c++ – Skia reminiscence points when used from static library on iOS

I’ve compiled Skia for iOS:

bin/gn gen out/ios-apple --args="target_os="ios" target_cpu="arm64" ios_use_simulator=false skia_enable_tools=false is_official_build=false is_debug=true is_trivial_abi=false skia_use_metal=true skia_use_expat=false skia_use_system_expat=false skia_use_system_libpng=false skia_use_system_libwebp=false skia_use_system_zlib=false skia_use_system_freetype2=false skia_use_system_harfbuzz=false skia_use_system_icu=false skia_enable_gpu=true skia_enable_skottie=false skia_compile_modules=true extra_cflags=["-F/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks"] extra_ldflags=["-framework", "CoreFoundation", "-framework", "Metal"]"

That is how I am utilizing it in a View Controller:

#import 
#import 
#import 

#outline SK_GANESH
#outline SK_METAL

#import 
#import 

@interface SkiaViewController : UIViewController 

@property (nonatomic, sturdy) MTKView *mtkView;
@property (nonatomic, sturdy) id metalDevice;
@property (nonatomic, sturdy) id metalQueue;

@property (nonatomic, assign) sk_sp grDirectContext;
@property (nonatomic, assign) sk_sp floor;
@finish

#import 
#import 

#outline SK_GANESH
#outline SK_METAL

#import "embody/gpu/ganesh/GrTypes.h"
#import "embody/gpu/ganesh/SkSurfaceGanesh.h"
#import "embody/gpu/ganesh/mtl/GrMtlTypes.h"

#import 
#import 
#import 
#import 
#import 
#import 

#import 
#import 
#import 
#import 

#import "SkiaViewController.h"

@implementation SkiaViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
#ifndef SK_GANESH
    NSLog(@"SK_GANESH is undefined");
#endif
    
#ifndef SK_METAL
    NSLog(@"SK_METAL is undefined");
#endif
    
    [self setMetalDevice:MTLCreateSystemDefaultDevice()];
    [self setMetalQueue:[[self metalDevice] newCommandQueue]];
    
    if(![self metalDevice]) {
        NSLog(@"Metallic will not be supported on this machine");
        return;
    }
    
    if(![self metalQueue]) {
        NSLog(@"Didn't create Metallic command queue");
        return;
    }
    
    // Initialize MTKView
    self.mtkView = [[MTKView alloc] initWithFrame:self.view.bounds machine:self.metalDevice];
    self.mtkView.delegate = self;
    self.mtkView.enableSetNeedsDisplay = YES;
    
    [self.mtkView setDepthStencilPixelFormat:MTLPixelFormatDepth32Float_Stencil8];
    [self.mtkView setColorPixelFormat:MTLPixelFormatBGRA8Unorm];
    [self.mtkView setSampleCount:1];
    
    NSLog(@"self.metalDevice.maxBufferLength=%lu", self.metalDevice.maxBufferLength);
    
    self.mtkView.layer.borderWidth = 2.0; // Set border width
    self.mtkView.layer.borderColor = [UIColor redColor].CGColor; // Set border colour
    
    [self.view addSubview:self.mtkView];
    
    // Initialize Skia with Metallic
    GrMtlBackendContext backendContext = {};
    backendContext.fDevice.retain((__bridge void*)[self metalDevice]); // additionally tried __bridge_retained
    backendContext.fQueue.retain((__bridge void*)[self metalQueue]);
    
    GrContextOptions grContextOptions;
    
    self.grDirectContext = GrDirectContexts::MakeMetal(backendContext, grContextOptions);
    
    if (![self grDirectContext]) {
        NSLog(@"Didn't create GrDirectContext");
        return;
    }
    
    NSLog(@"Created GrDirectContext");
}

#pragma mark - MTKViewDelegate

- (void)drawInMTKView:(nonnull MTKView *)view {
}

- (void)mtkView:(nonnull MTKView *)view drawableSizeWillChange:(CGSize)measurement {
    
}

@finish

On this case it really works effective.

But when I create a static library inside the identical undertaking, transfer ViewController into that static library and use view controller from the static library in my app, I am going through reminiscence points in GrDirectContexts::MakeMetal.

Typically it crashes with unhealthy entry error, typically a few of pointers have gotten nullptr, for instance in backendContext proper after setting these values.

Similar if I transfer this Skia initialization in a separate C++ library (compiled by CMake, not in Xcode instantly).

I suppose that that is some situation with Skia’s sensible pointers (possibly one thing is stripped when linking with static lib?), however I am not conversant in Obj-C improvement and interop with C++ for iOS.

What could also be improper right here?