Re: [ptxdist] year 2038 Toolchain

[Erwin Rol <mailinglists@erwinrol.com>]

On 5/23/24 12:38, Ian Abbott wrote:
> On 23/05/2024 07:41, Erwin Rol wrote:

>> The following code;
>>
>> auto t = std::chrono::system_clock::now();
>>
>> does not seem to work correctly. When the system date is less than 
>> 2038 it works and gives back the correct time, but for dates > 2038 it 
>> seems to return some 1970 date.
>>
> 
> I guess that libstdc++ in the toolchain would need to be rebuilt with 
> 64-bit time_t support.  Although <chrono> uses a 64-bit integer type 
> internally, some of the functions such as 
> std::chrono::system_clock::now() use compiled in code that picks up the 
> C system time ABI at the time libstdc++ was built.  So now() will read 
> the system time using the 32-bit system time ABI (so will suffer from 
> Y2038 problems) and convert it to its own internal 64-bit integer type. 
> Other functions such as 
> std::chrono::system_clock::from_time_t(std::time_t) are not compiled in 
> so will use whatever C system time ABI was selected when <chrono> was 
> included.
> 

I believe libstd++ uses gettimeofday internally, which should use time_t 
for the seconds field, which should be 64bit if _TIME_BITS=64 is 
defined. I just hacked the Toolchain to try it, but it is a slow 
process, build toolchain -> build project -> test :-)

If I figure it out I'll let you guys know (so it can be added to the 
official Toolchain)

- Erwin