Does not compile on Xcode 8 and code missing

[hofman]

Description of the problem

Sparkle does not compile in Xcode 8 on 10.11. The problem, at least, is in the SPU downloader classes. The availability directives and macros don't work there. I seriously doubt now whether Sparkle will even be backwards compatible with 10.7, which I need (when compiled in a newer Xcode version). Also, the content of the ed55519 directory is missing in the code of the latest release distributions. Is there any review of releases? This problem must have been present already for several releases. The website does say it is compatible with Xcode 8 with 10.10 SDK, and runtime 10.7. At least 2 out of three are not true anymore, what about 3? I need all to be true. Which version of Sparkle satisfies these requirements?

Do you use Sandboxing in your app?

No.

Version of Sparkle.framework in the latest version of your app

1.21.3

Version of Sparkle.framework in the old version of app that your users have (or N/A)

NA

Sparkle's output from Console.app

NA

Steps to reproduce the behavior

Just try to compile the sources from 1.21.3 in Xcode 8 on 10.11.

[hofman]

It looks like the compile problem is due to the use of @available in SPUDownloadData. It should check the OS version instead and ignore warnings, like for the touchbar code.

I also saw that the ed25519 code from the master branch give a lot of warnings due to implicit type casts between signed/unsigned types.

[kornelski]

Thanks for the report.

I've bumped minimum requirement to Xcode 9. That's what we have in CI, so earlier versions don't get tested and rot like that.

I'd rather keep using @available since that's an easy and reliable runtime check, but it could be OK to hide these completely with #ifdefs from old Xcode/SDKs. Would you like to make a PR for that?

[hofman]

I don't like that, I unfortunately need Xcode 8.

Why keep @available? All the rest of the code checks the OS version using SUOSOperatingSystem.

[hofman]

Why not define a macro that can be defined as @available when this is supported, for instance:

#if __clang_major__ >= 9
#define SUAVAILABLE(major, minor) @available(macOS major##.##minor, *)
#else 
#define SUAVAILABLE(major, minor) (floor(NSFoundationVersionNumber) >= NSFoundationVersionNumber##major##_##minor)
#fi 

[hofman]

Sorry, I guess the fallback should use SUOperatingSystemVersion as NSFoundationVersionNumber constants may not be available.

#if __clang_major__ >= 9
#define SUAVAILABLE(major, minor) @available(macOS major##.##minor, *)
#else 
#define SUAVAILABLE(major, minor) [SUOperatingSystem isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion){major, minor, 0}]
#fi 

[hofman]

Added a PR to do this