N-10: remove unused constant and modifiers

l1-contracts/contracts/bridge/asset-tracker/AssetTrackerBase.sol

@@ -6,16 +6,12 @@ import {Ownable2StepUpgradeable} from "@openzeppelin/contracts-upgradeable-v4/ac
 import {ReentrancyGuard} from "../../common/ReentrancyGuard.sol";
 
 import {IAssetTrackerBase} from "./IAssetTrackerBase.sol";
-import {GatewayToL1TokenBalanceMigrationData, L1ToGatewayTokenBalanceMigrationData} from "../../common/Messaging.sol";
-
-import {L2_TO_L1_MESSENGER_SYSTEM_CONTRACT} from "../../common/l2-helpers/L2ContractInterfaces.sol";
 import {INativeTokenVaultBase} from "../ntv/INativeTokenVaultBase.sol";
 import {Unauthorized} from "../../common/L1ContractErrors.sol";
 import {DynamicIncrementalMerkleMemory} from "../../common/libraries/DynamicIncrementalMerkleMemory.sol";
 import {SERVICE_TRANSACTION_SENDER} from "../../common/Config.sol";
 import {AssetHandlerModifiers} from "../interfaces/AssetHandlerModifiers.sol";
 import {InsufficientChainBalance} from "./AssetTrackerErrors.sol";
-import {IAssetTrackerDataEncoding} from "./IAssetTrackerDataEncoding.sol";
 
 abstract contract AssetTrackerBase is
     IAssetTrackerBase,
@@ -128,24 +124,6 @@ abstract contract AssetTrackerBase is
         chainBalance[_chainId][_assetId] -= _amount;
     }
 
-    /// @notice Sends L1 -> Gateway migration data to L1 through the L2->L1 messenger.
-    /// @param _data The migration payload.
-    function _sendL1ToGatewayMigrationDataToL1(L1ToGatewayTokenBalanceMigrationData memory _data) internal {
-        // slither-disable-next-line unused-return,reentrancy-no-eth
-        L2_TO_L1_MESSENGER_SYSTEM_CONTRACT.sendToL1(
-            abi.encodeCall(IAssetTrackerDataEncoding.receiveL1ToGatewayMigrationOnL1, _data)
-        );
-    }
-
-    /// @notice Sends Gateway -> L1 migration data to L1 through the L2->L1 messenger.
-    /// @param _data The migration payload.
-    function _sendGatewayToL1MigrationDataToL1(GatewayToL1TokenBalanceMigrationData memory _data) internal {
-        // slither-disable-next-line unused-return,reentrancy-no-eth
-        L2_TO_L1_MESSENGER_SYSTEM_CONTRACT.sendToL1(
-            abi.encodeCall(IAssetTrackerDataEncoding.receiveGatewayToL1MigrationOnL1, _data)
-        );
-    }
-
     /*//////////////////////////////////////////////////////////////
                     Token deposits and withdrawals
     //////////////////////////////////////////////////////////////*/

l1-contracts/contracts/bridge/asset-tracker/GWAssetTracker.sol

@@ -30,6 +30,7 @@ import {
     L2_KNOWN_CODE_STORAGE_SYSTEM_CONTRACT_ADDR,
     L2_MESSAGE_ROOT,
     L2_NATIVE_TOKEN_VAULT,
+    L2_TO_L1_MESSENGER_SYSTEM_CONTRACT,
     L2_TO_L1_MESSENGER_SYSTEM_CONTRACT_ADDR,
     MAX_BUILT_IN_CONTRACT_ADDR,
     L2_ASSET_ROUTER,
@@ -734,6 +735,15 @@ contract GWAssetTracker is AssetTrackerBase, IGWAssetTracker {
         emit GatewayToL1MigrationInitiated(_assetId, _chainId, amount);
     }
 
+    /// @notice Sends Gateway -> L1 migration data to L1 through the L2->L1 messenger.
+    /// @param _data The migration payload.
+    function _sendGatewayToL1MigrationDataToL1(GatewayToL1TokenBalanceMigrationData memory _data) internal {
+        // slither-disable-next-line unused-return,reentrancy-no-eth
+        L2_TO_L1_MESSENGER_SYSTEM_CONTRACT.sendToL1(
+            abi.encodeCall(IAssetTrackerDataEncoding.receiveGatewayToL1MigrationOnL1, _data)
+        );
+    }
+
     function _calculatePreviousChainMigrationNumber(uint256 _chainId) internal view returns (uint256) {
         uint256 settlementLayer = L2_BRIDGEHUB.settlementLayer(_chainId);
         uint256 chainMigrationNumber = _getChainMigrationNumber(_chainId);

l1-contracts/contracts/bridge/asset-tracker/IAssetTrackerBase.sol

@@ -4,7 +4,6 @@ pragma solidity ^0.8.21;
 
 bytes1 constant BALANCE_CHANGE_VERSION = bytes1(uint8(1));
 bytes1 constant TOKEN_BALANCE_MIGRATION_DATA_VERSION = bytes1(uint8(1));
-bytes1 constant INTEROP_BALANCE_CHANGE_VERSION = bytes1(uint8(1));
 uint256 constant MAX_TOKEN_BALANCE = type(uint256).max;
 
 struct SavedTotalSupply {

l1-contracts/contracts/bridge/asset-tracker/L2AssetTracker.sol

@@ -33,6 +33,8 @@ import {
 } from "./AssetTrackerErrors.sol";
 import {AssetTrackerBase} from "./AssetTrackerBase.sol";
 import {IL2AssetTracker} from "./IL2AssetTracker.sol";
+import {IAssetTrackerDataEncoding} from "./IAssetTrackerDataEncoding.sol";
+import {L2_TO_L1_MESSENGER_SYSTEM_CONTRACT} from "../../common/l2-helpers/L2ContractInterfaces.sol";
 
 contract L2AssetTracker is AssetTrackerBase, IL2AssetTracker {
     uint256 public L1_CHAIN_ID;
@@ -445,6 +447,15 @@ contract L2AssetTracker is AssetTrackerBase, IL2AssetTracker {
         emit IL2AssetTracker.L1ToGatewayMigrationInitiated(_assetId, block.chainid);
     }
 
+    /// @notice Sends L1 -> Gateway migration data to L1 through the L2->L1 messenger.
+    /// @param _data The migration payload.
+    function _sendL1ToGatewayMigrationDataToL1(L1ToGatewayTokenBalanceMigrationData memory _data) internal {
+        // slither-disable-next-line unused-return,reentrancy-no-eth
+        L2_TO_L1_MESSENGER_SYSTEM_CONTRACT.sendToL1(
+            abi.encodeCall(IAssetTrackerDataEncoding.receiveL1ToGatewayMigrationOnL1, _data)
+        );
+    }
+
     /// @notice Confirms a migration operation has been completed and updates the asset migration number.
     /// @dev This function is called by L1 after a migration has been processed to update local state.
     /// @param _data The migration confirmation data containing the asset ID and migration number.

system-contracts/contracts/abstract/SystemContractBase.sol

@@ -3,12 +3,10 @@
 pragma solidity ^0.8.20;
 
 import {SystemContractHelper} from "../libraries/SystemContractHelper.sol";
-import {BOOTLOADER_FORMAL_ADDRESS, L2_INTEROP_CENTER_ADDRESS, L2_INTEROP_HANDLER_ADDRESS} from "../Constants.sol";
-import {L2_NATIVE_TOKEN_VAULT} from "../Contracts.sol";
+import {BOOTLOADER_FORMAL_ADDRESS} from "../Constants.sol";
 import {
     CallerMustBeBootloader,
     CallerMustBeEvmContract,
-    CallerMustBeInteropCenterOrNTV,
     CallerMustBeSystemContract,
     SystemCallFlagRequired,
     Unauthorized
@@ -69,21 +67,4 @@ abstract contract SystemContractBase {
         _;
     }
 
-    /// @notice Modifier that makes sure that the method
-    /// can only be called from the bootloader.
-    modifier onlyCallFromBootloaderOrInteropHandler() {
-        if (msg.sender != BOOTLOADER_FORMAL_ADDRESS && msg.sender != L2_INTEROP_HANDLER_ADDRESS) {
-            revert CallerMustBeBootloader();
-        }
-        _;
-    }
-
-    /// @notice Modifier that makes sure that the method
-    /// can only be called from the interop center or the NTV.
-    modifier onlyCallFromInteropCenterOrNTV() {
-        if (msg.sender != L2_INTEROP_CENTER_ADDRESS && msg.sender != address(L2_NATIVE_TOKEN_VAULT)) {
-            revert CallerMustBeInteropCenterOrNTV();
-        }
-        _;
-    }
 }