[cfe-dev] Comparison of pointers between Objc subclasses
kremenek at apple.com
Tue Jul 1 23:30:48 PDT 2008
On Jul 1, 2008, at 9:48 PM, Eli Friedman wrote:
> On Tue, Jul 1, 2008 at 8:54 PM, Ted Kremenek <kremenek at apple.com>
>> So, I think the answers we are looking for are outside the letter
>> of C99
>> standard. The Objective-C and C++ object type systems are a
>> different animal.
> Okay, so in that case typesAreCompatible should say that non-identical
> ObjC types aren't compatible, and the necessary handling for
> comparison/assignment/conditionals/whatever else is needed for ObjC
> pointers should move into SemaExpr.
That sounds like a reasonable plan. Incidentally, what does:
do for these pointer types? I've never even used this builtin, so I'm
not quite certain how to use it in practice. I only ask because we
use ASTContext::typesAreCompatible to implement
Expr::isIntegerConstantExpr for TypesCompatibleExpr.
If we can cross-check GCC's behavior with this builtin, that should
give a definitive answer on whether or not NSArray* and
NSMutableArray* should be considered compatible types (and hence put
the logic in ASTContext::typesAreCompatible) or, if not, put (as you
suggest) the necessary handling for ObjC pointers in SemaExpr.
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