runtime-Clang编译

1. 可以将.m文件通过命令行 转化为cpp文件后查看源码

• 在终端中输入

  clang -rewrite-objc main.m
  

Clang编译示例-方法调用实质runtime

 objc_msgSend(<#id self#>, <#SEL op, ...#>)
    // receiver super_class
//    objc_msgSendSuper(<#struct objc_super *super#>, <#SEL op, ...#>)
    /*
        receiver -> self
        objc_msgSendSuper({self, class_getSuperclass(objc_getClass("Person"))}, sel_registerName("description"));
     */

/*
         // ():强转类型,是编译通过.
         Person *p = objc_msgSend(objc_getClass("Person"), sel_registerName("alloc"));

         p = objc_msgSend(p, sel_registerName("init"));

         objc_msgSend(p, sel_registerName("eat"));

         */

        Person *p = [Person alloc];
        //  Person *p = objc_msgSend(objc_getClass("Person"), sel_registerName("alloc"));

        p = [p init];
        // p = objc_msgSend(p, sel_registerName("init"));

        [p run:2];
        //  objc_msgSend(p, sel_registerName("run:"), 2);

        // objc_msgSend(p, sel_registerName("eat"));