[cfe-commits] r101953 - /cfe/trunk/lib/AST/Decl.cpp

[Douglas Gregor]

On Apr 20, 2010, at 5:20 PM, Fariborz Jahanian wrote:

> 
> On Apr 20, 2010, at 4:59 PM, Douglas Gregor wrote:
> 
>> 
>> On Apr 20, 2010, at 4:24 PM, Fariborz Jahanian wrote:
>> 
>>> 
>>> On Apr 20, 2010, at 4:15 PM, Ted Kremenek wrote:
>>> 
>>>> Author: kremenek
>>>> Date: Tue Apr 20 18:15:35 2010
>>>> New Revision: 101953
>>>> 
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=101953&view=rev
>>>> Log:
>>>> Specify linkage for Objective-C declarations.
>>> 
>>> This makes me uncomfortable. This looks like something you need to
>>> move the indexer forward (your next patch). Maybe you need to add
>>> a new psuedo_linkage for your purpose.
>> 
>> Can you explain a bit about why this makes you uncomfortable? From my perspective, all of the Objective-C declarations have external linkage since they are visible from multiple translation units.
> 
> Except for meta-data for the class (and its metaclass), othere meta-data have non-external linkage.
> Content of all non-external metadata, however,  can be inspected with various APIs. In that respect they are 'external'.
> But not wrt linkage.

I'm looking at linkage more from the language perspective. For example, say we have:

  @interface A
  @end

  A *an_A;

Is this code well-formed? In C++, it actually depends on the linkage of A: if A has no linkage, then the program is ill-formed because an_A does have linkage. Also, one could imagine instantiating a template over an Objective-C class (or pointer to one), e.g.,

  std::vector<A *> a_objects;

which also requires A to have linkage.

	- Doug