try to cast constant input string to target type

Author: okbob

expected/plpgsql_check_active.out

@@ -1715,11 +1715,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      7 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      7 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 create or replace function foreach_array_loop()
 returns void as
@@ -1771,11 +1770,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      5 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      5 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 drop function foreach_array_loop();
 create or replace function scan_rows(int[]) returns void AS $$

expected/plpgsql_check_active_2.out

@@ -1715,11 +1715,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      7 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      7 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 create or replace function foreach_array_loop()
 returns void as
@@ -1771,11 +1770,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      5 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      5 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 drop function foreach_array_loop();
 create or replace function scan_rows(int[]) returns void AS $$

expected/plpgsql_check_active_3.out

@@ -1715,11 +1715,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      7 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      7 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 create or replace function foreach_array_loop()
 returns void as
@@ -1771,11 +1770,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      5 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      5 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 drop function foreach_array_loop();
 create or replace function scan_rows(int[]) returns void AS $$

expected/plpgsql_check_active_4.out

@@ -1715,11 +1715,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      7 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      7 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 create or replace function foreach_array_loop()
 returns void as
@@ -1771,11 +1770,10 @@ end;
 $body$
 language 'plpgsql' stable;
 select * from plpgsql_check_function_tb('foreach_array_loop()', performance_warnings := true);
-     functionid     | lineno |     statement      | sqlstate |                     message                      |               detail                |                                       hint                                        |    level    | position | query |        context        
---------------------+--------+--------------------+----------+--------------------------------------------------+-------------------------------------+-----------------------------------------------------------------------------------+-------------+----------+-------+-----------------------
- foreach_array_loop |      5 | FOREACH over array | 42804    | target type is different type than source type   | cast "date" value to "integer" type | There are no possible explicit coercion between those types, possibly bug!        | warning     |          |       | at FOREACH over array
- foreach_array_loop |        |                    | 00000    | routine is marked as STABLE, should be IMMUTABLE |                                     | When you fix this issue, please, recheck other functions that uses this function. | performance |          |       | 
-(2 rows)
+     functionid     | lineno |     statement      | sqlstate |                       message                       | detail | hint | level | position | query | context 
+--------------------+--------+--------------------+----------+-----------------------------------------------------+--------+------+-------+----------+-------+---------
+ foreach_array_loop |      5 | FOREACH over array | 22P02    | invalid input syntax for type integer: "01-01-2014" |        |      | error |          |       | 
+(1 row)
 
 drop function foreach_array_loop();
 create or replace function scan_rows(int[]) returns void AS $$

src/check_expr.c

@@ -1282,6 +1282,28 @@ plpgsql_check_expr_as_rvalue(PLpgSQL_checkstate *cstate, PLpgSQL_expr *expr,
 
 			node = plpgsql_check_expr_get_node(cstate, expr, false);
 
+			if (node && exprType((Node *) node) != expected_typoid)
+			{
+				char	   *str;
+
+				/* When expr is constant string, try it cast to target type */
+				str = plpgsql_check_get_const_string(cstate, node, NULL);
+
+				if (str)
+				{
+					Oid		infunc;
+					Oid		intypeioparam;
+					Oid		typeid;
+
+					typeid = use_element_type ? get_array_type(expected_typoid) : expected_typoid;
+
+					getTypeInputInfo(typeid, &infunc, &intypeioparam);
+					(void) OidInputFunctionCall(infunc, str, intypeioparam, -1);
+
+					pfree(str);
+				}
+			}
+
 			if (bms_is_member(target_dno, expr->paramnos))
 			{
 				/*