[ETHEREUM-CONTRACTS] use eip 1967 slot for admin (#1710)

* use eip 1967 slot for admin

* Update CHANGELOG.md

* Update SuperToken.sol

packages/ethereum-contracts/CHANGELOG.md

@@ -18,11 +18,12 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Expose `_toUnderlyingAmount(uint256 amount)` with `toUnderlyingAmount(uint256 amount)`
 - `batchCall` supports payable `OPERATION_TYPE_SUPERFLUID_CALL_APP_ACTION`: only the first `OPERATION_TYPE_SUPERFLUID_CALL_APP_ACTION` will be payable
 - Added two new functions to `SuperfluidGovernanceBase.sol`: `changeSuperTokenAdmin` and `batchChangeSuperTokenAdmin`
-- `Superfluid.changeSuperTokenAdmin()` function added to be called via governance for tokens with no admin override
-- Added an overloaded `initialize` to `SuperToken.sol`, which additionally takes `address adminOverride` if you want to initialize the token with an admin override
+- `Superfluid.changeSuperTokenAdmin()` function added to be called via governance for tokens with no admin address
+- Added an overloaded `initialize` to `SuperToken.sol`, which additionally takes `address admin` if you want to initialize the token with an admin address
 - `SuperToken.changeAdmin(address newAdmin)` added which is only callable by the current admin, the "admin" of a SuperToken can change the admin and update the proxy contract's pointer to a logic contract
   > Note that the default admin (when address(0)) is the host contract as is currently the case
-- `SuperToken.getAdminOverride()` added to retrieve the AdminOverride struct (currently only holds one property: `address admin`), but is future-proofed with 12 additional bits that can be packed in the struct
+- Note that the admin is stored in the EIP-1967 admin storage slot (`0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`)
+- `SuperToken.getAdmin()` added to retrieve the admin address
 - `SuperTokenFactory.createERC20Wrapper()` overloads added to create a SuperToken AND explicitly initialize a SuperToken with an admin
 
 ### Changed

packages/ethereum-contracts/contracts/interfaces/superfluid/ISuperToken.sol

@@ -13,12 +13,6 @@ import { IConstantInflowNFT } from "./IConstantInflowNFT.sol";
  */
 interface ISuperToken is ISuperfluidToken, IERC20Metadata, IERC777 {
 
-    struct AdminOverride {
-        address admin;
-        /// @note we use a struct so the 12 remaining
-        /// packed bytes may be used later on
-    }
-
     /**************************************************************************
      * Errors
      *************************************************************************/
@@ -48,30 +42,30 @@ interface ISuperToken is ISuperfluidToken, IERC20Metadata, IERC777 {
     ) external;
 
     /**
-     * @dev Initialize the contract with admin override
+     * @dev Initialize the contract with an admin
      */
-    function initializeWithAdminOverride(
+    function initializeWithAdmin(
         IERC20 underlyingToken,
         uint8 underlyingDecimals,
         string calldata n,
         string calldata s,
-        address adminOverride
+        address admin
     ) external;
 
     /**
-     * @notice Changes the admin override for the SuperToken
+     * @notice Changes the admin for the SuperToken
      * @dev Only the current admin can call this function
-     * if adminOverride is address(0), it is implicitly the host address
-     * @param newAdmin New admin override address
+     * if admin is address(0), it is implicitly the host address
+     * @param newAdmin New admin address
      */
     function changeAdmin(address newAdmin) external;
 
     event AdminChanged(address indexed oldAdmin, address indexed newAdmin);
 
     /**
-     * @dev Returns the admin override struct for the SuperToken
+     * @dev Returns the admin address for the SuperToken
      */
-    function getAdminOverride() external view returns (AdminOverride memory);
+    function getAdmin() external view returns (address admin);
 
     /**************************************************************************
     * Immutable variables

packages/ethereum-contracts/contracts/interfaces/superfluid/ISuperTokenFactory.sol

@@ -55,7 +55,7 @@ interface ISuperTokenFactory {
      * @param upgradability Upgradability mode
      * @param name Super token name
      * @param symbol Super token symbol
-     * @param adminOverride Admin address override
+     * @param admin Admin address
      * @return superToken The deployed and initialized wrapper super token
      */
     function createERC20Wrapper(
@@ -64,7 +64,7 @@ interface ISuperTokenFactory {
         Upgradability upgradability,
         string calldata name,
         string calldata symbol,
-        address adminOverride
+        address admin
     )
         external
         returns (ISuperToken superToken);
@@ -94,15 +94,15 @@ interface ISuperTokenFactory {
      * @param upgradability Upgradability mode
      * @param name Super token name
      * @param symbol Super token symbol
-     * @param adminOverride Admin address override
+     * @param admin Admin address
      * @return superToken The deployed and initialized wrapper super token
      */
     function createERC20Wrapper(
         IERC20Metadata underlyingToken,
         Upgradability upgradability,
         string calldata name,
         string calldata symbol,
-        address adminOverride
+        address admin
     )
         external
         returns (ISuperToken superToken);

packages/ethereum-contracts/contracts/interfaces/superfluid/ISuperfluid.sol

@@ -234,8 +234,8 @@ interface ISuperfluid {
     event SuperTokenLogicUpdated(ISuperToken indexed token, address code);
 
     /**
-     * @notice Change the SuperToken admin override
-     * @dev The admin override is the only account allowed to update the token logic
+     * @notice Change the SuperToken admin address
+     * @dev The admin is the only account allowed to update the token logic
      * For backward compatibility, the "host" is the default "admin" if unset (address(0)).
      */
     function changeSuperTokenAdmin(ISuperToken token, address newAdmin) external;

packages/ethereum-contracts/contracts/mocks/SuperTokenMock.sol

@@ -59,11 +59,8 @@ contract SuperTokenStorageLayoutTester is SuperToken {
         require (slot == 18 && offset == 0, "_operators changed location");
         // uses 4 slots
 
-        assembly { slot:= _adminOverride.slot offset := _adminOverride.offset }
-        require (slot == 22 && offset == 0, "_adminOverride changed location");
-
-        assembly { slot:= _reserve23.slot offset := _reserve23.offset }
-        require (slot == 23 && offset == 0, "_reserve23 changed location");
+        assembly { slot:= _reserve22.slot offset := _reserve22.offset }
+        require (slot == 22 && offset == 0, "_reserve22 changed location");
 
         assembly { slot:= _reserve31.slot offset := _reserve31.offset }
         require (slot == 31 && offset == 0, "_reserve31 changed location");

packages/ethereum-contracts/contracts/superfluid/SuperToken.sol

@@ -38,6 +38,9 @@ contract SuperToken is
     using ERC777Helper for ERC777Helper.Operators;
     using SafeERC20 for IERC20;
 
+    // See: https://eips.ethereum.org/EIPS/eip-1967#admin-address
+    bytes32 constant private _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
+
     uint8 constant private _STANDARD_DECIMALS = 18;
 
     // solhint-disable-next-line var-name-mixedcase
@@ -69,17 +72,15 @@ contract SuperToken is
     /// @dev ERC777 operators support data
     ERC777Helper.Operators internal _operators;
 
-    /// @dev A struct which contains the address of the admin override
-    AdminOverride internal _adminOverride;
-
     // NOTE: for future compatibility, these are reserved solidity slots
     // The sub-class of SuperToken solidity slot will start after _reserve22
 
     // NOTE: Whenever modifying the storage layout here it is important to update the validateStorageLayout
     // function in its respective mock contract to ensure that it doesn't break anything or lead to unexpected
     // behaviors/layout when upgrading
 
-    uint256 internal _reserve23;
+    uint256 internal _reserve22;
+    uint256 private _reserve23;
     uint256 private _reserve24;
     uint256 private _reserve25;
     uint256 private _reserve26;
@@ -130,13 +131,13 @@ contract SuperToken is
         _initialize(underlyingToken, underlyingDecimals, n, s, address(0));
     }
 
-    /// @dev Initialize the Super Token proxy with an admin override
-    function initializeWithAdminOverride(
+    /// @dev Initialize the Super Token proxy with an admin
+    function initializeWithAdmin(
         IERC20 underlyingToken,
         uint8 underlyingDecimals,
         string calldata n,
         string calldata s,
-        address adminOverride
+        address admin
     )
         external
         virtual
@@ -147,7 +148,7 @@ contract SuperToken is
         // deployment of the proxy contract.
 
         // initialize the Super Token
-        _initialize(underlyingToken, underlyingDecimals, n, s, adminOverride);
+        _initialize(underlyingToken, underlyingDecimals, n, s, admin);
     }
 
     function proxiableUUID() public pure virtual override returns (bytes32) {
@@ -156,7 +157,7 @@ contract SuperToken is
 
     /**
      * @notice Updates the logic contract the proxy is pointing at
-     * @dev Only the admin can call this function (host if adminOverride.admin == address(0))
+     * @dev Only the admin can call this function (host if admin == address(0))
      * @param newAddress Address of the new logic contract
      */
     function updateCode(address newAddress) external virtual override onlyAdmin {
@@ -176,16 +177,31 @@ contract SuperToken is
     }
 
     function changeAdmin(address newAdmin) external override onlyAdmin {
-        address oldAdmin = _adminOverride.admin;
-        _adminOverride.admin = newAdmin;
+        address oldAdmin = _getAdmin();
+        _setAdmin(newAdmin);
 
         emit AdminChanged(oldAdmin, newAdmin);
     }
 
-    function getAdminOverride() external view override returns (AdminOverride memory) {
-        return _adminOverride;
+    function getAdmin() external view override returns (address) {
+        return _getAdmin();
+    }
+
+    function _getAdmin() internal view returns (address admin) {
+        assembly {
+            // solium-disable-line
+            admin := sload(_ADMIN_SLOT)
+        }
     }
 
+    function _setAdmin(address newAdmin) internal {
+        assembly {
+            // solium-disable-line
+            sstore(_ADMIN_SLOT, newAdmin)
+        }
+    }
+
+
     /**************************************************************************
      * ERC20 Token Info
      *************************************************************************/
@@ -211,15 +227,15 @@ contract SuperToken is
         uint8 underlyingDecimals,
         string calldata n,
         string calldata s,
-        address adminOverride
+        address admin
     ) internal {
         _underlyingToken = underlyingToken;
         _underlyingDecimals = underlyingDecimals;
 
         _name = n;
         _symbol = s;
 
-        _adminOverride.admin = adminOverride;
+        _setAdmin(admin);
 
         // register interfaces
         ERC777Helper.register(address(this));
@@ -228,7 +244,7 @@ contract SuperToken is
         emit Transfer(address(0), address(0), 0);
 
         // previous admin will always be the zero address in an uninitialized contract
-        emit AdminChanged(address(0), adminOverride);
+        emit AdminChanged(address(0), admin);
     }
 
     /**
@@ -865,7 +881,8 @@ contract SuperToken is
      * override address
      */
     modifier onlyAdmin() {
-        address admin = _adminOverride.admin == address(0) ? address(_host) : _adminOverride.admin;
+        address adminSlotAdmin = _getAdmin();
+        address admin = adminSlotAdmin == address(0) ? address(_host) : adminSlotAdmin;
         if (msg.sender != admin) revert SUPER_TOKEN_ONLY_ADMIN();
         _;
     }

packages/ethereum-contracts/contracts/superfluid/SuperTokenFactory.sol

@@ -212,7 +212,7 @@ abstract contract SuperTokenFactoryBase is
         Upgradability upgradability,
         string calldata name,
         string calldata symbol,
-        address adminOverride
+        address admin
     ) public override returns (ISuperToken superToken) {
         if (address(underlyingToken) == address(0)) {
             revert SUPER_TOKEN_FACTORY_ZERO_ADDRESS();
@@ -232,12 +232,12 @@ abstract contract SuperTokenFactoryBase is
         }
 
         // initialize the token
-        superToken.initializeWithAdminOverride(
+        superToken.initializeWithAdmin(
             underlyingToken,
             underlyingDecimals,
             name,
             symbol,
-            adminOverride
+            admin
         );
 
         emit SuperTokenCreated(superToken);
@@ -270,7 +270,7 @@ abstract contract SuperTokenFactoryBase is
         Upgradability upgradability,
         string calldata name,
         string calldata symbol,
-        address adminOverride
+        address admin
     )
         external override
         returns (ISuperToken superToken)
@@ -281,7 +281,7 @@ abstract contract SuperTokenFactoryBase is
             upgradability,
             name,
             symbol,
-            adminOverride
+            admin
         );
     }
 

packages/ethereum-contracts/contracts/utils/SuperfluidFrameworkDeployer.sol

@@ -161,21 +161,21 @@ contract SuperfluidFrameworkDeployer is SuperfluidFrameworkDeploymentSteps {
     /// @param _underlyingSymbol The token symbol
     /// @param _decimals The token decimals
     /// @param _mintLimit The mint limit of the underlying token
-    /// @param adminOverride The admin override address for the Super Token
+    /// @param _admin The admin address for the Super Token
     /// @return underlyingToken and superToken
     function deployWrapperSuperToken(
         string calldata _underlyingName,
         string calldata _underlyingSymbol,
         uint8 _decimals,
         uint256 _mintLimit,
-        address adminOverride
+        address _admin
     )
         external
         requiresSuperTokenFactory
         deploySuperTokenRequires1820
         returns (TestToken underlyingToken, SuperToken superToken)
     {
-        return _deployWrapperSuperToken(_underlyingName, _underlyingSymbol, _decimals, _mintLimit, adminOverride);
+        return _deployWrapperSuperToken(_underlyingName, _underlyingSymbol, _decimals, _mintLimit, _admin);
     }
 
     /// @notice Deploys an ERC20 and a Wrapper Super Token for the ERC20 and lists both in the resolver
@@ -257,7 +257,7 @@ contract SuperfluidFrameworkDeployer is SuperfluidFrameworkDeploymentSteps {
         string calldata _underlyingSymbol,
         uint8 _decimals,
         uint256 _mintLimit,
-        address _adminOverride
+        address _admin
     ) internal returns (TestToken underlyingToken, SuperToken superToken) {
         underlyingToken =
             TokenDeployerLibrary.deployTestToken(_underlyingName, _underlyingSymbol, _decimals, _mintLimit);
@@ -272,7 +272,7 @@ contract SuperfluidFrameworkDeployer is SuperfluidFrameworkDeploymentSteps {
                     ISuperTokenFactory.Upgradability.SEMI_UPGRADABLE,
                     string.concat("Super ", _underlyingSymbol),
                     superTokenSymbol,
-                    _adminOverride
+                    _admin
                 )
             )
         );

packages/ethereum-contracts/test/foundry/FoundrySuperfluidTester.sol

@@ -614,14 +614,14 @@ contract FoundrySuperfluidTester is Test {
         uint8 underlyingDecimals,
         string memory name,
         string memory symbol,
-        address adminOverride
+        address admin
     ) internal returns (SuperToken localSuperToken) {
         localSuperToken = new SuperToken(
             sf.host,
             previousSuperToken.CONSTANT_OUTFLOW_NFT(),
             previousSuperToken.CONSTANT_INFLOW_NFT()
         );
-        localSuperToken.initializeWithAdminOverride(underlyingToken, underlyingDecimals, name, symbol, adminOverride);
+        localSuperToken.initializeWithAdmin(underlyingToken, underlyingDecimals, name, symbol, admin);
     }
 
     // Write Helpers - ConstantFlowAgreementV1

packages/ethereum-contracts/test/foundry/gov/SuperfluidGovernanceII.t.sol

@@ -21,7 +21,7 @@ contract SuperfluidGovernanceIntegrationTest is FoundrySuperfluidTester {
         sf.governance.changeSuperTokenAdmin(sf.host, superToken, newAdmin);
         vm.stopPrank();
 
-        assertEq(superToken.getAdminOverride().admin, newAdmin, "Superfluid.t: super token admin not changed");
+        assertEq(superToken.getAdmin(), newAdmin, "Superfluid.t: super token admin not changed");
     }
 
     function testRevertChangeSuperTokenAdminWhenCallerIsNotNotGovOwner(address newAdmin) public {
@@ -64,7 +64,7 @@ contract SuperfluidGovernanceIntegrationTest is FoundrySuperfluidTester {
         sf.governance.batchChangeSuperTokenAdmin(sf.host, superTokens, newAdmins);
         vm.stopPrank();
 
-        assertEq(superToken.getAdminOverride().admin, newAdmin, "Superfluid.t: super token admin not changed");
+        assertEq(superToken.getAdmin(), newAdmin, "Superfluid.t: super token admin not changed");
     }
 
     function testRevertBatchChangeSuperTokenAdminWhenHostNotAdmin(address newAdmin) public {