Databus programs panic with `MemoryInit block type must be Memory` in Noir→R1CS compilation

[x-senpai-x]

Description

Databus-style programs trigger a panic during Noir-to-R1CS compilation when they use calldata or returndata block types in memory initialization. Only Memory block type is accepted, which is more restrictive than ACIR's spec.

Details

• Panic location: noir_to_r1cs.rs#L469
• Opcode: Opcode::MemoryInit
• ACIR block types:
  • Memory, CallData(u32), ReturnData
  • acir/src/circuit/opcodes.rs#L25
  • acir/src/circuit/opcodes.rs#L112
• Provekit code only accepts: BlockType::Memory

Impact

Databus-oriented circuits (using calldata/returndata memory semantics) panic during the prepare step in r1cs-compiler.

Error: MemoryInit block type must be Memory

This prevents compiling and proving valid programs leveraging the expanded ACIR memory semantics.