从 Xcode 9.4 升级到 Xcode 11 和从 Swift 3.0 升级到 Swift 4.2 后在 iOS 应用程序中使用 Realm 时指针损坏

Question

我有一个包含 Swift 和 Objective-C 代码的混合应用程序。在 Xcode 9.4 中运行代码时没有问题。升级到 Xcode 11（加上请求升级到 Swift 4.2）后，应用程序在尝试引用 Realm 0.93.2 库中已释放的实例时崩溃并出现 EXC_BAD_ACCESS 错误。

以下是事件的顺序：

1. 启动：

        @UIApplicationMain
    class VGPAppDelegate: UIResponder, UIApplicationDelegate, BITCrashManagerDelegate, BITHockeyManagerDelegate {

        var window: UIWindow?

        internal func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
            //trigger the ui appearance
            VGPUIAppearance.triggerAppearance()

            //setup network monitoring
            TSReachabilityManager.default()
            //Update Realm Scheme
            VGPRealmMigrator.updateRealmSchema()

            setUpHockeyApp()
            setupAppearance()

            if didCrashInLastSessionOnStartup() {
                // Delay launch for sending the crash report
            } else {
                setupApplication()
            }

            return true
        }

1. 在调用 VGPRealmMigrator.updateRealmSchema() 之后

    for (Class cls in s_localNameToClass.allValues) {
    RLMObjectSchema *schema = [RLMObjectSchema 
    schemaForObjectClass:cls];
    [schemaArray addObject:schema];

            // override sharedSchema classs methods for performance
            RLMReplaceSharedSchemaMethod(cls, schema);

            // set standalone class on shared shema for standalone object creation
            schema.standaloneClass = RLMStandaloneAccessorClassForObjectClass(schema.objectClass, schema);
        }
        free(classes);

注意：架构在 Realm > RLMSchema.mm > Intitialise 中有一个有效的指针

1. 现在在 Realm > RLMAccessor.mm

    static Class RLMCreateAccessorClass(Class objectClass,
                                        RLMObjectSchema *schema,
                                        NSString *accessorClassPrefix,
                                        IMP (*getterGetter)(RLMProperty *, RLMAccessorCode, NSString *),
                                        IMP (*setterGetter)(RLMProperty *, RLMAccessorCode)) {
        // throw if no schema, prefix, or object class
        if (!objectClass || !schema || !accessorClassPrefix) {
            @throw RLMException(@"Missing arguments");
        }
        if (!RLMIsKindOfClass(objectClass, RLMObjectBase.class)) {
            @throw RLMException(@"objectClass must derive from RLMObject or Object");
        }

        // create and register proxy class which derives from object class
        NSString *accessorClassName = [accessorClassPrefix stringByAppendingString:schema.className];
        Class accClass = objc_getClass(accessorClassName.UTF8String);
        if (!accClass) {
            accClass = objc_allocateClassPair(objectClass, accessorClassName.UTF8String, 0);
            objc_registerClassPair(accClass);
        }

应用程序在包含引用 schema.className 的语句中崩溃。这里模式有空指针。 Zombie 显示“消息已发送到已释放的实例”。

Answer 1

我使用的是 Realm 的一个古老版本 (0.93.2)。通过以下方式解决了问题：

1. pod install --repo-update
2. pod install（这给了我最新版本，即 3.17.3）