Indeed XCode now includes the arm64 architecture.
NSInteger is something completely different now as it is define in NSObjCRuntime.h :
#if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif
To deal with it you should improve your codebase. First of all, you have to be really consistent. Assign NSInteger only to NSInteger and not to int. Avoid all kind of :
int i = [aString integerValue] ( as it returns a NSInteger)
but
NSInteger i = [aString integerValue] (and if it's a long type then you won't have any trouble.)
Moreover, another issue you might have is when you want to create a string from a value.
What you could do is something like:
#define cL(v) (long)(v)
#define cUL(v) (unsigned long)(v)
NSLog(@"array.count: %ld", cUL(anArray.count));
array.count returns an unsigned int under armv7(s) and an unsigned long under arm64. By always casting into an unsigned long you will not face any warning anymore and, more important, do not get any bug.
This "logic" have been introduced by Apple itself on some tech-talks videos there:
https://developer.apple.com/tech-talks/videos/ (video "Architecting Modern iOS Games". Play the video around 10m00s)