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util-linux/lib/parse-date.y

1645 lines
41 KiB

%{
/**
* Parse a string into an internal timestamp.
*
* This file is based on gnulib parse-datetime.y-dd7a871 with
* the other gnulib dependencies removed for use in util-linux.
*
* Copyright (C) 1999-2000, 2002-2017 Free Software Foundation, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Originally written by Steven M. Bellovin <smb@research.att.com> while
* at the University of North Carolina at Chapel Hill. Later tweaked by
* a couple of people on Usenet. Completely overhauled by Rich $alz
* <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. Also modified by Paul Eggert
* <eggert@cs.ucla.edu> in February 2004 to support
* nanosecond-resolution timestamps, and in October 2004 to support
* TZ strings in dates.
*/
/**
* FIXME: Check for arithmetic overflow in all cases, not just
* some of them.
*/
#include <sys/time.h>
#include <time.h>
#include "c.h"
#include "timeutils.h"
/**
* There's no need to extend the stack, so there's no need to involve
* alloca.
*/
#define YYSTACK_USE_ALLOCA 0
/**
* Tell Bison how much stack space is needed. 20 should be plenty for
* this grammar, which is not right recursive. Beware setting it too
* high, since that might cause problems on machines whose
* implementations have lame stack-overflow checking.
*/
#define YYMAXDEPTH 20
#define YYINITDEPTH YYMAXDEPTH
/**
* Since the code of parse-datetime.y is not included in the Emacs executable
* itself, there is no need to #define static in this file. Even if
* the code were included in the Emacs executable, it probably
* wouldn't do any harm to #undef it here; this will only cause
* problems if we try to write to a static variable, which I don't
* think this code needs to do.
*/
#ifdef emacs
# undef static
#endif
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "cctype.h"
#include "nls.h"
#include "xalloc.h"
/**
* Bison's skeleton tests _STDLIB_H, while some stdlib.h headers
* use _STDLIB_H_ as witness. Map the latter to the one bison uses.
* FIXME: this is temporary. Remove when we have a mechanism to ensure
* that the version we're using is fixed, too.
*/
#ifdef _STDLIB_H_
# undef _STDLIB_H
# define _STDLIB_H 1
#endif
/**
* ISDIGIT differs from isdigit, as follows:
* - Its arg may be any int or unsigned int; it need not be an unsigned char
* or EOF.
* - It's typically faster.
* POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
* 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)
/**
* Shift A right by B bits portably, by dividing A by 2**B and
* truncating towards minus infinity. A and B should be free of side
* effects, and B should be in the range 0 <= B <= INT_BITS - 2, where
* INT_BITS is the number of useful bits in an int. GNU code can
* assume that INT_BITS is at least 32.
*
* ISO C99 says that A >> B is implementation-defined if A < 0. Some
* implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift
* right in the usual way when A < 0, so SHR falls back on division if
* ordinary A >> B doesn't seem to be the usual signed shift.
*/
#define SHR(a, b) \
(-1 >> 1 == -1 \
? (a) >> (b) \
: (a) / (1 << (b)) - ((a) % (1 << (b)) < 0))
#define EPOCH_YEAR 1970
#define TM_YEAR_BASE 1900
#define HOUR(x) ((x) * 60)
#define STREQ(a, b) (strcmp (a, b) == 0)
/**
* Convert a possibly-signed character to an unsigned character. This is
* a bit safer than casting to unsigned char, since it catches some type
* errors that the cast doesn't.
*/
static unsigned char to_uchar (char ch) { return ch; }
/**
* FIXME: It also assumes that signed integer overflow silently wraps around,
* but this is not true any more with recent versions of GCC 4.
*/
/**
* An integer value, and the number of digits in its textual
* representation.
*/
typedef struct {
int negative;
long int value;
size_t digits;
} textint;
/* An entry in the lexical lookup table. */
typedef struct {
char const *name;
int type;
int value;
} table;
/* Meridian: am, pm, or 24-hour style. */
enum { MERam, MERpm, MER24 };
enum { BILLION = 1000000000, LOG10_BILLION = 9 };
/* Relative year, month, day, hour, minutes, seconds, and nanoseconds. */
typedef struct {
long int year;
long int month;
long int day;
long int hour;
long int minutes;
time_t seconds;
long int ns;
} relative_time;
#if HAVE_COMPOUND_LITERALS
# define RELATIVE_TIME_0 ((relative_time) { 0, 0, 0, 0, 0, 0, 0 })
#else
static relative_time const RELATIVE_TIME_0;
#endif
/* Information passed to and from the parser. */
typedef struct {
/* The input string remaining to be parsed. */
const char *input;
/* N, if this is the Nth Tuesday. */
long int day_ordinal;
/* Day of week; Sunday is 0. */
int day_number;
/* tm_isdst flag for the local zone. */
int local_isdst;
/* Time zone, in minutes east of UTC. */
long int time_zone;
/* Style used for time. */
int meridian;
/* Gregorian year, month, day, hour, minutes, seconds, and ns. */
textint year;
long int month;
long int day;
long int hour;
long int minutes;
struct timespec seconds; /* includes nanoseconds */
/* Relative year, month, day, hour, minutes, seconds, and ns. */
relative_time rel;
/* Presence or counts of some nonterminals parsed so far. */
int timespec_seen;
int rels_seen;
size_t dates_seen;
size_t days_seen;
size_t local_zones_seen;
size_t dsts_seen;
size_t times_seen;
size_t zones_seen;
size_t year_seen;
/* 1 if the user specified explicit ordinal day value, */
int ordinal_day_seen;
/* Table of local time zone abbreviations, null terminated. */
table local_time_zone_table[3];
} parser_control;
union YYSTYPE;
static int yylex (union YYSTYPE *, parser_control *);
static int yyerror (parser_control const *, char const *);
static long int time_zone_hhmm (parser_control *, textint, long int);
/**
* Extract into *PC any date and time info from a string of digits
* of the form e.g., YYYYMMDD, YYMMDD, HHMM, HH (and sometimes YYY,
* YYYY, ...).
*/
static void digits_to_date_time(parser_control *pc, textint text_int)
{
if (pc->dates_seen && ! pc->year.digits
&& ! pc->rels_seen && (pc->times_seen || 2 < text_int.digits)) {
pc->year_seen++;
pc->year = text_int;
} else {
if (4 < text_int.digits) {
pc->dates_seen++;
pc->day = text_int.value % 100;
pc->month = (text_int.value / 100) % 100;
pc->year.value = text_int.value / 10000;
pc->year.digits = text_int.digits - 4;
} else {
pc->times_seen++;
if (text_int.digits <= 2) {
pc->hour = text_int.value;
pc->minutes = 0;
}
else {
pc->hour = text_int.value / 100;
pc->minutes = text_int.value % 100;
}
pc->seconds.tv_sec = 0;
pc->seconds.tv_nsec = 0;
pc->meridian = MER24;
}
}
}
/* Increment PC->rel by FACTOR * REL (FACTOR is 1 or -1). */
static void apply_relative_time(parser_control *pc, relative_time rel,
int factor)
{
pc->rel.ns += factor * rel.ns;
pc->rel.seconds += factor * rel.seconds;
pc->rel.minutes += factor * rel.minutes;
pc->rel.hour += factor * rel.hour;
pc->rel.day += factor * rel.day;
pc->rel.month += factor * rel.month;
pc->rel.year += factor * rel.year;
pc->rels_seen = 1;
}
/* Set PC-> hour, minutes, seconds and nanoseconds members from arguments. */
static void
set_hhmmss(parser_control *pc, long int hour, long int minutes,
time_t sec, long int nsec)
{
pc->hour = hour;
pc->minutes = minutes;
pc->seconds.tv_sec = sec;
pc->seconds.tv_nsec = nsec;
}
%}
/**
* 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 }
/* This grammar has 31 shift/reduce conflicts. */
%expect 31
%union {
long int intval;
textint textintval;
struct timespec timespec;
relative_time rel;
}
%token <intval> tAGO
%token tDST
%token tYEAR_UNIT tMONTH_UNIT tHOUR_UNIT tMINUTE_UNIT tSEC_UNIT
%token <intval> tDAY_UNIT tDAY_SHIFT
%token <intval> tDAY tDAYZONE tLOCAL_ZONE tMERIDIAN
%token <intval> tMONTH tORDINAL tZONE
%token <textintval> tSNUMBER tUNUMBER
%token <timespec> tSDECIMAL_NUMBER tUDECIMAL_NUMBER
%type <intval> o_colon_minutes
%type <timespec> seconds signed_seconds unsigned_seconds
%type <rel> relunit relunit_snumber dayshift
%%
spec:
timespec
| items
;
timespec:
'@' seconds {
pc->seconds = $2;
pc->timespec_seen = 1;
}
;
items:
/* empty */
| items item
;
item:
datetime {
pc->times_seen++; pc->dates_seen++;
}
| time {
pc->times_seen++;
}
| local_zone {
pc->local_zones_seen++;
}
| zone {
pc->zones_seen++;
}
| date {
pc->dates_seen++;
}
| day {
pc->days_seen++;
}
| rel
| number
| hybrid
;
datetime:
iso_8601_datetime
;
iso_8601_datetime:
iso_8601_date 'T' iso_8601_time
;
time:
tUNUMBER tMERIDIAN {
set_hhmmss (pc, $1.value, 0, 0, 0);
pc->meridian = $2;
}
| tUNUMBER ':' tUNUMBER tMERIDIAN {
set_hhmmss (pc, $1.value, $3.value, 0, 0);
pc->meridian = $4;
}
| tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN {
set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
pc->meridian = $6;
}
| iso_8601_time
;
iso_8601_time:
tUNUMBER zone_offset {
set_hhmmss (pc, $1.value, 0, 0, 0);
pc->meridian = MER24;
}
| tUNUMBER ':' tUNUMBER o_zone_offset {
set_hhmmss (pc, $1.value, $3.value, 0, 0);
pc->meridian = MER24;
}
| tUNUMBER ':' tUNUMBER ':' unsigned_seconds o_zone_offset {
set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
pc->meridian = MER24;
}
;
o_zone_offset:
/* empty */
| zone_offset
;
zone_offset:
tSNUMBER o_colon_minutes {
pc->zones_seen++;
pc->time_zone = time_zone_hhmm (pc, $1, $2);
}
;
/**
* Local zone strings only affect DST setting,
* and only take affect if the current TZ setting is relevant.
*
* Example 1:
* 'EEST' is parsed as tLOCAL_ZONE, as it relates to the effective TZ:
* TZ=Europe/Helsinki date -d '2016-12-30 EEST'
*
* Example 2:
* 'EEST' is parsed as 'zone' (TZ=+03:00):
* TZ=Asia/Tokyo ./src/date --debug -d '2011-06-11 EEST'
*
* This is implemented by probing the next three calendar quarters
* of the effective timezone and looking for DST changes -
* if found, the timezone name (EEST) is inserted into
* the lexical lookup table with type tLOCAL_ZONE.
* (Search for 'quarter' comment in 'parse_date').
*/
local_zone:
tLOCAL_ZONE {
pc->local_isdst = $1;
pc->dsts_seen += (0 < $1);
}
| tLOCAL_ZONE tDST {
pc->local_isdst = 1;
pc->dsts_seen += (0 < $1) + 1;
}
;
/**
* Note 'T' is a special case, as it is used as the separator in ISO
* 8601 date and time of day representation.
*/
zone:
tZONE {
pc->time_zone = $1;
}
| 'T' {
pc->time_zone = HOUR(7);
}
| tZONE relunit_snumber {
pc->time_zone = $1;
apply_relative_time (pc, $2, 1);
}
| 'T' relunit_snumber {
pc->time_zone = HOUR(7);
apply_relative_time (pc, $2, 1);
}
| tZONE tSNUMBER o_colon_minutes {
pc->time_zone = $1 + time_zone_hhmm (pc, $2, $3);
}
| tDAYZONE {
pc->time_zone = $1 + 60;
}
| tZONE tDST {
pc->time_zone = $1 + 60;
}
;
day:
tDAY {
pc->day_ordinal = 0;
pc->day_number = $1;
}
| tDAY ',' {
pc->day_ordinal = 0;
pc->day_number = $1;
}
| tORDINAL tDAY {
pc->day_ordinal = $1;
pc->day_number = $2;
pc->ordinal_day_seen = 1;
}
| tUNUMBER tDAY {
pc->day_ordinal = $1.value;
pc->day_number = $2;
pc->ordinal_day_seen = 1;
}
;
date:
tUNUMBER '/' tUNUMBER {
pc->month = $1.value;
pc->day = $3.value;
}
| tUNUMBER '/' tUNUMBER '/' tUNUMBER {
/**
* Interpret as YYYY/MM/DD if the first value has 4 or more digits,
* otherwise as MM/DD/YY.
* The goal in recognizing YYYY/MM/DD is solely to support legacy
* machine-generated dates like those in an RCS log listing. If
* you want portability, use the ISO 8601 format.
*/
if (4 <= $1.digits) {
pc->year = $1;
pc->month = $3.value;
pc->day = $5.value;
} else {
pc->month = $1.value;
pc->day = $3.value;
pc->year = $5;
}
}
| tUNUMBER tMONTH tSNUMBER {
/* e.g. 17-JUN-1992. */
pc->day = $1.value;
pc->month = $2;
pc->year.value = -$3.value;
pc->year.digits = $3.digits;
}
| tMONTH tSNUMBER tSNUMBER {
/* e.g. JUN-17-1992. */
pc->month = $1;
pc->day = -$2.value;
pc->year.value = -$3.value;
pc->year.digits = $3.digits;
}
| tMONTH tUNUMBER {
pc->month = $1;
pc->day = $2.value;
}
| tMONTH tUNUMBER ',' tUNUMBER {
pc->month = $1;
pc->day = $2.value;
pc->year = $4;
}
| tUNUMBER tMONTH {
pc->day = $1.value;
pc->month = $2;
}
| tUNUMBER tMONTH tUNUMBER {
pc->day = $1.value;
pc->month = $2;
pc->year = $3;
}
| iso_8601_date
;
iso_8601_date:
tUNUMBER tSNUMBER tSNUMBER {
/* ISO 8601 format.YYYY-MM-DD. */
pc->year = $1;
pc->month = -$2.value;
pc->day = -$3.value;
}
;
rel:
relunit tAGO
{ apply_relative_time (pc, $1, $2); }
| relunit
{ apply_relative_time (pc, $1, 1); }
| dayshift
{ apply_relative_time (pc, $1, 1); }
;
relunit:
tORDINAL tYEAR_UNIT
{ $$ = RELATIVE_TIME_0; $$.year = $1; }
| tUNUMBER tYEAR_UNIT
{ $$ = RELATIVE_TIME_0; $$.year = $1.value; }
| tYEAR_UNIT
{ $$ = RELATIVE_TIME_0; $$.year = 1; }
| tORDINAL tMONTH_UNIT
{ $$ = RELATIVE_TIME_0; $$.month = $1; }
| tUNUMBER tMONTH_UNIT
{ $$ = RELATIVE_TIME_0; $$.month = $1.value; }
| tMONTH_UNIT
{ $$ = RELATIVE_TIME_0; $$.month = 1; }
| tORDINAL tDAY_UNIT
{ $$ = RELATIVE_TIME_0; $$.day = $1 * $2; }
| tUNUMBER tDAY_UNIT
{ $$ = RELATIVE_TIME_0; $$.day = $1.value * $2; }
| tDAY_UNIT
{ $$ = RELATIVE_TIME_0; $$.day = $1; }
| tORDINAL tHOUR_UNIT
{ $$ = RELATIVE_TIME_0; $$.hour = $1; }
| tUNUMBER tHOUR_UNIT
{ $$ = RELATIVE_TIME_0; $$.hour = $1.value; }
| tHOUR_UNIT
{ $$ = RELATIVE_TIME_0; $$.hour = 1; }
| tORDINAL tMINUTE_UNIT
{ $$ = RELATIVE_TIME_0; $$.minutes = $1; }
| tUNUMBER tMINUTE_UNIT
{ $$ = RELATIVE_TIME_0; $$.minutes = $1.value; }
| tMINUTE_UNIT
{ $$ = RELATIVE_TIME_0; $$.minutes = 1; }
| tORDINAL tSEC_UNIT
{ $$ = RELATIVE_TIME_0; $$.seconds = $1; }
| tUNUMBER tSEC_UNIT
{ $$ = RELATIVE_TIME_0; $$.seconds = $1.value; }
| tSDECIMAL_NUMBER tSEC_UNIT {
$$ = RELATIVE_TIME_0;
$$.seconds = $1.tv_sec;
$$.ns = $1.tv_nsec;
}
| tUDECIMAL_NUMBER tSEC_UNIT {
$$ = RELATIVE_TIME_0;
$$.seconds = $1.tv_sec;
$$.ns = $1.tv_nsec;
}
| tSEC_UNIT
{ $$ = RELATIVE_TIME_0; $$.seconds = 1; }
| relunit_snumber
;
relunit_snumber:
tSNUMBER tYEAR_UNIT
{ $$ = RELATIVE_TIME_0; $$.year = $1.value; }
| tSNUMBER tMONTH_UNIT
{ $$ = RELATIVE_TIME_0; $$.month = $1.value; }
| tSNUMBER tDAY_UNIT
{ $$ = RELATIVE_TIME_0; $$.day = $1.value * $2; }
| tSNUMBER tHOUR_UNIT
{ $$ = RELATIVE_TIME_0; $$.hour = $1.value; }
| tSNUMBER tMINUTE_UNIT
{ $$ = RELATIVE_TIME_0; $$.minutes = $1.value; }
| tSNUMBER tSEC_UNIT
{ $$ = RELATIVE_TIME_0; $$.seconds = $1.value; }
;
dayshift:
tDAY_SHIFT
{ $$ = RELATIVE_TIME_0; $$.day = $1; }
;
seconds: signed_seconds | unsigned_seconds;
signed_seconds:
tSDECIMAL_NUMBER
| tSNUMBER
{ $$.tv_sec = $1.value; $$.tv_nsec = 0; }
;
unsigned_seconds:
tUDECIMAL_NUMBER
| tUNUMBER
{ $$.tv_sec = $1.value; $$.tv_nsec = 0; }
;
number:
tUNUMBER
{ digits_to_date_time (pc, $1); }
;
hybrid:
tUNUMBER relunit_snumber {
/**
* Hybrid all-digit and relative offset, so that we accept e.g.,
* "YYYYMMDD +N days" as well as "YYYYMMDD N days".
*/
digits_to_date_time (pc, $1);
apply_relative_time (pc, $2, 1);
}
;
o_colon_minutes:
/* empty */
{ $$ = -1; }
| ':' tUNUMBER
{ $$ = $2.value; }
;
%%
static table const meridian_table[] = {
{ "AM", tMERIDIAN, MERam },
{ "A.M.", tMERIDIAN, MERam },
{ "PM", tMERIDIAN, MERpm },
{ "P.M.", tMERIDIAN, MERpm },
{ NULL, 0, 0 }
};
static table const dst_table[] = {
{ "DST", tDST, 0 }
};
static table const month_and_day_table[] = {
{ "JANUARY", tMONTH, 1 },
{ "FEBRUARY", tMONTH, 2 },
{ "MARCH", tMONTH, 3 },
{ "APRIL", tMONTH, 4 },
{ "MAY", tMONTH, 5 },
{ "JUNE", tMONTH, 6 },
{ "JULY", tMONTH, 7 },
{ "AUGUST", tMONTH, 8 },
{ "SEPTEMBER",tMONTH, 9 },
{ "SEPT", tMONTH, 9 },
{ "OCTOBER", tMONTH, 10 },
{ "NOVEMBER", tMONTH, 11 },
{ "DECEMBER", tMONTH, 12 },
{ "SUNDAY", tDAY, 0 },
{ "MONDAY", tDAY, 1 },
{ "TUESDAY", tDAY, 2 },
{ "TUES", tDAY, 2 },
{ "WEDNESDAY",tDAY, 3 },
{ "WEDNES", tDAY, 3 },
{ "THURSDAY", tDAY, 4 },
{ "THUR", tDAY, 4 },
{ "THURS", tDAY, 4 },
{ "FRIDAY", tDAY, 5 },
{ "SATURDAY", tDAY, 6 },
{ NULL, 0, 0 }
};
static table const time_units_table[] = {
{ "YEAR", tYEAR_UNIT, 1 },
{ "MONTH", tMONTH_UNIT, 1 },
{ "FORTNIGHT",tDAY_UNIT, 14 },
{ "WEEK", tDAY_UNIT, 7 },
{ "DAY", tDAY_UNIT, 1 },
{ "HOUR", tHOUR_UNIT, 1 },
{ "MINUTE", tMINUTE_UNIT, 1 },
{ "MIN", tMINUTE_UNIT, 1 },
{ "SECOND", tSEC_UNIT, 1 },
{ "SEC", tSEC_UNIT, 1 },
{ NULL, 0, 0 }
};
/* Assorted relative-time words. */
static table const relative_time_table[] = {
{ "TOMORROW", tDAY_SHIFT, 1 },
{ "YESTERDAY",tDAY_SHIFT, -1 },
{ "TODAY", tDAY_SHIFT, 0 },
{ "NOW", tDAY_SHIFT, 0 },
{ "LAST", tORDINAL, -1 },
{ "THIS", tORDINAL, 0 },
{ "NEXT", tORDINAL, 1 },
{ "FIRST", tORDINAL, 1 },
/*{ "SECOND", tORDINAL, 2 }, */
{ "THIRD", tORDINAL, 3 },
{ "FOURTH", tORDINAL, 4 },
{ "FIFTH", tORDINAL, 5 },
{ "SIXTH", tORDINAL, 6 },
{ "SEVENTH", tORDINAL, 7 },
{ "EIGHTH", tORDINAL, 8 },
{ "NINTH", tORDINAL, 9 },
{ "TENTH", tORDINAL, 10 },
{ "ELEVENTH", tORDINAL, 11 },
{ "TWELFTH", tORDINAL, 12 },
{ "AGO", tAGO, -1 },
{ "HENCE", tAGO, 1 },
{ NULL, 0, 0 }
};
/**
* The universal time zone table. These labels can be used even for
* timestamps that would not otherwise be valid, e.g., GMT timestamps
* in London during summer.
*/
static table const universal_time_zone_table[] = {
{ "GMT", tZONE, HOUR ( 0) }, /* Greenwich Mean */
{ "UT", tZONE, HOUR ( 0) }, /* Universal (Coordinated) */
{ "UTC", tZONE, HOUR ( 0) },
{ NULL, 0, 0 }
};
/**
* The time zone table. This table is necessarily incomplete, as time
* zone abbreviations are ambiguous; e.g. Australians interpret "EST"
* as Eastern time in Australia, not as US Eastern Standard Time.
* You cannot rely on parse_date to handle arbitrary time zone
* abbreviations; use numeric abbreviations like "-0500" instead.
*/
static table const time_zone_table[] = {
{ "WET", tZONE, HOUR ( 0) }, /* Western European */
{ "WEST", tDAYZONE, HOUR ( 0) }, /* Western European Summer */
{ "BST", tDAYZONE, HOUR ( 0) }, /* British Summer */
{ "ART", tZONE, -HOUR ( 3) }, /* Argentina */
{ "BRT", tZONE, -HOUR ( 3) }, /* Brazil */
{ "BRST", tDAYZONE, -HOUR ( 3) }, /* Brazil Summer */
{ "NST", tZONE, -(HOUR ( 3) + 30) }, /* Newfoundland Standard */
{ "NDT", tDAYZONE,-(HOUR ( 3) + 30) }, /* Newfoundland Daylight */
{ "AST", tZONE, -HOUR ( 4) }, /* Atlantic Standard */
{ "ADT", tDAYZONE, -HOUR ( 4) }, /* Atlantic Daylight */
{ "CLT", tZONE, -HOUR ( 4) }, /* Chile */
{ "CLST", tDAYZONE, -HOUR ( 4) }, /* Chile Summer */
{ "EST", tZONE, -HOUR ( 5) }, /* Eastern Standard */
{ "EDT", tDAYZONE, -HOUR ( 5) }, /* Eastern Daylight */
{ "CST", tZONE, -HOUR ( 6) }, /* Central Standard */
{ "CDT", tDAYZONE, -HOUR ( 6) }, /* Central Daylight */
{ "MST", tZONE, -HOUR ( 7) }, /* Mountain Standard */
{ "MDT", tDAYZONE, -HOUR ( 7) }, /* Mountain Daylight */
{ "PST", tZONE, -HOUR ( 8) }, /* Pacific Standard */
{ "PDT", tDAYZONE, -HOUR ( 8) }, /* Pacific Daylight */
{ "AKST", tZONE, -HOUR ( 9) }, /* Alaska Standard */
{ "AKDT", tDAYZONE, -HOUR ( 9) }, /* Alaska Daylight */
{ "HST", tZONE, -HOUR (10) }, /* Hawaii Standard */
{ "HAST", tZONE, -HOUR (10) }, /* Hawaii-Aleutian Standard */
{ "HADT", tDAYZONE, -HOUR (10) }, /* Hawaii-Aleutian Daylight */
{ "SST", tZONE, -HOUR (12) }, /* Samoa Standard */
{ "WAT", tZONE, HOUR ( 1) }, /* West Africa */
{ "CET", tZONE, HOUR ( 1) }, /* Central European */
{ "CEST", tDAYZONE, HOUR ( 1) }, /* Central European Summer */
{ "MET", tZONE, HOUR ( 1) }, /* Middle European */
{ "MEZ", tZONE, HOUR ( 1) }, /* Middle European */
{ "MEST", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */
{ "MESZ", tDAYZONE, HOUR ( 1) }, /* Middle European Summer */
{ "EET", tZONE, HOUR ( 2) }, /* Eastern European */
{ "EEST", tDAYZONE, HOUR ( 2) }, /* Eastern European Summer */
{ "CAT", tZONE, HOUR ( 2) }, /* Central Africa */
{ "SAST", tZONE, HOUR ( 2) }, /* South Africa Standard */
{ "EAT", tZONE, HOUR ( 3) }, /* East Africa */
{ "MSK", tZONE, HOUR ( 3) }, /* Moscow */
{ "MSD", tDAYZONE, HOUR ( 3) }, /* Moscow Daylight */
{ "IST", tZONE, (HOUR ( 5) + 30) }, /* India Standard */
{ "SGT", tZONE, HOUR ( 8) }, /* Singapore */
{ "KST", tZONE, HOUR ( 9) }, /* Korea Standard */
{ "JST", tZONE, HOUR ( 9) }, /* Japan Standard */
{ "GST", tZONE, HOUR (10) }, /* Guam Standard */
{ "NZST", tZONE, HOUR (12) }, /* New Zealand Standard */
{ "NZDT", tDAYZONE, HOUR (12) }, /* New Zealand Daylight */
{ NULL, 0, 0 }
};
/**
* Military time zone table.
*
* Note 'T' is a special case, as it is used as the separator in ISO
* 8601 date and time of day representation.
*/
static table const military_table[] = {
{ "A", tZONE, -HOUR ( 1) },
{ "B", tZONE, -HOUR ( 2) },
{ "C", tZONE, -HOUR ( 3) },
{ "D", tZONE, -HOUR ( 4) },
{ "E", tZONE, -HOUR ( 5) },
{ "F", tZONE, -HOUR ( 6) },
{ "G", tZONE, -HOUR ( 7) },
{ "H", tZONE, -HOUR ( 8) },
{ "I", tZONE, -HOUR ( 9) },
{ "K", tZONE, -HOUR (10) },
{ "L", tZONE, -HOUR (11) },
{ "M", tZONE, -HOUR (12) },
{ "N", tZONE, HOUR ( 1) },
{ "O", tZONE, HOUR ( 2) },
{ "P", tZONE, HOUR ( 3) },
{ "Q", tZONE, HOUR ( 4) },
{ "R", tZONE, HOUR ( 5) },
{ "S", tZONE, HOUR ( 6) },
{ "T", 'T', 0 },
{ "U", tZONE, HOUR ( 8) },
{ "V", tZONE, HOUR ( 9) },
{ "W", tZONE, HOUR (10) },
{ "X", tZONE, HOUR (11) },
{ "Y", tZONE, HOUR (12) },
{ "Z", tZONE, HOUR ( 0) },
{ NULL, 0, 0 }
};
/**
* Convert a time zone expressed as HH:MM into an integer count of
* minutes. If MM is negative, then S is of the form HHMM and needs
* to be picked apart; otherwise, S is of the form HH. As specified in
* http://www.opengroup.org/susv3xbd/xbd_chap08.html#tag_08_03, allow
* only valid TZ range, and consider first two digits as hours, if no
* minutes specified.
*/
static long int time_zone_hhmm(parser_control *pc, textint s, long int mm)
{
long int n_minutes;
/**
* If the length of S is 1 or 2 and no minutes are specified,
* interpret it as a number of hours.
*/
if (s.digits <= 2 && mm < 0)
s.value *= 100;
if (mm < 0)
n_minutes = (s.value / 100) * 60 + s.value % 100;
else
n_minutes = s.value * 60 + (s.negative ? -mm : mm);
/**
* If the absolute number of minutes is larger than 24 hours,
* arrange to reject it by incrementing pc->zones_seen. Thus,
* we allow only values in the range UTC-24:00 to UTC+24:00.
*/
if (24 * 60 < abs (n_minutes))
pc->zones_seen++;
return n_minutes;
}
static int to_hour(long int hours, int meridian)
{
switch (meridian) {
default: /* Pacify GCC. */
case MER24:
return 0 <= hours && hours < 24 ? hours : -1;
case MERam:
return 0 < hours && hours < 12 ? hours : hours == 12 ? 0 : -1;
case MERpm:
return 0 < hours && hours < 12 ? hours + 12 : hours == 12 ? 12 : -1;
}
}
static long int to_year(textint textyear)
{
long int year = textyear.value;
if (year < 0)
year = -year;
/**
* XPG4 suggests that years 00-68 map to 2000-2068, and
* years 69-99 map to 1969-1999.
*/
else if (textyear.digits == 2)
year += year < 69 ? 2000 : 1900;
return year;
}
static table const * lookup_zone(parser_control const *pc, char const *name)
{
table const *tp;
for (tp = universal_time_zone_table; tp->name; tp++)
if (strcmp (name, tp->name) == 0)
return tp;
/**
* Try local zone abbreviations before those in time_zone_table, as
* the local ones are more likely to be right.
*/
for (tp = pc->local_time_zone_table; tp->name; tp++)
if (strcmp (name, tp->name) == 0)
return tp;
for (tp = time_zone_table; tp->name; tp++)
if (strcmp (name, tp->name) == 0)
return tp;
return NULL;
}
#if ! HAVE_TM_GMTOFF
/**
* Yield the difference between *A and *B,
* measured in seconds, ignoring leap seconds.
* The body of this function is taken directly from the GNU C Library;
* see src/strftime.c.
*/
static long int tm_diff(struct tm const *a, struct tm const *b)
{
/**
* Compute intervening leap days correctly even if year is negative.
* Take care to avoid int overflow in leap day calculations.
*/
int a4 = SHR (a->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (a->tm_year & 3);
int b4 = SHR (b->tm_year, 2) + SHR (TM_YEAR_BASE, 2) - ! (b->tm_year & 3);
int a100 = a4 / 25 - (a4 % 25 < 0);
int b100 = b4 / 25 - (b4 % 25 < 0);
int a400 = SHR (a100, 2);
int b400 = SHR (b100, 2);
int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
long int ayear = a->tm_year;
long int years = ayear - b->tm_year;
long int days = (365 * years + intervening_leap_days
+ (a->tm_yday - b->tm_yday));
return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour))
+ (a->tm_min - b->tm_min))
+ (a->tm_sec - b->tm_sec));
}
#endif /* ! HAVE_TM_GMTOFF */
static table const * lookup_word(parser_control const *pc, char *word)
{
char *p;
char *q;
size_t wordlen;
table const *tp;
int period_found;
int abbrev;
/* Make it uppercase. */
for (p = word; *p; p++) {
unsigned char ch = *p;
*p = c_toupper (ch);
}
for (tp = meridian_table; tp->name; tp++)
if (strcmp (word, tp->name) == 0)
return tp;
/* See if we have an abbreviation for a month. */
wordlen = strlen (word);
abbrev = wordlen == 3 || (wordlen == 4 && word[3] == '.');
for (tp = month_and_day_table; tp->name; tp++)
if ((abbrev ? strncmp (word, tp->name, 3) :
strcmp (word, tp->name)) == 0)
return tp;
if ((tp = lookup_zone (pc, word)))
return tp;
if (strcmp (word, dst_table[0].name) == 0)
return dst_table;
for (tp = time_units_table; tp->name; tp++)
if (strcmp (word, tp->name) == 0)
return tp;
/* Strip off any plural and try the units table again. */
if (word[wordlen - 1] == 'S') {
word[wordlen - 1] = '\0';
for (tp = time_units_table; tp->name; tp++)
if (strcmp (word, tp->name) == 0)
return tp;
word[wordlen - 1] = 'S'; /* For "this" in relative_time_table. */
}
for (tp = relative_time_table; tp->name; tp++)
if (strcmp (word, tp->name) == 0)
return tp;
/* Military time zones. */
if (wordlen == 1)
for (tp = military_table; tp->name; tp++)
if (word[0] == tp->name[0])
return tp;
/* Drop out any periods and try the time zone table again. */
for (period_found = 0, p = q = word; (*p = *q); q++)
if (*q == '.')
period_found = 1;
else
p++;
if (period_found && (tp = lookup_zone (pc, word)))
return tp;
return NULL;
}
static int yylex (union YYSTYPE *lvalp, parser_control *pc)
{
unsigned char c;
size_t count;
for (;;) {
while (c = *pc->input, c_isspace (c))
pc->input++;
if (ISDIGIT (c) || c == '-' || c == '+') {
char const *p;
int sign;
unsigned long int value;
if (c == '-' || c == '+') {
sign = c == '-' ? -1 : 1;
while (c = *++pc->input, c_isspace (c))
continue;
if (! ISDIGIT (c))
/* skip the '-' sign */
continue;
} else
sign = 0;
p = pc->input;
for (value = 0; ; value *= 10) {
unsigned long int value1 = value + (c - '0');
if (value1 < value)
return '?';
value = value1;
c = *++p;
if (! ISDIGIT (c))
break;
if (ULONG_MAX / 10 < value)
return '?';
}
if ((c == '.' || c == ',') && ISDIGIT (p[1])) {
time_t s;
int ns;
int digits;
unsigned long int value1;
/* Check for overflow when converting value to
* time_t.
*/
if (sign < 0) {
s = - value;
if (0 < s)
return '?';
value1 = -s;
} else {
s = value;
if (s < 0)
return '?';
value1 = s;
}
if (value != value1)
return '?';
/* Accumulate fraction, to ns precision. */
p++;
ns = *p++ - '0';
for (digits = 2;
digits <= LOG10_BILLION; digits++) {
ns *= 10;
if (ISDIGIT (*p))
ns += *p++ - '0';
}
/* Skip excess digits, truncating toward
* -Infinity.
*/
if (sign < 0)
for (; ISDIGIT (*p); p++)
if (*p != '0') {
ns++;
break;
}
while (ISDIGIT (*p))
p++;
/* Adjust to the timespec convention, which is
* that tv_nsec is always a positive offset even
* if tv_sec is negative.
*/
if (sign < 0 && ns) {
s--;
if (! (s < 0))
return '?';
ns = BILLION - ns;
}
lvalp->timespec.tv_sec = s;
lvalp->timespec.tv_nsec = ns;
pc->input = p;
return
sign ? tSDECIMAL_NUMBER : tUDECIMAL_NUMBER;
} else {
lvalp->textintval.negative = sign < 0;
if (sign < 0) {
lvalp->textintval.value = - value;
if (0 < lvalp->textintval.value)
return '?';
} else {
lvalp->textintval.value = value;
if (lvalp->textintval.value < 0)
return '?';
}
lvalp->textintval.digits = p - pc->input;
pc->input = p;
return sign ? tSNUMBER : tUNUMBER;
}
}
if (c_isalpha (c)) {
char buff[20];
char *p = buff;
table const *tp;
do {
if (p < buff + sizeof buff - 1)
*p++ = c;
c = *++pc->input;
}
while (c_isalpha (c) || c == '.');
*p = '\0';
tp = lookup_word (pc, buff);
if (! tp) {
return '?';
}
lvalp->intval = tp->value;
return tp->type;
}
if (c != '(')
return to_uchar (*pc->input++);
count = 0;
do {
c = *pc->input++;
if (c == '\0')
return c;
if (c == '(')
count++;
else if (c == ')')
count--;
}
while (count != 0);
}
}
/* Do nothing if the parser reports an error. */
static int yyerror(parser_control const *pc __attribute__((__unused__)),
char const *s __attribute__((__unused__)))
{
return 0;
}
/**
* If *TM0 is the old and *TM1 is the new value of a struct tm after
* passing it to mktime, return 1 if it's OK that mktime returned T.
* It's not OK if *TM0 has out-of-range members.
*/
static int 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
* timestamp that happens to equal (time_t) -1, on a host that
* supports such a timestamp.
*/
tm1 = localtime (&t);
if (!tm1)
return 0;
}
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)
: xstrdup (tz));
}
return tz;
}
/**
* Parse a date/time string, storing the resulting time value into *result.
* The string itself is pointed to by *p. Return 1 if successful.
* *p can be an incomplete or relative time specification; if so, use
* *now as the basis for the returned time.
*/
int parse_date(struct timespec *result, char const *p,
struct timespec const *now)
{
time_t Start;
long int Start_ns;
struct tm const *tmp;
struct tm tm;
struct tm tm0;
parser_control pc;
struct timespec gettime_buffer;
unsigned char c;
int tz_was_altered = 0;
char *tz0 = NULL;
char tz0buf[TZBUFSIZE];
int ok = 1;
struct timeval tv;
if (! now) {
gettimeofday (&tv, NULL);
gettime_buffer.tv_sec = tv.tv_sec;
gettime_buffer.tv_nsec = tv.tv_usec * 1000;
now = &gettime_buffer;
}
Start = now->tv_sec;
Start_ns = now->tv_nsec;
tmp = localtime (&now->tv_sec);
if (! tmp)
return 0;
while (c = *p, c_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];
int large_tz = TZBUFSIZE < tzsize;
int setenv_ok;
tz0 = get_tz (tz0buf);
z = tz1 = large_tz ? malloc (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 = 1;
p = s + 1;
while (c = *p, c_isspace (c))
p++;
break;
}
}
/**
* As documented, be careful to treat the empty string just like
* a date string of "0". Without this, an empty string would be
* declared invalid when parsed during a DST transition.
*/
if (*p == '\0')
p = "0";
pc.input = p;
pc.year.value = tmp->tm_year;
pc.year.value += TM_YEAR_BASE;
pc.year.digits = 0;
pc.month = tmp->tm_mon + 1;
pc.day = tmp->tm_mday;
pc.hour = tmp->tm_hour;
pc.minutes = tmp->tm_min;
pc.seconds.tv_sec = tmp->tm_sec;
pc.seconds.tv_nsec = Start_ns;
tm.tm_isdst = tmp->tm_isdst;
pc.meridian = MER24;
pc.rel = RELATIVE_TIME_0;
pc.timespec_seen = 0;
pc.rels_seen = 0;
pc.dates_seen = 0;
pc.days_seen = 0;
pc.times_seen = 0;
pc.local_zones_seen = 0;
pc.dsts_seen = 0;
pc.zones_seen = 0;
pc.year_seen = 0;
pc.ordinal_day_seen = 0;
#if HAVE_STRUCT_TM_TM_ZONE
pc.local_time_zone_table[0].name = tmp->tm_zone;
pc.local_time_zone_table[0].type = tLOCAL_ZONE;
pc.local_time_zone_table[0].value = tmp->tm_isdst;
pc.local_time_zone_table[1].name = NULL;
/**
* Probe the names used in the next three calendar quarters, looking
* for a tm_isdst different from the one we already have.
*/
{
int quarter;
for (quarter = 1; quarter <= 3; quarter++) {
time_t probe = Start + quarter * (90 * 24 * 60 * 60);
struct tm const *probe_tm = localtime (&probe);
if (probe_tm && probe_tm->tm_zone
&& probe_tm->tm_isdst
!= pc.local_time_zone_table[0].value) {
{
pc.local_time_zone_table[1].name
= probe_tm->tm_zone;
pc.local_time_zone_table[1].type
= tLOCAL_ZONE;
pc.local_time_zone_table[1].value
= probe_tm->tm_isdst;
pc.local_time_zone_table[2].name
= NULL;
}
break;
}
}
}
#else
#if HAVE_TZNAME
{
# if !HAVE_DECL_TZNAME
extern char *tzname[];
# endif
int i;
for (i = 0; i < 2; i++) {
pc.local_time_zone_table[i].name = tzname[i];
pc.local_time_zone_table[i].type = tLOCAL_ZONE;
pc.local_time_zone_table[i].value = i;
}
pc.local_time_zone_table[i].name = NULL;
}
#else
pc.local_time_zone_table[0].name = NULL;
#endif
#endif
if (pc.local_time_zone_table[0].name && pc.local_time_zone_table[1].name
&& ! strcmp (pc.local_time_zone_table[0].name,
pc.local_time_zone_table[1].name)) {
/**
* This locale uses the same abbreviation for standard and
* daylight times. So if we see that abbreviation, we don't
* know whether it's daylight time.
*/
pc.local_time_zone_table[0].value = -1;
pc.local_time_zone_table[1].name = NULL;
}
if (yyparse (&pc) != 0) {
goto fail;
}
if (pc.timespec_seen)
*result = pc.seconds;
else {
if (1 < (pc.times_seen | pc.dates_seen | pc.days_seen
| pc.dsts_seen
| (pc.local_zones_seen + pc.zones_seen))) {
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;
}
/**
* Let mktime deduce tm_isdst if we have an absolute timestamp.
*/
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)) {
if (! pc.zones_seen) {
goto fail;
} else {
/** 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 = 1;
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_wday != pc.day_number)));
tm.tm_isdst = -1;
Start = mktime (&tm);
if (Start == (time_t) -1) {
goto fail;
}
}
/* 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;
tm.tm_hour = tm0.tm_hour;
tm.tm_min = tm0.tm_min;
tm.tm_sec = tm0.tm_sec;
tm.tm_isdst = tm0.tm_isdst;
Start = mktime (&tm);
if (Start == (time_t) -1) {
goto fail;
}
}
/**
* The only "output" of this if-block is an updated Start value,
* so this block must follow others that clobber Start.
*/
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;
}
/**
* 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;
time_t d3 = pc.rel.seconds;
time_t t3 = t2 + d3;
long int d4 = (sum_ns - normalized_ns) / BILLION;
time_t t4 = t3 + d4;
time_t t5 = t4;
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))
| (t5 != t4)) {
goto fail;
}
result->tv_sec = t5;
result->tv_nsec = normalized_ns;
}
goto done;
fail:
ok = 0;
done:
if (tz_was_altered)
ok &= (tz0 ? setenv ("TZ", tz0, 1)
: unsetenv ("TZ")) == 0;
if (tz0 != tz0buf)
free (tz0);
return ok;
}