Re: resurrect __attribute__((atomic)) work

[Andrew MacLeod <amacleod at redhat dot com>]

On 05/06/2015 06:41 PM, Sandra Loosemore wrote:
> On 05/06/2015 03:22 PM, Andrew MacLeod wrote:
>
> >     gcc
> >     * c-family/c-common.c (const struct attribute_spec c_common_att):
> >     Add "atomic" attribute.
> >     (handle_atomic_attribute): New.  Deal with __attribute__((atomic)).
> >     (resolve_overloaded_builtin): If an atomic object is passed by 
> > address
> >     at an __atomic function, cast the atomic-ness away for processing.
> >     * c-family/c-pretty-print.c (pp_c_cv_qualifiers): Print attribute
> >     when not ISO c11.
> >
> >     libstdc++-v3
> >     * include/bits/atomic_base.h (struct __atomic_base): Make 
> > template type
> >     use attribute__((atomic)).
> >     (template __atomic_base<_PTp*>): Likewise.
> >     * include/std/atomic (template atomic<_Tp>): Likewise.
> >     * testsuite/29_atomics/atomic/60695.cc: Adjust error line number.
>
> I see no documentation here....
>
> -Sandra
There is none as yet.. its just a WIP...  Over the past year or so I've 
had a few  people inquire into what ever happened to it and/or expressed 
an interest in finishing it...   I extracted it from the old branch and  
brought it up to a compile-able state.  Whether its extended to work 
just on types, or flushed out to be virtually the same as C11 _Atomic, 
or eventually abandoned  remains to be seen..

All c++ needs is a hook into the type and size of an atomic... maybe it 
can be tweaked instead to just provide an object with the size and 
alignment of an atomic object, but not actually be atomic. C++ doesn't 
actually need an atomic object...   That is probably the simplest thing 
to do...

we can document however  it ends up.

Andrew