[cfe-commits] r143219 - in /cfe/trunk: include/clang/Basic/DiagnosticSemaKinds.td lib/Sema/SemaExprObjC.cpp test/SemaObjC/arc-objc-lifetime.m test/SemaObjC/arc-unavailable-for-weakref.m test/SemaObjCXX/arc-unavailable-for-weakref.mm

[John McCall]

On Oct 28, 2011, at 1:06 PM, Fariborz Jahanian wrote:

> Author: fjahanian
> Date: Fri Oct 28 15:06:07 2011
> New Revision: 143219
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=143219&view=rev
> Log:
> objective-c arc: type-casting of an objc pointer to
> an rvalue retainable object type with life-time qualifier has no
> effect and wil be diagnosed as error. // rdar://10244607
> 
> Added:
>    cfe/trunk/test/SemaObjC/arc-objc-lifetime.m
> Modified:
>    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
>    cfe/trunk/lib/Sema/SemaExprObjC.cpp
>    cfe/trunk/test/SemaObjC/arc-unavailable-for-weakref.m
>    cfe/trunk/test/SemaObjCXX/arc-unavailable-for-weakref.mm
> 
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=143219&r1=143218&r2=143219&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Fri Oct 28 15:06:07 2011
> @@ -3042,6 +3042,9 @@
>   "%select{%2|a non-Objective-C pointer type %2|a block pointer|"
>   "an Objective-C pointer|an indirect pointer to an Objective-C pointer}1"
>   " to %3 is disallowed with ARC">;
> +def err_arc_nolifetime_behavior : Error<
> +  "casting expression of type %1 to type %0 with qualified lifetime"
> +  "will not change object lifetime">;

We use the term "ownership" externally;  I just haven't changed the name
internally everywhere.

Also, what do you think about this wording?
  error: explicit ownership qualifier on cast result would have no effect

> +    if ((castACTC == ACTC_retainable) && 
> +        isa<AttributedType>(castType) &&
> +        (castType.getObjCLifetime() !=  Qualifiers::OCL_None) &&
> +        (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&

I don't think the CCK restriction is meaningful.

I know it's kindof marginal, but please do look through ParenTypes
and other AttributedTypes here.  Also, AttributedTypes are not
necessarily only ownership attributes.  Also also, please add a
comment explaining that you're intentionally looking at type sugar
and that you don't want to look through certain kinds of sugar.

I don't know if it's currently possible to get a good test case for other
AttributedTypes, but (__strong NSString(*)) is a good test case for
ParenTypes.

John.