Xcode 7.3无法在使用手动引用计数的文件中创建__weak引用

Question

在更新到Xcode 7.3之后，它会在pod文件中引发错误Cannot create __weak reference in file using manual reference counting。有没有人解决过这个问题？

Answer 1

Set Build Settings -> Apple LLVM 7.1 - Language - Objective C -> Weak References in Manual Retain Release to YES。

从Apple Developers Forums - Xcode 7.3b4, non-arc, cannot create __weak reference服用。

Answer 2

我已经找到了。

我猜它的意思删除__weak

https://forums.developer.apple.com/thread/38934

Erm, was there ever such a thing as a weak variable reference under MRR [manual retain-release]? "__weak" means one or both of two things:

1. An unowned reference (i.e. not representing a retain count).

2. A zeroing reference (i.e. that the runtime zeroes when the referenced object is deallocated).

#1 doesn't apply to MRR, because you just don't retain the variable anyway.

#2 doesn't apply to MRR either, because the runtime support is in GC and ARC [automatic reference counting], which you're not using.

It sounds like the compiler is now just complaining that it can't do what it could never do. (And in the case of an app delegate, you wouldn't be able to tell the difference at run-time, since the app delegate generally is never deallocated.)

Answer 3

这是官方的回答从苹果公司的链接：

This issue behaves as intended based on the following: We are in the process of implementing weak references in all Objective-C language modes. Since “__weak” has historically been ignored in non-ARC (and non-GC) language modes, we’ve added this error to point out places where the semantics will change in the future. Please update your bug report to let us know if this is still an issue for you.

所以基本上，如果你使用的吊舱对第三方库，您必须删除非ARC中的__weak或等待更新。

更新@ 3/23

我应该研究更多关于我可以通过以编译绕过这些还挺充塞标志。但从根本上说，从现在开始，您不应该在非ARC模式下使用__weak以避免任何意外冲突。对于cocoapods用户，您不需要删除__weak或等待更新，但将生成设置中的Weak References in Manual Retain Release标志设置为YES，如Lean所述。希望这个帮助。

Answer 4

就跳转到你的目标在“构建阶段”选项卡中寻找在“编译来源”荚文件，点击这些文件，并添加编译标志“-fobjc弧”

Answer 5

解决这是最好的方法将post_install脚本添加到您的Podfile，将Weak References in Manual Retain Release标志设置为yes在您的所有Pod目标中。要做到这一点，只需将以下代码粘贴到您的Podfile的底部即可。

post_install do |installer_representation| 
    installer_representation.pods_project.targets.each do |target| 
     target.build_configurations.each do |config| 
      config.build_settings['CLANG_ENABLE_OBJC_WEAK'] ||= 'YES' 
     end 
    end 
end 

有时，这样做会导致错误-fobjc-weak is not supported on the current deployment target。您可以解决通过添加其他配置选项，迫使所有的吊舱的目标，你想要的版本（based on this answer）：

post_install do |installer_representation| 
    installer_representation.pods_project.targets.each do |target| 
     target.build_configurations.each do |config| 
      config.build_settings['CLANG_ENABLE_OBJC_WEAK'] ||= 'YES' 
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.3' 
     end 
    end 
end 

Answer 6

或更改__weak到__unsafeunretained。这将解决传统中的问题。由于MRC（在xCode 4之前）__weak不在iOS中。

Answer 7

解决方法在FBSettings.m

Facebook的弱引用Podfile，可以编写一个脚本吊舱后，运行安装/更新，介绍了以下那里。

post_install do | installer | 
    classy_pods_target = installer.pods_project.targets.find {| target | target.name == 'Facebook-iOS-SDK'} 
    classy_pods_target.build_configurations.each do | config | 
     config.build_settings['CLANG_ENABLE_OBJC_WEAK'] ||= 'YES' 
    end 
end 

CLANG_ENABLE_OBJC_WEAK如何找到这个魔法字的那个。 。