macho/research/custom_loader/a.mm

#import <Foundation/Foundation.h>

@interface Foo : NSObject
@end

@implementation Foo
- (void)bar {
  NSLog(@"%@", self);
}
@end

@interface Bar : NSObject
@end

@implementation Bar
+ (void)load {
  NSLog(@"%@", self);
}
@end

@implementation Baz : Bar
@end

int main(int argc, const char * argv[]) {
  @autoreleasepool {
    NSLog(@"Hello, World!");
    Foo *foo = [[Foo alloc] init];
    [foo bar];
  }
  return 0;
}