In glibc 2.34 on Linux kernels where time_t is traditionally 32-bit,
defining _FILE_OFFSET_BITS=64 and _TIME_BITS=64 makes time_t 64-bit.
Apps must define both macros. Gnulib applications that use either
the largefile or the year2038 modules will want this behavior;
largefile because it deals with the off_t and ino_t components of
struct stat already, and so should also deal with time_t.
* NEWS, doc/largefile.texi, doc/posix-headers/time.texi:
Mention this.
* m4/largefile.m4: Override two macros even in Autoconf 2.70 and later.
(_AC_SYS_LARGEFILE_MACRO_VALUE): #undef $1 before #defining it, in
case some other Gnulib macro has #defined it.
(AC_SYS_LARGEFILE): Use AS_IF and AS_CASE to propagate AC_REQUIREs.
Invoke gl_YEAR2038_BODY if we need to set _FILE_OFFSET_BITS=64.
* m4/year2038.m4 (gl_YEAR2038_TEST_INCLUDES): New macro.
(gl_YEAR2038_BODY): New macro, with gl_YEAR2038’s old body; this
macro is designed to be used directly instead of being
AC_REQUIREd. It takes an argument specifying whether 64-bit is
required. Set _TIME_BITS=64 if this makes a difference in time_t
width when setting _FILE_OFFSET_BITS=64. Do not warn about
32-bit time_t more than once.
* modules/largefile (Files): Add year2038.m4.
(Depends-on): Require gl_YEAR2038_EARLY.