- tz - lists.iana.org

[PROPOSED] Fix to2050.tzs timestamp in distributed tarball
by Paul Eggert Dec. 11, 2024

Dec. 11, 2024

* Makefile (TZS_DEPS): Remove asctime.c and add localtime.c. --- Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 5473dedd..2aafdc24 100644 --- a/Makefile +++ b/Makefile @@ -615,8 +615,8 @@ TZS_YEAR= 2050 TZS_CUTOFF_FLAG= -c $(TZS_YEAR) TZS= to$(TZS_YEAR).tzs TZS_NEW= to$(TZS_YEAR)new.tzs -TZS_DEPS= $(YDATA) asctime.c localtime.c \ - private.h tzfile.h zdump.c zic.c +TZS_DEPS= $(YDATA) localtime.c private.h \ + strftime.c tzfile.h zdump.c zic.c TZDATA_DIST = $(COMMON) $(DATA) $(MISC) # EIGHT_YARDS is just a yard short of the whole ENCHILADA. EIGHT_YARDS = $(TZDATA_DIST) $(DOCS) $(SOURCES) tzdata.zi -- 2.47.1

1 0

Add ICU's Etc/Unknown Zone to IANA Time Zone Database?
by Justin Grant Dec. 11, 2024

Dec. 11, 2024

Hi TZ friends - Should the time zone identifier "Etc/Unknown" (standardized in Unicode Technical Standard 35 and used by the ICU <https://icu.unicode.org/> library that implements time zone support in all major web browsers, in Java, and in other platforms) be added to the IANA Time Zone Database? Etc/Unknown would behave the same as the existing time zone identifier "Factory". Ideally, Etc/Unknown could be a Zone and Factory could be turned into a Link pointing to Etc/Unknown, because both of them have the meaning of "the time zone of this computer is not known" but Etc/Unknown is more self-describing and is better aligned with modern Zone naming conventions. Here's more context: "Etc/Unknown" is standardized in https://unicode.org/reports/tr35/#Time_Zone_Identifiers. Here's the relevant text from the standard: > There is a special code "unk" for an Unknown or Invalid time zone. > This can be expressed in the tz database style ID "Etc/Unknown", > although it is not defined in the tz database. Following this standard, Etc/Unknown is returned by ICU <https://icu.unicode.org/> when the time zone of a computer cannot be determined. Here's an example of an ICU method that can return Etc/Unknown: icu::TimeZone::detectHostTimeZone() <https://unicode-org.github.io/icu-docs/apidoc/dev/icu4c/classicu_1_1TimeZon…> . The fact that Etc/Unknown looks like an IANA identifier but is not actually in TZDB has been a long-running source of problems. Most recently, this week Chrome is rushing out a patch <https://issues.chromium.org/issues/381620359> that reverted a recent change that added support for the "Factory" zone by making it an alias for "Etc/Unknown". GIven that ICU previously didn't recognize Factory and so returned Etc/Unknown for computers in the Factory zone, this was assumed by everyone to be a safe change. But this change turned out to break some 3rd-party libraries and had to be reverted. After discussing this recent bug with engineers at Google, our consensus was that it'd be helpful for the time zone ecosystem if Etc/Unknown stopped being a special case and started being a regular Zone in the IANA Time Zone database. Especially if we could Link-ify Factory at the same time so that Zone picker UIs won't have two distinct "I don't know what time zone this is" choices. Thanks for considering this proposal. Best, Justin Grant

10 28

[PROPOSED] Fix unlikely multithreaded file descriptor leak
by Paul Eggert Dec. 9, 2024

Dec. 9, 2024

On multithreaded platforms, tzset could leak a file descriptor into a forked or execed process. Fix the leak. While we’re at it, don’t let the TZif file become the controlling tty. * NEWS: Mention this. * localtime.c (O_CLOEXEC, O_CLOFORK, O_IGNORE_CTTY, O_NOCTTY): Default to 0. (tzloadbody): Use these flags when opening the TZif file. --- NEWS | 5 +++++ localtime.c | 22 +++++++++++++++++----- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/NEWS b/NEWS index 79686147..2fc7bb19 100644 --- a/NEWS +++ b/NEWS @@ -56,6 +56,11 @@ Unreleased, experimental changes PTRDIFF_MAX, a limit forced by C anyway; formerly tzcode silently misbehaved unless TZNAME_MAXIMUM was less than INT_MAX. + tzset and related functions no longer leak a file descriptor if + another thread forks or execs at about the same time and if the + platform has O_CLOFORK and O_CLOEXEC respectively. Also, the + functions no longer let a TZif file become a controlling terminal. + Changes to documentation The name Etc/Unknown is now reserved: it will not be used by TZDB. diff --git a/localtime.c b/localtime.c index 492965d9..f92676c6 100644 --- a/localtime.c +++ b/localtime.c @@ -96,12 +96,23 @@ typedef intmax_t timex_t; # define TZ_ABBR_ERR_CHAR '_' #endif /* !defined TZ_ABBR_ERR_CHAR */ -/* -** Support non-POSIX platforms that distinguish between text and binary files. -*/ +/* Port to platforms that lack some O_* flags. Unless otherwise + specified, the flags are standardized by POSIX. */ #ifndef O_BINARY -# define O_BINARY 0 +# define O_BINARY 0 /* MS-Windows */ +#endif +#ifndef O_CLOEXEC +# define O_CLOEXEC 0 +#endif +#ifndef O_CLOFORK +# define O_CLOFORK 0 +#endif +#ifndef O_IGNORE_CTTY +# define O_IGNORE_CTTY 0 /* GNU/Hurd */ +#endif +#ifndef O_NOCTTY +# define O_NOCTTY 0 #endif #ifndef WILDABBR @@ -542,7 +553,8 @@ tzloadbody(char const *name, struct state *sp, bool doextend, } if (doaccess && access(name, R_OK) != 0) return errno; - fid = open(name, O_RDONLY | O_BINARY); + fid = open(name, (O_RDONLY | O_BINARY | O_CLOEXEC | O_CLOFORK + | O_IGNORE_CTTY | O_NOCTTY)); if (fid < 0) return errno; -- 2.47.0

1 0

US Department of Transportation map of US timezones
by Roozbeh Pournader Dec. 7, 2024

Dec. 7, 2024

I just found out through https://x.com/RedistrictNet/status/1863742503242875046 That the US Department of Transportation has just rolled out an official map of US timezones. It's supposed to be at: https://geodata.bts.gov/datasets/usdot::time-zones/about (It doesn't load for me at the moment, possibly due to high demand.) Roozbeh

11 12

[PROPOSED] Fix checknow confusing diagnostics
by Paul Eggert Dec. 7, 2024

Dec. 7, 2024

* checknow.awk: Do not report a duplicate (and confusing) diagnostic when a zone has no data. --- checknow.awk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/checknow.awk b/checknow.awk index 8b7881d2..450490ee 100644 --- a/checknow.awk +++ b/checknow.awk @@ -44,7 +44,7 @@ BEGIN { END { for (zone in zone_data) { data = zone_data[zone] - if (!zonenow[data]) { + if (data && !zonenow[data]) { printf "Zone table should have one of:%s\n", zones[data] zonenow[data] = zone # This suppresses duplicate diagnostics. status = 1 -- 2.47.0

1 0

[PROPOSED 1/3] Pacify gcc -Wsuggest-attribute=format sans snprintf in zdump
by Paul Eggert Dec. 1, 2024

Dec. 1, 2024

* zdump.c (my_snprintf): Now a static function defined only if !HAVE_SNPRINTF, with "#define snprintf my_sprintf" at the end. This lessens disruption to mainline code. All uses changed. Add ATTRIBUTE_FORMAT((printf, 3, 4)) to pacify gcc -Wsuggest-attribute=format. --- zdump.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/zdump.c b/zdump.c index c988f6b3..ea051adf 100644 --- a/zdump.c +++ b/zdump.c @@ -914,13 +914,10 @@ showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi) } } -#if HAVE_SNPRINTF -# define my_snprintf snprintf -#else +/* On pre-C99 platforms, a snprintf substitute good enough for us. */ +#if !HAVE_SNPRINTF # include <stdarg.h> - -/* A substitute for snprintf that is good enough for zdump. */ -static int +ATTRIBUTE_FORMAT((printf, 3, 4)) static int my_snprintf(char *s, size_t size, char const *format, ...) { int n; @@ -948,6 +945,7 @@ my_snprintf(char *s, size_t size, char const *format, ...) va_end(args); return n; } +# define snprintf my_snprintf #endif /* Store into BUF, of size SIZE, a formatted local time taken from *TM. @@ -962,10 +960,10 @@ format_local_time(char *buf, ptrdiff_t size, struct tm const *tm) { int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour; return (ss - ? my_snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss) + ? snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss) : mm - ? my_snprintf(buf, size, "%02d:%02d", hh, mm) - : my_snprintf(buf, size, "%02d", hh)); + ? snprintf(buf, size, "%02d:%02d", hh, mm) + : snprintf(buf, size, "%02d", hh)); } /* Store into BUF, of size SIZE, a formatted UT offset for the @@ -1000,10 +998,10 @@ format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t) mm = off / 60 % 60; hh = off / 60 / 60; return (ss || 100 <= hh - ? my_snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss) + ? snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss) : mm - ? my_snprintf(buf, size, "%c%02ld%02d", sign, hh, mm) - : my_snprintf(buf, size, "%c%02ld", sign, hh)); + ? snprintf(buf, size, "%c%02ld%02d", sign, hh, mm) + : snprintf(buf, size, "%c%02ld", sign, hh)); } /* Store into BUF (of size SIZE) a quoted string representation of P. @@ -1106,7 +1104,7 @@ istrftime(char *buf, ptrdiff_t size, char const *time_fmt, for (abp = ab; is_alpha(*abp); abp++) continue; len = (!*abp && *ab - ? my_snprintf(b, s, "%s", ab) + ? snprintf(b, s, "%s", ab) : format_quoted_string(b, s, ab)); if (s <= len) return false; @@ -1114,7 +1112,7 @@ istrftime(char *buf, ptrdiff_t size, char const *time_fmt, } formatted_len = (tm->tm_isdst - ? my_snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst) + ? snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst) : 0); } break; -- 2.43.0

1 2

[PATCH 1/2] Be more consistent about macro true/false vs 1/0
by Paul Eggert Nov. 29, 2024

Nov. 29, 2024

* private.h (HAVE_GETTEXT, HAVE_SYS_STAT_H, HAVE_UNISTD_H) (HAVE_STDINT_H, HAVE_STRTOLL, HAVE_STDCKDINT_H) (HAVE_DECL_TIMEGM): * strftime.c (MKTIME_MIGHT_OVERFLOW, DEPRECATE_TWO_DIGIT_YEARS): Default to 1 or 0, not to true or false, since these can be set via the command line as per the Makefile. * private.h (TZ_TIME_T): Set to true or false, not to 1 or 0, since this is boolean and is not set via the command line. --- private.h | 26 +++++++++++++------------- strftime.c | 6 +++--- 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/private.h b/private.h index 6088d885..1e4e69a4 100644 --- a/private.h +++ b/private.h @@ -88,11 +88,11 @@ #if !defined HAVE_GETTEXT && defined __has_include # if __has_include(<libintl.h>) -# define HAVE_GETTEXT true +# define HAVE_GETTEXT 1 # endif #endif #ifndef HAVE_GETTEXT -# define HAVE_GETTEXT false +# define HAVE_GETTEXT 0 #endif #ifndef HAVE_INCOMPATIBLE_CTIME_R @@ -125,20 +125,20 @@ #if !defined HAVE_SYS_STAT_H && defined __has_include # if !__has_include(<sys/stat.h>) -# define HAVE_SYS_STAT_H false +# define HAVE_SYS_STAT_H 0 # endif #endif #ifndef HAVE_SYS_STAT_H -# define HAVE_SYS_STAT_H true +# define HAVE_SYS_STAT_H 1 #endif #if !defined HAVE_UNISTD_H && defined __has_include # if !__has_include(<unistd.h>) -# define HAVE_UNISTD_H false +# define HAVE_UNISTD_H 0 # endif #endif #ifndef HAVE_UNISTD_H -# define HAVE_UNISTD_H true +# define HAVE_UNISTD_H 1 #endif #ifndef NETBSD_INSPIRED @@ -312,7 +312,7 @@ ** stdint.h, even with pre-C99 compilers. */ #if !defined HAVE_STDINT_H && defined __has_include -# define HAVE_STDINT_H true /* C23 __has_include implies C99 stdint.h. */ +# define HAVE_STDINT_H 1 /* C23 __has_include implies C99 stdint.h. */ #endif #ifndef HAVE_STDINT_H # define HAVE_STDINT_H \ @@ -386,7 +386,7 @@ typedef int int_fast32_t; # ifdef LLONG_MAX typedef long long intmax_t; # ifndef HAVE_STRTOLL -# define HAVE_STRTOLL true +# define HAVE_STRTOLL 1 # endif # if HAVE_STRTOLL # define strtoimax strtoll @@ -466,7 +466,7 @@ typedef unsigned long uintmax_t; hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG. */ #if !defined HAVE_STDCKDINT_H && defined __has_include # if __has_include(<stdckdint.h>) -# define HAVE_STDCKDINT_H true +# define HAVE_STDCKDINT_H 1 # endif #endif #ifdef HAVE_STDCKDINT_H @@ -634,9 +634,9 @@ typedef unsigned long uintmax_t; ** typical platforms. */ #if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0 -# define TZ_TIME_T 1 +# define TZ_TIME_T true #else -# define TZ_TIME_T 0 +# define TZ_TIME_T false #endif #if defined LOCALTIME_IMPLEMENTATION && TZ_TIME_T @@ -753,9 +753,9 @@ void tzset(void); || defined __GLIBC__ || defined __tm_zone /* musl */ \ || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \ || (defined __APPLE__ && defined __MACH__)) -# define HAVE_DECL_TIMEGM true +# define HAVE_DECL_TIMEGM 1 # else -# define HAVE_DECL_TIMEGM false +# define HAVE_DECL_TIMEGM 0 # endif #endif #if !HAVE_DECL_TIMEGM && !defined timegm diff --git a/strftime.c b/strftime.c index fc0c87d2..487a5234 100644 --- a/strftime.c +++ b/strftime.c @@ -79,9 +79,9 @@ !defined __NetBSD_Version__ || __NetBSD_Version__ < 600000000) \ && (/* OpenBSD 5.5 (2014-05-01) and later has 64-bit time_t. */ \ !defined OpenBSD || OpenBSD < 201405))) -# define MKTIME_MIGHT_OVERFLOW true +# define MKTIME_MIGHT_OVERFLOW 1 # else -# define MKTIME_MIGHT_OVERFLOW false +# define MKTIME_MIGHT_OVERFLOW 0 # endif #endif /* Check that MKTIME_MIGHT_OVERFLOW is consistent with time_t's range. */ @@ -95,7 +95,7 @@ static_assert(MKTIME_MIGHT_OVERFLOW #endif #ifndef DEPRECATE_TWO_DIGIT_YEARS -# define DEPRECATE_TWO_DIGIT_YEARS false +# define DEPRECATE_TWO_DIGIT_YEARS 0 #endif struct lc_time_T { -- 2.43.0

1 1

[PROPOSED 1/2] Remove dependency of asctime on strftime
by Paul Eggert Nov. 28, 2024

Nov. 28, 2024

Also, remove calls to strlen and strcpy. * asctime.c (ASCTIME_FMT, ASCTIME_FMT_B): Remove; the strings are now merely literals in asctime_r. (SNPRINTF, SNPRINTFBUF): New macros. (asctime_r): Do not call strftime %Y, as this is dicey when tm_year is not a value that could be yielded by localtime. Instead, use snprintf, or sprintf on ancient hosts lacking snprintf. Also, rely on snprintf/sprintf's return value instead of calling strlen, as it's safe to assume C89 b6 now. If snprintf is available, output to the result buffer directly instead of to the stack and then copying. This saves one call to strftime, two calls to strlen, and one call to strcpy. * private.h (HAVE_SNPRINTF): Move here ... * zdump.c: ... from here. --- asctime.c | 96 +++++++++++++++++++++++++++++++------------------------ private.h | 4 +++ zdump.c | 4 --- 3 files changed, 58 insertions(+), 46 deletions(-) diff --git a/asctime.c b/asctime.c index f75ec868..7bc19fd1 100644 --- a/asctime.c +++ b/asctime.c @@ -7,6 +7,7 @@ /* ** Avoid the temptation to punt entirely to strftime; +** strftime can behave badly when tm components are out of range, and ** the output of strftime is supposed to be locale specific ** whereas the output of asctime is supposed to be constant. */ @@ -16,27 +17,6 @@ #include "private.h" #include <stdio.h> -/* -** All years associated with 32-bit time_t values are exactly four digits long; -** some years associated with 64-bit time_t values are not. -** Vintage programs are coded for years that are always four digits long -** and may assume that the newline always lands in the same place. -** For years that are less than four digits, we pad the output with -** leading zeroes to get the newline in the traditional place. -** The -4 ensures that we get four characters of output even if -** we call a strftime variant that produces fewer characters for some years. -** This conforms to recent ISO C and POSIX standards, which say behavior -** is undefined when the year is less than 1000 or greater than 9999. -*/ -static char const ASCTIME_FMT[] = "%s %s%3d %.2d:%.2d:%.2d %-4s\n"; -/* -** For years that are more than four digits we put extra spaces before the year -** so that code trying to overwrite the newline won't end up overwriting -** a digit within a year and truncating the year (operating on the assumption -** that no output is better than wrong output). -*/ -static char const ASCTIME_FMT_B[] = "%s %s%3d %.2d:%.2d:%.2d %s\n"; - enum { STD_ASCTIME_BUF_SIZE = 26 }; /* ** Big enough for something such as @@ -84,8 +64,20 @@ asctime_r(struct tm const *restrict timeptr, char *restrict buf) }; register const char * wn; register const char * mn; - char year[INT_STRLEN_MAXIMUM(int) + 2]; - char result[sizeof buf_asctime]; + int year, mday, hour, min, sec; + size_t bufsize = ((buf == buf_ctime + || (!SUPPORT_C89 && buf == buf_asctime)) + ? sizeof buf_asctime : STD_ASCTIME_BUF_SIZE); +#if HAVE_SNPRINTF + char *result = buf; +# define SNPRINTF snprintf +# define SNPRINTFBUF(buf, bufsize) buf, bufsize +#else + char stackbuf[sizeof buf_asctime]; + char *result = stackbuf; +# define SNPRINTF sprintf +# define SNPRINTFBUF(buf, bufsize) buf +#endif if (timeptr == NULL) { errno = EINVAL; @@ -97,26 +89,46 @@ asctime_r(struct tm const *restrict timeptr, char *restrict buf) if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR) mn = "???"; else mn = mon_name[timeptr->tm_mon]; - /* - ** Use strftime's %Y to generate the year, to avoid overflow problems - ** when computing timeptr->tm_year + TM_YEAR_BASE. - ** Assume that strftime is unaffected by other out-of-range members - ** (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, - timeptr->tm_mday, timeptr->tm_hour, - timeptr->tm_min, timeptr->tm_sec, - year); - if (strlen(result) < STD_ASCTIME_BUF_SIZE - || buf == buf_ctime || buf == buf_asctime) + + year = timeptr->tm_year; + mday = timeptr->tm_mday; + hour = timeptr->tm_hour; + min = timeptr->tm_min; + sec = timeptr->tm_sec; + + /* Vintage programs are coded for years that are always four bytes long + and may assume that the newline always lands in the same place. + For years that are less than four bytes, pad the output with + leading zeroes to get the newline in the traditional place. + For years longer than four bytes, put extra spaces before the year + so that vintage code trying to overwrite the newline + won't overwrite a digit within a year and truncate the year, + using the principle that no output is better than wrong output. + This conforms to ISO C and POSIX standards, which say behavior + is undefined when the year is less than 1000 or greater than 9999. + + Also, avoid overflow when formatting tm_year + TM_YEAR_BASE. */ + + if ((year <= INT_MAX - TM_YEAR_BASE + ? SNPRINTF (SNPRINTFBUF(result, bufsize), + ((-999 - TM_YEAR_BASE <= year + && year <= 9999 - TM_YEAR_BASE) + ? "%s %s%3d %.2d:%.2d:%.2d %04d\n" + : "%s %s%3d %.2d:%.2d:%.2d %d\n"), + wn, mn, mday, hour, min, sec, + year + TM_YEAR_BASE) + : SNPRINTF (SNPRINTFBUF(result, bufsize), + "%s %s%3d %.2d:%.2d:%.2d %d%d\n", + wn, mn, mday, hour, min, sec, + year / 10 + TM_YEAR_BASE / 10, + year % 10)) + < bufsize) { +#if HAVE_SNPRINTF + return buf; +#else return strcpy(buf, result); - else { +#endif + } else { errno = EOVERFLOW; return NULL; } diff --git a/private.h b/private.h index da6dc790..6088d885 100644 --- a/private.h +++ b/private.h @@ -263,6 +263,10 @@ # endif #endif +#ifndef HAVE_SNPRINTF +# define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__) +#endif + #ifndef HAVE_STRFTIME_L # if _POSIX_VERSION < 200809 # define HAVE_STRFTIME_L 0 diff --git a/zdump.c b/zdump.c index 2c6725e5..c988f6b3 100644 --- a/zdump.c +++ b/zdump.c @@ -14,10 +14,6 @@ #include "private.h" #include <stdio.h> -#ifndef HAVE_SNPRINTF -# define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__) -#endif - #ifndef HAVE_LOCALTIME_R # define HAVE_LOCALTIME_R 1 #endif -- 2.43.0

1 1

[PROPOSED 1/2] Move MKTIME_MIGHT_OVERFLOW definition
by Paul Eggert Nov. 27, 2024

Nov. 27, 2024

* private.h (MKTIME_FITS_IN, MKTIME_MIGHT_OVERFLOW): Move definitions from here ... * strftime.c: ... to here, as it’s the only file needing them. --- private.h | 49 ------------------------------------------------- strftime.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 49 deletions(-) diff --git a/private.h b/private.h index fc0b8755..95ab2e1d 100644 --- a/private.h +++ b/private.h @@ -914,55 +914,6 @@ enum { SIGNED_PADDING_CHECK_NEEDED = true }; static_assert(! TYPE_SIGNED(time_t) || ! SIGNED_PADDING_CHECK_NEEDED || TIME_T_MAX >> (TYPE_BIT(time_t) - 2) == 1); -/* If true, the value returned by an idealized unlimited-range mktime - always fits into an integer type with bounds MIN and MAX. - If false, the value might not fit. - This macro is usable in #if if its arguments are. - Add or subtract 2**31 - 1 for the maximum UT offset allowed in a TZif file, - divide by the maximum number of non-leap seconds in a year, - divide again by two just to be safe, - and account for the tm_year origin (1900) and time_t origin (1970). */ -#define MKTIME_FITS_IN(min, max) \ - ((min) < 0 \ - && ((min) + 0x7fffffff) / 366 / 24 / 60 / 60 / 2 + 1970 - 1900 < INT_MIN \ - && INT_MAX < ((max) - 0x7fffffff) / 366 / 24 / 60 / 60 / 2 + 1970 - 1900) - -/* MKTIME_MIGHT_OVERFLOW is true if mktime can fail due to time_t overflow - or if it is not known whether mktime can fail, - and is false if mktime definitely cannot fail. - This macro is usable in #if, and so does not use TIME_T_MAX or sizeof. - If the builder has not configured this macro, guess based on what - known platforms do. When in doubt, guess true. */ -#ifndef MKTIME_MIGHT_OVERFLOW -# if defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ -# include <sys/param.h> -# endif -# if ((/* The following heuristics assume native time_t. */ \ - defined_time_tz) \ - || ((/* Traditional time_t is 'long', so if 'long' is not wide enough \ - assume overflow unless we're on a known-safe host. */ \ - !MKTIME_FITS_IN(LONG_MIN, LONG_MAX)) \ - && (/* GNU C Library 2.29 (2019-02-01) and later has 64-bit time_t \ - if __TIMESIZE is 64. */ \ - !defined __TIMESIZE || __TIMESIZE < 64) \ - && (/* FreeBSD 12 r320347 (__FreeBSD_version 1200036; 2017-06-26), \ - and later has 64-bit time_t on all platforms but i386 which \ - is currently scheduled for end-of-life on 2028-11-30. */ \ - !defined __FreeBSD_version || __FreeBSD_version < 1200036 \ - || defined __i386) \ - && (/* NetBSD 6.0 (2012-10-17) and later has 64-bit time_t. */ \ - !defined __NetBSD_Version__ || __NetBSD_Version__ < 600000000) \ - && (/* OpenBSD 5.5 (2014-05-01) and later has 64-bit time_t. */ \ - !defined OpenBSD || OpenBSD < 201405))) -# define MKTIME_MIGHT_OVERFLOW true -# else -# define MKTIME_MIGHT_OVERFLOW false -# endif -#endif -/* Check that MKTIME_MIGHT_OVERFLOW is consistent with time_t's range. */ -static_assert(MKTIME_MIGHT_OVERFLOW - || MKTIME_FITS_IN(TIME_T_MIN, TIME_T_MAX)); - /* ** 302 / 1000 is log10(2.0) rounded up. ** Subtract one for the sign bit if the type is signed; diff --git a/strftime.c b/strftime.c index 7be94de3..fc0c87d2 100644 --- a/strftime.c +++ b/strftime.c @@ -39,6 +39,55 @@ #include <locale.h> #include <stdio.h> +/* If true, the value returned by an idealized unlimited-range mktime + always fits into an integer type with bounds MIN and MAX. + If false, the value might not fit. + This macro is usable in #if if its arguments are. + Add or subtract 2**31 - 1 for the maximum UT offset allowed in a TZif file, + divide by the maximum number of non-leap seconds in a year, + divide again by two just to be safe, + and account for the tm_year origin (1900) and time_t origin (1970). */ +#define MKTIME_FITS_IN(min, max) \ + ((min) < 0 \ + && ((min) + 0x7fffffff) / 366 / 24 / 60 / 60 / 2 + 1970 - 1900 < INT_MIN \ + && INT_MAX < ((max) - 0x7fffffff) / 366 / 24 / 60 / 60 / 2 + 1970 - 1900) + +/* MKTIME_MIGHT_OVERFLOW is true if mktime can fail due to time_t overflow + or if it is not known whether mktime can fail, + and is false if mktime definitely cannot fail. + This macro is usable in #if, and so does not use TIME_T_MAX or sizeof. + If the builder has not configured this macro, guess based on what + known platforms do. When in doubt, guess true. */ +#ifndef MKTIME_MIGHT_OVERFLOW +# if defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ +# include <sys/param.h> +# endif +# if ((/* The following heuristics assume native time_t. */ \ + defined_time_tz) \ + || ((/* Traditional time_t is 'long', so if 'long' is not wide enough \ + assume overflow unless we're on a known-safe host. */ \ + !MKTIME_FITS_IN(LONG_MIN, LONG_MAX)) \ + && (/* GNU C Library 2.29 (2019-02-01) and later has 64-bit time_t \ + if __TIMESIZE is 64. */ \ + !defined __TIMESIZE || __TIMESIZE < 64) \ + && (/* FreeBSD 12 r320347 (__FreeBSD_version 1200036; 2017-06-26), \ + and later has 64-bit time_t on all platforms but i386 which \ + is currently scheduled for end-of-life on 2028-11-30. */ \ + !defined __FreeBSD_version || __FreeBSD_version < 1200036 \ + || defined __i386) \ + && (/* NetBSD 6.0 (2012-10-17) and later has 64-bit time_t. */ \ + !defined __NetBSD_Version__ || __NetBSD_Version__ < 600000000) \ + && (/* OpenBSD 5.5 (2014-05-01) and later has 64-bit time_t. */ \ + !defined OpenBSD || OpenBSD < 201405))) +# define MKTIME_MIGHT_OVERFLOW true +# else +# define MKTIME_MIGHT_OVERFLOW false +# endif +#endif +/* Check that MKTIME_MIGHT_OVERFLOW is consistent with time_t's range. */ +static_assert(MKTIME_MIGHT_OVERFLOW + || MKTIME_FITS_IN(TIME_T_MIN, TIME_T_MAX)); + #if MKTIME_MIGHT_OVERFLOW /* Do this after system includes as it redefines time_t, mktime, timeoff. */ # define USE_TIMEX_T true -- 2.47.0

1 1

[PROPOSED 1/2] Pacify GCC 15ish -Wleading-whitespace=blanks
by Paul Eggert Nov. 27, 2024

Nov. 27, 2024

Normalize indentation in a few source files to pacify gcc -Wleading-whitespace=blanks (in the forthcoming GCC 15). --- localtime.c | 2 +- private.h | 2 +- zdump.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/localtime.c b/localtime.c index ea2a6fb8..e6d79d05 100644 --- a/localtime.c +++ b/localtime.c @@ -1770,7 +1770,7 @@ timesub(const time_t *timep, int_fast32_t offset, dayoff = offset / SECSPERDAY - corr / SECSPERDAY + rem / SECSPERDAY - 3; rem %= SECSPERDAY; /* y = (EPOCH_YEAR - + floor((tdays + dayoff) / DAYSPERREPEAT) * YEARSPERREPEAT), + + floor((tdays + dayoff) / DAYSPERREPEAT) * YEARSPERREPEAT), sans overflow. But calculate against 1570 (EPOCH_YEAR - YEARSPERREPEAT) instead of against 1970 so that things work for localtime values before 1970 when time_t is unsigned. */ diff --git a/private.h b/private.h index bdd00013..fc0b8755 100644 --- a/private.h +++ b/private.h @@ -897,7 +897,7 @@ ATTRIBUTE_PURE time_t time2posix_z(timezone_t, time_t); default: TIME_T_MAX_NO_PADDING) \ : (time_t) -1) enum { SIGNED_PADDING_CHECK_NEEDED - = _Generic((time_t) 0, + = _Generic((time_t) 0, signed char: false, short: false, int: false, long: false, long long: false, default: true) }; diff --git a/zdump.c b/zdump.c index b668022d..2c6725e5 100644 --- a/zdump.c +++ b/zdump.c @@ -687,7 +687,7 @@ yeartot(intmax_t y) return absolute_max_time; seconds = diff400 * SECSPER400YEARS; years = diff400 * 400; - } else { + } else { seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR; years = 1; } -- 2.43.0

1 1