Subject: [PATCH v1] Add an assertion in get_object_address()

From: Bertrand Drouvot <[email-masked]>
Date: Mon, 11 Nov 2024 07:07:02 +0000

Some places declared a Relation before calling get_object_address() only to
assert that the relation is NULL after the call.

The new assertion allows passing NULL as the relation argument at those places
making the code cleaner and easier to understand.
---
 src/backend/catalog/objectaddress.c |  8 +++++---
 src/backend/commands/alter.c        | 15 ++++-----------
 2 files changed, 9 insertions(+), 14 deletions(-)
  48.8% src/backend/catalog/
  51.1% src/backend/commands/

diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 85a7b7e641..e089582285 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -896,8 +896,8 @@ static void getRelationIdentity(StringInfo buffer, Oid relid, List **object,
  *
  * If the object is a relation or a child object of a relation (e.g. an
  * attribute or constraint), the relation is also opened and *relp receives
- * the open relcache entry pointer; otherwise, *relp is set to NULL.  This
- * is a bit grotty but it makes life simpler, since the caller will
+ * the open relcache entry pointer (if *relp is not passed as a NULL argument).
+ * This is a bit grotty but it makes life simpler, since the caller will
  * typically need the relcache entry too.  Caller must close the relcache
  * entry when done with it.  The relation is locked with the specified lockmode
  * if the target object is the relation itself or an attribute, but for other
@@ -1204,8 +1204,10 @@ get_object_address(ObjectType objtype, Node *object,
 		old_address = address;
 	}
 
+	Assert(!relation || relp);
 	/* Return the object address and the relation. */
-	*relp = relation;
+	if (relp)
+		*relp = relation;
 	return address;
 }
 
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 4f99ebb447..a45f3bb6b8 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -421,13 +421,11 @@ ExecRenameStmt(RenameStmt *stmt)
 			{
 				ObjectAddress address;
 				Relation	catalog;
-				Relation	relation;
 
 				address = get_object_address(stmt->renameType,
 											 stmt->object,
-											 &relation,
+											 NULL,
 											 AccessExclusiveLock, false);
-				Assert(relation == NULL);
 
 				catalog = table_open(address.classId, RowExclusiveLock);
 				AlterObjectRename_internal(catalog,
@@ -482,8 +480,7 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt *stmt, ObjectAddress *refAddre
 		table_close(rel, NoLock);
 
 	refAddr = get_object_address(OBJECT_EXTENSION, (Node *) stmt->extname,
-								 &rel, AccessExclusiveLock, false);
-	Assert(rel == NULL);
+								 NULL, AccessExclusiveLock, false);
 	if (refAddress)
 		*refAddress = refAddr;
 
@@ -563,16 +560,14 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
 		case OBJECT_TSTEMPLATE:
 			{
 				Relation	catalog;
-				Relation	relation;
 				Oid			classId;
 				Oid			nspOid;
 
 				address = get_object_address(stmt->objectType,
 											 stmt->object,
-											 &relation,
+											 NULL,
 											 AccessExclusiveLock,
 											 false);
-				Assert(relation == NULL);
 				classId = address.classId;
 				catalog = table_open(classId, RowExclusiveLock);
 				nspOid = LookupCreationNamespace(stmt->newschema);
@@ -876,15 +871,13 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 		case OBJECT_TSDICTIONARY:
 		case OBJECT_TSCONFIGURATION:
 			{
-				Relation	relation;
 				ObjectAddress address;
 
 				address = get_object_address(stmt->objectType,
 											 stmt->object,
-											 &relation,
+											 NULL,
 											 AccessExclusiveLock,
 											 false);
-				Assert(relation == NULL);
 
 				AlterObjectOwner_internal(address.classId, address.objectId,
 										  newowner);
-- 
2.34.1

--mystdgN+2sVzv+rS--