Retain cylcle warnings

test-cycle-warnings.m

// Illustrates that not all causes of retain cycles are detected by clang.  Compile with:
// clang -fobjc-arc -Wall -framework Foundation test-cycle-warnings.m && ./a.out

#import <Foundation/Foundation.h>


@interface Foo : NSObject

typedef void (^Block)();
@property (readwrite, copy) Block asd;

@end

@implementation Foo
@synthesize asd = _asd;

@end


int main (int argc, char const *argv[])
{
    Foo *self = [[Foo alloc] init];
    self.asd = ^()
    {
        // Causes no retain cycle warning: (FAIL)
        Block b = self.asd;
        // Causes a retain cycle warning:
        [self description];
    };
    
    return 0;
}