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libc: Move gmtime_r into common

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gmtime_r() has been in the minimal libc for years, however it was not
added to expcetions due to an overlook. In order to do this however, it
has to be moved first to the common libc area, so that it's available
to any libc that may not implement it.

Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
This commit is contained in:
Robert Lubos 2024-02-01 13:36:17 +01:00 committed by Stephanos Ioannidis
parent 109a045e57
commit 0966be01fc
5 changed files with 104 additions and 90 deletions
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1
lib/libc/common/CMakeLists.txt
View file

@ -5,6 +5,7 @@ zephyr_system_include_directories(include)
zephyr_library()
zephyr_library_property(ALLOW_EMPTY TRUE)
zephyr_library_sources_ifdef(CONFIG_COMMON_LIBC_ABORT source/stdlib/abort.c)
zephyr_library_sources_ifdef(CONFIG_COMMON_LIBC_GMTIME_R source/time/gmtime_r.c)
zephyr_library_sources_ifdef(CONFIG_COMMON_LIBC_TIME source/time/time.c)
zephyr_library_sources_ifdef(CONFIG_COMMON_LIBC_MALLOC source/stdlib/malloc.c)
zephyr_library_sources_ifdef(CONFIG_COMMON_LIBC_STRNLEN source/string/strnlen.c)

5
lib/libc/common/Kconfig
View file

@ -6,6 +6,11 @@ config COMMON_LIBC_ABORT
help
common implementation of abort().
config COMMON_LIBC_GMTIME_R
bool
help
common implementation of gmtime_r().
config COMMON_LIBC_TIME
bool
help

97
lib/libc/common/source/time/gmtime_r.c Normal file
View file

@ -0,0 +1,97 @@
/*
* Copyright (c) 2019 Peter Bigot Consulting, LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
/*
* The time_civil_from_days function is derived directly from public
* domain content written by Howard Hinnant and available at:
* http://howardhinnant.github.io/date_algorithms.html#civil_from_days
*/
#include <time.h>
/* A signed type with the representation of time_t without its
* implications.
*/
typedef time_t bigint_type;
/** Convert a UNIX time to civil time.
*
* This converts integral seconds since (before) 1970-01-01T00:00:00
* to the POSIX standard civil time representation. Any adjustments
* due to time zone, leap seconds, or a different epoch must be
* applied to @p time before invoking this function.
*
* @param time the time represented as seconds.
*
* @return the time information for corresponding to the provided
* instant.
*
* @see http://howardhinnant.github.io/date_algorithms.html#civil_from_days
*/
static void time_civil_from_days(bigint_type z,
struct tm *ZRESTRICT tp)
{
tp->tm_wday = (z >= -4) ? ((z + 4) % 7) : ((z + 5) % 7 + 6);
z += 719468;
bigint_type era = ((z >= 0) ? z : (z - 146096)) / 146097;
unsigned int doe = (z - era * (bigint_type)146097);
unsigned int yoe = (doe - doe / 1460U + doe / 36524U - doe / 146096U)
/ 365U;
bigint_type y = (time_t)yoe + era * 400;
unsigned int doy = doe - (365U * yoe + yoe / 4U - yoe / 100U);
unsigned int mp = (5U * doy + 2U) / 153U;
unsigned int d = doy - (153U * mp + 2U) / 5U + 1U;
unsigned int m = mp + ((mp < 10) ? 3 : -9);
tp->tm_year = y + (m <= 2) - 1900;
tp->tm_mon = m - 1;
tp->tm_mday = d;
/* Everything above is explained on the referenced page, but
* doy is relative to --03-01 and we need it relative to
* --01-01.
*
* doy=306 corresponds to --01-01, doy=364 to --02-28, and
* doy=365 to --02-29. So we can just subtract 306 to handle
* January and February.
*
* For doy<306 we have to add the number of days before
* --03-01, which is 59 in a common year and 60 in a leap
* year. Note that the first year in the era is a leap year.
*/
if (doy >= 306U) {
tp->tm_yday = doy - 306U;
} else {
tp->tm_yday = doy + 59U + (((yoe % 4U == 0U) && (yoe % 100U != 0U)) || (yoe == 0U));
}
}
/* Convert a UNIX time to civil time.
*
* This converts integral seconds since (before) 1970-01-01T00:00:00
* to the POSIX standard civil time representation. Any adjustments
* due to time zone, leap seconds, or a different epoch must be
* applied to @p time before invoking this function.
*/
struct tm *gmtime_r(const time_t *ZRESTRICT timep,
struct tm *ZRESTRICT result)
{
time_t z = *timep;
bigint_type days = (z >= 0 ? z : z - 86399) / 86400;
unsigned int rem = z - days * 86400;
*result = (struct tm){ 0 };
time_civil_from_days(days, result);
result->tm_hour = rem / 60U / 60U;
rem -= result->tm_hour * 60 * 60;
result->tm_min = rem / 60;
result->tm_sec = rem - result->tm_min * 60;
return result;
}

1
lib/libc/minimal/Kconfig
View file

@ -79,6 +79,7 @@ config MINIMAL_LIBC_RAND
config MINIMAL_LIBC_TIME
bool "Time functions"
select COMMON_LIBC_TIME if POSIX_CLOCK
select COMMON_LIBC_GMTIME_R
default y
help
Enable time() and gmtime_r() for the minimal libc.

90
lib/libc/minimal/source/time/gmtime.c
View file

@ -4,99 +4,9 @@
* SPDX-License-Identifier: Apache-2.0
*/
/*
* The time_civil_from_days function is derived directly from public
* domain content written by Howard Hinnant and available at:
* http://howardhinnant.github.io/date_algorithms.html#civil_from_days
*/
#include <time.h>
#include <zephyr/sys/libc-hooks.h>
/* A signed type with the representation of time_t without its
* implications.
*/
typedef time_t bigint_type;
/** Convert a UNIX time to civil time.
*
* This converts integral seconds since (before) 1970-01-01T00:00:00
* to the POSIX standard civil time representation. Any adjustments
* due to time zone, leap seconds, or a different epoch must be
* applied to @p time before invoking this function.
*
* @param time the time represented as seconds.
*
* @return the time information for corresponding to the provided
* instant.
*
* @see http://howardhinnant.github.io/date_algorithms.html#civil_from_days
*/
static void time_civil_from_days(bigint_type z,
struct tm *ZRESTRICT tp)
{
tp->tm_wday = (z >= -4) ? ((z + 4) % 7) : ((z + 5) % 7 + 6);
z += 719468;
bigint_type era = ((z >= 0) ? z : (z - 146096)) / 146097;
unsigned int doe = (z - era * (bigint_type)146097);
unsigned int yoe = (doe - doe / 1460U + doe / 36524U - doe / 146096U)
/ 365U;
bigint_type y = (time_t)yoe + era * 400;
unsigned int doy = doe - (365U * yoe + yoe / 4U - yoe / 100U);
unsigned int mp = (5U * doy + 2U) / 153U;
unsigned int d = doy - (153U * mp + 2U) / 5U + 1U;
unsigned int m = mp + ((mp < 10) ? 3 : -9);
tp->tm_year = y + (m <= 2) - 1900;
tp->tm_mon = m - 1;
tp->tm_mday = d;
/* Everything above is explained on the referenced page, but
* doy is relative to --03-01 and we need it relative to
* --01-01.
*
* doy=306 corresponds to --01-01, doy=364 to --02-28, and
* doy=365 to --02-29. So we can just subtract 306 to handle
* January and February.
*
* For doy<306 we have to add the number of days before
* --03-01, which is 59 in a common year and 60 in a leap
* year. Note that the first year in the era is a leap year.
*/
if (doy >= 306U) {
tp->tm_yday = doy - 306U;
} else {
tp->tm_yday = doy + 59U + (((yoe % 4U == 0U) && (yoe % 100U != 0U)) || (yoe == 0U));
}
}
/* Convert a UNIX time to civil time.
*
* This converts integral seconds since (before) 1970-01-01T00:00:00
* to the POSIX standard civil time representation. Any adjustments
* due to time zone, leap seconds, or a different epoch must be
* applied to @p time before invoking this function.
*/
struct tm *gmtime_r(const time_t *ZRESTRICT timep,
struct tm *ZRESTRICT result)
{
time_t z = *timep;
bigint_type days = (z >= 0 ? z : z - 86399) / 86400;
unsigned int rem = z - days * 86400;
*result = (struct tm){ 0 };
time_civil_from_days(days, result);
result->tm_hour = rem / 60U / 60U;
rem -= result->tm_hour * 60 * 60;
result->tm_min = rem / 60;
result->tm_sec = rem - result->tm_min * 60;
return result;
}
#ifdef CONFIG_MINIMAL_LIBC_NON_REENTRANT_FUNCTIONS
static Z_LIBC_DATA struct tm gmtime_result;