#pragma clang diagnostic

使用格式大致如下：

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-相关命令"
//需要操作的代码
#pragma clang diagnostic pop

常见用法

1.方法弃用告警

#pragma clang diagnostic push       
#pragma clang diagnostic ignored "-Wdeprecated-declarations"           
#pragma clang diagnostic pop     

2.不兼容指针类型

#pragma clang diagnostic push     
#pragma clang diagnostic ignored "-Wincompatible-pointer-types"        
#pragma clang diagnostic pop   

3.循环引用

#pragma clang diagnostic push    
#pragma clang diagnostic ignored "-Warc-retain-cycles"      
#pragma clang diagnostic pop    

4.未使用变量

#pragma clang diagnostic push     
#pragma clang diagnostic ignored "-Wunused-variable"       
#pragma clang diagnostic pop    

5：未使用default

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcovered-switch-default"
#pragma clang diagnostic pop