How to get parameters using symbolic breakpoints in Objective-C
If you debug your code on the device the parameters when you hit your breakpoint will consistently be in registers r0, r1, and r2. If you use po $r0
you'll see the object receiving setSelected. If you use po $r1
you'll get "no Objective-C description available" because that's the selector. Inspect $r2 to see if selected is being set to YES or NO. It's a similar story on i386, but I can't remember off hand which registers are used.
In LLDB on Simulator use
p $arg3
for the first parameter.