- tz - lists.iana.org

2014g soon
by Paul Eggert Aug. 26, 2014

Aug. 26, 2014

It's time for a new tz release: we have one change to near-future data (for the Turks & Caicos) that should go out sooner rather than later, and there've been several changes to the code as well. To help simplify reviewing I've pushed an integrated version of the proposed changes to <https://github.com/eggert/tz>, and you can read the news here: https://github.com/eggert/tz/blob/master/NEWS

1 0

[PROPOSED PATCH] * NEWS: Coalesce discussions of zdump, localtime_rz, and localtime_r.
by Paul Eggert Aug. 26, 2014

Aug. 26, 2014

--- NEWS | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/NEWS b/NEWS index 8302547..b031a32 100644 --- a/NEWS +++ b/NEWS @@ -52,10 +52,6 @@ Unreleased, experimental changes Although not needed for tz's own applications, which are single-threaded, this supports POSIX better if the tz library is used in multithreaded apps. - zdump now uses localtime_r and tzset if available, as this is a - bit cleaner and faster than plain localtime. Compile with - -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system lacks them. - Unless NETBSD_INSPIRED is defined to 0, the tz library now supplies functions that let callers create and use objects representing time zones. This is intended for applications that need to deal with many time @@ -89,7 +85,11 @@ Unreleased, experimental changes zdump now uses localtime_rz if available, as it's significantly faster. Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_TZ - defaults to 1 if NETBSD_INSPIRED && USE_LTZ. + defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is + not available, zdump now uses localtime_r and tzset if available, + as this is a bit cleaner and faster than plain localtime. Compile + with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system + lacks these two functions. tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) -- 1.9.1

1 0

[PROPOSED PATCH] * Makefile, NEWS: Say that backzone's contents are not all low-quality
by Paul Eggert Aug. 26, 2014

Aug. 26, 2014

and give credit to Lester Caine for some of its high-quality entries. --- Makefile | 4 ++-- NEWS | 9 +++++---- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/Makefile b/Makefile index 2354a3f..8ccbaf4 100644 --- a/Makefile +++ b/Makefile @@ -84,8 +84,8 @@ LIBDIR= $(TOPDIR)/lib # below. If you want both sets of data available, with leap seconds counted # normally, use # REDO= right_posix -# below. If you want just POSIX-compatible time values, but with extra -# lower-quality data from the file 'backzone', use +# below. If you want just POSIX-compatible time values, but with +# out-of-scope and often-wrong data from the file 'backzone', use # REDO= posix_packrat # POSIX mandates that leap seconds not be counted; for compatibility with it, # use "posix_only", "posix_right", or "posix_packrat". diff --git a/NEWS b/NEWS index 3c8b84b..8302547 100644 --- a/NEWS +++ b/NEWS @@ -26,10 +26,11 @@ Unreleased, experimental changes A new file 'backzone' contains data which may appeal to connoisseurs of old time stamps, although it is out of scope for - the tz database and is often poorly sourced. The new file is not - recommended for ordinary use and its entries are not installed by - default. (Thanks to Lester Caine for the Guernsey, Jersey, and - Isle of Man entries in 'backzone'.) + the tz database, is often poorly sourced, and contains some data + that is known to be incorrect. The new file is not recommended + for ordinary use and its entries are not installed by default. + (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and + Isle of Man entries.) Some more zones have been turned into links, when they differed from existing zones only for older time stamps. As usual, -- 1.9.1

1 0

[PROPOSED PATCH] Port 'bool' usage to clang 3.4.
by Paul Eggert Aug. 26, 2014

Aug. 26, 2014

* date.c (convert, reset): Fix prototype to match function, as the C standard requires. --- date.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/date.c b/date.c index 3b44c94..b77de79 100644 --- a/date.c +++ b/date.c @@ -55,14 +55,14 @@ extern char * tzname[2]; static int retval = EXIT_SUCCESS; static void checkfinal(char const *, bool, time_t, time_t); -static time_t convert(const char *, int, time_t); +static time_t convert(const char *, bool, time_t); static void display(const char *, time_t); static void dogmt(void); static void errensure(void); static void iffy(time_t, time_t, const char *, const char *); static const char * nondigit(const char *); static void oops(const char *); -static void reset(time_t, int); +static void reset(time_t, bool); static void timeout(FILE *, const char *, const struct tm *); static void usage(void); static void wildinput(const char *, const char *, -- 1.9.1

1 0

[PROPOSED PATCH 1/3] Port 'make check_time_t_alternatives' to Solaris 10.
by Paul Eggert Aug. 26, 2014

Aug. 26, 2014

* Makefile (check_time_t_alternatives): Don't assume 'diff' has the -q option, since POSIX does not require -q. * NEWS: Document this. --- Makefile | 9 ++++++++- NEWS | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 0fc8e2c..92fad4d 100644 --- a/Makefile +++ b/Makefile @@ -569,6 +569,11 @@ check_public: $(ENCHILADA) # Check that the code works under various alternative # implementations of time_t. check_time_t_alternatives: + if diff -q Makefile Makefile 2>/dev/null; then \ + quiet_option='-q'; \ + else \ + quiet_option=''; \ + fi && \ zones=`$(AWK) '/^[^#]/ { print $$3 }' <zone1970.tab` && \ for type in $(TIME_T_ALTERNATIVES); do \ mkdir -p tzpublic/$$type && \ @@ -577,7 +582,9 @@ check_time_t_alternatives: CFLAGS='$(CFLAGS) -Dtime_tz='"'$$type'" \ REDO='$(REDO)' \ install && \ - diff -qr tzpublic/int64_t/etc/zoneinfo tzpublic/$$type/etc/zoneinfo && \ + diff $$quiet_option -r \ + tzpublic/int64_t/etc/zoneinfo \ + tzpublic/$$type/etc/zoneinfo && \ case $$type in \ int32_t) range=-2147483648,2147483647;; \ uint32_t) range=0,4294967296;; \ diff --git a/NEWS b/NEWS index fb2f31b..a453ef6 100644 --- a/NEWS +++ b/NEWS @@ -112,6 +112,8 @@ Unreleased, experimental changes 'zdump' no longer links in ialloc.o, as it's not needed. + 'make check_time_t_alternatives' no longer assumes GNU diff. + Changes affecting distribution tarballs The files checktab.awk and zoneinfo2tdf.pl are now distributed in -- 1.9.1

1 2

[PROPOSED PATCH 1/3] date: port to Ubuntu 14.04 with -DHAVE_UTMPX_H=1
by Paul Eggert Aug. 25, 2014

Aug. 25, 2014

* date.c (WTMPX_FILE): Define to _PATH_WTMPX if not already defined and if _PATH_WTMPX is defined. (reset): Do not use WTMPX_FILE if it is not defined. * NEWS: Document this. --- NEWS | 5 +++++ date.c | 7 +++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/NEWS b/NEWS index 2c8b474..a8218f1 100644 --- a/NEWS +++ b/NEWS @@ -39,6 +39,11 @@ Unreleased, experimental changes tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) + When HAVE_UTMPX_H is set the 'date' command now builds on systems + whose <utmpx.h> file does not define WTMPX_FILE, and when setting + the date it updates the wtmpx file if _PATH_WTMPX is defined. + This affects GNU/Linux and similar systems. + Changes affecting distribution tarballs The files checktab.awk and zoneinfo2tdf.pl are now distributed in diff --git a/date.c b/date.c index 9a0b84c..3d78914 100644 --- a/date.c +++ b/date.c @@ -31,6 +31,9 @@ #ifndef NTIME_MSG #define NTIME_MSG "new time" #endif +#if !defined WTMPX_FILE && defined _PATH_WTMPX +# define WTMPX_FILE _PATH_WTMPX +#endif /* ** The two things date knows about time are. . . @@ -378,7 +381,7 @@ reset(const time_t newt, const int nflag) sx.after.ut_type = NEW_TIME; sx.after.ut_tv.tv_sec = newt; (void) strcpy(sx.after.ut_line, NTIME_MSG); -#if !SUPPRESS_WTMPX_FILE_UPDATE +#if defined WTMPX_FILE && !SUPPRESS_WTMPX_FILE_UPDATE /* In Solaris 2.5 (and presumably other systems), 'date' does not update /var/adm/wtmpx. This must be a bug. If you'd like to reproduce the bug, @@ -390,7 +393,7 @@ reset(const time_t newt, const int nflag) oops(_("log file write")); if (close(fid) != 0) oops(_("log file close")); -#endif /* !SUPPRESS_WTMPX_FILE_UPDATE */ +# endif pututxline(&sx.before); pututxline(&sx.after); #endif /* HAVE_UTMPX_H */ -- 1.9.1

5 17

[PROPOSED PATCH] Make the library thread-safe if THREAD_SAFE is defined.
by Paul Eggert Aug. 25, 2014

Aug. 25, 2014

* localtime.c [THREAD_SAFE]: Include pthread.h. (VOLATILE): New macro. (locallock) [THREAD_SAFE]: New static var. (lock, unlock): New functions. (lcl_is_set, gmt_is_set): Now VOLATILE. (tzsetwall): Move cleaned-up guts to new function tzsetwall_unlocked, for which this is now merely a locking wrapper. (tzset): Similarly, for new function tzset_unlocked. (localtime_tzset): New function, which does proper locking. (localtime, localtime_r): Use it. (gmtsub): Do not worry about initializing gmtptr, as that's now the caller's responsibility. (gmtime): Reimplement in terms of gmtime_r. (timegm): Reimplement in terms of timeoff. (gmtime_r, offtime, mktime, timeoff, time2posix, posix2time): Lock at start and unlock at end. * Makefile, NEWS: Document this. --- Makefile | 3 + NEWS | 4 + localtime.c | 249 ++++++++++++++++++++++++++++++++++++++++-------------------- 3 files changed, 173 insertions(+), 83 deletions(-) diff --git a/Makefile b/Makefile index 5bbd7e7..3d24c2a 100644 --- a/Makefile +++ b/Makefile @@ -123,6 +123,9 @@ LDLIBS= # -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 +# -DTHREAD_SAFE=1 to make localtime.c thread-safe, as POSIX requires; +# 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 # -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz" # -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory; diff --git a/NEWS b/NEWS index 28974c9..1a78041 100644 --- a/NEWS +++ b/NEWS @@ -36,6 +36,10 @@ Unreleased, experimental changes Changes affecting code + The tz library is now thread-safe if compiled with THREAD_SAFE defined. + Although not needed for tz's own applications, which are single-threaded, + this supports POSIX better if the tz library is used in multithreaded apps. + tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) diff --git a/localtime.c b/localtime.c index 551b5a2..f499583 100644 --- a/localtime.c +++ b/localtime.c @@ -16,6 +16,18 @@ #include "tzfile.h" #include "fcntl.h" +#if THREAD_SAFE +# include <pthread.h> +# define VOLATILE volatile +static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER; +static int lock(void) { return pthread_mutex_lock(&locallock); } +static void unlock(void) { pthread_mutex_unlock(&locallock); } +#else +# define VOLATILE +static int lock(void) { return 0; } +static void unlock(void) { } +#endif + #ifndef TZ_ABBR_MAX_LEN #define TZ_ABBR_MAX_LEN 16 #endif /* !defined TZ_ABBR_MAX_LEN */ @@ -154,8 +166,8 @@ static struct state gmtmem; #endif /* !defined TZ_STRLEN_MAX */ static char lcl_TZname[TZ_STRLEN_MAX + 1]; -static int lcl_is_set; -static int gmt_is_set; +static int VOLATILE lcl_is_set; +static int VOLATILE gmt_is_set; char * tzname[2] = { (char *) wildabbr, @@ -1139,6 +1151,21 @@ gmtload(struct state *const sp) (void) tzparse(gmt, sp, TRUE); } +static void +tzsetwall_unlocked(void) +{ + if (lcl_is_set < 0) + return; +#ifdef ALL_STATE + if (! lclptr) + lclptr = malloc(sizeof *lclptr); +#endif + if (lclptr && tzload(NULL, lclptr, TRUE) != 0) + gmtload(lclptr); + settzname(); + lcl_is_set = -1; +} + #ifndef STD_INSPIRED /* ** A non-static declaration of tzsetwall in a system header file @@ -1149,65 +1176,71 @@ static void tzsetwall(void) { - if (lcl_is_set < 0) - return; - lcl_is_set = -1; + if (lock() != 0) + return; + tzsetwall_unlocked(); + unlock(); +} +static void +tzset_unlocked(void) +{ + int shortname; + register char const *name = getenv("TZ"); + + if (!name) { + tzsetwall_unlocked(); + return; + } + shortname = strlen(name) < sizeof lcl_TZname; + if (0 < lcl_is_set && strcmp(lcl_TZname, name) == 0) + return; + if (shortname) + strcpy(lcl_TZname, name); #ifdef ALL_STATE - if (lclptr == NULL) { - lclptr = malloc(sizeof *lclptr); - if (lclptr == NULL) { - settzname(); /* all we can do */ - return; - } - } + if (! lclptr) + lclptr = malloc(sizeof *lclptr); #endif /* defined ALL_STATE */ - if (tzload(NULL, lclptr, TRUE) != 0) - gmtload(lclptr); - settzname(); + if (lclptr) { + if (*name == '\0') { + /* + ** User wants it fast rather than right. + */ + lclptr->leapcnt = 0; /* so, we're off a little */ + lclptr->timecnt = 0; + lclptr->typecnt = 0; + lclptr->ttis[0].tt_isdst = 0; + lclptr->ttis[0].tt_gmtoff = 0; + lclptr->ttis[0].tt_abbrind = 0; + strcpy(lclptr->chars, gmt); + } else if (tzload(name, lclptr, TRUE) != 0) + if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) + gmtload(lclptr); + } + settzname(); + lcl_is_set = shortname; } void tzset(void) { - register const char * name; - - name = getenv("TZ"); - if (name == NULL) { - tzsetwall(); - return; - } - - if (lcl_is_set > 0 && strcmp(lcl_TZname, name) == 0) - return; - lcl_is_set = strlen(name) < sizeof lcl_TZname; - if (lcl_is_set) - (void) strcpy(lcl_TZname, name); + if (lock() != 0) + return; + tzset_unlocked(); + unlock(); +} +static void +gmtcheck(void) +{ + if (gmt_is_set) + return; #ifdef ALL_STATE - if (lclptr == NULL) { - lclptr = malloc(sizeof *lclptr); - if (lclptr == NULL) { - settzname(); /* all we can do */ - return; - } - } -#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->typecnt = 0; - lclptr->ttis[0].tt_isdst = 0; - lclptr->ttis[0].tt_gmtoff = 0; - lclptr->ttis[0].tt_abbrind = 0; - (void) strcpy(lclptr->chars, gmt); - } else if (tzload(name, lclptr, TRUE) != 0) - if (name[0] == ':' || tzparse(name, lclptr, FALSE) != 0) - (void) gmtload(lclptr); - settzname(); + gmtptr = malloc(sizeof *gmtptr); +#endif + if (gmtptr) + gmtload(gmtptr); + gmt_is_set = TRUE; } /* @@ -1296,11 +1329,25 @@ localsub(const time_t *const timep, const int_fast32_t offset, return result; } +static struct tm * +localtime_tzset(time_t const *timep, struct tm *tmp, int skip_tzset) +{ + int err = lock(); + if (err) { + errno = err; + return NULL; + } + if (!skip_tzset) + tzset_unlocked(); + tmp = localsub(timep, 0, tmp); + unlock(); + return tmp; +} + struct tm * localtime(const time_t *const timep) { - tzset(); - return localsub(timep, 0L, &tm); + return localtime_tzset(timep, &tm, 0); } /* @@ -1310,7 +1357,7 @@ localtime(const time_t *const timep) struct tm * localtime_r(const time_t *const timep, struct tm *tmp) { - return localsub(timep, 0L, tmp); + return localtime_tzset(timep, tmp, lcl_is_set); } /* @@ -1323,16 +1370,6 @@ gmtsub(const time_t *const timep, const int_fast32_t offset, { register struct tm * result; - if (!gmt_is_set) { -#ifdef ALL_STATE - gmtptr = malloc(sizeof *gmtptr); - gmt_is_set = gmtptr != NULL; -#else - gmt_is_set = TRUE; -#endif /* defined ALL_STATE */ - if (gmt_is_set) - gmtload(gmtptr); - } result = timesub(timep, offset, gmtptr, tmp); #ifdef TM_ZONE /* @@ -1348,7 +1385,7 @@ gmtsub(const time_t *const timep, const int_fast32_t offset, struct tm * gmtime(const time_t *const timep) { - return gmtsub(timep, 0L, &tm); + return gmtime_r(timep, &tm); } /* @@ -1358,7 +1395,15 @@ gmtime(const time_t *const timep) struct tm * gmtime_r(const time_t *const timep, struct tm *tmp) { - return gmtsub(timep, 0L, tmp); + int err = lock(); + if (err) { + errno = err; + return NULL; + } + gmtcheck(); + tmp = gmtsub(timep, 0, tmp); + unlock(); + return tmp; } #ifdef STD_INSPIRED @@ -1366,7 +1411,16 @@ gmtime_r(const time_t *const timep, struct tm *tmp) struct tm * offtime(const time_t *const timep, const long offset) { - return gmtsub(timep, offset, &tm); + struct tm *tmp; + int err = lock(); + if (err) { + errno = err; + return NULL; + } + gmtcheck(); + tmp = gmtsub(timep, offset, &tm); + unlock(); + return tmp; } #endif /* defined STD_INSPIRED */ @@ -1901,8 +1955,16 @@ time1(struct tm *const tmp, time_t mktime(struct tm *const tmp) { - tzset(); - return time1(tmp, localsub, 0L); + time_t t; + int err = lock(); + if (err) { + errno = err; + return -1; + } + tzset_unlocked(); + t = time1(tmp, localsub, 0); + unlock(); + return t; } #ifdef STD_INSPIRED @@ -1918,17 +1980,25 @@ timelocal(struct tm *const tmp) time_t timegm(struct tm *const tmp) { - if (tmp != NULL) - tmp->tm_isdst = 0; - return time1(tmp, gmtsub, 0L); + return timeoff(tmp, 0); } time_t timeoff(struct tm *const tmp, const long offset) { - if (tmp != NULL) - tmp->tm_isdst = 0; - return time1(tmp, gmtsub, offset); + time_t t; + int err; + if (tmp) + tmp->tm_isdst = 0; + err = lock(); + if (err) { + errno = err; + return -1; + } + gmtcheck(); + t = time1(tmp, gmtsub, offset); + unlock(); + return t; } #endif /* defined STD_INSPIRED */ @@ -1986,8 +2056,17 @@ leapcorr(time_t *timep) time_t time2posix(time_t t) { - tzset(); - return t - leapcorr(&t); + time_t p; + int err = lock(); + if (err) { + errno = err; + return -1; + } + if (!lcl_is_set) + tzset_unlocked(); + p = t - leapcorr(&t); + unlock(); + return p; } time_t @@ -1995,8 +2074,13 @@ posix2time(time_t t) { time_t x; time_t y; - - tzset(); + int err = lock(); + if (err) { + errno = err; + return -1; + } + if (!lcl_is_set) + tzset_unlocked(); /* ** For a positive leap second hit, the result ** is not unique. For a negative leap second @@ -2010,16 +2094,15 @@ posix2time(time_t t) x++; y = x - leapcorr(&x); } while (y < t); - if (t != y) - return x - 1; + x -= y != t; } else if (y > t) { do { --x; y = x - leapcorr(&x); } while (y > t); - if (t != y) - return x + 1; + x += y != t; } + unlock(); return x; } -- 1.9.1

2 6

[PROPOSED PATCH 1/4] Fix unlikely buffer overrun when setting date across network.
by Paul Eggert Aug. 23, 2014

Aug. 23, 2014

* date.c (netsettime) [TSP_SETDATE]: Don't assume gethostname returns a null-terminated string. --- date.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/date.c b/date.c index c8fab75..3b44c94 100644 --- a/date.c +++ b/date.c @@ -819,7 +819,6 @@ netsettime(struct timeval ntv) { int s, length, port, timed_ack, found, err, waittime; fd_set ready; - char hostname[MAXHOSTNAMELEN]; struct timeval tout; struct servent *sp; struct tsp msg; @@ -858,11 +857,15 @@ netsettime(struct timeval ntv) } msg.tsp_type = TSP_SETDATE; msg.tsp_vers = TSPVERSION; - if (gethostname(hostname, sizeof (hostname))) { + msg.tsp_name[sizeof msg.tsp_name - 1] = '\0'; + if (gethostname(msg.tsp_name, sizeof msg.tsp_name) != 0) { perror("gethostname"); goto bad; } - strncpy(msg.tsp_name, hostname, sizeof (hostname)); + if (msg.tsp_name[sizeof msg.tsp_name - 1]) { + fprintf(stderr, "hostname too long\n"); + goto bad; + } msg.tsp_seq = htons(0); msg.tsp_time.tv_sec = htonl(ntv.tv_sec); msg.tsp_time.tv_usec = htonl(ntv.tv_usec); -- 1.9.1

1 5

[PATCH] * asia (Asia/Kolkata): Add comment about 19th-century Madras time.
by Paul Eggert Aug. 23, 2014

Aug. 23, 2014

--- asia | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/asia b/asia index b3afc5d..00e0df3 100644 --- a/asia +++ b/asia @@ -880,6 +880,14 @@ Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1 # India +# From Paul Eggert (2014-08-21): +# In tomorrow's The Hindu, Nitya Menon reports that India had two civil time +# zones starting in 1884, one in Bombay and one in Calcutta, and that railways +# used a third time zone based on Madras time (80 deg. 18'30" E). Also, +# in 1881 Bombay briefly switched to Madras Time, but switched back. See: +# http://www.thehindu.com/news/cities/chennai/madras-375-when-madras-clocked-… +# Ignore this as it predates our 1970 cutoff. + # From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne: # According to a Portuguese decree (1911-05-26) # http://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf -- 1.9.1

2 4

[PROPOSED PATCH] Simplify configuration of TM_GMTOFF and TM_ZONE.
by Paul Eggert Aug. 23, 2014

Aug. 23, 2014

* private.h, zdump.c (_GNU_SOURCE): New macro. * private.h (TM_GMTOFF) [!NO_TM_GMTOFF]: (TM_ZONE) [!NO_TM_ZONE]: Guess definition if not already defined. * Makefile, NEWS: Document the above. --- Makefile | 23 +++++------------------ NEWS | 4 ++++ private.h | 16 ++++++++++++++++ zdump.c | 3 +++ 4 files changed, 28 insertions(+), 18 deletions(-) diff --git a/Makefile b/Makefile index 4703cba..fa110e2 100644 --- a/Makefile +++ b/Makefile @@ -161,25 +161,12 @@ GCC_DEBUG_FLAGS = -Dlint -g3 -O3 -fno-common -fstrict-aliasing \ # (or if you decide to add such a field in your system's "time.h" file), # add the name to a define such as # -DTM_GMTOFF=tm_gmtoff -# or -# -DTM_GMTOFF=_tm_gmtoff -# to the end of the "CFLAGS=" line. -# Neither tm_gmtoff nor _tm_gmtoff is described in X3J11's work; -# in its work, use of "tm_gmtoff" is described as non-conforming. -# Both Linux and BSD have done the equivalent of defining TM_GMTOFF in -# their recent releases. -# -# If your system has a "zone abbreviation" 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 +# to the end of the "CFLAGS=" line. If not defined, the code attempts to +# guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this. +# Similarly, if your system has a "zone abbreviation" field, define # -DTM_ZONE=tm_zone -# or -# -DTM_ZONE=_tm_zone -# to the end of the "CFLAGS=" line. -# Neither tm_zone nor _tm_zone is described in X3J11's work; -# in its work, use of "tm_zone" is described as non-conforming. -# Both UCB and Sun have done the equivalent of defining TM_ZONE in -# their recent releases. +# 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 dystems. # # If you want functions that were inspired by early versions of X3J11's work, # add diff --git a/NEWS b/NEWS index 335a7cf..7bc8b05 100644 --- a/NEWS +++ b/NEWS @@ -51,6 +51,10 @@ Unreleased, experimental changes Although not needed for tz's own applications, which are single-threaded, this supports POSIX better if the tz library is used in multithreaded apps. + The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not + already defined, to make it easier to configure on common platforms. + Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this. + tzselect -c now uses a hybrid distance measure that works better in Africa. (Thanks to Alan Barrett for noting the problem.) diff --git a/private.h b/private.h index 9482790..2389e37 100644 --- a/private.h +++ b/private.h @@ -71,6 +71,9 @@ #define ctime_r _incompatible_ctime_r #endif /* HAVE_INCOMPATIBLE_CTIME_R */ +/* Enable tm_gmtoff and tm_zone on GNUish systems. */ +#define _GNU_SOURCE 1 + /* ** Nested includes */ @@ -337,6 +340,19 @@ time_t posix2time(time_t); # endif #endif +/* Infer TM_ZONE on systems where this information is known, but suppress + guessing if NO_TM_ZONE is defined. Similarly for TM_GMTOFF. */ +#if (defined __GLIBC__ \ + || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \ + || (defined __APPLE__ && defined __MACH__)) +# if !defined TM_GMTOFF && !defined NO_TM_GMTOFF +# define TM_GMTOFF tm_gmtoff +# endif +# if !defined TM_ZONE && !defined NO_TM_ZONE +# define TM_ZONE tm_zone +# endif +#endif + /* ** Private function declarations. */ diff --git a/zdump.c b/zdump.c index e9a42fd..070ad3c 100644 --- a/zdump.c +++ b/zdump.c @@ -18,6 +18,9 @@ # include "private.h" #endif +/* Enable tm_gmtoff and tm_zone on GNUish systems. */ +#define _GNU_SOURCE 1 + #include "stdio.h" /* for stdout, stderr, perror */ #include "string.h" /* for strcpy */ #include "sys/types.h" /* for time_t */ -- 1.9.1

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