Crash on RLMSchema sharedShema Xcode 15, Below iOS 17 when using with SwiftData

[yasheedv]

How frequently does the bug occur?

Always

Description

A App is crashing when running below iOS 17 with the project having SwiftData model The crash is happening inside RLMSchema sharedShema unsigned int numClasses; using malloc_ptr = std::unique_ptr<__unsafe_unretained Class[], decltype(&free)>; malloc_ptr classes(objc_copyClassList(&numClasses), &free);

Tried adding the -Wl,-ld_classic options to the OTHER_LDFLAGS build in the project settings. But same crash is happening.

Stacktrace & log output

No response

Can you reproduce the bug?

Always

Reproduction Steps

1. Create a new project.
2. Set Minimum deployment target to iOS 13
3. Create a SwiftData Model using @available(iOS 17, *) check
4. Install Realm using SPM
5. Create a Realm Model
6. Access the default Realm in AppDelegate didFinishLaunchingWithOptions
7. Run the application on a device that is below iOS 17
8. Then the application will crash

Project URL: SwiftDataRealm.zip

Version

v10.43.1

What Atlas Services are you using?

Local Database only

Are you using encryption?

No

Platform OS and version(s)

iOS 16.6.1

Build environment

Xcode version: Xcode 15 Dependency manager and version: SPM

[yasheedv]

The crash is happening if I add a SwiftData model inside the project.

[liujieyuu]

@yasheedv Has this problem been solved? I also encountered this problem

[showchi]

10.48.0 still crashes; RealmWithConfiguration:error: is called when starting.

Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)

Crash Below iOS17, Xcode 15.2

+ (instancetype)sharedSchema {
    @synchronized(s_localNameToClass) {
        // We replace this method with one which just returns s_sharedSchema
        // once initialization is complete, but we still need to check if it's
        // already complete because it may have been done by another thread
        // while we were waiting for the lock
        if (s_sharedSchemaState == SharedSchemaState::Initialized) {
            return s_sharedSchema;
        }

        if (s_sharedSchemaState == SharedSchemaState::Initializing) {
            @throw RLMException(@"Illegal recursive call of +[%@ %@]. Note: Properties of Swift `Object` classes must not be prepopulated with queried results from a Realm.", self, NSStringFromSelector(_cmd));
        }

        s_sharedSchemaState = SharedSchemaState::Initializing;
        try {
            // Make sure we've discovered all classes
            {
                unsigned int numClasses;
                using malloc_ptr = std::unique_ptr<__unsafe_unretained Class[], decltype(&free)>;
                malloc_ptr classes(objc_copyClassList(&numClasses), &free); # Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)
                RLMRegisterClassLocalNames(classes.get(), numClasses);
            }

            [s_localNameToClass enumerateKeysAndObjectsUsingBlock:^(NSString *, Class cls, BOOL *) {
                registerClass(cls);
            }];
        }
        catch (...) {
            s_sharedSchemaState = SharedSchemaState::Uninitialized;
            throw;
        }

        // Replace this method with one that doesn't need to acquire a lock
        Class metaClass = objc_getMetaClass(class_getName(self));
        IMP imp = imp_implementationWithBlock(^{ return s_sharedSchema; });
        class_replaceMethod(metaClass, @selector(sharedSchema), imp, "@@:");

        s_sharedSchemaState = SharedSchemaState::Initialized;
    }

    return s_sharedSchema;
}

[lizp-peng]

请问如何解决，有人知道吗

[jln19]

Same problem for me. Fatal for our app. Is there a workaround?

[jln19]

Still crashing as of 10.49.1. We wrote a whole new feature for our app using SwiftData and can't release it because Realm crashes on all devices running iOS16 or below.

Line 300 Pods/Realm/Realm/RLMSchema.mm:300 malloc_ptr classes(objc_copyClassList(&numClasses), &free);

[tgoyne]

You can avoid the call to objc_copyClassList() by explicitly setting objectTypes on your Realm configuration.

[jln19]

You can avoid the call to objc_copyClassList() by explicitly setting objectTypes on your Realm configuration.

@tgoyne Thank you much for this. I'm able to avoid the crash by setting those types.

[TomasWell]

You can avoid the call to objc_copyClassList() by explicitly setting objectTypes on your Realm configuration.

对我有效

• (void)initDataBase { [ART_RLM_DataBaseTool RLM_setDataBaseName:@"ART_ALM_DATABASE"]; NSLog(@"数据库初始化 ART_ALM_DATABASE");

  RLMRealmConfiguration *config = [RLMRealmConfiguration defaultConfiguration]; config.objectClasses = @[ [ART_RLM_ARTIST class], [ART_RLM_SHIYARTIST_MONITOR class], [ART_RLM_CATEGORY_MONITOR class], [ART_RLM_TOURIST_MONITOR class], [ART_RLM_LOG_MONITOR class]]; // 这里你可以添加更多的模型类 [RLMRealmConfiguration setDefaultConfiguration:config]; }

[rvenable]

Is this related to this known issue in objc_getClassList when there are objects that don't exist on lower platform versions? https://github.com/swiftlang/swift/issues/61215

[lkuraer]

I had the same issue. Realm crashed on devices below ios 17, when I have added SwiftData to the project. @tgoyne is right, his comment helped me to solve this. For those who is wondering what he means

let objectTypes: [Object.Type] = [DownloadObject.self, AnotherModel.self, YetAnotherModel.self]

let config = Realm.Configuration( schemaVersion: 10, migrationBlock: { migration, oldSchemaVersion in // Migration logic }, objectTypes: objectTypes )

Realm.Configuration.defaultConfiguration = config

just define realm Object types and list them into the config. And everything will work again.