[cfe-dev] Unexpected warning in -std=gnu89 -pedantic mode.

[Eli Friedman]

On Wed, Aug 26, 2009 at 3:57 PM, Douglas Gregor<dgregor at apple.com> wrote:
>
> On Aug 26, 2009, at 1:44 PM, Eli Friedman wrote:
>
>> On Wed, Aug 26, 2009 at 1:32 PM, Douglas Gregor<dgregor at apple.com> wrote:
>>>
>>> On Aug 26, 2009, at 1:28 PM, Eli Friedman wrote:
>>>
>>> On Wed, Aug 26, 2009 at 12:57 PM, Enea Zaffanella<zaffanella at cs.unipr.it>
>>> wrote:
>>> The issue here is that arguably, almost everything which we print a
>>> warning for with -pedantic is a GNU extension, since they're
>>> violations of the standard and implemented by gcc.  Also, I'm not sure
>>> what we would gain by classifying extension warnings into GNU
>>> extensions and "generic" extensions.
>>>
>>> Well, we also support some Microsoft extensions and OpenCL constructs.
>>> One
>>> could imagine keeping these separate, so that users could call Clang in a
>>> GCC-like mode, Microsoft-like mode, or whatever.
>>> - Doug
>>
>> Okay... so then a GNU extension would be anything we don't want in
>> msvc-like mode?  That's a reasonable classification, I guess.  I doubt
>> anyone would want the set of warnings which are not GNU extensions
>> using that classification scheme, though.
>
> A GNU extension is something that GNU supports and isn't part of the base
> language. Same deal with Microsoft extensions, and it's natural that some
> extensions will be available in both modes.

So a GNU extension any diagnostic currently classified as Extension
right now, plus the?  Okay, but that makes the whole thing seem
orthogonal to this discussion...

-Eli