去除警告的方法：
#pragma clang diagnostic push
#pragma clang diagnostic ignored"-Wunused-function"
local void free_linkedlist(ll)
linkedlist_data* ll;
{
free_datablock(ll->first_block);
ll->first_block = ll->last_block = NULL;
}
#pragma clang diagnostic pop
上述的代码块中，正常的代码是没有下方这些代码的。但是呢，这个方法我是已经写了，但是在项目中没有运用到，所以会报出这样的错误，如图错误信息图所示：
代码块：
#pragma clang diagnostic push
#pragma clang diagnostic ignored"-Wunused-function"
// edit code
#pragma clang diagnostic pop
错误信息图：
错误信息图.png
在Xcode中选中警告的消息，右击选择Reveal in Log，然后右边会有报告的消息
-Wunused-function
所以上面去除警告是使用
-Wunused-function
这个来写的。其他的警告同理做法就能去除。
Snip20161122_3.png
示例：
我们知道，UIAlertView虽然简单易用，但是呢Apple在iOS 9.0的时候丢弃这个类了，我们在其头文件中可以看到
NS_CLASS_DEPRECATED_IOS(2_0, 9_0, "UIAlertView is deprecated. Use UIAlertController with a preferredStyle of UIAlertControllerStyleAlert instead") __TVOS_PROHIBITED
所以平时用到这个方法的时候，项目中Xcode就会给这个地方给出警告。但是也有办法处理这样的警告，如下图所示：
QQ20161126-1@2x.png
<p>
下方罗列出来是一些iOS中常见的一些警告消息，在使用第三方库或者Apple官方过时的方法的时候，都会报警告。
| Warning | Message |
|---|---|
| -WCFString-literal | input conversion stopped due to an input byte that does not belong to the input codeset UTF-8 |
| -WNSObject-attribute | __attribute ((NSObject)) may be put on a typedef only, attribute is ignored |
| -Wabstract-vbase-init | initializer for virtual base class %0 of abstract class %1 will never be used |
| -Waddress-of-array-temporary | pointer is initialized by a temporary array, which will be destroyed at the end of the full-expression |
| -Warc-maybe-repeated-use-of-weak | "weak %select{variable property implicit property instance variable}0 %1 may be accessed multiple times in this %select{function method block lambda}2 and may be unpredictably set to nil assign to a strong variable to keep the object alive |
| -Warc-non-pod-memaccess | %select{destination for source of}0 this %1 call is a pointer to ownership-qualified type %2 |
| -Warc-performSelector-leaks | performSelector may cause a leak because its selector is unknown |
| -Warc-repeated-use-of-weak | "weak %select{variable property implicit property instance variable}0 %1 is accessed multiple times in this %select{function method block lambda}2 but may be unpredictably set to nil assign to a strong variable to keep the object alive |
关于附件更多信息至链接iOS 项目警告处理(附表)
