1/* Portions are Copyright (C) 2011 Google Inc */
2/* ***** BEGIN LICENSE BLOCK *****
3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
6 * 1.1 (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 * http://www.mozilla.org/MPL/
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the
13 * License.
14 *
15 * The Original Code is the Netscape Portable Runtime (NSPR).
16 *
17 * The Initial Developer of the Original Code is
18 * Netscape Communications Corporation.
19 * Portions created by the Initial Developer are Copyright (C) 1998-2000
20 * the Initial Developer. All Rights Reserved.
21 *
22 * Contributor(s):
23 *
24 * Alternatively, the contents of this file may be used under the terms of
25 * either the GNU General Public License Version 2 or later (the "GPL"), or
26 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
27 * in which case the provisions of the GPL or the LGPL are applicable instead
28 * of those above. If you wish to allow use of your version of this file only
29 * under the terms of either the GPL or the LGPL, and not to allow others to
30 * use your version of this file under the terms of the MPL, indicate your
31 * decision by deleting the provisions above and replace them with the notice
32 * and other provisions required by the GPL or the LGPL. If you do not delete
33 * the provisions above, a recipient may use your version of this file under
34 * the terms of any one of the MPL, the GPL or the LGPL.
35 *
36 * ***** END LICENSE BLOCK ***** */
37
38/*
39 * prtime.cc --
40 * NOTE: The original nspr file name is prtime.c
41 *
42 *     NSPR date and time functions
43 *
44 * CVS revision 3.37
45 */
46
47/*
48 * The following functions were copied from the NSPR prtime.c file.
49 * PR_ParseTimeString
50 *   We inlined the new PR_ParseTimeStringToExplodedTime function to avoid
51 *   copying PR_ExplodeTime and PR_LocalTimeParameters.  (The PR_ExplodeTime
52 *   and PR_ImplodeTime calls cancel each other out.)
53 * PR_NormalizeTime
54 * PR_GMTParameters
55 * PR_ImplodeTime
56 *   Upstream implementation from
57 *   http://lxr.mozilla.org/nspr/source/pr/src/misc/prtime.c#221
58 * All types and macros are defined in the base/third_party/prtime.h file.
59 * These have been copied from the following nspr files. We have only copied
60 * over the types we need.
61 * 1. prtime.h
62 * 2. prtypes.h
63 * 3. prlong.h
64 *
65 * Unit tests are in base/time/pr_time_unittest.cc.
66 */
67
68#include <limits.h>
69
70#include "base/logging.h"
71#include "base/third_party/nspr/prtime.h"
72#include "build/build_config.h"
73
74#include <errno.h>  /* for EINVAL */
75#include <time.h>
76
77/*
78 * The COUNT_LEAPS macro counts the number of leap years passed by
79 * till the start of the given year Y.  At the start of the year 4
80 * A.D. the number of leap years passed by is 0, while at the start of
81 * the year 5 A.D. this count is 1. The number of years divisible by
82 * 100 but not divisible by 400 (the non-leap years) is deducted from
83 * the count to get the correct number of leap years.
84 *
85 * The COUNT_DAYS macro counts the number of days since 01/01/01 till the
86 * start of the given year Y. The number of days at the start of the year
87 * 1 is 0 while the number of days at the start of the year 2 is 365
88 * (which is ((2)-1) * 365) and so on. The reference point is 01/01/01
89 * midnight 00:00:00.
90 */
91
92#define COUNT_LEAPS(Y) (((Y)-1) / 4 - ((Y)-1) / 100 + ((Y)-1) / 400)
93#define COUNT_DAYS(Y) (((Y)-1) * 365 + COUNT_LEAPS(Y))
94#define DAYS_BETWEEN_YEARS(A, B) (COUNT_DAYS(B) - COUNT_DAYS(A))
95
96/* Implements the Unix localtime_r() function for windows */
97#if defined(OS_WIN)
98static void localtime_r(const time_t* secs, struct tm* time) {
99  (void) localtime_s(time, secs);
100}
101#endif
102
103/*
104 * Static variables used by functions in this file
105 */
106
107/*
108 * The following array contains the day of year for the last day of
109 * each month, where index 1 is January, and day 0 is January 1.
110 */
111
112static const int lastDayOfMonth[2][13] = {
113    {-1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364},
114    {-1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365}
115};
116
117/*
118 * The number of days in a month
119 */
120
121static const PRInt8 nDays[2][12] = {
122    {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
123    {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
124};
125
126/*
127 *------------------------------------------------------------------------
128 *
129 * PR_ImplodeTime --
130 *
131 *     Cf. time_t mktime(struct tm *tp)
132 *     Note that 1 year has < 2^25 seconds.  So an PRInt32 is large enough.
133 *
134 *------------------------------------------------------------------------
135 */
136PRTime
137PR_ImplodeTime(const PRExplodedTime *exploded)
138{
139  PRExplodedTime copy;
140  PRTime retVal;
141  PRInt64 secPerDay, usecPerSec;
142  PRInt64 temp;
143  PRInt64 numSecs64;
144  PRInt32 numDays;
145  PRInt32 numSecs;
146
147  /* Normalize first.  Do this on our copy */
148  copy = *exploded;
149  PR_NormalizeTime(&copy, PR_GMTParameters);
150
151  numDays = DAYS_BETWEEN_YEARS(1970, copy.tm_year);
152
153  numSecs = copy.tm_yday * 86400 + copy.tm_hour * 3600 + copy.tm_min * 60 +
154            copy.tm_sec;
155
156  LL_I2L(temp, numDays);
157  LL_I2L(secPerDay, 86400);
158  LL_MUL(temp, temp, secPerDay);
159  LL_I2L(numSecs64, numSecs);
160  LL_ADD(numSecs64, numSecs64, temp);
161
162  /* apply the GMT and DST offsets */
163  LL_I2L(temp, copy.tm_params.tp_gmt_offset);
164  LL_SUB(numSecs64, numSecs64, temp);
165  LL_I2L(temp, copy.tm_params.tp_dst_offset);
166  LL_SUB(numSecs64, numSecs64, temp);
167
168  LL_I2L(usecPerSec, 1000000L);
169  LL_MUL(temp, numSecs64, usecPerSec);
170  LL_I2L(retVal, copy.tm_usec);
171  LL_ADD(retVal, retVal, temp);
172
173  return retVal;
174}
175
176/*
177 *-------------------------------------------------------------------------
178 *
179 * IsLeapYear --
180 *
181 *     Returns 1 if the year is a leap year, 0 otherwise.
182 *
183 *-------------------------------------------------------------------------
184 */
185
186static int IsLeapYear(PRInt16 year)
187{
188    if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
189        return 1;
190    else
191        return 0;
192}
193
194/*
195 * 'secOffset' should be less than 86400 (i.e., a day).
196 * 'time' should point to a normalized PRExplodedTime.
197 */
198
199static void
200ApplySecOffset(PRExplodedTime *time, PRInt32 secOffset)
201{
202    time->tm_sec += secOffset;
203
204    /* Note that in this implementation we do not count leap seconds */
205    if (time->tm_sec < 0 || time->tm_sec >= 60) {
206        time->tm_min += time->tm_sec / 60;
207        time->tm_sec %= 60;
208        if (time->tm_sec < 0) {
209            time->tm_sec += 60;
210            time->tm_min--;
211        }
212    }
213
214    if (time->tm_min < 0 || time->tm_min >= 60) {
215        time->tm_hour += time->tm_min / 60;
216        time->tm_min %= 60;
217        if (time->tm_min < 0) {
218            time->tm_min += 60;
219            time->tm_hour--;
220        }
221    }
222
223    if (time->tm_hour < 0) {
224        /* Decrement mday, yday, and wday */
225        time->tm_hour += 24;
226        time->tm_mday--;
227        time->tm_yday--;
228        if (time->tm_mday < 1) {
229            time->tm_month--;
230            if (time->tm_month < 0) {
231                time->tm_month = 11;
232                time->tm_year--;
233                if (IsLeapYear(time->tm_year))
234                    time->tm_yday = 365;
235                else
236                    time->tm_yday = 364;
237            }
238            time->tm_mday = nDays[IsLeapYear(time->tm_year)][time->tm_month];
239        }
240        time->tm_wday--;
241        if (time->tm_wday < 0)
242            time->tm_wday = 6;
243    } else if (time->tm_hour > 23) {
244        /* Increment mday, yday, and wday */
245        time->tm_hour -= 24;
246        time->tm_mday++;
247        time->tm_yday++;
248        if (time->tm_mday >
249                nDays[IsLeapYear(time->tm_year)][time->tm_month]) {
250            time->tm_mday = 1;
251            time->tm_month++;
252            if (time->tm_month > 11) {
253                time->tm_month = 0;
254                time->tm_year++;
255                time->tm_yday = 0;
256            }
257        }
258        time->tm_wday++;
259        if (time->tm_wday > 6)
260            time->tm_wday = 0;
261    }
262}
263
264void
265PR_NormalizeTime(PRExplodedTime *time, PRTimeParamFn params)
266{
267    int daysInMonth;
268    PRInt32 numDays;
269
270    /* Get back to GMT */
271    time->tm_sec -= time->tm_params.tp_gmt_offset
272            + time->tm_params.tp_dst_offset;
273    time->tm_params.tp_gmt_offset = 0;
274    time->tm_params.tp_dst_offset = 0;
275
276    /* Now normalize GMT */
277
278    if (time->tm_usec < 0 || time->tm_usec >= 1000000) {
279        time->tm_sec +=  time->tm_usec / 1000000;
280        time->tm_usec %= 1000000;
281        if (time->tm_usec < 0) {
282            time->tm_usec += 1000000;
283            time->tm_sec--;
284        }
285    }
286
287    /* Note that we do not count leap seconds in this implementation */
288    if (time->tm_sec < 0 || time->tm_sec >= 60) {
289        time->tm_min += time->tm_sec / 60;
290        time->tm_sec %= 60;
291        if (time->tm_sec < 0) {
292            time->tm_sec += 60;
293            time->tm_min--;
294        }
295    }
296
297    if (time->tm_min < 0 || time->tm_min >= 60) {
298        time->tm_hour += time->tm_min / 60;
299        time->tm_min %= 60;
300        if (time->tm_min < 0) {
301            time->tm_min += 60;
302            time->tm_hour--;
303        }
304    }
305
306    if (time->tm_hour < 0 || time->tm_hour >= 24) {
307        time->tm_mday += time->tm_hour / 24;
308        time->tm_hour %= 24;
309        if (time->tm_hour < 0) {
310            time->tm_hour += 24;
311            time->tm_mday--;
312        }
313    }
314
315    /* Normalize month and year before mday */
316    if (time->tm_month < 0 || time->tm_month >= 12) {
317        time->tm_year += static_cast<PRInt16>(time->tm_month / 12);
318        time->tm_month %= 12;
319        if (time->tm_month < 0) {
320            time->tm_month += 12;
321            time->tm_year--;
322        }
323    }
324
325    /* Now that month and year are in proper range, normalize mday */
326
327    if (time->tm_mday < 1) {
328        /* mday too small */
329        do {
330            /* the previous month */
331            time->tm_month--;
332            if (time->tm_month < 0) {
333                time->tm_month = 11;
334                time->tm_year--;
335            }
336            time->tm_mday += nDays[IsLeapYear(time->tm_year)][time->tm_month];
337        } while (time->tm_mday < 1);
338    } else {
339        daysInMonth = nDays[IsLeapYear(time->tm_year)][time->tm_month];
340        while (time->tm_mday > daysInMonth) {
341            /* mday too large */
342            time->tm_mday -= daysInMonth;
343            time->tm_month++;
344            if (time->tm_month > 11) {
345                time->tm_month = 0;
346                time->tm_year++;
347            }
348            daysInMonth = nDays[IsLeapYear(time->tm_year)][time->tm_month];
349        }
350    }
351
352    /* Recompute yday and wday */
353    time->tm_yday = static_cast<PRInt16>(time->tm_mday +
354            lastDayOfMonth[IsLeapYear(time->tm_year)][time->tm_month]);
355
356    numDays = DAYS_BETWEEN_YEARS(1970, time->tm_year) + time->tm_yday;
357    time->tm_wday = (numDays + 4) % 7;
358    if (time->tm_wday < 0) {
359        time->tm_wday += 7;
360    }
361
362    /* Recompute time parameters */
363
364    time->tm_params = params(time);
365
366    ApplySecOffset(time, time->tm_params.tp_gmt_offset
367            + time->tm_params.tp_dst_offset);
368}
369
370/*
371 *------------------------------------------------------------------------
372 *
373 * PR_GMTParameters --
374 *
375 *     Returns the PRTimeParameters for Greenwich Mean Time.
376 *     Trivially, both the tp_gmt_offset and tp_dst_offset fields are 0.
377 *
378 *------------------------------------------------------------------------
379 */
380
381PRTimeParameters
382PR_GMTParameters(const PRExplodedTime* /*gmt*/)
383{
384    PRTimeParameters retVal = { 0, 0 };
385    return retVal;
386}
387
388/*
389 * The following code implements PR_ParseTimeString().  It is based on
390 * ns/lib/xp/xp_time.c, revision 1.25, by Jamie Zawinski <jwz@netscape.com>.
391 */
392
393/*
394 * We only recognize the abbreviations of a small subset of time zones
395 * in North America, Europe, and Japan.
396 *
397 * PST/PDT: Pacific Standard/Daylight Time
398 * MST/MDT: Mountain Standard/Daylight Time
399 * CST/CDT: Central Standard/Daylight Time
400 * EST/EDT: Eastern Standard/Daylight Time
401 * AST: Atlantic Standard Time
402 * NST: Newfoundland Standard Time
403 * GMT: Greenwich Mean Time
404 * BST: British Summer Time
405 * MET: Middle Europe Time
406 * EET: Eastern Europe Time
407 * JST: Japan Standard Time
408 */
409
410typedef enum
411{
412  TT_UNKNOWN,
413
414  TT_SUN, TT_MON, TT_TUE, TT_WED, TT_THU, TT_FRI, TT_SAT,
415
416  TT_JAN, TT_FEB, TT_MAR, TT_APR, TT_MAY, TT_JUN,
417  TT_JUL, TT_AUG, TT_SEP, TT_OCT, TT_NOV, TT_DEC,
418
419  TT_PST, TT_PDT, TT_MST, TT_MDT, TT_CST, TT_CDT, TT_EST, TT_EDT,
420  TT_AST, TT_NST, TT_GMT, TT_BST, TT_MET, TT_EET, TT_JST
421} TIME_TOKEN;
422
423/*
424 * This parses a time/date string into a PRTime
425 * (microseconds after "1-Jan-1970 00:00:00 GMT").
426 * It returns PR_SUCCESS on success, and PR_FAILURE
427 * if the time/date string can't be parsed.
428 *
429 * Many formats are handled, including:
430 *
431 *   14 Apr 89 03:20:12
432 *   14 Apr 89 03:20 GMT
433 *   Fri, 17 Mar 89 4:01:33
434 *   Fri, 17 Mar 89 4:01 GMT
435 *   Mon Jan 16 16:12 PDT 1989
436 *   Mon Jan 16 16:12 +0130 1989
437 *   6 May 1992 16:41-JST (Wednesday)
438 *   22-AUG-1993 10:59:12.82
439 *   22-AUG-1993 10:59pm
440 *   22-AUG-1993 12:59am
441 *   22-AUG-1993 12:59 PM
442 *   Friday, August 04, 1995 3:54 PM
443 *   06/21/95 04:24:34 PM
444 *   20/06/95 21:07
445 *   95-06-08 19:32:48 EDT
446 *   1995-06-17T23:11:25.342156Z
447 *
448 * If the input string doesn't contain a description of the timezone,
449 * we consult the `default_to_gmt' to decide whether the string should
450 * be interpreted relative to the local time zone (PR_FALSE) or GMT (PR_TRUE).
451 * The correct value for this argument depends on what standard specified
452 * the time string which you are parsing.
453 */
454
455PRStatus
456PR_ParseTimeString(
457        const char *string,
458        PRBool default_to_gmt,
459        PRTime *result_imploded)
460{
461  PRExplodedTime tm;
462  PRExplodedTime *result = &tm;
463  TIME_TOKEN dotw = TT_UNKNOWN;
464  TIME_TOKEN month = TT_UNKNOWN;
465  TIME_TOKEN zone = TT_UNKNOWN;
466  int zone_offset = -1;
467  int dst_offset = 0;
468  int date = -1;
469  PRInt32 year = -1;
470  int hour = -1;
471  int min = -1;
472  int sec = -1;
473  int usec = -1;
474
475  const char *rest = string;
476
477  int iterations = 0;
478
479  PR_ASSERT(string && result);
480  if (!string || !result) return PR_FAILURE;
481
482  while (*rest)
483        {
484
485          if (iterations++ > 1000)
486                {
487                  return PR_FAILURE;
488                }
489
490          switch (*rest)
491                {
492                case 'a': case 'A':
493                  if (month == TT_UNKNOWN &&
494                          (rest[1] == 'p' || rest[1] == 'P') &&
495                          (rest[2] == 'r' || rest[2] == 'R'))
496                        month = TT_APR;
497                  else if (zone == TT_UNKNOWN &&
498                                   (rest[1] == 's' || rest[1] == 'S') &&
499                                   (rest[2] == 't' || rest[2] == 'T'))
500                        zone = TT_AST;
501                  else if (month == TT_UNKNOWN &&
502                                   (rest[1] == 'u' || rest[1] == 'U') &&
503                                   (rest[2] == 'g' || rest[2] == 'G'))
504                        month = TT_AUG;
505                  break;
506                case 'b': case 'B':
507                  if (zone == TT_UNKNOWN &&
508                          (rest[1] == 's' || rest[1] == 'S') &&
509                          (rest[2] == 't' || rest[2] == 'T'))
510                        zone = TT_BST;
511                  break;
512                case 'c': case 'C':
513                  if (zone == TT_UNKNOWN &&
514                          (rest[1] == 'd' || rest[1] == 'D') &&
515                          (rest[2] == 't' || rest[2] == 'T'))
516                        zone = TT_CDT;
517                  else if (zone == TT_UNKNOWN &&
518                                   (rest[1] == 's' || rest[1] == 'S') &&
519                                   (rest[2] == 't' || rest[2] == 'T'))
520                        zone = TT_CST;
521                  break;
522                case 'd': case 'D':
523                  if (month == TT_UNKNOWN &&
524                          (rest[1] == 'e' || rest[1] == 'E') &&
525                          (rest[2] == 'c' || rest[2] == 'C'))
526                        month = TT_DEC;
527                  break;
528                case 'e': case 'E':
529                  if (zone == TT_UNKNOWN &&
530                          (rest[1] == 'd' || rest[1] == 'D') &&
531                          (rest[2] == 't' || rest[2] == 'T'))
532                        zone = TT_EDT;
533                  else if (zone == TT_UNKNOWN &&
534                                   (rest[1] == 'e' || rest[1] == 'E') &&
535                                   (rest[2] == 't' || rest[2] == 'T'))
536                        zone = TT_EET;
537                  else if (zone == TT_UNKNOWN &&
538                                   (rest[1] == 's' || rest[1] == 'S') &&
539                                   (rest[2] == 't' || rest[2] == 'T'))
540                        zone = TT_EST;
541                  break;
542                case 'f': case 'F':
543                  if (month == TT_UNKNOWN &&
544                          (rest[1] == 'e' || rest[1] == 'E') &&
545                          (rest[2] == 'b' || rest[2] == 'B'))
546                        month = TT_FEB;
547                  else if (dotw == TT_UNKNOWN &&
548                                   (rest[1] == 'r' || rest[1] == 'R') &&
549                                   (rest[2] == 'i' || rest[2] == 'I'))
550                        dotw = TT_FRI;
551                  break;
552                case 'g': case 'G':
553                  if (zone == TT_UNKNOWN &&
554                          (rest[1] == 'm' || rest[1] == 'M') &&
555                          (rest[2] == 't' || rest[2] == 'T'))
556                        zone = TT_GMT;
557                  break;
558                case 'j': case 'J':
559                  if (month == TT_UNKNOWN &&
560                          (rest[1] == 'a' || rest[1] == 'A') &&
561                          (rest[2] == 'n' || rest[2] == 'N'))
562                        month = TT_JAN;
563                  else if (zone == TT_UNKNOWN &&
564                                   (rest[1] == 's' || rest[1] == 'S') &&
565                                   (rest[2] == 't' || rest[2] == 'T'))
566                        zone = TT_JST;
567                  else if (month == TT_UNKNOWN &&
568                                   (rest[1] == 'u' || rest[1] == 'U') &&
569                                   (rest[2] == 'l' || rest[2] == 'L'))
570                        month = TT_JUL;
571                  else if (month == TT_UNKNOWN &&
572                                   (rest[1] == 'u' || rest[1] == 'U') &&
573                                   (rest[2] == 'n' || rest[2] == 'N'))
574                        month = TT_JUN;
575                  break;
576                case 'm': case 'M':
577                  if (month == TT_UNKNOWN &&
578                          (rest[1] == 'a' || rest[1] == 'A') &&
579                          (rest[2] == 'r' || rest[2] == 'R'))
580                        month = TT_MAR;
581                  else if (month == TT_UNKNOWN &&
582                                   (rest[1] == 'a' || rest[1] == 'A') &&
583                                   (rest[2] == 'y' || rest[2] == 'Y'))
584                        month = TT_MAY;
585                  else if (zone == TT_UNKNOWN &&
586                                   (rest[1] == 'd' || rest[1] == 'D') &&
587                                   (rest[2] == 't' || rest[2] == 'T'))
588                        zone = TT_MDT;
589                  else if (zone == TT_UNKNOWN &&
590                                   (rest[1] == 'e' || rest[1] == 'E') &&
591                                   (rest[2] == 't' || rest[2] == 'T'))
592                        zone = TT_MET;
593                  else if (dotw == TT_UNKNOWN &&
594                                   (rest[1] == 'o' || rest[1] == 'O') &&
595                                   (rest[2] == 'n' || rest[2] == 'N'))
596                        dotw = TT_MON;
597                  else if (zone == TT_UNKNOWN &&
598                                   (rest[1] == 's' || rest[1] == 'S') &&
599                                   (rest[2] == 't' || rest[2] == 'T'))
600                        zone = TT_MST;
601                  break;
602                case 'n': case 'N':
603                  if (month == TT_UNKNOWN &&
604                          (rest[1] == 'o' || rest[1] == 'O') &&
605                          (rest[2] == 'v' || rest[2] == 'V'))
606                        month = TT_NOV;
607                  else if (zone == TT_UNKNOWN &&
608                                   (rest[1] == 's' || rest[1] == 'S') &&
609                                   (rest[2] == 't' || rest[2] == 'T'))
610                        zone = TT_NST;
611                  break;
612                case 'o': case 'O':
613                  if (month == TT_UNKNOWN &&
614                          (rest[1] == 'c' || rest[1] == 'C') &&
615                          (rest[2] == 't' || rest[2] == 'T'))
616                        month = TT_OCT;
617                  break;
618                case 'p': case 'P':
619                  if (zone == TT_UNKNOWN &&
620                          (rest[1] == 'd' || rest[1] == 'D') &&
621                          (rest[2] == 't' || rest[2] == 'T'))
622                        zone = TT_PDT;
623                  else if (zone == TT_UNKNOWN &&
624                                   (rest[1] == 's' || rest[1] == 'S') &&
625                                   (rest[2] == 't' || rest[2] == 'T'))
626                        zone = TT_PST;
627                  break;
628                case 's': case 'S':
629                  if (dotw == TT_UNKNOWN &&
630                          (rest[1] == 'a' || rest[1] == 'A') &&
631                          (rest[2] == 't' || rest[2] == 'T'))
632                        dotw = TT_SAT;
633                  else if (month == TT_UNKNOWN &&
634                                   (rest[1] == 'e' || rest[1] == 'E') &&
635                                   (rest[2] == 'p' || rest[2] == 'P'))
636                        month = TT_SEP;
637                  else if (dotw == TT_UNKNOWN &&
638                                   (rest[1] == 'u' || rest[1] == 'U') &&
639                                   (rest[2] == 'n' || rest[2] == 'N'))
640                        dotw = TT_SUN;
641                  break;
642                case 't': case 'T':
643                  if (dotw == TT_UNKNOWN &&
644                          (rest[1] == 'h' || rest[1] == 'H') &&
645                          (rest[2] == 'u' || rest[2] == 'U'))
646                        dotw = TT_THU;
647                  else if (dotw == TT_UNKNOWN &&
648                                   (rest[1] == 'u' || rest[1] == 'U') &&
649                                   (rest[2] == 'e' || rest[2] == 'E'))
650                        dotw = TT_TUE;
651                  break;
652                case 'u': case 'U':
653                  if (zone == TT_UNKNOWN &&
654                          (rest[1] == 't' || rest[1] == 'T') &&
655                          !(rest[2] >= 'A' && rest[2] <= 'Z') &&
656                          !(rest[2] >= 'a' && rest[2] <= 'z'))
657                        /* UT is the same as GMT but UTx is not. */
658                        zone = TT_GMT;
659                  break;
660                case 'w': case 'W':
661                  if (dotw == TT_UNKNOWN &&
662                          (rest[1] == 'e' || rest[1] == 'E') &&
663                          (rest[2] == 'd' || rest[2] == 'D'))
664                        dotw = TT_WED;
665                  break;
666
667                case '+': case '-':
668                  {
669                        const char *end;
670                        int sign;
671                        if (zone_offset != -1)
672                          {
673                                /* already got one... */
674                                rest++;
675                                break;
676                          }
677                        if (zone != TT_UNKNOWN && zone != TT_GMT)
678                          {
679                                /* GMT+0300 is legal, but PST+0300 is not. */
680                                rest++;
681                                break;
682                          }
683
684                        sign = ((*rest == '+') ? 1 : -1);
685                        rest++; /* move over sign */
686                        end = rest;
687                        while (*end >= '0' && *end <= '9')
688                          end++;
689                        if (rest == end) /* no digits here */
690                          break;
691
692                        if ((end - rest) == 4)
693                          /* offset in HHMM */
694                          zone_offset = (((((rest[0]-'0')*10) + (rest[1]-'0')) * 60) +
695                                                         (((rest[2]-'0')*10) + (rest[3]-'0')));
696                        else if ((end - rest) == 2)
697                          /* offset in hours */
698                          zone_offset = (((rest[0]-'0')*10) + (rest[1]-'0')) * 60;
699                        else if ((end - rest) == 1)
700                          /* offset in hours */
701                          zone_offset = (rest[0]-'0') * 60;
702                        else
703                          /* 3 or >4 */
704                          break;
705
706                        zone_offset *= sign;
707                        zone = TT_GMT;
708                        break;
709                  }
710
711                case '0': case '1': case '2': case '3': case '4':
712                case '5': case '6': case '7': case '8': case '9':
713                  {
714                        int tmp_hour = -1;
715                        int tmp_min = -1;
716                        int tmp_sec = -1;
717                        int tmp_usec = -1;
718                        const char *end = rest + 1;
719                        while (*end >= '0' && *end <= '9')
720                          end++;
721
722                        /* end is now the first character after a range of digits. */
723
724                        if (*end == ':')
725                          {
726                                if (hour >= 0 && min >= 0) /* already got it */
727                                  break;
728
729                                /* We have seen "[0-9]+:", so this is probably HH:MM[:SS] */
730                                if ((end - rest) > 2)
731                                  /* it is [0-9][0-9][0-9]+: */
732                                  break;
733                                else if ((end - rest) == 2)
734                                  tmp_hour = ((rest[0]-'0')*10 +
735                                                          (rest[1]-'0'));
736                                else
737                                  tmp_hour = (rest[0]-'0');
738
739                                /* move over the colon, and parse minutes */
740
741                                rest = ++end;
742                                while (*end >= '0' && *end <= '9')
743                                  end++;
744
745                                if (end == rest)
746                                  /* no digits after first colon? */
747                                  break;
748                                else if ((end - rest) > 2)
749                                  /* it is [0-9][0-9][0-9]+: */
750                                  break;
751                                else if ((end - rest) == 2)
752                                  tmp_min = ((rest[0]-'0')*10 +
753                                                         (rest[1]-'0'));
754                                else
755                                  tmp_min = (rest[0]-'0');
756
757                                /* now go for seconds */
758                                rest = end;
759                                if (*rest == ':')
760                                  rest++;
761                                end = rest;
762                                while (*end >= '0' && *end <= '9')
763                                  end++;
764
765                                if (end == rest)
766                                  /* no digits after second colon - that's ok. */
767                                  ;
768                                else if ((end - rest) > 2)
769                                  /* it is [0-9][0-9][0-9]+: */
770                                  break;
771                                else if ((end - rest) == 2)
772                                  tmp_sec = ((rest[0]-'0')*10 +
773                                                         (rest[1]-'0'));
774                                else
775                                  tmp_sec = (rest[0]-'0');
776
777                                /* fractional second */
778                                rest = end;
779                                if (*rest == '.')
780                                  {
781                                    rest++;
782                                    end++;
783                                    tmp_usec = 0;
784                                    /* use up to 6 digits, skip over the rest */
785                                    while (*end >= '0' && *end <= '9')
786                                      {
787                                        if (end - rest < 6)
788                                          tmp_usec = tmp_usec * 10 + *end - '0';
789                                        end++;
790                                      }
791                                    int ndigits = end - rest;
792                                    while (ndigits++ < 6)
793                                      tmp_usec *= 10;
794                                    rest = end;
795                                  }
796
797                                if (*rest == 'Z')
798                                  {
799                                    zone = TT_GMT;
800                                    rest++;
801                                  }
802                                else if (tmp_hour <= 12)
803                                  {
804                                    /* If we made it here, we've parsed hour and min,
805                                       and possibly sec, so the current token is a time.
806                                       Now skip over whitespace and see if there's an AM
807                                       or PM directly following the time.
808                                    */
809                                        const char *s = end;
810                                        while (*s && (*s == ' ' || *s == '\t'))
811                                          s++;
812                                        if ((s[0] == 'p' || s[0] == 'P') &&
813                                                (s[1] == 'm' || s[1] == 'M'))
814                                          /* 10:05pm == 22:05, and 12:05pm == 12:05 */
815                                          tmp_hour = (tmp_hour == 12 ? 12 : tmp_hour + 12);
816                                        else if (tmp_hour == 12 &&
817                                                         (s[0] == 'a' || s[0] == 'A') &&
818                                                         (s[1] == 'm' || s[1] == 'M'))
819                                          /* 12:05am == 00:05 */
820                                          tmp_hour = 0;
821                                  }
822
823                                hour = tmp_hour;
824                                min = tmp_min;
825                                sec = tmp_sec;
826                                usec = tmp_usec;
827                                rest = end;
828                                break;
829                          }
830                        else if ((*end == '/' || *end == '-') &&
831                                         end[1] >= '0' && end[1] <= '9')
832                          {
833                                /* Perhaps this is 6/16/95, 16/6/95, 6-16-95, or 16-6-95
834                                   or even 95-06-05 or 1995-06-22.
835                                 */
836                                int n1, n2, n3;
837                                const char *s;
838
839                                if (month != TT_UNKNOWN)
840                                  /* if we saw a month name, this can't be. */
841                                  break;
842
843                                s = rest;
844
845                                n1 = (*s++ - '0');                                /* first 1, 2 or 4 digits */
846                                if (*s >= '0' && *s <= '9')
847                                  {
848                                    n1 = n1*10 + (*s++ - '0');
849
850                                    if (*s >= '0' && *s <= '9')            /* optional digits 3 and 4 */
851                                      {
852                                        n1 = n1*10 + (*s++ - '0');
853                                        if (*s < '0' || *s > '9')
854                                          break;
855                                        n1 = n1*10 + (*s++ - '0');
856                                      }
857                                  }
858
859                                if (*s != '/' && *s != '-')                /* slash */
860                                  break;
861                                s++;
862
863                                if (*s < '0' || *s > '9')                /* second 1 or 2 digits */
864                                  break;
865                                n2 = (*s++ - '0');
866                                if (*s >= '0' && *s <= '9')
867                                  n2 = n2*10 + (*s++ - '0');
868
869                                if (*s != '/' && *s != '-')                /* slash */
870                                  break;
871                                s++;
872
873                                if (*s < '0' || *s > '9')                /* third 1, 2, 4, or 5 digits */
874                                  break;
875                                n3 = (*s++ - '0');
876                                if (*s >= '0' && *s <= '9')
877                                  n3 = n3*10 + (*s++ - '0');
878
879                                if (*s >= '0' && *s <= '9')            /* optional digits 3, 4, and 5 */
880                                  {
881                                        n3 = n3*10 + (*s++ - '0');
882                                        if (*s < '0' || *s > '9')
883                                          break;
884                                        n3 = n3*10 + (*s++ - '0');
885                                        if (*s >= '0' && *s <= '9')
886                                          n3 = n3*10 + (*s++ - '0');
887                                  }
888
889                                if (*s == 'T' && s[1] >= '0' && s[1] <= '9')
890                                  /* followed by ISO 8601 T delimiter and number is ok */
891                                  ;
892                                else if ((*s >= '0' && *s <= '9') ||
893                                         (*s >= 'A' && *s <= 'Z') ||
894                                         (*s >= 'a' && *s <= 'z'))
895                                  /* but other alphanumerics are not ok */
896                                  break;
897
898                                /* Ok, we parsed three multi-digit numbers, with / or -
899                                   between them.  Now decide what the hell they are
900                                   (DD/MM/YY or MM/DD/YY or [YY]YY/MM/DD.)
901                                 */
902
903                                if (n1 > 31 || n1 == 0)  /* must be [YY]YY/MM/DD */
904                                  {
905                                        if (n2 > 12) break;
906                                        if (n3 > 31) break;
907                                        year = n1;
908                                        if (year < 70)
909                                            year += 2000;
910                                        else if (year < 100)
911                                            year += 1900;
912                                        month = (TIME_TOKEN)(n2 + ((int)TT_JAN) - 1);
913                                        date = n3;
914                                        rest = s;
915                                        break;
916                                  }
917
918                                if (n1 > 12 && n2 > 12)  /* illegal */
919                                  {
920                                        rest = s;
921                                        break;
922                                  }
923
924                                if (n3 < 70)
925                                    n3 += 2000;
926                                else if (n3 < 100)
927                                    n3 += 1900;
928
929                                if (n1 > 12)  /* must be DD/MM/YY */
930                                  {
931                                        date = n1;
932                                        month = (TIME_TOKEN)(n2 + ((int)TT_JAN) - 1);
933                                        year = n3;
934                                  }
935                                else                  /* assume MM/DD/YY */
936                                  {
937                                        /* #### In the ambiguous case, should we consult the
938                                           locale to find out the local default? */
939                                        month = (TIME_TOKEN)(n1 + ((int)TT_JAN) - 1);
940                                        date = n2;
941                                        year = n3;
942                                  }
943                                rest = s;
944                          }
945                        else if ((*end >= 'A' && *end <= 'Z') ||
946                                         (*end >= 'a' && *end <= 'z'))
947                          /* Digits followed by non-punctuation - what's that? */
948                          ;
949                        else if ((end - rest) == 5)                /* five digits is a year */
950                          year = (year < 0
951                                          ? ((rest[0]-'0')*10000L +
952                                                 (rest[1]-'0')*1000L +
953                                                 (rest[2]-'0')*100L +
954                                                 (rest[3]-'0')*10L +
955                                                 (rest[4]-'0'))
956                                          : year);
957                        else if ((end - rest) == 4)                /* four digits is a year */
958                          year = (year < 0
959                                          ? ((rest[0]-'0')*1000L +
960                                                 (rest[1]-'0')*100L +
961                                                 (rest[2]-'0')*10L +
962                                                 (rest[3]-'0'))
963                                          : year);
964                        else if ((end - rest) == 2)                /* two digits - date or year */
965                          {
966                                int n = ((rest[0]-'0')*10 +
967                                                 (rest[1]-'0'));
968                                /* If we don't have a date (day of the month) and we see a number
969                                     less than 32, then assume that is the date.
970
971                                         Otherwise, if we have a date and not a year, assume this is the
972                                         year.  If it is less than 70, then assume it refers to the 21st
973                                         century.  If it is two digits (>= 70), assume it refers to this
974                                         century.  Otherwise, assume it refers to an unambiguous year.
975
976                                         The world will surely end soon.
977                                   */
978                                if (date < 0 && n < 32)
979                                  date = n;
980                                else if (year < 0)
981                                  {
982                                        if (n < 70)
983                                          year = 2000 + n;
984                                        else if (n < 100)
985                                          year = 1900 + n;
986                                        else
987                                          year = n;
988                                  }
989                                /* else what the hell is this. */
990                          }
991                        else if ((end - rest) == 1)                /* one digit - date */
992                          date = (date < 0 ? (rest[0]-'0') : date);
993                        /* else, three or more than five digits - what's that? */
994
995                        break;
996                  }   /* case '0' .. '9' */
997                }   /* switch */
998
999          /* Skip to the end of this token, whether we parsed it or not.
1000             Tokens are delimited by whitespace, or ,;-+/()[] but explicitly not .:
1001             'T' is also treated as delimiter when followed by a digit (ISO 8601).
1002           */
1003          while (*rest &&
1004                         *rest != ' ' && *rest != '\t' &&
1005                         *rest != ',' && *rest != ';' &&
1006                         *rest != '-' && *rest != '+' &&
1007                         *rest != '/' &&
1008                         *rest != '(' && *rest != ')' && *rest != '[' && *rest != ']' &&
1009                         !(*rest == 'T' && rest[1] >= '0' && rest[1] <= '9')
1010                )
1011                rest++;
1012          /* skip over uninteresting chars. */
1013        SKIP_MORE:
1014          while (*rest == ' ' || *rest == '\t' ||
1015                 *rest == ',' || *rest == ';' || *rest == '/' ||
1016                 *rest == '(' || *rest == ')' || *rest == '[' || *rest == ']')
1017                rest++;
1018
1019          /* "-" is ignored at the beginning of a token if we have not yet
1020                 parsed a year (e.g., the second "-" in "30-AUG-1966"), or if
1021                 the character after the dash is not a digit. */
1022          if (*rest == '-' && ((rest > string &&
1023              isalpha((unsigned char)rest[-1]) && year < 0) ||
1024              rest[1] < '0' || rest[1] > '9'))
1025                {
1026                  rest++;
1027                  goto SKIP_MORE;
1028                }
1029
1030          /* Skip T that may precede ISO 8601 time. */
1031          if (*rest == 'T' && rest[1] >= '0' && rest[1] <= '9')
1032            rest++;
1033        }   /* while */
1034
1035  if (zone != TT_UNKNOWN && zone_offset == -1)
1036        {
1037          switch (zone)
1038                {
1039                case TT_PST: zone_offset = -8 * 60; break;
1040                case TT_PDT: zone_offset = -8 * 60; dst_offset = 1 * 60; break;
1041                case TT_MST: zone_offset = -7 * 60; break;
1042                case TT_MDT: zone_offset = -7 * 60; dst_offset = 1 * 60; break;
1043                case TT_CST: zone_offset = -6 * 60; break;
1044                case TT_CDT: zone_offset = -6 * 60; dst_offset = 1 * 60; break;
1045                case TT_EST: zone_offset = -5 * 60; break;
1046                case TT_EDT: zone_offset = -5 * 60; dst_offset = 1 * 60; break;
1047                case TT_AST: zone_offset = -4 * 60; break;
1048                case TT_NST: zone_offset = -3 * 60 - 30; break;
1049                case TT_GMT: zone_offset =  0 * 60; break;
1050                case TT_BST: zone_offset =  0 * 60; dst_offset = 1 * 60; break;
1051                case TT_MET: zone_offset =  1 * 60; break;
1052                case TT_EET: zone_offset =  2 * 60; break;
1053                case TT_JST: zone_offset =  9 * 60; break;
1054                default:
1055                  PR_ASSERT (0);
1056                  break;
1057                }
1058        }
1059
1060  /* If we didn't find a year, month, or day-of-the-month, we can't
1061         possibly parse this, and in fact, mktime() will do something random
1062         (I'm seeing it return "Tue Feb  5 06:28:16 2036", which is no doubt
1063         a numerologically significant date... */
1064  if (month == TT_UNKNOWN || date == -1 || year == -1 || year > PR_INT16_MAX)
1065      return PR_FAILURE;
1066
1067  memset(result, 0, sizeof(*result));
1068  if (usec != -1)
1069        result->tm_usec = usec;
1070  if (sec != -1)
1071        result->tm_sec = sec;
1072  if (min != -1)
1073        result->tm_min = min;
1074  if (hour != -1)
1075        result->tm_hour = hour;
1076  if (date != -1)
1077        result->tm_mday = date;
1078  if (month != TT_UNKNOWN)
1079        result->tm_month = (((int)month) - ((int)TT_JAN));
1080  if (year != -1)
1081        result->tm_year = static_cast<PRInt16>(year);
1082  if (dotw != TT_UNKNOWN)
1083        result->tm_wday = static_cast<PRInt8>(((int)dotw) - ((int)TT_SUN));
1084  /*
1085   * Mainly to compute wday and yday, but normalized time is also required
1086   * by the check below that works around a Visual C++ 2005 mktime problem.
1087   */
1088  PR_NormalizeTime(result, PR_GMTParameters);
1089  /* The remaining work is to set the gmt and dst offsets in tm_params. */
1090
1091  if (zone == TT_UNKNOWN && default_to_gmt)
1092        {
1093          /* No zone was specified, so pretend the zone was GMT. */
1094          zone = TT_GMT;
1095          zone_offset = 0;
1096        }
1097
1098  if (zone_offset == -1)
1099         {
1100           /* no zone was specified, and we're to assume that everything
1101             is local. */
1102          struct tm localTime;
1103          time_t secs;
1104
1105          PR_ASSERT(result->tm_month > -1 &&
1106                    result->tm_mday > 0 &&
1107                    result->tm_hour > -1 &&
1108                    result->tm_min > -1 &&
1109                    result->tm_sec > -1);
1110
1111            /*
1112             * To obtain time_t from a tm structure representing the local
1113             * time, we call mktime().  However, we need to see if we are
1114             * on 1-Jan-1970 or before.  If we are, we can't call mktime()
1115             * because mktime() will crash on win16. In that case, we
1116             * calculate zone_offset based on the zone offset at
1117             * 00:00:00, 2 Jan 1970 GMT, and subtract zone_offset from the
1118             * date we are parsing to transform the date to GMT.  We also
1119             * do so if mktime() returns (time_t) -1 (time out of range).
1120           */
1121
1122          /* month, day, hours, mins and secs are always non-negative
1123             so we dont need to worry about them. */
1124          if (result->tm_year >= 1970)
1125                {
1126                  localTime.tm_sec = result->tm_sec;
1127                  localTime.tm_min = result->tm_min;
1128                  localTime.tm_hour = result->tm_hour;
1129                  localTime.tm_mday = result->tm_mday;
1130                  localTime.tm_mon = result->tm_month;
1131                  localTime.tm_year = result->tm_year - 1900;
1132                  /* Set this to -1 to tell mktime "I don't care".  If you set
1133                     it to 0 or 1, you are making assertions about whether the
1134                     date you are handing it is in daylight savings mode or not;
1135                     and if you're wrong, it will "fix" it for you. */
1136                  localTime.tm_isdst = -1;
1137
1138#if _MSC_VER == 1400  /* 1400 = Visual C++ 2005 (8.0) */
1139                  /*
1140                   * mktime will return (time_t) -1 if the input is a date
1141                   * after 23:59:59, December 31, 3000, US Pacific Time (not
1142                   * UTC as documented):
1143                   * http://msdn.microsoft.com/en-us/library/d1y53h2a(VS.80).aspx
1144                   * But if the year is 3001, mktime also invokes the invalid
1145                   * parameter handler, causing the application to crash.  This
1146                   * problem has been reported in
1147                   * http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=266036.
1148                   * We avoid this crash by not calling mktime if the date is
1149                   * out of range.  To use a simple test that works in any time
1150                   * zone, we consider year 3000 out of range as well.  (See
1151                   * bug 480740.)
1152                   */
1153                  if (result->tm_year >= 3000) {
1154                      /* Emulate what mktime would have done. */
1155                      errno = EINVAL;
1156                      secs = (time_t) -1;
1157                  } else {
1158                      secs = mktime(&localTime);
1159                  }
1160#else
1161                  secs = mktime(&localTime);
1162#endif
1163                  if (secs != (time_t) -1)
1164                    {
1165                      *result_imploded = (PRInt64)secs * PR_USEC_PER_SEC;
1166                      *result_imploded += result->tm_usec;
1167                      return PR_SUCCESS;
1168                    }
1169                }
1170
1171                /* So mktime() can't handle this case.  We assume the
1172                   zone_offset for the date we are parsing is the same as
1173                   the zone offset on 00:00:00 2 Jan 1970 GMT. */
1174                secs = 86400;
1175                localtime_r(&secs, &localTime);
1176                zone_offset = localTime.tm_min
1177                              + 60 * localTime.tm_hour
1178                              + 1440 * (localTime.tm_mday - 2);
1179        }
1180
1181  result->tm_params.tp_gmt_offset = zone_offset * 60;
1182  result->tm_params.tp_dst_offset = dst_offset * 60;
1183
1184  *result_imploded = PR_ImplodeTime(result);
1185  return PR_SUCCESS;
1186}
1187