使用格式

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

• 忽略弃用的警告

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    UIAlertView *alertViewTmp = [[UIAlertView alloc]initWithTitle:@"" message:@"" delegate:nil cancelButtonTitle:@"" otherButtonTitles:@"", nil];
    [alertViewTmp show];
#pragma clang diagnostic pop

• 忽略不兼容指针类型

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

• 循环引用

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-retain-cycles"
//    self.completionBlock = ^ {
//        ...
//    };
#pragma clang diagnostic pop

• 未使用变量

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-variable"
    int a;
#pragma clang diagnostic pop

• 未使用default

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcovered-switch-default"
//    switch (style) {
//        case UITableViewCellStyleDefault:
//        default:
//            return;
//    }
#pragma clang diagnostic pop

参考 Clang's source code