Add strptime(3) support for %U and %W

Add support for the missing POSIX-2001 %U and %W features: the
existing  FreeBSD strptime code recognizes both directives and
validates that the week number lies in the permitted range,
but then simply discards the value.

Initial support for the feature was written by Paul Green with
important fixes by Andrey Chernov. Additional support for
handling tm_wday/tm_yday was written by David Carlier.

PR:		137307
MFC after:	1 month
This commit is contained in:
Pedro F. Giffuni 2014-09-25 18:52:17 +00:00
parent 9de2fdafa8
commit ce1d331eee

View File

@ -55,10 +55,32 @@ __FBSDID("$FreeBSD$");
#include "un-namespace.h"
#include "libc_private.h"
#include "timelocal.h"
#include "tzfile.h"
static char * _strptime(const char *, const char *, struct tm *, int *, locale_t);
#define asizeof(a) (sizeof (a) / sizeof ((a)[0]))
#define asizeof(a) (sizeof(a) / sizeof((a)[0]))
#define FLAG_NONE (1 << 0)
#define FLAG_YEAR (1 << 1)
#define FLAG_MONTH (1 << 2)
#define FLAG_YDAY (1 << 3)
#define FLAG_MDAY (1 << 4)
#define FLAG_WDAY (1 << 5)
/*
* Calculate the week day of the first day of a year. Valid for
* the Gregorian calendar, which began Sept 14, 1752 in the UK
* and its colonies. Ref:
* http://en.wikipedia.org/wiki/Calculating_the_day_of_the_week/
*/
static int
first_wday_of(int year)
{
return (((2 * (3 - (year / 100) % 4)) + (year % 100) +
((year % 100) / 4) + (isleap(year) ? 6 : 0) + 1) % 7);
}
static char *
_strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp,
@ -66,9 +88,17 @@ _strptime(const char *buf, const char *fmt, struct tm *tm, int *GMTp,
{
char c;
const char *ptr;
int day_offset = -1, wday_offset;
int i, len;
int flags;
int Ealternative, Oalternative;
struct lc_time_T *tptr = __get_current_time_locale(locale);
const struct lc_time_T *tptr = __get_current_time_locale(locale);
static int start_of_month[2][13] = {
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
};
flags = FLAG_NONE;
ptr = fmt;
while (*ptr != 0) {
@ -119,7 +149,9 @@ label:
if (i < 19)
return (NULL);
tm->tm_year = i * 100 - 1900;
tm->tm_year = i * 100 - TM_YEAR_BASE;
flags |= FLAG_YEAR;
break;
case 'c':
@ -197,6 +229,8 @@ label:
return (NULL);
tm->tm_yday = i - 1;
flags |= FLAG_YDAY;
break;
case 'M':
@ -303,7 +337,32 @@ label:
return (NULL);
tm->tm_wday = i;
if (day_offset >= 0 && (i - day_offset) != 0) {
tm->tm_yday += i - day_offset;
i = 0;
while (tm->tm_yday >=
start_of_month[isleap(tm->tm_year +
TM_YEAR_BASE)][i])
i++;
if (i > 12)
{
i = 1;
tm->tm_yday -=
start_of_month[isleap(tm->tm_year +
TM_YEAR_BASE)]
[12];
tm->tm_year++;
}
tm->tm_mon = i - 1;
tm->tm_mday = tm->tm_yday -
start_of_month[isleap(tm->tm_year +
TM_YEAR_BASE)]
[i - 1] + 1;
}
buf += len;
flags |= FLAG_YEAR | FLAG_MONTH | FLAG_YDAY |
FLAG_MDAY | FLAG_WDAY;
break;
case 'U':
@ -313,6 +372,8 @@ label:
* information present in the tm structure at this
* point to calculate a real value, so just check the
* range for now.
* We expect that the year has already been
* parsed.
*/
if (!isdigit_l((unsigned char)*buf, locale))
return (NULL);
@ -327,6 +388,45 @@ label:
if (i > 53)
return (NULL);
/* Week numbers are l-origin. So that we can always
* return the date of a Sunday (or Monday), treat week
* 0 as week 1.
*/
if (i == 0)
i = 1;
if (c == 'U')
day_offset = TM_SUNDAY;
else
day_offset = TM_MONDAY;
/* Set the date to the first Sunday (or Monday)
* of the specified week of the year.
*/
tm->tm_yday = (7 - first_wday_of(tm->tm_year +
TM_YEAR_BASE) + day_offset) % 7 + (i - 1) * 7;
i = 0;
while (tm->tm_yday >=
start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)][i])
i++;
if (i > 12)
{
i = 1;
tm->tm_yday -=
start_of_month[isleap(tm->tm_year +
TM_YEAR_BASE)][12];
tm->tm_year++;
}
tm->tm_mon = i - 1;
tm->tm_mday = tm->tm_yday -
start_of_month[isleap(tm->tm_year + TM_YEAR_BASE)]
[i - 1] + 1;
tm->tm_wday = day_offset;
flags |= FLAG_YEAR | FLAG_MONTH | FLAG_YDAY |
FLAG_MDAY | FLAG_WDAY;
break;
case 'w':
@ -338,6 +438,7 @@ label:
return (NULL);
tm->tm_wday = i;
flags != FLAG_WDAY;
break;
@ -374,6 +475,7 @@ label:
return (NULL);
tm->tm_mday = i;
flags |= FLAG_MDAY;
break;
@ -413,6 +515,8 @@ label:
tm->tm_mon = i;
buf += len;
flags |= FLAG_MONTH;
break;
case 'm':
@ -430,6 +534,7 @@ label:
return (NULL);
tm->tm_mon = i - 1;
flags |= FLAG_MONTH;
break;
@ -471,13 +576,14 @@ label:
len--;
}
if (c == 'Y')
i -= 1900;
i -= TM_YEAR_BASE;
if (c == 'y' && i < 69)
i += 100;
if (i < 0)
return (NULL);
tm->tm_year = i;
flags |= FLAG_YEAR;
break;
@ -543,10 +649,25 @@ label:
break;
}
}
if (flags & (FLAG_YEAR | FLAG_MONTH)) {
if (!tm->tm_yday && (flags & FLAG_MDAY))
tm->tm_yday = start_of_month[isleap(tm->tm_year
+ TM_YEAR_BASE)][tm->tm_mon] + (tm->tm_mday - 1);
if (!tm->tm_wday) {
i = 0;
wday_offset = first_wday_of(tm->tm_year);
while (i++ <= tm->tm_yday)
if (wday_offset++ >= 6)
wday_offset = 0;
tm->tm_wday = wday_offset;
}
}
return ((char *)buf);
}
char *
strptime_l(const char * __restrict buf, const char * __restrict fmt,
struct tm * __restrict tm, locale_t loc)