Update JIT/EE interface to get the enclosing class name from metadata

[fiigii]

We exposed 64-bit-only hardware intrinsic in nested classes X64 dotnet/coreclr#20146, so we need the JIT/EE interface getMethodNameFromMetaData to return the enclosing class name as well.

Which vm interface I can use to get the enclosing class names of X64?
@jkotas @AndyAyersMS @CarolEidt @tannergooding

[fiigii]

Currently, we are using GetFullyQualifiedNameInfo to implement getMethodNameFromMetadata. Is there a similar function can get the enclosing class name?
https://github.com/dotnet/coreclr/blob/cd0fe8e2d781b21d18254b6414521f6399997f6e/src/vm/jitinterface.cpp#L6574-L6614

[tannergooding]

What does it currently return? I would think we could do nested partial comparisons to make this efficient?

Basically:

if (namespaceName.StartsWith("System.Runtime.Intrinsics"))
{
    namespaceName += "System.Runtime.Intrinsics".Length;

    if (namespaceName[0] == '\-0')
    {
        // className must be Vector64, Vector64<T>, Vector128, Vector128<T>, Vector256, or Vector256<T>
    }
    else if (namespaceName.Equals("X86"))
    {
        // clasName must be Sse, Sse2, .... 
    }
}

[fiigii]

What does it currently return?

For X64 nested classes, getMethodNameFromMetadata returns empty string for namespace and X64 for class name.

I would think we could do nested partial comparisons to make this efficient?

Yes, we can.

[jkotas]

I would add an extra char** argument to getMethodNameFromMetadata to return the nested type name if there is one.

You can use pMT->GetEnclosingCl() to get the token of the enclosing type.

[fiigii]

@jkotas Thank you! Will try.

[fiigii]

You can use pMT->GetEnclosingCl() to get the token of the enclosing type.

@jkotas How can I get the MethodTable pointer from the token?

[jkotas]

You do not need to fetch the MethodTable. You can get the name & namespace using:

        LPCUTF8 szName, szNamespace;
        if (FAILED(pMT->GetMDImport()->GetNameOfTypeDef(pMT->GetEnclosingCl(), &szName, &szNamespace)))
        {
...
        }

[fiigii]

@jkotas It works, thank you!