Fix warning (-Wexpansion-to-defined) in Xcode 9.3

[anderscarling]

Xcode 9.3 seems to run with -Wexpansion-to-defined by default, which creates a warning in both the Mixpanel target and (due to this happening in headers) in my app target.

I believe this should fix is, but probably if someone more experience in macro expansion trickery could weight in.

Fix is adapted from https://stackoverflow.com/a/42074134

[wileykestner]

@anderscarling Have you received any feedback about this PR? I'm encountering the same issue - have you been using this patch successfully?

[anderscarling]

@wileykestner I've heard nothing - and I've not really used the patch in production builds or anything :/

[wileykestner]

@anderscarling Thanks for the update - I think we may give it a try in our staging environment.

[anderscarling]

Hope it works for you! It feels like simple enough a change not to mess anything up - but as I've no real knowledge in the intricate behaviors of C macros I don't want to make any promises. :)

[kdawgwilk]

I was just about to open a PR with a fix for this. I think it can be simplified down to this:

#if defined(MIXPANEL_TVOS) || defined(MIXPANEL_WATCHOS) || defined(MIXPANEL_MACOS)
    #define MIXPANEL_NO_REACHABILITY_SUPPORT 1
    #define MIXPANEL_NO_AUTOMATIC_EVENTS_SUPPORT 1
    #define MIXPANEL_NO_NOTIFICATION_AB_TEST_SUPPORT 1
    #define MIXPANEL_NO_CONNECT_INTEGRATION_SUPPORT 1
#elseif defined(MIXPANEL_WATCHOS) || defined(MIXPANEL_MACOS)
    #define MIXPANEL_NO_UIAPPLICATION_ACCESS 1
#elseif defined(MIXPANEL_WATCHOS)
    #define MIXPANEL_FLUSH_IMMEDIATELY 1
#endif

You don't need to actually define them as zero since not defining them at all has the same effect

[kdawgwilk]

And

#if defined(MIXPANEL_TVOS) || defined(MIXPANEL_WATCHOS) || defined(MIXPANEL_MACOS)
    #define MIXPANEL_NO_NETWORK_ACTIVITY_INDICATOR 1
#endif

[kdawgwilk]

Now that Xcode 9.3 is released it seems that this should get released soon so we can rid our projects of these warnings

[charliebartel]

What is the status on getting this released?

[delebedev]

@zihejia could you or other maintainers make a release with this change, please? Xcode 9.3 is now live

[anderscarling]

I pushed new commits where i rebased on latest master, and removed the #else-cases that #defined zero values (as per suggestion from @kdawgwilk).

I didn't pull in the #elseifs from @kdawgwilk though, as I think they would actually block MIXPANEL_NO_UIAPPLICATION_ACCESS and MIXPANEL_FLUSH_IMMEDIATELY from ever being defined.

Travis CI seems to fail for unrelated reason.

[zihejia]

@garnett yes, we will be working on this.

[zihejia]

Thanks Anders for making the changes