contracts-bedrock: L1CrossDomainMessenger single impl

packages/contracts-bedrock/.storage-layout

@@ -25,6 +25,7 @@
 | msgNonce           | uint240                  | 205  | 0      | 30    | src/L1/L1CrossDomainMessenger.sol:L1CrossDomainMessenger |
 | failedMessages     | mapping(bytes32 => bool) | 206  | 0      | 32    | src/L1/L1CrossDomainMessenger.sol:L1CrossDomainMessenger |
 | __gap              | uint256[42]              | 207  | 0      | 1344  | src/L1/L1CrossDomainMessenger.sol:L1CrossDomainMessenger |
+| _PORTAL            | contract OptimismPortal  | 249  | 0      | 20    | src/L1/L1CrossDomainMessenger.sol:L1CrossDomainMessenger |
 
 =======================
 ➡ src/L1/L1StandardBridge.sol:L1StandardBridge

packages/contracts-bedrock/scripts/Deploy.s.sol

@@ -277,12 +277,13 @@ contract Deploy is Deployer {
 
     /// @notice Deploy the L1CrossDomainMessenger
     function deployL1CrossDomainMessenger() broadcast() public returns (address) {
-        address portal = mustGetAddress("OptimismPortalProxy");
-        L1CrossDomainMessenger messenger = new L1CrossDomainMessenger({
-            _portal: OptimismPortal(payable(portal))
-        });
+        L1CrossDomainMessenger messenger = new L1CrossDomainMessenger();
+
+        require(address(messenger.PORTAL()) == address(0));
+        require(address(messenger.portal()) == address(0));
 
-        require(address(messenger.PORTAL()) == portal);
+        bytes32 xdmSenderSlot = vm.load(address(messenger), bytes32(uint256(204)));
+        require(address(uint160(uint256(xdmSenderSlot))) == Constants.DEFAULT_L2_SENDER);
 
         save("L1CrossDomainMessenger", address(messenger));
         console.log("L1CrossDomainMessenger deployed at %s", address(messenger));
@@ -619,7 +620,12 @@ contract Deploy is Deployer {
         proxyAdmin.upgradeAndCall({
             _proxy: payable(l1CrossDomainMessengerProxy),
             _implementation: l1CrossDomainMessenger,
-            _data: abi.encodeCall(L1CrossDomainMessenger.initialize, ())
+            _data: abi.encodeCall(
+                L1CrossDomainMessenger.initialize,
+                (
+                    OptimismPortal(payable(optimismPortalProxy))
+                )
+            )
         });
 
         L1CrossDomainMessenger messenger = L1CrossDomainMessenger(l1CrossDomainMessengerProxy);
@@ -627,6 +633,9 @@ contract Deploy is Deployer {
         console.log("L1CrossDomainMessenger version: %s", version);
 
         require(address(messenger.PORTAL()) == optimismPortalProxy);
+        require(address(messenger.portal()) == address(0));
+        bytes32 xdmSenderSlot = vm.load(address(messenger), bytes32(uint256(204)));
+        require(address(uint160(uint256(xdmSenderSlot))) == Constants.DEFAULT_L2_SENDER);
     }
 
     /// @notice Initialize the L2OutputOracle

packages/contracts-bedrock/src/L1/L1CrossDomainMessenger.sol

@@ -13,24 +13,37 @@ import { Semver } from "../universal/Semver.sol";
 ///         interface instead of interacting with lower-level contracts directly.
 contract L1CrossDomainMessenger is CrossDomainMessenger, Semver {
     /// @notice Address of the OptimismPortal.
-    OptimismPortal public immutable PORTAL;
+    OptimismPortal internal _PORTAL;
 
-    /// @custom:semver 1.4.1
+    /// @custom:semver 1.5.0
     /// @notice Constructs the L1CrossDomainMessenger contract.
-    /// @param _portal Address of the OptimismPortal contract on this network.
-    constructor(OptimismPortal _portal)
-        Semver(1, 4, 1)
+    constructor()
+        Semver(1, 5, 0)
         CrossDomainMessenger(Predeploys.L2_CROSS_DOMAIN_MESSENGER)
     {
-        PORTAL = _portal;
-        initialize();
+        initialize({
+            _portal: OptimismPortal(payable(0))
+        });
     }
 
     /// @notice Initializes the contract.
-    function initialize() public initializer {
+    /// @param _portal Address of the OptimismPortal contract on this network.
+    function initialize(OptimismPortal _portal) public reinitializer(2) {
+        _PORTAL = _portal;
         __CrossDomainMessenger_init();
     }
 
+    /// @notice Getter for the OptimismPortal address.
+    /// @custom:legacy
+    function PORTAL() external view returns (address) {
+        return address(_PORTAL);
+    }
+
+    /// @notice Getter for the OptimismPortal address.
+    function portal() external view returns (address) {
+        return address(_PORTAL);
+    }
+
     /// @inheritdoc CrossDomainMessenger
     function _sendMessage(
         address _to,
@@ -38,16 +51,16 @@ contract L1CrossDomainMessenger is CrossDomainMessenger, Semver {
         uint256 _value,
         bytes memory _data
     ) internal override {
-        PORTAL.depositTransaction{ value: _value }(_to, _value, _gasLimit, false, _data);
+        _PORTAL.depositTransaction{ value: _value }(_to, _value, _gasLimit, false, _data);
     }
 
     /// @inheritdoc CrossDomainMessenger
     function _isOtherMessenger() internal view override returns (bool) {
-        return msg.sender == address(PORTAL) && PORTAL.l2Sender() == OTHER_MESSENGER;
+        return msg.sender == address(_PORTAL) && _PORTAL.l2Sender() == OTHER_MESSENGER;
     }
 
     /// @inheritdoc CrossDomainMessenger
     function _isUnsafeTarget(address _target) internal view override returns (bool) {
-        return _target == address(this) || _target == address(PORTAL);
+        return _target == address(this) || _target == address(_PORTAL);
     }
 }

packages/contracts-bedrock/test/CommonTest.t.sol

@@ -272,7 +272,7 @@ contract Messenger_Initializer is Portal_Initializer {
         addressManager = new AddressManager();
 
         // Setup implementation
-        L1CrossDomainMessenger L1MessengerImpl = new L1CrossDomainMessenger(op);
+        L1CrossDomainMessenger L1MessengerImpl = new L1CrossDomainMessenger();
 
         // Setup the address manager and proxy
         vm.prank(multisig);
@@ -282,7 +282,7 @@ contract Messenger_Initializer is Portal_Initializer {
             "OVM_L1CrossDomainMessenger"
         );
         L1Messenger = L1CrossDomainMessenger(address(proxy));
-        L1Messenger.initialize();
+        L1Messenger.initialize(op);
 
         vm.etch(
             Predeploys.L2_CROSS_DOMAIN_MESSENGER,