D for Android beta

[Joakim via Digitalmars-d-announce]

On Friday, 2 June 2017 at 10:40:48 UTC, Petar Kirov [ZombineDev] 
wrote:
> On Friday, 2 June 2017 at 10:12:27 UTC, Joakim wrote:
>> On Friday, 2 June 2017 at 09:39:46 UTC, Petar Kirov 
>> [ZombineDev] wrote:
>>> On Friday, 2 June 2017 at 08:58:01 UTC, Joakim wrote:
>>>> On Friday, 2 June 2017 at 08:36:49 UTC, Dušan Pavkov wrote:
>>>>> [...]
>>>>
>>>> I'd guess that's the issue, as I haven't tested against 
>>>> those older versions of Android and this app links against 
>>>> Android API 21, ie 5.0 Lollipop:
>>>>
>>>> https://github.com/joakim-noah/android/blob/master/samples/Teapot/build-apk#L17
>>>>
>>>> I'm pretty sure it'd work for your older Android versions if 
>>>> built slightly differently, as I used to support back to 
>>>> Android API 9 until a couple months ago:
>>>>
>>>> https://gist.github.com/joakim-noah/f475b0be37b3834b4e50d68996b6ee1d#file-ldc_1-1-0_android_arm-L3438
>>>>
>>>> It can be still made to so but I set API 21 as the minimum, 
>>>> because anything older has been declining for some time now:
>>>>
>>>> http://blog.davidecoppola.com/2016/12/android-version-distribution-history-visualization-2012-2016/
>>>
>>> Just FYI, I have the same issue with Android 6.0.1.
>>
>> Hmm, is that the 64-bit Xiaomi device you mentioned in the 
>> github issues just now?
>
> Yep
>
>> My guess there would be that it's because ldc only supports 
>> 32-bit Android/ARM devices right now, and 64-bit devices like 
>> Xiaomi probably don't run 32-bit native Android libraries in 
>> their apps, though I don't know that for sure.  I just tried 
>> installing the teapot app on another 32-bit 6.0.1 phone that 
>> I'd never tried before, worked fine.
>
> Running 32-bit apps on 64-bit Android, shouldn't be an issue as 
> far I know. See:
> https://stackoverflow.com/questions/30782848/how-to-use-32-bit-native-libraries-on-64-bit-android-device

64-bit ARMv8 hardware should run 32-bit ARMv7 binaries, but it 
depends on software support too, like providing the 32-bit system 
shared libraries that this 32-bit teapot shared library links 
against.  I found that SO link inconclusive, but I just found 
this blog post from a couple years ago that says that it depends 
on the device:

https://ph0b.com/android-abis-and-so-files/

With your 64-bit device, either it doesn't list ARMv7 as a 
supported ABI or there's some bug that's stopping it from running 
this 32-bit ARMv7 library on ARMv8.

>> This is not an issue for Java, because the Android runtime 
>> compiles Java bytecode to native code _after_ the app is 
>> downloaded, but other languages have to provide pre-compiled 
>> libraries for each CPU architecture.  Not a big deal as there 
>> are only really two in wide deployment, 32-bit and 64-bit ARM, 
>> with the vast majority 32-bit right now.
>>
>> Perhaps you can help us get on 64-bit ARM, as you mentioned in 
>> the github issues.
>
> Yes, ultimately I'm interested in writing a Vulkan library that 
> runs on both 32 and 64-bit Linux, Windows and Android, so I'm 
> interested in helping with the AArch64 support too, though my 
> compiler-foo is pretty slim. As mentioned in the GH issue [0], 
> what do I need to bootstrap LDC on Android?
>
> [0]: https://github.com/joakim-noah/android/issues/10

I've followed up on github, we can discuss there.