SQL procedures

This adds a new object type "procedure" that is similar to a function
but does not have a return type and is invoked by the new CALL statement
instead of SELECT or similar.  This implementation is aligned with the
SQL standard and compatible with or similar to other SQL implementations.

This commit adds new commands CALL, CREATE/ALTER/DROP PROCEDURE, as well
as ALTER/DROP ROUTINE that can refer to either a function or a
procedure (or an aggregate function, as an extension to SQL).  There is
also support for procedures in various utility commands such as COMMENT
and GRANT, as well as support in pg_dump and psql.  Support for defining
procedures is available in all the languages supplied by the core
distribution.

While this commit is mainly syntax sugar around existing functionality,
future features will rely on having procedures as a separate object
type.

Reviewed-by: Andrew Dunstan <[email protected]>

1 files changed, 9 insertions, 4 deletions

diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 6d97ddc99bd..e0792d93e1c 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -146,6 +146,7 @@ typedef struct pltcl_proc_desc
 	Oid			result_typid;	/* OID of fn's result type */
 	FmgrInfo	result_in_func; /* input function for fn's result type */
 	Oid			result_typioparam;	/* param to pass to same */
+	bool		fn_is_procedure;/* true if this is a procedure */
 	bool		fn_retisset;	/* true if function returns a set */
 	bool		fn_retistuple;	/* true if function returns composite */
 	bool		fn_retisdomain; /* true if function returns domain */
@@ -968,7 +969,7 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 		retval = (Datum) 0;
 		fcinfo->isnull = true;
 	}
-	else if (fcinfo->isnull)
+	else if (fcinfo->isnull && !prodesc->fn_is_procedure)
 	{
 		retval = InputFunctionCall(&prodesc->result_in_func,
 								   NULL,
@@ -1026,11 +1027,13 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
 									   call_state);
 		retval = HeapTupleGetDatum(tup);
 	}
-	else
+	else if (!prodesc->fn_is_procedure)
 		retval = InputFunctionCall(&prodesc->result_in_func,
 								   utf_u2e(Tcl_GetStringResult(interp)),
 								   prodesc->result_typioparam,
 								   -1);
+	else
+		retval = 0;
 
 	return retval;
 }
@@ -1506,7 +1509,9 @@ compile_pltcl_function(Oid fn_oid, Oid tgreloid,
 		 * Get the required information for input conversion of the
 		 * return value.
 		 ************************************************************/
-		if (!is_trigger && !is_event_trigger)
+		prodesc->fn_is_procedure = (procStruct->prorettype == InvalidOid);
+
+		if (!is_trigger && !is_event_trigger && procStruct->prorettype)
 		{
 			Oid			rettype = procStruct->prorettype;
 
@@ -2199,7 +2204,7 @@ pltcl_returnnext(ClientData cdata, Tcl_Interp *interp,
 				tuplestore_puttuple(call_state->tuple_store, tuple);
 			}
 		}
-		else
+		else if (!prodesc->fn_is_procedure)
 		{
 			Datum		retval;
 			bool		isNull = false;