NoBey/openzeppelin-contracts
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Allow the re-initialization of contracts (#3232)

Browse Source 
* allow re-initialization of contracts

* fix lint

* use a private function to avoid code duplication

* use oz-retyped-from syntax

* add documentation

* rephrase

* documentation

* Update contracts/proxy/utils/Initializable.sol

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

* reinitialize test

* lint

* typos and style

* add note about relation between initializer and reinitializer

* lint

* set _initializing in the modifier

* remove unnecessary variable set

* rename _preventInitialize -> _disableInitializers

* rename preventInitialize -> disableInitializers

* test nested reinitializers in reverse order

* docs typos and style

* edit docs for consistency between initializer and reinitializer

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
This commit is contained in:
Hadrien Croubois
2022-03-22 19:06:29 +01:00
committed by GitHub
parent b13bdb0249
commit 0eba5112c8
3 changed files with 176 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

94
contracts/proxy/utils/Initializable.sol
View File

@ -11,6 +11,26 @@ import "../../utils/Address.sol";
* external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
* function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
*
* The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
* reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
* case an upgrade adds a module that needs to be initialized.
*
* For example:
*
* [.hljs-theme-light.nopadding]
* ```
* contract MyToken is ERC20Upgradeable {
* function initialize() initializer public {
* __ERC20_init("MyToken", "MTK");
* }
* }
* contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
* function initializeV2() reinitializer(2) public {
* __ERC20Permit_init("MyToken");
* }
* }
* ```
*
* TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
* possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
*
@ -22,21 +42,24 @@ import "../../utils/Address.sol";
* Avoid leaving a contract uninitialized.
*
* An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
* contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
* initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
* contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
* the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
*
* [.hljs-theme-light.nopadding]
* ```
* /// @custom:oz-upgrades-unsafe-allow constructor
* constructor() initializer {}
* constructor() {
* _disableInitializers();
* }
* ```
* ====
*/
abstract contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
* @custom:oz-retyped-from bool
*/
bool private _initialized;
uint8 private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
@ -44,22 +67,38 @@ abstract contract Initializable {
bool private _initializing;
/**
* @dev Modifier to protect an initializer function from being invoked twice.
* @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
* `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
*/
modifier initializer() {
// If the contract is initializing we ignore whether _initialized is set in order to support multiple
// inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
// contract may have been reentered.
require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
bool isTopLevelCall = !_initializing;
bool isTopLevelCall = _setInitializedVersion(1);
if (isTopLevelCall) {
_initializing = true;
_initialized = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
}
}
/**
* @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
* contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
* used to initialize parent contracts.
*
* `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
* initialization step. This is essential to configure modules that are added through upgrades and that require
* initialization.
*
* Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
* a contract, executing them in the right order is up to the developer or operator.
*/
modifier reinitializer(uint8 version) {
bool isTopLevelCall = _setInitializedVersion(version);
if (isTopLevelCall) {
_initializing = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
}
@ -67,14 +106,37 @@ abstract contract Initializable {
/**
* @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
* {initializer} modifier, directly or indirectly.
* {initializer} and {reinitializer} modifiers, directly or indirectly.
*/
modifier onlyInitializing() {
require(_initializing, "Initializable: contract is not initializing");
_;
}
function _isConstructor() private view returns (bool) {
return !Address.isContract(address(this));
/**
* @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
* Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
* to any version. It is recommended to use this to lock implementation contracts that are designed to be called
* through proxies.
*/
function _disableInitializers() internal virtual {
_setInitializedVersion(type(uint8).max);
}
function _setInitializedVersion(uint8 version) private returns (bool) {
// If the contract is initializing we ignore whether _initialized is set in order to support multiple
// inheritance patterns, but we only do this in the context of a constructor, and for the lowest level
// of initializers, because in other contexts the contract may have been reentered.
if (_initializing) {
require(
version == 1 && !Address.isContract(address(this)),
"Initializable: contract is already initialized"
);
return false;
} else {
require(_initialized < version, "Initializable: contract is already initialized");
_initialized = version;
return true;
}
}
}