1.2.6.3. alpha.osx.cocoa.InstanceVariableInvalidation (ObjC)
Check that the invalidatable instance variables are invalidated in the methods annotated with objc_instance_variable_invalidator.

Examples:

@protocol Invalidation <NSObject>
- (void) invalidate
  __attribute__((annotate("objc_instance_variable_invalidator")));
@end

@interface InvalidationImpObj : NSObject <Invalidation>
@end

@interface SubclassInvalidationImpObj : InvalidationImpObj {
  InvalidationImpObj *var;
}
- (void)invalidate;
@end

@implementation SubclassInvalidationImpObj
- (void) invalidate {}
@end
// warn: var needs to be invalidated or set to nil