On 19/05/21 15:37 +0000, Joseph Myers wrote:
>On Wed, 19 May 2021, Jonathan Wakely via Libc-alpha wrote:
>
>> +#pragma GCC diagnostic push
>> +#pragma GCC diagnostic ignored "-Wcast-qual"
>>  	return (void *) __p;
>> +#pragma GCC diagnostic pop
>
>I think such pragma uses in installed headers should be conditional on
>__GNUC_PREREQ (4, 6) (either directly or via conditionally defining a
>macro in sys/cdefs.h).

Good point.

I spent about two minutes trying to do something with _Pragma in
sys/cdefs.h to allow:

__GLIBC_IGNORE_WARNING("-Wcast-qual")
   return (void *) __p;
__GLIBC_UNIGNORE_WARNING

but didn't get it working, so here's a patch that just tests
__GNUC_PREREQ directly.