__attribute__（（deprecated））不适用于objective-c协议方法？ [英] __attribute__ ((deprecated)) does not work on objective-c protocol methods?

问题描述

我需要在objective-c协议中弃用一个方法。在正常的类/实例方法上，我添加 __ attribute__（（deprecated））;

I need to deprecate a single method in objective-c protocol. On normal class/instance methods I add __attribute__ ((deprecated)); after declaration.

它不适用于协议方法。如果我标记他们已弃用，并在项目编译正确，没有预期的deprecation警告。

It seems, that it does not work on protocol methods. If I mark them deprecated and use them somewhere the project compiles OK, without expected deprecation warning.

这是一个缺陷在苹果LLVM 3.1，或者我做错了吗？

Is it a flaw in Apple LLVM 3.1, or am I doing something wrong?

推荐答案

虽然这里的答案提供了一些非常好的信息，但它们已经过时。从Xcode 5.0和LLVM 5.0开始，它看起来像Objective-C协议方法的deprecation警告被识别。当实现该方法时，Xcode 5标记它：

Although the answers here provide some very good information, they are outdated. Starting with Xcode 5.0 and LLVM 5.0 it looks like deprecation warnings for Objective-C protocol methods are recognized. When implementing the method, Xcode 5 flags it:

警告：实现已弃用的方法

Warning: Implementing deprecated method

这里是我用来产生一个废弃的协议方法实现的废弃警告的步骤：

Here are the steps I used to produce a deprecation warning for the implementation of a deprecated protocol method:

1. 使用 __ deprecated 将协议方法标记为已弃用。从新的SDK 7.0文档：

1. Mark the protocol method as deprecated using __deprecated. From the new SDK 7.0 documentation:

__不推荐导致编译器产生警告当遇到使用已弃用的功能的代码。 __ deprecated_msg（）也是这样，支持它的编译器将打印一条消息以及废弃警告。这可能需要使用 -Wdeprecated 标志打开此类警告。 __ deprecated_enum_msg（）应用于枚举，支持它的编译器将打印废弃警告。

__deprecated causes the compiler to produce a warning when encountering code using the deprecated functionality. __deprecated_msg() does the same, and compilers that support it will print a message along with the deprecation warning. This may require turning on such warning with the -Wdeprecated flag. __deprecated_enum_msg() should be used on enums, and compilers that support it will print the deprecation warning.

#define __deprecated    __attribute__((deprecated))

若要弃用您的方法，请执行以下操作：

To deprecate your method, do something like this:

- (void)aDeprecatedProtocolMethod __deprecated;

这个单独的应该足以让Xcode显示一个弃用警告。

This alone should be enough for Xcode to display a deprecation warning. However, you should follow the next few steps (knowing that Xcode can be very finicky at times) to ensure the warning displays.

添加一个文档注释，其中包含一个文档注释弃用警告标记。请参阅下面的代码示例，了解如何操作：

Add a documentation comment with a deprecation warning tag. See the code example below to learn how:

/** Describe the method here - what does it do, how does it work, etc. Very brief.
    @deprecated This delegate method is deprecated starting in version 2.0, please use otherMethodNameHere:withAnExtraParameter: instead. */
- (void)aDeprecatedProtocolMethod __deprecated;

清除项目（⌘ + + K ），然后构建项目（⌘ + B

Clean the project (⌘+⇧+K) and then Build the project (⌘+B) - just because Xcode can be funky sometimes.

我不能100％确定此功能的引入时间或地点（可能是SDK 7.0和10.9或Xcode 5.0 / 5.0 .1或LLVM 5.0） - 但它仍然有效。

I'm not 100% sure when or where this feature was introduced (maybe with SDK 7.0 and 10.9, or Xcode 5.0 / 5.0.1, or with LLVM 5.0) - but it works nonetheless.

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