在编译时检查框架是否存在？ [英] Check for framework's existence at compile time?

问题描述

我正在开发一个可以选择使用闭源框架的开源项目。如果闭源框架包含在项目中，则会有其他功能。但是如果框架没有包含在项目中，项目仍然应该正确编译。

I'm working on an open-source project that can optionally use a closed-source framework. If the closed-source framework is included in the project, there will be additional functionality. But if the framework isn't included in the project, the project should still compile properly.

如何在编译时检查如果该框架包含在项目中？

How do I check at compile-time if the framework is included in the project?

基本上，我想做这样的事情：

Basically, I want to do something like this:

#ifdef _MY_FRAMEWORK_EXISTS
#import <MyFramework/MyFramework.h>
#endif

我见过2年前的旧问题喜欢这个，但没有答案浮出水面，所以我现在可能会遗漏一些新东西。

I've seen older questions from 2 years ago like this one, but no answer has surfaced so I might be missing something new now.

我不想在运行时通过 NSClassFromString（）进行检查，因为这会在编译时失败当我尝试导入 MyFramework 并且它不存在时。

I DON'T want to check at run-time via NSClassFromString(), because this will fail at compile time when I try to import MyFramework and it doesn't exist.

推荐答案

您可以使用__has_include语言扩展名检查是否存在头文件。
http://clang.llvm.org/docs/LanguageExtensions.html#包含文件检查宏

You can check for the presence of a header file using the __has_include language extension. http://clang.llvm.org/docs/LanguageExtensions.html#include-file-checking-macros

但是，这只会告诉您是否安装了头文件。它无法告诉您Link Binary With Libraries是否与其框架相关联。

However, that only tells you if the header file is installed. It can't tell you if "Link Binary With Libraries" has linked to its framework.

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