Merge ERC1967Storage into ERC1967Upgrade (#2644)

(cherry picked from commit 5756e31999009f906b6179e42bf062889ba4081e)

contracts/proxy/ERC1967/ERC1967Proxy.sol

@@ -27,6 +27,6 @@ contract ERC1967Proxy is Proxy, ERC1967Upgrade {
      * @dev Returns the current implementation address.
      */
     function _implementation() internal view virtual override returns (address impl) {
-        return ERC1967Storage._getImplementation();
+        return ERC1967Upgrade._getImplementation();
     }
 }

contracts/proxy/ERC1967/ERC1967Storage.sol

@@ -1,87 +0,0 @@
-// SPDX-License-Identifier: MIT
-
-pragma solidity ^0.8.0;
-
-import "../beacon/IBeacon.sol";
-import "../../utils/Address.sol";
-import "../../utils/StorageSlot.sol";
-
-/**
- * @dev This abstract contract provides setters and getters for the different
- * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] storage slots.
- *
- * _Available since v4.1._
- */
-abstract contract ERC1967Storage {
-    /**
-     * @dev Storage slot with the address of the current implementation.
-     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
-     * validated in the constructor.
-     */
-    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
-
-    /**
-     * @dev Returns the current implementation address.
-     */
-    function _getImplementation() internal view returns (address) {
-        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
-    }
-
-    /**
-     * @dev Stores a new address in the EIP1967 implementation slot.
-     */
-    function _setImplementation(address newImplementation) internal {
-        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
-        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
-    }
-
-    /**
-     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
-     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
-     */
-    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
-
-    /**
-     * @dev Returns the current beacon.
-     */
-    function _getBeacon() internal view returns (address) {
-        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
-    }
-
-    /**
-     * @dev Stores a new beacon in the EIP1967 beacon slot.
-     */
-    function _setBeacon(address newBeacon) internal {
-        require(
-            Address.isContract(newBeacon),
-            "ERC1967: new beacon is not a contract"
-        );
-        require(
-            Address.isContract(IBeacon(newBeacon).implementation()),
-            "ERC1967: beacon implementation is not a contract"
-        );
-        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
-    }
-
-    /**
-     * @dev Storage slot with the admin of the contract.
-     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
-     * validated in the constructor.
-     */
-    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
-
-    /**
-     * @dev Returns the current admin.
-     */
-    function _getAdmin() internal view returns (address) {
-        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
-    }
-
-    /**
-     * @dev Stores a new address in the EIP1967 admin slot.
-     */
-    function _setAdmin(address newAdmin) internal {
-        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
-        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
-    }
-}

contracts/proxy/ERC1967/ERC1967Upgrade.sol

@@ -2,34 +2,48 @@
 
 pragma solidity ^0.8.2;
 
-import "./ERC1967Storage.sol";
+import "../beacon/IBeacon.sol";
+import "../../utils/Address.sol";
+import "../../utils/StorageSlot.sol";
 
 /**
- * @dev This abstract contract provides event emitting update functions for
+ * @dev This abstract contract provides getters and event emitting update functions for
  * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
  *
  * _Available since v4.1._
  *
  * @custom:oz-upgrades-unsafe-allow delegatecall
  */
-abstract contract ERC1967Upgrade is ERC1967Storage {
+abstract contract ERC1967Upgrade {
     // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
     bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
 
+    /**
+     * @dev Storage slot with the address of the current implementation.
+     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
+     * validated in the constructor.
+     */
+    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
+
     /**
      * @dev Emitted when the implementation is upgraded.
      */
     event Upgraded(address indexed implementation);
 
     /**
-     * @dev Emitted when the beacon is upgraded.
+     * @dev Returns the current implementation address.
      */
-    event BeaconUpgraded(address indexed beacon);
+    function _getImplementation() internal view returns (address) {
+        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
+    }
 
     /**
-     * @dev Emitted when the admin account has changed.
+     * @dev Stores a new address in the EIP1967 implementation slot.
      */
-    event AdminChanged(address previousAdmin, address newAdmin);
+    function _setImplementation(address newImplementation) private {
+        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
+        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
+    }
 
     /**
      * @dev Perform implementation upgrade
@@ -103,6 +117,33 @@ abstract contract ERC1967Upgrade is ERC1967Storage {
         }
     }
 
+    /**
+     * @dev Storage slot with the admin of the contract.
+     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
+     * validated in the constructor.
+     */
+    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
+
+    /**
+     * @dev Emitted when the admin account has changed.
+     */
+    event AdminChanged(address previousAdmin, address newAdmin);
+
+    /**
+     * @dev Returns the current admin.
+     */
+    function _getAdmin() internal view returns (address) {
+        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
+    }
+
+    /**
+     * @dev Stores a new address in the EIP1967 admin slot.
+     */
+    function _setAdmin(address newAdmin) private {
+        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
+        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
+    }
+
     /**
      * @dev Changes the admin of the proxy.
      *
@@ -112,4 +153,37 @@ abstract contract ERC1967Upgrade is ERC1967Storage {
         emit AdminChanged(_getAdmin(), newAdmin);
         _setAdmin(newAdmin);
     }
+
+    /**
+     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
+     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
+     */
+    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
+
+    /**
+     * @dev Emitted when the beacon is upgraded.
+     */
+    event BeaconUpgraded(address indexed beacon);
+
+    /**
+     * @dev Returns the current beacon.
+     */
+    function _getBeacon() internal view returns (address) {
+        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
+    }
+
+    /**
+     * @dev Stores a new beacon in the EIP1967 beacon slot.
+     */
+    function _setBeacon(address newBeacon) private {
+        require(
+            Address.isContract(newBeacon),
+            "ERC1967: new beacon is not a contract"
+        );
+        require(
+            Address.isContract(IBeacon(newBeacon).implementation()),
+            "ERC1967: beacon implementation is not a contract"
+        );
+        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
+    }
 }

contracts/proxy/README.adoc

@@ -40,8 +40,6 @@ When doing an upgrade, the second parameter of the {upgradeToAndCall} function a
 
 {{ERC1967Proxy}}
 
-{{ERC1967Storage}}
-
 {{ERC1967Upgrade}}
 
 == UUPS