Commit | Line | Data |
---|---|---|
a272e669 MS |
1 | /* |
2 | ||
3 | Copyright (c) 2007-2008 Michael G Schwern | |
4 | ||
5 | This software originally derived from Paul Sheer's pivotal_gmtime_r.c. | |
6 | ||
7 | The MIT License: | |
8 | ||
9 | Permission is hereby granted, free of charge, to any person obtaining a copy | |
10 | of this software and associated documentation files (the "Software"), to deal | |
11 | in the Software without restriction, including without limitation the rights | |
12 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
13 | copies of the Software, and to permit persons to whom the Software is | |
14 | furnished to do so, subject to the following conditions: | |
15 | ||
16 | The above copyright notice and this permission notice shall be included in | |
17 | all copies or substantial portions of the Software. | |
18 | ||
19 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
20 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
21 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
22 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
23 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
24 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
25 | THE SOFTWARE. | |
26 | ||
27 | */ | |
28 | ||
29 | /* | |
30 | ||
31 | Programmers who have available to them 64-bit time values as a 'long | |
32 | long' type can use localtime64_r() and gmtime64_r() which correctly | |
33 | converts the time even on 32-bit systems. Whether you have 64-bit time | |
34 | values will depend on the operating system. | |
35 | ||
f832b29a | 36 | Perl_localtime64_r() is a 64-bit equivalent of localtime_r(). |
a272e669 | 37 | |
f832b29a | 38 | Perl_gmtime64_r() is a 64-bit equivalent of gmtime_r(). |
a272e669 MS |
39 | |
40 | */ | |
41 | ||
f832b29a JH |
42 | #include "EXTERN.h" |
43 | #define PERL_IN_TIME64_C | |
44 | #include "perl.h" | |
7643e68f | 45 | #include "time64.h" |
af9b2bf5 | 46 | |
4bb2f1fc | 47 | static const char days_in_month[2][12] = { |
a272e669 MS |
48 | {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, |
49 | {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}, | |
50 | }; | |
51 | ||
4bb2f1fc | 52 | static const short julian_days_by_month[2][12] = { |
a272e669 MS |
53 | {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}, |
54 | {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}, | |
55 | }; | |
56 | ||
4bb2f1fc | 57 | static const short length_of_year[2] = { 365, 366 }; |
a272e669 MS |
58 | |
59 | /* Number of days in a 400 year Gregorian cycle */ | |
806a119a | 60 | static const Year years_in_gregorian_cycle = 400; |
a272e669 MS |
61 | static const int days_in_gregorian_cycle = (365 * 400) + 100 - 4 + 1; |
62 | ||
63 | /* 28 year calendar cycle between 2010 and 2037 */ | |
806a119a | 64 | #define SOLAR_CYCLE_LENGTH 28 |
4bb2f1fc | 65 | static const short safe_years[SOLAR_CYCLE_LENGTH] = { |
a272e669 MS |
66 | 2016, 2017, 2018, 2019, |
67 | 2020, 2021, 2022, 2023, | |
68 | 2024, 2025, 2026, 2027, | |
69 | 2028, 2029, 2030, 2031, | |
70 | 2032, 2033, 2034, 2035, | |
71 | 2036, 2037, 2010, 2011, | |
72 | 2012, 2013, 2014, 2015 | |
73 | }; | |
74 | ||
9af24521 MS |
75 | /* Let's assume people are going to be looking for dates in the future. |
76 | Let's provide some cheats so you can skip ahead. | |
77 | This has a 4x speed boost when near 2008. | |
78 | */ | |
79 | /* Number of days since epoch on Jan 1st, 2008 GMT */ | |
80 | #define CHEAT_DAYS (1199145600 / 24 / 60 / 60) | |
81 | #define CHEAT_YEARS 108 | |
a272e669 MS |
82 | |
83 | #define IS_LEAP(n) ((!(((n) + 1900) % 400) || (!(((n) + 1900) % 4) && (((n) + 1900) % 100))) != 0) | |
d584a308 | 84 | #undef WRAP /* some <termios.h> define this */ |
a272e669 MS |
85 | #define WRAP(a,b,m) ((a) = ((a) < 0 ) ? ((b)--, (a) + (m)) : (a)) |
86 | ||
b86b480f MS |
87 | #ifdef USE_SYSTEM_LOCALTIME |
88 | # define SHOULD_USE_SYSTEM_LOCALTIME(a) ( \ | |
7bda3dfc MS |
89 | (a) <= SYSTEM_LOCALTIME_MAX && \ |
90 | (a) >= SYSTEM_LOCALTIME_MIN \ | |
91 | ) | |
b86b480f MS |
92 | #else |
93 | # define SHOULD_USE_SYSTEM_LOCALTIME(a) (0) | |
94 | #endif | |
95 | ||
96 | #ifdef USE_SYSTEM_GMTIME | |
97 | # define SHOULD_USE_SYSTEM_GMTIME(a) ( \ | |
7bda3dfc MS |
98 | (a) <= SYSTEM_GMTIME_MAX && \ |
99 | (a) >= SYSTEM_GMTIME_MIN \ | |
100 | ) | |
b86b480f MS |
101 | #else |
102 | # define SHOULD_USE_SYSTEM_GMTIME(a) (0) | |
103 | #endif | |
a64acb40 | 104 | |
d4fb0a1f | 105 | /* Multi varadic macros are a C99 thing, alas */ |
461d5a49 | 106 | #ifdef TIME_64_DEBUG |
7430375d CB |
107 | # define TIME64_TRACE(format) (fprintf(stderr, format)) |
108 | # define TIME64_TRACE1(format, var1) (fprintf(stderr, format, var1)) | |
109 | # define TIME64_TRACE2(format, var1, var2) (fprintf(stderr, format, var1, var2)) | |
110 | # define TIME64_TRACE3(format, var1, var2, var3) (fprintf(stderr, format, var1, var2, var3)) | |
461d5a49 | 111 | #else |
7430375d CB |
112 | # define TIME64_TRACE(format) ((void)0) |
113 | # define TIME64_TRACE1(format, var1) ((void)0) | |
114 | # define TIME64_TRACE2(format, var1, var2) ((void)0) | |
115 | # define TIME64_TRACE3(format, var1, var2, var3) ((void)0) | |
461d5a49 | 116 | #endif |
a64acb40 | 117 | |
7430375d | 118 | static int S_is_exception_century(Year year) |
a272e669 | 119 | { |
c75442a5 | 120 | const int is_exception = ((year % 100 == 0) && !(year % 400 == 0)); |
7430375d | 121 | TIME64_TRACE1("# is_exception_century: %s\n", is_exception ? "yes" : "no"); |
a272e669 MS |
122 | |
123 | return(is_exception); | |
124 | } | |
125 | ||
9af24521 | 126 | |
c75442a5 | 127 | static Time64_T S_timegm64(const struct TM *date) { |
b86b480f MS |
128 | int days = 0; |
129 | Time64_T seconds = 0; | |
a272e669 | 130 | |
9af24521 | 131 | if( date->tm_year > 70 ) { |
c75442a5 | 132 | Year year = 70; |
9af24521 MS |
133 | while( year < date->tm_year ) { |
134 | days += length_of_year[IS_LEAP(year)]; | |
135 | year++; | |
a272e669 MS |
136 | } |
137 | } | |
9af24521 | 138 | else if ( date->tm_year < 70 ) { |
c75442a5 | 139 | Year year = 69; |
9af24521 MS |
140 | do { |
141 | days -= length_of_year[IS_LEAP(year)]; | |
142 | year--; | |
143 | } while( year >= date->tm_year ); | |
144 | } | |
145 | ||
146 | days += julian_days_by_month[IS_LEAP(date->tm_year)][date->tm_mon]; | |
147 | days += date->tm_mday - 1; | |
148 | ||
ea722b76 MS |
149 | /* Avoid overflowing the days integer */ |
150 | seconds = days; | |
151 | seconds = seconds * 60 * 60 * 24; | |
152 | ||
9af24521 MS |
153 | seconds += date->tm_hour * 60 * 60; |
154 | seconds += date->tm_min * 60; | |
155 | seconds += date->tm_sec; | |
156 | ||
b86b480f | 157 | return(seconds); |
9af24521 MS |
158 | } |
159 | ||
160 | ||
554fcfb9 | 161 | #ifdef DEBUGGING |
c75442a5 | 162 | static int S_check_tm(const struct TM *tm) |
9af24521 | 163 | { |
9af24521 | 164 | /* Don't forget leap seconds */ |
af9b2bf5 | 165 | assert(tm->tm_sec >= 0); |
9af24521 MS |
166 | assert(tm->tm_sec <= 61); |
167 | ||
af9b2bf5 | 168 | assert(tm->tm_min >= 0); |
9af24521 MS |
169 | assert(tm->tm_min <= 59); |
170 | ||
171 | assert(tm->tm_hour >= 0); | |
172 | assert(tm->tm_hour <= 23); | |
173 | ||
174 | assert(tm->tm_mday >= 1); | |
af9b2bf5 | 175 | assert(tm->tm_mday <= days_in_month[IS_LEAP(tm->tm_year)][tm->tm_mon]); |
9af24521 MS |
176 | |
177 | assert(tm->tm_mon >= 0); | |
178 | assert(tm->tm_mon <= 11); | |
179 | ||
180 | assert(tm->tm_wday >= 0); | |
181 | assert(tm->tm_wday <= 6); | |
182 | ||
183 | assert(tm->tm_yday >= 0); | |
af9b2bf5 | 184 | assert(tm->tm_yday <= length_of_year[IS_LEAP(tm->tm_year)]); |
9af24521 MS |
185 | |
186 | #ifdef HAS_TM_TM_GMTOFF | |
187 | assert(tm->tm_gmtoff >= -24 * 60 * 60); | |
188 | assert(tm->tm_gmtoff <= 24 * 60 * 60); | |
189 | #endif | |
af9b2bf5 MS |
190 | |
191 | return 1; | |
a272e669 | 192 | } |
554fcfb9 | 193 | #endif |
a64acb40 | 194 | |
a272e669 MS |
195 | |
196 | /* The exceptional centuries without leap years cause the cycle to | |
197 | shift by 16 | |
198 | */ | |
7430375d | 199 | static Year S_cycle_offset(Year year) |
a272e669 | 200 | { |
750c447b MS |
201 | const Year start_year = 2000; |
202 | Year year_diff = year - start_year; | |
203 | Year exceptions; | |
003c3b95 MS |
204 | |
205 | if( year > start_year ) | |
206 | year_diff--; | |
207 | ||
750c447b MS |
208 | exceptions = year_diff / 100; |
209 | exceptions -= year_diff / 400; | |
a272e669 | 210 | |
7430375d | 211 | TIME64_TRACE3("# year: %lld, exceptions: %lld, year_diff: %lld\n", |
461d5a49 | 212 | year, exceptions, year_diff); |
a272e669 MS |
213 | |
214 | return exceptions * 16; | |
215 | } | |
216 | ||
217 | /* For a given year after 2038, pick the latest possible matching | |
218 | year in the 28 year calendar cycle. | |
ea722b76 MS |
219 | |
220 | A matching year... | |
221 | 1) Starts on the same day of the week. | |
222 | 2) Has the same leap year status. | |
223 | ||
224 | This is so the calendars match up. | |
225 | ||
226 | Also the previous year must match. When doing Jan 1st you might | |
227 | wind up on Dec 31st the previous year when doing a -UTC time zone. | |
003c3b95 MS |
228 | |
229 | Finally, the next year must have the same start day of week. This | |
230 | is for Dec 31st with a +UTC time zone. | |
231 | It doesn't need the same leap year status since we only care about | |
232 | January 1st. | |
a272e669 | 233 | */ |
7430375d | 234 | static int S_safe_year(Year year) |
a272e669 MS |
235 | { |
236 | int safe_year; | |
7430375d | 237 | Year year_cycle = year + S_cycle_offset(year); |
a272e669 MS |
238 | |
239 | /* Change non-leap xx00 years to an equivalent */ | |
7430375d | 240 | if( S_is_exception_century(year) ) |
a272e669 MS |
241 | year_cycle += 11; |
242 | ||
003c3b95 | 243 | /* Also xx01 years, since the previous year will be wrong */ |
7430375d | 244 | if( S_is_exception_century(year - 1) ) |
003c3b95 MS |
245 | year_cycle += 17; |
246 | ||
a272e669 | 247 | year_cycle %= SOLAR_CYCLE_LENGTH; |
ea722b76 MS |
248 | if( year_cycle < 0 ) |
249 | year_cycle = SOLAR_CYCLE_LENGTH + year_cycle; | |
a272e669 | 250 | |
003c3b95 MS |
251 | assert( year_cycle >= 0 ); |
252 | assert( year_cycle < SOLAR_CYCLE_LENGTH ); | |
a272e669 MS |
253 | safe_year = safe_years[year_cycle]; |
254 | ||
255 | assert(safe_year <= 2037 && safe_year >= 2010); | |
256 | ||
7430375d | 257 | TIME64_TRACE3("# year: %lld, year_cycle: %lld, safe_year: %d\n", |
461d5a49 | 258 | year, year_cycle, safe_year); |
a272e669 MS |
259 | |
260 | return safe_year; | |
261 | } | |
262 | ||
750c447b | 263 | |
7430375d | 264 | static void S_copy_little_tm_to_big_TM(const struct tm *src, struct TM *dest) { |
606599e1 AD |
265 | assert(src); |
266 | assert(dest); | |
55971e21 DD |
267 | #ifdef USE_TM64 |
268 | dest->tm_sec = src->tm_sec; | |
269 | dest->tm_min = src->tm_min; | |
270 | dest->tm_hour = src->tm_hour; | |
271 | dest->tm_mday = src->tm_mday; | |
272 | dest->tm_mon = src->tm_mon; | |
273 | dest->tm_year = (Year)src->tm_year; | |
274 | dest->tm_wday = src->tm_wday; | |
275 | dest->tm_yday = src->tm_yday; | |
276 | dest->tm_isdst = src->tm_isdst; | |
277 | ||
278 | # ifdef HAS_TM_TM_GMTOFF | |
279 | dest->tm_gmtoff = src->tm_gmtoff; | |
280 | # endif | |
281 | ||
282 | # ifdef HAS_TM_TM_ZONE | |
283 | dest->tm_zone = src->tm_zone; | |
284 | # endif | |
285 | ||
286 | #else | |
287 | /* They're the same type */ | |
288 | memcpy(dest, src, sizeof(*dest)); | |
289 | #endif | |
806a119a MS |
290 | } |
291 | ||
292 | ||
7430375d | 293 | #ifndef HAS_LOCALTIME_R |
948ea7a9 | 294 | /* Simulate localtime_r() to the best of our ability */ |
7430375d | 295 | static struct tm * S_localtime_r(const time_t *clock, struct tm *result) { |
c97ab489 CB |
296 | #ifdef __VMS |
297 | dTHX; /* the following is defined as Perl_my_localtime(aTHX_ ...) */ | |
dbf7dff6 | 298 | #endif |
c75442a5 | 299 | const struct tm * const static_result = localtime(clock); |
948ea7a9 MS |
300 | |
301 | assert(result != NULL); | |
302 | ||
303 | if( static_result == NULL ) { | |
304 | memset(result, 0, sizeof(*result)); | |
305 | return NULL; | |
306 | } | |
307 | else { | |
308 | memcpy(result, static_result, sizeof(*result)); | |
309 | return result; | |
310 | } | |
311 | } | |
7430375d | 312 | #endif |
948ea7a9 | 313 | |
7430375d | 314 | #ifndef HAS_GMTIME_R |
948ea7a9 | 315 | /* Simulate gmtime_r() to the best of our ability */ |
7430375d | 316 | static struct tm * S_gmtime_r(const time_t *clock, struct tm *result) { |
c97ab489 CB |
317 | #ifdef __VMS |
318 | dTHX; /* the following is defined as Perl_my_localtime(aTHX_ ...) */ | |
319 | #endif | |
c75442a5 | 320 | const struct tm * const static_result = gmtime(clock); |
948ea7a9 MS |
321 | |
322 | assert(result != NULL); | |
323 | ||
324 | if( static_result == NULL ) { | |
325 | memset(result, 0, sizeof(*result)); | |
326 | return NULL; | |
327 | } | |
328 | else { | |
329 | memcpy(result, static_result, sizeof(*result)); | |
330 | return result; | |
331 | } | |
332 | } | |
7430375d | 333 | #endif |
948ea7a9 | 334 | |
f832b29a | 335 | struct TM *Perl_gmtime64_r (const Time64_T *in_time, struct TM *p) |
a272e669 MS |
336 | { |
337 | int v_tm_sec, v_tm_min, v_tm_hour, v_tm_mon, v_tm_wday; | |
b86b480f | 338 | Time64_T v_tm_tday; |
a272e669 | 339 | int leap; |
b86b480f | 340 | Time64_T m; |
a272e669 | 341 | Time64_T time = *in_time; |
750c447b | 342 | Year year = 70; |
a272e669 | 343 | |
948ea7a9 MS |
344 | assert(p != NULL); |
345 | ||
a64acb40 MS |
346 | /* Use the system gmtime() if time_t is small enough */ |
347 | if( SHOULD_USE_SYSTEM_GMTIME(*in_time) ) { | |
cd1759d8 | 348 | time_t safe_time = (time_t)*in_time; |
806a119a MS |
349 | struct tm safe_date; |
350 | GMTIME_R(&safe_time, &safe_date); | |
351 | ||
7430375d CB |
352 | S_copy_little_tm_to_big_TM(&safe_date, p); |
353 | assert(S_check_tm(p)); | |
806a119a | 354 | |
a64acb40 MS |
355 | return p; |
356 | } | |
357 | ||
9af24521 | 358 | #ifdef HAS_TM_TM_GMTOFF |
a272e669 MS |
359 | p->tm_gmtoff = 0; |
360 | #endif | |
361 | p->tm_isdst = 0; | |
362 | ||
9af24521 | 363 | #ifdef HAS_TM_TM_ZONE |
1cefca6b | 364 | p->tm_zone = (char *)"UTC"; |
a272e669 MS |
365 | #endif |
366 | ||
42033175 JH |
367 | v_tm_sec = (int)Perl_fmod(time, 60.0); |
368 | time = time >= 0 ? Perl_floor(time / 60.0) : Perl_ceil(time / 60.0); | |
369 | v_tm_min = (int)Perl_fmod(time, 60.0); | |
370 | time = time >= 0 ? Perl_floor(time / 60.0) : Perl_ceil(time / 60.0); | |
371 | v_tm_hour = (int)Perl_fmod(time, 24.0); | |
372 | time = time >= 0 ? Perl_floor(time / 24.0) : Perl_ceil(time / 24.0); | |
455f2c6c | 373 | v_tm_tday = time; |
750c447b | 374 | |
a272e669 MS |
375 | WRAP (v_tm_sec, v_tm_min, 60); |
376 | WRAP (v_tm_min, v_tm_hour, 60); | |
377 | WRAP (v_tm_hour, v_tm_tday, 24); | |
750c447b | 378 | |
42033175 | 379 | v_tm_wday = (int)Perl_fmod((v_tm_tday + 4.0), 7.0); |
750c447b | 380 | if (v_tm_wday < 0) |
a272e669 MS |
381 | v_tm_wday += 7; |
382 | m = v_tm_tday; | |
a272e669 | 383 | |
9af24521 MS |
384 | if (m >= CHEAT_DAYS) { |
385 | year = CHEAT_YEARS; | |
386 | m -= CHEAT_DAYS; | |
387 | } | |
388 | ||
389 | if (m >= 0) { | |
a272e669 | 390 | /* Gregorian cycles, this is huge optimization for distant times */ |
c75442a5 | 391 | const int cycles = (int)Perl_floor(m / (Time64_T) days_in_gregorian_cycle); |
806a119a MS |
392 | if( cycles ) { |
393 | m -= (cycles * (Time64_T) days_in_gregorian_cycle); | |
394 | year += (cycles * years_in_gregorian_cycle); | |
a272e669 MS |
395 | } |
396 | ||
397 | /* Years */ | |
398 | leap = IS_LEAP (year); | |
399 | while (m >= (Time64_T) length_of_year[leap]) { | |
400 | m -= (Time64_T) length_of_year[leap]; | |
401 | year++; | |
402 | leap = IS_LEAP (year); | |
403 | } | |
404 | ||
405 | /* Months */ | |
406 | v_tm_mon = 0; | |
407 | while (m >= (Time64_T) days_in_month[leap][v_tm_mon]) { | |
408 | m -= (Time64_T) days_in_month[leap][v_tm_mon]; | |
409 | v_tm_mon++; | |
410 | } | |
411 | } else { | |
c75442a5 AL |
412 | int cycles; |
413 | ||
9af24521 | 414 | year--; |
a272e669 MS |
415 | |
416 | /* Gregorian cycles */ | |
42033175 | 417 | cycles = (int)Perl_ceil((m / (Time64_T) days_in_gregorian_cycle) + 1); |
806a119a MS |
418 | if( cycles ) { |
419 | m -= (cycles * (Time64_T) days_in_gregorian_cycle); | |
420 | year += (cycles * years_in_gregorian_cycle); | |
a272e669 MS |
421 | } |
422 | ||
423 | /* Years */ | |
424 | leap = IS_LEAP (year); | |
425 | while (m < (Time64_T) -length_of_year[leap]) { | |
426 | m += (Time64_T) length_of_year[leap]; | |
427 | year--; | |
428 | leap = IS_LEAP (year); | |
429 | } | |
430 | ||
431 | /* Months */ | |
432 | v_tm_mon = 11; | |
433 | while (m < (Time64_T) -days_in_month[leap][v_tm_mon]) { | |
434 | m += (Time64_T) days_in_month[leap][v_tm_mon]; | |
435 | v_tm_mon--; | |
436 | } | |
437 | m += (Time64_T) days_in_month[leap][v_tm_mon]; | |
438 | } | |
439 | ||
440 | p->tm_year = year; | |
441 | if( p->tm_year != year ) { | |
9af24521 | 442 | #ifdef EOVERFLOW |
a272e669 | 443 | errno = EOVERFLOW; |
9af24521 | 444 | #endif |
a272e669 MS |
445 | return NULL; |
446 | } | |
447 | ||
b86b480f | 448 | /* At this point m is less than a year so casting to an int is safe */ |
a272e669 | 449 | p->tm_mday = (int) m + 1; |
b86b480f MS |
450 | p->tm_yday = julian_days_by_month[leap][v_tm_mon] + (int)m; |
451 | p->tm_sec = v_tm_sec; | |
452 | p->tm_min = v_tm_min; | |
453 | p->tm_hour = v_tm_hour; | |
454 | p->tm_mon = v_tm_mon; | |
455 | p->tm_wday = v_tm_wday; | |
a272e669 | 456 | |
7430375d | 457 | assert(S_check_tm(p)); |
a272e669 MS |
458 | |
459 | return p; | |
460 | } | |
461 | ||
462 | ||
f832b29a | 463 | struct TM *Perl_localtime64_r (const Time64_T *time, struct TM *local_tm) |
a272e669 MS |
464 | { |
465 | time_t safe_time; | |
806a119a MS |
466 | struct tm safe_date; |
467 | struct TM gm_tm; | |
750c447b | 468 | Year orig_year; |
a272e669 MS |
469 | int month_diff; |
470 | ||
948ea7a9 MS |
471 | assert(local_tm != NULL); |
472 | ||
a64acb40 MS |
473 | /* Use the system localtime() if time_t is small enough */ |
474 | if( SHOULD_USE_SYSTEM_LOCALTIME(*time) ) { | |
cd1759d8 | 475 | safe_time = (time_t)*time; |
806a119a | 476 | |
7430375d | 477 | TIME64_TRACE1("Using system localtime for %lld\n", *time); |
461d5a49 | 478 | |
806a119a MS |
479 | LOCALTIME_R(&safe_time, &safe_date); |
480 | ||
7430375d CB |
481 | S_copy_little_tm_to_big_TM(&safe_date, local_tm); |
482 | assert(S_check_tm(local_tm)); | |
806a119a | 483 | |
a64acb40 MS |
484 | return local_tm; |
485 | } | |
486 | ||
f832b29a | 487 | if( Perl_gmtime64_r(time, &gm_tm) == NULL ) { |
7430375d | 488 | TIME64_TRACE1("gmtime64_r returned null for %lld\n", *time); |
af832814 | 489 | return NULL; |
461d5a49 | 490 | } |
af832814 | 491 | |
a272e669 MS |
492 | orig_year = gm_tm.tm_year; |
493 | ||
c07fe26c | 494 | if (gm_tm.tm_year > (2037 - 1900) || |
461d5a49 | 495 | gm_tm.tm_year < (1970 - 1900) |
c07fe26c MS |
496 | ) |
497 | { | |
7430375d CB |
498 | TIME64_TRACE1("Mapping tm_year %lld to safe_year\n", (Year)gm_tm.tm_year); |
499 | gm_tm.tm_year = S_safe_year((Year)(gm_tm.tm_year + 1900)) - 1900; | |
c07fe26c | 500 | } |
a272e669 | 501 | |
7430375d | 502 | safe_time = (time_t)S_timegm64(&gm_tm); |
461d5a49 | 503 | if( LOCALTIME_R(&safe_time, &safe_date) == NULL ) { |
7430375d | 504 | TIME64_TRACE1("localtime_r(%d) returned NULL\n", (int)safe_time); |
af832814 | 505 | return NULL; |
461d5a49 | 506 | } |
a272e669 | 507 | |
7430375d | 508 | S_copy_little_tm_to_big_TM(&safe_date, local_tm); |
806a119a | 509 | |
a272e669 | 510 | local_tm->tm_year = orig_year; |
af832814 | 511 | if( local_tm->tm_year != orig_year ) { |
7430375d | 512 | TIME64_TRACE2("tm_year overflow: tm_year %lld, orig_year %lld\n", |
461d5a49 MS |
513 | (Year)local_tm->tm_year, (Year)orig_year); |
514 | ||
af832814 MS |
515 | #ifdef EOVERFLOW |
516 | errno = EOVERFLOW; | |
517 | #endif | |
518 | return NULL; | |
519 | } | |
520 | ||
521 | ||
a272e669 MS |
522 | month_diff = local_tm->tm_mon - gm_tm.tm_mon; |
523 | ||
524 | /* When localtime is Dec 31st previous year and | |
525 | gmtime is Jan 1st next year. | |
526 | */ | |
527 | if( month_diff == 11 ) { | |
528 | local_tm->tm_year--; | |
529 | } | |
530 | ||
531 | /* When localtime is Jan 1st, next year and | |
532 | gmtime is Dec 31st, previous year. | |
533 | */ | |
534 | if( month_diff == -11 ) { | |
535 | local_tm->tm_year++; | |
536 | } | |
537 | ||
538 | /* GMT is Jan 1st, xx01 year, but localtime is still Dec 31st | |
539 | in a non-leap xx00. There is one point in the cycle | |
540 | we can't account for which the safe xx00 year is a leap | |
486ec47a | 541 | year. So we need to correct for Dec 31st coming out as |
a272e669 MS |
542 | the 366th day of the year. |
543 | */ | |
544 | if( !IS_LEAP(local_tm->tm_year) && local_tm->tm_yday == 365 ) | |
545 | local_tm->tm_yday--; | |
546 | ||
7430375d | 547 | assert(S_check_tm(local_tm)); |
a272e669 MS |
548 | |
549 | return local_tm; | |
550 | } |