How to print call stack in Swift?

In Objective-C, you can print the call stack by doing the following:

NSLog(@"%@", [NSThread callStackSymbols]);

How do you do this in Swift without using Foundation class?

Solution 1:

As Jacobson says, use the following:

Swift 2:

print(NSThread.callStackSymbols())

Swift 3 / Swift 4:

print(Thread.callStackSymbols)

That's Swift code. It's using a Foundation method, but so does 90%+ of what you do on iOS.

EDIT:

Note that the formatting looks better if you use:

Thread.callStackSymbols.forEach{print($0)}

From the debugger command line you can type

e Thread.callStackSymbols.forEach{print($0)}

Solution 2:

For Swift 3 use:

print(Thread.callStackSymbols)

or for better formatting

for symbol: String in Thread.callStackSymbols {
    print(symbol)
}

Solution 3:

This improves the output a little.

for symbol: String in NSThread.callStackSymbols() {
    NSLog("%@", symbol)
}

Solution 4:

Here's a great utility class I found on github:

https://github.com/nurun/swiftcallstacktrace

You get a tuple (class,method) of any stack trace symbol so you can do a clean printout.

CallStackAnalyser.classAndMethodForStackSymbol(NSThread.callStackSymbols()[2])

Edit: swift 4.1 update

https://github.com/GDXRepo/CallStackParser

Solution 5:

I needed to write the callstack to a log file so I tweaked it like so.

var ErrorStack = String()
Thread.callStackSymbols.forEach {
    print($0)
    ErrorStack = "\(ErrorStack)\n" + $0
}