tree 5a2184ce514660420fe17c9a5ee419033a74e4e1
parent 4517417c018c12de387207e51e0f3728c5164e50
author Pali Rohár <pali.rohar@gmail.com> 1726688244 +0200
committer Martin Storsjö <martin@martin.st> 1727438477 +0300

crt: Provide __daylight(), __dstbias(), __timezone() and __tzname() functions for pre-msvcr80 builds

These functions return pointer to global variables with same name but
without the first leading underscore. These functions are available also
under name with leading "__p" prefix.

Functions __daylight(), __dstbias(), __timezone() and __tzname() are
available in msvcr80+ libraries and also in UCRT.

Functions __daylight(), __dstbias() are also available in later versions of
i386 and x64 msvcrt.dll and are available in all ARM versions of msvcrt.dll.

Functions __p__daylight(), __p__timezone() and __p__tzname() are available
since msvcrt20.dll and are present in all later msvcrt versions except the
UCRT and non-i386 OS system version of msvcrt.dll.

Function __p__dstbias() is available since msvcrt40.dll and is present also
in all later msvcrt versions except the UCRT and non-i386 OS system version
of msvcrt.dll.

Global variables _daylight, _timezone and _tzname are available in all
msvcrt versions except UCRT.

Global variable _dstbias is present since msvcrt40.dll, except UCRT and
non-i386 OS system versions of msvcrt.dll.

Define __daylight, __dstbias, __timezone and __tzname for all CRT import
libraries either as aliases to __p__daylight, __p__dstbias, __p__timezone,
and __p__tzname or as function wrappers around variables _daylight,
_dstbias, _timezone and _tzname, based on what each DLL library provides.

With this change also unifies time.h file to define _daylight, _dstbias,
_timezone and _tzname for all CRT builds via functions. This removes
another ifdef _UCRT and improves ABI compatibility between UCRT and
non-UCRT builds.

Signed-off-by: Martin Storsjö <martin@martin.st>