Add prokind column, replacing proisagg and proiswindow

The new column distinguishes normal functions, procedures, aggregates,
and window functions.  This replaces the existing columns proisagg and
proiswindow, and replaces the convention that procedures are indicated
by prorettype == 0.  Also change prorettype to be VOIDOID for procedures.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Michael Paquier <michael@paquier.xyz>

1 files changed, 18 insertions, 21 deletions

diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index 7e249f575f3..78bc4ab34bd 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -573,8 +573,7 @@ init_execution_state(List *queryTree_list,
 	 *
 	 * Note: don't set setsResult if the function returns VOID, as evidenced
 	 * by not having made a junkfilter.  This ensures we'll throw away any
-	 * output from a utility statement that check_sql_fn_retval deemed to not
-	 * have output.
+	 * output from the last statement in such a function.
 	 */
 	if (lasttages && fcache->junkFilter)
 	{
@@ -659,8 +658,7 @@ init_sql_fcache(FmgrInfo *finfo, Oid collation, bool lazyEvalOK)
 	fcache->rettype = rettype;
 
 	/* Fetch the typlen and byval info for the result type */
-	if (rettype)
-		get_typlenbyval(rettype, &fcache->typlen, &fcache->typbyval);
+	get_typlenbyval(rettype, &fcache->typlen, &fcache->typbyval);
 
 	/* Remember whether we're returning setof something */
 	fcache->returnsSet = procedureStruct->proretset;
@@ -1324,8 +1322,8 @@ fmgr_sql(PG_FUNCTION_ARGS)
 		}
 		else
 		{
-			/* Should only get here for procedures and VOID functions */
-			Assert(fcache->rettype == InvalidOid || fcache->rettype == VOIDOID);
+			/* Should only get here for VOID functions and procedures */
+			Assert(fcache->rettype == VOIDOID);
 			fcinfo->isnull = true;
 			result = (Datum) 0;
 		}
@@ -1549,9 +1547,13 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList,
 	if (modifyTargetList)
 		*modifyTargetList = false;	/* initialize for no change */
 	if (junkFilter)
-		*junkFilter = NULL;		/* initialize in case of procedure/VOID result */
+		*junkFilter = NULL;		/* initialize in case of VOID result */
 
-	if (!rettype)
+	/*
+	 * If it's declared to return VOID, we don't care what's in the function.
+	 * (This takes care of the procedure case, as well.)
+	 */
+	if (rettype == VOIDOID)
 		return false;
 
 	/*
@@ -1597,21 +1599,17 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList,
 	else
 	{
 		/* Empty function body, or last statement is a utility command */
-		if (rettype && rettype != VOIDOID)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-					 errmsg("return type mismatch in function declared to return %s",
-							format_type_be(rettype)),
-					 errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE RETURNING.")));
-		return false;
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+				 errmsg("return type mismatch in function declared to return %s",
+						format_type_be(rettype)),
+				 errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE RETURNING.")));
+		return false;			/* keep compiler quiet */
 	}
 
 	/*
 	 * OK, check that the targetlist returns something matching the declared
-	 * type.  (We used to insist that the declared type not be VOID in this
-	 * case, but that makes it hard to write a void function that exits after
-	 * calling another void function.  Instead, we insist that the tlist
-	 * return void ... so void is treated as if it were a scalar type below.)
+	 * type.
 	 */
 
 	/*
@@ -1624,8 +1622,7 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList,
 	if (fn_typtype == TYPTYPE_BASE ||
 		fn_typtype == TYPTYPE_DOMAIN ||
 		fn_typtype == TYPTYPE_ENUM ||
-		fn_typtype == TYPTYPE_RANGE ||
-		rettype == VOIDOID)
+		fn_typtype == TYPTYPE_RANGE)
 	{
 		/*
 		 * For scalar-type returns, the target list must have exactly one