Mercurial > hg > octave-lojdl > gnulib-hg
changeset 5373:2169bf8a12fc
Add support for TZ="foo" within a date string.
Fix some bugs near time_t boundaries. Reject dates with
out-of-range components, e.g., "Sept 31".
Include <stdlib.h>, "setenv.h", "xalloc.h".
(ISDIGIT_LOCALE): Remove; unused.
Note that the TZ and time functions used here are not reentrant.
(mktime_ok, get_tz): New functions.
(TZBUFSIZE): New constant.
(get_date): Parse leading TZ="foo". Reject out-of-range components;.
This requires that we sometimes generate our own TZ="XXX..." setting.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Fri, 29 Oct 2004 20:59:53 +0000 |
parents | 7985d9b0b731 |
children | 145d10b97661 |
files | lib/getdate.y |
diffstat | 1 files changed, 252 insertions(+), 133 deletions(-) [+] |
line wrap: on
line diff
--- a/lib/getdate.y +++ b/lib/getdate.y @@ -22,16 +22,13 @@ <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990. Modified by Paul Eggert <eggert@twinsun.com> in August 1999 to do - the right thing about local DST, and in February 2004 to support - nanosecond-resolution time stamps. Unlike previous versions, this - version is reentrant. */ + the right thing about local DST. Also modified by Paul Eggert + <eggert@cs.ucla.edu> in February 2004 to support + nanosecond-resolution time stamps, and in October 2004 to support + TZ strings in dates. */ /* FIXME: Check for arithmetic overflow in all cases, not just - some of them. - - FIXME: The current code uses 'int' to count seconds; it should use - something like 'intmax_t' to support time stamps that don't fit in - 32 bits. */ + some of them. */ #ifdef HAVE_CONFIG_H # include <config.h> @@ -53,6 +50,11 @@ #include <ctype.h> #include <limits.h> +#include <stdlib.h> +#include <string.h> + +#include "setenv.h" +#include "xalloc.h" #if STDC_HEADERS || (! defined isascii && ! HAVE_ISASCII) # define IN_CTYPE_DOMAIN(c) 1 @@ -63,19 +65,16 @@ #define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c)) #define ISALPHA(c) (IN_CTYPE_DOMAIN (c) && isalpha (c)) #define ISLOWER(c) (IN_CTYPE_DOMAIN (c) && islower (c)) -#define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c)) -/* ISDIGIT differs from ISDIGIT_LOCALE, as follows: +/* ISDIGIT differs from isdigit, as follows: - Its arg may be any int or unsigned int; it need not be an unsigned char. - It's guaranteed to evaluate its argument exactly once. - It's typically faster. POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to - ISDIGIT_LOCALE unless it's important to use the locale's definition + isdigit unless it's important to use the locale's definition of `digit' even when the host does not conform to POSIX. */ #define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9) -#include <string.h> - #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ # define __attribute__(x) #endif @@ -167,7 +166,8 @@ %} -/* We want a reentrant parser. */ +/* We want a reentrant parser, even if the TZ manipulation and the calls to + localtime and gmtime are not reentrant. */ %pure-parser %parse-param { parser_control *pc } %lex-param { parser_control *pc } @@ -990,6 +990,51 @@ return 0; } +/* If *TM0 is the old and *TM1 is the new value of a struct tm after + passing it to mktime, return true if it's OK that mktime returned T. + It's not OK if *TM0 has out-of-range members. */ + +static bool +mktime_ok (struct tm const *tm0, struct tm const *tm1, time_t t) +{ + if (t == (time_t) -1) + { + /* Guard against falsely reporting an error when parsing a time + stamp that happens to equal (time_t) -1, on a host that + supports such a time stamp. */ + tm1 = localtime (&t); + if (!tm1) + return false; + } + + return ! ((tm0->tm_sec ^ tm1->tm_sec) + | (tm0->tm_min ^ tm1->tm_min) + | (tm0->tm_hour ^ tm1->tm_hour) + | (tm0->tm_mday ^ tm1->tm_mday) + | (tm0->tm_mon ^ tm1->tm_mon) + | (tm0->tm_year ^ tm1->tm_year)); +} + +/* A reasonable upper bound for the size of ordinary TZ strings. + Use heap allocation if TZ's length exceeds this. */ +enum { TZBUFSIZE = 100 }; + +/* Return a copy of TZ, stored in TZBUF if it fits, and heap-allocated + otherwise. */ +static char * +get_tz (char tzbuf[TZBUFSIZE]) +{ + char *tz = getenv ("TZ"); + if (tz) + { + size_t tzsize = strlen (tz) + 1; + tz = (tzsize <= TZBUFSIZE + ? memcpy (tzbuf, tz, tzsize) + : xmemdup (tz, tzsize)); + } + return tz; +} + /* Parse a date/time string, storing the resulting time value into *RESULT. The string itself is pointed to by P. Return true if successful. P can be an incomplete or relative time specification; if so, use @@ -1004,6 +1049,11 @@ struct tm tm0; parser_control pc; struct timespec gettime_buffer; + unsigned char c; + bool tz_was_altered = false; + char *tz0 = NULL; + char tz0buf[TZBUFSIZE]; + bool ok = true; if (! now) { @@ -1019,6 +1069,44 @@ if (! tmp) return false; + while (c = *p, ISSPACE (c)) + p++; + + if (strncmp (p, "TZ=\"", 4) == 0) + { + char const *tzbase = p + 4; + size_t tzsize = 1; + char const *s; + + for (s = tzbase; *s; s++, tzsize++) + if (*s == '\\') + { + s++; + if (! (*s == '\\' || *s == '"')) + break; + } + else if (*s == '"') + { + char *z; + char *tz1; + char tz1buf[TZBUFSIZE]; + bool large_tz = TZBUFSIZE < tzsize; + bool setenv_ok; + tz0 = get_tz (tz0buf); + z = tz1 = large_tz ? xmalloc (tzsize) : tz1buf; + for (s = tzbase; *s != '"'; s++) + *z++ = *(s += *s == '\\'); + *z = '\0'; + setenv_ok = setenv ("TZ", tz1, 1) == 0; + if (large_tz) + free (tz1); + if (!setenv_ok) + goto fail; + tz_was_altered = true; + p = s + 1; + } + } + pc.input = p; pc.year.value = tmp->tm_year; pc.year.value += TM_YEAR_BASE; @@ -1106,142 +1194,173 @@ } if (yyparse (&pc) != 0) - return false; + goto fail; if (pc.timespec_seen) - { - *result = pc.seconds; - return true; - } - - if (1 < pc.times_seen || 1 < pc.dates_seen || 1 < pc.days_seen - || 1 < (pc.local_zones_seen + pc.zones_seen) - || (pc.local_zones_seen && 1 < pc.local_isdst)) - return false; - - tm.tm_year = to_year (pc.year) - TM_YEAR_BASE + pc.rel_year; - tm.tm_mon = pc.month - 1 + pc.rel_month; - tm.tm_mday = pc.day + pc.rel_day; - if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen)) - { - tm.tm_hour = to_hour (pc.hour, pc.meridian); - if (tm.tm_hour < 0) - return false; - tm.tm_min = pc.minutes; - tm.tm_sec = pc.seconds.tv_sec; - } + *result = pc.seconds; else { - tm.tm_hour = tm.tm_min = tm.tm_sec = 0; - pc.seconds.tv_nsec = 0; - } - - /* Let mktime deduce tm_isdst if we have an absolute time stamp, - or if the relative time stamp mentions days, months, or years. */ - if (pc.dates_seen | pc.days_seen | pc.times_seen | pc.rel_day - | pc.rel_month | pc.rel_year) - tm.tm_isdst = -1; - - /* But if the input explicitly specifies local time with or without - DST, give mktime that information. */ - if (pc.local_zones_seen) - tm.tm_isdst = pc.local_isdst; - - tm0 = tm; - - Start = mktime (&tm); + if (1 < pc.times_seen || 1 < pc.dates_seen || 1 < pc.days_seen + || 1 < (pc.local_zones_seen + pc.zones_seen) + || (pc.local_zones_seen && 1 < pc.local_isdst)) + goto fail; - if (Start == (time_t) -1) - { + tm.tm_year = to_year (pc.year) - TM_YEAR_BASE; + tm.tm_mon = pc.month - 1; + tm.tm_mday = pc.day; + if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen)) + { + tm.tm_hour = to_hour (pc.hour, pc.meridian); + if (tm.tm_hour < 0) + goto fail; + tm.tm_min = pc.minutes; + tm.tm_sec = pc.seconds.tv_sec; + } + else + { + tm.tm_hour = tm.tm_min = tm.tm_sec = 0; + pc.seconds.tv_nsec = 0; + } - /* Guard against falsely reporting errors near the time_t boundaries - when parsing times in other time zones. For example, if the min - time_t value is 1970-01-01 00:00:00 UTC and we are 8 hours ahead - of UTC, then the min localtime value is 1970-01-01 08:00:00; if - we apply mktime to 1970-01-01 00:00:00 we will get an error, so - we apply mktime to 1970-01-02 08:00:00 instead and adjust the time - zone by 24 hours to compensate. This algorithm assumes that - there is no DST transition within a day of the time_t boundaries. */ - if (pc.zones_seen) + /* Let mktime deduce tm_isdst if we have an absolute time stamp. */ + if (pc.dates_seen | pc.days_seen | pc.times_seen) + tm.tm_isdst = -1; + + /* But if the input explicitly specifies local time with or without + DST, give mktime that information. */ + if (pc.local_zones_seen) + tm.tm_isdst = pc.local_isdst; + + tm0 = tm; + + Start = mktime (&tm); + + if (! mktime_ok (&tm0, &tm, Start)) { - tm = tm0; - if (tm.tm_year <= EPOCH_YEAR - TM_YEAR_BASE) - { - tm.tm_mday++; - pc.time_zone += 24 * 60; - } + if (! pc.zones_seen) + goto fail; else { - tm.tm_mday--; - pc.time_zone -= 24 * 60; + /* Guard against falsely reporting errors near the time_t + boundaries when parsing times in other time zones. For + example, suppose the input string "1969-12-31 23:00:00 -0100", + the current time zone is 8 hours ahead of UTC, and the min + time_t value is 1970-01-01 00:00:00 UTC. Then the min + localtime value is 1970-01-01 08:00:00, and mktime will + therefore fail on 1969-12-31 23:00:00. To work around the + problem, set the time zone to 1 hour behind UTC temporarily + by setting TZ="XXX1:00" and try mktime again. */ + + long int time_zone = pc.time_zone; + long int abs_time_zone = time_zone < 0 ? - time_zone : time_zone; + long int abs_time_zone_hour = abs_time_zone / 60; + int abs_time_zone_min = abs_time_zone % 60; + char tz1buf[sizeof "XXX+0:00" + + sizeof pc.time_zone * CHAR_BIT / 3]; + if (!tz_was_altered) + tz0 = get_tz (tz0buf); + sprintf (tz1buf, "XXX%s%ld:%02d", "-" + (time_zone < 0), + abs_time_zone_hour, abs_time_zone_min); + if (setenv ("TZ", tz1buf, 1) != 0) + goto fail; + tz_was_altered = true; + tm = tm0; + Start = mktime (&tm); + if (! mktime_ok (&tm0, &tm, Start)) + goto fail; } + } + + if (pc.days_seen && ! pc.dates_seen) + { + tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7 + + 7 * (pc.day_ordinal - (0 < pc.day_ordinal))); + tm.tm_isdst = -1; Start = mktime (&tm); + if (Start == (time_t) -1) + goto fail; } - if (Start == (time_t) -1) - return false; - } + if (pc.zones_seen) + { + long int delta = pc.time_zone * 60; + time_t t1; +#ifdef HAVE_TM_GMTOFF + delta -= tm.tm_gmtoff; +#else + time_t t = Start; + struct tm const *gmt = gmtime (&t); + if (! gmt) + goto fail; + delta -= tm_diff (&tm, gmt); +#endif + t1 = Start - delta; + if ((Start < t1) != (delta < 0)) + goto fail; /* time_t overflow */ + Start = t1; + } - if (pc.days_seen && ! pc.dates_seen) - { - tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7 - + 7 * (pc.day_ordinal - (0 < pc.day_ordinal))); - tm.tm_isdst = -1; - Start = mktime (&tm); - if (Start == (time_t) -1) - return false; + /* Add relative date. */ + if (pc.rel_year | pc.rel_month | pc.rel_day) + { + int year = tm.tm_year + pc.rel_year; + int month = tm.tm_mon + pc.rel_month; + int day = tm.tm_mday + pc.rel_day; + if (((year < tm.tm_year) ^ (pc.rel_year < 0)) + | (month < tm.tm_mon) ^ (pc.rel_month < 0) + | (day < tm.tm_mday) ^ (pc.rel_day < 0)) + goto fail; + tm.tm_year = year; + tm.tm_mon = month; + tm.tm_mday = day; + Start = mktime (&tm); + if (Start == (time_t) -1) + goto fail; + } + + /* Add relative hours, minutes, and seconds. On hosts that support + leap seconds, ignore the possibility of leap seconds; e.g., + "+ 10 minutes" adds 600 seconds, even if one of them is a + leap second. Typically this is not what the user wants, but it's + too hard to do it the other way, because the time zone indicator + must be applied before relative times, and if mktime is applied + again the time zone will be lost. */ + { + long int sum_ns = pc.seconds.tv_nsec + pc.rel_ns; + long int normalized_ns = (sum_ns % BILLION + BILLION) % BILLION; + time_t t0 = Start; + long int d1 = 60 * 60 * pc.rel_hour; + time_t t1 = t0 + d1; + long int d2 = 60 * pc.rel_minutes; + time_t t2 = t1 + d2; + long int d3 = pc.rel_seconds; + time_t t3 = t2 + d3; + long int d4 = (sum_ns - normalized_ns) / BILLION; + time_t t4 = t3 + d4; + + if ((d1 / (60 * 60) ^ pc.rel_hour) + | (d2 / 60 ^ pc.rel_minutes) + | ((t1 < t0) ^ (d1 < 0)) + | ((t2 < t1) ^ (d2 < 0)) + | ((t3 < t2) ^ (d3 < 0)) + | ((t4 < t3) ^ (d4 < 0))) + goto fail; + + result->tv_sec = t4; + result->tv_nsec = normalized_ns; + } } - if (pc.zones_seen) - { - long int delta = pc.time_zone * 60; - time_t t1; -#ifdef HAVE_TM_GMTOFF - delta -= tm.tm_gmtoff; -#else - time_t t = Start; - struct tm const *gmt = gmtime (&t); - if (! gmt) - return false; - delta -= tm_diff (&tm, gmt); -#endif - t1 = Start - delta; - if ((Start < t1) != (delta < 0)) - return false; /* time_t overflow */ - Start = t1; - } + goto done; - /* Add relative hours, minutes, and seconds. Ignore leap seconds; - i.e. "+ 10 minutes" means 600 seconds, even if one of them is a - leap second. Typically this is not what the user wants, but it's - too hard to do it the other way, because the time zone indicator - must be applied before relative times, and if mktime is applied - again the time zone will be lost. */ - { - long int sum_ns = pc.seconds.tv_nsec + pc.rel_ns; - long int normalized_ns = (sum_ns % BILLION + BILLION) % BILLION; - time_t t0 = Start; - long int d1 = 60 * 60 * pc.rel_hour; - time_t t1 = t0 + d1; - long int d2 = 60 * pc.rel_minutes; - time_t t2 = t1 + d2; - long int d3 = pc.rel_seconds; - time_t t3 = t2 + d3; - long int d4 = (sum_ns - normalized_ns) / BILLION; - time_t t4 = t3 + d4; - - if ((d1 / (60 * 60) ^ pc.rel_hour) - | (d2 / 60 ^ pc.rel_minutes) - | ((t1 < t0) ^ (d1 < 0)) - | ((t2 < t1) ^ (d2 < 0)) - | ((t3 < t2) ^ (d3 < 0)) - | ((t4 < t3) ^ (d4 < 0))) - return false; - - result->tv_sec = t4; - result->tv_nsec = normalized_ns; - return true; - } + fail: + ok = false; + done: + if (tz_was_altered) + ok &= (tz0 ? setenv ("TZ", tz0, 1) : unsetenv ("TZ")) == 0; + if (tz0 != tz0buf) + free (tz0); + return ok; } #if TEST