Add a missing_ok argument to get_object_address().

This lays the groundwork for an upcoming patch to streamline the
handling of DROP commands.

KaiGai Kohei

src/backend/commands/comment.c

@@ -69,7 +69,7 @@ CommentObject(CommentStmt *stmt)
 	 * against concurrent DROP operations.
 	 */
 	address = get_object_address(stmt->objtype, stmt->objname, stmt->objargs,
-								 &relation, ShareUpdateExclusiveLock);
+								 &relation, ShareUpdateExclusiveLock, false);
 
 	/* Require ownership of the target object. */
 	check_object_ownership(GetUserId(), stmt->objtype, address,

src/backend/commands/extension.c

@@ -2703,7 +2703,7 @@ ExecAlterExtensionContentsStmt(AlterExtensionContentsStmt *stmt)
 	 * against concurrent DROP and ALTER EXTENSION ADD/DROP operations.
 	 */
 	object = get_object_address(stmt->objtype, stmt->objname, stmt->objargs,
-								&relation, ShareUpdateExclusiveLock);
+								&relation, ShareUpdateExclusiveLock, false);
 
 	/* Permission check: must own target object, too */
 	check_object_ownership(GetUserId(), stmt->objtype, object,

src/backend/commands/seclabel.c

@@ -88,7 +88,7 @@ ExecSecLabelStmt(SecLabelStmt *stmt)
 	 * guard against concurrent modifications.
 	 */
 	address = get_object_address(stmt->objtype, stmt->objname, stmt->objargs,
-								 &relation, ShareUpdateExclusiveLock);
+								 &relation, ShareUpdateExclusiveLock, false);
 
 	/* Require ownership of the target object. */
 	check_object_ownership(GetUserId(), stmt->objtype, address,

src/backend/rewrite/rewriteSupport.c

@@ -132,7 +132,8 @@ get_rewrite_oid(Oid relid, const char *rulename, bool missing_ok)
  * were unique across the entire database.
  */
 Oid
-get_rewrite_oid_without_relid(const char *rulename, Oid *reloid)
+get_rewrite_oid_without_relid(const char *rulename,
+							  Oid *reloid, bool missing_ok)
 {
 	Relation	RewriteRelation;
 	HeapScanDesc scanDesc;
@@ -151,20 +152,26 @@ get_rewrite_oid_without_relid(const char *rulename, Oid *reloid)
 
 	htup = heap_getnext(scanDesc, ForwardScanDirection);
 	if (!HeapTupleIsValid(htup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("rule \"%s\" does not exist", rulename)));
-
-	ruleoid = HeapTupleGetOid(htup);
-	if (reloid != NULL)
-		*reloid = ((Form_pg_rewrite) GETSTRUCT(htup))->ev_class;
-
-	if (HeapTupleIsValid(htup = heap_getnext(scanDesc, ForwardScanDirection)))
-		ereport(ERROR,
-				(errcode(ERRCODE_DUPLICATE_OBJECT),
-				 errmsg("there are multiple rules named \"%s\"", rulename),
-				 errhint("Specify a relation name as well as a rule name.")));
-
+	{
+		if (!missing_ok)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("rule \"%s\" does not exist", rulename)));
+		ruleoid = InvalidOid;
+	}
+	else
+	{
+		ruleoid = HeapTupleGetOid(htup);
+		if (reloid != NULL)
+			*reloid = ((Form_pg_rewrite) GETSTRUCT(htup))->ev_class;
+
+		htup = heap_getnext(scanDesc, ForwardScanDirection);
+		if (HeapTupleIsValid(htup))
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("there are multiple rules named \"%s\"", rulename),
+					 errhint("Specify a relation name as well as a rule name.")));
+	}
 	heap_endscan(scanDesc);
 	heap_close(RewriteRelation, AccessShareLock);
 

src/include/catalog/objectaddress.h

@@ -28,7 +28,8 @@ typedef struct ObjectAddress
 } ObjectAddress;
 
 extern ObjectAddress get_object_address(ObjectType objtype, List *objname,
-				   List *objargs, Relation *relp, LOCKMODE lockmode);
+										List *objargs, Relation *relp,
+										LOCKMODE lockmode, bool missing_ok);
 
 extern void check_object_ownership(Oid roleid,
 					   ObjectType objtype, ObjectAddress address,

src/include/rewrite/rewriteSupport.h

@@ -23,6 +23,7 @@ extern void SetRelationRuleStatus(Oid relationId, bool relHasRules,
 					  bool relIsBecomingView);
 
 extern Oid	get_rewrite_oid(Oid relid, const char *rulename, bool missing_ok);
-extern Oid	get_rewrite_oid_without_relid(const char *rulename, Oid *relid);
+extern Oid	get_rewrite_oid_without_relid(const char *rulename,
+										  Oid *relid, bool missing_ok);
 
 #endif   /* REWRITESUPPORT_H */