Question

我正在研究Swift项目（XCode 6.3.1）。在运行时我获得EXC_BAD_ACCESS（我在模拟器iPhone 6上测试，但是当我使用单元测试类时，我也得到了这个错误）：

这显示了我的代码结构：

// File IPerson.swift    
public protocol IPerson {
    var firstName : String? { get set }
    var secondName : String? { get set }    
}

// File PersonHelper.swift    
public class PersonHelper<T:IPerson> {
    public init(){
    }

    public func doSomething(person : T) -> Int {
        var secondName = person.secondName;
        //...
        return 0;
    }    
}

// File SamplePerson.swift    
public class SamplePerson: IPerson {
    public init() {
    }

    public var firstName : String?;
    public var secondName : String?;
}

// In some viewController (or in test class)
…
 var helper = PersonHelper<SamplePerson>();
 var person = SamplePerson();
 var result = helper.doSomething(person)
…

当我使用此版本的IPerson协议（更改属性的顺序！）时，evrything就可以了。

// File IPerson.swift    
public protocol IPerson {
    var secondName : String? { get set }
    var firstName : String? { get set }    
}

这种行为对我来说很奇怪 - 协议中的属性顺序很重要？当我使用非泛型PersonHelper时，一切都还可以，但我需要泛型类。当我将所有协议和类放在一个文件中时（从我执行doSomething方法 - viewController或testclass）也一切正常。

我的代码中有什么问题，或者这是Swift语言中的错误？

堆栈追踪：

#0  0x00007f8d4840e350 in 0x7f8d4840e350 ()
#1  0x000000010449e253 in protocol witness for SampleProject.IPerson.firstName.materializeForSet : Swift.Optional<Swift.String> in conformance SampleProject.SamplePerson : SampleProject.IPerson in SampleProject at /Users/bjarko/Documents/XCode Projects/SampleProject/SampleProject/SamplePerson.swift:20
#2  0x000000010449e53e in SampleProject.PersonHelper.doSomething <A : SampleProject.IPerson>(SampleProject.PersonHelper<A>)(A) -> Swift.Int at /Users/bjarko/Documents/XCode Projects/SampleProject/SampleProject/Helper.swift:16
#3  0x0000000104499d35 in SampleProject.ViewController.viewDidLoad (SampleProject.ViewController)() -> () at /Users/bjarko/Documents/XCode Projects/SampleProject/SampleProject/ViewController.swift:18
#4  0x0000000104499dc2 in @objc SampleProject.ViewController.viewDidLoad (SampleProject.ViewController)() -> () ()
#5  0x0000000105058210 in -[UIViewController loadViewIfRequired] ()
#6  0x000000010505840e in -[UIViewController view] ()
#7  0x0000000104f732c9 in -[UIWindow addRootViewControllerViewIfPossible] ()
#8  0x0000000104f7368f in -[UIWindow _setHidden:forced:] ()
#9  0x0000000104f7fe21 in -[UIWindow makeKeyAndVisible] ()
#10 0x0000000104f23457 in -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] ()
#11 0x0000000104f261de in -[UIApplication _runWithMainScene:transitionContext:completion:] ()
#12 0x0000000104f250d5 in -[UIApplication workspaceDidEndTransaction:] ()
#13 0x0000000107d035e5 in __31-[FBSSerialQueue performAsync:]_block_invoke_2 ()
#14 0x00000001045bc41c in __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ ()
#15 0x00000001045b2165 in __CFRunLoopDoBlocks ()
#16 0x00000001045b1f25 in __CFRunLoopRun ()
#17 0x00000001045b1366 in CFRunLoopRunSpecific ()
#18 0x0000000104f24b42 in -[UIApplication _run] ()
#19 0x0000000104f27900 in UIApplicationMain ()
#20 0x000000010449d777 in main at /Users/bjarko/Documents/XCode Projects/SampleProject/SampleProject/AppDelegate.swift:12
#21 0x000000010694b145 in start ()
#22 0x000000010694b145 in start ()

Answer 1

最后我找到了解决方案！在项目设置中，应在是（默认为否）上设置整个模块优化，并且它可以正常工作。我找到了关于优化的文章https://developer.apple.com/swift/blog/?id=27，这提供了以下信息：

“（...）如果启用了整个模块优化，则编译所有模块同时在一起（...）“

这就是为什么当我把所有文件放在一个文件中时没有出现问题。

Swift中的泛型和EXC_BAD_ACCESS

1 个答案: