Don't try to constant-fold functions returning RECORD. We were never

tglsfdc · tglsfdc · commit ae9a07bf9e34 · 2005-07-03T21:14:18.000Z
able to do this before, but I had tried to make an exception for functions
with OUT parameters.  Michael Fuhr found one problem with it already, and
I found another, which was it didn't work for strict functions with a
NULL input.  While both of these could be worked around, the probability
that there are more gotchas seems high; I think prudence dictates just
reverting to the former behavior for now.  Accordingly, remove the kluge
added to get_expr_result_type() for Michael's case.
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.199 2005/06/26 22:05:38 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.200 2005/07/03 21:14:17 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -2200,13 +2200,17 @@ evaluate_function(Oid funcid, Oid result_type, List *args,
 		return NULL;
 
 	/*
-	 * Can't simplify if it returns RECORD, except in the case where it has
-	 * OUT parameters, since it will be needing an expected tupdesc which we
-	 * can't supply here.
+	 * Can't simplify if it returns RECORD.  The immediate problem is that
+	 * it will be needing an expected tupdesc which we can't supply here.
+	 *
+	 * In the case where it has OUT parameters, it could get by without an
+	 * expected tupdesc, but we still have issues: get_expr_result_type()
+	 * doesn't know how to extract type info from a RECORD constant, and
+	 * in the case of a NULL function result there doesn't seem to be any
+	 * clean way to fix that.  In view of the likelihood of there being
+	 * still other gotchas, seems best to leave the function call unreduced.
 	 */
-	if (funcform->prorettype == RECORDOID &&
-		(heap_attisnull(func_tuple, Anum_pg_proc_proallargtypes) ||
-		 heap_attisnull(func_tuple, Anum_pg_proc_proargmodes)))
+	if (funcform->prorettype == RECORDOID)
 		return NULL;
 
 	/*
diff --git a/src/backend/utils/fmgr/funcapi.c b/src/backend/utils/fmgr/funcapi.c
@@ -7,7 +7,7 @@
  * Copyright (c) 2002-2005, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/fmgr/funcapi.c,v 1.23 2005/05/30 23:09:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/fmgr/funcapi.c,v 1.24 2005/07/03 21:14:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -235,36 +235,6 @@ get_expr_result_type(Node *expr,
 										  NULL,
 										  resultTypeId,
 										  resultTupleDesc);
-	else if (expr && IsA(expr, Const) &&
-			 ((Const *) expr)->consttype == RECORDOID &&
-			 !((Const *) expr)->constisnull)
-	{
-		/*
-		 * Pull embedded type info from a RECORD constant.  We have to be
-		 * prepared to handle this case in the wake of constant-folding of
-		 * record-returning functions.
-		 */
-		HeapTupleHeader td;
-		int32	typmod;
-
-		td = DatumGetHeapTupleHeader(((Const *) expr)->constvalue);
-		Assert(HeapTupleHeaderGetTypeId(td) == RECORDOID);
-		typmod = HeapTupleHeaderGetTypMod(td);
-		if (resultTypeId)
-			*resultTypeId = RECORDOID;
-		if (typmod >= 0)
-		{
-			if (resultTupleDesc)
-				*resultTupleDesc = lookup_rowtype_tupdesc(RECORDOID, typmod);
-			result = TYPEFUNC_COMPOSITE;
-		}
-		else
-		{
-			if (resultTupleDesc)
-				*resultTupleDesc = NULL;
-			result = TYPEFUNC_RECORD;
-		}
-	}
 	else
 	{
 		/* handle as a generic expression; no chance to resolve RECORD */
