1/*
2 * Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
3 * Copyright (C) 2006-2019 Apple Inc. All rights reserved.
4 * Copyright (C) 2009 Google Inc. All rights reserved.
5 * Copyright (C) 2007-2009 Torch Mobile, Inc.
6 * Copyright (C) 2010 &yet, LLC. (nate@andyet.net)
7 *
8 * The Original Code is Mozilla Communicator client code, released
9 * March 31, 1998.
10 *
11 * The Initial Developer of the Original Code is
12 * Netscape Communications Corporation.
13 * Portions created by the Initial Developer are Copyright (C) 1998
14 * the Initial Developer. All Rights Reserved.
15 *
16 * This library is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU Lesser General Public
18 * License as published by the Free Software Foundation; either
19 * version 2.1 of the License, or (at your option) any later version.
20 *
21 * This library is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 * Lesser General Public License for more details.
25 *
26 * You should have received a copy of the GNU Lesser General Public
27 * License along with this library; if not, write to the Free Software
28 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 *
30 * Alternatively, the contents of this file may be used under the terms
31 * of either the Mozilla Public License Version 1.1, found at
32 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
33 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
34 * (the "GPL"), in which case the provisions of the MPL or the GPL are
35 * applicable instead of those above. If you wish to allow use of your
36 * version of this file only under the terms of one of those two
37 * licenses (the MPL or the GPL) and not to allow others to use your
38 * version of this file under the LGPL, indicate your decision by
39 * deletingthe provisions above and replace them with the notice and
40 * other provisions required by the MPL or the GPL, as the case may be.
41 * If you do not delete the provisions above, a recipient may use your
42 * version of this file under any of the LGPL, the MPL or the GPL.
43
44 * Copyright 2006-2008 the V8 project authors. All rights reserved.
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions are
47 * met:
48 *
49 * * Redistributions of source code must retain the above copyright
50 * notice, this list of conditions and the following disclaimer.
51 * * Redistributions in binary form must reproduce the above
52 * copyright notice, this list of conditions and the following
53 * disclaimer in the documentation and/or other materials provided
54 * with the distribution.
55 * * Neither the name of Google Inc. nor the names of its
56 * contributors may be used to endorse or promote products derived
57 * from this software without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
60 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
61 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
62 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
63 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
64 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
65 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
66 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
67 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
68 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
69 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
70 */
71
72#include "config.h"
73#include <wtf/DateMath.h>
74
75#include <algorithm>
76#include <limits.h>
77#include <limits>
78#include <stdint.h>
79#include <time.h>
80#include <wtf/Assertions.h>
81#include <wtf/ASCIICType.h>
82#include <wtf/MathExtras.h>
83#include <wtf/StdLibExtras.h>
84#include <wtf/text/StringBuilder.h>
85
86#if OS(WINDOWS)
87#include <windows.h>
88#endif
89
90#if HAVE(ERRNO_H)
91#include <errno.h>
92#endif
93
94#if HAVE(SYS_TIME_H)
95#include <sys/time.h>
96#endif
97
98#if HAVE(SYS_TIMEB_H)
99#include <sys/timeb.h>
100#endif
101
102namespace WTF {
103
104// FIXME: Should this function go into StringCommon.h or some other header?
105template<unsigned length> inline bool startsWithLettersIgnoringASCIICase(const char* string, const char (&lowercaseLetters)[length])
106{
107 return equalLettersIgnoringASCIICase(string, lowercaseLetters, length - 1);
108}
109
110/* Constants */
111
112const char* const weekdayName[7] = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
113const char* const monthName[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
114const char* const monthFullName[12] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" };
115
116// Day of year for the first day of each month, where index 0 is January, and day 0 is January 1.
117// First for non-leap years, then for leap years.
118const int firstDayOfMonth[2][12] = {
119 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
120 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
121};
122
123#if !OS(WINDOWS) || HAVE(TM_GMTOFF)
124static inline void getLocalTime(const time_t* localTime, struct tm* localTM)
125{
126#if HAVE(LOCALTIME_R)
127 localtime_r(localTime, localTM);
128#else
129 localtime_s(localTime, localTM);
130#endif
131}
132#endif
133
134static void appendTwoDigitNumber(StringBuilder& builder, int number)
135{
136 ASSERT(number >= 0);
137 ASSERT(number < 100);
138 builder.append(static_cast<LChar>('0' + number / 10));
139 builder.append(static_cast<LChar>('0' + number % 10));
140}
141
142static inline double msToMilliseconds(double ms)
143{
144 double result = fmod(ms, msPerDay);
145 if (result < 0)
146 result += msPerDay;
147 return result;
148}
149
150// There is a hard limit at 2038 that we currently do not have a workaround
151// for (rdar://problem/5052975).
152static inline int maximumYearForDST()
153{
154 return 2037;
155}
156
157static inline int minimumYearForDST()
158{
159 // Because of the 2038 issue (see maximumYearForDST) if the current year is
160 // greater than the max year minus 27 (2010), we want to use the max year
161 // minus 27 instead, to ensure there is a range of 28 years that all years
162 // can map to.
163 return std::min(msToYear(jsCurrentTime()), maximumYearForDST() - 27) ;
164}
165
166/*
167 * Find an equivalent year for the one given, where equivalence is deterined by
168 * the two years having the same leapness and the first day of the year, falling
169 * on the same day of the week.
170 *
171 * This function returns a year between this current year and 2037, however this
172 * function will potentially return incorrect results if the current year is after
173 * 2010, (rdar://problem/5052975), if the year passed in is before 1900 or after
174 * 2100, (rdar://problem/5055038).
175 */
176int equivalentYearForDST(int year)
177{
178 // It is ok if the cached year is not the current year as long as the rules
179 // for DST did not change between the two years; if they did the app would need
180 // to be restarted.
181 static int minYear = minimumYearForDST();
182 int maxYear = maximumYearForDST();
183
184 int difference;
185 if (year > maxYear)
186 difference = minYear - year;
187 else if (year < minYear)
188 difference = maxYear - year;
189 else
190 return year;
191
192 int quotient = difference / 28;
193 int product = (quotient) * 28;
194
195 year += product;
196 return year;
197}
198
199#if OS(WINDOWS)
200typedef BOOL(WINAPI* callGetTimeZoneInformationForYear_t)(USHORT, PDYNAMIC_TIME_ZONE_INFORMATION, LPTIME_ZONE_INFORMATION);
201
202static callGetTimeZoneInformationForYear_t timeZoneInformationForYearFunction()
203{
204 static callGetTimeZoneInformationForYear_t getTimeZoneInformationForYear = nullptr;
205
206 if (getTimeZoneInformationForYear)
207 return getTimeZoneInformationForYear;
208
209 HMODULE module = ::GetModuleHandleW(L"kernel32.dll");
210 if (!module)
211 return nullptr;
212
213 getTimeZoneInformationForYear = reinterpret_cast<callGetTimeZoneInformationForYear_t>(::GetProcAddress(module, "GetTimeZoneInformationForYear"));
214
215 return getTimeZoneInformationForYear;
216}
217#endif
218
219static int32_t calculateUTCOffset()
220{
221#if OS(WINDOWS)
222 TIME_ZONE_INFORMATION timeZoneInformation;
223 DWORD rc = 0;
224
225 if (callGetTimeZoneInformationForYear_t timeZoneFunction = timeZoneInformationForYearFunction()) {
226 // If available, use the Windows API call that takes into account the varying DST from
227 // year to year.
228 SYSTEMTIME systemTime;
229 ::GetSystemTime(&systemTime);
230 rc = timeZoneFunction(systemTime.wYear, nullptr, &timeZoneInformation);
231 if (rc == TIME_ZONE_ID_INVALID)
232 return 0;
233 } else {
234 rc = ::GetTimeZoneInformation(&timeZoneInformation);
235 if (rc == TIME_ZONE_ID_INVALID)
236 return 0;
237 }
238
239 int32_t bias = timeZoneInformation.Bias;
240
241 if (rc == TIME_ZONE_ID_DAYLIGHT)
242 bias += timeZoneInformation.DaylightBias;
243 else if (rc == TIME_ZONE_ID_STANDARD || rc == TIME_ZONE_ID_UNKNOWN)
244 bias += timeZoneInformation.StandardBias;
245
246 return -bias * 60 * 1000;
247#else
248 time_t localTime = time(0);
249 tm localt;
250 getLocalTime(&localTime, &localt);
251
252 // Get the difference between this time zone and UTC on the 1st of January of this year.
253 localt.tm_sec = 0;
254 localt.tm_min = 0;
255 localt.tm_hour = 0;
256 localt.tm_mday = 1;
257 localt.tm_mon = 0;
258 // Not setting localt.tm_year!
259 localt.tm_wday = 0;
260 localt.tm_yday = 0;
261 localt.tm_isdst = 0;
262#if HAVE(TM_GMTOFF)
263 localt.tm_gmtoff = 0;
264#endif
265#if HAVE(TM_ZONE)
266 localt.tm_zone = 0;
267#endif
268
269#if HAVE(TIMEGM)
270 time_t utcOffset = timegm(&localt) - mktime(&localt);
271#else
272 // Using a canned date of 01/01/2019 on platforms with weaker date-handling foo.
273 localt.tm_year = 119;
274 time_t utcOffset = 1546300800 - mktime(&localt);
275#endif
276
277 return static_cast<int32_t>(utcOffset * 1000);
278#endif
279}
280
281#if !HAVE(TM_GMTOFF)
282
283#if OS(WINDOWS)
284// Code taken from http://support.microsoft.com/kb/167296
285static void UnixTimeToFileTime(time_t t, LPFILETIME pft)
286{
287 // Note that LONGLONG is a 64-bit value
288 LONGLONG ll;
289
290 ll = Int32x32To64(t, 10000000) + 116444736000000000;
291 pft->dwLowDateTime = (DWORD)ll;
292 pft->dwHighDateTime = ll >> 32;
293}
294#endif
295
296/*
297 * Get the DST offset for the time passed in.
298 */
299static double calculateDSTOffset(time_t localTime, double utcOffset)
300{
301 // input is UTC so we have to shift back to local time to determine DST thus the + getUTCOffset()
302 double offsetTime = (localTime * msPerSecond) + utcOffset;
303
304 // Offset from UTC but doesn't include DST obviously
305 int offsetHour = msToHours(offsetTime);
306 int offsetMinute = msToMinutes(offsetTime);
307
308#if OS(WINDOWS)
309 FILETIME utcFileTime;
310 UnixTimeToFileTime(localTime, &utcFileTime);
311 SYSTEMTIME utcSystemTime, localSystemTime;
312 if (!::FileTimeToSystemTime(&utcFileTime, &utcSystemTime))
313 return 0;
314 if (!::SystemTimeToTzSpecificLocalTime(nullptr, &utcSystemTime, &localSystemTime))
315 return 0;
316
317 double diff = ((localSystemTime.wHour - offsetHour) * secondsPerHour) + ((localSystemTime.wMinute - offsetMinute) * 60);
318#else
319 tm localTM;
320 getLocalTime(&localTime, &localTM);
321
322 double diff = ((localTM.tm_hour - offsetHour) * secondsPerHour) + ((localTM.tm_min - offsetMinute) * 60);
323#endif
324
325 if (diff < 0)
326 diff += secondsPerDay;
327
328 return (diff * msPerSecond);
329}
330
331#endif
332
333// Returns combined offset in millisecond (UTC + DST).
334LocalTimeOffset calculateLocalTimeOffset(double ms, TimeType inputTimeType)
335{
336#if HAVE(TM_GMTOFF)
337 double localToUTCTimeOffset = inputTimeType == LocalTime ? calculateUTCOffset() : 0;
338#else
339 double localToUTCTimeOffset = calculateUTCOffset();
340#endif
341 if (inputTimeType == LocalTime)
342 ms -= localToUTCTimeOffset;
343
344 // On Mac OS X, the call to localtime (see calculateDSTOffset) will return historically accurate
345 // DST information (e.g. New Zealand did not have DST from 1946 to 1974) however the JavaScript
346 // standard explicitly dictates that historical information should not be considered when
347 // determining DST. For this reason we shift away from years that localtime can handle but would
348 // return historically accurate information.
349 int year = msToYear(ms);
350 int equivalentYear = equivalentYearForDST(year);
351 if (year != equivalentYear) {
352 bool leapYear = isLeapYear(year);
353 int dayInYearLocal = dayInYear(ms, year);
354 int dayInMonth = dayInMonthFromDayInYear(dayInYearLocal, leapYear);
355 int month = monthFromDayInYear(dayInYearLocal, leapYear);
356 double day = dateToDaysFrom1970(equivalentYear, month, dayInMonth);
357 ms = (day * msPerDay) + msToMilliseconds(ms);
358 }
359
360 double localTimeSeconds = ms / msPerSecond;
361 if (localTimeSeconds > maxUnixTime)
362 localTimeSeconds = maxUnixTime;
363 else if (localTimeSeconds < 0) // Go ahead a day to make localtime work (does not work with 0).
364 localTimeSeconds += secondsPerDay;
365 // FIXME: time_t has a potential problem in 2038.
366 time_t localTime = static_cast<time_t>(localTimeSeconds);
367
368#if HAVE(TM_GMTOFF)
369 tm localTM;
370 getLocalTime(&localTime, &localTM);
371 return LocalTimeOffset(localTM.tm_isdst, localTM.tm_gmtoff * msPerSecond);
372#else
373 double dstOffset = calculateDSTOffset(localTime, localToUTCTimeOffset);
374 return LocalTimeOffset(dstOffset, localToUTCTimeOffset + dstOffset);
375#endif
376}
377
378void initializeDates()
379{
380#if !ASSERT_DISABLED
381 static bool alreadyInitialized;
382 ASSERT(!alreadyInitialized);
383 alreadyInitialized = true;
384#endif
385
386 equivalentYearForDST(2000); // Need to call once to initialize a static used in this function.
387}
388
389static inline double ymdhmsToSeconds(int year, long mon, long day, long hour, long minute, double second)
390{
391 int mday = firstDayOfMonth[isLeapYear(year)][mon - 1];
392 double ydays = daysFrom1970ToYear(year);
393
394 double dateSeconds = second + minute * secondsPerMinute + hour * secondsPerHour + (mday + day - 1 + ydays) * secondsPerDay;
395
396 // Clamp to EcmaScript standard (ecma262/#sec-time-values-and-time-range) of
397 // +/- 100,000,000 days from 01 January, 1970.
398 if (dateSeconds < -8640000000000.0 || dateSeconds > 8640000000000.0)
399 return std::numeric_limits<double>::quiet_NaN();
400
401 return dateSeconds;
402}
403
404// We follow the recommendation of RFC 2822 to consider all
405// obsolete time zones not listed here equivalent to "-0000".
406static const struct KnownZone {
407#if !OS(WINDOWS)
408 const
409#endif
410 char tzName[4];
411 int tzOffset;
412} knownZones[] = {
413 { "ut", 0 },
414 { "gmt", 0 },
415 { "est", -300 },
416 { "edt", -240 },
417 { "cst", -360 },
418 { "cdt", -300 },
419 { "mst", -420 },
420 { "mdt", -360 },
421 { "pst", -480 },
422 { "pdt", -420 }
423};
424
425inline static void skipSpacesAndComments(const char*& s)
426{
427 int nesting = 0;
428 char ch;
429 while ((ch = *s)) {
430 if (!isASCIISpace(ch)) {
431 if (ch == '(')
432 nesting++;
433 else if (ch == ')' && nesting > 0)
434 nesting--;
435 else if (nesting == 0)
436 break;
437 }
438 s++;
439 }
440}
441
442// returns 0-11 (Jan-Dec); -1 on failure
443static int findMonth(const char* monthStr)
444{
445 ASSERT(monthStr);
446 char needle[4];
447 for (int i = 0; i < 3; ++i) {
448 if (!*monthStr)
449 return -1;
450 needle[i] = static_cast<char>(toASCIILower(*monthStr++));
451 }
452 needle[3] = '\0';
453 const char *haystack = "janfebmaraprmayjunjulaugsepoctnovdec";
454 const char *str = strstr(haystack, needle);
455 if (str) {
456 int position = static_cast<int>(str - haystack);
457 if (position % 3 == 0)
458 return position / 3;
459 }
460 return -1;
461}
462
463static bool parseInt(const char* string, char** stopPosition, int base, int* result)
464{
465 long longResult = strtol(string, stopPosition, base);
466 // Avoid the use of errno as it is not available on Windows CE
467 if (string == *stopPosition || longResult <= std::numeric_limits<int>::min() || longResult >= std::numeric_limits<int>::max())
468 return false;
469 *result = static_cast<int>(longResult);
470 return true;
471}
472
473static bool parseLong(const char* string, char** stopPosition, int base, long* result)
474{
475 *result = strtol(string, stopPosition, base);
476 // Avoid the use of errno as it is not available on Windows CE
477 if (string == *stopPosition || *result == std::numeric_limits<long>::min() || *result == std::numeric_limits<long>::max())
478 return false;
479 return true;
480}
481
482// Parses a date with the format YYYY[-MM[-DD]].
483// Year parsing is lenient, allows any number of digits, and +/-.
484// Returns 0 if a parse error occurs, else returns the end of the parsed portion of the string.
485static char* parseES5DatePortion(const char* currentPosition, int& year, long& month, long& day)
486{
487 char* postParsePosition;
488
489 // This is a bit more lenient on the year string than ES5 specifies:
490 // instead of restricting to 4 digits (or 6 digits with mandatory +/-),
491 // it accepts any integer value. Consider this an implementation fallback.
492 if (!parseInt(currentPosition, &postParsePosition, 10, &year))
493 return 0;
494
495 // Check for presence of -MM portion.
496 if (*postParsePosition != '-')
497 return postParsePosition;
498 currentPosition = postParsePosition + 1;
499
500 if (!isASCIIDigit(*currentPosition))
501 return 0;
502 if (!parseLong(currentPosition, &postParsePosition, 10, &month))
503 return 0;
504 if ((postParsePosition - currentPosition) != 2)
505 return 0;
506
507 // Check for presence of -DD portion.
508 if (*postParsePosition != '-')
509 return postParsePosition;
510 currentPosition = postParsePosition + 1;
511
512 if (!isASCIIDigit(*currentPosition))
513 return 0;
514 if (!parseLong(currentPosition, &postParsePosition, 10, &day))
515 return 0;
516 if ((postParsePosition - currentPosition) != 2)
517 return 0;
518 return postParsePosition;
519}
520
521// Parses a time with the format HH:mm[:ss[.sss]][Z|(+|-)00:00].
522// Fractional seconds parsing is lenient, allows any number of digits.
523// Returns 0 if a parse error occurs, else returns the end of the parsed portion of the string.
524static char* parseES5TimePortion(char* currentPosition, long& hours, long& minutes, double& seconds, long& timeZoneSeconds)
525{
526 char* postParsePosition;
527 if (!isASCIIDigit(*currentPosition))
528 return 0;
529 if (!parseLong(currentPosition, &postParsePosition, 10, &hours))
530 return 0;
531 if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2)
532 return 0;
533 currentPosition = postParsePosition + 1;
534
535 if (!isASCIIDigit(*currentPosition))
536 return 0;
537 if (!parseLong(currentPosition, &postParsePosition, 10, &minutes))
538 return 0;
539 if ((postParsePosition - currentPosition) != 2)
540 return 0;
541 currentPosition = postParsePosition;
542
543 // Seconds are optional.
544 if (*currentPosition == ':') {
545 ++currentPosition;
546
547 long intSeconds;
548 if (!isASCIIDigit(*currentPosition))
549 return 0;
550 if (!parseLong(currentPosition, &postParsePosition, 10, &intSeconds))
551 return 0;
552 if ((postParsePosition - currentPosition) != 2)
553 return 0;
554 seconds = intSeconds;
555 if (*postParsePosition == '.') {
556 currentPosition = postParsePosition + 1;
557
558 // In ECMA-262-5 it's a bit unclear if '.' can be present without milliseconds, but
559 // a reasonable interpretation guided by the given examples and RFC 3339 says "no".
560 // We check the next character to avoid reading +/- timezone hours after an invalid decimal.
561 if (!isASCIIDigit(*currentPosition))
562 return 0;
563
564 // We are more lenient than ES5 by accepting more or less than 3 fraction digits.
565 long fracSeconds;
566 if (!parseLong(currentPosition, &postParsePosition, 10, &fracSeconds))
567 return 0;
568
569 long numFracDigits = postParsePosition - currentPosition;
570 seconds += fracSeconds * pow(10.0, static_cast<double>(-numFracDigits));
571 }
572 currentPosition = postParsePosition;
573 }
574
575 if (*currentPosition == 'Z')
576 return currentPosition + 1;
577
578 bool tzNegative;
579 if (*currentPosition == '-')
580 tzNegative = true;
581 else if (*currentPosition == '+')
582 tzNegative = false;
583 else
584 return currentPosition; // no timezone
585 ++currentPosition;
586
587 long tzHours;
588 long tzHoursAbs;
589 long tzMinutes;
590
591 if (!isASCIIDigit(*currentPosition))
592 return 0;
593 if (!parseLong(currentPosition, &postParsePosition, 10, &tzHours))
594 return 0;
595 if (*postParsePosition != ':' || (postParsePosition - currentPosition) != 2)
596 return 0;
597 tzHoursAbs = labs(tzHours);
598 currentPosition = postParsePosition + 1;
599
600 if (!isASCIIDigit(*currentPosition))
601 return 0;
602 if (!parseLong(currentPosition, &postParsePosition, 10, &tzMinutes))
603 return 0;
604 if ((postParsePosition - currentPosition) != 2)
605 return 0;
606 currentPosition = postParsePosition;
607
608 if (tzHoursAbs > 24)
609 return 0;
610 if (tzMinutes < 0 || tzMinutes > 59)
611 return 0;
612
613 timeZoneSeconds = 60 * (tzMinutes + (60 * tzHoursAbs));
614 if (tzNegative)
615 timeZoneSeconds = -timeZoneSeconds;
616
617 return currentPosition;
618}
619
620double parseES5DateFromNullTerminatedCharacters(const char* dateString)
621{
622 // This parses a date of the form defined in ecma262/#sec-date-time-string-format
623 // (similar to RFC 3339 / ISO 8601: YYYY-MM-DDTHH:mm:ss[.sss]Z).
624 // In most cases it is intentionally strict (e.g. correct field widths, no stray whitespace).
625
626 static const long daysPerMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
627
628 // The year must be present, but the other fields may be omitted - see ES5.1 15.9.1.15.
629 int year = 0;
630 long month = 1;
631 long day = 1;
632 long hours = 0;
633 long minutes = 0;
634 double seconds = 0;
635 long timeZoneSeconds = 0;
636
637 // Parse the date YYYY[-MM[-DD]]
638 char* currentPosition = parseES5DatePortion(dateString, year, month, day);
639 if (!currentPosition)
640 return std::numeric_limits<double>::quiet_NaN();
641 // Look for a time portion.
642 if (*currentPosition == 'T') {
643 // Parse the time HH:mm[:ss[.sss]][Z|(+|-)00:00]
644 currentPosition = parseES5TimePortion(currentPosition + 1, hours, minutes, seconds, timeZoneSeconds);
645 if (!currentPosition)
646 return std::numeric_limits<double>::quiet_NaN();
647 }
648 // Check that we have parsed all characters in the string.
649 if (*currentPosition)
650 return std::numeric_limits<double>::quiet_NaN();
651
652 // A few of these checks could be done inline above, but since many of them are interrelated
653 // we would be sacrificing readability to "optimize" the (presumably less common) failure path.
654 if (month < 1 || month > 12)
655 return std::numeric_limits<double>::quiet_NaN();
656 if (day < 1 || day > daysPerMonth[month - 1])
657 return std::numeric_limits<double>::quiet_NaN();
658 if (month == 2 && day > 28 && !isLeapYear(year))
659 return std::numeric_limits<double>::quiet_NaN();
660 if (hours < 0 || hours > 24)
661 return std::numeric_limits<double>::quiet_NaN();
662 if (hours == 24 && (minutes || seconds))
663 return std::numeric_limits<double>::quiet_NaN();
664 if (minutes < 0 || minutes > 59)
665 return std::numeric_limits<double>::quiet_NaN();
666 if (seconds < 0 || seconds >= 61)
667 return std::numeric_limits<double>::quiet_NaN();
668 if (seconds > 60) {
669 // Discard leap seconds by clamping to the end of a minute.
670 seconds = 60;
671 }
672
673 double dateSeconds = ymdhmsToSeconds(year, month, day, hours, minutes, seconds) - timeZoneSeconds;
674 return dateSeconds * msPerSecond;
675}
676
677// Odd case where 'exec' is allowed to be 0, to accomodate a caller in WebCore.
678double parseDateFromNullTerminatedCharacters(const char* dateString, bool& haveTZ, int& offset)
679{
680 haveTZ = false;
681 offset = 0;
682
683 // This parses a date in the form:
684 // Tuesday, 09-Nov-99 23:12:40 GMT
685 // or
686 // Sat, 01-Jan-2000 08:00:00 GMT
687 // or
688 // Sat, 01 Jan 2000 08:00:00 GMT
689 // or
690 // 01 Jan 99 22:00 +0100 (exceptions in rfc822/rfc2822)
691 // ### non RFC formats, added for Javascript:
692 // [Wednesday] January 09 1999 23:12:40 GMT
693 // [Wednesday] January 09 23:12:40 GMT 1999
694 //
695 // We ignore the weekday.
696
697 // Skip leading space
698 skipSpacesAndComments(dateString);
699
700 long month = -1;
701 const char *wordStart = dateString;
702 // Check contents of first words if not number
703 while (*dateString && !isASCIIDigit(*dateString)) {
704 if (isASCIISpace(*dateString) || *dateString == '(') {
705 if (dateString - wordStart >= 3)
706 month = findMonth(wordStart);
707 skipSpacesAndComments(dateString);
708 wordStart = dateString;
709 } else
710 dateString++;
711 }
712
713 // Missing delimiter between month and day (like "January29")?
714 if (month == -1 && wordStart != dateString)
715 month = findMonth(wordStart);
716
717 skipSpacesAndComments(dateString);
718
719 if (!*dateString)
720 return std::numeric_limits<double>::quiet_NaN();
721
722 // ' 09-Nov-99 23:12:40 GMT'
723 char* newPosStr;
724 long day;
725 if (!parseLong(dateString, &newPosStr, 10, &day))
726 return std::numeric_limits<double>::quiet_NaN();
727 dateString = newPosStr;
728
729 if (day < 0)
730 return std::numeric_limits<double>::quiet_NaN();
731
732 Optional<int> year;
733 if (day > 31) {
734 // ### where is the boundary and what happens below?
735 if (*dateString != '/')
736 return std::numeric_limits<double>::quiet_NaN();
737 // looks like a YYYY/MM/DD date
738 if (!*++dateString)
739 return std::numeric_limits<double>::quiet_NaN();
740 if (day <= std::numeric_limits<int>::min() || day >= std::numeric_limits<int>::max())
741 return std::numeric_limits<double>::quiet_NaN();
742 year = static_cast<int>(day);
743 if (!parseLong(dateString, &newPosStr, 10, &month))
744 return std::numeric_limits<double>::quiet_NaN();
745 month -= 1;
746 dateString = newPosStr;
747 if (*dateString++ != '/' || !*dateString)
748 return std::numeric_limits<double>::quiet_NaN();
749 if (!parseLong(dateString, &newPosStr, 10, &day))
750 return std::numeric_limits<double>::quiet_NaN();
751 dateString = newPosStr;
752 } else if (*dateString == '/' && month == -1) {
753 dateString++;
754 // This looks like a MM/DD/YYYY date, not an RFC date.
755 month = day - 1; // 0-based
756 if (!parseLong(dateString, &newPosStr, 10, &day))
757 return std::numeric_limits<double>::quiet_NaN();
758 if (day < 1 || day > 31)
759 return std::numeric_limits<double>::quiet_NaN();
760 dateString = newPosStr;
761 if (*dateString == '/')
762 dateString++;
763 if (!*dateString)
764 return std::numeric_limits<double>::quiet_NaN();
765 } else {
766 if (*dateString == '-')
767 dateString++;
768
769 skipSpacesAndComments(dateString);
770
771 if (*dateString == ',')
772 dateString++;
773
774 if (month == -1) { // not found yet
775 month = findMonth(dateString);
776 if (month == -1)
777 return std::numeric_limits<double>::quiet_NaN();
778
779 while (*dateString && *dateString != '-' && *dateString != ',' && !isASCIISpace(*dateString))
780 dateString++;
781
782 if (!*dateString)
783 return std::numeric_limits<double>::quiet_NaN();
784
785 // '-99 23:12:40 GMT'
786 if (*dateString != '-' && *dateString != '/' && *dateString != ',' && !isASCIISpace(*dateString))
787 return std::numeric_limits<double>::quiet_NaN();
788 dateString++;
789 }
790 }
791
792 if (month < 0 || month > 11)
793 return std::numeric_limits<double>::quiet_NaN();
794
795 // '99 23:12:40 GMT'
796 if (*dateString && !year) {
797 int result = 0;
798 if (!parseInt(dateString, &newPosStr, 10, &result))
799 return std::numeric_limits<double>::quiet_NaN();
800 year = result;
801 }
802
803 // Don't fail if the time is missing.
804 long hour = 0;
805 long minute = 0;
806 long second = 0;
807 if (!*newPosStr)
808 dateString = newPosStr;
809 else {
810 // ' 23:12:40 GMT'
811 if (!(isASCIISpace(*newPosStr) || *newPosStr == ',')) {
812 if (*newPosStr != ':')
813 return std::numeric_limits<double>::quiet_NaN();
814 // There was no year; the number was the hour.
815 year = WTF::nullopt;
816 } else {
817 // in the normal case (we parsed the year), advance to the next number
818 dateString = ++newPosStr;
819 skipSpacesAndComments(dateString);
820 }
821
822 parseLong(dateString, &newPosStr, 10, &hour);
823 // Do not check for errno here since we want to continue
824 // even if errno was set becasue we are still looking
825 // for the timezone!
826
827 // Read a number? If not, this might be a timezone name.
828 if (newPosStr != dateString) {
829 dateString = newPosStr;
830
831 if (hour < 0 || hour > 23)
832 return std::numeric_limits<double>::quiet_NaN();
833
834 if (!*dateString)
835 return std::numeric_limits<double>::quiet_NaN();
836
837 // ':12:40 GMT'
838 if (*dateString++ != ':')
839 return std::numeric_limits<double>::quiet_NaN();
840
841 if (!parseLong(dateString, &newPosStr, 10, &minute))
842 return std::numeric_limits<double>::quiet_NaN();
843 dateString = newPosStr;
844
845 if (minute < 0 || minute > 59)
846 return std::numeric_limits<double>::quiet_NaN();
847
848 // ':40 GMT'
849 if (*dateString && *dateString != ':' && !isASCIISpace(*dateString))
850 return std::numeric_limits<double>::quiet_NaN();
851
852 // seconds are optional in rfc822 + rfc2822
853 if (*dateString ==':') {
854 dateString++;
855
856 if (!parseLong(dateString, &newPosStr, 10, &second))
857 return std::numeric_limits<double>::quiet_NaN();
858 dateString = newPosStr;
859
860 if (second < 0 || second > 59)
861 return std::numeric_limits<double>::quiet_NaN();
862 }
863
864 skipSpacesAndComments(dateString);
865
866 if (startsWithLettersIgnoringASCIICase(dateString, "am")) {
867 if (hour > 12)
868 return std::numeric_limits<double>::quiet_NaN();
869 if (hour == 12)
870 hour = 0;
871 dateString += 2;
872 skipSpacesAndComments(dateString);
873 } else if (startsWithLettersIgnoringASCIICase(dateString, "pm")) {
874 if (hour > 12)
875 return std::numeric_limits<double>::quiet_NaN();
876 if (hour != 12)
877 hour += 12;
878 dateString += 2;
879 skipSpacesAndComments(dateString);
880 }
881 }
882 }
883
884 // The year may be after the time but before the time zone.
885 if (isASCIIDigit(*dateString) && !year) {
886 int result = 0;
887 if (!parseInt(dateString, &newPosStr, 10, &result))
888 return std::numeric_limits<double>::quiet_NaN();
889 year = result;
890 dateString = newPosStr;
891 skipSpacesAndComments(dateString);
892 }
893
894 // Don't fail if the time zone is missing.
895 // Some websites omit the time zone (4275206).
896 if (*dateString) {
897 if (startsWithLettersIgnoringASCIICase(dateString, "gmt") || startsWithLettersIgnoringASCIICase(dateString, "utc")) {
898 dateString += 3;
899 haveTZ = true;
900 }
901
902 if (*dateString == '+' || *dateString == '-') {
903 int o;
904 if (!parseInt(dateString, &newPosStr, 10, &o))
905 return std::numeric_limits<double>::quiet_NaN();
906 dateString = newPosStr;
907
908 if (o < -9959 || o > 9959)
909 return std::numeric_limits<double>::quiet_NaN();
910
911 int sgn = (o < 0) ? -1 : 1;
912 o = abs(o);
913 if (*dateString != ':') {
914 if (o >= 24)
915 offset = ((o / 100) * 60 + (o % 100)) * sgn;
916 else
917 offset = o * 60 * sgn;
918 } else { // GMT+05:00
919 ++dateString; // skip the ':'
920 int o2;
921 if (!parseInt(dateString, &newPosStr, 10, &o2))
922 return std::numeric_limits<double>::quiet_NaN();
923 dateString = newPosStr;
924 offset = (o * 60 + o2) * sgn;
925 }
926 haveTZ = true;
927 } else {
928 for (auto& knownZone : knownZones) {
929 // Since the passed-in length is used for both strings, the following checks that
930 // dateString has the time zone name as a prefix, not that it is equal.
931 auto length = strlen(knownZone.tzName);
932 if (equalLettersIgnoringASCIICase(dateString, knownZone.tzName, length)) {
933 offset = knownZone.tzOffset;
934 dateString += length;
935 haveTZ = true;
936 break;
937 }
938 }
939 }
940 }
941
942 skipSpacesAndComments(dateString);
943
944 if (*dateString && !year) {
945 int result = 0;
946 if (!parseInt(dateString, &newPosStr, 10, &result))
947 return std::numeric_limits<double>::quiet_NaN();
948 year = result;
949 dateString = newPosStr;
950 skipSpacesAndComments(dateString);
951 }
952
953 // Trailing garbage
954 if (*dateString)
955 return std::numeric_limits<double>::quiet_NaN();
956
957 // Y2K: Handle 2 digit years.
958 if (year) {
959 int yearValue = year.value();
960 if (yearValue >= 0 && yearValue < 100) {
961 if (yearValue < 50)
962 yearValue += 2000;
963 else
964 yearValue += 1900;
965 }
966 year = yearValue;
967 } else {
968 // We select 2000 as default value. This is because of the following reasons.
969 // 1. Year 2000 was used for the initial value of the variable `year`. While it won't be posed to users in WebKit,
970 // V8 used this 2000 as its default value. (As of April 2017, V8 is using the year 2001 and Spider Monkey is
971 // not doing this kind of fallback.)
972 // 2. It is a leap year. When using `new Date("Feb 29")`, we assume that people want to save month and day.
973 // Leap year can save user inputs if they is valid. If we use the current year instead, the current year
974 // may not be a leap year. In that case, `new Date("Feb 29").getMonth()` becomes 2 (March).
975 year = 2000;
976 }
977 ASSERT(year);
978
979 return ymdhmsToSeconds(year.value(), month + 1, day, hour, minute, second) * msPerSecond;
980}
981
982double parseDateFromNullTerminatedCharacters(const char* dateString)
983{
984 bool haveTZ;
985 int offset;
986 double ms = parseDateFromNullTerminatedCharacters(dateString, haveTZ, offset);
987 if (std::isnan(ms))
988 return std::numeric_limits<double>::quiet_NaN();
989
990 // fall back to local timezone
991 if (!haveTZ)
992 offset = calculateLocalTimeOffset(ms, LocalTime).offset / msPerMinute; // ms value is in local time milliseconds.
993
994 return ms - (offset * msPerMinute);
995}
996
997// See http://tools.ietf.org/html/rfc2822#section-3.3 for more information.
998String makeRFC2822DateString(unsigned dayOfWeek, unsigned day, unsigned month, unsigned year, unsigned hours, unsigned minutes, unsigned seconds, int utcOffset)
999{
1000 StringBuilder stringBuilder;
1001 stringBuilder.append(weekdayName[dayOfWeek], ", ", day, ' ', monthName[month], ' ', year, ' ');
1002
1003 appendTwoDigitNumber(stringBuilder, hours);
1004 stringBuilder.append(':');
1005 appendTwoDigitNumber(stringBuilder, minutes);
1006 stringBuilder.append(':');
1007 appendTwoDigitNumber(stringBuilder, seconds);
1008 stringBuilder.append(' ');
1009
1010 stringBuilder.append(utcOffset > 0 ? '+' : '-');
1011 int absoluteUTCOffset = abs(utcOffset);
1012 appendTwoDigitNumber(stringBuilder, absoluteUTCOffset / 60);
1013 appendTwoDigitNumber(stringBuilder, absoluteUTCOffset % 60);
1014
1015 return stringBuilder.toString();
1016}
1017
1018} // namespace WTF
1019