Make some private functions internal to allow the developpement of…

Make some private functions internal to allow the developpement of "withSignature" functions (like permit) (#2568)

* add internal _setOwner in Ownable

* address issues raised in #2567

* updte changelog entry

* improve changelog and documentation

* rephrasing doc

* add cahngelog improvement lost in merge

* notify deprecation of _setupRole in changelog

* Demote caution to note

* Update CHANGELOG.md

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

CHANGELOG.md

 # Changelog
 
+## Unreleased
+
+ * `Ownable`: add an internal `_transferOwnership(address)`. ([#2568](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/#2568))
+ * `AccessControl`: add internal `_grantRole(bytes32,address)` and `_revokeRole(bytes32,address)`. ([#2568](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/#2568))
+ * `AccessControl`: mark `_setupRole(bytes32,address)` as deprecated in favor of `_grantRole(bytes32,address)`. ([#2568](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/#2568))
+
 ## 4.3.1
 
  * `TimelockController`: Add additional isOperationReady check.

contracts/access/AccessControl.sol

@@ -178,6 +178,8 @@ abstract contract AccessControl is Context, IAccessControl, ERC165 {
      * Using this function in any other way is effectively circumventing the admin
      * system imposed by {AccessControl}.
      * ====
+     *
+     * NOTE: This function is deprecated in favor of {_grantRole}.
      */
     function _setupRole(bytes32 role, address account) internal virtual {
         _grantRole(role, account);
@@ -194,14 +196,24 @@ abstract contract AccessControl is Context, IAccessControl, ERC165 {
         emit RoleAdminChanged(role, previousAdminRole, adminRole);
     }
 
-    function _grantRole(bytes32 role, address account) private {
+    /**
+     * @dev Grants `role` to `account`.
+     *
+     * Internal function without access restriction.
+     */
+    function _grantRole(bytes32 role, address account) internal virtual {
         if (!hasRole(role, account)) {
             _roles[role].members[account] = true;
             emit RoleGranted(role, account, _msgSender());
         }
     }
 
-    function _revokeRole(bytes32 role, address account) private {
+    /**
+     * @dev Revokes `role` from `account`.
+     *
+     * Internal function without access restriction.
+     */
+    function _revokeRole(bytes32 role, address account) internal virtual {
         if (hasRole(role, account)) {
             _roles[role].members[account] = false;
             emit RoleRevoked(role, account, _msgSender());

contracts/access/Ownable.sol

@@ -25,7 +25,7 @@ abstract contract Ownable is Context {
      * @dev Initializes the contract setting the deployer as the initial owner.
      */
     constructor() {
-        _setOwner(_msgSender());
+        _transferOwnership(_msgSender());
     }
 
     /**
@@ -51,7 +51,7 @@ abstract contract Ownable is Context {
      * thereby removing any functionality that is only available to the owner.
      */
     function renounceOwnership() public virtual onlyOwner {
-        _setOwner(address(0));
+        _transferOwnership(address(0));
     }
 
     /**
@@ -60,10 +60,14 @@ abstract contract Ownable is Context {
      */
     function transferOwnership(address newOwner) public virtual onlyOwner {
         require(newOwner != address(0), "Ownable: new owner is the zero address");
-        _setOwner(newOwner);
+        _transferOwnership(newOwner);
     }
 
-    function _setOwner(address newOwner) private {
+    /**
+     * @dev Transfers ownership of the contract to a new account (`newOwner`).
+     * Internal function without access restriction.
+     */
+    function _transferOwnership(address newOwner) internal virtual {
         address oldOwner = _owner;
         _owner = newOwner;
         emit OwnershipTransferred(oldOwner, newOwner);