time64 functions for glibc

Adhemerval Zanella adhemerval.zanella@linaro.org
Mon May 31 19:08:24 GMT 2021



On 31/05/2021 15:56, Florian Weimer wrote:
> * Paul Eggert:
> 
>> On 5/31/21 9:01 AM, Adhemerval Zanella via Libc-alpha wrote:
>>> It is on 2.34 plan [1], Carlos O'Donnel is reviewing it.  Similar to LFS,
>>> you will need a newer flag to actually enable it (-D_TIME_BITS=64).
>>
>> One place where Microsoft got it right and we're arguably getting it
>> wrong, is that 64-bit time_t is the default on 32-bit MS-Windows,
>> where one must opt into 32-bit by #defining _USE_32BIT_TIME_T.
>>
>> It's too late in 2.34 to make 64-bit time_t the default, but we should
>> at least document that 64-bit time_t is planned to be default in the
>> future. That is, programmers should not *rely* on 32-bit being the
>> default.
> 
> I strongly object to that for i386-linux-gnu.  It's pretty much for
> compatibility with legacy applications at this point, and changing the
> default will only make it harder for distributions to support legacy
> use.  Software that can be recompiled (and thus switch to 64-bit time_t)
> really should be ported to a 64-bit architecture.

We either make it default for all affected architectures or we should
keep as is, I see not point in making it architecture dependent.

And I don't see your point here: if the legacy is being recompiled
it is in essence not in compatibility mode.  We really need to move
from non-LFS and 32-bit time_t interfaces.

> 
> I don't have an opinion about what people to do with 32-bit Arm.
> 
> Thanks,
> Florian
> 


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