[NativeAOT] OperatingSystem.IsAndroid returns false

[emmauss]

Android framework version

net10.0-android (Preview)

Affected platform version

.Net 10

Description

OperatingSystem apis which query android versions will return false when compile with NativeAOT. This includes OperatingSystem.IsAndroid and OperatingSystem.IsAndroidVersionAtLeast methods. Internally, native aot binaries are built target linux-bionic so they are treated like linux binaries and not android.

Steps to Reproduce

1. Build the native aot sample
2. Call OperatingSystem.IsAndroid
3. Method returns false.

Did you find any workaround?

I'm able to check if running on android with RuntimeInformation.RuntimeIdentifier.StartsWith("linux-bionic-"), and to query android version, I use Android's Build apis. But Android's Build api isn't available in plain .net projects.

Relevant log output

[jonathanpeppers]

This likely won't work until Android runtime packs for NativeAOT exist.

Moving to dotnet/runtime.

[dotnet-policy-service]

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

[MichalStrehovsky]

What OperatingSystem will report is hardcoded at the time we build CoreLib:

runtime/src/libraries/System.Private.CoreLib/src/System/OperatingSystem.cs

Lines 14 to 43 in 9fe86ca

	private const string OSPlatformName =
	#if TARGET_BROWSER
	"BROWSER"
	#elif TARGET_WASI
	"WASI"
	#elif TARGET_WINDOWS
	"WINDOWS"
	#elif TARGET_OSX
	"OSX"
	#elif TARGET_MACCATALYST
	"MACCATALYST"
	#elif TARGET_IOS
	"IOS"
	#elif TARGET_TVOS
	"TVOS"
	#elif TARGET_ANDROID
	"ANDROID"
	#elif TARGET_LINUX
	"LINUX"
	#elif TARGET_FREEBSD
	"FREEBSD"
	#elif TARGET_NETBSD
	"NETBSD"
	#elif TARGET_ILLUMOS
	"ILLUMOS"
	#elif TARGET_SOLARIS
	"SOLARIS"
	#else
	#error Unknown OS, add a corresponding TARGET_* constant to System.Private.CoreLib.Shared.projitems
	#endif

Currently the only Android flavor of CoreLib that works with native AOT is the Bionic one. Bionic is Linux (TARGET_LINUX, not TARGET_ANDROID). We only call the flavor with Java interop Android.

This will be fixed automagically if/when we start publishing runtime packs for the Android RID. We don't currently build a CoreLib for the Android RID with native AOT.