Re: [C PATCH] PR43651: add warning for duplicate qualifier

[Martin Sebor <msebor@gmail.com>]

On 04/09/2016 06:28 AM, Mikhail Maltsev wrote:
> On 04/08/2016 08:54 PM, Martin Sebor wrote:
>>> The name for new option "-Wduplicate-decl-specifier" and wording was
>>> chosen to match the same option in Clang.
>>
>> My version of Clang also warns in C++ mode but if I'm reading
>> the patch right, GCC would warn only C mode.  I would find it
>> surprising if GCC provided the same option as Clang but didn't
>> make it available in the same languages.  Do you have some
>> reason for leaving it out that I'm not thinking of?
> It is an error in C++ mode. Do we want to change this behavior?

You're right, G++ does give an error.  I missed it in my testing.
Unlike C11, C++ requires a diagnostic for duplicated cv-qualifiers
so by issuing a warning Clang is more permissive.  My personal
inclination would be to treat this consistently between C and C++
but whether or not to change it is something Jason would need to
weigh in on.

>> Also, in C11 mode, Clang issues the warning for duplicated
>> _Atomic qualifiers but it doesn't look like GCC would with
>> the patch.  Here again, unless there's some reason not to,
>> I would expect GCC to issue the same warning as Clang for
>> the same code.
>>
> Fixed.

Great, thank you.

Martin