r209172 - Get ARCMT/GC-check-warn-nsalloc.m working

[Jordan Rose]

> On May 19, 2014, at 16:36, Alp Toker <alp at nuanti.com> wrote:
> 
> 
> On 20/05/2014 02:10, Jordan Rose wrote:
>> 
>>> On May 19, 2014, at 15:51, Alp Toker <alp at nuanti.com <mailto:alp at nuanti.com>> wrote:
>>> 
>>> -  Diags->setDiagnosticMapping(diag::err_arcmt_nsalloc_realloc,
>>> -                              NoNSAllocReallocError ? diag::MAP_WARNING
>>> -                                                    : diag::MAP_ERROR,
>>> -                              SourceLocation());
>>> +  if (NoNSAllocReallocError)
>>> +    Diags->setDiagnosticMapping(diag::warn_arcmt_nsalloc_realloc,
>>> +                                diag::MAP_IGNORE, SourceLocation());
>>> 
>> 
>> This changes the behavior of the existing flag from (effectively) -Wno-error= to -Wno-. I don't think we should do that—any existing tools of ours that rely on the frontend flag probably still want the warning, and new tools should just use -W*.
> 
> You'll have to choose -- we can't support both.
> 
> If we give -no-ns-alloc-error control over the diagnostic mapping, the -W* mappings will no longer take precedence and the diagnostic won't need a named group (so it'll end up the way it was before, but actually working now). That seems fine by me -- ready to commit if it sounds good to you.

Fariborz is the one dealing with the migrators these days. Argyrios may also have an opinion, since he put a lot of work in in the past.

I don't know myself who's actually using this flag (even internally).

Jordan