path: root/time/tzfile.c

/* Copyright (C) 1991-1993,1995-2001,2003,2004,2006,2007,2009
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>

#define	NOID
#include <timezone/tzfile.h>

int __use_tzfile;
static dev_t tzfile_dev;
static ino64_t tzfile_ino;
static time_t tzfile_mtime;

struct ttinfo
  {
    long int offset;		/* Seconds east of GMT.  */
    unsigned char isdst;	/* Used to set tm_isdst.  */
    unsigned char idx;		/* Index into `zone_names'.  */
    unsigned char isstd;	/* Transition times are in standard time.  */
    unsigned char isgmt;	/* Transition times are in GMT.  */
  };

struct leap
  {
    time_t transition;		/* Time the transition takes effect.  */
    long int change;		/* Seconds of correction to apply.  */
  };

static void compute_tzname_max (size_t) internal_function;

static size_t num_transitions;
libc_freeres_ptr (static time_t *transitions);
static unsigned char *type_idxs;
static size_t num_types;
static struct ttinfo *types;
static char *zone_names;
static long int rule_stdoff;
static long int rule_dstoff;
static size_t num_leaps;
static struct leap *leaps;
static char *tzspec;

#include <endian.h>
#include <byteswap.h>

/* Decode the four bytes at PTR as a signed integer in network byte order.  */
static inline int
__attribute ((always_inline))
decode (const void *ptr)
{
  if (BYTE_ORDER == BIG_ENDIAN && sizeof (int) == 4)
    return *(const int *) ptr;
  if (sizeof (int) == 4)
    return bswap_32 (*