super(二) 以及内存分布

@interface Person : NSObject
@property (nonatomic, strong) NSString *age;
- (void)test;
@end

@implementation Person
- (void)test{
    NSLog(@"age = %@",self.age);
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    id cls = [Person class];
    void * temp = &cls;
    [(__bridge id)temp test];
    
    
    Person *per = [[Person alloc] init];
    [per test];
    
}

age = <ViewController: 0x7fb25241d9c0>
age = (null)

.loc	1 18 5 prologue_end     ## /Users/iOS/Desktop/Demo/Demo/ViewController.m:18:5
movq	-8(%rbp), %rsi
movq	%rsi, -32(%rbp)
movq	L_OBJC_CLASSLIST_SUP_REFS_$_(%rip), %rsi
movq	%rsi, -24(%rbp)
movq	L_OBJC_SELECTOR_REFERENCES_(%rip), %rsi
leaq	-32(%rbp), %rdi
callq	_objc_msgSendSuper2

// rewrite-objc 结果
_objc_msgSendSuper(
	struct {
		id self
		Class superClass
  },@selector(viewDidLoad)
)
// 底层实现 汇编结果
  _objc_msgSendSuper2(
	struct {
		id receiver
		Class current_class
  },@selector(viewDidLoad)
)

	ENTRY _objc_msgSendSuper2
	UNWIND _objc_msgSendSuper2, NoFrame

	ldp	p0, p16, [x0]		// p0 = real receiver, p16 = class
	ldr	p16, [x16, #SUPERCLASS]	// p16 = class->superclass
	CacheLookup NORMAL

	END_ENTRY _objc_msgSendSuper2

ldr	p16, [x16, #SUPERCLASS]	// p16 = class->superclass

+ (BOOL)isMemberOfClass:(Class)cls {
  // 当类传进来的时候 获取的是mate-class
    return object_getClass((id)self) == cls;
}

- (BOOL)isMemberOfClass:(Class)cls {
    return [self class] == cls;
}

+ (BOOL)isKindOfClass:(Class)cls {
    for (Class tcls = object_getClass((id)self); tcls; tcls = tcls->superclass) {
				// 循环遍历父类 直到nil 或者相等
        if (tcls == cls) return YES;
    }
    return NO;
}

- (BOOL)isKindOfClass:(Class)cls {
    for (Class tcls = [self class]; tcls; tcls = tcls->superclass) {
        if (tcls == cls) return YES;
    }
    return NO;
}