https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69179
Iain Sandoe <iains at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2016-01-10
Ever confirmed|0 |1
--- Comment #2 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Jack Howarth from comment #1)
> Note that weak_import was added by Geoffrey Keating in...
>
> https://gcc.gnu.org/ml/gcc-patches/2004-10/msg02441.html
>
> and tweaked in...
>
> https://gcc.gnu.org/ml/gcc-patches/2005-01/msg00146.html
>
> The last time Geoff referenced it in a patch, he claimed it was 'effectively
> deprecated' in gcc...
>
> https://gcc.gnu.org/ml/gcc-patches/2005-12/msg00378.html
>
> It might be worth checking with the Apple clang developers to see what their
> current position is on the feature. I would note that
> http://clang.llvm.org/docs/AttributeReference.html has...
>
> A declaration can be used even when deploying back to a platform version
> prior to when the declaration was introduced. When this happens, the
> declaration is weakly linked, as if the weak_import attribute were added to
> the declaration. A weakly-linked declaration may or may not be present a
> run-time, and a program can determine whether the declaration is present by
> checking whether the address of that declaration is non-NULL.
>
> in the section describing the availability attribute so I guess they still
> intend to support into the future.
GCC currently treats "weak_import" as a different spelling for "weak" (barring
one additional check for inlined functions made in the "weak" case - which we
should probably add for weak_import). AFAIU, there is no practical difference
in the meaning of weak_import, c.f. weak.
