UUPS.sol

// SPDX-License-Identifier: MIT
pragma solidity 0.8.22;

import { IUUPS } from "../../interfaces/IUUPS.sol";
import { ERC1967Upgrade } from "./ERC1967Upgrade.sol";

/// @title UUPS
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (proxy/utils/UUPSUpgradeable.sol)
/// - Uses custom errors declared in IUUPS
/// - Inherits a modern, minimal ERC1967Upgrade
abstract contract UUPS is IUUPS, ERC1967Upgrade {
    ///                                                          ///
    ///                          IMMUTABLES                      ///
    ///                                                          ///

    /// @dev The address of the implementation
    address private immutable __self = address(this);

    ///                                                          ///
    ///                           MODIFIERS                      ///
    ///                                                          ///

    /// @dev Ensures that execution is via proxy delegatecall with the correct implementation
    modifier onlyProxy() {
        if (address(this) == __self) revert ONLY_DELEGATECALL();
        if (_getImplementation() != __self) revert ONLY_PROXY();
        _;
    }

    /// @dev Ensures that execution is via direct call
    modifier notDelegated() {
        if (address(this) != __self) revert ONLY_CALL();
        _;
    }

    ///                                                          ///
    ///                           FUNCTIONS                      ///
    ///                                                          ///

    /// @dev Hook to authorize an implementation upgrade
    /// @param _newImpl The new implementation address
    function _authorizeUpgrade(address _newImpl) internal virtual;

    /// @notice Upgrades to an implementation
    /// @param _newImpl The new implementation address
    function upgradeTo(address _newImpl) external onlyProxy {
        _authorizeUpgrade(_newImpl);
        _upgradeToAndCallUUPS(_newImpl, "", false);
    }

    /// @notice Upgrades to an implementation with an additional function call
    /// @param _newImpl The new implementation address
    /// @param _data The encoded function call
    function upgradeToAndCall(address _newImpl, bytes memory _data) external payable onlyProxy {
        _authorizeUpgrade(_newImpl);
        _upgradeToAndCallUUPS(_newImpl, _data, true);
    }

    /// @notice The storage slot of the implementation address
    function proxiableUUID() external view notDelegated returns (bytes32) {
        return _IMPLEMENTATION_SLOT;
    }
}