带有"Release:Fastest,Smallest [-Os]"的Xcode 8有一些奇怪的问题,在某些情况下效果不佳

Question

我的项目中有1个目标,并且有3个构建配置

Debug Production & Release

当我运行我的应用程序debug或production配置和它的工作正常没有任何问题,但当我改变我build configuration给release它一些奇怪的问题,如一些字符串值不存储在plist文件中,当我调试我的发布模式时,我没有我的调试器中没有任何值.

在对我的代码和构建设置以及一些建议表单进行过多调查之后,我SO在下面的构建设置中进行了以下更改.

Apple LLVM 8.0代码生成标题下的更改优化级别

获得以下优化级别的问题:

解决了以下优化级别更改的问题:

不知道为什么它在无[-O0]中工作.

任何人都可以帮助我补丁吗？

这是上面的优化级别受影响的一个敏感部分.

我保存的书签代码我有价值,但它仍然在plist中存储NULL.

- (IBAction)bookmark:(id)sender{

    DimensionModel *aDimensionModel = APPDELEGATE.selected_dimensionModel;
    EmirateModel *aEmirateModel = APPDELEGATE.selected_emirateModel;
    DivisionModel *aDivisionModel = APPDELEGATE.selected_divisionModel;
    __weak NSString *aStrVCName = self.bookMarkViewModel.selectedStrVCName;

    //Add Title string in Dictionary and then in Plist
    __weak NSString *aStrTitle = [NSString stringWithFormat:@"%@",aDimensionModel.dimension_description];
    aStrTitle = [aStrTitle stringByReplacingOccurrencesOfString:@"(null)" withString:@""];

    if (IS_ENGLISH) {
        aStrTitle = [aStrTitle stringByAppendingString:[NSString stringWithFormat:@" - %@ - %@ - %@",aDivisionModel.division_name,aEmirateModel.emirate_name,[self.bookMarkViewModel.strDataType isEqualToString:@"Number"]?@"(0)":@"(%)"]];
    }else{
        aStrTitle = [aStrTitle stringByAppendingString:[NSString stringWithFormat:@" - %@ - %@ - %@",aDivisionModel.division_name,[Utilities getEmirateNameinArabicByCode:aEmirateModel.emirate_code],[self.bookMarkViewModel.strDataType isEqualToString:@"Number"]?@"(0)":@"(%)"]];
    }

    if (APPDELEGATE.selectedDimRecordTimeModel.record_year == -1) {
        aStrTitle = [aStrTitle stringByAppendingString:[NSString stringWithFormat:@" - %@",[LanguageUtility getLocalizedStringForKey:@"All Years"]]];
    }else{
        aStrTitle = [aStrTitle stringByAppendingString:[NSString stringWithFormat:@" - %ld",(long)APPDELEGATE.selectedDimRecordTimeModel.record_year]];
    }


    NSMutableDictionary *aMutDicGraphDetail = [NSMutableDictionary new];

    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",self.bookMarkViewModel.strSelectedDim] forKey:@"DimCode"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",aStrVCName] forKey:@"VCName"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",PLIST_TITLE_BOOKMARK] forKey:@"PlistBookmark"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",IS_ENGLISH?@"ENGLISH":@"ARABIC"] forKey:@"Language"];
    if (self.bookMarkViewModel.strSelectedDim == nil) {
        [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",[LanguageUtility getLocalizedStringForKey:aStrVCName]] forKey:@"Title"];
    }else{
        [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",aStrTitle] forKey:@"Title"];
    }


    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",APPDELEGATE.selectedDimRecordTimeModel.record_time] forKey:@"RecordTime"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%ld",(long)APPDELEGATE.selectedDimRecordTimeModel.record_year] forKey:@"RecordYear"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",aEmirateModel.emirate_code] forKey:@"EmirateCode"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",self.bookMarkViewModel.strDataType] forKey:@"DataType"];

    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",aDivisionModel.division_code] forKey:@"DivisionCode"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%d",APPDELEGATE.isDataTypeSwitchHide] forKey:@"switchHide"];
    [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",APPDELEGATE.strYearOrMonthFromRbtnCtrl] forKey:@"YearOrMonthFromRbtnCtrl"];
    [aMutDicGraphDetail setObject:@(self.bookMarkViewModel.selectedIndexPath).stringValue forKey:DimSelectedIndex];

    /* Check for RegionVC  and CountryVC*/
    if ([aStrVCName isEqualToString:@"RegionMainVC"] || [aStrVCName isEqualToString:@"CountryMainVC"]){
        [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%@",self.bookMarkViewModel.strComparison] forKey:@"Comparison"];
        [aMutDicGraphDetail setObject:[NSString stringWithFormat:@"%ld",self.bookMarkViewModel.intSelectedRegionId] forKey:@"RegionId"];
    }
    [self.bookMarkViewModel saveBookmark:aMutDicGraphDetail];

    aStrVCName = nil;
}

使用上面的代码,所有值都成功存储到plist中,但aStrTitle在其中有值,但仍然存储为null.

Answer 1

你的问题在于这一行:

__weak NSString *aStrTitle = [NSString stringWithFormat:@"%@",aDimensionModel.dimension_description];

+[NSString stringWithFormat:]创建一个保留计数等于零的新字符串.这通常没问题,因为这个值要么被赋值给strong变量,要么作为参数传递给方法调用.在这两种情况下,它的保留计数都会增加,并且值保持不变.但是你要将这个新字符串分配给__weak变量!弱变量不会影响保留计数,因此在执行此行后它仍为零.因此创建的字符串会在创建后立即删除.

解决方案很简单:删除__weak说明符,你会很高兴.

将局部变量声明为弱(除非它们被块捕获)是没有意义的.像这样的"清理":aStrVCName = nil;根本没有效果.

• 方法完成执行后,将自动释放所有局部变量.
• aStrVCName 无论如何都是弱的,因此它永远不会影响它指向的对象的保留计数.

Answer 2

我在迁移到 xcode 8 和 swift 3 时遇到了类似的问题。事实证明，swift 不喜欢我从扩展中的基类覆盖函数这一事实。请参阅Swift 扩展中的覆盖方法

出于某种原因，编译器并没有抱怨它，更糟糕的是，“奇怪的问题”才开始发生在Fastest, Smallest [-Os]优化级别。

似乎在Fastest, Smallest [-Os]优化级别，编译器会从基类中调用函数，而不是从扩展中调用函数。在None [-O0]优化级别，编译器会从扩展中调用函数。

例如：

public class BaseController : UIViewController {
    override func reloadInterface() {
      println("ok")
    }
}

public class NewController : BaseController {
    override func viewDidLoad() {
      super.viewDidLoad()

      reloadInterface()
     }

}

extension NewController {
   override func reloadInterface() {
      println("extended function")
    }
}

将在无优化级别打印出“扩展功能”，并在最快优化级别打印出“确定”...

简而言之，不要覆盖 swift 扩展中的函数