[cfe-dev] Fix for PR4701

[David Chisnall]

On 18 Aug 2009, at 16:47, Daniel Dunbar wrote:

> I think you missed the point here.
>
> If ObjCIdRedefinitionType has not been assigned, then it will be the
> null QualType. The comparison will succeed (since BaseType is not
> null), then BaseType will be assigned to the null type, then the code
> will crash a few lines later.

Once again, can you provide a test case which demonstrates this?  I  
have tests which attempt to access fields on an id-typed variable with  
no definition of id provided, and they do not crash and do use this  
code path.  If you can demonstrate a condition where this manifests as  
a bug, then I would be more than happy to fix it.  As, at the moment,  
it is working as I expect it to work, so I can't fix it because I am  
not seeing any breakage.

The comparison is only there to avoid a redundant implicit cast when  
there is one already (which can only happen in cases where a  
redefinition is supplied).

David