App converted to ARC, now getting warnings about my properties

Question

I just converted my app to ARC, and while it builds fine, I get like 600 warnings, all pertaining to my properties. Such as:

Default property attribute 'assign' not appropriate for non-gc object

No 'assign', 'retain' or 'copy' attribute is specified - 'assign' is assumed

After Xcode converted my code, here is what my properties look like:

@property (nonatomic) EKEventStore *eventStore;
@property (nonatomic) EKCalendar *defaultCalendar;
@property (nonatomic) UIActionSheet *currentActionSheet;
@property (nonatomic) UILabel *noEventLabel;

Someone talked about needing to add strong to all of these. Is this the case? Did Xcode forget to add something?

Answer 1

Sorry to add a second answer, but this turns out to be more intricate than I thought. It turns out that you're seeing a changed behavior (perhaps a bug?) in Xcode 4.3.

In Xcode 4.2, the converter would have offered to change (nonatomic, retain) to (nonatomic, strong). But in Xcode 4.3, it offers to change it to (nonatomic); I guess if you don't want that, changing retain to strong is up to you before converting.

On the other hand, in Xcode 4.2, (nonatomic) alone was absolutely illegal for a synthesized property; in Xcode 4.3, it is not: you get a warning, but it assumes you mean assign and so it isn't illegal.

So there's been a change in how ARC works in LLVM 3.1 and an accompanying change in the Xcode 4.3 ARC converter.

Answer 2

I think the answers are wrong.

In Xcode 4.3 you get a warning. However, it assumes you mean RETAIN. Retain is the new default for codes under ARC. Someone told me that xcode is fixing this.

Please correct me if I am wrong.