[cfe-commits] [PATCH] Initial clang support for C++0x atomic operations

[Eli Friedman]

On Wed, Sep 21, 2011 at 11:34 AM, John McCall <rjmccall at apple.com> wrote:
> On Sep 21, 2011, at 11:30 AM, Eli Friedman wrote:
>> On Wed, Sep 21, 2011 at 10:39 AM, John McCall <rjmccall at apple.com> wrote:
>>> On Sep 20, 2011, at 7:02 PM, Eli Friedman wrote:
>>>> Attached.  Adds AtomicExpr nodes, creates them in Sema, and lowers
>>>> them in IRGen.
>>>
>>> Why is this a new expression node instead of a builtin call with custom
>>> typechecking?
>>
>> The return type of (most of) the builtins depends on the type of the
>> first argument... can we model that without a new expression node?
>
> Yes.  All the GCC atomic builtins are overloaded like this.  Just mark the
> builtin as requiring custom type-checking.
>
> There are also several builtins which take l-value operands, if that's important.

Hmm... the issue here, which the GCC atomic builtins don't face, is
that we need arbitrary return types.  And I'm not sure if the AST will
be completely happy with a call where the return type of the callee is
different from the return type of the call?

-Eli