{
    "Function": "permit",
    "File": "src/ERC20Permit.sol",
    "Parent Contracts": [
        "src/ERC20.sol",
        "src/interfaces/IERC20.sol",
        "src/Context.sol"
    ],
    "High-Level Calls": [],
    "Internal Calls": [
        "keccak256(bytes)",
        "require(bool,string)",
        "keccak256(bytes)",
        "abi.encodePacked()",
        "require(bool,string)",
        "abi.encode()",
        "ecrecover(bytes32,uint8,bytes32,bytes32)",
        "_approve",
        "require(bool,string)",
        "require(bool,string)"
    ],
    "Library Calls": [],
    "Low-Level Calls": [],
    "Code": "function permit(\n        address issuer,\n        address spender,\n        uint256 value,\n        uint256 deadline,\n        uint8 v,\n        bytes32 r,\n        bytes32 s\n    ) external {\n        require(block.timestamp < deadline, 'EXPIRED');\n        require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, 'INV_S');\n        require(v == 27 || v == 28, 'INV_V');\n\n        bytes32 digest = keccak256(\n            abi.encodePacked(\n                EIP191_PREFIX_FOR_EIP712_STRUCTURED_DATA,\n                DOMAIN_SEPARATOR,\n                keccak256(abi.encode(PERMIT_SIGNATURE_HASH, issuer, spender, value, nonces[issuer]++, deadline))\n            )\n        );\n\n        address recoveredAddress = ecrecover(digest, v, r, s);\n        require(recoveredAddress == issuer, 'INV_SIG');\n\n        // _approve will revert if issuer is address(0x0)\n        _approve(issuer, spender, value);\n    }"
}