Refactor our checks for valid function and aggregate signatures.

pg_proc.c and pg_aggregate.c had near-duplicate copies of the logic
to decide whether a function or aggregate's signature is legal.
This seems like a bad thing even without the problem that the
upcoming "anycompatible" patch would roughly double the complexity
of that logic.  Hence, refactor so that the rules are localized
in new subroutines supplied by parse_coerce.c.  (One could quibble
about just where to add that code, but putting it beside
enforce_generic_type_consistency seems not totally unreasonable.)

The fact that the rules are about to change would mandate some
changes in the wording of the associated error messages in any case.
I ended up spelling things out in a fairly literal fashion in the
errdetail messages, eg "A result of type anyelement requires at
least one input of type anyelement, anyarray, anynonarray, anyenum,
or anyrange."  Perhaps this is overkill, but once there's more than
one subgroup of polymorphic types, people might get confused by
more-abstract messages.

Discussion: https://postgr.es/m/24137.1584139352@sss.pgh.pa.us

src/backend/catalog/pg_aggregate.c

@@ -93,8 +93,6 @@ AggregateCreate(const char *aggName,
 	Oid			mfinalfn = InvalidOid;	/* can be omitted */
 	Oid			sortop = InvalidOid;	/* can be omitted */
 	Oid		   *aggArgTypes = parameterTypes->values;
-	bool		hasPolyArg;
-	bool		hasInternalArg;
 	bool		mtransIsStrict = false;
 	Oid			rettype;
 	Oid			finaltype;
@@ -103,6 +101,7 @@ AggregateCreate(const char *aggName,
 	int			nargs_finalfn;
 	Oid			procOid;
 	TupleDesc	tupDesc;
+	char	   *detailmsg;
 	int			i;
 	ObjectAddress myself,
 				referenced;
@@ -131,36 +130,33 @@ AggregateCreate(const char *aggName,
 							   FUNC_MAX_ARGS - 1,
 							   FUNC_MAX_ARGS - 1)));
 
-	/* check for polymorphic and INTERNAL arguments */
-	hasPolyArg = false;
-	hasInternalArg = false;
-	for (i = 0; i < numArgs; i++)
-	{
-		if (IsPolymorphicType(aggArgTypes[i]))
-			hasPolyArg = true;
-		else if (aggArgTypes[i] == INTERNALOID)
-			hasInternalArg = true;
-	}
-
 	/*
 	 * If transtype is polymorphic, must have polymorphic argument also; else
 	 * we will have no way to deduce the actual transtype.
 	 */
-	if (IsPolymorphicType(aggTransType) && !hasPolyArg)
+	detailmsg = check_valid_polymorphic_signature(aggTransType,
+												  aggArgTypes,
+												  numArgs);
+	if (detailmsg)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 				 errmsg("cannot determine transition data type"),
-				 errdetail("An aggregate using a polymorphic transition type must have at least one polymorphic argument.")));
+				 errdetail_internal("%s", detailmsg)));
 
 	/*
 	 * Likewise for moving-aggregate transtype, if any
 	 */
-	if (OidIsValid(aggmTransType) &&
-		IsPolymorphicType(aggmTransType) && !hasPolyArg)
+	if (OidIsValid(aggmTransType))
+	{
+		detailmsg = check_valid_polymorphic_signature(aggmTransType,
+													  aggArgTypes,
+													  numArgs);
+		if (detailmsg)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 					 errmsg("cannot determine transition data type"),
-				 errdetail("An aggregate using a polymorphic transition type must have at least one polymorphic argument.")));
+					 errdetail_internal("%s", detailmsg)));
+	}
 
 	/*
 	 * An ordered-set aggregate that is VARIADIC must be VARIADIC ANY.  In
@@ -492,12 +488,14 @@ AggregateCreate(const char *aggName,
 	 * that itself violates the rule against polymorphic result with no
 	 * polymorphic input.)
 	 */
-	if (IsPolymorphicType(finaltype) && !hasPolyArg)
+	detailmsg = check_valid_polymorphic_signature(finaltype,
+												  aggArgTypes,
+												  numArgs);
+	if (detailmsg)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATATYPE_MISMATCH),
 				 errmsg("cannot determine result data type"),
-				 errdetail("An aggregate returning a polymorphic type "
-						   "must have at least one polymorphic argument.")));
+				 errdetail_internal("%s", detailmsg)));
 
 	/*
 	 * Also, the return type can't be INTERNAL unless there's at least one
@@ -505,11 +503,14 @@ AggregateCreate(const char *aggName,
 	 * for regular functions, but at the level of aggregates.  We must test
 	 * this explicitly because we allow INTERNAL as the transtype.
 	 */
-	if (finaltype == INTERNALOID && !hasInternalArg)
+	detailmsg = check_valid_internal_signature(finaltype,
+											   aggArgTypes,
+											   numArgs);
+	if (detailmsg)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 				 errmsg("unsafe use of pseudo-type \"internal\""),
-				 errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
+				 errdetail_internal("%s", detailmsg)));
 
 	/*
 	 * If a moving-aggregate implementation is supplied, look up its finalfn

src/backend/catalog/pg_proc.c

@@ -32,6 +32,7 @@
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "parser/parse_type.h"
 #include "tcop/pquery.h"
 #include "tcop/tcopprot.h"
@@ -97,12 +98,6 @@ ProcedureCreate(const char *procedureName,
 	int			allParamCount;
 	Oid		   *allParams;
 	char	   *paramModes = NULL;
-	bool		genericInParam = false;
-	bool		genericOutParam = false;
-	bool		anyrangeInParam = false;
-	bool		anyrangeOutParam = false;
-	bool		internalInParam = false;
-	bool		internalOutParam = false;
 	Oid			variadicType = InvalidOid;
 	Acl		   *proacl = NULL;
 	Relation	rel;
@@ -116,6 +111,7 @@ ProcedureCreate(const char *procedureName,
 	bool		is_update;
 	ObjectAddress myself,
 				referenced;
+	char	   *detailmsg;
 	int			i;
 	Oid			trfid;
 
@@ -178,29 +174,34 @@ ProcedureCreate(const char *procedureName,
 	}
 
 	/*
-	 * Detect whether we have polymorphic or INTERNAL arguments.  The first
-	 * loop checks input arguments, the second output arguments.
+	 * Do not allow polymorphic return type unless there is a polymorphic
+	 * input argument that we can use to deduce the actual return type.
 	 */
-	for (i = 0; i < parameterCount; i++)
-	{
-		switch (parameterTypes->values[i])
-		{
-			case ANYARRAYOID:
-			case ANYELEMENTOID:
-			case ANYNONARRAYOID:
-			case ANYENUMOID:
-				genericInParam = true;
-				break;
-			case ANYRANGEOID:
-				genericInParam = true;
-				anyrangeInParam = true;
-				break;
-			case INTERNALOID:
-				internalInParam = true;
-				break;
-		}
-	}
+	detailmsg = check_valid_polymorphic_signature(returnType,
+												  parameterTypes->values,
+												  parameterCount);
+	if (detailmsg)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+				 errmsg("cannot determine result data type"),
+				 errdetail_internal("%s", detailmsg)));
 
+	/*
+	 * Also, do not allow return type INTERNAL unless at least one input
+	 * argument is INTERNAL.
+	 */
+	detailmsg = check_valid_internal_signature(returnType,
+											   parameterTypes->values,
+											   parameterCount);
+	if (detailmsg)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+				 errmsg("unsafe use of pseudo-type \"internal\""),
+				 errdetail_internal("%s", detailmsg)));
+
+	/*
+	 * Apply the same tests to any OUT arguments.
+	 */
 	if (allParameterTypes != PointerGetDatum(NULL))
 	{
 		for (i = 0; i < allParamCount; i++)
@@ -210,52 +211,26 @@ ProcedureCreate(const char *procedureName,
 				paramModes[i] == PROARGMODE_VARIADIC)
 				continue;		/* ignore input-only params */
 
-			switch (allParams[i])
-			{
-				case ANYARRAYOID:
-				case ANYELEMENTOID:
-				case ANYNONARRAYOID:
-				case ANYENUMOID:
-					genericOutParam = true;
-					break;
-				case ANYRANGEOID:
-					genericOutParam = true;
-					anyrangeOutParam = true;
-					break;
-				case INTERNALOID:
-					internalOutParam = true;
-					break;
-			}
-		}
-	}
-
-	/*
-	 * Do not allow polymorphic return type unless at least one input argument
-	 * is polymorphic.  ANYRANGE return type is even stricter: must have an
-	 * ANYRANGE input (since we can't deduce the specific range type from
-	 * ANYELEMENT).  Also, do not allow return type INTERNAL unless at least
-	 * one input argument is INTERNAL.
-	 */
-	if ((IsPolymorphicType(returnType) || genericOutParam)
-		&& !genericInParam)
+			detailmsg = check_valid_polymorphic_signature(allParams[i],
+														  parameterTypes->values,
+														  parameterCount);
+			if (detailmsg)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 						 errmsg("cannot determine result data type"),
-				 errdetail("A function returning a polymorphic type must have at least one polymorphic argument.")));
-
-	if ((returnType == ANYRANGEOID || anyrangeOutParam) &&
-		!anyrangeInParam)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-				 errmsg("cannot determine result data type"),
-				 errdetail("A function returning \"anyrange\" must have at least one \"anyrange\" argument.")));
-
-	if ((returnType == INTERNALOID || internalOutParam) && !internalInParam)
+						 errdetail_internal("%s", detailmsg)));
+			detailmsg = check_valid_internal_signature(allParams[i],
+													   parameterTypes->values,
+													   parameterCount);
+			if (detailmsg)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
 						 errmsg("unsafe use of pseudo-type \"internal\""),
-				 errdetail("A function returning \"internal\" must have at least one \"internal\" argument.")));
+						 errdetail_internal("%s", detailmsg)));
+		}
+	}
 
+	/* Identify variadic argument type, if any */
 	if (paramModes != NULL)
 	{
 		/*

src/backend/parser/parse_coerce.c

@@ -1971,6 +1971,77 @@ enforce_generic_type_consistency(const Oid *actual_arg_types,
 	return rettype;
 }
 
+/*
+ * check_valid_polymorphic_signature()
+ *		Is a proposed function signature valid per polymorphism rules?
+ *
+ * Returns NULL if the signature is valid (either ret_type is not polymorphic,
+ * or it can be deduced from the given declared argument types).  Otherwise,
+ * returns a palloc'd, already translated errdetail string saying why not.
+ */
+char *
+check_valid_polymorphic_signature(Oid ret_type,
+								  const Oid *declared_arg_types,
+								  int nargs)
+{
+	if (ret_type == ANYRANGEOID)
+	{
+		/*
+		 * ANYRANGE requires an ANYRANGE input, else we can't tell which of
+		 * several range types with the same element type to use.
+		 */
+		for (int i = 0; i < nargs; i++)
+		{
+			if (declared_arg_types[i] == ret_type)
+				return NULL;	/* OK */
+		}
+		return psprintf(_("A result of type %s requires at least one input of type %s."),
+						format_type_be(ret_type), format_type_be(ret_type));
+	}
+	else if (IsPolymorphicType(ret_type))
+	{
+		/* Otherwise, any polymorphic type can be deduced from any other */
+		for (int i = 0; i < nargs; i++)
+		{
+			if (IsPolymorphicType(declared_arg_types[i]))
+				return NULL;	/* OK */
+		}
+		return psprintf(_("A result of type %s requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange."),
+						format_type_be(ret_type));
+	}
+	else
+		return NULL;			/* OK, ret_type is not polymorphic */
+}
+
+/*
+ * check_valid_internal_signature()
+ *		Is a proposed function signature valid per INTERNAL safety rules?
+ *
+ * Returns NULL if OK, or a suitable error message if ret_type is INTERNAL but
+ * none of the declared arg types are.  (It's unsafe to create such a function
+ * since it would allow invocation of INTERNAL-consuming functions directly
+ * from SQL.)  It's overkill to return the error detail message, since there
+ * is only one possibility, but we do it like this to keep the API similar to
+ * check_valid_polymorphic_signature().
+ */
+char *
+check_valid_internal_signature(Oid ret_type,
+							   const Oid *declared_arg_types,
+							   int nargs)
+{
+	if (ret_type == INTERNALOID)
+	{
+		for (int i = 0; i < nargs; i++)
+		{
+			if (declared_arg_types[i] == ret_type)
+				return NULL;	/* OK */
+		}
+		return pstrdup(_("A result of type internal requires at least one input of type internal."));
+	}
+	else
+		return NULL;			/* OK, ret_type is not INTERNAL */
+}
+
 
 /* TypeCategory()
  *		Assign a category to the specified type OID.

src/include/parser/parse_coerce.h

@@ -80,6 +80,13 @@ extern Oid	enforce_generic_type_consistency(const Oid *actual_arg_types,
 											 Oid rettype,
 											 bool allow_poly);
 
+extern char *check_valid_polymorphic_signature(Oid ret_type,
+											   const Oid *declared_arg_types,
+											   int nargs);
+extern char *check_valid_internal_signature(Oid ret_type,
+											const Oid *declared_arg_types,
+											int nargs);
+
 extern CoercionPathType find_coercion_pathway(Oid targetTypeId,
 											  Oid sourceTypeId,
 											  CoercionContext ccontext,

src/test/regress/expected/plpgsql.out

@@ -1811,7 +1811,7 @@ begin
   return array[x + 1, x + 2];
 end$$ language plpgsql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 create function f1(x anyrange) returns anyarray as $$
 begin
   return array[lower(x), upper(x)];

src/test/regress/expected/polymorphism.out

@@ -61,7 +61,7 @@ create function polyf(x anyelement) returns anyrange as $$
   select array[x + 1, x + 2]
 $$ language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 create function polyf(x anyrange) returns anyarray as $$
   select array[lower(x), upper(x)]
 $$ language sql;
@@ -155,7 +155,7 @@ CREATE AGGREGATE myaggp01a(*) (SFUNC = stfnp, STYPE = int4[],
 CREATE AGGREGATE myaggp02a(*) (SFUNC = stfnp, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --     N    P
 -- should CREATE
 CREATE AGGREGATE myaggp03a(*) (SFUNC = stfp, STYPE = int4[],
@@ -167,11 +167,11 @@ CREATE AGGREGATE myaggp03b(*) (SFUNC = stfp, STYPE = int4[],
 CREATE AGGREGATE myaggp04a(*) (SFUNC = stfp, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggp04b(*) (SFUNC = stfp, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    Case2 (R = P) && ((B = P) || (B = N))
 --    -------------------------------------
 --    S    tf1      B    tf2
@@ -226,13 +226,13 @@ ERROR:  function tfp(integer[], anyelement) does not exist
 CREATE AGGREGATE myaggp13a(BASETYPE = int, SFUNC = tfnp, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    N        N    P
 -- should ERROR: tf2p(anyarray, int) not matched by tf2p(int[],anyelement)
 CREATE AGGREGATE myaggp14a(BASETYPE = int, SFUNC = tf2p, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    N        P    N
 -- should ERROR: tfnp(anyarray, anyelement) not matched by tfnp(int[],int)
 CREATE AGGREGATE myaggp15a(BASETYPE = anyelement, SFUNC = tfnp,
@@ -248,21 +248,21 @@ ERROR:  function tf2p(anyarray, anyelement) does not exist
 CREATE AGGREGATE myaggp17a(BASETYPE = int, SFUNC = tf1p, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggp17b(BASETYPE = int, SFUNC = tf1p, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    P        N    P
 -- should ERROR: tfp(anyarray, int) not matched by tfp(anyarray, anyelement)
 CREATE AGGREGATE myaggp18a(BASETYPE = int, SFUNC = tfp, STYPE = anyarray,
   FINALFUNC = ffp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggp18b(BASETYPE = int, SFUNC = tfp, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    P        P    N
 -- should ERROR: tf1p(anyarray, anyelement) not matched by tf1p(anyarray, int)
 CREATE AGGREGATE myaggp19a(BASETYPE = anyelement, SFUNC = tf1p,
@@ -292,11 +292,11 @@ CREATE AGGREGATE myaggn01b(*) (SFUNC = stfnp, STYPE = int4[],
 CREATE AGGREGATE myaggn02a(*) (SFUNC = stfnp, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggn02b(*) (SFUNC = stfnp, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --     N    P
 -- should CREATE
 CREATE AGGREGATE myaggn03a(*) (SFUNC = stfp, STYPE = int4[],
@@ -306,7 +306,7 @@ CREATE AGGREGATE myaggn03a(*) (SFUNC = stfp, STYPE = int4[],
 CREATE AGGREGATE myaggn04a(*) (SFUNC = stfp, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    Case4 (R = N) && ((B = P) || (B = N))
 --    -------------------------------------
 --    S    tf1      B    tf2
@@ -360,21 +360,21 @@ ERROR:  function tfp(integer[], anyelement) does not exist
 CREATE AGGREGATE myaggn13a(BASETYPE = int, SFUNC = tfnp, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggn13b(BASETYPE = int, SFUNC = tfnp, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    N        N    P
 -- should ERROR: tf2p(anyarray, int) not matched by tf2p(int[],anyelement)
 CREATE AGGREGATE myaggn14a(BASETYPE = int, SFUNC = tf2p, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 CREATE AGGREGATE myaggn14b(BASETYPE = int, SFUNC = tf2p, STYPE = anyarray,
   INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    N        P    N
 -- should ERROR: tfnp(anyarray, anyelement) not matched by tfnp(int[],int)
 CREATE AGGREGATE myaggn15a(BASETYPE = anyelement, SFUNC = tfnp,
@@ -396,13 +396,13 @@ ERROR:  function tf2p(anyarray, anyelement) does not exist
 CREATE AGGREGATE myaggn17a(BASETYPE = int, SFUNC = tf1p, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    P        N    P
 -- should ERROR: tfp(anyarray, int) not matched by tfp(anyarray, anyelement)
 CREATE AGGREGATE myaggn18a(BASETYPE = int, SFUNC = tfp, STYPE = anyarray,
   FINALFUNC = ffnp, INITCOND = '{}');
 ERROR:  cannot determine transition data type
-DETAIL:  An aggregate using a polymorphic transition type must have at least one polymorphic argument.
+DETAIL:  A result of type anyarray requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --    P    P        P    N
 -- should ERROR: tf1p(anyarray, anyelement) not matched by tf1p(anyarray, int)
 CREATE AGGREGATE myaggn19a(BASETYPE = anyelement, SFUNC = tf1p,

src/test/regress/expected/rangefuncs.out

@@ -1556,7 +1556,7 @@ DROP FUNCTION dup(anyelement);
 CREATE FUNCTION bad (f1 int, out f2 anyelement, out f3 anyarray)
 AS 'select $1, array[$1,$1]' LANGUAGE sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning a polymorphic type must have at least one polymorphic argument.
+DETAIL:  A result of type anyelement requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange.
 --
 -- table functions
 --

src/test/regress/expected/rangetypes.out

@@ -1371,12 +1371,12 @@ drop function anyarray_anyrange_func(anyarray, anyrange);
 create function bogus_func(anyelement)
   returns anyrange as 'select int4range(1,10)' language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 -- should fail
 create function bogus_func(int)
   returns anyrange as 'select int4range(1,10)' language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning a polymorphic type must have at least one polymorphic argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 create function range_add_bounds(anyrange)
   returns anyelement as 'select lower($1) + upper($1)' language sql;
 select range_add_bounds(int4range(1, 17));
@@ -1521,14 +1521,14 @@ select * from table_succeed(int4range(1,11));
 create function outparam_fail(i anyelement, out r anyrange, out t text)
   as $$ select '[1,10]', 'foo' $$ language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 --should fail
 create function inoutparam_fail(inout i anyelement, out r anyrange)
   as $$ select $1, '[1,10]' $$ language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.
 --should fail
 create function table_fail(i anyelement) returns table(i anyelement, r anyrange)
   as $$ select $1, '[1,10]' $$ language sql;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning "anyrange" must have at least one "anyrange" argument.
+DETAIL:  A result of type anyrange requires at least one input of type anyrange.