Why does LLDB refuse to break on compiled objective C methods?

Question

I have a compiled objective-C binary on iOS 8.1 which I am attempting to debug with lldb on my machine and debugserver on the handset. (No XCode involved- though I am willing to get it involved if that is the issue.)

Ida can correctly recognize the binary as objective-C and decompose objects and component messages. Because of this, I would expect commands like

platform select remote-ios
connect://ip:port
breakpoint set --name "-[Login doLoginStuff]"

to correctly function, but this method is called in code without breaking in lldb.

Is there the need for some type of target call to hint to the debugger what the remote architecture or SDK target is?

Answer 1

Without the symbols I don't believe lldb can map -[Login doLoginStuff] to a memory address. If it cant find the name it fails silently as far as I remember.