1.在iOS 引用「1.NSObject--- clang編譯OC成C++或者C文件」的類：BaseObj

    給此類.h文件添加非原子屬性：@property (nonatomic,copy) NSString *name;
       此時 BaseObj_IMPL這個結構體中會自動添加_name的變量
      struct BaseObj_IMPL {
         struct NSObject_IMPL NSObject_IVARS;
         NSString * _Nonnull _name;//變量
        }
     在@implementation BaseObj也發(fā)生變化了
         生成底層相關的代碼：
         可以看出：1）、自動生成成員變量 2）、setter  3 ）、get
          static NSString * _Nonnull _I_BaseObj_name(BaseObj * self, SEL _cmd) { return (*(NSString * _Nonnull *)((char *)self + OBJC_IVAR_$_baseObj$_name)); }
          extern "C" __declspec(dllimport) void objc_setProperty (id, SEL, long, id, bool, bool);

          static void _I_BaseObj_setName_(BaseObj * self, SEL _cmd, NSString * _Nonnull name) { objc_setProperty (self, _cmd, __OFFSETOFIVAR__(struct BaseObj, _name), (id)name, 0, 1); }

2.生成一大堆結構體

      {  _prop_t    
          _protocol_t   
          _objc_method    
          _ivar_t
          _class_ro_t
          _class_t
          _category_t
       }

3.類實例變量的生成

      extern "C" unsigned long int OBJC_IVAR_$_BaseObj$_name __attribute__ ((used, section ("__DATA,__objc_ivar"))) = __OFFSETOFIVAR__(struct BaseObj, _name);

      static struct /*_ivar_list_t*/ {
        unsigned int entsize;  // sizeof(struct _prop_t)
        unsigned int count;
        struct _ivar_t ivar_list[1];
     } _OBJC_$_INSTANCE_VARIABLES_BaseObj __attribute__ ((used, section ("__DATA,__objc_const"))) = {
       sizeof(_ivar_t),
       1,
      {{(unsigned long int *)&OBJC_IVAR_$_BaseObj$_name, "_name", "@\"NSString\"", 3, 8}}
    };

4.類實例方法的生成

   NSString :
        setter:(struct objc_selector *)"setName:", "v24@0:8@16", (void *)_I_BaseObj_setName_
        get :(struct objc_selector *)"name", "@16@0:8", (void *)_I_BaseObj_name

   NSInteger:
        setter:(struct objc_selector *)"setAge:", "v24@0:8q16", (void *)_I_BaseObj_setAge_
        get :{(struct objc_selector *)"age", "q16@0:8", (void *)_I_BaseObj_age

   static struct /*_method_list_t*/ {
          unsigned int entsize;  // sizeof(struct _objc_method)
         unsigned int method_count;
        struct _objc_method method_list[2];
    } _OBJC_$_INSTANCE_METHODS_BaseObj __attribute__ ((used, section ("__DATA,__objc_const"))) = {
         sizeof(_objc_method),
         2,   //NSString 所創(chuàng)建的 大致占有 2個字節(jié)   NSInteger：占有 2個字節(jié)
        {{(struct objc_selector *)"name", "@16@0:8", (void *)_I_BaseObj_name},
        {(struct objc_selector *)"setName:", "v24@0:8@16", (void *)_I_BaseObj_setName_}}
          /*如果添加屬性age 并有assgin修飾 
                {{(struct objc_selector *)"age", "q16@0:8", (void *)_I_BaseObj_age}
                {(struct objc_selector *)"setAge:", "v24@0:8q16", (void *)_I_BaseObj_setAge_}}
         */
    };

5.類屬性的生成_prop_list_t

 NSString生成屬性的格式：{"name","T@\"NSString\",C,N,V_name"}
 NSInteger生成屬性的格式：{"age","Tq,N,V_age"}

 static struct /*_prop_list_t*/ {
     unsigned int entsize;  // sizeof(struct _prop_t)
     unsigned int count_of_properties;
     struct _prop_t prop_list[1];
  } _OBJC_$_PROP_LIST_BaseObj __attribute__ ((used, section ("__DATA,__objc_const"))) = {
          sizeof(_prop_t),
          1,
          {{"name","T@\"NSString\",C,N,V_name"},{"age","Tq,N,V_age"}}
  };

5.生成_class_ro_t
class_ro_t 和 class_rw_t 的區(qū)別？
ObjC 類中的屬性、方法還有遵循的協(xié)議等信息都保存在 class_rw_t 中：
其中還有一個指向常量的指針 ro，其中存儲了當前類在編譯期就已經(jīng)確定的屬性、方法以及遵循的協(xié)議。

 1)、_OBJC_METACLASS_RO_ 沒有發(fā)生變化
 static struct _class_ro_t _OBJC_METACLASS_RO_$_BaseObj __attribute__ ((used, section ("__DATA,__objc_const"))) = {
     1, sizeof(struct _class_t), sizeof(struct _class_t), 
     (unsigned int)0, 
     0, 
     "BaseObj",
     0, 
     0, 
     0, 
     0, 
     0, 
  };

2)、_OBJC_CLASS_RO_ 發(fā)生變化
     （1）、添加實例方法 （2）、添加成員變量 （3）、添加屬性列表
static struct _class_ro_t _OBJC_CLASS_RO_$_BaseObj __attribute__ ((used, section ("__DATA,__objc_const"))) = {
      0, __OFFSETOFIVAR__(struct BaseObj, _name), sizeof(struct BaseObj_IMPL), 
      (unsigned int)0, 
      0, 
      "BaseObj",
      (const struct _method_list_t *)&_OBJC_$_INSTANCE_METHODS_BaseObj,
      0, 
      (const struct _ivar_list_t *)&_OBJC_$_INSTANCE_VARIABLES_BaseObj,
      0, 
      (const struct _prop_list_t *)&_OBJC_$_PROP_LIST_BaseObj,
};