rjmccall added a comment. In D55869#1337733 <https://reviews.llvm.org/D55869#1337733>, @pete wrote:
> In D55869#1337723 <https://reviews.llvm.org/D55869#1337723>, @js wrote: > > > In D55869#1337711 <https://reviews.llvm.org/D55869#1337711>, @dexonsmith > > wrote: > > > > > In D55869#1337706 <https://reviews.llvm.org/D55869#1337706>, @js wrote: > > > > > > > The ObjFW runtime itself does not contain anything about release, > > > > retain or autorelease - these are all part of ObjFW (as in the > > > > framework). As ObjFW also supports the Apple runtime, as well as mixing > > > > with Foundation code, it so far only provides objc_retain and > > > > objc_release when they are missing, to make ARC work. They just call > > > > into the corresponding methods on the object and do nothing else. > > > > > > > > How will this change work from the Apple runtime? Will > > > > objc_retain/objc_release call the retain/release on the object if it > > > > implements its own? Should I drop my own retain/release implementation > > > > from my root object if I am compiling against the Apple runtime? > > > > > > > > > Yes, the idea is that the specialized runtime functions are fast paths > > > for the common case, but they still fall back if the object has > > > overridden them. > > > > > > I am guessing not just overridden, but also a root class providing one? > > IOW, the fast path is used when the class does not have the retain or > > release method at all? In that case, LGTM as is. > > > The Apple runtime is using a bit on each realized class to track the > overriding. The root class defaults to not having a custom RR, ie, it > appears that its version of RR is considered equivalent to objc_retain. > > Presumably that would apply to other root classes too, although i'm not 100% > sure. I did see some special handling of NSObject in there too so perhaps > only its RR is equivalent to objc_retain/objc_release. `objc_retain` and `objc_release` are always defined as being equivalent to doing a normal message send of the corresponding messages. Apple's implementations detect when a class simply inherits `NSObject`'s implementations: if so, they just directly use the `NSObject` RR implementation, and if no, they do a normal message send. That fast path is only triggered if the class's root class is `NSObject` and it doesn't override any of the RR methods. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D55869/new/ https://reviews.llvm.org/D55869 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
