// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v4.8.0) (utils/Create2.sol) pragma solidity ^0.8.0; /** * @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer. * `CREATE2` can be used to compute in advance the address where a smart * contract will be deployed, which allows for interesting new mechanisms known * as 'counterfactual interactions'. * * See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more * information. */ library Create2 { /** * @dev Deploys a contract using `CREATE2`. The address where the contract * will be deployed can be known in advance via {computeAddress}. * * The bytecode for a contract can be obtained from Solidity with * `type(contractName).creationCode`. * * Requirements: * * - `bytecode` must not be empty. * - `salt` must have not been used for `bytecode` already. * - the factory must have a balance of at least `amount`. * - if `amount` is non-zero, `bytecode` must have a `payable` constructor. */ function deploy(uint256 amount, bytes32 salt, bytes memory bytecode) internal returns (address addr) { require(address(this).balance >= amount, "Create2: insufficient balance"); require(bytecode.length != 0, "Create2: bytecode length is zero"); /// @solidity memory-safe-assembly assembly { addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt) } require(addr != address(0), "Create2: Failed on deploy"); } /** * @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the * `bytecodeHash` or `salt` will result in a new destination address. */ function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) { return computeAddress(salt, bytecodeHash, address(this)); } /** * @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at * `deployer`. If `deployer` is this contract's address, returns the same value as {computeAddress}. */ function computeAddress(bytes32 salt, bytes32 bytecodeHash, address deployer) internal pure returns (address addr) { /// @solidity memory-safe-assembly assembly { let ptr := mload(0x40) // Get free memory pointer // | | ↓ ptr ... ↓ ptr + 0x0B (start) ... ↓ ptr + 0x20 ... ↓ ptr + 0x40 ... | // |-------------------|---------------------------------------------------------------------------| // | bytecodeHash | CCCCCCCCCCCCC...CC | // | salt | BBBBBBBBBBBBB...BB | // | deployer | 000000...0000AAAAAAAAAAAAAAAAAAA...AA | // | 0xFF | FF | // |-------------------|---------------------------------------------------------------------------| // | memory | 000000...00FFAAAAAAAAAAAAAAAAAAA...AABBBBBBBBBBBBB...BBCCCCCCCCCCCCC...CC | // | keccak(start, 85) | ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑ | mstore(add(ptr, 0x40), bytecodeHash) mstore(add(ptr, 0x20), salt) mstore(ptr, deployer) // Right-aligned with 12 preceding garbage bytes let start := add(ptr, 0x0b) // The hashed data starts at the final garbage byte which we will set to 0xff mstore8(start, 0xff) addr := keccak256(start, 85) } } }