From 622da12896f0372ace7b61e81f5649ee02a57a3b Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 6 Jan 2000 18:07:38 +0000 Subject: [PATCH] Sync tm_diff with the GNU C Library. (TM_YEAR_BASE): Renamed from TM_YEAR_ORIGIN. All uses changed. (tm_diff): Renamed from difftm. All uses changed. Replace body with that taken from GNU C Library 2.1.3pre1. (get_date): Prefer tm_gmtoff to tm_diff if available. --- lib/getdate.y | 52 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 31 insertions(+), 21 deletions(-) diff --git a/lib/getdate.y b/lib/getdate.y index eb1fe7b..75c6d2a 100644 --- a/lib/getdate.y +++ b/lib/getdate.y @@ -82,7 +82,7 @@ #endif #define EPOCH_YEAR 1970 -#define TM_YEAR_ORIGIN 1900 +#define TM_YEAR_BASE 1900 #define HOUR(x) ((x) * 60) @@ -99,7 +99,7 @@ enum { MERam, MERpm, MER24 }; /* Information passed to and from the parser. */ struct parser_control -{ +{ /* The input string remaining to be parsed. */ const char *input; @@ -664,26 +664,32 @@ lookup_zone (struct parser_control const *pc, char const *name) return 0; } -/* Yield A - B, measured in seconds. */ +#if ! HAVE_TM_GMTOFF +/* Yield the difference between *A and *B, + measured in seconds, ignoring leap seconds. + The body of this function is taken directly from the GNU C Library; + see src/strftime.c. */ static int -difftm (struct tm *a, struct tm *b) +tm_diff (struct tm const *a, struct tm const *b) { - int ay = a->tm_year + (TM_YEAR_ORIGIN - 1); - int by = b->tm_year + (TM_YEAR_ORIGIN - 1); - int days = ( - /* difference in day of year */ - a->tm_yday - b->tm_yday - /* + intervening leap days */ - + ((ay >> 2) - (by >> 2)) - - (ay / 100 - by / 100) - + ((ay / 100 >> 2) - (by / 100 >> 2)) - /* + difference in years * 365 */ - + (int) (ay - by) * 365 - ); + /* Compute intervening leap days correctly even if year is negative. + Take care to avoid int overflow in leap day calculations, + but it's OK to assume that A and B are close to each other. */ + int a4 = (a->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (a->tm_year & 3); + int b4 = (b->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (b->tm_year & 3); + int a100 = a4 / 25 - (a4 % 25 < 0); + int b100 = b4 / 25 - (b4 % 25 < 0); + int a400 = a100 >> 2; + int b400 = b100 >> 2; + int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); + int years = a->tm_year - b->tm_year; + int days = (365 * years + intervening_leap_days + + (a->tm_yday - b->tm_yday)); return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour)) + (a->tm_min - b->tm_min)) + (a->tm_sec - b->tm_sec)); } +#endif /* ! HAVE_TM_GMTOFF */ static table const * lookup_word (struct parser_control const *pc, char *word) @@ -848,7 +854,7 @@ get_date (const char *p, const time_t *now) return -1; pc.input = p; - pc.year = tmp->tm_year + TM_YEAR_ORIGIN; + pc.year = tmp->tm_year + TM_YEAR_BASE; pc.month = tmp->tm_mon + 1; pc.day = tmp->tm_mday; pc.hour = tmp->tm_hour; @@ -934,7 +940,7 @@ get_date (const char *p, const time_t *now) || (pc.local_zones_seen && 1 < pc.local_isdst)) return -1; - tm.tm_year = to_year (pc.year) - TM_YEAR_ORIGIN + pc.rel_year; + tm.tm_year = to_year (pc.year) - TM_YEAR_BASE + pc.rel_year; tm.tm_mon = pc.month - 1 + pc.rel_month; tm.tm_mday = pc.day + pc.rel_day; if (pc.times_seen || (pc.rels_seen && ! pc.dates_seen && ! pc.days_seen)) @@ -981,7 +987,7 @@ get_date (const char *p, const time_t *now) if (pc.zones_seen) { tm = tm0; - if (tm.tm_year <= EPOCH_YEAR - TM_YEAR_ORIGIN) + if (tm.tm_year <= EPOCH_YEAR - TM_YEAR_BASE) { tm.tm_mday++; pc.time_zone += 24 * 60; @@ -1009,11 +1015,15 @@ get_date (const char *p, const time_t *now) if (pc.zones_seen) { - int delta; + int delta = pc.time_zone * 60; +#ifdef HAVE_TM_GMTOFF + delta -= tm.tm_gmtoff; +#else struct tm *gmt = gmtime (&Start); if (! gmt) return -1; - delta = pc.time_zone * 60 + difftm (gmt, &tm); + delta -= tm_diff (&tm, gmt); +#endif if ((Start < Start - delta) != (delta < 0)) return -1; /* time_t overflow */ Start -= delta; -- 2.45.2