Re: ANSI C standard of zsh

[Clinton Bunch <cdb_zsh@zentaur.org>]

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On 3/25/2024 19:32, Clinton Bunch wrote:
> 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.
>
>
If we're going to say Zsh expects C99 we should probably update autoconf 
to check for C99 (and set any options needed)

I've attached a patch for the trivial change needed.



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diff --git a/configure.ac b/configure.ac
index 78621042d..5984b667e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -462,7 +462,7 @@ dnl We want these before the checks, so the checks can modify their values.
 test -z "${CFLAGS+set}"  && CFLAGS=  auto_cflags=1
 test -z "${LDFLAGS+set}" && LDFLAGS= auto_ldflags=1
 
-AC_PROG_CC
+AC_PROG_CC_C99
 
 dnl Check for large file support.