lib/time-internal.h

   1 /* Time internal interface
   2
   3    Copyright 2015-2020 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program 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 General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with this program; if not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 /* A time zone rule.  */
  21 struct tm_zone
  22 {
  23   /* More abbreviations, should they be needed.  Their TZ_IS_SET
  24      members are zero.  */
  25   struct tm_zone *next;
  26
  27 #if HAVE_TZNAME && !HAVE_TM_ZONE
  28   /* Copies of recent strings taken from tzname[0] and tzname[1].
  29      The copies are in ABBRS, so that they survive tzset.  Null if unknown.  */
  30   char *tzname_copy[2];
  31 #endif
  32
  33   /* If nonzero, the rule represents the TZ environment variable set
  34      to the first "abbreviation" (this may be the empty string).
  35      Otherwise, it represents an unset TZ.  */
  36   char tz_is_set;
  37
  38   /* A sequence of null-terminated strings packed next to each other.
  39      The strings are followed by an extra null byte.  If TZ_IS_SET,
  40      there must be at least one string and the first string (which is
  41      actually a TZ environment value) may be empty.  Otherwise all
  42      strings must be nonempty.
  43
  44      Abbreviations are stored here because otherwise the values of
  45      tm_zone and/or tzname would be dead after changing TZ and calling
  46      tzset.  Abbreviations never move once allocated, and are live
  47      until tzfree is called.  */
  48   char abbrs[FLEXIBLE_ARRAY_MEMBER];
  49 };