LegacyMintableERC20

Table of Contents

• Overview
• Definitions
• Assumptions
• Invariants
• Function Specification
  • constructor
  • supportsInterface
  • mint
  • burn

Overview

Deprecated legacy implementation of a mintable ERC20 token for cross-domain token bridging. This contract represents an L1 token on L2 and allows only the designated L2 bridge to mint and burn tokens. This contract should no longer be used for new deployments.

Definitions

N/A

Assumptions

N/A

Invariants

N/A

Function Specification

constructor

Initializes the token with bridge and L1 token addresses.

Parameters:

• _l2Bridge: Address of the L2 standard bridge authorized to mint and burn tokens
• _l1Token: Address of the corresponding token on L1
• _name: ERC20 token name
• _symbol: ERC20 token symbol

Behavior:

• MUST set l2Bridge to _l2Bridge
• MUST set l1Token to _l1Token
• MUST initialize ERC20 with _name and _symbol

supportsInterface

Returns whether the contract supports a given interface ID per EIP165.

Parameters:

• _interfaceId: 4-byte interface identifier to check

Behavior:

• MUST return true if _interfaceId matches the ERC165 supportsInterface(bytes4) selector
• MUST return true if _interfaceId matches the XOR of ILegacyMintableERC20.l1Token.selector, ILegacyMintableERC20.mint.selector, and ILegacyMintableERC20.burn.selector
• MUST return false otherwise

mint

Mints tokens to a specified address. Only callable by the L2 bridge.

Parameters:

• _to: Address to receive the minted tokens
• _amount: Amount of tokens to mint

Behavior:

• MUST revert if msg.sender is not l2Bridge
• MUST mint _amount tokens to _to
• MUST emit Mint event with _to and _amount

burn

Burns tokens from a specified address. Only callable by the L2 bridge.

Parameters:

• _from: Address from which tokens will be burned
• _amount: Amount of tokens to burn

Behavior:

• MUST revert if msg.sender is not l2Bridge
• MUST burn _amount tokens from _from
• MUST emit Burn event with _from and _amount