GASOL: Gas Analysis and Optimization for Ethereum Smart Contracts

TL;DR

GASOL is a tool for analyzing and optimizing gas consumption in Ethereum smart contracts, providing cost models, detecting inefficient storage patterns, and offering automatic optimization features within an Eclipse plugin.

Contribution

Introduces GASOL, a comprehensive tool for gas analysis and optimization in Ethereum smart contracts with customizable cost models and automatic optimization capabilities.

Findings

GASOL accurately estimates gas costs for specific functions.

It detects and suggests improvements for storage access patterns.

The tool integrates with Eclipse for ease of use.

Abstract

We present the main concepts, components, and usage of GASOL, a Gas AnalysiS and Optimization tooL for Ethereum smart contracts. GASOL offers a wide variety of cost models that allow inferring the gas consumption associated to selected types of EVM instructions and/or inferring the number of times that such types of bytecode instructions are executed. Among others, we have cost models to measure only storage opcodes, to measure a selected family of gas-consumption opcodes following the Ethereum's classification, to estimate the cost of a selected program line, etc. After choosing the desired cost model and the function of interest, GASOL returns to the user an upper bound of the cost for this function. As the gas consumption is often dominated by the instructions that access the storage, GASOL uses the gas analysis to detect under-optimized storage patterns, and includes an (optional) automatic optimization of the selected function. Our tool can be used within an Eclipse plugin for Solidity which displays the gas and instructions bounds and, when applicable, the gas-optimized Solidity function.