On Thu, Jul 19, 2018 at 04:21:26AM -0700, H.J. Lu wrote:
> The new indirect_return attribute is intended to mark swapcontext in
> <ucontext.h>. This patch defines __HAVE_INDIRECT_RETURN_ATTRIBUTE__
> so that it can be used checked before using indirect_return attribute
> in <ucontext.h>. It works when the indirect_return attribute is
> backported to GCC 8.
>
> OK for trunk?
No. Use
#ifdef __has_attribute
#if __has_attribute (indirect_return)
...
#endif
#endif
instead, like for any other attribute. Predefined macros aren't zero cost.
Jakub
