feat: migrating usdc to native flow

src/contracts/L1OpUSDCBridgeAdapter.sol

@@ -78,25 +78,22 @@ contract L1OpUSDCBridgeAdapter is OpUSDCBridgeAdapter, UUPSUpgradeable, IL1OpUSD
  /**
  * @notice Sets the amount of USDC tokens that will be burned when the burnLockedUSDC function is called
  * @param _amount The amount of USDC tokens that will be burned
- * @dev Only callable by the UpgradeManager
+ * @dev Only callable by a whitelisted messenger during its migration process
  */
- function setBurnAmount(uint256 _amount) external onlyUpgradeManager {
+ function setBurnAmount(uint256 _amount) external {
+ if (
+ messengerStatus[msg.sender] != Status.Upgrading
+ || ICrossDomainMessenger(msg.sender).xDomainMessageSender() != LINKED_ADAPTER
+ ) {
+ revert IOpUSDCBridgeAdapter_InvalidSender();
+ }
+
  burnAmount = _amount;
+ messengerStatus[msg.sender] = Status.Deprecated;
 
  emit BurnAmountSet(_amount);
  }
 
- /**
- * @notice Sets the address of the Circle contract
- * @param _circle The address of the Circle contract
- * @dev Only callable by the UpgradeManager
- */
- function setCircle(address _circle) external onlyUpgradeManager {
- circle = _circle;
-
- emit CircleSet(_circle);
- }
-
  /**
  * @notice Resume messaging on the messenger
  * @dev Only callable by the UpgradeManager
@@ -252,11 +249,34 @@ contract L1OpUSDCBridgeAdapter is OpUSDCBridgeAdapter, UUPSUpgradeable, IL1OpUSD
 
  /**
  * @notice Initiates the process to migrate the bridged USDC to native USDC
- * @param _l1Messenger The address of the L1 messenger
+ * @param _messenger The address of the L1 messenger
  * @param _circle The address to transfer ownerships to
+ * @param _minGasLimitReceiveOnL2 Minimum gas limit that the message can be executed with on L2
+ * @param _minGasLimitSetBurnAmount Minimum gas limit that the message can be executed with to set the burn amount
  */
- function migrateToNative(address _l1Messenger, address _circle) external {
- // TODO: Implement this in future PR
+ function migrateToNative(
+ address _messenger,
+ address _circle,
+ uint32 _minGasLimitReceiveOnL2,
+ uint32 _minGasLimitSetBurnAmount
+ ) external onlyUpgradeManager {
+ // Ensure messaging is enabled
+ // Leave this flow open to resend upgrading flow incase message fails on L2
+ if (messengerStatus[_messenger] != Status.Active && messengerStatus[_messenger] != Status.Upgrading) {
+ revert IOpUSDCBridgeAdapter_MessagingDisabled();
+ }
+ if (circle != address(0)) revert IOpUSDCBridgeAdapter_MigrationInProgress();
+
+ circle = _circle;
+ messengerStatus[_messenger] = Status.Upgrading;
+
+ ICrossDomainMessenger(_messenger).sendMessage(
+ LINKED_ADAPTER,
+ abi.encodeWithSignature('receiveMigrateToNative(address,uint32)', _circle, _minGasLimitSetBurnAmount),
+ _minGasLimitReceiveOnL2
+ );
+
+ emit MigratingToNative(_messenger, _circle);
  }
 
  /**

src/contracts/L2OpUSDCBridgeAdapter.sol

@@ -141,6 +141,27 @@ contract L2OpUSDCBridgeAdapter is IL2OpUSDCBridgeAdapter, Initializable, OpUSDCB
  emit MessagingResumed(MESSENGER);
  }
 
+ /**
+ * @notice Initiates the process to migrate the bridged USDC to native USDC
+ * @dev Full migration cant finish until L1 receives the message for setting the burn amount
+ * @param _newOwner The address to transfer ownerships to
+ * @param _setBurnAmountMinGasLimit Minimum gas limit that the setBurnAmount message can be executed on L1
+ */
+ function receiveMigrateToNative(address _newOwner, uint32 _setBurnAmountMinGasLimit) external checkSender {
+ // Transfer ownership of the USDC contract to the circle
+ IUSDC(USDC).transferOwnership(_newOwner);
+
+ uint256 _burnAmount = IUSDC(USDC).totalSupply();
+
+ ICrossDomainMessenger(MESSENGER).sendMessage(
+ LINKED_ADAPTER, abi.encodeWithSignature('setBurnAmount(uint256)', _burnAmount), _setBurnAmountMinGasLimit
+ );
+
+ isMessagingDisabled = true;
+
+ emit MigratingToNative(MESSENGER, _newOwner);
+ }
+
  /**
  * @notice Authorize the upgrade of the implementation of the contract
  * @param _newImplementation The address of the new implementation

src/contracts/L2OpUSDCFactory.sol

@@ -55,9 +55,9 @@ contract L2OpUSDCFactory is IL2OpUSDCFactory {
  }
 
  // Execute the L2 Adapter initialization transactions
- if (_l2AdapterInitTxs.length > 1) {
+ if (_l2AdapterInitTxs.length > 0) {
  // Initialize L2 adapter
- for (uint256 i = 1; i < _l2AdapterInitTxs.length; i++) {
+ for (uint256 i; i < _l2AdapterInitTxs.length; i++) {
  (bool _success,) = _adapterProxy.call(_l2AdapterInitTxs[i]);
  if (!_success) {
  revert IL2OpUSDCFactory_AdapterInitializationFailed();

src/contracts/UpgradeManager.sol

@@ -119,8 +119,14 @@ contract UpgradeManager is Initializable, OwnableUpgradeable, UUPSUpgradeable, I
  /**
  * @notice Execute the migration of the L1 Adapter to the native chain
  * @param _l1Messenger The address of the L1 messenger
+ * @param _minGasLimitReceiveOnL2 Minimum gas limit that the message can be executed with on L2
+ * @param _minGasLimitSetBurnAmount Minimum gas limit that the message can be executed with to set the burn amount
  */
- function executeMigration(address _l1Messenger) external {
+ function executeMigration(
+ address _l1Messenger,
+ uint32 _minGasLimitReceiveOnL2,
+ uint32 _minGasLimitSetBurnAmount
+ ) external {
  Migration memory _migration = migrations[_l1Messenger];
 
  // Check the migration is prepared, not executed and is being called by the executor
@@ -131,7 +137,9 @@ contract UpgradeManager is Initializable, OwnableUpgradeable, UUPSUpgradeable, I
  if (msg.sender != _migration.executor) revert IUpgradeManager_NotExecutor();
 
  // Migrate
- IL1OpUSDCBridgeAdapter(L1_ADAPTER).migrateToNative(_l1Messenger, _migration.circle);
+ IL1OpUSDCBridgeAdapter(L1_ADAPTER).migrateToNative(
+ _l1Messenger, _migration.circle, _minGasLimitReceiveOnL2, _minGasLimitSetBurnAmount
+ );
 
  migrations[_l1Messenger].executed = true;
 

src/interfaces/IL1OpUSDCBridgeAdapter.sol

@@ -11,12 +11,14 @@ interface IL1OpUSDCBridgeAdapter {
  * @param Uninitialized The messenger is Uninitialized
  * @param Active The messenger is active
  * @param Paused The messenger is paused
+ * @param Upgrading The messenger is upgrading
  * @param Deprecated The messenger is deprecated
  */
  enum Status {
  Uninitialized,
  Active,
  Paused,
+ Upgrading,
  Deprecated
  }
 
@@ -39,12 +41,6 @@ interface IL1OpUSDCBridgeAdapter {
  */
  event L2AdapterUpgradeSent(address _newImplementation, address _messenger, bytes _data, uint32 _minGasLimit);
 
- /**
- * @notice Emitted when circle is set
- * @param _circle The address of the Circle contract
- */
- event CircleSet(address _circle);
-
  /**
  * @notice Emitted when a new messenger is initialized
  * @param _messenger The address of the messenger
@@ -78,7 +74,7 @@ interface IL1OpUSDCBridgeAdapter {
  /**
  * @notice Sets the amount of USDC tokens that will be burned when the burnLockedUSDC function is called
  * @param _amount The amount of USDC tokens that will be burned
- * @dev Only callable by the owner
+ * @dev Only callable by a whitelisted messenger during its migration process
  */
  function setBurnAmount(uint256 _amount) external;
 
@@ -102,10 +98,17 @@ interface IL1OpUSDCBridgeAdapter {
 
  /**
  * @notice Initiates the process to migrate the bridged USDC to native USDC
- * @param _l1Messenger The address of the L1 messenger
+ * @param _messenger The address of the L1 messenger
  * @param _circle The address to transfer ownerships to
+ * @param _minGasLimitReceiveOnL2 Minimum gas limit that the message can be executed with on L2
+ * @param _minGasLimitSetBurnAmount Minimum gas limit that the message can be executed with to set the burn amount
  */
- function migrateToNative(address _l1Messenger, address _circle) external;
+ function migrateToNative(
+ address _messenger,
+ address _circle,
+ uint32 _minGasLimitReceiveOnL2,
+ uint32 _minGasLimitSetBurnAmount
+ ) external;
 
  /**
  * @notice Send the message to the linked adapter to mint the bridged representation on the linked chain

src/interfaces/IOpUSDCBridgeAdapter.sol

@@ -36,6 +36,13 @@ interface IOpUSDCBridgeAdapter {
  */
  event MessagingResumed(address _messenger);
 
+ /**
+ * @notice Emitted when the adapter is migrating usdc to native
+ * @param _messenger The address of the messenger contract that is doing the migration
+ * @param _newOwner The address of the new owner of bridged usdc
+ */
+ event MigratingToNative(address _messenger, address _newOwner);
+
  /*///////////////////////////////////////////////////////////////
  ERRORS
  //////////////////////////////////////////////////////////////*/
@@ -60,6 +67,11 @@ interface IOpUSDCBridgeAdapter {
  */
  error IOpUSDCBridgeAdapter_MessageExpired();
 
+ /**
+ * @notice Error when a migration is in progress
+ */
+ error IOpUSDCBridgeAdapter_MigrationInProgress();
+
  /*///////////////////////////////////////////////////////////////
  LOGIC
  //////////////////////////////////////////////////////////////*/

src/interfaces/IUpgradeManager.sol

@@ -130,8 +130,14 @@ interface IUpgradeManager {
  /**
  * @notice Execute the migration of the L1 Adapter to the native chain
  * @param _l1Messenger The address of the L1 messenger
- */
- function executeMigration(address _l1Messenger) external;
+ * @param _minGasLimitReceiveOnL2 Minimum gas limit that the message can be executed with on L2
+ * @param _minGasLimitSetBurnAmount Minimum gas limit that the message can be executed with to set the burn amount
+ */
+ function executeMigration(
+ address _l1Messenger,
+ uint32 _minGasLimitReceiveOnL2,
+ uint32 _minGasLimitSetBurnAmount
+ ) external;
 
  /**
  * @notice Stop messaging on the messenger

src/interfaces/external/IUSDC.sol

@@ -17,4 +17,10 @@ interface IUSDC is IERC20 {
  * @param _amount Amount of tokens to burn
  */
  function burn(address _account, uint256 _amount) external;
+
+ /**
+ * @notice Transfers USDC ownership to another address
+ * @param newOwner Address to transfer ownership to
+ */
+ function transferOwnership(address newOwner) external;
 }