Re: ANSI C standard of zsh

[Clinton Bunch <cdb_zsh@zentaur.org>]

On 3/25/2024 18:47, Oliver Kiddle wrote:
> Clinton Bunch wrote:
>> Here is my first cut at replacement wording for the first two paragraphs
>> of the C coding style section:
> This looks good to me.
>
>> If you wish to use features not present in the ANSI C 99 standard, there
>> are preprocessor macros to provide safe access to some of these.  Always
>> use the macros if you want to use these facilities.
> I was trying to think how this reads to someone completely unfamiliar
> with the zsh code and what macros we have that meet this description.
> Autoconf detects mostly system library/OS features and the macros
> related to that are either defined to 1 (or left undefined). So the
> macros allow you to make the use of such features conditional. "provide
> safe access" sounds more like a wrapper – I couldn't think of an
> example but that's not to say there aren't any. The preprocessor macros
> are for anything that isn't portable rather than a particular language
> standard.
>
> Oliver
I think what was intended was macros like _POSIX_C_SOURCE and 
_XOPEN_SOURCE and __STDC__.  The glibc man pages are littered with them.