reNFT - slvDev's results

Gas Findings

Initial gas report was saved with forge snapshot.

Total gas saved per issue represent Overall gas change from forge snapshot --diff.

More details from forge snapshot --diff can be found in Gas Findings Details.

Gas Findings Details

[G-01] Cache Function Calls for Efficiency

test_stopRent_payOrder_proRata_stoppedByLender() (gas: 11 (0.000%)) 
test_stopRent_payOrder_inFull_stoppedByRenter() (gas: -68 (-0.002%)) 
test_StopRent_PayOrder_InFull_StoppedByLender() (gas: -69 (-0.002%)) 
test_stopRentBatch_payOrders_allDifferentLenders() (gas: -207 (-0.002%)) 
test_Success_RewardShare() (gas: -69 (-0.003%)) 
test_Success_RewardShare() (gas: -69 (-0.003%)) 
test_Success_StopRent_NewStopPolicy() (gas: -69 (-0.004%)) 
test_StopRent_BaseOrder() (gas: -69 (-0.004%)) 
test_stopRentBatch_baseOrders_allSameLender() (gas: -207 (-0.005%)) 
test_Success_SettlePayment_PayOrder_NotEnded() (gas: 10 (0.010%)) 
test_Success_SettlePayment_BaseOrder_WithFeeTooSmall() (gas: -69 (-0.061%)) 
test_Success_SettlePayment_BaseOrder_WithFee() (gas: -86 (-0.068%)) 
test_Success_SettlePayment_BaseOrder() (gas: -69 (-0.076%)) 
test_Success_SettlePayment_PayOrder_Ended() (gas: -69 (-0.076%)) 
test_Success_SettlePaymentBatch() (gas: -207 (-0.167%)) 
test_Success_Upgrade() (gas: -2807 (-0.189%)) 
test_Success_Freeze() (gas: -2807 (-0.191%)) 
test_Success_UpgradePaymentEscrow() (gas: -2967 (-0.207%)) 
Overall gas change: -9887 (-0.012%)

<details> <summary><i>2 issue instances in 1 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

/// @audit cache `orderType.isPayOrder()`
255: if (orderType.isPayOrder() && !isRentalOver) {
268: (orderType.isPayOrder() && isRentalOver) || orderType.isBaseOrder()

255 | 268

</details>

[G-02] abi.encodePacked is more gas efficient than abi.encode

Tested only one instance due amount of them.

abi.encode() pads all elementary types to 32 bytes, whereas abi.encodePacked() will only use the minimal required memory to encode the data.

    function testPacking() public pure returns (bytes memory) {
        // return abi.encode("string"); // 1120 gas
        // return abi.encodePacked("string"); // 913 gas
    }

test_Reverts_RenterIsNotWhitelisted() (gas: -73 (-0.004%)) 
test_stopRentBatch_payOrders_allDifferentLenders() (gas: -668 (-0.008%)) 
test_Reverts_TrainSelector_Callable_NonRentedOnly() (gas: -189 (-0.009%)) 
test_Success_RenterIsWhitelisted() (gas: -189 (-0.009%)) 
test_Reverts_TrainSelector_Callable_RetireSelector_NotCallable() (gas: -189 (-0.009%)) 
test_Reverts_ChangeTeam_NotCallable() (gas: -189 (-0.010%)) 
test_Reverts_TrainSelector_NotCallable() (gas: -189 (-0.010%)) 
test_stopRent_payOrder_proRata_stoppedByLender() (gas: -299 (-0.010%)) 
test_stopRent_payOrder_inFull_stoppedByRenter() (gas: -299 (-0.010%)) 
test_StopRent_PayOrder_InFull_StoppedByLender() (gas: -299 (-0.010%)) 
test_Success_RewardShare() (gas: -233 (-0.011%)) 
test_Success_RewardShare() (gas: -232 (-0.011%)) 
test_Success_Rent_PayOrder() (gas: -325 (-0.011%)) 
test_Reverts_StopRent_OldStopPolicy() (gas: -189 (-0.011%)) 
test_Success_StopRent_NewStopPolicy() (gas: -231 (-0.013%)) 
test_StopRent_BaseOrder() (gas: -231 (-0.014%)) 
test_stopRentBatch_baseOrders_allSameLender() (gas: -668 (-0.015%)) 
test_Success_Rent_BaseOrder_ERC721() (gas: -257 (-0.016%)) 
test_Success_Rent_BaseOrder_ERC1155() (gas: -257 (-0.016%)) 
test_Success_Rent_BaseOrders() (gas: -770 (-0.017%)) 
test_Fuzz_SettlePaymentInFull(uint256,bool) (gas: -20 (-0.024%)) 
test_Success_ProcessBaseOrderConsideration() (gas: -32 (-0.162%)) 
test_Success_ProcessBaseOrderOffer() (gas: -32 (-0.183%)) 
test_Success_ConvertToItems_BaseOrder() (gas: -64 (-0.227%)) 
test_Success_ProcessPayOrderOffer() (gas: -64 (-0.233%)) 
test_Success_ConvertToItems_PayeeOrder() (gas: -64 (-0.236%)) 
test_Success_ConvertToItems_PayOrder() (gas: -64 (-0.242%)) 
Overall gas change: -6316 (-0.007%)

<details> <summary><i>9 issue instances in 2 files:</i></summary>

File: smart-contracts/src/packages/Signer.sol

129: abi.encode(
                    _ITEM_TYPEHASH,
                    item.itemType,
                    item.settleTo,
                    item.token,
                    item.amount,
                    item.identifier
                )
151: abi.encode(_HOOK_TYPEHASH, hook.target, hook.itemIndex, hook.extraData)
183: abi.encode(
                    _RENTAL_ORDER_TYPEHASH,
                    order.seaportOrderHash,
                    keccak256(abi.encodePacked(itemHashes)),
                    keccak256(abi.encodePacked(hookHashes)),
                    order.orderType,
                    order.lender,
                    order.renter,
                    order.startTimestamp,
                    order.endTimestamp
                )
208: abi.encode(_ORDER_FULFILLMENT_TYPEHASH, fulfillment.recipient)
233: abi.encode(
                    _ORDER_METADATA_TYPEHASH,
                    metadata.rentDuration,
                    keccak256(abi.encodePacked(hookHashes))
                )
254: abi.encode(
                    _RENT_PAYLOAD_TYPEHASH,
                    _deriveOrderFulfillmentHash(payload.fulfillment),
                    _deriveOrderMetadataHash(payload.metadata),
                    payload.expiration,
                    payload.intendedFulfiller
                )
280: abi.encode(
                    _eip712DomainTypeHash,
                    _nameHash,
                    _versionHash,
                    block.chainid,
                    address(this)
                )
374: abi.encode(rentalOrderTypeString, hookTypeString, itemTypeString)

129 | 151 | 183 | 208 | 233 | 254 | 280 | 374

File: smart-contracts/src/policies/Factory.sol

184: abi.encode(STORE.totalSafes() + 1, block.chainid)

184

</details>

[G-03] Stack variable is only used once

Tested only one instance due amount of them.

test_stopRent_payOrder_proRata_stoppedByLender() (gas: -5 (-0.000%)) 
test_Success_SettlePayment_PayOrder_NotEnded() (gas: -6 (-0.006%)) 
test_Fuzz_SettlePaymentProRata(uint256,uint256,uint256) (gas: -7 (-0.006%)) 
test_Fuzz_SettlePaymentInFull(uint256,bool) (gas: -20 (-0.024%)) 
test_Success_Upgrade() (gas: -600 (-0.040%)) 
test_Success_Freeze() (gas: -600 (-0.041%)) 
test_Success_UpgradePaymentEscrow() (gas: -600 (-0.042%)) 
test_Success_CalculatePaymentProRata() (gas: -42 (-0.217%)) 
Overall gas change: -1880 (-0.002%)

<details> <summary><i>10 issue instances in 5 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

/// @audit - `numerator` variable
138: uint256 numerator = (amount * elapsedTime) * 1000
/// @audit - `settleToAddress` variable
198: address settleToAddress = settleTo == SettleTo.LENDER ? lender : renter
/// @audit - `paymentFee` variable
244: uint256 paymentFee = _calculateFee(paymentAmount)
/// @audit - `syncedBalance` variable
399: uint256 syncedBalance = balanceOf[token]
/// @audit - `trueBalance` variable
402: uint256 trueBalance = IERC20(token).balanceOf(address(this))

138 | 198 | 244 | 399 | 402

File: smart-contracts/src/modules/Storage.sol

/// @audit - `rentalId` variable
124: RentalId rentalId = RentalUtils.getItemPointer(recipient, token, identifier)

124

File: smart-contracts/src/packages/Signer.sol

/// @audit - `digest` variable
112: bytes32 digest = _DOMAIN_SEPARATOR.toTypedDataHash(payloadHash)

112

File: smart-contracts/src/policies/Create.sol

/// @audit - `stringErrorCode` variable
509: string memory stringErrorCode = LibString.toString(errorCode)

509

File: smart-contracts/src/policies/Guard.sol

/// @audit - `stringErrorCode` variable
174: string memory stringErrorCode = LibString.toString(errorCode)
/// @audit - `isActive` variable
335: bool isActive = STORE.hookOnTransaction(hook)

174 | 335

</details>

[G-04] Unutilized Named Return Variables Waste Gas Without Optimizer

-   function VERSION() external pure override returns (uint8 major, uint8 minor) {
+   function VERSION() external pure override returns (uint8, uint8) {

test_Fuzz_SettlePaymentInFull(uint256,bool) (gas: -20 (-0.024%)) 
Overall gas change: -20 (-0.000%)

<details> <summary><i>2 issue instances in 2 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

/// @audit - Redundant `return (1, 0);` statement in functions with named return variables
68: function VERSION() external pure override returns (uint8 major, uint8 minor) {

68

File: smart-contracts/src/modules/Storage.sol

/// @audit - Redundant `return (1, 0);` statement in functions with named return variables
96: function VERSION() external pure override returns (uint8 major, uint8 minor) {

96

</details>

[G-05] Optimize Gas by Using Only Named Returns

Tested only one instance due amount of them.

Example:

/// 985 gas cost
function add(uint256 x, uint256 y) public pure returns (uint256) {
    return x + y;
}
/// 941 gas cost
function addNamed(uint256 x, uint256 y) public pure returns (uint256 res) {
    res = x + y;
}

-    function _calculateFee(uint256 amount) internal view returns (uint256) {
-        // Uses 10,000 as a denominator for the fee.
-        return (amount * fee) / 10000;
-    }

+    function _calculateFee(uint256 amount) internal view returns (uint256 result) {
+        // Uses 10,000 as a denominator for the fee.
+        result = (amount * fee) / 10000;
+    }

test_Fuzz_SettlePaymentInFull(uint256,bool) (gas: -20 (-0.024%)) 
Overall gas change: -20 (-0.000%)

<details> <summary><i>23 issue instances in 6 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

75: function KEYCODE() public pure override returns (Keycode) {
88: function _calculateFee(uint256 amount) internal view returns (uint256) {

75 | 88

File: smart-contracts/src/modules/Storage.sol

103: function KEYCODE() public pure override returns (Keycode) {
118: function isRentedOut(
        address recipient,
        address token,
        uint256 identifier
    ) external view returns (bool) {
135: function contractToHook(address to) external view returns (address) {
149: function hookOnTransaction(address hook) external view returns (bool) {
159: function hookOnStart(address hook) external view returns (bool) {
169: function hookOnStop(address hook) external view returns (bool) {

103 | 118 | 135 | 149 | 159 | 169

File: smart-contracts/src/packages/Signer.sol

107: function _recoverSignerFromPayload(
        bytes32 payloadHash,
        bytes memory signature
    ) internal view returns (address) {
125: function _deriveItemHash(Item memory item) internal view returns (bytes32) {
147: function _deriveHookHash(Hook memory hook) internal view returns (bytes32) {
162: function _deriveRentalOrderHash(
        RentalOrder memory order
    ) internal view returns (bytes32) {
204: function _deriveOrderFulfillmentHash(
        OrderFulfillment memory fulfillment
    ) internal view returns (bytes32) {
218: function _deriveOrderMetadataHash(
        OrderMetadata memory metadata
    ) internal view returns (bytes32) {
248: function _deriveRentPayloadHash(
        RentPayload memory payload
    ) internal view returns (bytes32) {
273: function _deriveDomainSeparator(
        bytes32 _eip712DomainTypeHash,
        bytes32 _nameHash,
        bytes32 _versionHash
    ) internal view virtual returns (bytes32) {

107 | 125 | 147 | 162 | 204 | 218 | 248 | 273

File: smart-contracts/src/policies/Create.sol

117: function domainSeparator() external view returns (bytes32) {
126: function getRentalOrderHash(
        RentalOrder memory order
    ) external view returns (bytes32) {
137: function getRentPayloadHash(
        RentPayload memory payload
    ) external view returns (bytes32) {
148: function getOrderMetadataHash(
        OrderMetadata memory metadata
    ) external view returns (bytes32) {

117 | 126 | 137 | 148

File: smart-contracts/src/Create2Deployer.sol

84: function getCreate2Address(
        bytes32 salt,
        bytes memory initCode
    ) public view returns (address) {

84

File: smart-contracts/src/Kernel.sol

90: function KEYCODE() public pure virtual returns (Keycode);
180: function getModuleAddress(Keycode keycode_) internal view returns (address) {

90 | 180

</details>

[G-06] Use uint256(1)/uint256(2) instead of true/false to save gas for changes

Boolean variables in Solidity are more expensive than uint256 or any type that takes up a full word, due to additional gas costs associated with write operations. When using boolean variables, each write operation emits an extra SLOAD to read the slot's contents, replace the bits taken up by the boolean, and then write back. This process cannot be disabled and leads to extra gas consumption.

By using uint256(1) and uint256(2) for representing true and false states, you can avoid a Gwarmaccess (100 gas) cost and also avoid a Gsset (20000 gas) cost when changing from false to true, after having been true in the past. This approach helps in optimizing gas usage, making your contract more cost-effective.

Usage in OpenZeppelin ReentrancyGuard.sol

<details> <summary><i>8 issue instances in 3 files:</i></summary>

File: smart-contracts/src/modules/Storage.sol

20: mapping(bytes32 orderHash => bool isActive) public orders;
55: mapping(address delegate => bool isWhitelisted) public whitelistedDelegates;
58: mapping(address extension => bool isWhitelisted) public whitelistedExtensions;

20 | 55 | 58

File: smart-contracts/src/Create2Deployer.sol

16: mapping(address => bool) public deployed;

16

File: smart-contracts/src/Kernel.sol

116: bool public isActive;
221: mapping(Keycode => mapping(Policy => mapping(bytes4 => bool)))
        public modulePermissions; // for policy addr, check if they have permission to call the function in the module.
229: mapping(address => mapping(Role => bool)) public hasRole;
230: mapping(Role => bool) public isRole;

116 | 221 | 229 | 230

</details>

[G-07] Use assembly to write mutable storage values

Writing to storage using assembly is more gas efficient.

    function writeStorage() external {
        // storageNumber = 10; // 2358 gas
        // assembly {
        //     sstore(storageNumber.slot, 10) // 2350 gas
        // }
        // storageAddr = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc3; // 2411 gas
        // assembly {
        //     sstore(storageAddr.slot, 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc3) // 2350 gas
        // }
    }

<details> <summary><i>42 issue instances in 9 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

61: kernel = kernel_
62: initialized = true
387: fee = feeNumerator

61 | 62 | 387

File: smart-contracts/src/modules/Storage.sol

89: kernel = kernel_
90: initialized = true
194: orders[orderHash] = true
279: deployedSafes[safe] = newSafeCount
282: totalSafes = newSafeCount
302: _contractToHook[to] = hook
325: hookStatus[hook] = bitmap
338: whitelistedDelegates[delegate] = isEnabled
351: whitelistedExtensions[extension] = isEnabled

89 | 90 | 194 | 279 | 282 | 302 | 325 | 338 | 351

File: smart-contracts/src/policies/Admin.sol

49: STORE = Storage(getModuleAddress(toKeycode("STORE")))
52: ESCRW = PaymentEscrow(getModuleAddress(toKeycode("ESCRW")))

49 | 52

File: smart-contracts/src/policies/Create.sol

81: STORE = Storage(getModuleAddress(toKeycode("STORE")))
84: ESCRW = PaymentEscrow(getModuleAddress(toKeycode("ESCRW")))

81 | 84

File: smart-contracts/src/policies/Factory.sol

82: STORE = Storage(getModuleAddress(toKeycode("STORE")))

82

File: smart-contracts/src/policies/Guard.sol

72: STORE = Storage(getModuleAddress(toKeycode("STORE")))

72

File: smart-contracts/src/policies/Stop.sol

72: STORE = Storage(getModuleAddress(toKeycode("STORE")))
75: ESCRW = PaymentEscrow(getModuleAddress(toKeycode("ESCRW")))

72 | 75

File: smart-contracts/src/Create2Deployer.sol

50: deployed[targetDeploymentAddress] = true

50

File: smart-contracts/src/Kernel.sol

34: kernel = kernel_
55: kernel = newKernel_
193: isActive = activate_
243: executor = _executor
244: admin = _admin
296: executor = target_
298: admin = target_
319: isRole[role_] = true
322: hasRole[addr_][role_] = true
342: hasRole[addr_][role_] = false
366: getModuleForKeycode[keycode] = newModule_
369: getKeycodeForModule[newModule_] = keycode
397: getKeycodeForModule[oldModule] = Keycode.wrap(bytes5(0))
400: getKeycodeForModule[newModule_] = keycode
403: getModuleForKeycode[keycode] = newModule_
431: getPolicyIndex[policy_] = activePolicies.length - 1
445: getDependentIndex[keycode][policy_] = moduleDependents[keycode].length - 1
472: activePolicies[idx] = lastPolicy
479: getPolicyIndex[lastPolicy] = idx
569: modulePermissions[request.keycode][policy_][request.funcSelector] = grant_
611: getDependentIndex[keycode][lastPolicy] = origIndex

34 | 55 | 193 | 243 | 244 | 296 | 298 | 319 | 322 | 342 | 366 | 369 | 397 | 400 | 403 | 431 | 445 | 472 | 479 | 569 | 611

</details>

[G-08] Use revert() to gain maximum gas savings

If you dont need Error messages, or you want gain maximum gas savings - revert() is a cheapest way to revert transaction in terms of gas.

    revert(); // 117 gas 
    require(false); // 132 gas
    revert CustomError(); // 157 gas
    assert(false); // 164 gas
    revert("Custom Error"); // 406 gas
    require(false, "Custom Error"); // 421 gas

<details> <summary><i>73 issue instances in 10 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

116: revert Errors.PaymentEscrowModule_PaymentTransferFailed(token, to, value)
279: revert Errors.Shared_OrderTypeNotSupported(uint8(orderType))
367: revert Errors.PaymentEscrow_ZeroPayment()
383: revert Errors.PaymentEscrow_InvalidFeeNumerator()

116 | 279 | 367 | 383

File: smart-contracts/src/modules/Storage.sol

222: revert Errors.StorageModule_OrderDoesNotExist(orderHash)
252: revert Errors.StorageModule_OrderDoesNotExist(orderHashes[i])
296: revert Errors.StorageModule_NotContract(to)
299: revert Errors.StorageModule_NotContract(hook)
318: revert Errors.StorageModule_NotContract(hook)
322: revert Errors.StorageModule_InvalidHookStatusBitmap(bitmap)

222 | 252 | 296 | 299 | 318 | 322

File: smart-contracts/src/packages/Reclaimer.sol

74: revert Errors.ReclaimerPackage_OnlyDelegateCallAllowed()
81: revert Errors.ReclaimerPackage_OnlyRentalSafeAllowed(
                rentalOrder.rentalWallet
            )

74 | 81

File: smart-contracts/src/packages/Signer.sol

82: revert Errors.SignerPackage_UnauthorizedFulfiller(
                actualFulfiller,
                intendedFulfiller
            )
97: revert Errors.SignerPackage_SignatureExpired(block.timestamp, expiration)

82 | 97

File: smart-contracts/src/policies/Create.sol

202: revert Errors.CreatePolicy_OfferCountZero()
223: revert Errors.CreatePolicy_SeaportItemTypeNotSupported(offer.itemType)
297: revert Errors.CreatePolicy_SeaportItemTypeNotSupported(offer.itemType)
312: revert Errors.CreatePolicy_ItemCountZero(totalRentals, totalPayments)
333: revert Errors.CreatePolicy_ConsiderationCountZero()
343: revert Errors.CreatePolicy_SeaportItemTypeNotSupported(
                    consideration.itemType
                )
389: revert Errors.CreatePolicy_SeaportItemTypeNotSupported(
                    consideration.itemType
                )
397: revert Errors.CreatePolicy_ItemCountZero(totalRentals, totalPayments)
434: revert Errors.CreatePolicy_ConsiderationCountNonZero(
                    considerations.length
                )
443: revert Errors.CreatePolicy_OfferCountNonZero(offers.length)
451: revert Errors.Shared_OrderTypeNotSupported(uint8(orderType))
481: revert Errors.Shared_DisabledHook(target)
492: revert Errors.Shared_NonRentalHookItem(itemIndex)
506: revert Errors.Shared_HookFailString(revertReason)
512: revert Errors.Shared_HookFailString(
                    string.concat("Hook reverted: Panic code ", stringErrorCode)
                )
517: revert Errors.Shared_HookFailBytes(revertData)
632: revert Errors.CreatePolicy_RentDurationZero()
637: revert Errors.CreatePolicy_InvalidOrderMetadataHash()
650: revert Errors.CreatePolicy_InvalidRentalSafe(safe)
655: revert Errors.CreatePolicy_InvalidSafeOwner(owner, safe)
671: revert Errors.CreatePolicy_UnexpectedTokenRecipient(
                execution.itemType,
                execution.token,
                execution.identifier,
                execution.amount,
                execution.recipient,
                expectedRecipient
            )
709: revert Errors.CreatePolicy_SeaportItemTypeNotSupported(
                    execution.itemType
                )
767: revert Errors.CreatePolicy_UnauthorizedCreatePolicySigner()

202 | 223 | 297 | 312 | 333 | 343 | 389 | 397 | 434 | 443 | 451 | 481 | 492 | 506 | 512 | 517 | 632 | 637 | 650 | 655 | 671 | 709 | 767

File: smart-contracts/src/policies/Factory.sol

144: revert Errors.FactoryPolicy_InvalidSafeThreshold(threshold, owners.length)

144

File: smart-contracts/src/policies/Guard.sol

134: revert Errors.GuardPolicy_UnauthorizedSelector(selector)
146: revert Errors.GuardPolicy_UnauthorizedExtension(extension)
171: revert Errors.Shared_HookFailString(revertReason)
177: revert Errors.Shared_HookFailString(
                string.concat("Hook reverted: Panic code ", stringErrorCode)
            )
182: revert Errors.Shared_HookFailBytes(revertData)
271: revert Errors.GuardPolicy_UnauthorizedSelector(
                    shared_set_approval_for_all_selector
                )
281: revert Errors.GuardPolicy_UnauthorizedSelector(
                    e1155_safe_batch_transfer_from_selector
                )
288: revert Errors.GuardPolicy_UnauthorizedSelector(
                    gnosis_safe_set_guard_selector
                )
325: revert Errors.GuardPolicy_UnauthorizedDelegateCall(to)
330: revert Errors.GuardPolicy_FunctionSelectorRequired()

134 | 146 | 171 | 177 | 182 | 271 | 281 | 288 | 325 | 330

File: smart-contracts/src/policies/Stop.sol

141: revert Errors.StopPolicy_CannotStopOrder(block.timestamp, msg.sender)
149: revert Errors.StopPolicy_CannotStopOrder(block.timestamp, msg.sender)
154: revert Errors.Shared_OrderTypeNotSupported(uint8(orderType))
181: revert Errors.StopPolicy_ReclaimFailed()
211: revert Errors.Shared_DisabledHook(target)
222: revert Errors.Shared_NonRentalHookItem(itemIndex)
236: revert Errors.Shared_HookFailString(revertReason)
242: revert Errors.Shared_HookFailString(
                    string.concat("Hook reverted: Panic code ", stringErrorCode)
                )
247: revert Errors.Shared_HookFailBytes(revertData)

141 | 149 | 154 | 181 | 211 | 222 | 236 | 242 | 247

File: smart-contracts/src/Create2Deployer.sol

38: revert Errors.Create2Deployer_UnauthorizedSender(msg.sender, salt)
46: revert Errors.Create2Deployer_AlreadyDeployed(targetDeploymentAddress, salt)
68: revert Errors.Create2Deployer_MismatchedDeploymentAddress(
                targetDeploymentAddress,
                deploymentAddress
            )

38 | 46 | 68

File: smart-contracts/src/Kernel.sol

42: revert Errors.KernelAdapter_OnlyKernel(msg.sender)
79: revert Errors.Module_PolicyNotAuthorized(msg.sender)
133: revert Errors.Policy_OnlyRole(role)
183: revert Errors.Policy_ModuleDoesNotExist(keycode_)
255: revert Errors.Kernel_OnlyExecutor(msg.sender)
263: revert Errors.Kernel_OnlyAdmin(msg.sender)
313: revert Errors.Kernel_AddressAlreadyHasRole(addr_, role_)
335: revert Errors.Kernel_RoleDoesNotExist(role_)
339: revert Errors.Kernel_AddressDoesNotHaveRole(addr_, role_)
362: revert Errors.Kernel_ModuleAlreadyInstalled(keycode)
393: revert Errors.Kernel_InvalidModuleUpgrade(keycode)
421: revert Errors.Kernel_PolicyAlreadyApproved(address(policy_))
458: revert Errors.Kernel_PolicyNotApproved(address(policy_))

42 | 79 | 133 | 183 | 255 | 263 | 313 | 335 | 339 | 362 | 393 | 421 | 458

</details>

[G-09] Use Cached Contracts for Multiple External Calls

When function makes multiple calls to the same external contract, it is more gas-efficient to use a local copy of the contract. This is because the EVM will cache the contract in memory, and subsequent calls will be cheaper. It's especially true for contracts that are large and/or have many functions.

    // local cache -> 6561 gas
    IToken localCache = storageContract;
    localCache.externalCall();
    localCache.externalCall();

    // direct call 6683 gas
    storageContract.externalCall();
    storageContract.externalCall();

<details> <summary><i>3 issue instances in 1 files:</i></summary>

File: smart-contracts/src/policies/Guard.sol

/// @audit function checkTransaction() make external call of `STORE` - 3 times
324: if (operation == Enum.Operation.DelegateCall && !STORE.whitelistedDelegates(to)) {
334: address hook = STORE.contractToHook(to);
335: bool isActive = STORE.hookOnTransaction(hook);

324 | 334 | 335

</details>

[G-10] Declare immutable as private to save gas

The compiler doesn't need to create non-payable getter functions for deployment calldata, store the bytes of the value outside of where it's used, or add another entry to the method ID table, saving 3406-3606 gas in deployment.

<details> <summary><i>5 issue instances in 1 files:</i></summary>

File: smart-contracts/src/policies/Factory.sol

31: Stop public immutable stopPolicy;
32: Guard public immutable guardPolicy;
35: TokenCallbackHandler public immutable fallbackHandler;
36: SafeProxyFactory public immutable safeProxyFactory;
37: SafeL2 public immutable safeSingleton;

31 | 32 | 35 | 36 | 37

</details>

[G-11] Avoid updating storage when the value hasn't changed

A check regarding whether the current value and the new value are the same should be added. This helps prevent unnecessary state changes and events in case the new value is the same as the current value.

<details> <summary><i>7 issue instances in 5 files:</i></summary>

File: smart-contracts/src/modules/PaymentEscrow.sol

387: fee = feeNumerator;

387

File: smart-contracts/src/modules/Storage.sol

/// @audit Missing `hook` check before state change
302: _contractToHook[to] = hook;
/// @audit Missing `bitmap` check before state change
325: hookStatus[hook] = bitmap;

302 | 325

File: smart-contracts/src/policies/Admin.sol

/// @audit Missing `feeNumerator` check before state change
174: ESCRW.setFee(feeNumerator);

174

File: smart-contracts/src/policies/Guard.sol

/// @audit Missing `hook` check before state change
363: STORE.updateHookPath(to, hook);
/// @audit Missing `bitmap` check before state change
377: STORE.updateHookStatus(hook, bitmap);

363 | 377

File: smart-contracts/src/Kernel.sol

/// @audit Missing `newKernel_` check before state change
55: kernel = newKernel_;

55

</details>

[G-12] Multiple address/ID mappings can be combined into a single mapping of an address/ID to a struct

Combining multiple address/ID mappings into a single mapping to a struct can lead to gas savings. By refactoring multiple mappings into a singular mapping with a struct, you can save on storage slots, which in turn can reduce the gas cost in certain operations. Prioritize this refactor if optimizing gas is a primary concern for your contract's operations.

<details> <summary><i>9 issue instances in 2 files:</i></summary>

File: smart-contracts/src/modules/Storage.sol

33: mapping(address safe => uint256 nonce) public deployedSafes
44: mapping(address to => address hook) internal _contractToHook
47: mapping(address hook => uint8 enabled) public hookStatus
55: mapping(address delegate => bool isWhitelisted) public whitelistedDelegates
58: mapping(address extension => bool isWhitelisted) public whitelistedExtensions

33 | 44 | 47 | 55 | 58

File: smart-contracts/src/Kernel.sol

213: mapping(Keycode => Module) public getModuleForKeycode
217: mapping(Keycode => Policy[]) public moduleDependents
218: mapping(Keycode => mapping(Policy => uint256)) public getDependentIndex
221: mapping(Keycode => mapping(Policy => mapping(bytes4 => bool)))
        public modulePermissions

213 | 217 | 218 | 221

</details>