iOS application crashes when trying to get device location - Thread 1: EXC_BAD_ACCESS

I am fairly new to iOS development, so sorry if this question has an easy fix of which I am unaware.

So I am currently creating an application which requires the user's current location as an address.

So in the class header I made sure to include CLLLocationManagerDelegate:

class SignupViewController: UIViewController, CLLocationManagerDelegate  {...}

Next I created an instance variable for the location manager:

let locationManager = CLLocationManager()

I also created the CLLocationManagerDelegate functions:

// MARK: CLLocationManagerDelegate functions

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    for location in locations {
        self.getLocationAddress(location)
    }
}

func getLocationAddress(location:CLLocation) -> CLPlacemark? {
    let geocoder = CLGeocoder()
    print("-> Finding user address...")
    var placemark:CLPlacemark!
    geocoder.reverseGeocodeLocation(location, completionHandler: {(placemarks, error)->Void in
        if error == nil && placemarks!.count > 0 {
            placemark = placemarks![0] as CLPlacemark
            print(location)
            if placemark != nil {
                print(CLPlacemark().toString(placemark))
            } else {
                print("Problem with data received from geocoder")
            }
        }
    })
    return placemark
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
    print("Error when updating location " + error.localizedDescription)
}

// MARK: Helper functions


func getLocation() {
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestWhenInUseAuthorization()
    locationManager.startUpdatingLocation()
}

I also have a function toString defined as an extension to CLPlacemark:

extension CLPlacemark {
func toString(placemark: CLPlacemark) -> String {
    var addressString : String = ""
    if placemark.ISOcountryCode == "TW" /*Address Format in Chinese*/ {
        if placemark.country != nil {
            addressString = placemark.country!
        }
        if placemark.subAdministrativeArea != nil {
            addressString = addressString + placemark.subAdministrativeArea! + ", "
        }
        if placemark.postalCode != nil {
            addressString = addressString + placemark.postalCode! + " "
        }
        if placemark.locality != nil {
            addressString = addressString + placemark.locality!
        }
        if placemark.thoroughfare != nil {
            addressString = addressString + placemark.thoroughfare!
        }
        if placemark.subThoroughfare != nil {
            addressString = addressString + placemark.subThoroughfare!
        }
    } else {
        if placemark.subThoroughfare != nil {
            addressString = placemark.subThoroughfare! + " "
        }
        if placemark.thoroughfare != nil {
            addressString = addressString + placemark.thoroughfare! + ", "
        }
        if placemark.postalCode != nil {
            addressString = addressString + placemark.postalCode! + " "
        }
        if placemark.locality != nil {
            addressString = addressString + placemark.locality! + ", "
        }
        if placemark.administrativeArea != nil {
            addressString = addressString + placemark.administrativeArea! + " "
        }
        if placemark.country != nil {
            addressString = addressString + placemark.country!
        }
    }
    return addressString
}

When I run my code everything seems to work fine initially, this is the output in the console:

-> Finding user address...
-> Finding user address...
-> Finding user address...
-> Finding user address...
<+40.10886714,-88.23303354> +/- 10.00m (speed 0.00 mps / course 0.00) @ 5/8/16, 11:34:22 PM Central Daylight Time
401 E John St, 61820 Champaign, IL United States
(lldb)

However, at the end it crashes with an (lldb)and displays the error Thread 1: EXC_BAD_ACCESS (code=1, address=0x8)

Not too sure as to why the app is crashing after printing the address.

Thanks in advance for the help!

but i don't know which fix this,

Instead of calling the extension function as

print(CLPlacemark().toString(placemark))

call it as like this,

print(placemark.toString(placemark))

because there is a memory leakage problem. Now, Its not crashing.