> Begin forwarded message:
>
> From: Jason Merrill <ja...@redhat.com>
> Subject: Re: [PATCH][RFC] c++: Accept elaborated-enum-base in system headers
> Date: 8 June 2023 at 19:06:36 BST
> To: Alex Coplan <alex.cop...@arm.com>, gcc-patches@gcc.gnu.org
> Cc: Nathan Sidwell <nat...@acm.org>, Iain Sandoe <i...@sandoe.co.uk>
>
> On 6/8/23 07:06, Alex Coplan wrote:
>> Hi,
>> macOS SDK headers using the CF_ENUM macro can expand to invalid C++ code
>> of the form:
>> typedef enum T : BaseType T;
>> i.e. an elaborated-type-specifier with an additional enum-base.
>> Upstream LLVM can be made to accept the above construct with
>> -Wno-error=elaborated-enum-base.
>
> I guess we might as well follow that example, and so instead of this check:
>
>> + || (underlying_type && !in_system_header_at (colon_loc)))
>
> Make the below an on-by-default pedwarn using OPT_Welaborated_enum_base, and
> don't return error_mark_node.
I was also wondering about (for this and other reasons) a -fclang-compat to put
some of these things behind (since std=clang++NN is not really going to work to
describe other non-standard extensions etc. since most are not synchronised to
std revisions.)
Iain
>
>> + cp_parser_commit_to_tentative_parse (parser);
>> + error_at (colon_loc,
>> + "declaration of enumeration with "
>> + "fixed underlying type and no enumerator list is "
>> + "only permitted as a standalone declaration");
>
>
