// -*- 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_FORMATTER_INTEGRAL_H
#define _LIBCPP___FORMAT_FORMATTER_INTEGRAL_H
#include <__charconv/to_chars_integral.h>
#include <__charconv/to_chars_result.h>
#include <__charconv/traits.h>
#include <__concepts/arithmetic.h>
#include <__concepts/same_as.h>
#include <__config>
#include <__format/concepts.h>
#include <__format/format_error.h>
#include <__format/formatter_output.h>
#include <__format/parser_std_format_spec.h>
#include <__iterator/concepts.h>
#include <__iterator/iterator_traits.h>
#include <__memory/pointer_traits.h>
#include <__system_error/errc.h>
#include <__type_traits/make_unsigned.h>
#include <__utility/unreachable.h>
#include <array>
#include <cstdint>
#include <limits>
#include <string>
#include <string_view>
#ifndef _LIBCPP_HAS_NO_LOCALIZATION
# include <__locale>
#endif
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
namespace __formatter {
//
// Generic
//
template <contiguous_iterator _Iterator>
requires same_as<char, iter_value_t<_Iterator>>
_LIBCPP_HIDE_FROM_ABI inline _Iterator __insert_sign(_Iterator __buf, bool __negative, __format_spec::__sign __sign) {
if (__negative)
*__buf++ = '-';
else
switch (__sign) {
case __format_spec::__sign::__default:
case __format_spec::__sign::__minus:
// No sign added.
break;
case __format_spec::__sign::__plus:
*__buf++ = '+';
break;
case __format_spec::__sign::__space:
*__buf++ = ' ';
break;
}
return __buf;
}
/**
* Determines the required grouping based on the size of the input.
*
* The grouping's last element will be repeated. For simplicity this repeating
* is unwrapped based on the length of the input. (When the input is short some
* groups are not processed.)
*
* @returns The size of the groups to write. This means the number of
* separator characters written is size() - 1.
*
* @note Since zero-sized groups cause issues they are silently ignored.
*
* @note The grouping field of the locale is always a @c std::string,
* regardless whether the @c std::numpunct's type is @c char or @c wchar_t.
*/
_LIBCPP_HIDE_FROM_ABI inline string __determine_grouping(ptrdiff_t __size, const string& __grouping) {
_LIBCPP_ASSERT_INTERNAL(!__grouping.empty() && __size > __grouping[0],
"The slow grouping formatting is used while there will be no separators written");
string __r;
auto __end = __grouping.end() - 1;
auto __ptr = __grouping.begin();
while (true) {
__size -= *__ptr;
if (__size > 0)
__r.push_back(*__ptr);
else {
// __size <= 0 so the value pushed will be <= *__ptr.
__r.push_back(*__ptr + __size);
return __r;
}
// Proceed to the next group.
if (__ptr != __end) {
do {
++__ptr;
// Skip grouping with a width of 0.
} while (*__ptr == 0 && __ptr != __end);
}
}
__libcpp_unreachable();
}
//
// Char
//
template <__fmt_char_type _CharT>
_LIBCPP_HIDE_FROM_ABI auto
__format_char(integral auto __value,
output_iterator<const _CharT&> auto __out_it,
__format_spec::__parsed_specifications<_CharT> __specs) -> decltype(__out_it) {
using _Tp = decltype(__value);
if constexpr (!same_as<_CharT, _Tp>) {
// cmp_less and cmp_greater can't be used for character types.
if constexpr (signed_integral<_CharT> == signed_integral<_Tp>) {
if (__value < numeric_limits<_CharT>::min() || __value > numeric_limits<_CharT>::max())
std::__throw_format_error("Integral value outside the range of the char type");
} else if constexpr (signed_integral<_CharT>) {
// _CharT is signed _Tp is unsigned
if (__value > static_cast<make_unsigned_t<_CharT>>(numeric_limits<_CharT>::max()))
std::__throw_format_error("Integral value outside the range of the char type");
} else {
// _CharT is unsigned _Tp is signed
if (__value < 0 || static_cast<make_unsigned_t<_Tp>>(__value) > numeric_limits<_CharT>::max())
std::__throw_format_error("Integral value outside the range of the char type");
}
}
const auto __c = static_cast<_CharT>(__value);
return __formatter::__write(std::addressof(__c), std::addressof(__c) + 1, std::move(__out_it), __specs);
}
//
// Integer
//
/** Wrapper around @ref to_chars, returning the output iterator. */
template <contiguous_iterator _Iterator, integral _Tp>
requires same_as<char, iter_value_t<_Iterator>>
_LIBCPP_HIDE_FROM_ABI _Iterator __to_buffer(_Iterator __first, _Iterator __last, _Tp __value, int __base) {
// TODO FMT Evaluate code overhead due to not calling the internal function
// directly. (Should be zero overhead.)
to_chars_result __r = std::to_chars(std::to_address(__first), std::to_address(__last), __value, __base);
_LIBCPP_ASSERT_INTERNAL(__r.ec == errc(0), "Internal buffer too small");
auto __diff = __r.ptr - std::to_address(__first);
return __first + __diff;
}
/**
* Helper to determine the buffer size to output a integer in Base @em x.
*
* There are several overloads for the supported bases. The function uses the
* base as template argument so it can be used in a constant expression.
*/
template <unsigned_integral _Tp, size_t _Base>
consteval size_t __buffer_size() noexcept
requires(_Base == 2)
{
return numeric_limits<_Tp>::digits // The number of binary digits.
+ 2 // Reserve space for the '0[Bb]' prefix.
+ 1; // Reserve space for the sign.
}
template <unsigned_integral _Tp, size_t _Base>
consteval size_t __buffer_size() noexcept
requires(_Base == 8)
{
return numeric_limits<_Tp>::digits // The number of binary digits.
/ 3 // Adjust to octal.
+ 1 // Turn floor to ceil.
+ 1 // Reserve space for the '0' prefix.
+ 1; // Reserve space for the sign.
}
template <unsigned_integral _Tp, size_t _Base>
consteval size_t __buffer_size() noexcept
requires(_Base == 10)
{
return numeric_limits<_Tp>::digits10 // The floored value.
+ 1 // Turn floor to ceil.
+ 1; // Reserve space for the sign.
}
template <unsigned_integral _Tp, size_t _Base>
consteval size_t __buffer_size() noexcept
requires(_Base == 16)
{
return numeric_limits<_Tp>::digits // The number of binary digits.
/ 4 // Adjust to hexadecimal.
+ 2 // Reserve space for the '0[Xx]' prefix.
+ 1; // Reserve space for the sign.
}
template <class _OutIt, contiguous_iterator _Iterator, class _CharT>
requires same_as<char, iter_value_t<_Iterator>>
_LIBCPP_HIDE_FROM_ABI _OutIt __write_using_decimal_separators(
_OutIt __out_it,
_Iterator __begin,
_Iterator __first,
_Iterator __last,
string&& __grouping,
_CharT __sep,
__format_spec::__parsed_specifications<_CharT> __specs) {
int __size = (__first - __begin) + // [sign][prefix]
(__last - __first) + // data
(__grouping.size() - 1); // number of separator characters
__padding_size_result __padding = {0, 0};
if (__specs.__alignment_ == __format_spec::__alignment::__zero_padding) {
// Write [sign][prefix].
__out_it = __formatter::__copy(__begin, __first, std::move(__out_it));
if (__specs.__width_ > __size) {
// Write zero padding.
__padding.__before_ = __specs.__width_ - __size;
__out_it = __formatter::__fill(std::move(__out_it), __specs.__width_ - __size, _CharT('0'));
}
} else {
if (__specs.__width_ > __size) {
// Determine padding and write padding.
__padding = __formatter::__padding_size(__size, __specs.__width_, __specs.__alignment_);
__out_it = __formatter::__fill(std::move(__out_it), __padding.__before_, __specs.__fill_);
}
// Write [sign][prefix].
__out_it = __formatter::__copy(__begin, __first, std::move(__out_it));
}
auto __r = __grouping.rbegin();
auto __e = __grouping.rend() - 1;
_LIBCPP_ASSERT_INTERNAL(
__r != __e, "The slow grouping formatting is used while there will be no separators written.");
// The output is divided in small groups of numbers to write:
// - A group before the first separator.
// - A separator and a group, repeated for the number of separators.
// - A group after the last separator.
// This loop achieves that process by testing the termination condition
// midway in the loop.
//
// TODO FMT This loop evaluates the loop invariant `__parser.__type !=
// _Flags::_Type::__hexadecimal_upper_case` for every iteration. (This test
// happens in the __write call.) Benchmark whether making two loops and
// hoisting the invariant is worth the effort.
while (true) {
if (__specs.__std_.__type_ == __format_spec::__type::__hexadecimal_upper_case) {
__last = __first + *__r;
__out_it = __formatter::__transform(__first, __last, std::move(__out_it), __hex_to_upper);
__first = __last;
} else {
__out_it = __formatter::__copy(__first, *__r, std::move(__out_it));
__first += *__r;
}
if (__r == __e)
break;
++__r;
*__out_it++ = __sep;
}
return __formatter::__fill(std::move(__out_it), __padding.__after_, __specs.__fill_);
}
template <unsigned_integral _Tp, contiguous_iterator _Iterator, class _CharT, class _FormatContext>
requires same_as<char, iter_value_t<_Iterator>>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator __format_integer(
_Tp __value,
_FormatContext& __ctx,
__format_spec::__parsed_specifications<_CharT> __specs,
bool __negative,
_Iterator __begin,
_Iterator __end,
const char* __prefix,
int __base) {
_Iterator __first = __formatter::__insert_sign(__begin, __negative, __specs.__std_.__sign_);
if (__specs.__std_.__alternate_form_ && __prefix)
while (*__prefix)
*__first++ = *__prefix++;
_Iterator __last = __formatter::__to_buffer(__first, __end, __value, __base);
# ifndef _LIBCPP_HAS_NO_LOCALIZATION
if (__specs.__std_.__locale_specific_form_) {
const auto& __np = std::use_facet<numpunct<_CharT>>(__ctx.locale());
string __grouping = __np.grouping();
ptrdiff_t __size = __last - __first;
// Writing the grouped form has more overhead than the normal output
// routines. If there will be no separators written the locale-specific
// form is identical to the normal routine. Test whether to grouped form
// is required.
if (!__grouping.empty() && __size > __grouping[0])
return __formatter::__write_using_decimal_separators(
__ctx.out(),
__begin,
__first,
__last,
__formatter::__determine_grouping(__size, __grouping),
__np.thousands_sep(),
__specs);
}
# endif
auto __out_it = __ctx.out();
if (__specs.__alignment_ != __format_spec::__alignment::__zero_padding)
__first = __begin;
else {
// __buf contains [sign][prefix]data
// ^ location of __first
// The zero padding is done like:
// - Write [sign][prefix]
// - Write data right aligned with '0' as fill character.
__out_it = __formatter::__copy(__begin, __first, std::move(__out_it));
__specs.__alignment_ = __format_spec::__alignment::__right;
__specs.__fill_.__data[0] = _CharT('0');
int32_t __size = __first - __begin;
__specs.__width_ -= std::min(__size, __specs.__width_);
}
if (__specs.__std_.__type_ != __format_spec::__type::__hexadecimal_upper_case) [[likely]]
return __formatter::__write(__first, __last, __ctx.out(), __specs);
return __formatter::__write_transformed(__first, __last, __ctx.out(), __specs, __formatter::__hex_to_upper);
}
template <unsigned_integral _Tp, class _CharT, class _FormatContext>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
__format_integer(_Tp __value,
_FormatContext& __ctx,
__format_spec::__parsed_specifications<_CharT> __specs,
bool __negative = false) {
switch (__specs.__std_.__type_) {
case __format_spec::__type::__binary_lower_case: {
array<char, __formatter::__buffer_size<decltype(__value), 2>()> __array;
return __formatter::__format_integer(__value, __ctx, __specs, __negative, __array.begin(), __array.end(), "0b", 2);
}
case __format_spec::__type::__binary_upper_case: {
array<char, __formatter::__buffer_size<decltype(__value), 2>()> __array;
return __formatter::__format_integer(__value, __ctx, __specs, __negative, __array.begin(), __array.end(), "0B", 2);
}
case __format_spec::__type::__octal: {
// Octal is special; if __value == 0 there's no prefix.
array<char, __formatter::__buffer_size<decltype(__value), 8>()> __array;
return __formatter::__format_integer(
__value, __ctx, __specs, __negative, __array.begin(), __array.end(), __value != 0 ? "0" : nullptr, 8);
}
case __format_spec::__type::__default:
case __format_spec::__type::__decimal: {
array<char, __formatter::__buffer_size<decltype(__value), 10>()> __array;
return __formatter::__format_integer(
__value, __ctx, __specs, __negative, __array.begin(), __array.end(), nullptr, 10);
}
case __format_spec::__type::__hexadecimal_lower_case: {
array<char, __formatter::__buffer_size<decltype(__value), 16>()> __array;
return __formatter::__format_integer(__value, __ctx, __specs, __negative, __array.begin(), __array.end(), "0x", 16);
}
case __format_spec::__type::__hexadecimal_upper_case: {
array<char, __formatter::__buffer_size<decltype(__value), 16>()> __array;
return __formatter::__format_integer(__value, __ctx, __specs, __negative, __array.begin(), __array.end(), "0X", 16);
}
default:
_LIBCPP_ASSERT_INTERNAL(false, "The parse function should have validated the type");
__libcpp_unreachable();
}
}
template <signed_integral _Tp, class _CharT, class _FormatContext>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
__format_integer(_Tp __value, _FormatContext& __ctx, __format_spec::__parsed_specifications<_CharT> __specs) {
// Depending on the std-format-spec string the sign and the value
// might not be outputted together:
// - alternate form may insert a prefix string.
// - zero-padding may insert additional '0' characters.
// Therefore the value is processed as a positive unsigned value.
// The function @ref __insert_sign will a '-' when the value was negative.
auto __r = std::__to_unsigned_like(__value);
bool __negative = __value < 0;
if (__negative)
__r = std::__complement(__r);
return __formatter::__format_integer(__r, __ctx, __specs, __negative);
}
//
// Formatter arithmetic (bool)
//
template <class _CharT>
struct _LIBCPP_TEMPLATE_VIS __bool_strings;
template <>
struct _LIBCPP_TEMPLATE_VIS __bool_strings<char> {
static constexpr string_view __true{"true"};
static constexpr string_view __false{"false"};
};
# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <>
struct _LIBCPP_TEMPLATE_VIS __bool_strings<wchar_t> {
static constexpr wstring_view __true{L"true"};
static constexpr wstring_view __false{L"false"};
};
# endif
template <class _CharT, class _FormatContext>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator
__format_bool(bool __value, _FormatContext& __ctx, __format_spec::__parsed_specifications<_CharT> __specs) {
# ifndef _LIBCPP_HAS_NO_LOCALIZATION
if (__specs.__std_.__locale_specific_form_) {
const auto& __np = std::use_facet<numpunct<_CharT>>(__ctx.locale());
basic_string<_CharT> __str = __value ? __np.truename() : __np.falsename();
return __formatter::__write_string_no_precision(basic_string_view<_CharT>{__str}, __ctx.out(), __specs);
}
# endif
basic_string_view<_CharT> __str =
__value ? __formatter::__bool_strings<_CharT>::__true : __formatter::__bool_strings<_CharT>::__false;
return __formatter::__write(__str.begin(), __str.end(), __ctx.out(), __specs);
}
} // namespace __formatter
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___FORMAT_FORMATTER_INTEGRAL_H
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