1// -*- C++ -*-
2//===------------------------------ charconv ------------------------------===//
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_CHARCONV
11#define _LIBCPP_CHARCONV
12
13/*
14 charconv synopsis
15
16namespace std {
17
18 // floating-point format for primitive numerical conversion
19 enum class chars_format {
20 scientific = unspecified,
21 fixed = unspecified,
22 hex = unspecified,
23 general = fixed | scientific
24 };
25
26 // 23.20.2, primitive numerical output conversion
27 struct to_chars_result {
28 char* ptr;
29 errc ec;
30 };
31
32 to_chars_result to_chars(char* first, char* last, see below value,
33 int base = 10);
34
35 to_chars_result to_chars(char* first, char* last, float value);
36 to_chars_result to_chars(char* first, char* last, double value);
37 to_chars_result to_chars(char* first, char* last, long double value);
38
39 to_chars_result to_chars(char* first, char* last, float value,
40 chars_format fmt);
41 to_chars_result to_chars(char* first, char* last, double value,
42 chars_format fmt);
43 to_chars_result to_chars(char* first, char* last, long double value,
44 chars_format fmt);
45
46 to_chars_result to_chars(char* first, char* last, float value,
47 chars_format fmt, int precision);
48 to_chars_result to_chars(char* first, char* last, double value,
49 chars_format fmt, int precision);
50 to_chars_result to_chars(char* first, char* last, long double value,
51 chars_format fmt, int precision);
52
53 // 23.20.3, primitive numerical input conversion
54 struct from_chars_result {
55 const char* ptr;
56 errc ec;
57 };
58
59 from_chars_result from_chars(const char* first, const char* last,
60 see below& value, int base = 10);
61
62 from_chars_result from_chars(const char* first, const char* last,
63 float& value,
64 chars_format fmt = chars_format::general);
65 from_chars_result from_chars(const char* first, const char* last,
66 double& value,
67 chars_format fmt = chars_format::general);
68 from_chars_result from_chars(const char* first, const char* last,
69 long double& value,
70 chars_format fmt = chars_format::general);
71
72} // namespace std
73
74*/
75
76#include <__errc>
77#include <type_traits>
78#include <limits>
79#include <stdint.h>
80#include <string.h>
81#include <math.h>
82
83#include <__debug>
84
85#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
86#pragma GCC system_header
87#endif
88
89_LIBCPP_PUSH_MACROS
90#include <__undef_macros>
91
92_LIBCPP_BEGIN_NAMESPACE_STD
93
94namespace __itoa {
95_LIBCPP_FUNC_VIS char* __u64toa(uint64_t __value, char* __buffer);
96_LIBCPP_FUNC_VIS char* __u32toa(uint32_t __value, char* __buffer);
97}
98
99#ifndef _LIBCPP_CXX03_LANG
100
101enum class _LIBCPP_ENUM_VIS chars_format
102{
103 scientific = 0x1,
104 fixed = 0x2,
105 hex = 0x4,
106 general = fixed | scientific
107};
108
109struct _LIBCPP_TYPE_VIS to_chars_result
110{
111 char* ptr;
112 errc ec;
113};
114
115struct _LIBCPP_TYPE_VIS from_chars_result
116{
117 const char* ptr;
118 errc ec;
119};
120
121void to_chars(char*, char*, bool, int = 10) = delete;
122void from_chars(const char*, const char*, bool, int = 10) = delete;
123
124namespace __itoa
125{
126
127static _LIBCPP_CONSTEXPR uint64_t __pow10_64[] = {
128 UINT64_C(0),
129 UINT64_C(10),
130 UINT64_C(100),
131 UINT64_C(1000),
132 UINT64_C(10000),
133 UINT64_C(100000),
134 UINT64_C(1000000),
135 UINT64_C(10000000),
136 UINT64_C(100000000),
137 UINT64_C(1000000000),
138 UINT64_C(10000000000),
139 UINT64_C(100000000000),
140 UINT64_C(1000000000000),
141 UINT64_C(10000000000000),
142 UINT64_C(100000000000000),
143 UINT64_C(1000000000000000),
144 UINT64_C(10000000000000000),
145 UINT64_C(100000000000000000),
146 UINT64_C(1000000000000000000),
147 UINT64_C(10000000000000000000),
148};
149
150static _LIBCPP_CONSTEXPR uint32_t __pow10_32[] = {
151 UINT32_C(0), UINT32_C(10), UINT32_C(100),
152 UINT32_C(1000), UINT32_C(10000), UINT32_C(100000),
153 UINT32_C(1000000), UINT32_C(10000000), UINT32_C(100000000),
154 UINT32_C(1000000000),
155};
156
157template <typename _Tp, typename = void>
158struct _LIBCPP_HIDDEN __traits_base
159{
160 using type = uint64_t;
161
162#if !defined(_LIBCPP_COMPILER_MSVC)
163 static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
164 {
165 auto __t = (64 - __builtin_clzll(__v | 1)) * 1233 >> 12;
166 return __t - (__v < __pow10_64[__t]) + 1;
167 }
168#endif
169
170 static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
171 {
172 return __u64toa(__v, __p);
173 }
174
175 static _LIBCPP_INLINE_VISIBILITY decltype(__pow10_64)& __pow() { return __pow10_64; }
176};
177
178template <typename _Tp>
179struct _LIBCPP_HIDDEN
180 __traits_base<_Tp, decltype(void(uint32_t{declval<_Tp>()}))>
181{
182 using type = uint32_t;
183
184#if !defined(_LIBCPP_COMPILER_MSVC)
185 static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
186 {
187 auto __t = (32 - __builtin_clz(__v | 1)) * 1233 >> 12;
188 return __t - (__v < __pow10_32[__t]) + 1;
189 }
190#endif
191
192 static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
193 {
194 return __u32toa(__v, __p);
195 }
196
197 static _LIBCPP_INLINE_VISIBILITY decltype(__pow10_32)& __pow() { return __pow10_32; }
198};
199
200template <typename _Tp>
201inline _LIBCPP_INLINE_VISIBILITY bool
202__mul_overflowed(unsigned char __a, _Tp __b, unsigned char& __r)
203{
204 auto __c = __a * __b;
205 __r = __c;
206 return __c > (numeric_limits<unsigned char>::max)();
207}
208
209template <typename _Tp>
210inline _LIBCPP_INLINE_VISIBILITY bool
211__mul_overflowed(unsigned short __a, _Tp __b, unsigned short& __r)
212{
213 auto __c = __a * __b;
214 __r = __c;
215 return __c > (numeric_limits<unsigned short>::max)();
216}
217
218template <typename _Tp>
219inline _LIBCPP_INLINE_VISIBILITY bool
220__mul_overflowed(_Tp __a, _Tp __b, _Tp& __r)
221{
222 static_assert(is_unsigned<_Tp>::value, "");
223#if !defined(_LIBCPP_COMPILER_MSVC)
224 return __builtin_mul_overflow(__a, __b, &__r);
225#else
226 bool __did = __b && ((numeric_limits<_Tp>::max)() / __b) < __a;
227 __r = __a * __b;
228 return __did;
229#endif
230}
231
232template <typename _Tp, typename _Up>
233inline _LIBCPP_INLINE_VISIBILITY bool
234__mul_overflowed(_Tp __a, _Up __b, _Tp& __r)
235{
236 return __mul_overflowed(__a, static_cast<_Tp>(__b), __r);
237}
238
239template <typename _Tp>
240struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
241{
242 static _LIBCPP_CONSTEXPR int digits = numeric_limits<_Tp>::digits10 + 1;
243 using __traits_base<_Tp>::__pow;
244 using typename __traits_base<_Tp>::type;
245
246 // precondition: at least one non-zero character available
247 static _LIBCPP_INLINE_VISIBILITY char const*
248 __read(char const* __p, char const* __ep, type& __a, type& __b)
249 {
250 type __cprod[digits];
251 int __j = digits - 1;
252 int __i = digits;
253 do
254 {
255 if (!('0' <= *__p && *__p <= '9'))
256 break;
257 __cprod[--__i] = *__p++ - '0';
258 } while (__p != __ep && __i != 0);
259
260 __a = __inner_product(__cprod + __i + 1, __cprod + __j, __pow() + 1,
261 __cprod[__i]);
262 if (__mul_overflowed(__cprod[__j], __pow()[__j - __i], __b))
263 --__p;
264 return __p;
265 }
266
267 template <typename _It1, typename _It2, class _Up>
268 static _LIBCPP_INLINE_VISIBILITY _Up
269 __inner_product(_It1 __first1, _It1 __last1, _It2 __first2, _Up __init)
270 {
271 for (; __first1 < __last1; ++__first1, ++__first2)
272 __init = __init + *__first1 * *__first2;
273 return __init;
274 }
275};
276
277} // namespace __itoa
278
279template <typename _Tp>
280inline _LIBCPP_INLINE_VISIBILITY _Tp
281__complement(_Tp __x)
282{
283 static_assert(is_unsigned<_Tp>::value, "cast to unsigned first");
284 return _Tp(~__x + 1);
285}
286
287template <typename _Tp>
288inline _LIBCPP_INLINE_VISIBILITY typename make_unsigned<_Tp>::type
289__to_unsigned(_Tp __x)
290{
291 return static_cast<typename make_unsigned<_Tp>::type>(__x);
292}
293
294template <typename _Tp>
295inline _LIBCPP_INLINE_VISIBILITY to_chars_result
296__to_chars_itoa(char* __first, char* __last, _Tp __value, true_type)
297{
298 auto __x = __to_unsigned(__value);
299 if (__value < 0 && __first != __last)
300 {
301 *__first++ = '-';
302 __x = __complement(__x);
303 }
304
305 return __to_chars_itoa(__first, __last, __x, false_type());
306}
307
308template <typename _Tp>
309inline _LIBCPP_INLINE_VISIBILITY to_chars_result
310__to_chars_itoa(char* __first, char* __last, _Tp __value, false_type)
311{
312 using __tx = __itoa::__traits<_Tp>;
313 auto __diff = __last - __first;
314
315#if !defined(_LIBCPP_COMPILER_MSVC)
316 if (__tx::digits <= __diff || __tx::__width(__value) <= __diff)
317 return {__tx::__convert(__value, __first), errc(0)};
318 else
319 return {__last, errc::value_too_large};
320#else
321 if (__tx::digits <= __diff)
322 return {__tx::__convert(__value, __first), {}};
323 else
324 {
325 char __buf[__tx::digits];
326 auto __p = __tx::__convert(__value, __buf);
327 auto __len = __p - __buf;
328 if (__len <= __diff)
329 {
330 memcpy(__first, __buf, __len);
331 return {__first + __len, {}};
332 }
333 else
334 return {__last, errc::value_too_large};
335 }
336#endif
337}
338
339template <typename _Tp>
340inline _LIBCPP_INLINE_VISIBILITY to_chars_result
341__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
342 true_type)
343{
344 auto __x = __to_unsigned(__value);
345 if (__value < 0 && __first != __last)
346 {
347 *__first++ = '-';
348 __x = __complement(__x);
349 }
350
351 return __to_chars_integral(__first, __last, __x, __base, false_type());
352}
353
354template <typename _Tp>
355inline _LIBCPP_INLINE_VISIBILITY to_chars_result
356__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
357 false_type)
358{
359 if (__base == 10)
360 return __to_chars_itoa(__first, __last, __value, false_type());
361
362 auto __p = __last;
363 while (__p != __first)
364 {
365 auto __c = __value % __base;
366 __value /= __base;
367 *--__p = "0123456789abcdefghijklmnopqrstuvwxyz"[__c];
368 if (__value == 0)
369 break;
370 }
371
372 auto __len = __last - __p;
373 if (__value != 0 || !__len)
374 return {__last, errc::value_too_large};
375 else
376 {
377 memmove(__first, __p, __len);
378 return {__first + __len, {}};
379 }
380}
381
382template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
383inline _LIBCPP_INLINE_VISIBILITY to_chars_result
384to_chars(char* __first, char* __last, _Tp __value)
385{
386 return __to_chars_itoa(__first, __last, __value, is_signed<_Tp>());
387}
388
389template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
390inline _LIBCPP_INLINE_VISIBILITY to_chars_result
391to_chars(char* __first, char* __last, _Tp __value, int __base)
392{
393 _LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
394 return __to_chars_integral(__first, __last, __value, __base,
395 is_signed<_Tp>());
396}
397
398template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
399inline _LIBCPP_INLINE_VISIBILITY from_chars_result
400__sign_combinator(_It __first, _It __last, _Tp& __value, _Fn __f, _Ts... __args)
401{
402 using __tl = numeric_limits<_Tp>;
403 decltype(__to_unsigned(__value)) __x;
404
405 bool __neg = (__first != __last && *__first == '-');
406 auto __r = __f(__neg ? __first + 1 : __first, __last, __x, __args...);
407 switch (__r.ec)
408 {
409 case errc::invalid_argument:
410 return {__first, __r.ec};
411 case errc::result_out_of_range:
412 return __r;
413 default:
414 break;
415 }
416
417 if (__neg)
418 {
419 if (__x <= __complement(__to_unsigned(__tl::min())))
420 {
421 __x = __complement(__x);
422 memcpy(&__value, &__x, sizeof(__x));
423 return __r;
424 }
425 }
426 else
427 {
428 if (__x <= (__tl::max)())
429 {
430 __value = __x;
431 return __r;
432 }
433 }
434
435 return {__r.ptr, errc::result_out_of_range};
436}
437
438template <typename _Tp>
439inline _LIBCPP_INLINE_VISIBILITY bool
440__in_pattern(_Tp __c)
441{
442 return '0' <= __c && __c <= '9';
443}
444
445struct _LIBCPP_HIDDEN __in_pattern_result
446{
447 bool __ok;
448 int __val;
449
450 explicit _LIBCPP_INLINE_VISIBILITY operator bool() const { return __ok; }
451};
452
453template <typename _Tp>
454inline _LIBCPP_INLINE_VISIBILITY __in_pattern_result
455__in_pattern(_Tp __c, int __base)
456{
457 if (__base <= 10)
458 return {'0' <= __c && __c < '0' + __base, __c - '0'};
459 else if (__in_pattern(__c))
460 return {true, __c - '0'};
461 else if ('a' <= __c && __c < 'a' + __base - 10)
462 return {true, __c - 'a' + 10};
463 else
464 return {'A' <= __c && __c < 'A' + __base - 10, __c - 'A' + 10};
465}
466
467template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
468inline _LIBCPP_INLINE_VISIBILITY from_chars_result
469__subject_seq_combinator(_It __first, _It __last, _Tp& __value, _Fn __f,
470 _Ts... __args)
471{
472 auto __find_non_zero = [](_It __first, _It __last) {
473 for (; __first != __last; ++__first)
474 if (*__first != '0')
475 break;
476 return __first;
477 };
478
479 auto __p = __find_non_zero(__first, __last);
480 if (__p == __last || !__in_pattern(*__p, __args...))
481 {
482 if (__p == __first)
483 return {__first, errc::invalid_argument};
484 else
485 {
486 __value = 0;
487 return {__p, {}};
488 }
489 }
490
491 auto __r = __f(__p, __last, __value, __args...);
492 if (__r.ec == errc::result_out_of_range)
493 {
494 for (; __r.ptr != __last; ++__r.ptr)
495 {
496 if (!__in_pattern(*__r.ptr, __args...))
497 break;
498 }
499 }
500
501 return __r;
502}
503
504template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
505inline _LIBCPP_INLINE_VISIBILITY from_chars_result
506__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
507{
508 using __tx = __itoa::__traits<_Tp>;
509 using __output_type = typename __tx::type;
510
511 return __subject_seq_combinator(
512 __first, __last, __value,
513 [](const char* __first, const char* __last,
514 _Tp& __value) -> from_chars_result {
515 __output_type __a, __b;
516 auto __p = __tx::__read(__first, __last, __a, __b);
517 if (__p == __last || !__in_pattern(*__p))
518 {
519 __output_type __m = (numeric_limits<_Tp>::max)();
520 if (__m >= __a && __m - __a >= __b)
521 {
522 __value = __a + __b;
523 return {__p, {}};
524 }
525 }
526 return {__p, errc::result_out_of_range};
527 });
528}
529
530template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
531inline _LIBCPP_INLINE_VISIBILITY from_chars_result
532__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
533{
534 using __t = decltype(__to_unsigned(__value));
535 return __sign_combinator(__first, __last, __value, __from_chars_atoi<__t>);
536}
537
538template <typename _Tp, typename enable_if<is_unsigned<_Tp>::value, int>::type = 0>
539inline _LIBCPP_INLINE_VISIBILITY from_chars_result
540__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
541 int __base)
542{
543 if (__base == 10)
544 return __from_chars_atoi(__first, __last, __value);
545
546 return __subject_seq_combinator(
547 __first, __last, __value,
548 [](const char* __p, const char* __last, _Tp& __value,
549 int __base) -> from_chars_result {
550 using __tl = numeric_limits<_Tp>;
551 auto __digits = __tl::digits / log2f(float(__base));
552 _Tp __a = __in_pattern(*__p++, __base).__val, __b = 0;
553
554 for (int __i = 1; __p != __last; ++__i, ++__p)
555 {
556 if (auto __c = __in_pattern(*__p, __base))
557 {
558 if (__i < __digits - 1)
559 __a = __a * __base + __c.__val;
560 else
561 {
562 if (!__itoa::__mul_overflowed(__a, __base, __a))
563 ++__p;
564 __b = __c.__val;
565 break;
566 }
567 }
568 else
569 break;
570 }
571
572 if (__p == __last || !__in_pattern(*__p, __base))
573 {
574 if ((__tl::max)() - __a >= __b)
575 {
576 __value = __a + __b;
577 return {__p, {}};
578 }
579 }
580 return {__p, errc::result_out_of_range};
581 },
582 __base);
583}
584
585template <typename _Tp, typename enable_if<is_signed<_Tp>::value, int>::type = 0>
586inline _LIBCPP_INLINE_VISIBILITY from_chars_result
587__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
588 int __base)
589{
590 using __t = decltype(__to_unsigned(__value));
591 return __sign_combinator(__first, __last, __value,
592 __from_chars_integral<__t>, __base);
593}
594
595template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
596inline _LIBCPP_INLINE_VISIBILITY from_chars_result
597from_chars(const char* __first, const char* __last, _Tp& __value)
598{
599 return __from_chars_atoi(__first, __last, __value);
600}
601
602template <typename _Tp, typename enable_if<is_integral<_Tp>::value, int>::type = 0>
603inline _LIBCPP_INLINE_VISIBILITY from_chars_result
604from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
605{
606 _LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
607 return __from_chars_integral(__first, __last, __value, __base);
608}
609
610#endif // _LIBCPP_CXX03_LANG
611
612_LIBCPP_END_NAMESPACE_STD
613
614_LIBCPP_POP_MACROS
615
616#endif // _LIBCPP_CHARCONV
617