xref: /freebsd/contrib/llvm-project/libcxx/include/__chrono/parser_std_format_spec.h (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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___CHRONO_PARSER_STD_FORMAT_SPEC_H
11 #define _LIBCPP___CHRONO_PARSER_STD_FORMAT_SPEC_H
12 
13 #include <__config>
14 #include <__format/concepts.h>
15 #include <__format/format_error.h>
16 #include <__format/format_parse_context.h>
17 #include <__format/formatter_string.h>
18 #include <__format/parser_std_format_spec.h>
19 #include <string_view>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #  pragma GCC system_header
23 #endif
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 #if _LIBCPP_STD_VER >= 20
28 
29 namespace __format_spec {
30 
31 // By not placing this constant in the formatter class it's not duplicated for char and wchar_t
32 inline constexpr __fields __fields_chrono_fractional{
33     .__precision_ = true, .__locale_specific_form_ = true, .__type_ = false};
34 inline constexpr __fields __fields_chrono{.__locale_specific_form_ = true, .__type_ = false};
35 
36 /// Flags available or required in a chrono type.
37 ///
38 /// The caller of the chrono formatter lists the types it has available and the
39 /// validation tests whether the requested type spec (e.g. %M) is available in
40 /// the formatter.
41 /// When the type in the chrono-format-spec isn't present in the data a
42 /// \ref format_error is thrown.
43 enum class __flags {
44   __second = 0x1,
45   __minute = 0x2,
46   __hour   = 0x4,
47   __time   = __hour | __minute | __second,
48 
49   __day   = 0x8,
50   __month = 0x10,
51   __year  = 0x20,
52 
53   __weekday = 0x40,
54 
55   __month_day     = __day | __month,
56   __month_weekday = __weekday | __month,
57   __year_month    = __month | __year,
58   __date          = __day | __month | __year | __weekday,
59 
60   __date_time = __date | __time,
61 
62   __duration = 0x80 | __time,
63 
64   __time_zone = 0x100,
65 
66   __clock = __date_time | __time_zone
67 };
68 
69 _LIBCPP_HIDE_FROM_ABI constexpr __flags operator&(__flags __lhs, __flags __rhs) {
70   return static_cast<__flags>(static_cast<unsigned>(__lhs) & static_cast<unsigned>(__rhs));
71 }
72 
73 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_second(__flags __flags) {
74   if ((__flags & __flags::__second) != __flags::__second)
75     std::__throw_format_error("The supplied date time doesn't contain a second");
76 }
77 
78 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_minute(__flags __flags) {
79   if ((__flags & __flags::__minute) != __flags::__minute)
80     std::__throw_format_error("The supplied date time doesn't contain a minute");
81 }
82 
83 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_hour(__flags __flags) {
84   if ((__flags & __flags::__hour) != __flags::__hour)
85     std::__throw_format_error("The supplied date time doesn't contain an hour");
86 }
87 
88 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_time(__flags __flags) {
89   if ((__flags & __flags::__time) != __flags::__time)
90     std::__throw_format_error("The supplied date time doesn't contain a time");
91 }
92 
93 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_day(__flags __flags) {
94   if ((__flags & __flags::__day) != __flags::__day)
95     std::__throw_format_error("The supplied date time doesn't contain a day");
96 }
97 
98 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_month(__flags __flags) {
99   if ((__flags & __flags::__month) != __flags::__month)
100     std::__throw_format_error("The supplied date time doesn't contain a month");
101 }
102 
103 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_year(__flags __flags) {
104   if ((__flags & __flags::__year) != __flags::__year)
105     std::__throw_format_error("The supplied date time doesn't contain a year");
106 }
107 
108 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date(__flags __flags) {
109   if ((__flags & __flags::__date) != __flags::__date)
110     std::__throw_format_error("The supplied date time doesn't contain a date");
111 }
112 
113 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date_or_duration(__flags __flags) {
114   if (((__flags & __flags::__date) != __flags::__date) && ((__flags & __flags::__duration) != __flags::__duration))
115     std::__throw_format_error("The supplied date time doesn't contain a date or duration");
116 }
117 
118 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date_time(__flags __flags) {
119   if ((__flags & __flags::__date_time) != __flags::__date_time)
120     std::__throw_format_error("The supplied date time doesn't contain a date and time");
121 }
122 
123 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_weekday(__flags __flags) {
124   if ((__flags & __flags::__weekday) != __flags::__weekday)
125     std::__throw_format_error("The supplied date time doesn't contain a weekday");
126 }
127 
128 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_duration(__flags __flags) {
129   if ((__flags & __flags::__duration) != __flags::__duration)
130     std::__throw_format_error("The supplied date time doesn't contain a duration");
131 }
132 
133 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_time_zone(__flags __flags) {
134   if ((__flags & __flags::__time_zone) != __flags::__time_zone)
135     std::__throw_format_error("The supplied date time doesn't contain a time zone");
136 }
137 
138 template <class _CharT>
139 class _LIBCPP_TEMPLATE_VIS __parser_chrono {
140   using _ConstIterator = typename basic_format_parse_context<_CharT>::const_iterator;
141 
142 public:
143   template <class _ParseContext>
144   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator
145   __parse(_ParseContext& __ctx, __fields __fields, __flags __flags) {
146     _ConstIterator __begin = __parser_.__parse(__ctx, __fields);
147     _ConstIterator __end   = __ctx.end();
148     if (__begin == __end)
149       return __begin;
150 
151     _ConstIterator __last = __parse_chrono_specs(__begin, __end, __flags);
152     __chrono_specs_       = basic_string_view<_CharT>{__begin, __last};
153 
154     return __last;
155   }
156 
157   __parser<_CharT> __parser_;
158   basic_string_view<_CharT> __chrono_specs_;
159 
160 private:
161   _LIBCPP_HIDE_FROM_ABI constexpr _ConstIterator
162   __parse_chrono_specs(_ConstIterator __begin, _ConstIterator __end, __flags __flags) {
163     _LIBCPP_ASSERT_INTERNAL(__begin != __end,
164                             "When called with an empty input the function will cause "
165                             "undefined behavior by evaluating data not in the input");
166 
167     if (*__begin != _CharT('%') && *__begin != _CharT('}'))
168       std::__throw_format_error("The format specifier expects a '%' or a '}'");
169 
170     do {
171       switch (*__begin) {
172       case _CharT('{'):
173         std::__throw_format_error("The chrono specifiers contain a '{'");
174 
175       case _CharT('}'):
176         return __begin;
177 
178       case _CharT('%'):
179         __parse_conversion_spec(__begin, __end, __flags);
180         [[fallthrough]];
181 
182       default:
183         // All other literals
184         ++__begin;
185       }
186 
187     } while (__begin != __end && *__begin != _CharT('}'));
188 
189     return __begin;
190   }
191 
192   /// \pre *__begin == '%'
193   /// \post __begin points at the end parsed conversion-spec
194   _LIBCPP_HIDE_FROM_ABI constexpr void
195   __parse_conversion_spec(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
196     ++__begin;
197     if (__begin == __end)
198       std::__throw_format_error("End of input while parsing a conversion specifier");
199 
200     switch (*__begin) {
201     case _CharT('n'):
202     case _CharT('t'):
203     case _CharT('%'):
204       break;
205 
206     case _CharT('S'):
207       __format_spec::__validate_second(__flags);
208       break;
209 
210     case _CharT('M'):
211       __format_spec::__validate_minute(__flags);
212       break;
213 
214     case _CharT('p'): // TODO FMT does the formater require an hour or a time?
215     case _CharT('H'):
216     case _CharT('I'):
217       __parser_.__hour_ = true;
218       __validate_hour(__flags);
219       break;
220 
221     case _CharT('r'):
222     case _CharT('R'):
223     case _CharT('T'):
224     case _CharT('X'):
225       __parser_.__hour_ = true;
226       __format_spec::__validate_time(__flags);
227       break;
228 
229     case _CharT('d'):
230     case _CharT('e'):
231       __format_spec::__validate_day(__flags);
232       break;
233 
234     case _CharT('b'):
235     case _CharT('h'):
236     case _CharT('B'):
237       __parser_.__month_name_ = true;
238       [[fallthrough]];
239     case _CharT('m'):
240       __format_spec::__validate_month(__flags);
241       break;
242 
243     case _CharT('y'):
244     case _CharT('C'):
245     case _CharT('Y'):
246       __format_spec::__validate_year(__flags);
247       break;
248 
249     case _CharT('j'):
250       __parser_.__day_of_year_ = true;
251       __format_spec::__validate_date_or_duration(__flags);
252       break;
253 
254     case _CharT('g'):
255     case _CharT('G'):
256     case _CharT('U'):
257     case _CharT('V'):
258     case _CharT('W'):
259       __parser_.__week_of_year_ = true;
260       [[fallthrough]];
261     case _CharT('x'):
262     case _CharT('D'):
263     case _CharT('F'):
264       __format_spec::__validate_date(__flags);
265       break;
266 
267     case _CharT('c'):
268       __format_spec::__validate_date_time(__flags);
269       break;
270 
271     case _CharT('a'):
272     case _CharT('A'):
273       __parser_.__weekday_name_ = true;
274       [[fallthrough]];
275     case _CharT('u'):
276     case _CharT('w'):
277       __parser_.__weekday_ = true;
278       __validate_weekday(__flags);
279       __format_spec::__validate_weekday(__flags);
280       break;
281 
282     case _CharT('q'):
283     case _CharT('Q'):
284       __format_spec::__validate_duration(__flags);
285       break;
286 
287     case _CharT('E'):
288       __parse_modifier_E(__begin, __end, __flags);
289       break;
290 
291     case _CharT('O'):
292       __parse_modifier_O(__begin, __end, __flags);
293       break;
294 
295     case _CharT('z'):
296     case _CharT('Z'):
297       // Currently there's no time zone information. However some clocks have a
298       // hard-coded "time zone", for these clocks the information can be used.
299       // TODO FMT implement time zones.
300       __format_spec::__validate_time_zone(__flags);
301       break;
302 
303     default: // unknown type;
304       std::__throw_format_error("The date time type specifier is invalid");
305     }
306   }
307 
308   /// \pre *__begin == 'E'
309   /// \post __begin is incremented by one.
310   _LIBCPP_HIDE_FROM_ABI constexpr void
311   __parse_modifier_E(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
312     ++__begin;
313     if (__begin == __end)
314       std::__throw_format_error("End of input while parsing the modifier E");
315 
316     switch (*__begin) {
317     case _CharT('X'):
318       __parser_.__hour_ = true;
319       __format_spec::__validate_time(__flags);
320       break;
321 
322     case _CharT('y'):
323     case _CharT('C'):
324     case _CharT('Y'):
325       __format_spec::__validate_year(__flags);
326       break;
327 
328     case _CharT('x'):
329       __format_spec::__validate_date(__flags);
330       break;
331 
332     case _CharT('c'):
333       __format_spec::__validate_date_time(__flags);
334       break;
335 
336     case _CharT('z'):
337       // Currently there's no time zone information. However some clocks have a
338       // hard-coded "time zone", for these clocks the information can be used.
339       // TODO FMT implement time zones.
340       __format_spec::__validate_time_zone(__flags);
341       break;
342 
343     default:
344       std::__throw_format_error("The date time type specifier for modifier E is invalid");
345     }
346   }
347 
348   /// \pre *__begin == 'O'
349   /// \post __begin is incremented by one.
350   _LIBCPP_HIDE_FROM_ABI constexpr void
351   __parse_modifier_O(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
352     ++__begin;
353     if (__begin == __end)
354       std::__throw_format_error("End of input while parsing the modifier O");
355 
356     switch (*__begin) {
357     case _CharT('S'):
358       __format_spec::__validate_second(__flags);
359       break;
360 
361     case _CharT('M'):
362       __format_spec::__validate_minute(__flags);
363       break;
364 
365     case _CharT('I'):
366     case _CharT('H'):
367       __parser_.__hour_ = true;
368       __format_spec::__validate_hour(__flags);
369       break;
370 
371     case _CharT('d'):
372     case _CharT('e'):
373       __format_spec::__validate_day(__flags);
374       break;
375 
376     case _CharT('m'):
377       __format_spec::__validate_month(__flags);
378       break;
379 
380     case _CharT('y'):
381       __format_spec::__validate_year(__flags);
382       break;
383 
384     case _CharT('U'):
385     case _CharT('V'):
386     case _CharT('W'):
387       __parser_.__week_of_year_ = true;
388       __format_spec::__validate_date(__flags);
389       break;
390 
391     case _CharT('u'):
392     case _CharT('w'):
393       __parser_.__weekday_ = true;
394       __format_spec::__validate_weekday(__flags);
395       break;
396 
397     case _CharT('z'):
398       // Currently there's no time zone information. However some clocks have a
399       // hard-coded "time zone", for these clocks the information can be used.
400       // TODO FMT implement time zones.
401       __format_spec::__validate_time_zone(__flags);
402       break;
403 
404     default:
405       std::__throw_format_error("The date time type specifier for modifier O is invalid");
406     }
407   }
408 };
409 
410 } // namespace __format_spec
411 
412 #endif //_LIBCPP_STD_VER >= 20
413 
414 _LIBCPP_END_NAMESPACE_STD
415 
416 #endif // _LIBCPP___CHRONO_PARSER_STD_FORMAT_SPEC_H
417