libc/winsup/cygwin/localtime.cc

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
*/
/* Temporarily merged private.h and tzfile.h for ease of management - DJ */

#include "winsup.h"
#include "cygerrno.h"
#include "sync.h"
#include <ctype.h>
#define STD_INSPIRED
#define lint

#define USG_COMPAT

#ifndef lint
#ifndef NOID
static char	elsieid[] = "@(#)localtime.c	7.66";
#endif /* !defined NOID */
#endif /* !defined lint */

/*
** Leap second handling from Bradley White (bww@k.gp.cs.cmu.edu).
** POSIX-style TZ environment variable handling from Guy Harris
** (guy@auspex.com).
*/

/*LINTLIBRARY*/

#ifndef PRIVATE_H

#define PRIVATE_H

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
*/

/*
** This header is for use ONLY with the time conversion code.
** There is no guarantee that it will remain unchanged,
** or that it will remain at all.
** Do NOT copy it to any system include directory.
** Thank you!
*/

/*
** ID
*/

#ifndef lint
#ifndef NOID
static char	privatehid[] = "@(#)private.h	7.48";
#endif /* !defined NOID */
#endif /* !defined lint */

/*
** Defaults for preprocessor symbols.
** You can override these in your C compiler options, e.g. `-DHAVE_ADJTIME=0'.
*/

#ifndef HAVE_ADJTIME
#define HAVE_ADJTIME		1
#endif /* !defined HAVE_ADJTIME */

#ifndef HAVE_GETTEXT
#define HAVE_GETTEXT		0
#endif /* !defined HAVE_GETTEXT */

#ifndef HAVE_SETTIMEOFDAY
#define HAVE_SETTIMEOFDAY	3
#endif /* !defined HAVE_SETTIMEOFDAY */

#ifndef HAVE_STRERROR
#define HAVE_STRERROR		0
#endif /* !defined HAVE_STRERROR */

#ifndef HAVE_SYMLINK
#define HAVE_SYMLINK		1
#endif /* !defined HAVE_SYMLINK */

#ifndef HAVE_UNISTD_H
#define HAVE_UNISTD_H		1
#endif /* !defined HAVE_UNISTD_H */

#ifndef HAVE_UTMPX_H
#define HAVE_UTMPX_H		0
#endif /* !defined HAVE_UTMPX_H */

#ifndef LOCALE_HOME
#define LOCALE_HOME		"/usr/lib/locale"
#endif /* !defined LOCALE_HOME */

/*
** Nested includes
*/

#include "stdio.h"
#include "limits.h"	/* for CHAR_BIT */
#include "stdlib.h"

#if HAVE_GETTEXT - 0
#endif /* HAVE_GETTEXT - 0 */

#if HAVE_UNISTD_H - 0
#include "unistd.h"	/* for F_OK and R_OK */
#endif /* HAVE_UNISTD_H - 0 */

#if !(HAVE_UNISTD_H - 0)
#ifndef F_OK
#define F_OK	0
#endif /* !defined F_OK */
#ifndef R_OK
#define R_OK	4
#endif /* !defined R_OK */
#endif /* !(HAVE_UNISTD_H - 0) */

/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX.  */
#define is_digit(c) ((unsigned)(c) - '0' <= 9)

/*
** Workarounds for compilers/systems.
*/

/*
** SunOS 4.1.1 cc lacks const.
*/

#ifndef const
#ifndef __STDC__
#define const
#endif /* !defined __STDC__ */
#endif /* !defined const */

/*
** SunOS 4.1.1 cc lacks prototypes.
*/

#ifndef P
#ifdef __STDC__
#define P(x)	x
#endif /* defined __STDC__ */
#ifndef __STDC__
#define P(x)	()
#endif /* !defined __STDC__ */
#endif /* !defined P */

/*
** SunOS 4.1.1 headers lack EXIT_SUCCESS.
*/

#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS	0
#endif /* !defined EXIT_SUCCESS */

/*
** SunOS 4.1.1 headers lack EXIT_FAILURE.
*/

#ifndef EXIT_FAILURE
#define EXIT_FAILURE	1
#endif /* !defined EXIT_FAILURE */

/*
** SunOS 4.1.1 headers lack FILENAME_MAX.
*/

#ifndef FILENAME_MAX

#ifndef MAXPATHLEN
#ifdef unix
#endif /* defined unix */
#endif /* !defined MAXPATHLEN */

#ifdef MAXPATHLEN
#define FILENAME_MAX	MAXPATHLEN
#endif /* defined MAXPATHLEN */
#ifndef MAXPATHLEN
#define FILENAME_MAX	1024		/* Pure guesswork */
#endif /* !defined MAXPATHLEN */

#endif /* !defined FILENAME_MAX */

/*
** SunOS 4.1.1 libraries lack remove.
*/

#ifndef remove
extern int	unlink P((const char * filename));
#define remove	unlink
#endif /* !defined remove */

/*
** Finally, some convenience items.
*/

#ifndef TYPE_BIT
#define TYPE_BIT(type)	(sizeof (type) * CHAR_BIT)
#endif /* !defined TYPE_BIT */

#ifndef TYPE_SIGNED
#define TYPE_SIGNED(type) (((type) -1) < 0)
#endif /* !defined TYPE_SIGNED */

#ifndef INT_STRLEN_MAXIMUM
/*
** 302 / 1000 is log10(2.0) rounded up.
** Subtract one for the sign bit if the type is signed;
** add one for integer division truncation;
** add one more for a minus sign if the type is signed.
*/
#define INT_STRLEN_MAXIMUM(type) \
    ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + 1 + TYPE_SIGNED(type))
#endif /* !defined INT_STRLEN_MAXIMUM */

/*
** INITIALIZE(x)
*/

#ifndef GNUC_or_lint
#ifdef lint
#define GNUC_or_lint
#endif /* defined lint */
#ifndef lint
#ifdef __GNUC__
#define GNUC_or_lint
#endif /* defined __GNUC__ */
#endif /* !defined lint */
#endif /* !defined GNUC_or_lint */

#ifndef INITIALIZE
#ifdef GNUC_or_lint
#define INITIALIZE(x)	((x) = 0)
#endif /* defined GNUC_or_lint */
#ifndef GNUC_or_lint
#define INITIALIZE(x)
#endif /* !defined GNUC_or_lint */
#endif /* !defined INITIALIZE */

/*
** For the benefit of GNU folk...
** `_(MSGID)' uses the current locale's message library string for MSGID.
** The default is to use gettext if available, and use MSGID otherwise.
*/

#ifndef _
#if HAVE_GETTEXT - 0
#define _(msgid) gettext(msgid)
#else /* !(HAVE_GETTEXT - 0) */
#define _(msgid) msgid
#endif /* !(HAVE_GETTEXT - 0) */
#endif /* !defined _ */

#ifndef TZ_DOMAIN
#define TZ_DOMAIN "tz"
#endif /* !defined TZ_DOMAIN */

/*
** UNIX was a registered trademark of UNIX System Laboratories in 1993.
*/

#endif /* !defined PRIVATE_H */

#ifndef TZFILE_H

#define TZFILE_H

/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
*/

/*
** This header is for use ONLY with the time conversion code.
** There is no guarantee that it will remain unchanged,
** or that it will remain at all.
** Do NOT copy it to any system include directory.
** Thank you!
*/

/*
** ID
*/

#ifndef lint
#ifndef NOID
static char	tzfilehid[] = "@(#)tzfile.h	7.14";
#endif /* !defined NOID */
#endif /* !defined lint */

/*
** Information about time zone files.
*/

#ifndef TZDIR
#define TZDIR	"/usr/share/zoneinfo" /* Time zone object file directory */
#endif /* !defined TZDIR */

#ifndef TZDEFAULT
#define TZDEFAULT	"localtime"
#endif /* !defined TZDEFAULT */

#ifndef TZDEFRULES
#define TZDEFRULES	"posixrules"
#endif /* !defined TZDEFRULES */

/*
** Each file begins with. . .
*/

#define	TZ_MAGIC	"TZif"

struct tzhead {
	char	tzh_magic[4];		/* TZ_MAGIC */
	char	tzh_reserved[16];	/* reserved for future use */
	char	tzh_ttisgmtcnt[4];	/* coded number of trans. time flags */
	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
	char	tzh_leapcnt[4];		/* coded number of leap seconds */
	char	tzh_timecnt[4];		/* coded number of transition times */
	char	tzh_typecnt[4];		/* coded number of local time types */
	char	tzh_charcnt[4];		/* coded number of abbr. chars */
};

/*
** . . .followed by. . .
**
**	tzh_timecnt (char [4])s		coded transition times a la time(2)
**	tzh_timecnt (unsigned char)s	types of local time starting at above
**	tzh_typecnt repetitions of
**		one (char [4])		coded UTC offset in seconds
**		one (unsigned char)	used to set tm_isdst
**		one (unsigned char)	that's an abbreviation list index
**	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
**	tzh_leapcnt repetitions of
**		one (char [4])		coded leap second transition times
**		one (char [4])		total correction after above
**	tzh_ttisstdcnt (char)s		indexed by type; if true, transition
**					time is standard time, if false,
**					transition time is wall clock time
**					if absent, transition times are
**					assumed to be wall clock time
**	tzh_ttisgmtcnt (char)s		indexed by type; if true, transition
**					time is UTC, if false,
**					transition time is local time
**					if absent, transition times are
**					assumed to be local time
*/

/*
** In the current implementation, "tzset()" refuses to deal with files that
** exceed any of the limits below.
*/

#ifndef TZ_MAX_TIMES
/*
** The TZ_MAX_TIMES value below is enough to handle a bit more than a
** year's worth of solar time (corrected daily to the nearest second) or
** 138 years of Pacific Presidential Election time
** (where there are three time zone transitions every fourth year).
*/
#define TZ_MAX_TIMES	370
#endif /* !defined TZ_MAX_TIMES */

#ifndef TZ_MAX_TYPES
#ifndef NOSOLAR
#define TZ_MAX_TYPES	256 /* Limited by what (unsigned char)'s can hold */
#endif /* !defined NOSOLAR */
#ifdef NOSOLAR
/*
** Must be at least 14 for Europe/Riga as of Jan 12 1995,
** as noted by Earl Chew <earl@hpato.aus.hp.com>.
*/
#define TZ_MAX_TYPES	20	/* Maximum number of local time types */
#endif /* !defined NOSOLAR */
#endif /* !defined TZ_MAX_TYPES */

#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS	50	/* Maximum number of abbreviation characters */
				/* (limited by what unsigned chars can hold) */
#endif /* !defined TZ_MAX_CHARS */

#ifndef TZ_MAX_LEAPS
#define TZ_MAX_LEAPS	50	/* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */

#define SECSPERMIN	60
#define MINSPERHOUR	60
#define HOURSPERDAY	24
#define DAYSPERWEEK	7
#define DAYSPERNYEAR	365
#define DAYSPERLYEAR	366
#define SECSPERHOUR	(SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY	((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR	12

#define TM_SUNDAY	0
#define TM_MONDAY	1
#define TM_TUESDAY	2
#define TM_WEDNESDAY	3
#define TM_THURSDAY	4
#define TM_FRIDAY	5
#define TM_SATURDAY	6

#define TM_JANUARY	0
#define TM_FEBRUARY	1
#define TM_MARCH	2
#define TM_APRIL	3
#define TM_MAY		4
#define TM_JUNE		5
#define TM_JULY		6
#define TM_AUGUST	7
#define TM_SEPTEMBER	8
#define TM_OCTOBER	9
#define TM_NOVEMBER	10
#define TM_DECEMBER	11

#define TM_YEAR_BASE	1900

#define EPOCH_YEAR	1970
#define EPOCH_WDAY	TM_THURSDAY

/*
** Accurate only for the past couple of centuries;
** that will probably do.
*/

#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))

#ifndef USG

/*
** Use of the underscored variants may cause problems if you move your code to
** certain System-V-based systems; for maximum portability, use the
** underscore-free variants.  The underscored variants are provided for
** backward compatibility only; they may disappear from future versions of
** this file.
*/

#define SECS_PER_MIN	SECSPERMIN
#define MINS_PER_HOUR	MINSPERHOUR
#define HOURS_PER_DAY	HOURSPERDAY
#define DAYS_PER_WEEK	DAYSPERWEEK
#define DAYS_PER_NYEAR	DAYSPERNYEAR
#define DAYS_PER_LYEAR	DAYSPERLYEAR
#define SECS_PER_HOUR	SECSPERHOUR
#define SECS_PER_DAY	SECSPERDAY
#define MONS_PER_YEAR	MONSPERYEAR

#endif /* !defined USG */

#endif /* !defined TZFILE_H */

#include "fcntl.h"

/*
** SunOS 4.1.1 headers lack O_BINARY.
*/

#ifdef O_BINARY
#define OPEN_MODE	(O_RDONLY | O_BINARY)
#endif /* defined O_BINARY */
#ifndef O_BINARY
#define OPEN_MODE	O_RDONLY
#endif /* !defined O_BINARY */

#ifndef WILDABBR
/*
** Someone might make incorrect use of a time zone abbreviation:
**	1.	They might reference tzname[0] before calling tzset (explicitly
**		or implicitly).
**	2.	They might reference tzname[1] before calling tzset (explicitly
**		or implicitly).
**	3.	They might reference tzname[1] after setting to a time zone
**		in which Daylight Saving Time is never observed.
**	4.	They might reference tzname[0] after setting to a time zone
**		in which Standard Time is never observed.
**	5.	They might reference tm.TM_ZONE after calling offtime.
** What's best to do in the above cases is open to debate;
** for now, we just set things up so that in any of the five cases
** WILDABBR is used.  Another possibility:  initialize tzname[0] to the
** string "tzname[0] used before set", and similarly for the other cases.
** And another:  initialize tzname[0] to "ERA", with an explanation in the
** manual page of what this "time zone abbreviation" means (doing this so
** that tzname[0] has the "normal" length of three characters).
*/
#define WILDABBR	"   "
#endif /* !defined WILDABBR */

static char wildabbr[] NO_COPY = WILDABBR;

static char gmt[] NO_COPY = "GMT";

struct ttinfo {				/* time type information */
	long		tt_gmtoff;	/* UTC offset in seconds */
	int		tt_isdst;	/* used to set tm_isdst */
	int		tt_abbrind;	/* abbreviation list index */
	int		tt_ttisstd;	/* true if transition is std time */
	int		tt_ttisgmt;	/* true if transition is UTC */
};

struct lsinfo {				/* leap second information */
	time_t		ls_trans;	/* transition time */
	long		ls_corr;	/* correction to apply */
};

#define BIGGEST(a, b)	(((a) > (b)) ? (a) : (b))

#ifdef TZNAME_MAX
#define MY_TZNAME_MAX	TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX	255
#endif /* !defined TZNAME_MAX */

struct state {
	int		leapcnt;
	int		timecnt;
	int		typecnt;
	int		charcnt;
	time_t		ats[TZ_MAX_TIMES];
	unsigned char	types[TZ_MAX_TIMES];
	struct ttinfo	ttis[TZ_MAX_TYPES];
	char		chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
				(2 * (MY_TZNAME_MAX + 1)))];
	struct lsinfo	lsis[TZ_MAX_LEAPS];
};

struct rule {
	int		r_type;		/* type of rule--see below */
	int		r_day;		/* day number of rule */
	int		r_week;		/* week number of rule */
	int		r_mon;		/* month number of rule */
	long		r_time;		/* transition time of rule */
};

#define JULIAN_DAY		0	/* Jn - Julian day */
#define DAY_OF_YEAR		1	/* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK	2	/* Mm.n.d - month, week, day of week */

/*
** Prototypes for static functions.
*/

static long		detzcode P((const char * codep));
static const char *	getzname P((const char * strp));
static const char *	getnum P((const char * strp, int * nump, int min,
				int max));
static const char *	getsecs P((const char * strp, long * secsp));
static const char *	getoffset P((const char * strp, long * offsetp));
static const char *	getrule P((const char * strp, struct rule * rulep));
static void		gmtload P((struct state * sp));
static void		gmtsub P((const time_t * timep, long offset,
				struct tm * tmp));
static void		localsub P((const time_t * timep, long offset,
				struct tm * tmp));
static int		increment_overflow P((int * number, int delta));
static int		normalize_overflow P((int * tensptr, int * unitsptr,
				int base));
static void		settzname P((void));
static time_t		time1 P((struct tm * tmp,
				void(*funcp) P((const time_t *,
				long, struct tm *)),
				long offset));
static time_t		time2 P((struct tm *tmp,
				void(*funcp) P((const time_t *,
				long, struct tm*)),
				long offset, int * okayp));
static time_t		time2sub P((struct tm *tmp,
				void(*funcp) P((const time_t *,
				long, struct tm*)),
				long offset, int * okayp, int do_norm_secs));
static void		timesub P((const time_t * timep, long offset,
				const struct state * sp, struct tm * tmp));
static int		tmcomp P((const struct tm * atmp,
				const struct tm * btmp));
static time_t		transtime P((time_t janfirst, int year,
				const struct rule * rulep, long offset));
static int		tzload P((const char * name, struct state * sp));
static int		tzparse P((const char * name, struct state * sp,
				int lastditch));

#ifdef ALL_STATE
static struct state *	lclptr;
static struct state *	gmtptr;
#endif /* defined ALL_STATE */

#ifndef ALL_STATE
static struct state	lclmem;
static struct state	gmtmem;
#define lclptr		(&lclmem)
#define gmtptr		(&gmtmem)
#endif /* State Farm */

#ifndef TZ_STRLEN_MAX
#define TZ_STRLEN_MAX 255
#endif /* !defined TZ_STRLEN_MAX */

static char		lcl_TZname[TZ_STRLEN_MAX + 1];
static enum lcl_states
{
  lcl_setting = -1,
  lcl_unset = 0,
  lcl_from_environment = 1,
  lcl_from_default = 2
} lcl_is_set;
static int		gmt_is_set;

#define tzname _tzname
#undef _tzname

char *	tzname[2] = {
	wildabbr,
	wildabbr
};

/*
** Section 4.12.3 of X3.159-1989 requires that
**	Except for the strftime function, these functions [asctime,
**	ctime, gmtime, localtime] return values in one of two static
**	objects: a broken-down time structure and an array of char.
** Thanks to Paul Eggert (eggert@twinsun.com) for noting this.
*/

static struct tm	tm;


/* These variables are initialized by tzset.  The macro versions are
   defined in time.h, and indirect through the __imp_ pointers.  */

#define timezone _timezone
#define daylight _daylight
#undef _timezone
#undef _daylight

#ifdef USG_COMPAT
long		timezone;	/* was time_t but POSIX requires long. */
int		daylight;
#endif /* defined USG_COMPAT */

#ifdef ALTZONE
time_t		altzone;
#endif /* defined ALTZONE */

static long
detzcode(const char *codep)
{
	register long	result;
	register int	i;

	result = (codep[0] & 0x80) ? ~0L : 0L;
	for (i = 0; i < 4; ++i)
		result = (result << 8) | (codep[i] & 0xff);
	return result;
}

static void
settzname P((void))
{
	register struct state * const	sp = lclptr;
	register int			i;

	tzname[0] = wildabbr;
	tzname[1] = wildabbr;
#ifdef USG_COMPAT
	daylight = 0;
	timezone = 0;
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
	altzone = 0;
#endif /* defined ALTZONE */
#ifdef ALL_STATE
	if (sp == NULL) {
		tzname[0] = tzname[1] = gmt;
		return;
	}
#endif /* defined ALL_STATE */
	for (i = 0; i < sp->typecnt; ++i) {
		register const struct ttinfo * const	ttisp = &sp->ttis[i];

		tzname[ttisp->tt_isdst] =
			&sp->chars[ttisp->tt_abbrind];
#ifdef USG_COMPAT
		if (ttisp->tt_isdst)
			daylight = 1;
		if (i == 0 || !ttisp->tt_isdst)
			timezone = -(ttisp->tt_gmtoff);
#endif /* defined USG_COMPAT */
#ifdef ALTZONE
		if (i == 0 || ttisp->tt_isdst)
			altzone = -(ttisp->tt_gmtoff);
#endif /* defined ALTZONE */
	}
	/*
	** And to get the latest zone names into tzname. . .
	*/
	for (i = 0; i < sp->timecnt; ++i) {
		register const struct ttinfo * const	ttisp =
							&sp->ttis[
								sp->types[i]];

		tzname[ttisp->tt_isdst] =
			&sp->chars[ttisp->tt_abbrind];
	}
}

#include "tz_posixrules.h"

static int
tzload(const char *name, struct state *sp)
{
	register const char *	p;
	register int		i;
	register int		fid;
	save_errno		save;

	if (name == NULL && (name = TZDEFAULT) == NULL)
		return -1;
	{
		register int	doaccess;
		/*
		** Section 4.9.1 of the C standard says that
		** "FILENAME_MAX expands to an integral constant expression
		** that is the size needed for an array of char large enough
		** to hold the longest file name string that the implementation
		** guarantees can be opened."
		*/
		char		fullname[FILENAME_MAX + 1];

		if (name[0] == ':')
			++name;
		doaccess = name[0] == '/';
		if (!doaccess) {
			if ((p = TZDIR) == NULL)
				return -1;
			if ((strlen(p) + strlen(name) + 1) >= sizeof fullname)
				return -1;
			strcpy(fullname, p);
			strcat(fullname, "/");
			strcat(fullname, name);
			/*
			** Set doaccess if '.' (as in "../") shows up in name.
			*/
			if (strchr(name, '.') != NULL)
				doaccess = true;
			name = fullname;
		}
#if 0
		if (doaccess && access(name, R_OK) != 0)
			return -1;
#endif
		if ((fid = open(name, OPEN_MODE)) == -1)
		  {
		    const char *base = strrchr(name, '/');
		    if (base)
		      base++;
		    else
		      base = name;
		    if (strcmp(base, "posixrules"))
		      return -1;

		    /* We've got a built-in copy of posixrules just in case */
		    fid = -2;
		  }
	}
	{
		struct tzhead *	tzhp;
		union {
		  struct tzhead tzhead;
		  char		buf[sizeof *sp + sizeof *tzhp];
		} u;
		int		ttisstdcnt;
		int		ttisgmtcnt;

		if (fid == -2)
		  {
		    memcpy(u.buf, _posixrules_data, sizeof (_posixrules_data));
		    i = sizeof (_posixrules_data);
		  }
		else
		  {
		    i = read(fid, u.buf, sizeof u.buf);
		    if (close(fid) != 0)
			return -1;
		  }
		ttisstdcnt = (int) detzcode(u.tzhead.tzh_ttisgmtcnt);
		ttisgmtcnt = (int) detzcode(u.tzhead.tzh_ttisstdcnt);
		sp->leapcnt = (int) detzcode(u.tzhead.tzh_leapcnt);
		sp->timecnt = (int) detzcode(u.tzhead.tzh_timecnt);
		sp->typecnt = (int) detzcode(u.tzhead.tzh_typecnt);
		sp->charcnt = (int) detzcode(u.tzhead.tzh_charcnt);
		p = u.tzhead.tzh_charcnt + sizeof u.tzhead.tzh_charcnt;
		if (sp->leapcnt < 0 || sp->leapcnt > TZ_MAX_LEAPS ||
			sp->typecnt <= 0 || sp->typecnt > TZ_MAX_TYPES ||
			sp->timecnt < 0 || sp->timecnt > TZ_MAX_TIMES ||
			sp->charcnt < 0 || sp->charcnt > TZ_MAX_CHARS ||
			(ttisstdcnt != sp->typecnt && ttisstdcnt != 0) ||
			(ttisgmtcnt != sp->typecnt && ttisgmtcnt != 0))
				return -1;
		if (i - (p - u.buf) < sp->timecnt * 4 +	/* ats */
			sp->timecnt +			/* types */
			sp->typecnt * (4 + 2) +		/* ttinfos */
			sp->charcnt +			/* chars */
			sp->leapcnt * (4 + 4) +		/* lsinfos */
			ttisstdcnt +			/* ttisstds */
			ttisgmtcnt)			/* ttisgmts */
				return -1;
		for (i = 0; i < sp->timecnt; ++i) {
			sp->ats[i] = detzcode(p);
			p += 4;
		}
		for (i = 0; i < sp->timecnt; ++i) {
			sp->types[i] = (unsigned char) *p++;
			if (sp->types[i] >= sp->typecnt)
				return -1;
		}
		for (i = 0; i < sp->typecnt; ++i) {
			register struct ttinfo *	ttisp;

			ttisp = &sp->ttis[i];
			ttisp->tt_gmtoff = detzcode(p);
			p += 4;
			ttisp->tt_isdst = (unsigned char) *p++;
			if (ttisp->tt_isdst != 0 && ttisp->tt_isdst != 1)
				return -1;
			ttisp->tt_abbrind = (unsigned char) *p++;
			if (ttisp->tt_abbrind < 0 ||
				ttisp->tt_abbrind > sp->charcnt)
					return -1;
		}
		for (i = 0; i < sp->charcnt; ++i)
			sp->chars[i] = *p++;
		sp->chars[i] = '\0';	/* ensure '\0' at end */
		for (i = 0; i < sp->leapcnt; ++i) {
			register struct lsinfo *	lsisp;

			lsisp = &sp->lsis[i];
			lsisp->ls_trans = detzcode(p);
			p += 4;
			lsisp->ls_corr = detzcode(p);
			p += 4;
		}
		for (i = 0; i < sp->typecnt; ++i) {
			register struct ttinfo *	ttisp;

			ttisp = &sp->ttis[i];
			if (ttisstdcnt == 0)
				ttisp->tt_ttisstd = false;
			else {
				ttisp->tt_ttisstd = *p++;
				if (ttisp->tt_ttisstd != true &&
					ttisp->tt_ttisstd != false)
						return -1;
			}
		}
		for (i = 0; i < sp->typecnt; ++i) {
			register struct ttinfo *	ttisp;

			ttisp = &sp->ttis[i];
			if (ttisgmtcnt == 0)
				ttisp->tt_ttisgmt = false;
			else {
				ttisp->tt_ttisgmt = *p++;
				if (ttisp->tt_ttisgmt != true &&
					ttisp->tt_ttisgmt != false)
						return -1;
			}
		}
	}
	if (sp == lclptr)
	  {
	    __gettzinfo ()->__tzrule[0].offset
				    = -sp->ttis[1].tt_gmtoff;
	    __gettzinfo ()->__tzrule[1].offset
				    = -sp->ttis[0].tt_gmtoff;
	  }
	return 0;
}

static const int	mon_lengths[2][MONSPERYEAR] = {
	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
};

static const int	year_lengths[2] = {
	DAYSPERNYEAR, DAYSPERLYEAR
};

/*
** Given a pointer into a time zone string, scan until a character that is not
** a valid character in a zone name is found.  Return a pointer to that
** character.
*/

static const char *
getzname(const char *strp)
{
	register char	c;

	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
		c != '+')
			++strp;
	return strp;
}

/*
** Given a pointer into a time zone string, extract a number from that string.
** Check that the number is within a specified range; if it is not, return
** NULL.
** Otherwise, return a pointer to the first character not part of the number.
*/

static const char *
getnum(const char *strp, int *nump, const int min, const int max)
{
	register char	c;
	register int	num;

	if (strp == NULL || !is_digit(c = *strp))
		return NULL;
	num = 0;
	do {
		num = num * 10 + (c - '0');
		if (num > max)
			return NULL;	/* illegal value */
		c = *++strp;
	} while (is_digit(c));
	if (num < min)
		return NULL;		/* illegal value */
	*nump = num;
	return strp;
}

/*
** Given a pointer into a time zone string, extract a number of seconds,
** in hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the number
** of seconds.
*/

static const char *
getsecs(const char *strp, long *secsp)
{
	int	num;

	/*
	** `HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
	** "M10.4.6/26", which does not conform to Posix,
	** but which specifies the equivalent of
	** ``02:00 on the first Sunday on or after 23 Oct''.
	*/
	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
	if (strp == NULL)
		return NULL;
	*secsp = num * (long) SECSPERHOUR;
	if (*strp == ':') {
		++strp;
		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
		if (strp == NULL)
			return NULL;
		*secsp += num * SECSPERMIN;
		if (*strp == ':') {
			++strp;
			/* `SECSPERMIN' allows for leap seconds.  */
			strp = getnum(strp, &num, 0, SECSPERMIN);
			if (strp == NULL)
				return NULL;
			*secsp += num;
		}
	}
	return strp;
}

/*
** Given a pointer into a time zone string, extract an offset, in
** [+-]hh[:mm[:ss]] form, from the string.
** If any error occurs, return NULL.
** Otherwise, return a pointer to the first character not part of the time.
*/

static const char *
getoffset(const char *strp, long *offsetp)
{
	register int	neg = 0;

	if (*strp == '-') {
		neg = 1;
		++strp;
	} else if (*strp == '+')
		++strp;
	strp = getsecs(strp, offsetp);
	if (strp == NULL)
		return NULL;		/* illegal time */
	if (neg)
		*offsetp = -*offsetp;
	return strp;
}

/*
** Given a pointer into a time zone string, extract a rule in the form
** date[/time].  See POSIX section 8 for the format of "date" and "time".
** If a valid rule is not found, return NULL.
** Otherwise, return a pointer to the first character not part of the rule.
*/

static const char *
getrule(const char *strp, struct rule *rulep)
{
	if (*strp == 'J') {
		/*
		** Julian day.
		*/
		rulep->r_type = JULIAN_DAY;
		++strp;
		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
	} else if (*strp == 'M') {
		/*
		** Month, week, day.
		*/
		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
		++strp;
		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
		if (strp == NULL)
			return NULL;
		if (*strp++ != '.')
			return NULL;
		strp = getnum(strp, &rulep->r_week, 1, 5);
		if (strp == NULL)
			return NULL;
		if (*strp++ != '.')
			return NULL;
		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
	} else if (is_digit(*strp)) {
		/*
		** Day of year.
		*/
		rulep->r_type = DAY_OF_YEAR;
		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
	} else	return NULL;		/* invalid format */
	if (strp == NULL)
		return NULL;
	if (*strp == '/') {
		/*
		** Time specified.
		*/
		++strp;
		strp = getsecs(strp, &rulep->r_time);
	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
	return strp;
}

/*
** Given the Epoch-relative time of January 1, 00:00:00 UTC, in a year, the
** year, a rule, and the offset from UTC at the time that rule takes effect,
** calculate the Epoch-relative time that rule takes effect.
*/

static time_t
transtime(const time_t janfirst, const int year, const struct rule *rulep,
		long offset)
{
	register int	leapyear;
	register time_t	value;
	register int	i;
	int		d, m1, yy0, yy1, yy2, dow;

	INITIALIZE(value);
	leapyear = isleap(year);
	switch (rulep->r_type) {

	case JULIAN_DAY:
		/*
		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
		** years.
		** In non-leap years, or if the day number is 59 or less, just
		** add SECSPERDAY times the day number-1 to the time of
		** January 1, midnight, to get the day.
		*/
		value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
		if (leapyear && rulep->r_day >= 60)
			value += SECSPERDAY;
		break;

	case DAY_OF_YEAR:
		/*
		** n - day of year.
		** Just add SECSPERDAY times the day number to the time of
		** January 1, midnight, to get the day.
		*/
		value = janfirst + rulep->r_day * SECSPERDAY;
		break;

	case MONTH_NTH_DAY_OF_WEEK:
		/*
		** Mm.n.d - nth "dth day" of month m.
		*/
		value = janfirst;
		for (i = 0; i < rulep->r_mon - 1; ++i)
			value += mon_lengths[leapyear][i] * SECSPERDAY;

		/*
		** Use Zeller's Congruence to get day-of-week of first day of
		** month.
		*/
		m1 = (rulep->r_mon + 9) % 12 + 1;
		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
		yy1 = yy0 / 100;
		yy2 = yy0 % 100;
		dow = ((26 * m1 - 2) / 10 +
			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
		if (dow < 0)
			dow += DAYSPERWEEK;

		/*
		** "dow" is the day-of-week of the first day of the month.  Get
		** the day-of-month (zero-origin) of the first "dow" day of the
		** month.
		*/
		d = rulep->r_day - dow;
		if (d < 0)
			d += DAYSPERWEEK;
		for (i = 1; i < rulep->r_week; ++i) {
			if (d + DAYSPERWEEK >=
				mon_lengths[leapyear][rulep->r_mon - 1])
					break;
			d += DAYSPERWEEK;
		}

		/*
		** "d" is the day-of-month (zero-origin) of the day we want.
		*/
		value += d * SECSPERDAY;
		break;
	}

	/*
	** "value" is the Epoch-relative time of 00:00:00 UTC on the day in
	** question.  To get the Epoch-relative time of the specified local
	** time on that day, add the transition time and the current offset
	** from UTC.
	*/
	return value + rulep->r_time + offset;
}

/*
** Given a POSIX section 8-style TZ string, fill in the rule tables as
** appropriate.
*/

static int
tzparse(const char *name, struct state *sp, const int lastditch)
{
	const char *			stdname;
	const char *			dstname;
	size_t				stdlen;
	size_t				dstlen;
	long				stdoffset;
	long				dstoffset;
	register time_t *		atp;
	register unsigned char *	typep;
	register char *			cp;
	register int			load_result;

	INITIALIZE(dstname);
	stdname = name;
	if (lastditch) {
		stdlen = strlen(name);	/* length of standard zone name */
		name += stdlen;
		if (stdlen >= sizeof sp->chars)
			stdlen = (sizeof sp->chars) - 1;
		stdoffset = 0;
	} else {
		name = getzname(name);
		stdlen = name - stdname;
		if (stdlen < 3)
			return -1;
		if (*name == '\0')
			return -1;
		name = getoffset(name, &stdoffset);
		if (name == NULL)
			return -1;
	}
	load_result = tzload(TZDEFRULES, sp);
	if (load_result != 0)
		sp->leapcnt = 0;		/* so, we're off a little */
	if (*name != '\0') {
		dstname = name;
		name = getzname(name);
		dstlen = name - dstname;	/* length of DST zone name */
		if (dstlen < 3)
			return -1;
		if (*name != '\0' && *name != ',' && *name != ';') {
			name = getoffset(name, &dstoffset);
			if (name == NULL)
				return -1;
		} else	dstoffset = stdoffset - SECSPERHOUR;
		if (*name == ',' || *name == ';') {
			struct rule	start;
			struct rule	end;
			register int	year;
			register time_t	janfirst;
			time_t		starttime;
			time_t		endtime;

			++name;
			if ((name = getrule(name, &start)) == NULL)
				return -1;
			if (*name++ != ',')
				return -1;
			if ((name = getrule(name, &end)) == NULL)
				return -1;
			if (*name != '\0')
				return -1;
			sp->typecnt = 2;	/* standard time and DST */
			/*
			** Two transitions per year, from EPOCH_YEAR to 2037.
			*/
			sp->timecnt = 2 * (2037 - EPOCH_YEAR + 1);
			if (sp->timecnt > TZ_MAX_TIMES)
				return -1;
			sp->ttis[0].tt_gmtoff = -dstoffset;
			sp->ttis[0].tt_isdst = 1;
			sp->ttis[0].tt_abbrind = stdlen + 1;
			sp->ttis[1].tt_gmtoff = -stdoffset;
			sp->ttis[1].tt_isdst = 0;
			sp->ttis[1].tt_abbrind = 0;
			atp = sp->ats;
			typep = sp->types;
			janfirst = 0;
			for (year = EPOCH_YEAR; year <= 2037; ++year) {
				starttime = transtime(janfirst, year, &start,
					stdoffset);
				endtime = transtime(janfirst, year, &end,
					dstoffset);
				if (starttime > endtime) {
					*atp++ = endtime;
					*typep++ = 1;	/* DST ends */
					*atp++ = starttime;
					*typep++ = 0;	/* DST begins */
				} else {
					*atp++ = starttime;
					*typep++ = 0;	/* DST begins */
					*atp++ = endtime;
					*typep++ = 1;	/* DST ends */
				}
				janfirst += year_lengths[isleap(year)] *
					SECSPERDAY;
			}
			if (sp == lclptr)
			  {
			    __gettzinfo ()->__tzrule[0].offset
						    = -sp->ttis[1].tt_gmtoff;
			    __gettzinfo ()->__tzrule[1].offset
						    = -sp->ttis[0].tt_gmtoff;
			  }
		} else {
			register long	theirstdoffset;
			register long	theirdstoffset;
			register long	theiroffset;
			register int	isdst;
			register int	i;
			register int	j;

			if (*name != '\0')
				return -1;
			if (load_result != 0)
				return -1;
			/*
			** Initial values of theirstdoffset and theirdstoffset.
			*/
			theirstdoffset = 0;
			for (i = 0; i < sp->timecnt; ++i) {
				j = sp->types[i];
				if (!sp->ttis[j].tt_isdst) {
					theirstdoffset =
						-sp->ttis[j].tt_gmtoff;
					break;
				}
			}
			theirdstoffset = 0;
			for (i = 0; i < sp->timecnt; ++i) {
				j = sp->types[i];
				if (sp->ttis[j].tt_isdst) {
					theirdstoffset =
						-sp->ttis[j].tt_gmtoff;
					break;
				}
			}
			/*
			** Initially we're assumed to be in standard time.
			*/
			isdst = false;
			theiroffset = theirstdoffset;
			/*
			** Now juggle transition times and types
			** tracking offsets as you do.
			*/
			for (i = 0; i < sp->timecnt; ++i) {
				j = sp->types[i];
				sp->types[i] = sp->ttis[j].tt_isdst;
				if (sp->ttis[j].tt_ttisgmt) {
					/* No adjustment to transition time */
				} else {
					/*
					** If summer time is in effect, and the
					** transition time was not specified as
					** standard time, add the summer time
					** offset to the transition time;
					** otherwise, add the standard time
					** offset to the transition time.
					*/
					/*
					** Transitions from DST to DDST
					** will effectively disappear since
					** POSIX provides for only one DST
					** offset.
					*/
					if (isdst && !sp->ttis[j].tt_ttisstd) {
						sp->ats[i] += dstoffset -
							theirdstoffset;
					} else {
						sp->ats[i] += stdoffset -
							theirstdoffset;
					}
				}
				theiroffset = -sp->ttis[j].tt_gmtoff;
				if (sp->ttis[j].tt_isdst)
					theirdstoffset = theiroffset;
				else	theirstdoffset = theiroffset;
			}
			/*
			** Finally, fill in ttis.
			** ttisstd and ttisgmt need not be handled.
			*/
			sp->ttis[0].tt_gmtoff = -stdoffset;
			sp->ttis[0].tt_isdst = false;
			sp->ttis[0].tt_abbrind = 0;
			sp->ttis[1].tt_gmtoff = -dstoffset;
			sp->ttis[1].tt_isdst = true;
			sp->ttis[1].tt_abbrind = stdlen + 1;
			sp->typecnt = 2;
			if (sp == lclptr)
			  {
			    __gettzinfo ()->__tzrule[0].offset
						    = -sp->ttis[0].tt_gmtoff;
			    __gettzinfo ()->__tzrule[1].offset
						    = -sp->ttis[1].tt_gmtoff;
			  }
		}
	} else {
		dstlen = 0;
		sp->typecnt = 1;		/* only standard time */
		sp->timecnt = 0;
		sp->ttis[0].tt_gmtoff = -stdoffset;
		sp->ttis[0].tt_isdst = 0;
		sp->ttis[0].tt_abbrind = 0;
		if (sp == lclptr)
		  {
		    __gettzinfo ()->__tzrule[0].offset = -sp->ttis[0].tt_gmtoff;
		    __gettzinfo ()->__tzrule[1].offset = -sp->ttis[0].tt_gmtoff;
		  }
	}
	sp->charcnt = stdlen + 1;
	if (dstlen != 0)
		sp->charcnt += dstlen + 1;
	if ((size_t) sp->charcnt > sizeof sp->chars)
		return -1;
	cp = sp->chars;
	strncpy(cp, stdname, stdlen);
	cp += stdlen;
	*cp++ = '\0';
	if (dstlen != 0) {
		strncpy(cp, dstname, dstlen);
		*(cp + dstlen) = '\0';
	}
	return 0;
}

static void
gmtload(struct state *sp)
{
	if (tzload(gmt, sp) != 0)
		tzparse(gmt, sp, true);
}

#ifndef STD_INSPIRED
/*
** A non-static declaration of tzsetwall in a system header file
** may cause a warning about this upcoming static declaration...
*/
static
#endif /* !defined STD_INSPIRED */
void
tzsetwall P((void))
{
	if (lcl_is_set == lcl_setting)
		return;
	lcl_is_set = lcl_setting;

#ifdef ALL_STATE
	if (lclptr == NULL) {
		lclptr = (struct state *) malloc(sizeof *lclptr);
		if (lclptr == NULL) {
			settzname();	/* all we can do */
			return;
		}
	}
#endif /* defined ALL_STATE */
#if defined (__CYGWIN__)
	{
	    TIME_ZONE_INFORMATION tz;
	    char buf[BUFSIZ];
	    char *cp, *dst;
	    wchar_t *src;
	    div_t d;
	    GetTimeZoneInformation(&tz);
	    dst = cp = buf;
	    for (src = tz.StandardName; *src; src++)
	      if (isupper(*src)) *dst++ = *src;
	    if ((dst - cp) < 3)
	      {
		/* In non-english Windows, converted tz.StandardName
		   may not contain a valid standard timezone name. */
		strcpy(cp, wildabbr);
		cp += strlen(wildabbr);
	      }
	    else
	      cp = dst;
	    d = div(tz.Bias+tz.StandardBias, 60);
	    sprintf(cp, "%d", d.quot);
	    if (d.rem)
		sprintf(cp=strchr(cp, 0), ":%d", abs(d.rem));
	    if(tz.StandardDate.wMonth) {
		cp = strchr(cp, 0);
		dst = cp;
		for (src = tz.DaylightName; *src; src++)
		  if (isupper(*src)) *dst++ = *src;
		if ((dst - cp) < 3)
		  {
		    /* In non-english Windows, converted tz.DaylightName
		       may not contain a valid daylight timezone name. */
		    strcpy(cp, wildabbr);
		    cp += strlen(wildabbr);
		  }
		else
		  cp = dst;
		d = div(tz.Bias+tz.DaylightBias, 60);
		sprintf(cp, "%d", d.quot);
		if (d.rem)
		    sprintf(cp=strchr(cp, 0), ":%d", abs(d.rem));
		cp = strchr(cp, 0);
		sprintf(cp=strchr(cp, 0), ",M%d.%d.%d/%d",
		    tz.DaylightDate.wMonth,
		    tz.DaylightDate.wDay,
		    tz.DaylightDate.wDayOfWeek,
		    tz.DaylightDate.wHour);
		if (tz.DaylightDate.wMinute || tz.DaylightDate.wSecond)
		    sprintf(cp=strchr(cp, 0), ":%d", tz.DaylightDate.wMinute);
		if (tz.DaylightDate.wSecond)
		    sprintf(cp=strchr(cp, 0), ":%d", tz.DaylightDate.wSecond);
		cp = strchr(cp, 0);
		sprintf(cp=strchr(cp, 0), ",M%d.%d.%d/%d",
		    tz.StandardDate.wMonth,
		    tz.StandardDate.wDay,
		    tz.StandardDate.wDayOfWeek,
		    tz.StandardDate.wHour);
		if (tz.StandardDate.wMinute || tz.StandardDate.wSecond)
		    sprintf(cp=strchr(cp, 0), ":%d", tz.StandardDate.wMinute);
		if (tz.StandardDate.wSecond)
		    sprintf(cp=strchr(cp, 0), ":%d", tz.StandardDate.wSecond);
	    }
	    /* printf("TZ deduced as `%s'\n", buf); */
	    if (tzparse(buf, lclptr, false) == 0) {
		settzname();
		lcl_is_set = lcl_from_default;
		strlcpy(lcl_TZname, buf, sizeof (lcl_TZname));
#if 0
		/* Huh?  POSIX doesn't mention anywhere that tzset should
		   set $TZ.  That's not right. */
		setenv("TZ", lcl_TZname, 1);
#endif
		return;
	    }
	}
#endif
	if (tzload((char *) NULL, lclptr) != 0)
		gmtload(lclptr);
	settzname();
}

static NO_COPY muto tzset_guard;

extern "C" void
tzset P((void))
{
	tzset_guard.init ("tzset_guard")->acquire ();
	const char *	name = getenv("TZ");

	if (name == NULL) {
		if (lcl_is_set != lcl_from_default)
			tzsetwall();
		goto out;
	}

	if (lcl_is_set > 0 && strncmp(lcl_TZname, name, sizeof(lcl_TZname) - 1) == 0)
		goto out;
	lcl_is_set = (strlen(name) < sizeof (lcl_TZname)) ? lcl_from_environment : lcl_unset;
	if (lcl_is_set != lcl_unset)
		strlcpy(lcl_TZname, name, sizeof (lcl_TZname));

#ifdef ALL_STATE
	if (lclptr == NULL) {
		lclptr = (struct state *) malloc(sizeof *lclptr);
		if (lclptr == NULL) {
			settzname();	/* all we can do */
			goto out;
		}
	}
#endif /* defined ALL_STATE */
	if (*name == '\0') {
		/*
		** User wants it fast rather than right.
		*/
		lclptr->leapcnt = 0;		/* so, we're off a little */
		lclptr->timecnt = 0;
		lclptr->ttis[0].tt_gmtoff = 0;
		lclptr->ttis[0].tt_abbrind = 0;
		strcpy(lclptr->chars, gmt);
	} else if (tzload(name, lclptr) != 0) {
		if (name[0] == ':' || tzparse(name, lclptr, false) != 0)
			gmtload(lclptr);
	}
	settzname();
out:
	tzset_guard.release ();
}

/*
** The easy way to behave "as if no library function calls" localtime
** is to not call it--so we drop its guts into "localsub", which can be
** freely called.  (And no, the PANS doesn't require the above behavior--
** but it *is* desirable.)
**
** The unused offset argument is for the benefit of mktime variants.
*/

/*ARGSUSED*/
static void
localsub (const time_t * const	timep,
	  const long offset,
	  struct tm * const tmp)
{
	register struct state *		sp;
	register const struct ttinfo *	ttisp;
	register int			i;
	const time_t			t = *timep;

	sp = lclptr;
#ifdef ALL_STATE
	if (sp == NULL) {
		gmtsub(timep, offset, tmp);
		return;
	}
#endif /* defined ALL_STATE */
	if (sp->timecnt == 0 || t < sp->ats[0]) {
		i = 0;
		while (sp->ttis[i].tt_isdst)
			if (++i >= sp->typecnt) {
				i = 0;
				break;
			}
	} else {
		for (i = 1; i < sp->timecnt; ++i)
			if (t < sp->ats[i])
				break;
		i = sp->types[i - 1];
	}
	ttisp = &sp->ttis[i];
	/*
	** To get (wrong) behavior that's compatible with System V Release 2.0
	** you'd replace the statement below with
	**	t += ttisp->tt_gmtoff;
	**	timesub(&t, 0L, sp, tmp);
	*/
	timesub(&t, ttisp->tt_gmtoff, sp, tmp);
	tmp->tm_isdst = ttisp->tt_isdst;
	tzname[tmp->tm_isdst] = &sp->chars[ttisp->tt_abbrind];
#ifdef TM_ZONE
	tmp->TM_ZONE = &sp->chars[ttisp->tt_abbrind];
#endif /* defined TM_ZONE */
}

extern "C" struct tm *
localtime(const time_t *timep)
{
	tzset();
	localsub(timep, 0L, &tm);
	return &tm;
}

/*
 * Re-entrant version of localtime
 */
extern "C" struct tm *
localtime_r(const time_t *timep, struct tm *tm)
{
	tzset();
	localsub(timep, 0L, tm);
	return tm;
}

/*
** gmtsub is to gmtime as localsub is to localtime.
*/

static void
gmtsub(const time_t *timep, const long offset, struct tm *tmp)
{
	if (!gmt_is_set) {
		gmt_is_set = true;
#ifdef ALL_STATE
		gmtptr = (struct state *) malloc(sizeof *gmtptr);
		if (gmtptr != NULL)
#endif /* defined ALL_STATE */
			gmtload(gmtptr);
	}
	timesub(timep, offset, gmtptr, tmp);
#ifdef TM_ZONE
	/*
	** Could get fancy here and deliver something such as
	** "UTC+xxxx" or "UTC-xxxx" if offset is non-zero,
	** but this is no time for a treasure hunt.
	*/
	if (offset != 0)
		tmp->TM_ZONE = wildabbr;
	else {
#ifdef ALL_STATE
		if (gmtptr == NULL)
			tmp->TM_ZONE = gmt;
		else	tmp->TM_ZONE = gmtptr->chars;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
		tmp->TM_ZONE = gmtptr->chars;
#endif /* State Farm */
	}
#endif /* defined TM_ZONE */
}

extern "C" struct tm *
gmtime(const time_t *timep)
{
	gmtsub(timep, 0L, &tm);
	return &tm;
}

/*
 * Re-entrant version of gmtime
 */
extern "C" struct tm *
gmtime_r(const time_t *timep, struct tm *tm)
{
	gmtsub(timep, 0L, tm);
	return tm;
}

#ifdef STD_INSPIRED

extern "C" struct tm *
offtime(const time_t *timep, const long offset)
{
	gmtsub(timep, offset, &tm);
	return &tm;
}

#endif /* defined STD_INSPIRED */

static void
timesub(const time_t *timep, const long offset, const struct state *sp,
	struct tm *tmp)
{
	register const struct lsinfo *	lp;
	register long			days;
	register long			rem;
	register int			y;
	register int			yleap;
	register const int *		ip;
	register long			corr;
	register int			hit;
	register int			i;

	corr = 0;
	hit = 0;
#ifdef ALL_STATE
	i = (sp == NULL) ? 0 : sp->leapcnt;
#endif /* defined ALL_STATE */
#ifndef ALL_STATE
	i = sp->leapcnt;
#endif /* State Farm */
	while (--i >= 0) {
		lp = &sp->lsis[i];
		if (*timep >= lp->ls_trans) {
			if (*timep == lp->ls_trans) {
				hit = ((i == 0 && lp->ls_corr > 0) ||
					lp->ls_corr > sp->lsis[i - 1].ls_corr);
				if (hit)
					while (i > 0 &&
						sp->lsis[i].ls_trans ==
						sp->lsis[i - 1].ls_trans + 1 &&
						sp->lsis[i].ls_corr ==
						sp->lsis[i - 1].ls_corr + 1) {
							++hit;
							--i;
					}
			}
			corr = lp->ls_corr;
			break;
		}
	}
	days = *timep / SECSPERDAY;
	rem = *timep % SECSPERDAY;
#ifdef mc68k
	if (*timep == 0x80000000) {
		/*
		** A 3B1 muffs the division on the most negative number.
		*/
		days = -24855;
		rem = -11648;
	}
#endif /* defined mc68k */
	rem += (offset - corr);
	while (rem < 0) {
		rem += SECSPERDAY;
		--days;
	}
	while (rem >= SECSPERDAY) {
		rem -= SECSPERDAY;
		++days;
	}
	tmp->tm_hour = (int) (rem / SECSPERHOUR);
	rem = rem % SECSPERHOUR;
	tmp->tm_min = (int) (rem / SECSPERMIN);
	/*
	** A positive leap second requires a special
	** representation.  This uses "... ??:59:60" et seq.
	*/
	tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
	tmp->tm_wday = (int) ((EPOCH_WDAY + days) % DAYSPERWEEK);
	if (tmp->tm_wday < 0)
		tmp->tm_wday += DAYSPERWEEK;
	y = EPOCH_YEAR;
#define LEAPS_THRU_END_OF(y)	((y) / 4 - (y) / 100 + (y) / 400)
	while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
		register int	newy;

		newy = y + days / DAYSPERNYEAR;
		if (days < 0)
			--newy;
		days -= (newy - y) * DAYSPERNYEAR +
			LEAPS_THRU_END_OF(newy - 1) -
			LEAPS_THRU_END_OF(y - 1);
		y = newy;
	}
	tmp->tm_year = y - TM_YEAR_BASE;
	tmp->tm_yday = (int) days;
	ip = mon_lengths[yleap];
	for (tmp->tm_mon = 0; days >= (long) ip[tmp->tm_mon]; ++(tmp->tm_mon))
		days = days - (long) ip[tmp->tm_mon];
	tmp->tm_mday = (int) (days + 1);
	tmp->tm_isdst = 0;
#ifdef TM_GMTOFF
	tmp->TM_GMTOFF = offset;
#endif /* defined TM_GMTOFF */
}

extern "C" char *
ctime(const time_t *timep)
{
/*
** Section 4.12.3.2 of X3.159-1989 requires that
**	The ctime function converts the calendar time pointed to by timer
**	to local time in the form of a string.  It is equivalent to
**		asctime(localtime(timer))
*/
	return asctime(localtime(timep));
}

extern "C" char *
ctime_r(const time_t *timep, char *buf)
{
	struct tm	tm;

	return asctime_r(localtime_r(timep, &tm), buf);
}

/*
** Adapted from code provided by Robert Elz, who writes:
**	The "best" way to do mktime I think is based on an idea of Bob
**	Kridle's (so its said...) from a long time ago.
**	[kridle@xinet.com as of 1996-01-16.]
**	It does a binary search of the time_t space.  Since time_t's are
**	just 32 bits, its a max of 32 iterations (even at 64 bits it
**	would still be very reasonable).
*/

#ifndef WRONG
#define WRONG	(-1)
#endif /* !defined WRONG */

/*
** Simplified normalize logic courtesy Paul Eggert (eggert@twinsun.com).
*/

/* Mark as noinline to prevent a compiler warning. */
static int __attribute__((noinline))
increment_overflow(int *number, int delta)
{
	int	number0;

	number0 = *number;
	*number += delta;
	return (*number < number0) != (delta < 0);
}

static int
normalize_overflow(int *tensptr, int *unitsptr, const int base)
{
	register int	tensdelta;

	tensdelta = (*unitsptr >= 0) ?
		(*unitsptr / base) :
		(-1 - (-1 - *unitsptr) / base);
	*unitsptr -= tensdelta * base;
	return increment_overflow(tensptr, tensdelta);
}

static int
tmcomp(register const struct tm *atmp, register const struct tm *btmp)
{
	register int	result;

	if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
		(result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
		(result = (atmp->tm_min - btmp->tm_min)) == 0)
			result = atmp->tm_sec - btmp->tm_sec;
	return result;
}

static time_t
time2sub(struct tm *tmp, void (*funcp) P((const time_t*, long, struct tm*)),
	 const long offset, int *okayp, const int do_norm_secs)
{
	register const struct state *	sp;
	register int			dir;
	register int			bits;
	register int			i, j ;
	register int			saved_seconds;
	time_t				newt;
	time_t				t;
	struct tm			yourtm, mytm;

	*okayp = false;
	yourtm = *tmp;
	if (do_norm_secs) {
		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
			SECSPERMIN))
				return WRONG;
	}
	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
		return WRONG;
	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
		return WRONG;
	if (normalize_overflow(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR))
		return WRONG;
	/*
	** Turn yourtm.tm_year into an actual year number for now.
	** It is converted back to an offset from TM_YEAR_BASE later.
	*/
	if (increment_overflow(&yourtm.tm_year, TM_YEAR_BASE))
		return WRONG;
	while (yourtm.tm_mday <= 0) {
		if (increment_overflow(&yourtm.tm_year, -1))
			return WRONG;
		i = yourtm.tm_year + (1 < yourtm.tm_mon);
		yourtm.tm_mday += year_lengths[isleap(i)];
	}
	while (yourtm.tm_mday > DAYSPERLYEAR) {
		i = yourtm.tm_year + (1 < yourtm.tm_mon);
		yourtm.tm_mday -= year_lengths[isleap(i)];
		if (increment_overflow(&yourtm.tm_year, 1))
			return WRONG;
	}
	for ( ; ; ) {
		i = mon_lengths[isleap(yourtm.tm_year)][yourtm.tm_mon];
		if (yourtm.tm_mday <= i)
			break;
		yourtm.tm_mday -= i;
		if (++yourtm.tm_mon >= MONSPERYEAR) {
			yourtm.tm_mon = 0;
			if (increment_overflow(&yourtm.tm_year, 1))
				return WRONG;
		}
	}
	if (increment_overflow(&yourtm.tm_year, -TM_YEAR_BASE))
		return WRONG;
	if (yourtm.tm_year + TM_YEAR_BASE < EPOCH_YEAR) {
		/*
		** We can't set tm_sec to 0, because that might push the
		** time below the minimum representable time.
		** Set tm_sec to 59 instead.
		** This assumes that the minimum representable time is
		** not in the same minute that a leap second was deleted from,
		** which is a safer assumption than using 58 would be.
		*/
		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
			return WRONG;
		saved_seconds = yourtm.tm_sec;
		yourtm.tm_sec = SECSPERMIN - 1;
	} else {
		saved_seconds = yourtm.tm_sec;
		yourtm.tm_sec = 0;
	}
	/*
	** Divide the search space in half
	** (this works whether time_t is signed or unsigned).
	*/
	bits = TYPE_BIT(time_t) - 1;
	/*
	** If time_t is signed, then 0 is just above the median,
	** assuming two's complement arithmetic.
	** If time_t is unsigned, then (1 << bits) is just above the median.
	*/
	t = TYPE_SIGNED(time_t) ? 0 : (((time_t) 1) << bits);
	for ( ; ; ) {
		(*funcp)(&t, offset, &mytm);
		dir = tmcomp(&mytm, &yourtm);
		if (dir != 0) {
			if (bits-- < 0)
				return WRONG;
			if (bits < 0)
				--t; /* may be needed if new t is minimal */
			else if (dir > 0)
				t -= ((time_t) 1) << bits;
			else	t += ((time_t) 1) << bits;
			continue;
		}
		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
			break;
		/*
		** Right time, wrong type.
		** Hunt for right time, right type.
		** It's okay to guess wrong since the guess
		** gets checked.
		*/
		/*
		** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
		*/
		sp = (const struct state *)
			(((void *) funcp == (void *) localsub) ?
			lclptr : gmtptr);
#ifdef ALL_STATE
		if (sp == NULL)
			return WRONG;
#endif /* defined ALL_STATE */
		for (i = sp->typecnt - 1; i >= 0; --i) {
			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
				continue;
			for (j = sp->typecnt - 1; j >= 0; --j) {
				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
					continue;
				newt = t + sp->ttis[j].tt_gmtoff -
					sp->ttis[i].tt_gmtoff;
				(*funcp)(&newt, offset, &mytm);
				if (tmcomp(&mytm, &yourtm) != 0)
					continue;
				if (mytm.tm_isdst != yourtm.tm_isdst)
					continue;
				/*
				** We have a match.
				*/
				t = newt;
				goto label;
			}
		}
		return WRONG;
	}
label:
	newt = t + saved_seconds;
	if ((newt < t) != (saved_seconds < 0))
		return WRONG;
	t = newt;
	(*funcp)(&t, offset, tmp);
	*okayp = true;
	return t;
}

static time_t
time2(struct tm *tmp, void (*funcp) P((const time_t*, long, struct tm*)),
      const long offset, int *okayp)
{
	time_t	t;

	/*
	** First try without normalization of seconds
	** (in case tm_sec contains a value associated with a leap second).
	** If that fails, try with normalization of seconds.
	*/
	t = time2sub(tmp, funcp, offset, okayp, false);
	if (*okayp)
	  return t;
	t = time2sub(tmp, funcp, offset, okayp, true);
	if (*okayp)
	  return t;
	/* Workaround for the spring forward gap problem which results in
	   the autoconf mktime usability test failing.
	   What we do here is this:  The gap has 3600 seconds.  If we
	   subtract 3600 from the tm_sec value and get a valid result,
	   then we can simply add 3600 to the return value and are done.
	   If the result is still not valid, the problem is not the
	   spring forward gap and we can give up. */
	struct tm tmp2 = *tmp;
	tmp2.tm_sec -= 3600;
	t = time2sub(&tmp2, funcp, offset, okayp, true);
	if (*okayp)
	  {
	    if (t + 3600 < 0)	/* Sanity check */
	      return WRONG;
	    return t + 3600;
	  }
	return t;
}

static time_t
time1(struct tm *tmp, void (*funcp) P((const time_t *, long, struct tm *)),
      const long offset)
{
	register time_t			t;
	register const struct state *	sp;
	register int			samei, otheri;
	int				okay;

	if (tmp->tm_isdst > 1)
		tmp->tm_isdst = 1;
	t = time2(tmp, funcp, offset, &okay);
#ifdef PCTS
	/*
	** PCTS code courtesy Grant Sullivan (grant@osf.org).
	*/
	if (okay)
		return t;
	if (tmp->tm_isdst < 0)
		tmp->tm_isdst = 0;	/* reset to std and try again */
#endif /* defined PCTS */
#ifndef PCTS
	if (okay || tmp->tm_isdst < 0)
		return t;
#endif /* !defined PCTS */
	/*
	** We're supposed to assume that somebody took a time of one type
	** and did some math on it that yielded a "struct tm" that's bad.
	** We try to divine the type they started from and adjust to the
	** type they need.
	*/
	/*
	** The (void *) casts are the benefit of SunOS 3.3 on Sun 2's.
	*/
	sp = (const struct state *) (((void *) funcp == (void *) localsub) ?
		lclptr : gmtptr);
#ifdef ALL_STATE
	if (sp == NULL)
		return WRONG;
#endif /* defined ALL_STATE */
	for (samei = sp->typecnt - 1; samei >= 0; --samei) {
		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
			continue;
		for (otheri = sp->typecnt - 1; otheri >= 0; --otheri) {
			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
				continue;
			tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
					sp->ttis[samei].tt_gmtoff;
			tmp->tm_isdst = !tmp->tm_isdst;
			t = time2(tmp, funcp, offset, &okay);
			if (okay)
				return t;
			tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
					sp->ttis[samei].tt_gmtoff;
			tmp->tm_isdst = !tmp->tm_isdst;
		}
	}
	return WRONG;
}

extern "C" time_t
mktime(struct tm *tmp)
{
	tzset();
	return time1(tmp, localsub, 0L);
}

#ifdef STD_INSPIRED

extern "C" time_t
timelocal(struct tm *tmp)
{
	tmp->tm_isdst = -1;	/* in case it wasn't initialized */
	return mktime(tmp);
}

extern "C" time_t
timegm(struct tm *tmp)
{
	tmp->tm_isdst = 0;
	return time1(tmp, gmtsub, 0L);
}

extern "C" time_t
timeoff(struct tm *tmp, const long offset)
{
	tmp->tm_isdst = 0;
	return time1(tmp, gmtsub, offset);
}

#endif /* defined STD_INSPIRED */

#ifdef CMUCS

/*
** The following is supplied for compatibility with
** previous versions of the CMUCS runtime library.
*/

extern "C" long
gtime(struct tm *tmp)
{
	const time_t	t = mktime(tmp);

	if (t == WRONG)
		return -1;
	return t;
}

#endif /* defined CMUCS */

/*
** XXX--is the below the right way to conditionalize??
*/

#ifdef STD_INSPIRED

/*
** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599
** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
** is not the case if we are accounting for leap seconds.
** So, we provide the following conversion routines for use
** when exchanging timestamps with POSIX conforming systems.
*/

static long
leapcorr(time_t *timep)
{
	register struct state *		sp;
	register struct lsinfo *	lp;
	register int			i;

	sp = lclptr;
	i = sp->leapcnt;
	while (--i >= 0) {
		lp = &sp->lsis[i];
		if (*timep >= lp->ls_trans)
			return lp->ls_corr;
	}
	return 0;
}

extern "C" time_t
time2posix(time_t t)
{
	tzset();
	return t - leapcorr(&t);
}

extern "C" time_t
posix2time(time_t t)
{
	time_t	x;
	time_t	y;

	tzset();
	/*
	** For a positive leap second hit, the result
	** is not unique.  For a negative leap second
	** hit, the corresponding time doesn't exist,
	** so we return an adjacent second.
	*/
	x = t + leapcorr(&t);
	y = x - leapcorr(&x);
	if (y < t) {
		do {
			x++;
			y = x - leapcorr(&x);
		} while (y < t);
		if (t != y)
			return x - 1;
	} else if (y > t) {
		do {
			--x;
			y = x - leapcorr(&x);
		} while (y > t);
		if (t != y)
			return x + 1;
	}
	return x;
}

#endif /* defined STD_INSPIRED */