[cfe-commits] r134522 - in /cfe/trunk: include/clang/Basic/Attr.td include/clang/Basic/DiagnosticSemaKinds.td include/clang/Sema/AttributeList.h lib/Sema/AttributeList.cpp lib/Sema/SemaDeclAttr.cpp lib/Sema/SemaType.cpp test/SemaObjC/arc-unavailable-for-weakref.m

[Douglas Gregor]

On Jul 6, 2011, at 12:24 PM, Fariborz Jahanian wrote:

> Author: fjahanian
> Date: Wed Jul  6 14:24:05 2011
> New Revision: 134522
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=134522&view=rev
> Log:
> objc-arc: Support objc_arc_weak_unavailable on those
> classes which are incompatible with weak references.
> // rdar://9693477

Excellent. A few minor comments below.

> Modified: cfe/trunk/lib/Sema/SemaType.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaType.cpp?rev=134522&r1=134521&r2=134522&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaType.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaType.cpp Wed Jul  6 14:24:05 2011
> @@ -3207,7 +3207,30 @@
>     attr.setInvalid();
>     return true;
>   }
> -
> +    
> +  // Forbid __weak for class objects marked as 
> +  // objc_arc_weak_reference_unavailable
> +  if (lifetime == Qualifiers::OCL_Weak) {
> +    QualType T = type;
> +    if (T->isReferenceType()) {
> +      T = T->getAs<ReferenceType>()->getPointeeType();
> +    }

if (const ReferenceType *Ref = T->getAs<ReferenceType>())
  T = Ref->getPointeeType();

?

Since you used that pattern below.

> +    while (const PointerType *ptr = T->getAs<PointerType>())
> +      T = ptr->getPointeeType();
> +    if (const ObjCObjectPointerType *ObjT = T->getAs<ObjCObjectPointerType>()) {
> +      ObjCInterfaceDecl *Class = ObjT->getInterfaceDecl();
> +      while (Class) {
> +        if (Class->hasAttr<ArcWeakrefUnavailableAttr>()) {
> +          S.Diag(attr.getLoc(), diag::err_arc_unsupported_weak_class);
> +          S.Diag(ObjT->getInterfaceDecl()->getLocation(), 
> +                 diag::note_class_declared);
> +          break;
> +        }
> +        Class = Class->getSuperClass();
> +      }
> +    }
> +  }
> +  
>   return true;
> }

Should this hasAttr<ArcWeakrefUnavailableAttr>() loop over superclasses be moved in an isArcWeakrefUnavailable() method on the ObjCInterfaceDecl? I could imagine it being reused by, e.g., the migrator.

	- Doug