[Manually chasing memory leaks] #swift

logAllocation.swift

// can be made dry by adding a alloc/dealloc parameter 
// add the DEBUGALLOC flag to Active Compilation Conditions -> Debug and use it only when necessary. 
// note that you should be using Instruments for this, but this helps to catch issues in real time when running the app, and I gnenerally don't recommend following this approach for several reasons.


func LogDealloc<T>(from caller:T, filename: String = #file, line: Int = #line, funcname: String = #function){
    #if DEBUGALLOC
    let file = ("\(filename)" as NSString).lastPathComponent as String
    let objName = String(describing: type(of: caller))
    let objAddress = Unmanaged.passUnretained(caller as AnyObject).toOpaque()
    var logMessage = "[DEBUG] [DEALLOC] [\(file):\(line)] \(objName) @ \(objAddress)"
    print(logMessage)
    #endif
}

func LogAlloc<T>(from caller:T, filename: String = #file, line: Int = #line, funcname: String = #function){
    #if DEBUGALLOC
    let file = ("\(filename)" as NSString).lastPathComponent as String
    let objName = String(describing: type(of: caller))
    let objAddress = Unmanaged.passUnretained(caller as AnyObject).toOpaque()
    var logMessage = "[DEBUG] [ALLOC]   [\(file):\(line)] \(objName) @ \(objAddress)"
    print(logMessage)
    #endif
}

//usage:

class MyObject { 
 	init(){
    	LogAlloc(from: self)
    }
  	
  	deinit{
    	LogDealloc(from: self)
    }
}

// output is something like this:
/*
[DEBUG] [ALLOC]   [MyObject.swift:3] MyObjectOrInheritedOrProtocol @ 0x000060000154dca0
[DEBUG] [DEALLOC] [MyObject.swift:7] MyObjectOrInheritedOrProtocol @ 0x000060000154dca0
*/