[cfe-dev] [Patch] IDNS_NoLookup?

[Chris Lattner]

On Jan 18, 2009, at 8:00 PM, Douglas Gregor wrote:

>
> On Jan 18, 2009, at 5:58 PM, Chris Lattner wrote:
>
>> On Jan 18, 2009, at 5:02 PM, Douglas Gregor wrote:
>>> Ah, so that's the issue... the ObjCImplementationDecls need to  
>>> have an
>>> identifier namespace, because they have  name, but they aren't
>>> supposed to be found by name lookup (rather, we see them through the
>>> ObjCInterfaceDecl).
>>
>> Ah, very interesting.  I think the right fix is that  
>> ObjCImplementationDecl should not be scope decls and maybe not even  
>> NamedDecls.  They should never ever be "looked up".
>
> I think we should swap ScopedDecl and NamedDecl in the inheritance  
> hierarchy. Things without names---like, perhaps,  
> ObjCImplementationDecl---should still be ScopedDecls and live inside  
> DeclContexts (so we know where they occur, lexically, in the  
> program, and who their owners are) but they don't need any storage  
> for names. So, we would just have
>
>  class NamedDecl : public ScopedDecl {
>    DeclarationName Name;
>  public:
>    // ...
>  };
>
> Right now, the only ScopedDecl that isn't a NamedDecl is  
> OverloadedFunctionDecl, and it's probably going away in favor of  
> Argiris' idea for an OverloadedNameExpr. As Piotr had mentioned  
> before, using directives are also never found by name lookup, but  
> they do have scope, so they're natural ScopedDecls but not NamedDecls.

That makes a lot of sense to me!

-Chris