[sr #110286] Make it possible to request a specific (non-latest) version of a language standard

[Zack Weinberg]

URL:
  <https://savannah.gnu.org/support/?110286>

                 Summary: Make it possible to request a specific (non-latest)
version of a language standard
                 Project: Autoconf
            Submitted by: zackw
            Submitted on: Mon 27 Jul 2020 06:31:37 PM UTC
                Category: None
                Priority: 5 - Normal
                Severity: 1 - Wish
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
        Operating System: None

    _______________________________________________________

Details:

Feedback on the 2.69b beta indicates that users find the new behavior of
AC_PROG_CC and AC_PROG_CXX, automatically selecting the latest supported
language standard, problematic.  Quoting
https://lists.gnu.org/archive/html/autoconf/2020-07/msg00010.html :

> One issue we [PostgreSQL] would like to point out is that
> the new scheme of automatically checking for the latest
> version of the C and C++ standards (deprecating AC_PROG_CC_C99
> etc.) is problematic...
> 
> [W]e have set C99 as the project standard. So checking for
> C11 is (a) useless, and (b) bad because we don't want
> developers to accidentally make use of C11 features and have
> the compiler accept them silently.
>
> It looks like it's not easy to disable these tests even
> with low-level hackery. It would be better if there were
> still a way to set the preferred level of C and C++ in
> an official way.

and https://lists.gnu.org/archive/html/autoconf/2020-07/msg00012.html :

> Particularly as applies to C++, it is useful to be able
> to set an upper bar (and lower bar) for the C++ version
> requested because C++11 is in many ways not similar to
> older C++. I am already aware that some of my own software
> will not compile with C++11 because of removed deprecated
> features which I have not attended to yet in the code.
> Furthermore, the ABI often changes between C++ versions
> and it is useful to be able to specify the C++ version
> for purposes of the ABI.







    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/support/?110286>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/