llvm/libcxx
1
0
Fork 0
mirror of https://github.com/llvm-mirror/libcxx.git synced 2025-10-23 18:38:30 +08:00
Code Issues Packages Projects Releases Wiki Activity
Files
6ba69cac26f7cd31f1662338dd77a5748bb4b51d
libcxx/include/charconv
Chandler Carruth 7c3769df62 Update more file headers across all of the LLVM projects in the monorepo 
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@351648 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 10:56:40 +00:00

617 lines
17 KiB
C++
Raw Blame History

// -*- C++ -*-
//===------------------------------ charconv ------------------------------===//
//
// 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_CHARCONV
#define _LIBCPP_CHARCONV
/*
charconv synopsis
namespace std {
// floating-point format for primitive numerical conversion
enum class chars_format {
scientific = unspecified,
fixed = unspecified,
hex = unspecified,
general = fixed | scientific
};
// 23.20.2, primitive numerical output conversion
struct to_chars_result {
char* ptr;
errc ec;
};
to_chars_result to_chars(char* first, char* last, see below value,
int base = 10);
to_chars_result to_chars(char* first, char* last, float value);
to_chars_result to_chars(char* first, char* last, double value);
to_chars_result to_chars(char* first, char* last, long double value);
to_chars_result to_chars(char* first, char* last, float value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, double value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, long double value,
chars_format fmt);
to_chars_result to_chars(char* first, char* last, float value,
chars_format fmt, int precision);
to_chars_result to_chars(char* first, char* last, double value,
chars_format fmt, int precision);
to_chars_result to_chars(char* first, char* last, long double value,
chars_format fmt, int precision);
// 23.20.3, primitive numerical input conversion
struct from_chars_result {
const char* ptr;
errc ec;
};
from_chars_result from_chars(const char* first, const char* last,
see below& value, int base = 10);
from_chars_result from_chars(const char* first, const char* last,
float& value,
chars_format fmt = chars_format::general);
from_chars_result from_chars(const char* first, const char* last,
double& value,
chars_format fmt = chars_format::general);
from_chars_result from_chars(const char* first, const char* last,
long double& value,
chars_format fmt = chars_format::general);
} // namespace std
*/
#include <__errc>
#include <type_traits>
#include <limits>
#include <stdint.h>
#include <string.h>
#include <math.h>
#include <__debug>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
namespace __itoa {
_LIBCPP_FUNC_VIS char* __u64toa(uint64_t __value, char* __buffer);
_LIBCPP_FUNC_VIS char* __u32toa(uint32_t __value, char* __buffer);
}
#if _LIBCPP_STD_VER > 11
enum class _LIBCPP_ENUM_VIS chars_format
{
scientific = 0x1,
fixed = 0x2,
hex = 0x4,
general = fixed | scientific
};
struct _LIBCPP_TYPE_VIS to_chars_result
{
char* ptr;
errc ec;
};
struct _LIBCPP_TYPE_VIS from_chars_result
{
const char* ptr;
errc ec;
};
void to_chars(char*, char*, bool, int = 10) = delete;
void from_chars(const char*, const char*, bool, int = 10) = delete;
namespace __itoa
{
static constexpr uint64_t __pow10_64[] = {
UINT64_C(0),
UINT64_C(10),
UINT64_C(100),
UINT64_C(1000),
UINT64_C(10000),
UINT64_C(100000),
UINT64_C(1000000),
UINT64_C(10000000),
UINT64_C(100000000),
UINT64_C(1000000000),
UINT64_C(10000000000),
UINT64_C(100000000000),
UINT64_C(1000000000000),
UINT64_C(10000000000000),
UINT64_C(100000000000000),
UINT64_C(1000000000000000),
UINT64_C(10000000000000000),
UINT64_C(100000000000000000),
UINT64_C(1000000000000000000),
UINT64_C(10000000000000000000),
};
static constexpr uint32_t __pow10_32[] = {
UINT32_C(0), UINT32_C(10), UINT32_C(100),
UINT32_C(1000), UINT32_C(10000), UINT32_C(100000),
UINT32_C(1000000), UINT32_C(10000000), UINT32_C(100000000),
UINT32_C(1000000000),
};
template <typename _Tp, typename = void>
struct _LIBCPP_HIDDEN __traits_base
{
using type = uint64_t;
#if !defined(_LIBCPP_COMPILER_MSVC)
static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
{
auto __t = (64 - __builtin_clzll(__v | 1)) * 1233 >> 12;
return __t - (__v < __pow10_64[__t]) + 1;
}
#endif
static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
{
return __u64toa(__v, __p);
}
static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_64; }
};
template <typename _Tp>
struct _LIBCPP_HIDDEN
__traits_base<_Tp, decltype(void(uint32_t{declval<_Tp>()}))>
{
using type = uint32_t;
#if !defined(_LIBCPP_COMPILER_MSVC)
static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
{
auto __t = (32 - __builtin_clz(__v | 1)) * 1233 >> 12;
return __t - (__v < __pow10_32[__t]) + 1;
}
#endif
static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
{
return __u32toa(__v, __p);
}
static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_32; }
};
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY bool
__mul_overflowed(unsigned char __a, _Tp __b, unsigned char& __r)
{
auto __c = __a * __b;
__r = __c;
return __c > (numeric_limits<unsigned char>::max)();
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY bool
__mul_overflowed(unsigned short __a, _Tp __b, unsigned short& __r)
{
auto __c = __a * __b;
__r = __c;
return __c > (numeric_limits<unsigned short>::max)();
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY bool
__mul_overflowed(_Tp __a, _Tp __b, _Tp& __r)
{
static_assert(is_unsigned<_Tp>::value, "");
#if !defined(_LIBCPP_COMPILER_MSVC)
return __builtin_mul_overflow(__a, __b, &__r);
#else
bool __did = __b && ((numeric_limits<_Tp>::max)() / __b) < __a;
__r = __a * __b;
return __did;
#endif
}
template <typename _Tp, typename _Up>
inline _LIBCPP_INLINE_VISIBILITY bool
__mul_overflowed(_Tp __a, _Up __b, _Tp& __r)
{
return __mul_overflowed(__a, static_cast<_Tp>(__b), __r);
}
template <typename _Tp>
struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
{
static constexpr int digits = numeric_limits<_Tp>::digits10 + 1;
using __traits_base<_Tp>::__pow;
using typename __traits_base<_Tp>::type;
// precondition: at least one non-zero character available
static _LIBCPP_INLINE_VISIBILITY char const*
__read(char const* __p, char const* __ep, type& __a, type& __b)
{
type __cprod[digits];
int __j = digits - 1;
int __i = digits;
do
{
if (!('0' <= *__p && *__p <= '9'))
break;
__cprod[--__i] = *__p++ - '0';
} while (__p != __ep && __i != 0);
__a = __inner_product(__cprod + __i + 1, __cprod + __j, __pow() + 1,
__cprod[__i]);
if (__mul_overflowed(__cprod[__j], __pow()[__j - __i], __b))
--__p;
return __p;
}
template <typename _It1, typename _It2, class _Up>
static _LIBCPP_INLINE_VISIBILITY _Up
__inner_product(_It1 __first1, _It1 __last1, _It2 __first2, _Up __init)
{
for (; __first1 < __last1; ++__first1, ++__first2)
__init = __init + *__first1 * *__first2;
return __init;
}
};
} // namespace __itoa
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY _Tp
__complement(_Tp __x)
{
static_assert(is_unsigned<_Tp>::value, "cast to unsigned first");
return _Tp(~__x + 1);
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY auto
__to_unsigned(_Tp __x)
{
return static_cast<make_unsigned_t<_Tp>>(__x);
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
__to_chars_itoa(char* __first, char* __last, _Tp __value, true_type)
{
auto __x = __to_unsigned(__value);
if (__value < 0 && __first != __last)
{
*__first++ = '-';
__x = __complement(__x);
}
return __to_chars_itoa(__first, __last, __x, false_type());
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
__to_chars_itoa(char* __first, char* __last, _Tp __value, false_type)
{
using __tx = __itoa::__traits<_Tp>;
auto __diff = __last - __first;
#if !defined(_LIBCPP_COMPILER_MSVC)
if (__tx::digits <= __diff || __tx::__width(__value) <= __diff)
return {__tx::__convert(__value, __first), {}};
else
return {__last, errc::value_too_large};
#else
if (__tx::digits <= __diff)
return {__tx::__convert(__value, __first), {}};
else
{
char __buf[__tx::digits];
auto __p = __tx::__convert(__value, __buf);
auto __len = __p - __buf;
if (__len <= __diff)
{
memcpy(__first, __buf, __len);
return {__first + __len, {}};
}
else
return {__last, errc::value_too_large};
}
#endif
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
true_type)
{
auto __x = __to_unsigned(__value);
if (__value < 0 && __first != __last)
{
*__first++ = '-';
__x = __complement(__x);
}
return __to_chars_integral(__first, __last, __x, __base, false_type());
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
false_type)
{
if (__base == 10)
return __to_chars_itoa(__first, __last, __value, false_type());
auto __p = __last;
while (__p != __first)
{
auto __c = __value % __base;
__value /= __base;
*--__p = "0123456789abcdefghijklmnopqrstuvwxyz"[__c];
if (__value == 0)
break;
}
auto __len = __last - __p;
if (__value != 0 || !__len)
return {__last, errc::value_too_large};
else
{
memmove(__first, __p, __len);
return {__first + __len, {}};
}
}
template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
to_chars(char* __first, char* __last, _Tp __value)
{
return __to_chars_itoa(__first, __last, __value, is_signed<_Tp>());
}
template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY to_chars_result
to_chars(char* __first, char* __last, _Tp __value, int __base)
{
_LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
return __to_chars_integral(__first, __last, __value, __base,
is_signed<_Tp>());
}
template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__sign_combinator(_It __first, _It __last, _Tp& __value, _Fn __f, _Ts... __args)
{
using __tl = numeric_limits<_Tp>;
decltype(__to_unsigned(__value)) __x;
bool __neg = (__first != __last && *__first == '-');
auto __r = __f(__neg ? __first + 1 : __first, __last, __x, __args...);
switch (__r.ec)
{
case errc::invalid_argument:
return {__first, __r.ec};
case errc::result_out_of_range:
return __r;
default:
break;
}
if (__neg)
{
if (__x <= __complement(__to_unsigned(__tl::min())))
{
__x = __complement(__x);
memcpy(&__value, &__x, sizeof(__x));
return __r;
}
}
else
{
if (__x <= (__tl::max)())
{
__value = __x;
return __r;
}
}
return {__r.ptr, errc::result_out_of_range};
}
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY bool
__in_pattern(_Tp __c)
{
return '0' <= __c && __c <= '9';
}
struct _LIBCPP_HIDDEN __in_pattern_result
{
bool __ok;
int __val;
explicit _LIBCPP_INLINE_VISIBILITY operator bool() const { return __ok; }
};
template <typename _Tp>
inline _LIBCPP_INLINE_VISIBILITY __in_pattern_result
__in_pattern(_Tp __c, int __base)
{
if (__base <= 10)
return {'0' <= __c && __c < '0' + __base, __c - '0'};
else if (__in_pattern(__c))
return {true, __c - '0'};
else if ('a' <= __c && __c < 'a' + __base - 10)
return {true, __c - 'a' + 10};
else
return {'A' <= __c && __c < 'A' + __base - 10, __c - 'A' + 10};
}
template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__subject_seq_combinator(_It __first, _It __last, _Tp& __value, _Fn __f,
_Ts... __args)
{
auto __find_non_zero = [](_It __first, _It __last) {
for (; __first != __last; ++__first)
if (*__first != '0')
break;
return __first;
};
auto __p = __find_non_zero(__first, __last);
if (__p == __last || !__in_pattern(*__p, __args...))
{
if (__p == __first)
return {__first, errc::invalid_argument};
else
{
__value = 0;
return {__p, {}};
}
}
auto __r = __f(__p, __last, __value, __args...);
if (__r.ec == errc::result_out_of_range)
{
for (; __r.ptr != __last; ++__r.ptr)
{
if (!__in_pattern(*__r.ptr, __args...))
break;
}
}
return __r;
}
template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
{
using __tx = __itoa::__traits<_Tp>;
using __output_type = typename __tx::type;
return __subject_seq_combinator(
__first, __last, __value,
[](const char* __first, const char* __last,
_Tp& __value) -> from_chars_result {
__output_type __a, __b;
auto __p = __tx::__read(__first, __last, __a, __b);
if (__p == __last || !__in_pattern(*__p))
{
__output_type __m = (numeric_limits<_Tp>::max)();
if (__m >= __a && __m - __a >= __b)
{
__value = __a + __b;
return {__p, {}};
}
}
return {__p, errc::result_out_of_range};
});
}
template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
{
using __t = decltype(__to_unsigned(__value));
return __sign_combinator(__first, __last, __value, __from_chars_atoi<__t>);
}
template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
int __base)
{
if (__base == 10)
return __from_chars_atoi(__first, __last, __value);
return __subject_seq_combinator(
__first, __last, __value,
[](const char* __p, const char* __last, _Tp& __value,
int __base) -> from_chars_result {
using __tl = numeric_limits<_Tp>;
auto __digits = __tl::digits / log2f(float(__base));
_Tp __a = __in_pattern(*__p++, __base).__val, __b = 0;
for (int __i = 1; __p != __last; ++__i, ++__p)
{
if (auto __c = __in_pattern(*__p, __base))
{
if (__i < __digits - 1)
__a = __a * __base + __c.__val;
else
{
if (!__itoa::__mul_overflowed(__a, __base, __a))
++__p;
__b = __c.__val;
break;
}
}
else
break;
}
if (__p == __last || !__in_pattern(*__p, __base))
{
if ((__tl::max)() - __a >= __b)
{
__value = __a + __b;
return {__p, {}};
}
}
return {__p, errc::result_out_of_range};
},
__base);
}
template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
int __base)
{
using __t = decltype(__to_unsigned(__value));
return __sign_combinator(__first, __last, __value,
__from_chars_integral<__t>, __base);
}
template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
from_chars(const char* __first, const char* __last, _Tp& __value)
{
return __from_chars_atoi(__first, __last, __value);
}
template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
inline _LIBCPP_INLINE_VISIBILITY from_chars_result
from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
{
_LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
return __from_chars_integral(__first, __last, __value, __base);
}
#endif // _LIBCPP_STD_VER > 11
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP_CHARCONV
Reference in New Issue View Git Blame Copy Permalink