Re: [[maude-bugs]] [EXTERNAL] Re: Maude fails to build on armhf

[Steven Eker <eker@csl.sri.com>]

Hi Sebastian,

The lack of long long support in GMP has been the subject of some 
discussions:

https://gmplib.org/list-archives/gmp-bugs/2020-June/thread.html#4771
https://gmplib.org/list-archives/gmp-discuss/2021-January/thread.html#6625

I don't see it happening soon - it took years for the x18 issue on Apple 
silicon to be fixed.
In my development version I've modified the code to:

  Index seconds = timeValue.tv_sec;  // this is 32-bit on 32-bit 
machines so mpz_class constuctor is defined
  mpz_class nanoSeconds(seconds);
  nanoSeconds *= BILLION;
  nanoSeconds += timeValue.tv_nsec;

This is harmless on 64-bit architectures since Index will be a signed 
64-bit integer and if it works on 32-bit architectures, it's a work 
around until GMP is fixed (hopefully before 2038).

Steven

On 4/9/24 00:01, Sebastian Ramacher wrote:
> Hi Steven
>
> On 2024-04-08 15:38:50 -0700, Steven Eker wrote:
> > Hi Nilish,
> >
> > I don't have a 32-bit machine to test on, but my understanding is that Linux
> > has moved to a 64-bit signed integer for time_t and this is a long long on
> > 32-bit machines which is explicitly not supported by GMP's C++ API.
> This sounds like it needs to fixed in GMP then.
>
> > https://urldefense.com/v3/__https://en.wikipedia.org/wiki/Year_2038_problem__;!!DZ3fjg!--tzUBTnQHRKfnkc8PqaPE5gHxPm2QWswg2_MWTbLaWxFFDXu6jiPCjltocalTdckv2oG8G8tDajml0HNO6JIFyo$
> > https://urldefense.com/v3/__https://gmplib.org/manual/C_002b_002b-Interface-Integers__;!!DZ3fjg!--tzUBTnQHRKfnkc8PqaPE5gHxPm2QWswg2_MWTbLaWxFFDXu6jiPCjltocalTdckv2oG8G8tDajml0HNHAQQdRg$
> >
> > I'm not happy converting a signed value to an unsigned value for all
> > architectures. But
> >
> >    mpz_class nanoSeconds(static_cast<Index>(timeValue.tv_sec));
> >
> > should fix the problem, at least until 2038. Can you check that this works?
> > If so I'll put it in the next public alpha.
> And this does not sound like a fix which we want.
>
> Best
> Sebastian