stdlib/public/SwiftShims/Visibility.h - third_party/swift - Git at Google

 //===--- Visibility.h - Visibility macros for runtime exports ---*- 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
 //
 //===----------------------------------------------------------------------===//
 //
 //  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)
 #define __has_feature(x) 0
 #endif

 #if !defined(__has_attribute)
 #define __has_attribute(x) 0
 #endif

 #if !defined(__has_builtin)
 #define __has_builtin(builtin) 0
 #endif

 #if !defined(__has_cpp_attribute)
 #define __has_cpp_attribute(attribute) 0
 #endif

 #if __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

 #define SWIFT_MACRO_CONCAT(A, B) A ## B
 #define SWIFT_MACRO_IF_0(IF_TRUE, IF_FALSE) IF_FALSE
 #define SWIFT_MACRO_IF_1(IF_TRUE, IF_FALSE) IF_TRUE
 #define SWIFT_MACRO_IF(COND, IF_TRUE, IF_FALSE) \
   SWIFT_MACRO_CONCAT(SWIFT_MACRO_IF_, COND)(IF_TRUE, IF_FALSE)

 #if __has_attribute(pure)
 #define SWIFT_READONLY __attribute__((__pure__))
 #else
 #define SWIFT_READONLY
 #endif

 #if __has_attribute(const)
 #define SWIFT_READNONE __attribute__((__const__))
 #else
 #define SWIFT_READNONE
 #endif

 #if __has_attribute(always_inline)
 #define SWIFT_ALWAYS_INLINE __attribute__((always_inline))
 #else
 #define SWIFT_ALWAYS_INLINE
 #endif

 #if __has_attribute(noinline)
 #define SWIFT_NOINLINE __attribute__((__noinline__))
 #else
 #define SWIFT_NOINLINE
 #endif

 #if __has_attribute(noreturn)
 #define SWIFT_NORETURN __attribute__((__noreturn__))
 #else
 #define SWIFT_NORETURN
 #endif

 #if __has_attribute(used)
 #define SWIFT_USED __attribute__((__used__))
 #else
 #define SWIFT_USED
 #endif

 #if __has_attribute(unavailable)
 #define SWIFT_ATTRIBUTE_UNAVAILABLE __attribute__((__unavailable__))
 #else
 #define SWIFT_ATTRIBUTE_UNAVAILABLE
 #endif

 // Define the appropriate attributes for sharing symbols across
 // image (executable / shared-library) boundaries.
 //
 // SWIFT_ATTRIBUTE_FOR_EXPORTS will be placed on declarations that
 // are known to be exported from the current image.  Typically, they
 // are placed on header declarations and then inherited by the actual
 // definitions.
 //
 // SWIFT_ATTRIBUTE_FOR_IMPORTS will be placed on declarations that
 // are known to be exported from a different image.  This never
 // includes a definition.
 //
 // Getting the right attribute on a declaratioon can be pretty awkward,
 // but it's necessary under the C translation model.  All of this
 // ceremony is familiar to Windows programmers; C/C++ programmers
 // everywhere else usually don't bother, but since we have to get it
 // right for Windows, we have everything set up to get it right on
 // other targets as well, and doing so lets the compiler use more
 // efficient symbol access patterns.
 #if defined(__MACH__) || defined(__wasi__)

 // On Mach-O and WebAssembly, we use non-hidden visibility.  We just use
 // default visibility on both imports and exports, both because these
 // targets don't support protected visibility but because they don't
 // need it: symbols are not interposable outside the current image
 // by default.
 # define SWIFT_ATTRIBUTE_FOR_EXPORTS __attribute__((__visibility__("default")))
 # define SWIFT_ATTRIBUTE_FOR_IMPORTS __attribute__((__visibility__("default")))

 #elif defined(__ELF__)

 // On ELF, we use non-hidden visibility.  For exports, we must use
 // protected visibility to tell the compiler and linker that the symbols
 // can't be interposed outside the current image.  For imports, we must
 // use default visibility because protected visibility guarantees that
 // the symbol is defined in the current library, which isn't true for
 // an import.
 //
 // The compiler does assume that the runtime and standard library can
 // refer to each other's symbols as DSO-local, so it's important that
 // we get this right or we can get linker errors.
 # define SWIFT_ATTRIBUTE_FOR_EXPORTS __attribute__((__visibility__("protected")))
 # define SWIFT_ATTRIBUTE_FOR_IMPORTS __attribute__((__visibility__("default")))

 #elif defined(__CYGWIN__)

 // For now, we ignore all this on Cygwin.
 # define SWIFT_ATTRIBUTE_FOR_EXPORTS
 # define SWIFT_ATTRIBUTE_FOR_IMPORTS

 // FIXME: this #else should be some sort of #elif Windows
 #else // !__MACH__ && !__ELF__

 // On PE/COFF, we use dllimport and dllexport.
 # define SWIFT_ATTRIBUTE_FOR_EXPORTS __declspec(dllexport)
 # define SWIFT_ATTRIBUTE_FOR_IMPORTS __declspec(dllimport)

 #endif

 // CMake conventionally passes -DlibraryName_EXPORTS when building
 // code that goes into libraryName.  This isn't the best macro name,
 // but it's conventional.  We do have to pass it explicitly in a few
 // places in the build system for a variety of reasons.
 //
 // Unfortunately, defined(D) is a special function you can use in
 // preprocessor conditions, not a macro you can use anywhere, so we
 // need to manually check for all the libraries we know about so that
 // we can use them in our condition below.s
 #if defined(swiftCore_EXPORTS)
 #define SWIFT_IMAGE_EXPORTS_swiftCore 1
 #else
 #define SWIFT_IMAGE_EXPORTS_swiftCore 0
 #endif
 #if defined(swift_Concurrency_EXPORTS)
 #define SWIFT_IMAGE_EXPORTS_swift_Concurrency 1
 #else
 #define SWIFT_IMAGE_EXPORTS_swift_Concurrency 0
 #endif
 #if defined(swift_Differentiation_EXPORTS)
 #define SWIFT_IMAGE_EXPORTS_swift_Differentiation 1
 #else
 #define SWIFT_IMAGE_EXPORTS_swift_Differentiation 0
 #endif

 #define SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY)                          \
   SWIFT_MACRO_IF(SWIFT_IMAGE_EXPORTS_##LIBRARY,                       \
                  SWIFT_ATTRIBUTE_FOR_EXPORTS,                         \
                  SWIFT_ATTRIBUTE_FOR_IMPORTS)

 // SWIFT_EXPORT_FROM(LIBRARY) declares something to be a C-linkage
 // entity exported by the given library.
 //
 // SWIFT_RUNTIME_EXPORT is just SWIFT_EXPORT_FROM(swiftCore).
 //
 // TODO: use this in shims headers in overlays.
 #if defined(__cplusplus)
 #define SWIFT_EXPORT_FROM(LIBRARY) extern "C" SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY)
 #else
 #define SWIFT_EXPORT_FROM(LIBRARY) SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY)
 #endif
 #define SWIFT_RUNTIME_EXPORT SWIFT_EXPORT_FROM(swiftCore)

 #if __cplusplus > 201402l && __has_cpp_attribute(fallthrough)
 #define SWIFT_FALLTHROUGH [[fallthrough]]
 #elif __has_cpp_attribute(gnu::fallthrough)
 #define SWIFT_FALLTHROUGH [[gnu::fallthrough]]
 #elif __has_cpp_attribute(clang::fallthrough)
 #define SWIFT_FALLTHROUGH [[clang::fallthrough]]
 #elif __has_attribute(fallthrough)
 #define SWIFT_FALLTHROUGH __attribute__((__fallthrough__))
 #else
 #define SWIFT_FALLTHROUGH
 #endif

 #if __cplusplus >= 201402l && __has_cpp_attribute(nodiscard)
 #define SWIFT_NODISCARD [[nodiscard]]
 #elif __has_cpp_attribute(clang::warn_unused_result)
 #define SWIFT_NODISCARD [[clang::warn_unused_result]]
 #else
 #define SWIFT_NODISCARD
 #endif


 /// Attributes for runtime-stdlib interfaces.
 /// Use these for C implementations that are imported into Swift via SwiftShims
 /// and for C implementations of Swift @_silgen_name declarations
 /// Note that @_silgen_name implementations must also be marked SWIFT_CC(swift).
 ///
 /// SWIFT_RUNTIME_STDLIB_API functions are called by compiler-generated code
 /// or by @inlinable Swift code.
 /// Such functions must be exported and must be supported forever as API.
 /// The function name should be prefixed with `swift_`.
 ///
 /// SWIFT_RUNTIME_STDLIB_SPI functions are called by overlay code.
 /// Such functions must be exported, but are still SPI
 /// and may be changed at any time.
 /// The function name should be prefixed with `_swift_`.
 ///
 /// SWIFT_RUNTIME_STDLIB_INTERNAL functions are called only by the stdlib.
 /// Such functions are internal and are not exported.
 #define SWIFT_RUNTIME_STDLIB_API       SWIFT_RUNTIME_EXPORT
 #define SWIFT_RUNTIME_STDLIB_SPI       SWIFT_RUNTIME_EXPORT

 // Match the definition of LLVM_LIBRARY_VISIBILITY from LLVM's
 // Compiler.h. That header requires C++ and this needs to work in C.
 #if __has_attribute(visibility) && (defined(__ELF__) || defined(__MACH__))
 #define SWIFT_LIBRARY_VISIBILITY __attribute__ ((__visibility__("hidden")))
 #else
 #define SWIFT_LIBRARY_VISIBILITY
 #endif

 #if defined(__cplusplus)
 #define SWIFT_RUNTIME_STDLIB_INTERNAL extern "C" SWIFT_LIBRARY_VISIBILITY
 #else
 #define SWIFT_RUNTIME_STDLIB_INTERNAL SWIFT_LIBRARY_VISIBILITY
 #endif

 #if __has_builtin(__builtin_expect)
 #define SWIFT_LIKELY(expression) (__builtin_expect(!!(expression), 1))
 #define SWIFT_UNLIKELY(expression) (__builtin_expect(!!(expression), 0))
 #else
 #define SWIFT_LIKELY(expression) ((expression))
 #define SWIFT_UNLIKELY(expression) ((expression))
 #endif

 // SWIFT_STDLIB_SHIMS_VISIBILITY_H
 #endif
	//===--- Visibility.h - Visibility macros for runtime exports ---- 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
	//
	//===----------------------------------------------------------------------===//
	//
	// 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)
	#define __has_feature(x) 0
	#endif

	#if !defined(__has_attribute)
	#define __has_attribute(x) 0
	#endif

	#if !defined(__has_builtin)
	#define __has_builtin(builtin) 0
	#endif

	#if !defined(__has_cpp_attribute)
	#define __has_cpp_attribute(attribute) 0
	#endif

	#if __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

	#define SWIFT_MACRO_CONCAT(A, B) A ## B
	#define SWIFT_MACRO_IF_0(IF_TRUE, IF_FALSE) IF_FALSE
	#define SWIFT_MACRO_IF_1(IF_TRUE, IF_FALSE) IF_TRUE
	#define SWIFT_MACRO_IF(COND, IF_TRUE, IF_FALSE) \
	SWIFT_MACRO_CONCAT(SWIFT_MACRO_IF_, COND)(IF_TRUE, IF_FALSE)

	#if __has_attribute(pure)
	#define SWIFT_READONLY __attribute__((__pure__))
	#else
	#define SWIFT_READONLY
	#endif

	#if __has_attribute(const)
	#define SWIFT_READNONE __attribute__((__const__))
	#else
	#define SWIFT_READNONE
	#endif

	#if __has_attribute(always_inline)
	#define SWIFT_ALWAYS_INLINE __attribute__((always_inline))
	#else
	#define SWIFT_ALWAYS_INLINE
	#endif

	#if __has_attribute(noinline)
	#define SWIFT_NOINLINE __attribute__((__noinline__))
	#else
	#define SWIFT_NOINLINE
	#endif

	#if __has_attribute(noreturn)
	#define SWIFT_NORETURN __attribute__((__noreturn__))
	#else
	#define SWIFT_NORETURN
	#endif

	#if __has_attribute(used)
	#define SWIFT_USED __attribute__((__used__))
	#else
	#define SWIFT_USED
	#endif

	#if __has_attribute(unavailable)
	#define SWIFT_ATTRIBUTE_UNAVAILABLE __attribute__((__unavailable__))
	#else
	#define SWIFT_ATTRIBUTE_UNAVAILABLE
	#endif

	// Define the appropriate attributes for sharing symbols across
	// image (executable / shared-library) boundaries.
	//
	// SWIFT_ATTRIBUTE_FOR_EXPORTS will be placed on declarations that
	// are known to be exported from the current image. Typically, they
	// are placed on header declarations and then inherited by the actual
	// definitions.
	//
	// SWIFT_ATTRIBUTE_FOR_IMPORTS will be placed on declarations that
	// are known to be exported from a different image. This never
	// includes a definition.
	//
	// Getting the right attribute on a declaratioon can be pretty awkward,
	// but it's necessary under the C translation model. All of this
	// ceremony is familiar to Windows programmers; C/C++ programmers
	// everywhere else usually don't bother, but since we have to get it
	// right for Windows, we have everything set up to get it right on
	// other targets as well, and doing so lets the compiler use more
	// efficient symbol access patterns.
	#if defined(__MACH__) \|\| defined(__wasi__)

	// On Mach-O and WebAssembly, we use non-hidden visibility. We just use
	// default visibility on both imports and exports, both because these
	// targets don't support protected visibility but because they don't
	// need it: symbols are not interposable outside the current image
	// by default.
	# define SWIFT_ATTRIBUTE_FOR_EXPORTS __attribute__((__visibility__("default")))
	# define SWIFT_ATTRIBUTE_FOR_IMPORTS __attribute__((__visibility__("default")))

	#elif defined(__ELF__)

	// On ELF, we use non-hidden visibility. For exports, we must use
	// protected visibility to tell the compiler and linker that the symbols
	// can't be interposed outside the current image. For imports, we must
	// use default visibility because protected visibility guarantees that
	// the symbol is defined in the current library, which isn't true for
	// an import.
	//
	// The compiler does assume that the runtime and standard library can
	// refer to each other's symbols as DSO-local, so it's important that
	// we get this right or we can get linker errors.
	# define SWIFT_ATTRIBUTE_FOR_EXPORTS __attribute__((__visibility__("protected")))
	# define SWIFT_ATTRIBUTE_FOR_IMPORTS __attribute__((__visibility__("default")))

	#elif defined(__CYGWIN__)

	// For now, we ignore all this on Cygwin.
	# define SWIFT_ATTRIBUTE_FOR_EXPORTS
	# define SWIFT_ATTRIBUTE_FOR_IMPORTS

	// FIXME: this #else should be some sort of #elif Windows
	#else // !__MACH__ && !__ELF__

	// On PE/COFF, we use dllimport and dllexport.
	# define SWIFT_ATTRIBUTE_FOR_EXPORTS __declspec(dllexport)
	# define SWIFT_ATTRIBUTE_FOR_IMPORTS __declspec(dllimport)

	#endif

	// CMake conventionally passes -DlibraryName_EXPORTS when building
	// code that goes into libraryName. This isn't the best macro name,
	// but it's conventional. We do have to pass it explicitly in a few
	// places in the build system for a variety of reasons.
	//
	// Unfortunately, defined(D) is a special function you can use in
	// preprocessor conditions, not a macro you can use anywhere, so we
	// need to manually check for all the libraries we know about so that
	// we can use them in our condition below.s
	#if defined(swiftCore_EXPORTS)
	#define SWIFT_IMAGE_EXPORTS_swiftCore 1
	#else
	#define SWIFT_IMAGE_EXPORTS_swiftCore 0
	#endif
	#if defined(swift_Concurrency_EXPORTS)
	#define SWIFT_IMAGE_EXPORTS_swift_Concurrency 1
	#else
	#define SWIFT_IMAGE_EXPORTS_swift_Concurrency 0
	#endif
	#if defined(swift_Differentiation_EXPORTS)
	#define SWIFT_IMAGE_EXPORTS_swift_Differentiation 1
	#else
	#define SWIFT_IMAGE_EXPORTS_swift_Differentiation 0
	#endif

	#define SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY) \
	SWIFT_MACRO_IF(SWIFT_IMAGE_EXPORTS_##LIBRARY, \
	SWIFT_ATTRIBUTE_FOR_EXPORTS, \
	SWIFT_ATTRIBUTE_FOR_IMPORTS)

	// SWIFT_EXPORT_FROM(LIBRARY) declares something to be a C-linkage
	// entity exported by the given library.
	//
	// SWIFT_RUNTIME_EXPORT is just SWIFT_EXPORT_FROM(swiftCore).
	//
	// TODO: use this in shims headers in overlays.
	#if defined(__cplusplus)
	#define SWIFT_EXPORT_FROM(LIBRARY) extern "C" SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY)
	#else
	#define SWIFT_EXPORT_FROM(LIBRARY) SWIFT_EXPORT_FROM_ATTRIBUTE(LIBRARY)
	#endif
	#define SWIFT_RUNTIME_EXPORT SWIFT_EXPORT_FROM(swiftCore)

	#if __cplusplus > 201402l && __has_cpp_attribute(fallthrough)
	#define SWIFT_FALLTHROUGH [[fallthrough]]
	#elif __has_cpp_attribute(gnu::fallthrough)
	#define SWIFT_FALLTHROUGH [[gnu::fallthrough]]
	#elif __has_cpp_attribute(clang::fallthrough)
	#define SWIFT_FALLTHROUGH [[clang::fallthrough]]
	#elif __has_attribute(fallthrough)
	#define SWIFT_FALLTHROUGH __attribute__((__fallthrough__))
	#else
	#define SWIFT_FALLTHROUGH
	#endif

	#if __cplusplus >= 201402l && __has_cpp_attribute(nodiscard)
	#define SWIFT_NODISCARD [[nodiscard]]
	#elif __has_cpp_attribute(clang::warn_unused_result)
	#define SWIFT_NODISCARD [[clang::warn_unused_result]]
	#else
	#define SWIFT_NODISCARD
	#endif


	/// Attributes for runtime-stdlib interfaces.
	/// Use these for C implementations that are imported into Swift via SwiftShims
	/// and for C implementations of Swift @_silgen_name declarations
	/// Note that @_silgen_name implementations must also be marked SWIFT_CC(swift).
	///
	/// SWIFT_RUNTIME_STDLIB_API functions are called by compiler-generated code
	/// or by @inlinable Swift code.
	/// Such functions must be exported and must be supported forever as API.
	/// The function name should be prefixed with `swift_`.
	///
	/// SWIFT_RUNTIME_STDLIB_SPI functions are called by overlay code.
	/// Such functions must be exported, but are still SPI
	/// and may be changed at any time.
	/// The function name should be prefixed with `_swift_`.
	///
	/// SWIFT_RUNTIME_STDLIB_INTERNAL functions are called only by the stdlib.
	/// Such functions are internal and are not exported.
	#define SWIFT_RUNTIME_STDLIB_API SWIFT_RUNTIME_EXPORT
	#define SWIFT_RUNTIME_STDLIB_SPI SWIFT_RUNTIME_EXPORT

	// Match the definition of LLVM_LIBRARY_VISIBILITY from LLVM's
	// Compiler.h. That header requires C++ and this needs to work in C.
	#if __has_attribute(visibility) && (defined(__ELF__) \|\| defined(__MACH__))
	#define SWIFT_LIBRARY_VISIBILITY __attribute__ ((__visibility__("hidden")))
	#else
	#define SWIFT_LIBRARY_VISIBILITY
	#endif

	#if defined(__cplusplus)
	#define SWIFT_RUNTIME_STDLIB_INTERNAL extern "C" SWIFT_LIBRARY_VISIBILITY
	#else
	#define SWIFT_RUNTIME_STDLIB_INTERNAL SWIFT_LIBRARY_VISIBILITY
	#endif

	#if __has_builtin(__builtin_expect)
	#define SWIFT_LIKELY(expression) (__builtin_expect(!!(expression), 1))
	#define SWIFT_UNLIKELY(expression) (__builtin_expect(!!(expression), 0))
	#else
	#define SWIFT_LIKELY(expression) ((expression))
	#define SWIFT_UNLIKELY(expression) ((expression))
	#endif

	// SWIFT_STDLIB_SHIMS_VISIBILITY_H
	#endif