[Bug c++/68257] New: Reject empty abi_tag attribute on inline namespace

[sbergman at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68257

            Bug ID: 68257
           Summary: Reject empty abi_tag attribute on inline namespace
           Product: gcc
           Version: 5.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sbergman at redhat dot com
  Target Milestone: ---

Quoting <https://gcc.gnu.org/ml/gcc/2015-11/msg00017.html> "Re: abi_tag
questions" by Jonathan Wakely:

> On 4 November 2015 at 14:37, Stephan Bergmann <sbergman@redhat.com> wrote:
>> I have two questions regarding the abi_tag attribute (as documented at
>> <https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Attributes.html>):
[...]
>> 2  "The argument can be a list of strings of arbitrary length."
>>
>> Does that mean the list can be empty?
>>
>>> void f() __attribute__((__abi_tag__()));
>>
>> fails with "error: wrong number of arguments specified for ‘__abi_tag__’
>> attribute" while
>>
>>> inline namespace n __attribute__((__abi_tag__())) {}
>>
>> is accepted by recent trunk GCC (as well as older versions).
>
> That seems like a bug.

That would apparently have flagged the code fixed with
<https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=226022> "Fix abi_tag in
special modes."