See what methods are being called in Xcode

Question

I have a view controller that keeps reloading over and over again. I would like to be able to see which methods are being called so that I can see the one that keeps firing the reload. I know I can see what was called if an error occurs and the app crashes. However, in this case there is no crash. Is there a way to monitor all of the methods being called throughout the app?

just put `NSLog("method called");` in the methods and it will do purpose — nsgulliver, Mar 07 '13 at 22:39
Put a breakpoint in the general vicinity of the reload method (or even in it) to get a stack trace in Xcode. — CodaFi, Mar 07 '13 at 22:40
Use the debugger and set a breakpoint on the method you want to check. When the code reaches that point, execution will stop. Look at the stack trace in the debugger to see who called it. — rmaddy, Mar 07 '13 at 22:40
Ok I'll give these a shot @nsgulliver - great idea! Thanks all! — Brandon, Mar 07 '13 at 22:44
The problem with using `NSLog` instead of breakpoints is that you can't see who called the method and you can't inspect variable values easily. Learn to use the debugger. It's a powerful and useful tool. — rmaddy, Mar 07 '13 at 22:49

score 3 · Answer 1 · answered Mar 07 '13 at 22:49

3

If you are new to XCode and Objective C and looking for something lightweight and you do not have a large code/ many methods, I would put:

 NSLog(@"%s",__PRETTY_FUNCTION__);

in every method.

answered Mar 07 '13 at 22:49

Khaled Barazi

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You don't want all of those logs ending up in your final app to Apple. – rmaddy Mar 07 '13 at 22:50
@rmaddy you can set the log for the debug mode only also – nsgulliver Mar 07 '13 at 22:51
@rmaddy, Agree 100%. That is why I prefaced my question with conditions. – Khaled Barazi Mar 07 '13 at 22:52

score 2 · Answer 2 · answered Mar 07 '13 at 22:43

Use Instruments. Start your code in a profiling mode and select the CPU time instrument. As the app runs, Instruments will gather information about every call stack at regular intervals, which will allow you to see what calls what. (Use the "Invert Call Tree" option to see callers of a given function.)

score 1 · Answer 3 · edited May 23 '17 at 12:03

I use this macro:

#define DEBUG 1

#if DEBUG
#   define NLog(fmt, ...) printf("%s\n", [[NSString stringWithFormat:@"%s:%d  %@", __PRETTY_FUNCTION__, __LINE__, [NSString stringWithFormat:fmt, ##__VA_ARGS__]] UTF8String])
#else
#   define NLog(...)
#endif

Then I include my Macros.h in my Application_Prefix.pch file, so that it's available everywhere. Before I ship, I set DEBUG to 0 so that all NLogs disappear.

So now, instead of using NSLog, I use NLog. The output looks something like this:

-[ApplicationDelegate applicationDidBecomeActive:]:86  applicationDidBecomeActive called!

This solution was based on these earlier posts:

You can just place the NLog calls in several places, to see which functions are called right before your view controller reloads. If you need to know the exact function that triggered the reload, your best bet would be to place a breakpoint and examine the call stack, as others have mentioned.

See what methods are being called in Xcode

3 Answers3