[petsc-dev] Request for comments: allow C99 internally

[Jed Brown]

Satish Balay <balay at mcs.anl.gov> writes:

> On Fri, 6 Mar 2020, Jed Brown wrote:
>>   PetscInt some,several,variables;
>> 
>>   // code
>>   if (PetscDefined(HAVE_MAGIC)) {
>>     function(several,&variables);
>>   }
>>   use(some,variables);
>
> One minor issue: we haven't yet fixed up clang analyzer build. Likely this will be listed as 'dead code' block or something like that.

As with #ifdef, accurate code coverage needs to be aggregated across
multiple configurations.  Are you aware of other problems?

>> This approach could also be used to avoid needing separate macros for
>> every SETERRQ1-SETERRQ9, etc.  I have an example implementation in this
>> MR, and it passes the full pipeline (after relaxing the -std=c89
>> -pedantic build).
>
> These are in public includes. So apps using -std=c89 won't have access to this part of the API?

Oh, I would keep the macros for a while (perhaps with gradual
deprecation starting eventually), just define the new ones for supported
dialects and use the new ones internally.