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https://git.savannah.gnu.org/git/gnulib.git
synced 2025-08-16 01:22:18 +03:00
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.
This commit is contained in:
Paul Eggert
385
lib/getdate.y
385
lib/getdate.y
@@ -22,16 +22,13 @@
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<rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990.
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Modified by Paul Eggert <eggert@twinsun.com> in August 1999 to do
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the right thing about local DST, and in February 2004 to support
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nanosecond-resolution time stamps. Unlike previous versions, this
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version is reentrant. */
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the right thing about local DST. Also modified by Paul Eggert
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<eggert@cs.ucla.edu> in February 2004 to support
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nanosecond-resolution time stamps, and in October 2004 to support
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TZ strings in dates. */
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/* FIXME: Check for arithmetic overflow in all cases, not just
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some of them.
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FIXME: The current code uses 'int' to count seconds; it should use
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something like 'intmax_t' to support time stamps that don't fit in
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32 bits. */
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some of them. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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@@ -53,6 +50,11 @@
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#include <ctype.h>
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#include <limits.h>
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#include <stdlib.h>
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#include <string.h>
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#include "setenv.h"
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#include "xalloc.h"
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#if STDC_HEADERS || (! defined isascii && ! HAVE_ISASCII)
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# define IN_CTYPE_DOMAIN(c) 1
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@@ -63,19 +65,16 @@
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#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
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#define ISALPHA(c) (IN_CTYPE_DOMAIN (c) && isalpha (c))
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#define ISLOWER(c) (IN_CTYPE_DOMAIN (c) && islower (c))
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#define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))
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/* ISDIGIT differs from ISDIGIT_LOCALE, as follows:
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/* ISDIGIT differs from isdigit, as follows:
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- Its arg may be any int or unsigned int; it need not be an unsigned char.
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- It's guaranteed to evaluate its argument exactly once.
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- It's typically faster.
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POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
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ISDIGIT_LOCALE unless it's important to use the locale's definition
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isdigit unless it's important to use the locale's definition
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of `digit' even when the host does not conform to POSIX. */
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#define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
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#include <string.h>
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#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
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# define __attribute__(x)
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#endif
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@@ -167,7 +166,8 @@ static int yyerror (parser_control *, char *);
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%}
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/* We want a reentrant parser. */
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/* We want a reentrant parser, even if the TZ manipulation and the calls to
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localtime and gmtime are not reentrant. */
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%pure-parser
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%parse-param { parser_control *pc }
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%lex-param { parser_control *pc }
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@@ -990,6 +990,51 @@ yyerror (parser_control *pc ATTRIBUTE_UNUSED, char *s ATTRIBUTE_UNUSED)
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return 0;
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}
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/* If *TM0 is the old and *TM1 is the new value of a struct tm after
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passing it to mktime, return true if it's OK that mktime returned T.
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It's not OK if *TM0 has out-of-range members. */
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static bool
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mktime_ok (struct tm const *tm0, struct tm const *tm1, time_t t)
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{
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if (t == (time_t) -1)
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{
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/* Guard against falsely reporting an error when parsing a time
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stamp that happens to equal (time_t) -1, on a host that
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supports such a time stamp. */
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tm1 = localtime (&t);
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if (!tm1)
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return false;
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}
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return ! ((tm0->tm_sec ^ tm1->tm_sec)
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| (tm0->tm_min ^ tm1->tm_min)
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| (tm0->tm_hour ^ tm1->tm_hour)
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| (tm0->tm_mday ^ tm1->tm_mday)
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| (tm0->tm_mon ^ tm1->tm_mon)
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| (tm0->tm_year ^ tm1->tm_year));
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}
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/* A reasonable upper bound for the size of ordinary TZ strings.
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Use heap allocation if TZ's length exceeds this. */
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enum { TZBUFSIZE = 100 };
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/* Return a copy of TZ, stored in TZBUF if it fits, and heap-allocated
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otherwise. */
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static char *
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get_tz (char tzbuf[TZBUFSIZE])
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{
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char *tz = getenv ("TZ");
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if (tz)
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{
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size_t tzsize = strlen (tz) + 1;
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tz = (tzsize <= TZBUFSIZE
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? memcpy (tzbuf, tz, tzsize)
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: xmemdup (tz, tzsize));
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}
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return tz;
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}
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/* Parse a date/time string, storing the resulting time value into *RESULT.
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The string itself is pointed to by P. Return true if successful.
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P can be an incomplete or relative time specification; if so, use
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@@ -1004,6 +1049,11 @@ get_date (struct timespec *result, char const *p, struct timespec const *now)
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struct tm tm0;
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parser_control pc;
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struct timespec gettime_buffer;
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unsigned char c;
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bool tz_was_altered = false;
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char *tz0 = NULL;
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char tz0buf[TZBUFSIZE];
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bool ok = true;
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if (! now)
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{
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@@ -1019,6 +1069,44 @@ get_date (struct timespec *result, char const *p, struct timespec const *now)
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if (! tmp)
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return false;
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while (c = *p, ISSPACE (c))
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p++;
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if (strncmp (p, "TZ=\"", 4) == 0)
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{
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char const *tzbase = p + 4;
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size_t tzsize = 1;
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char const *s;
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for (s = tzbase; *s; s++, tzsize++)
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if (*s == '\\')
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{
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s++;
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if (! (*s == '\\' || *s == '"'))
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break;
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}
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else if (*s == '"')
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{
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char *z;
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char *tz1;
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char tz1buf[TZBUFSIZE];
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bool large_tz = TZBUFSIZE < tzsize;
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bool setenv_ok;
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tz0 = get_tz (tz0buf);
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z = tz1 = large_tz ? xmalloc (tzsize) : tz1buf;
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for (s = tzbase; *s != '"'; s++)
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*z++ = *(s += *s == '\\');
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*z = '\0';
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setenv_ok = setenv ("TZ", tz1, 1) == 0;
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if (large_tz)
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free (tz1);
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if (!setenv_ok)
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goto fail;
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tz_was_altered = true;
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p = s + 1;
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}
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}
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pc.input = p;
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pc.year.value = tmp->tm_year;
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pc.year.value += TM_YEAR_BASE;
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@@ -1106,142 +1194,173 @@ get_date (struct timespec *result, char const *p, struct timespec const *now)
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}
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if (yyparse (&pc) != 0)
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return false;
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goto fail;
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if (pc.timespec_seen)
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{
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*result = pc.seconds;
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return true;
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}
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if (1 < pc.times_seen || 1 < pc.dates_seen || 1 < pc.days_seen
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|| 1 < (pc.local_zones_seen + pc.zones_seen)
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|| (pc.local_zones_seen && 1 < pc.local_isdst))
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return false;
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tm.tm_year = to_year (pc.year) - TM_YEAR_BASE + pc.rel_year;
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tm.tm_mon = pc.month - 1 + pc.rel_month;
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tm.tm_mday = pc.day + pc.rel_day;
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if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen))
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{
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tm.tm_hour = to_hour (pc.hour, pc.meridian);
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if (tm.tm_hour < 0)
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return false;
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tm.tm_min = pc.minutes;
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tm.tm_sec = pc.seconds.tv_sec;
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}
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*result = pc.seconds;
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else
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{
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tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
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pc.seconds.tv_nsec = 0;
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}
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if (1 < pc.times_seen || 1 < pc.dates_seen || 1 < pc.days_seen
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|| 1 < (pc.local_zones_seen + pc.zones_seen)
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|| (pc.local_zones_seen && 1 < pc.local_isdst))
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goto fail;
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/* Let mktime deduce tm_isdst if we have an absolute time stamp,
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or if the relative time stamp mentions days, months, or years. */
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if (pc.dates_seen | pc.days_seen | pc.times_seen | pc.rel_day
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| pc.rel_month | pc.rel_year)
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tm.tm_isdst = -1;
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/* But if the input explicitly specifies local time with or without
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DST, give mktime that information. */
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if (pc.local_zones_seen)
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tm.tm_isdst = pc.local_isdst;
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tm0 = tm;
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Start = mktime (&tm);
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if (Start == (time_t) -1)
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{
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/* Guard against falsely reporting errors near the time_t boundaries
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when parsing times in other time zones. For example, if the min
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time_t value is 1970-01-01 00:00:00 UTC and we are 8 hours ahead
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of UTC, then the min localtime value is 1970-01-01 08:00:00; if
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we apply mktime to 1970-01-01 00:00:00 we will get an error, so
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we apply mktime to 1970-01-02 08:00:00 instead and adjust the time
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zone by 24 hours to compensate. This algorithm assumes that
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there is no DST transition within a day of the time_t boundaries. */
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if (pc.zones_seen)
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tm.tm_year = to_year (pc.year) - TM_YEAR_BASE;
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tm.tm_mon = pc.month - 1;
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tm.tm_mday = pc.day;
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if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen))
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{
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tm = tm0;
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if (tm.tm_year <= EPOCH_YEAR - TM_YEAR_BASE)
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{
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tm.tm_mday++;
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pc.time_zone += 24 * 60;
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}
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else
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{
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tm.tm_mday--;
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pc.time_zone -= 24 * 60;
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}
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Start = mktime (&tm);
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tm.tm_hour = to_hour (pc.hour, pc.meridian);
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if (tm.tm_hour < 0)
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goto fail;
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tm.tm_min = pc.minutes;
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tm.tm_sec = pc.seconds.tv_sec;
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}
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else
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{
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tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
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pc.seconds.tv_nsec = 0;
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}
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if (Start == (time_t) -1)
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return false;
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}
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/* Let mktime deduce tm_isdst if we have an absolute time stamp. */
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if (pc.dates_seen | pc.days_seen | pc.times_seen)
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tm.tm_isdst = -1;
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/* But if the input explicitly specifies local time with or without
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DST, give mktime that information. */
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if (pc.local_zones_seen)
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tm.tm_isdst = pc.local_isdst;
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tm0 = tm;
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if (pc.days_seen && ! pc.dates_seen)
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{
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tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7
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+ 7 * (pc.day_ordinal - (0 < pc.day_ordinal)));
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tm.tm_isdst = -1;
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Start = mktime (&tm);
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if (Start == (time_t) -1)
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return false;
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}
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if (pc.zones_seen)
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{
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long int delta = pc.time_zone * 60;
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time_t t1;
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if (! mktime_ok (&tm0, &tm, Start))
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{
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if (! pc.zones_seen)
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goto fail;
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else
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{
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/* Guard against falsely reporting errors near the time_t
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boundaries when parsing times in other time zones. For
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example, suppose the input string "1969-12-31 23:00:00 -0100",
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the current time zone is 8 hours ahead of UTC, and the min
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time_t value is 1970-01-01 00:00:00 UTC. Then the min
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localtime value is 1970-01-01 08:00:00, and mktime will
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therefore fail on 1969-12-31 23:00:00. To work around the
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problem, set the time zone to 1 hour behind UTC temporarily
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by setting TZ="XXX1:00" and try mktime again. */
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long int time_zone = pc.time_zone;
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long int abs_time_zone = time_zone < 0 ? - time_zone : time_zone;
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long int abs_time_zone_hour = abs_time_zone / 60;
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int abs_time_zone_min = abs_time_zone % 60;
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char tz1buf[sizeof "XXX+0:00"
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+ sizeof pc.time_zone * CHAR_BIT / 3];
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if (!tz_was_altered)
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tz0 = get_tz (tz0buf);
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sprintf (tz1buf, "XXX%s%ld:%02d", "-" + (time_zone < 0),
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abs_time_zone_hour, abs_time_zone_min);
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if (setenv ("TZ", tz1buf, 1) != 0)
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goto fail;
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tz_was_altered = true;
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tm = tm0;
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Start = mktime (&tm);
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if (! mktime_ok (&tm0, &tm, Start))
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goto fail;
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}
|
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}
|
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|
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if (pc.days_seen && ! pc.dates_seen)
|
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{
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tm.tm_mday += ((pc.day_number - tm.tm_wday + 7) % 7
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+ 7 * (pc.day_ordinal - (0 < pc.day_ordinal)));
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tm.tm_isdst = -1;
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Start = mktime (&tm);
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if (Start == (time_t) -1)
|
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goto fail;
|
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}
|
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|
||||
if (pc.zones_seen)
|
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{
|
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long int delta = pc.time_zone * 60;
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time_t t1;
|
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#ifdef HAVE_TM_GMTOFF
|
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delta -= tm.tm_gmtoff;
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delta -= tm.tm_gmtoff;
|
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#else
|
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time_t t = Start;
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struct tm const *gmt = gmtime (&t);
|
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if (! gmt)
|
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return false;
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delta -= tm_diff (&tm, gmt);
|
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time_t t = Start;
|
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struct tm const *gmt = gmtime (&t);
|
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if (! gmt)
|
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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;
|
||||
goto done;
|
||||
|
||||
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
|
||||
|
||||
Reference in New Issue
Block a user