How to obtain Noir circuit and witness in ACIR format?

[ihyunnam]

Hi, I'm trying to prove a Noir circuit with Groth16. To do so, I need the Noir-compiled circuit in the "acvm::acir::circuit::Circuit" type and its witnesses in the "acvm::acir::native_types::Witness" type. I'm pretty sure this should be possible. However, I haven't been able to figure out how to do that from parsing through the Noir library. For instance, is there a way to run "nargo execute" and turn the resulting circuit.json and circuit.gz (witness) files into the Circuit and Witness types, respectively? I'd appreciate any help from anyone, thank you!

[Savio-Sou]

Proving backends would have to figure out if and how to perform such deserialization of compiled circuits and executed witnesses, depending on their needs and preferences. (Barretenberg's JS package test taking in a Noir circuit and witness as an example.)

As to specifically deserializing compiled circuits and executed witnesses back into ACVM types, I don't think there is any current tooling for it. Do share if you plan to work on one.