c4-common-issues's Introduction

`c4-common-issues`

This repository aims to provide a list of issues found regularly in Code4Rena contests.

Introduction

Code4Rena runs community-driven contests for smart contract audits in which wardens search for issues and judges allocate awards to wardens based on performance.

A problem currently in the community is how to handle commonly found issues as they increase the judge's workload.

This repo aims to identify common issues and provide background information.

The goal is, that wardens include the issue's identifier in a contest submission.

This would help judges mark the issues as duplicates and hopefully decrease their workload.

Gas Optimization Issues

Identifier	Title
G001	Don't Initialize Variables with Default Value
G002	Cache Array Length Outside of Loop
G003	Use `!= 0` instead of `> 0` for Unsigned Integer Comparison
G004	Remove Unused Variables
G005	Make Variable `constant`/`immutable`
G006	Use `immutable` for OpenZeppelin `AccessControl`'s Roles Declarations
G007	Long Revert Strings
G008	Use Shift Right/Left instead of Division/Multiplication if possible
G009	Make Function `external` instead of `public`
G010	Make Function `payable`
G011	Unnecessary checked arithmetic in for loop
G012	Use Prefix Increment instead of Postfix Increment if possible

Non-Critical Issues

Identifier	Title
NC001	Functions Mutating Storage Should Emit Events

Low Risk Issues

Identifier	Title
L001	Unsafe ERC20 Operation(s)
L002	FeeOnTransfer Tokens not Supported
L003	Unspecific Compiler Version Pragma
L004	Use Two-Step Transfer Pattern for Access Controls
L005	Do not use Deprecated Library Functions
L006	Check that Contract Exists before using `solmate`'s `SafeTransferLib`