[cfe-commits] [PATCH] Implement member pointer support for the MS ABI in Sema

[Charles Davis]

On 8/15/10 8:17 PM, John McCall wrote:
> 
> On Aug 15, 2010, at 6:58 PM, Eli Friedman wrote:
> 
>> On Sun, Aug 15, 2010 at 6:16 PM, Charles Davis <cdavis at mymail.mines.edu> wrote:
>>> On 8/15/10 12:34 AM, Eli Friedman wrote:
>>>> It would be nice to add the appropriate warning about constructing a
>>>> member pointer to an incomplete type along with this... otherwise we
>>>> can end up silently generating bad code.
>>> It would be, but I don't know how to issue a diagnostic from the AST
>>> library, so I've left that out for now.
>>
>> Erm, I was thinking more along the lines of tossing a call to
>> RequireCompleteType into Sema::BuildMemberPointerType in SemaType.cpp
>> if we're using the MS ABI.  That should be a separate patch, though...
> 
> We definitely need a RequireCompleteType here in MS mode — if nothing
> else, to force instantiation.  MSVC does permit the base to be an incomplete
> type (falling back to the maximally general 8-byte representation), so if we want
> to be perfectly compatible we'll eventually need to pass an empty PDiag.  For
> now, though, we should probably just forbid it so that we can audit use cases
> instead of silently compiling them differently from MSVC.  Hopefully it's not being
> used in system headers.
I see now.

On Aug 15, 2010, at 6:58 PM, Eli Friedman wrote:
> Also, I think some extra checks in TryReinterpretCast in
> SemaCXXCast.cpp are necessary; we shouldn't allow reinterpret_casting
> between member pointers of different sizes.
That sounds reasonable.

But this is all for a separate patch. Is this one OK to commit?

Chip