By default, Newlib uses a huge object of type struct _reent to store
thread-specific data. This object is returned by __getreent() if the
__DYNAMIC_REENT__ Newlib configuration option is defined.
The reentrancy structure contains for example errno and the standard input,
output, and error file streams. This means that if an application only uses
errno it has a dependency on the file stream support even if it does not use
it. This is an issue for lower end targets and applications which need to
qualify the software according to safety standards (for example ECSS-E-ST-40C,
ECSS-Q-ST-80C, IEC 61508, ISO 26262, DO-178, DO-330, DO-333).
If the new _REENT_THREAD_LOCAL configuration option is enabled, then struct
_reent is replaced by dedicated thread-local objects for each struct _reent
member. The thread-local objects are defined in translation units which use
the corresponding object.
* libc/include/time.h (tzset, _tzset_r): Added prototypes.
(strptime): Moved prototype to be within !__STRICT_ANSI__.
(_tzname, _daylight, _timezone): No long __CYGWIN__ only.
(tzname): Defined for all platforms.
(daylight, timezone): Defined only for CYGWIN.
* libc/sys/linux/machine/i386/crt0.c: Add call to tzset() after
environment set up.
* libc/stdlib/setenv_r.c (_setenv_r): Call tzset() if the TZ
environment variable is set.
* libc/time/Makefile.am: Add support for tzset.c, tzlock.c, and
tzset_r.c.
* libc/time/Makefile.in: Regenerated.
* libc/time/gmtime.c (gmtime): Changed to call gmtime_r.
* libc/time/gmtime_r.c (gmtime_r): Changed to call _mktm_r.
* libc/time/lcltime_r.c (lcltime_r): Ditto.
* libc/time/local.h: New local header file.
* libc/time/mktime.c (mktime): Add timezone support.
* libc/time/mktm_r.c: New file which is the common engine
for gmtime_r and lcltime_r. This code has timezone support.
* libc/time/strftime.c (strftime): Add %Z timezone support.
* libc/time/tzlock.c: New file containing timezone lock stubs.
* libc/time/tzset.c: New file containing tzset() routine.
* libc/time/tzset_r.c: New file containing _tzset_r and
internal routine for calculating timezone changes for specified year.