Subject: bug#53256: [bug-diffutils] bug#53256: Compiling 3.8 with nvhpc 22.1 : malloca.c 64 bits operations with signed and unsigned operands are currently unsupported by __builtin_add_overflow

From: Olivier Cessenat <[email-masked]>
Date: Sat, 15 Jan 2022 09:35:48 +0100

Thanks so much ! It's great.

I will try to report the bug to NVIDIA, but that will be with my words, 
I do not have the full understanding of the problem.

Olivier Cessenat

Le 15/01/2022 à 04:53, Paul Eggert a écrit :
> On 1/14/22 03:33, Olivier Cessenat wrote:
>> "diffutils-3.8/lib/malloca.c", line 52: error: 64 bits operations 
>> with signed and unsigned operands are currently unsupported by 
>> __builtin_add_overflow
>
> Thanks for the bug report. Although nvc 22.1 defines __GNUC__ to be 11 
> which means it supports GNU C as of GCC 11, that's obviously untrue 
> for __builtin_add_overflow. That's unfortunate. Perhaps you could 
> report this as a bug to NVIDIA, as their compiler shouldn't claim to 
> support GNU C features that it lacks. nvc can set __GNUC__ to be the 
> version of GNU C that it actually does support.
>
> To work around the bug I installed the attached into Gnulib and this 
> should appear in the next diffutils release. In the meantime you can 
> compile with gcc.