Assertion failed 'node->AsCall()->IsAsync()'

[MichalStrehovsky]

Hitting this with native AOT, only when optimizations are disabled (/p:Optimize=false).

Repro steps:

1. Add:

  <PropertyGroup>
    <Features>$(Features);runtime-async=on</Features>
    <NoWarn>$(NoWarn);xUnit1013;CS1998;SYSLIB5007</NoWarn>
  </PropertyGroup>>

At the bottom of src\libraries\Directory.Build.props.

2. build.cmd clr.aot+libs -rc Checked -lc Release
3. dotnet.cmd build src\libraries\System.Text.Json\tests\System.Text.Json.SourceGeneration.Tests\System.Text.Json.SourceGeneration.Roslyn4.4.Tests.csproj -c Release /p:RuntimeConfiguration=Checked /p:TestNativeAot=true /p:Optimize=false -f net11.0

Hitting:

  ILC: D:\git\runtime3\src\coreclr\jit\lower.cpp:5930
  ILC: Assertion failed 'node->AsCall()->IsAsync()' in 'System.Text.Json.Serialization.Tests.StreamingJsonSerializerWrapper:DeserializeWrapper[System.Text.Json.Serialization.Tests.Struct_With_Ctor_With_65_Params](System.String,System.Text.Json.JsonSerializerOptions):System.Threading.Tasks.Task`1[System.Text.Json.Serialization.Tests.Struct_With_Ctor_With_65_Params]:this' during 'Lowering nodeinfo' (IL size 76; hash 0x61a38a3d; MinOpts)

[dotnet-policy-service]

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

[jakobbotsch]

It means NativeAOT is using the AsyncCallContinuation intrinsic on a call that was not marked with runtime async call convention when the JIT queried the calling convention. This is most likely a NAOT issue.

[dotnet-policy-service]

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

[MichalStrehovsky]

It means NativeAOT is using the AsyncCallContinuation intrinsic on a call that was not marked with runtime async call convention when the JIT queried the calling convention. This is most likely a NAOT issue.

Here's JitDump:
issue122582.txt

The parts that look relevant:

    [ 3]  11 (0x00b) call 0A000002
In Compiler::impImportCall: opcode is call, kind=0, callRetType is struct, structSize is 260
Call is an async non-task await

    [ 0]  17 (0x011) call 0A000003
In Compiler::impImportCall: opcode is call, kind=0, callRetType is ref, structSize is 0
Named Intrinsic System.Runtime.CompilerServices.AsyncHelpers.AsyncCallContinuation: Recognized****

Looks like the previous call was reported as async?

[jakobbotsch]

It means NativeAOT is using the AsyncCallContinuation intrinsic on a call that was not marked with runtime async call convention when the JIT queried the calling convention. This is most likely a NAOT issue.

Here's JitDump: issue122582.txt

The parts that look relevant:

    [ 3]  11 (0x00b) call 0A000002
In Compiler::impImportCall: opcode is call, kind=0, callRetType is struct, structSize is 260
Call is an async non-task await

    [ 0]  17 (0x011) call 0A000003
In Compiler::impImportCall: opcode is call, kind=0, callRetType is ref, structSize is 0
Named Intrinsic System.Runtime.CompilerServices.AsyncHelpers.AsyncCallContinuation: Recognized****

Looks like the previous call was reported as async?

Yes, indeed.
From a quick reading it looks like the stloc between the call and AsyncCallContinuation is making a call appear between them that gets the JIT confused. I think the JIT can work a bit harder to match the intrinsic to the preceding call now after #121952. I can look at that from the JIT side (after new years).

Alternatively the IL can be shaped to avoid the stloc between them -- that may or may not work.