Application crash on 64 bit

Question

Recently I have transitioned my application to 64 bit and have started seeing few crashes with below message in the crash report:

-[__NSArrayI objectAtIndex:]: index 18446744073709551615 beyond bounds [0 .. 0]'

Crash report is pointing to below piece of code but when I run it in debug, it do not crash for me. Anyone faced the similar issue?

NSArray *allViewControllers = self.firstModalViewController.viewControllers;
UIViewController *aViewController = allViewControllers[allViewControllers.count - 2];

Answer 1

The objectAtIndex: method takes a NSUInteger. As specified in the docs you have a 64 bit unsigned integer in 64 bit application.

When building 32-bit applications, NSUInteger is a 32-bit unsigned integer. A 64-bit application treats NSUInteger as a 64-bit unsigned integer

You are trying to access the index (64^2)-2

To be honest, reading the code provided, i can't say that is a 64 bit related problem. It seems that you are accessing that array before that it is filled with something.

Have you tried to print the array with the debugger?