60 lines
2.4 KiB
Solidity
60 lines
2.4 KiB
Solidity
// SPDX-License-Identifier: MIT
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pragma solidity ^0.6.0;
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/**
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* @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer.
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* `CREATE2` can be used to compute in advance the address where a smart
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* contract will be deployed, which allows for interesting new mechanisms known
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* as 'counterfactual interactions'.
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*
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* See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more
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* information.
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*/
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library Create2 {
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/**
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* @dev Deploys a contract using `CREATE2`. The address where the contract
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* will be deployed can be known in advance via {computeAddress}.
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*
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* The bytecode for a contract can be obtained from Solidity with
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* `type(contractName).creationCode`.
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*
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* Requirements:
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*
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* - `bytecode` must not be empty.
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* - `salt` must have not been used for `bytecode` already.
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* - the factory must have a balance of at least `amount`.
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* - if `amount` is non-zero, `bytecode` must have a `payable` constructor.
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*/
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function deploy(uint256 amount, bytes32 salt, bytes memory bytecode) internal returns (address) {
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address addr;
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require(address(this).balance >= amount, "Create2: insufficient balance");
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require(bytecode.length != 0, "Create2: bytecode length is zero");
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// solhint-disable-next-line no-inline-assembly
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assembly {
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addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt)
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}
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require(addr != address(0), "Create2: Failed on deploy");
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return addr;
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}
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/**
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* @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the
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* `bytecodeHash` or `salt` will result in a new destination address.
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*/
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function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) {
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return computeAddress(salt, bytecodeHash, address(this));
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}
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/**
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* @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at
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* `deployer`. If `deployer` is this contract's address, returns the same value as {computeAddress}.
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*/
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function computeAddress(bytes32 salt, bytes32 bytecodeHash, address deployer) internal pure returns (address) {
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bytes32 _data = keccak256(
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abi.encodePacked(bytes1(0xff), deployer, salt, bytecodeHash)
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);
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return address(uint256(_data));
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}
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}
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