[PATCH v3 2/7] malloc/obstack.h: Assume GCC supports __extension__

[Paul Eggert]

On 2025-11-10 06:17, Alejandro Colomar wrote:
> -# if ! (2 < __GNUC__ + (8 <= __GNUC_MINOR__))
> -#  define __extension__
> -# endif

If we're dropping support for GCC 2.7 and earlier in public-facing 
include files, this should be accompanied by an item in NEWS.

Also, there should be a section in the manual that says what user 
compilers are supported. For GCC we can simply say something like "2.8 
or later"; for other compilers we needn't list specific compilers or 
versions, merely what C features are assumed. I suggest doing this by 
uncommenting the last paragraph in maint.texi (and thus bringing back an 
old compatibility appendix) and bringing it up to date. For the patches 
in this series, the following features should be documented in that part 
of the manual:

* #warning
* statement expressions (assuming we insist on them)
* long long and associated macros like LLONG_MAX
* a stdarg.h that defines va_list

Doing this documentation would perhaps be the most painful and important 
part of the whole exercise.