Warning: unnecessary check for minimum deployment target

Question

I have a Swift class which is linked against several targets with different deployment targets, the main project has iOS 7 minimum requirement and there is an extension with iOS 8 target.

Now when I compile project, the compiler throws warning on this line of code:

    if #available(iOS 8.0, *) { ... }

"Unnecessary check for 'iOSApplicationExtension'; minimum deployment target ensures guard will always be true"

I have checked build settings options and found no switch to kill swift warnings.

I tried to define iOSApplicationExtension version target separately by this line but without success:

    if #available(iOS 8.0, iOSApplicationExtension 8.0, *) { ... }

Is there any way to suppress this annoying message?

Answer 1

Found an ugly workaround to silence warning, but I hope there is a better way:

In iOS 8+ targets build settings, I defined a precompile flag in Build Settings -> Swift Compiler - Custom Flags -> Other Swift Flags:

-D iOS8target

Then I changed code to this way:

#if iOS8target
    // iOS 8+ compatible code
#else
    if #available(iOS 8.0, *) {
        // repeat iOS 8+ compatible code again!
    } else {
        // iOS 7 code
    }
#endif

It's not refactored and ugly, but it works!

UPDATE: There is a swift compiler switch -suppress-warnings to omit all warnings. But it also suppress useful warnings. Also if there is only one specific file which emits warnings, you can use -w flag in Building Phases pane. It will also suppress useful warnings but limited to one file.

Answer 2

The next release of Cocoapod (after 0.39.0) should have this issue addressed. Check this for more details.