Gas Optimizations #267

code423n4 · 2022-08-06T15:51:48Z

Should Use Unchecked Block where Over/Underflow is not Possible
Minimize the Number of SLOADs by Caching State Variable
Defined Variables Used Only Once
Storage Variables can be Packed into Fewer Storage Slots
Use Already Defined Variable
Duplicate require() Checks Should be a Modifier or a Function
Both named returns and return statement are used
Use require instead of &&
Internal Function Called Only Once can be Inlined
Use Calldata instead of Memory for Read Only Function Parameters
Using Elements Smaller than 32 bytes (256 bits) Might Use More Gas
Unnecessary Default Value Initialization
Store Array's Length as a Variable
++i Costs Less Gas than i++
!= 0 costs less gass than > 0
Use Custom Errors to Save Gas

Should Use Unchecked Block where Over/Underflow is not Possible

Issue

Since Solidity 0.8.0, all arithmetic operations revert on overflow and underflow by default.
However in places where overflow and underflow is not possible, it is better to use unchecked block to reduce the gas usage.
Reference: https://docs.soliditylang.org/en/v0.8.15/control-structures.html#checked-or-unchecked-arithmetic

PoC

Total of 4 issues found.

_reduceDebt() of Community.sol

Wrap line 794 with unchecked since underflow is not possible due to line 792 check
792:            require(_lentAndInterest >= _repayAmount, "Community::!Liquid");
794:            _lentAmount = _lentAndInterest - _repayAmount;

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L792-L794

changeOrder() of Project.sol

Wrap line 427 with unchecked since underflow is not possible due to line 425 check
425:                if (_newCost < _taskCost) { 
427:                    uint256 _withdrawDifference = _taskCost - _newCost;

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L425-L427

allocateFunds() of Project.sol

Wrap line 616 with unchecked since underflow is not possible due to line 614 check
614:                if (_costToAllocate >= _taskCost) {
616:                    _costToAllocate -= _taskCost;

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L614-L616

allocateFunds() of Project.sol

Wrap line 663 with unchecked since underflow is not possible due to line 661 check
661:                if (_costToAllocate >= _taskCost) {
663:                    _costToAllocate -= _taskCost;

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L661-L663

Mitigation

Wrap the code with uncheck like described in above PoC.

Minimize the Number of SLOADs by Caching State Variable

Issue

SLOADs cost 100 gas where MLOADs/MSTOREs cost only 3 gas.
Whenever function reads storage value more than once, it should be cached to save gas.

PoC

Cache homeFi storage variable of createProject() of ProjectFactory.sol
2 SLOADs to 1 SLOAD, 1 MSTORE and 2 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/ProjectFactory.sol#L84
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/ProjectFactory.sol#L90

Cache projectCount storage variable of createProject() of HomeFi.sol
3 SLOADs to 1 SLOAD, 1 MSTORE and 3 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/HomeFi.sol#L228-L231

Cache projectCount storage variable of mintNFT() of HomeFi.sol
4 SLOADs to 1 SLOAD, 1 MSTORE and 4 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/HomeFi.sol#L292-L296

Cache tasks[_taskID] storage variable of setComplete() of Project.sol
3 SLOADs to 1 SLOAD, 1 MSTORE and 3 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L350
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L354-L355

Cache tasks[_taskID] storage variable of changeOrder() of Project.sol
8 SLOADs to 1 SLOAD, 1 MSTORE and 8 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L409
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L423
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L449
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L452
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L464
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L470
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L474
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L485

Cache tasks[_task] storage variable of raiseDispute() of Project.sol
2 SLOADs to 1 SLOAD, 1 MSTORE and 2 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L524
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L528

Cache tasks[id] storage variable of getTask() of Project.sol
3 SLOADs to 1 SLOAD, 1 MSTORE and 3 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L553-L555

Cache builder storage variable of lendToProject() of Project.sol
2 SLOADs to 1 SLOAD, 1 MSTORE and 2 MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L190
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L204

Cache taskCount storage variable of allocateFunds() of Project.sol
5 or more SLOADs to 1 SLOAD, 1 MSTORE and 5 or more MLOAD

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L592
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L648
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L650
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L681
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L682

Mitigation

When certain state variable is read more than once, cache it to local variable to save gas.

Defined Variables Used Only Once

Issue

Certain variables is defined even though they are used only once.
Remove these unnecessary variables to save gas.
For cases where it will reduce the readability, one can use comments to help describe
what the code is doing.

PoC

Remove '_totalAllocated' variable of changeOrder() Project.sol
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L420
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L438
Delete line 420 and replace line 438 to line shown below

else if (totalLent - totalAllocated >= _newCost - _taskCost) {

Mitigation

Don't define variable that is used only once.

Storage Variables can be Packed into Fewer Storage Slots

Issue

The order of storage variables can be reordered in a way to reduce the usage amount of storage slots.

Reference from solidity documentation:
Finally, in order to allow the EVM to optimize for this, ensure that you try to order your storage 
variables and struct members such that they can be packed tightly. For example, declaring your 
storage variables in the order of uint128, uint128, uint256 instead of uint128, uint256, uint128, 
as the former will only take up two slots of storage whereas the latter will take up three.

https://docs.soliditylang.org/en/v0.8.15/internals/layout_in_storage.html#layout-of-state-variables-in-storage

PoC

Total of 1 issue found.

Project.sol
We can save 1 storage slot by reordering it like below.
Move bool variable (1 byte size) to pack it within 1 slot (32 bytes size) with
address variable (20 bytes size) and other bool variable.

Originally
66:    address public override contractor; // 20 bytes
68:    bool public override contractorConfirmed; // 1 byte
70:    uint256 public override hashChangeNonce; // 32 bytes
72:    uint256 public override totalLent; // 32 bytes
74:    uint256 public override totalAllocated; // 32 bytes
76:    uint256 public override taskCount; // 32 bytes
78:    bool public override contractorDelegated; // 1 byte
80:    uint256 public override lastAllocatedTask; // 32 bytes
82:    uint256 public override lastAllocatedChangeOrderTask; // 32 bytes
84:    mapping(address => mapping(bytes32 => bool)) public override approvedHashes; // 32 bytes

Change to
    address public override contractor; // 20 bytes
    bool public override contractorConfirmed; // 1 byte
    bool public override contractorDelegated; // 1 byte
    uint256 public override hashChangeNonce; // 32 bytes
    uint256 public override totalLent; // 32 bytes
    uint256 public override totalAllocated; // 32 bytes
    uint256 public override taskCount; // 32 bytes
    uint256 public override lastAllocatedTask; // 32 bytes
    uint256 public override lastAllocatedChangeOrderTask; // 32 bytes
    mapping(address => mapping(bytes32 => bool)) public override approvedHashes; // 32 bytes

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L65-L84

Mitigation

Reorder storage variables like shown in above PoC.

Use Already Defined Variable

Issue

Use already defined variable rather than reading the storage variable again and wasting gas.

PoC

lendToProject() of Community.sol
Use cached variable of _sender instead of reading the storage variable
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L380

Change _msgSender() to _sender

Originally
443: _currency.safeTransferFrom(_msgSender(), homeFi.treasury(), _lenderFee);
446: _currency.safeTransferFrom(_msgSender(), _project, _amountToProject);

Change To
443: _currency.safeTransferFrom(_sender, homeFi.treasury(), _lenderFee);
446: _currency.safeTransferFrom(_sender, _project, _amountToProject);

Mitigation

Use the already defined variable like shown in above PoC.

Duplicate require() Checks Should be a Modifier or a Function

Issue

Since below require checks are used more than once,
I recommend making these to a modifier or a function.

PoC

./Project.sol:132:        require(_projectAddress == address(this), "Project::!projectAddress");
./Project.sol:241:        require(_projectAddress == address(this), "Project::!projectAddress");

./Project.sol:176:        require(_nonce == hashChangeNonce, "Project::!Nonce");
./Project.sol:277:        require(_nonce == hashChangeNonce, "Project::!Nonce");

./Project.sol:406:        require(_project == address(this), "Project::!projectAddress");
./Project.sol:511:        require(_project == address(this), "Project::!projectAddress");

Mitigation

I recommend making duplicate require statement into modifier or a function.

Both named returns and return statement are used

Issue

In some function return statement are used even though named returns is set.
This is redundant because return statement is not needed when using named returns and
named returns is not needed when using return statement.
Removing unused named returns variable in below code can save gas and improve code readability.

PoC

1, Remove returns variable "sender" of _msgSender() Community.sol
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Community.sol#L903

Mitigation

Remove unused named returns variable as mentioned in above PoC.

Use require instead of &&

Issue

When there are multiple conditions in require statement, break down the require statement into
multiple require statements instead of using && can save gas.

PoC

Total of 4 issues found.

./Community.sol:353-357:        require(_lendingNeeded >= _communityProject.totalLent && _lendingNeeded <= IProject(_project).projectCost(), "Community::invalid lending");
./Disputes.sol:61-65:        require(_disputeID < disputeCount && disputes[_disputeID].status == Status.Active, "Disputes::!Resolvable");
./Disputes.sol:106-109:        require(_actionType > 0 && _actionType <= uint8(ActionType.TaskPay), "Disputes::!ActionType");
./Project.sol:189-192:        require(_sender == builder || _sender == homeFi.communityContract(), "Project::!Builder&&!Community");

Mitigation

Break down into several require statement.
For example,

require(_lendingNeeded >= _communityProject.totalLent);
require(_lendingNeeded <= IProject(_project).projectCost(), "Community::invalid lending");

Internal Function Called Only Once Can be Inlined

Issue

Certain function is defined even though it is called only once.
Inline it instead to where it is called to avoid usage of extra gas.

PoC

Total of 3 issues found.

resolveHandler() of Disputes.sol

./Disputes.sol:207:    function resolveHandler(uint256 _disputeID) internal {

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Disputes.sol#L207

resolveHandler function called only once at line 149
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Disputes.sol#L149

autoWithdraw() of Project.sol

./Project.sol:770:    function autoWithdraw(uint256 _amount) internal {

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L770

autoWithdraw function called only once at line 435
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/Project.sol#L435

_replaceImplementation() of HomeFiProxy.sol

197:    function _replaceImplementation(
198:        bytes2 _contractName,
199:        address _contractAddress
200:    ) internal nonZero(_contractAddress) {

https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/HomeFiProxy.sol#L197-L200

_replaceImplementation function called only once at line 137
https://github.com/code-423n4/2022-08-rigor/blob/b17b2a11d04289f9e927c71703b42771dd7b86a4/contracts/HomeFiProxy.sol#L137

Mitigation

I recommend to not define above functions and instead inline it at place it is called.

Use Calldata instead of Memory for Read Only Function Parameters

Issue

It is cheaper gas to use calldata than memory if the function parameter is read only.
Calldata is a non-modifiable, non-persistent area where function arguments are stored,
and behaves mostly like memory. More details on following link.

link: https://docs.soliditylang.org/en/v0.8.15/types.html#data-location

PoC

Total of 2 issues found.

./Community.sol:488:        bytes memory _details
./HomeFi.sol:210:    function createProject(bytes memory _hash, address _currency)

Mitigation

Change memory to calldata

Using Elements Smaller than 32 bytes (256 bits) Might Use More Gas

Issue

Since EVM operates on 32 bytes at a time, if the element is smaller than that, the EVM must use more operations
in order to reduce the elements from 32 bytes to specified size.

Reference: https://docs.soliditylang.org/en/v0.8.15/internals/layout_in_storage.html

PoC

Total of 8 issues found.

./DebtToken.sol:16:    uint8 internal _decimals;
./DebtToken.sol:47:        uint8 decimals_
./DebtToken.sol:82:    function decimals() public view virtual override returns (uint8) {
./SignatureDecoder.sol:29:        uint8 v;
./SignatureDecoder.sol:65:            uint8 v,
./Disputes.sol:100:            uint8 _actionType,

Mitigation

I suggest using uint256 instead of anything smaller or downcast where needed.

Unnecessary Default Value Initialization

Issue

When variable is not initialized, it will have its default values.
For example, 0 for uint, false for bool and address(0) for address.
Reference: https://docs.soliditylang.org/en/v0.8.15/control-structures.html#scoping-and-declarations

PoC

Total of 8 issues found.

./Community.sol:624:        for (uint256 i = 0; i < _communities[_communityID].memberCount; i++) {
./Tasks.sol:181:        for (uint256 i = 0; i < _length; i++) _alerts[i] = _self.alerts[i];
./Project.sol:248:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:311:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:322:        for (uint256 i = 0; i < _length; i++) {
./HomeFiProxy.sol:87:        for (uint256 i = 0; i < _length; i++) {
./HomeFiProxy.sol:136:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:412:        bool _unapproved = false;

Mitigation

I suggest removing default value initialization.
For example,

bool _unapproved;

Store Array's Length as a Variable

Issue

By storing an array's length as a variable before the for-loop,
can save 3 gas per iteration.

PoC

Total of 1 issue found.

./Project.sol:603:            for (; i < _changeOrderedTask.length; i++) {

Mitigation

Store array's length as a variable before looping it.
For example, I suggest changing it to

uint256 length = _changeOrderedTask.length;
for (; i < length; i++) {

++i Costs Less Gas than i++

Issue

Prefix increments/decrements (++i or --i) costs cheaper gas than
postfix increment/decrements (i++ or i--).

PoC

Total of 11 issues found.

./Community.sol:624:        for (uint256 i = 0; i < _communities[_communityID].memberCount; i++) {
./Tasks.sol:181:        for (uint256 i = 0; i < _length; i++) _alerts[i] = _self.alerts[i];
./Project.sol:248:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:311:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:322:        for (uint256 i = 0; i < _length; i++) {
./Project.sol:368:            for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {
./Project.sol:603:            for (; i < _changeOrderedTask.length; i++) {
./Project.sol:650:            for (++j; j <= taskCount; j++) {
./Project.sol:710:        for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {
./HomeFiProxy.sol:87:        for (uint256 i = 0; i < _length; i++) {
./HomeFiProxy.sol:136:        for (uint256 i = 0; i < _length; i++) {

Mitigation

Change it to postfix increments/decrements.
It saves 6 gas per loop.
For example,

for (uint256 i = 0; i < _communities[_communityID].memberCount; ++i) {

!= 0 costs less gass than > 0

Issue

!= 0 costs less gas when optimizer is enabled and is used for unsigned integers in require statement.

PoC

Total of 2 issues found.

./Community.sol:764:        require(_repayAmount > 0, "Community::!repay");
./Project.sol:195:        require(_cost > 0, "Project::!value>0");

Mitigation

I suggest changing > 0 to != 0
For example:

require(_repayAmount != 0, "Community::!repay");

Use Custom Errors to Save Gas

Issue

Custom errors from Solidity 0.8.4 are cheaper than revert strings.
Details are explained here: https://blog.soliditylang.org/2021/04/21/custom-errors/

PoC

Total of 74 issues found.

./ProjectFactory.sol:36:        require(_address != address(0), "PF::0 address");
./ProjectFactory.sol:64-67:        require(_msgSender() == IHomeFi(homeFi).admin(), "ProjectFactory::!Owner");
./ProjectFactory.sol:84:        require(_msgSender() == homeFi, "PF::!HomeFiContract");
./DebtToken.sol:31-34:        require(communityContract == _msgSender(), "DebtToken::!CommunityContract");
./DebtToken.sol:50:        require(_communityContract != address(0), "DebtToken::0 address");
./Community.sol:69:        require(_address != address(0), "Community::0 address");
./Community.sol:75:        require(_msgSender() == homeFi.admin(), "Community::!admin");
./Community.sol:81-84:        require(projectPublished[_project] == _communityID, "Community::!published");
./Community.sol:90-93:        require(_msgSender() == IProject(_project).builder(), "Community::!Builder");
./Community.sol:131-134:        require(!restrictedToAdmin || _sender == homeFi.admin(), "Community::!admin");
./Community.sol:159-162:        require(_communities[_communityID].owner == _msgSender(), "Community::!owner");
./Community.sol:191-192:        require(!_community.isMember[_newMemberAddr], "Community::Member Exists");
./Community.sol:235-238:        require(_publishNonce == _community.publishNonce, "Community::invalid publishNonce");
./Community.sol:241:        require(homeFi.isProjectExist(_project), "Community::Project !Exists");
./Community.sol:248:        require(_community.isMember[_builder], "Community::!Member");
./Community.sol:251-254:        require(_projectInstance.currency() == _community.currency, "Community::!Currency");
./Community.sol:312-315:        require(!_communityProject.publishFeePaid, "Community::publish fee paid");
./Community.sol:347-350:        require(_communityProject.publishFeePaid, "Community::publish fee !paid");
./Community.sol:353-357:        require(_lendingNeeded >= _communityProject.totalLent && _lendingNeeded <=
                                          IProject(_project).projectCost(), "Community::invalid lending");
./Community.sol:384-387:        require(_sender == _communities[_communityID].owner, "Community::!owner");
./Community.sol:400-409:        require(_amountToProject <= _communities[_communityID].projectDetails[_project].lendingNeeded -
                                          _communities[_communityID].projectDetails[_project].totalLent, "Community::lending>needed");
./Community.sol:491-494:        require(_msgSender() == _communities[_communityID].owner, "Community::!Owner");
./Community.sol:536:        require(_builder == _projectInstance.builder(), "Community::!Builder");
./Community.sol:539-542:        require(_lender == _communities[_communityID].owner, "Community::!Owner");
./Community.sol:557:        require(!restrictedToAdmin, "Community::restricted");
./Community.sol:568:        require(restrictedToAdmin, "Community::!restricted");
./Community.sol:764:        require(_repayAmount > 0, "Community::!repay");
./Community.sol:792:            require(_lentAndInterest >= _repayAmount, "Community::!Liquid");
./Community.sol:886-889:        require(_recoveredSignature == _address || approvedHashes[_address][_hash], "Community::invalid signature");
./Tasks.sol:44:        require(_self.state == TaskStatus.Inactive, "Task::active");
./Tasks.sol:50:        require(_self.state == TaskStatus.Active, "Task::!Active");
./Tasks.sol:56-59:        require(_self.alerts[uint256(Lifecycle.TaskAllocated)], "Task::!funded");
./Tasks.sol:124:        require(_self.subcontractor == _sc, "Task::!SC");
./Disputes.sol:39:        require(_address != address(0), "Disputes::0 address");
./Disputes.sol:46:        require(homeFi.admin() == _msgSender(), "Disputes::!Admin");
./Disputes.sol:52:        require(homeFi.isProjectExist(_msgSender()), "Disputes::!Project");
./Disputes.sol:61-65:        require(_disputeID < disputeCount && disputes[_disputeID].status == Status.Active, "Disputes::!Resolvable");
./Disputes.sol:106-109:        require(_actionType > 0 && _actionType <= uint8(ActionType.TaskPay), "Disputes::!ActionType");
./Disputes.sol:183:        require(_result, "Disputes::!Member");
./HomeFi.sol:73:        require(admin == _msgSender(), "HomeFi::!Admin");
./HomeFi.sol:78:        require(_address != address(0), "HomeFi::0 address");
./HomeFi.sol:84:        require(_oldAddress != _newAddress, "HomeFi::!Change");
./HomeFi.sol:142:        require(!addrSet, "HomeFi::Set");
./HomeFi.sol:191:        require(lenderFee != _newLenderFee, "HomeFi::!Change");
./HomeFi.sol:255-260:        require(_currency == tokenCurrency1 || _currency == tokenCurrency2 || _currency == tokenCurrency3, "HomeFi::!Currency");
./Project.sol:123:        require(!contractorConfirmed, "Project::GC accepted");
./Project.sol:132:        require(_projectAddress == address(this), "Project::!projectAddress");
./Project.sol:135:        require(_contractor != address(0), "Project::0 address");
./Project.sol:150:        require(_msgSender() == builder, "Project::!B");
./Project.sol:153:        require(contractor != address(0), "Project::0 address");
./Project.sol:176:        require(_nonce == hashChangeNonce, "Project::!Nonce");
./Project.sol:189-192:        require(_sender == builder || _sender == homeFi.communityContract(), "Project::!Builder&&!Community");
./Project.sol:195:        require(_cost > 0, "Project::!value>0");
./Project.sol:199-202:        require(projectCost() >= uint256(_newTotalLent), "Project::value>required");
./Project.sol:238:        require(_taskCount == taskCount, "Project::!taskCount");
./Project.sol:241:        require(_projectAddress == address(this), "Project::!projectAddress");
./Project.sol:245:        require(_length == _taskCosts.length, "Project::Lengths !match");
./Project.sol:277:        require(_nonce == hashChangeNonce, "Project::!Nonce");
./Project.sol:301-304:        require(_msgSender() == builder || _msgSender() == contractor, "Project::!Builder||!GC");
./Project.sol:308:        require(_length == _scList.length, "Project::Lengths !match");
./Project.sol:341:        require(_projectAddress == address(this), "Project::!Project");
./Project.sol:369:                require(tasks[_taskID].getState() == 3, "Project::!Complete");
./Project.sol:406:        require(_project == address(this), "Project::!projectAddress");
./Project.sol:511:        require(_project == address(this), "Project::!projectAddress");
./Project.sol:515-518:            require(signer == builder || signer == contractor, "Project::!(GC||Builder)");
./Project.sol:521-526:            require(signer == builder || signer == contractor || signer == tasks[_task].subcontractor, "Project::!(GC||Builder||SC)");
./Project.sol:530:                require(getAlerts(_task)[2], "Project::!SCConfirmed");
./Project.sol:753:        require(_sc != address(0), "Project::0 address");
./Project.sol:886-889:        require(_recoveredSignature == _address || approvedHashes[_address][_hash], "Project::invalid signature");
./Project.sol:906-909:        require(((_amount / 1000) * 1000) == _amount, "Project::Precision>=1000");
./HomeFiProxy.sol:41:        require(_address != address(0), "Proxy::0 address");
./HomeFiProxy.sol:81:        require(_length == _implementations.length, "Proxy::Lengths !match");
./HomeFiProxy.sol:105-108:        require(contractAddress[_contractName] == address(0), "Proxy::Name !OK");
./HomeFiProxy.sol:133:        require(_length == _contractAddresses.length, "Proxy::Lengths !match");

Mitigation

I suggest implementing custom errors to save gas.

The text was updated successfully, but these errors were encountered:

code423n4 added bug Something isn't working G (Gas Optimization) labels Aug 6, 2022

code423n4 added a commit that referenced this issue Aug 6, 2022

TomJ issue #267

ca8f5de

jack-the-pug added the valid label Aug 28, 2022

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Gas Optimizations #267

Gas Optimizations #267

code423n4 commented Aug 6, 2022

Gas Optimizations #267

Gas Optimizations #267

Comments

code423n4 commented Aug 6, 2022

Table of Contents

Should Use Unchecked Block where Over/Underflow is not Possible

Issue

PoC

Mitigation

Minimize the Number of SLOADs by Caching State Variable

Issue

PoC

Mitigation

Defined Variables Used Only Once

Issue

PoC

Mitigation

Storage Variables can be Packed into Fewer Storage Slots

Issue

PoC

Mitigation

Use Already Defined Variable

Issue

PoC

Mitigation

Duplicate require() Checks Should be a Modifier or a Function

Issue

PoC

Mitigation

Both named returns and return statement are used

Issue

PoC

Mitigation

Use require instead of &&

Issue

PoC

Mitigation

Internal Function Called Only Once Can be Inlined

Issue

PoC

Mitigation

Use Calldata instead of Memory for Read Only Function Parameters

Issue

PoC

Mitigation

Using Elements Smaller than 32 bytes (256 bits) Might Use More Gas

Issue

PoC

Mitigation

Unnecessary Default Value Initialization

Issue

PoC

Mitigation

Store Array's Length as a Variable

Issue

PoC

Mitigation

++i Costs Less Gas than i++

Issue

PoC

Mitigation

!= 0 costs less gass than > 0

Issue

PoC

Mitigation

Use Custom Errors to Save Gas

Issue

PoC

Mitigation