Bug#24736: UDF functions parsed as Stored Functions

Before this fix, a call to a User Defined Function (UDF) could,
under some circumstances, be interpreted as a call to a Stored function
instead. This occurred if a native function was invoked in the parameters
for the UDF, as in "select my_udf(abs(x))".

The root cause of this defect is the introduction, by the fix for Bug 21809,
of st_select_lex::udf_list, and it's usage in the parser in sql_yacc.yy
in the rule function_call_generic (in 5.1).

While the fix itself for Bug 21809 is correct in 5.0, the code change
merged into the 5.1 release created the issue, because the calls in 5.1 to :
- lex->current_select->udf_list.push_front(udf)
- lex->current_select->udf_list.pop()
are not balanced in case of native functions, causing the udf_list,
which is really a stack, to be out of sync with the internal stack
maintained by the bison parser.

Instead of moving the call to udf_list.pop(), which would have fixed the
symptom, this patch goes further and removes the need for udf_list.

This is motivated by two reasons:

a) Maintaining a stack in the MySQL code in sync with the stack maintained
internally in sql_yacc.cc (not .yy) is extremely dependent of the
implementation of yacc/bison, and extremely difficult to maintain.
It's also totally dependent of the structure of the grammar, and has a risk
to break with regression defects each time the grammar itself is changed.

b) The previous code did report construct like "foo(expr AS name)" as
syntax errors (ER_PARSER_ERROR), which is incorrect, and misleading.
The syntax is perfectly valid, as this expression is valid when "foo" is
a UDF. Whether this syntax is legal or not depends of the semantic of "foo".

With this change:

a) There is only one stack (in bison), and no List<udf_func> to maintain.

b) "foo(expr AS name)", when used incorrectly, is reported as semantic error:
- ER_WRONG_PARAMETERS_TO_NATIVE_FCT (for native functions)
- ER_WRONG_PARAMETERS_TO_STORED_FCT (for stored functions)
This is achieved by the changes implemented in item_create.cc

mysql-test/r/parser.result

@@ -386,3 +386,104 @@ select yearweek();
 ERROR 42000: Incorrect parameter count in the call to native function 'yearweek'
 select yearweek(1, 2, 3);
 ERROR 42000: Incorrect parameter count in the call to native function 'yearweek'
+select abs(3);
+abs(3)
+3
+select abs(3 AS three);
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
+select abs(3 three);
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
+select abs(3 AS "three");
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
+select abs(3 "three");
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
+set @bar="bar";
+set @foobar="foobar";
+select instr("foobar", "bar");
+instr("foobar", "bar")
+4
+select instr("foobar" AS p1, "bar");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar" p1, "bar");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar" AS "p1", "bar");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar" "p1", "bar");
+instr("foobar" "p1", "bar")
+4
+select instr(@foobar "p1", "bar");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar", "bar" AS p2);
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar", "bar" p2);
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar", "bar" AS "p2");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar", "bar" "p2");
+instr("foobar", "bar" "p2")
+0
+select instr("foobar", @bar "p2");
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select instr("foobar" AS p1, "bar" AS p2);
+ERROR 42000: Incorrect parameters in the call to native function 'instr'
+select conv(255, 10, 16);
+conv(255, 10, 16)
+FF
+select conv(255 AS p1, 10, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255 p1, 10, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255 AS "p1", 10, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255 "p1", 10, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10 AS p2, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10 p2, 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10 AS "p2", 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10 "p2", 16);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10, 16 AS p3);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10, 16 p3);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10, 16 AS "p3");
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255, 10, 16 "p3");
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select conv(255 AS p1, 10 AS p2, 16 AS p3);
+ERROR 42000: Incorrect parameters in the call to native function 'conv'
+select atan(10);
+atan(10)
+1.4711276743037
+select atan(10 AS p1);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 p1);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 AS "p1");
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 "p1");
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10, 20);
+atan(10, 20)
+0.46364760900081
+select atan(10 AS p1, 20);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 p1, 20);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 AS "p1", 20);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 "p1", 20);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10, 20 AS p2);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10, 20 p2);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10, 20 AS "p2");
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10, 20 "p2");
+ERROR 42000: Incorrect parameters in the call to native function 'atan'
+select atan(10 AS p1, 20 AS p2);
+ERROR 42000: Incorrect parameters in the call to native function 'atan'

mysql-test/r/udf.result

@@ -132,9 +132,9 @@ a	c
 1	1
 2	2
 SELECT a, fn(MIN(b) xx) as c FROM t1 GROUP BY a;
-ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xx) as c FROM t1 GROUP BY a' at line 1
+ERROR 42000: Incorrect parameters in the call to stored function 'fn'
 SELECT myfunc_int(fn(MIN(b) xx)) as c FROM t1 GROUP BY a;
-ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xx)) as c FROM t1 GROUP BY a' at line 1
+ERROR 42000: Incorrect parameters in the call to stored function 'fn'
 SELECT myfunc_int(test.fn(MIN(b) xx)) as c FROM t1 GROUP BY a;
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'xx)) as c FROM t1 GROUP BY a' at line 1
 SELECT myfunc_int(fn(MIN(b)) xx) as c FROM t1 GROUP BY a;
@@ -185,6 +185,28 @@ DROP VIEW v1;
 DROP TABLE t1;
 DROP FUNCTION fn;
 End of 5.0 tests.
+select myfunc_double(3);
+myfunc_double(3)
+51.00
+select myfunc_double(3 AS three);
+myfunc_double(3 AS three)
+51.00
+select myfunc_double(abs(3));
+myfunc_double(abs(3))
+51.00
+select myfunc_double(abs(3) AS named_param);
+myfunc_double(abs(3) AS named_param)
+51.00
+select abs(myfunc_double(3));
+abs(myfunc_double(3))
+51.00
+select abs(myfunc_double(3 AS three));
+abs(myfunc_double(3 AS three))
+51.00
+select myfunc_double(abs(3 AS wrong));
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
+select abs(myfunc_double(3) AS wrong);
+ERROR 42000: Incorrect parameters in the call to native function 'abs'
 DROP FUNCTION metaphon;
 DROP FUNCTION myfunc_double;
 DROP FUNCTION myfunc_nonexist;

mysql-test/t/parser.test

@@ -508,3 +508,113 @@ select yearweek();
 -- error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
 select yearweek(1, 2, 3);
 
+#
+# Bug#24736: UDF functions parsed as Stored Functions
+#
+
+# Verify that the syntax for calling UDF : foo(expr AS param, ...)
+# can not be used when calling native functions
+
+# Native function with 1 argument
+
+select abs(3);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select abs(3 AS three);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select abs(3 three);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select abs(3 AS "three");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select abs(3 "three");
+
+# Native function with 2 arguments
+
+set @bar="bar";
+set @foobar="foobar";
+
+select instr("foobar", "bar");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar" AS p1, "bar");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar" p1, "bar");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar" AS "p1", "bar");
+## String concatenation, valid syntax
+select instr("foobar" "p1", "bar");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr(@foobar "p1", "bar");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar", "bar" AS p2);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar", "bar" p2);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar", "bar" AS "p2");
+## String concatenation, valid syntax
+select instr("foobar", "bar" "p2");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar", @bar "p2");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select instr("foobar" AS p1, "bar" AS p2);
+
+# Native function with 3 arguments
+
+select conv(255, 10, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255 AS p1, 10, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255 p1, 10, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255 AS "p1", 10, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255 "p1", 10, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10 AS p2, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10 p2, 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10 AS "p2", 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10 "p2", 16);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10, 16 AS p3);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10, 16 p3);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10, 16 AS "p3");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255, 10, 16 "p3");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select conv(255 AS p1, 10 AS p2, 16 AS p3);
+
+# Native function with a variable number of arguments
+
+select atan(10);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 AS p1);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 p1);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 AS "p1");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 "p1");
+
+select atan(10, 20);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 AS p1, 20);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 p1, 20);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 AS "p1", 20);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 "p1", 20);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10, 20 AS p2);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10, 20 p2);
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10, 20 AS "p2");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10, 20 "p2");
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select atan(10 AS p1, 20 AS p2);
+

mysql-test/t/udf.test

@@ -149,9 +149,9 @@ EXPLAIN EXTENDED SELECT myfunc_int(a AS attr_name) FROM t1;
 EXPLAIN EXTENDED SELECT myfunc_int(a) FROM t1;
 SELECT a,c FROM v1;
 
---error ER_PARSE_ERROR
+--error ER_WRONG_PARAMETERS_TO_STORED_FCT
 SELECT a, fn(MIN(b) xx) as c FROM t1 GROUP BY a;
---error ER_PARSE_ERROR
+--error ER_WRONG_PARAMETERS_TO_STORED_FCT
 SELECT myfunc_int(fn(MIN(b) xx)) as c FROM t1 GROUP BY a;
 --error ER_PARSE_ERROR
 SELECT myfunc_int(test.fn(MIN(b) xx)) as c FROM t1 GROUP BY a;
@@ -173,6 +173,22 @@ DROP FUNCTION fn;
 
 --echo End of 5.0 tests.
 
+#
+# Bug#24736: UDF functions parsed as Stored Functions
+#
+
+select myfunc_double(3);
+select myfunc_double(3 AS three);
+select myfunc_double(abs(3));
+select myfunc_double(abs(3) AS named_param);
+select abs(myfunc_double(3));
+select abs(myfunc_double(3 AS three));
+
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select myfunc_double(abs(3 AS wrong));
+-- error ER_WRONG_PARAMETERS_TO_NATIVE_FCT
+select abs(myfunc_double(3) AS wrong);
+
 #
 # Drop the example functions from udf_example
 #

sql/share/errmsg.txt

@@ -6010,4 +6010,6 @@ ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT 42000
         eng "Incorrect parameter count in the call to native function '%-.64s'"
 ER_WRONG_PARAMETERS_TO_NATIVE_FCT 42000
         eng "Incorrect parameters in the call to native function '%-.64s'"
+ER_WRONG_PARAMETERS_TO_STORED_FCT 42000  
+        eng "Incorrect parameters in the call to stored function '%-.64s'"
 

sql/sql_lex.cc

@@ -164,7 +164,6 @@ void lex_start(THD *thd, const uchar *buf, uint length)
   lex->select_lex.ftfunc_list= &lex->select_lex.ftfunc_list_alloc;
   lex->select_lex.group_list.empty();
   lex->select_lex.order_list.empty();
-  lex->select_lex.udf_list.empty();
   lex->ignore_space=test(thd->variables.sql_mode & MODE_IGNORE_SPACE);
   lex->sql_command= SQLCOM_END;
   lex->duplicates= DUP_ERROR;
@@ -1176,7 +1175,6 @@ void st_select_lex::init_select()
   braces= 0;
   when_list.empty();
   expr_list.empty();
-  udf_list.empty();
   interval_list.empty();
   use_index.empty();
   ftfunc_list_alloc.empty();

sql/sql_lex.h

@@ -609,8 +609,6 @@ public:
   /* exclude this select from check of unique_table() */
   bool exclude_from_table_unique_test;
 
-  List<udf_func>     udf_list;                  /* udf function calls stack */
-
   void init_query();
   void init_select();
   st_select_lex_unit* master_unit();

sql/sql_yacc.yy

@@ -6375,7 +6375,7 @@ function_call_generic:
             }
           }
           /* Temporary placing the result of find_udf in $3 */
-          lex->current_select->udf_list.push_front(udf);
+          $<udf>$= udf;
 #endif
         }
         udf_expr_list ')'
@@ -6403,10 +6403,10 @@ function_call_generic:
           {
 #ifdef HAVE_DLOPEN
             /* Retrieving the result of find_udf */
-            udf_func *udf;
+            udf_func *udf= $<udf>3;
             LEX *lex= Lex;
 
-            if (NULL != (udf= lex->current_select->udf_list.pop()))
+            if (udf)
             {
               if (udf->type == UDFTYPE_AGGREGATE)
               {
@@ -6502,7 +6502,6 @@ udf_expr_list3:
 udf_expr:
 	remember_name expr remember_end select_alias
 	{
-          udf_func *udf= Select->udf_list.head();
           /*
            Use Item::name as a storage for the attribute value of user
            defined function argument. It is safe to use Item::name
@@ -6511,20 +6510,10 @@ udf_expr:
           */
 	  if ($4.str)
           {
-            if (!udf)
-            {
-              /*
-                Disallow using AS to specify explicit names for the arguments
-                of stored routine calls
-              */
-              yyerror(ER(ER_SYNTAX_ERROR));
-              YYABORT;
-            }
-
             $2->is_autogenerated_name= FALSE;
 	    $2->set_name($4.str, $4.length, system_charset_info);
           }
-	  else if (udf)
+	  else
 	    $2->set_name($1, (uint) ($3 - $1), YYTHD->charset());
 	  $$= $2;
 	}