libcxx/include/__chrono/parser_std_format_spec.h

   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
  15 #if _LIBCPP_HAS_LOCALIZATION
  16
  17 #  include <__format/concepts.h>
  18 #  include <__format/format_error.h>
  19 #  include <__format/format_parse_context.h>
  20 #  include <__format/formatter_string.h>
  21 #  include <__format/parser_std_format_spec.h>
  22 #  include <string_view>
  23
  24 #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  25 #    pragma GCC system_header
  26 #  endif
  27
  28 _LIBCPP_BEGIN_NAMESPACE_STD
  29
  30 #  if _LIBCPP_STD_VER >= 20
  31
  32 namespace __format_spec {
  33
  34 // By not placing this constant in the formatter class it's not duplicated for char and wchar_t
  35 inline constexpr __fields __fields_chrono_fractional{
  36     .__precision_ = true, .__locale_specific_form_ = true, .__type_ = false};
  37 inline constexpr __fields __fields_chrono{.__locale_specific_form_ = true, .__type_ = false};
  38
  39 /// Flags available or required in a chrono type.
  40 ///
  41 /// The caller of the chrono formatter lists the types it has available and the
  42 /// validation tests whether the requested type spec (e.g. %M) is available in
  43 /// the formatter.
  44 /// When the type in the chrono-format-spec isn't present in the data a
  45 /// \ref format_error is thrown.
  46 enum class __flags {
  47   __second = 0x1,
  48   __minute = 0x2,
  49   __hour   = 0x4,
  50   __time   = __hour | __minute | __second,
  51
  52   __day   = 0x8,
  53   __month = 0x10,
  54   __year  = 0x20,
  55
  56   __weekday = 0x40,
  57
  58   __month_day     = __day | __month,
  59   __month_weekday = __weekday | __month,
  60   __year_month    = __month | __year,
  61   __date          = __day | __month | __year | __weekday,
  62
  63   __date_time = __date | __time,
  64
  65   __duration = 0x80 | __time,
  66
  67   __time_zone = 0x100,
  68
  69   __clock = __date_time | __time_zone
  70 };
  71
  72 _LIBCPP_HIDE_FROM_ABI constexpr __flags operator&(__flags __lhs, __flags __rhs) {
  73   return static_cast<__flags>(static_cast<unsigned>(__lhs) & static_cast<unsigned>(__rhs));
  74 }
  75
  76 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_second(__flags __flags) {
  77   if ((__flags & __flags::__second) != __flags::__second)
  78     std::__throw_format_error("The supplied date time doesn't contain a second");
  79 }
  80
  81 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_minute(__flags __flags) {
  82   if ((__flags & __flags::__minute) != __flags::__minute)
  83     std::__throw_format_error("The supplied date time doesn't contain a minute");
  84 }
  85
  86 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_hour(__flags __flags) {
  87   if ((__flags & __flags::__hour) != __flags::__hour)
  88     std::__throw_format_error("The supplied date time doesn't contain an hour");
  89 }
  90
  91 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_time(__flags __flags) {
  92   if ((__flags & __flags::__time) != __flags::__time)
  93     std::__throw_format_error("The supplied date time doesn't contain a time");
  94 }
  95
  96 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_day(__flags __flags) {
  97   if ((__flags & __flags::__day) != __flags::__day)
  98     std::__throw_format_error("The supplied date time doesn't contain a day");
  99 }
 100
 101 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_month(__flags __flags) {
 102   if ((__flags & __flags::__month) != __flags::__month)
 103     std::__throw_format_error("The supplied date time doesn't contain a month");
 104 }
 105
 106 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_year(__flags __flags) {
 107   if ((__flags & __flags::__year) != __flags::__year)
 108     std::__throw_format_error("The supplied date time doesn't contain a year");
 109 }
 110
 111 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date(__flags __flags) {
 112   if ((__flags & __flags::__date) != __flags::__date)
 113     std::__throw_format_error("The supplied date time doesn't contain a date");
 114 }
 115
 116 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date_or_duration(__flags __flags) {
 117   if (((__flags & __flags::__date) != __flags::__date) && ((__flags & __flags::__duration) != __flags::__duration))
 118     std::__throw_format_error("The supplied date time doesn't contain a date or duration");
 119 }
 120
 121 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_date_time(__flags __flags) {
 122   if ((__flags & __flags::__date_time) != __flags::__date_time)
 123     std::__throw_format_error("The supplied date time doesn't contain a date and time");
 124 }
 125
 126 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_weekday(__flags __flags) {
 127   if ((__flags & __flags::__weekday) != __flags::__weekday)
 128     std::__throw_format_error("The supplied date time doesn't contain a weekday");
 129 }
 130
 131 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_duration(__flags __flags) {
 132   if ((__flags & __flags::__duration) != __flags::__duration)
 133     std::__throw_format_error("The supplied date time doesn't contain a duration");
 134 }
 135
 136 _LIBCPP_HIDE_FROM_ABI constexpr void __validate_time_zone(__flags __flags) {
 137   if ((__flags & __flags::__time_zone) != __flags::__time_zone)
 138     std::__throw_format_error("The supplied date time doesn't contain a time zone");
 139 }
 140
 141 template <class _CharT>
 142 class _LIBCPP_TEMPLATE_VIS __parser_chrono {
 143   using _ConstIterator = typename basic_format_parse_context<_CharT>::const_iterator;
 144
 145 public:
 146   template <class _ParseContext>
 147   _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator
 148   __parse(_ParseContext& __ctx, __fields __fields, __flags __flags) {
 149     _ConstIterator __begin = __parser_.__parse(__ctx, __fields);
 150     _ConstIterator __end   = __ctx.end();
 151     if (__begin == __end)
 152       return __begin;
 153
 154     _ConstIterator __last = __parse_chrono_specs(__begin, __end, __flags);
 155     __chrono_specs_       = basic_string_view<_CharT>{__begin, __last};
 156
 157     return __last;
 158   }
 159
 160   __parser<_CharT> __parser_;
 161   basic_string_view<_CharT> __chrono_specs_;
 162
 163 private:
 164   _LIBCPP_HIDE_FROM_ABI constexpr _ConstIterator
 165   __parse_chrono_specs(_ConstIterator __begin, _ConstIterator __end, __flags __flags) {
 166     _LIBCPP_ASSERT_INTERNAL(__begin != __end,
 167                             "When called with an empty input the function will cause "
 168                             "undefined behavior by evaluating data not in the input");
 169
 170     if (*__begin != _CharT('%') && *__begin != _CharT('}'))
 171       std::__throw_format_error("The format specifier expects a '%' or a '}'");
 172
 173     do {
 174       switch (*__begin) {
 175       case _CharT('{'):
 176         std::__throw_format_error("The chrono specifiers contain a '{'");
 177
 178       case _CharT('}'):
 179         return __begin;
 180
 181       case _CharT('%'):
 182         __parse_conversion_spec(__begin, __end, __flags);
 183         [[fallthrough]];
 184
 185       default:
 186         // All other literals
 187         ++__begin;
 188       }
 189
 190     } while (__begin != __end && *__begin != _CharT('}'));
 191
 192     return __begin;
 193   }
 194
 195   /// \pre *__begin == '%'
 196   /// \post __begin points at the end parsed conversion-spec
 197   _LIBCPP_HIDE_FROM_ABI constexpr void
 198   __parse_conversion_spec(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 199     ++__begin;
 200     if (__begin == __end)
 201       std::__throw_format_error("End of input while parsing a conversion specifier");
 202
 203     switch (*__begin) {
 204     case _CharT('n'):
 205     case _CharT('t'):
 206     case _CharT('%'):
 207       break;
 208
 209     case _CharT('S'):
 210       __format_spec::__validate_second(__flags);
 211       break;
 212
 213     case _CharT('M'):
 214       __format_spec::__validate_minute(__flags);
 215       break;
 216
 217     case _CharT('p'): // TODO FMT does the formater require an hour or a time?
 218     case _CharT('H'):
 219     case _CharT('I'):
 220       __parser_.__hour_ = true;
 221       __validate_hour(__flags);
 222       break;
 223
 224     case _CharT('r'):
 225     case _CharT('R'):
 226     case _CharT('T'):
 227     case _CharT('X'):
 228       __parser_.__hour_ = true;
 229       __format_spec::__validate_time(__flags);
 230       break;
 231
 232     case _CharT('d'):
 233     case _CharT('e'):
 234       __format_spec::__validate_day(__flags);
 235       break;
 236
 237     case _CharT('b'):
 238     case _CharT('h'):
 239     case _CharT('B'):
 240       __parser_.__month_name_ = true;
 241       [[fallthrough]];
 242     case _CharT('m'):
 243       __format_spec::__validate_month(__flags);
 244       break;
 245
 246     case _CharT('y'):
 247     case _CharT('C'):
 248     case _CharT('Y'):
 249       __format_spec::__validate_year(__flags);
 250       break;
 251
 252     case _CharT('j'):
 253       __parser_.__day_of_year_ = true;
 254       __format_spec::__validate_date_or_duration(__flags);
 255       break;
 256
 257     case _CharT('g'):
 258     case _CharT('G'):
 259     case _CharT('U'):
 260     case _CharT('V'):
 261     case _CharT('W'):
 262       __parser_.__week_of_year_ = true;
 263       [[fallthrough]];
 264     case _CharT('x'):
 265     case _CharT('D'):
 266     case _CharT('F'):
 267       __format_spec::__validate_date(__flags);
 268       break;
 269
 270     case _CharT('c'):
 271       __format_spec::__validate_date_time(__flags);
 272       break;
 273
 274     case _CharT('a'):
 275     case _CharT('A'):
 276       __parser_.__weekday_name_ = true;
 277       [[fallthrough]];
 278     case _CharT('u'):
 279     case _CharT('w'):
 280       __parser_.__weekday_ = true;
 281       __validate_weekday(__flags);
 282       __format_spec::__validate_weekday(__flags);
 283       break;
 284
 285     case _CharT('q'):
 286     case _CharT('Q'):
 287       __format_spec::__validate_duration(__flags);
 288       break;
 289
 290     case _CharT('E'):
 291       __parse_modifier_E(__begin, __end, __flags);
 292       break;
 293
 294     case _CharT('O'):
 295       __parse_modifier_O(__begin, __end, __flags);
 296       break;
 297
 298     case _CharT('z'):
 299     case _CharT('Z'):
 300       // Currently there's no time zone information. However some clocks have a
 301       // hard-coded "time zone", for these clocks the information can be used.
 302       // TODO FMT implement time zones.
 303       __format_spec::__validate_time_zone(__flags);
 304       break;
 305
 306     default: // unknown type;
 307       std::__throw_format_error("The date time type specifier is invalid");
 308     }
 309   }
 310
 311   /// \pre *__begin == 'E'
 312   /// \post __begin is incremented by one.
 313   _LIBCPP_HIDE_FROM_ABI constexpr void
 314   __parse_modifier_E(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 315     ++__begin;
 316     if (__begin == __end)
 317       std::__throw_format_error("End of input while parsing the modifier E");
 318
 319     switch (*__begin) {
 320     case _CharT('X'):
 321       __parser_.__hour_ = true;
 322       __format_spec::__validate_time(__flags);
 323       break;
 324
 325     case _CharT('y'):
 326     case _CharT('C'):
 327     case _CharT('Y'):
 328       __format_spec::__validate_year(__flags);
 329       break;
 330
 331     case _CharT('x'):
 332       __format_spec::__validate_date(__flags);
 333       break;
 334
 335     case _CharT('c'):
 336       __format_spec::__validate_date_time(__flags);
 337       break;
 338
 339     case _CharT('z'):
 340       // Currently there's no time zone information. However some clocks have a
 341       // hard-coded "time zone", for these clocks the information can be used.
 342       // TODO FMT implement time zones.
 343       __format_spec::__validate_time_zone(__flags);
 344       break;
 345
 346     default:
 347       std::__throw_format_error("The date time type specifier for modifier E is invalid");
 348     }
 349   }
 350
 351   /// \pre *__begin == 'O'
 352   /// \post __begin is incremented by one.
 353   _LIBCPP_HIDE_FROM_ABI constexpr void
 354   __parse_modifier_O(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 355     ++__begin;
 356     if (__begin == __end)
 357       std::__throw_format_error("End of input while parsing the modifier O");
 358
 359     switch (*__begin) {
 360     case _CharT('S'):
 361       __format_spec::__validate_second(__flags);
 362       break;
 363
 364     case _CharT('M'):
 365       __format_spec::__validate_minute(__flags);
 366       break;
 367
 368     case _CharT('I'):
 369     case _CharT('H'):
 370       __parser_.__hour_ = true;
 371       __format_spec::__validate_hour(__flags);
 372       break;
 373
 374     case _CharT('d'):
 375     case _CharT('e'):
 376       __format_spec::__validate_day(__flags);
 377       break;
 378
 379     case _CharT('m'):
 380       __format_spec::__validate_month(__flags);
 381       break;
 382
 383     case _CharT('y'):
 384       __format_spec::__validate_year(__flags);
 385       break;
 386
 387     case _CharT('U'):
 388     case _CharT('V'):
 389     case _CharT('W'):
 390       __parser_.__week_of_year_ = true;
 391       __format_spec::__validate_date(__flags);
 392       break;
 393
 394     case _CharT('u'):
 395     case _CharT('w'):
 396       __parser_.__weekday_ = true;
 397       __format_spec::__validate_weekday(__flags);
 398       break;
 399
 400     case _CharT('z'):
 401       // Currently there's no time zone information. However some clocks have a
 402       // hard-coded "time zone", for these clocks the information can be used.
 403       // TODO FMT implement time zones.
 404       __format_spec::__validate_time_zone(__flags);
 405       break;
 406
 407     default:
 408       std::__throw_format_error("The date time type specifier for modifier O is invalid");
 409     }
 410   }
 411 };
 412
 413 } // namespace __format_spec
 414
 415 #  endif // _LIBCPP_STD_VER >= 20
 416
 417 _LIBCPP_END_NAMESPACE_STD
 418
 419 #endif // _LIBCPP_HAS_LOCALIZATION
 420
 421 #endif // _LIBCPP___CHRONO_PARSER_STD_FORMAT_SPEC_H