1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___CONFIGURATION_ABI_H 11 #define _LIBCPP___CONFIGURATION_ABI_H 12 13 #include <__config_site> 14 #include <__configuration/compiler.h> 15 #include <__configuration/platform.h> 16 17 #ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER 18 # pragma GCC system_header 19 #endif 20 21 #if _LIBCPP_ABI_VERSION >= 2 22 // Change short string representation so that string data starts at offset 0, 23 // improving its alignment in some cases. 24 # define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT 25 // Fix deque iterator type in order to support incomplete types. 26 # define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE 27 // Fix undefined behavior in how std::list stores its linked nodes. 28 # define _LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB 29 // Fix undefined behavior in how __tree stores its end and parent nodes. 30 # define _LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB 31 // Fix undefined behavior in how __hash_table stores its pointer types. 32 # define _LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB 33 # define _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB 34 # define _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE 35 // Override the default return value of exception::what() for bad_function_call::what() 36 // with a string that is specific to bad_function_call (see http://wg21.link/LWG2233). 37 // This is an ABI break on platforms that sign and authenticate vtable function pointers 38 // because it changes the mangling of the virtual function located in the vtable, which 39 // changes how it gets signed. 40 # define _LIBCPP_ABI_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE 41 // Enable optimized version of __do_get_(un)signed which avoids redundant copies. 42 # define _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET 43 // Give reverse_iterator<T> one data member of type T, not two. 44 // Also, in C++17 and later, don't derive iterator types from std::iterator. 45 # define _LIBCPP_ABI_NO_ITERATOR_BASES 46 // Use the smallest possible integer type to represent the index of the variant. 47 // Previously libc++ used "unsigned int" exclusively. 48 # define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION 49 // Unstable attempt to provide a more optimized std::function 50 # define _LIBCPP_ABI_OPTIMIZED_FUNCTION 51 // All the regex constants must be distinct and nonzero. 52 # define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO 53 // Re-worked external template instantiations for std::string with a focus on 54 // performance and fast-path inlining. 55 # define _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION 56 // Enable clang::trivial_abi on std::unique_ptr. 57 # define _LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI 58 // Enable clang::trivial_abi on std::shared_ptr and std::weak_ptr 59 # define _LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI 60 // std::random_device holds some state when it uses an implementation that gets 61 // entropy from a file (see _LIBCPP_USING_DEV_RANDOM). When switching from this 62 // implementation to another one on a platform that has already shipped 63 // std::random_device, one needs to retain the same object layout to remain ABI 64 // compatible. This switch removes these workarounds for platforms that don't care 65 // about ABI compatibility. 66 # define _LIBCPP_ABI_NO_RANDOM_DEVICE_COMPATIBILITY_LAYOUT 67 // Don't export the legacy __basic_string_common class and its methods from the built library. 68 # define _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON 69 // Don't export the legacy __vector_base_common class and its methods from the built library. 70 # define _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON 71 // According to the Standard, `bitset::operator[] const` returns bool 72 # define _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL 73 // Fix the implementation of CityHash used for std::hash<fundamental-type>. 74 // This is an ABI break because `std::hash` will return a different result, 75 // which means that hashing the same object in translation units built against 76 // different versions of libc++ can return inconsistent results. This is especially 77 // tricky since std::hash is used in the implementation of unordered containers. 78 // 79 // The incorrect implementation of CityHash has the problem that it drops some 80 // bits on the floor. 81 # define _LIBCPP_ABI_FIX_CITYHASH_IMPLEMENTATION 82 // Remove the base 10 implementation of std::to_chars from the dylib. 83 // The implementation moved to the header, but we still export the symbols from 84 // the dylib for backwards compatibility. 85 # define _LIBCPP_ABI_DO_NOT_EXPORT_TO_CHARS_BASE_10 86 // Define std::array/std::string_view iterators to be __wrap_iters instead of raw 87 // pointers, which prevents people from relying on a non-portable implementation 88 // detail. This is especially useful because enabling bounded iterators hardening 89 // requires code not to make these assumptions. 90 # define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY 91 # define _LIBCPP_ABI_USE_WRAP_ITER_IN_STD_STRING_VIEW 92 // Dont' add an inline namespace for `std::filesystem` 93 # define _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE 94 // std::basic_ios uses WEOF to indicate that the fill value is 95 // uninitialized. However, on platforms where the size of char_type is 96 // equal to or greater than the size of int_type and char_type is unsigned, 97 // std::char_traits<char_type>::eq_int_type() cannot distinguish between WEOF 98 // and WCHAR_MAX. This ABI setting determines whether we should instead track whether the fill 99 // value has been initialized using a separate boolean, which changes the ABI. 100 # define _LIBCPP_ABI_IOS_ALLOW_ARBITRARY_FILL_VALUE 101 // Make a std::pair of trivially copyable types trivially copyable. 102 // While this technically doesn't change the layout of pair itself, other types may decide to programatically change 103 // their representation based on whether something is trivially copyable. 104 # define _LIBCPP_ABI_TRIVIALLY_COPYABLE_PAIR 105 #elif _LIBCPP_ABI_VERSION == 1 106 # if !(defined(_LIBCPP_OBJECT_FORMAT_COFF) || defined(_LIBCPP_OBJECT_FORMAT_XCOFF)) 107 // Enable compiling copies of now inline methods into the dylib to support 108 // applications compiled against older libraries. This is unnecessary with 109 // COFF dllexport semantics, since dllexport forces a non-inline definition 110 // of inline functions to be emitted anyway. Our own non-inline copy would 111 // conflict with the dllexport-emitted copy, so we disable it. For XCOFF, 112 // the linker will take issue with the symbols in the shared object if the 113 // weak inline methods get visibility (such as from -fvisibility-inlines-hidden), 114 // so disable it. 115 # define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS 116 # endif 117 // Feature macros for disabling pre ABI v1 features. All of these options 118 // are deprecated. 119 # if defined(__FreeBSD__) 120 # define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR 121 # endif 122 #endif 123 124 // We had some bugs where we use [[no_unique_address]] together with construct_at, 125 // which causes UB as the call on construct_at could write to overlapping subobjects 126 // 127 // https://github.com/llvm/llvm-project/issues/70506 128 // https://github.com/llvm/llvm-project/issues/70494 129 // 130 // To fix the bug we had to change the ABI of some classes to remove [[no_unique_address]] under certain conditions. 131 // The macro below is used for all classes whose ABI have changed as part of fixing these bugs. 132 #define _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS __attribute__((__abi_tag__("llvm18_nua"))) 133 134 // Changes the iterator type of select containers (see below) to a bounded iterator that keeps track of whether it's 135 // within the bounds of the original container and asserts it on every dereference. 136 // 137 // ABI impact: changes the iterator type of the relevant containers. 138 // 139 // Supported containers: 140 // - `span`; 141 // - `string_view`. 142 // #define _LIBCPP_ABI_BOUNDED_ITERATORS 143 144 // Changes the iterator type of `basic_string` to a bounded iterator that keeps track of whether it's within the bounds 145 // of the original container and asserts it on every dereference and when performing iterator arithmetics. 146 // 147 // ABI impact: changes the iterator type of `basic_string` and its specializations, such as `string` and `wstring`. 148 // #define _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING 149 150 // Changes the iterator type of `vector` to a bounded iterator that keeps track of whether it's within the bounds of the 151 // original container and asserts it on every dereference and when performing iterator arithmetics. Note: this doesn't 152 // yet affect `vector<bool>`. 153 // 154 // ABI impact: changes the iterator type of `vector` (except `vector<bool>`). 155 // #define _LIBCPP_ABI_BOUNDED_ITERATORS_IN_VECTOR 156 157 #if defined(_LIBCPP_COMPILER_CLANG_BASED) 158 # if defined(__APPLE__) 159 # if defined(__i386__) || defined(__x86_64__) 160 // use old string layout on x86_64 and i386 161 # elif defined(__arm__) 162 // use old string layout on arm (which does not include aarch64/arm64), except on watch ABIs 163 # if defined(__ARM_ARCH_7K__) && __ARM_ARCH_7K__ >= 2 164 # define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT 165 # endif 166 # else 167 # define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT 168 # endif 169 # endif 170 #endif 171 172 #endif // _LIBCPP___CONFIGURATION_ABI_H 173