[cfe-commits] Add -Wno-extension-used to filter ext_token_used

[Eli Friedman]

On Wed, Oct 5, 2011 at 10:43 AM, Ivan Krasin <krasin at google.com> wrote:
> Eli,
> I have updated the patch. Now I use language-extension-token parameter to
> suppress the warning "extension used".
> Is it fine now? Alternatively, I can introduce more fine-grained warning
> asm-token with higher priority than ext_token_used.
> So far, ext_token_used complains about the following tokens (see
> lib/Basic/IdentifierTable.cpp):
>
>   else if (LangOpts.GNUKeywords && (Flags & KEYGNU)) AddResult = 1;
>   else if (LangOpts.MicrosoftExt && (Flags & KEYMS)) AddResult = 1;
>   else if (LangOpts.Borland && (Flags & KEYBORLAND)) AddResult = 1;
> So, it's GNU, Microsoft and Borland extensions.

-Wlanguage-extension-token is fine.

-Eli

> On Tue, Oct 4, 2011 at 3:33 PM, Ivan Krasin <krasin at google.com> wrote:
>>
>> like, in my particular case, this warning complains about asm directive,
>> which is not a part of ANSI C (-pedantic)
>>
>> On Tue, Oct 4, 2011 at 3:32 PM, Ivan Krasin <krasin at google.com> wrote:
>>>
>>>
>>> On Tue, Oct 4, 2011 at 3:24 PM, Eli Friedman <eli.friedman at gmail.com>
>>> wrote:
>>>>
>>>> On Tue, Oct 4, 2011 at 11:13 AM, Ivan Krasin <krasin at chromium.org>
>>>> wrote:
>>>> > Hi llvm team!
>>>> >
>>>> > This patch adds support of -Wno-extension-used to make it possible to
>>>> > suppress the warning:
>>>> >
>>>> > lala.c:1:21: warning: extension used [-pedantic]
>>>> > double lala(double) asm("llvm.log.f64");
>>>> >
>>>> > r140770 has started to promote this warning to error if -Werror is
>>>> > specified (which is absolutely correct).
>>>> > We have a test that checks some llvm intrinsics and it's not Clangy to
>>>> > drop -Werror just because one particular warning is expected.
>>>> > I have added the option to suppress this warning and has removed it
>>>> > from the test for warnings w/o suppression options.
>>>> >
>>>> > OK to commit?
>>>>
>>>> We really ought to clarify what exactly this is warning about and name
>>>> the warning group in a more intuitive way.  -Wno-extension-used
>>>> doesn't give the user any idea what warning it is actually
>>>> suppressing.  I'm drawing a blank as to what exactly to call it,
>>>> though.
>>>
>>> Hi Eli,
>>> It suppresses any language extension used in the program source. I have
>>> no preference on how the flag should be named and I have chosen
>>> "extension-used" just to fit to the existing warning message:
>>>  "warning: extension used [-pedantic]"
>>> Probably, a better name would be language-extension or
>>> language-extension-used. In this case -Wno-language-extension would give a
>>> good idea of what warning does it suppress.
>>> Are you fine with any of the options above? Do you have a better idea?
>>>>
>>>> -Eli
>>>
>>
>
>