Compiler issue. All cases in a switch statement shares a same scope, and ARC works by inserting code into beginning and end of scopes. switch() statement jumps around, making code path very unpredictable, confusing ARC.
Sent from my iPhone > On 2013年10月22日, at 16:02, "Gerriet M. Denkmann" <[email protected]> wrote: > > >> On 22 Oct 2013, at 14:48, ChanMaxthon <[email protected]> wrote: >> >> Just put a set of braces after every case: and it should be okay. A set of >> braces here actually sets up a mini stack frame that makes ARC work. > > 非常感谢 > Works perfectly now. > (I still would like to know whether my code was faulty, or whether this is a > compiler bug) > > > Kind regards > > Gerriet. > >>> On 2013年10月22日, at 15:41, "Gerriet M. Denkmann" <[email protected]> >>> wrote: >>> >>> Converting to Arc (Xcode 5.0). >>> >>> This works fine without Arc (regardless whether TRIGGER_ERROR is defined or >>> not): >>> >>> NSMutableString *mus = [ NSMutableString string ]; >>> NSString *word = @"abc"; >>> >>> switch( self.colourType ) >>> { >>> case colour_link: >>> [ mus appendString: @"<a href=\"" ]; >>> #define TRIGGER_ERROR >>> #ifdef TRIGGER_ERROR >>> NSString *urlStr = [ word stringByAddingPercentEscapesUsingEncoding: >>> NSUTF8StringEncoding ]; >>> [ mus appendString: urlStr ]; >>> #else // no_ERROR >>> [ mus appendString: [ word stringByAddingPercentEscapesUsingEncoding: >>> NSUTF8StringEncoding ] ]; >>> #endif // no_ERROR >>> >>> break; >>> >>> default: >>> [ mus appendString: word ]; >>> }; >>> >>> But with Arc, if TRIGGER_ERROR is defined, I get an error: "Switch case is >>> in protected scope" with the further explanation: "Jump bypasses >>> initialization of retaining variable". >>> >>> >>> Was the old (non-arc) code faulty (but the compiler did not notice this)? >>> Why is the arc-version (with TRIGGER_ERROR defined) wrong? > _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
