Re: Fixing configure failures from newer gcc

[Ismael Luceno <ismael%iodev.co.uk@localhost>]

On 20/Oct/2025 14:10, Greg A. Woods wrote:
<...> 
> I think C23 is showing us that deep backward compatability for legacy
> code is gone for good, and good riddance.  However that means code can
> no longer be expected to have future forward compatability either.  If
> it's tested at C99, then let's keep it there until it can be tested
> further.  So long as compilers continue to offer something like "-std="
> to compile at older levels then there is no need to ride the bleeding
> edge of the latest and greatest -- just stick firmly to the middle
> ground and thus continue to also support older systems with older
> compilers.

Some codebases use new features when available and do a no-op on older
dialects, generally through the use of compatibility wrappers; in such
context it makes sense to test for a range of dialects and use the
newest of these that's supported by the compiler.

Also, the fact that a flag is valid for a compiler doesn't mean the
support for the dialect is sufficient, it might be incomplete or
broken in some way, so it's important to let the user override it..