Fix min target flag for xros and xros-simulator

[NoWiseMan]

Changelog: Fix: Fix min target flag for xros and xros-simulator.
Docs: omit

Apple changes the way the "min target os version" flag is created
see: https://developer.apple.com/forums/thread/737595

This fixes the generation of the min target version flag for visionsOS and visionsOS simulator

[memsharded]

These lines were added by @stevn in #14504, it would be great to get their feedback.

Also, this functionality is clearly not covered by tests if we can change it and it doesn't break anything, it would be good to add some tests that validate this, or at least do some checking.

[NoWiseMan]

FYI:
The current CMake nightly build has a similar "bug"

[memsharded]

Any feedback wrt this change @stevn?
Do you think that you could try to add some tests to cover this change @NoWiseMan? If not sure, please ask for help, or we can try to contribute a test ourselves.

Thanks to both!

[NoWiseMan]

Besides conan I did not any python development.
I can try to implement a test, but I first need to understand how to run them locally

[memsharded]

Don't worry @NoWiseMan if you don't have much experience with Python, we can contribute the tests, no need to do a very large effort, thanks!

[NoWiseMan]

I'm not sure if there is any support for visionOS in the Intel-based simulator.
If yes this PR need more work.

[NoWiseMan]

There is an intel-based simulator.

So the flag -target arm64-apple-xros{os_version} is only correct for arm
the intel version needs -target x86_64-apple-xros{os_version}
d
for that def apple_min_version_flag(os_version, os_sdk, subsystem): needs an additional archparameter

[memsharded]

Hi @NoWiseMan

@stevn hasn't given any feedback regarding this change, and we are also overwhelmed, so difficult to test this too on our side.
If this change is working for you @NoWiseMan, I am happy to merge it as-is. If you could please explicitly comment on the different versions (cmake, OSX, sdk, etc) that are needed for this to work, that could be enough, and I could merge this for next 2.0.14. Thanks again!

[stevn]

Hi,
yeah sorry for going quiet - I meant to look into this but currently can't find the time. Thanks

[memsharded]

yeah sorry for going quiet - I meant to look into this but currently can't find the time. Thanks

No prob! Thanks for following up 🙂

[NoWiseMan]

Yes for me this is working.
Luckily with Xcode 15.1 Beta Apple has removed the x86_64 target
-target x86_64-apple-xros1.0
and we no longer need the arch parameter I mentioned earlier and the PR is perfectly fine yet.

But there is still a unfixed issue in cmake 3.28rc2.
It is not possible to build cmake based libs with conan and cmake for visionOS simulator without patching

Apple-Clang.cmake

....
  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/XRSimulator")
    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "")
....

and replacing the flag with an empty string

[memsharded]

Ok, so the PR seems good, and the patch that is still missing seems something on the CMake side, not something that Conan should fix, but if you think it would be easy to add something to the CMakeToolchain that automatically adds set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "") conditioned on the VisionOS and that could work, that could be added, feel free to open another PR if you'd like.

I am merging this, thanks very much!