1.clang -rewrite-objc main.m

#import <Foundation/Foundation.h>

@interface Person : NSObject
//為了方便檢視重寫的程式碼將name改成cjmName
@property (nonatomic, copy) NSString *cjmName;
@property (nonatomic, assign) NSUInteger age;
- (void)showMyself;

@end

@implementation Person

@synthesize cjmName = _cjmName;
 
@synthesize age = _age;

- (void)showMyself {
    NSLog(@"Name: %@ Age: %ld", self.cjmName, self.age);
}

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        
        Person *p = [[Person alloc] init];
        
        [p setValue:@"Jiaming Chen" forKey:@"cjmName
 
"];
        [p setValue:@22 forKey:@"age"];
        
        p.cjmName = @"CCCC";
        
        [p showMyself];
    }
    return 0;
}

接著使用clang -rewrite-objc main.m重寫為cpp檔案，檢視main函式重寫後的程式碼如下:

int main(int argc, const char * argv[]) {
    /* @autoreleasepool */ { __AtAutoreleasePool __autoreleasepool;

        Person 
 
*p = ((Person *(*)(id, SEL))(void *)objc_msgSend)((id)((Person *(*)(id, SEL))(void *)objc_msgSend)((id)objc_getClass("Person"), sel_registerName("alloc")), sel_registerName("init"));

        ((void (*)(id, SEL, id _Nullable, NSString *))(void *)objc_msgSend)((id)p, sel_registerName("setValue:forKey:"), (id _Nullable)(NSString *)&__NSConstantStringImpl__var_folders_1f_dz4kq57d4b19s4tfmds1mysh0000gn_T_main_080287_mi_1, (NSString *)&__NSConstantStringImpl__var_folders_1f_dz4kq57d4b19s4tfmds1mysh0000gn_T_main_080287_mi_2);
        ((void (*)(id, SEL, id _Nullable, NSString *))(void *)objc_msgSend)((id)p, sel_registerName("setValue:forKey:"), (id _Nullable)((NSNumber *(*)(Class, SEL, int))(void *)objc_msgSend)(objc_getClass("NSNumber"), sel_registerName("numberWithInt:"), 22), (NSString *)&__NSConstantStringImpl__var_folders_1f_dz4kq57d4b19s4tfmds1mysh0000gn_T_main_080287_mi_3);

        ((void (*)(id, SEL, NSString *))(void *)objc_msgSend)((id)p, sel_registerName("setCjmName:"), (NSString *)&__NSConstantStringImpl__var_folders_1f_dz4kq57d4b19s4tfmds1mysh0000gn_T_main_080287_mi_4);

        ((void (*)(id, SEL))(void *)objc_msgSend)((id)p, sel_registerName("showMyself"));
    }
    return 0;
}

https://www.jianshu.com/p/fa941b769606