How to Save My Gas Fees: Understanding and Detecting Real-world Gas Issues in Solidity Programs

TL;DR

This paper investigates gas inefficiencies in Ethereum smart contracts, providing empirical insights and a static analysis tool to detect and fix gas-wasting code, ultimately saving millions in fees daily.

Contribution

It offers the first comprehensive empirical study on gas wastes in Solidity and introduces PeCatch, a static tool for detecting such issues in smart contracts.

Findings

Identified 11 key insights about gas waste patterns.

Developed PeCatch, a static analysis tool for Solidity.

Estimated daily savings of $0.76 million by fixing bugs.

Abstract

The execution of smart contracts on Ethereum, a public blockchain system, incurs a fee called gas fee for its computation and data storage. When programmers develop smart contracts (e.g., in the Solidity programming language), they could unknowingly write code snippets that unnecessarily cause more gas fees. These issues, or what we call gas wastes, can lead to significant monetary losses for users. This paper takes the initiative in helping Ethereum users reduce their gas fees in two key steps. First, we conduct an empirical study on gas wastes in open-source Solidity programs and Ethereum transaction traces. Second, to validate our study findings, we develop a static tool called PeCatch to effectively detect gas wastes in Solidity programs, and manually examine the Solidity compiler's code to pinpoint implementation errors causing gas wastes. Overall, we make 11 insights and four suggestions, which can foster future tool development and programmer awareness, and fixing our detected bugs can save $0.76 million in gas fees daily.