/* Time internal interface

   Copyright 2015-2020 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3, or (at your option)

   any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License along

   with this program; if not, see <https://www.gnu.org/licenses/>.  */

/* Written by Paul Eggert.  */

/* A time zone rule.  */

struct tm_zone

{

  /* More abbreviations, should they be needed.  Their TZ_IS_SET

     members are zero.  */

  struct tm_zone *next;

#if HAVE_TZNAME && !HAVE_TM_ZONE

  /* Copies of recent strings taken from tzname[0] and tzname[1].

     The copies are in ABBRS, so that they survive tzset.  Null if unknown.  */

  char *tzname_copy[2];

#endif

  /* If nonzero, the rule represents the TZ environment variable set

     to the first "abbreviation" (this may be the empty string).

     Otherwise, it represents an unset TZ.  */

  char tz_is_set;

  /* A sequence of null-terminated strings packed next to each other.

     The strings are followed by an extra null byte.  If TZ_IS_SET,

     there must be at least one string and the first string (which is

     actually a TZ environment value) may be empty.  Otherwise all

     strings must be nonempty.

     Abbreviations are stored here because otherwise the values of

     tm_zone and/or tzname would be dead after changing TZ and calling

     tzset.  Abbreviations never move once allocated, and are live

     until tzfree is called.  */

  char abbrs[FLEXIBLE_ARRAY_MEMBER];

};