| //===--- Notifications.h - SIL Undef Value Representation -------*- C++ -*-===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SWIFT_SIL_NOTIFICATIONS_H |
| #define SWIFT_SIL_NOTIFICATIONS_H |
| |
| namespace swift { |
| |
| class SILNode; |
| |
| /// A protocol (or interface) for handling value deletion notifications. |
| /// |
| /// This class is used as a base class for any class that need to accept |
| /// instruction deletion notification messages. This is used by passes and |
| /// analysis that need to invalidate data structures that contain pointers. |
| /// This is similar to LLVM's ValueHandle. |
| struct DeleteNotificationHandler { |
| |
| DeleteNotificationHandler() { } |
| virtual ~DeleteNotificationHandler() {} |
| |
| /// Handle the invalidation message for the value \p Value. |
| virtual void handleDeleteNotification(SILNode *value) { } |
| |
| /// Returns True if the pass, analysis or other entity wants to receive |
| /// notifications. This callback is called once when the class is being |
| /// registered, and not once per notification. Entities that implement |
| /// this callback should always return a constant answer (true/false). |
| virtual bool needsNotifications() { return false; } |
| }; |
| |
| } // end swift namespace |
| |
| #endif |
| |
