Show architecture name in DLL containing unmanaged code for ReadToRun targeting Linux

[sudoudaisuke]

Is your feature request related to a problem? Please describe.
Publish the dll for linux-x64 ReadyToRun.

<PropertyGroup>
    <PublishReadyToRun>true</PublishReadyToRun>
    <RuntimeIdentifier>linux-x64</RuntimeIdentifier>
</PropertyGroup>

And display the dll header in ILSpy 9.0.0.7833-preview3.

// /tmp/sample.dll
// sample, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
// Global type: <Module>
// Entry point: Program.<Main>$
// Architecture: 64797
// This assembly contains unmanaged code.
// Runtime: v4.0.30319
// Hash algorithm: SHA1
[assembly: CompilationRelaxations(8)]
[assembly: RuntimeCompatibility(WrapNonExceptionThrows = true)]
[assembly: Debuggable(/*Could not decode attribute arguments.*/)]
[assembly: TargetFramework(".NETCoreApp,Version=v8.0", FrameworkDisplayName = ".NET 8.0")]

"Architecture: 64797 (0xFD1D)" means Linux X64 binary. So please show detailed description instead of numbers.

Additional context

• ILSpy/ILSpy/Languages/Language.cs

  Lines 545 to 570 in 9986104

  	public static string GetPlatformDisplayName(PEFile module)
  	{
  	var headers = module.Reader.PEHeaders;
  	var architecture = headers.CoffHeader.Machine;
  	var characteristics = headers.CoffHeader.Characteristics;
  	var corflags = headers.CorHeader.Flags;
  	switch (architecture)
  	{
  	case Machine.I386:
  	if ((corflags & CorFlags.Prefers32Bit) != 0)
  	return "AnyCPU (32-bit preferred)";
  	if ((corflags & CorFlags.Requires32Bit) != 0)
  	return "x86";
  	// According to ECMA-335, II.25.3.3.1 CorFlags.Requires32Bit and Characteristics.Bit32Machine must be in sync
  	// for assemblies containing managed code. However, this is not true for C++/CLI assemblies.
  	if ((corflags & CorFlags.ILOnly) == 0 && (characteristics & Characteristics.Bit32Machine) != 0)
  	return "x86";
  	return "AnyCPU (64-bit preferred)";
  	case Machine.Amd64:
  	return "x64";
  	case Machine.IA64:
  	return "Itanium";
  	default:
  	return architecture.ToString();
  	}
  	}

• Undocumented PE Header Machine Type dotnet/runtime#36364
• https://github.com/dotnet/runtime/blob/1e3544ec04e27538f3d38d274f7a65277f0d681f/src/coreclr/inc/pedecoder.h#L96-L111

[cshung]

This doesn't look like logic inside the R2R plugin.

[siegfriedpammer]

@cshung thanks for pointing this out... I just tried to create an R2R image from ICSharpCode.Decompiler.dll using the following command-line (after reading this guide: https://learn.microsoft.com/en-us/dotnet/core/deploying/ready-to-run):

dotnet publish ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj --runtime win-x64 -p:PublishReadyToRun=true

and then load "\ICSharpCode.Decompiler\bin\Debug\netstandard2.0\win-x64\publish\ICSharpCode.Decompiler.dll" in ILSpy...

no matter, which RID I use.... ILSpy always shows "; The file is not a ReadyToRun image"... I am a bit puzzled by this... if R2R is not supported I would expect the dotnet publish command to fail and provide an error message.

@sudoudaisuke to make it easier for me to look into this problem, may I ask you to provide an example binary; thank you very much!