| //===--- CompatibiltyOverride.h - Back-deploying compatibility fixes --*- C++ -*-===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2018 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Support back-deploying compatibility fixes for newer apps running on older runtimes. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef COMPATIBILITY_OVERRIDE_H |
| #define COMPATIBILITY_OVERRIDE_H |
| |
| #include "Private.h" |
| #include "swift/Runtime/Metadata.h" |
| #include "swift/Runtime/Once.h" |
| #include <type_traits> |
| |
| namespace swift { |
| |
| #define COMPATIBILITY_UNPAREN(...) __VA_ARGS__ |
| |
| #define OVERRIDE(name, ret, attrs, ccAttrs, namespace, typedArgs, namedArgs) \ |
| ccAttrs typedef ret (*Original_ ## name) typedArgs; |
| #include "CompatibilityOverride.def" |
| |
| #define OVERRIDE(name, ret, attrs, ccAttrs, namespace, typedArgs, namedArgs) \ |
| ccAttrs typedef ret (*Override_ ## name)(COMPATIBILITY_UNPAREN typedArgs, \ |
| Original_ ## name originalImpl); |
| #include "CompatibilityOverride.def" |
| |
| #define OVERRIDE(name, ret, attrs, ccAttrs, namespace, typedArgs, namedArgs) \ |
| Override_ ## name getOverride_ ## name(); |
| #include "CompatibilityOverride.def" |
| |
| |
| /// Used to define an override point. The override point #defines the appropriate |
| /// OVERRIDE macro from CompatibilityOverride.def to this macro, then includes |
| /// the file to generate the override points. The original implementation of the |
| /// functionality must be available as swift_funcNameHereImpl. |
| #define COMPATIBILITY_OVERRIDE(name, ret, attrs, ccAttrs, namespace, typedArgs, namedArgs) \ |
| attrs ccAttrs ret namespace swift_ ## name typedArgs { \ |
| static Override_ ## name Override; \ |
| static swift_once_t Predicate; \ |
| swift_once(&Predicate, [](void *) { \ |
| Override = getOverride_ ## name(); \ |
| }, nullptr); \ |
| if (Override != nullptr) \ |
| return Override(COMPATIBILITY_UNPAREN namedArgs, swift_ ## name ## Impl); \ |
| return swift_ ## name ## Impl namedArgs; \ |
| } |
| |
| } /* end namespace swift */ |
| |
| #endif /* COMPATIBILITY_OVERRIDE_H */ |
