[PATCH] Add atomic type qualifier

[Andrew MacLeod]

On 07/26/2013 07:21 PM, Joseph S. Myers wrote:
> On Fri, 26 Jul 2013, Andrew MacLeod wrote:
>
>> This patch adds an atomic type qualifier to GCC.   It can be accessed via
>> __attribute__((atomic)) or in C11 mode via the _Atomic keyword.
> Why the attribute - why not just the keyword?
>
>
> * When C11 refers to qualified types, by default it does not include
> atomic types (6.2.5#27).  What's your rationale for including "atomic" in
> TYPE_QUALS rather than making it separate?  With either approach, a review
> of every reference to qualifiers in the front end is needed to determine
> what's correct for "atomic"; did you find that including "atomic" in
> qualifiers in the implementation made for fewer changes?
>
Ive gotten the expressions mostly working  (= and op= work great), but 
am having some issues with plain loads and identifying the correct time 
to emit the load...   I've also hacked up a rough approximation of what 
stdatomic.h would need.

I also think I'll revisit how atomic values are marked in the front 
end... now that Im doing  all the real work in the front end, I don't 
think I want that attribute all over the place like I did before.     I 
may well decide to remove it from the qualifiers and make it a separate 
type now...   So don't worry about reviewing those files...

I likely wont get to this until I get back from vacation in a couple of 
weeks however.  I will post the state of things before I go, both for my 
own recollection when I return, and in case anyone just happens to feel 
really interested and wants to have a look at some of  the remaining 
required changes.  ha. I wish.    Its starting to get close tho.

Andrew