Re: [sr #111072] "[[]] attributes are a C23 extension warning" with clang

[Bruno Haible]

Adding to what Paul Eggert wrote:
> It looks like -Wc23-extensions is the problem. If you stop using it (or 
> if you also use -std=gnu23), you shouldn't get those warnings. At least, 
> that's the behavior I see with clang 18.1.6 (a bit later than your 
> clang) on Fedora.
> 
> -Wc23-extensions is more trouble than it's worth when programs (as is 
> commonly the case) use C23 extensions only when available.

As written in the Gnulib manual [1]:
  "Many GCC warning options usually don’t point to mistakes in the
   code; these warnings enforce a certain programming style."

You chose to desire warnings for C language constructs that are not
yet contained in C 23. You got such warnings.

Gnulib will not bow to your desired programming style, because it's
not a programming style suitable for the future.

But you can deactivate Gnulib's definition of _GL_ATTRIBUTE_NODISCARD
by adding "-D_GL_ATTRIBUTE_NODISCARD=" to the CPPFLAGS or CFLAGS of your
compilation.

Bruno

[1] https://www.gnu.org/software/gnulib/manual/html_node/manywarnings.html