// SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import {ERC20} from "../ERC20.sol"; import {ERC165, IERC165} from "../../../utils/introspection/ERC165.sol"; import {IERC7802} from "../../../interfaces/draft-IERC7802.sol"; /** * @dev ERC20 extension that implements the standard token interface according to * https://eips.ethereum.org/EIPS/eip-7802[ERC-7802]. */ abstract contract ERC20Bridgeable is ERC20, ERC165, IERC7802 { /// @dev Modifier to restrict access to the token bridge. modifier onlyTokenBridge() { // Token bridge should never be impersonated using a relayer/forwarder. Using msg.sender is preferable to // _msgSender() for security reasons. _checkTokenBridge(msg.sender); _; } /// @inheritdoc ERC165 function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { return interfaceId == type(IERC7802).interfaceId || super.supportsInterface(interfaceId); } /** * @dev See {IERC7802-crosschainMint}. Emits a {IERC7802-CrosschainMint} event. */ function crosschainMint(address to, uint256 value) public virtual override onlyTokenBridge { _mint(to, value); emit CrosschainMint(to, value, _msgSender()); } /** * @dev See {IERC7802-crosschainBurn}. Emits a {IERC7802-CrosschainBurn} event. */ function crosschainBurn(address from, uint256 value) public virtual override onlyTokenBridge { _burn(from, value); emit CrosschainBurn(from, value, _msgSender()); } /** * @dev Checks if the caller is a trusted token bridge. MUST revert otherwise. * * Developers should implement this function using an access control mechanism that allows * customizing the list of allowed senders. Consider using {AccessControl} or {AccessManaged}. */ function _checkTokenBridge(address caller) internal virtual; }