Gas Optimizations

[code423n4]

[G-01] != cost 6 gas less than > in require

Recommend to use the != for comparisons with 0 in require statemnent. This is type of gas optimization is 6 gas cheaper than >

There have 3 instance of this issues:

File: L1GraphTokenGateway.sol lines 201, 217

require(_amount > 0, "INVALID_ZERO_AMOUNT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol#L201

require(maxSubmissionCost > 0, "NO_SUBMISSION_COST");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol#L217

File: L2GraphTokenGateway.sol line 146

2022-10-thegraph => require(_amount > 0, "INVALID_ZERO_AMOUNT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol#L146

[G-02] Recommend to use short require string to save deployment gas

If you use longer require strings than 32 bytes that will cost more expensive than short require string.

There are 8 instances of this issue:

File: GraphTokenGateway.sol line 21

"Only Governor or Guardian can call"

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/GraphTokenGateway.sol#L21

File: Managed.sol line 53

require(msg.sender == controller.getGovernor(), "Caller must be Controller governor");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol#L53

File: GraphProxy.sol lines 105, 141, 144

require(_newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol#L105

require(Address.isContract(_pendingImplementation), "Implementation must be a contract");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol#L141

"Caller must be the pending implementation"

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol#L144

File: GraphUpgradeable.sol line 32

require(msg.sender == _implementation(), "Caller must be the implementation");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphUpgradeable.sol#L32

[G-03] Recommend to use uint256(1)/uint256(2) for true and false

If you don't use boolean for storage you will avoid Gwarmaccess 100 gas. Also boolean from true to false cost 20000 gas rather than uint256(2) to uint256(1) that cost less.

There have 3 instance of this issues:

File: L1GraphTokenGateway.sol line 35

mapping(address => bool) public callhookWhitelist;

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol#L35

File: Pausable.sol lines 8, 10

bool internal _partialPaused;

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Pausable.sol#L8

bool internal _paused;

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Pausable.sol#L10

[G-04] Using of custom errors than are came from 0.8.4 instead of require()/revert() strings will save deployment gas

Use more recent version of solidity compiler and take advantage of custom errors and save from deployment gas and when condtions are done for reverting.

There have 64 instance of this issues:

File: GraphTokenGateway.sol lines 19,31,40

require(

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/GraphTokenGateway.sol/#L19

require(_newPauseGuardian != address(0), "PauseGuardian must be set");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/GraphTokenGateway.sol/#L31

require(!_paused, "Paused (contract)");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/GraphTokenGateway.sol/#L40

File: L1GraphTokenGateway.sol lines 74,78,82,110,111,122,132,142,153,154,165,166,200,201,202,213,217,224,271,275

require(inbox != address(0), "INBOX_NOT_SET");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L74

require(msg.sender == address(bridge), "NOT_FROM_BRIDGE");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L78

require(l2ToL1Sender == l2Counterpart, "ONLY_COUNTERPART_GATEWAY");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L82

require(_inbox != address(0), "INVALID_INBOX");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L110

require(_l1Router != address(0), "INVALID_L1_ROUTER");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L111

require(_l2GRT != address(0), "INVALID_L2_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L122

require(_l2Counterpart != address(0), "INVALID_L2_COUNTERPART");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L132

require(_escrow != address(0) && Address.isContract(_escrow), "INVALID_ESCROW");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L142

require(_newWhitelisted != address(0), "INVALID_ADDRESS");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L153

require(!callhookWhitelist[_newWhitelisted], "ALREADY_WHITELISTED");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L154

require(_notWhitelisted != address(0), "INVALID_ADDRESS");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L165

require(callhookWhitelist[_notWhitelisted], "NOT_WHITELISTED");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L166

require(_l1Token == address(token), "TOKEN_NOT_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L200

require(_amount > 0, "INVALID_ZERO_AMOUNT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L201

require(_to != address(0), "INVALID_DESTINATION");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L202

require(

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L213

require(maxSubmissionCost > 0, "NO_SUBMISSION_COST");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L217

require(msg.value >= expectedEth, "WRONG_ETH_VALUE");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L224

require(_l1Token == address(token), "TOKEN_NOT_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L271

require(_amount <= escrowBalance, "BRIDGE_OUT_OF_FUNDS");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol/#L275

File: Governed.sol lines 24,41,54

require(msg.sender == governor, "Only Governor can call");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Governed.sol/#L24

require(_newGovernor != address(0), "Governor must be set");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Governed.sol/#L41

require(

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Governed.sol/#L54

File: Managed.sol lines 44,45,49,53,57,104

require(!controller.paused(), "Paused");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L44

require(!controller.partialPaused(), "Partial-paused");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L45

require(!controller.paused(), "Paused");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L49

require(msg.sender == controller.getGovernor(), "Caller must be Controller governor");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L53

require(msg.sender == address(controller), "Caller must be Controller");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L57

require(_controller != address(0), "Controller must be set");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/governance/Managed.sol/#L104

File: L2GraphTokenGateway.sol lines 69,98,108,118,145,146,147,148,153,233,234

require(

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L69

require(_l2Router != address(0), "INVALID_L2_ROUTER");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L98

require(_l1GRT != address(0), "INVALID_L1_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L108

require(_l1Counterpart != address(0), "INVALID_L1_COUNTERPART");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L118

require(_l1Token == l1GRT, "TOKEN_NOT_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L145

require(_amount > 0, "INVALID_ZERO_AMOUNT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L146

require(msg.value == 0, "INVALID_NONZERO_VALUE");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L147

require(_to != address(0), "INVALID_DESTINATION");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L148

require(outboundCalldata.extraData.length == 0, "CALL_HOOK_DATA_NOT_ALLOWED");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L153

require(_l1Token == l1GRT, "TOKEN_NOT_GRT");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L233

require(msg.value == 0, "INVALID_NONZERO_VALUE");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol/#L234

File: GraphTokenUpgradeable.sol lines 60,94,95,106,115,123

require(isMinter(msg.sender), "Only minter can call");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L60

require(_owner == recoveredAddress, "GRT: invalid permit");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L94

require(_deadline == 0 || block.timestamp <= _deadline, "GRT: expired permit");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L95

require(_account != address(0), "INVALID_MINTER");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L106

require(_minters[_account], "NOT_A_MINTER");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L115

require(_minters[msg.sender], "NOT_A_MINTER");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/GraphTokenUpgradeable.sol/#L123

File: L2GraphToken.sol lines 36,49,60,70

require(msg.sender == gateway, "NOT_GATEWAY");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/L2GraphToken.sol/#L36

require(_owner != address(0), "Owner must be set");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/L2GraphToken.sol/#L49

require(_gw != address(0), "INVALID_GATEWAY");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/L2GraphToken.sol/#L60

require(_addr != address(0), "INVALID_L1_ADDRESS");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/token/L2GraphToken.sol/#L70

File: GraphProxy.sol lines 105,133,141,142,157

require(_newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol/#L105

require(success);

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol/#L133

require(Address.isContract(_pendingImplementation), "Implementation must be a contract");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol/#L141

require(

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol/#L142

require(msg.sender != _admin(), "Cannot fallback to proxy target");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol/#L157

File: GraphProxyAdmin.sol lines 34,47,59

require(success);

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxyAdmin.sol/#L34

require(success);

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxyAdmin.sol/#L47

require(success);

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxyAdmin.sol/#L59

File: GraphProxyStorage.sol line 62

require(msg.sender == _admin(), "Caller must be admin");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxyStorage.sol/#L62

File: GraphUpgradeable.sol lines 24,32

require(msg.sender == _proxy.admin(), "Caller must be the proxy admin");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphUpgradeable.sol/#L24

require(msg.sender == _implementation(), "Caller must be the implementation");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphUpgradeable.sol/#L32

[G-05] Recommending to not use constructor parameters where is possible because of their cost.

If you not use constructor parameters, deployment will be cheaper. I recomend instead of them to hard code them and change in time if needed with custome function for that purpose.

There have 1 instance of this issues:

File: GraphProxy.sol line 46

constructor(address _impl, address _admin) {

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/upgrades/GraphProxy.sol#L46

[G-06] Recommend to use one operator for comparison

If you use >= or <= this will cost more gas because in the EVM there is no implementation of Opcodes for >= and `<= and two operations are done.

There have 3 instance of this issues:

File: L1GraphTokenGateway.sol line 224, 275

require(msg.value >= expectedEth, "WRONG_ETH_VALUE");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/gateway/L1GraphTokenGateway.sol#L224

require(_amount <= escrowBalance, "BRIDGE_OUT_OF_FUNDS");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529fc4udit/2022-10-thegraph/contracts/gateway/L1GraphTokenGateway.sol/#L275

File: GraphTokenUpgradeable.sol line 95

require(_deadline == 0 || block.timestamp <= _deadline, "GRT: expired permit");

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529fc4udit/2022-10-thegraph/contracts/l2/token/GraphTokenUpgradeable.sol/#L95

[G‑07] Recommend to change memory to calldata for read-only arguments for functions that are called extnally

There have 1 instance of this issues:

File: L2GraphTokenGateway.sol line 286

function parseOutboundData(bytes memory _data)

https://github.com/code-423n4/2022-10-thegraph/blob/fce4d7761db12f6f3edae9051cb54bf4ef11529f/contracts/l2/gateway/L2GraphTokenGateway.sol#L286