Merge branch 'solc-0.7' into solc-0.8

contracts/proxy/TransparentUpgradeableProxy.sol

@@ -6,22 +6,22 @@ import "./UpgradeableProxy.sol";
 
 /**
  * @dev This contract implements a proxy that is upgradeable by an admin.
- * 
+ *
  * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
  * clashing], which can potentially be used in an attack, this contract uses the
  * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
  * things that go hand in hand:
- * 
+ *
  * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
  * that call matches one of the admin functions exposed by the proxy itself.
  * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
  * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
  * "admin cannot fallback to proxy target".
- * 
+ *
  * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
  * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
  * to sudden errors when trying to call a function from the proxy implementation.
- * 
+ *
  * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
  * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
  */
@@ -60,9 +60,9 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
 
     /**
      * @dev Returns the current admin.
-     * 
+     *
      * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
-     * 
+     *
      * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
      * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
      * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
@@ -73,9 +73,9 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
 
     /**
      * @dev Returns the current implementation.
-     * 
+     *
      * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
-     * 
+     *
      * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
      * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
      * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
@@ -86,12 +86,12 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
 
     /**
      * @dev Changes the admin of the proxy.
-     * 
+     *
      * Emits an {AdminChanged} event.
-     * 
+     *
      * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
      */
-    function changeAdmin(address newAdmin) external ifAdmin {
+    function changeAdmin(address newAdmin) external virtual ifAdmin {
         require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
         emit AdminChanged(_admin(), newAdmin);
         _setAdmin(newAdmin);
@@ -99,10 +99,10 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
 
     /**
      * @dev Upgrade the implementation of the proxy.
-     * 
+     *
      * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
      */
-    function upgradeTo(address newImplementation) external ifAdmin {
+    function upgradeTo(address newImplementation) external virtual ifAdmin {
         _upgradeTo(newImplementation);
     }
 
@@ -110,20 +110,18 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
      * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
      * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
      * proxied contract.
-     * 
+     *
      * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
      */
-    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
+    function upgradeToAndCall(address newImplementation, bytes calldata data) external payable virtual ifAdmin {
         _upgradeTo(newImplementation);
-        // solhint-disable-next-line avoid-low-level-calls
-        (bool success,) = newImplementation.delegatecall(data);
-        require(success);
+        Address.functionDelegateCall(newImplementation, data);
     }
 
     /**
      * @dev Returns the current admin.
      */
-    function _admin() internal view returns (address adm) {
+    function _admin() internal view virtual returns (address adm) {
         bytes32 slot = _ADMIN_SLOT;
         // solhint-disable-next-line no-inline-assembly
         assembly {
@@ -146,7 +144,7 @@ contract TransparentUpgradeableProxy is UpgradeableProxy {
     /**
      * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
      */
-    function _beforeFallback() internal override virtual {
+    function _beforeFallback() internal virtual override {
         require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
         super._beforeFallback();
     }