OffchainLabs · gzeoneth · Oct 26, 2023 · Apr 3, 2023 · Apr 3, 2023 · Apr 4, 2023
diff --git a/.circleci/config.yml b/.circleci/config.yml
diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
@@ -0,0 +1,30 @@
+name: Build and test
+
+on:
+  workflow_dispatch:
+  pull_request:
+
+jobs:
+  test-unit:
+    name: Test storage layout
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: recursive
+
+      - name: Setup node/yarn
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'yarn'
+          cache-dependency-path: '**/yarn.lock'
+
+      - name: Install packages
+        run: yarn
+
+      - name: Build
+        run: yarn build
+
+      - name: Test Storage Layouts
+        run: yarn run test:storage
diff --git a/contracts/rpc-utils/NodeInterface.sol b/contracts/rpc-utils/NodeInterface.sol
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Apache-2.0
 // solhint-disable-next-line compiler-version
-pragma solidity >=0.4.21 <0.7.0;
+pragma solidity >=0.4.21 <0.9.0;
 
 /** @title Interface for providing Outbox proof data
  *  @notice This contract doesn't exist on-chain. Instead it is a virtual interface accessible at 0x00000000000000000000000000000000000000C8

diff --git a/contracts/rpc-utils/RetryableTicketCreator.sol b/contracts/rpc-utils/RetryableTicketCreator.sol
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Apache-2.0
 // solhint-disable-next-line compiler-version
-pragma solidity >=0.4.21 <0.7.0;
+pragma solidity >=0.4.21 <0.9.0;
 
 interface RetryableTicketCreator {
     /**

diff --git a/contracts/tokenbridge/arbitrum/L2ArbitrumMessenger.sol b/contracts/tokenbridge/arbitrum/L2ArbitrumMessenger.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "@arbitrum/nitro-contracts/src/precompiles/ArbSys.sol";
 

diff --git a/contracts/tokenbridge/arbitrum/StandardArbERC20.sol b/contracts/tokenbridge/arbitrum/StandardArbERC20.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "../libraries/Cloneable.sol";
 import "../libraries/L2GatewayToken.sol";

diff --git a/contracts/tokenbridge/arbitrum/gateway/L2ArbitrumGateway.sol b/contracts/tokenbridge/arbitrum/gateway/L2ArbitrumGateway.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "@openzeppelin/contracts/utils/Address.sol";
 import "../../libraries/AddressAliasHelper.sol";

diff --git a/contracts/tokenbridge/arbitrum/gateway/L2CustomGateway.sol b/contracts/tokenbridge/arbitrum/gateway/L2CustomGateway.sol
@@ -16,12 +16,10 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L2ArbitrumGateway.sol";
 import "../../libraries/gateway/ICustomGateway.sol";
-
-import "@openzeppelin/contracts/math/SafeMath.sol";
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 contract L2CustomGateway is L2ArbitrumGateway, ICustomGateway {

diff --git a/contracts/tokenbridge/arbitrum/gateway/L2ERC20Gateway.sol b/contracts/tokenbridge/arbitrum/gateway/L2ERC20Gateway.sol
@@ -16,9 +16,9 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
-import "@openzeppelin/contracts/proxy/UpgradeableBeacon.sol";
+import "@openzeppelin/contracts/proxy/beacon/UpgradeableBeacon.sol";
 import "@openzeppelin/contracts/utils/Create2.sol";
 import "./L2ArbitrumGateway.sol";
 import "../StandardArbERC20.sol";

diff --git a/contracts/tokenbridge/arbitrum/gateway/L2GatewayRouter.sol b/contracts/tokenbridge/arbitrum/gateway/L2GatewayRouter.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "../../libraries/gateway/GatewayRouter.sol";
 import "../../ethereum/gateway/L1GatewayRouter.sol";

diff --git a/contracts/tokenbridge/arbitrum/gateway/L2ReverseCustomGateway.sol b/contracts/tokenbridge/arbitrum/gateway/L2ReverseCustomGateway.sol
@@ -16,12 +16,10 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L2CustomGateway.sol";
-
-import "@openzeppelin/contracts/math/SafeMath.sol";
-import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 /**
  * @title   L2 Gateway for reverse "custom" bridging functionality
@@ -58,6 +56,6 @@ contract L2ReverseCustomGateway is L2CustomGateway {
         // and after to calculate the amount of tokens that were transferred
         IERC20(_l2Token).safeTransferFrom(_from, address(this), _amount);
         uint256 postBalance = IERC20(_l2Token).balanceOf(address(this));
-        return SafeMath.sub(postBalance, prevBalance);
+        return postBalance - prevBalance;
     }
 }
diff --git a/contracts/tokenbridge/arbitrum/gateway/L2WethGateway.sol b/contracts/tokenbridge/arbitrum/gateway/L2WethGateway.sol
@@ -16,12 +16,12 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L2ArbitrumGateway.sol";
 import "../../libraries/IWETH9.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
-import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
 contract L2WethGateway is L2ArbitrumGateway {
     using SafeERC20 for IERC20;

diff --git a/contracts/tokenbridge/ethereum/ICustomToken.sol b/contracts/tokenbridge/ethereum/ICustomToken.sol
@@ -20,7 +20,9 @@
 pragma solidity >=0.6.9 <0.9.0;
 
 interface ArbitrumEnabledToken {
-    /// @notice should return `0xa4b1` if token is enabled for arbitrum gateways
+    /// @notice should return `0xb1` if token is enabled for arbitrum gateways
+    /// @dev Previous implmentation used to return `uint8(0xa4b1)`, however that causes compile time error in Solidity 0.8. due to type mismatch.
+    ///      In current version `uint8(0xb1)` shall be returned, which results in no change as that's the same value as truncated `uint8(0xa4b1)`.
     function isArbitrumEnabled() external view returns (uint8);
 }
 

diff --git a/contracts/tokenbridge/ethereum/L1ArbitrumMessenger.sol b/contracts/tokenbridge/ethereum/L1ArbitrumMessenger.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "@arbitrum/nitro-contracts/src/bridge/IInbox.sol";
 import "@arbitrum/nitro-contracts/src/bridge/IOutbox.sol";

diff --git a/contracts/tokenbridge/ethereum/gateway/L1ArbitrumExtendedGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1ArbitrumExtendedGateway.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "../../libraries/ITransferAndCall.sol";
 
@@ -31,6 +31,8 @@ interface ITradeableExitReceiver {
 }
 
 abstract contract L1ArbitrumExtendedGateway is L1ArbitrumGateway {
+    using Address for address;
+
     struct ExitData {
         bool isExit;
         address _newTo;

diff --git a/contracts/tokenbridge/ethereum/gateway/L1ArbitrumGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1ArbitrumGateway.sol
@@ -16,13 +16,12 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
-import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "@openzeppelin/contracts/utils/Create2.sol";
 import "@openzeppelin/contracts/utils/Address.sol";
-import "@openzeppelin/contracts/math/SafeMath.sol";
 import "../L1ArbitrumMessenger.sol";
 import "./IL1ArbitrumGateway.sol";
 import "../../libraries/ProxyUtil.sol";
@@ -298,7 +297,7 @@ abstract contract L1ArbitrumGateway is
         uint256 prevBalance = IERC20(_l1Token).balanceOf(address(this));
         IERC20(_l1Token).safeTransferFrom(_from, address(this), _amount);
         uint256 postBalance = IERC20(_l1Token).balanceOf(address(this));
-        return SafeMath.sub(postBalance, prevBalance);
+        return postBalance - prevBalance;
     }
 
     function getOutboundCalldata(

diff --git a/contracts/tokenbridge/ethereum/gateway/L1CustomGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1CustomGateway.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import { ArbitrumEnabledToken } from "../ICustomToken.sol";
 import "./L1ArbitrumExtendedGateway.sol";
@@ -113,7 +113,7 @@ contract L1CustomGateway is L1ArbitrumExtendedGateway, ICustomGateway {
      * @param l1ERC20 address of L1 token
      * @return L2 address of a bridged ERC20 token
      */
-    function calculateL2TokenAddress(address l1ERC20) public view override returns (address) {
+    function calculateL2TokenAddress(address l1ERC20) public view override(ITokenGateway, TokenGateway) returns (address) {
         return l1ToL2Token[l1ERC20];
     }
 
@@ -151,7 +151,7 @@ contract L1CustomGateway is L1ArbitrumExtendedGateway, ICustomGateway {
         address _creditBackAddress
     ) public payable virtual returns (uint256) {
         require(
-            ArbitrumEnabledToken(msg.sender).isArbitrumEnabled() == uint8(0xa4b1),
+            ArbitrumEnabledToken(msg.sender).isArbitrumEnabled() == uint8(0xb1),
             "NOT_ARB_ENABLED"
         );
 

diff --git a/contracts/tokenbridge/ethereum/gateway/L1ERC20Gateway.sol b/contracts/tokenbridge/ethereum/gateway/L1ERC20Gateway.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L1ArbitrumExtendedGateway.sol";
 import "@openzeppelin/contracts/utils/Create2.sol";
@@ -149,7 +149,7 @@ contract L1ERC20Gateway is L1ArbitrumExtendedGateway {
         return outboundCalldata;
     }
 
-    function calculateL2TokenAddress(address l1ERC20) public view override returns (address) {
+    function calculateL2TokenAddress(address l1ERC20) public view override(ITokenGateway, TokenGateway) returns (address) {
         bytes32 salt = getSalt(l1ERC20);
         return Create2.computeAddress(salt, cloneableProxyHash, l2BeaconProxyFactory);
     }

diff --git a/contracts/tokenbridge/ethereum/gateway/L1ForceOnlyReverseCustomGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1ForceOnlyReverseCustomGateway.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L1ReverseCustomGateway.sol";
 

diff --git a/contracts/tokenbridge/ethereum/gateway/L1GatewayRouter.sol b/contracts/tokenbridge/ethereum/gateway/L1GatewayRouter.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "../../libraries/Whitelist.sol";
 
@@ -39,6 +39,8 @@ contract L1GatewayRouter is
     ERC165,
     IL1GatewayRouter
 {
+    using Address for address;
+
     address public override owner;
     address public override inbox;
 
@@ -185,9 +187,10 @@ contract L1GatewayRouter is
         address _creditBackAddress
     ) public payable override returns (uint256) {
         require(
-            ArbitrumEnabledToken(msg.sender).isArbitrumEnabled() == uint8(0xa4b1),
+            ArbitrumEnabledToken(msg.sender).isArbitrumEnabled() == uint8(0xb1),
             "NOT_ARB_ENABLED"
         );
+
         require(_gateway.isContract(), "NOT_TO_CONTRACT");
 
         address currGateway = getGateway(msg.sender);

diff --git a/contracts/tokenbridge/ethereum/gateway/L1ReverseCustomGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1ReverseCustomGateway.sol
@@ -16,11 +16,9 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "./L1CustomGateway.sol";
-
-import "@openzeppelin/contracts/math/SafeMath.sol";
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 /**

diff --git a/contracts/tokenbridge/ethereum/gateway/L1WethGateway.sol b/contracts/tokenbridge/ethereum/gateway/L1WethGateway.sol
@@ -16,10 +16,10 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 import "@arbitrum/nitro-contracts/src/bridge/IInbox.sol";
-import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "../../libraries/IWETH9.sol";
 import "../../test/TestWETH9.sol";
@@ -101,7 +101,7 @@ contract L1WethGateway is L1ArbitrumExtendedGateway {
      * @param l1ERC20 address of L1 token
      * @return L2 address of a bridged ERC20 token
      */
-    function calculateL2TokenAddress(address l1ERC20) public view override returns (address) {
+    function calculateL2TokenAddress(address l1ERC20) public view override(ITokenGateway, TokenGateway) returns (address) {
         if (l1ERC20 != l1Weth) {
             // invalid L1 weth address
             return address(0);

diff --git a/contracts/tokenbridge/libraries/AddressAliasHelper.sol b/contracts/tokenbridge/libraries/AddressAliasHelper.sol
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 library AddressAliasHelper {
     uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
@@ -26,14 +26,18 @@ library AddressAliasHelper {
     /// @param l1Address the address in the L1 that triggered the tx to L2
     /// @return l2Address L2 address as viewed in msg.sender
     function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
-        l2Address = address(uint160(l1Address) + offset);
+        unchecked {
+            l2Address = address(uint160(l1Address) + offset);
+        }
     }
 
     /// @notice Utility function that converts the msg.sender viewed in the L2 to the
     /// address in the L1 that submitted a tx to the inbox
     /// @param l2Address L2 address as viewed in msg.sender
     /// @return l1Address the address in the L1 that triggered the tx to L2
     function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
-        l1Address = address(uint160(l2Address) - offset);
+        unchecked {
+            l1Address = address(uint160(l2Address) - offset);
+        }
     }
 }
diff --git a/contracts/tokenbridge/libraries/BytesLib.sol b/contracts/tokenbridge/libraries/BytesLib.sol
@@ -8,7 +8,7 @@
  *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
  */
 
-pragma solidity ^0.6.11;
+pragma solidity ^0.8.0;
 
 /* solhint-disable no-inline-assembly */
 library BytesLib {