 
  /*

    BACKPATCH: Resolving forward jump from

    "case_stmt_action_when" to "case_stmt_action_then"

    (jump_if_not from instruction 2 to 5, 5 to 8 ... in the example)

  */



  sp->backpatch(ctx->pop_label());



  /*

    BACKPATCH: Registering forward jump from

    "case_stmt_action_when" to "case_stmt_action_end_case"

    "case_stmt_action_then" to "case_stmt_action_end_case"

    (jump from instruction 4 to 12, 7 to 12 ... in the example)

  */



  sp->push_backpatch(i, ctx->last_label());
@@ -227,6 +267,7 @@ void case_stmt_action_end_case(LEX *lex, bool simple) 
  /*

    BACKPATCH: Resolving forward jump from

    "case_stmt_action_then" to "case_stmt_action_end_case"

    (jump from instruction 4 to 12, 7 to 12 ... in the example)

  */

  lex->sphead->backpatch(lex->spcont->pop_label());