JSSetBreakpointOnMethodForObject

C function that makes the debugger stop whenever an Objective-C method with the specified selector is called on the specified object.

extern void js_setBreakpointOnMethodForObject(id object, SEL selector);

Simply by calling this C function passing an object and a selector, it will set up a breakpoint that will pause the debugger only when that method is called on that object, as opposed to adding a symbolic breakpoint on Xcode like -[UIView setNeedsLayout].

Warning

This uses very dangerous and scary code. Don't compile on production apps (hence the #if DEBUG). It also uses private APIs, so it wouldn't be approved by Apple.

Limited Support

Right now it will only work with Objective-C methods that take parameters of type id and int, it's trivial to add support for other types, except for structs.