| //===--- Visibility.h - Visibility macros for runtime exports ---*- C++ -*-===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See http://swift.org/LICENSE.txt for license information |
| // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // These macros are used to declare symbols that should be exported from the |
| // Swift runtime. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SWIFT_STDLIB_SHIMS_VISIBILITY_H |
| #define SWIFT_STDLIB_SHIMS_VISIBILITY_H |
| |
| #if defined(__has_feature) && __has_feature(nullability) |
| // Provide macros to temporarily suppress warning about the use of |
| // _Nullable and _Nonnull. |
| # define SWIFT_BEGIN_NULLABILITY_ANNOTATIONS \ |
| _Pragma("clang diagnostic push") \ |
| _Pragma("clang diagnostic ignored \"-Wnullability-extension\"") |
| # define SWIFT_END_NULLABILITY_ANNOTATIONS \ |
| _Pragma("clang diagnostic pop") |
| |
| #else |
| // #define _Nullable and _Nonnull to nothing if we're not being built |
| // with a compiler that supports them. |
| # define _Nullable |
| # define _Nonnull |
| # define SWIFT_BEGIN_NULLABILITY_ANNOTATIONS |
| # define SWIFT_END_NULLABILITY_ANNOTATIONS |
| #endif |
| |
| // TODO: support using shims headers in overlays by parameterizing |
| // SWIFT_RUNTIME_EXPORT on the library it's exported from, then setting |
| // protected vs. default based on the current value of __SWIFT_CURRENT_DYLIB. |
| |
| /// Attribute used to export symbols from the runtime. |
| #if __MACH__ |
| # define SWIFT_RUNTIME_EXPORT __attribute__((__visibility__("default"))) |
| #elif __ELF__ |
| |
| // Use protected visibility for ELF, since we don't want Swift symbols to be |
| // interposable. The relative relocations we form to metadata aren't |
| // valid in ELF shared objects, and leaving them relocatable at load time |
| // defeats the purpose of the relative references. |
| // |
| // Protected visibility on a declaration is interpreted to mean that the |
| // symbol is defined in the current dynamic library, so if we're building |
| // something else, we need to fall back on using default visibility. |
| #ifdef __SWIFT_CURRENT_DYLIB |
| # define SWIFT_RUNTIME_EXPORT __attribute__((__visibility__("protected"))) |
| #else |
| # define SWIFT_RUNTIME_EXPORT __attribute__((__visibility__("default"))) |
| #endif |
| |
| #else |
| # if defined(__CYGWIN__) |
| # define SWIFT_RUNTIME_EXPORT |
| # else |
| # if defined(swiftCore_EXPORTS) |
| # define SWIFT_RUNTIME_EXPORT __declspec(dllexport) |
| # else |
| # define SWIFT_RUNTIME_EXPORT __declspec(dllimport) |
| # endif |
| # endif |
| #endif |
| |
| /// Attribute for runtime-stdlib SPI interfaces. |
| /// |
| /// Since the stdlib is currently fully fragile, runtime-stdlib SPI currently |
| /// needs to be exported from the core dylib. When the stdlib admits more |
| /// resilience we may be able to make this hidden. |
| #define SWIFT_RUNTIME_STDLIB_INTERFACE SWIFT_RUNTIME_EXPORT |
| |
| #endif |
