How to Identify the Calling Method in iOS

caller

Recently I was troubleshooting multithreading issues in an iOS app. Here is some code that can identify what method and class called a given method. Useful for logging and debugging race conditions.

//Add this private instance method to the class you want to trace from
-(void)trace
{
  //Go back 2 frames to account for calling this helper method
  //If not using a helper method use 1
  NSArray* stack = [NSThread callStacksSymbols];
  if (stack.count > 2)
    NSLog(@"Caller: %@", [stack objectAtIndex:2]);
}

//Add this line to the method you want to trace from
[self trace];

In the output window you will see something like:

Caller: 2 MyApp 0x0004e8ae -[IINClassroomInit buildMenu] + 86

You can also parse this string to extract more data about the stack frame:

2 = Thread id
My App = Your app name
0x0004e8ae = Memory address of caller
-[IINClassroomInit buildMenu] = Class and method name of caller
+86 = Number of bytes from the entry point of the caller that your method was called

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About Martin Rybak

I am a New York area software developer and MBA with 10+ years of server-side experience on the Microsoft stack. I've also been a native iOS developer since before the days of ARC. I architect and develop full-stack web applications, iOS apps, database systems, and backend services.

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