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authorDimitry Andric <dim@FreeBSD.org>2022-07-03 14:10:23 +0000
committerDimitry Andric <dim@FreeBSD.org>2022-07-03 14:10:23 +0000
commit145449b1e420787bb99721a429341fa6be3adfb6 (patch)
tree1d56ae694a6de602e348dd80165cf881a36600ed /libcxx/include/__format/format_arg_store.h
parentecbca9f5fb7d7613d2b94982c4825eb0d33d6842 (diff)
downloadsrc-145449b1e420787bb99721a429341fa6be3adfb6.tar.gz
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Vendor import of llvm-project main llvmorg-15-init-15358-g53dc0f107877.vendor/llvm-project/llvmorg-15-init-15358-g53dc0f107877
Diffstat (limited to 'libcxx/include/__format/format_arg_store.h')
-rw-r--r--libcxx/include/__format/format_arg_store.h253
1 files changed, 253 insertions, 0 deletions
diff --git a/libcxx/include/__format/format_arg_store.h b/libcxx/include/__format/format_arg_store.h
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+// -*- 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___FORMAT_FORMAT_ARG_STORE_H
+#define _LIBCPP___FORMAT_FORMAT_ARG_STORE_H
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+#include <__concepts/arithmetic.h>
+#include <__concepts/same_as.h>
+#include <__config>
+#include <__format/concepts.h>
+#include <__format/format_arg.h>
+#include <cstring>
+#include <string>
+#include <string_view>
+#include <type_traits>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 17
+
+namespace __format {
+
+/// \returns The @c __arg_t based on the type of the formatting argument.
+///
+/// \pre \c __formattable<_Tp, typename _Context::char_type>
+template <class _Context, class _Tp>
+consteval __arg_t __determine_arg_t();
+
+// Boolean
+template <class, same_as<bool> _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__boolean;
+}
+
+// Char
+template <class _Context, same_as<typename _Context::char_type> _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__char_type;
+}
+# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+template <class _Context, class _CharT>
+ requires(same_as<typename _Context::char_type, wchar_t> && same_as<_CharT, char>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__char_type;
+}
+# endif
+
+// Signed integers
+template <class, __libcpp_signed_integer _Tp>
+consteval __arg_t __determine_arg_t() {
+ if constexpr (sizeof(_Tp) <= sizeof(int))
+ return __arg_t::__int;
+ else if constexpr (sizeof(_Tp) <= sizeof(long long))
+ return __arg_t::__long_long;
+# ifndef _LIBCPP_HAS_NO_INT128
+ else if constexpr (sizeof(_Tp) == sizeof(__int128_t))
+ return __arg_t::__i128;
+# endif
+ else
+ static_assert(sizeof(_Tp) == 0, "an unsupported signed integer was used");
+}
+
+// Unsigned integers
+template <class, __libcpp_unsigned_integer _Tp>
+consteval __arg_t __determine_arg_t() {
+ if constexpr (sizeof(_Tp) <= sizeof(unsigned))
+ return __arg_t::__unsigned;
+ else if constexpr (sizeof(_Tp) <= sizeof(unsigned long long))
+ return __arg_t::__unsigned_long_long;
+# ifndef _LIBCPP_HAS_NO_INT128
+ else if constexpr (sizeof(_Tp) == sizeof(__uint128_t))
+ return __arg_t::__u128;
+# endif
+ else
+ static_assert(sizeof(_Tp) == 0, "an unsupported unsigned integer was used");
+}
+
+// Floating-point
+template <class, same_as<float> _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__float;
+}
+template <class, same_as<double> _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__double;
+}
+template <class, same_as<long double> _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__long_double;
+}
+
+// Char pointer
+template <class _Context, class _Tp>
+ requires(same_as<typename _Context::char_type*, _Tp> || same_as<const typename _Context::char_type*, _Tp>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__const_char_type_ptr;
+}
+
+// Char array
+template <class _Context, class _Tp>
+ requires(is_array_v<_Tp> && same_as<_Tp, typename _Context::char_type[extent_v<_Tp>]>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__string_view;
+}
+
+// String view
+template <class _Context, class _Tp>
+ requires(same_as<typename _Context::char_type, typename _Tp::value_type> &&
+ same_as<_Tp, basic_string_view<typename _Tp::value_type, typename _Tp::traits_type>>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__string_view;
+}
+
+// String
+template <class _Context, class _Tp>
+ requires(
+ same_as<typename _Context::char_type, typename _Tp::value_type> &&
+ same_as<_Tp, basic_string<typename _Tp::value_type, typename _Tp::traits_type, typename _Tp::allocator_type>>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__string_view;
+}
+
+// Pointers
+template <class, class _Ptr>
+ requires(same_as<_Ptr, void*> || same_as<_Ptr, const void*> || same_as<_Ptr, nullptr_t>)
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__ptr;
+}
+
+// Handle
+//
+// Note this version can't be constrained avoiding ambiguous overloads.
+// That means it can be instantiated by disabled formatters. To solve this, a
+// constrained version for not formattable formatters is added. That overload
+// is marked as deleted to fail creating a storage type for disabled formatters.
+template <class _Context, class _Tp>
+consteval __arg_t __determine_arg_t() {
+ return __arg_t::__handle;
+}
+
+template <class _Context, class _Tp>
+ requires(!__formattable<_Tp, typename _Context::char_type>)
+consteval __arg_t __determine_arg_t() = delete;
+
+template <class _Context, class _Tp>
+_LIBCPP_HIDE_FROM_ABI basic_format_arg<_Context> __create_format_arg(_Tp&& __value) noexcept {
+ constexpr __arg_t __arg = __determine_arg_t<_Context, remove_cvref_t<_Tp>>();
+ static_assert(__arg != __arg_t::__none);
+
+ // Not all types can be used to directly initialize the
+ // __basic_format_arg_value. First handle all types needing adjustment, the
+ // final else requires no adjustment.
+ if constexpr (__arg == __arg_t::__char_type)
+ // On some platforms initializing a wchar_t from a char is a narrowing
+ // conversion.
+ return basic_format_arg<_Context>{__arg, static_cast<typename _Context::char_type>(__value)};
+ else if constexpr (__arg == __arg_t::__int)
+ return basic_format_arg<_Context>{__arg, static_cast<int>(__value)};
+ else if constexpr (__arg == __arg_t::__long_long)
+ return basic_format_arg<_Context>{__arg, static_cast<long long>(__value)};
+ else if constexpr (__arg == __arg_t::__unsigned)
+ return basic_format_arg<_Context>{__arg, static_cast<unsigned>(__value)};
+ else if constexpr (__arg == __arg_t::__unsigned_long_long)
+ return basic_format_arg<_Context>{__arg, static_cast<unsigned long long>(__value)};
+ else if constexpr (__arg == __arg_t::__string_view)
+ // Using std::size on a character array will add the NUL-terminator to the size.
+ if constexpr (is_array_v<remove_cvref_t<_Tp>>)
+ return basic_format_arg<_Context>{
+ __arg, basic_string_view<typename _Context::char_type>{__value, extent_v<remove_cvref_t<_Tp>> - 1}};
+ else
+ // When the _Traits or _Allocator are different an implicit conversion will
+ // fail.
+ return basic_format_arg<_Context>{
+ __arg, basic_string_view<typename _Context::char_type>{__value.data(), __value.size()}};
+ else if constexpr (__arg == __arg_t::__ptr)
+ return basic_format_arg<_Context>{__arg, static_cast<const void*>(__value)};
+ else if constexpr (__arg == __arg_t::__handle)
+ return basic_format_arg<_Context>{
+ __arg, typename __basic_format_arg_value<_Context>::__handle{_VSTD::forward<_Tp>(__value)}};
+ else
+ return basic_format_arg<_Context>{__arg, __value};
+}
+
+template <class _Context, class... _Args>
+_LIBCPP_HIDE_FROM_ABI void __create_packed_storage(uint64_t& __types, __basic_format_arg_value<_Context>* __values,
+ _Args&&... __args) noexcept {
+ int __shift = 0;
+ (
+ [&] {
+ basic_format_arg<_Context> __arg = __create_format_arg<_Context>(_VSTD::forward<_Args>(__args));
+ if (__shift != 0)
+ __types |= static_cast<uint64_t>(__arg.__type_) << __shift;
+ else
+ // Assigns the initial value.
+ __types = static_cast<uint64_t>(__arg.__type_);
+ __shift += __packed_arg_t_bits;
+ *__values++ = __arg.__value_;
+ }(),
+ ...);
+}
+
+template <class _Context, class... _Args>
+_LIBCPP_HIDE_FROM_ABI void __store_basic_format_arg(basic_format_arg<_Context>* __data, _Args&&... __args) noexcept {
+ ([&] { *__data++ = __create_format_arg<_Context>(_VSTD::forward<_Args>(__args)); }(), ...);
+}
+
+template <class _Context, size_t N>
+struct __packed_format_arg_store {
+ __basic_format_arg_value<_Context> __values_[N];
+ uint64_t __types_;
+};
+
+template <class _Context, size_t N>
+struct __unpacked_format_arg_store {
+ basic_format_arg<_Context> __args_[N];
+};
+
+} // namespace __format
+
+template <class _Context, class... _Args>
+struct _LIBCPP_TEMPLATE_VIS __format_arg_store {
+ _LIBCPP_HIDE_FROM_ABI
+ __format_arg_store(_Args&&... __args) noexcept {
+ if constexpr (sizeof...(_Args) != 0) {
+ if constexpr (__format::__use_packed_format_arg_store(sizeof...(_Args)))
+ __format::__create_packed_storage(__storage.__types_, __storage.__values_, _VSTD::forward<_Args>(__args)...);
+ else
+ __format::__store_basic_format_arg<_Context>(__storage.__args_, _VSTD::forward<_Args>(__args)...);
+ }
+ }
+
+ using _Storage = conditional_t<__format::__use_packed_format_arg_store(sizeof...(_Args)),
+ __format::__packed_format_arg_store<_Context, sizeof...(_Args)>,
+ __format::__unpacked_format_arg_store<_Context, sizeof...(_Args)>>;
+
+ _Storage __storage;
+};
+
+#endif //_LIBCPP_STD_VER > 17
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___FORMAT_FORMAT_ARG_STORE_H