UWP Optimized code for ARM64 throws exception

[jsonbailey]

Description

I have a UWP app that builds and run without issue in debug mode. When we attempt to run the release version with code optimization enabled and targeting ARM64 it throws an exception. If I target x64, there is no exception.

LDTest.zip

Reproduction Steps

Run the provided sample application with code optimization enabled and targeting ARM64.

Expected behavior

The optimized code should not trigger an exception and run like it does for other architectures.

Actual behavior

When it processes the WithGreeting method on an optimized build for ARM64 it throws an exception.

Unhandled exception at 0x00007FFA3A2AD520 (SharedLibrary.dll) in LDTest.exe: 0x00001007.

System.Private.SharedLibrary.Interop.Generated.dll!__Interop.api_ms_win_core_kernel32_legacy_l1_1_0_dll.PInvoke_RaiseFailFastException(Interop._EXCEPTION_RECORD* pExceptionRecord = 0x0000000000000000, System.IntPtr pContextRecord = 0x0000000000000007, uint dwFlags = 2248957584)
System.Private.CoreLib.dll!System.RuntimeExceptionHelpers.FailFast(string message, System.Exception exception, System.RuntimeExceptionHelpers.RhFailFastReason reason = Unknown, System.IntPtr pExAddress = 0x0000000000000007, System.IntPtr pExContext = 0x000000495cbfc930) Line 236
	at f:\dd\ndp\fxcore\CoreRT\src\System.Private.CoreLib\src\System\RuntimeExceptionHelpers.cs(236)
System.Private.CoreLib.dll!System.RuntimeExceptionHelpers.RuntimeFailFast(System.RuntimeExceptionHelpers.RhFailFastReason reason, System.Exception exception, System.IntPtr pExAddress, System.IntPtr pExContext) Line 193
	at f:\dd\ndp\fxcore\CoreRT\src\System.Private.CoreLib\src\System\RuntimeExceptionHelpers.cs(193)

Regression?

No response

Known Workarounds

Using a foreach loop and removing the Where method as shown in this PR https://github.com/launchdarkly/dotnet-sdk-internal/pull/42/files seems to prevent the error from happening.

Configuration

No response

Other information

No response

[Sergio0694]

Just to help with triage: the supplied repro is UWP .NET Native, not UWP with .NET 9 and Native AOT.

Partially related: @jsonbailey have you considered using Native AOT instead? It's the recommended path for UWP apps now 🙂

[jkotas]

@jsonbailey thank you for reporting this issue. .NET Native for UWP is in maintenance mode. We do not plan to fix issues in .NET Native that have workarounds.

@jsonbailey have you considered using Native AOT instead? It's the recommended path for UWP apps now

More details are at https://devblogs.microsoft.com/ifdef-windows/preview-uwp-support-for-dotnet-9-native-aot/

@Sergio0694 Is there more up to date documentation than this blog post?

[Sergio0694]

"Is there more up to date documentation than this blog post?"

We haven't had time to update the docs just yet 🥲

However all the tooling is GA now (.NET SDK, Windows SDK, etc.), and we replaced all the project templates in Visual Studio with new ones using .NET 9, so basically just creating a new blank UWP app will give you a starting point for a UWP .NET 9 app.

[jsonbailey]

Thank you. I will review the UWP with .NET 9 and Native AOT.