add Versioned contract

contracts/token/ERC20Bridged.sol

@@ -56,7 +56,7 @@ contract ERC20Bridged is IERC20Bridged, ERC20Core, ERC20Metadata {
     /// @notice Sets the name and the symbol of the tokens if they both are empty
     /// @param name_ The name of the token
     /// @param symbol_ The symbol of the token
-    function initializeERC20Metadata(string memory name_, string memory symbol_) public {
+    function _initializeERC20Metadata(string memory name_, string memory symbol_) internal {
         _setERC20MetadataName(name_);
         _setERC20MetadataSymbol(symbol_);
     }

contracts/token/ERC20BridgedPermit.sol

@@ -5,9 +5,10 @@ pragma solidity 0.8.10;
 
 import {ERC20Bridged} from "./ERC20Bridged.sol";
 import {PermitExtension} from "./PermitExtension.sol";
+import {Versioned} from "../utils/Versioned.sol";
 
 /// @author kovalgek
-contract ERC20BridgedPermit is ERC20Bridged, PermitExtension {
+contract ERC20BridgedPermit is ERC20Bridged, PermitExtension, Versioned {
 
     /// @param name_ The name of the token
     /// @param symbol_ The symbol of the token
@@ -26,13 +27,30 @@ contract ERC20BridgedPermit is ERC20Bridged, PermitExtension {
     {
     }
 
-    /// @notice Sets the name, the symbol and the version of the tokens if they are empty
+    /// @notice Initializes the contract from scratch.
     /// @param name_ The name of the token
     /// @param symbol_ The symbol of the token
     /// @param version_ The version of the token
     function initialize(string memory name_, string memory symbol_, string memory version_) external {
-        initializeERC20Metadata(name_, symbol_);
-        initializeEIP5267Metadata(name_, version_);
+        _initialize_v2(name_, symbol_, version_);
+    }
+
+    /// @notice A function to finalize upgrade to v2 (from v1).
+    function finalizeUpgrade_v2(string memory name_, string memory version_) external {
+        // name and symbol from ERCMetadata already set up in storage, then it is defenetly was v1
+        if (bytes(name()).length > 0 && bytes(symbol()).length > 0) {
+            _updateContractVersion(2);
+            _initializeEIP5267Metadata(name_, version_);
+        } else {
+            // metadata is epmty, incorrect function to call
+            // error?
+        }
+    }
+
+    function _initialize_v2(string memory name_, string memory symbol_, string memory version_) internal {
+        _updateContractVersion(2);
+        _initializeERC20Metadata(name_, symbol_);
+        _initializeEIP5267Metadata(name_, version_);
     }
 
     /// @inheritdoc PermitExtension

contracts/token/ERC20Metadata.sol

@@ -60,17 +60,11 @@ contract ERC20Metadata is IERC20Metadata {
 
     /// @dev Sets the name of the token. Might be called only when the name is empty
     function _setERC20MetadataName(string memory name_) internal {
-        if (bytes(name()).length > 0) {
-            revert ErrorNameAlreadySet();
-        }
         _loadDynamicMetadata().name = name_;
     }
 
     /// @dev Sets the symbol of the token. Might be called only when the symbol is empty
     function _setERC20MetadataSymbol(string memory symbol_) internal {
-        if (bytes(symbol()).length > 0) {
-            revert ErrorSymbolAlreadySet();
-        }
         _loadDynamicMetadata().symbol = symbol_;
     }
 
@@ -85,7 +79,4 @@ contract ERC20Metadata is IERC20Metadata {
             r.slot := slot
         }
     }
-
-    error ErrorNameAlreadySet();
-    error ErrorSymbolAlreadySet();
 }

contracts/token/ERC20RebasableBridged.sol

@@ -8,8 +8,8 @@ import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol
 import {IERC20Wrapper} from "./interfaces/IERC20Wrapper.sol";
 import {ITokenRateOracle} from "../optimism/TokenRateOracle.sol";
 import {ERC20Metadata} from "./ERC20Metadata.sol";
-import {UnstructuredRefStorage} from "./UnstructuredRefStorage.sol";
-import {UnstructuredStorage} from "./UnstructuredStorage.sol";
+import {UnstructuredRefStorage} from "../lib/UnstructuredRefStorage.sol";
+import {UnstructuredStorage} from "../lib/UnstructuredStorage.sol";
 
 /// @author kovalgek
 /// @notice Extends the ERC20 functionality that allows the bridge to mint/burn shares
@@ -207,14 +207,6 @@ contract ERC20RebasableBridged is IERC20, IERC20Wrapper, IERC20BridgedShares, ER
         return tokensAmount;
     }
 
-    /// @notice Sets the name and the symbol of the tokens if they both are empty
-    /// @param name_ The name of the token
-    /// @param symbol_ The symbol of the token
-    function initializeERC20Metadata(string memory name_, string memory symbol_) public {
-        _setERC20MetadataName(name_);
-        _setERC20MetadataSymbol(symbol_);
-    }
-
     function _getTokenAllowance() internal pure returns (mapping(address => mapping(address => uint256)) storage) {
         return TOKEN_ALLOWANCE_POSITION.storageMapAddressMapAddressUint256();
     }
@@ -371,6 +363,14 @@ contract ERC20RebasableBridged is IERC20, IERC20Wrapper, IERC20BridgedShares, ER
         emit TransferShares(_from, _to, _sharesAmount);
     }
 
+    /// @notice Sets the name and the symbol of the tokens if they both are empty
+    /// @param name_ The name of the token
+    /// @param symbol_ The symbol of the token
+    function _initializeERC20Metadata(string memory name_, string memory symbol_) internal {
+        _setERC20MetadataName(name_);
+        _setERC20MetadataSymbol(symbol_);
+    }
+
     /// @dev validates that account_ is not zero address
     modifier onlyNonZeroAccount(address account_) {
         if (account_ == address(0)) {

contracts/token/ERC20RebasableBridgedPermit.sol

@@ -5,9 +5,10 @@ pragma solidity 0.8.10;
 
 import {ERC20RebasableBridged} from "./ERC20RebasableBridged.sol";
 import {PermitExtension} from "./PermitExtension.sol";
+import {Versioned} from "../utils/Versioned.sol";
 
 /// @author kovalgek
-contract ERC20RebasableBridgedPermit is ERC20RebasableBridged, PermitExtension {
+contract ERC20RebasableBridgedPermit is ERC20RebasableBridged, PermitExtension, Versioned {
 
     /// @param name_ The name of the token
     /// @param symbol_ The symbol of the token
@@ -35,8 +36,9 @@ contract ERC20RebasableBridgedPermit is ERC20RebasableBridged, PermitExtension {
     /// @param symbol_ The symbol of the token
     /// @param version_ The version of the token
     function initialize(string memory name_, string memory symbol_, string memory version_) external {
-        initializeERC20Metadata(name_, symbol_);
-        initializeEIP5267Metadata(name_, version_);
+        _initializeContractVersionTo(1);
+        _initializeERC20Metadata(name_, symbol_);
+        _initializeEIP5267Metadata(name_, version_);
     }
 
     /// @inheritdoc PermitExtension

contracts/token/PermitExtension.sol

@@ -3,7 +3,7 @@
 
 pragma solidity 0.8.10;
 
-import {UnstructuredRefStorage} from "./UnstructuredRefStorage.sol";
+import {UnstructuredRefStorage} from "../lib//UnstructuredRefStorage.sol";
 import {EIP712} from "@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol";
 import {IERC2612} from "@openzeppelin/contracts/interfaces/draft-IERC2612.sol";
 import {SignatureChecker} from "../lib/SignatureChecker.sol";
@@ -33,13 +33,13 @@ abstract contract PermitExtension is IERC2612, EIP712 {
     /// @param name_ The name of the token
     /// @param version_ The current major version of the signing domain (aka token version)
     constructor(string memory name_, string memory version_) EIP712(name_, version_) {
-        initializeEIP5267Metadata(name_, version_);
+        _initializeEIP5267Metadata(name_, version_);
     }
 
     /// @notice Sets the name and the version of the tokens if they both are empty
     /// @param name_ The name of the token
     /// @param version_ The version of the token
-    function initializeEIP5267Metadata(string memory name_, string memory version_) public {
+    function _initializeEIP5267Metadata(string memory name_, string memory version_) internal {
         _setEIP5267MetadataName(name_);
         _setEIP5267MetadataVersion(version_);
     }
@@ -142,22 +142,14 @@ abstract contract PermitExtension is IERC2612, EIP712 {
 
     /// @dev Sets the name of the token. Might be called only when the name is empty
     function _setEIP5267MetadataName(string memory name_) internal {
-        if (bytes(_loadEIP5267Metadata().name).length > 0) {
-            revert ErrorEIP5267NameAlreadySet();
-        }
         _loadEIP5267Metadata().name = name_;
     }
 
     /// @dev Sets the version of the token. Might be called only when the version is empty
     function _setEIP5267MetadataVersion(string memory version_) internal {
-        if (bytes(_loadEIP5267Metadata().version).length > 0) {
-            revert ErrorEIP5267VersionAlreadySet();
-        }
         _loadEIP5267Metadata().version = version_;
     }
 
     error ErrorInvalidSignature();
     error ErrorDeadlineExpired();
-    error ErrorEIP5267NameAlreadySet();
-    error ErrorEIP5267VersionAlreadySet();
 }

contracts/utils/Versioned.sol

@@ -0,0 +1,60 @@
+// SPDX-FileCopyrightText: 2022 Lido <[email protected]>
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.10;
+
+import {UnstructuredStorage} from "../lib//UnstructuredStorage.sol";
+
+contract Versioned {
+    using UnstructuredStorage for bytes32;
+
+    event ContractVersionSet(uint256 version);
+
+    error NonZeroContractVersionOnInit();
+    error InvalidContractVersionIncrement();
+    error UnexpectedContractVersion(uint256 expected, uint256 received);
+
+    /// @dev Storage slot: uint256 version
+    /// Version of the initialized contract storage.
+    /// The version stored in CONTRACT_VERSION_POSITION equals to:
+    /// - 0 right after the deployment, before an initializer is invoked (and only at that moment);
+    /// - N after calling initialize(), where N is the initially deployed contract version;
+    /// - N after upgrading contract by calling finalizeUpgrade_vN().
+    bytes32 internal constant CONTRACT_VERSION_POSITION = keccak256("lido.Versioned.contractVersion");
+
+    uint256 internal constant PETRIFIED_VERSION_MARK = type(uint256).max;
+
+    constructor() {
+        // lock version in the implementation's storage to prevent initialization
+        CONTRACT_VERSION_POSITION.setStorageUint256(PETRIFIED_VERSION_MARK);
+    }
+
+    /// @notice Returns the current contract version.
+    function getContractVersion() public view returns (uint256) {
+        return CONTRACT_VERSION_POSITION.getStorageUint256();
+    }
+
+    function _checkContractVersion(uint256 version) internal view {
+        uint256 expectedVersion = getContractVersion();
+        if (version != expectedVersion) {
+            revert UnexpectedContractVersion(expectedVersion, version);
+        }
+    }
+
+    /// @dev Sets the contract version to N. Should be called from the initialize() function.
+    function _initializeContractVersionTo(uint256 version) internal {
+        if (getContractVersion() != 0) revert NonZeroContractVersionOnInit();
+        _setContractVersion(version);
+    }
+
+    /// @dev Updates the contract version. Should be called from a finalizeUpgrade_vN() function.
+    function _updateContractVersion(uint256 newVersion) internal {
+        if (newVersion != getContractVersion() + 1) revert InvalidContractVersionIncrement();
+        _setContractVersion(newVersion);
+    }
+
+    function _setContractVersion(uint256 version) private {
+        CONTRACT_VERSION_POSITION.setStorageUint256(version);
+        emit ContractVersionSet(version);
+    }
+}