Qt 5.12 and Android arm64 build

[Thiago Macieira]

On Wednesday, 14 November 2018 13:28:04 PST Jan Mulder wrote:
> With Qt 5.12 coming soon (end this month), I gave the beta #4 a try
> today. My focus was on the cross build of Subsurface-mobile for Android.
> Obviously, I ran in some problems, but nothing that seems mayor. One
> weird thing I could not solve up to now is an undefined reference from
> the linker (QtAndroid::runOnAndroidThread); a construct to set the color
> of the header and footer to our liking.

That sounds like a mix of two Qt versions, since runOnAndroidThread is defined 
in qjnihelpers.cpp, inside QtCore, without any #if. That is, you're compiling 
against 5.12, but linking (or running) against 5.11. Check your environment.

> With Qt 5.12 also a build for arm64 architecture becomes feasible. And I
> succeeded in a running arm64 app on my device. Also here, relatively
> straightforward (in hindsight). This requires a newer API that the
> currently used 16. I used API 21 (corresponding to Android 5.0).

Note that this will make use of Clang to build, instead of GCC of the older 
SDKs. Clang produces much larger binaries, even at extreme size optimisation 
(-Oz).

> So, my question for Dirk: interested in set of patches for all this?
> Obviously, no hurry here, as 5.12 is still beta. I between I might take
> a look into clang instead of gcc for the mobile app, as Android had
> moved away from gcc, and support will end someday.

The first -rc is expected next week and these days it means any RC could be 
the final release one week later, if nothing major is found. If you have 
issues, please report them so we decide whether the RC is good or not.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel Open Source Technology Center