Support named and default arguments in CALL

We need to call expand_function_arguments() to expand named and default
arguments.

In PL/pgSQL, we also need to deal with named and default INOUT arguments
when receiving the output values into variables.

Author: Pavel Stehule <pavel.stehule@gmail.com>

src/backend/commands/functioncmds.c

@@ -52,6 +52,7 @@
 #include "executor/execdesc.h"
 #include "executor/executor.h"
 #include "miscadmin.h"
+#include "optimizer/clauses.h"
 #include "optimizer/var.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_collate.h"
@@ -2226,34 +2227,40 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params, bool atomic, DestReceiver
 	if (aclresult != ACLCHECK_OK)
 		aclcheck_error(aclresult, OBJECT_PROCEDURE, get_func_name(fexpr->funcid));
 
-	nargs = list_length(fexpr->args);
-
-	/* safety check; see ExecInitFunc() */
-	if (nargs > FUNC_MAX_ARGS)
-		ereport(ERROR,
-				(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
-				 errmsg_plural("cannot pass more than %d argument to a procedure",
-							   "cannot pass more than %d arguments to a procedure",
-							   FUNC_MAX_ARGS,
-							   FUNC_MAX_ARGS)));
-
 	/* Prep the context object we'll pass to the procedure */
 	callcontext = makeNode(CallContext);
 	callcontext->atomic = atomic;
 
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
+
 	/*
 	 * If proconfig is set we can't allow transaction commands because of the
 	 * way the GUC stacking works: The transaction boundary would have to pop
 	 * the proconfig setting off the stack.  That restriction could be lifted
 	 * by redesigning the GUC nesting mechanism a bit.
 	 */
-	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(fexpr->funcid));
-	if (!HeapTupleIsValid(tp))
-		elog(ERROR, "cache lookup failed for function %u", fexpr->funcid);
 	if (!heap_attisnull(tp, Anum_pg_proc_proconfig, NULL))
 		callcontext->atomic = true;
+
+	/*
+	 * Expand named arguments, defaults, etc.
+	 */
+	fexpr->args = expand_function_arguments(fexpr->args, fexpr->funcresulttype, tp);
+	nargs = list_length(fexpr->args);
+
 	ReleaseSysCache(tp);
 
+	/* safety check; see ExecInitFunc() */
+	if (nargs > FUNC_MAX_ARGS)
+		ereport(ERROR,
+				(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
+				 errmsg_plural("cannot pass more than %d argument to a procedure",
+							   "cannot pass more than %d arguments to a procedure",
+							   FUNC_MAX_ARGS,
+							   FUNC_MAX_ARGS)));
+
 	/* Initialize function call structure */
 	InvokeFunctionExecuteHook(fexpr->funcid);
 	fmgr_info(fexpr->funcid, &flinfo);

src/backend/optimizer/util/clauses.c

@@ -130,8 +130,6 @@ static Expr *simplify_function(Oid funcid,
 				  Oid result_collid, Oid input_collid, List **args_p,
 				  bool funcvariadic, bool process_args, bool allow_non_const,
 				  eval_const_expressions_context *context);
-static List *expand_function_arguments(List *args, Oid result_type,
-						  HeapTuple func_tuple);
 static List *reorder_function_arguments(List *args, HeapTuple func_tuple);
 static List *add_function_defaults(List *args, HeapTuple func_tuple);
 static List *fetch_function_defaults(HeapTuple func_tuple);
@@ -4112,7 +4110,7 @@ simplify_function(Oid funcid, Oid result_type, int32 result_typmod,
  * cases it handles should never occur there.  This should be OK since it
  * will fall through very quickly if there's nothing to do.
  */
-static List *
+List *
 expand_function_arguments(List *args, Oid result_type, HeapTuple func_tuple)
 {
 	Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple);

src/include/optimizer/clauses.h

@@ -14,9 +14,9 @@
 #ifndef CLAUSES_H
 #define CLAUSES_H
 
+#include "access/htup.h"
 #include "nodes/relation.h"
 
-
 #define is_opclause(clause)		((clause) != NULL && IsA(clause, OpExpr))
 #define is_funcclause(clause)	((clause) != NULL && IsA(clause, FuncExpr))
 
@@ -85,4 +85,7 @@ extern Node *estimate_expression_value(PlannerInfo *root, Node *node);
 extern Query *inline_set_returning_function(PlannerInfo *root,
 							  RangeTblEntry *rte);
 
+extern List *expand_function_arguments(List *args, Oid result_type,
+						  HeapTuple func_tuple);
+
 #endif							/* CLAUSES_H */

src/pl/plpgsql/src/expected/plpgsql_call.out

@@ -152,6 +152,93 @@ CALL test_proc7(100, -1, -1);
  0 | 1
 (1 row)
 
+-- named parameters and defaults
+CREATE PROCEDURE test_proc8a(INOUT a int, INOUT b int)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %', a, b;
+  a := a * 10;
+  b := b + 10;
+END;
+$$;
+CALL test_proc8a(10, 20);
+NOTICE:  a: 10, b: 20
+  a  | b  
+-----+----
+ 100 | 30
+(1 row)
+
+CALL test_proc8a(b => 20, a => 10);
+NOTICE:  a: 10, b: 20
+  a  | b  
+-----+----
+ 100 | 30
+(1 row)
+
+DO $$
+DECLARE _a int; _b int;
+BEGIN
+  _a := 10; _b := 30;
+  CALL test_proc8a(_a, _b);
+  RAISE NOTICE '_a: %, _b: %', _a, _b;
+  CALL test_proc8a(b => _b, a => _a);
+  RAISE NOTICE '_a: %, _b: %', _a, _b;
+END
+$$;
+NOTICE:  a: 10, b: 30
+NOTICE:  _a: 100, _b: 40
+NOTICE:  a: 100, b: 40
+NOTICE:  _a: 1000, _b: 50
+CREATE PROCEDURE test_proc8b(INOUT a int, INOUT b int, INOUT c int)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %, c: %', a, b, c;
+  a := a * 10;
+  b := b + 10;
+  c := c * -10;
+END;
+$$;
+DO $$
+DECLARE _a int; _b int; _c int;
+BEGIN
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8b(_a, _b, _c);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+  CALL test_proc8b(_a, c => _c, b => _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+END
+$$;
+NOTICE:  a: 10, b: 30, c: 50
+NOTICE:  _a: 100, _b: 40, _c: -500
+NOTICE:  a: 100, b: 40, c: -500
+NOTICE:  _a: 1000, _b: 50, _c: 5000
+CREATE PROCEDURE test_proc8c(INOUT a int, INOUT b int, INOUT c int DEFAULT 11)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %, c: %', a, b, c;
+  a := a * 10;
+  b := b + 10;
+  c := c * -10;
+END;
+$$;
+DO $$
+DECLARE _a int; _b int; _c int;
+BEGIN
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8c(_a, _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8c(_a, b => _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+END
+$$;
+NOTICE:  a: 10, b: 30, c: 11
+NOTICE:  _a: 100, _b: 40, _c: 50
+NOTICE:  a: 10, b: 30, c: 11
+NOTICE:  _a: 100, _b: 40, _c: 50
 -- transition variable assignment
 TRUNCATE test1;
 CREATE FUNCTION triggerfunc1() RETURNS trigger

src/pl/plpgsql/src/pl_exec.c

@@ -2146,7 +2146,6 @@ exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt)
 			FuncExpr   *funcexpr;
 			int			i;
 			HeapTuple	tuple;
-			int			numargs PG_USED_FOR_ASSERTS_ONLY;
 			Oid		   *argtypes;
 			char	  **argnames;
 			char	   *argmodes;
@@ -2169,11 +2168,9 @@ exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt)
 			tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcexpr->funcid));
 			if (!HeapTupleIsValid(tuple))
 				elog(ERROR, "cache lookup failed for function %u", funcexpr->funcid);
-			numargs = get_func_arg_info(tuple, &argtypes, &argnames, &argmodes);
+			get_func_arg_info(tuple, &argtypes, &argnames, &argmodes);
 			ReleaseSysCache(tuple);
 
-			Assert(numargs == list_length(funcexpr->args));
-
 			/*
 			 * Construct row
 			 */
@@ -2192,16 +2189,36 @@ exec_stmt_call(PLpgSQL_execstate *estate, PLpgSQL_stmt_call *stmt)
 
 				if (argmodes && argmodes[i] == PROARGMODE_INOUT)
 				{
-					Param	   *param;
+					if (IsA(n, Param))
+					{
+						Param	   *param = castNode(Param, n);
+
+						/* paramid is offset by 1 (see make_datum_param()) */
+						row->varnos[nfields++] = param->paramid - 1;
+					}
+					else if (IsA(n, NamedArgExpr))
+					{
+						NamedArgExpr *nexpr = castNode(NamedArgExpr, n);
+						Param	   *param;
+
+						if (!IsA(nexpr->arg, Param))
+							ereport(ERROR,
+									(errcode(ERRCODE_SYNTAX_ERROR),
+									 errmsg("argument %d is an output argument but is not writable", i + 1)));
 
-					if (!IsA(n, Param))
+						param = castNode(Param, nexpr->arg);
+
+						/*
+						 * Named arguments must be after positional arguments,
+						 * so we can increase nfields.
+						 */
+						row->varnos[nexpr->argnumber] = param->paramid - 1;
+						nfields++;
+					}
+					else
 						ereport(ERROR,
 								(errcode(ERRCODE_SYNTAX_ERROR),
 								 errmsg("argument %d is an output argument but is not writable", i + 1)));
-
-					param = castNode(Param, n);
-					/* paramid is offset by 1 (see make_datum_param()) */
-					row->varnos[nfields++] = param->paramid - 1;
 				}
 				i++;
 			}

src/pl/plpgsql/src/sql/plpgsql_call.sql

@@ -142,6 +142,80 @@ $$;
 CALL test_proc7(100, -1, -1);
 
 
+-- named parameters and defaults
+
+CREATE PROCEDURE test_proc8a(INOUT a int, INOUT b int)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %', a, b;
+  a := a * 10;
+  b := b + 10;
+END;
+$$;
+
+CALL test_proc8a(10, 20);
+CALL test_proc8a(b => 20, a => 10);
+
+DO $$
+DECLARE _a int; _b int;
+BEGIN
+  _a := 10; _b := 30;
+  CALL test_proc8a(_a, _b);
+  RAISE NOTICE '_a: %, _b: %', _a, _b;
+  CALL test_proc8a(b => _b, a => _a);
+  RAISE NOTICE '_a: %, _b: %', _a, _b;
+END
+$$;
+
+
+CREATE PROCEDURE test_proc8b(INOUT a int, INOUT b int, INOUT c int)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %, c: %', a, b, c;
+  a := a * 10;
+  b := b + 10;
+  c := c * -10;
+END;
+$$;
+
+DO $$
+DECLARE _a int; _b int; _c int;
+BEGIN
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8b(_a, _b, _c);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+  CALL test_proc8b(_a, c => _c, b => _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+END
+$$;
+
+
+CREATE PROCEDURE test_proc8c(INOUT a int, INOUT b int, INOUT c int DEFAULT 11)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  RAISE NOTICE 'a: %, b: %, c: %', a, b, c;
+  a := a * 10;
+  b := b + 10;
+  c := c * -10;
+END;
+$$;
+
+DO $$
+DECLARE _a int; _b int; _c int;
+BEGIN
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8c(_a, _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+  _a := 10; _b := 30; _c := 50;
+  CALL test_proc8c(_a, b => _b);
+  RAISE NOTICE '_a: %, _b: %, _c: %', _a, _b, _c;
+END
+$$;
+
+
 -- transition variable assignment
 
 TRUNCATE test1;

src/test/regress/expected/create_procedure.out

@@ -91,6 +91,31 @@ $$;
 ERROR:  calling procedures with output arguments is not supported in SQL functions
 CONTEXT:  SQL function "ptest4b"
 DROP PROCEDURE ptest4a;
+-- named and default parameters
+CREATE OR REPLACE PROCEDURE ptest5(a int, b text, c int default 100)
+LANGUAGE SQL
+AS $$
+INSERT INTO cp_test VALUES(a, b);
+INSERT INTO cp_test VALUES(c, b);
+$$;
+TRUNCATE cp_test;
+CALL ptest5(10, 'Hello', 20);
+CALL ptest5(10, 'Hello');
+CALL ptest5(10, b => 'Hello');
+CALL ptest5(b => 'Hello', a => 10);
+SELECT * FROM cp_test;
+  a  |   b   
+-----+-------
+  10 | Hello
+  20 | Hello
+  10 | Hello
+ 100 | Hello
+  10 | Hello
+ 100 | Hello
+  10 | Hello
+ 100 | Hello
+(8 rows)
+
 -- various error cases
 CALL version();  -- error: not a procedure
 ERROR:  version() is not a procedure

src/test/regress/sql/create_procedure.sql

@@ -65,6 +65,25 @@ $$;
 DROP PROCEDURE ptest4a;
 
 
+-- named and default parameters
+
+CREATE OR REPLACE PROCEDURE ptest5(a int, b text, c int default 100)
+LANGUAGE SQL
+AS $$
+INSERT INTO cp_test VALUES(a, b);
+INSERT INTO cp_test VALUES(c, b);
+$$;
+
+TRUNCATE cp_test;
+
+CALL ptest5(10, 'Hello', 20);
+CALL ptest5(10, 'Hello');
+CALL ptest5(10, b => 'Hello');
+CALL ptest5(b => 'Hello', a => 10);
+
+SELECT * FROM cp_test;
+
+
 -- various error cases
 
 CALL version();  -- error: not a procedure