[Bug c/120570] -pedantic option may not direct GCC to print a warning message if __attribute__ feature is used

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120570

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Pavel M from comment #2)
> (In reply to Andrew Pinski from comment #1)
> > Since __ is the implementation space, we don't error out on purpose.
> Then why does "__int128 x;" lead to "warning: ISO C does not support
> '__int128' types [-Wpedantic]"?

Because that is different.

For most attributes it does not change the meaning and you could use do:
#define __attribute__(a)

Which is why there are two (( around the attribute part :).