contracts-bedrock: migrate GovernanceToken (#3386)

Moves the `GovernanceToken` into `contracts-bedrock`
so that its artifact can be easily inspected. This
is the first step in deleting `contracts-governance`.
The other files should be moved to `contracts-periphery`.

op-bindings/Makefile

@@ -86,7 +86,7 @@ l1-blocknumber-bindings: compile
 
 more:
 	go run ./gen/main.go \
-		-artifacts ../packages/contracts-bedrock/artifacts,../packages/contracts-governance/artifacts \
+		-artifacts ../packages/contracts-bedrock/artifacts \
 		-out ./bindings \
 		-contracts OptimismMintableERC20Factory,L2StandardBridge,L1BlockNumber,DeployerWhitelist,Proxy,OptimismPortal,L2ToL1MessagePasser,L2CrossDomainMessenger,GasPriceOracle,SequencerFeeVault,L1Block,LegacyERC20ETH,WETH9,GovernanceToken \
 		-package bindings

op-bindings/bindings/gaspriceoracle_more.go

@@ -9,7 +9,7 @@ import (
 	"github.com/ethereum-optimism/optimism/op-bindings/solc"
 )
 
-const GasPriceOracleStorageLayoutJSON = "{\"storage\":[{\"astId\":26690,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"_owner\",\"offset\":0,\"slot\":\"0\",\"type\":\"t_address\"},{\"astId\":1663,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"spacer0\",\"offset\":0,\"slot\":\"1\",\"type\":\"t_uint256\"},{\"astId\":1666,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"spacer1\",\"offset\":0,\"slot\":\"2\",\"type\":\"t_uint256\"},{\"astId\":1669,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"overhead\",\"offset\":0,\"slot\":\"3\",\"type\":\"t_uint256\"},{\"astId\":1672,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"scalar\",\"offset\":0,\"slot\":\"4\",\"type\":\"t_uint256\"},{\"astId\":1675,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"decimals\",\"offset\":0,\"slot\":\"5\",\"type\":\"t_uint256\"}],\"types\":{\"t_address\":{\"encoding\":\"inplace\",\"label\":\"address\",\"numberOfBytes\":\"20\"},\"t_uint256\":{\"encoding\":\"inplace\",\"label\":\"uint256\",\"numberOfBytes\":\"32\"}}}"
+const GasPriceOracleStorageLayoutJSON = "{\"storage\":[{\"astId\":50056,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"_owner\",\"offset\":0,\"slot\":\"0\",\"type\":\"t_address\"},{\"astId\":1663,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"spacer0\",\"offset\":0,\"slot\":\"1\",\"type\":\"t_uint256\"},{\"astId\":1666,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"spacer1\",\"offset\":0,\"slot\":\"2\",\"type\":\"t_uint256\"},{\"astId\":1669,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"overhead\",\"offset\":0,\"slot\":\"3\",\"type\":\"t_uint256\"},{\"astId\":1672,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"scalar\",\"offset\":0,\"slot\":\"4\",\"type\":\"t_uint256\"},{\"astId\":1675,\"contract\":\"contracts/L2/GasPriceOracle.sol:GasPriceOracle\",\"label\":\"decimals\",\"offset\":0,\"slot\":\"5\",\"type\":\"t_uint256\"}],\"types\":{\"t_address\":{\"encoding\":\"inplace\",\"label\":\"address\",\"numberOfBytes\":\"20\"},\"t_uint256\":{\"encoding\":\"inplace\",\"label\":\"uint256\",\"numberOfBytes\":\"32\"}}}"
 
 var GasPriceOracleStorageLayout = new(solc.StorageLayout)
 

op-bindings/bindings/legacyerc20eth_more.go

@@ -9,7 +9,7 @@ import (
 	"github.com/ethereum-optimism/optimism/op-bindings/solc"
 )
 
-const LegacyERC20ETHStorageLayoutJSON = "{\"storage\":[{\"astId\":26811,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_balances\",\"offset\":0,\"slot\":\"0\",\"type\":\"t_mapping(t_address,t_uint256)\"},{\"astId\":26817,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_allowances\",\"offset\":0,\"slot\":\"1\",\"type\":\"t_mapping(t_address,t_mapping(t_address,t_uint256))\"},{\"astId\":26819,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_totalSupply\",\"offset\":0,\"slot\":\"2\",\"type\":\"t_uint256\"},{\"astId\":26821,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_name\",\"offset\":0,\"slot\":\"3\",\"type\":\"t_string_storage\"},{\"astId\":26823,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_symbol\",\"offset\":0,\"slot\":\"4\",\"type\":\"t_string_storage\"},{\"astId\":24078,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"remoteToken\",\"offset\":0,\"slot\":\"5\",\"type\":\"t_address\"},{\"astId\":24081,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"bridge\",\"offset\":0,\"slot\":\"6\",\"type\":\"t_address\"}],\"types\":{\"t_address\":{\"encoding\":\"inplace\",\"label\":\"address\",\"numberOfBytes\":\"20\"},\"t_mapping(t_address,t_mapping(t_address,t_uint256))\":{\"encoding\":\"mapping\",\"label\":\"mapping(address =\u003e mapping(address =\u003e uint256))\",\"numberOfBytes\":\"32\",\"key\":\"t_address\",\"value\":\"t_mapping(t_address,t_uint256)\"},\"t_mapping(t_address,t_uint256)\":{\"encoding\":\"mapping\",\"label\":\"mapping(address =\u003e uint256)\",\"numberOfBytes\":\"32\",\"key\":\"t_address\",\"value\":\"t_uint256\"},\"t_string_storage\":{\"encoding\":\"bytes\",\"label\":\"string\",\"numberOfBytes\":\"32\"},\"t_uint256\":{\"encoding\":\"inplace\",\"label\":\"uint256\",\"numberOfBytes\":\"32\"}}}"
+const LegacyERC20ETHStorageLayoutJSON = "{\"storage\":[{\"astId\":50177,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_balances\",\"offset\":0,\"slot\":\"0\",\"type\":\"t_mapping(t_address,t_uint256)\"},{\"astId\":50183,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_allowances\",\"offset\":0,\"slot\":\"1\",\"type\":\"t_mapping(t_address,t_mapping(t_address,t_uint256))\"},{\"astId\":50185,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_totalSupply\",\"offset\":0,\"slot\":\"2\",\"type\":\"t_uint256\"},{\"astId\":50187,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_name\",\"offset\":0,\"slot\":\"3\",\"type\":\"t_string_storage\"},{\"astId\":50189,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"_symbol\",\"offset\":0,\"slot\":\"4\",\"type\":\"t_string_storage\"},{\"astId\":24078,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"remoteToken\",\"offset\":0,\"slot\":\"5\",\"type\":\"t_address\"},{\"astId\":24081,\"contract\":\"contracts/legacy/LegacyERC20ETH.sol:LegacyERC20ETH\",\"label\":\"bridge\",\"offset\":0,\"slot\":\"6\",\"type\":\"t_address\"}],\"types\":{\"t_address\":{\"encoding\":\"inplace\",\"label\":\"address\",\"numberOfBytes\":\"20\"},\"t_mapping(t_address,t_mapping(t_address,t_uint256))\":{\"encoding\":\"mapping\",\"label\":\"mapping(address =\u003e mapping(address =\u003e uint256))\",\"numberOfBytes\":\"32\",\"key\":\"t_address\",\"value\":\"t_mapping(t_address,t_uint256)\"},\"t_mapping(t_address,t_uint256)\":{\"encoding\":\"mapping\",\"label\":\"mapping(address =\u003e uint256)\",\"numberOfBytes\":\"32\",\"key\":\"t_address\",\"value\":\"t_uint256\"},\"t_string_storage\":{\"encoding\":\"bytes\",\"label\":\"string\",\"numberOfBytes\":\"32\"},\"t_uint256\":{\"encoding\":\"inplace\",\"label\":\"uint256\",\"numberOfBytes\":\"32\"}}}"
 
 var LegacyERC20ETHStorageLayout = new(solc.StorageLayout)
 

packages/contracts-bedrock/contracts/L2/GovernanceToken.sol

+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.12;
+
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Votes.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+/**
+ * @custom:predeploy 0x4200000000000000000000000000000000000042
+ * @title GovernanceToken
+ * @notice The Optimism token used in governance and supporting voting and delegation. Implements
+ *         EIP 2612 allowing signed approvals. Contract is "owned" by a `MintManager` instance with
+ *         permission to the `mint` function only, for the purposes of enforcing the token inflation
+ *         schedule.
+ */
+contract GovernanceToken is ERC20Burnable, ERC20Votes, Ownable {
+    constructor() ERC20("Optimism", "OP") ERC20Permit("Optimism") {}
+
+    /**
+     * @notice Allows the owner to mint tokens
+     *
+     * @param _account The account receiving minted tokens
+     * @param _amount The amount of tokens to mint
+     */
+    function mint(address _account, uint256 _amount) public onlyOwner {
+        _mint(_account, _amount);
+    }
+
+    /**
+     * @notice Callback called after a token transfer
+     *
+     * @param from The account sending tokens
+     * @param to The account receiving tokens
+     * @param amount The amount of tokens being transfered
+     */
+    function _afterTokenTransfer(
+        address from,
+        address to,
+        uint256 amount
+    ) internal override(ERC20, ERC20Votes) {
+        super._afterTokenTransfer(from, to, amount);
+    }
+
+    /**
+     * @notice Internal mint function
+     *
+     * @param to The account receiving minted tokens
+     * @param amount The amount of tokens to mint
+     */
+    function _mint(address to, uint256 amount) internal override(ERC20, ERC20Votes) {
+        super._mint(to, amount);
+    }
+
+    /**
+     * @notice Internal burn function
+     *
+     * @param account The account that tokens will be burned from
+     * @param amount The amount of tokens that will be burned
+     */
+    function _burn(address account, uint256 amount) internal override(ERC20, ERC20Votes) {
+        super._burn(account, amount);
+    }
+}