@jkotas PTAL
cc @dotnet/jit-contrib

I think we need the same check in crossgen2 for R2R

I think we need the same check in crossgen2 for R2R

Would the check go into CrossModuleInlineableUncached?

Would the check go into CrossModuleInlineableUncached?

I do not see caller and callee in CrossModuleInlineableUncached. I think it needs to be earlier.

Would the check go into CrossModuleInlineableUncached?

I do not see caller and callee in CrossModuleInlineableUncached. I think it needs to be earlier.

@jkotas I started in on crossgen2 support, but I can't see where custom attributes on modules are recorded, so could use some help finishing it off.

Also I think it would be better to either always return INLINE_FAIL from canInline or else distinguish between INLINE_FAIL and INLINE_NEVER and use the latter to short-circuit some work... at least to remember context-free decisions within the current process.

@davidwrighton maybe you can give me some pointers? How do we find module attributes in crossgen2? I see support for assembly attributes but nothing for modules.

@davidwrighton maybe you can give me some pointers? How do we find module attributes in crossgen2? I see support for assembly attributes but nothing for modules.

We don't have higher level facilities for this in crossgen2, this will have to use System.Reflection.Metadata APIs, something along the lines of:

var reader = rootMod.MetadataReader;
var c = reader.StringComparer;
foreach (var attr in reader.GetModuleDefinition().GetCustomAttributes())
{
    if (reader.GetAttributeNamespaceAndName(attr, out var ns, out var n))
    {
        if (c.Equals(ns, "System.Runtime.CompilerServices") && c.Equals(n, "RuntimeCompatibilityAttribute"))
        {
            var dec = reader.GetCustomAttribute(attr).DecodeValue(new CustomAttributeTypeProvider(mod));
            // Go over dec.NamedArguments and find WrapNonExceptionThrows
        }
    }
}

We'll probably want to cache this on EcmaModule.