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 #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_UNCATEGORIZED(
 164         __begin != __end,
 165         "When called with an empty input the function will cause "
 166         "undefined behavior by evaluating data not in the input");
 167
 168     if (*__begin != _CharT('%') && *__begin != _CharT('}'))
 169       std::__throw_format_error("The format specifier expects a '%' or a '}'");
 170
 171     do {
 172       switch (*__begin) {
 173       case _CharT('{'):
 174         std::__throw_format_error("The chrono specifiers contain a '{'");
 175
 176       case _CharT('}'):
 177         return __begin;
 178
 179       case _CharT('%'):
 180         __parse_conversion_spec(__begin, __end, __flags);
 181         [[fallthrough]];
 182
 183       default:
 184         // All other literals
 185         ++__begin;
 186       }
 187
 188     } while (__begin != __end && *__begin != _CharT('}'));
 189
 190     return __begin;
 191   }
 192
 193   /// \pre *__begin == '%'
 194   /// \post __begin points at the end parsed conversion-spec
 195   _LIBCPP_HIDE_FROM_ABI constexpr void
 196   __parse_conversion_spec(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 197     ++__begin;
 198     if (__begin == __end)
 199       std::__throw_format_error("End of input while parsing a conversion specifier");
 200
 201     switch (*__begin) {
 202     case _CharT('n'):
 203     case _CharT('t'):
 204     case _CharT('%'):
 205       break;
 206
 207     case _CharT('S'):
 208       __format_spec::__validate_second(__flags);
 209       break;
 210
 211     case _CharT('M'):
 212       __format_spec::__validate_minute(__flags);
 213       break;
 214
 215     case _CharT('p'): // TODO FMT does the formater require an hour or a time?
 216     case _CharT('H'):
 217     case _CharT('I'):
 218       __parser_.__hour_ = true;
 219       __validate_hour(__flags);
 220       break;
 221
 222     case _CharT('r'):
 223     case _CharT('R'):
 224     case _CharT('T'):
 225     case _CharT('X'):
 226       __parser_.__hour_ = true;
 227       __format_spec::__validate_time(__flags);
 228       break;
 229
 230     case _CharT('d'):
 231     case _CharT('e'):
 232       __format_spec::__validate_day(__flags);
 233       break;
 234
 235     case _CharT('b'):
 236     case _CharT('h'):
 237     case _CharT('B'):
 238       __parser_.__month_name_ = true;
 239       [[fallthrough]];
 240     case _CharT('m'):
 241       __format_spec::__validate_month(__flags);
 242       break;
 243
 244     case _CharT('y'):
 245     case _CharT('C'):
 246     case _CharT('Y'):
 247       __format_spec::__validate_year(__flags);
 248       break;
 249
 250     case _CharT('j'):
 251       __parser_.__day_of_year_ = true;
 252       __format_spec::__validate_date_or_duration(__flags);
 253       break;
 254
 255     case _CharT('g'):
 256     case _CharT('G'):
 257     case _CharT('U'):
 258     case _CharT('V'):
 259     case _CharT('W'):
 260       __parser_.__week_of_year_ = true;
 261       [[fallthrough]];
 262     case _CharT('x'):
 263     case _CharT('D'):
 264     case _CharT('F'):
 265       __format_spec::__validate_date(__flags);
 266       break;
 267
 268     case _CharT('c'):
 269       __format_spec::__validate_date_time(__flags);
 270       break;
 271
 272     case _CharT('a'):
 273     case _CharT('A'):
 274       __parser_.__weekday_name_ = true;
 275       [[fallthrough]];
 276     case _CharT('u'):
 277     case _CharT('w'):
 278       __parser_.__weekday_ = true;
 279       __validate_weekday(__flags);
 280       __format_spec::__validate_weekday(__flags);
 281       break;
 282
 283     case _CharT('q'):
 284     case _CharT('Q'):
 285       __format_spec::__validate_duration(__flags);
 286       break;
 287
 288     case _CharT('E'):
 289       __parse_modifier_E(__begin, __end, __flags);
 290       break;
 291
 292     case _CharT('O'):
 293       __parse_modifier_O(__begin, __end, __flags);
 294       break;
 295
 296     case _CharT('z'):
 297     case _CharT('Z'):
 298       // Currently there's no time zone information. However some clocks have a
 299       // hard-coded "time zone", for these clocks the information can be used.
 300       // TODO FMT implement time zones.
 301       __format_spec::__validate_time_zone(__flags);
 302       break;
 303
 304     default: // unknown type;
 305       std::__throw_format_error("The date time type specifier is invalid");
 306     }
 307   }
 308
 309   /// \pre *__begin == 'E'
 310   /// \post __begin is incremented by one.
 311   _LIBCPP_HIDE_FROM_ABI constexpr void
 312   __parse_modifier_E(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 313     ++__begin;
 314     if (__begin == __end)
 315       std::__throw_format_error("End of input while parsing the modifier E");
 316
 317     switch (*__begin) {
 318     case _CharT('X'):
 319       __parser_.__hour_ = true;
 320       __format_spec::__validate_time(__flags);
 321       break;
 322
 323     case _CharT('y'):
 324     case _CharT('C'):
 325     case _CharT('Y'):
 326       __format_spec::__validate_year(__flags);
 327       break;
 328
 329     case _CharT('x'):
 330       __format_spec::__validate_date(__flags);
 331       break;
 332
 333     case _CharT('c'):
 334       __format_spec::__validate_date_time(__flags);
 335       break;
 336
 337     case _CharT('z'):
 338       // Currently there's no time zone information. However some clocks have a
 339       // hard-coded "time zone", for these clocks the information can be used.
 340       // TODO FMT implement time zones.
 341       __format_spec::__validate_time_zone(__flags);
 342       break;
 343
 344     default:
 345       std::__throw_format_error("The date time type specifier for modifier E is invalid");
 346     }
 347   }
 348
 349   /// \pre *__begin == 'O'
 350   /// \post __begin is incremented by one.
 351   _LIBCPP_HIDE_FROM_ABI constexpr void
 352   __parse_modifier_O(_ConstIterator& __begin, _ConstIterator __end, __flags __flags) {
 353     ++__begin;
 354     if (__begin == __end)
 355       std::__throw_format_error("End of input while parsing the modifier O");
 356
 357     switch (*__begin) {
 358     case _CharT('S'):
 359       __format_spec::__validate_second(__flags);
 360       break;
 361
 362     case _CharT('M'):
 363       __format_spec::__validate_minute(__flags);
 364       break;
 365
 366     case _CharT('I'):
 367     case _CharT('H'):
 368       __parser_.__hour_ = true;
 369       __format_spec::__validate_hour(__flags);
 370       break;
 371
 372     case _CharT('d'):
 373     case _CharT('e'):
 374       __format_spec::__validate_day(__flags);
 375       break;
 376
 377     case _CharT('m'):
 378       __format_spec::__validate_month(__flags);
 379       break;
 380
 381     case _CharT('y'):
 382       __format_spec::__validate_year(__flags);
 383       break;
 384
 385     case _CharT('U'):
 386     case _CharT('V'):
 387     case _CharT('W'):
 388       __parser_.__week_of_year_ = true;
 389       __format_spec::__validate_date(__flags);
 390       break;
 391
 392     case _CharT('u'):
 393     case _CharT('w'):
 394       __parser_.__weekday_ = true;
 395       __format_spec::__validate_weekday(__flags);
 396       break;
 397
 398     case _CharT('z'):
 399       // Currently there's no time zone information. However some clocks have a
 400       // hard-coded "time zone", for these clocks the information can be used.
 401       // TODO FMT implement time zones.
 402       __format_spec::__validate_time_zone(__flags);
 403       break;
 404
 405     default:
 406       std::__throw_format_error("The date time type specifier for modifier O is invalid");
 407     }
 408   }
 409 };
 410
 411 } // namespace __format_spec
 412
 413 #endif //_LIBCPP_STD_VER >= 20
 414
 415 _LIBCPP_END_NAMESPACE_STD
 416
 417 #endif // _LIBCPP___CHRONO_PARSER_STD_FORMAT_SPEC_H