On May 17, 2012, at 11:16 AM, Argyrios Kyrtzidis wrote: > Author: akirtzidis > Date: Thu May 17 13:16:05 2012 > New Revision: 156999 > > URL: http://llvm.org/viewvc/llvm-project?rev=156999&view=rev > Log: > [arcmt] Remove the "it is not safe to remove an unused 'autorelease' message" > ARC > migration error. > > This is more trouble that it is worth; autoreleasing a value without holding > on it > is a valid use-case, we should not "punish" correct code for the minority of > broken/fragile programs that depend on the behavior of -autorelease. > > rdar://9914061
I wish you'd asked me about this. The user in question is doing an autorelease to avoid a temporary during an assignment operation. That seems like a perfectly reasonable idiom to recognize and so delete the autorelease. However, I am not comfortable with deleting arbitrary instances of [foo autorelease]; because there are some common patterns in GUI programming where this is intentionally done to cause something to be deleted "later". For example, if -[Widget handleEvent] calls -[Controller nextPage] and the latter wants to destroy the widget, it might intentionally autorelease instead of releasing so that self won't disappear out from under -[Widget handleEvent]. Turning that into "delete this now" is just papering over problems that the user really ought to deal with during the migration process. John. _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
