1  /* Time internal interface
       2  
       3     Copyright 2015-2023 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 3 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  /* 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_STRUCT_TM_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  };