gl/time.in.h

   1 /* A more-standard <time.h>.
   2
   3    Copyright (C) 2007-2023 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #if __GNUC__ >= 3
  19 @PRAGMA_SYSTEM_HEADER@
  20 #endif
  21 @PRAGMA_COLUMNS@
  22
  23 /* Don't get in the way of glibc when it includes time.h merely to
  24    declare a few standard symbols, rather than to declare all the
  25    symbols.  (However, skip this for MinGW as it treats __need_time_t
  26    incompatibly.)  Also, Solaris 8 <time.h> eventually includes itself
  27    recursively; if that is happening, just include the system <time.h>
  28    without adding our own declarations.  */
  29 #if (((defined __need_time_t || defined __need_clock_t \
  30        || defined __need_timespec)                     \
  31       && !defined __MINGW32__)                         \
  32      || defined _@GUARD_PREFIX@_TIME_H)
  33
  34 # @INCLUDE_NEXT@ @NEXT_TIME_H@
  35
  36 #else
  37
  38 # define _@GUARD_PREFIX@_TIME_H
  39
  40 /* mingw's <time.h> provides the functions asctime_r, ctime_r, gmtime_r,
  41    localtime_r only if <unistd.h> or <pthread.h> has been included before.  */
  42 # if defined __MINGW32__
  43 #  include <unistd.h>
  44 # endif
  45
  46 # @INCLUDE_NEXT@ @NEXT_TIME_H@
  47
  48 /* NetBSD 5.0 mis-defines NULL.  */
  49 # include <stddef.h>
  50
  51 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
  52
  53 /* The definition of _GL_ARG_NONNULL is copied here.  */
  54
  55 /* The definition of _GL_WARN_ON_USE is copied here.  */
  56
  57 /* Some systems don't define struct timespec (e.g., AIX 4.1).
  58    Or they define it with the wrong member names or define it in <sys/time.h>
  59    (e.g., FreeBSD circa 1997).  Stock Mingw prior to 3.0 does not define it,
  60    but the pthreads-win32 library defines it in <pthread.h>.  */
  61 # if ! @TIME_H_DEFINES_STRUCT_TIMESPEC@
  62 #  if @SYS_TIME_H_DEFINES_STRUCT_TIMESPEC@
  63 #   include <sys/time.h>
  64 #  elif @PTHREAD_H_DEFINES_STRUCT_TIMESPEC@
  65 #   include <pthread.h>
  66 #  elif @UNISTD_H_DEFINES_STRUCT_TIMESPEC@
  67 #   include <unistd.h>
  68 #  else
  69
  70 #   ifdef __cplusplus
  71 extern "C" {
  72 #   endif
  73
  74 #   if !GNULIB_defined_struct_timespec
  75 #    undef timespec
  76 #    define timespec rpl_timespec
  77 struct timespec
  78 {
  79   time_t tv_sec;
  80   long int tv_nsec;
  81 };
  82 #    define GNULIB_defined_struct_timespec 1
  83 #   endif
  84
  85 #   ifdef __cplusplus
  86 }
  87 #   endif
  88
  89 #  endif
  90 # endif
  91
  92 # if !GNULIB_defined_struct_time_t_must_be_integral
  93 /* https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_types.h.html
  94    requires time_t to be an integer type, even though C99 permits floating
  95    point.  We don't know of any implementation that uses floating
  96    point, and it is much easier to write code that doesn't have to
  97    worry about that corner case, so we force the issue.  */
  98 struct __time_t_must_be_integral {
  99   unsigned int __floating_time_t_unsupported : (time_t) 1;
 100 };
 101 #  define GNULIB_defined_struct_time_t_must_be_integral 1
 102 # endif
 103
 104 /* Define TIME_UTC, a positive integer constant used for timespec_get().  */
 105 # if ! @TIME_H_DEFINES_TIME_UTC@
 106 #  if !GNULIB_defined_TIME_UTC
 107 #   define TIME_UTC 1
 108 #   define GNULIB_defined_TIME_UTC 1
 109 #  endif
 110 # endif
 111
 112 /* Set *TS to the current time, and return BASE.
 113    Upon failure, return 0.  */
 114 # if @GNULIB_TIMESPEC_GET@
 115 #  if ! @HAVE_TIMESPEC_GET@
 116 _GL_FUNCDECL_SYS (timespec_get, int, (struct timespec *ts, int base)
 117                                      _GL_ARG_NONNULL ((1)));
 118 #  endif
 119 _GL_CXXALIAS_SYS (timespec_get, int, (struct timespec *ts, int base));
 120 _GL_CXXALIASWARN (timespec_get);
 121 # endif
 122
 123 /* Set *TS to the current time resolution, and return BASE.
 124    Upon failure, return 0.  */
 125 # if @GNULIB_TIMESPEC_GETRES@
 126 #  if ! @HAVE_TIMESPEC_GETRES@
 127 _GL_FUNCDECL_SYS (timespec_getres, int, (struct timespec *ts, int base)
 128                                         _GL_ARG_NONNULL ((1)));
 129 #  endif
 130 _GL_CXXALIAS_SYS (timespec_getres, int, (struct timespec *ts, int base));
 131 _GL_CXXALIASWARN (timespec_getres);
 132 # endif
 133
 134 /* Sleep for at least RQTP seconds unless interrupted,  If interrupted,
 135    return -1 and store the remaining time into RMTP.  See
 136    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanosleep.html>.  */
 137 # if @GNULIB_NANOSLEEP@
 138 #  if @REPLACE_NANOSLEEP@
 139 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 140 #    define nanosleep rpl_nanosleep
 141 #   endif
 142 _GL_FUNCDECL_RPL (nanosleep, int,
 143                   (struct timespec const *__rqtp, struct timespec *__rmtp)
 144                   _GL_ARG_NONNULL ((1)));
 145 _GL_CXXALIAS_RPL (nanosleep, int,
 146                   (struct timespec const *__rqtp, struct timespec *__rmtp));
 147 #  else
 148 #   if ! @HAVE_NANOSLEEP@
 149 _GL_FUNCDECL_SYS (nanosleep, int,
 150                   (struct timespec const *__rqtp, struct timespec *__rmtp)
 151                   _GL_ARG_NONNULL ((1)));
 152 #   endif
 153 _GL_CXXALIAS_SYS (nanosleep, int,
 154                   (struct timespec const *__rqtp, struct timespec *__rmtp));
 155 #  endif
 156 _GL_CXXALIASWARN (nanosleep);
 157 # endif
 158
 159 /* Initialize time conversion information.  */
 160 # if @GNULIB_TZSET@
 161 #  if @REPLACE_TZSET@
 162 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 163 #    undef tzset
 164 #    define tzset rpl_tzset
 165 #   endif
 166 _GL_FUNCDECL_RPL (tzset, void, (void));
 167 _GL_CXXALIAS_RPL (tzset, void, (void));
 168 #  elif defined _WIN32 && !defined __CYGWIN__
 169 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 170 #    undef tzset
 171 #    define tzset _tzset
 172 #   endif
 173 _GL_CXXALIAS_MDA (tzset, void, (void));
 174 #  else
 175 _GL_CXXALIAS_SYS (tzset, void, (void));
 176 #  endif
 177 _GL_CXXALIASWARN (tzset);
 178 # elif @GNULIB_MDA_TZSET@
 179 /* On native Windows, map 'tzset' to '_tzset', so that -loldnames is not
 180    required.  In C++ with GNULIB_NAMESPACE, avoid differences between
 181    platforms by defining GNULIB_NAMESPACE::tzset always.  */
 182 #  if defined _WIN32 && !defined __CYGWIN__
 183 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 184 #    undef tzset
 185 #    define tzset _tzset
 186 #   endif
 187 _GL_CXXALIAS_MDA (tzset, void, (void));
 188 #  else
 189 _GL_CXXALIAS_SYS (tzset, void, (void));
 190 #  endif
 191 _GL_CXXALIASWARN (tzset);
 192 # endif
 193
 194 /* Return the 'time_t' representation of TP and normalize TP.  */
 195 # if @GNULIB_MKTIME@
 196 #  if @REPLACE_MKTIME@
 197 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 198 #    define mktime rpl_mktime
 199 #   endif
 200 _GL_FUNCDECL_RPL (mktime, time_t, (struct tm *__tp) _GL_ARG_NONNULL ((1)));
 201 _GL_CXXALIAS_RPL (mktime, time_t, (struct tm *__tp));
 202 #  else
 203 _GL_CXXALIAS_SYS (mktime, time_t, (struct tm *__tp));
 204 #  endif
 205 #  if __GLIBC__ >= 2
 206 _GL_CXXALIASWARN (mktime);
 207 #  endif
 208 # endif
 209
 210 /* Convert TIMER to RESULT, assuming local time and UTC respectively.  See
 211    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime_r.html> and
 212    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime_r.html>.  */
 213 # if @GNULIB_TIME_R@
 214 #  if @REPLACE_LOCALTIME_R@
 215 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 216 #    undef localtime_r
 217 #    define localtime_r rpl_localtime_r
 218 #   endif
 219 _GL_FUNCDECL_RPL (localtime_r, struct tm *, (time_t const *restrict __timer,
 220                                              struct tm *restrict __result)
 221                                             _GL_ARG_NONNULL ((1, 2)));
 222 _GL_CXXALIAS_RPL (localtime_r, struct tm *, (time_t const *restrict __timer,
 223                                              struct tm *restrict __result));
 224 #  else
 225 #   if ! @HAVE_DECL_LOCALTIME_R@
 226 _GL_FUNCDECL_SYS (localtime_r, struct tm *, (time_t const *restrict __timer,
 227                                              struct tm *restrict __result)
 228                                             _GL_ARG_NONNULL ((1, 2)));
 229 #   endif
 230 _GL_CXXALIAS_SYS (localtime_r, struct tm *, (time_t const *restrict __timer,
 231                                              struct tm *restrict __result));
 232 #  endif
 233 #  if @HAVE_DECL_LOCALTIME_R@
 234 _GL_CXXALIASWARN (localtime_r);
 235 #  endif
 236 #  if @REPLACE_LOCALTIME_R@
 237 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 238 #    undef gmtime_r
 239 #    define gmtime_r rpl_gmtime_r
 240 #   endif
 241 _GL_FUNCDECL_RPL (gmtime_r, struct tm *, (time_t const *restrict __timer,
 242                                           struct tm *restrict __result)
 243                                          _GL_ARG_NONNULL ((1, 2)));
 244 _GL_CXXALIAS_RPL (gmtime_r, struct tm *, (time_t const *restrict __timer,
 245                                           struct tm *restrict __result));
 246 #  else
 247 #   if ! @HAVE_DECL_LOCALTIME_R@
 248 _GL_FUNCDECL_SYS (gmtime_r, struct tm *, (time_t const *restrict __timer,
 249                                           struct tm *restrict __result)
 250                                          _GL_ARG_NONNULL ((1, 2)));
 251 #   endif
 252 _GL_CXXALIAS_SYS (gmtime_r, struct tm *, (time_t const *restrict __timer,
 253                                           struct tm *restrict __result));
 254 #  endif
 255 #  if @HAVE_DECL_LOCALTIME_R@
 256 _GL_CXXALIASWARN (gmtime_r);
 257 #  endif
 258 # endif
 259
 260 /* Convert TIMER to RESULT, assuming local time and UTC respectively.  See
 261    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime.html> and
 262    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime.html>.  */
 263 # if @GNULIB_LOCALTIME@ || @REPLACE_LOCALTIME@
 264 #  if @REPLACE_LOCALTIME@
 265 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 266 #    undef localtime
 267 #    define localtime rpl_localtime
 268 #   endif
 269 _GL_FUNCDECL_RPL (localtime, struct tm *, (time_t const *__timer)
 270                                           _GL_ARG_NONNULL ((1)));
 271 _GL_CXXALIAS_RPL (localtime, struct tm *, (time_t const *__timer));
 272 #  else
 273 _GL_CXXALIAS_SYS (localtime, struct tm *, (time_t const *__timer));
 274 #  endif
 275 #  if __GLIBC__ >= 2
 276 _GL_CXXALIASWARN (localtime);
 277 #  endif
 278 # endif
 279
 280 # if 0 || @REPLACE_GMTIME@
 281 #  if @REPLACE_GMTIME@
 282 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 283 #    undef gmtime
 284 #    define gmtime rpl_gmtime
 285 #   endif
 286 _GL_FUNCDECL_RPL (gmtime, struct tm *, (time_t const *__timer)
 287                                        _GL_ARG_NONNULL ((1)));
 288 _GL_CXXALIAS_RPL (gmtime, struct tm *, (time_t const *__timer));
 289 #  else
 290 _GL_CXXALIAS_SYS (gmtime, struct tm *, (time_t const *__timer));
 291 #  endif
 292 _GL_CXXALIASWARN (gmtime);
 293 # endif
 294
 295 /* Parse BUF as a timestamp, assuming FORMAT specifies its layout, and store
 296    the resulting broken-down time into TM.  See
 297    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html>.  */
 298 # if @GNULIB_STRPTIME@
 299 #  if ! @HAVE_STRPTIME@
 300 _GL_FUNCDECL_SYS (strptime, char *, (char const *restrict __buf,
 301                                      char const *restrict __format,
 302                                      struct tm *restrict __tm)
 303                                     _GL_ARG_NONNULL ((1, 2, 3)));
 304 #  endif
 305 _GL_CXXALIAS_SYS (strptime, char *, (char const *restrict __buf,
 306                                      char const *restrict __format,
 307                                      struct tm *restrict __tm));
 308 _GL_CXXALIASWARN (strptime);
 309 # endif
 310
 311 /* Convert *TP to a date and time string.  See
 312    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime.html>.  */
 313 # if @GNULIB_CTIME@
 314 #  if @REPLACE_CTIME@
 315 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 316 #    define ctime rpl_ctime
 317 #   endif
 318 _GL_ATTRIBUTE_DEPRECATED
 319 _GL_FUNCDECL_RPL (ctime, char *, (time_t const *__tp)
 320                                  _GL_ARG_NONNULL ((1)));
 321 _GL_CXXALIAS_RPL (ctime, char *, (time_t const *__tp));
 322 #  else
 323 _GL_CXXALIAS_SYS (ctime, char *, (time_t const *__tp));
 324 #  endif
 325 #  if __GLIBC__ >= 2
 326 _GL_CXXALIASWARN (ctime);
 327 #  endif
 328 # endif
 329
 330 /* Convert *TP to a date and time string.  See
 331    <https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html>.  */
 332 # if @GNULIB_STRFTIME@
 333 #  if @REPLACE_STRFTIME@
 334 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 335 #    define strftime rpl_strftime
 336 #   endif
 337 _GL_FUNCDECL_RPL (strftime, size_t,
 338                   (char *restrict __buf, size_t __bufsize,
 339                    const char *restrict __fmt, const struct tm *restrict __tp)
 340                   _GL_ARG_NONNULL ((1, 3, 4)));
 341 _GL_CXXALIAS_RPL (strftime, size_t,
 342                   (char *restrict __buf, size_t __bufsize,
 343                    const char *restrict __fmt, const struct tm *restrict __tp));
 344 #  else
 345 _GL_CXXALIAS_SYS (strftime, size_t,
 346                   (char *restrict __buf, size_t __bufsize,
 347                    const char *restrict __fmt, const struct tm *restrict __tp));
 348 #  endif
 349 #  if __GLIBC__ >= 2
 350 _GL_CXXALIASWARN (strftime);
 351 #  endif
 352 # endif
 353
 354 # if defined _GNU_SOURCE && @GNULIB_TIME_RZ@ && ! @HAVE_TIMEZONE_T@
 355 /* Functions that use a first-class time zone data type, instead of
 356    relying on an implicit global time zone.
 357    Inspired by NetBSD.  */
 358
 359 /* Represents a time zone.
 360    (timezone_t) NULL stands for UTC.  */
 361 typedef struct tm_zone *timezone_t;
 362
 363 /* tzalloc (name)
 364    Returns a time zone object for the given time zone NAME.  This object
 365    represents the time zone that other functions would use it the TZ
 366    environment variable was set to NAME.
 367    If NAME is NULL, the result represents the time zone that other functions
 368    would use it the TZ environment variable was unset.
 369    May return NULL if NAME is invalid (this is platform dependent) or
 370    upon memory allocation failure.  */
 371 _GL_FUNCDECL_SYS (tzalloc, timezone_t, (char const *__name));
 372 _GL_CXXALIAS_SYS (tzalloc, timezone_t, (char const *__name));
 373
 374 /* tzfree (tz)
 375    Frees a time zone object.
 376    The argument must have been returned by tzalloc().  */
 377 _GL_FUNCDECL_SYS (tzfree, void, (timezone_t __tz));
 378 _GL_CXXALIAS_SYS (tzfree, void, (timezone_t __tz));
 379
 380 /* localtime_rz (tz, &t, &result)
 381    Converts an absolute time T to a broken-down time RESULT, assuming the
 382    time zone TZ.
 383    This function is like 'localtime_r', but relies on the argument TZ instead
 384    of an implicit global time zone.  */
 385 _GL_FUNCDECL_SYS (localtime_rz, struct tm *,
 386                   (timezone_t __tz, time_t const *restrict __timer,
 387                    struct tm *restrict __result) _GL_ARG_NONNULL ((2, 3)));
 388 _GL_CXXALIAS_SYS (localtime_rz, struct tm *,
 389                   (timezone_t __tz, time_t const *restrict __timer,
 390                    struct tm *restrict __result));
 391
 392 /* mktime_z (tz, &tm)
 393    Normalizes the broken-down time TM and converts it to an absolute time,
 394    assuming the time zone TZ.  Returns the absolute time.
 395    This function is like 'mktime', but relies on the argument TZ instead
 396    of an implicit global time zone.  */
 397 _GL_FUNCDECL_SYS (mktime_z, time_t,
 398                   (timezone_t __tz, struct tm *restrict __tm)
 399                   _GL_ARG_NONNULL ((2)));
 400 _GL_CXXALIAS_SYS (mktime_z, time_t,
 401                   (timezone_t __tz, struct tm *restrict __tm));
 402
 403 /* Time zone abbreviation strings (returned by 'localtime_rz' or 'mktime_z'
 404    in the 'tm_zone' member of 'struct tm') are valid as long as
 405      - the 'struct tm' argument is not destroyed or overwritten,
 406    and
 407      - the 'timezone_t' argument is not freed through tzfree().  */
 408
 409 # endif
 410
 411 /* Convert TM to a time_t value, assuming UTC.  */
 412 # if @GNULIB_TIMEGM@
 413 #  if @REPLACE_TIMEGM@
 414 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 415 #    undef timegm
 416 #    define timegm rpl_timegm
 417 #   endif
 418 _GL_FUNCDECL_RPL (timegm, time_t, (struct tm *__tm) _GL_ARG_NONNULL ((1)));
 419 _GL_CXXALIAS_RPL (timegm, time_t, (struct tm *__tm));
 420 #  else
 421 #   if ! @HAVE_TIMEGM@
 422 _GL_FUNCDECL_SYS (timegm, time_t, (struct tm *__tm) _GL_ARG_NONNULL ((1)));
 423 #   endif
 424 _GL_CXXALIAS_SYS (timegm, time_t, (struct tm *__tm));
 425 #  endif
 426 _GL_CXXALIASWARN (timegm);
 427 # endif
 428
 429 /* Encourage applications to avoid unsafe functions that can overrun
 430    buffers when given outlandish struct tm values.  Portable
 431    applications should use strftime (or even sprintf) instead.  */
 432 # if defined GNULIB_POSIXCHECK
 433 #  undef asctime
 434 _GL_WARN_ON_USE (asctime, "asctime can overrun buffers in some cases - "
 435                  "better use strftime (or even sprintf) instead");
 436 # endif
 437 # if defined GNULIB_POSIXCHECK
 438 #  undef asctime_r
 439 #  if HAVE_RAW_DECL_ASCTIME_R
 440 _GL_WARN_ON_USE (asctime_r, "asctime_r can overrun buffers in some cases - "
 441                  "better use strftime (or even sprintf) instead");
 442 #  endif
 443 # endif
 444 # if defined GNULIB_POSIXCHECK
 445 #  undef ctime
 446 _GL_WARN_ON_USE (ctime, "ctime can overrun buffers in some cases - "
 447                  "better use strftime (or even sprintf) instead");
 448 # endif
 449 # if defined GNULIB_POSIXCHECK
 450 #  undef ctime_r
 451 #  if HAVE_RAW_DECL_CTIME_R
 452 _GL_WARN_ON_USE (ctime_r, "ctime_r can overrun buffers in some cases - "
 453                  "better use strftime (or even sprintf) instead");
 454 #  endif
 455 # endif
 456
 457 #endif