On 10/13/22 22:58, Sam James wrote:
Some notes: * glibc is the only libc I'm aware of implementing _TIME_BITS for time64 compatibility. It was introduced in glibc-2.34; * musl libc made a hard switch in 1.2.0, see https://musl.libc.org/time64.html; * Using _TIME_BITS=64 with glibc requires _FILE_OFFSET_BITS=64 (which is used for Large File Support)! Extraordinary claims require (some) evidence, so see https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/features-time64.h;h=84d56ee3ff2ecfa0d2499385623f30606f84a1bf. Reference: https://wiki.gentoo.org/wiki/Project:Toolchain/time64_migration Reference: https://sourceware.org/pipermail/libc-alpha/2022-January/134985.html Signed-off-by: Sam James <sam@xxxxxxxxxx>
Patch applied. Thanks, Alex
--- man7/feature_test_macros.7 | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/man7/feature_test_macros.7 b/man7/feature_test_macros.7 index cdd962f7f..bcd6e6ae9 100644 --- a/man7/feature_test_macros.7 +++ b/man7/feature_test_macros.7 @@ -412,6 +412,17 @@ large files with only a recompilation being required.) 64-bit systems naturally permit file sizes greater than 2 Gigabytes, and on those systems this macro has no effect. .TP +.B _TIME_BITS +Defining this macro with the value 64 +changes the width of +.BR time_t (3type) +to 64-bit which allows handling of timestamps beyond +2038. +It is closely related to +.B _FILE_OFFSET_BITS +and depending on implementation, may require it set. +This macro is available as of glibc 2.34. +.TP .BR _BSD_SOURCE " (deprecated since glibc 2.20)" Defining this macro with any value causes header files to expose BSD-derived definitions. @@ -854,6 +865,10 @@ main(int argc, char *argv[]) printf("_FILE_OFFSET_BITS defined: %d\en", _FILE_OFFSET_BITS); #endif+#ifdef _TIME_BITS+ printf("_TIME_BITS defined: %d\en", _TIME_BITS); +#endif + #ifdef _BSD_SOURCE printf("_BSD_SOURCE defined\en"); #endif
-- <http://www.alejandro-colomar.es/>
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