Re: [PATCH v6 0/14] MR372: vkd3d-shader/dxil: Read metadata and signatures.

[Giovanni Mascellani (＠giomasce)]

Giovanni Mascellani (@giomasce) commented about libs/vkd3d-shader/dxil.c:
> -
> - for (i = 0; i < record->operand_count; ++i)
> - {
> -
>    uint64_t ref;
> -
> -
>    ref = record->operands[i] - 1;
> -
>    if (record->operands[i] >= 1 && ref >= end_count)
> -
>    {
> -
>        WARN("Invalid metadata index %"PRIu64".\n", ref);
> -
>        vkd3d_shader_parser_error(&sm6->p, VKD3D_SHADER_ERROR_DXIL_INVALID_METADATA,
> -
>                "Metadata index %"PRIu64" is invalid.", ref);
> -
>        vkd3d_free(node);
> -
>        return VKD3D_ERROR_INVALID_SHADER;
> -
>    }
> -
> -
>    if (!node->is_distinct && ref == dst_idx)

Here it seems that the point of non-distinct nodes is that they can't reference themselves. However, they can still reference later nodes, so it's still possible that reference cycles exist. Is that expected? I'm asking because I find it somewhat strange that you disallow self-references but still allow cycles. But if that's what LLVM/DXC intended, ¯\_(ツ)_/¯.