Precompile Registry on Tangle

Introduction

The Precompile Registry is a single source of truth for all available precompiles on Tangle. It can be used to determine whether an address corresponds to a precompile and whether a precompile is active or deprecated. This helps developers prepare for potential backward-incompatible changes by providing an exit strategy or deprecation plan when precompiles evolve over time.

A key additional purpose of the Precompile Registry is to allow any user to set "dummy code" (0x60006000fd) for a precompile address. By default, precompiles do not have bytecode. Some Solidity checks require contract bytecode to be non-empty in order to call functions. The dummy code can be used to bypass such checks.

Precompile Registry Addresses

Below are the addresses for the Registry Precompile on Tangle:

• Tangle Mainnet: 0x0000000000000000000000000000000000000807
• Tangle Testnet: 0x0000000000000000000000000000000000000807

The Solidity Interface

Below is the Solidity interface for interacting with the Precompile Registry. It exposes three main functions: isPrecompile, isActivePrecompile, and updateAccountCode.

Interact with the Precompile Registry Using Remix

You can interact with the Precompile Registry via Remix (opens in a new tab). Below is a general guide:

1. Create a new file in Remix and paste the interface above (or load it from a GitHub repo of your choice).
2. In the "Compile" tab, compile the interface.
3. Go to the "Deploy and run transactions" tab:
   • Choose "Injected Provider - MetaMask" in the ENVIRONMENT dropdown (or another environment that points to Tangle).
   • Select the compiled interface in the CONTRACT dropdown.
   • In the "At Address" field, input the Tangle Mainnet or Tangle Testnet address of the Registry Precompile (for example, 0x0000000000000000000000000000000000000806 for Tangle Testnet).
   • Click "At Address." The precompile interface will appear under "Deployed Contracts."
4. Interact with any of the methods (e.g., call isPrecompile to check if an address is recognized as a precompile).