- tz - lists.iana.org

[PROPOSED] Use more up-to-date citation for leap seconds
by Paul Eggert July 18, 2017

July 18, 2017

* leapseconds.awk: Cite Levine 2016 instead of Quinn 1991. --- leapseconds.awk | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/leapseconds.awk b/leapseconds.awk index 405ce3a..66eb64d 100644 --- a/leapseconds.awk +++ b/leapseconds.awk @@ -17,11 +17,9 @@ BEGIN { print "# The International Earth Rotation and Reference Systems Service" print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1" print "# (which measures the true angular orientation of the earth in space); see" - print "# Terry J Quinn, The BIPM and the accurate measure of time," - print "# Proc IEEE 79, 7 (July 1991), 894-905 <http://dx.doi.org/10.1109/5.84965>," - print "# reprinted in: Hackman C, Sullivan DB (eds), Time and frequency measurement," - print "# American Association of Physics Teachers (1996)," - print "# <http://tf.nist.gov/general/pdf/1168.pdf>, 75-86." + print "# Levine J. Coordinated Universal Time and the leap second." + print "# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995" + print "# http://ieeexplore.ieee.org/document/7909995/" print "# There were no leap seconds before 1972, because the official mechanism" print "# accounting for the discrepancy between atomic time and the earth's rotation" print "# did not exist until the early 1970s." -- 2.7.4

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Pedantic correction to Theory regarding size of time zone names
by Howard Hinnant July 16, 2017

July 16, 2017

Line 91 of Theory: https://github.com/eggert/tz/blob/master/Theory#L91 reads: > A file name component must not exceed 14 characters … I found one exception to this rule: The Link: Canada/East-Saskatchewan in backward. East-Saskatchewan is 17 characters. I recommend simply changing the 14 to 17. Howard

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Unix time_t hits 1.5Gs early Friday UTC
by Brian Inglis July 14, 2017

July 14, 2017

Unix time_t will hit 1 500 000 000 at 2017 Jul 14 Fri 02:40:00+0000 which is Thursday evening in North America: $ for city in Vancouver Edmonton Regina Winnipeg Toronto Halifax St_Johns; do TZ=America/$city date -d@1500000000 +%c\ %Z; done 2017 Jul 13 Thu 19:40:00 PDT 2017 Jul 13 Thu 20:40:00 MDT 2017 Jul 13 Thu 20:40:00 CST 2017 Jul 13 Thu 21:40:00 CDT 2017 Jul 13 Thu 22:40:00 EDT 2017 Jul 13 Thu 23:40:00 ADT 2017 Jul 14 Fri 00:10:00 NDT and on some other time scales, which may not be aligned to UTC: $ gpstime.sh @1500000000 2017 Jul 14 Fri 02:40:00+0000 JD 2457948.611111 MJD 57948.111111 ToD 9599 NTP 3708988800 Unix 1500000000 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 1957 Cy 1 Wn 933 Wa 165 ToW 441618 DoW 5 ToD 9618 As usual there will be some Europeans staying up late to celebrate and party. Unix time won't hit 1.5Gis until: $ gpstime.sh @`bc <<< 2^30*3/2` 2021 Jan 14 Thu 08:25:36+0000 JD 2459228.851111 MJD 59228.351111 ToD 30336 NTP 3819601536 Unix 1610612736 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 2140 Cy 2 Wn 92 Wa 92 ToW 375954 DoW 4 ToD 30354 and it will be a while before it hits 2Gs: $ gpstime.sh @2000000000 2033 May 18 Wed 03:33:20+0000 JD 2463735.648148 MJD 63735.148148 ToD 12799 NTP 4208988800 Unix 2000000000 TAI-UTC 37 TAI-GPS 19 GPS-UTC 18 GPS We 2784 Cy 2 Wn 736 Wa 224 ToW 272018 DoW 3 ToD 12818 -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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Use GST abbreviation for Asia/Dubai, Asia/Muscat
by Mohamed Akram July 14, 2017

July 14, 2017

I noticed Asia/Dubai and Asia/Muscat currently use +04, but there is an existing abbreviation (GST - Gulf Standard Time).

3 3

Etc/GMT timezone offsets are inverted
by Pedro A. López-Valencia July 11, 2017

July 11, 2017

I just noticed that all GMT+- timezones are inverted so that GMT+5 is really GMT-5. This applies to all GMT-offset timezone definitions. -- https://about.me/palopezv

2 1

IERS Bulletin C54
by Michael Deckers July 11, 2017

July 11, 2017

The IERS has issued Bulletin C54 which assures that no leap second will occur near 2018-01-01. Interestingly, the issue date 2017-07-06 in the txt version at [https://datacenter.iers.org/eop/-/somos/5Rgv/getTX/16/bulletinc-054.txt] differs from the issue date 2017-07-09 in the xml version at [https://datacenter.iers.org/eop/-/somos/5Rgv/latestXL/16/bulletinc-054.txt/…] Michael Deckers. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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backzone/Europe/Guernsey
by Michael Deckers July 10, 2017

July 10, 2017

For the connoisseurs of olde time stamps: The "LMT location" for backzone/Europe/Guernsey is given as "49.27N -2.33E" -- seemingly in degrees and decimal fractions of degrees. But the point ( +49.27°, -2.33° ) = ( +49°16′12″, -002°19′48″ ) is in open waters about 15 km south of Guernsey and east of Sark in the Channel. The point ( +49°27′, -002°33′ ), however, is in St Peter Port on the island, so that arc minutes and not hundredths of degrees must be meant. This also agrees with zone.tab. Hence: -# LMT Location - 49.27N -2.33E - St.Peter Port +# LMT Location - 49°27′N -2°33′E - St.Peter Port -Zone Europe/Guernsey -0:09:19 - LMT 1913 Jun 18 +Zone Europe/Guernsey -0:10:12 - LMT 1913 Jun 18 Michael Deckers. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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Re: [tz] TZ & AIX
by Paul Eggert July 8, 2017

July 8, 2017

Jorge Fábregas wrote: > https://www.ibm.com/developerworks/aix/library/au-aix-olson-time-zone/index… Thanks for the heads-up. I installed the attached.

2 1

Orillia's 1912 DST pops up again in Toronto Star
by Paul Eggert July 8, 2017

July 8, 2017

Today's Toronto Star reports on the two-week daylight saving time interlude in Orillia, Ontario. Today's article doesn't mention the same newspaper's 1997-10-14 article on the same topic, and it's not clear what's new this time around. Still, the story is amusingly told. Proposed patch attached.

1 0

DST in the (odd) news
by Arthur David Olson July 7, 2017

July 7, 2017

"Alarm clock removed from family's home after 14 years of daily beeping" "Over the years, it beeped at 6.50pm or 7.50pm each day, depending on whether Daylight [Saving] Time was in place." https://www.theguardian.com/us-news/2017/jul/07/alarm-clock-wall-pennsylvan… @dashdashado

1 0

[PROPOSED] Avoid zic problems with errno == EOVERFLOW
by Paul Eggert June 26, 2017

June 26, 2017

Although this patch does not fix any bugs, it makes zic’s ‘stat’ calls less likely to fail unnecessarily with errno == EOVERFLOW, and this should be a bit faster in some cases. Problem reported by Nick Alcock in: https://sourceware.org/ml/libc-alpha/2017-06/msg01264.html * private.h (_FILE_OFFSET_BITS, _LARGE_FILES) (_DARWIN_USE_64_BIT_INODE): New macros. --- private.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/private.h b/private.h index f5e39b5..2e8415e 100644 --- a/private.h +++ b/private.h @@ -102,6 +102,16 @@ /* Enable strtoimax on pre-C99 Solaris 11. */ #define __EXTENSIONS__ 1 +/* To avoid having 'stat' fail unnecessarily with errno == EOVERFLOW, + enable large files on GNUish systems ... */ +#ifndef _FILE_OFFSET_BITS +# define _FILE_OFFSET_BITS 64 +#endif +/* ... and on AIX ... */ +#define _LARGE_FILES 1 +/* ... and enable large inode numbers on Mac OS X 10.5 and later. */ +#define _DARWIN_USE_64_BIT_INODE 1 + /* ** Nested includes */ -- 2.9.4

1 0

[PROPOSED] Port to GCC 4.8.4
by Paul Eggert June 16, 2017

June 16, 2017

Problem reported by Stan Shebs and Joseph Myers in: https://sourceware.org/ml/libc-alpha/2017-06/msg00741.html * NEWS, Makefile: Document this. * private.h (HAVE_GENERIC): New macro, so that we do not use _Generic with GCC 4.8. (TIME_T_MIN_NO_PADDING, TIME_T_MAX_NO_PADDING): New macros. (TIME_T_MIN, TIME_T_MAX): Rename from time_t_min and time_t_max, and turn them into macros so that problems are less likely to occur for subset uses like glibc where these macros are never expanded. All uses changed. Use new macros to work around GCC 4.8 bug. --- Makefile | 1 + NEWS | 3 +++ date.c | 2 +- localtime.c | 26 +++++++++++++------------- private.h | 60 ++++++++++++++++++++++++++++++++++++++++-------------------- 5 files changed, 58 insertions(+), 34 deletions(-) diff --git a/Makefile b/Makefile index 2b31f3f..347ece7 100644 --- a/Makefile +++ b/Makefile @@ -142,6 +142,7 @@ LDLIBS= # -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r # -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ' # -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows) +# -DHAVE_GENERIC=0 if _Generic does not work # -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris) # -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares # ctime_r and asctime_r incompatibly with the POSIX standard diff --git a/NEWS b/NEWS index ca4fd8e..cfdd620 100644 --- a/NEWS +++ b/NEWS @@ -94,6 +94,9 @@ Unreleased, experimental changes zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.) + Calculation of time_t extrema works around a bug in GCC 4.8.4 + (Reported by Stan Shebs and Joseph Myers.) + Several minor changes have been made to the code to make it a bit easier to port to MS-Windows and Solaris. (Thanks to Kees Dekker for reporting the problems.) diff --git a/date.c b/date.c index b29e162..2cc533f 100644 --- a/date.c +++ b/date.c @@ -97,7 +97,7 @@ main(const int argc, char *argv[]) secs = strtoimax (optarg, &endarg, 0); if (*endarg || optarg == endarg) errno = EINVAL; - else if (! (time_t_min <= secs && secs <= time_t_max)) + else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX)) errno = ERANGE; if (errno) { perror(optarg); diff --git a/localtime.c b/localtime.c index 8c944f3..2e1d621 100644 --- a/localtime.c +++ b/localtime.c @@ -464,17 +464,17 @@ tzloadbody(char const *name, struct state *sp, bool doextend, sp->charcnt = charcnt; /* Read transitions, discarding those out of time_t range. - But pretend the last transition before time_t_min - occurred at time_t_min. */ + But pretend the last transition before TIME_T_MIN + occurred at TIME_T_MIN. */ timecnt = 0; for (i = 0; i < sp->timecnt; ++i) { int_fast64_t at = stored == 4 ? detzcode(p) : detzcode64(p); - sp->types[i] = at <= time_t_max; + sp->types[i] = at <= TIME_T_MAX; if (sp->types[i]) { time_t attime - = ((TYPE_SIGNED(time_t) ? at < time_t_min : at < 0) - ? time_t_min : at); + = ((TYPE_SIGNED(time_t) ? at < TIME_T_MIN : at < 0) + ? TIME_T_MIN : at); if (timecnt && attime <= sp->ats[timecnt - 1]) { if (attime < sp->ats[timecnt - 1]) return EINVAL; @@ -524,7 +524,7 @@ tzloadbody(char const *name, struct state *sp, bool doextend, /* Leap seconds cannot occur before the Epoch. */ if (tr < 0) return EINVAL; - if (tr <= time_t_max) { + if (tr <= TIME_T_MAX) { /* Leap seconds cannot occur more than once per UTC month, and UTC months are at least 28 days long (minus 1 second for a negative leap second). Each leap second's @@ -1795,12 +1795,12 @@ increment_overflow_time(time_t *tp, int_fast32_t j) { /* ** This is like - ** 'if (! (time_t_min <= *tp + j && *tp + j <= time_t_max)) ...', + ** 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...', ** except that it does the right thing even if *tp + j would overflow. */ if (! (j < 0 - ? (TYPE_SIGNED(time_t) ? time_t_min - j <= *tp : -1 - j < *tp) - : *tp <= time_t_max - j)) + ? (TYPE_SIGNED(time_t) ? TIME_T_MIN - j <= *tp : -1 - j < *tp) + : *tp <= TIME_T_MAX - j)) return true; *tp += j; return false; @@ -1936,8 +1936,8 @@ time2sub(struct tm *const tmp, /* ** Do a binary search (this works whatever time_t's type is). */ - lo = time_t_min; - hi = time_t_max; + lo = TIME_T_MIN; + hi = TIME_T_MAX; for ( ; ; ) { t = lo / 2 + hi / 2; if (t < lo) @@ -1954,12 +1954,12 @@ time2sub(struct tm *const tmp, } else dir = tmcomp(&mytm, &yourtm); if (dir != 0) { if (t == lo) { - if (t == time_t_max) + if (t == TIME_T_MAX) return WRONG; ++t; ++lo; } else if (t == hi) { - if (t == time_t_min) + if (t == TIME_T_MIN) return WRONG; --t; --hi; diff --git a/private.h b/private.h index 2b07251..f5e39b5 100644 --- a/private.h +++ b/private.h @@ -27,6 +27,21 @@ #define HAVE_DECL_ASCTIME_R 1 #endif +#if !defined HAVE_GENERIC && defined __has_extension +# if __has_extension(c_generic_selections) +# define HAVE_GENERIC 1 +# else +# define HAVE_GENERIC 0 +# endif +#endif +/* _Generic is buggy in pre-4.9 GCC. */ +#if !defined HAVE_GENERIC && defined __GNUC__ +# define HAVE_GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__)) +#endif +#ifndef HAVE_GENERIC +# define HAVE_GENERIC (201112 <= __STDC_VERSION__) +#endif + #ifndef HAVE_GETTEXT #define HAVE_GETTEXT 0 #endif /* !defined HAVE_GETTEXT */ @@ -561,27 +576,32 @@ time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_PURE; #define MINVAL(t, b) \ ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0)) -/* The minimum and maximum finite time values. This implementation - assumes no padding if time_t is signed and either the compiler is - pre-C11 or time_t is not one of the standard signed integer types. */ -#if 201112 <= __STDC_VERSION__ -static time_t const time_t_min - = (TYPE_SIGNED(time_t) - ? _Generic((time_t) 0, - signed char: SCHAR_MIN, short: SHRT_MIN, - int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, - default: MINVAL(time_t, TYPE_BIT(time_t))) - : 0); -static time_t const time_t_max - = (TYPE_SIGNED(time_t) - ? _Generic((time_t) 0, - signed char: SCHAR_MAX, short: SHRT_MAX, - int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, - default: MAXVAL(time_t, TYPE_BIT(time_t))) - : -1); +/* The extreme time values, assuming no padding. */ +#define TIME_T_MIN_NO_PADDING MINVAL(time_t, TYPE_BIT(time_t)) +#define TIME_T_MAX_NO_PADDING MAXVAL(time_t, TYPE_BIT(time_t)) + +/* The extreme time values. These are macros, not constants, so that + any portability problem occur only when compiling .c files that use + the macros, which is safer for applications that need only zdump and zic. + This implementation assumes no padding if time_t is signed and + either the compiler lacks support for _Generic or time_t is not one + of the standard signed integer types. */ +#if HAVE_GENERIC +# define TIME_T_MIN \ + _Generic((time_t) 0, \ + signed char: SCHAR_MIN, short: SHRT_MIN, \ + int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, \ + default: TIME_T_MIN_NO_PADDING) +# define TIME_T_MAX \ + (TYPE_SIGNED(time_t) \ + ? _Generic((time_t) 0, \ + signed char: SCHAR_MAX, short: SHRT_MAX, \ + int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, \ + default: TIME_T_MAX_NO_PADDING) \ + : (time_t) -1) #else -static time_t const time_t_min = MINVAL(time_t, TYPE_BIT(time_t)); -static time_t const time_t_max = MAXVAL(time_t, TYPE_BIT(time_t)); +# define TIME_T_MIN TIME_T_MIN_NO_PADDING +# define TIME_T_MAX TIME_T_MAX_NO_PADDING #endif /* -- 2.9.4

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[PROPOSED] Port check_time_t_alternatives to June 8 AIX fix
by Paul Eggert June 16, 2017

June 16, 2017

* private.h (TZ_TIME_T): Declare strftime. This is helpful now that we use our own strftime. Declare strftime_l too, if present. --- private.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/private.h b/private.h index 982ddf3..2b07251 100644 --- a/private.h +++ b/private.h @@ -424,6 +424,12 @@ typedef time_tz tz_time_t; char *ctime(time_t const *); char *ctime_r(time_t const *, char *); double difftime(time_t, time_t) ATTRIBUTE_CONST; +size_t strftime(char *restrict, size_t, char const *restrict, + struct tm const *restrict); +# if HAVE_STRFTIME_L +size_t strftime_l(char *restrict, size_t, char const *restrict, + struct tm const *restrict, locale_t); +# endif struct tm *gmtime(time_t const *); struct tm *gmtime_r(time_t const *restrict, struct tm *restrict); struct tm *localtime(time_t const *); -- 2.9.4

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Re: [tz] 1 s error in America/Adak and America/Nome
by Paul Eggert June 15, 2017

June 15, 2017

On 06/10/2017 07:42 AM, Michael H Deckers wrote: > I do not understand the evidence for the proposed changes. A change of > time scale by 24 h is only observable though the day of the week and > the day number in a calendar (which may be combined with a switch of > calendars), but not through the time of day. > > Where two successive days are observed as Sundays, this is evidence > for the change of time scale having occurred at the instant between > the two. Yes. However, the the question is whether America/Sitka should record the time kept by those in formal control of Sitka, or the time kept by Toomas Ahllund and his fellow workers who made the transition on Sunday in order to have a longer weekend. If the former, the transition should be at 15:30 Friday (Gregorian); if the latter, it should presumably be at 00:00 Sunday (Gregorian). I chose the former, partly because it reflects formal transfer of control, and partly because we have a specific time-of-day recorded for it. > And if a precise instant for the acquisition of Alaska is > to be taken as the instant of the time zone change, then this > assumption > should be applied to all locations (where nothing else is known). > But the proposed changes to tzdb amount to the change happening when > UT = 1867-10-19 + 00:41:37 h for Yakutat > UT = 1867-10-19 + 00:31:13 h for Sitka, Juneau, Metlakatla > UT = 1867-10-19 + 00:31:03 h for Adak, Nome > UT = 1867-10-19 + 00:30:59 h for Anchorage > I do not see support for such variations. Thanks for reporting that; those were due to bugs in my calculations. I installed the attached patch to fix the bugs, and to try to clarify the point you mentioned.

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[PROPOSED] Remove incorrect #endif comments
by Paul Eggert June 14, 2017

June 14, 2017

--- localtime.c | 2 +- private.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/localtime.c b/localtime.c index 1f5bbb2..8c944f3 100644 --- a/localtime.c +++ b/localtime.c @@ -94,7 +94,7 @@ static const char gmt[] = "GMT"; */ #ifndef TZDEFRULESTRING #define TZDEFRULESTRING ",M3.2.0,M11.1.0" -#endif /* !defined TZDEFDST */ +#endif struct ttinfo { /* time type information */ int_fast32_t tt_gmtoff; /* UT offset in seconds */ diff --git a/private.h b/private.h index e6cb21d..982ddf3 100644 --- a/private.h +++ b/private.h @@ -33,7 +33,7 @@ #ifndef HAVE_INCOMPATIBLE_CTIME_R #define HAVE_INCOMPATIBLE_CTIME_R 0 -#endif /* !defined INCOMPATIBLE_CTIME_R */ +#endif #ifndef HAVE_LINK #define HAVE_LINK 1 -- 2.9.4

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[PROPOSED] Remove old Y2K code
by Paul Eggert June 14, 2017

June 14, 2017

The circa-1996 runtime tests to catch potential Y2K problems are no longer worth the maintenance hassle, as the Y2K transition was done many years ago. * Makefile, NEWS: Mention this. * strftime.c (YEAR_2000_NAME, IN_NONE, IN_SOME, IN_THIS, IN_ALL): Remove. All uses removed. (strftime): Do not warn about Y2K problems. (_fmt): Omit last (warning) arg; all uses changed. --- Makefile | 3 --- NEWS | 2 ++ strftime.c | 71 ++++++++++++-------------------------------------------------- 3 files changed, 15 insertions(+), 61 deletions(-) diff --git a/Makefile b/Makefile index 07f4f77..65915ea 100644 --- a/Makefile +++ b/Makefile @@ -162,9 +162,6 @@ LDLIBS= # than what POSIX specifies, assuming local time is UT. # For example, N is 252460800 on AmigaOS. # -Dlocale_t=XXX if your system uses XXX instead of locale_t -# -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU=1 -# if you do not want run time warnings about formats that may cause -# year 2000 grief # -Dssize_t=long on hosts like MS-Windows that lack ssize_t # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; # not needed by the main-program tz code, which is single-threaded. diff --git a/NEWS b/NEWS index 2c86e90..40285bf 100644 --- a/NEWS +++ b/NEWS @@ -81,6 +81,8 @@ Unreleased, experimental changes other two variables as optional. Also, USG_COMPAT is now 1 or 0: if not defined, the code attempts to guess it from other macros. + Y2K runtime checks have been removed, as Y2K was years ago. + Several minor changes have been made to the code to make it a bit easier to port to MS-Windows and Solaris. (Thanks to Kees Dekker for reporting the problems.) diff --git a/strftime.c b/strftime.c index 173ff8b..9df4176 100644 --- a/strftime.c +++ b/strftime.c @@ -101,19 +101,9 @@ static const struct lc_time_T C_time_locale = { static char * _add(const char *, char *, const char *); static char * _conv(int, const char *, char *, const char *); -static char * _fmt(const char *, const struct tm *, char *, const char *, - int *); +static char * _fmt(const char *, const struct tm *, char *, const char *); static char * _yconv(int, int, bool, bool, char *, char const *); -#ifndef YEAR_2000_NAME -#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" -#endif /* !defined YEAR_2000_NAME */ - -#define IN_NONE 0 -#define IN_SOME 1 -#define IN_THIS 2 -#define IN_ALL 3 - #if HAVE_STRFTIME_L size_t strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t, @@ -128,24 +118,9 @@ size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *t) { char * p; - int warn; tzset(); - warn = IN_NONE; - p = _fmt(format, t, s, s + maxsize, &warn); -#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU - if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { - fprintf(stderr, "\n"); - fprintf(stderr, "strftime format \"%s\" ", format); - fprintf(stderr, "yields only two digits of years in "); - if (warn == IN_SOME) - fprintf(stderr, "some locales"); - else if (warn == IN_THIS) - fprintf(stderr, "the current locale"); - else fprintf(stderr, "all locales"); - fprintf(stderr, "\n"); - } -#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ + p = _fmt(format, t, s, s + maxsize); if (p == s + maxsize) return 0; *p = '\0'; @@ -153,8 +128,7 @@ strftime(char *s, size_t maxsize, const char *format, const struct tm *t) } static char * -_fmt(const char *format, const struct tm *t, char *pt, - const char *ptlim, int *warnp) +_fmt(const char *format, const struct tm *t, char *pt, const char *ptlim) { for ( ; *format; ++format) { if (*format == '%') { @@ -200,18 +174,10 @@ label: true, false, pt, ptlim); continue; case 'c': - { - int warn2 = IN_SOME; - - pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2); - if (warn2 == IN_ALL) - warn2 = IN_THIS; - if (warn2 > *warnp) - *warnp = warn2; - } + pt = _fmt(Locale->c_fmt, t, pt, ptlim); continue; case 'D': - pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); + pt = _fmt("%m/%d/%y", t, pt, ptlim); continue; case 'd': pt = _conv(t->tm_mday, "%02d", pt, ptlim); @@ -232,7 +198,7 @@ label: pt = _conv(t->tm_mday, "%2d", pt, ptlim); continue; case 'F': - pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); + pt = _fmt("%Y-%m-%d", t, pt, ptlim); continue; case 'H': pt = _conv(t->tm_hour, "%02d", pt, ptlim); @@ -296,10 +262,10 @@ label: pt, ptlim); continue; case 'R': - pt = _fmt("%H:%M", t, pt, ptlim, warnp); + pt = _fmt("%H:%M", t, pt, ptlim); continue; case 'r': - pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); + pt = _fmt("%I:%M:%S %p", t, pt, ptlim); continue; case 'S': pt = _conv(t->tm_sec, "%02d", pt, ptlim); @@ -322,7 +288,7 @@ label: } continue; case 'T': - pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); + pt = _fmt("%H:%M:%S", t, pt, ptlim); continue; case 't': pt = _add("\t", pt, ptlim); @@ -424,7 +390,6 @@ label: pt = _conv(w, "%02d", pt, ptlim); else if (*format == 'g') { - *warnp = IN_ALL; pt = _yconv(year, base, false, true, pt, ptlim); @@ -439,7 +404,7 @@ label: ** "date as dd-bbb-YYYY" ** (ado, 1993-05-24) */ - pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); + pt = _fmt("%e-%b-%Y", t, pt, ptlim); continue; case 'W': pt = _conv((t->tm_yday + DAYSPERWEEK - @@ -452,21 +417,12 @@ label: pt = _conv(t->tm_wday, "%d", pt, ptlim); continue; case 'X': - pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp); + pt = _fmt(Locale->X_fmt, t, pt, ptlim); continue; case 'x': - { - int warn2 = IN_SOME; - - pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2); - if (warn2 == IN_ALL) - warn2 = IN_THIS; - if (warn2 > *warnp) - *warnp = warn2; - } + pt = _fmt(Locale->x_fmt, t, pt, ptlim); continue; case 'y': - *warnp = IN_ALL; pt = _yconv(t->tm_year, TM_YEAR_BASE, false, true, pt, ptlim); @@ -559,8 +515,7 @@ label: #endif continue; case '+': - pt = _fmt(Locale->date_fmt, t, pt, ptlim, - warnp); + pt = _fmt(Locale->date_fmt, t, pt, ptlim); continue; case '%': /* -- 2.9.4

8 12

Re: [tz] defensive value for define on Solaris causes load of timerule to fail
by Kees Dekker June 13, 2017

June 13, 2017

Retry, now to the mailing list as well. >> So, FILENAME_MAX is probably the better choice, but may be, a >> >> #if FILENAME_MAX < 260 >> #undef FILENAME_MAX >> #define FILENAME_MAX 260 >> #endif >> >> code part is needed? Then FILENAME_MAX is at a defined minimum value >> (of course, the limit of 260 is also quite an arbitrary choice). >I don't like the idea of redefining `FILENAME_MAX`. Just use some >reasonably large value of our choosing for the length of `fullname`. >Even with a modern GNU/Linux `FILENAME_MAX` value of 4096 (on my system >at least), the `fullname` member of `union local_storage` is smaller >than the `u` member. Anything else is also ok, but the union now does not have 'take largest value of somethong' for the fullname member. It is also ok for me to say: #if FILENAME_MAX < 260 #define TZ_FILENAME_MAX 260 #else #define TZ_FILENAME_MAX FILENAME_MAX #endif And use TZ_FILENAME_MAX in the union. My message is just to say 'please take care for platforms where FILENAME_MAX is arbitrary (too) short'. And the value of 14, as used on Solaris, is too short, as some time rules already exceed this length. It makes no sense (i.e. it does not help for the other platforms) in this case that Linux has a much bigger value for this define. As I have checked now, on most platforms, except Solaris, it is 260. Linux uses (as one of the few) a larger value. I've checked HPUX, AIX, Windows, Solaris and several Linux flavors. Kees

7 10

core dumps on AIX7.1 and HPUX11.31 and tzcode 2017B.
by Kees Dekker June 13, 2017

June 13, 2017

Hi, When using the IANA tz data and code (version 2017B) on AIX and/or HPUX, I got core dumps. I was not able to figure out the root cause, but after I had renamed the timezone, daylight and tzname variables to something else (i.e., prefixed with olson_), the error disappeared. A similar crash happened on AIX 7.2, but in only one test case (compared to all our test cases on AIX 7.1 and HPUX 11.31). I don't have a good explanation for the different behavior between AIX 7.1 and 7.2. The tz code was incorporated into two parts of our product: 1. The tzcode was built with USG_COMPAT enabled, i.e. timezone, daylight and tzname symbols are used and incorporated into our binaries 2. The tzcode was also built into a shared library that uses another shared library that calls some of the time functions from libc (e.g. tzset(), or gettimeofday()) BTW: in our code, I'm renaming (using defines) all tz functions too, and prefix them with 'olson_'. So, at symbol level, no duplicates between system functions and TZ code functions should exist. In our code, the error happened under the following circumstances: 1. A binary of us is using the tz library (using USG_COMPAT) 2. That binary loads dynamically (with dlopen(), with RTLD_GLOBAL flag) another shared library of us, also containing the tz library 3. A 3rd party shared library was loaded by our own shared library. Also with dlopen/RTLD_GLOBAL flag. Both our binary (#1) a shared library (#2) were creating using export lists/versions scripts. None of the tz code or variables was exported. And our shared library is using a flag that forces the loader to perform 'innermost symbol resolution' (in such way that C++ exceptions still work). The 3rd party library was either the Oracle or DB2 client database library. Both perform a call to libc that triggers a time function (gettimeofday() or tzset()). The core dump happens in libc, on one of the time functions, called by the 3rd party shared library. Using IANA tz functions from our binaries, without loading 3rd party shared libraries works fine. Hypothesis: the fact that the tzcode (compiled with USG_COMPAT) changes (one of) the (libc exported) timezone, daylight, tzname, causes the time functions in libc to crash. Notes: a. making timezone, daylight, tzname static in the IANA localtime.c and added a get_xxx function did not help either. b. Building without USG_COMPAT did not help either. It is quite strange that none of these both (#a and #b) did help, but I lack time to do more research. As I now have a suitable workaround (by renaming/prefixing involved variables), it is fine for me now. This mail is just intended to inform about conflicts/core dumps, most probably related to 'similar named' variables with the system libc (and thus generate a trap on some platforms). If the tz code can get changed (ever/in the future) to prevent such conflicts, it would be great. No other action is needed (by me) for now. Regards, Kees

2 5

[PROPOSED] Commentary fixes
by Paul Eggert June 12, 2017

June 12, 2017

* Makefile: Mention constraints on TZDIR_BASENAME. * asctime.c: Remove obsolete comment, as zdump now uses snprintf. --- Makefile | 1 + asctime.c | 3 --- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/Makefile b/Makefile index 05b40bb..07f4f77 100644 --- a/Makefile +++ b/Makefile @@ -49,6 +49,7 @@ TOPDIR= /usr/local # "Compiled" time zone information is placed in the "TZDIR" directory # (and subdirectories). # Use an absolute path name for TZDIR unless you're just testing the software. +# TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty. TZDIR_BASENAME= zoneinfo TZDIR= $(TOPDIR)/etc/$(TZDIR_BASENAME) diff --git a/asctime.c b/asctime.c index 1613f78..de681ce 100644 --- a/asctime.c +++ b/asctime.c @@ -99,9 +99,6 @@ asctime_r(register const struct tm *timeptr, char *buf) ** (e.g., timeptr->tm_mday) when processing "%Y". */ strftime(year, sizeof year, "%Y", timeptr); - /* - ** We avoid using snprintf since it's not available on all systems. - */ sprintf(result, ((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B), wn, mn, -- 2.9.4

2 2

defensive value for define on Solaris causes load of timerule to fail
by Kees Dekker June 12, 2017

June 12, 2017

Hi, The FILENAME_MAX macro, as used in the local_storage union in localtime.c, has on Solaris the very low/defensive value of 14 (from stdio.h). Please consider using PATH_MAX, from limits.h instead, as that value is (usually) 250 or beyond. Or anything else, that can hold reasonable lengths of file names. Loading zonefiles now fails on Solaris if a filename exceeds the used macro. Regards, Kees

2 2

Re: [tz] [PROPOSED] Clean up configuration of tzname etc.
by vanadovv＠hetnet.nl June 9, 2017

June 9, 2017

I found a small language error. Sorry I can't produce a diff/patch. The error can be found as follows: >----Origineel Bericht---- >Van : eggert(a)cs.ucla.edu >Datum : 09/06/2017 02:50 >Aan : tz(a)iana.org >Onderwerp : [tz] [PROPOSED] Clean up configuration of tzname etc. > ...... ...... >diff --git a/strftime.c b/strftime.c >index 4b9fd2c..d09a0db 100644 >--- a/strftime.c >+++ b/strftime.c ....... >@@ -513,20 +509,20 @@ label: > ** altzone and timezone), and the > ** magic might not have the correct > ** offset. Doing things correctly is >- ** tricky and requires disobeying C99; >+ ** tricky and requires disobeying the standard; > ** see GNU C strftime for details. > ** For now, punt and conform to the > ** standard, even though it's incorrect. > ** >- ** C99 says that %z must be replaced by the >- ** empty string if the time zone is not >+ ** C99 and later that %z must be replaced by >+ ** the empty string if the time zone is not ..... The error is: >+ ** C99 and later that %z must be replaced by This should be: >+ ** C99 and later say that %z must be replaced by --------------- Yours, Oscar van Vlijmen [ends]

2 1

1 s error in America/Adak and America/Nome
by Michael H Deckers June 9, 2017

June 9, 2017

The switch from 1867-10-18 to 1867-10-17 in Alaska is incorrectly represented as a jump from 1867-10-18 to 1867-10-17 + 00:00:01 h in the time scales for Adak and for Nome. Proposed corrections: -Zone America/Adak 12:13:21 - LMT 1867 Oct 18 +Zone America/Adak 12:13:22 - LMT 1867 Oct 18 -11:46:38 - LMT 1900 Aug 20 12:00 -Zone America/Nome 12:58:21 - LMT 1867 Oct 18 +Zone America/Nome 12:58:22 - LMT 1867 Oct 18 -11:01:38 - LMT 1900 Aug 20 12:00 Michael Deckers.

2 1

[PROPOSED] Clean up configuration of tzname etc.
by Paul Eggert June 9, 2017

June 9, 2017

This documents a bit of software archaeology better. tzname is standardized by POSIX, whereas timezone and daylight are standardized by POSIX SI, so allow them to be configured separately. * Makefile, NEWS, Theory: Document this. * date.c, strftime.c, zdump.c (tzname): Remove decl; private.h declares tzname as needed now. * localtime.c (tzname, timezone, daylight, altzone): Also define if TZ_TIME_T. However, define only if the relevant other macro (HAVE_TZNAME, USG_COMPAT, ALTZONE) is set or defined. (update_tzname_etc, settzname): Set tzname only if HAVE_TZNAME. At the end, simplify ifdef by using TZ_TIME_T. * newctime.3: Document optional vars and fields more carefully. * private.h (USG_COMPAT): Set default from _XOPEN_VERSION. All uses changed to assume it is 1 or 0. (HAVE_TZNAME): Set default from that and from _POSIX_VERSION. (TZ_TIME_T): New macro. (daylight, timezone, tzname, altzone): Rename if needed to avoid collision with standard library. (tzname): Declare if (!HAVE_POSIX_DECLS || TZ_TIME_T) && HAVE_TZNAME. (timezone, daylight): Declare if (!HAVE_POSIX_DECLS || TZ_TIME_T) && USG_COMPAT, not if not defined and !HAVE_POSIX_DECLS. (altzone): Declare even if not defined. (tzsetwall, offtime, timegm, timelocal, timeoff, time2posix) (posix2time, posix2time_z, time2posix_z): Use TZ_TIME_T instead of (defined time_tz). * strftime.c (_fmt): * zdump.c (abbr): Use tzname only if HAVE_TZNAME. --- Makefile | 37 +++++++++++++++++++++++---------- NEWS | 8 +++++++ Theory | 6 +++--- date.c | 1 - localtime.c | 34 ++++++++++++++++-------------- newctime.3 | 46 ++++++++++++++++++++++++++--------------- private.h | 69 ++++++++++++++++++++++++++++++++++++++++++++++--------------- strftime.c | 38 ++++++++++++++++------------------ zdump.c | 9 ++++---- 9 files changed, 160 insertions(+), 88 deletions(-) diff --git a/Makefile b/Makefile index 476f259..e6d497d 100644 --- a/Makefile +++ b/Makefile @@ -164,6 +164,7 @@ LDLIBS= # not needed by the main-program tz code, which is single-threaded. # Append other compiler flags as needed, e.g., -pthread on GNU/Linux. # -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t +# This is intended for internal use only; it mangles external names. # -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz" # -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory; # the default is system-supplied, typically "/usr/lib/locale" @@ -199,12 +200,6 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ -Wno-address -Wno-format-nonliteral -Wno-sign-compare \ -Wno-type-limits -Wno-unused-parameter # -# If you want to use System V compatibility code, add -# -DUSG_COMPAT -# to the end of the "CFLAGS=" line. This arrange for "timezone" and "daylight" -# variables to be kept up-to-date by the time conversion functions. Neither -# "timezone" nor "daylight" is described in X3J11's work. -# # If your system has a "GMT offset" field in its "struct tm"s # (or if you decide to add such a field in your system's "time.h" file), # add the name to a define such as @@ -216,6 +211,31 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # and define NO_TM_ZONE to suppress any guessing. These two fields are not # required by POSIX, but are widely available on GNU/Linux and BSD systems. # +# The next batch of options control support for external variables +# exported by tzcode. In practice these variables are less useful +# than TM_GMTOFF and TM_ZONE. However, most of them are standardized. +# # +# # To omit or support the external variable "tzname", add one of: +# # -DHAVE_TZNAME=0 +# # -DHAVE_TZNAME=1 +# # to the "CFLAGS=" line. "tzname" is required by POSIX 1988 and later. +# # If not defined, the code attempts to guess HAVE_TZNAME from other macros. +# # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause +# # crashes when combined with some platforms' standard libraries, +# # presumably due to memory allocation issues. +# # +# # To omit or support the external variables "timezone" and "daylight", add +# # -DUSG_COMPAT=0 +# # -DUSG_COMPAT=1 +# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by +# # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later. +# # If not defined, the code attempts to guess USG_COMPAT from other macros. +# # +# # To support the external variable "altzone", add +# # -DALTZONE +# # to the end of the "CFLAGS=" line; although "altzone" appeared in +# # System V Release 3.1 it has not been standardized. +# # If you want functions that were inspired by early versions of X3J11's work, # add # -DSTD_INSPIRED @@ -253,11 +273,6 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # -DALL_STATE # to the end of the "CFLAGS=" line. Storage is obtained by calling malloc. # -# If you want an "altzone" variable (a la System V Release 3.1), add -# -DALTZONE -# to the end of the "CFLAGS=" line. -# This variable is not described in X3J11's work. -# # NIST-PCTS:151-2, Version 1.4, (1993-12-03) is a test suite put # out by the National Institute of Standards and Technology # which claims to test C and Posix conformance. If you want to pass PCTS, add diff --git a/NEWS b/NEWS index 99f5d64..44135ae 100644 --- a/NEWS +++ b/NEWS @@ -57,6 +57,14 @@ Unreleased, experimental changes ordinary lines in leap second input. Formerly, zic sometimes warned about this undocumented usage and handled it incorrectly. + The new macro HAVE_TZNAME governs whether the tzname external + variable is exported, instead of USG_COMPAT. USG_COMPAT now + governs only the external variables "timezone" and "daylight". + This change is needed because the three variables are not in the + same category: although POSIX requires tzname, it specifies the + other two variables as optional. Also, USG_COMPAT is now 1 or 0: + if not defined, the code attempts to guess it from other macros. + Several minor changes have been made to the code to make it a bit easier to port to MS-Windows. (Thanks to Kees Dekker for reporting the problems.) diff --git a/Theory b/Theory index 2bfadc6..8aeccb2 100644 --- a/Theory +++ b/Theory @@ -581,9 +581,9 @@ Points of interest to folks with other systems: of GMT" value and a "daylight saving time in effect" flag) to a time zone abbreviation, and we refuse to guess. Programs that in the past used the timezone function may now examine - tzname[localtime(&clock)->tm_isdst] to learn the correct time - zone abbreviation to use. Alternatively, use - localtime(&clock)->tm_zone if this has been enabled. + localtime(&clock)->tm_zone (if TM_ZONE is defined) or + tzname[localtime(&clock)->tm_isdst] (if HAVE_TZNAME is defined) + to learn the correct time zone abbreviation to use. * The 4.2BSD gettimeofday function is not used in this package. This formerly let users obtain the current UTC offset and DST flag, diff --git a/date.c b/date.c index 269825d..0d64b8a 100644 --- a/date.c +++ b/date.c @@ -45,7 +45,6 @@ #if !HAVE_POSIX_DECLS extern char * optarg; extern int optind; -extern char * tzname[]; #endif static int retval = EXIT_SUCCESS; diff --git a/localtime.c b/localtime.c index 8f103aa..b23fe43 100644 --- a/localtime.c +++ b/localtime.c @@ -188,20 +188,21 @@ static int lcl_is_set; static struct tm tm; -#if !HAVE_POSIX_DECLS +#if !HAVE_POSIX_DECLS || TZ_TIME_T +# if HAVE_TZNAME char * tzname[2] = { (char *) wildabbr, (char *) wildabbr }; -# ifdef USG_COMPAT +# endif +# if USG_COMPAT long timezone; int daylight; # endif -#endif - -#ifdef ALTZONE +# ifdef ALTZONE long altzone; -#endif /* defined ALTZONE */ +# endif +#endif /* Initialize *S to a value based on GMTOFF, ISDST, and ABBRIND. */ static void @@ -263,8 +264,10 @@ detzcode64(const char *const codep) static void update_tzname_etc(struct state const *sp, struct ttinfo const *ttisp) { +#if HAVE_TZNAME tzname[ttisp->tt_isdst] = (char *) &sp->chars[ttisp->tt_abbrind]; -#ifdef USG_COMPAT +#endif +#if USG_COMPAT if (!ttisp->tt_isdst) timezone = - ttisp->tt_gmtoff; #endif @@ -280,16 +283,17 @@ settzname(void) register struct state * const sp = lclptr; register int i; - tzname[0] = tzname[1] = (char *) wildabbr; -#ifdef USG_COMPAT +#if HAVE_TZNAME + tzname[0] = tzname[1] = (char *) (sp ? wildabbr : gmt); +#endif +#if USG_COMPAT daylight = 0; timezone = 0; -#endif /* defined USG_COMPAT */ +#endif #ifdef ALTZONE altzone = 0; #endif /* defined ALTZONE */ if (sp == NULL) { - tzname[0] = tzname[1] = (char *) gmt; return; } /* @@ -304,10 +308,10 @@ settzname(void) &sp->ttis[ sp->types[i]]; update_tzname_etc(sp, ttisp); -#ifdef USG_COMPAT +#if USG_COMPAT if (ttisp->tt_isdst) daylight = 1; -#endif /* defined USG_COMPAT */ +#endif } } @@ -2286,9 +2290,9 @@ posix2time(time_t t) #endif /* defined STD_INSPIRED */ -#if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0 +#if TZ_TIME_T -# ifndef USG_COMPAT +# if !USG_COMPAT # define daylight 0 # define timezone 0 # endif diff --git a/newctime.3 b/newctime.3 index 169c919..8b89935 100644 --- a/newctime.3 +++ b/newctime.3 @@ -7,7 +7,7 @@ asctime, ctime, difftime, gmtime, localtime, mktime \- convert date and time .el ds - \- .B #include <time.h> .PP -.B extern char *tzname[2]; +.BR "extern char *tzname[];" " /\(** (optional) \(**/" .PP .B char *ctime(time_t const *clock); .PP @@ -213,7 +213,7 @@ includes the following fields: .RS .PP .nf -.ta .5i +\w'long tm_gmtoff;\0\0'u +.ta 2n +\w'long tm_gmtoff;nn'u int tm_sec; /\(** seconds (0\*(en60) \(**/ int tm_min; /\(** minutes (0\*(en59) \(**/ int tm_hour; /\(** hours (0\*(en23) \(**/ @@ -223,21 +223,11 @@ includes the following fields: int tm_wday; /\(** day of week (Sunday = 0) \(**/ int tm_yday; /\(** day of year (0\*(en365) \(**/ int tm_isdst; /\(** is summer time in effect? \(**/ - char \(**tm_zone; /\(** abbreviation of time zone name \(**/ - long tm_gmtoff; /\(** offset from UT in seconds \(**/ + char \(**tm_zone; /\(** time zone abbreviation (optional) \(**/ + long tm_gmtoff; /\(** offset from UT in seconds (optional) \(**/ .fi .RE .PP -The -.I tm_zone -and -.I tm_gmtoff -fields exist, and are filled in, only if arrangements to do -so were made when the library containing these functions was -created. -There is no guarantee that these fields will continue to exist -in this form in future releases of this code. -.PP .I Tm_isdst is non-zero if summer time is in effect. .PP @@ -246,6 +236,21 @@ is the offset (in seconds) of the time represented from UT, with positive values indicating east of the Prime Meridian. The field's name is derived from Greenwich Mean Time, a precursor of UT. +.PP +In +.B struct tm +the +.I tm_zone +and +.I tm_gmtoff +fields exist, and are filled in, only if arrangements to do +so were made when the library containing these functions was +created. +Similarly, the +.B tzname +variable is optional. +There is no guarantee that these fields and this variable will +continue to exist in this form in future releases of this code. .SH FILES .ta \w'/usr/local/etc/zoneinfo/posixrules\0\0'u /usr/local/etc/zoneinfo time zone information directory @@ -277,12 +282,19 @@ and point to static data overwritten by each call. The +.B tzname +variable (once set) and the .B tm_zone field of a returned .B "struct tm" -points to a static array of characters, which -can be overwritten by later calls to -.IR tzset . +both point to an array of characters that +can be freed or overwritten by later calls to the functions +.IR localtime , +.IR tzfree , +and +.IR tzset , +if these functions affect the time zone information that specifies the +abbreviation in question. The remaining functions and data are thread-safe. .PP .IR Asctime , diff --git a/private.h b/private.h index 1e61592..ad9fcb9 100644 --- a/private.h +++ b/private.h @@ -153,6 +153,22 @@ # endif #endif +#ifndef USG_COMPAT +# ifndef _XOPEN_VERSION +# define USG_COMPAT 0 +# else +# define USG_COMPAT 1 +# endif +#endif + +#ifndef HAVE_TZNAME +# if _POSIX_VERSION < 198808 && !USG_COMPAT +# define HAVE_TZNAME 0 +# else +# define HAVE_TZNAME 1 +# endif +#endif + #ifndef F_OK #define F_OK 0 #endif /* !defined F_OK */ @@ -339,6 +355,12 @@ typedef unsigned long uintmax_t; ** typical platforms. */ #if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0 +# define TZ_TIME_T 1 +#else +# define TZ_TIME_T 0 +#endif + +#if TZ_TIME_T # ifdef LOCALTIME_IMPLEMENTATION static time_t sys_time(time_t *x) { return time(x); } # endif @@ -393,6 +415,20 @@ typedef time_tz tz_time_t; # define tzset tz_tzset # undef tzsetwall # define tzsetwall tz_tzsetwall +# if HAVE_TZNAME +# undef tzname +# define tzname tz_tzname +# endif +# if USG_COMPAT +# undef daylight +# define daylight tz_daylight +# undef timezone +# define timezone tz_timezone +# endif +# ifdef ALTZONE +# undef altzone +# define altzone tz_altzone +# endif char *ctime(time_t const *); char *ctime_r(time_t const *, char *); @@ -422,18 +458,17 @@ extern char *asctime_r(struct tm const *restrict, char *restrict); extern char **environ; #endif -#if !HAVE_POSIX_DECLS -# ifdef USG_COMPAT -# ifndef timezone +#if TZ_TIME_T || !HAVE_POSIX_DECLS +# if HAVE_TZNAME +extern char *tzname[]; +# endif +# if USG_COMPAT extern long timezone; -# endif -# ifndef daylight extern int daylight; -# endif # endif #endif -#if defined ALTZONE && !defined altzone +#ifdef ALTZONE extern long altzone; #endif @@ -443,25 +478,25 @@ extern long altzone; */ #ifdef STD_INSPIRED -# if !defined tzsetwall || defined time_tz +# if TZ_TIME_T || !defined tzsetwall void tzsetwall(void); # endif -# if !defined offtime || defined time_tz +# if TZ_TIME_T || !defined offtime struct tm *offtime(time_t const *, long); # endif -# if !defined timegm || defined time_tz +# if TZ_TIME_T || !defined timegm time_t timegm(struct tm *); # endif -# if !defined timelocal || defined time_tz +# if TZ_TIME_T || !defined timelocal time_t timelocal(struct tm *); # endif -# if !defined timeoff || defined time_tz +# if TZ_TIME_T || !defined timeoff time_t timeoff(struct tm *, long); # endif -# if !defined time2posix || defined time_tz +# if TZ_TIME_T || !defined time2posix time_t time2posix(time_t); # endif -# if !defined posix2time || defined time_tz +# if TZ_TIME_T || !defined posix2time time_t posix2time(time_t); # endif #endif @@ -495,10 +530,10 @@ time_t mktime_z(timezone_t restrict, struct tm *restrict); timezone_t tzalloc(char const *); void tzfree(timezone_t); # ifdef STD_INSPIRED -# if !defined posix2time_z || defined time_tz +# if TZ_TIME_T || !defined posix2time_z time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_PURE; # endif -# if !defined time2posix_z || defined time_tz +# if TZ_TIME_T || !defined time2posix_z time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_PURE; # endif # endif @@ -649,7 +684,7 @@ char *ctime_r(time_t const *, char *); ** or ** isleap(a + b) == isleap(a % 400 + b % 400) ** This is true even if % means modulo rather than Fortran remainder -** (which is allowed by C89 but not C99). +** (which is allowed by C89 but not by C99 or later). ** We use this to avoid addition overflow problems. */ diff --git a/strftime.c b/strftime.c index 4b9fd2c..d09a0db 100644 --- a/strftime.c +++ b/strftime.c @@ -73,7 +73,7 @@ static const struct lc_time_T C_time_locale = { /* ** x_fmt - ** C99 requires this format. + ** C99 and later require this format. ** Using just numbers (as here) makes Quakers happier; ** it's also compatible with SVR4. */ @@ -81,7 +81,7 @@ static const struct lc_time_T C_time_locale = { /* ** c_fmt - ** C99 requires this format. + ** C99 and later require this format. ** Previously this code used "%D %X", but we now conform to C99. ** Note that ** "%a %b %d %H:%M:%S %Y" @@ -105,10 +105,6 @@ static char * _fmt(const char *, const struct tm *, char *, const char *, int *); static char * _yconv(int, int, bool, bool, char *, char const *); -#if !HAVE_POSIX_DECLS -extern char * tzname[]; -#endif - #ifndef YEAR_2000_NAME #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" #endif /* !defined YEAR_2000_NAME */ @@ -223,7 +219,7 @@ label: case 'E': case 'O': /* - ** C99 locale modifiers. + ** Locale modifiers of C99 and later. ** The sequences ** %Ec %EC %Ex %EX %Ey %EY ** %Od %oe %OH %OI %Om %OM @@ -483,19 +479,19 @@ label: case 'Z': #ifdef TM_ZONE pt = _add(t->TM_ZONE, pt, ptlim); -#else +#elif HAVE_TZNAME if (t->tm_isdst >= 0) pt = _add(tzname[t->tm_isdst != 0], pt, ptlim); #endif /* - ** C99 says that %Z must be replaced by the - ** empty string if the time zone is not - ** determinable. + ** C99 and later say that %Z must be + ** replaced by the empty string if the + ** time zone is not determinable. */ continue; case 'z': -#if defined TM_GMTOFF || defined USG_COMPAT || defined ALTZONE +#if defined TM_GMTOFF || USG_COMPAT || defined ALTZONE { long diff; char const * sign; @@ -505,7 +501,7 @@ label: diff = t->TM_GMTOFF; # else /* - ** C99 says that the UT offset must + ** C99 and later say that the UT offset must ** be computed by looking only at ** tm_isdst. This requirement is ** incorrect, since it means the code @@ -513,20 +509,20 @@ label: ** altzone and timezone), and the ** magic might not have the correct ** offset. Doing things correctly is - ** tricky and requires disobeying C99; + ** tricky and requires disobeying the standard; ** see GNU C strftime for details. ** For now, punt and conform to the ** standard, even though it's incorrect. ** - ** C99 says that %z must be replaced by the - ** empty string if the time zone is not + ** C99 and later that %z must be replaced by + ** the empty string if the time zone is not ** determinable, so output nothing if the ** appropriate variables are not available. */ if (t->tm_isdst < 0) continue; if (t->tm_isdst == 0) -# ifdef USG_COMPAT +# if USG_COMPAT diff = -timezone; # else continue; @@ -543,9 +539,11 @@ label: #ifdef TM_ZONE negative = t->TM_ZONE[0] == '-'; #else - negative - = (t->tm_isdst < 0 - || tzname[t->tm_isdst != 0][0] == '-'); + negative = t->tm_isdst < 0; +# if HAVE_TZNAME + if (tzname[t->tm_isdst != 0][0] == '-') + negative = true; +# endif #endif } if (negative) { diff --git a/zdump.c b/zdump.c index 7cde3d3..b69b1e9 100644 --- a/zdump.c +++ b/zdump.c @@ -77,7 +77,6 @@ extern int getopt(int argc, char * const argv[], const char * options); extern char * optarg; extern int optind; -extern char * tzname[]; #endif /* The minimum and maximum finite time values. */ @@ -997,9 +996,11 @@ abbr(struct tm const *tmp) #ifdef TM_ZONE return tmp->TM_ZONE; #else - return (0 <= tmp->tm_isdst && tzname[0 < tmp->tm_isdst] - ? tzname[0 < tmp->tm_isdst] - : ""); +# if HAVE_TZNAME + if (0 <= tmp->tm_isdst && tzname[0 < tmp->tm_isdst]) + return tzname[0 < tmp->tm_isdst]; +# endif + return ""; #endif } -- 2.9.4

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[PATCH 1/2] * Makefile (check_character_set): Fix typo in filename.
by Paul Eggert June 8, 2017

June 8, 2017

--- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index c3ef931..476f259 100644 --- a/Makefile +++ b/Makefile @@ -605,7 +605,7 @@ check_character_set: $(ENCHILADA) ! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \ $(MISC) $(SOURCES) $(WEB_PAGES) \ CONTRIBUTING LICENSE Makefile README \ - version tzdata.ic && \ + version tzdata.zi && \ ! grep -Env $(SAFE_SHARP_LINE) $(TDATA) backzone \ leapseconds yearistype.sh zone.tab && \ ! grep -Env $(OK_LINE) $(ENCHILADA) -- 2.7.4

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[PATCH 1/2] Fix zic parsing of abbreviated line codes
by Paul Eggert June 2, 2017

June 2, 2017

* NEWS: Document this. * zic.8: Document more clearly that "Zone" etc. can be abbreviated. * zic.c (line_codes): Remove, replacing with ... (zi_line_codes, leap_line_codes): ... these new constants. (infile): Use them to distinguish context more accurately. Remove no-longer-applicable warning. --- NEWS | 9 +++++++++ zic.8 | 9 ++++++++- zic.c | 16 +++++++++------- 3 files changed, 26 insertions(+), 8 deletions(-) diff --git a/NEWS b/NEWS index 0a76781..99f5d64 100644 --- a/NEWS +++ b/NEWS @@ -48,6 +48,15 @@ Unreleased, experimental changes Also, zic warns about the undocumented usage with a "last-" prefix, e.g., "last-Fri". + Similarly, zic now accepts the unambiguous abbreviation "L" for + "Link" in ordinary context and for "Leap" in leap-second context. + Conversely, zic no longer accepts non-prefixes such as "La" as + abbreviations for words like "Leap". + + zic no longer accepts leap second lines in ordinary input, or + ordinary lines in leap second input. Formerly, zic sometimes + warned about this undocumented usage and handled it incorrectly. + Several minor changes have been made to the code to make it a bit easier to port to MS-Windows. (Thanks to Kees Dekker for reporting the problems.) diff --git a/zic.8 b/zic.8 index 6fee96d..ab95b08 100644 --- a/zic.8 +++ b/zic.8 @@ -147,7 +147,14 @@ Any line that is blank (after comment stripping) is ignored. Non-blank lines are expected to be of one of three types: rule lines, zone lines, and link lines. .PP -Names (such as month names) must be in English and are case insensitive. +Names must be in English and are case insensitive. +They appear in several contexts, and include month and weekday names +and keywords such as +.BR "maximum" , +.BR "only" , +.BR "Rolling" , +and +.BR "Zone" . A name can be abbreviated by omitting all but an initial prefix; any abbreviation must be unambiguous in context. .PP diff --git a/zic.c b/zic.c index 33cb4e7..ff71af6 100644 --- a/zic.c +++ b/zic.c @@ -298,10 +298,13 @@ struct lookup { static struct lookup const * byword(const char * string, const struct lookup * lp); -static struct lookup const line_codes[] = { +static struct lookup const zi_line_codes[] = { { "Rule", LC_RULE }, { "Zone", LC_ZONE }, { "Link", LC_LINK }, + { NULL, 0 } +}; +static struct lookup const leap_line_codes[] = { { "Leap", LC_LEAP }, { NULL, 0} }; @@ -1114,6 +1117,8 @@ infile(const char *name) } else if (wantcont) { wantcont = inzcont(fields, nfields); } else { + struct lookup const *line_codes + = name == leapsec ? leap_line_codes : zi_line_codes; lp = byword(fields[0], line_codes); if (lp == NULL) error(_("input line of unknown type")); @@ -1130,11 +1135,7 @@ infile(const char *name) wantcont = false; break; case LC_LEAP: - if (name != leapsec) - warning(_("%s: Leap line in non leap" - " seconds file %s"), - progname, name); - else inleap(fields, nfields); + inleap(fields, nfields); wantcont = false; break; default: /* "cannot happen" */ @@ -1586,7 +1587,8 @@ rulesub(struct rule *rp, const char *loyearp, const char *hiyearp, ** Day work. ** Accept things such as: ** 1 - ** last-Sunday + ** lastSunday + ** last-Sunday (undocumented; warn about this) ** Sun<=20 ** Sun>=7 */ -- 2.9.4

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