libcxx/include/__configuration/abi.h - llvm-project - Git at Google

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef _LIBCPP___CONFIGURATION_ABI_H
 #define _LIBCPP___CONFIGURATION_ABI_H

 #include <__config_site>
 #include <__configuration/compiler.h>
 #include <__configuration/platform.h>

 #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
 #  pragma GCC system_header
 #endif

 // FIXME: ABI detection should be done via compiler builtin macros. This
 // is just a placeholder until Clang implements such macros. For now assume
 // that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
 // and allow the user to explicitly specify the ABI to handle cases where this
 // heuristic falls short.
 #if _LIBCPP_ABI_FORCE_ITANIUM && _LIBCPP_ABI_FORCE_MICROSOFT
 #  error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be true"
 #elif _LIBCPP_ABI_FORCE_ITANIUM
 #  define _LIBCPP_ABI_ITANIUM
 #elif _LIBCPP_ABI_FORCE_MICROSOFT
 #  define _LIBCPP_ABI_MICROSOFT
 #else
 #  if defined(_WIN32) && defined(_MSC_VER)
 #    define _LIBCPP_ABI_MICROSOFT
 #  else
 #    define _LIBCPP_ABI_ITANIUM
 #  endif
 #endif

 #if _LIBCPP_ABI_VERSION >= 2
 // TODO: Move the description of the remaining ABI flags to ABIGuarantees.rst or remove them.

 // Override the default return value of exception::what() for bad_function_call::what()
 // with a string that is specific to bad_function_call (see http://wg21.link/LWG2233).
 // This is an ABI break on platforms that sign and authenticate vtable function pointers
 // because it changes the mangling of the virtual function located in the vtable, which
 // changes how it gets signed.
 #  define _LIBCPP_ABI_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE
 // According to the Standard, `bitset::operator[] const` returns bool
 #  define _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL

 // In LLVM 20, we've changed to take these ABI breaks unconditionally. These flags only exist in case someone is running
 // into the static_asserts we added to catch the ABI break and don't care that it is one.
 // TODO(LLVM 22): Remove these flags
 #  define _LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB
 #  define _LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB
 #  define _LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB
 #  define _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB

 // These flags are documented in ABIGuarantees.rst
 #  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
 #  define _LIBCPP_ABI_DO_NOT_EXPORT_TO_CHARS_BASE_10
 #  define _LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI
 #  define _LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI
 #  define _LIBCPP_ABI_FIX_CITYHASH_IMPLEMENTATION
 #  define _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
 #  define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
 #  define _LIBCPP_ABI_IOS_ALLOW_ARBITRARY_FILL_VALUE
 #  define _LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING
 #  define _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
 #  define _LIBCPP_ABI_NO_ITERATOR_BASES
 #  define _LIBCPP_ABI_NO_RANDOM_DEVICE_COMPATIBILITY_LAYOUT
 #  define _LIBCPP_ABI_OPTIMIZED_FUNCTION
 #  define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO
 #  define _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
 #  define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY
 #  define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_STRING_VIEW
 #  define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION

 #elif _LIBCPP_ABI_VERSION == 1
 #  if !(defined(_LIBCPP_OBJECT_FORMAT_COFF) || defined(_LIBCPP_OBJECT_FORMAT_XCOFF))
 // Enable compiling copies of now inline methods into the dylib to support
 // applications compiled against older libraries. This is unnecessary with
 // COFF dllexport semantics, since dllexport forces a non-inline definition
 // of inline functions to be emitted anyway. Our own non-inline copy would
 // conflict with the dllexport-emitted copy, so we disable it. For XCOFF,
 // the linker will take issue with the symbols in the shared object if the
 // weak inline methods get visibility (such as from -fvisibility-inlines-hidden),
 // so disable it.
 #    define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
 #  endif
 // Feature macros for disabling pre ABI v1 features. All of these options
 // are deprecated.
 #  if defined(__FreeBSD__)
 #    define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR
 #  endif
 #endif

 // We had some bugs where we use [[no_unique_address]] together with construct_at,
 // which causes UB as the call on construct_at could write to overlapping subobjects
 //
 // https://github.com/llvm/llvm-project/issues/70506
 // https://github.com/llvm/llvm-project/issues/70494
 //
 // To fix the bug we had to change the ABI of some classes to remove [[no_unique_address]] under certain conditions.
 // The macro below is used for all classes whose ABI have changed as part of fixing these bugs.
 #define _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS __attribute__((__abi_tag__("llvm18_nua")))

 // [[msvc::no_unique_address]] seems to mostly affect empty classes, so the padding scheme for Itanium doesn't work.
 #if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING)
 #  define _LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING
 #endif

 // Tracks the bounds of the array owned by std::unique_ptr<T[]>, allowing it to trap when accessed out-of-bounds.
 // Note that limited bounds checking is also available outside of this ABI configuration, but only some categories
 // of types can be checked.
 //
 // ABI impact: This causes the layout of std::unique_ptr<T[]> to change and its size to increase.
 //             This also affects the representation of a few library types that use std::unique_ptr
 //             internally, such as the unordered containers.
 // #define _LIBCPP_ABI_BOUNDED_UNIQUE_PTR

 #if defined(_LIBCPP_COMPILER_CLANG_BASED)
 #  if defined(__APPLE__)
 #    if defined(__i386__) || defined(__x86_64__)
 // use old string layout on x86_64 and i386
 #    elif defined(__arm__)
 // use old string layout on arm (which does not include aarch64/arm64), except on watch ABIs
 #      if defined(__ARM_ARCH_7K__) && __ARM_ARCH_7K__ >= 2
 #        define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
 #      endif
 #    else
 #      define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
 #    endif
 #  endif
 #endif

 #endif // _LIBCPP___CONFIGURATION_ABI_H
	// -- C++ --
	//===----------------------------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef _LIBCPP___CONFIGURATION_ABI_H
	#define _LIBCPP___CONFIGURATION_ABI_H

	#include <__config_site>
	#include <__configuration/compiler.h>
	#include <__configuration/platform.h>

	#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
	# pragma GCC system_header
	#endif

	// FIXME: ABI detection should be done via compiler builtin macros. This
	// is just a placeholder until Clang implements such macros. For now assume
	// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
	// and allow the user to explicitly specify the ABI to handle cases where this
	// heuristic falls short.
	#if _LIBCPP_ABI_FORCE_ITANIUM && _LIBCPP_ABI_FORCE_MICROSOFT
	# error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be true"
	#elif _LIBCPP_ABI_FORCE_ITANIUM
	# define _LIBCPP_ABI_ITANIUM
	#elif _LIBCPP_ABI_FORCE_MICROSOFT
	# define _LIBCPP_ABI_MICROSOFT
	#else
	# if defined(_WIN32) && defined(_MSC_VER)
	# define _LIBCPP_ABI_MICROSOFT
	# else
	# define _LIBCPP_ABI_ITANIUM
	# endif
	#endif

	#if _LIBCPP_ABI_VERSION >= 2
	// TODO: Move the description of the remaining ABI flags to ABIGuarantees.rst or remove them.

	// Override the default return value of exception::what() for bad_function_call::what()
	// with a string that is specific to bad_function_call (see http://wg21.link/LWG2233).
	// This is an ABI break on platforms that sign and authenticate vtable function pointers
	// because it changes the mangling of the virtual function located in the vtable, which
	// changes how it gets signed.
	# define _LIBCPP_ABI_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE
	// According to the Standard, `bitset::operator[] const` returns bool
	# define _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL

	// In LLVM 20, we've changed to take these ABI breaks unconditionally. These flags only exist in case someone is running
	// into the static_asserts we added to catch the ABI break and don't care that it is one.
	// TODO(LLVM 22): Remove these flags
	# define _LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB
	# define _LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB
	# define _LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB
	# define _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB

	// These flags are documented in ABIGuarantees.rst
	# define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
	# define _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
	# define _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
	# define _LIBCPP_ABI_DO_NOT_EXPORT_TO_CHARS_BASE_10
	# define _LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI
	# define _LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI
	# define _LIBCPP_ABI_FIX_CITYHASH_IMPLEMENTATION
	# define _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
	# define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
	# define _LIBCPP_ABI_IOS_ALLOW_ARBITRARY_FILL_VALUE
	# define _LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING
	# define _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
	# define _LIBCPP_ABI_NO_ITERATOR_BASES
	# define _LIBCPP_ABI_NO_RANDOM_DEVICE_COMPATIBILITY_LAYOUT
	# define _LIBCPP_ABI_OPTIMIZED_FUNCTION
	# define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO
	# define _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
	# define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY
	# define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_STRING_VIEW
	# define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION

	#elif _LIBCPP_ABI_VERSION == 1
	# if !(defined(_LIBCPP_OBJECT_FORMAT_COFF) \|\| defined(_LIBCPP_OBJECT_FORMAT_XCOFF))
	// Enable compiling copies of now inline methods into the dylib to support
	// applications compiled against older libraries. This is unnecessary with
	// COFF dllexport semantics, since dllexport forces a non-inline definition
	// of inline functions to be emitted anyway. Our own non-inline copy would
	// conflict with the dllexport-emitted copy, so we disable it. For XCOFF,
	// the linker will take issue with the symbols in the shared object if the
	// weak inline methods get visibility (such as from -fvisibility-inlines-hidden),
	// so disable it.
	# define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
	# endif
	// Feature macros for disabling pre ABI v1 features. All of these options
	// are deprecated.
	# if defined(__FreeBSD__)
	# define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR
	# endif
	#endif

	// We had some bugs where we use [[no_unique_address]] together with construct_at,
	// which causes UB as the call on construct_at could write to overlapping subobjects
	//
	// https://github.com/llvm/llvm-project/issues/70506
	// https://github.com/llvm/llvm-project/issues/70494
	//
	// To fix the bug we had to change the ABI of some classes to remove [[no_unique_address]] under certain conditions.
	// The macro below is used for all classes whose ABI have changed as part of fixing these bugs.
	#define _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS __attribute__((__abi_tag__("llvm18_nua")))

	// [[msvc::no_unique_address]] seems to mostly affect empty classes, so the padding scheme for Itanium doesn't work.
	#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING)
	# define _LIBCPP_ABI_NO_COMPRESSED_PAIR_PADDING
	#endif

	// Tracks the bounds of the array owned by std::unique_ptr<T[]>, allowing it to trap when accessed out-of-bounds.
	// Note that limited bounds checking is also available outside of this ABI configuration, but only some categories
	// of types can be checked.
	//
	// ABI impact: This causes the layout of std::unique_ptr<T[]> to change and its size to increase.
	// This also affects the representation of a few library types that use std::unique_ptr
	// internally, such as the unordered containers.
	// #define _LIBCPP_ABI_BOUNDED_UNIQUE_PTR

	#if defined(_LIBCPP_COMPILER_CLANG_BASED)
	# if defined(__APPLE__)
	# if defined(__i386__) \|\| defined(__x86_64__)
	// use old string layout on x86_64 and i386
	# elif defined(__arm__)
	// use old string layout on arm (which does not include aarch64/arm64), except on watch ABIs
	# if defined(__ARM_ARCH_7K__) && __ARM_ARCH_7K__ >= 2
	# define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
	# endif
	# else
	# define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
	# endif
	# endif
	#endif

	#endif // _LIBCPP___CONFIGURATION_ABI_H