<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>
#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
#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
%}
-/* 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 }
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
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)
{
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;
}
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;
+ 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;
+
+ 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;
+ }
- /* 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;
+ /* 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;
- tm0 = tm;
+ /* 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;
- Start = mktime (&tm);
+ tm0 = tm;
- if (Start == (time_t) -1)
- {
+ Start = mktime (&tm);
- /* 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)
+ 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;
}
- Start = mktime (&tm);
}
- if (Start == (time_t) -1)
- return false;
- }
-
- 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;
- }
+ 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 (pc.zones_seen)
- {
- long int delta = pc.time_zone * 60;
- time_t t1;
+ if (pc.zones_seen)
+ {
+ long int delta = pc.time_zone * 60;
+ time_t t1;
#ifdef HAVE_TM_GMTOFF
- delta -= tm.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);
+ 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))
- return false; /* time_t overflow */
- Start = t1;
+ t1 = Start - delta;
+ if ((Start < t1) != (delta < 0))
+ goto fail; /* time_t overflow */
+ Start = t1;
+ }
+
+ /* 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;
+ }
}
- /* 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;
- }
+ goto done;
+
+ 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
projects / pspp / commitdiff